linux-2.6.24: nand and ubifs patches for HIPOX machine

2 files changed, 44307 insertions, 0 deletions

diff --git a/recipes/linux/linux-2.6.24/hipox/hipox-nand.patch b/recipes/linux/linux-2.6.24/hipox/hipox-nand.patch
new file mode 100644
index 0000000000..1e37d12774
--- /dev/null
+++ b/recipes/linux/linux-2.6.24/hipox/hipox-nand.patch
@@ -0,0 +1,333 @@
+diff -Nurd linux-2.6.24-base/arch/arm/mach-hipox/hipox.c linux-2.6.24/arch/arm/mach-hipox/hipox.c
+--- linux-2.6.24-base/arch/arm/mach-hipox/hipox.c	2009-04-16 13:21:06.000000000 +0000
++++ linux-2.6.24/arch/arm/mach-hipox/hipox.c	2009-04-17 07:04:33.000000000 +0000
+@@ -155,7 +155,7 @@
+     { CORE_MODULE_BASE,     __phys_to_pfn(CORE_MODULE_BASE_PA),     SZ_4K,   MT_DEVICE },
+     { APB_BRIDGE_A_BASE,    __phys_to_pfn(APB_BRIDGE_A_BASE_PA),    SZ_16M,  MT_DEVICE },
+     { STATIC_CONTROL_BASE,  __phys_to_pfn(STATIC_CONTROL_BASE_PA),  SZ_4K,   MT_DEVICE },
+-    { STATIC_CS0_BASE,      __phys_to_pfn(STATIC_CS0_BASE_PA),      SZ_4K,   MT_DEVICE },
++    { STATIC_CS0_BASE,      __phys_to_pfn(STATIC_CS0_BASE_PA),      SZ_4M,   MT_DEVICE },
+     { STATIC_CS1_BASE,      __phys_to_pfn(STATIC_CS1_BASE_PA),      SZ_4K,   MT_DEVICE },
+     { STATIC_CS2_BASE,      __phys_to_pfn(STATIC_CS2_BASE_PA),      SZ_4K,   MT_DEVICE },
+     { APB_BRIDGE_B_BASE,    __phys_to_pfn(APB_BRIDGE_B_BASE_PA),    SZ_16M,  MT_DEVICE },
+diff -Nurd linux-2.6.24-base/drivers/mtd/maps/physmap.c linux-2.6.24/drivers/mtd/maps/physmap.c
+--- linux-2.6.24-base/drivers/mtd/maps/physmap.c	2008-01-24 22:58:37.000000000 +0000
++++ linux-2.6.24/drivers/mtd/maps/physmap.c	2009-04-17 07:04:33.000000000 +0000
+@@ -22,6 +22,12 @@
+ #include <linux/mtd/physmap.h>
+ #include <asm/io.h>
+ 
++#if defined (CONFIG_ARCH_HIPOX)
++#include <asm/arch/hardware.h>
++/* timing for NOR flash */
++#define STATIC_BUS_FLASH_CONFIG 0x4f1f3f0d  /* fast ASIC settings, 70ns */
++#endif /* CONFIG_ARCH_HIPOX */
++
+ struct physmap_flash_info {
+ 	struct mtd_info		*mtd;
+ 	struct map_info		map;
+@@ -88,6 +94,11 @@
+ 	if (physmap_data == NULL)
+ 		return -ENODEV;
+ 
++#if defined (CONFIG_ARCH_HIPOX)
++/* init timing for static memory controller */
++		 writel(STATIC_BUS_FLASH_CONFIG, STATIC_CONTROL_BANK0);
++#endif /* CONFIG_ARCH_HIPOX */
++
+        	printk(KERN_NOTICE "physmap platform flash device: %.8llx at %.8llx\n",
+ 	    (unsigned long long)(dev->resource->end - dev->resource->start + 1),
+ 	    (unsigned long long)dev->resource->start);
+@@ -207,6 +218,10 @@
+ #endif
+ 
+ #ifdef PHYSMAP_COMPAT
++static void physmap_flash_release(struct device *dev)
++{
++}
++
+ static struct physmap_flash_data physmap_flash_data = {
+ 	.width		= CONFIG_MTD_PHYSMAP_BANKWIDTH,
+ };
+@@ -222,6 +237,7 @@
+ 	.id		= 0,
+ 	.dev		= {
+ 		.platform_data	= &physmap_flash_data,
++		.release	= physmap_flash_release, /* needed for module build */
+ 	},
+ 	.num_resources	= 1,
+ 	.resource	= &physmap_flash_resource,
+diff -Nurd linux-2.6.24-base/drivers/mtd/nand/Kconfig linux-2.6.24/drivers/mtd/nand/Kconfig
+--- linux-2.6.24-base/drivers/mtd/nand/Kconfig	2008-01-24 22:58:37.000000000 +0000
++++ linux-2.6.24/drivers/mtd/nand/Kconfig	2009-04-17 07:04:33.000000000 +0000
+@@ -283,6 +283,11 @@
+ 	tristate "Support for NAND Flash on CM-X270 modules"
+ 	depends on MTD_NAND && MACH_ARMCORE
+ 
++config MTD_NAND_HIPOX
++	tristate "NAND Flash device on OXE810 based HydraIP board"
++	depends on MTD_NAND && ARCH_HIPOX
++	help
++	  Support for NAND flash on OXE180 based HydraIP platform.
+ 
+ config MTD_NAND_NANDSIM
+ 	tristate "Support for NAND Flash Simulator"
+diff -Nurd linux-2.6.24-base/drivers/mtd/nand/Makefile linux-2.6.24/drivers/mtd/nand/Makefile
+--- linux-2.6.24-base/drivers/mtd/nand/Makefile	2008-01-24 22:58:37.000000000 +0000
++++ linux-2.6.24/drivers/mtd/nand/Makefile	2009-04-17 07:04:33.000000000 +0000
+@@ -29,5 +29,6 @@
+ obj-$(CONFIG_MTD_NAND_BASLER_EXCITE)	+= excite_nandflash.o
+ obj-$(CONFIG_MTD_NAND_PLATFORM)		+= plat_nand.o
+ obj-$(CONFIG_MTD_ALAUDA)		+= alauda.o
++obj-$(CONFIG_MTD_NAND_HIPOX)    += hipox_nand.o
+ 
+ nand-objs := nand_base.o nand_bbt.o
+diff -Nurd linux-2.6.24-base/drivers/mtd/nand/hipox_nand.c linux-2.6.24/drivers/mtd/nand/hipox_nand.c
+--- linux-2.6.24-base/drivers/mtd/nand/hipox_nand.c	1970-01-01 00:00:00.000000000 +0000
++++ linux-2.6.24/drivers/mtd/nand/hipox_nand.c	2009-04-17 07:26:17.000000000 +0000
+@@ -0,0 +1,230 @@
++/*
++ * drivers/mtd/nand/hipox_nand.c
++ *
++ * Copyright (C) 2009 DResearch Digital Media Systems GmbH
++ *
++ * $Id:$
++ *
++ * This program is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License version 2 as
++ * published by the Free Software Foundation.
++ *
++ * Overview:
++ *   This is a device driver for the NAND flash device found on the
++ *   OXE810 based HydraIP board.
++ */
++
++#include <linux/slab.h>
++#include <linux/module.h>
++#include <linux/init.h>
++#include <linux/mtd/mtd.h>
++#include <linux/mtd/nand.h>
++#include <linux/mtd/partitions.h>
++#include <linux/delay.h>
++#include <asm/io.h>
++#include <asm/arch/hardware.h>
++#include <asm/sizes.h>
++#include <asm/mach-types.h>
++
++// the testboards ran down to a value of 4
++//#define STATIC_BUS_FLASH_CONFIG 0x4f1f3f3f  /* slow settings, 345 ns */
++//#define STATIC_BUS_FLASH_CONFIG 0x4f1f3f0d  /* fast settings, 70 ns */
++//#define STATIC_BUS_FLASH_CONFIG 0x4f1f3f09  /* ultra fast settings, 50 ns */
++#define STATIC_BUS_FLASH_CONFIG 0x4f1f3f04  /* warp settings, 27 ns */
++
++/*
++ * MTD structure for HydraIP board
++ */
++static struct mtd_info *hipox_nand_mtd = NULL;
++
++#ifdef CONFIG_MTD_PARTITIONS
++static const char *part_probes[] = { "cmdlinepart", NULL };
++
++#define NUM_PARTITIONS 2
++
++/*
++ * Define static partitions for flash device
++ */
++static struct mtd_partition partition_info[NUM_PARTITIONS] = {
++	{
++		.name		= "boot",
++		.offset		= 0x00000000,
++		.size		= 0x02000000,
++	}, {
++		.name		= "system",
++		.offset		= 0x02000000,
++		.size		= 0x0e000000,
++	},
++};
++#endif
++
++
++/*
++ *	hardware specific access to control-lines
++ */
++static void hipox_nand_hwcontrol(struct mtd_info *mtd, int cmd, unsigned int ctrl)
++{
++	struct nand_chip *this = mtd->priv;
++
++	if (ctrl & NAND_CTRL_CHANGE) {
++		unsigned long IO_ADDR_W = (unsigned long) this->IO_ADDR_W;
++
++		IO_ADDR_W = CONFIG_SYS_NAND_BASE;
++
++		if (ctrl & NAND_NCE)
++			writel(0x20000000, GPIO_A_OUTPUT_CLEAR); /* assert CS-NAND */
++		else
++			writel(0x20000000, GPIO_A_OUTPUT_SET); /* deassert CS-NAND */
++
++		if (ctrl & NAND_CLE)
++			IO_ADDR_W = CONFIG_SYS_NAND_COMMAND_LATCH;
++		if (ctrl & NAND_ALE)
++			IO_ADDR_W = CONFIG_SYS_NAND_ADDRESS_LATCH;
++
++		this->IO_ADDR_W = (void *)IO_ADDR_W;
++	}
++
++	if (cmd != NAND_CMD_NONE)
++		writeb(cmd, this->IO_ADDR_W);
++}
++
++static void hipox_read_buf(struct mtd_info *mtd, uint8_t *buf, int len)
++{
++   struct nand_chip *chip = mtd->priv;
++   volatile uint8_t *io = chip->IO_ADDR_R;
++
++	if((((int)buf) & 1) || (len & 1))
++	{
++		while(len-- > 0)
++			*buf++ = *io;
++
++		return;
++	}
++
++	// now it's aligned, group to 16 bit access
++	{
++		uint16_t *ptr16 = (uint16_t *)buf;
++		len >>= 1;
++ 
++		while(len-- > 0)
++			*ptr16++ = *io | (*io << 8);
++	}
++}
++
++/*
++ * Main initialization routine
++ */
++static int __init hipox_nand_init(void)
++{
++	struct nand_chip *this;
++	const char *part_type = NULL;
++	int mtd_parts_nb = 0;
++	struct mtd_partition *mtd_parts = NULL;
++
++	if (!machine_is_hipox())
++		return -ENXIO;
++
++	/* Allocate memory for MTD device structure and private data */
++	hipox_nand_mtd = kmalloc(sizeof(struct mtd_info)+sizeof(struct nand_chip), GFP_KERNEL);
++
++	if (!hipox_nand_mtd) {
++		printk("Unable to allocate HIPOX_NAND MTD device structure.\n");
++		return -ENOMEM;
++	}
++
++	/* Get pointer to private data */
++	this = (struct nand_chip *)&hipox_nand_mtd[1];
++
++	if (!this) {
++		printk("Unable to allocate HIPOX_NAND MTD NAND device structure.\n");
++		kfree(hipox_nand_mtd);
++		return -ENOMEM;
++	}
++
++	writel(STATIC_BUS_FLASH_CONFIG, STATIC_CONTROL_BANK0);
++
++	/* Initialize structures */
++	memset(hipox_nand_mtd, 0, sizeof(struct mtd_info));
++	memset(this, 0, sizeof(struct nand_chip));
++
++	// assert CS-NAND
++	writel(0x20000000, GPIO_A_OUTPUT_SET);
++	writel(0x20000000, GPIO_A_OUTPUT_ENABLE_SET);
++
++	// deselect alternate function
++   writel(readl(SYS_CTRL_GPIO_PRIMSEL_CTRL_0) & ~0x20000000,
++		SYS_CTRL_GPIO_PRIMSEL_CTRL_0);
++   writel(readl(SYS_CTRL_GPIO_SECSEL_CTRL_0) & ~0x20000000,
++		SYS_CTRL_GPIO_SECSEL_CTRL_0);
++   writel(readl(SYS_CTRL_GPIO_TERTSEL_CTRL_0) & ~0x20000000,
++		SYS_CTRL_GPIO_TERTSEL_CTRL_0);
++
++	writel(0x20000000, GPIO_A_OUTPUT_CLEAR);
++
++	// reset NAND unit
++	writeb(0xff, CONFIG_SYS_NAND_COMMAND_LATCH); // reset command
++	udelay(500);
++
++	// deassert CS-NAND
++	writel(0x20000000, GPIO_A_OUTPUT_SET);
++
++	/* Link the private data with the MTD structure */
++	hipox_nand_mtd->priv = this;
++	hipox_nand_mtd->owner = THIS_MODULE;
++
++	/* insert callbacks */
++	this->IO_ADDR_R = (void *)CONFIG_SYS_NAND_BASE;
++	this->IO_ADDR_W = (void *)CONFIG_SYS_NAND_BASE;
++	this->cmd_ctrl = hipox_nand_hwcontrol;
++	this->read_buf = hipox_read_buf;
++	this->chip_delay = 25; // 23 still worked on our EvalBoard
++	this->ecc.mode = NAND_ECC_SOFT;
++	printk("Searching for NAND flash...\n");
++
++	/* Scan to find existence of the device */
++	if (nand_scan(hipox_nand_mtd, 1)) {
++		kfree(hipox_nand_mtd);
++		return -ENXIO;
++	}
++#ifdef CONFIG_MTD_PARTITIONS
++	hipox_nand_mtd->name = "hipox-nand";
++	mtd_parts_nb = parse_mtd_partitions(hipox_nand_mtd, part_probes, &mtd_parts, 0);
++	if (mtd_parts_nb > 0)
++		part_type = "command line";
++	else
++		mtd_parts_nb = 0;
++#endif
++	if (mtd_parts_nb == 0) {
++		mtd_parts = partition_info;
++		mtd_parts_nb = NUM_PARTITIONS;
++		part_type = "static";
++	}
++
++	/* Register the partitions */
++	printk(KERN_NOTICE "Using %s partition definition\n", part_type);
++	add_mtd_partitions(hipox_nand_mtd, mtd_parts, mtd_parts_nb);
++
++	/* Return happy */
++	return 0;
++}
++
++module_init(hipox_nand_init);
++
++/*
++ * Clean up routine
++ */
++static void __exit hipox_nand_cleanup(void)
++{
++	/* Unregister the device */
++	//del_mtd_device(hipox_nand_mtd);
++	nand_release(hipox_nand_mtd);
++
++	/* Free the MTD device structure */
++	kfree(hipox_nand_mtd);
++}
++
++module_exit(hipox_nand_cleanup);
++
++MODULE_LICENSE("GPL");
++MODULE_AUTHOR("Rene Grosser <rgrosser@dresearch.de>, Steffen Sledz <sledz@dresearch.de>");
++MODULE_DESCRIPTION("MTD map driver for OXE810 based HydraIP device");
+diff -Nurd linux-2.6.24-base/include/asm-arm/arch-hipox/hardware.h linux-2.6.24/include/asm-arm/arch-hipox/hardware.h
+--- linux-2.6.24-base/include/asm-arm/arch-hipox/hardware.h	2009-04-16 13:21:35.000000000 +0000
++++ linux-2.6.24/include/asm-arm/arch-hipox/hardware.h	2009-04-17 07:25:53.000000000 +0000
+@@ -134,6 +134,11 @@
+ #define COPRO_REGS_BASE        (APB_BRIDGE_B_BASE + 0xB00000)
+ #define DMA_SG_BASE            (APB_BRIDGE_B_BASE + 0xC00000)
+ 
++/* NAND access */
++#define CONFIG_SYS_NAND_BASE    STATIC_CS0_BASE
++#define CONFIG_SYS_NAND_ADDRESS_LATCH   (CONFIG_SYS_NAND_BASE + 0x8000)
++#define CONFIG_SYS_NAND_COMMAND_LATCH   (CONFIG_SYS_NAND_BASE + 0x4000)
++
+ /* Interrupt Controller registers */
+ #define RPS_IC_BASE         RPS_BASE
+ #define RPS_IRQ_STATUS     (RPS_IC_BASE)
diff --git a/recipes/linux/linux-2.6.24/hipox/hipox-ubifs.patch b/recipes/linux/linux-2.6.24/hipox/hipox-ubifs.patch
new file mode 100644
index 0000000000..2aef97d4eb
--- /dev/null
+++ b/recipes/linux/linux-2.6.24/hipox/hipox-ubifs.patch
@@ -0,0 +1,43974 @@
+diff -Nurd linux-2.6.24.orig/crypto/Kconfig linux-2.6.24/crypto/Kconfig
+--- linux-2.6.24.orig/crypto/Kconfig	2009-04-17 09:45:12.000000000 +0200
++++ linux-2.6.24/crypto/Kconfig	2009-04-17 09:49:26.000000000 +0200
+@@ -502,6 +502,14 @@
+ 	  Authenc: Combined mode wrapper for IPsec.
+ 	  This is required for IPSec.
+ 
++config CRYPTO_LZO
++   tristate "LZO compression algorithm"
++   select CRYPTO_ALGAPI
++   select LZO_COMPRESS
++   select LZO_DECOMPRESS
++   help
++     This is the LZO algorithm.
++
+ source "drivers/crypto/Kconfig"
+ 
+ endif	# if CRYPTO
+diff -Nurd linux-2.6.24.orig/crypto/Makefile linux-2.6.24/crypto/Makefile
+--- linux-2.6.24.orig/crypto/Makefile	2009-04-17 09:45:12.000000000 +0200
++++ linux-2.6.24/crypto/Makefile	2009-04-17 09:49:26.000000000 +0200
+@@ -51,6 +51,7 @@
+ obj-$(CONFIG_CRYPTO_DEFLATE) += deflate.o
+ obj-$(CONFIG_CRYPTO_MICHAEL_MIC) += michael_mic.o
+ obj-$(CONFIG_CRYPTO_CRC32C) += crc32c.o
++obj-$(CONFIG_CRYPTO_LZO) += lzo.o
+ obj-$(CONFIG_CRYPTO_AUTHENC) += authenc.o
+ 
+ obj-$(CONFIG_CRYPTO_TEST) += tcrypt.o
+diff -Nurd linux-2.6.24.orig/crypto/lzo.c linux-2.6.24/crypto/lzo.c
+--- linux-2.6.24.orig/crypto/lzo.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/crypto/lzo.c	2009-04-17 09:49:26.000000000 +0200
+@@ -0,0 +1,106 @@
++/*
++ * Cryptographic API.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ */
++
++#include <linux/init.h>
++#include <linux/module.h>
++#include <linux/crypto.h>
++#include <linux/vmalloc.h>
++#include <linux/lzo.h>
++
++struct lzo_ctx {
++	void *lzo_comp_mem;
++};
++
++static int lzo_init(struct crypto_tfm *tfm)
++{
++	struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
++
++	ctx->lzo_comp_mem = vmalloc(LZO1X_MEM_COMPRESS);
++	if (!ctx->lzo_comp_mem)
++		return -ENOMEM;
++
++	return 0;
++}
++
++static void lzo_exit(struct crypto_tfm *tfm)
++{
++	struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
++
++	vfree(ctx->lzo_comp_mem);
++}
++
++static int lzo_compress(struct crypto_tfm *tfm, const u8 *src,
++			    unsigned int slen, u8 *dst, unsigned int *dlen)
++{
++	struct lzo_ctx *ctx = crypto_tfm_ctx(tfm);
++	size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */
++	int err;
++
++	err = lzo1x_1_compress(src, slen, dst, &tmp_len, ctx->lzo_comp_mem);
++
++	if (err != LZO_E_OK)
++		return -EINVAL;
++
++	*dlen = tmp_len;
++	return 0;
++}
++
++static int lzo_decompress(struct crypto_tfm *tfm, const u8 *src,
++			      unsigned int slen, u8 *dst, unsigned int *dlen)
++{
++	int err;
++	size_t tmp_len = *dlen; /* size_t(ulong) <-> uint on 64 bit */
++
++	err = lzo1x_decompress_safe(src, slen, dst, &tmp_len);
++
++	if (err != LZO_E_OK)
++		return -EINVAL;
++
++	*dlen = tmp_len;
++	return 0;
++
++}
++
++static struct crypto_alg alg = {
++	.cra_name		= "lzo",
++	.cra_flags		= CRYPTO_ALG_TYPE_COMPRESS,
++	.cra_ctxsize		= sizeof(struct lzo_ctx),
++	.cra_module		= THIS_MODULE,
++	.cra_list		= LIST_HEAD_INIT(alg.cra_list),
++	.cra_init		= lzo_init,
++	.cra_exit		= lzo_exit,
++	.cra_u			= { .compress = {
++	.coa_compress 		= lzo_compress,
++	.coa_decompress  	= lzo_decompress } }
++};
++
++static int __init init(void)
++{
++	return crypto_register_alg(&alg);
++}
++
++static void __exit fini(void)
++{
++	crypto_unregister_alg(&alg);
++}
++
++module_init(init);
++module_exit(fini);
++
++MODULE_LICENSE("GPL");
++MODULE_DESCRIPTION("LZO Compression Algorithm");
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/Kconfig linux-2.6.24/drivers/mtd/ubi/Kconfig
+--- linux-2.6.24.orig/drivers/mtd/ubi/Kconfig	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/Kconfig	2009-04-17 09:49:26.000000000 +0200
+@@ -24,8 +24,13 @@
+ 	  erase counter value and the lowest erase counter value of eraseblocks
+ 	  of UBI devices. When this threshold is exceeded, UBI starts performing
+ 	  wear leveling by means of moving data from eraseblock with low erase
+-	  counter to eraseblocks with high erase counter. Leave the default
+-	  value if unsure.
++	  counter to eraseblocks with high erase counter.
++
++	  The default value should be OK for SLC NAND flashes, NOR flashes and
++	  other flashes which have eraseblock life-cycle 100000 or more.
++	  However, in case of MLC NAND flashes which typically have eraseblock
++	  life-cycle less then 10000, the threshold should be lessened (e.g.,
++	  to 128 or 256, although it does not have to be power of 2).
+ 
+ config MTD_UBI_BEB_RESERVE
+ 	int "Percentage of reserved eraseblocks for bad eraseblocks handling"
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/build.c linux-2.6.24/drivers/mtd/ubi/build.c
+--- linux-2.6.24.orig/drivers/mtd/ubi/build.c	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/build.c	2009-04-17 09:49:26.000000000 +0200
+@@ -21,11 +21,16 @@
+  */
+ 
+ /*
+- * This file includes UBI initialization and building of UBI devices. At the
+- * moment UBI devices may only be added while UBI is initialized, but dynamic
+- * device add/remove functionality is planned. Also, at the moment we only
+- * attach UBI devices by scanning, which will become a bottleneck when flashes
+- * reach certain large size. Then one may improve UBI and add other methods.
++ * This file includes UBI initialization and building of UBI devices.
++ *
++ * When UBI is initialized, it attaches all the MTD devices specified as the
++ * module load parameters or the kernel boot parameters. If MTD devices were
++ * specified, UBI does not attach any MTD device, but it is possible to do
++ * later using the "UBI control device".
++ *
++ * At the moment we only attach UBI devices by scanning, which will become a
++ * bottleneck when flashes reach certain large size. Then one may improve UBI
++ * and add other methods, although it does not seem to be easy to do.
+  */
+ 
+ #include <linux/err.h>
+@@ -33,7 +38,9 @@
+ #include <linux/moduleparam.h>
+ #include <linux/stringify.h>
+ #include <linux/stat.h>
++#include <linux/miscdevice.h>
+ #include <linux/log2.h>
++#include <linux/kthread.h>
+ #include "ubi.h"
+ 
+ /* Maximum length of the 'mtd=' parameter */
+@@ -43,29 +50,39 @@
+  * struct mtd_dev_param - MTD device parameter description data structure.
+  * @name: MTD device name or number string
+  * @vid_hdr_offs: VID header offset
+- * @data_offs: data offset
+  */
+-struct mtd_dev_param
+-{
++struct mtd_dev_param {
+ 	char name[MTD_PARAM_LEN_MAX];
+ 	int vid_hdr_offs;
+-	int data_offs;
+ };
+ 
+ /* Numbers of elements set in the @mtd_dev_param array */
+-static int mtd_devs = 0;
++static int mtd_devs;
+ 
+ /* MTD devices specification parameters */
+ static struct mtd_dev_param mtd_dev_param[UBI_MAX_DEVICES];
+ 
+-/* Number of UBI devices in system */
+-int ubi_devices_cnt;
++/* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
++struct class *ubi_class;
++
++/* Slab cache for wear-leveling entries */
++struct kmem_cache *ubi_wl_entry_slab;
++
++/* UBI control character device */
++static struct miscdevice ubi_ctrl_cdev = {
++	.minor = MISC_DYNAMIC_MINOR,
++	.name = "ubi_ctrl",
++	.fops = &ubi_ctrl_cdev_operations,
++};
+ 
+ /* All UBI devices in system */
+-struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
++static struct ubi_device *ubi_devices[UBI_MAX_DEVICES];
+ 
+-/* Root UBI "class" object (corresponds to '/<sysfs>/class/ubi/') */
+-struct class *ubi_class;
++/* Serializes UBI devices creations and removals */
++DEFINE_MUTEX(ubi_devices_mutex);
++
++/* Protects @ubi_devices and @ubi->ref_count */
++static DEFINE_SPINLOCK(ubi_devices_lock);
+ 
+ /* "Show" method for files in '/<sysfs>/class/ubi/' */
+ static ssize_t ubi_version_show(struct class *class, char *buf)
+@@ -101,42 +118,157 @@
+ 	__ATTR(min_io_size, S_IRUGO, dev_attribute_show, NULL);
+ static struct device_attribute dev_bgt_enabled =
+ 	__ATTR(bgt_enabled, S_IRUGO, dev_attribute_show, NULL);
++static struct device_attribute dev_mtd_num =
++	__ATTR(mtd_num, S_IRUGO, dev_attribute_show, NULL);
++
++/**
++ * ubi_get_device - get UBI device.
++ * @ubi_num: UBI device number
++ *
++ * This function returns UBI device description object for UBI device number
++ * @ubi_num, or %NULL if the device does not exist. This function increases the
++ * device reference count to prevent removal of the device. In other words, the
++ * device cannot be removed if its reference count is not zero.
++ */
++struct ubi_device *ubi_get_device(int ubi_num)
++{
++	struct ubi_device *ubi;
++
++	spin_lock(&ubi_devices_lock);
++	ubi = ubi_devices[ubi_num];
++	if (ubi) {
++		ubi_assert(ubi->ref_count >= 0);
++		ubi->ref_count += 1;
++		get_device(&ubi->dev);
++	}
++	spin_unlock(&ubi_devices_lock);
++
++	return ubi;
++}
++
++/**
++ * ubi_put_device - drop an UBI device reference.
++ * @ubi: UBI device description object
++ */
++void ubi_put_device(struct ubi_device *ubi)
++{
++	spin_lock(&ubi_devices_lock);
++	ubi->ref_count -= 1;
++	put_device(&ubi->dev);
++	spin_unlock(&ubi_devices_lock);
++}
++
++/**
++ * ubi_get_by_major - get UBI device by character device major number.
++ * @major: major number
++ *
++ * This function is similar to 'ubi_get_device()', but it searches the device
++ * by its major number.
++ */
++struct ubi_device *ubi_get_by_major(int major)
++{
++	int i;
++	struct ubi_device *ubi;
++
++	spin_lock(&ubi_devices_lock);
++	for (i = 0; i < UBI_MAX_DEVICES; i++) {
++		ubi = ubi_devices[i];
++		if (ubi && MAJOR(ubi->cdev.dev) == major) {
++			ubi_assert(ubi->ref_count >= 0);
++			ubi->ref_count += 1;
++			get_device(&ubi->dev);
++			spin_unlock(&ubi_devices_lock);
++			return ubi;
++		}
++	}
++	spin_unlock(&ubi_devices_lock);
++
++	return NULL;
++}
++
++/**
++ * ubi_major2num - get UBI device number by character device major number.
++ * @major: major number
++ *
++ * This function searches UBI device number object by its major number. If UBI
++ * device was not found, this function returns -ENODEV, otherwise the UBI device
++ * number is returned.
++ */
++int ubi_major2num(int major)
++{
++	int i, ubi_num = -ENODEV;
++
++	spin_lock(&ubi_devices_lock);
++	for (i = 0; i < UBI_MAX_DEVICES; i++) {
++		struct ubi_device *ubi = ubi_devices[i];
++
++		if (ubi && MAJOR(ubi->cdev.dev) == major) {
++			ubi_num = ubi->ubi_num;
++			break;
++		}
++	}
++	spin_unlock(&ubi_devices_lock);
++
++	return ubi_num;
++}
+ 
+ /* "Show" method for files in '/<sysfs>/class/ubi/ubiX/' */
+ static ssize_t dev_attribute_show(struct device *dev,
+ 				  struct device_attribute *attr, char *buf)
+ {
+-	const struct ubi_device *ubi;
++	ssize_t ret;
++	struct ubi_device *ubi;
+ 
++	/*
++	 * The below code looks weird, but it actually makes sense. We get the
++	 * UBI device reference from the contained 'struct ubi_device'. But it
++	 * is unclear if the device was removed or not yet. Indeed, if the
++	 * device was removed before we increased its reference count,
++	 * 'ubi_get_device()' will return -ENODEV and we fail.
++	 *
++	 * Remember, 'struct ubi_device' is freed in the release function, so
++	 * we still can use 'ubi->ubi_num'.
++	 */
+ 	ubi = container_of(dev, struct ubi_device, dev);
++	ubi = ubi_get_device(ubi->ubi_num);
++	if (!ubi)
++		return -ENODEV;
++
+ 	if (attr == &dev_eraseblock_size)
+-		return sprintf(buf, "%d\n", ubi->leb_size);
++		ret = sprintf(buf, "%d\n", ubi->leb_size);
+ 	else if (attr == &dev_avail_eraseblocks)
+-		return sprintf(buf, "%d\n", ubi->avail_pebs);
++		ret = sprintf(buf, "%d\n", ubi->avail_pebs);
+ 	else if (attr == &dev_total_eraseblocks)
+-		return sprintf(buf, "%d\n", ubi->good_peb_count);
++		ret = sprintf(buf, "%d\n", ubi->good_peb_count);
+ 	else if (attr == &dev_volumes_count)
+-		return sprintf(buf, "%d\n", ubi->vol_count);
++		ret = sprintf(buf, "%d\n", ubi->vol_count - UBI_INT_VOL_COUNT);
+ 	else if (attr == &dev_max_ec)
+-		return sprintf(buf, "%d\n", ubi->max_ec);
++		ret = sprintf(buf, "%d\n", ubi->max_ec);
+ 	else if (attr == &dev_reserved_for_bad)
+-		return sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
++		ret = sprintf(buf, "%d\n", ubi->beb_rsvd_pebs);
+ 	else if (attr == &dev_bad_peb_count)
+-		return sprintf(buf, "%d\n", ubi->bad_peb_count);
++		ret = sprintf(buf, "%d\n", ubi->bad_peb_count);
+ 	else if (attr == &dev_max_vol_count)
+-		return sprintf(buf, "%d\n", ubi->vtbl_slots);
++		ret = sprintf(buf, "%d\n", ubi->vtbl_slots);
+ 	else if (attr == &dev_min_io_size)
+-		return sprintf(buf, "%d\n", ubi->min_io_size);
++		ret = sprintf(buf, "%d\n", ubi->min_io_size);
+ 	else if (attr == &dev_bgt_enabled)
+-		return sprintf(buf, "%d\n", ubi->thread_enabled);
++		ret = sprintf(buf, "%d\n", ubi->thread_enabled);
++	else if (attr == &dev_mtd_num)
++		ret = sprintf(buf, "%d\n", ubi->mtd->index);
+ 	else
+-		BUG();
++		ret = -EINVAL;
+ 
+-	return 0;
++	ubi_put_device(ubi);
++	return ret;
+ }
+ 
+-/* Fake "release" method for UBI devices */
+-static void dev_release(struct device *dev) { }
++static void dev_release(struct device *dev)
++{
++	struct ubi_device *ubi = container_of(dev, struct ubi_device, dev);
++
++	kfree(ubi);
++}
+ 
+ /**
+  * ubi_sysfs_init - initialize sysfs for an UBI device.
+@@ -150,68 +282,44 @@
+ 	int err;
+ 
+ 	ubi->dev.release = dev_release;
+-	ubi->dev.devt = MKDEV(ubi->major, 0);
++	ubi->dev.devt = ubi->cdev.dev;
+ 	ubi->dev.class = ubi_class;
+ 	sprintf(&ubi->dev.bus_id[0], UBI_NAME_STR"%d", ubi->ubi_num);
+ 	err = device_register(&ubi->dev);
+ 	if (err)
+-		goto out;
++		return err;
+ 
+ 	err = device_create_file(&ubi->dev, &dev_eraseblock_size);
+ 	if (err)
+-		goto out_unregister;
++		return err;
+ 	err = device_create_file(&ubi->dev, &dev_avail_eraseblocks);
+ 	if (err)
+-		goto out_eraseblock_size;
++		return err;
+ 	err = device_create_file(&ubi->dev, &dev_total_eraseblocks);
+ 	if (err)
+-		goto out_avail_eraseblocks;
++		return err;
+ 	err = device_create_file(&ubi->dev, &dev_volumes_count);
+ 	if (err)
+-		goto out_total_eraseblocks;
++		return err;
+ 	err = device_create_file(&ubi->dev, &dev_max_ec);
+ 	if (err)
+-		goto out_volumes_count;
++		return err;
+ 	err = device_create_file(&ubi->dev, &dev_reserved_for_bad);
+ 	if (err)
+-		goto out_volumes_max_ec;
++		return err;
+ 	err = device_create_file(&ubi->dev, &dev_bad_peb_count);
+ 	if (err)
+-		goto out_reserved_for_bad;
++		return err;
+ 	err = device_create_file(&ubi->dev, &dev_max_vol_count);
+ 	if (err)
+-		goto out_bad_peb_count;
++		return err;
+ 	err = device_create_file(&ubi->dev, &dev_min_io_size);
+ 	if (err)
+-		goto out_max_vol_count;
++		return err;
+ 	err = device_create_file(&ubi->dev, &dev_bgt_enabled);
+ 	if (err)
+-		goto out_min_io_size;
+-
+-	return 0;
+-
+-out_min_io_size:
+-	device_remove_file(&ubi->dev, &dev_min_io_size);
+-out_max_vol_count:
+-	device_remove_file(&ubi->dev, &dev_max_vol_count);
+-out_bad_peb_count:
+-	device_remove_file(&ubi->dev, &dev_bad_peb_count);
+-out_reserved_for_bad:
+-	device_remove_file(&ubi->dev, &dev_reserved_for_bad);
+-out_volumes_max_ec:
+-	device_remove_file(&ubi->dev, &dev_max_ec);
+-out_volumes_count:
+-	device_remove_file(&ubi->dev, &dev_volumes_count);
+-out_total_eraseblocks:
+-	device_remove_file(&ubi->dev, &dev_total_eraseblocks);
+-out_avail_eraseblocks:
+-	device_remove_file(&ubi->dev, &dev_avail_eraseblocks);
+-out_eraseblock_size:
+-	device_remove_file(&ubi->dev, &dev_eraseblock_size);
+-out_unregister:
+-	device_unregister(&ubi->dev);
+-out:
+-	ubi_err("failed to initialize sysfs for %s", ubi->ubi_name);
++		return err;
++	err = device_create_file(&ubi->dev, &dev_mtd_num);
+ 	return err;
+ }
+ 
+@@ -221,6 +329,7 @@
+  */
+ static void ubi_sysfs_close(struct ubi_device *ubi)
+ {
++	device_remove_file(&ubi->dev, &dev_mtd_num);
+ 	device_remove_file(&ubi->dev, &dev_bgt_enabled);
+ 	device_remove_file(&ubi->dev, &dev_min_io_size);
+ 	device_remove_file(&ubi->dev, &dev_max_vol_count);
+@@ -244,7 +353,26 @@
+ 
+ 	for (i = 0; i < ubi->vtbl_slots; i++)
+ 		if (ubi->volumes[i])
+-			ubi_free_volume(ubi, i);
++			ubi_free_volume(ubi, ubi->volumes[i]);
++}
++
++/**
++ * free_user_volumes - free all user volumes.
++ * @ubi: UBI device description object
++ *
++ * Normally the volumes are freed at the release function of the volume device
++ * objects. However, on error paths the volumes have to be freed before the
++ * device objects have been initialized.
++ */
++static void free_user_volumes(struct ubi_device *ubi)
++{
++	int i;
++
++	for (i = 0; i < ubi->vtbl_slots; i++)
++		if (ubi->volumes[i]) {
++			kfree(ubi->volumes[i]->eba_tbl);
++			kfree(ubi->volumes[i]);
++		}
+ }
+ 
+ /**
+@@ -252,16 +380,13 @@
+  * @ubi: UBI device description object
+  *
+  * This function returns zero in case of success and a negative error code in
+- * case of failure.
++ * case of failure. Note, this function destroys all volumes if it failes.
+  */
+ static int uif_init(struct ubi_device *ubi)
+ {
+ 	int i, err;
+ 	dev_t dev;
+ 
+-	mutex_init(&ubi->vtbl_mutex);
+-	spin_lock_init(&ubi->volumes_lock);
+-
+ 	sprintf(ubi->ubi_name, UBI_NAME_STR "%d", ubi->ubi_num);
+ 
+ 	/*
+@@ -278,52 +403,72 @@
+ 		return err;
+ 	}
+ 
++	ubi_assert(MINOR(dev) == 0);
+ 	cdev_init(&ubi->cdev, &ubi_cdev_operations);
+-	ubi->major = MAJOR(dev);
+-	dbg_msg("%s major is %u", ubi->ubi_name, ubi->major);
++	dbg_gen("%s major is %u", ubi->ubi_name, MAJOR(dev));
+ 	ubi->cdev.owner = THIS_MODULE;
+ 
+-	dev = MKDEV(ubi->major, 0);
+ 	err = cdev_add(&ubi->cdev, dev, 1);
+ 	if (err) {
+-		ubi_err("cannot add character device %s", ubi->ubi_name);
++		ubi_err("cannot add character device");
+ 		goto out_unreg;
+ 	}
+ 
+ 	err = ubi_sysfs_init(ubi);
+ 	if (err)
+-		goto out_cdev;
++		goto out_sysfs;
+ 
+ 	for (i = 0; i < ubi->vtbl_slots; i++)
+ 		if (ubi->volumes[i]) {
+-			err = ubi_add_volume(ubi, i);
+-			if (err)
++			err = ubi_add_volume(ubi, ubi->volumes[i]);
++			if (err) {
++				ubi_err("cannot add volume %d", i);
+ 				goto out_volumes;
++			}
+ 		}
+ 
+ 	return 0;
+ 
+ out_volumes:
+ 	kill_volumes(ubi);
++out_sysfs:
+ 	ubi_sysfs_close(ubi);
+-out_cdev:
+ 	cdev_del(&ubi->cdev);
+ out_unreg:
+-	unregister_chrdev_region(MKDEV(ubi->major, 0),
+-				 ubi->vtbl_slots + 1);
++	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
++	ubi_err("cannot initialize UBI %s, error %d", ubi->ubi_name, err);
+ 	return err;
+ }
+ 
+ /**
+  * uif_close - close user interfaces for an UBI device.
+  * @ubi: UBI device description object
++ *
++ * Note, since this function un-registers UBI volume device objects (@vol->dev),
++ * the memory allocated voe the volumes is freed as well (in the release
++ * function).
+  */
+ static void uif_close(struct ubi_device *ubi)
+ {
+ 	kill_volumes(ubi);
+ 	ubi_sysfs_close(ubi);
+ 	cdev_del(&ubi->cdev);
+-	unregister_chrdev_region(MKDEV(ubi->major, 0), ubi->vtbl_slots + 1);
++	unregister_chrdev_region(ubi->cdev.dev, ubi->vtbl_slots + 1);
++}
++
++/**
++ * free_internal_volumes - free internal volumes.
++ * @ubi: UBI device description object
++ */
++static void free_internal_volumes(struct ubi_device *ubi)
++{
++	int i;
++
++	for (i = ubi->vtbl_slots;
++	     i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
++		kfree(ubi->volumes[i]->eba_tbl);
++		kfree(ubi->volumes[i]);
++	}
+ }
+ 
+ /**
+@@ -370,6 +515,7 @@
+ out_wl:
+ 	ubi_wl_close(ubi);
+ out_vtbl:
++	free_internal_volumes(ubi);
+ 	vfree(ubi->vtbl);
+ out_si:
+ 	ubi_scan_destroy_si(si);
+@@ -377,16 +523,16 @@
+ }
+ 
+ /**
+- * io_init - initialize I/O unit for a given UBI device.
++ * io_init - initialize I/O sub-system for a given UBI device.
+  * @ubi: UBI device description object
+  *
+  * If @ubi->vid_hdr_offset or @ubi->leb_start is zero, default offsets are
+  * assumed:
+  *   o EC header is always at offset zero - this cannot be changed;
+  *   o VID header starts just after the EC header at the closest address
+- *   aligned to @io->@hdrs_min_io_size;
++ *     aligned to @io->hdrs_min_io_size;
+  *   o data starts just after the VID header at the closest address aligned to
+- *     @io->@min_io_size
++ *     @io->min_io_size
+  *
+  * This function returns zero in case of success and a negative error code in
+  * case of failure.
+@@ -407,6 +553,9 @@
+ 		return -EINVAL;
+ 	}
+ 
++	if (ubi->vid_hdr_offset < 0)
++		return -EINVAL;
++
+ 	/*
+ 	 * Note, in this implementation we support MTD devices with 0x7FFFFFFF
+ 	 * physical eraseblocks maximum.
+@@ -422,9 +571,14 @@
+ 	ubi->min_io_size = ubi->mtd->writesize;
+ 	ubi->hdrs_min_io_size = ubi->mtd->writesize >> ubi->mtd->subpage_sft;
+ 
+-	/* Make sure minimal I/O unit is power of 2 */
++	/*
++	 * Make sure minimal I/O unit is power of 2. Note, there is no
++	 * fundamental reason for this assumption. It is just an optimization
++	 * which allows us to avoid costly division operations.
++	 */
+ 	if (!is_power_of_2(ubi->min_io_size)) {
+-		ubi_err("bad min. I/O unit");
++		ubi_err("min. I/O unit (%d) is not power of 2",
++			ubi->min_io_size);
+ 		return -EINVAL;
+ 	}
+ 
+@@ -453,10 +607,8 @@
+ 	}
+ 
+ 	/* Similar for the data offset */
+-	if (ubi->leb_start == 0) {
+-		ubi->leb_start = ubi->vid_hdr_offset + ubi->vid_hdr_alsize;
+-		ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
+-	}
++	ubi->leb_start = ubi->vid_hdr_offset + UBI_EC_HDR_SIZE;
++	ubi->leb_start = ALIGN(ubi->leb_start, ubi->min_io_size);
+ 
+ 	dbg_msg("vid_hdr_offset   %d", ubi->vid_hdr_offset);
+ 	dbg_msg("vid_hdr_aloffset %d", ubi->vid_hdr_aloffset);
+@@ -474,7 +626,7 @@
+ 	if (ubi->vid_hdr_offset < UBI_EC_HDR_SIZE ||
+ 	    ubi->leb_start < ubi->vid_hdr_offset + UBI_VID_HDR_SIZE ||
+ 	    ubi->leb_start > ubi->peb_size - UBI_VID_HDR_SIZE ||
+-	    ubi->leb_start % ubi->min_io_size) {
++	    ubi->leb_start & (ubi->min_io_size - 1)) {
+ 		ubi_err("bad VID header (%d) or data offsets (%d)",
+ 			ubi->vid_hdr_offset, ubi->leb_start);
+ 		return -EINVAL;
+@@ -499,8 +651,16 @@
+ 		ubi->ro_mode = 1;
+ 	}
+ 
+-	dbg_msg("leb_size         %d", ubi->leb_size);
+-	dbg_msg("ro_mode          %d", ubi->ro_mode);
++	ubi_msg("physical eraseblock size:   %d bytes (%d KiB)",
++		ubi->peb_size, ubi->peb_size >> 10);
++	ubi_msg("logical eraseblock size:    %d bytes", ubi->leb_size);
++	ubi_msg("smallest flash I/O unit:    %d", ubi->min_io_size);
++	if (ubi->hdrs_min_io_size != ubi->min_io_size)
++		ubi_msg("sub-page size:              %d",
++			ubi->hdrs_min_io_size);
++	ubi_msg("VID header offset:          %d (aligned %d)",
++		ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
++	ubi_msg("data offset:                %d", ubi->leb_start);
+ 
+ 	/*
+ 	 * Note, ideally, we have to initialize ubi->bad_peb_count here. But
+@@ -514,89 +674,162 @@
+ }
+ 
+ /**
+- * attach_mtd_dev - attach an MTD device.
+- * @mtd_dev: MTD device name or number string
+- * @vid_hdr_offset: VID header offset
+- * @data_offset: data offset
++ * autoresize - re-size the volume which has the "auto-resize" flag set.
++ * @ubi: UBI device description object
++ * @vol_id: ID of the volume to re-size
+  *
+- * This function attaches an MTD device to UBI. It first treats @mtd_dev as the
+- * MTD device name, and tries to open it by this name. If it is unable to open,
+- * it tries to convert @mtd_dev to an integer and open the MTD device by its
+- * number. Returns zero in case of success and a negative error code in case of
+- * failure.
++ * This function re-sizes the volume marked by the @UBI_VTBL_AUTORESIZE_FLG in
++ * the volume table to the largest possible size. See comments in ubi-header.h
++ * for more description of the flag. Returns zero in case of success and a
++ * negative error code in case of failure.
+  */
+-static int attach_mtd_dev(const char *mtd_dev, int vid_hdr_offset,
+-			  int data_offset)
++static int autoresize(struct ubi_device *ubi, int vol_id)
+ {
+-	struct ubi_device *ubi;
+-	struct mtd_info *mtd;
+-	int i, err;
++	struct ubi_volume_desc desc;
++	struct ubi_volume *vol = ubi->volumes[vol_id];
++	int err, old_reserved_pebs = vol->reserved_pebs;
+ 
+-	mtd = get_mtd_device_nm(mtd_dev);
+-	if (IS_ERR(mtd)) {
+-		int mtd_num;
+-		char *endp;
++	/*
++	 * Clear the auto-resize flag in the volume in-memory copy of the
++	 * volume table, and 'ubi_resize_volume()' will propagate this change
++	 * to the flash.
++	 */
++	ubi->vtbl[vol_id].flags &= ~UBI_VTBL_AUTORESIZE_FLG;
+ 
+-		if (PTR_ERR(mtd) != -ENODEV)
+-			return PTR_ERR(mtd);
++	if (ubi->avail_pebs == 0) {
++		struct ubi_vtbl_record vtbl_rec;
+ 
+ 		/*
+-		 * Probably this is not MTD device name but MTD device number -
+-		 * check this out.
++		 * No available PEBs to re-size the volume, clear the flag on
++		 * flash and exit.
+ 		 */
+-		mtd_num = simple_strtoul(mtd_dev, &endp, 0);
+-		if (*endp != '\0' || mtd_dev == endp) {
+-			ubi_err("incorrect MTD device: \"%s\"", mtd_dev);
+-			return -ENODEV;
++		memcpy(&vtbl_rec, &ubi->vtbl[vol_id],
++		       sizeof(struct ubi_vtbl_record));
++		err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
++		if (err)
++			ubi_err("cannot clean auto-resize flag for volume %d",
++				vol_id);
++	} else {
++		desc.vol = vol;
++		err = ubi_resize_volume(&desc,
++					old_reserved_pebs + ubi->avail_pebs);
++		if (err)
++			ubi_err("cannot auto-resize volume %d", vol_id);
++	}
++
++	if (err)
++		return err;
++
++	ubi_msg("volume %d (\"%s\") re-sized from %d to %d LEBs", vol_id,
++		vol->name, old_reserved_pebs, vol->reserved_pebs);
++	return 0;
++}
++
++/**
++ * ubi_attach_mtd_dev - attach an MTD device.
++ * @mtd: MTD device description object
++ * @ubi_num: number to assign to the new UBI device
++ * @vid_hdr_offset: VID header offset
++ *
++ * This function attaches MTD device @mtd_dev to UBI and assign @ubi_num number
++ * to the newly created UBI device, unless @ubi_num is %UBI_DEV_NUM_AUTO, in
++ * which case this function finds a vacant device number and assigns it
++ * automatically. Returns the new UBI device number in case of success and a
++ * negative error code in case of failure.
++ *
++ * Note, the invocations of this function has to be serialized by the
++ * @ubi_devices_mutex.
++ */
++int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset)
++{
++	struct ubi_device *ubi;
++	int i, err, do_free = 1;
++
++	/*
++	 * Check if we already have the same MTD device attached.
++	 *
++	 * Note, this function assumes that UBI devices creations and deletions
++	 * are serialized, so it does not take the &ubi_devices_lock.
++	 */
++	for (i = 0; i < UBI_MAX_DEVICES; i++) {
++		ubi = ubi_devices[i];
++		if (ubi && mtd->index == ubi->mtd->index) {
++			dbg_err("mtd%d is already attached to ubi%d",
++				mtd->index, i);
++			return -EEXIST;
+ 		}
++	}
+ 
+-		mtd = get_mtd_device(NULL, mtd_num);
+-		if (IS_ERR(mtd))
+-			return PTR_ERR(mtd);
++	/*
++	 * Make sure this MTD device is not emulated on top of an UBI volume
++	 * already. Well, generally this recursion works fine, but there are
++	 * different problems like the UBI module takes a reference to itself
++	 * by attaching (and thus, opening) the emulated MTD device. This
++	 * results in inability to unload the module. And in general it makes
++	 * no sense to attach emulated MTD devices, so we prohibit this.
++	 */
++	if (mtd->type == MTD_UBIVOLUME) {
++		ubi_err("refuse attaching mtd%d - it is already emulated on "
++			"top of UBI", mtd->index);
++		return -EINVAL;
+ 	}
+ 
+-	/* Check if we already have the same MTD device attached */
+-	for (i = 0; i < ubi_devices_cnt; i++)
+-		if (ubi_devices[i]->mtd->index == mtd->index) {
+-			ubi_err("mtd%d is already attached to ubi%d",
+-				mtd->index, i);
+-			err = -EINVAL;
+-			goto out_mtd;
++	if (ubi_num == UBI_DEV_NUM_AUTO) {
++		/* Search for an empty slot in the @ubi_devices array */
++		for (ubi_num = 0; ubi_num < UBI_MAX_DEVICES; ubi_num++)
++			if (!ubi_devices[ubi_num])
++				break;
++		if (ubi_num == UBI_MAX_DEVICES) {
++			dbg_err("only %d UBI devices may be created",
++				UBI_MAX_DEVICES);
++			return -ENFILE;
+ 		}
++	} else {
++		if (ubi_num >= UBI_MAX_DEVICES)
++			return -EINVAL;
+ 
+-	ubi = ubi_devices[ubi_devices_cnt] = kzalloc(sizeof(struct ubi_device),
+-						     GFP_KERNEL);
+-	if (!ubi) {
+-		err = -ENOMEM;
+-		goto out_mtd;
++		/* Make sure ubi_num is not busy */
++		if (ubi_devices[ubi_num]) {
++			dbg_err("ubi%d already exists", ubi_num);
++			return -EEXIST;
++		}
+ 	}
+ 
+-	ubi->ubi_num = ubi_devices_cnt;
++	ubi = kzalloc(sizeof(struct ubi_device), GFP_KERNEL);
++	if (!ubi)
++		return -ENOMEM;
++
+ 	ubi->mtd = mtd;
++	ubi->ubi_num = ubi_num;
++	ubi->vid_hdr_offset = vid_hdr_offset;
++	ubi->autoresize_vol_id = -1;
+ 
+-	dbg_msg("attaching mtd%d to ubi%d: VID header offset %d data offset %d",
+-		ubi->mtd->index, ubi_devices_cnt, vid_hdr_offset, data_offset);
++	mutex_init(&ubi->buf_mutex);
++	mutex_init(&ubi->ckvol_mutex);
++	mutex_init(&ubi->mult_mutex);
++	mutex_init(&ubi->volumes_mutex);
++	spin_lock_init(&ubi->volumes_lock);
++
++	ubi_msg("attaching mtd%d to ubi%d", mtd->index, ubi_num);
+ 
+-	ubi->vid_hdr_offset = vid_hdr_offset;
+-	ubi->leb_start = data_offset;
+ 	err = io_init(ubi);
+ 	if (err)
+ 		goto out_free;
+ 
+-	mutex_init(&ubi->buf_mutex);
++	err = -ENOMEM;
+ 	ubi->peb_buf1 = vmalloc(ubi->peb_size);
+ 	if (!ubi->peb_buf1)
+ 		goto out_free;
+ 
+ 	ubi->peb_buf2 = vmalloc(ubi->peb_size);
+ 	if (!ubi->peb_buf2)
+-		 goto out_free;
++		goto out_free;
+ 
+ #ifdef CONFIG_MTD_UBI_DEBUG
+ 	mutex_init(&ubi->dbg_buf_mutex);
+ 	ubi->dbg_peb_buf = vmalloc(ubi->peb_size);
+ 	if (!ubi->dbg_peb_buf)
+-		 goto out_free;
++		goto out_free;
+ #endif
+ 
+ 	err = attach_by_scanning(ubi);
+@@ -605,22 +838,29 @@
+ 		goto out_free;
+ 	}
+ 
++	if (ubi->autoresize_vol_id != -1) {
++		err = autoresize(ubi, ubi->autoresize_vol_id);
++		if (err)
++			goto out_detach;
++	}
++
+ 	err = uif_init(ubi);
+ 	if (err)
+-		goto out_detach;
++		goto out_nofree;
+ 
+-	ubi_msg("attached mtd%d to ubi%d", ubi->mtd->index, ubi_devices_cnt);
+-	ubi_msg("MTD device name:            \"%s\"", ubi->mtd->name);
++	ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
++	if (IS_ERR(ubi->bgt_thread)) {
++		err = PTR_ERR(ubi->bgt_thread);
++		ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
++			err);
++		goto out_uif;
++	}
++
++	ubi_msg("attached mtd%d to ubi%d", mtd->index, ubi_num);
++	ubi_msg("MTD device name:            \"%s\"", mtd->name);
+ 	ubi_msg("MTD device size:            %llu MiB", ubi->flash_size >> 20);
+-	ubi_msg("physical eraseblock size:   %d bytes (%d KiB)",
+-		ubi->peb_size, ubi->peb_size >> 10);
+-	ubi_msg("logical eraseblock size:    %d bytes", ubi->leb_size);
+ 	ubi_msg("number of good PEBs:        %d", ubi->good_peb_count);
+ 	ubi_msg("number of bad PEBs:         %d", ubi->bad_peb_count);
+-	ubi_msg("smallest flash I/O unit:    %d", ubi->min_io_size);
+-	ubi_msg("VID header offset:          %d (aligned %d)",
+-		ubi->vid_hdr_offset, ubi->vid_hdr_aloffset);
+-	ubi_msg("data offset:                %d", ubi->leb_start);
+ 	ubi_msg("max. allowed volumes:       %d", ubi->vtbl_slots);
+ 	ubi_msg("wear-leveling threshold:    %d", CONFIG_MTD_UBI_WL_THRESHOLD);
+ 	ubi_msg("number of internal volumes: %d", UBI_INT_VOL_COUNT);
+@@ -632,18 +872,22 @@
+ 		ubi->beb_rsvd_pebs);
+ 	ubi_msg("max/mean erase counter: %d/%d", ubi->max_ec, ubi->mean_ec);
+ 
+-	/* Enable the background thread */
+-	if (!DBG_DISABLE_BGT) {
++	if (!DBG_DISABLE_BGT)
+ 		ubi->thread_enabled = 1;
+-		wake_up_process(ubi->bgt_thread);
+-	}
++	wake_up_process(ubi->bgt_thread);
+ 
+-	ubi_devices_cnt += 1;
+-	return 0;
++	ubi_devices[ubi_num] = ubi;
++	return ubi_num;
+ 
++out_uif:
++	uif_close(ubi);
++out_nofree:
++	do_free = 0;
+ out_detach:
+-	ubi_eba_close(ubi);
+ 	ubi_wl_close(ubi);
++	if (do_free)
++		free_user_volumes(ubi);
++	free_internal_volumes(ubi);
+ 	vfree(ubi->vtbl);
+ out_free:
+ 	vfree(ubi->peb_buf1);
+@@ -652,24 +896,67 @@
+ 	vfree(ubi->dbg_peb_buf);
+ #endif
+ 	kfree(ubi);
+-out_mtd:
+-	put_mtd_device(mtd);
+-	ubi_devices[ubi_devices_cnt] = NULL;
+ 	return err;
+ }
+ 
+ /**
+- * detach_mtd_dev - detach an MTD device.
+- * @ubi: UBI device description object
++ * ubi_detach_mtd_dev - detach an MTD device.
++ * @ubi_num: UBI device number to detach from
++ * @anyway: detach MTD even if device reference count is not zero
++ *
++ * This function destroys an UBI device number @ubi_num and detaches the
++ * underlying MTD device. Returns zero in case of success and %-EBUSY if the
++ * UBI device is busy and cannot be destroyed, and %-EINVAL if it does not
++ * exist.
++ *
++ * Note, the invocations of this function has to be serialized by the
++ * @ubi_devices_mutex.
+  */
+-static void detach_mtd_dev(struct ubi_device *ubi)
++int ubi_detach_mtd_dev(int ubi_num, int anyway)
+ {
+-	int ubi_num = ubi->ubi_num, mtd_num = ubi->mtd->index;
++	struct ubi_device *ubi;
+ 
++	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
++		return -EINVAL;
++
++	spin_lock(&ubi_devices_lock);
++	ubi = ubi_devices[ubi_num];
++	if (!ubi) {
++		spin_unlock(&ubi_devices_lock);
++		return -EINVAL;
++	}
++
++	if (ubi->ref_count) {
++		if (!anyway) {
++			spin_unlock(&ubi_devices_lock);
++			return -EBUSY;
++		}
++		/* This may only happen if there is a bug */
++		ubi_err("%s reference count %d, destroy anyway",
++			ubi->ubi_name, ubi->ref_count);
++	}
++	ubi_devices[ubi_num] = NULL;
++	spin_unlock(&ubi_devices_lock);
++
++	ubi_assert(ubi_num == ubi->ubi_num);
+ 	dbg_msg("detaching mtd%d from ubi%d", ubi->mtd->index, ubi_num);
++
++	/*
++	 * Before freeing anything, we have to stop the background thread to
++	 * prevent it from doing anything on this device while we are freeing.
++	 */
++	if (ubi->bgt_thread)
++		kthread_stop(ubi->bgt_thread);
++
++	/*
++	 * Get a reference to the device in order to prevent 'dev_release()'
++	 * from freeing @ubi object.
++	 */
++	get_device(&ubi->dev);
++
+ 	uif_close(ubi);
+-	ubi_eba_close(ubi);
+ 	ubi_wl_close(ubi);
++	free_internal_volumes(ubi);
+ 	vfree(ubi->vtbl);
+ 	put_mtd_device(ubi->mtd);
+ 	vfree(ubi->peb_buf1);
+@@ -677,11 +964,37 @@
+ #ifdef CONFIG_MTD_UBI_DEBUG
+ 	vfree(ubi->dbg_peb_buf);
+ #endif
+-	kfree(ubi_devices[ubi_num]);
+-	ubi_devices[ubi_num] = NULL;
+-	ubi_devices_cnt -= 1;
+-	ubi_assert(ubi_devices_cnt >= 0);
+-	ubi_msg("mtd%d is detached from ubi%d", mtd_num, ubi_num);
++	ubi_msg("mtd%d is detached from ubi%d", ubi->mtd->index, ubi->ubi_num);
++	put_device(&ubi->dev);
++	return 0;
++}
++
++/**
++ * find_mtd_device - open an MTD device by its name or number.
++ * @mtd_dev: name or number of the device
++ *
++ * This function tries to open and MTD device described by @mtd_dev string,
++ * which is first treated as an ASCII number, and if it is not true, it is
++ * treated as MTD device name. Returns MTD device description object in case of
++ * success and a negative error code in case of failure.
++ */
++static struct mtd_info * __init open_mtd_device(const char *mtd_dev)
++{
++	struct mtd_info *mtd;
++	int mtd_num;
++	char *endp;
++
++	mtd_num = simple_strtoul(mtd_dev, &endp, 0);
++	if (*endp != '\0' || mtd_dev == endp) {
++		/*
++		 * This does not look like an ASCII integer, probably this is
++		 * MTD device name.
++		 */
++		mtd = get_mtd_device_nm(mtd_dev);
++	} else
++		mtd = get_mtd_device(NULL, mtd_num);
++
++	return mtd;
+ }
+ 
+ static int __init ubi_init(void)
+@@ -693,55 +1006,101 @@
+ 	BUILD_BUG_ON(sizeof(struct ubi_vid_hdr) != 64);
+ 
+ 	if (mtd_devs > UBI_MAX_DEVICES) {
+-		printk("UBI error: too many MTD devices, maximum is %d\n",
+-		       UBI_MAX_DEVICES);
++		ubi_err("too many MTD devices, maximum is %d", UBI_MAX_DEVICES);
+ 		return -EINVAL;
+ 	}
+ 
++	/* Create base sysfs directory and sysfs files */
+ 	ubi_class = class_create(THIS_MODULE, UBI_NAME_STR);
+-	if (IS_ERR(ubi_class))
+-		return PTR_ERR(ubi_class);
++	if (IS_ERR(ubi_class)) {
++		err = PTR_ERR(ubi_class);
++		ubi_err("cannot create UBI class");
++		goto out;
++	}
+ 
+ 	err = class_create_file(ubi_class, &ubi_version);
+-	if (err)
++	if (err) {
++		ubi_err("cannot create sysfs file");
+ 		goto out_class;
++	}
++
++	err = misc_register(&ubi_ctrl_cdev);
++	if (err) {
++		ubi_err("cannot register device");
++		goto out_version;
++	}
++
++	ubi_wl_entry_slab = kmem_cache_create("ubi_wl_entry_slab",
++					      sizeof(struct ubi_wl_entry),
++					      0, 0, NULL);
++	if (!ubi_wl_entry_slab)
++		goto out_dev_unreg;
+ 
+ 	/* Attach MTD devices */
+ 	for (i = 0; i < mtd_devs; i++) {
+ 		struct mtd_dev_param *p = &mtd_dev_param[i];
++		struct mtd_info *mtd;
+ 
+ 		cond_resched();
+-		err = attach_mtd_dev(p->name, p->vid_hdr_offs, p->data_offs);
+-		if (err)
++
++		mtd = open_mtd_device(p->name);
++		if (IS_ERR(mtd)) {
++			err = PTR_ERR(mtd);
+ 			goto out_detach;
++		}
++
++		mutex_lock(&ubi_devices_mutex);
++		err = ubi_attach_mtd_dev(mtd, UBI_DEV_NUM_AUTO,
++					 p->vid_hdr_offs);
++		mutex_unlock(&ubi_devices_mutex);
++		if (err < 0) {
++			put_mtd_device(mtd);
++			ubi_err("cannot attach mtd%d", mtd->index);
++			goto out_detach;
++		}
+ 	}
+ 
+ 	return 0;
+ 
+ out_detach:
+ 	for (k = 0; k < i; k++)
+-		detach_mtd_dev(ubi_devices[k]);
++		if (ubi_devices[k]) {
++			mutex_lock(&ubi_devices_mutex);
++			ubi_detach_mtd_dev(ubi_devices[k]->ubi_num, 1);
++			mutex_unlock(&ubi_devices_mutex);
++		}
++	kmem_cache_destroy(ubi_wl_entry_slab);
++out_dev_unreg:
++	misc_deregister(&ubi_ctrl_cdev);
++out_version:
+ 	class_remove_file(ubi_class, &ubi_version);
+ out_class:
+ 	class_destroy(ubi_class);
++out:
++	ubi_err("UBI error: cannot initialize UBI, error %d", err);
+ 	return err;
+ }
+ module_init(ubi_init);
+ 
+ static void __exit ubi_exit(void)
+ {
+-	int i, n = ubi_devices_cnt;
++	int i;
+ 
+-	for (i = 0; i < n; i++)
+-		detach_mtd_dev(ubi_devices[i]);
++	for (i = 0; i < UBI_MAX_DEVICES; i++)
++		if (ubi_devices[i]) {
++			mutex_lock(&ubi_devices_mutex);
++			ubi_detach_mtd_dev(ubi_devices[i]->ubi_num, 1);
++			mutex_unlock(&ubi_devices_mutex);
++		}
++	kmem_cache_destroy(ubi_wl_entry_slab);
++	misc_deregister(&ubi_ctrl_cdev);
+ 	class_remove_file(ubi_class, &ubi_version);
+ 	class_destroy(ubi_class);
+ }
+ module_exit(ubi_exit);
+ 
+ /**
+- * bytes_str_to_int - convert a string representing number of bytes to an
+- * integer.
++ * bytes_str_to_int - convert a number of bytes string into an integer.
+  * @str: the string to convert
+  *
+  * This function returns positive resulting integer in case of success and a
+@@ -754,7 +1113,8 @@
+ 
+ 	result = simple_strtoul(str, &endp, 0);
+ 	if (str == endp || result < 0) {
+-		printk("UBI error: incorrect bytes count: \"%s\"\n", str);
++		printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
++		       str);
+ 		return -EINVAL;
+ 	}
+ 
+@@ -764,15 +1124,14 @@
+ 	case 'M':
+ 		result *= 1024;
+ 	case 'K':
+-	case 'k':
+ 		result *= 1024;
+-		if (endp[1] == 'i' && (endp[2] == '\0' ||
+-			  endp[2] == 'B'  || endp[2] == 'b'))
++		if (endp[1] == 'i' && endp[2] == 'B')
+ 			endp += 2;
+ 	case '\0':
+ 		break;
+ 	default:
+-		printk("UBI error: incorrect bytes count: \"%s\"\n", str);
++		printk(KERN_ERR "UBI error: incorrect bytes count: \"%s\"\n",
++		       str);
+ 		return -EINVAL;
+ 	}
+ 
+@@ -793,23 +1152,27 @@
+ 	struct mtd_dev_param *p;
+ 	char buf[MTD_PARAM_LEN_MAX];
+ 	char *pbuf = &buf[0];
+-	char *tokens[3] = {NULL, NULL, NULL};
++	char *tokens[2] = {NULL, NULL};
++
++	if (!val)
++		return -EINVAL;
+ 
+ 	if (mtd_devs == UBI_MAX_DEVICES) {
+-		printk("UBI error: too many parameters, max. is %d\n",
++		printk(KERN_ERR "UBI error: too many parameters, max. is %d\n",
+ 		       UBI_MAX_DEVICES);
+ 		return -EINVAL;
+ 	}
+ 
+ 	len = strnlen(val, MTD_PARAM_LEN_MAX);
+ 	if (len == MTD_PARAM_LEN_MAX) {
+-		printk("UBI error: parameter \"%s\" is too long, max. is %d\n",
+-		       val, MTD_PARAM_LEN_MAX);
++		printk(KERN_ERR "UBI error: parameter \"%s\" is too long, "
++		       "max. is %d\n", val, MTD_PARAM_LEN_MAX);
+ 		return -EINVAL;
+ 	}
+ 
+ 	if (len == 0) {
+-		printk("UBI warning: empty 'mtd=' parameter - ignored\n");
++		printk(KERN_WARNING "UBI warning: empty 'mtd=' parameter - "
++		       "ignored\n");
+ 		return 0;
+ 	}
+ 
+@@ -819,11 +1182,12 @@
+ 	if (buf[len - 1] == '\n')
+ 		buf[len - 1] = '\0';
+ 
+-	for (i = 0; i < 3; i++)
++	for (i = 0; i < 2; i++)
+ 		tokens[i] = strsep(&pbuf, ",");
+ 
+ 	if (pbuf) {
+-		printk("UBI error: too many arguments at \"%s\"\n", val);
++		printk(KERN_ERR "UBI error: too many arguments at \"%s\"\n",
++		       val);
+ 		return -EINVAL;
+ 	}
+ 
+@@ -832,13 +1196,9 @@
+ 
+ 	if (tokens[1])
+ 		p->vid_hdr_offs = bytes_str_to_int(tokens[1]);
+-	if (tokens[2])
+-		p->data_offs = bytes_str_to_int(tokens[2]);
+ 
+ 	if (p->vid_hdr_offs < 0)
+ 		return p->vid_hdr_offs;
+-	if (p->data_offs < 0)
+-		return p->data_offs;
+ 
+ 	mtd_devs += 1;
+ 	return 0;
+@@ -846,16 +1206,15 @@
+ 
+ module_param_call(mtd, ubi_mtd_param_parse, NULL, NULL, 000);
+ MODULE_PARM_DESC(mtd, "MTD devices to attach. Parameter format: "
+-		      "mtd=<name|num>[,<vid_hdr_offs>,<data_offs>]. "
++		      "mtd=<name|num>[,<vid_hdr_offs>].\n"
+ 		      "Multiple \"mtd\" parameters may be specified.\n"
+-		      "MTD devices may be specified by their number or name. "
+-		      "Optional \"vid_hdr_offs\" and \"data_offs\" parameters "
+-		      "specify UBI VID header position and data starting "
+-		      "position to be used by UBI.\n"
+-		      "Example: mtd=content,1984,2048 mtd=4 - attach MTD device"
+-		      "with name content using VID header offset 1984 and data "
+-		      "start 2048, and MTD device number 4 using default "
+-		      "offsets");
++		      "MTD devices may be specified by their number or name.\n"
++		      "Optional \"vid_hdr_offs\" parameter specifies UBI VID "
++		      "header position and data starting position to be used "
++		      "by UBI.\n"
++		      "Example: mtd=content,1984 mtd=4 - attach MTD device"
++		      "with name \"content\" using VID header offset 1984, and "
++		      "MTD device number 4 with default VID header offset.");
+ 
+ MODULE_VERSION(__stringify(UBI_VERSION));
+ MODULE_DESCRIPTION("UBI - Unsorted Block Images");
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/cdev.c linux-2.6.24/drivers/mtd/ubi/cdev.c
+--- linux-2.6.24.orig/drivers/mtd/ubi/cdev.c	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/cdev.c	2009-04-17 09:49:26.000000000 +0200
+@@ -28,45 +28,22 @@
+  *
+  * Major and minor numbers are assigned dynamically to both UBI and volume
+  * character devices.
++ *
++ * Well, there is the third kind of character devices - the UBI control
++ * character device, which allows to manipulate by UBI devices - create and
++ * delete them. In other words, it is used for attaching and detaching MTD
++ * devices.
+  */
+ 
+ #include <linux/module.h>
+ #include <linux/stat.h>
+ #include <linux/ioctl.h>
+ #include <linux/capability.h>
++#include <linux/uaccess.h>
++#include <linux/compat.h>
+ #include <mtd/ubi-user.h>
+-#include <asm/uaccess.h>
+-#include <asm/div64.h>
+ #include "ubi.h"
+ 
+-/*
+- * Maximum sequence numbers of UBI and volume character device IOCTLs (direct
+- * logical eraseblock erase is a debug-only feature).
+- */
+-#define UBI_CDEV_IOC_MAX_SEQ 2
+-#ifndef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
+-#define VOL_CDEV_IOC_MAX_SEQ 1
+-#else
+-#define VOL_CDEV_IOC_MAX_SEQ 2
+-#endif
+-
+-/**
+- * major_to_device - get UBI device object by character device major number.
+- * @major: major number
+- *
+- * This function returns a pointer to the UBI device object.
+- */
+-static struct ubi_device *major_to_device(int major)
+-{
+-	int i;
+-
+-	for (i = 0; i < ubi_devices_cnt; i++)
+-		if (ubi_devices[i] && ubi_devices[i]->major == major)
+-			return ubi_devices[i];
+-	BUG();
+-	return NULL;
+-}
+-
+ /**
+  * get_exclusive - get exclusive access to an UBI volume.
+  * @desc: volume descriptor
+@@ -124,18 +101,20 @@
+ static int vol_cdev_open(struct inode *inode, struct file *file)
+ {
+ 	struct ubi_volume_desc *desc;
+-	const struct ubi_device *ubi = major_to_device(imajor(inode));
+-	int vol_id = iminor(inode) - 1;
+-	int mode;
++	int vol_id = iminor(inode) - 1, mode, ubi_num;
++
++	ubi_num = ubi_major2num(imajor(inode));
++	if (ubi_num < 0)
++		return ubi_num;
+ 
+ 	if (file->f_mode & FMODE_WRITE)
+ 		mode = UBI_READWRITE;
+ 	else
+ 		mode = UBI_READONLY;
+ 
+-	dbg_msg("open volume %d, mode %d", vol_id, mode);
++	dbg_gen("open volume %d, mode %d", vol_id, mode);
+ 
+-	desc = ubi_open_volume(ubi->ubi_num, vol_id, mode);
++	desc = ubi_open_volume(ubi_num, vol_id, mode);
+ 	if (IS_ERR(desc))
+ 		return PTR_ERR(desc);
+ 
+@@ -148,13 +127,20 @@
+ 	struct ubi_volume_desc *desc = file->private_data;
+ 	struct ubi_volume *vol = desc->vol;
+ 
+-	dbg_msg("release volume %d, mode %d", vol->vol_id, desc->mode);
++	dbg_gen("release volume %d, mode %d", vol->vol_id, desc->mode);
+ 
+ 	if (vol->updating) {
+ 		ubi_warn("update of volume %d not finished, volume is damaged",
+ 			 vol->vol_id);
++		ubi_assert(!vol->changing_leb);
+ 		vol->updating = 0;
+ 		vfree(vol->upd_buf);
++	} else if (vol->changing_leb) {
++		dbg_gen("only %lld of %lld bytes received for atomic LEB change"
++			" for volume %d:%d, cancel", vol->upd_received,
++			vol->upd_bytes, vol->ubi->ubi_num, vol->vol_id);
++		vol->changing_leb = 0;
++		vfree(vol->upd_buf);
+ 	}
+ 
+ 	ubi_close_volume(desc);
+@@ -192,7 +178,7 @@
+ 		return -EINVAL;
+ 	}
+ 
+-	dbg_msg("seek volume %d, offset %lld, origin %d, new offset %lld",
++	dbg_gen("seek volume %d, offset %lld, origin %d, new offset %lld",
+ 		vol->vol_id, offset, origin, new_offset);
+ 
+ 	file->f_pos = new_offset;
+@@ -205,13 +191,12 @@
+ 	struct ubi_volume_desc *desc = file->private_data;
+ 	struct ubi_volume *vol = desc->vol;
+ 	struct ubi_device *ubi = vol->ubi;
+-	int err, lnum, off, len,  vol_id = desc->vol->vol_id, tbuf_size;
++	int err, lnum, off, len,  tbuf_size;
+ 	size_t count_save = count;
+ 	void *tbuf;
+-	uint64_t tmp;
+ 
+-	dbg_msg("read %zd bytes from offset %lld of volume %d",
+-		count, *offp, vol_id);
++	dbg_gen("read %zd bytes from offset %lld of volume %d",
++		count, *offp, vol->vol_id);
+ 
+ 	if (vol->updating) {
+ 		dbg_err("updating");
+@@ -225,7 +210,7 @@
+ 		return 0;
+ 
+ 	if (vol->corrupted)
+-		dbg_msg("read from corrupted volume %d", vol_id);
++		dbg_gen("read from corrupted volume %d", vol->vol_id);
+ 
+ 	if (*offp + count > vol->used_bytes)
+ 		count_save = count = vol->used_bytes - *offp;
+@@ -238,10 +223,7 @@
+ 		return -ENOMEM;
+ 
+ 	len = count > tbuf_size ? tbuf_size : count;
+-
+-	tmp = *offp;
+-	off = do_div(tmp, vol->usable_leb_size);
+-	lnum = tmp;
++	lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
+ 
+ 	do {
+ 		cond_resched();
+@@ -249,7 +231,7 @@
+ 		if (off + len >= vol->usable_leb_size)
+ 			len = vol->usable_leb_size - off;
+ 
+-		err = ubi_eba_read_leb(ubi, vol_id, lnum, tbuf, off, len, 0);
++		err = ubi_eba_read_leb(ubi, vol, lnum, tbuf, off, len, 0);
+ 		if (err)
+ 			break;
+ 
+@@ -289,22 +271,18 @@
+ 	struct ubi_volume_desc *desc = file->private_data;
+ 	struct ubi_volume *vol = desc->vol;
+ 	struct ubi_device *ubi = vol->ubi;
+-	int lnum, off, len, tbuf_size, vol_id = vol->vol_id, err = 0;
++	int lnum, off, len, tbuf_size, err = 0;
+ 	size_t count_save = count;
+ 	char *tbuf;
+-	uint64_t tmp;
+ 
+-	dbg_msg("requested: write %zd bytes to offset %lld of volume %u",
+-		count, *offp, desc->vol->vol_id);
++	dbg_gen("requested: write %zd bytes to offset %lld of volume %u",
++		count, *offp, vol->vol_id);
+ 
+ 	if (vol->vol_type == UBI_STATIC_VOLUME)
+ 		return -EROFS;
+ 
+-	tmp = *offp;
+-	off = do_div(tmp, vol->usable_leb_size);
+-	lnum = tmp;
+-
+-	if (off % ubi->min_io_size) {
++	lnum = div_u64_rem(*offp, vol->usable_leb_size, &off);
++	if (off & (ubi->min_io_size - 1)) {
+ 		dbg_err("unaligned position");
+ 		return -EINVAL;
+ 	}
+@@ -313,7 +291,7 @@
+ 		count_save = count = vol->used_bytes - *offp;
+ 
+ 	/* We can write only in fractions of the minimum I/O unit */
+-	if (count % ubi->min_io_size) {
++	if (count & (ubi->min_io_size - 1)) {
+ 		dbg_err("unaligned write length");
+ 		return -EINVAL;
+ 	}
+@@ -339,7 +317,7 @@
+ 			break;
+ 		}
+ 
+-		err = ubi_eba_write_leb(ubi, vol_id, lnum, tbuf, off, len,
++		err = ubi_eba_write_leb(ubi, vol, lnum, tbuf, off, len,
+ 					UBI_UNKNOWN);
+ 		if (err)
+ 			break;
+@@ -361,7 +339,7 @@
+ }
+ 
+ #else
+-#define vol_cdev_direct_write(file, buf, count, offp) -EPERM
++#define vol_cdev_direct_write(file, buf, count, offp) (-EPERM)
+ #endif /* CONFIG_MTD_UBI_DEBUG_USERSPACE_IO */
+ 
+ static ssize_t vol_cdev_write(struct file *file, const char __user *buf,
+@@ -372,22 +350,32 @@
+ 	struct ubi_volume *vol = desc->vol;
+ 	struct ubi_device *ubi = vol->ubi;
+ 
+-	if (!vol->updating)
++	if (!vol->updating && !vol->changing_leb)
+ 		return vol_cdev_direct_write(file, buf, count, offp);
+ 
+-	err = ubi_more_update_data(ubi, vol->vol_id, buf, count);
++	if (vol->updating)
++		err = ubi_more_update_data(ubi, vol, buf, count);
++	else
++		err = ubi_more_leb_change_data(ubi, vol, buf, count);
++
+ 	if (err < 0) {
+-		ubi_err("cannot write %zd bytes of update data", count);
++		ubi_err("cannot accept more %zd bytes of data, error %d",
++			count, err);
+ 		return err;
+ 	}
+ 
+ 	if (err) {
+ 		/*
+-		 * Update is finished, @err contains number of actually written
+-		 * bytes now.
++		 * The operation is finished, @err contains number of actually
++		 * written bytes.
+ 		 */
+ 		count = err;
+ 
++		if (vol->changing_leb) {
++			revoke_exclusive(desc, UBI_READWRITE);
++			return count;
++		}
++
+ 		err = ubi_check_volume(ubi, vol->vol_id);
+ 		if (err < 0)
+ 			return err;
+@@ -402,12 +390,11 @@
+ 		revoke_exclusive(desc, UBI_READWRITE);
+ 	}
+ 
+-	*offp += count;
+ 	return count;
+ }
+ 
+-static int vol_cdev_ioctl(struct inode *inode, struct file *file,
+-			  unsigned int cmd, unsigned long arg)
++static long vol_cdev_ioctl(struct file *file, unsigned int cmd,
++			   unsigned long arg)
+ {
+ 	int err = 0;
+ 	struct ubi_volume_desc *desc = file->private_data;
+@@ -437,7 +424,8 @@
+ 			break;
+ 		}
+ 
+-		rsvd_bytes = vol->reserved_pebs * (ubi->leb_size-vol->data_pad);
++		rsvd_bytes = (long long)vol->reserved_pebs *
++					ubi->leb_size-vol->data_pad;
+ 		if (bytes < 0 || bytes > rsvd_bytes) {
+ 			err = -EINVAL;
+ 			break;
+@@ -447,15 +435,49 @@
+ 		if (err < 0)
+ 			break;
+ 
+-		err = ubi_start_update(ubi, vol->vol_id, bytes);
++		err = ubi_start_update(ubi, vol, bytes);
+ 		if (bytes == 0)
+ 			revoke_exclusive(desc, UBI_READWRITE);
++		break;
++	}
+ 
+-		file->f_pos = 0;
++	/* Atomic logical eraseblock change command */
++	case UBI_IOCEBCH:
++	{
++		struct ubi_leb_change_req req;
++
++		err = copy_from_user(&req, argp,
++				     sizeof(struct ubi_leb_change_req));
++		if (err) {
++			err = -EFAULT;
++			break;
++		}
++
++		if (desc->mode == UBI_READONLY ||
++		    vol->vol_type == UBI_STATIC_VOLUME) {
++			err = -EROFS;
++			break;
++		}
++
++		/* Validate the request */
++		err = -EINVAL;
++		if (req.lnum < 0 || req.lnum >= vol->reserved_pebs ||
++		    req.bytes < 0 || req.lnum >= vol->usable_leb_size)
++			break;
++		if (req.dtype != UBI_LONGTERM && req.dtype != UBI_SHORTTERM &&
++		    req.dtype != UBI_UNKNOWN)
++			break;
++
++		err = get_exclusive(desc);
++		if (err < 0)
++			break;
++
++		err = ubi_start_leb_change(ubi, vol, &req);
++		if (req.bytes == 0)
++			revoke_exclusive(desc, UBI_READWRITE);
+ 		break;
+ 	}
+ 
+-#ifdef CONFIG_MTD_UBI_DEBUG_USERSPACE_IO
+ 	/* Logical eraseblock erasure command */
+ 	case UBI_IOCEBER:
+ 	{
+@@ -467,7 +489,8 @@
+ 			break;
+ 		}
+ 
+-		if (desc->mode == UBI_READONLY) {
++		if (desc->mode == UBI_READONLY ||
++		    vol->vol_type == UBI_STATIC_VOLUME) {
+ 			err = -EROFS;
+ 			break;
+ 		}
+@@ -477,26 +500,61 @@
+ 			break;
+ 		}
+ 
+-		if (vol->vol_type != UBI_DYNAMIC_VOLUME) {
+-			err = -EROFS;
++		dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
++		err = ubi_eba_unmap_leb(ubi, vol, lnum);
++		if (err)
++			break;
++
++		err = ubi_wl_flush(ubi);
++		break;
++	}
++
++	/* Logical eraseblock map command */
++	case UBI_IOCEBMAP:
++	{
++		struct ubi_map_req req;
++
++		err = copy_from_user(&req, argp, sizeof(struct ubi_map_req));
++		if (err) {
++			err = -EFAULT;
+ 			break;
+ 		}
++		err = ubi_leb_map(desc, req.lnum, req.dtype);
++		break;
++	}
+ 
+-		dbg_msg("erase LEB %d:%d", vol->vol_id, lnum);
+-		err = ubi_eba_unmap_leb(ubi, vol->vol_id, lnum);
+-		if (err)
++	/* Logical eraseblock un-map command */
++	case UBI_IOCEBUNMAP:
++	{
++		int32_t lnum;
++
++		err = get_user(lnum, (__user int32_t *)argp);
++		if (err) {
++			err = -EFAULT;
+ 			break;
++		}
++		err = ubi_leb_unmap(desc, lnum);
++		break;
++	}
+ 
+-		err = ubi_wl_flush(ubi);
++	/* Check if logical eraseblock is mapped command */
++	case UBI_IOCEBISMAP:
++	{
++		int32_t lnum;
++
++		err = get_user(lnum, (__user int32_t *)argp);
++		if (err) {
++			err = -EFAULT;
++			break;
++		}
++		err = ubi_is_mapped(desc, lnum);
+ 		break;
+ 	}
+-#endif
+ 
+ 	default:
+ 		err = -ENOTTY;
+ 		break;
+ 	}
+-
+ 	return err;
+ }
+ 
+@@ -533,7 +591,7 @@
+ 	if (req->alignment > ubi->leb_size)
+ 		goto bad;
+ 
+-	n = req->alignment % ubi->min_io_size;
++	n = req->alignment & (ubi->min_io_size - 1);
+ 	if (req->alignment != 1 && n)
+ 		goto bad;
+ 
+@@ -542,6 +600,10 @@
+ 		goto bad;
+ 	}
+ 
++	n = strnlen(req->name, req->name_len + 1);
++	if (n != req->name_len)
++		goto bad;
++
+ 	return 0;
+ 
+ bad:
+@@ -569,8 +631,169 @@
+ 	return 0;
+ }
+ 
+-static int ubi_cdev_ioctl(struct inode *inode, struct file *file,
+-			  unsigned int cmd, unsigned long arg)
++/**
++ * rename_volumes - rename UBI volumes.
++ * @ubi: UBI device description object
++ * @req: volumes re-name request
++ *
++ * This is a helper function for the volume re-name IOCTL which validates the
++ * the request, opens the volume and calls corresponding volumes management
++ * function. Returns zero in case of success and a negative error code in case
++ * of failure.
++ */
++static int rename_volumes(struct ubi_device *ubi,
++			  struct ubi_rnvol_req *req)
++{
++	int i, n, err;
++	struct list_head rename_list;
++	struct ubi_rename_entry *re, *re1;
++
++	if (req->count < 0 || req->count > UBI_MAX_RNVOL)
++		return -EINVAL;
++
++	if (req->count == 0)
++		return 0;
++
++	/* Validate volume IDs and names in the request */
++	for (i = 0; i < req->count; i++) {
++		if (req->ents[i].vol_id < 0 ||
++		    req->ents[i].vol_id >= ubi->vtbl_slots)
++			return -EINVAL;
++		if (req->ents[i].name_len < 0)
++			return -EINVAL;
++		if (req->ents[i].name_len > UBI_VOL_NAME_MAX)
++			return -ENAMETOOLONG;
++		req->ents[i].name[req->ents[i].name_len] = '\0';
++		n = strlen(req->ents[i].name);
++		if (n != req->ents[i].name_len)
++			err = -EINVAL;
++	}
++
++	/* Make sure volume IDs and names are unique */
++	for (i = 0; i < req->count - 1; i++) {
++		for (n = i + 1; n < req->count; n++) {
++			if (req->ents[i].vol_id == req->ents[n].vol_id) {
++				dbg_err("duplicated volume id %d",
++					req->ents[i].vol_id);
++				return -EINVAL;
++			}
++			if (!strcmp(req->ents[i].name, req->ents[n].name)) {
++				dbg_err("duplicated volume name \"%s\"",
++					req->ents[i].name);
++				return -EINVAL;
++			}
++		}
++	}
++
++	/* Create the re-name list */
++	INIT_LIST_HEAD(&rename_list);
++	for (i = 0; i < req->count; i++) {
++		int vol_id = req->ents[i].vol_id;
++		int name_len = req->ents[i].name_len;
++		const char *name = req->ents[i].name;
++
++		re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
++		if (!re) {
++			err = -ENOMEM;
++			goto out_free;
++		}
++
++		re->desc = ubi_open_volume(ubi->ubi_num, vol_id, UBI_EXCLUSIVE);
++		if (IS_ERR(re->desc)) {
++			err = PTR_ERR(re->desc);
++			dbg_err("cannot open volume %d, error %d", vol_id, err);
++			kfree(re);
++			goto out_free;
++		}
++
++		/* Skip this re-naming if the name does not really change */
++		if (re->desc->vol->name_len == name_len &&
++		    !memcmp(re->desc->vol->name, name, name_len)) {
++			ubi_close_volume(re->desc);
++			kfree(re);
++			continue;
++		}
++
++		re->new_name_len = name_len;
++		memcpy(re->new_name, name, name_len);
++		list_add_tail(&re->list, &rename_list);
++		dbg_msg("will rename volume %d from \"%s\" to \"%s\"",
++			vol_id, re->desc->vol->name, name);
++	}
++
++	if (list_empty(&rename_list))
++		return 0;
++
++	/* Find out the volumes which have to be removed */
++	list_for_each_entry(re, &rename_list, list) {
++		struct ubi_volume_desc *desc;
++		int no_remove_needed = 0;
++
++		/*
++		 * Volume @re->vol_id is going to be re-named to
++		 * @re->new_name, while its current name is @name. If a volume
++		 * with name @re->new_name currently exists, it has to be
++		 * removed, unless it is also re-named in the request (@req).
++		 */
++		list_for_each_entry(re1, &rename_list, list) {
++			if (re->new_name_len == re1->desc->vol->name_len &&
++			    !memcmp(re->new_name, re1->desc->vol->name,
++				    re1->desc->vol->name_len)) {
++				no_remove_needed = 1;
++				break;
++			}
++		}
++
++		if (no_remove_needed)
++			continue;
++
++		/*
++		 * It seems we need to remove volume with name @re->new_name,
++		 * if it exists.
++		 */
++		desc = ubi_open_volume_nm(ubi->ubi_num, re->new_name,
++					  UBI_EXCLUSIVE);
++		if (IS_ERR(desc)) {
++			err = PTR_ERR(desc);
++			if (err == -ENODEV)
++				/* Re-naming into a non-existing volume name */
++				continue;
++
++			/* The volume exists but busy, or an error occurred */
++			dbg_err("cannot open volume \"%s\", error %d",
++				re->new_name, err);
++			goto out_free;
++		}
++
++		re = kzalloc(sizeof(struct ubi_rename_entry), GFP_KERNEL);
++		if (!re) {
++			err = -ENOMEM;
++			ubi_close_volume(desc);
++			goto out_free;
++		}
++
++		re->remove = 1;
++		re->desc = desc;
++		list_add(&re->list, &rename_list);
++		dbg_msg("will remove volume %d, name \"%s\"",
++			re->desc->vol->vol_id, re->desc->vol->name);
++	}
++
++	mutex_lock(&ubi->volumes_mutex);
++	err = ubi_rename_volumes(ubi, &rename_list);
++	mutex_unlock(&ubi->volumes_mutex);
++
++out_free:
++	list_for_each_entry_safe(re, re1, &rename_list, list) {
++		ubi_close_volume(re->desc);
++		list_del(&re->list);
++		kfree(re);
++	}
++	return err;
++}
++
++static long ubi_cdev_ioctl(struct file *file, unsigned int cmd,
++			   unsigned long arg)
+ {
+ 	int err = 0;
+ 	struct ubi_device *ubi;
+@@ -580,9 +803,9 @@
+ 	if (!capable(CAP_SYS_RESOURCE))
+ 		return -EPERM;
+ 
+-	ubi = major_to_device(imajor(inode));
+-	if (IS_ERR(ubi))
+-		return PTR_ERR(ubi);
++	ubi = ubi_get_by_major(imajor(file->f_mapping->host));
++	if (!ubi)
++		return -ENODEV;
+ 
+ 	switch (cmd) {
+ 	/* Create volume command */
+@@ -590,21 +813,21 @@
+ 	{
+ 		struct ubi_mkvol_req req;
+ 
+-		dbg_msg("create volume");
+-		err = copy_from_user(&req, argp,
+-				       sizeof(struct ubi_mkvol_req));
++		dbg_gen("create volume");
++		err = copy_from_user(&req, argp, sizeof(struct ubi_mkvol_req));
+ 		if (err) {
+ 			err = -EFAULT;
+ 			break;
+ 		}
+ 
++		req.name[req.name_len] = '\0';
+ 		err = verify_mkvol_req(ubi, &req);
+ 		if (err)
+ 			break;
+ 
+-		req.name[req.name_len] = '\0';
+-
++		mutex_lock(&ubi->volumes_mutex);
+ 		err = ubi_create_volume(ubi, &req);
++		mutex_unlock(&ubi->volumes_mutex);
+ 		if (err)
+ 			break;
+ 
+@@ -620,7 +843,7 @@
+ 	{
+ 		int vol_id;
+ 
+-		dbg_msg("remove volume");
++		dbg_gen("remove volume");
+ 		err = get_user(vol_id, (__user int32_t *)argp);
+ 		if (err) {
+ 			err = -EFAULT;
+@@ -633,10 +856,16 @@
+ 			break;
+ 		}
+ 
+-		err = ubi_remove_volume(desc);
+-		if (err)
+-			ubi_close_volume(desc);
++		mutex_lock(&ubi->volumes_mutex);
++		err = ubi_remove_volume(desc, 0);
++		mutex_unlock(&ubi->volumes_mutex);
+ 
++		/*
++		 * The volume is deleted (unless an error occurred), and the
++		 * 'struct ubi_volume' object will be freed when
++		 * 'ubi_close_volume()' will call 'put_device()'.
++		 */
++		ubi_close_volume(desc);
+ 		break;
+ 	}
+ 
+@@ -644,12 +873,10 @@
+ 	case UBI_IOCRSVOL:
+ 	{
+ 		int pebs;
+-		uint64_t tmp;
+ 		struct ubi_rsvol_req req;
+ 
+-		dbg_msg("re-size volume");
+-		err = copy_from_user(&req, argp,
+-				       sizeof(struct ubi_rsvol_req));
++		dbg_gen("re-size volume");
++		err = copy_from_user(&req, argp, sizeof(struct ubi_rsvol_req));
+ 		if (err) {
+ 			err = -EFAULT;
+ 			break;
+@@ -665,15 +892,120 @@
+ 			break;
+ 		}
+ 
+-		tmp = req.bytes;
+-		pebs = !!do_div(tmp, desc->vol->usable_leb_size);
+-		pebs += tmp;
++		pebs = div_u64(req.bytes + desc->vol->usable_leb_size - 1,
++			       desc->vol->usable_leb_size);
+ 
++		mutex_lock(&ubi->volumes_mutex);
+ 		err = ubi_resize_volume(desc, pebs);
++		mutex_unlock(&ubi->volumes_mutex);
+ 		ubi_close_volume(desc);
+ 		break;
+ 	}
+ 
++	/* Re-name volumes command */
++	case UBI_IOCRNVOL:
++	{
++		struct ubi_rnvol_req *req;
++
++		dbg_msg("re-name volumes");
++		req = kmalloc(sizeof(struct ubi_rnvol_req), GFP_KERNEL);
++		if (!req) {
++			err = -ENOMEM;
++			break;
++		};
++
++		err = copy_from_user(req, argp, sizeof(struct ubi_rnvol_req));
++		if (err) {
++			err = -EFAULT;
++			kfree(req);
++			break;
++		}
++
++		mutex_lock(&ubi->mult_mutex);
++		err = rename_volumes(ubi, req);
++		mutex_unlock(&ubi->mult_mutex);
++		kfree(req);
++		break;
++	}
++
++	default:
++		err = -ENOTTY;
++		break;
++	}
++
++	ubi_put_device(ubi);
++	return err;
++}
++
++static long ctrl_cdev_ioctl(struct file *file, unsigned int cmd,
++			    unsigned long arg)
++{
++	int err = 0;
++	void __user *argp = (void __user *)arg;
++
++	if (!capable(CAP_SYS_RESOURCE))
++		return -EPERM;
++
++	switch (cmd) {
++	/* Attach an MTD device command */
++	case UBI_IOCATT:
++	{
++		struct ubi_attach_req req;
++		struct mtd_info *mtd;
++
++		dbg_gen("attach MTD device");
++		err = copy_from_user(&req, argp, sizeof(struct ubi_attach_req));
++		if (err) {
++			err = -EFAULT;
++			break;
++		}
++
++		if (req.mtd_num < 0 ||
++		    (req.ubi_num < 0 && req.ubi_num != UBI_DEV_NUM_AUTO)) {
++			err = -EINVAL;
++			break;
++		}
++
++		mtd = get_mtd_device(NULL, req.mtd_num);
++		if (IS_ERR(mtd)) {
++			err = PTR_ERR(mtd);
++			break;
++		}
++
++		/*
++		 * Note, further request verification is done by
++		 * 'ubi_attach_mtd_dev()'.
++		 */
++		mutex_lock(&ubi_devices_mutex);
++		err = ubi_attach_mtd_dev(mtd, req.ubi_num, req.vid_hdr_offset);
++		mutex_unlock(&ubi_devices_mutex);
++		if (err < 0)
++			put_mtd_device(mtd);
++		else
++			/* @err contains UBI device number */
++			err = put_user(err, (__user int32_t *)argp);
++
++		break;
++	}
++
++	/* Detach an MTD device command */
++	case UBI_IOCDET:
++	{
++		int ubi_num;
++
++		dbg_gen("dettach MTD device");
++		err = get_user(ubi_num, (__user int32_t *)argp);
++		if (err) {
++			err = -EFAULT;
++			break;
++		}
++
++		mutex_lock(&ubi_devices_mutex);
++		err = ubi_detach_mtd_dev(ubi_num, 0);
++		mutex_unlock(&ubi_devices_mutex);
++		break;
++	}
++
+ 	default:
+ 		err = -ENOTTY;
+ 		break;
+@@ -682,20 +1014,59 @@
+ 	return err;
+ }
+ 
++#ifdef CONFIG_COMPAT
++static long vol_cdev_compat_ioctl(struct file *file, unsigned int cmd,
++				  unsigned long arg)
++{
++	unsigned long translated_arg = (unsigned long)compat_ptr(arg);
++
++	return vol_cdev_ioctl(file, cmd, translated_arg);
++}
++
++static long ubi_cdev_compat_ioctl(struct file *file, unsigned int cmd,
++				  unsigned long arg)
++{
++	unsigned long translated_arg = (unsigned long)compat_ptr(arg);
++
++	return ubi_cdev_ioctl(file, cmd, translated_arg);
++}
++
++static long ctrl_cdev_compat_ioctl(struct file *file, unsigned int cmd,
++				   unsigned long arg)
++{
++	unsigned long translated_arg = (unsigned long)compat_ptr(arg);
++
++	return ctrl_cdev_ioctl(file, cmd, translated_arg);
++}
++#else
++#define vol_cdev_compat_ioctl  NULL
++#define ubi_cdev_compat_ioctl  NULL
++#define ctrl_cdev_compat_ioctl NULL
++#endif
++
++/* UBI volume character device operations */
++const struct file_operations ubi_vol_cdev_operations = {
++	.owner          = THIS_MODULE,
++	.open           = vol_cdev_open,
++	.release        = vol_cdev_release,
++	.llseek         = vol_cdev_llseek,
++	.read           = vol_cdev_read,
++	.write          = vol_cdev_write,
++	.unlocked_ioctl = vol_cdev_ioctl,
++	.compat_ioctl   = vol_cdev_compat_ioctl,
++};
++
+ /* UBI character device operations */
+-struct file_operations ubi_cdev_operations = {
+-	.owner = THIS_MODULE,
+-	.ioctl = ubi_cdev_ioctl,
+-	.llseek = no_llseek,
++const struct file_operations ubi_cdev_operations = {
++	.owner          = THIS_MODULE,
++	.llseek         = no_llseek,
++	.unlocked_ioctl = ubi_cdev_ioctl,
++	.compat_ioctl   = ubi_cdev_compat_ioctl,
+ };
+ 
+-/* UBI volume character device operations */
+-struct file_operations ubi_vol_cdev_operations = {
+-	.owner   = THIS_MODULE,
+-	.open    = vol_cdev_open,
+-	.release = vol_cdev_release,
+-	.llseek  = vol_cdev_llseek,
+-	.read    = vol_cdev_read,
+-	.write   = vol_cdev_write,
+-	.ioctl   = vol_cdev_ioctl,
++/* UBI control character device operations */
++const struct file_operations ubi_ctrl_cdev_operations = {
++	.owner          = THIS_MODULE,
++	.unlocked_ioctl = ctrl_cdev_ioctl,
++	.compat_ioctl   = ctrl_cdev_compat_ioctl,
+ };
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/debug.c linux-2.6.24/drivers/mtd/ubi/debug.c
+--- linux-2.6.24.orig/drivers/mtd/ubi/debug.c	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/debug.c	2009-04-17 09:49:26.000000000 +0200
+@@ -24,7 +24,7 @@
+  * changes.
+  */
+ 
+-#ifdef CONFIG_MTD_UBI_DEBUG_MSG
++#ifdef CONFIG_MTD_UBI_DEBUG
+ 
+ #include "ubi.h"
+ 
+@@ -34,14 +34,19 @@
+  */
+ void ubi_dbg_dump_ec_hdr(const struct ubi_ec_hdr *ec_hdr)
+ {
+-	dbg_msg("erase counter header dump:");
+-	dbg_msg("magic          %#08x", be32_to_cpu(ec_hdr->magic));
+-	dbg_msg("version        %d",    (int)ec_hdr->version);
+-	dbg_msg("ec             %llu",  (long long)be64_to_cpu(ec_hdr->ec));
+-	dbg_msg("vid_hdr_offset %d",    be32_to_cpu(ec_hdr->vid_hdr_offset));
+-	dbg_msg("data_offset    %d",    be32_to_cpu(ec_hdr->data_offset));
+-	dbg_msg("hdr_crc        %#08x", be32_to_cpu(ec_hdr->hdr_crc));
+-	dbg_msg("erase counter header hexdump:");
++	printk(KERN_DEBUG "Erase counter header dump:\n");
++	printk(KERN_DEBUG "\tmagic          %#08x\n",
++	       be32_to_cpu(ec_hdr->magic));
++	printk(KERN_DEBUG "\tversion        %d\n", (int)ec_hdr->version);
++	printk(KERN_DEBUG "\tec             %llu\n",
++	       (long long)be64_to_cpu(ec_hdr->ec));
++	printk(KERN_DEBUG "\tvid_hdr_offset %d\n",
++	       be32_to_cpu(ec_hdr->vid_hdr_offset));
++	printk(KERN_DEBUG "\tdata_offset    %d\n",
++	       be32_to_cpu(ec_hdr->data_offset));
++	printk(KERN_DEBUG "\thdr_crc        %#08x\n",
++	       be32_to_cpu(ec_hdr->hdr_crc));
++	printk(KERN_DEBUG "erase counter header hexdump:\n");
+ 	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+ 		       ec_hdr, UBI_EC_HDR_SIZE, 1);
+ }
+@@ -52,22 +57,23 @@
+  */
+ void ubi_dbg_dump_vid_hdr(const struct ubi_vid_hdr *vid_hdr)
+ {
+-	dbg_msg("volume identifier header dump:");
+-	dbg_msg("magic     %08x", be32_to_cpu(vid_hdr->magic));
+-	dbg_msg("version   %d",   (int)vid_hdr->version);
+-	dbg_msg("vol_type  %d",   (int)vid_hdr->vol_type);
+-	dbg_msg("copy_flag %d",   (int)vid_hdr->copy_flag);
+-	dbg_msg("compat    %d",   (int)vid_hdr->compat);
+-	dbg_msg("vol_id    %d",   be32_to_cpu(vid_hdr->vol_id));
+-	dbg_msg("lnum      %d",   be32_to_cpu(vid_hdr->lnum));
+-	dbg_msg("leb_ver   %u",   be32_to_cpu(vid_hdr->leb_ver));
+-	dbg_msg("data_size %d",   be32_to_cpu(vid_hdr->data_size));
+-	dbg_msg("used_ebs  %d",   be32_to_cpu(vid_hdr->used_ebs));
+-	dbg_msg("data_pad  %d",   be32_to_cpu(vid_hdr->data_pad));
+-	dbg_msg("sqnum     %llu",
++	printk(KERN_DEBUG "Volume identifier header dump:\n");
++	printk(KERN_DEBUG "\tmagic     %08x\n", be32_to_cpu(vid_hdr->magic));
++	printk(KERN_DEBUG "\tversion   %d\n",   (int)vid_hdr->version);
++	printk(KERN_DEBUG "\tvol_type  %d\n",   (int)vid_hdr->vol_type);
++	printk(KERN_DEBUG "\tcopy_flag %d\n",   (int)vid_hdr->copy_flag);
++	printk(KERN_DEBUG "\tcompat    %d\n",   (int)vid_hdr->compat);
++	printk(KERN_DEBUG "\tvol_id    %d\n",   be32_to_cpu(vid_hdr->vol_id));
++	printk(KERN_DEBUG "\tlnum      %d\n",   be32_to_cpu(vid_hdr->lnum));
++	printk(KERN_DEBUG "\tdata_size %d\n",   be32_to_cpu(vid_hdr->data_size));
++	printk(KERN_DEBUG "\tused_ebs  %d\n",   be32_to_cpu(vid_hdr->used_ebs));
++	printk(KERN_DEBUG "\tdata_pad  %d\n",   be32_to_cpu(vid_hdr->data_pad));
++	printk(KERN_DEBUG "\tsqnum     %llu\n",
+ 		(unsigned long long)be64_to_cpu(vid_hdr->sqnum));
+-	dbg_msg("hdr_crc   %08x", be32_to_cpu(vid_hdr->hdr_crc));
+-	dbg_msg("volume identifier header hexdump:");
++	printk(KERN_DEBUG "\thdr_crc   %08x\n", be32_to_cpu(vid_hdr->hdr_crc));
++	printk(KERN_DEBUG "Volume identifier header hexdump:\n");
++	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
++		       vid_hdr, UBI_VID_HDR_SIZE, 1);
+ }
+ 
+ /**
+@@ -76,27 +82,27 @@
+  */
+ void ubi_dbg_dump_vol_info(const struct ubi_volume *vol)
+ {
+-	dbg_msg("volume information dump:");
+-	dbg_msg("vol_id          %d", vol->vol_id);
+-	dbg_msg("reserved_pebs   %d", vol->reserved_pebs);
+-	dbg_msg("alignment       %d", vol->alignment);
+-	dbg_msg("data_pad        %d", vol->data_pad);
+-	dbg_msg("vol_type        %d", vol->vol_type);
+-	dbg_msg("name_len        %d", vol->name_len);
+-	dbg_msg("usable_leb_size %d", vol->usable_leb_size);
+-	dbg_msg("used_ebs        %d", vol->used_ebs);
+-	dbg_msg("used_bytes      %lld", vol->used_bytes);
+-	dbg_msg("last_eb_bytes   %d", vol->last_eb_bytes);
+-	dbg_msg("corrupted       %d", vol->corrupted);
+-	dbg_msg("upd_marker      %d", vol->upd_marker);
++	printk(KERN_DEBUG "Volume information dump:\n");
++	printk(KERN_DEBUG "\tvol_id          %d\n", vol->vol_id);
++	printk(KERN_DEBUG "\treserved_pebs   %d\n", vol->reserved_pebs);
++	printk(KERN_DEBUG "\talignment       %d\n", vol->alignment);
++	printk(KERN_DEBUG "\tdata_pad        %d\n", vol->data_pad);
++	printk(KERN_DEBUG "\tvol_type        %d\n", vol->vol_type);
++	printk(KERN_DEBUG "\tname_len        %d\n", vol->name_len);
++	printk(KERN_DEBUG "\tusable_leb_size %d\n", vol->usable_leb_size);
++	printk(KERN_DEBUG "\tused_ebs        %d\n", vol->used_ebs);
++	printk(KERN_DEBUG "\tused_bytes      %lld\n", vol->used_bytes);
++	printk(KERN_DEBUG "\tlast_eb_bytes   %d\n", vol->last_eb_bytes);
++	printk(KERN_DEBUG "\tcorrupted       %d\n", vol->corrupted);
++	printk(KERN_DEBUG "\tupd_marker      %d\n", vol->upd_marker);
+ 
+ 	if (vol->name_len <= UBI_VOL_NAME_MAX &&
+ 	    strnlen(vol->name, vol->name_len + 1) == vol->name_len) {
+-		dbg_msg("name            %s", vol->name);
++		printk(KERN_DEBUG "\tname            %s\n", vol->name);
+ 	} else {
+-		dbg_msg("the 1st 5 characters of the name: %c%c%c%c%c",
+-			vol->name[0], vol->name[1], vol->name[2],
+-			vol->name[3], vol->name[4]);
++		printk(KERN_DEBUG "\t1st 5 characters of name: %c%c%c%c%c\n",
++		       vol->name[0], vol->name[1], vol->name[2],
++		       vol->name[3], vol->name[4]);
+ 	}
+ }
+ 
+@@ -109,28 +115,29 @@
+ {
+ 	int name_len = be16_to_cpu(r->name_len);
+ 
+-	dbg_msg("volume table record %d dump:", idx);
+-	dbg_msg("reserved_pebs   %d", be32_to_cpu(r->reserved_pebs));
+-	dbg_msg("alignment       %d", be32_to_cpu(r->alignment));
+-	dbg_msg("data_pad        %d", be32_to_cpu(r->data_pad));
+-	dbg_msg("vol_type        %d", (int)r->vol_type);
+-	dbg_msg("upd_marker      %d", (int)r->upd_marker);
+-	dbg_msg("name_len        %d", name_len);
++	printk(KERN_DEBUG "Volume table record %d dump:\n", idx);
++	printk(KERN_DEBUG "\treserved_pebs   %d\n",
++	       be32_to_cpu(r->reserved_pebs));
++	printk(KERN_DEBUG "\talignment       %d\n", be32_to_cpu(r->alignment));
++	printk(KERN_DEBUG "\tdata_pad        %d\n", be32_to_cpu(r->data_pad));
++	printk(KERN_DEBUG "\tvol_type        %d\n", (int)r->vol_type);
++	printk(KERN_DEBUG "\tupd_marker      %d\n", (int)r->upd_marker);
++	printk(KERN_DEBUG "\tname_len        %d\n", name_len);
+ 
+ 	if (r->name[0] == '\0') {
+-		dbg_msg("name            NULL");
++		printk(KERN_DEBUG "\tname            NULL\n");
+ 		return;
+ 	}
+ 
+ 	if (name_len <= UBI_VOL_NAME_MAX &&
+ 	    strnlen(&r->name[0], name_len + 1) == name_len) {
+-		dbg_msg("name            %s", &r->name[0]);
++		printk(KERN_DEBUG "\tname            %s\n", &r->name[0]);
+ 	} else {
+-		dbg_msg("1st 5 characters of the name: %c%c%c%c%c",
++		printk(KERN_DEBUG "\t1st 5 characters of name: %c%c%c%c%c\n",
+ 			r->name[0], r->name[1], r->name[2], r->name[3],
+ 			r->name[4]);
+ 	}
+-	dbg_msg("crc             %#08x", be32_to_cpu(r->crc));
++	printk(KERN_DEBUG "\tcrc             %#08x\n", be32_to_cpu(r->crc));
+ }
+ 
+ /**
+@@ -139,15 +146,15 @@
+  */
+ void ubi_dbg_dump_sv(const struct ubi_scan_volume *sv)
+ {
+-	dbg_msg("volume scanning information dump:");
+-	dbg_msg("vol_id         %d", sv->vol_id);
+-	dbg_msg("highest_lnum   %d", sv->highest_lnum);
+-	dbg_msg("leb_count      %d", sv->leb_count);
+-	dbg_msg("compat         %d", sv->compat);
+-	dbg_msg("vol_type       %d", sv->vol_type);
+-	dbg_msg("used_ebs       %d", sv->used_ebs);
+-	dbg_msg("last_data_size %d", sv->last_data_size);
+-	dbg_msg("data_pad       %d", sv->data_pad);
++	printk(KERN_DEBUG "Volume scanning information dump:\n");
++	printk(KERN_DEBUG "\tvol_id         %d\n", sv->vol_id);
++	printk(KERN_DEBUG "\thighest_lnum   %d\n", sv->highest_lnum);
++	printk(KERN_DEBUG "\tleb_count      %d\n", sv->leb_count);
++	printk(KERN_DEBUG "\tcompat         %d\n", sv->compat);
++	printk(KERN_DEBUG "\tvol_type       %d\n", sv->vol_type);
++	printk(KERN_DEBUG "\tused_ebs       %d\n", sv->used_ebs);
++	printk(KERN_DEBUG "\tlast_data_size %d\n", sv->last_data_size);
++	printk(KERN_DEBUG "\tdata_pad       %d\n", sv->data_pad);
+ }
+ 
+ /**
+@@ -157,14 +164,13 @@
+  */
+ void ubi_dbg_dump_seb(const struct ubi_scan_leb *seb, int type)
+ {
+-	dbg_msg("eraseblock scanning information dump:");
+-	dbg_msg("ec       %d", seb->ec);
+-	dbg_msg("pnum     %d", seb->pnum);
++	printk(KERN_DEBUG "eraseblock scanning information dump:\n");
++	printk(KERN_DEBUG "\tec       %d\n", seb->ec);
++	printk(KERN_DEBUG "\tpnum     %d\n", seb->pnum);
+ 	if (type == 0) {
+-		dbg_msg("lnum     %d", seb->lnum);
+-		dbg_msg("scrub    %d", seb->scrub);
+-		dbg_msg("sqnum    %llu", seb->sqnum);
+-		dbg_msg("leb_ver  %u", seb->leb_ver);
++		printk(KERN_DEBUG "\tlnum     %d\n", seb->lnum);
++		printk(KERN_DEBUG "\tscrub    %d\n", seb->scrub);
++		printk(KERN_DEBUG "\tsqnum    %llu\n", seb->sqnum);
+ 	}
+ }
+ 
+@@ -176,16 +182,16 @@
+ {
+ 	char nm[17];
+ 
+-	dbg_msg("volume creation request dump:");
+-	dbg_msg("vol_id    %d",   req->vol_id);
+-	dbg_msg("alignment %d",   req->alignment);
+-	dbg_msg("bytes     %lld", (long long)req->bytes);
+-	dbg_msg("vol_type  %d",   req->vol_type);
+-	dbg_msg("name_len  %d",   req->name_len);
++	printk(KERN_DEBUG "Volume creation request dump:\n");
++	printk(KERN_DEBUG "\tvol_id    %d\n",   req->vol_id);
++	printk(KERN_DEBUG "\talignment %d\n",   req->alignment);
++	printk(KERN_DEBUG "\tbytes     %lld\n", (long long)req->bytes);
++	printk(KERN_DEBUG "\tvol_type  %d\n",   req->vol_type);
++	printk(KERN_DEBUG "\tname_len  %d\n",   req->name_len);
+ 
+ 	memcpy(nm, req->name, 16);
+ 	nm[16] = 0;
+-	dbg_msg("the 1st 16 characters of the name: %s", nm);
++	printk(KERN_DEBUG "\t1st 16 characters of name: %s\n", nm);
+ }
+ 
+-#endif /* CONFIG_MTD_UBI_DEBUG_MSG */
++#endif /* CONFIG_MTD_UBI_DEBUG */
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/debug.h linux-2.6.24/drivers/mtd/ubi/debug.h
+--- linux-2.6.24.orig/drivers/mtd/ubi/debug.h	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/debug.h	2009-04-17 09:49:26.000000000 +0200
+@@ -24,23 +24,19 @@
+ #ifdef CONFIG_MTD_UBI_DEBUG
+ #include <linux/random.h>
+ 
+-#define ubi_assert(expr)  BUG_ON(!(expr))
+ #define dbg_err(fmt, ...) ubi_err(fmt, ##__VA_ARGS__)
+-#else
+-#define ubi_assert(expr)  ({})
+-#define dbg_err(fmt, ...) ({})
+-#endif
+ 
+-#ifdef CONFIG_MTD_UBI_DEBUG_DISABLE_BGT
+-#define DBG_DISABLE_BGT 1
+-#else
+-#define DBG_DISABLE_BGT 0
+-#endif
++#define ubi_assert(expr)  do {                                               \
++	if (unlikely(!(expr))) {                                             \
++		printk(KERN_CRIT "UBI assert failed in %s at %u (pid %d)\n", \
++		       __func__, __LINE__, current->pid);                    \
++		ubi_dbg_dump_stack();                                        \
++	}                                                                    \
++} while (0)
+ 
+-#ifdef CONFIG_MTD_UBI_DEBUG_MSG
+-/* Generic debugging message */
+-#define dbg_msg(fmt, ...) \
+-	printk(KERN_DEBUG "UBI DBG: %s: " fmt "\n", __FUNCTION__, ##__VA_ARGS__)
++#define dbg_msg(fmt, ...)                                    \
++	printk(KERN_DEBUG "UBI DBG (pid %d): %s: " fmt "\n", \
++	       current->pid, __FUNCTION__, ##__VA_ARGS__)
+ 
+ #define ubi_dbg_dump_stack() dump_stack()
+ 
+@@ -60,54 +56,47 @@
+ void ubi_dbg_dump_seb(const struct ubi_scan_leb *seb, int type);
+ void ubi_dbg_dump_mkvol_req(const struct ubi_mkvol_req *req);
+ 
++#ifdef CONFIG_MTD_UBI_DEBUG_MSG
++/* General debugging messages */
++#define dbg_gen(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
+ #else
+-
+-#define dbg_msg(fmt, ...)    ({})
+-#define ubi_dbg_dump_stack() ({})
+-#define ubi_dbg_dump_ec_hdr(ec_hdr)      ({})
+-#define ubi_dbg_dump_vid_hdr(vid_hdr)    ({})
+-#define ubi_dbg_dump_vol_info(vol)       ({})
+-#define ubi_dbg_dump_vtbl_record(r, idx) ({})
+-#define ubi_dbg_dump_sv(sv)              ({})
+-#define ubi_dbg_dump_seb(seb, type)      ({})
+-#define ubi_dbg_dump_mkvol_req(req)      ({})
+-
+-#endif /* CONFIG_MTD_UBI_DEBUG_MSG */
++#define dbg_gen(fmt, ...) ({})
++#endif
+ 
+ #ifdef CONFIG_MTD_UBI_DEBUG_MSG_EBA
+-/* Messages from the eraseblock association unit */
+-#define dbg_eba(fmt, ...) \
+-	printk(KERN_DEBUG "UBI DBG eba: %s: " fmt "\n", __FUNCTION__, \
+-	       ##__VA_ARGS__)
++/* Messages from the eraseblock association sub-system */
++#define dbg_eba(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
+ #else
+ #define dbg_eba(fmt, ...) ({})
+ #endif
+ 
+ #ifdef CONFIG_MTD_UBI_DEBUG_MSG_WL
+-/* Messages from the wear-leveling unit */
+-#define dbg_wl(fmt, ...) \
+-	printk(KERN_DEBUG "UBI DBG wl: %s: " fmt "\n", __FUNCTION__, \
+-	       ##__VA_ARGS__)
++/* Messages from the wear-leveling sub-system */
++#define dbg_wl(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
+ #else
+ #define dbg_wl(fmt, ...) ({})
+ #endif
+ 
+ #ifdef CONFIG_MTD_UBI_DEBUG_MSG_IO
+-/* Messages from the input/output unit */
+-#define dbg_io(fmt, ...) \
+-	printk(KERN_DEBUG "UBI DBG io: %s: " fmt "\n", __FUNCTION__, \
+-	       ##__VA_ARGS__)
++/* Messages from the input/output sub-system */
++#define dbg_io(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
+ #else
+ #define dbg_io(fmt, ...) ({})
+ #endif
+ 
+ #ifdef CONFIG_MTD_UBI_DEBUG_MSG_BLD
+ /* Initialization and build messages */
+-#define dbg_bld(fmt, ...) \
+-	printk(KERN_DEBUG "UBI DBG bld: %s: " fmt "\n", __FUNCTION__, \
+-	       ##__VA_ARGS__)
++#define dbg_bld(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
++#define UBI_IO_DEBUG 1
+ #else
+ #define dbg_bld(fmt, ...) ({})
++#define UBI_IO_DEBUG 0
++#endif
++
++#ifdef CONFIG_MTD_UBI_DEBUG_DISABLE_BGT
++#define DBG_DISABLE_BGT 1
++#else
++#define DBG_DISABLE_BGT 0
+ #endif
+ 
+ #ifdef CONFIG_MTD_UBI_DEBUG_EMULATE_BITFLIPS
+@@ -154,4 +143,50 @@
+ #define ubi_dbg_is_erase_failure() 0
+ #endif
+ 
++#else
++
++#define ubi_assert(expr)                 ({})
++#define dbg_err(fmt, ...)                ({})
++#define dbg_msg(fmt, ...)                ({})
++#define dbg_gen(fmt, ...)                ({})
++#define dbg_eba(fmt, ...)                ({})
++#define dbg_wl(fmt, ...)                 ({})
++#define dbg_io(fmt, ...)                 ({})
++#define dbg_bld(fmt, ...)                ({})
++#define ubi_dbg_dump_stack()             ({})
++#define ubi_dbg_dump_ec_hdr(ec_hdr)      ({})
++#define ubi_dbg_dump_vid_hdr(vid_hdr)    ({})
++#define ubi_dbg_dump_vol_info(vol)       ({})
++#define ubi_dbg_dump_vtbl_record(r, idx) ({})
++#define ubi_dbg_dump_sv(sv)              ({})
++#define ubi_dbg_dump_seb(seb, type)      ({})
++#define ubi_dbg_dump_mkvol_req(req)      ({})
++
++#define UBI_IO_DEBUG               0
++#define DBG_DISABLE_BGT            0
++#define ubi_dbg_is_bitflip()       0
++#define ubi_dbg_is_write_failure() 0
++#define ubi_dbg_is_erase_failure() 0
++
++#endif /* !CONFIG_MTD_UBI_DEBUG */
++
++/*
++ * Some compatibility stuff goes here.
++ */
++
++#include <asm/div64.h>
++
++static inline uint64_t div_u64(uint64_t dividend, uint64_t divisor)
++{
++	do_div(dividend, divisor);
++	return dividend;
++}
++
++static inline uint64_t div_u64_rem(uint64_t dividend, uint32_t divisor,
++				   uint32_t *remainder)
++{
++	*remainder = do_div(dividend, divisor);
++	return dividend;
++}
++
+ #endif /* !__UBI_DEBUG_H__ */
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/eba.c linux-2.6.24/drivers/mtd/ubi/eba.c
+--- linux-2.6.24.orig/drivers/mtd/ubi/eba.c	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/eba.c	2009-04-17 09:49:26.000000000 +0200
+@@ -19,20 +19,20 @@
+  */
+ 
+ /*
+- * The UBI Eraseblock Association (EBA) unit.
++ * The UBI Eraseblock Association (EBA) sub-system.
+  *
+- * This unit is responsible for I/O to/from logical eraseblock.
++ * This sub-system is responsible for I/O to/from logical eraseblock.
+  *
+  * Although in this implementation the EBA table is fully kept and managed in
+  * RAM, which assumes poor scalability, it might be (partially) maintained on
+  * flash in future implementations.
+  *
+- * The EBA unit implements per-logical eraseblock locking. Before accessing a
+- * logical eraseblock it is locked for reading or writing. The per-logical
+- * eraseblock locking is implemented by means of the lock tree. The lock tree
+- * is an RB-tree which refers all the currently locked logical eraseblocks. The
+- * lock tree elements are &struct ltree_entry objects. They are indexed by
+- * (@vol_id, @lnum) pairs.
++ * The EBA sub-system implements per-logical eraseblock locking. Before
++ * accessing a logical eraseblock it is locked for reading or writing. The
++ * per-logical eraseblock locking is implemented by means of the lock tree. The
++ * lock tree is an RB-tree which refers all the currently locked logical
++ * eraseblocks. The lock tree elements are &struct ubi_ltree_entry objects.
++ * They are indexed by (@vol_id, @lnum) pairs.
+  *
+  * EBA also maintains the global sequence counter which is incremented each
+  * time a logical eraseblock is mapped to a physical eraseblock and it is
+@@ -50,29 +50,6 @@
+ #define EBA_RESERVED_PEBS 1
+ 
+ /**
+- * struct ltree_entry - an entry in the lock tree.
+- * @rb: links RB-tree nodes
+- * @vol_id: volume ID of the locked logical eraseblock
+- * @lnum: locked logical eraseblock number
+- * @users: how many tasks are using this logical eraseblock or wait for it
+- * @mutex: read/write mutex to implement read/write access serialization to
+- * the (@vol_id, @lnum) logical eraseblock
+- *
+- * When a logical eraseblock is being locked - corresponding &struct ltree_entry
+- * object is inserted to the lock tree (@ubi->ltree).
+- */
+-struct ltree_entry {
+-	struct rb_node rb;
+-	int vol_id;
+-	int lnum;
+-	int users;
+-	struct rw_semaphore mutex;
+-};
+-
+-/* Slab cache for lock-tree entries */
+-static struct kmem_cache *ltree_slab;
+-
+-/**
+  * next_sqnum - get next sequence number.
+  * @ubi: UBI device description object
+  *
+@@ -101,7 +78,7 @@
+  */
+ static int ubi_get_compat(const struct ubi_device *ubi, int vol_id)
+ {
+-	if (vol_id == UBI_LAYOUT_VOL_ID)
++	if (vol_id == UBI_LAYOUT_VOLUME_ID)
+ 		return UBI_LAYOUT_VOLUME_COMPAT;
+ 	return 0;
+ }
+@@ -112,20 +89,20 @@
+  * @vol_id: volume ID
+  * @lnum: logical eraseblock number
+  *
+- * This function returns a pointer to the corresponding &struct ltree_entry
++ * This function returns a pointer to the corresponding &struct ubi_ltree_entry
+  * object if the logical eraseblock is locked and %NULL if it is not.
+  * @ubi->ltree_lock has to be locked.
+  */
+-static struct ltree_entry *ltree_lookup(struct ubi_device *ubi, int vol_id,
+-					int lnum)
++static struct ubi_ltree_entry *ltree_lookup(struct ubi_device *ubi, int vol_id,
++					    int lnum)
+ {
+ 	struct rb_node *p;
+ 
+ 	p = ubi->ltree.rb_node;
+ 	while (p) {
+-		struct ltree_entry *le;
++		struct ubi_ltree_entry *le;
+ 
+-		le = rb_entry(p, struct ltree_entry, rb);
++		le = rb_entry(p, struct ubi_ltree_entry, rb);
+ 
+ 		if (vol_id < le->vol_id)
+ 			p = p->rb_left;
+@@ -155,15 +132,17 @@
+  * Returns pointer to the lock tree entry or %-ENOMEM if memory allocation
+  * failed.
+  */
+-static struct ltree_entry *ltree_add_entry(struct ubi_device *ubi, int vol_id,
+-					   int lnum)
++static struct ubi_ltree_entry *ltree_add_entry(struct ubi_device *ubi,
++					       int vol_id, int lnum)
+ {
+-	struct ltree_entry *le, *le1, *le_free;
++	struct ubi_ltree_entry *le, *le1, *le_free;
+ 
+-	le = kmem_cache_alloc(ltree_slab, GFP_NOFS);
++	le = kmalloc(sizeof(struct ubi_ltree_entry), GFP_NOFS);
+ 	if (!le)
+ 		return ERR_PTR(-ENOMEM);
+ 
++	le->users = 0;
++	init_rwsem(&le->mutex);
+ 	le->vol_id = vol_id;
+ 	le->lnum = lnum;
+ 
+@@ -189,7 +168,7 @@
+ 		p = &ubi->ltree.rb_node;
+ 		while (*p) {
+ 			parent = *p;
+-			le1 = rb_entry(parent, struct ltree_entry, rb);
++			le1 = rb_entry(parent, struct ubi_ltree_entry, rb);
+ 
+ 			if (vol_id < le1->vol_id)
+ 				p = &(*p)->rb_left;
+@@ -210,9 +189,7 @@
+ 	le->users += 1;
+ 	spin_unlock(&ubi->ltree_lock);
+ 
+-	if (le_free)
+-		kmem_cache_free(ltree_slab, le_free);
+-
++	kfree(le_free);
+ 	return le;
+ }
+ 
+@@ -227,7 +204,7 @@
+  */
+ static int leb_read_lock(struct ubi_device *ubi, int vol_id, int lnum)
+ {
+-	struct ltree_entry *le;
++	struct ubi_ltree_entry *le;
+ 
+ 	le = ltree_add_entry(ubi, vol_id, lnum);
+ 	if (IS_ERR(le))
+@@ -244,22 +221,18 @@
+  */
+ static void leb_read_unlock(struct ubi_device *ubi, int vol_id, int lnum)
+ {
+-	int free = 0;
+-	struct ltree_entry *le;
++	struct ubi_ltree_entry *le;
+ 
+ 	spin_lock(&ubi->ltree_lock);
+ 	le = ltree_lookup(ubi, vol_id, lnum);
+ 	le->users -= 1;
+ 	ubi_assert(le->users >= 0);
++	up_read(&le->mutex);
+ 	if (le->users == 0) {
+ 		rb_erase(&le->rb, &ubi->ltree);
+-		free = 1;
++		kfree(le);
+ 	}
+ 	spin_unlock(&ubi->ltree_lock);
+-
+-	up_read(&le->mutex);
+-	if (free)
+-		kmem_cache_free(ltree_slab, le);
+ }
+ 
+ /**
+@@ -273,7 +246,7 @@
+  */
+ static int leb_write_lock(struct ubi_device *ubi, int vol_id, int lnum)
+ {
+-	struct ltree_entry *le;
++	struct ubi_ltree_entry *le;
+ 
+ 	le = ltree_add_entry(ubi, vol_id, lnum);
+ 	if (IS_ERR(le))
+@@ -283,6 +256,40 @@
+ }
+ 
+ /**
++ * leb_write_lock - lock logical eraseblock for writing.
++ * @ubi: UBI device description object
++ * @vol_id: volume ID
++ * @lnum: logical eraseblock number
++ *
++ * This function locks a logical eraseblock for writing if there is no
++ * contention and does nothing if there is contention. Returns %0 in case of
++ * success, %1 in case of contention, and and a negative error code in case of
++ * failure.
++ */
++static int leb_write_trylock(struct ubi_device *ubi, int vol_id, int lnum)
++{
++	struct ubi_ltree_entry *le;
++
++	le = ltree_add_entry(ubi, vol_id, lnum);
++	if (IS_ERR(le))
++		return PTR_ERR(le);
++	if (down_write_trylock(&le->mutex))
++		return 0;
++
++	/* Contention, cancel */
++	spin_lock(&ubi->ltree_lock);
++	le->users -= 1;
++	ubi_assert(le->users >= 0);
++	if (le->users == 0) {
++		rb_erase(&le->rb, &ubi->ltree);
++		kfree(le);
++	}
++	spin_unlock(&ubi->ltree_lock);
++
++	return 1;
++}
++
++/**
+  * leb_write_unlock - unlock logical eraseblock.
+  * @ubi: UBI device description object
+  * @vol_id: volume ID
+@@ -290,39 +297,34 @@
+  */
+ static void leb_write_unlock(struct ubi_device *ubi, int vol_id, int lnum)
+ {
+-	int free;
+-	struct ltree_entry *le;
++	struct ubi_ltree_entry *le;
+ 
+ 	spin_lock(&ubi->ltree_lock);
+ 	le = ltree_lookup(ubi, vol_id, lnum);
+ 	le->users -= 1;
+ 	ubi_assert(le->users >= 0);
++	up_write(&le->mutex);
+ 	if (le->users == 0) {
+ 		rb_erase(&le->rb, &ubi->ltree);
+-		free = 1;
+-	} else
+-		free = 0;
++		kfree(le);
++	}
+ 	spin_unlock(&ubi->ltree_lock);
+-
+-	up_write(&le->mutex);
+-	if (free)
+-		kmem_cache_free(ltree_slab, le);
+ }
+ 
+ /**
+  * ubi_eba_unmap_leb - un-map logical eraseblock.
+  * @ubi: UBI device description object
+- * @vol_id: volume ID
++ * @vol: volume description object
+  * @lnum: logical eraseblock number
+  *
+  * This function un-maps logical eraseblock @lnum and schedules corresponding
+  * physical eraseblock for erasure. Returns zero in case of success and a
+  * negative error code in case of failure.
+  */
+-int ubi_eba_unmap_leb(struct ubi_device *ubi, int vol_id, int lnum)
++int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
++		      int lnum)
+ {
+-	int idx = vol_id2idx(ubi, vol_id), err, pnum;
+-	struct ubi_volume *vol = ubi->volumes[idx];
++	int err, pnum, vol_id = vol->vol_id;
+ 
+ 	if (ubi->ro_mode)
+ 		return -EROFS;
+@@ -349,7 +351,7 @@
+ /**
+  * ubi_eba_read_leb - read data.
+  * @ubi: UBI device description object
+- * @vol_id: volume ID
++ * @vol: volume description object
+  * @lnum: logical eraseblock number
+  * @buf: buffer to store the read data
+  * @offset: offset from where to read
+@@ -365,12 +367,11 @@
+  * returned for any volume type if an ECC error was detected by the MTD device
+  * driver. Other negative error cored may be returned in case of other errors.
+  */
+-int ubi_eba_read_leb(struct ubi_device *ubi, int vol_id, int lnum, void *buf,
+-		     int offset, int len, int check)
++int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
++		     void *buf, int offset, int len, int check)
+ {
+-	int err, pnum, scrub = 0, idx = vol_id2idx(ubi, vol_id);
++	int err, pnum, scrub = 0, vol_id = vol->vol_id;
+ 	struct ubi_vid_hdr *vid_hdr;
+-	struct ubi_volume *vol = ubi->volumes[idx];
+ 	uint32_t uninitialized_var(crc);
+ 
+ 	err = leb_read_lock(ubi, vol_id, lnum);
+@@ -500,16 +501,12 @@
+ 	struct ubi_vid_hdr *vid_hdr;
+ 
+ 	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+-	if (!vid_hdr) {
++	if (!vid_hdr)
+ 		return -ENOMEM;
+-	}
+-
+-	mutex_lock(&ubi->buf_mutex);
+ 
+ retry:
+ 	new_pnum = ubi_wl_get_peb(ubi, UBI_UNKNOWN);
+ 	if (new_pnum < 0) {
+-		mutex_unlock(&ubi->buf_mutex);
+ 		ubi_free_vid_hdr(ubi, vid_hdr);
+ 		return new_pnum;
+ 	}
+@@ -529,20 +526,23 @@
+ 		goto write_error;
+ 
+ 	data_size = offset + len;
++	mutex_lock(&ubi->buf_mutex);
+ 	memset(ubi->peb_buf1 + offset, 0xFF, len);
+ 
+ 	/* Read everything before the area where the write failure happened */
+ 	if (offset > 0) {
+ 		err = ubi_io_read_data(ubi, ubi->peb_buf1, pnum, 0, offset);
+ 		if (err && err != UBI_IO_BITFLIPS)
+-			goto out_put;
++			goto out_unlock;
+ 	}
+ 
+ 	memcpy(ubi->peb_buf1 + offset, buf, len);
+ 
+ 	err = ubi_io_write_data(ubi, ubi->peb_buf1, new_pnum, 0, data_size);
+-	if (err)
++	if (err) {
++		mutex_unlock(&ubi->buf_mutex);
+ 		goto write_error;
++	}
+ 
+ 	mutex_unlock(&ubi->buf_mutex);
+ 	ubi_free_vid_hdr(ubi, vid_hdr);
+@@ -553,8 +553,9 @@
+ 	ubi_msg("data was successfully recovered");
+ 	return 0;
+ 
+-out_put:
++out_unlock:
+ 	mutex_unlock(&ubi->buf_mutex);
++out_put:
+ 	ubi_wl_put_peb(ubi, new_pnum, 1);
+ 	ubi_free_vid_hdr(ubi, vid_hdr);
+ 	return err;
+@@ -567,7 +568,6 @@
+ 	ubi_warn("failed to write to PEB %d", new_pnum);
+ 	ubi_wl_put_peb(ubi, new_pnum, 1);
+ 	if (++tries > UBI_IO_RETRIES) {
+-		mutex_unlock(&ubi->buf_mutex);
+ 		ubi_free_vid_hdr(ubi, vid_hdr);
+ 		return err;
+ 	}
+@@ -578,7 +578,7 @@
+ /**
+  * ubi_eba_write_leb - write data to dynamic volume.
+  * @ubi: UBI device description object
+- * @vol_id: volume ID
++ * @vol: volume description object
+  * @lnum: logical eraseblock number
+  * @buf: the data to write
+  * @offset: offset within the logical eraseblock where to write
+@@ -586,15 +586,14 @@
+  * @dtype: data type
+  *
+  * This function writes data to logical eraseblock @lnum of a dynamic volume
+- * @vol_id. Returns zero in case of success and a negative error code in case
++ * @vol. Returns zero in case of success and a negative error code in case
+  * of failure. In case of error, it is possible that something was still
+  * written to the flash media, but may be some garbage.
+  */
+-int ubi_eba_write_leb(struct ubi_device *ubi, int vol_id, int lnum,
++int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
+ 		      const void *buf, int offset, int len, int dtype)
+ {
+-	int idx = vol_id2idx(ubi, vol_id), err, pnum, tries = 0;
+-	struct ubi_volume *vol = ubi->volumes[idx];
++	int err, pnum, tries = 0, vol_id = vol->vol_id;
+ 	struct ubi_vid_hdr *vid_hdr;
+ 
+ 	if (ubi->ro_mode)
+@@ -613,7 +612,8 @@
+ 		if (err) {
+ 			ubi_warn("failed to write data to PEB %d", pnum);
+ 			if (err == -EIO && ubi->bad_allowed)
+-				err = recover_peb(ubi, pnum, vol_id, lnum, buf, offset, len);
++				err = recover_peb(ubi, pnum, vol_id, lnum, buf,
++						  offset, len);
+ 			if (err)
+ 				ubi_ro_mode(ubi);
+ 		}
+@@ -656,11 +656,14 @@
+ 		goto write_error;
+ 	}
+ 
+-	err = ubi_io_write_data(ubi, buf, pnum, offset, len);
+-	if (err) {
+-		ubi_warn("failed to write %d bytes at offset %d of LEB %d:%d, "
+-			 "PEB %d", len, offset, vol_id, lnum, pnum);
+-		goto write_error;
++	if (len) {
++		err = ubi_io_write_data(ubi, buf, pnum, offset, len);
++		if (err) {
++			ubi_warn("failed to write %d bytes at offset %d of "
++				 "LEB %d:%d, PEB %d", len, offset, vol_id,
++				 lnum, pnum);
++			goto write_error;
++		}
+ 	}
+ 
+ 	vol->eba_tbl[lnum] = pnum;
+@@ -698,7 +701,7 @@
+ /**
+  * ubi_eba_write_leb_st - write data to static volume.
+  * @ubi: UBI device description object
+- * @vol_id: volume ID
++ * @vol: volume description object
+  * @lnum: logical eraseblock number
+  * @buf: data to write
+  * @len: how many bytes to write
+@@ -706,7 +709,7 @@
+  * @used_ebs: how many logical eraseblocks will this volume contain
+  *
+  * This function writes data to logical eraseblock @lnum of static volume
+- * @vol_id. The @used_ebs argument should contain total number of logical
++ * @vol. The @used_ebs argument should contain total number of logical
+  * eraseblock in this static volume.
+  *
+  * When writing to the last logical eraseblock, the @len argument doesn't have
+@@ -718,12 +721,11 @@
+  * volumes. This function returns zero in case of success and a negative error
+  * code in case of failure.
+  */
+-int ubi_eba_write_leb_st(struct ubi_device *ubi, int vol_id, int lnum,
+-			 const void *buf, int len, int dtype, int used_ebs)
++int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
++			 int lnum, const void *buf, int len, int dtype,
++			 int used_ebs)
+ {
+-	int err, pnum, tries = 0, data_size = len;
+-	int idx = vol_id2idx(ubi, vol_id);
+-	struct ubi_volume *vol = ubi->volumes[idx];
++	int err, pnum, tries = 0, data_size = len, vol_id = vol->vol_id;
+ 	struct ubi_vid_hdr *vid_hdr;
+ 	uint32_t crc;
+ 
+@@ -734,7 +736,7 @@
+ 		/* If this is the last LEB @len may be unaligned */
+ 		len = ALIGN(data_size, ubi->min_io_size);
+ 	else
+-		ubi_assert(len % ubi->min_io_size == 0);
++		ubi_assert(!(len & (ubi->min_io_size - 1)));
+ 
+ 	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+ 	if (!vid_hdr)
+@@ -819,7 +821,7 @@
+ /*
+  * ubi_eba_atomic_leb_change - change logical eraseblock atomically.
+  * @ubi: UBI device description object
+- * @vol_id: volume ID
++ * @vol: volume description object
+  * @lnum: logical eraseblock number
+  * @buf: data to write
+  * @len: how many bytes to write
+@@ -834,17 +836,27 @@
+  * UBI reserves one LEB for the "atomic LEB change" operation, so only one
+  * LEB change may be done at a time. This is ensured by @ubi->alc_mutex.
+  */
+-int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum,
+-			      const void *buf, int len, int dtype)
++int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
++			      int lnum, const void *buf, int len, int dtype)
+ {
+-	int err, pnum, tries = 0, idx = vol_id2idx(ubi, vol_id);
+-	struct ubi_volume *vol = ubi->volumes[idx];
++	int err, pnum, tries = 0, vol_id = vol->vol_id;
+ 	struct ubi_vid_hdr *vid_hdr;
+ 	uint32_t crc;
+ 
+ 	if (ubi->ro_mode)
+ 		return -EROFS;
+ 
++	if (len == 0) {
++		/*
++		 * Special case when data length is zero. In this case the LEB
++		 * has to be unmapped and mapped somewhere else.
++		 */
++		err = ubi_eba_unmap_leb(ubi, vol, lnum);
++		if (err)
++			return err;
++		return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0, dtype);
++	}
++
+ 	vid_hdr = ubi_zalloc_vid_hdr(ubi, GFP_NOFS);
+ 	if (!vid_hdr)
+ 		return -ENOMEM;
+@@ -891,7 +903,7 @@
+ 	}
+ 
+ 	if (vol->eba_tbl[lnum] >= 0) {
+-		err = ubi_wl_put_peb(ubi, vol->eba_tbl[lnum], 1);
++		err = ubi_wl_put_peb(ubi, vol->eba_tbl[lnum], 0);
+ 		if (err)
+ 			goto out_leb_unlock;
+ 	}
+@@ -928,20 +940,6 @@
+ }
+ 
+ /**
+- * ltree_entry_ctor - lock tree entries slab cache constructor.
+- * @obj: the lock-tree entry to construct
+- * @cache: the lock tree entry slab cache
+- * @flags: constructor flags
+- */
+-static void ltree_entry_ctor(struct kmem_cache *cache, void *obj)
+-{
+-	struct ltree_entry *le = obj;
+-
+-	le->users = 0;
+-	init_rwsem(&le->mutex);
+-}
+-
+-/**
+  * ubi_eba_copy_leb - copy logical eraseblock.
+  * @ubi: UBI device description object
+  * @from: physical eraseblock number from where to copy
+@@ -950,14 +948,20 @@
+  *
+  * This function copies logical eraseblock from physical eraseblock @from to
+  * physical eraseblock @to. The @vid_hdr buffer may be changed by this
+- * function. Returns zero in case of success, %UBI_IO_BITFLIPS if the operation
+- * was canceled because bit-flips were detected at the target PEB, and a
+- * negative error code in case of failure.
++ * function. Returns:
++ *   o %0 in case of success;
++ *   o %1 if the operation was canceled because the volume is being deleted
++ *        or because the PEB was put meanwhile;
++ *   o %2 if the operation was canceled because there was a write error to the
++ *        target PEB;
++ *   o %-EAGAIN if the operation was canceled because a bit-flip was detected
++ *     in the target PEB;
++ *   o a negative error code in case of failure.
+  */
+ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
+ 		     struct ubi_vid_hdr *vid_hdr)
+ {
+-	int err, vol_id, lnum, data_size, aldata_size, pnum, idx;
++	int err, vol_id, lnum, data_size, aldata_size, idx;
+ 	struct ubi_volume *vol;
+ 	uint32_t crc;
+ 
+@@ -973,51 +977,67 @@
+ 		data_size = aldata_size =
+ 			    ubi->leb_size - be32_to_cpu(vid_hdr->data_pad);
+ 
+-	/*
+-	 * We do not want anybody to write to this logical eraseblock while we
+-	 * are moving it, so we lock it.
+-	 */
+-	err = leb_write_lock(ubi, vol_id, lnum);
+-	if (err)
+-		return err;
+-
+-	mutex_lock(&ubi->buf_mutex);
+-
+-	/*
+-	 * But the logical eraseblock might have been put by this time.
+-	 * Cancel if it is true.
+-	 */
+ 	idx = vol_id2idx(ubi, vol_id);
+-
++	spin_lock(&ubi->volumes_lock);
+ 	/*
+-	 * We may race with volume deletion/re-size, so we have to hold
+-	 * @ubi->volumes_lock.
++	 * Note, we may race with volume deletion, which means that the volume
++	 * this logical eraseblock belongs to might be being deleted. Since the
++	 * volume deletion un-maps all the volume's logical eraseblocks, it will
++	 * be locked in 'ubi_wl_put_peb()' and wait for the WL worker to finish.
+ 	 */
+-	spin_lock(&ubi->volumes_lock);
+ 	vol = ubi->volumes[idx];
+ 	if (!vol) {
+-		dbg_eba("volume %d was removed meanwhile", vol_id);
++		/* No need to do further work, cancel */
++		dbg_eba("volume %d is being removed, cancel", vol_id);
+ 		spin_unlock(&ubi->volumes_lock);
+-		goto out_unlock;
++		return 1;
+ 	}
++	spin_unlock(&ubi->volumes_lock);
+ 
+-	pnum = vol->eba_tbl[lnum];
+-	if (pnum != from) {
+-		dbg_eba("LEB %d:%d is no longer mapped to PEB %d, mapped to "
+-			"PEB %d, cancel", vol_id, lnum, from, pnum);
+-		spin_unlock(&ubi->volumes_lock);
+-		goto out_unlock;
++	/*
++	 * We do not want anybody to write to this logical eraseblock while we
++	 * are moving it, so lock it.
++	 *
++	 * Note, we are using non-waiting locking here, because we cannot sleep
++	 * on the LEB, since it may cause deadlocks. Indeed, imagine a task is
++	 * unmapping the LEB which is mapped to the PEB we are going to move
++	 * (@from). This task locks the LEB and goes sleep in the
++	 * 'ubi_wl_put_peb()' function on the @ubi->move_mutex. In turn, we are
++	 * holding @ubi->move_mutex and go sleep on the LEB lock. So, if the
++	 * LEB is already locked, we just do not move it and return %1.
++	 */
++	err = leb_write_trylock(ubi, vol_id, lnum);
++	if (err) {
++		dbg_eba("contention on LEB %d:%d, cancel", vol_id, lnum);
++		return err;
+ 	}
+-	spin_unlock(&ubi->volumes_lock);
+ 
+-	/* OK, now the LEB is locked and we can safely start moving it */
++	/*
++	 * The LEB might have been put meanwhile, and the task which put it is
++	 * probably waiting on @ubi->move_mutex. No need to continue the work,
++	 * cancel it.
++	 */
++	if (vol->eba_tbl[lnum] != from) {
++		dbg_eba("LEB %d:%d is no longer mapped to PEB %d, mapped to "
++			"PEB %d, cancel", vol_id, lnum, from,
++			vol->eba_tbl[lnum]);
++		err = 1;
++		goto out_unlock_leb;
++	}
+ 
++	/*
++	 * OK, now the LEB is locked and we can safely start moving it. Since
++	 * this function utilizes the @ubi->peb1_buf buffer which is shared
++	 * with some other functions, so lock the buffer by taking the
++	 * @ubi->buf_mutex.
++	 */
++	mutex_lock(&ubi->buf_mutex);
+ 	dbg_eba("read %d bytes of data", aldata_size);
+ 	err = ubi_io_read_data(ubi, ubi->peb_buf1, from, 0, aldata_size);
+ 	if (err && err != UBI_IO_BITFLIPS) {
+ 		ubi_warn("error %d while reading data from PEB %d",
+ 			 err, from);
+-		goto out_unlock;
++		goto out_unlock_buf;
+ 	}
+ 
+ 	/*
+@@ -1052,8 +1072,11 @@
+ 	vid_hdr->sqnum = cpu_to_be64(next_sqnum(ubi));
+ 
+ 	err = ubi_io_write_vid_hdr(ubi, to, vid_hdr);
+-	if (err)
+-		goto out_unlock;
++	if (err) {
++		if (err == -EIO)
++			err = 2;
++		goto out_unlock_buf;
++	}
+ 
+ 	cond_resched();
+ 
+@@ -1062,13 +1085,18 @@
+ 	if (err) {
+ 		if (err != UBI_IO_BITFLIPS)
+ 			ubi_warn("cannot read VID header back from PEB %d", to);
+-		goto out_unlock;
++		else
++			err = -EAGAIN;
++		goto out_unlock_buf;
+ 	}
+ 
+ 	if (data_size > 0) {
+ 		err = ubi_io_write_data(ubi, ubi->peb_buf1, to, 0, aldata_size);
+-		if (err)
+-			goto out_unlock;
++		if (err) {
++			if (err == -EIO)
++				err = 2;
++			goto out_unlock_buf;
++		}
+ 
+ 		cond_resched();
+ 
+@@ -1082,29 +1110,33 @@
+ 			if (err != UBI_IO_BITFLIPS)
+ 				ubi_warn("cannot read data back from PEB %d",
+ 					 to);
+-			goto out_unlock;
++			else
++				err = -EAGAIN;
++			goto out_unlock_buf;
+ 		}
+ 
+ 		cond_resched();
+ 
+ 		if (memcmp(ubi->peb_buf1, ubi->peb_buf2, aldata_size)) {
+-			ubi_warn("read data back from PEB %d - it is different",
+-				 to);
+-			goto out_unlock;
++			ubi_warn("read data back from PEB %d and it is "
++				 "different", to);
++			err = -EINVAL;
++			goto out_unlock_buf;
+ 		}
+ 	}
+ 
+ 	ubi_assert(vol->eba_tbl[lnum] == from);
+ 	vol->eba_tbl[lnum] = to;
+ 
+-out_unlock:
++out_unlock_buf:
+ 	mutex_unlock(&ubi->buf_mutex);
++out_unlock_leb:
+ 	leb_write_unlock(ubi, vol_id, lnum);
+ 	return err;
+ }
+ 
+ /**
+- * ubi_eba_init_scan - initialize the EBA unit using scanning information.
++ * ubi_eba_init_scan - initialize the EBA sub-system using scanning information.
+  * @ubi: UBI device description object
+  * @si: scanning information
+  *
+@@ -1119,20 +1151,12 @@
+ 	struct ubi_scan_leb *seb;
+ 	struct rb_node *rb;
+ 
+-	dbg_eba("initialize EBA unit");
++	dbg_eba("initialize EBA sub-system");
+ 
+ 	spin_lock_init(&ubi->ltree_lock);
+ 	mutex_init(&ubi->alc_mutex);
+ 	ubi->ltree = RB_ROOT;
+ 
+-	if (ubi_devices_cnt == 0) {
+-		ltree_slab = kmem_cache_create("ubi_ltree_slab",
+-					       sizeof(struct ltree_entry), 0,
+-					       0, &ltree_entry_ctor);
+-		if (!ltree_slab)
+-			return -ENOMEM;
+-	}
+-
+ 	ubi->global_sqnum = si->max_sqnum + 1;
+ 	num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT;
+ 
+@@ -1168,6 +1192,15 @@
+ 		}
+ 	}
+ 
++	if (ubi->avail_pebs < EBA_RESERVED_PEBS) {
++		ubi_err("no enough physical eraseblocks (%d, need %d)",
++			ubi->avail_pebs, EBA_RESERVED_PEBS);
++		err = -ENOSPC;
++		goto out_free;
++	}
++	ubi->avail_pebs -= EBA_RESERVED_PEBS;
++	ubi->rsvd_pebs += EBA_RESERVED_PEBS;
++
+ 	if (ubi->bad_allowed) {
+ 		ubi_calculate_reserved(ubi);
+ 
+@@ -1184,16 +1217,7 @@
+ 		ubi->rsvd_pebs  += ubi->beb_rsvd_pebs;
+ 	}
+ 
+-	if (ubi->avail_pebs < EBA_RESERVED_PEBS) {
+-		ubi_err("no enough physical eraseblocks (%d, need %d)",
+-			ubi->avail_pebs, EBA_RESERVED_PEBS);
+-		err = -ENOSPC;
+-		goto out_free;
+-	}
+-	ubi->avail_pebs -= EBA_RESERVED_PEBS;
+-	ubi->rsvd_pebs += EBA_RESERVED_PEBS;
+-
+-	dbg_eba("EBA unit is initialized");
++	dbg_eba("EBA sub-system is initialized");
+ 	return 0;
+ 
+ out_free:
+@@ -1202,26 +1226,5 @@
+ 			continue;
+ 		kfree(ubi->volumes[i]->eba_tbl);
+ 	}
+-	if (ubi_devices_cnt == 0)
+-		kmem_cache_destroy(ltree_slab);
+ 	return err;
+ }
+-
+-/**
+- * ubi_eba_close - close EBA unit.
+- * @ubi: UBI device description object
+- */
+-void ubi_eba_close(const struct ubi_device *ubi)
+-{
+-	int i, num_volumes = ubi->vtbl_slots + UBI_INT_VOL_COUNT;
+-
+-	dbg_eba("close EBA unit");
+-
+-	for (i = 0; i < num_volumes; i++) {
+-		if (!ubi->volumes[i])
+-			continue;
+-		kfree(ubi->volumes[i]->eba_tbl);
+-	}
+-	if (ubi_devices_cnt == 1)
+-		kmem_cache_destroy(ltree_slab);
+-}
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/gluebi.c linux-2.6.24/drivers/mtd/ubi/gluebi.c
+--- linux-2.6.24.orig/drivers/mtd/ubi/gluebi.c	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/gluebi.c	2009-04-17 09:49:26.000000000 +0200
+@@ -28,7 +28,6 @@
+  * eraseblock size is equivalent to the logical eraseblock size of the volume.
+  */
+ 
+-#include <asm/div64.h>
+ #include "ubi.h"
+ 
+ /**
+@@ -109,9 +108,8 @@
+ 	int err = 0, lnum, offs, total_read;
+ 	struct ubi_volume *vol;
+ 	struct ubi_device *ubi;
+-	uint64_t tmp = from;
+ 
+-	dbg_msg("read %zd bytes from offset %lld", len, from);
++	dbg_gen("read %zd bytes from offset %lld", len, from);
+ 
+ 	if (len < 0 || from < 0 || from + len > mtd->size)
+ 		return -EINVAL;
+@@ -119,9 +117,7 @@
+ 	vol = container_of(mtd, struct ubi_volume, gluebi_mtd);
+ 	ubi = vol->ubi;
+ 
+-	offs = do_div(tmp, mtd->erasesize);
+-	lnum = tmp;
+-
++	lnum = div_u64_rem(from, mtd->erasesize, &offs);
+ 	total_read = len;
+ 	while (total_read) {
+ 		size_t to_read = mtd->erasesize - offs;
+@@ -129,8 +125,7 @@
+ 		if (to_read > total_read)
+ 			to_read = total_read;
+ 
+-		err = ubi_eba_read_leb(ubi, vol->vol_id, lnum, buf, offs,
+-				       to_read, 0);
++		err = ubi_eba_read_leb(ubi, vol, lnum, buf, offs, to_read, 0);
+ 		if (err)
+ 			break;
+ 
+@@ -161,9 +156,8 @@
+ 	int err = 0, lnum, offs, total_written;
+ 	struct ubi_volume *vol;
+ 	struct ubi_device *ubi;
+-	uint64_t tmp = to;
+ 
+-	dbg_msg("write %zd bytes to offset %lld", len, to);
++	dbg_gen("write %zd bytes to offset %lld", len, to);
+ 
+ 	if (len < 0 || to < 0 || len + to > mtd->size)
+ 		return -EINVAL;
+@@ -174,8 +168,7 @@
+ 	if (ubi->ro_mode)
+ 		return -EROFS;
+ 
+-	offs = do_div(tmp, mtd->erasesize);
+-	lnum = tmp;
++	lnum = div_u64_rem(to, mtd->erasesize, &offs);
+ 
+ 	if (len % mtd->writesize || offs % mtd->writesize)
+ 		return -EINVAL;
+@@ -187,8 +180,8 @@
+ 		if (to_write > total_written)
+ 			to_write = total_written;
+ 
+-		err = ubi_eba_write_leb(ubi, vol->vol_id, lnum, buf, offs,
+-					to_write, UBI_UNKNOWN);
++		err = ubi_eba_write_leb(ubi, vol, lnum, buf, offs, to_write,
++					UBI_UNKNOWN);
+ 		if (err)
+ 			break;
+ 
+@@ -216,7 +209,7 @@
+ 	struct ubi_volume *vol;
+ 	struct ubi_device *ubi;
+ 
+-	dbg_msg("erase %u bytes at offset %u", instr->len, instr->addr);
++	dbg_gen("erase %u bytes at offset %u", instr->len, instr->addr);
+ 
+ 	if (instr->addr < 0 || instr->addr > mtd->size - mtd->erasesize)
+ 		return -EINVAL;
+@@ -237,7 +230,7 @@
+ 		return -EROFS;
+ 
+ 	for (i = 0; i < count; i++) {
+-		err = ubi_eba_unmap_leb(ubi, vol->vol_id, lnum + i);
++		err = ubi_eba_unmap_leb(ubi, vol, lnum + i);
+ 		if (err)
+ 			goto out_err;
+ 	}
+@@ -250,8 +243,8 @@
+ 	if (err)
+ 		goto out_err;
+ 
+-        instr->state = MTD_ERASE_DONE;
+-        mtd_erase_callback(instr);
++	instr->state = MTD_ERASE_DONE;
++	mtd_erase_callback(instr);
+ 	return 0;
+ 
+ out_err:
+@@ -292,19 +285,20 @@
+ 	/*
+ 	 * In case of dynamic volume, MTD device size is just volume size. In
+ 	 * case of a static volume the size is equivalent to the amount of data
+-	 * bytes, which is zero at this moment and will be changed after volume
+-	 * update.
++	 * bytes.
+ 	 */
+ 	if (vol->vol_type == UBI_DYNAMIC_VOLUME)
+ 		mtd->size = vol->usable_leb_size * vol->reserved_pebs;
++	else
++		mtd->size = vol->used_bytes;
+ 
+ 	if (add_mtd_device(mtd)) {
+-		ubi_err("cannot not add MTD device\n");
++		ubi_err("cannot not add MTD device");
+ 		kfree(mtd->name);
+ 		return -ENFILE;
+ 	}
+ 
+-	dbg_msg("added mtd%d (\"%s\"), size %u, EB size %u",
++	dbg_gen("added mtd%d (\"%s\"), size %u, EB size %u",
+ 		mtd->index, mtd->name, mtd->size, mtd->erasesize);
+ 	return 0;
+ }
+@@ -322,7 +316,7 @@
+ 	int err;
+ 	struct mtd_info *mtd = &vol->gluebi_mtd;
+ 
+-	dbg_msg("remove mtd%d", mtd->index);
++	dbg_gen("remove mtd%d", mtd->index);
+ 	err = del_mtd_device(mtd);
+ 	if (err)
+ 		return err;
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/io.c linux-2.6.24/drivers/mtd/ubi/io.c
+--- linux-2.6.24.orig/drivers/mtd/ubi/io.c	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/io.c	2009-04-17 09:49:26.000000000 +0200
+@@ -20,15 +20,15 @@
+  */
+ 
+ /*
+- * UBI input/output unit.
++ * UBI input/output sub-system.
+  *
+- * This unit provides a uniform way to work with all kinds of the underlying
+- * MTD devices. It also implements handy functions for reading and writing UBI
+- * headers.
++ * This sub-system provides a uniform way to work with all kinds of the
++ * underlying MTD devices. It also implements handy functions for reading and
++ * writing UBI headers.
+  *
+  * We are trying to have a paranoid mindset and not to trust to what we read
+- * from the flash media in order to be more secure and robust. So this unit
+- * validates every single header it reads from the flash media.
++ * from the flash media in order to be more secure and robust. So this
++ * sub-system validates every single header it reads from the flash media.
+  *
+  * Some words about how the eraseblock headers are stored.
+  *
+@@ -79,11 +79,11 @@
+  * 512-byte chunks, we have to allocate one more buffer and copy our VID header
+  * to offset 448 of this buffer.
+  *
+- * The I/O unit does the following trick in order to avoid this extra copy.
+- * It always allocates a @ubi->vid_hdr_alsize bytes buffer for the VID header
+- * and returns a pointer to offset @ubi->vid_hdr_shift of this buffer. When the
+- * VID header is being written out, it shifts the VID header pointer back and
+- * writes the whole sub-page.
++ * The I/O sub-system does the following trick in order to avoid this extra
++ * copy. It always allocates a @ubi->vid_hdr_alsize bytes buffer for the VID
++ * header and returns a pointer to offset @ubi->vid_hdr_shift of this buffer.
++ * When the VID header is being written out, it shifts the VID header pointer
++ * back and writes the whole sub-page.
+  */
+ 
+ #include <linux/crc32.h>
+@@ -156,15 +156,19 @@
+ 			/*
+ 			 * -EUCLEAN is reported if there was a bit-flip which
+ 			 * was corrected, so this is harmless.
++			 *
++			 * We do not report about it here unless debugging is
++			 * enabled. A corresponding message will be printed
++			 * later, when it is has been scrubbed.
+ 			 */
+-			ubi_msg("fixable bit-flip detected at PEB %d", pnum);
++			dbg_msg("fixable bit-flip detected at PEB %d", pnum);
+ 			ubi_assert(len == read);
+ 			return UBI_IO_BITFLIPS;
+ 		}
+ 
+ 		if (read != len && retries++ < UBI_IO_RETRIES) {
+-			dbg_io("error %d while reading %d bytes from PEB %d:%d, "
+-			       "read only %zd bytes, retry",
++			dbg_io("error %d while reading %d bytes from PEB %d:%d,"
++			       " read only %zd bytes, retry",
+ 			       err, len, pnum, offset, read);
+ 			yield();
+ 			goto retry;
+@@ -173,11 +177,21 @@
+ 		ubi_err("error %d while reading %d bytes from PEB %d:%d, "
+ 			"read %zd bytes", err, len, pnum, offset, read);
+ 		ubi_dbg_dump_stack();
++
++		/*
++		 * The driver should never return -EBADMSG if it failed to read
++		 * all the requested data. But some buggy drivers might do
++		 * this, so we change it to -EIO.
++		 */
++		if (read != len && err == -EBADMSG) {
++			ubi_assert(0);
++			err = -EIO;
++		}
+ 	} else {
+ 		ubi_assert(len == read);
+ 
+ 		if (ubi_dbg_is_bitflip()) {
+-			dbg_msg("bit-flip (emulated)");
++			dbg_gen("bit-flip (emulated)");
+ 			err = UBI_IO_BITFLIPS;
+ 		}
+ 	}
+@@ -381,6 +395,7 @@
+ {
+ 	int err, i, patt_count;
+ 
++	ubi_msg("run torture test for PEB %d", pnum);
+ 	patt_count = ARRAY_SIZE(patterns);
+ 	ubi_assert(patt_count > 0);
+ 
+@@ -424,6 +439,7 @@
+ 	}
+ 
+ 	err = patt_count;
++	ubi_msg("PEB %d passed torture test, do not mark it a bad", pnum);
+ 
+ out:
+ 	mutex_unlock(&ubi->buf_mutex);
+@@ -667,6 +683,9 @@
+ 			if (verbose)
+ 				ubi_warn("no EC header found at PEB %d, "
+ 					 "only 0xFF bytes", pnum);
++			else if (UBI_IO_DEBUG)
++				dbg_msg("no EC header found at PEB %d, "
++					"only 0xFF bytes", pnum);
+ 			return UBI_IO_PEB_EMPTY;
+ 		}
+ 
+@@ -678,7 +697,9 @@
+ 			ubi_warn("bad magic number at PEB %d: %08x instead of "
+ 				 "%08x", pnum, magic, UBI_EC_HDR_MAGIC);
+ 			ubi_dbg_dump_ec_hdr(ec_hdr);
+-		}
++		} else if (UBI_IO_DEBUG)
++			dbg_msg("bad magic number at PEB %d: %08x instead of "
++				"%08x", pnum, magic, UBI_EC_HDR_MAGIC);
+ 		return UBI_IO_BAD_EC_HDR;
+ 	}
+ 
+@@ -687,10 +708,12 @@
+ 
+ 	if (hdr_crc != crc) {
+ 		if (verbose) {
+-			ubi_warn("bad EC header CRC at PEB %d, calculated %#08x,"
+-				 " read %#08x", pnum, crc, hdr_crc);
++			ubi_warn("bad EC header CRC at PEB %d, calculated "
++				 "%#08x, read %#08x", pnum, crc, hdr_crc);
+ 			ubi_dbg_dump_ec_hdr(ec_hdr);
+-		}
++		} else if (UBI_IO_DEBUG)
++			dbg_msg("bad EC header CRC at PEB %d, calculated "
++				"%#08x, read %#08x", pnum, crc, hdr_crc);
+ 		return UBI_IO_BAD_EC_HDR;
+ 	}
+ 
+@@ -940,6 +963,9 @@
+ 			if (verbose)
+ 				ubi_warn("no VID header found at PEB %d, "
+ 					 "only 0xFF bytes", pnum);
++			else if (UBI_IO_DEBUG)
++				dbg_msg("no VID header found at PEB %d, "
++					"only 0xFF bytes", pnum);
+ 			return UBI_IO_PEB_FREE;
+ 		}
+ 
+@@ -951,7 +977,9 @@
+ 			ubi_warn("bad magic number at PEB %d: %08x instead of "
+ 				 "%08x", pnum, magic, UBI_VID_HDR_MAGIC);
+ 			ubi_dbg_dump_vid_hdr(vid_hdr);
+-		}
++		} else if (UBI_IO_DEBUG)
++			dbg_msg("bad magic number at PEB %d: %08x instead of "
++				"%08x", pnum, magic, UBI_VID_HDR_MAGIC);
+ 		return UBI_IO_BAD_VID_HDR;
+ 	}
+ 
+@@ -963,7 +991,9 @@
+ 			ubi_warn("bad CRC at PEB %d, calculated %#08x, "
+ 				 "read %#08x", pnum, crc, hdr_crc);
+ 			ubi_dbg_dump_vid_hdr(vid_hdr);
+-		}
++		} else if (UBI_IO_DEBUG)
++			dbg_msg("bad CRC at PEB %d, calculated %#08x, "
++				"read %#08x", pnum, crc, hdr_crc);
+ 		return UBI_IO_BAD_VID_HDR;
+ 	}
+ 
+@@ -1004,7 +1034,7 @@
+ 
+ 	err = paranoid_check_peb_ec_hdr(ubi, pnum);
+ 	if (err)
+-		return err > 0 ? -EINVAL: err;
++		return err > 0 ? -EINVAL : err;
+ 
+ 	vid_hdr->magic = cpu_to_be32(UBI_VID_HDR_MAGIC);
+ 	vid_hdr->version = UBI_VERSION;
+@@ -1081,8 +1111,7 @@
+ }
+ 
+ /**
+- * paranoid_check_peb_ec_hdr - check that the erase counter header of a
+- * physical eraseblock is in-place and is all right.
++ * paranoid_check_peb_ec_hdr - check erase counter header.
+  * @ubi: UBI device description object
+  * @pnum: the physical eraseblock number to check
+  *
+@@ -1160,8 +1189,7 @@
+ }
+ 
+ /**
+- * paranoid_check_peb_vid_hdr - check that the volume identifier header of a
+- * physical eraseblock is in-place and is all right.
++ * paranoid_check_peb_vid_hdr - check volume identifier header.
+  * @ubi: UBI device description object
+  * @pnum: the physical eraseblock number to check
+  *
+@@ -1242,7 +1270,7 @@
+ 
+ fail:
+ 	ubi_err("paranoid check failed for PEB %d", pnum);
+-	dbg_msg("hex dump of the %d-%d region", offset, offset + len);
++	ubi_msg("hex dump of the %d-%d region", offset, offset + len);
+ 	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
+ 		       ubi->dbg_peb_buf, len, 1);
+ 	err = 1;
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/kapi.c linux-2.6.24/drivers/mtd/ubi/kapi.c
+--- linux-2.6.24.orig/drivers/mtd/ubi/kapi.c	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/kapi.c	2009-04-17 09:49:26.000000000 +0200
+@@ -30,23 +30,27 @@
+  * @ubi_num: UBI device number
+  * @di: the information is stored here
+  *
+- * This function returns %0 in case of success and a %-ENODEV if there is no
+- * such UBI device.
++ * This function returns %0 in case of success, %-EINVAL if the UBI device
++ * number is invalid, and %-ENODEV if there is no such UBI device.
+  */
+ int ubi_get_device_info(int ubi_num, struct ubi_device_info *di)
+ {
+-	const struct ubi_device *ubi;
++	struct ubi_device *ubi;
+ 
+-	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES ||
+-	    !ubi_devices[ubi_num])
++	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
++		return -EINVAL;
++
++	ubi = ubi_get_device(ubi_num);
++	if (!ubi)
+ 		return -ENODEV;
+ 
+-	ubi = ubi_devices[ubi_num];
+ 	di->ubi_num = ubi->ubi_num;
+ 	di->leb_size = ubi->leb_size;
+ 	di->min_io_size = ubi->min_io_size;
+ 	di->ro_mode = ubi->ro_mode;
+-	di->cdev = MKDEV(ubi->major, 0);
++	di->cdev = ubi->cdev.dev;
++
++	ubi_put_device(ubi);
+ 	return 0;
+ }
+ EXPORT_SYMBOL_GPL(ubi_get_device_info);
+@@ -73,7 +77,7 @@
+ 	vi->usable_leb_size = vol->usable_leb_size;
+ 	vi->name_len = vol->name_len;
+ 	vi->name = vol->name;
+-	vi->cdev = MKDEV(ubi->major, vi->vol_id + 1);
++	vi->cdev = vol->cdev.dev;
+ }
+ EXPORT_SYMBOL_GPL(ubi_get_volume_info);
+ 
+@@ -102,39 +106,41 @@
+ 	struct ubi_device *ubi;
+ 	struct ubi_volume *vol;
+ 
+-	dbg_msg("open device %d volume %d, mode %d", ubi_num, vol_id, mode);
+-
+-	err = -ENODEV;
+-	if (ubi_num < 0)
+-		return ERR_PTR(err);
+-
+-	ubi = ubi_devices[ubi_num];
+-
+-	if (!try_module_get(THIS_MODULE))
+-		return ERR_PTR(err);
++	dbg_gen("open device %d volume %d, mode %d", ubi_num, vol_id, mode);
+ 
+-	if (ubi_num >= UBI_MAX_DEVICES || !ubi)
+-		goto out_put;
++	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
++		return ERR_PTR(-EINVAL);
+ 
+-	err = -EINVAL;
+-	if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
+-		goto out_put;
+ 	if (mode != UBI_READONLY && mode != UBI_READWRITE &&
+ 	    mode != UBI_EXCLUSIVE)
+-		goto out_put;
++		return ERR_PTR(-EINVAL);
++
++	/*
++	 * First of all, we have to get the UBI device to prevent its removal.
++	 */
++	ubi = ubi_get_device(ubi_num);
++	if (!ubi)
++		return ERR_PTR(-ENODEV);
++
++	if (vol_id < 0 || vol_id >= ubi->vtbl_slots) {
++		err = -EINVAL;
++		goto out_put_ubi;
++	}
+ 
+ 	desc = kmalloc(sizeof(struct ubi_volume_desc), GFP_KERNEL);
+ 	if (!desc) {
+ 		err = -ENOMEM;
+-		goto out_put;
++		goto out_put_ubi;
+ 	}
+ 
++	err = -ENODEV;
++	if (!try_module_get(THIS_MODULE))
++		goto out_free;
++
+ 	spin_lock(&ubi->volumes_lock);
+ 	vol = ubi->volumes[vol_id];
+-	if (!vol) {
+-		err = -ENODEV;
++	if (!vol)
+ 		goto out_unlock;
+-	}
+ 
+ 	err = -EBUSY;
+ 	switch (mode) {
+@@ -156,21 +162,19 @@
+ 		vol->exclusive = 1;
+ 		break;
+ 	}
++	get_device(&vol->dev);
++	vol->ref_count += 1;
+ 	spin_unlock(&ubi->volumes_lock);
+ 
+ 	desc->vol = vol;
+ 	desc->mode = mode;
+ 
+-	/*
+-	 * To prevent simultaneous checks of the same volume we use @vtbl_mutex,
+-	 * although it is not the purpose it was introduced for.
+-	 */
+-	mutex_lock(&ubi->vtbl_mutex);
++	mutex_lock(&ubi->ckvol_mutex);
+ 	if (!vol->checked) {
+ 		/* This is the first open - check the volume */
+ 		err = ubi_check_volume(ubi, vol_id);
+ 		if (err < 0) {
+-			mutex_unlock(&ubi->vtbl_mutex);
++			mutex_unlock(&ubi->ckvol_mutex);
+ 			ubi_close_volume(desc);
+ 			return ERR_PTR(err);
+ 		}
+@@ -181,14 +185,17 @@
+ 		}
+ 		vol->checked = 1;
+ 	}
+-	mutex_unlock(&ubi->vtbl_mutex);
++	mutex_unlock(&ubi->ckvol_mutex);
++
+ 	return desc;
+ 
+ out_unlock:
+ 	spin_unlock(&ubi->volumes_lock);
+-	kfree(desc);
+-out_put:
+ 	module_put(THIS_MODULE);
++out_free:
++	kfree(desc);
++out_put_ubi:
++	ubi_put_device(ubi);
+ 	return ERR_PTR(err);
+ }
+ EXPORT_SYMBOL_GPL(ubi_open_volume);
+@@ -205,10 +212,10 @@
+ 					   int mode)
+ {
+ 	int i, vol_id = -1, len;
+-	struct ubi_volume_desc *ret;
+ 	struct ubi_device *ubi;
++	struct ubi_volume_desc *ret;
+ 
+-	dbg_msg("open volume %s, mode %d", name, mode);
++	dbg_gen("open volume %s, mode %d", name, mode);
+ 
+ 	if (!name)
+ 		return ERR_PTR(-EINVAL);
+@@ -217,14 +224,12 @@
+ 	if (len > UBI_VOL_NAME_MAX)
+ 		return ERR_PTR(-EINVAL);
+ 
+-	ret = ERR_PTR(-ENODEV);
+-	if (!try_module_get(THIS_MODULE))
+-		return ret;
+-
+-	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES || !ubi_devices[ubi_num])
+-		goto out_put;
++	if (ubi_num < 0 || ubi_num >= UBI_MAX_DEVICES)
++		return ERR_PTR(-EINVAL);
+ 
+-	ubi = ubi_devices[ubi_num];
++	ubi = ubi_get_device(ubi_num);
++	if (!ubi)
++		return ERR_PTR(-ENODEV);
+ 
+ 	spin_lock(&ubi->volumes_lock);
+ 	/* Walk all volumes of this UBI device */
+@@ -238,13 +243,16 @@
+ 	}
+ 	spin_unlock(&ubi->volumes_lock);
+ 
+-	if (vol_id < 0)
+-		goto out_put;
+-
+-	ret = ubi_open_volume(ubi_num, vol_id, mode);
++	if (vol_id >= 0)
++		ret = ubi_open_volume(ubi_num, vol_id, mode);
++	else
++		ret = ERR_PTR(-ENODEV);
+ 
+-out_put:
+-	module_put(THIS_MODULE);
++	/*
++	 * We should put the UBI device even in case of success, because
++	 * 'ubi_open_volume()' took a reference as well.
++	 */
++	ubi_put_device(ubi);
+ 	return ret;
+ }
+ EXPORT_SYMBOL_GPL(ubi_open_volume_nm);
+@@ -256,10 +264,11 @@
+ void ubi_close_volume(struct ubi_volume_desc *desc)
+ {
+ 	struct ubi_volume *vol = desc->vol;
++	struct ubi_device *ubi = vol->ubi;
+ 
+-	dbg_msg("close volume %d, mode %d", vol->vol_id, desc->mode);
++	dbg_gen("close volume %d, mode %d", vol->vol_id, desc->mode);
+ 
+-	spin_lock(&vol->ubi->volumes_lock);
++	spin_lock(&ubi->volumes_lock);
+ 	switch (desc->mode) {
+ 	case UBI_READONLY:
+ 		vol->readers -= 1;
+@@ -270,9 +279,12 @@
+ 	case UBI_EXCLUSIVE:
+ 		vol->exclusive = 0;
+ 	}
+-	spin_unlock(&vol->ubi->volumes_lock);
++	vol->ref_count -= 1;
++	spin_unlock(&ubi->volumes_lock);
+ 
+ 	kfree(desc);
++	put_device(&vol->dev);
++	ubi_put_device(ubi);
+ 	module_put(THIS_MODULE);
+ }
+ EXPORT_SYMBOL_GPL(ubi_close_volume);
+@@ -311,7 +323,7 @@
+ 	struct ubi_device *ubi = vol->ubi;
+ 	int err, vol_id = vol->vol_id;
+ 
+-	dbg_msg("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
++	dbg_gen("read %d bytes from LEB %d:%d:%d", len, vol_id, lnum, offset);
+ 
+ 	if (vol_id < 0 || vol_id >= ubi->vtbl_slots || lnum < 0 ||
+ 	    lnum >= vol->used_ebs || offset < 0 || len < 0 ||
+@@ -332,7 +344,7 @@
+ 	if (len == 0)
+ 		return 0;
+ 
+-	err = ubi_eba_read_leb(ubi, vol_id, lnum, buf, offset, len, check);
++	err = ubi_eba_read_leb(ubi, vol, lnum, buf, offset, len, check);
+ 	if (err && err == -EBADMSG && vol->vol_type == UBI_STATIC_VOLUME) {
+ 		ubi_warn("mark volume %d as corrupted", vol_id);
+ 		vol->corrupted = 1;
+@@ -376,7 +388,7 @@
+ 	struct ubi_device *ubi = vol->ubi;
+ 	int vol_id = vol->vol_id;
+ 
+-	dbg_msg("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset);
++	dbg_gen("write %d bytes to LEB %d:%d:%d", len, vol_id, lnum, offset);
+ 
+ 	if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
+ 		return -EINVAL;
+@@ -385,8 +397,8 @@
+ 		return -EROFS;
+ 
+ 	if (lnum < 0 || lnum >= vol->reserved_pebs || offset < 0 || len < 0 ||
+-	    offset + len > vol->usable_leb_size || offset % ubi->min_io_size ||
+-	    len % ubi->min_io_size)
++	    offset + len > vol->usable_leb_size ||
++	    offset & (ubi->min_io_size - 1) || len & (ubi->min_io_size - 1))
+ 		return -EINVAL;
+ 
+ 	if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
+@@ -399,7 +411,7 @@
+ 	if (len == 0)
+ 		return 0;
+ 
+-	return ubi_eba_write_leb(ubi, vol_id, lnum, buf, offset, len, dtype);
++	return ubi_eba_write_leb(ubi, vol, lnum, buf, offset, len, dtype);
+ }
+ EXPORT_SYMBOL_GPL(ubi_leb_write);
+ 
+@@ -426,7 +438,7 @@
+ 	struct ubi_device *ubi = vol->ubi;
+ 	int vol_id = vol->vol_id;
+ 
+-	dbg_msg("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum);
++	dbg_gen("atomically write %d bytes to LEB %d:%d", len, vol_id, lnum);
+ 
+ 	if (vol_id < 0 || vol_id >= ubi->vtbl_slots)
+ 		return -EINVAL;
+@@ -435,7 +447,7 @@
+ 		return -EROFS;
+ 
+ 	if (lnum < 0 || lnum >= vol->reserved_pebs || len < 0 ||
+-	    len > vol->usable_leb_size || len % ubi->min_io_size)
++	    len > vol->usable_leb_size || len & (ubi->min_io_size - 1))
+ 		return -EINVAL;
+ 
+ 	if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
+@@ -448,7 +460,7 @@
+ 	if (len == 0)
+ 		return 0;
+ 
+-	return ubi_eba_atomic_leb_change(ubi, vol_id, lnum, buf, len, dtype);
++	return ubi_eba_atomic_leb_change(ubi, vol, lnum, buf, len, dtype);
+ }
+ EXPORT_SYMBOL_GPL(ubi_leb_change);
+ 
+@@ -468,9 +480,9 @@
+ {
+ 	struct ubi_volume *vol = desc->vol;
+ 	struct ubi_device *ubi = vol->ubi;
+-	int err, vol_id = vol->vol_id;
++	int err;
+ 
+-	dbg_msg("erase LEB %d:%d", vol_id, lnum);
++	dbg_gen("erase LEB %d:%d", vol->vol_id, lnum);
+ 
+ 	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
+ 		return -EROFS;
+@@ -481,7 +493,7 @@
+ 	if (vol->upd_marker)
+ 		return -EBADF;
+ 
+-	err = ubi_eba_unmap_leb(ubi, vol_id, lnum);
++	err = ubi_eba_unmap_leb(ubi, vol, lnum);
+ 	if (err)
+ 		return err;
+ 
+@@ -529,9 +541,8 @@
+ {
+ 	struct ubi_volume *vol = desc->vol;
+ 	struct ubi_device *ubi = vol->ubi;
+-	int vol_id = vol->vol_id;
+ 
+-	dbg_msg("unmap LEB %d:%d", vol_id, lnum);
++	dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum);
+ 
+ 	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
+ 		return -EROFS;
+@@ -542,11 +553,55 @@
+ 	if (vol->upd_marker)
+ 		return -EBADF;
+ 
+-	return ubi_eba_unmap_leb(ubi, vol_id, lnum);
++	return ubi_eba_unmap_leb(ubi, vol, lnum);
+ }
+ EXPORT_SYMBOL_GPL(ubi_leb_unmap);
+ 
+ /**
++ * ubi_leb_map - map logical erasblock to a physical eraseblock.
++ * @desc: volume descriptor
++ * @lnum: logical eraseblock number
++ * @dtype: expected data type
++ *
++ * This function maps an un-mapped logical eraseblock @lnum to a physical
++ * eraseblock. This means, that after a successfull invocation of this
++ * function the logical eraseblock @lnum will be empty (contain only %0xFF
++ * bytes) and be mapped to a physical eraseblock, even if an unclean reboot
++ * happens.
++ *
++ * This function returns zero in case of success, %-EBADF if the volume is
++ * damaged because of an interrupted update, %-EBADMSG if the logical
++ * eraseblock is already mapped, and other negative error codes in case of
++ * other failures.
++ */
++int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype)
++{
++	struct ubi_volume *vol = desc->vol;
++	struct ubi_device *ubi = vol->ubi;
++
++	dbg_gen("unmap LEB %d:%d", vol->vol_id, lnum);
++
++	if (desc->mode == UBI_READONLY || vol->vol_type == UBI_STATIC_VOLUME)
++		return -EROFS;
++
++	if (lnum < 0 || lnum >= vol->reserved_pebs)
++		return -EINVAL;
++
++	if (dtype != UBI_LONGTERM && dtype != UBI_SHORTTERM &&
++	    dtype != UBI_UNKNOWN)
++		return -EINVAL;
++
++	if (vol->upd_marker)
++		return -EBADF;
++
++	if (vol->eba_tbl[lnum] >= 0)
++		return -EBADMSG;
++
++	return ubi_eba_write_leb(ubi, vol, lnum, NULL, 0, 0, dtype);
++}
++EXPORT_SYMBOL_GPL(ubi_leb_map);
++
++/**
+  * ubi_is_mapped - check if logical eraseblock is mapped.
+  * @desc: volume descriptor
+  * @lnum: logical eraseblock number
+@@ -566,7 +621,7 @@
+ {
+ 	struct ubi_volume *vol = desc->vol;
+ 
+-	dbg_msg("test LEB %d:%d", vol->vol_id, lnum);
++	dbg_gen("test LEB %d:%d", vol->vol_id, lnum);
+ 
+ 	if (lnum < 0 || lnum >= vol->reserved_pebs)
+ 		return -EINVAL;
+@@ -577,3 +632,27 @@
+ 	return vol->eba_tbl[lnum] >= 0;
+ }
+ EXPORT_SYMBOL_GPL(ubi_is_mapped);
++
++/**
++ * ubi_sync - synchronize UBI device buffers.
++ * @ubi_num: UBI device to synchronize
++ *
++ * The underlying MTD device may cache data in hardware or in software. This
++ * function ensures the caches are flushed. Returns zero in case of success and
++ * a negative error code in case of failure.
++ */
++int ubi_sync(int ubi_num)
++{
++	struct ubi_device *ubi;
++
++	ubi = ubi_get_device(ubi_num);
++	if (!ubi)
++		return -ENODEV;
++
++	if (ubi->mtd->sync)
++		ubi->mtd->sync(ubi->mtd);
++
++	ubi_put_device(ubi);
++	return 0;
++}
++EXPORT_SYMBOL_GPL(ubi_sync);
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/misc.c linux-2.6.24/drivers/mtd/ubi/misc.c
+--- linux-2.6.24.orig/drivers/mtd/ubi/misc.c	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/misc.c	2009-04-17 09:49:26.000000000 +0200
+@@ -37,7 +37,7 @@
+ {
+ 	int i;
+ 
+-	ubi_assert(length % ubi->min_io_size == 0);
++	ubi_assert(!(length & (ubi->min_io_size - 1)));
+ 
+ 	for (i = length - 1; i >= 0; i--)
+ 		if (((const uint8_t *)buf)[i] != 0xFF)
+@@ -79,7 +79,7 @@
+ 		else
+ 			size = vol->usable_leb_size;
+ 
+-		err = ubi_eba_read_leb(ubi, vol_id, i, buf, 0, size, 1);
++		err = ubi_eba_read_leb(ubi, vol, i, buf, 0, size, 1);
+ 		if (err) {
+ 			if (err == -EBADMSG)
+ 				err = 1;
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/scan.c linux-2.6.24/drivers/mtd/ubi/scan.c
+--- linux-2.6.24.orig/drivers/mtd/ubi/scan.c	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/scan.c	2009-04-17 09:49:26.000000000 +0200
+@@ -19,9 +19,9 @@
+  */
+ 
+ /*
+- * UBI scanning unit.
++ * UBI scanning sub-system.
+  *
+- * This unit is responsible for scanning the flash media, checking UBI
++ * This sub-system is responsible for scanning the flash media, checking UBI
+  * headers and providing complete information about the UBI flash image.
+  *
+  * The scanning information is represented by a &struct ubi_scan_info' object.
+@@ -92,29 +92,7 @@
+ }
+ 
+ /**
+- * commit_to_mean_value - commit intermediate results to the final mean erase
+- * counter value.
+- * @si: scanning information
+- *
+- * This is a helper function which calculates partial mean erase counter mean
+- * value and adds it to the resulting mean value. As we can work only in
+- * integer arithmetic and we want to calculate the mean value of erase counter
+- * accurately, we first sum erase counter values in @si->ec_sum variable and
+- * count these components in @si->ec_count. If this temporary @si->ec_sum is
+- * going to overflow, we calculate the partial mean value
+- * (@si->ec_sum/@si->ec_count) and add it to @si->mean_ec.
+- */
+-static void commit_to_mean_value(struct ubi_scan_info *si)
+-{
+-	si->ec_sum /= si->ec_count;
+-	if (si->ec_sum % si->ec_count >= si->ec_count / 2)
+-		si->mean_ec += 1;
+-	si->mean_ec += si->ec_sum;
+-}
+-
+-/**
+- * validate_vid_hdr - check that volume identifier header is correct and
+- * consistent.
++ * validate_vid_hdr - check volume identifier header.
+  * @vid_hdr: the volume identifier header to check
+  * @sv: information about the volume this logical eraseblock belongs to
+  * @pnum: physical eraseblock number the VID header came from
+@@ -123,7 +101,7 @@
+  * non-zero if an inconsistency was found and zero if not.
+  *
+  * Note, UBI does sanity check of everything it reads from the flash media.
+- * Most of the checks are done in the I/O unit. Here we check that the
++ * Most of the checks are done in the I/O sub-system. Here we check that the
+  * information in the VID header is consistent to the information in other VID
+  * headers of the same volume.
+  */
+@@ -267,40 +245,21 @@
+ 	struct ubi_vid_hdr *vh = NULL;
+ 	unsigned long long sqnum2 = be64_to_cpu(vid_hdr->sqnum);
+ 
+-	if (seb->sqnum == 0 && sqnum2 == 0) {
+-		long long abs, v1 = seb->leb_ver, v2 = be32_to_cpu(vid_hdr->leb_ver);
+-
++	if (sqnum2 == seb->sqnum) {
+ 		/*
+-		 * UBI constantly increases the logical eraseblock version
+-		 * number and it can overflow. Thus, we have to bear in mind
+-		 * that versions that are close to %0xFFFFFFFF are less then
+-		 * versions that are close to %0.
+-		 *
+-		 * The UBI WL unit guarantees that the number of pending tasks
+-		 * is not greater then %0x7FFFFFFF. So, if the difference
+-		 * between any two versions is greater or equivalent to
+-		 * %0x7FFFFFFF, there was an overflow and the logical
+-		 * eraseblock with lower version is actually newer then the one
+-		 * with higher version.
+-		 *
+-		 * FIXME: but this is anyway obsolete and will be removed at
+-		 * some point.
++		 * This must be a really ancient UBI image which has been
++		 * created before sequence numbers support has been added. At
++		 * that times we used 32-bit LEB versions stored in logical
++		 * eraseblocks. That was before UBI got into mainline. We do not
++		 * support these images anymore. Well, those images will work
++		 * still work, but only if no unclean reboots happened.
+ 		 */
++		ubi_err("unsupported on-flash UBI format\n");
++		return -EINVAL;
++	}
+ 
+-		dbg_bld("using old crappy leb_ver stuff");
+-
+-		abs = v1 - v2;
+-		if (abs < 0)
+-			abs = -abs;
+-
+-		if (abs < 0x7FFFFFFF)
+-			/* Non-overflow situation */
+-			second_is_newer = (v2 > v1);
+-		else
+-			second_is_newer = (v2 < v1);
+-	} else
+-		/* Obviously the LEB with lower sequence counter is older */
+-		second_is_newer = sqnum2 > seb->sqnum;
++	/* Obviously the LEB with lower sequence counter is older */
++	second_is_newer = !!(sqnum2 > seb->sqnum);
+ 
+ 	/*
+ 	 * Now we know which copy is newer. If the copy flag of the PEB with
+@@ -308,7 +267,7 @@
+ 	 * check data CRC. For the second PEB we already have the VID header,
+ 	 * for the first one - we'll need to re-read it from flash.
+ 	 *
+-	 * FIXME: this may be optimized so that we wouldn't read twice.
++	 * Note: this may be optimized so that we wouldn't read twice.
+ 	 */
+ 
+ 	if (second_is_newer) {
+@@ -360,7 +319,7 @@
+ 	}
+ 
+ 	err = ubi_io_read_data(ubi, buf, pnum, 0, len);
+-	if (err && err != UBI_IO_BITFLIPS)
++	if (err && err != UBI_IO_BITFLIPS && err != -EBADMSG)
+ 		goto out_free_buf;
+ 
+ 	data_crc = be32_to_cpu(vid_hdr->data_crc);
+@@ -390,13 +349,11 @@
+ 	vfree(buf);
+ out_free_vidh:
+ 	ubi_free_vid_hdr(ubi, vh);
+-	ubi_assert(err < 0);
+ 	return err;
+ }
+ 
+ /**
+- * ubi_scan_add_used - add information about a physical eraseblock to the
+- * scanning information.
++ * ubi_scan_add_used - add physical eraseblock to the scanning information.
+  * @ubi: UBI device description object
+  * @si: scanning information
+  * @pnum: the physical eraseblock number
+@@ -416,7 +373,6 @@
+ 		      int bitflips)
+ {
+ 	int err, vol_id, lnum;
+-	uint32_t leb_ver;
+ 	unsigned long long sqnum;
+ 	struct ubi_scan_volume *sv;
+ 	struct ubi_scan_leb *seb;
+@@ -425,13 +381,12 @@
+ 	vol_id = be32_to_cpu(vid_hdr->vol_id);
+ 	lnum = be32_to_cpu(vid_hdr->lnum);
+ 	sqnum = be64_to_cpu(vid_hdr->sqnum);
+-	leb_ver = be32_to_cpu(vid_hdr->leb_ver);
+ 
+-	dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, ver %u, bitflips %d",
+-		pnum, vol_id, lnum, ec, sqnum, leb_ver, bitflips);
++	dbg_bld("PEB %d, LEB %d:%d, EC %d, sqnum %llu, bitflips %d",
++		pnum, vol_id, lnum, ec, sqnum, bitflips);
+ 
+ 	sv = add_volume(si, vol_id, pnum, vid_hdr);
+-	if (IS_ERR(sv) < 0)
++	if (IS_ERR(sv))
+ 		return PTR_ERR(sv);
+ 
+ 	if (si->max_sqnum < sqnum)
+@@ -461,25 +416,20 @@
+ 		 */
+ 
+ 		dbg_bld("this LEB already exists: PEB %d, sqnum %llu, "
+-			"LEB ver %u, EC %d", seb->pnum, seb->sqnum,
+-			seb->leb_ver, seb->ec);
+-
+-		/*
+-		 * Make sure that the logical eraseblocks have different
+-		 * versions. Otherwise the image is bad.
+-		 */
+-		if (seb->leb_ver == leb_ver && leb_ver != 0) {
+-			ubi_err("two LEBs with same version %u", leb_ver);
+-			ubi_dbg_dump_seb(seb, 0);
+-			ubi_dbg_dump_vid_hdr(vid_hdr);
+-			return -EINVAL;
+-		}
++			"EC %d", seb->pnum, seb->sqnum, seb->ec);
+ 
+ 		/*
+ 		 * Make sure that the logical eraseblocks have different
+ 		 * sequence numbers. Otherwise the image is bad.
+ 		 *
+-		 * FIXME: remove 'sqnum != 0' check when leb_ver is removed.
++		 * However, if the sequence number is zero, we assume it must
++		 * be an ancient UBI image from the era when UBI did not have
++		 * sequence numbers. We still can attach these images, unless
++		 * there is a need to distinguish between old and new
++		 * eraseblocks, in which case we'll refuse the image in
++		 * 'compare_lebs()'. In other words, we attach old clean
++		 * images, but refuse attaching old images with duplicated
++		 * logical eraseblocks because there was an unclean reboot.
+ 		 */
+ 		if (seb->sqnum == sqnum && sqnum != 0) {
+ 			ubi_err("two LEBs with same sequence number %llu",
+@@ -519,7 +469,6 @@
+ 			seb->pnum = pnum;
+ 			seb->scrub = ((cmp_res & 2) || bitflips);
+ 			seb->sqnum = sqnum;
+-			seb->leb_ver = leb_ver;
+ 
+ 			if (sv->highest_lnum == lnum)
+ 				sv->last_data_size =
+@@ -556,7 +505,6 @@
+ 	seb->lnum = lnum;
+ 	seb->sqnum = sqnum;
+ 	seb->scrub = bitflips;
+-	seb->leb_ver = leb_ver;
+ 
+ 	if (sv->highest_lnum <= lnum) {
+ 		sv->highest_lnum = lnum;
+@@ -570,8 +518,7 @@
+ }
+ 
+ /**
+- * ubi_scan_find_sv - find information about a particular volume in the
+- * scanning information.
++ * ubi_scan_find_sv - find volume in the scanning information.
+  * @si: scanning information
+  * @vol_id: the requested volume ID
+  *
+@@ -600,8 +547,7 @@
+ }
+ 
+ /**
+- * ubi_scan_find_seb - find information about a particular logical
+- * eraseblock in the volume scanning information.
++ * ubi_scan_find_seb - find LEB in the volume scanning information.
+  * @sv: a pointer to the volume scanning information
+  * @lnum: the requested logical eraseblock
+  *
+@@ -661,9 +607,9 @@
+  *
+  * This function erases physical eraseblock 'pnum', and writes the erase
+  * counter header to it. This function should only be used on UBI device
+- * initialization stages, when the EBA unit had not been yet initialized. This
+- * function returns zero in case of success and a negative error code in case
+- * of failure.
++ * initialization stages, when the EBA sub-system had not been yet initialized.
++ * This function returns zero in case of success and a negative error code in
++ * case of failure.
+  */
+ int ubi_scan_erase_peb(struct ubi_device *ubi, const struct ubi_scan_info *si,
+ 		       int pnum, int ec)
+@@ -703,9 +649,10 @@
+  * @si: scanning information
+  *
+  * This function returns a free physical eraseblock. It is supposed to be
+- * called on the UBI initialization stages when the wear-leveling unit is not
+- * initialized yet. This function picks a physical eraseblocks from one of the
+- * lists, writes the EC header if it is needed, and removes it from the list.
++ * called on the UBI initialization stages when the wear-leveling sub-system is
++ * not initialized yet. This function picks a physical eraseblocks from one of
++ * the lists, writes the EC header if it is needed, and removes it from the
++ * list.
+  *
+  * This function returns scanning physical eraseblock information in case of
+  * success and an error code in case of failure.
+@@ -758,8 +705,7 @@
+ }
+ 
+ /**
+- * process_eb - read UBI headers, check them and add corresponding data
+- * to the scanning information.
++ * process_eb - read, check UBI headers, and add them to scanning information.
+  * @ubi: UBI device description object
+  * @si: scanning information
+  * @pnum: the physical eraseblock number
+@@ -767,9 +713,10 @@
+  * This function returns a zero if the physical eraseblock was successfully
+  * handled and a negative error code in case of failure.
+  */
+-static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si, int pnum)
++static int process_eb(struct ubi_device *ubi, struct ubi_scan_info *si,
++		      int pnum)
+ {
+-	long long ec;
++	long long uninitialized_var(ec);
+ 	int err, bitflips = 0, vol_id, ec_corr = 0;
+ 
+ 	dbg_bld("scan PEB %d", pnum);
+@@ -780,8 +727,9 @@
+ 		return err;
+ 	else if (err) {
+ 		/*
+-		 * FIXME: this is actually duty of the I/O unit to initialize
+-		 * this, but MTD does not provide enough information.
++		 * FIXME: this is actually duty of the I/O sub-system to
++		 * initialize this, but MTD does not provide enough
++		 * information.
+ 		 */
+ 		si->bad_peb_count += 1;
+ 		return 0;
+@@ -854,7 +802,7 @@
+ 	}
+ 
+ 	vol_id = be32_to_cpu(vidh->vol_id);
+-	if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOL_ID) {
++	if (vol_id > UBI_MAX_VOLUMES && vol_id != UBI_LAYOUT_VOLUME_ID) {
+ 		int lnum = be32_to_cpu(vidh->lnum);
+ 
+ 		/* Unsupported internal volume */
+@@ -897,15 +845,8 @@
+ 
+ adjust_mean_ec:
+ 	if (!ec_corr) {
+-		if (si->ec_sum + ec < ec) {
+-			commit_to_mean_value(si);
+-			si->ec_sum = 0;
+-			si->ec_count = 0;
+-		} else {
+-			si->ec_sum += ec;
+-			si->ec_count += 1;
+-		}
+-
++		si->ec_sum += ec;
++		si->ec_count += 1;
+ 		if (ec > si->max_ec)
+ 			si->max_ec = ec;
+ 		if (ec < si->min_ec)
+@@ -953,7 +894,7 @@
+ 	for (pnum = 0; pnum < ubi->peb_count; pnum++) {
+ 		cond_resched();
+ 
+-		dbg_msg("process PEB %d", pnum);
++		dbg_gen("process PEB %d", pnum);
+ 		err = process_eb(ubi, si, pnum);
+ 		if (err < 0)
+ 			goto out_vidh;
+@@ -961,9 +902,9 @@
+ 
+ 	dbg_msg("scanning is finished");
+ 
+-	/* Finish mean erase counter calculations */
++	/* Calculate mean erase counter */
+ 	if (si->ec_count)
+-		commit_to_mean_value(si);
++		si->mean_ec = div_u64(si->ec_sum, si->ec_count);
+ 
+ 	if (si->is_empty)
+ 		ubi_msg("empty MTD device detected");
+@@ -1100,8 +1041,7 @@
+ #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
+ 
+ /**
+- * paranoid_check_si - check if the scanning information is correct and
+- * consistent.
++ * paranoid_check_si - check the scanning information.
+  * @ubi: UBI device description object
+  * @si: scanning information
+  *
+@@ -1286,11 +1226,6 @@
+ 				ubi_err("bad data_pad %d", sv->data_pad);
+ 				goto bad_vid_hdr;
+ 			}
+-
+-			if (seb->leb_ver != be32_to_cpu(vidh->leb_ver)) {
+-				ubi_err("bad leb_ver %u", seb->leb_ver);
+-				goto bad_vid_hdr;
+-			}
+ 		}
+ 
+ 		if (!last_seb)
+@@ -1320,8 +1255,7 @@
+ 		if (err < 0) {
+ 			kfree(buf);
+ 			return err;
+-		}
+-		else if (err)
++		} else if (err)
+ 			buf[pnum] = 1;
+ 	}
+ 
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/scan.h linux-2.6.24/drivers/mtd/ubi/scan.h
+--- linux-2.6.24.orig/drivers/mtd/ubi/scan.h	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/scan.h	2009-04-17 09:49:26.000000000 +0200
+@@ -34,7 +34,6 @@
+  * @u: unions RB-tree or @list links
+  * @u.rb: link in the per-volume RB-tree of &struct ubi_scan_leb objects
+  * @u.list: link in one of the eraseblock lists
+- * @leb_ver: logical eraseblock version (obsolete)
+  *
+  * One object of this type is allocated for each physical eraseblock during
+  * scanning.
+@@ -49,7 +48,6 @@
+ 		struct rb_node rb;
+ 		struct list_head list;
+ 	} u;
+-	uint32_t leb_ver;
+ };
+ 
+ /**
+@@ -59,16 +57,16 @@
+  * @leb_count: number of logical eraseblocks in this volume
+  * @vol_type: volume type
+  * @used_ebs: number of used logical eraseblocks in this volume (only for
+- * static volumes)
++ *            static volumes)
+  * @last_data_size: amount of data in the last logical eraseblock of this
+- * volume (always equivalent to the usable logical eraseblock size in case of
+- * dynamic volumes)
++ *                  volume (always equivalent to the usable logical eraseblock
++ *                  size in case of dynamic volumes)
+  * @data_pad: how many bytes at the end of logical eraseblocks of this volume
+- * are not used (due to volume alignment)
++ *            are not used (due to volume alignment)
+  * @compat: compatibility flags of this volume
+  * @rb: link in the volume RB-tree
+  * @root: root of the RB-tree containing all the eraseblock belonging to this
+- * volume (&struct ubi_scan_leb objects)
++ *        volume (&struct ubi_scan_leb objects)
+  *
+  * One object of this type is allocated for each volume during scanning.
+  */
+@@ -92,8 +90,8 @@
+  * @free: list of free physical eraseblocks
+  * @erase: list of physical eraseblocks which have to be erased
+  * @alien: list of physical eraseblocks which should not be used by UBI (e.g.,
++ *         those belonging to "preserve"-compatible internal volumes)
+  * @bad_peb_count: count of bad physical eraseblocks
+- * those belonging to "preserve"-compatible internal volumes)
+  * @vols_found: number of volumes found during scanning
+  * @highest_vol_id: highest volume ID
+  * @alien_peb_count: count of physical eraseblocks in the @alien list
+@@ -106,8 +104,8 @@
+  * @ec_count: a temporary variable used when calculating @mean_ec
+  *
+  * This data structure contains the result of scanning and may be used by other
+- * UBI units to build final UBI data structures, further error-recovery and so
+- * on.
++ * UBI sub-systems to build final UBI data structures, further error-recovery
++ * and so on.
+  */
+ struct ubi_scan_info {
+ 	struct rb_root volumes;
+@@ -124,7 +122,7 @@
+ 	int max_ec;
+ 	unsigned long long max_sqnum;
+ 	int mean_ec;
+-	int ec_sum;
++	uint64_t ec_sum;
+ 	int ec_count;
+ };
+ 
+@@ -132,8 +130,7 @@
+ struct ubi_vid_hdr;
+ 
+ /*
+- * ubi_scan_move_to_list - move a physical eraseblock from the volume tree to a
+- * list.
++ * ubi_scan_move_to_list - move a PEB from the volume tree to a list.
+  *
+  * @sv: volume scanning information
+  * @seb: scanning eraseblock infprmation
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/ubi-media.h linux-2.6.24/drivers/mtd/ubi/ubi-media.h
+--- linux-2.6.24.orig/drivers/mtd/ubi/ubi-media.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/drivers/mtd/ubi/ubi-media.h	2009-04-17 09:49:26.000000000 +0200
+@@ -0,0 +1,368 @@
++/*
++ * Copyright (c) International Business Machines Corp., 2006
++ *
++ * This program is free software; you can redistribute it and/or modify
++ * it under the terms of the GNU General Public License as published by
++ * the Free Software Foundation; either version 2 of the License, or
++ * (at your option) any later version.
++ *
++ * This program is distributed in the hope that it will be useful,
++ * but WITHOUT ANY WARRANTY; without even the implied warranty of
++ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See
++ * the GNU General Public License for more details.
++ *
++ * You should have received a copy of the GNU General Public License
++ * along with this program; if not, write to the Free Software
++ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Thomas Gleixner
++ *          Frank Haverkamp
++ *          Oliver Lohmann
++ *          Andreas Arnez
++ */
++
++/*
++ * This file defines the layout of UBI headers and all the other UBI on-flash
++ * data structures.
++ */
++
++#ifndef __UBI_MEDIA_H__
++#define __UBI_MEDIA_H__
++
++#include <asm/byteorder.h>
++
++/* The version of UBI images supported by this implementation */
++#define UBI_VERSION 1
++
++/* The highest erase counter value supported by this implementation */
++#define UBI_MAX_ERASECOUNTER 0x7FFFFFFF
++
++/* The initial CRC32 value used when calculating CRC checksums */
++#define UBI_CRC32_INIT 0xFFFFFFFFU
++
++/* Erase counter header magic number (ASCII "UBI#") */
++#define UBI_EC_HDR_MAGIC  0x55424923
++/* Volume identifier header magic number (ASCII "UBI!") */
++#define UBI_VID_HDR_MAGIC 0x55424921
++
++/*
++ * Volume type constants used in the volume identifier header.
++ *
++ * @UBI_VID_DYNAMIC: dynamic volume
++ * @UBI_VID_STATIC: static volume
++ */
++enum {
++	UBI_VID_DYNAMIC = 1,
++	UBI_VID_STATIC  = 2
++};
++
++/*
++ * Volume flags used in the volume table record.
++ *
++ * @UBI_VTBL_AUTORESIZE_FLG: auto-resize this volume
++ *
++ * %UBI_VTBL_AUTORESIZE_FLG flag can be set only for one volume in the volume
++ * table. UBI automatically re-sizes the volume which has this flag and makes
++ * the volume to be of largest possible size. This means that if after the
++ * initialization UBI finds out that there are available physical eraseblocks
++ * present on the device, it automatically appends all of them to the volume
++ * (the physical eraseblocks reserved for bad eraseblocks handling and other
++ * reserved physical eraseblocks are not taken). So, if there is a volume with
++ * the %UBI_VTBL_AUTORESIZE_FLG flag set, the amount of available logical
++ * eraseblocks will be zero after UBI is loaded, because all of them will be
++ * reserved for this volume. Note, the %UBI_VTBL_AUTORESIZE_FLG bit is cleared
++ * after the volume had been initialized.
++ *
++ * The auto-resize feature is useful for device production purposes. For
++ * example, different NAND flash chips may have different amount of initial bad
++ * eraseblocks, depending of particular chip instance. Manufacturers of NAND
++ * chips usually guarantee that the amount of initial bad eraseblocks does not
++ * exceed certain percent, e.g. 2%. When one creates an UBI image which will be
++ * flashed to the end devices in production, he does not know the exact amount
++ * of good physical eraseblocks the NAND chip on the device will have, but this
++ * number is required to calculate the volume sized and put them to the volume
++ * table of the UBI image. In this case, one of the volumes (e.g., the one
++ * which will store the root file system) is marked as "auto-resizable", and
++ * UBI will adjust its size on the first boot if needed.
++ *
++ * Note, first UBI reserves some amount of physical eraseblocks for bad
++ * eraseblock handling, and then re-sizes the volume, not vice-versa. This
++ * means that the pool of reserved physical eraseblocks will always be present.
++ */
++enum {
++	UBI_VTBL_AUTORESIZE_FLG = 0x01,
++};
++
++/*
++ * Compatibility constants used by internal volumes.
++ *
++ * @UBI_COMPAT_DELETE: delete this internal volume before anything is written
++ *                     to the flash
++ * @UBI_COMPAT_RO: attach this device in read-only mode
++ * @UBI_COMPAT_PRESERVE: preserve this internal volume - do not touch its
++ *                       physical eraseblocks, don't allow the wear-leveling
++ *                       sub-system to move them
++ * @UBI_COMPAT_REJECT: reject this UBI image
++ */
++enum {
++	UBI_COMPAT_DELETE   = 1,
++	UBI_COMPAT_RO       = 2,
++	UBI_COMPAT_PRESERVE = 4,
++	UBI_COMPAT_REJECT   = 5
++};
++
++/* Sizes of UBI headers */
++#define UBI_EC_HDR_SIZE  sizeof(struct ubi_ec_hdr)
++#define UBI_VID_HDR_SIZE sizeof(struct ubi_vid_hdr)
++
++/* Sizes of UBI headers without the ending CRC */
++#define UBI_EC_HDR_SIZE_CRC  (UBI_EC_HDR_SIZE  - sizeof(__be32))
++#define UBI_VID_HDR_SIZE_CRC (UBI_VID_HDR_SIZE - sizeof(__be32))
++
++/**
++ * struct ubi_ec_hdr - UBI erase counter header.
++ * @magic: erase counter header magic number (%UBI_EC_HDR_MAGIC)
++ * @version: version of UBI implementation which is supposed to accept this
++ *           UBI image
++ * @padding1: reserved for future, zeroes
++ * @ec: the erase counter
++ * @vid_hdr_offset: where the VID header starts
++ * @data_offset: where the user data start
++ * @padding2: reserved for future, zeroes
++ * @hdr_crc: erase counter header CRC checksum
++ *
++ * The erase counter header takes 64 bytes and has a plenty of unused space for
++ * future usage. The unused fields are zeroed. The @version field is used to
++ * indicate the version of UBI implementation which is supposed to be able to
++ * work with this UBI image. If @version is greater then the current UBI
++ * version, the image is rejected. This may be useful in future if something
++ * is changed radically. This field is duplicated in the volume identifier
++ * header.
++ *
++ * The @vid_hdr_offset and @data_offset fields contain the offset of the the
++ * volume identifier header and user data, relative to the beginning of the
++ * physical eraseblock. These values have to be the same for all physical
++ * eraseblocks.
++ */
++struct ubi_ec_hdr {
++	__be32  magic;
++	__u8    version;
++	__u8    padding1[3];
++	__be64  ec; /* Warning: the current limit is 31-bit anyway! */
++	__be32  vid_hdr_offset;
++	__be32  data_offset;
++	__u8    padding2[36];
++	__be32  hdr_crc;
++} __attribute__ ((packed));
++
++/**
++ * struct ubi_vid_hdr - on-flash UBI volume identifier header.
++ * @magic: volume identifier header magic number (%UBI_VID_HDR_MAGIC)
++ * @version: UBI implementation version which is supposed to accept this UBI
++ *           image (%UBI_VERSION)
++ * @vol_type: volume type (%UBI_VID_DYNAMIC or %UBI_VID_STATIC)
++ * @copy_flag: if this logical eraseblock was copied from another physical
++ *             eraseblock (for wear-leveling reasons)
++ * @compat: compatibility of this volume (%0, %UBI_COMPAT_DELETE,
++ *          %UBI_COMPAT_IGNORE, %UBI_COMPAT_PRESERVE, or %UBI_COMPAT_REJECT)
++ * @vol_id: ID of this volume
++ * @lnum: logical eraseblock number
++ * @padding1: reserved for future, zeroes
++ * @data_size: how many bytes of data this logical eraseblock contains
++ * @used_ebs: total number of used logical eraseblocks in this volume
++ * @data_pad: how many bytes at the end of this physical eraseblock are not
++ *            used
++ * @data_crc: CRC checksum of the data stored in this logical eraseblock
++ * @padding2: reserved for future, zeroes
++ * @sqnum: sequence number
++ * @padding3: reserved for future, zeroes
++ * @hdr_crc: volume identifier header CRC checksum
++ *
++ * The @sqnum is the value of the global sequence counter at the time when this
++ * VID header was created. The global sequence counter is incremented each time
++ * UBI writes a new VID header to the flash, i.e. when it maps a logical
++ * eraseblock to a new physical eraseblock. The global sequence counter is an
++ * unsigned 64-bit integer and we assume it never overflows. The @sqnum
++ * (sequence number) is used to distinguish between older and newer versions of
++ * logical eraseblocks.
++ *
++ * There are 2 situations when there may be more then one physical eraseblock
++ * corresponding to the same logical eraseblock, i.e., having the same @vol_id
++ * and @lnum values in the volume identifier header. Suppose we have a logical
++ * eraseblock L and it is mapped to the physical eraseblock P.
++ *
++ * 1. Because UBI may erase physical eraseblocks asynchronously, the following
++ * situation is possible: L is asynchronously erased, so P is scheduled for
++ * erasure, then L is written to,i.e. mapped to another physical eraseblock P1,
++ * so P1 is written to, then an unclean reboot happens. Result - there are 2
++ * physical eraseblocks P and P1 corresponding to the same logical eraseblock
++ * L. But P1 has greater sequence number, so UBI picks P1 when it attaches the
++ * flash.
++ *
++ * 2. From time to time UBI moves logical eraseblocks to other physical
++ * eraseblocks for wear-leveling reasons. If, for example, UBI moves L from P
++ * to P1, and an unclean reboot happens before P is physically erased, there
++ * are two physical eraseblocks P and P1 corresponding to L and UBI has to
++ * select one of them when the flash is attached. The @sqnum field says which
++ * PEB is the original (obviously P will have lower @sqnum) and the copy. But
++ * it is not enough to select the physical eraseblock with the higher sequence
++ * number, because the unclean reboot could have happen in the middle of the
++ * copying process, so the data in P is corrupted. It is also not enough to
++ * just select the physical eraseblock with lower sequence number, because the
++ * data there may be old (consider a case if more data was added to P1 after
++ * the copying). Moreover, the unclean reboot may happen when the erasure of P
++ * was just started, so it result in unstable P, which is "mostly" OK, but
++ * still has unstable bits.
++ *
++ * UBI uses the @copy_flag field to indicate that this logical eraseblock is a
++ * copy. UBI also calculates data CRC when the data is moved and stores it at
++ * the @data_crc field of the copy (P1). So when UBI needs to pick one physical
++ * eraseblock of two (P or P1), the @copy_flag of the newer one (P1) is
++ * examined. If it is cleared, the situation* is simple and the newer one is
++ * picked. If it is set, the data CRC of the copy (P1) is examined. If the CRC
++ * checksum is correct, this physical eraseblock is selected (P1). Otherwise
++ * the older one (P) is selected.
++ *
++ * There are 2 sorts of volumes in UBI: user volumes and internal volumes.
++ * Internal volumes are not seen from outside and are used for various internal
++ * UBI purposes. In this implementation there is only one internal volume - the
++ * layout volume. Internal volumes are the main mechanism of UBI extensions.
++ * For example, in future one may introduce a journal internal volume. Internal
++ * volumes have their own reserved range of IDs.
++ *
++ * The @compat field is only used for internal volumes and contains the "degree
++ * of their compatibility". It is always zero for user volumes. This field
++ * provides a mechanism to introduce UBI extensions and to be still compatible
++ * with older UBI binaries. For example, if someone introduced a journal in
++ * future, he would probably use %UBI_COMPAT_DELETE compatibility for the
++ * journal volume.  And in this case, older UBI binaries, which know nothing
++ * about the journal volume, would just delete this volume and work perfectly
++ * fine. This is similar to what Ext2fs does when it is fed by an Ext3fs image
++ * - it just ignores the Ext3fs journal.
++ *
++ * The @data_crc field contains the CRC checksum of the contents of the logical
++ * eraseblock if this is a static volume. In case of dynamic volumes, it does
++ * not contain the CRC checksum as a rule. The only exception is when the
++ * data of the physical eraseblock was moved by the wear-leveling sub-system,
++ * then the wear-leveling sub-system calculates the data CRC and stores it in
++ * the @data_crc field. And of course, the @copy_flag is %in this case.
++ *
++ * The @data_size field is used only for static volumes because UBI has to know
++ * how many bytes of data are stored in this eraseblock. For dynamic volumes,
++ * this field usually contains zero. The only exception is when the data of the
++ * physical eraseblock was moved to another physical eraseblock for
++ * wear-leveling reasons. In this case, UBI calculates CRC checksum of the
++ * contents and uses both @data_crc and @data_size fields. In this case, the
++ * @data_size field contains data size.
++ *
++ * The @used_ebs field is used only for static volumes and indicates how many
++ * eraseblocks the data of the volume takes. For dynamic volumes this field is
++ * not used and always contains zero.
++ *
++ * The @data_pad is calculated when volumes are created using the alignment
++ * parameter. So, effectively, the @data_pad field reduces the size of logical
++ * eraseblocks of this volume. This is very handy when one uses block-oriented
++ * software (say, cramfs) on top of the UBI volume.
++ */
++struct ubi_vid_hdr {
++	__be32  magic;
++	__u8    version;
++	__u8    vol_type;
++	__u8    copy_flag;
++	__u8    compat;
++	__be32  vol_id;
++	__be32  lnum;
++	__u8    padding1[4];
++	__be32  data_size;
++	__be32  used_ebs;
++	__be32  data_pad;
++	__be32  data_crc;
++	__u8    padding2[4];
++	__be64  sqnum;
++	__u8    padding3[12];
++	__be32  hdr_crc;
++} __attribute__ ((packed));
++
++/* Internal UBI volumes count */
++#define UBI_INT_VOL_COUNT 1
++
++/*
++ * Starting ID of internal volumes. There is reserved room for 4096 internal
++ * volumes.
++ */
++#define UBI_INTERNAL_VOL_START (0x7FFFFFFF - 4096)
++
++/* The layout volume contains the volume table */
++
++#define UBI_LAYOUT_VOLUME_ID     UBI_INTERNAL_VOL_START
++#define UBI_LAYOUT_VOLUME_TYPE   UBI_VID_DYNAMIC
++#define UBI_LAYOUT_VOLUME_ALIGN  1
++#define UBI_LAYOUT_VOLUME_EBS    2
++#define UBI_LAYOUT_VOLUME_NAME   "layout volume"
++#define UBI_LAYOUT_VOLUME_COMPAT UBI_COMPAT_REJECT
++
++/* The maximum number of volumes per one UBI device */
++#define UBI_MAX_VOLUMES 128
++
++/* The maximum volume name length */
++#define UBI_VOL_NAME_MAX 127
++
++/* Size of the volume table record */
++#define UBI_VTBL_RECORD_SIZE sizeof(struct ubi_vtbl_record)
++
++/* Size of the volume table record without the ending CRC */
++#define UBI_VTBL_RECORD_SIZE_CRC (UBI_VTBL_RECORD_SIZE - sizeof(__be32))
++
++/**
++ * struct ubi_vtbl_record - a record in the volume table.
++ * @reserved_pebs: how many physical eraseblocks are reserved for this volume
++ * @alignment: volume alignment
++ * @data_pad: how many bytes are unused at the end of the each physical
++ * eraseblock to satisfy the requested alignment
++ * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
++ * @upd_marker: if volume update was started but not finished
++ * @name_len: volume name length
++ * @name: the volume name
++ * @flags: volume flags (%UBI_VTBL_AUTORESIZE_FLG)
++ * @padding: reserved, zeroes
++ * @crc: a CRC32 checksum of the record
++ *
++ * The volume table records are stored in the volume table, which is stored in
++ * the layout volume. The layout volume consists of 2 logical eraseblock, each
++ * of which contains a copy of the volume table (i.e., the volume table is
++ * duplicated). The volume table is an array of &struct ubi_vtbl_record
++ * objects indexed by the volume ID.
++ *
++ * If the size of the logical eraseblock is large enough to fit
++ * %UBI_MAX_VOLUMES records, the volume table contains %UBI_MAX_VOLUMES
++ * records. Otherwise, it contains as many records as it can fit (i.e., size of
++ * logical eraseblock divided by sizeof(struct ubi_vtbl_record)).
++ *
++ * The @upd_marker flag is used to implement volume update. It is set to %1
++ * before update and set to %0 after the update. So if the update operation was
++ * interrupted, UBI knows that the volume is corrupted.
++ *
++ * The @alignment field is specified when the volume is created and cannot be
++ * later changed. It may be useful, for example, when a block-oriented file
++ * system works on top of UBI. The @data_pad field is calculated using the
++ * logical eraseblock size and @alignment. The alignment must be multiple to the
++ * minimal flash I/O unit. If @alignment is 1, all the available space of
++ * the physical eraseblocks is used.
++ *
++ * Empty records contain all zeroes and the CRC checksum of those zeroes.
++ */
++struct ubi_vtbl_record {
++	__be32  reserved_pebs;
++	__be32  alignment;
++	__be32  data_pad;
++	__u8    vol_type;
++	__u8    upd_marker;
++	__be16  name_len;
++	__u8    name[UBI_VOL_NAME_MAX+1];
++	__u8    flags;
++	__u8    padding[23];
++	__be32  crc;
++} __attribute__ ((packed));
++
++#endif /* !__UBI_MEDIA_H__ */
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/ubi.h linux-2.6.24/drivers/mtd/ubi/ubi.h
+--- linux-2.6.24.orig/drivers/mtd/ubi/ubi.h	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/ubi.h	2009-04-17 09:49:26.000000000 +0200
+@@ -37,10 +37,9 @@
+ #include <linux/string.h>
+ #include <linux/vmalloc.h>
+ #include <linux/mtd/mtd.h>
+-
+-#include <mtd/ubi-header.h>
+ #include <linux/mtd/ubi.h>
+ 
++#include "ubi-media.h"
+ #include "scan.h"
+ #include "debug.h"
+ 
+@@ -75,15 +74,22 @@
+ #define UBI_IO_RETRIES 3
+ 
+ /*
+- * Error codes returned by the I/O unit.
++ * Length of the protection queue. The length is effectively equivalent to the
++ * number of (global) erase cycles PEBs are protected from the wear-leveling
++ * worker.
++ */
++#define UBI_PROT_QUEUE_LEN 10
++
++/*
++ * Error codes returned by the I/O sub-system.
+  *
+  * UBI_IO_PEB_EMPTY: the physical eraseblock is empty, i.e. it contains only
+- * 0xFF bytes
++ *                   %0xFF bytes
+  * UBI_IO_PEB_FREE: the physical eraseblock is free, i.e. it contains only a
+- * valid erase counter header, and the rest are %0xFF bytes
++ *                  valid erase counter header, and the rest are %0xFF bytes
+  * UBI_IO_BAD_EC_HDR: the erase counter header is corrupted (bad magic or CRC)
+  * UBI_IO_BAD_VID_HDR: the volume identifier header is corrupted (bad magic or
+- * CRC)
++ *                     CRC)
+  * UBI_IO_BITFLIPS: bit-flips were detected and corrected
+  */
+ enum {
+@@ -94,8 +100,68 @@
+ 	UBI_IO_BITFLIPS
+ };
+ 
+-extern int ubi_devices_cnt;
+-extern struct ubi_device *ubi_devices[];
++/**
++ * struct ubi_wl_entry - wear-leveling entry.
++ * @u.rb: link in the corresponding (free/used) RB-tree
++ * @u.list: link in the protection queue
++ * @ec: erase counter
++ * @pnum: physical eraseblock number
++ *
++ * This data structure is used in the WL sub-system. Each physical eraseblock
++ * has a corresponding &struct wl_entry object which may be kept in different
++ * RB-trees. See WL sub-system for details.
++ */
++struct ubi_wl_entry {
++	union {
++		struct rb_node rb;
++		struct list_head list;
++	} u;
++	int ec;
++	int pnum;
++};
++
++/**
++ * struct ubi_ltree_entry - an entry in the lock tree.
++ * @rb: links RB-tree nodes
++ * @vol_id: volume ID of the locked logical eraseblock
++ * @lnum: locked logical eraseblock number
++ * @users: how many tasks are using this logical eraseblock or wait for it
++ * @mutex: read/write mutex to implement read/write access serialization to
++ *         the (@vol_id, @lnum) logical eraseblock
++ *
++ * This data structure is used in the EBA sub-system to implement per-LEB
++ * locking. When a logical eraseblock is being locked - corresponding
++ * &struct ubi_ltree_entry object is inserted to the lock tree (@ubi->ltree).
++ * See EBA sub-system for details.
++ */
++struct ubi_ltree_entry {
++	struct rb_node rb;
++	int vol_id;
++	int lnum;
++	int users;
++	struct rw_semaphore mutex;
++};
++
++/**
++ * struct ubi_rename_entry - volume re-name description data structure.
++ * @new_name_len: new volume name length
++ * @new_name: new volume name
++ * @remove: if not zero, this volume should be removed, not re-named
++ * @desc: descriptor of the volume
++ * @list: links re-name entries into a list
++ *
++ * This data structure is utilized in the multiple volume re-name code. Namely,
++ * UBI first creates a list of &struct ubi_rename_entry objects from the
++ * &struct ubi_rnvol_req request object, and then utilizes this list to do all
++ * the job.
++ */
++struct ubi_rename_entry {
++	int new_name_len;
++	char new_name[UBI_VOL_NAME_MAX + 1];
++	int remove;
++	struct ubi_volume_desc *desc;
++	struct list_head list;
++};
+ 
+ struct ubi_volume_desc;
+ 
+@@ -105,11 +171,10 @@
+  * @cdev: character device object to create character device
+  * @ubi: reference to the UBI device description object
+  * @vol_id: volume ID
++ * @ref_count: volume reference count
+  * @readers: number of users holding this volume in read-only mode
+  * @writers: number of users holding this volume in read-write mode
+  * @exclusive: whether somebody holds this volume in exclusive mode
+- * @removed: if the volume was removed
+- * @checked: if this static volume was checked
+  *
+  * @reserved_pebs: how many physical eraseblocks are reserved for this volume
+  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
+@@ -117,21 +182,30 @@
+  * @used_ebs: how many logical eraseblocks in this volume contain data
+  * @last_eb_bytes: how many bytes are stored in the last logical eraseblock
+  * @used_bytes: how many bytes of data this volume contains
+- * @upd_marker: non-zero if the update marker is set for this volume
+- * @corrupted: non-zero if the volume is corrupted (static volumes only)
+  * @alignment: volume alignment
+  * @data_pad: how many bytes are not used at the end of physical eraseblocks to
+- * satisfy the requested alignment
++ *            satisfy the requested alignment
+  * @name_len: volume name length
+  * @name: volume name
+  *
+- * @updating: whether the volume is being updated
+  * @upd_ebs: how many eraseblocks are expected to be updated
+- * @upd_bytes: how many bytes are expected to be received
+- * @upd_received: how many update bytes were already received
+- * @upd_buf: update buffer which is used to collect update data
++ * @ch_lnum: LEB number which is being changing by the atomic LEB change
++ *           operation
++ * @ch_dtype: data persistency type which is being changing by the atomic LEB
++ *            change operation
++ * @upd_bytes: how many bytes are expected to be received for volume update or
++ *             atomic LEB change
++ * @upd_received: how many bytes were already received for volume update or
++ *                atomic LEB change
++ * @upd_buf: update buffer which is used to collect update data or data for
++ *           atomic LEB change
+  *
+  * @eba_tbl: EBA table of this volume (LEB->PEB mapping)
++ * @checked: %1 if this static volume was checked
++ * @corrupted: %1 if the volume is corrupted (static volumes only)
++ * @upd_marker: %1 if the update marker is set for this volume
++ * @updating: %1 if the volume is being updated
++ * @changing_leb: %1 if the atomic LEB change ioctl command is in progress
+  *
+  * @gluebi_desc: gluebi UBI volume descriptor
+  * @gluebi_refcount: reference count of the gluebi MTD device
+@@ -150,11 +224,10 @@
+ 	struct cdev cdev;
+ 	struct ubi_device *ubi;
+ 	int vol_id;
++	int ref_count;
+ 	int readers;
+ 	int writers;
+ 	int exclusive;
+-	int removed;
+-	int checked;
+ 
+ 	int reserved_pebs;
+ 	int vol_type;
+@@ -162,23 +235,31 @@
+ 	int used_ebs;
+ 	int last_eb_bytes;
+ 	long long used_bytes;
+-	int upd_marker;
+-	int corrupted;
+ 	int alignment;
+ 	int data_pad;
+ 	int name_len;
+-	char name[UBI_VOL_NAME_MAX+1];
++	char name[UBI_VOL_NAME_MAX + 1];
+ 
+-	int updating;
+ 	int upd_ebs;
++	int ch_lnum;
++	int ch_dtype;
+ 	long long upd_bytes;
+ 	long long upd_received;
+ 	void *upd_buf;
+ 
+ 	int *eba_tbl;
++	unsigned int checked:1;
++	unsigned int corrupted:1;
++	unsigned int upd_marker:1;
++	unsigned int updating:1;
++	unsigned int changing_leb:1;
+ 
+ #ifdef CONFIG_MTD_UBI_GLUEBI
+-	/* Gluebi-related stuff may be compiled out */
++	/*
++	 * Gluebi-related stuff may be compiled out.
++	 * Note: this should not be built into UBI but should be a separate
++	 * ubimtd driver which works on top of UBI and emulates MTD devices.
++	 */
+ 	struct ubi_volume_desc *gluebi_desc;
+ 	int gluebi_refcount;
+ 	struct mtd_info gluebi_mtd;
+@@ -186,8 +267,7 @@
+ };
+ 
+ /**
+- * struct ubi_volume_desc - descriptor of the UBI volume returned when it is
+- * opened.
++ * struct ubi_volume_desc - UBI volume descriptor returned when it is opened.
+  * @vol: reference to the corresponding volume description object
+  * @mode: open mode (%UBI_READONLY, %UBI_READWRITE, or %UBI_EXCLUSIVE)
+  */
+@@ -200,28 +280,31 @@
+ 
+ /**
+  * struct ubi_device - UBI device description structure
+- * @dev: class device object to use the the Linux device model
++ * @dev: UBI device object to use the the Linux device model
+  * @cdev: character device object to create character device
+  * @ubi_num: UBI device number
+  * @ubi_name: UBI device name
+- * @major: character device major number
+  * @vol_count: number of volumes in this UBI device
+  * @volumes: volumes of this UBI device
+  * @volumes_lock: protects @volumes, @rsvd_pebs, @avail_pebs, beb_rsvd_pebs,
+- * @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count, @vol->readers,
+- * @vol->writers, @vol->exclusive, @vol->removed, @vol->mapping and
+- * @vol->eba_tbl.
++ *                @beb_rsvd_level, @bad_peb_count, @good_peb_count, @vol_count,
++ *                @vol->readers, @vol->writers, @vol->exclusive,
++ *                @vol->ref_count, @vol->mapping and @vol->eba_tbl.
++ * @ref_count: count of references on the UBI device
+  *
+  * @rsvd_pebs: count of reserved physical eraseblocks
+  * @avail_pebs: count of available physical eraseblocks
+  * @beb_rsvd_pebs: how many physical eraseblocks are reserved for bad PEB
+- * handling
++ *                 handling
+  * @beb_rsvd_level: normal level of PEBs reserved for bad PEB handling
+  *
++ * @autoresize_vol_id: ID of the volume which has to be auto-resized at the end
++ *                     of UBI initialization
+  * @vtbl_slots: how many slots are available in the volume table
+  * @vtbl_size: size of the volume table in bytes
+  * @vtbl: in-RAM volume table copy
+- * @vtbl_mutex: protects on-flash volume table
++ * @volumes_mutex: protects on-flash volume table and serializes volume
++ *                 changes, like creation, deletion, update, re-size and re-name
+  *
+  * @max_ec: current highest erase counter value
+  * @mean_ec: current mean erase counter value
+@@ -234,19 +317,19 @@
+  * @used: RB-tree of used physical eraseblocks
+  * @free: RB-tree of free physical eraseblocks
+  * @scrub: RB-tree of physical eraseblocks which need scrubbing
+- * @prot: protection trees
+- * @prot.pnum: protection tree indexed by physical eraseblock numbers
+- * @prot.aec: protection tree indexed by absolute erase counter value
+- * @wl_lock: protects the @used, @free, @prot, @lookuptbl, @abs_ec, @move_from,
+- * @move_to, @move_to_put @erase_pending, @wl_scheduled, and @works
+- * fields
++ * @pq: protection queue (contain physical eraseblocks which are temporarily
++ *      protected from the wear-leveling worker)
++ * @pq_head: protection queue head
++ * @wl_lock: protects the @used, @free, @pq, @pq_head, @lookuptbl, @move_from,
++ * 	     @move_to, @move_to_put @erase_pending, @wl_scheduled and @works
++ * 	     fields
++ * @move_mutex: serializes eraseblock moves
++ * @work_sem: synchronizes the WL worker with use tasks
+  * @wl_scheduled: non-zero if the wear-leveling was scheduled
+  * @lookuptbl: a table to quickly find a &struct ubi_wl_entry object for any
+- * physical eraseblock
+- * @abs_ec: absolute erase counter
++ *             physical eraseblock
+  * @move_from: physical eraseblock from where the data is being moved
+  * @move_to: physical eraseblock where the data is being moved to
+- * @move_from_put: if the "from" PEB was put
+  * @move_to_put: if the "to" PEB was put
+  * @works: list of pending works
+  * @works_count: count of pending works
+@@ -264,68 +347,70 @@
+  * @ro_mode: if the UBI device is in read-only mode
+  * @leb_size: logical eraseblock size
+  * @leb_start: starting offset of logical eraseblocks within physical
+- * eraseblocks
++ *             eraseblocks
+  * @ec_hdr_alsize: size of the EC header aligned to @hdrs_min_io_size
+  * @vid_hdr_alsize: size of the VID header aligned to @hdrs_min_io_size
+  * @vid_hdr_offset: starting offset of the volume identifier header (might be
+- * unaligned)
++ *                  unaligned)
+  * @vid_hdr_aloffset: starting offset of the VID header aligned to
+  * @hdrs_min_io_size
+  * @vid_hdr_shift: contains @vid_hdr_offset - @vid_hdr_aloffset
+  * @bad_allowed: whether the MTD device admits of bad physical eraseblocks or
+- * not
++ *               not
+  * @mtd: MTD device descriptor
+  *
+  * @peb_buf1: a buffer of PEB size used for different purposes
+  * @peb_buf2: another buffer of PEB size used for different purposes
+- * @buf_mutex: proptects @peb_buf1 and @peb_buf2
+- * @dbg_peb_buf:  buffer of PEB size used for debugging
+- * @dbg_buf_mutex: proptects @dbg_peb_buf
++ * @buf_mutex: protects @peb_buf1 and @peb_buf2
++ * @ckvol_mutex: serializes static volume checking when opening
++ * @mult_mutex: serializes operations on multiple volumes, like re-naming
++ * @dbg_peb_buf: buffer of PEB size used for debugging
++ * @dbg_buf_mutex: protects @dbg_peb_buf
+  */
+ struct ubi_device {
+ 	struct cdev cdev;
+ 	struct device dev;
+ 	int ubi_num;
+ 	char ubi_name[sizeof(UBI_NAME_STR)+5];
+-	int major;
+ 	int vol_count;
+ 	struct ubi_volume *volumes[UBI_MAX_VOLUMES+UBI_INT_VOL_COUNT];
+ 	spinlock_t volumes_lock;
++	int ref_count;
+ 
+ 	int rsvd_pebs;
+ 	int avail_pebs;
+ 	int beb_rsvd_pebs;
+ 	int beb_rsvd_level;
+ 
++	int autoresize_vol_id;
+ 	int vtbl_slots;
+ 	int vtbl_size;
+ 	struct ubi_vtbl_record *vtbl;
+-	struct mutex vtbl_mutex;
++	struct mutex volumes_mutex;
+ 
+ 	int max_ec;
++	/* Note, mean_ec is not updated run-time - should be fixed */
+ 	int mean_ec;
+ 
+-	/* EBA unit's stuff */
++	/* EBA sub-system's stuff */
+ 	unsigned long long global_sqnum;
+ 	spinlock_t ltree_lock;
+ 	struct rb_root ltree;
+ 	struct mutex alc_mutex;
+ 
+-	/* Wear-leveling unit's stuff */
++	/* Wear-leveling sub-system's stuff */
+ 	struct rb_root used;
+ 	struct rb_root free;
+ 	struct rb_root scrub;
+-	struct {
+-		struct rb_root pnum;
+-		struct rb_root aec;
+-	} prot;
++	struct list_head pq[UBI_PROT_QUEUE_LEN];
++	int pq_head;
+ 	spinlock_t wl_lock;
++	struct mutex move_mutex;
++	struct rw_semaphore work_sem;
+ 	int wl_scheduled;
+ 	struct ubi_wl_entry **lookuptbl;
+-	unsigned long long abs_ec;
+ 	struct ubi_wl_entry *move_from;
+ 	struct ubi_wl_entry *move_to;
+-	int move_from_put;
+ 	int move_to_put;
+ 	struct list_head works;
+ 	int works_count;
+@@ -333,7 +418,7 @@
+ 	int thread_enabled;
+ 	char bgt_name[sizeof(UBI_BGT_NAME_PATTERN)+2];
+ 
+-	/* I/O unit's stuff */
++	/* I/O sub-system's stuff */
+ 	long long flash_size;
+ 	int peb_count;
+ 	int peb_size;
+@@ -355,35 +440,49 @@
+ 	void *peb_buf1;
+ 	void *peb_buf2;
+ 	struct mutex buf_mutex;
++	struct mutex ckvol_mutex;
++	struct mutex mult_mutex;
+ #ifdef CONFIG_MTD_UBI_DEBUG
+ 	void *dbg_peb_buf;
+ 	struct mutex dbg_buf_mutex;
+ #endif
+ };
+ 
+-extern struct file_operations ubi_cdev_operations;
+-extern struct file_operations ubi_vol_cdev_operations;
++extern struct kmem_cache *ubi_wl_entry_slab;
++extern const struct file_operations ubi_ctrl_cdev_operations;
++extern const struct file_operations ubi_cdev_operations;
++extern const struct file_operations ubi_vol_cdev_operations;
+ extern struct class *ubi_class;
++extern struct mutex ubi_devices_mutex;
+ 
+ /* vtbl.c */
+ int ubi_change_vtbl_record(struct ubi_device *ubi, int idx,
+ 			   struct ubi_vtbl_record *vtbl_rec);
++int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
++			    struct list_head *rename_list);
+ int ubi_read_volume_table(struct ubi_device *ubi, struct ubi_scan_info *si);
+ 
+ /* vmt.c */
+ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req);
+-int ubi_remove_volume(struct ubi_volume_desc *desc);
++int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl);
+ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs);
+-int ubi_add_volume(struct ubi_device *ubi, int vol_id);
+-void ubi_free_volume(struct ubi_device *ubi, int vol_id);
++int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list);
++int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol);
++void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol);
+ 
+ /* upd.c */
+-int ubi_start_update(struct ubi_device *ubi, int vol_id, long long bytes);
+-int ubi_more_update_data(struct ubi_device *ubi, int vol_id,
++int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
++		     long long bytes);
++int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
+ 			 const void __user *buf, int count);
++int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
++			 const struct ubi_leb_change_req *req);
++int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
++			     const void __user *buf, int count);
+ 
+ /* misc.c */
+-int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf, int length);
++int ubi_calc_data_len(const struct ubi_device *ubi, const void *buf,
++		      int length);
+ int ubi_check_volume(struct ubi_device *ubi, int vol_id);
+ void ubi_calculate_reserved(struct ubi_device *ubi);
+ 
+@@ -399,20 +498,20 @@
+ #endif
+ 
+ /* eba.c */
+-int ubi_eba_unmap_leb(struct ubi_device *ubi, int vol_id, int lnum);
+-int ubi_eba_read_leb(struct ubi_device *ubi, int vol_id, int lnum, void *buf,
+-		     int offset, int len, int check);
+-int ubi_eba_write_leb(struct ubi_device *ubi, int vol_id, int lnum,
++int ubi_eba_unmap_leb(struct ubi_device *ubi, struct ubi_volume *vol,
++		      int lnum);
++int ubi_eba_read_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
++		     void *buf, int offset, int len, int check);
++int ubi_eba_write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
+ 		      const void *buf, int offset, int len, int dtype);
+-int ubi_eba_write_leb_st(struct ubi_device *ubi, int vol_id, int lnum,
+-			 const void *buf, int len, int dtype,
++int ubi_eba_write_leb_st(struct ubi_device *ubi, struct ubi_volume *vol,
++			 int lnum, const void *buf, int len, int dtype,
+ 			 int used_ebs);
+-int ubi_eba_atomic_leb_change(struct ubi_device *ubi, int vol_id, int lnum,
+-			      const void *buf, int len, int dtype);
++int ubi_eba_atomic_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
++			      int lnum, const void *buf, int len, int dtype);
+ int ubi_eba_copy_leb(struct ubi_device *ubi, int from, int to,
+ 		     struct ubi_vid_hdr *vid_hdr);
+ int ubi_eba_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
+-void ubi_eba_close(const struct ubi_device *ubi);
+ 
+ /* wl.c */
+ int ubi_wl_get_peb(struct ubi_device *ubi, int dtype);
+@@ -421,6 +520,7 @@
+ int ubi_wl_scrub_peb(struct ubi_device *ubi, int pnum);
+ int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si);
+ void ubi_wl_close(struct ubi_device *ubi);
++int ubi_thread(void *u);
+ 
+ /* io.c */
+ int ubi_io_read(const struct ubi_device *ubi, void *buf, int pnum, int offset,
+@@ -439,6 +539,14 @@
+ int ubi_io_write_vid_hdr(struct ubi_device *ubi, int pnum,
+ 			 struct ubi_vid_hdr *vid_hdr);
+ 
++/* build.c */
++int ubi_attach_mtd_dev(struct mtd_info *mtd, int ubi_num, int vid_hdr_offset);
++int ubi_detach_mtd_dev(int ubi_num, int anyway);
++struct ubi_device *ubi_get_device(int ubi_num);
++void ubi_put_device(struct ubi_device *ubi);
++struct ubi_device *ubi_get_by_major(int major);
++int ubi_major2num(int major);
++
+ /*
+  * ubi_rb_for_each_entry - walk an RB-tree.
+  * @rb: a pointer to type 'struct rb_node' to to use as a loop counter
+@@ -523,8 +631,10 @@
+  */
+ static inline void ubi_ro_mode(struct ubi_device *ubi)
+ {
+-	ubi->ro_mode = 1;
+-	ubi_warn("switch to read-only mode");
++	if (!ubi->ro_mode) {
++		ubi->ro_mode = 1;
++		ubi_warn("switch to read-only mode");
++	}
+ }
+ 
+ /**
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/upd.c linux-2.6.24/drivers/mtd/ubi/upd.c
+--- linux-2.6.24.orig/drivers/mtd/ubi/upd.c	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/upd.c	2009-04-17 09:49:26.000000000 +0200
+@@ -22,7 +22,8 @@
+  */
+ 
+ /*
+- * This file contains implementation of the volume update functionality.
++ * This file contains implementation of the volume update and atomic LEB change
++ * functionality.
+  *
+  * The update operation is based on the per-volume update marker which is
+  * stored in the volume table. The update marker is set before the update
+@@ -38,36 +39,37 @@
+  */
+ 
+ #include <linux/err.h>
+-#include <asm/uaccess.h>
+-#include <asm/div64.h>
++#include <linux/uaccess.h>
+ #include "ubi.h"
+ 
+ /**
+  * set_update_marker - set update marker.
+  * @ubi: UBI device description object
+- * @vol_id: volume ID
++ * @vol: volume description object
+  *
+- * This function sets the update marker flag for volume @vol_id. Returns zero
++ * This function sets the update marker flag for volume @vol. Returns zero
+  * in case of success and a negative error code in case of failure.
+  */
+-static int set_update_marker(struct ubi_device *ubi, int vol_id)
++static int set_update_marker(struct ubi_device *ubi, struct ubi_volume *vol)
+ {
+ 	int err;
+ 	struct ubi_vtbl_record vtbl_rec;
+-	struct ubi_volume *vol = ubi->volumes[vol_id];
+ 
+-	dbg_msg("set update marker for volume %d", vol_id);
++	dbg_gen("set update marker for volume %d", vol->vol_id);
+ 
+ 	if (vol->upd_marker) {
+-		ubi_assert(ubi->vtbl[vol_id].upd_marker);
+-		dbg_msg("already set");
++		ubi_assert(ubi->vtbl[vol->vol_id].upd_marker);
++		dbg_gen("already set");
+ 		return 0;
+ 	}
+ 
+-	memcpy(&vtbl_rec, &ubi->vtbl[vol_id], sizeof(struct ubi_vtbl_record));
++	memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id],
++	       sizeof(struct ubi_vtbl_record));
+ 	vtbl_rec.upd_marker = 1;
+ 
+-	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
++	mutex_lock(&ubi->volumes_mutex);
++	err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
++	mutex_unlock(&ubi->volumes_mutex);
+ 	vol->upd_marker = 1;
+ 	return err;
+ }
+@@ -75,38 +77,40 @@
+ /**
+  * clear_update_marker - clear update marker.
+  * @ubi: UBI device description object
+- * @vol_id: volume ID
++ * @vol: volume description object
+  * @bytes: new data size in bytes
+  *
+- * This function clears the update marker for volume @vol_id, sets new volume
++ * This function clears the update marker for volume @vol, sets new volume
+  * data size and clears the "corrupted" flag (static volumes only). Returns
+  * zero in case of success and a negative error code in case of failure.
+  */
+-static int clear_update_marker(struct ubi_device *ubi, int vol_id, long long bytes)
++static int clear_update_marker(struct ubi_device *ubi, struct ubi_volume *vol,
++			       long long bytes)
+ {
+ 	int err;
+-	uint64_t tmp;
+ 	struct ubi_vtbl_record vtbl_rec;
+-	struct ubi_volume *vol = ubi->volumes[vol_id];
+ 
+-	dbg_msg("clear update marker for volume %d", vol_id);
++	dbg_gen("clear update marker for volume %d", vol->vol_id);
+ 
+-	memcpy(&vtbl_rec, &ubi->vtbl[vol_id], sizeof(struct ubi_vtbl_record));
++	memcpy(&vtbl_rec, &ubi->vtbl[vol->vol_id],
++	       sizeof(struct ubi_vtbl_record));
+ 	ubi_assert(vol->upd_marker && vtbl_rec.upd_marker);
+ 	vtbl_rec.upd_marker = 0;
+ 
+ 	if (vol->vol_type == UBI_STATIC_VOLUME) {
+ 		vol->corrupted = 0;
+-		vol->used_bytes = tmp = bytes;
+-		vol->last_eb_bytes = do_div(tmp, vol->usable_leb_size);
+-		vol->used_ebs = tmp;
++		vol->used_bytes = bytes;
++		vol->used_ebs = div_u64_rem(bytes, vol->usable_leb_size,
++					    &vol->last_eb_bytes);
+ 		if (vol->last_eb_bytes)
+ 			vol->used_ebs += 1;
+ 		else
+ 			vol->last_eb_bytes = vol->usable_leb_size;
+ 	}
+ 
+-	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
++	mutex_lock(&ubi->volumes_mutex);
++	err = ubi_change_vtbl_record(ubi, vol->vol_id, &vtbl_rec);
++	mutex_unlock(&ubi->volumes_mutex);
+ 	vol->upd_marker = 0;
+ 	return err;
+ }
+@@ -114,35 +118,35 @@
+ /**
+  * ubi_start_update - start volume update.
+  * @ubi: UBI device description object
+- * @vol_id: volume ID
++ * @vol: volume description object
+  * @bytes: update bytes
+  *
+  * This function starts volume update operation. If @bytes is zero, the volume
+  * is just wiped out. Returns zero in case of success and a negative error code
+  * in case of failure.
+  */
+-int ubi_start_update(struct ubi_device *ubi, int vol_id, long long bytes)
++int ubi_start_update(struct ubi_device *ubi, struct ubi_volume *vol,
++		     long long bytes)
+ {
+ 	int i, err;
+-	uint64_t tmp;
+-	struct ubi_volume *vol = ubi->volumes[vol_id];
+ 
+-	dbg_msg("start update of volume %d, %llu bytes", vol_id, bytes);
++	dbg_gen("start update of volume %d, %llu bytes", vol->vol_id, bytes);
++	ubi_assert(!vol->updating && !vol->changing_leb);
+ 	vol->updating = 1;
+ 
+-	err = set_update_marker(ubi, vol_id);
++	err = set_update_marker(ubi, vol);
+ 	if (err)
+ 		return err;
+ 
+ 	/* Before updating - wipe out the volume */
+ 	for (i = 0; i < vol->reserved_pebs; i++) {
+-		err = ubi_eba_unmap_leb(ubi, vol_id, i);
++		err = ubi_eba_unmap_leb(ubi, vol, i);
+ 		if (err)
+ 			return err;
+ 	}
+ 
+ 	if (bytes == 0) {
+-		err = clear_update_marker(ubi, vol_id, 0);
++		err = clear_update_marker(ubi, vol, 0);
+ 		if (err)
+ 			return err;
+ 		err = ubi_wl_flush(ubi);
+@@ -154,18 +158,50 @@
+ 	if (!vol->upd_buf)
+ 		return -ENOMEM;
+ 
+-	tmp = bytes;
+-	vol->upd_ebs = !!do_div(tmp, vol->usable_leb_size);
+-	vol->upd_ebs += tmp;
++	vol->upd_ebs = div_u64(bytes + vol->usable_leb_size - 1,
++			       vol->usable_leb_size);
+ 	vol->upd_bytes = bytes;
+ 	vol->upd_received = 0;
+ 	return 0;
+ }
+ 
+ /**
++ * ubi_start_leb_change - start atomic LEB change.
++ * @ubi: UBI device description object
++ * @vol: volume description object
++ * @req: operation request
++ *
++ * This function starts atomic LEB change operation. Returns zero in case of
++ * success and a negative error code in case of failure.
++ */
++int ubi_start_leb_change(struct ubi_device *ubi, struct ubi_volume *vol,
++			 const struct ubi_leb_change_req *req)
++{
++	ubi_assert(!vol->updating && !vol->changing_leb);
++
++	dbg_gen("start changing LEB %d:%d, %u bytes",
++		vol->vol_id, req->lnum, req->bytes);
++	if (req->bytes == 0)
++		return ubi_eba_atomic_leb_change(ubi, vol, req->lnum, NULL, 0,
++						 req->dtype);
++
++	vol->upd_bytes = req->bytes;
++	vol->upd_received = 0;
++	vol->changing_leb = 1;
++	vol->ch_lnum = req->lnum;
++	vol->ch_dtype = req->dtype;
++
++	vol->upd_buf = vmalloc(req->bytes);
++	if (!vol->upd_buf)
++		return -ENOMEM;
++
++	return 0;
++}
++
++/**
+  * write_leb - write update data.
+  * @ubi: UBI device description object
+- * @vol_id: volume ID
++ * @vol: volume description object
+  * @lnum: logical eraseblock number
+  * @buf: data to write
+  * @len: data size
+@@ -191,25 +227,22 @@
+  * This function returns zero in case of success and a negative error code in
+  * case of failure.
+  */
+-static int write_leb(struct ubi_device *ubi, int vol_id, int lnum, void *buf,
+-		     int len, int used_ebs)
++static int write_leb(struct ubi_device *ubi, struct ubi_volume *vol, int lnum,
++		     void *buf, int len, int used_ebs)
+ {
+-	int err, l;
+-	struct ubi_volume *vol = ubi->volumes[vol_id];
++	int err;
+ 
+ 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
+-		l = ALIGN(len, ubi->min_io_size);
+-		memset(buf + len, 0xFF, l - len);
++		int l = ALIGN(len, ubi->min_io_size);
+ 
+-		l = ubi_calc_data_len(ubi, buf, l);
+-		if (l == 0) {
+-			dbg_msg("all %d bytes contain 0xFF - skip", len);
++		memset(buf + len, 0xFF, l - len);
++		len = ubi_calc_data_len(ubi, buf, l);
++		if (len == 0) {
++			dbg_gen("all %d bytes contain 0xFF - skip", len);
+ 			return 0;
+ 		}
+-		if (len != l)
+-			dbg_msg("skip last %d bytes (0xFF)", len - l);
+ 
+-		err = ubi_eba_write_leb(ubi, vol_id, lnum, buf, 0, l,
++		err = ubi_eba_write_leb(ubi, vol, lnum, buf, 0, len,
+ 					UBI_UNKNOWN);
+ 	} else {
+ 		/*
+@@ -222,7 +255,7 @@
+ 		 * contain zeros, not random trash.
+ 		 */
+ 		memset(buf + len, 0, vol->usable_leb_size - len);
+-		err = ubi_eba_write_leb_st(ubi, vol_id, lnum, buf, len,
++		err = ubi_eba_write_leb_st(ubi, vol, lnum, buf, len,
+ 					   UBI_UNKNOWN, used_ebs);
+ 	}
+ 
+@@ -231,33 +264,29 @@
+ 
+ /**
+  * ubi_more_update_data - write more update data.
++ * @ubi: UBI device description object
+  * @vol: volume description object
+  * @buf: write data (user-space memory buffer)
+  * @count: how much bytes to write
+  *
+  * This function writes more data to the volume which is being updated. It may
+- * be called arbitrary number of times until all of the update data arrive.
+- * This function returns %0 in case of success, number of bytes written during
+- * the last call if the whole volume update was successfully finished, and a
++ * be called arbitrary number of times until all the update data arriveis. This
++ * function returns %0 in case of success, number of bytes written during the
++ * last call if the whole volume update has been successfully finished, and a
+  * negative error code in case of failure.
+  */
+-int ubi_more_update_data(struct ubi_device *ubi, int vol_id,
++int ubi_more_update_data(struct ubi_device *ubi, struct ubi_volume *vol,
+ 			 const void __user *buf, int count)
+ {
+-	uint64_t tmp;
+-	struct ubi_volume *vol = ubi->volumes[vol_id];
+ 	int lnum, offs, err = 0, len, to_write = count;
+ 
+-	dbg_msg("write %d of %lld bytes, %lld already passed",
++	dbg_gen("write %d of %lld bytes, %lld already passed",
+ 		count, vol->upd_bytes, vol->upd_received);
+ 
+ 	if (ubi->ro_mode)
+ 		return -EROFS;
+ 
+-	tmp = vol->upd_received;
+-	offs = do_div(tmp, vol->usable_leb_size);
+-	lnum = tmp;
+-
++	lnum = div_u64_rem(vol->upd_received,  vol->usable_leb_size, &offs);
+ 	if (vol->upd_received + count > vol->upd_bytes)
+ 		to_write = count = vol->upd_bytes - vol->upd_received;
+ 
+@@ -290,8 +319,8 @@
+ 			 * is the last chunk, it's time to flush the buffer.
+ 			 */
+ 			ubi_assert(flush_len <= vol->usable_leb_size);
+-			err = write_leb(ubi, vol_id, lnum, vol->upd_buf,
+-					flush_len, vol->upd_ebs);
++			err = write_leb(ubi, vol, lnum, vol->upd_buf, flush_len,
++					vol->upd_ebs);
+ 			if (err)
+ 				return err;
+ 		}
+@@ -318,8 +347,8 @@
+ 
+ 		if (len == vol->usable_leb_size ||
+ 		    vol->upd_received + len == vol->upd_bytes) {
+-			err = write_leb(ubi, vol_id, lnum, vol->upd_buf, len,
+-					vol->upd_ebs);
++			err = write_leb(ubi, vol, lnum, vol->upd_buf,
++					len, vol->upd_ebs);
+ 			if (err)
+ 				break;
+ 		}
+@@ -333,16 +362,72 @@
+ 	ubi_assert(vol->upd_received <= vol->upd_bytes);
+ 	if (vol->upd_received == vol->upd_bytes) {
+ 		/* The update is finished, clear the update marker */
+-		err = clear_update_marker(ubi, vol_id, vol->upd_bytes);
++		err = clear_update_marker(ubi, vol, vol->upd_bytes);
+ 		if (err)
+ 			return err;
+ 		err = ubi_wl_flush(ubi);
+ 		if (err == 0) {
++			vol->updating = 0;
+ 			err = to_write;
+ 			vfree(vol->upd_buf);
+-			vol->updating = 0;
+ 		}
+ 	}
+ 
+ 	return err;
+ }
++
++/**
++ * ubi_more_leb_change_data - accept more data for atomic LEB change.
++ * @ubi: UBI device description object
++ * @vol: volume description object
++ * @buf: write data (user-space memory buffer)
++ * @count: how much bytes to write
++ *
++ * This function accepts more data to the volume which is being under the
++ * "atomic LEB change" operation. It may be called arbitrary number of times
++ * until all data arrives. This function returns %0 in case of success, number
++ * of bytes written during the last call if the whole "atomic LEB change"
++ * operation has been successfully finished, and a negative error code in case
++ * of failure.
++ */
++int ubi_more_leb_change_data(struct ubi_device *ubi, struct ubi_volume *vol,
++			     const void __user *buf, int count)
++{
++	int err;
++
++	dbg_gen("write %d of %lld bytes, %lld already passed",
++		count, vol->upd_bytes, vol->upd_received);
++
++	if (ubi->ro_mode)
++		return -EROFS;
++
++	if (vol->upd_received + count > vol->upd_bytes)
++		count = vol->upd_bytes - vol->upd_received;
++
++	err = copy_from_user(vol->upd_buf + vol->upd_received, buf, count);
++	if (err)
++		return -EFAULT;
++
++	vol->upd_received += count;
++
++	if (vol->upd_received == vol->upd_bytes) {
++		int len = ALIGN((int)vol->upd_bytes, ubi->min_io_size);
++
++		memset(vol->upd_buf + vol->upd_bytes, 0xFF,
++		       len - vol->upd_bytes);
++		len = ubi_calc_data_len(ubi, vol->upd_buf, len);
++		err = ubi_eba_atomic_leb_change(ubi, vol, vol->ch_lnum,
++						vol->upd_buf, len, UBI_UNKNOWN);
++		if (err)
++			return err;
++	}
++
++	ubi_assert(vol->upd_received <= vol->upd_bytes);
++	if (vol->upd_received == vol->upd_bytes) {
++		vol->changing_leb = 0;
++		err = count;
++		vfree(vol->upd_buf);
++	}
++
++	return err;
++}
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/vmt.c linux-2.6.24/drivers/mtd/ubi/vmt.c
+--- linux-2.6.24.orig/drivers/mtd/ubi/vmt.c	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/vmt.c	2009-04-17 09:49:26.000000000 +0200
+@@ -24,13 +24,12 @@
+  */
+ 
+ #include <linux/err.h>
+-#include <asm/div64.h>
+ #include "ubi.h"
+ 
+ #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
+-static void paranoid_check_volumes(struct ubi_device *ubi);
++static int paranoid_check_volumes(struct ubi_device *ubi);
+ #else
+-#define paranoid_check_volumes(ubi)
++#define paranoid_check_volumes(ubi) 0
+ #endif
+ 
+ static ssize_t vol_attribute_show(struct device *dev,
+@@ -63,21 +62,30 @@
+  * B. process 2 removes volume Y;
+  * C. process 1 starts reading the /<sysfs>/class/ubi/ubiX_Y/reserved_ebs file;
+  *
+- * What we want to do in a situation like that is to return error when the file
+- * is read. This is done by means of the 'removed' flag and the 'vol_lock' of
+- * the UBI volume description object.
++ * In this situation, this function will return %-ENODEV because it will find
++ * out that the volume was removed from the @ubi->volumes array.
+  */
+ static ssize_t vol_attribute_show(struct device *dev,
+ 				  struct device_attribute *attr, char *buf)
+ {
+ 	int ret;
+ 	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
++	struct ubi_device *ubi;
+ 
+-	spin_lock(&vol->ubi->volumes_lock);
+-	if (vol->removed) {
+-		spin_unlock(&vol->ubi->volumes_lock);
++	ubi = ubi_get_device(vol->ubi->ubi_num);
++	if (!ubi)
++		return -ENODEV;
++
++	spin_lock(&ubi->volumes_lock);
++	if (!ubi->volumes[vol->vol_id]) {
++		spin_unlock(&ubi->volumes_lock);
++		ubi_put_device(ubi);
+ 		return -ENODEV;
+ 	}
++	/* Take a reference to prevent volume removal */
++	vol->ref_count += 1;
++	spin_unlock(&ubi->volumes_lock);
++
+ 	if (attr == &attr_vol_reserved_ebs)
+ 		ret = sprintf(buf, "%d\n", vol->reserved_pebs);
+ 	else if (attr == &attr_vol_type) {
+@@ -94,15 +102,22 @@
+ 		ret = sprintf(buf, "%d\n", vol->corrupted);
+ 	else if (attr == &attr_vol_alignment)
+ 		ret = sprintf(buf, "%d\n", vol->alignment);
+-	else if (attr == &attr_vol_usable_eb_size) {
++	else if (attr == &attr_vol_usable_eb_size)
+ 		ret = sprintf(buf, "%d\n", vol->usable_leb_size);
+-	} else if (attr == &attr_vol_data_bytes)
++	else if (attr == &attr_vol_data_bytes)
+ 		ret = sprintf(buf, "%lld\n", vol->used_bytes);
+ 	else if (attr == &attr_vol_upd_marker)
+ 		ret = sprintf(buf, "%d\n", vol->upd_marker);
+ 	else
+-		BUG();
+-	spin_unlock(&vol->ubi->volumes_lock);
++		/* This must be a bug */
++		ret = -EINVAL;
++
++	/* We've done the operation, drop volume and UBI device references */
++	spin_lock(&ubi->volumes_lock);
++	vol->ref_count -= 1;
++	ubi_assert(vol->ref_count >= 0);
++	spin_unlock(&ubi->volumes_lock);
++	ubi_put_device(ubi);
+ 	return ret;
+ }
+ 
+@@ -110,7 +125,8 @@
+ static void vol_release(struct device *dev)
+ {
+ 	struct ubi_volume *vol = container_of(dev, struct ubi_volume, dev);
+-	ubi_assert(vol->removed);
++
++	kfree(vol->eba_tbl);
+ 	kfree(vol);
+ }
+ 
+@@ -152,9 +168,7 @@
+ 	if (err)
+ 		return err;
+ 	err = device_create_file(&vol->dev, &attr_vol_upd_marker);
+-	if (err)
+-		return err;
+-	return 0;
++	return err;
+ }
+ 
+ /**
+@@ -180,16 +194,17 @@
+  * @req: volume creation request
+  *
+  * This function creates volume described by @req. If @req->vol_id id
+- * %UBI_VOL_NUM_AUTO, this function automatically assigne ID to the new volume
++ * %UBI_VOL_NUM_AUTO, this function automatically assign ID to the new volume
+  * and saves it in @req->vol_id. Returns zero in case of success and a negative
+- * error code in case of failure.
++ * error code in case of failure. Note, the caller has to have the
++ * @ubi->volumes_mutex locked.
+  */
+ int ubi_create_volume(struct ubi_device *ubi, struct ubi_mkvol_req *req)
+ {
+-	int i, err, vol_id = req->vol_id;
++	int i, err, vol_id = req->vol_id, do_free = 1;
+ 	struct ubi_volume *vol;
+ 	struct ubi_vtbl_record vtbl_rec;
+-	uint64_t bytes;
++	dev_t dev;
+ 
+ 	if (ubi->ro_mode)
+ 		return -EROFS;
+@@ -199,10 +214,9 @@
+ 		return -ENOMEM;
+ 
+ 	spin_lock(&ubi->volumes_lock);
+-
+ 	if (vol_id == UBI_VOL_NUM_AUTO) {
+ 		/* Find unused volume ID */
+-		dbg_msg("search for vacant volume ID");
++		dbg_gen("search for vacant volume ID");
+ 		for (i = 0; i < ubi->vtbl_slots; i++)
+ 			if (!ubi->volumes[i]) {
+ 				vol_id = i;
+@@ -217,7 +231,7 @@
+ 		req->vol_id = vol_id;
+ 	}
+ 
+-	dbg_msg("volume ID %d, %llu bytes, type %d, name %s",
++	dbg_gen("volume ID %d, %llu bytes, type %d, name %s",
+ 		vol_id, (unsigned long long)req->bytes,
+ 		(int)req->vol_type, req->name);
+ 
+@@ -237,12 +251,10 @@
+ 			goto out_unlock;
+ 		}
+ 
+-        /* Calculate how many eraseblocks are requested */
++	/* Calculate how many eraseblocks are requested */
+ 	vol->usable_leb_size = ubi->leb_size - ubi->leb_size % req->alignment;
+-	bytes = req->bytes;
+-	if (do_div(bytes, vol->usable_leb_size))
+-		vol->reserved_pebs = 1;
+-	vol->reserved_pebs += bytes;
++	vol->reserved_pebs += div_u64(req->bytes + vol->usable_leb_size - 1,
++				      vol->usable_leb_size);
+ 
+ 	/* Reserve physical eraseblocks */
+ 	if (vol->reserved_pebs > ubi->avail_pebs) {
+@@ -252,17 +264,15 @@
+ 	}
+ 	ubi->avail_pebs -= vol->reserved_pebs;
+ 	ubi->rsvd_pebs += vol->reserved_pebs;
++	spin_unlock(&ubi->volumes_lock);
+ 
+ 	vol->vol_id    = vol_id;
+ 	vol->alignment = req->alignment;
+ 	vol->data_pad  = ubi->leb_size % vol->alignment;
+ 	vol->vol_type  = req->vol_type;
+ 	vol->name_len  = req->name_len;
+-	memcpy(vol->name, req->name, vol->name_len + 1);
+-	vol->exclusive = 1;
++	memcpy(vol->name, req->name, vol->name_len);
+ 	vol->ubi = ubi;
+-	ubi->volumes[vol_id] = vol;
+-	spin_unlock(&ubi->volumes_lock);
+ 
+ 	/*
+ 	 * Finish all pending erases because there may be some LEBs belonging
+@@ -287,10 +297,10 @@
+ 		vol->used_bytes =
+ 			(long long)vol->used_ebs * vol->usable_leb_size;
+ 	} else {
+-		bytes = vol->used_bytes;
+-		vol->last_eb_bytes = do_div(bytes, vol->usable_leb_size);
+-		vol->used_ebs = bytes;
+-		if (vol->last_eb_bytes)
++		vol->used_ebs = div_u64_rem(vol->used_bytes,
++					    vol->usable_leb_size,
++					    &vol->last_eb_bytes);
++		if (vol->last_eb_bytes != 0)
+ 			vol->used_ebs += 1;
+ 		else
+ 			vol->last_eb_bytes = vol->usable_leb_size;
+@@ -299,9 +309,10 @@
+ 	/* Register character device for the volume */
+ 	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
+ 	vol->cdev.owner = THIS_MODULE;
+-	err = cdev_add(&vol->cdev, MKDEV(ubi->major, vol_id + 1), 1);
++	dev = MKDEV(MAJOR(ubi->cdev.dev), vol_id + 1);
++	err = cdev_add(&vol->cdev, dev, 1);
+ 	if (err) {
+-		ubi_err("cannot add character device for volume %d", vol_id);
++		ubi_err("cannot add character device");
+ 		goto out_mapping;
+ 	}
+ 
+@@ -311,12 +322,15 @@
+ 
+ 	vol->dev.release = vol_release;
+ 	vol->dev.parent = &ubi->dev;
+-	vol->dev.devt = MKDEV(ubi->major, vol->vol_id + 1);
++	vol->dev.devt = dev;
+ 	vol->dev.class = ubi_class;
++
+ 	sprintf(&vol->dev.bus_id[0], "%s_%d", ubi->ubi_name, vol->vol_id);
+ 	err = device_register(&vol->dev);
+-	if (err)
++	if (err) {
++		ubi_err("cannot register device");
+ 		goto out_gluebi;
++	}
+ 
+ 	err = volume_sysfs_init(ubi, vol);
+ 	if (err)
+@@ -332,98 +346,108 @@
+ 		vtbl_rec.vol_type = UBI_VID_DYNAMIC;
+ 	else
+ 		vtbl_rec.vol_type = UBI_VID_STATIC;
+-	memcpy(vtbl_rec.name, vol->name, vol->name_len + 1);
++	memcpy(vtbl_rec.name, vol->name, vol->name_len);
+ 
+ 	err = ubi_change_vtbl_record(ubi, vol_id, &vtbl_rec);
+ 	if (err)
+ 		goto out_sysfs;
+ 
+ 	spin_lock(&ubi->volumes_lock);
++	ubi->volumes[vol_id] = vol;
+ 	ubi->vol_count += 1;
+-	vol->exclusive = 0;
+ 	spin_unlock(&ubi->volumes_lock);
+ 
+-	paranoid_check_volumes(ubi);
+-	return 0;
++	err = paranoid_check_volumes(ubi);
++	return err;
+ 
++out_sysfs:
++	/*
++	 * We have registered our device, we should not free the volume
++	 * description object in this function in case of an error - it is
++	 * freed by the release function.
++	 *
++	 * Get device reference to prevent the release function from being
++	 * called just after sysfs has been closed.
++	 */
++	do_free = 0;
++	get_device(&vol->dev);
++	volume_sysfs_close(vol);
+ out_gluebi:
+-	err = ubi_destroy_gluebi(vol);
++	if (ubi_destroy_gluebi(vol))
++		dbg_err("cannot destroy gluebi for volume %d:%d",
++			ubi->ubi_num, vol_id);
+ out_cdev:
+ 	cdev_del(&vol->cdev);
+ out_mapping:
+-	kfree(vol->eba_tbl);
++	if (do_free)
++		kfree(vol->eba_tbl);
+ out_acc:
+ 	spin_lock(&ubi->volumes_lock);
+ 	ubi->rsvd_pebs -= vol->reserved_pebs;
+ 	ubi->avail_pebs += vol->reserved_pebs;
+-	ubi->volumes[vol_id] = NULL;
+ out_unlock:
+ 	spin_unlock(&ubi->volumes_lock);
+-	kfree(vol);
+-	return err;
+-
+-	/*
+-	 * We are registered, so @vol is destroyed in the release function and
+-	 * we have to de-initialize differently.
+-	 */
+-out_sysfs:
+-	err = ubi_destroy_gluebi(vol);
+-	cdev_del(&vol->cdev);
+-	kfree(vol->eba_tbl);
+-	spin_lock(&ubi->volumes_lock);
+-	ubi->rsvd_pebs -= vol->reserved_pebs;
+-	ubi->avail_pebs += vol->reserved_pebs;
+-	ubi->volumes[vol_id] = NULL;
+-	spin_unlock(&ubi->volumes_lock);
+-	volume_sysfs_close(vol);
++	if (do_free)
++		kfree(vol);
++	else
++		put_device(&vol->dev);
++	ubi_err("cannot create volume %d, error %d", vol_id, err);
+ 	return err;
+ }
+ 
+ /**
+  * ubi_remove_volume - remove volume.
+  * @desc: volume descriptor
++ * @no_vtbl: do not change volume table if not zero
+  *
+  * This function removes volume described by @desc. The volume has to be opened
+  * in "exclusive" mode. Returns zero in case of success and a negative error
+- * code in case of failure.
++ * code in case of failure. The caller has to have the @ubi->volumes_mutex
++ * locked.
+  */
+-int ubi_remove_volume(struct ubi_volume_desc *desc)
++int ubi_remove_volume(struct ubi_volume_desc *desc, int no_vtbl)
+ {
+ 	struct ubi_volume *vol = desc->vol;
+ 	struct ubi_device *ubi = vol->ubi;
+ 	int i, err, vol_id = vol->vol_id, reserved_pebs = vol->reserved_pebs;
+ 
+-	dbg_msg("remove UBI volume %d", vol_id);
++	dbg_gen("remove UBI volume %d", vol_id);
+ 	ubi_assert(desc->mode == UBI_EXCLUSIVE);
+ 	ubi_assert(vol == ubi->volumes[vol_id]);
+ 
+ 	if (ubi->ro_mode)
+ 		return -EROFS;
+ 
++	spin_lock(&ubi->volumes_lock);
++	if (vol->ref_count > 1) {
++		/*
++		 * The volume is busy, probably someone is reading one of its
++		 * sysfs files.
++		 */
++		err = -EBUSY;
++		goto out_unlock;
++	}
++	ubi->volumes[vol_id] = NULL;
++	spin_unlock(&ubi->volumes_lock);
++
+ 	err = ubi_destroy_gluebi(vol);
+ 	if (err)
+-		return err;
++		goto out_err;
+ 
+-	err = ubi_change_vtbl_record(ubi, vol_id, NULL);
+-	if (err)
+-		return err;
++	if (!no_vtbl) {
++		err = ubi_change_vtbl_record(ubi, vol_id, NULL);
++		if (err)
++			goto out_err;
++	}
+ 
+ 	for (i = 0; i < vol->reserved_pebs; i++) {
+-		err = ubi_eba_unmap_leb(ubi, vol_id, i);
++		err = ubi_eba_unmap_leb(ubi, vol, i);
+ 		if (err)
+-			return err;
++			goto out_err;
+ 	}
+ 
+-	spin_lock(&ubi->volumes_lock);
+-	vol->removed = 1;
+-	ubi->volumes[vol_id] = NULL;
+-	spin_unlock(&ubi->volumes_lock);
+-
+-	kfree(vol->eba_tbl);
+-	vol->eba_tbl = NULL;
+ 	cdev_del(&vol->cdev);
+ 	volume_sysfs_close(vol);
+-	kfree(desc);
+ 
+ 	spin_lock(&ubi->volumes_lock);
+ 	ubi->rsvd_pebs -= reserved_pebs;
+@@ -440,9 +464,17 @@
+ 	ubi->vol_count -= 1;
+ 	spin_unlock(&ubi->volumes_lock);
+ 
+-	paranoid_check_volumes(ubi);
+-	module_put(THIS_MODULE);
+-	return 0;
++	if (!no_vtbl)
++		err = paranoid_check_volumes(ubi);
++	return err;
++
++out_err:
++	ubi_err("cannot remove volume %d, error %d", vol_id, err);
++	spin_lock(&ubi->volumes_lock);
++	ubi->volumes[vol_id] = vol;
++out_unlock:
++	spin_unlock(&ubi->volumes_lock);
++	return err;
+ }
+ 
+ /**
+@@ -450,8 +482,9 @@
+  * @desc: volume descriptor
+  * @reserved_pebs: new size in physical eraseblocks
+  *
+- * This function returns zero in case of success, and a negative error code in
+- * case of failure.
++ * This function re-sizes the volume and returns zero in case of success, and a
++ * negative error code in case of failure. The caller has to have the
++ * @ubi->volumes_mutex locked.
+  */
+ int ubi_resize_volume(struct ubi_volume_desc *desc, int reserved_pebs)
+ {
+@@ -464,10 +497,8 @@
+ 	if (ubi->ro_mode)
+ 		return -EROFS;
+ 
+-	dbg_msg("re-size volume %d to from %d to %d PEBs",
++	dbg_gen("re-size volume %d to from %d to %d PEBs",
+ 		vol_id, vol->reserved_pebs, reserved_pebs);
+-	ubi_assert(desc->mode == UBI_EXCLUSIVE);
+-	ubi_assert(vol == ubi->volumes[vol_id]);
+ 
+ 	if (vol->vol_type == UBI_STATIC_VOLUME &&
+ 	    reserved_pebs < vol->used_ebs) {
+@@ -487,6 +518,14 @@
+ 	for (i = 0; i < reserved_pebs; i++)
+ 		new_mapping[i] = UBI_LEB_UNMAPPED;
+ 
++	spin_lock(&ubi->volumes_lock);
++	if (vol->ref_count > 1) {
++		spin_unlock(&ubi->volumes_lock);
++		err = -EBUSY;
++		goto out_free;
++	}
++	spin_unlock(&ubi->volumes_lock);
++
+ 	/* Reserve physical eraseblocks */
+ 	pebs = reserved_pebs - vol->reserved_pebs;
+ 	if (pebs > 0) {
+@@ -516,7 +555,7 @@
+ 
+ 	if (pebs < 0) {
+ 		for (i = 0; i < -pebs; i++) {
+-			err = ubi_eba_unmap_leb(ubi, vol_id, reserved_pebs + i);
++			err = ubi_eba_unmap_leb(ubi, vol, reserved_pebs + i);
+ 			if (err)
+ 				goto out_acc;
+ 		}
+@@ -547,8 +586,8 @@
+ 			(long long)vol->used_ebs * vol->usable_leb_size;
+ 	}
+ 
+-	paranoid_check_volumes(ubi);
+-	return 0;
++	err = paranoid_check_volumes(ubi);
++	return err;
+ 
+ out_acc:
+ 	if (pebs > 0) {
+@@ -563,29 +602,67 @@
+ }
+ 
+ /**
++ * ubi_rename_volumes - re-name UBI volumes.
++ * @ubi: UBI device description object
++ * @rename_list: list of &struct ubi_rename_entry objects
++ *
++ * This function re-names or removes volumes specified in the re-name list.
++ * Returns zero in case of success and a negative error code in case of
++ * failure.
++ */
++int ubi_rename_volumes(struct ubi_device *ubi, struct list_head *rename_list)
++{
++	int err;
++	struct ubi_rename_entry *re;
++
++	err = ubi_vtbl_rename_volumes(ubi, rename_list);
++	if (err)
++		return err;
++
++	list_for_each_entry(re, rename_list, list) {
++		if (re->remove) {
++			err = ubi_remove_volume(re->desc, 1);
++			if (err)
++				break;
++		} else {
++			struct ubi_volume *vol = re->desc->vol;
++
++			spin_lock(&ubi->volumes_lock);
++			vol->name_len = re->new_name_len;
++			memcpy(vol->name, re->new_name, re->new_name_len + 1);
++			spin_unlock(&ubi->volumes_lock);
++		}
++	}
++
++	if (!err)
++		err = paranoid_check_volumes(ubi);
++	return err;
++}
++
++/**
+  * ubi_add_volume - add volume.
+  * @ubi: UBI device description object
+- * @vol_id: volume ID
++ * @vol: volume description object
+  *
+- * This function adds an existin volume and initializes all its data
+- * structures. Returnes zero in case of success and a negative error code in
++ * This function adds an existing volume and initializes all its data
++ * structures. Returns zero in case of success and a negative error code in
+  * case of failure.
+  */
+-int ubi_add_volume(struct ubi_device *ubi, int vol_id)
++int ubi_add_volume(struct ubi_device *ubi, struct ubi_volume *vol)
+ {
+-	int err;
+-	struct ubi_volume *vol = ubi->volumes[vol_id];
++	int err, vol_id = vol->vol_id;
++	dev_t dev;
+ 
+-	dbg_msg("add volume %d", vol_id);
+-	ubi_dbg_dump_vol_info(vol);
+-	ubi_assert(vol);
++	dbg_gen("add volume %d", vol_id);
+ 
+ 	/* Register character device for the volume */
+ 	cdev_init(&vol->cdev, &ubi_vol_cdev_operations);
+ 	vol->cdev.owner = THIS_MODULE;
+-	err = cdev_add(&vol->cdev, MKDEV(ubi->major, vol->vol_id + 1), 1);
++	dev = MKDEV(MAJOR(ubi->cdev.dev), vol->vol_id + 1);
++	err = cdev_add(&vol->cdev, dev, 1);
+ 	if (err) {
+-		ubi_err("cannot add character device for volume %d", vol_id);
++		ubi_err("cannot add character device for volume %d, error %d",
++			vol_id, err);
+ 		return err;
+ 	}
+ 
+@@ -595,7 +672,7 @@
+ 
+ 	vol->dev.release = vol_release;
+ 	vol->dev.parent = &ubi->dev;
+-	vol->dev.devt = MKDEV(ubi->major, vol->vol_id + 1);
++	vol->dev.devt = dev;
+ 	vol->dev.class = ubi_class;
+ 	sprintf(&vol->dev.bus_id[0], "%s_%d", ubi->ubi_name, vol->vol_id);
+ 	err = device_register(&vol->dev);
+@@ -610,8 +687,8 @@
+ 		return err;
+ 	}
+ 
+-	paranoid_check_volumes(ubi);
+-	return 0;
++	err = paranoid_check_volumes(ubi);
++	return err;
+ 
+ out_gluebi:
+ 	err = ubi_destroy_gluebi(vol);
+@@ -623,22 +700,19 @@
+ /**
+  * ubi_free_volume - free volume.
+  * @ubi: UBI device description object
+- * @vol_id: volume ID
++ * @vol: volume description object
+  *
+- * This function frees all resources for volume @vol_id but does not remove it.
++ * This function frees all resources for volume @vol but does not remove it.
+  * Used only when the UBI device is detached.
+  */
+-void ubi_free_volume(struct ubi_device *ubi, int vol_id)
++void ubi_free_volume(struct ubi_device *ubi, struct ubi_volume *vol)
+ {
+ 	int err;
+-	struct ubi_volume *vol = ubi->volumes[vol_id];
+ 
+-	dbg_msg("free volume %d", vol_id);
+-	ubi_assert(vol);
++	dbg_gen("free volume %d", vol->vol_id);
+ 
+-	vol->removed = 1;
++	ubi->volumes[vol->vol_id] = NULL;
+ 	err = ubi_destroy_gluebi(vol);
+-	ubi->volumes[vol_id] = NULL;
+ 	cdev_del(&vol->cdev);
+ 	volume_sysfs_close(vol);
+ }
+@@ -649,8 +723,10 @@
+  * paranoid_check_volume - check volume information.
+  * @ubi: UBI device description object
+  * @vol_id: volume ID
++ *
++ * Returns zero if volume is all right and a a negative error code if not.
+  */
+-static void paranoid_check_volume(struct ubi_device *ubi, int vol_id)
++static int paranoid_check_volume(struct ubi_device *ubi, int vol_id)
+ {
+ 	int idx = vol_id2idx(ubi, vol_id);
+ 	int reserved_pebs, alignment, data_pad, vol_type, name_len, upd_marker;
+@@ -668,16 +744,7 @@
+ 			goto fail;
+ 		}
+ 		spin_unlock(&ubi->volumes_lock);
+-		return;
+-	}
+-
+-	if (vol->exclusive) {
+-		/*
+-		 * The volume may be being created at the moment, do not check
+-		 * it (e.g., it may be in the middle of ubi_create_volume().
+-		 */
+-		spin_unlock(&ubi->volumes_lock);
+-		return;
++		return 0;
+ 	}
+ 
+ 	if (vol->reserved_pebs < 0 || vol->alignment < 0 || vol->data_pad < 0 ||
+@@ -690,7 +757,7 @@
+ 		goto fail;
+ 	}
+ 
+-	n = vol->alignment % ubi->min_io_size;
++	n = vol->alignment & (ubi->min_io_size - 1);
+ 	if (vol->alignment != 1 && n) {
+ 		ubi_err("alignment is not multiple of min I/O unit");
+ 		goto fail;
+@@ -708,11 +775,6 @@
+ 		goto fail;
+ 	}
+ 
+-	if (vol->upd_marker != 0 && vol->upd_marker != 1) {
+-		ubi_err("bad upd_marker");
+-		goto fail;
+-	}
+-
+ 	if (vol->upd_marker && vol->corrupted) {
+ 		dbg_err("update marker and corrupted simultaneously");
+ 		goto fail;
+@@ -747,7 +809,7 @@
+ 
+ 	n = (long long)vol->used_ebs * vol->usable_leb_size;
+ 	if (vol->vol_type == UBI_DYNAMIC_VOLUME) {
+-		if (vol->corrupted != 0) {
++		if (vol->corrupted) {
+ 			ubi_err("corrupted dynamic volume");
+ 			goto fail;
+ 		}
+@@ -764,10 +826,6 @@
+ 			goto fail;
+ 		}
+ 	} else {
+-		if (vol->corrupted != 0 && vol->corrupted != 1) {
+-			ubi_err("bad corrupted");
+-			goto fail;
+-		}
+ 		if (vol->used_ebs < 0 || vol->used_ebs > vol->reserved_pebs) {
+ 			ubi_err("bad used_ebs");
+ 			goto fail;
+@@ -796,33 +854,39 @@
+ 
+ 	if (alignment != vol->alignment || data_pad != vol->data_pad ||
+ 	    upd_marker != vol->upd_marker || vol_type != vol->vol_type ||
+-	    name_len!= vol->name_len || strncmp(name, vol->name, name_len)) {
++	    name_len != vol->name_len || strncmp(name, vol->name, name_len)) {
+ 		ubi_err("volume info is different");
+ 		goto fail;
+ 	}
+ 
+ 	spin_unlock(&ubi->volumes_lock);
+-	return;
++	return 0;
+ 
+ fail:
+ 	ubi_err("paranoid check failed for volume %d", vol_id);
+-	ubi_dbg_dump_vol_info(vol);
++	if (vol)
++		ubi_dbg_dump_vol_info(vol);
+ 	ubi_dbg_dump_vtbl_record(&ubi->vtbl[vol_id], vol_id);
+ 	spin_unlock(&ubi->volumes_lock);
+-	BUG();
++	return -EINVAL;
+ }
+ 
+ /**
+  * paranoid_check_volumes - check information about all volumes.
+  * @ubi: UBI device description object
++ *
++ * Returns zero if volumes are all right and a a negative error code if not.
+  */
+-static void paranoid_check_volumes(struct ubi_device *ubi)
++static int paranoid_check_volumes(struct ubi_device *ubi)
+ {
+-	int i;
++	int i, err = 0;
+ 
+-	mutex_lock(&ubi->vtbl_mutex);
+-	for (i = 0; i < ubi->vtbl_slots; i++)
+-		paranoid_check_volume(ubi, i);
+-	mutex_unlock(&ubi->vtbl_mutex);
++	for (i = 0; i < ubi->vtbl_slots; i++) {
++		err = paranoid_check_volume(ubi, i);
++		if (err)
++			break;
++	}
++
++	return err;
+ }
+ #endif
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/vtbl.c linux-2.6.24/drivers/mtd/ubi/vtbl.c
+--- linux-2.6.24.orig/drivers/mtd/ubi/vtbl.c	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/vtbl.c	2009-04-17 09:49:26.000000000 +0200
+@@ -86,8 +86,10 @@
+ {
+ 	int i, err;
+ 	uint32_t crc;
++	struct ubi_volume *layout_vol;
+ 
+ 	ubi_assert(idx >= 0 && idx < ubi->vtbl_slots);
++	layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)];
+ 
+ 	if (!vtbl_rec)
+ 		vtbl_rec = &empty_vtbl_record;
+@@ -96,31 +98,75 @@
+ 		vtbl_rec->crc = cpu_to_be32(crc);
+ 	}
+ 
+-	mutex_lock(&ubi->vtbl_mutex);
+ 	memcpy(&ubi->vtbl[idx], vtbl_rec, sizeof(struct ubi_vtbl_record));
+ 	for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) {
+-		err = ubi_eba_unmap_leb(ubi, UBI_LAYOUT_VOL_ID, i);
+-		if (err) {
+-			mutex_unlock(&ubi->vtbl_mutex);
++		err = ubi_eba_unmap_leb(ubi, layout_vol, i);
++		if (err)
+ 			return err;
+-		}
+-		err = ubi_eba_write_leb(ubi, UBI_LAYOUT_VOL_ID, i, ubi->vtbl, 0,
++
++		err = ubi_eba_write_leb(ubi, layout_vol, i, ubi->vtbl, 0,
+ 					ubi->vtbl_size, UBI_LONGTERM);
+-		if (err) {
+-			mutex_unlock(&ubi->vtbl_mutex);
++		if (err)
+ 			return err;
+-		}
+ 	}
+ 
+ 	paranoid_vtbl_check(ubi);
+-	mutex_unlock(&ubi->vtbl_mutex);
+-	return ubi_wl_flush(ubi);
++	return 0;
+ }
+ 
+ /**
+- * vol_til_check - check if volume table is not corrupted and contains sensible
+- * data.
++ * ubi_vtbl_rename_volumes - rename UBI volumes in the volume table.
++ * @ubi: UBI device description object
++ * @rename_list: list of &struct ubi_rename_entry objects
+  *
++ * This function re-names multiple volumes specified in @req in the volume
++ * table. Returns zero in case of success and a negative error code in case of
++ * failure.
++ */
++int ubi_vtbl_rename_volumes(struct ubi_device *ubi,
++			    struct list_head *rename_list)
++{
++	int i, err;
++	struct ubi_rename_entry *re;
++	struct ubi_volume *layout_vol;
++
++	list_for_each_entry(re, rename_list, list) {
++		uint32_t crc;
++		struct ubi_volume *vol = re->desc->vol;
++		struct ubi_vtbl_record *vtbl_rec = &ubi->vtbl[vol->vol_id];
++
++		if (re->remove) {
++			memcpy(vtbl_rec, &empty_vtbl_record,
++			       sizeof(struct ubi_vtbl_record));
++			continue;
++		}
++
++		vtbl_rec->name_len = cpu_to_be16(re->new_name_len);
++		memcpy(vtbl_rec->name, re->new_name, re->new_name_len);
++		memset(vtbl_rec->name + re->new_name_len, 0,
++		       UBI_VOL_NAME_MAX + 1 - re->new_name_len);
++		crc = crc32(UBI_CRC32_INIT, vtbl_rec,
++			    UBI_VTBL_RECORD_SIZE_CRC);
++		vtbl_rec->crc = cpu_to_be32(crc);
++	}
++
++	layout_vol = ubi->volumes[vol_id2idx(ubi, UBI_LAYOUT_VOLUME_ID)];
++	for (i = 0; i < UBI_LAYOUT_VOLUME_EBS; i++) {
++		err = ubi_eba_unmap_leb(ubi, layout_vol, i);
++		if (err)
++			return err;
++
++		err = ubi_eba_write_leb(ubi, layout_vol, i, ubi->vtbl, 0,
++					ubi->vtbl_size, UBI_LONGTERM);
++		if (err)
++			return err;
++	}
++
++	return 0;
++}
++
++/**
++ * vtbl_check - check if volume table is not corrupted and sensible.
+  * @ubi: UBI device description object
+  * @vtbl: volume table
+  *
+@@ -131,7 +177,7 @@
+ 		      const struct ubi_vtbl_record *vtbl)
+ {
+ 	int i, n, reserved_pebs, alignment, data_pad, vol_type, name_len;
+-	int upd_marker;
++	int upd_marker, err;
+ 	uint32_t crc;
+ 	const char *name;
+ 
+@@ -157,7 +203,7 @@
+ 		if (reserved_pebs == 0) {
+ 			if (memcmp(&vtbl[i], &empty_vtbl_record,
+ 						UBI_VTBL_RECORD_SIZE)) {
+-				dbg_err("bad empty record");
++				err = 2;
+ 				goto bad;
+ 			}
+ 			continue;
+@@ -165,56 +211,57 @@
+ 
+ 		if (reserved_pebs < 0 || alignment < 0 || data_pad < 0 ||
+ 		    name_len < 0) {
+-			dbg_err("negative values");
++			err = 3;
+ 			goto bad;
+ 		}
+ 
+ 		if (alignment > ubi->leb_size || alignment == 0) {
+-			dbg_err("bad alignment");
++			err = 4;
+ 			goto bad;
+ 		}
+ 
+-		n = alignment % ubi->min_io_size;
++		n = alignment & (ubi->min_io_size - 1);
+ 		if (alignment != 1 && n) {
+-			dbg_err("alignment is not multiple of min I/O unit");
++			err = 5;
+ 			goto bad;
+ 		}
+ 
+ 		n = ubi->leb_size % alignment;
+ 		if (data_pad != n) {
+ 			dbg_err("bad data_pad, has to be %d", n);
++			err = 6;
+ 			goto bad;
+ 		}
+ 
+ 		if (vol_type != UBI_VID_DYNAMIC && vol_type != UBI_VID_STATIC) {
+-			dbg_err("bad vol_type");
++			err = 7;
+ 			goto bad;
+ 		}
+ 
+ 		if (upd_marker != 0 && upd_marker != 1) {
+-			dbg_err("bad upd_marker");
++			err = 8;
+ 			goto bad;
+ 		}
+ 
+ 		if (reserved_pebs > ubi->good_peb_count) {
+-			dbg_err("too large reserved_pebs, good PEBs %d",
+-				ubi->good_peb_count);
++			dbg_err("too large reserved_pebs %d, good PEBs %d",
++				reserved_pebs, ubi->good_peb_count);
++			err = 9;
+ 			goto bad;
+ 		}
+ 
+ 		if (name_len > UBI_VOL_NAME_MAX) {
+-			dbg_err("too long volume name, max %d",
+-				UBI_VOL_NAME_MAX);
++			err = 10;
+ 			goto bad;
+ 		}
+ 
+ 		if (name[0] == '\0') {
+-			dbg_err("NULL volume name");
++			err = 11;
+ 			goto bad;
+ 		}
+ 
+ 		if (name_len != strnlen(name, name_len + 1)) {
+-			dbg_err("bad name_len");
++			err = 12;
+ 			goto bad;
+ 		}
+ 	}
+@@ -239,7 +286,7 @@
+ 	return 0;
+ 
+ bad:
+-	ubi_err("volume table check failed, record %d", i);
++	ubi_err("volume table check failed: record %d, error %d", i, err);
+ 	ubi_dbg_dump_vtbl_record(&vtbl[i], i);
+ 	return -EINVAL;
+ }
+@@ -273,7 +320,7 @@
+ 	 * this volume table copy was found during scanning. It has to be wiped
+ 	 * out.
+ 	 */
+-	sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOL_ID);
++	sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID);
+ 	if (sv)
+ 		old_seb = ubi_scan_find_seb(sv, copy);
+ 
+@@ -285,13 +332,12 @@
+ 	}
+ 
+ 	vid_hdr->vol_type = UBI_VID_DYNAMIC;
+-	vid_hdr->vol_id = cpu_to_be32(UBI_LAYOUT_VOL_ID);
++	vid_hdr->vol_id = cpu_to_be32(UBI_LAYOUT_VOLUME_ID);
+ 	vid_hdr->compat = UBI_LAYOUT_VOLUME_COMPAT;
+ 	vid_hdr->data_size = vid_hdr->used_ebs =
+ 			     vid_hdr->data_pad = cpu_to_be32(0);
+ 	vid_hdr->lnum = cpu_to_be32(copy);
+ 	vid_hdr->sqnum = cpu_to_be64(++si->max_sqnum);
+-	vid_hdr->leb_ver = cpu_to_be32(old_seb ? old_seb->leb_ver + 1: 0);
+ 
+ 	/* The EC header is already there, write the VID header */
+ 	err = ubi_io_write_vid_hdr(ubi, new_seb->pnum, vid_hdr);
+@@ -374,7 +420,7 @@
+ 	 *    to LEB 0.
+ 	 */
+ 
+-	dbg_msg("check layout volume");
++	dbg_gen("check layout volume");
+ 
+ 	/* Read both LEB 0 and LEB 1 into memory */
+ 	ubi_rb_for_each_entry(rb, seb, &sv->root, u.rb) {
+@@ -388,7 +434,16 @@
+ 		err = ubi_io_read_data(ubi, leb[seb->lnum], seb->pnum, 0,
+ 				       ubi->vtbl_size);
+ 		if (err == UBI_IO_BITFLIPS || err == -EBADMSG)
+-			/* Scrub the PEB later */
++			/*
++			 * Scrub the PEB later. Note, -EBADMSG indicates an
++			 * uncorrectable ECC error, but we have our own CRC and
++			 * the data will be checked later. If the data is OK,
++			 * the PEB will be scrubbed (because we set
++			 * seb->scrub). If the data is not OK, the contents of
++			 * the PEB will be recovered from the second copy, and
++			 * seb->scrub will be cleared in
++			 * 'ubi_scan_add_used()'.
++			 */
+ 			seb->scrub = 1;
+ 		else if (err)
+ 			goto out_free;
+@@ -404,7 +459,8 @@
+ 	if (!leb_corrupted[0]) {
+ 		/* LEB 0 is OK */
+ 		if (leb[1])
+-			leb_corrupted[1] = memcmp(leb[0], leb[1], ubi->vtbl_size);
++			leb_corrupted[1] = memcmp(leb[0], leb[1],
++						  ubi->vtbl_size);
+ 		if (leb_corrupted[1]) {
+ 			ubi_warn("volume table copy #2 is corrupted");
+ 			err = create_vtbl(ubi, si, 1, leb[0]);
+@@ -518,6 +574,17 @@
+ 		vol->name[vol->name_len] = '\0';
+ 		vol->vol_id = i;
+ 
++		if (vtbl[i].flags & UBI_VTBL_AUTORESIZE_FLG) {
++			/* Auto re-size flag may be set only for one volume */
++			if (ubi->autoresize_vol_id != -1) {
++				ubi_err("more then one auto-resize volume (%d "
++					"and %d)", ubi->autoresize_vol_id, i);
++				return -EINVAL;
++			}
++
++			ubi->autoresize_vol_id = i;
++		}
++
+ 		ubi_assert(!ubi->volumes[i]);
+ 		ubi->volumes[i] = vol;
+ 		ubi->vol_count += 1;
+@@ -568,6 +635,7 @@
+ 		vol->last_eb_bytes = sv->last_data_size;
+ 	}
+ 
++	/* And add the layout volume */
+ 	vol = kzalloc(sizeof(struct ubi_volume), GFP_KERNEL);
+ 	if (!vol)
+ 		return -ENOMEM;
+@@ -582,7 +650,8 @@
+ 	vol->last_eb_bytes = vol->reserved_pebs;
+ 	vol->used_bytes =
+ 		(long long)vol->used_ebs * (ubi->leb_size - vol->data_pad);
+-	vol->vol_id = UBI_LAYOUT_VOL_ID;
++	vol->vol_id = UBI_LAYOUT_VOLUME_ID;
++	vol->ref_count = 1;
+ 
+ 	ubi_assert(!ubi->volumes[i]);
+ 	ubi->volumes[vol_id2idx(ubi, vol->vol_id)] = vol;
+@@ -610,30 +679,32 @@
+ static int check_sv(const struct ubi_volume *vol,
+ 		    const struct ubi_scan_volume *sv)
+ {
++	int err;
++
+ 	if (sv->highest_lnum >= vol->reserved_pebs) {
+-		dbg_err("bad highest_lnum");
++		err = 1;
+ 		goto bad;
+ 	}
+ 	if (sv->leb_count > vol->reserved_pebs) {
+-		dbg_err("bad leb_count");
++		err = 2;
+ 		goto bad;
+ 	}
+ 	if (sv->vol_type != vol->vol_type) {
+-		dbg_err("bad vol_type");
++		err = 3;
+ 		goto bad;
+ 	}
+ 	if (sv->used_ebs > vol->reserved_pebs) {
+-		dbg_err("bad used_ebs");
++		err = 4;
+ 		goto bad;
+ 	}
+ 	if (sv->data_pad != vol->data_pad) {
+-		dbg_err("bad data_pad");
++		err = 5;
+ 		goto bad;
+ 	}
+ 	return 0;
+ 
+ bad:
+-	ubi_err("bad scanning information");
++	ubi_err("bad scanning information, error %d", err);
+ 	ubi_dbg_dump_sv(sv);
+ 	ubi_dbg_dump_vol_info(vol);
+ 	return -EINVAL;
+@@ -662,14 +733,13 @@
+ 		return -EINVAL;
+ 	}
+ 
+-	if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT&&
++	if (si->highest_vol_id >= ubi->vtbl_slots + UBI_INT_VOL_COUNT &&
+ 	    si->highest_vol_id < UBI_INTERNAL_VOL_START) {
+ 		ubi_err("too large volume ID %d found by scanning",
+ 			si->highest_vol_id);
+ 		return -EINVAL;
+ 	}
+ 
+-
+ 	for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
+ 		cond_resched();
+ 
+@@ -707,8 +777,7 @@
+ }
+ 
+ /**
+- * ubi_read_volume_table - read volume table.
+- * information.
++ * ubi_read_volume_table - read the volume table.
+  * @ubi: UBI device description object
+  * @si: scanning information
+  *
+@@ -734,7 +803,7 @@
+ 	ubi->vtbl_size = ubi->vtbl_slots * UBI_VTBL_RECORD_SIZE;
+ 	ubi->vtbl_size = ALIGN(ubi->vtbl_size, ubi->min_io_size);
+ 
+-	sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOL_ID);
++	sv = ubi_scan_find_sv(si, UBI_LAYOUT_VOLUME_ID);
+ 	if (!sv) {
+ 		/*
+ 		 * No logical eraseblocks belonging to the layout volume were
+@@ -787,11 +856,10 @@
+ 
+ out_free:
+ 	vfree(ubi->vtbl);
+-	for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++)
+-		if (ubi->volumes[i]) {
+-			kfree(ubi->volumes[i]);
+-			ubi->volumes[i] = NULL;
+-		}
++	for (i = 0; i < ubi->vtbl_slots + UBI_INT_VOL_COUNT; i++) {
++		kfree(ubi->volumes[i]);
++		ubi->volumes[i] = NULL;
++	}
+ 	return err;
+ }
+ 
+diff -Nurd linux-2.6.24.orig/drivers/mtd/ubi/wl.c linux-2.6.24/drivers/mtd/ubi/wl.c
+--- linux-2.6.24.orig/drivers/mtd/ubi/wl.c	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/drivers/mtd/ubi/wl.c	2009-04-17 09:49:26.000000000 +0200
+@@ -19,22 +19,22 @@
+  */
+ 
+ /*
+- * UBI wear-leveling unit.
++ * UBI wear-leveling sub-system.
+  *
+- * This unit is responsible for wear-leveling. It works in terms of physical
+- * eraseblocks and erase counters and knows nothing about logical eraseblocks,
+- * volumes, etc. From this unit's perspective all physical eraseblocks are of
+- * two types - used and free. Used physical eraseblocks are those that were
+- * "get" by the 'ubi_wl_get_peb()' function, and free physical eraseblocks are
+- * those that were put by the 'ubi_wl_put_peb()' function.
++ * This sub-system is responsible for wear-leveling. It works in terms of
++ * physical eraseblocks and erase counters and knows nothing about logical
++ * eraseblocks, volumes, etc. From this sub-system's perspective all physical
++ * eraseblocks are of two types - used and free. Used physical eraseblocks are
++ * those that were "get" by the 'ubi_wl_get_peb()' function, and free physical
++ * eraseblocks are those that were put by the 'ubi_wl_put_peb()' function.
+  *
+  * Physical eraseblocks returned by 'ubi_wl_get_peb()' have only erase counter
+- * header. The rest of the physical eraseblock contains only 0xFF bytes.
++ * header. The rest of the physical eraseblock contains only %0xFF bytes.
+  *
+- * When physical eraseblocks are returned to the WL unit by means of the
++ * When physical eraseblocks are returned to the WL sub-system by means of the
+  * 'ubi_wl_put_peb()' function, they are scheduled for erasure. The erasure is
+  * done asynchronously in context of the per-UBI device background thread,
+- * which is also managed by the WL unit.
++ * which is also managed by the WL sub-system.
+  *
+  * The wear-leveling is ensured by means of moving the contents of used
+  * physical eraseblocks with low erase counter to free physical eraseblocks
+@@ -43,34 +43,64 @@
+  * The 'ubi_wl_get_peb()' function accepts data type hints which help to pick
+  * an "optimal" physical eraseblock. For example, when it is known that the
+  * physical eraseblock will be "put" soon because it contains short-term data,
+- * the WL unit may pick a free physical eraseblock with low erase counter, and
+- * so forth.
++ * the WL sub-system may pick a free physical eraseblock with low erase
++ * counter, and so forth.
+  *
+- * If the WL unit fails to erase a physical eraseblock, it marks it as bad.
++ * If the WL sub-system fails to erase a physical eraseblock, it marks it as
++ * bad.
+  *
+- * This unit is also responsible for scrubbing. If a bit-flip is detected in a
+- * physical eraseblock, it has to be moved. Technically this is the same as
+- * moving it for wear-leveling reasons.
++ * This sub-system is also responsible for scrubbing. If a bit-flip is detected
++ * in a physical eraseblock, it has to be moved. Technically this is the same
++ * as moving it for wear-leveling reasons.
+  *
+- * As it was said, for the UBI unit all physical eraseblocks are either "free"
+- * or "used". Free eraseblock are kept in the @wl->free RB-tree, while used
+- * eraseblocks are kept in a set of different RB-trees: @wl->used,
+- * @wl->prot.pnum, @wl->prot.aec, and @wl->scrub.
++ * As it was said, for the UBI sub-system all physical eraseblocks are either
++ * "free" or "used". Free eraseblock are kept in the @wl->free RB-tree, while
++ * used eraseblocks are kept in @wl->used or @wl->scrub RB-trees, or
++ * (temporarily) in the @wl->pq queue.
++ *
++ * When the WL sub-system returns a physical eraseblock, the physical
++ * eraseblock is protected from being moved for some "time". For this reason,
++ * the physical eraseblock is not directly moved from the @wl->free tree to the
++ * @wl->used tree. There is a protection queue in between where this
++ * physical eraseblock is temporarily stored (@wl->pq).
++ *
++ * All this protection stuff is needed because:
++ *  o we don't want to move physical eraseblocks just after we have given them
++ *    to the user; instead, we first want to let users fill them up with data;
++ *
++ *  o there is a chance that the user will put the physical eraseblock very
++ *    soon, so it makes sense not to move it for some time, but wait; this is
++ *    especially important in case of "short term" physical eraseblocks.
++ *
++ * Physical eraseblocks stay protected only for limited time. But the "time" is
++ * measured in erase cycles in this case. This is implemented with help of the
++ * protection queue. Eraseblocks are put to the tail of this queue when they
++ * are returned by the 'ubi_wl_get_peb()', and eraseblocks are removed from the
++ * head of the queue on each erase operation (for any eraseblock). So the
++ * length of the queue defines how may (global) erase cycles PEBs are protected.
++ *
++ * To put it differently, each physical eraseblock has 2 main states: free and
++ * used. The former state corresponds to the @wl->free tree. The latter state
++ * is split up on several sub-states:
++ * o the WL movement is allowed (@wl->used tree);
++ * o the WL movement is temporarily prohibited (@wl->pq queue);
++ * o scrubbing is needed (@wl->scrub tree).
++ *
++ * Depending on the sub-state, wear-leveling entries of the used physical
++ * eraseblocks may be kept in one of those structures.
+  *
+  * Note, in this implementation, we keep a small in-RAM object for each physical
+  * eraseblock. This is surely not a scalable solution. But it appears to be good
+  * enough for moderately large flashes and it is simple. In future, one may
+- * re-work this unit and make it more scalable.
++ * re-work this sub-system and make it more scalable.
+  *
+- * At the moment this unit does not utilize the sequence number, which was
+- * introduced relatively recently. But it would be wise to do this because the
+- * sequence number of a logical eraseblock characterizes how old is it. For
++ * At the moment this sub-system does not utilize the sequence number, which
++ * was introduced relatively recently. But it would be wise to do this because
++ * the sequence number of a logical eraseblock characterizes how old is it. For
+  * example, when we move a PEB with low erase counter, and we need to pick the
+  * target PEB, we pick a PEB with the highest EC if our PEB is "old" and we
+  * pick target PEB with an average EC if our PEB is not very "old". This is a
+- * room for future re-works of the WL unit.
+- *
+- * FIXME: looks too complex, should be simplified (later).
++ * room for future re-works of the WL sub-system.
+  */
+ 
+ #include <linux/slab.h>
+@@ -83,29 +113,22 @@
+ #define WL_RESERVED_PEBS 1
+ 
+ /*
+- * How many erase cycles are short term, unknown, and long term physical
+- * eraseblocks protected.
+- */
+-#define ST_PROTECTION 16
+-#define U_PROTECTION  10
+-#define LT_PROTECTION 4
+-
+-/*
+  * Maximum difference between two erase counters. If this threshold is
+- * exceeded, the WL unit starts moving data from used physical eraseblocks with
+- * low erase counter to free physical eraseblocks with high erase counter.
++ * exceeded, the WL sub-system starts moving data from used physical
++ * eraseblocks with low erase counter to free physical eraseblocks with high
++ * erase counter.
+  */
+ #define UBI_WL_THRESHOLD CONFIG_MTD_UBI_WL_THRESHOLD
+ 
+ /*
+- * When a physical eraseblock is moved, the WL unit has to pick the target
++ * When a physical eraseblock is moved, the WL sub-system has to pick the target
+  * physical eraseblock to move to. The simplest way would be just to pick the
+  * one with the highest erase counter. But in certain workloads this could lead
+  * to an unlimited wear of one or few physical eraseblock. Indeed, imagine a
+  * situation when the picked physical eraseblock is constantly erased after the
+  * data is written to it. So, we have a constant which limits the highest erase
+- * counter of the free physical eraseblock to pick. Namely, the WL unit does
+- * not pick eraseblocks with erase counter greater then the lowest erase
++ * counter of the free physical eraseblock to pick. Namely, the WL sub-system
++ * does not pick eraseblocks with erase counter greater then the lowest erase
+  * counter plus %WL_FREE_MAX_DIFF.
+  */
+ #define WL_FREE_MAX_DIFF (2*UBI_WL_THRESHOLD)
+@@ -117,80 +140,9 @@
+ #define WL_MAX_FAILURES 32
+ 
+ /**
+- * struct ubi_wl_entry - wear-leveling entry.
+- * @rb: link in the corresponding RB-tree
+- * @ec: erase counter
+- * @pnum: physical eraseblock number
+- *
+- * Each physical eraseblock has a corresponding &struct wl_entry object which
+- * may be kept in different RB-trees.
+- */
+-struct ubi_wl_entry {
+-	struct rb_node rb;
+-	int ec;
+-	int pnum;
+-};
+-
+-/**
+- * struct ubi_wl_prot_entry - PEB protection entry.
+- * @rb_pnum: link in the @wl->prot.pnum RB-tree
+- * @rb_aec: link in the @wl->prot.aec RB-tree
+- * @abs_ec: the absolute erase counter value when the protection ends
+- * @e: the wear-leveling entry of the physical eraseblock under protection
+- *
+- * When the WL unit returns a physical eraseblock, the physical eraseblock is
+- * protected from being moved for some "time". For this reason, the physical
+- * eraseblock is not directly moved from the @wl->free tree to the @wl->used
+- * tree. There is one more tree in between where this physical eraseblock is
+- * temporarily stored (@wl->prot).
+- *
+- * All this protection stuff is needed because:
+- *  o we don't want to move physical eraseblocks just after we have given them
+- *    to the user; instead, we first want to let users fill them up with data;
+- *
+- *  o there is a chance that the user will put the physical eraseblock very
+- *    soon, so it makes sense not to move it for some time, but wait; this is
+- *    especially important in case of "short term" physical eraseblocks.
+- *
+- * Physical eraseblocks stay protected only for limited time. But the "time" is
+- * measured in erase cycles in this case. This is implemented with help of the
+- * absolute erase counter (@wl->abs_ec). When it reaches certain value, the
+- * physical eraseblocks are moved from the protection trees (@wl->prot.*) to
+- * the @wl->used tree.
+- *
+- * Protected physical eraseblocks are searched by physical eraseblock number
+- * (when they are put) and by the absolute erase counter (to check if it is
+- * time to move them to the @wl->used tree). So there are actually 2 RB-trees
+- * storing the protected physical eraseblocks: @wl->prot.pnum and
+- * @wl->prot.aec. They are referred to as the "protection" trees. The
+- * first one is indexed by the physical eraseblock number. The second one is
+- * indexed by the absolute erase counter. Both trees store
+- * &struct ubi_wl_prot_entry objects.
+- *
+- * Each physical eraseblock has 2 main states: free and used. The former state
+- * corresponds to the @wl->free tree. The latter state is split up on several
+- * sub-states:
+- * o the WL movement is allowed (@wl->used tree);
+- * o the WL movement is temporarily prohibited (@wl->prot.pnum and
+- * @wl->prot.aec trees);
+- * o scrubbing is needed (@wl->scrub tree).
+- *
+- * Depending on the sub-state, wear-leveling entries of the used physical
+- * eraseblocks may be kept in one of those trees.
+- */
+-struct ubi_wl_prot_entry {
+-	struct rb_node rb_pnum;
+-	struct rb_node rb_aec;
+-	unsigned long long abs_ec;
+-	struct ubi_wl_entry *e;
+-};
+-
+-/**
+  * struct ubi_work - UBI work description data structure.
+  * @list: a link in the list of pending works
+  * @func: worker function
+- * @priv: private data of the worker function
+- *
+  * @e: physical eraseblock to erase
+  * @torture: if the physical eraseblock has to be tortured
+  *
+@@ -211,14 +163,13 @@
+ static int paranoid_check_ec(struct ubi_device *ubi, int pnum, int ec);
+ static int paranoid_check_in_wl_tree(struct ubi_wl_entry *e,
+ 				     struct rb_root *root);
++static int paranoid_check_in_pq(struct ubi_device *ubi, struct ubi_wl_entry *e);
+ #else
+ #define paranoid_check_ec(ubi, pnum, ec) 0
+ #define paranoid_check_in_wl_tree(e, root)
++#define paranoid_check_in_pq(ubi, e) 0
+ #endif
+ 
+-/* Slab cache for wear-leveling entries */
+-static struct kmem_cache *wl_entries_slab;
+-
+ /**
+  * wl_tree_add - add a wear-leveling entry to a WL RB-tree.
+  * @e: the wear-leveling entry to add
+@@ -236,7 +187,7 @@
+ 		struct ubi_wl_entry *e1;
+ 
+ 		parent = *p;
+-		e1 = rb_entry(parent, struct ubi_wl_entry, rb);
++		e1 = rb_entry(parent, struct ubi_wl_entry, u.rb);
+ 
+ 		if (e->ec < e1->ec)
+ 			p = &(*p)->rb_left;
+@@ -251,8 +202,8 @@
+ 		}
+ 	}
+ 
+-	rb_link_node(&e->rb, parent, p);
+-	rb_insert_color(&e->rb, root);
++	rb_link_node(&e->u.rb, parent, p);
++	rb_insert_color(&e->u.rb, root);
+ }
+ 
+ /**
+@@ -267,15 +218,26 @@
+ 	int err;
+ 	struct ubi_work *wrk;
+ 
+-	spin_lock(&ubi->wl_lock);
++	cond_resched();
+ 
++	/*
++	 * @ubi->work_sem is used to synchronize with the workers. Workers take
++	 * it in read mode, so many of them may be doing works at a time. But
++	 * the queue flush code has to be sure the whole queue of works is
++	 * done, and it takes the mutex in write mode.
++	 */
++	down_read(&ubi->work_sem);
++	spin_lock(&ubi->wl_lock);
+ 	if (list_empty(&ubi->works)) {
+ 		spin_unlock(&ubi->wl_lock);
++		up_read(&ubi->work_sem);
+ 		return 0;
+ 	}
+ 
+ 	wrk = list_entry(ubi->works.next, struct ubi_work, list);
+ 	list_del(&wrk->list);
++	ubi->works_count -= 1;
++	ubi_assert(ubi->works_count >= 0);
+ 	spin_unlock(&ubi->wl_lock);
+ 
+ 	/*
+@@ -286,11 +248,8 @@
+ 	err = wrk->func(ubi, wrk, 0);
+ 	if (err)
+ 		ubi_err("work failed with error code %d", err);
++	up_read(&ubi->work_sem);
+ 
+-	spin_lock(&ubi->wl_lock);
+-	ubi->works_count -= 1;
+-	ubi_assert(ubi->works_count >= 0);
+-	spin_unlock(&ubi->wl_lock);
+ 	return err;
+ }
+ 
+@@ -339,7 +298,7 @@
+ 	while (p) {
+ 		struct ubi_wl_entry *e1;
+ 
+-		e1 = rb_entry(p, struct ubi_wl_entry, rb);
++		e1 = rb_entry(p, struct ubi_wl_entry, u.rb);
+ 
+ 		if (e->pnum == e1->pnum) {
+ 			ubi_assert(e == e1);
+@@ -363,50 +322,24 @@
+ }
+ 
+ /**
+- * prot_tree_add - add physical eraseblock to protection trees.
++ * prot_queue_add - add physical eraseblock to the protection queue.
+  * @ubi: UBI device description object
+  * @e: the physical eraseblock to add
+- * @pe: protection entry object to use
+- * @abs_ec: absolute erase counter value when this physical eraseblock has
+- * to be removed from the protection trees.
+  *
+- * @wl->lock has to be locked.
++ * This function adds @e to the tail of the protection queue @ubi->pq, where
++ * @e will stay for %UBI_PROT_QUEUE_LEN erase operations and will be
++ * temporarily protected from the wear-leveling worker. Note, @wl->lock has to
++ * be locked.
+  */
+-static void prot_tree_add(struct ubi_device *ubi, struct ubi_wl_entry *e,
+-			  struct ubi_wl_prot_entry *pe, int abs_ec)
++static void prot_queue_add(struct ubi_device *ubi, struct ubi_wl_entry *e)
+ {
+-	struct rb_node **p, *parent = NULL;
+-	struct ubi_wl_prot_entry *pe1;
+-
+-	pe->e = e;
+-	pe->abs_ec = ubi->abs_ec + abs_ec;
+-
+-	p = &ubi->prot.pnum.rb_node;
+-	while (*p) {
+-		parent = *p;
+-		pe1 = rb_entry(parent, struct ubi_wl_prot_entry, rb_pnum);
+-
+-		if (e->pnum < pe1->e->pnum)
+-			p = &(*p)->rb_left;
+-		else
+-			p = &(*p)->rb_right;
+-	}
+-	rb_link_node(&pe->rb_pnum, parent, p);
+-	rb_insert_color(&pe->rb_pnum, &ubi->prot.pnum);
+-
+-	p = &ubi->prot.aec.rb_node;
+-	parent = NULL;
+-	while (*p) {
+-		parent = *p;
+-		pe1 = rb_entry(parent, struct ubi_wl_prot_entry, rb_aec);
++	int pq_tail = ubi->pq_head - 1;
+ 
+-		if (pe->abs_ec < pe1->abs_ec)
+-			p = &(*p)->rb_left;
+-		else
+-			p = &(*p)->rb_right;
+-	}
+-	rb_link_node(&pe->rb_aec, parent, p);
+-	rb_insert_color(&pe->rb_aec, &ubi->prot.aec);
++	if (pq_tail < 0)
++		pq_tail = UBI_PROT_QUEUE_LEN - 1;
++	ubi_assert(pq_tail >= 0 && pq_tail < UBI_PROT_QUEUE_LEN);
++	list_add_tail(&e->u.list, &ubi->pq[pq_tail]);
++	dbg_wl("added PEB %d EC %d to the protection queue", e->pnum, e->ec);
+ }
+ 
+ /**
+@@ -422,14 +355,14 @@
+ 	struct rb_node *p;
+ 	struct ubi_wl_entry *e;
+ 
+-	e = rb_entry(rb_first(root), struct ubi_wl_entry, rb);
++	e = rb_entry(rb_first(root), struct ubi_wl_entry, u.rb);
+ 	max += e->ec;
+ 
+ 	p = root->rb_node;
+ 	while (p) {
+ 		struct ubi_wl_entry *e1;
+ 
+-		e1 = rb_entry(p, struct ubi_wl_entry, rb);
++		e1 = rb_entry(p, struct ubi_wl_entry, u.rb);
+ 		if (e1->ec >= max)
+ 			p = p->rb_left;
+ 		else {
+@@ -451,17 +384,12 @@
+  */
+ int ubi_wl_get_peb(struct ubi_device *ubi, int dtype)
+ {
+-	int err, protect, medium_ec;
++	int err, medium_ec;
+ 	struct ubi_wl_entry *e, *first, *last;
+-	struct ubi_wl_prot_entry *pe;
+ 
+ 	ubi_assert(dtype == UBI_LONGTERM || dtype == UBI_SHORTTERM ||
+ 		   dtype == UBI_UNKNOWN);
+ 
+-	pe = kmalloc(sizeof(struct ubi_wl_prot_entry), GFP_NOFS);
+-	if (!pe)
+-		return -ENOMEM;
+-
+ retry:
+ 	spin_lock(&ubi->wl_lock);
+ 	if (!ubi->free.rb_node) {
+@@ -469,110 +397,91 @@
+ 			ubi_assert(list_empty(&ubi->works));
+ 			ubi_err("no free eraseblocks");
+ 			spin_unlock(&ubi->wl_lock);
+-			kfree(pe);
+ 			return -ENOSPC;
+ 		}
+ 		spin_unlock(&ubi->wl_lock);
+ 
+ 		err = produce_free_peb(ubi);
+-		if (err < 0) {
+-			kfree(pe);
++		if (err < 0)
+ 			return err;
+-		}
+ 		goto retry;
+ 	}
+ 
+ 	switch (dtype) {
+-		case UBI_LONGTERM:
+-			/*
+-			 * For long term data we pick a physical eraseblock
+-			 * with high erase counter. But the highest erase
+-			 * counter we can pick is bounded by the the lowest
+-			 * erase counter plus %WL_FREE_MAX_DIFF.
+-			 */
+-			e = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF);
+-			protect = LT_PROTECTION;
+-			break;
+-		case UBI_UNKNOWN:
+-			/*
+-			 * For unknown data we pick a physical eraseblock with
+-			 * medium erase counter. But we by no means can pick a
+-			 * physical eraseblock with erase counter greater or
+-			 * equivalent than the lowest erase counter plus
+-			 * %WL_FREE_MAX_DIFF.
+-			 */
+-			first = rb_entry(rb_first(&ubi->free),
+-					 struct ubi_wl_entry, rb);
+-			last = rb_entry(rb_last(&ubi->free),
+-					struct ubi_wl_entry, rb);
++	case UBI_LONGTERM:
++		/*
++		 * For long term data we pick a physical eraseblock with high
++		 * erase counter. But the highest erase counter we can pick is
++		 * bounded by the the lowest erase counter plus
++		 * %WL_FREE_MAX_DIFF.
++		 */
++		e = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF);
++		break;
++	case UBI_UNKNOWN:
++		/*
++		 * For unknown data we pick a physical eraseblock with medium
++		 * erase counter. But we by no means can pick a physical
++		 * eraseblock with erase counter greater or equivalent than the
++		 * lowest erase counter plus %WL_FREE_MAX_DIFF.
++		 */
++		first = rb_entry(rb_first(&ubi->free), struct ubi_wl_entry,
++					u.rb);
++		last = rb_entry(rb_last(&ubi->free), struct ubi_wl_entry, u.rb);
+ 
+-			if (last->ec - first->ec < WL_FREE_MAX_DIFF)
+-				e = rb_entry(ubi->free.rb_node,
+-						struct ubi_wl_entry, rb);
+-			else {
+-				medium_ec = (first->ec + WL_FREE_MAX_DIFF)/2;
+-				e = find_wl_entry(&ubi->free, medium_ec);
+-			}
+-			protect = U_PROTECTION;
+-			break;
+-		case UBI_SHORTTERM:
+-			/*
+-			 * For short term data we pick a physical eraseblock
+-			 * with the lowest erase counter as we expect it will
+-			 * be erased soon.
+-			 */
+-			e = rb_entry(rb_first(&ubi->free),
+-				     struct ubi_wl_entry, rb);
+-			protect = ST_PROTECTION;
+-			break;
+-		default:
+-			protect = 0;
+-			e = NULL;
+-			BUG();
++		if (last->ec - first->ec < WL_FREE_MAX_DIFF)
++			e = rb_entry(ubi->free.rb_node,
++					struct ubi_wl_entry, u.rb);
++		else {
++			medium_ec = (first->ec + WL_FREE_MAX_DIFF)/2;
++			e = find_wl_entry(&ubi->free, medium_ec);
++		}
++		break;
++	case UBI_SHORTTERM:
++		/*
++		 * For short term data we pick a physical eraseblock with the
++		 * lowest erase counter as we expect it will be erased soon.
++		 */
++		e = rb_entry(rb_first(&ubi->free), struct ubi_wl_entry, u.rb);
++		break;
++	default:
++		BUG();
+ 	}
+ 
++	paranoid_check_in_wl_tree(e, &ubi->free);
++
+ 	/*
+-	 * Move the physical eraseblock to the protection trees where it will
++	 * Move the physical eraseblock to the protection queue where it will
+ 	 * be protected from being moved for some time.
+ 	 */
+-	paranoid_check_in_wl_tree(e, &ubi->free);
+-	rb_erase(&e->rb, &ubi->free);
+-	prot_tree_add(ubi, e, pe, protect);
+-
+-	dbg_wl("PEB %d EC %d, protection %d", e->pnum, e->ec, protect);
++	rb_erase(&e->u.rb, &ubi->free);
++	dbg_wl("PEB %d EC %d", e->pnum, e->ec);
++	prot_queue_add(ubi, e);
+ 	spin_unlock(&ubi->wl_lock);
+-
+ 	return e->pnum;
+ }
+ 
+ /**
+- * prot_tree_del - remove a physical eraseblock from the protection trees
++ * prot_queue_del - remove a physical eraseblock from the protection queue.
+  * @ubi: UBI device description object
+  * @pnum: the physical eraseblock to remove
++ *
++ * This function deletes PEB @pnum from the protection queue and returns zero
++ * in case of success and %-ENODEV if the PEB was not found.
+  */
+-static void prot_tree_del(struct ubi_device *ubi, int pnum)
++static int prot_queue_del(struct ubi_device *ubi, int pnum)
+ {
+-	struct rb_node *p;
+-	struct ubi_wl_prot_entry *pe = NULL;
+-
+-	p = ubi->prot.pnum.rb_node;
+-	while (p) {
+-
+-		pe = rb_entry(p, struct ubi_wl_prot_entry, rb_pnum);
++	struct ubi_wl_entry *e;
+ 
+-		if (pnum == pe->e->pnum)
+-			break;
++	e = ubi->lookuptbl[pnum];
++	if (!e)
++		return -ENODEV;
+ 
+-		if (pnum < pe->e->pnum)
+-			p = p->rb_left;
+-		else
+-			p = p->rb_right;
+-	}
++	if (paranoid_check_in_pq(ubi, e))
++		return -ENODEV;
+ 
+-	ubi_assert(pe->e->pnum == pnum);
+-	rb_erase(&pe->rb_aec, &ubi->prot.aec);
+-	rb_erase(&pe->rb_pnum, &ubi->prot.pnum);
+-	kfree(pe);
++	list_del(&e->u.list);
++	dbg_wl("deleted PEB %d from the protection queue", e->pnum);
++	return 0;
+ }
+ 
+ /**
+@@ -584,7 +493,8 @@
+  * This function returns zero in case of success and a negative error code in
+  * case of failure.
+  */
+-static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e, int torture)
++static int sync_erase(struct ubi_device *ubi, struct ubi_wl_entry *e,
++		      int torture)
+ {
+ 	int err;
+ 	struct ubi_ec_hdr *ec_hdr;
+@@ -636,48 +546,47 @@
+ }
+ 
+ /**
+- * check_protection_over - check if it is time to stop protecting some
+- * physical eraseblocks.
++ * serve_prot_queue - check if it is time to stop protecting PEBs.
+  * @ubi: UBI device description object
+  *
+- * This function is called after each erase operation, when the absolute erase
+- * counter is incremented, to check if some physical eraseblock  have not to be
+- * protected any longer. These physical eraseblocks are moved from the
+- * protection trees to the used tree.
++ * This function is called after each erase operation and removes PEBs from the
++ * tail of the protection queue. These PEBs have been protected for long enough
++ * and should be moved to the used tree.
+  */
+-static void check_protection_over(struct ubi_device *ubi)
++static void serve_prot_queue(struct ubi_device *ubi)
+ {
+-	struct ubi_wl_prot_entry *pe;
++	struct ubi_wl_entry *e, *tmp;
++	int count;
+ 
+ 	/*
+ 	 * There may be several protected physical eraseblock to remove,
+ 	 * process them all.
+ 	 */
+-	while (1) {
+-		spin_lock(&ubi->wl_lock);
+-		if (!ubi->prot.aec.rb_node) {
+-			spin_unlock(&ubi->wl_lock);
+-			break;
+-		}
+-
+-		pe = rb_entry(rb_first(&ubi->prot.aec),
+-			      struct ubi_wl_prot_entry, rb_aec);
++repeat:
++	count = 0;
++	spin_lock(&ubi->wl_lock);
++	list_for_each_entry_safe(e, tmp, &ubi->pq[ubi->pq_head], u.list) {
++		dbg_wl("PEB %d EC %d protection over, move to used tree",
++			e->pnum, e->ec);
+ 
+-		if (pe->abs_ec > ubi->abs_ec) {
++		list_del(&e->u.list);
++		wl_tree_add(e, &ubi->used);
++		if (count++ > 32) {
++			/*
++			 * Let's be nice and avoid holding the spinlock for
++			 * too long.
++			 */
+ 			spin_unlock(&ubi->wl_lock);
+-			break;
++			cond_resched();
++			goto repeat;
+ 		}
+-
+-		dbg_wl("PEB %d protection over, abs_ec %llu, PEB abs_ec %llu",
+-		       pe->e->pnum, ubi->abs_ec, pe->abs_ec);
+-		rb_erase(&pe->rb_aec, &ubi->prot.aec);
+-		rb_erase(&pe->rb_pnum, &ubi->prot.pnum);
+-		wl_tree_add(pe->e, &ubi->used);
+-		spin_unlock(&ubi->wl_lock);
+-
+-		kfree(pe);
+-		cond_resched();
+ 	}
++
++	ubi->pq_head += 1;
++	if (ubi->pq_head == UBI_PROT_QUEUE_LEN)
++		ubi->pq_head = 0;
++	ubi_assert(ubi->pq_head >= 0 && ubi->pq_head < UBI_PROT_QUEUE_LEN);
++	spin_unlock(&ubi->wl_lock);
+ }
+ 
+ /**
+@@ -685,8 +594,8 @@
+  * @ubi: UBI device description object
+  * @wrk: the work to schedule
+  *
+- * This function enqueues a work defined by @wrk to the tail of the pending
+- * works list.
++ * This function adds a work defined by @wrk to the tail of the pending works
++ * list.
+  */
+ static void schedule_ubi_work(struct ubi_device *ubi, struct ubi_work *wrk)
+ {
+@@ -744,12 +653,11 @@
+ static int wear_leveling_worker(struct ubi_device *ubi, struct ubi_work *wrk,
+ 				int cancel)
+ {
+-	int err, put = 0;
++	int err, scrubbing = 0, torture = 0;
+ 	struct ubi_wl_entry *e1, *e2;
+ 	struct ubi_vid_hdr *vid_hdr;
+ 
+ 	kfree(wrk);
+-
+ 	if (cancel)
+ 		return 0;
+ 
+@@ -757,21 +665,17 @@
+ 	if (!vid_hdr)
+ 		return -ENOMEM;
+ 
++	mutex_lock(&ubi->move_mutex);
+ 	spin_lock(&ubi->wl_lock);
++	ubi_assert(!ubi->move_from && !ubi->move_to);
++	ubi_assert(!ubi->move_to_put);
+ 
+-	/*
+-	 * Only one WL worker at a time is supported at this implementation, so
+-	 * make sure a PEB is not being moved already.
+-	 */
+-	if (ubi->move_to || !ubi->free.rb_node ||
++	if (!ubi->free.rb_node ||
+ 	    (!ubi->used.rb_node && !ubi->scrub.rb_node)) {
+ 		/*
+-		 * Only one WL worker at a time is supported at this
+-		 * implementation, so if a LEB is already being moved, cancel.
+-		 *
+-		 * No free physical eraseblocks? Well, we cancel wear-leveling
+-		 * then. It will be triggered again when a free physical
+-		 * eraseblock appears.
++		 * No free physical eraseblocks? Well, they must be waiting in
++		 * the queue to be erased. Cancel movement - it will be
++		 * triggered again when a free physical eraseblock appears.
+ 		 *
+ 		 * No used physical eraseblocks? They must be temporarily
+ 		 * protected from being moved. They will be moved to the
+@@ -780,10 +684,7 @@
+ 		 */
+ 		dbg_wl("cancel WL, a list is empty: free %d, used %d",
+ 		       !ubi->free.rb_node, !ubi->used.rb_node);
+-		ubi->wl_scheduled = 0;
+-		spin_unlock(&ubi->wl_lock);
+-		ubi_free_vid_hdr(ubi, vid_hdr);
+-		return 0;
++		goto out_cancel;
+ 	}
+ 
+ 	if (!ubi->scrub.rb_node) {
+@@ -792,33 +693,30 @@
+ 		 * highly worn-out free physical eraseblock. If the erase
+ 		 * counters differ much enough, start wear-leveling.
+ 		 */
+-		e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, rb);
++		e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, u.rb);
+ 		e2 = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF);
+ 
+ 		if (!(e2->ec - e1->ec >= UBI_WL_THRESHOLD)) {
+ 			dbg_wl("no WL needed: min used EC %d, max free EC %d",
+ 			       e1->ec, e2->ec);
+-			ubi->wl_scheduled = 0;
+-			spin_unlock(&ubi->wl_lock);
+-			ubi_free_vid_hdr(ubi, vid_hdr);
+-			return 0;
++			goto out_cancel;
+ 		}
+ 		paranoid_check_in_wl_tree(e1, &ubi->used);
+-		rb_erase(&e1->rb, &ubi->used);
++		rb_erase(&e1->u.rb, &ubi->used);
+ 		dbg_wl("move PEB %d EC %d to PEB %d EC %d",
+ 		       e1->pnum, e1->ec, e2->pnum, e2->ec);
+ 	} else {
+-		e1 = rb_entry(rb_first(&ubi->scrub), struct ubi_wl_entry, rb);
++		/* Perform scrubbing */
++		scrubbing = 1;
++		e1 = rb_entry(rb_first(&ubi->scrub), struct ubi_wl_entry, u.rb);
+ 		e2 = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF);
+ 		paranoid_check_in_wl_tree(e1, &ubi->scrub);
+-	rb_erase(&e1->rb, &ubi->scrub);
++		rb_erase(&e1->u.rb, &ubi->scrub);
+ 		dbg_wl("scrub PEB %d to PEB %d", e1->pnum, e2->pnum);
+ 	}
+ 
+ 	paranoid_check_in_wl_tree(e2, &ubi->free);
+-	rb_erase(&e2->rb, &ubi->free);
+-	ubi_assert(!ubi->move_from && !ubi->move_to);
+-	ubi_assert(!ubi->move_to_put && !ubi->move_from_put);
++	rb_erase(&e2->u.rb, &ubi->free);
+ 	ubi->move_from = e1;
+ 	ubi->move_to = e2;
+ 	spin_unlock(&ubi->wl_lock);
+@@ -828,6 +726,10 @@
+ 	 * We so far do not know which logical eraseblock our physical
+ 	 * eraseblock (@e1) belongs to. We have to read the volume identifier
+ 	 * header first.
++	 *
++	 * Note, we are protected from this PEB being unmapped and erased. The
++	 * 'ubi_wl_put_peb()' would wait for moving to be finished if the PEB
++	 * which is being moved was unmapped.
+ 	 */
+ 
+ 	err = ubi_io_read_vid_hdr(ubi, e1->pnum, vid_hdr, 0);
+@@ -842,97 +744,145 @@
+ 			 * likely have the VID header in place.
+ 			 */
+ 			dbg_wl("PEB %d has no VID header", e1->pnum);
+-			err = 0;
+-		} else {
+-			ubi_err("error %d while reading VID header from PEB %d",
+-				err, e1->pnum);
+-			if (err > 0)
+-				err = -EIO;
++			goto out_not_moved;
+ 		}
+-		goto error;
++
++		ubi_err("error %d while reading VID header from PEB %d",
++			err, e1->pnum);
++		if (err > 0)
++			err = -EIO;
++		goto out_error;
+ 	}
+ 
+ 	err = ubi_eba_copy_leb(ubi, e1->pnum, e2->pnum, vid_hdr);
+ 	if (err) {
+-		if (err == UBI_IO_BITFLIPS)
+-			err = 0;
+-		goto error;
++		if (err == -EAGAIN)
++			goto out_not_moved;
++		if (err < 0)
++			goto out_error;
++		if (err == 2) {
++			/* Target PEB write error, torture it */
++			torture = 1;
++			goto out_not_moved;
++		}
++
++		/*
++		 * The LEB has not been moved because the volume is being
++		 * deleted or the PEB has been put meanwhile. We should prevent
++		 * this PEB from being selected for wear-leveling movement
++		 * again, so put it to the protection queue.
++		 */
++
++		dbg_wl("canceled moving PEB %d", e1->pnum);
++		ubi_assert(err == 1);
++
++		ubi_free_vid_hdr(ubi, vid_hdr);
++		vid_hdr = NULL;
++
++		spin_lock(&ubi->wl_lock);
++		prot_queue_add(ubi, e1);
++		ubi_assert(!ubi->move_to_put);
++		ubi->move_from = ubi->move_to = NULL;
++		ubi->wl_scheduled = 0;
++		spin_unlock(&ubi->wl_lock);
++
++		e1 = NULL;
++		err = schedule_erase(ubi, e2, 0);
++		if (err)
++			goto out_error;
++		mutex_unlock(&ubi->move_mutex);
++		return 0;
+ 	}
+ 
++	/* The PEB has been successfully moved */
+ 	ubi_free_vid_hdr(ubi, vid_hdr);
++	vid_hdr = NULL;
++	if (scrubbing)
++		ubi_msg("scrubbed PEB %d, data moved to PEB %d",
++			e1->pnum, e2->pnum);
++
+ 	spin_lock(&ubi->wl_lock);
+-	if (!ubi->move_to_put)
++	if (!ubi->move_to_put) {
+ 		wl_tree_add(e2, &ubi->used);
+-	else
+-		put = 1;
++		e2 = NULL;
++	}
+ 	ubi->move_from = ubi->move_to = NULL;
+-	ubi->move_from_put = ubi->move_to_put = 0;
+-	ubi->wl_scheduled = 0;
++	ubi->move_to_put = ubi->wl_scheduled = 0;
+ 	spin_unlock(&ubi->wl_lock);
+ 
+-	if (put) {
++	err = schedule_erase(ubi, e1, 0);
++	if (err) {
++		e1 = NULL;
++		goto out_error;
++	}
++
++	if (e2) {
+ 		/*
+ 		 * Well, the target PEB was put meanwhile, schedule it for
+ 		 * erasure.
+ 		 */
+ 		dbg_wl("PEB %d was put meanwhile, erase", e2->pnum);
+ 		err = schedule_erase(ubi, e2, 0);
+-		if (err) {
+-			kmem_cache_free(wl_entries_slab, e2);
+-			ubi_ro_mode(ubi);
+-		}
+-	}
+-
+-	err = schedule_erase(ubi, e1, 0);
+-	if (err) {
+-		kmem_cache_free(wl_entries_slab, e1);
+-		ubi_ro_mode(ubi);
++		if (err)
++			goto out_error;
+ 	}
+ 
+ 	dbg_wl("done");
+-	return err;
++	mutex_unlock(&ubi->move_mutex);
++	return 0;
+ 
+ 	/*
+-	 * Some error occurred. @e1 was not changed, so return it back. @e2
+-	 * might be changed, schedule it for erasure.
++	 * For some reasons the LEB was not moved, might be an error, might be
++	 * something else. @e1 was not changed, so return it back. @e2 might
++	 * have been changed, schedule it for erasure.
+ 	 */
+-error:
+-	if (err)
+-		dbg_wl("error %d occurred, cancel operation", err);
+-	ubi_assert(err <= 0);
+-
++out_not_moved:
++	dbg_wl("canceled moving PEB %d", e1->pnum);
+ 	ubi_free_vid_hdr(ubi, vid_hdr);
++	vid_hdr = NULL;
+ 	spin_lock(&ubi->wl_lock);
+-	ubi->wl_scheduled = 0;
+-	if (ubi->move_from_put)
+-		put = 1;
++	if (scrubbing)
++		wl_tree_add(e1, &ubi->scrub);
+ 	else
+ 		wl_tree_add(e1, &ubi->used);
++	ubi_assert(!ubi->move_to_put);
+ 	ubi->move_from = ubi->move_to = NULL;
+-	ubi->move_from_put = ubi->move_to_put = 0;
++	ubi->wl_scheduled = 0;
+ 	spin_unlock(&ubi->wl_lock);
+ 
+-	if (put) {
+-		/*
+-		 * Well, the target PEB was put meanwhile, schedule it for
+-		 * erasure.
+-		 */
+-		dbg_wl("PEB %d was put meanwhile, erase", e1->pnum);
+-		err = schedule_erase(ubi, e1, 0);
+-		if (err) {
+-			kmem_cache_free(wl_entries_slab, e1);
+-			ubi_ro_mode(ubi);
+-		}
+-	}
++	e1 = NULL;
++	err = schedule_erase(ubi, e2, torture);
++	if (err)
++		goto out_error;
+ 
+-	err = schedule_erase(ubi, e2, 0);
+-	if (err) {
+-		kmem_cache_free(wl_entries_slab, e2);
+-		ubi_ro_mode(ubi);
+-	}
++	mutex_unlock(&ubi->move_mutex);
++	return 0;
+ 
+-	yield();
++out_error:
++	ubi_err("error %d while moving PEB %d to PEB %d",
++		err, e1->pnum, e2->pnum);
++
++	ubi_free_vid_hdr(ubi, vid_hdr);
++	spin_lock(&ubi->wl_lock);
++	ubi->move_from = ubi->move_to = NULL;
++	ubi->move_to_put = ubi->wl_scheduled = 0;
++	spin_unlock(&ubi->wl_lock);
++
++	if (e1)
++		kmem_cache_free(ubi_wl_entry_slab, e1);
++	if (e2)
++		kmem_cache_free(ubi_wl_entry_slab, e2);
++	ubi_ro_mode(ubi);
++
++	mutex_unlock(&ubi->move_mutex);
+ 	return err;
++
++out_cancel:
++	ubi->wl_scheduled = 0;
++	spin_unlock(&ubi->wl_lock);
++	mutex_unlock(&ubi->move_mutex);
++	ubi_free_vid_hdr(ubi, vid_hdr);
++	return 0;
+ }
+ 
+ /**
+@@ -970,7 +920,7 @@
+ 		 * erase counter of free physical eraseblocks is greater then
+ 		 * %UBI_WL_THRESHOLD.
+ 		 */
+-		e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, rb);
++		e1 = rb_entry(rb_first(&ubi->used), struct ubi_wl_entry, u.rb);
+ 		e2 = find_wl_entry(&ubi->free, WL_FREE_MAX_DIFF);
+ 
+ 		if (!(e2->ec - e1->ec >= UBI_WL_THRESHOLD))
+@@ -1020,7 +970,7 @@
+ 	if (cancel) {
+ 		dbg_wl("cancel erasure of PEB %d EC %d", pnum, e->ec);
+ 		kfree(wl_wrk);
+-		kmem_cache_free(wl_entries_slab, e);
++		kmem_cache_free(ubi_wl_entry_slab, e);
+ 		return 0;
+ 	}
+ 
+@@ -1032,15 +982,14 @@
+ 		kfree(wl_wrk);
+ 
+ 		spin_lock(&ubi->wl_lock);
+-		ubi->abs_ec += 1;
+ 		wl_tree_add(e, &ubi->free);
+ 		spin_unlock(&ubi->wl_lock);
+ 
+ 		/*
+-		 * One more erase operation has happened, take care about protected
+-		 * physical eraseblocks.
++		 * One more erase operation has happened, take care about
++		 * protected physical eraseblocks.
+ 		 */
+-		check_protection_over(ubi);
++		serve_prot_queue(ubi);
+ 
+ 		/* And take care about wear-leveling */
+ 		err = ensure_wear_leveling(ubi);
+@@ -1049,7 +998,7 @@
+ 
+ 	ubi_err("failed to erase PEB %d, error %d", pnum, err);
+ 	kfree(wl_wrk);
+-	kmem_cache_free(wl_entries_slab, e);
++	kmem_cache_free(ubi_wl_entry_slab, e);
+ 
+ 	if (err == -EINTR || err == -ENOMEM || err == -EAGAIN ||
+ 	    err == -EBUSY) {
+@@ -1119,8 +1068,7 @@
+ }
+ 
+ /**
+- * ubi_wl_put_peb - return a physical eraseblock to the wear-leveling
+- * unit.
++ * ubi_wl_put_peb - return a PEB to the wear-leveling sub-system.
+  * @ubi: UBI device description object
+  * @pnum: physical eraseblock to return
+  * @torture: if this physical eraseblock has to be tortured
+@@ -1128,7 +1076,7 @@
+  * This function is called to return physical eraseblock @pnum to the pool of
+  * free physical eraseblocks. The @torture flag has to be set if an I/O error
+  * occurred to this @pnum and it has to be tested. This function returns zero
+- * in case of success and a negative error code in case of failure.
++ * in case of success, and a negative error code in case of failure.
+  */
+ int ubi_wl_put_peb(struct ubi_device *ubi, int pnum, int torture)
+ {
+@@ -1139,8 +1087,8 @@
+ 	ubi_assert(pnum >= 0);
+ 	ubi_assert(pnum < ubi->peb_count);
+ 
++retry:
+ 	spin_lock(&ubi->wl_lock);
+-
+ 	e = ubi->lookuptbl[pnum];
+ 	if (e == ubi->move_from) {
+ 		/*
+@@ -1148,17 +1096,22 @@
+ 		 * be moved. It will be scheduled for erasure in the
+ 		 * wear-leveling worker.
+ 		 */
+-		dbg_wl("PEB %d is being moved", pnum);
+-		ubi_assert(!ubi->move_from_put);
+-		ubi->move_from_put = 1;
++		dbg_wl("PEB %d is being moved, wait", pnum);
+ 		spin_unlock(&ubi->wl_lock);
+-		return 0;
++
++		/* Wait for the WL worker by taking the @ubi->move_mutex */
++		mutex_lock(&ubi->move_mutex);
++		mutex_unlock(&ubi->move_mutex);
++		goto retry;
+ 	} else if (e == ubi->move_to) {
+ 		/*
+ 		 * User is putting the physical eraseblock which was selected
+ 		 * as the target the data is moved to. It may happen if the EBA
+-		 * unit already re-mapped the LEB but the WL unit did has not
+-		 * put the PEB to the "used" tree.
++		 * sub-system already re-mapped the LEB in 'ubi_eba_copy_leb()'
++		 * but the WL sub-system has not put the PEB to the "used" tree
++		 * yet, but it is about to do this. So we just set a flag which
++		 * will tell the WL worker that the PEB is not needed anymore
++		 * and should be scheduled for erasure.
+ 		 */
+ 		dbg_wl("PEB %d is the target of data moving", pnum);
+ 		ubi_assert(!ubi->move_to_put);
+@@ -1168,12 +1121,19 @@
+ 	} else {
+ 		if (in_wl_tree(e, &ubi->used)) {
+ 			paranoid_check_in_wl_tree(e, &ubi->used);
+-			rb_erase(&e->rb, &ubi->used);
++			rb_erase(&e->u.rb, &ubi->used);
+ 		} else if (in_wl_tree(e, &ubi->scrub)) {
+ 			paranoid_check_in_wl_tree(e, &ubi->scrub);
+-			rb_erase(&e->rb, &ubi->scrub);
+-		} else
+-			prot_tree_del(ubi, e->pnum);
++			rb_erase(&e->u.rb, &ubi->scrub);
++		} else {
++			err = prot_queue_del(ubi, e->pnum);
++			if (err) {
++				ubi_err("PEB %d not found", pnum);
++				ubi_ro_mode(ubi);
++				spin_unlock(&ubi->wl_lock);
++				return err;
++			}
++		}
+ 	}
+ 	spin_unlock(&ubi->wl_lock);
+ 
+@@ -1201,7 +1161,7 @@
+ {
+ 	struct ubi_wl_entry *e;
+ 
+-	ubi_msg("schedule PEB %d for scrubbing", pnum);
++	dbg_msg("schedule PEB %d for scrubbing", pnum);
+ 
+ retry:
+ 	spin_lock(&ubi->wl_lock);
+@@ -1226,9 +1186,18 @@
+ 
+ 	if (in_wl_tree(e, &ubi->used)) {
+ 		paranoid_check_in_wl_tree(e, &ubi->used);
+-		rb_erase(&e->rb, &ubi->used);
+-	} else
+-		prot_tree_del(ubi, pnum);
++		rb_erase(&e->u.rb, &ubi->used);
++	} else {
++		int err;
++
++		err = prot_queue_del(ubi, e->pnum);
++		if (err) {
++			ubi_err("PEB %d not found", pnum);
++			ubi_ro_mode(ubi);
++			spin_unlock(&ubi->wl_lock);
++			return err;
++		}
++	}
+ 
+ 	wl_tree_add(e, &ubi->scrub);
+ 	spin_unlock(&ubi->wl_lock);
+@@ -1249,17 +1218,32 @@
+  */
+ int ubi_wl_flush(struct ubi_device *ubi)
+ {
+-	int err, pending_count;
++	int err;
+ 
+-	pending_count = ubi->works_count;
++	/*
++	 * Erase while the pending works queue is not empty, but not more than
++	 * the number of currently pending works.
++	 */
++	dbg_wl("flush (%d pending works)", ubi->works_count);
++	while (ubi->works_count) {
++		err = do_work(ubi);
++		if (err)
++			return err;
++	}
+ 
+-	dbg_wl("flush (%d pending works)", pending_count);
++	/*
++	 * Make sure all the works which have been done in parallel are
++	 * finished.
++	 */
++	down_write(&ubi->work_sem);
++	up_write(&ubi->work_sem);
+ 
+ 	/*
+-	 * Erase while the pending works queue is not empty, but not more then
+-	 * the number of currently pending works.
++	 * And in case last was the WL worker and it canceled the LEB
++	 * movement, flush again.
+ 	 */
+-	while (pending_count-- > 0) {
++	while (ubi->works_count) {
++		dbg_wl("flush more (%d pending works)", ubi->works_count);
+ 		err = do_work(ubi);
+ 		if (err)
+ 			return err;
+@@ -1284,17 +1268,17 @@
+ 		else if (rb->rb_right)
+ 			rb = rb->rb_right;
+ 		else {
+-			e = rb_entry(rb, struct ubi_wl_entry, rb);
++			e = rb_entry(rb, struct ubi_wl_entry, u.rb);
+ 
+ 			rb = rb_parent(rb);
+ 			if (rb) {
+-				if (rb->rb_left == &e->rb)
++				if (rb->rb_left == &e->u.rb)
+ 					rb->rb_left = NULL;
+ 				else
+ 					rb->rb_right = NULL;
+ 			}
+ 
+-			kmem_cache_free(wl_entries_slab, e);
++			kmem_cache_free(ubi_wl_entry_slab, e);
+ 		}
+ 	}
+ }
+@@ -1303,7 +1287,7 @@
+  * ubi_thread - UBI background thread.
+  * @u: the UBI device description object pointer
+  */
+-static int ubi_thread(void *u)
++int ubi_thread(void *u)
+ {
+ 	int failures = 0;
+ 	struct ubi_device *ubi = u;
+@@ -1316,7 +1300,7 @@
+ 		int err;
+ 
+ 		if (kthread_should_stop())
+-			goto out;
++			break;
+ 
+ 		if (try_to_freeze())
+ 			continue;
+@@ -1343,7 +1327,8 @@
+ 				ubi_msg("%s: %d consecutive failures",
+ 					ubi->bgt_name, WL_MAX_FAILURES);
+ 				ubi_ro_mode(ubi);
+-				break;
++				ubi->thread_enabled = 0;
++				continue;
+ 			}
+ 		} else
+ 			failures = 0;
+@@ -1351,7 +1336,6 @@
+ 		cond_resched();
+ 	}
+ 
+-out:
+ 	dbg_wl("background thread \"%s\" is killed", ubi->bgt_name);
+ 	return 0;
+ }
+@@ -1374,8 +1358,7 @@
+ }
+ 
+ /**
+- * ubi_wl_init_scan - initialize the wear-leveling unit using scanning
+- * information.
++ * ubi_wl_init_scan - initialize the WL sub-system using scanning information.
+  * @ubi: UBI device description object
+  * @si: scanning information
+  *
+@@ -1384,46 +1367,34 @@
+  */
+ int ubi_wl_init_scan(struct ubi_device *ubi, struct ubi_scan_info *si)
+ {
+-	int err;
++	int err, i;
+ 	struct rb_node *rb1, *rb2;
+ 	struct ubi_scan_volume *sv;
+ 	struct ubi_scan_leb *seb, *tmp;
+ 	struct ubi_wl_entry *e;
+ 
+-
+ 	ubi->used = ubi->free = ubi->scrub = RB_ROOT;
+-	ubi->prot.pnum = ubi->prot.aec = RB_ROOT;
+ 	spin_lock_init(&ubi->wl_lock);
++	mutex_init(&ubi->move_mutex);
++	init_rwsem(&ubi->work_sem);
+ 	ubi->max_ec = si->max_ec;
+ 	INIT_LIST_HEAD(&ubi->works);
+ 
+ 	sprintf(ubi->bgt_name, UBI_BGT_NAME_PATTERN, ubi->ubi_num);
+ 
+-	ubi->bgt_thread = kthread_create(ubi_thread, ubi, ubi->bgt_name);
+-	if (IS_ERR(ubi->bgt_thread)) {
+-		err = PTR_ERR(ubi->bgt_thread);
+-		ubi_err("cannot spawn \"%s\", error %d", ubi->bgt_name,
+-			err);
+-		return err;
+-	}
+-
+-	if (ubi_devices_cnt == 0) {
+-		wl_entries_slab = kmem_cache_create("ubi_wl_entry_slab",
+-						    sizeof(struct ubi_wl_entry),
+-						    0, 0, NULL);
+-		if (!wl_entries_slab)
+-			return -ENOMEM;
+-	}
+-
+ 	err = -ENOMEM;
+ 	ubi->lookuptbl = kzalloc(ubi->peb_count * sizeof(void *), GFP_KERNEL);
+ 	if (!ubi->lookuptbl)
+-		goto out_free;
++		return err;
++
++	for (i = 0; i < UBI_PROT_QUEUE_LEN; i++)
++		INIT_LIST_HEAD(&ubi->pq[i]);
++	ubi->pq_head = 0;
+ 
+ 	list_for_each_entry_safe(seb, tmp, &si->erase, u.list) {
+ 		cond_resched();
+ 
+-		e = kmem_cache_alloc(wl_entries_slab, GFP_KERNEL);
++		e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
+ 		if (!e)
+ 			goto out_free;
+ 
+@@ -1431,7 +1402,7 @@
+ 		e->ec = seb->ec;
+ 		ubi->lookuptbl[e->pnum] = e;
+ 		if (schedule_erase(ubi, e, 0)) {
+-			kmem_cache_free(wl_entries_slab, e);
++			kmem_cache_free(ubi_wl_entry_slab, e);
+ 			goto out_free;
+ 		}
+ 	}
+@@ -1439,7 +1410,7 @@
+ 	list_for_each_entry(seb, &si->free, u.list) {
+ 		cond_resched();
+ 
+-		e = kmem_cache_alloc(wl_entries_slab, GFP_KERNEL);
++		e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
+ 		if (!e)
+ 			goto out_free;
+ 
+@@ -1453,7 +1424,7 @@
+ 	list_for_each_entry(seb, &si->corr, u.list) {
+ 		cond_resched();
+ 
+-		e = kmem_cache_alloc(wl_entries_slab, GFP_KERNEL);
++		e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
+ 		if (!e)
+ 			goto out_free;
+ 
+@@ -1461,7 +1432,7 @@
+ 		e->ec = seb->ec;
+ 		ubi->lookuptbl[e->pnum] = e;
+ 		if (schedule_erase(ubi, e, 0)) {
+-			kmem_cache_free(wl_entries_slab, e);
++			kmem_cache_free(ubi_wl_entry_slab, e);
+ 			goto out_free;
+ 		}
+ 	}
+@@ -1470,7 +1441,7 @@
+ 		ubi_rb_for_each_entry(rb2, seb, &sv->root, u.rb) {
+ 			cond_resched();
+ 
+-			e = kmem_cache_alloc(wl_entries_slab, GFP_KERNEL);
++			e = kmem_cache_alloc(ubi_wl_entry_slab, GFP_KERNEL);
+ 			if (!e)
+ 				goto out_free;
+ 
+@@ -1510,70 +1481,45 @@
+ 	tree_destroy(&ubi->free);
+ 	tree_destroy(&ubi->scrub);
+ 	kfree(ubi->lookuptbl);
+-	if (ubi_devices_cnt == 0)
+-		kmem_cache_destroy(wl_entries_slab);
+ 	return err;
+ }
+ 
+ /**
+- * protection_trees_destroy - destroy the protection RB-trees.
++ * protection_queue_destroy - destroy the protection queue.
+  * @ubi: UBI device description object
+  */
+-static void protection_trees_destroy(struct ubi_device *ubi)
++static void protection_queue_destroy(struct ubi_device *ubi)
+ {
+-	struct rb_node *rb;
+-	struct ubi_wl_prot_entry *pe;
+-
+-	rb = ubi->prot.aec.rb_node;
+-	while (rb) {
+-		if (rb->rb_left)
+-			rb = rb->rb_left;
+-		else if (rb->rb_right)
+-			rb = rb->rb_right;
+-		else {
+-			pe = rb_entry(rb, struct ubi_wl_prot_entry, rb_aec);
+-
+-			rb = rb_parent(rb);
+-			if (rb) {
+-				if (rb->rb_left == &pe->rb_aec)
+-					rb->rb_left = NULL;
+-				else
+-					rb->rb_right = NULL;
+-			}
++	int i;
++	struct ubi_wl_entry *e, *tmp;
+ 
+-			kmem_cache_free(wl_entries_slab, pe->e);
+-			kfree(pe);
++	for (i = 0; i < UBI_PROT_QUEUE_LEN; ++i) {
++		list_for_each_entry_safe(e, tmp, &ubi->pq[i], u.list) {
++			list_del(&e->u.list);
++			kmem_cache_free(ubi_wl_entry_slab, e);
+ 		}
+ 	}
+ }
+ 
+ /**
+- * ubi_wl_close - close the wear-leveling unit.
++ * ubi_wl_close - close the wear-leveling sub-system.
+  * @ubi: UBI device description object
+  */
+ void ubi_wl_close(struct ubi_device *ubi)
+ {
+-	dbg_wl("disable \"%s\"", ubi->bgt_name);
+-	if (ubi->bgt_thread)
+-		kthread_stop(ubi->bgt_thread);
+-
+-	dbg_wl("close the UBI wear-leveling unit");
+-
++	dbg_wl("close the WL sub-system");
+ 	cancel_pending(ubi);
+-	protection_trees_destroy(ubi);
++	protection_queue_destroy(ubi);
+ 	tree_destroy(&ubi->used);
+ 	tree_destroy(&ubi->free);
+ 	tree_destroy(&ubi->scrub);
+ 	kfree(ubi->lookuptbl);
+-	if (ubi_devices_cnt == 1)
+-		kmem_cache_destroy(wl_entries_slab);
+ }
+ 
+ #ifdef CONFIG_MTD_UBI_DEBUG_PARANOID
+ 
+ /**
+- * paranoid_check_ec - make sure that the erase counter of a physical eraseblock
+- * is correct.
++ * paranoid_check_ec - make sure that the erase counter of a PEB is correct.
+  * @ubi: UBI device description object
+  * @pnum: the physical eraseblock number to check
+  * @ec: the erase counter to check
+@@ -1614,13 +1560,12 @@
+ }
+ 
+ /**
+- * paranoid_check_in_wl_tree - make sure that a wear-leveling entry is present
+- * in a WL RB-tree.
++ * paranoid_check_in_wl_tree - check that wear-leveling entry is in WL RB-tree.
+  * @e: the wear-leveling entry to check
+  * @root: the root of the tree
+  *
+- * This function returns zero if @e is in the @root RB-tree and %1 if it
+- * is not.
++ * This function returns zero if @e is in the @root RB-tree and %1 if it is
++ * not.
+  */
+ static int paranoid_check_in_wl_tree(struct ubi_wl_entry *e,
+ 				     struct rb_root *root)
+@@ -1634,4 +1579,27 @@
+ 	return 1;
+ }
+ 
++/**
++ * paranoid_check_in_pq - check if wear-leveling entry is in the protection
++ *                        queue.
++ * @ubi: UBI device description object
++ * @e: the wear-leveling entry to check
++ *
++ * This function returns zero if @e is in @ubi->pq and %1 if it is not.
++ */
++static int paranoid_check_in_pq(struct ubi_device *ubi, struct ubi_wl_entry *e)
++{
++	struct ubi_wl_entry *p;
++	int i;
++
++	for (i = 0; i < UBI_PROT_QUEUE_LEN; ++i)
++		list_for_each_entry(p, &ubi->pq[i], u.list)
++			if (p == e)
++				return 0;
++
++	ubi_err("paranoid check failed for PEB %d, EC %d, Protect queue",
++		e->pnum, e->ec);
++	ubi_dbg_dump_stack();
++	return 1;
++}
+ #endif /* CONFIG_MTD_UBI_DEBUG_PARANOID */
+diff -Nurd linux-2.6.24.orig/fs/Kconfig linux-2.6.24/fs/Kconfig
+--- linux-2.6.24.orig/fs/Kconfig	2009-04-17 09:45:12.000000000 +0200
++++ linux-2.6.24/fs/Kconfig	2009-04-17 09:49:26.000000000 +0200
+@@ -1385,6 +1385,9 @@
+ 
+ endchoice
+ 
++# UBIFS File system configuration
++source "fs/ubifs/Kconfig"
++
+ config CRAMFS
+ 	tristate "Compressed ROM file system support (cramfs)"
+ 	depends on BLOCK
+diff -Nurd linux-2.6.24.orig/fs/Makefile linux-2.6.24/fs/Makefile
+--- linux-2.6.24.orig/fs/Makefile	2009-04-17 09:45:12.000000000 +0200
++++ linux-2.6.24/fs/Makefile	2009-04-17 09:49:28.000000000 +0200
+@@ -100,6 +100,7 @@
+ obj-$(CONFIG_UFS_FS)		+= ufs/
+ obj-$(CONFIG_EFS_FS)		+= efs/
+ obj-$(CONFIG_JFFS2_FS)		+= jffs2/
++obj-$(CONFIG_UBIFS_FS)     += ubifs/
+ obj-$(CONFIG_AFFS_FS)		+= affs/
+ obj-$(CONFIG_ROMFS_FS)		+= romfs/
+ obj-$(CONFIG_QNX4FS_FS)		+= qnx4/
+diff -Nurd linux-2.6.24.orig/fs/fs-writeback.c linux-2.6.24/fs/fs-writeback.c
+--- linux-2.6.24.orig/fs/fs-writeback.c	2009-04-17 09:45:12.000000000 +0200
++++ linux-2.6.24/fs/fs-writeback.c	2009-04-17 09:49:28.000000000 +0200
+@@ -386,8 +386,6 @@
+  * WB_SYNC_HOLD is a hack for sys_sync(): reattach the inode to sb->s_dirty so
+  * that it can be located for waiting on in __writeback_single_inode().
+  *
+- * Called under inode_lock.
+- *
+  * If `bdi' is non-zero then we're being asked to writeback a specific queue.
+  * This function assumes that the blockdev superblock's inodes are backed by
+  * a variety of queues, so all inodes are searched.  For other superblocks,
+@@ -403,11 +401,12 @@
+  * on the writer throttling path, and we get decent balancing between many
+  * throttled threads: we don't want them all piling up on inode_sync_wait.
+  */
+-static void
+-sync_sb_inodes(struct super_block *sb, struct writeback_control *wbc)
++void generic_sync_sb_inodes(struct super_block *sb,
++				struct writeback_control *wbc)
+ {
+ 	const unsigned long start = jiffies;	/* livelock avoidance */
+ 
++	spin_lock(&inode_lock);
+ 	if (!wbc->for_kupdate || list_empty(&sb->s_io))
+ 		queue_io(sb, wbc->older_than_this);
+ 
+@@ -482,8 +481,16 @@
+ 		if (wbc->nr_to_write <= 0)
+ 			break;
+ 	}
++	spin_unlock(&inode_lock);
+ 	return;		/* Leave any unwritten inodes on s_io */
+ }
++EXPORT_SYMBOL_GPL(generic_sync_sb_inodes);
++
++static void sync_sb_inodes(struct super_block *sb,
++				struct writeback_control *wbc)
++{
++	generic_sync_sb_inodes(sb, wbc);
++}
+ 
+ /*
+  * Start writeback of dirty pagecache data against all unlocked inodes.
+@@ -524,11 +531,8 @@
+ 			 * be unmounted by the time it is released.
+ 			 */
+ 			if (down_read_trylock(&sb->s_umount)) {
+-				if (sb->s_root) {
+-					spin_lock(&inode_lock);
++				if (sb->s_root)
+ 					sync_sb_inodes(sb, wbc);
+-					spin_unlock(&inode_lock);
+-				}
+ 				up_read(&sb->s_umount);
+ 			}
+ 			spin_lock(&sb_lock);
+@@ -566,9 +570,7 @@
+ 			(inodes_stat.nr_inodes - inodes_stat.nr_unused) +
+ 			nr_dirty + nr_unstable;
+ 	wbc.nr_to_write += wbc.nr_to_write / 2;		/* Bit more for luck */
+-	spin_lock(&inode_lock);
+ 	sync_sb_inodes(sb, &wbc);
+-	spin_unlock(&inode_lock);
+ }
+ 
+ /*
+diff -Nurd linux-2.6.24.orig/fs/ubifs/Kconfig linux-2.6.24/fs/ubifs/Kconfig
+--- linux-2.6.24.orig/fs/ubifs/Kconfig	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/Kconfig	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,72 @@
++config UBIFS_FS
++	tristate "UBIFS file system support"
++	select CRC16
++	select CRC32
++	select CRYPTO if UBIFS_FS_ADVANCED_COMPR
++	select CRYPTO if UBIFS_FS_LZO
++	select CRYPTO if UBIFS_FS_ZLIB
++	select CRYPTO_LZO if UBIFS_FS_LZO
++	select CRYPTO_DEFLATE if UBIFS_FS_ZLIB
++	depends on MTD_UBI
++	help
++	  UBIFS is a file system for flash devices which works on top of UBI.
++
++config UBIFS_FS_XATTR
++	bool "Extended attributes support"
++	depends on UBIFS_FS
++	help
++	  This option enables support of extended attributes.
++
++config UBIFS_FS_ADVANCED_COMPR
++	bool "Advanced compression options"
++	depends on UBIFS_FS
++	help
++	  This option allows to explicitly choose which compressions, if any,
++	  are enabled in UBIFS. Removing compressors means inbility to read
++	  existing file systems.
++
++	  If unsure, say 'N'.
++
++config UBIFS_FS_LZO
++	bool "LZO compression support" if UBIFS_FS_ADVANCED_COMPR
++	depends on UBIFS_FS
++	default y
++	help
++	   LZO compressor is generally faster then zlib but compresses worse.
++	   Say 'Y' if unsure.
++
++config UBIFS_FS_ZLIB
++	bool "ZLIB compression support" if UBIFS_FS_ADVANCED_COMPR
++	depends on UBIFS_FS
++	default y
++	help
++	  Zlib copresses better then LZO but it is slower. Say 'Y' if unsure.
++
++# Debugging-related stuff
++config UBIFS_FS_DEBUG
++	bool "Enable debugging"
++	depends on UBIFS_FS
++	select DEBUG_FS
++	select KALLSYMS_ALL
++	help
++	  This option enables UBIFS debugging.
++
++config UBIFS_FS_DEBUG_MSG_LVL
++	int "Default message level (0 = no extra messages, 3 = lots)"
++	depends on UBIFS_FS_DEBUG
++	default "0"
++	help
++	  This controls the amount of debugging messages produced by UBIFS.
++	  If reporting bugs, please try to have available a full dump of the
++	  messages at level 1 while the misbehaviour was occurring. Level 2
++	  may become necessary if level 1 messages were not enough to find the
++	  bug. Generally Level 3 should be avoided.
++
++config UBIFS_FS_DEBUG_CHKS
++	bool "Enable extra checks"
++	depends on UBIFS_FS_DEBUG
++	help
++	  If extra checks are enabled UBIFS will check the consistency of its
++	  internal data structures during operation. However, UBIFS performance
++	  is dramatically slower when this option is selected especially if the
++	  file system is large.
+diff -Nurd linux-2.6.24.orig/fs/ubifs/Makefile linux-2.6.24/fs/ubifs/Makefile
+--- linux-2.6.24.orig/fs/ubifs/Makefile	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/Makefile	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,9 @@
++obj-$(CONFIG_UBIFS_FS) += ubifs.o
++
++ubifs-y += shrinker.o journal.o file.o dir.o super.o sb.o io.o
++ubifs-y += tnc.o master.o scan.o replay.o log.o commit.o gc.o orphan.o
++ubifs-y += budget.o find.o tnc_commit.o compress.o lpt.o lprops.o
++ubifs-y += recovery.o ioctl.o lpt_commit.o tnc_misc.o
++
++ubifs-$(CONFIG_UBIFS_FS_DEBUG) += debug.o
++ubifs-$(CONFIG_UBIFS_FS_XATTR) += xattr.o
+diff -Nurd linux-2.6.24.orig/fs/ubifs/budget.c linux-2.6.24/fs/ubifs/budget.c
+--- linux-2.6.24.orig/fs/ubifs/budget.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/budget.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,758 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Adrian Hunter
++ *          Artem Bityutskiy (Битюцкий Артём)
++ */
++
++/*
++ * This file implements the budgeting sub-system which is responsible for UBIFS
++ * space management.
++ *
++ * Factors such as compression, wasted space at the ends of LEBs, space in other
++ * journal heads, the effect of updates on the index, and so on, make it
++ * impossible to accurately predict the amount of space needed. Consequently
++ * approximations are used.
++ */
++
++#include "ubifs.h"
++#include <linux/writeback.h>
++
++/*
++ * When pessimistic budget calculations say that there is no enough space,
++ * UBIFS starts writing back dirty inodes and pages, doing garbage collection,
++ * or committing. The below constant defines maximum number of times UBIFS
++ * repeats the operations.
++ */
++#define MAX_MKSPC_RETRIES 3
++
++/*
++ * The below constant defines amount of dirty pages which should be written
++ * back at when trying to shrink the liability.
++ */
++#define NR_TO_WRITE 16
++
++/**
++ * shrink_liability - write-back some dirty pages/inodes.
++ * @c: UBIFS file-system description object
++ * @nr_to_write: how many dirty pages to write-back
++ *
++ * This function shrinks UBIFS liability by means of writing back some amount
++ * of dirty inodes and their pages. Returns the amount of pages which were
++ * written back. The returned value does not include dirty inodes which were
++ * synchronized.
++ *
++ * Note, this function synchronizes even VFS inodes which are locked
++ * (@i_mutex) by the caller of the budgeting function, because write-back does
++ * not touch @i_mutex.
++ */
++static int shrink_liability(struct ubifs_info *c, int nr_to_write)
++{
++	int nr_written;
++	struct writeback_control wbc = {
++		.sync_mode   = WB_SYNC_NONE,
++		.range_end   = LLONG_MAX,
++		.nr_to_write = nr_to_write,
++	};
++
++	generic_sync_sb_inodes(c->vfs_sb, &wbc);
++	nr_written = nr_to_write - wbc.nr_to_write;
++
++	if (!nr_written) {
++		/*
++		 * Re-try again but wait on pages/inodes which are being
++		 * written-back concurrently (e.g., by pdflush).
++		 */
++		memset(&wbc, 0, sizeof(struct writeback_control));
++		wbc.sync_mode   = WB_SYNC_ALL;
++		wbc.range_end   = LLONG_MAX;
++		wbc.nr_to_write = nr_to_write;
++		generic_sync_sb_inodes(c->vfs_sb, &wbc);
++		nr_written = nr_to_write - wbc.nr_to_write;
++	}
++
++	dbg_budg("%d pages were written back", nr_written);
++	return nr_written;
++}
++
++
++/**
++ * run_gc - run garbage collector.
++ * @c: UBIFS file-system description object
++ *
++ * This function runs garbage collector to make some more free space. Returns
++ * zero if a free LEB has been produced, %-EAGAIN if commit is required, and a
++ * negative error code in case of failure.
++ */
++static int run_gc(struct ubifs_info *c)
++{
++	int err, lnum;
++
++	/* Make some free space by garbage-collecting dirty space */
++	down_read(&c->commit_sem);
++	lnum = ubifs_garbage_collect(c, 1);
++	up_read(&c->commit_sem);
++	if (lnum < 0)
++		return lnum;
++
++	/* GC freed one LEB, return it to lprops */
++	dbg_budg("GC freed LEB %d", lnum);
++	err = ubifs_return_leb(c, lnum);
++	if (err)
++		return err;
++	return 0;
++}
++
++/**
++ * get_liability - calculate current liability.
++ * @c: UBIFS file-system description object
++ *
++ * This function calculates and returns current UBIFS liability, i.e. the
++ * amount of bytes UBIFS has "promised" to write to the media.
++ */
++static long long get_liability(struct ubifs_info *c)
++{
++	long long liab;
++
++	spin_lock(&c->space_lock);
++	liab = c->budg_idx_growth + c->budg_data_growth + c->budg_dd_growth;
++	spin_unlock(&c->space_lock);
++	return liab;
++}
++
++/**
++ * make_free_space - make more free space on the file-system.
++ * @c: UBIFS file-system description object
++ *
++ * This function is called when an operation cannot be budgeted because there
++ * is supposedly no free space. But in most cases there is some free space:
++ *   o budgeting is pessimistic, so it always budgets more then it is actually
++ *     needed, so shrinking the liability is one way to make free space - the
++ *     cached data will take less space then it was budgeted for;
++ *   o GC may turn some dark space into free space (budgeting treats dark space
++ *     as not available);
++ *   o commit may free some LEB, i.e., turn freeable LEBs into free LEBs.
++ *
++ * So this function tries to do the above. Returns %-EAGAIN if some free space
++ * was presumably made and the caller has to re-try budgeting the operation.
++ * Returns %-ENOSPC if it couldn't do more free space, and other negative error
++ * codes on failures.
++ */
++static int make_free_space(struct ubifs_info *c)
++{
++	int err, retries = 0;
++	long long liab1, liab2;
++
++	do {
++		liab1 = get_liability(c);
++		/*
++		 * We probably have some dirty pages or inodes (liability), try
++		 * to write them back.
++		 */
++		dbg_budg("liability %lld, run write-back", liab1);
++		shrink_liability(c, NR_TO_WRITE);
++
++		liab2 = get_liability(c);
++		if (liab2 < liab1)
++			return -EAGAIN;
++
++		dbg_budg("new liability %lld (not shrinked)", liab2);
++
++		/* Liability did not shrink again, try GC */
++		dbg_budg("Run GC");
++		err = run_gc(c);
++		if (!err)
++			return -EAGAIN;
++
++		if (err != -EAGAIN && err != -ENOSPC)
++			/* Some real error happened */
++			return err;
++
++		dbg_budg("Run commit (retries %d)", retries);
++		err = ubifs_run_commit(c);
++		if (err)
++			return err;
++	} while (retries++ < MAX_MKSPC_RETRIES);
++
++	return -ENOSPC;
++}
++
++/**
++ * ubifs_calc_min_idx_lebs - calculate amount of eraseblocks for the index.
++ * @c: UBIFS file-system description object
++ *
++ * This function calculates and returns the number of eraseblocks which should
++ * be kept for index usage.
++ */
++int ubifs_calc_min_idx_lebs(struct ubifs_info *c)
++{
++	int idx_lebs, eff_leb_size = c->leb_size - c->max_idx_node_sz;
++	long long idx_size;
++
++	idx_size = c->old_idx_sz + c->budg_idx_growth + c->budg_uncommitted_idx;
++
++	/* And make sure we have thrice the index size of space reserved */
++	idx_size = idx_size + (idx_size << 1);
++
++	/*
++	 * We do not maintain 'old_idx_size' as 'old_idx_lebs'/'old_idx_bytes'
++	 * pair, nor similarly the two variables for the new index size, so we
++	 * have to do this costly 64-bit division on fast-path.
++	 */
++	idx_size += eff_leb_size - 1;
++	idx_lebs = div_u64(idx_size, eff_leb_size);
++	/*
++	 * The index head is not available for the in-the-gaps method, so add an
++	 * extra LEB to compensate.
++	 */
++	idx_lebs += 1;
++	if (idx_lebs < MIN_INDEX_LEBS)
++		idx_lebs = MIN_INDEX_LEBS;
++	return idx_lebs;
++}
++
++/**
++ * ubifs_calc_available - calculate available FS space.
++ * @c: UBIFS file-system description object
++ * @min_idx_lebs: minimum number of LEBs reserved for the index
++ *
++ * This function calculates and returns amount of FS space available for use.
++ */
++long long ubifs_calc_available(const struct ubifs_info *c, int min_idx_lebs)
++{
++	int subtract_lebs;
++	long long available;
++
++	available = c->main_bytes - c->lst.total_used;
++
++	/*
++	 * Now 'available' contains theoretically available flash space
++	 * assuming there is no index, so we have to subtract the space which
++	 * is reserved for the index.
++	 */
++	subtract_lebs = min_idx_lebs;
++
++	/* Take into account that GC reserves one LEB for its own needs */
++	subtract_lebs += 1;
++
++	/*
++	 * The GC journal head LEB is not really accessible. And since
++	 * different write types go to different heads, we may count only on
++	 * one head's space.
++	 */
++	subtract_lebs += c->jhead_cnt - 1;
++
++	/* We also reserve one LEB for deletions, which bypass budgeting */
++	subtract_lebs += 1;
++
++	available -= (long long)subtract_lebs * c->leb_size;
++
++	/* Subtract the dead space which is not available for use */
++	available -= c->lst.total_dead;
++
++	/*
++	 * Subtract dark space, which might or might not be usable - it depends
++	 * on the data which we have on the media and which will be written. If
++	 * this is a lot of uncompressed or not-compressible data, the dark
++	 * space cannot be used.
++	 */
++	available -= c->lst.total_dark;
++
++	/*
++	 * However, there is more dark space. The index may be bigger than
++	 * @min_idx_lebs. Those extra LEBs are assumed to be available, but
++	 * their dark space is not included in total_dark, so it is subtracted
++	 * here.
++	 */
++	if (c->lst.idx_lebs > min_idx_lebs) {
++		subtract_lebs = c->lst.idx_lebs - min_idx_lebs;
++		available -= subtract_lebs * c->dark_wm;
++	}
++
++	/* The calculations are rough and may end up with a negative number */
++	return available > 0 ? available : 0;
++}
++
++/**
++ * can_use_rp - check whether the user is allowed to use reserved pool.
++ * @c: UBIFS file-system description object
++ *
++ * UBIFS has so-called "reserved pool" which is flash space reserved
++ * for the superuser and for uses whose UID/GID is recorded in UBIFS superblock.
++ * This function checks whether current user is allowed to use reserved pool.
++ * Returns %1  current user is allowed to use reserved pool and %0 otherwise.
++ */
++static int can_use_rp(struct ubifs_info *c)
++{
++	if (current->fsuid == c->rp_uid || capable(CAP_SYS_RESOURCE) ||
++	    (c->rp_gid != 0 && in_group_p(c->rp_gid)))
++		return 1;
++	return 0;
++}
++
++/**
++ * do_budget_space - reserve flash space for index and data growth.
++ * @c: UBIFS file-system description object
++ *
++ * This function makes sure UBIFS has enough free eraseblocks for index growth
++ * and data.
++ *
++ * When budgeting index space, UBIFS reserves thrice as many LEBs as the index
++ * would take if it was consolidated and written to the flash. This guarantees
++ * that the "in-the-gaps" commit method always succeeds and UBIFS will always
++ * be able to commit dirty index. So this function basically adds amount of
++ * budgeted index space to the size of the current index, multiplies this by 3,
++ * and makes sure this does not exceed the amount of free eraseblocks.
++ *
++ * Notes about @c->min_idx_lebs and @c->lst.idx_lebs variables:
++ * o @c->lst.idx_lebs is the number of LEBs the index currently uses. It might
++ *    be large, because UBIFS does not do any index consolidation as long as
++ *    there is free space. IOW, the index may take a lot of LEBs, but the LEBs
++ *    will contain a lot of dirt.
++ * o @c->min_idx_lebs is the the index presumably takes. IOW, the index may be
++ *   consolidated to take up to @c->min_idx_lebs LEBs.
++ *
++ * This function returns zero in case of success, and %-ENOSPC in case of
++ * failure.
++ */
++static int do_budget_space(struct ubifs_info *c)
++{
++	long long outstanding, available;
++	int lebs, rsvd_idx_lebs, min_idx_lebs;
++
++	/* First budget index space */
++	min_idx_lebs = ubifs_calc_min_idx_lebs(c);
++
++	/* Now 'min_idx_lebs' contains number of LEBs to reserve */
++	if (min_idx_lebs > c->lst.idx_lebs)
++		rsvd_idx_lebs = min_idx_lebs - c->lst.idx_lebs;
++	else
++		rsvd_idx_lebs = 0;
++
++	/*
++	 * The number of LEBs that are available to be used by the index is:
++	 *
++	 *    @c->lst.empty_lebs + @c->freeable_cnt + @c->idx_gc_cnt -
++	 *    @c->lst.taken_empty_lebs
++	 *
++	 * @c->lst.empty_lebs are available because they are empty.
++	 * @c->freeable_cnt are available because they contain only free and
++	 * dirty space, @c->idx_gc_cnt are available because they are index
++	 * LEBs that have been garbage collected and are awaiting the commit
++	 * before they can be used. And the in-the-gaps method will grab these
++	 * if it needs them. @c->lst.taken_empty_lebs are empty LEBs that have
++	 * already been allocated for some purpose.
++	 *
++	 * Note, @c->idx_gc_cnt is included to both @c->lst.empty_lebs (because
++	 * these LEBs are empty) and to @c->lst.taken_empty_lebs (because they
++	 * are taken until after the commit).
++	 *
++	 * Note, @c->lst.taken_empty_lebs may temporarily be higher by one
++	 * because of the way we serialize LEB allocations and budgeting. See a
++	 * comment in 'ubifs_find_free_space()'.
++	 */
++	lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt -
++	       c->lst.taken_empty_lebs;
++	if (unlikely(rsvd_idx_lebs > lebs)) {
++		dbg_budg("out of indexing space: min_idx_lebs %d (old %d), "
++			 "rsvd_idx_lebs %d", min_idx_lebs, c->min_idx_lebs,
++			 rsvd_idx_lebs);
++		return -ENOSPC;
++	}
++
++	available = ubifs_calc_available(c, min_idx_lebs);
++	outstanding = c->budg_data_growth + c->budg_dd_growth;
++
++	if (unlikely(available < outstanding)) {
++		dbg_budg("out of data space: available %lld, outstanding %lld",
++			 available, outstanding);
++		return -ENOSPC;
++	}
++
++	if (available - outstanding <= c->rp_size && !can_use_rp(c))
++		return -ENOSPC;
++
++	c->min_idx_lebs = min_idx_lebs;
++	return 0;
++}
++
++/**
++ * calc_idx_growth - calculate approximate index growth from budgeting request.
++ * @c: UBIFS file-system description object
++ * @req: budgeting request
++ *
++ * For now we assume each new node adds one znode. But this is rather poor
++ * approximation, though.
++ */
++static int calc_idx_growth(const struct ubifs_info *c,
++			   const struct ubifs_budget_req *req)
++{
++	int znodes;
++
++	znodes = req->new_ino + (req->new_page << UBIFS_BLOCKS_PER_PAGE_SHIFT) +
++		 req->new_dent;
++	return znodes * c->max_idx_node_sz;
++}
++
++/**
++ * calc_data_growth - calculate approximate amount of new data from budgeting
++ * request.
++ * @c: UBIFS file-system description object
++ * @req: budgeting request
++ */
++static int calc_data_growth(const struct ubifs_info *c,
++			    const struct ubifs_budget_req *req)
++{
++	int data_growth;
++
++	data_growth = req->new_ino  ? c->inode_budget : 0;
++	if (req->new_page)
++		data_growth += c->page_budget;
++	if (req->new_dent)
++		data_growth += c->dent_budget;
++	data_growth += req->new_ino_d;
++	return data_growth;
++}
++
++/**
++ * calc_dd_growth - calculate approximate amount of data which makes other data
++ * dirty from budgeting request.
++ * @c: UBIFS file-system description object
++ * @req: budgeting request
++ */
++static int calc_dd_growth(const struct ubifs_info *c,
++			  const struct ubifs_budget_req *req)
++{
++	int dd_growth;
++
++	dd_growth = req->dirtied_page ? c->page_budget : 0;
++
++	if (req->dirtied_ino)
++		dd_growth += c->inode_budget << (req->dirtied_ino - 1);
++	if (req->mod_dent)
++		dd_growth += c->dent_budget;
++	dd_growth += req->dirtied_ino_d;
++	return dd_growth;
++}
++
++/**
++ * ubifs_budget_space - ensure there is enough space to complete an operation.
++ * @c: UBIFS file-system description object
++ * @req: budget request
++ *
++ * This function allocates budget for an operation. It uses pessimistic
++ * approximation of how much flash space the operation needs. The goal of this
++ * function is to make sure UBIFS always has flash space to flush all dirty
++ * pages, dirty inodes, and dirty znodes (liability). This function may force
++ * commit, garbage-collection or write-back. Returns zero in case of success,
++ * %-ENOSPC if there is no free space and other negative error codes in case of
++ * failures.
++ */
++int ubifs_budget_space(struct ubifs_info *c, struct ubifs_budget_req *req)
++{
++	int uninitialized_var(cmt_retries), uninitialized_var(wb_retries);
++	int err, idx_growth, data_growth, dd_growth, retried = 0;
++
++	ubifs_assert(req->new_page <= 1);
++	ubifs_assert(req->dirtied_page <= 1);
++	ubifs_assert(req->new_dent <= 1);
++	ubifs_assert(req->mod_dent <= 1);
++	ubifs_assert(req->new_ino <= 1);
++	ubifs_assert(req->new_ino_d <= UBIFS_MAX_INO_DATA);
++	ubifs_assert(req->dirtied_ino <= 4);
++	ubifs_assert(req->dirtied_ino_d <= UBIFS_MAX_INO_DATA * 4);
++	ubifs_assert(!(req->new_ino_d & 7));
++	ubifs_assert(!(req->dirtied_ino_d & 7));
++
++	data_growth = calc_data_growth(c, req);
++	dd_growth = calc_dd_growth(c, req);
++	if (!data_growth && !dd_growth)
++		return 0;
++	idx_growth = calc_idx_growth(c, req);
++
++again:
++	spin_lock(&c->space_lock);
++	ubifs_assert(c->budg_idx_growth >= 0);
++	ubifs_assert(c->budg_data_growth >= 0);
++	ubifs_assert(c->budg_dd_growth >= 0);
++
++	if (unlikely(c->nospace) && (c->nospace_rp || !can_use_rp(c))) {
++		dbg_budg("no space");
++		spin_unlock(&c->space_lock);
++		return -ENOSPC;
++	}
++
++	c->budg_idx_growth += idx_growth;
++	c->budg_data_growth += data_growth;
++	c->budg_dd_growth += dd_growth;
++
++	err = do_budget_space(c);
++	if (likely(!err)) {
++		req->idx_growth = idx_growth;
++		req->data_growth = data_growth;
++		req->dd_growth = dd_growth;
++		spin_unlock(&c->space_lock);
++		return 0;
++	}
++
++	/* Restore the old values */
++	c->budg_idx_growth -= idx_growth;
++	c->budg_data_growth -= data_growth;
++	c->budg_dd_growth -= dd_growth;
++	spin_unlock(&c->space_lock);
++
++	if (req->fast) {
++		dbg_budg("no space for fast budgeting");
++		return err;
++	}
++
++	err = make_free_space(c);
++	cond_resched();
++	if (err == -EAGAIN) {
++		dbg_budg("try again");
++		goto again;
++	} else if (err == -ENOSPC) {
++		if (!retried) {
++			retried = 1;
++			dbg_budg("-ENOSPC, but anyway try once again");
++			goto again;
++		}
++		dbg_budg("FS is full, -ENOSPC");
++		c->nospace = 1;
++		if (can_use_rp(c) || c->rp_size == 0)
++			c->nospace_rp = 1;
++		smp_wmb();
++	} else
++		ubifs_err("cannot budget space, error %d", err);
++	return err;
++}
++
++/**
++ * ubifs_release_budget - release budgeted free space.
++ * @c: UBIFS file-system description object
++ * @req: budget request
++ *
++ * This function releases the space budgeted by 'ubifs_budget_space()'. Note,
++ * since the index changes (which were budgeted for in @req->idx_growth) will
++ * only be written to the media on commit, this function moves the index budget
++ * from @c->budg_idx_growth to @c->budg_uncommitted_idx. The latter will be
++ * zeroed by the commit operation.
++ */
++void ubifs_release_budget(struct ubifs_info *c, struct ubifs_budget_req *req)
++{
++	ubifs_assert(req->new_page <= 1);
++	ubifs_assert(req->dirtied_page <= 1);
++	ubifs_assert(req->new_dent <= 1);
++	ubifs_assert(req->mod_dent <= 1);
++	ubifs_assert(req->new_ino <= 1);
++	ubifs_assert(req->new_ino_d <= UBIFS_MAX_INO_DATA);
++	ubifs_assert(req->dirtied_ino <= 4);
++	ubifs_assert(req->dirtied_ino_d <= UBIFS_MAX_INO_DATA * 4);
++	ubifs_assert(!(req->new_ino_d & 7));
++	ubifs_assert(!(req->dirtied_ino_d & 7));
++	if (!req->recalculate) {
++		ubifs_assert(req->idx_growth >= 0);
++		ubifs_assert(req->data_growth >= 0);
++		ubifs_assert(req->dd_growth >= 0);
++	}
++
++	if (req->recalculate) {
++		req->data_growth = calc_data_growth(c, req);
++		req->dd_growth = calc_dd_growth(c, req);
++		req->idx_growth = calc_idx_growth(c, req);
++	}
++
++	if (!req->data_growth && !req->dd_growth)
++		return;
++
++	c->nospace = c->nospace_rp = 0;
++	smp_wmb();
++
++	spin_lock(&c->space_lock);
++	c->budg_idx_growth -= req->idx_growth;
++	c->budg_uncommitted_idx += req->idx_growth;
++	c->budg_data_growth -= req->data_growth;
++	c->budg_dd_growth -= req->dd_growth;
++	c->min_idx_lebs = ubifs_calc_min_idx_lebs(c);
++
++	ubifs_assert(c->budg_idx_growth >= 0);
++	ubifs_assert(c->budg_data_growth >= 0);
++	ubifs_assert(c->budg_dd_growth >= 0);
++	ubifs_assert(c->min_idx_lebs < c->main_lebs);
++	ubifs_assert(!(c->budg_idx_growth & 7));
++	ubifs_assert(!(c->budg_data_growth & 7));
++	ubifs_assert(!(c->budg_dd_growth & 7));
++	spin_unlock(&c->space_lock);
++}
++
++/**
++ * ubifs_convert_page_budget - convert budget of a new page.
++ * @c: UBIFS file-system description object
++ *
++ * This function converts budget which was allocated for a new page of data to
++ * the budget of changing an existing page of data. The latter is smaller then
++ * the former, so this function only does simple re-calculation and does not
++ * involve any write-back.
++ */
++void ubifs_convert_page_budget(struct ubifs_info *c)
++{
++	spin_lock(&c->space_lock);
++	/* Release the index growth reservation */
++	c->budg_idx_growth -= c->max_idx_node_sz << UBIFS_BLOCKS_PER_PAGE_SHIFT;
++	/* Release the data growth reservation */
++	c->budg_data_growth -= c->page_budget;
++	/* Increase the dirty data growth reservation instead */
++	c->budg_dd_growth += c->page_budget;
++	/* And re-calculate the indexing space reservation */
++	c->min_idx_lebs = ubifs_calc_min_idx_lebs(c);
++	spin_unlock(&c->space_lock);
++}
++
++/**
++ * ubifs_release_dirty_inode_budget - release dirty inode budget.
++ * @c: UBIFS file-system description object
++ * @ui: UBIFS inode to release the budget for
++ *
++ * This function releases budget corresponding to a dirty inode. It is usually
++ * called when after the inode has been written to the media and marked as
++ * clean.
++ */
++void ubifs_release_dirty_inode_budget(struct ubifs_info *c,
++				      struct ubifs_inode *ui)
++{
++	struct ubifs_budget_req req;
++
++	memset(&req, 0, sizeof(struct ubifs_budget_req));
++	req.dd_growth = c->inode_budget + ALIGN(ui->data_len, 8);
++	ubifs_release_budget(c, &req);
++}
++
++/**
++ * ubifs_reported_space - calculate reported free space.
++ * @c: the UBIFS file-system description object
++ * @free: amount of free space
++ *
++ * This function calculates amount of free space which will be reported to
++ * user-space. User-space application tend to expect that if the file-system
++ * (e.g., via the 'statfs()' call) reports that it has N bytes available, they
++ * are able to write a file of size N. UBIFS attaches node headers to each data
++ * node and it has to write indexing nodes as well. This introduces additional
++ * overhead, and UBIFS has to report slightly less free space to meet the above
++ * expectations.
++ *
++ * This function assumes free space is made up of uncompressed data nodes and
++ * full index nodes (one per data node, tripled because we always allow enough
++ * space to write the index thrice).
++ *
++ * Note, the calculation is pessimistic, which means that most of the time
++ * UBIFS reports less space than it actually has.
++ */
++long long ubifs_reported_space(const struct ubifs_info *c, long long free)
++{
++	int divisor, factor, f;
++
++	/*
++	 * Reported space size is @free * X, where X is UBIFS block size
++	 * divided by UBIFS block size + all overhead one data block
++	 * introduces. The overhead is the node header + indexing overhead.
++	 *
++	 * Indexing overhead calculations are based on the following formula:
++	 * I = N/(f - 1) + 1, where I - number of indexing nodes, N - number
++	 * of data nodes, f - fanout. Because effective UBIFS fanout is twice
++	 * as less than maximum fanout, we assume that each data node
++	 * introduces 3 * @c->max_idx_node_sz / (@c->fanout/2 - 1) bytes.
++	 * Note, the multiplier 3 is because UBIFS reserves thrice as more space
++	 * for the index.
++	 */
++	f = c->fanout > 3 ? c->fanout >> 1 : 2;
++	factor = UBIFS_BLOCK_SIZE;
++	divisor = UBIFS_MAX_DATA_NODE_SZ;
++	divisor += (c->max_idx_node_sz * 3) / (f - 1);
++	free *= factor;
++	return div_u64(free, divisor);
++}
++
++/**
++ * ubifs_get_free_space_nolock - return amount of free space.
++ * @c: UBIFS file-system description object
++ *
++ * This function calculates amount of free space to report to user-space.
++ *
++ * Because UBIFS may introduce substantial overhead (the index, node headers,
++ * alignment, wastage at the end of eraseblocks, etc), it cannot report real
++ * amount of free flash space it has (well, because not all dirty space is
++ * reclaimable, UBIFS does not actually know the real amount). If UBIFS did so,
++ * it would bread user expectations about what free space is. Users seem to
++ * accustomed to assume that if the file-system reports N bytes of free space,
++ * they would be able to fit a file of N bytes to the FS. This almost works for
++ * traditional file-systems, because they have way less overhead than UBIFS.
++ * So, to keep users happy, UBIFS tries to take the overhead into account.
++ */
++long long ubifs_get_free_space_nolock(struct ubifs_info *c)
++{
++	int rsvd_idx_lebs, lebs;
++	long long available, outstanding, free;
++
++	ubifs_assert(c->min_idx_lebs == ubifs_calc_min_idx_lebs(c));
++	outstanding = c->budg_data_growth + c->budg_dd_growth;
++	available = ubifs_calc_available(c, c->min_idx_lebs);
++
++	/*
++	 * When reporting free space to user-space, UBIFS guarantees that it is
++	 * possible to write a file of free space size. This means that for
++	 * empty LEBs we may use more precise calculations than
++	 * 'ubifs_calc_available()' is using. Namely, we know that in empty
++	 * LEBs we would waste only @c->leb_overhead bytes, not @c->dark_wm.
++	 * Thus, amend the available space.
++	 *
++	 * Note, the calculations below are similar to what we have in
++	 * 'do_budget_space()', so refer there for comments.
++	 */
++	if (c->min_idx_lebs > c->lst.idx_lebs)
++		rsvd_idx_lebs = c->min_idx_lebs - c->lst.idx_lebs;
++	else
++		rsvd_idx_lebs = 0;
++	lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt -
++	       c->lst.taken_empty_lebs;
++	lebs -= rsvd_idx_lebs;
++	available += lebs * (c->dark_wm - c->leb_overhead);
++
++	if (available > outstanding)
++		free = ubifs_reported_space(c, available - outstanding);
++	else
++		free = 0;
++	return free;
++}
++
++/**
++ * ubifs_get_free_space - return amount of free space.
++ * @c: UBIFS file-system description object
++ *
++ * This function calculates and retuns amount of free space to report to
++ * user-space.
++ */
++long long ubifs_get_free_space(struct ubifs_info *c)
++{
++	long long free;
++
++	spin_lock(&c->space_lock);
++	free = ubifs_get_free_space_nolock(c);
++	spin_unlock(&c->space_lock);
++
++	return free;
++}
+diff -Nurd linux-2.6.24.orig/fs/ubifs/commit.c linux-2.6.24/fs/ubifs/commit.c
+--- linux-2.6.24.orig/fs/ubifs/commit.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/commit.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,679 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Adrian Hunter
++ *          Artem Bityutskiy (Битюцкий Артём)
++ */
++
++/*
++ * This file implements functions that manage the running of the commit process.
++ * Each affected module has its own functions to accomplish their part in the
++ * commit and those functions are called here.
++ *
++ * The commit is the process whereby all updates to the index and LEB properties
++ * are written out together and the journal becomes empty. This keeps the
++ * file system consistent - at all times the state can be recreated by reading
++ * the index and LEB properties and then replaying the journal.
++ *
++ * The commit is split into two parts named "commit start" and "commit end".
++ * During commit start, the commit process has exclusive access to the journal
++ * by holding the commit semaphore down for writing. As few I/O operations as
++ * possible are performed during commit start, instead the nodes that are to be
++ * written are merely identified. During commit end, the commit semaphore is no
++ * longer held and the journal is again in operation, allowing users to continue
++ * to use the file system while the bulk of the commit I/O is performed. The
++ * purpose of this two-step approach is to prevent the commit from causing any
++ * latency blips. Note that in any case, the commit does not prevent lookups
++ * (as permitted by the TNC mutex), or access to VFS data structures e.g. page
++ * cache.
++ */
++
++#include <linux/freezer.h>
++#include <linux/kthread.h>
++#include "ubifs.h"
++
++/**
++ * do_commit - commit the journal.
++ * @c: UBIFS file-system description object
++ *
++ * This function implements UBIFS commit. It has to be called with commit lock
++ * locked. Returns zero in case of success and a negative error code in case of
++ * failure.
++ */
++static int do_commit(struct ubifs_info *c)
++{
++	int err, new_ltail_lnum, old_ltail_lnum, i;
++	struct ubifs_zbranch zroot;
++	struct ubifs_lp_stats lst;
++
++	dbg_cmt("start");
++	if (c->ro_media) {
++		err = -EROFS;
++		goto out_up;
++	}
++
++	/* Sync all write buffers (necessary for recovery) */
++	for (i = 0; i < c->jhead_cnt; i++) {
++		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
++		if (err)
++			goto out_up;
++	}
++
++	c->cmt_no += 1;
++	err = ubifs_gc_start_commit(c);
++	if (err)
++		goto out_up;
++	err = dbg_check_lprops(c);
++	if (err)
++		goto out_up;
++	err = ubifs_log_start_commit(c, &new_ltail_lnum);
++	if (err)
++		goto out_up;
++	err = ubifs_tnc_start_commit(c, &zroot);
++	if (err)
++		goto out_up;
++	err = ubifs_lpt_start_commit(c);
++	if (err)
++		goto out_up;
++	err = ubifs_orphan_start_commit(c);
++	if (err)
++		goto out_up;
++
++	ubifs_get_lp_stats(c, &lst);
++
++	up_write(&c->commit_sem);
++
++	err = ubifs_tnc_end_commit(c);
++	if (err)
++		goto out;
++	err = ubifs_lpt_end_commit(c);
++	if (err)
++		goto out;
++	err = ubifs_orphan_end_commit(c);
++	if (err)
++		goto out;
++	old_ltail_lnum = c->ltail_lnum;
++	err = ubifs_log_end_commit(c, new_ltail_lnum);
++	if (err)
++		goto out;
++	err = dbg_check_old_index(c, &zroot);
++	if (err)
++		goto out;
++
++	mutex_lock(&c->mst_mutex);
++	c->mst_node->cmt_no      = cpu_to_le64(c->cmt_no);
++	c->mst_node->log_lnum    = cpu_to_le32(new_ltail_lnum);
++	c->mst_node->root_lnum   = cpu_to_le32(zroot.lnum);
++	c->mst_node->root_offs   = cpu_to_le32(zroot.offs);
++	c->mst_node->root_len    = cpu_to_le32(zroot.len);
++	c->mst_node->ihead_lnum  = cpu_to_le32(c->ihead_lnum);
++	c->mst_node->ihead_offs  = cpu_to_le32(c->ihead_offs);
++	c->mst_node->index_size  = cpu_to_le64(c->old_idx_sz);
++	c->mst_node->lpt_lnum    = cpu_to_le32(c->lpt_lnum);
++	c->mst_node->lpt_offs    = cpu_to_le32(c->lpt_offs);
++	c->mst_node->nhead_lnum  = cpu_to_le32(c->nhead_lnum);
++	c->mst_node->nhead_offs  = cpu_to_le32(c->nhead_offs);
++	c->mst_node->ltab_lnum   = cpu_to_le32(c->ltab_lnum);
++	c->mst_node->ltab_offs   = cpu_to_le32(c->ltab_offs);
++	c->mst_node->lsave_lnum  = cpu_to_le32(c->lsave_lnum);
++	c->mst_node->lsave_offs  = cpu_to_le32(c->lsave_offs);
++	c->mst_node->lscan_lnum  = cpu_to_le32(c->lscan_lnum);
++	c->mst_node->empty_lebs  = cpu_to_le32(lst.empty_lebs);
++	c->mst_node->idx_lebs    = cpu_to_le32(lst.idx_lebs);
++	c->mst_node->total_free  = cpu_to_le64(lst.total_free);
++	c->mst_node->total_dirty = cpu_to_le64(lst.total_dirty);
++	c->mst_node->total_used  = cpu_to_le64(lst.total_used);
++	c->mst_node->total_dead  = cpu_to_le64(lst.total_dead);
++	c->mst_node->total_dark  = cpu_to_le64(lst.total_dark);
++	if (c->no_orphs)
++		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
++	else
++		c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_NO_ORPHS);
++	err = ubifs_write_master(c);
++	mutex_unlock(&c->mst_mutex);
++	if (err)
++		goto out;
++
++	err = ubifs_log_post_commit(c, old_ltail_lnum);
++	if (err)
++		goto out;
++	err = ubifs_gc_end_commit(c);
++	if (err)
++		goto out;
++	err = ubifs_lpt_post_commit(c);
++	if (err)
++		goto out;
++
++	spin_lock(&c->cs_lock);
++	c->cmt_state = COMMIT_RESTING;
++	wake_up(&c->cmt_wq);
++	dbg_cmt("commit end");
++	spin_unlock(&c->cs_lock);
++
++	return 0;
++
++out_up:
++	up_write(&c->commit_sem);
++out:
++	ubifs_err("commit failed, error %d", err);
++	spin_lock(&c->cs_lock);
++	c->cmt_state = COMMIT_BROKEN;
++	wake_up(&c->cmt_wq);
++	spin_unlock(&c->cs_lock);
++	ubifs_ro_mode(c, err);
++	return err;
++}
++
++/**
++ * run_bg_commit - run background commit if it is needed.
++ * @c: UBIFS file-system description object
++ *
++ * This function runs background commit if it is needed. Returns zero in case
++ * of success and a negative error code in case of failure.
++ */
++static int run_bg_commit(struct ubifs_info *c)
++{
++	spin_lock(&c->cs_lock);
++	/*
++	 * Run background commit only if background commit was requested or if
++	 * commit is required.
++	 */
++	if (c->cmt_state != COMMIT_BACKGROUND &&
++	    c->cmt_state != COMMIT_REQUIRED)
++		goto out;
++	spin_unlock(&c->cs_lock);
++
++	down_write(&c->commit_sem);
++	spin_lock(&c->cs_lock);
++	if (c->cmt_state == COMMIT_REQUIRED)
++		c->cmt_state = COMMIT_RUNNING_REQUIRED;
++	else if (c->cmt_state == COMMIT_BACKGROUND)
++		c->cmt_state = COMMIT_RUNNING_BACKGROUND;
++	else
++		goto out_cmt_unlock;
++	spin_unlock(&c->cs_lock);
++
++	return do_commit(c);
++
++out_cmt_unlock:
++	up_write(&c->commit_sem);
++out:
++	spin_unlock(&c->cs_lock);
++	return 0;
++}
++
++/**
++ * ubifs_bg_thread - UBIFS background thread function.
++ * @info: points to the file-system description object
++ *
++ * This function implements various file-system background activities:
++ * o when a write-buffer timer expires it synchronizes the appropriate
++ *   write-buffer;
++ * o when the journal is about to be full, it starts in-advance commit.
++ *
++ * Note, other stuff like background garbage collection may be added here in
++ * future.
++ */
++int ubifs_bg_thread(void *info)
++{
++	int err;
++	struct ubifs_info *c = info;
++
++	dbg_msg("background thread \"%s\" started, PID %d",
++		c->bgt_name, current->pid);
++	set_freezable();
++
++	while (1) {
++		if (kthread_should_stop())
++			break;
++
++		if (try_to_freeze())
++			continue;
++
++		set_current_state(TASK_INTERRUPTIBLE);
++		/* Check if there is something to do */
++		if (!c->need_bgt) {
++			/*
++			 * Nothing prevents us from going sleep now and
++			 * be never woken up and block the task which
++			 * could wait in 'kthread_stop()' forever.
++			 */
++			if (kthread_should_stop())
++				break;
++			schedule();
++			continue;
++		} else
++			__set_current_state(TASK_RUNNING);
++
++		c->need_bgt = 0;
++		err = ubifs_bg_wbufs_sync(c);
++		if (err)
++			ubifs_ro_mode(c, err);
++
++		run_bg_commit(c);
++		cond_resched();
++	}
++
++	dbg_msg("background thread \"%s\" stops", c->bgt_name);
++	return 0;
++}
++
++/**
++ * ubifs_commit_required - set commit state to "required".
++ * @c: UBIFS file-system description object
++ *
++ * This function is called if a commit is required but cannot be done from the
++ * calling function, so it is just flagged instead.
++ */
++void ubifs_commit_required(struct ubifs_info *c)
++{
++	spin_lock(&c->cs_lock);
++	switch (c->cmt_state) {
++	case COMMIT_RESTING:
++	case COMMIT_BACKGROUND:
++		dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
++			dbg_cstate(COMMIT_REQUIRED));
++		c->cmt_state = COMMIT_REQUIRED;
++		break;
++	case COMMIT_RUNNING_BACKGROUND:
++		dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
++			dbg_cstate(COMMIT_RUNNING_REQUIRED));
++		c->cmt_state = COMMIT_RUNNING_REQUIRED;
++		break;
++	case COMMIT_REQUIRED:
++	case COMMIT_RUNNING_REQUIRED:
++	case COMMIT_BROKEN:
++		break;
++	}
++	spin_unlock(&c->cs_lock);
++}
++
++/**
++ * ubifs_request_bg_commit - notify the background thread to do a commit.
++ * @c: UBIFS file-system description object
++ *
++ * This function is called if the journal is full enough to make a commit
++ * worthwhile, so background thread is kicked to start it.
++ */
++void ubifs_request_bg_commit(struct ubifs_info *c)
++{
++	spin_lock(&c->cs_lock);
++	if (c->cmt_state == COMMIT_RESTING) {
++		dbg_cmt("old: %s, new: %s", dbg_cstate(c->cmt_state),
++			dbg_cstate(COMMIT_BACKGROUND));
++		c->cmt_state = COMMIT_BACKGROUND;
++		spin_unlock(&c->cs_lock);
++		ubifs_wake_up_bgt(c);
++	} else
++		spin_unlock(&c->cs_lock);
++}
++
++/**
++ * wait_for_commit - wait for commit.
++ * @c: UBIFS file-system description object
++ *
++ * This function sleeps until the commit operation is no longer running.
++ */
++static int wait_for_commit(struct ubifs_info *c)
++{
++	dbg_cmt("pid %d goes sleep", current->pid);
++
++	/*
++	 * The following sleeps if the condition is false, and will be woken
++	 * when the commit ends. It is possible, although very unlikely, that we
++	 * will wake up and see the subsequent commit running, rather than the
++	 * one we were waiting for, and go back to sleep.  However, we will be
++	 * woken again, so there is no danger of sleeping forever.
++	 */
++	wait_event(c->cmt_wq, c->cmt_state != COMMIT_RUNNING_BACKGROUND &&
++			      c->cmt_state != COMMIT_RUNNING_REQUIRED);
++	dbg_cmt("commit finished, pid %d woke up", current->pid);
++	return 0;
++}
++
++/**
++ * ubifs_run_commit - run or wait for commit.
++ * @c: UBIFS file-system description object
++ *
++ * This function runs commit and returns zero in case of success and a negative
++ * error code in case of failure.
++ */
++int ubifs_run_commit(struct ubifs_info *c)
++{
++	int err = 0;
++
++	spin_lock(&c->cs_lock);
++	if (c->cmt_state == COMMIT_BROKEN) {
++		err = -EINVAL;
++		goto out;
++	}
++
++	if (c->cmt_state == COMMIT_RUNNING_BACKGROUND)
++		/*
++		 * We set the commit state to 'running required' to indicate
++		 * that we want it to complete as quickly as possible.
++		 */
++		c->cmt_state = COMMIT_RUNNING_REQUIRED;
++
++	if (c->cmt_state == COMMIT_RUNNING_REQUIRED) {
++		spin_unlock(&c->cs_lock);
++		return wait_for_commit(c);
++	}
++	spin_unlock(&c->cs_lock);
++
++	/* Ok, the commit is indeed needed */
++
++	down_write(&c->commit_sem);
++	spin_lock(&c->cs_lock);
++	/*
++	 * Since we unlocked 'c->cs_lock', the state may have changed, so
++	 * re-check it.
++	 */
++	if (c->cmt_state == COMMIT_BROKEN) {
++		err = -EINVAL;
++		goto out_cmt_unlock;
++	}
++
++	if (c->cmt_state == COMMIT_RUNNING_BACKGROUND)
++		c->cmt_state = COMMIT_RUNNING_REQUIRED;
++
++	if (c->cmt_state == COMMIT_RUNNING_REQUIRED) {
++		up_write(&c->commit_sem);
++		spin_unlock(&c->cs_lock);
++		return wait_for_commit(c);
++	}
++	c->cmt_state = COMMIT_RUNNING_REQUIRED;
++	spin_unlock(&c->cs_lock);
++
++	err = do_commit(c);
++	return err;
++
++out_cmt_unlock:
++	up_write(&c->commit_sem);
++out:
++	spin_unlock(&c->cs_lock);
++	return err;
++}
++
++/**
++ * ubifs_gc_should_commit - determine if it is time for GC to run commit.
++ * @c: UBIFS file-system description object
++ *
++ * This function is called by garbage collection to determine if commit should
++ * be run. If commit state is @COMMIT_BACKGROUND, which means that the journal
++ * is full enough to start commit, this function returns true. It is not
++ * absolutely necessary to commit yet, but it feels like this should be better
++ * then to keep doing GC. This function returns %1 if GC has to initiate commit
++ * and %0 if not.
++ */
++int ubifs_gc_should_commit(struct ubifs_info *c)
++{
++	int ret = 0;
++
++	spin_lock(&c->cs_lock);
++	if (c->cmt_state == COMMIT_BACKGROUND) {
++		dbg_cmt("commit required now");
++		c->cmt_state = COMMIT_REQUIRED;
++	} else
++		dbg_cmt("commit not requested");
++	if (c->cmt_state == COMMIT_REQUIRED)
++		ret = 1;
++	spin_unlock(&c->cs_lock);
++	return ret;
++}
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++
++/**
++ * struct idx_node - hold index nodes during index tree traversal.
++ * @list: list
++ * @iip: index in parent (slot number of this indexing node in the parent
++ *       indexing node)
++ * @upper_key: all keys in this indexing node have to be less or equivalent to
++ *             this key
++ * @idx: index node (8-byte aligned because all node structures must be 8-byte
++ *       aligned)
++ */
++struct idx_node {
++	struct list_head list;
++	int iip;
++	union ubifs_key upper_key;
++	struct ubifs_idx_node idx __attribute__((aligned(8)));
++};
++
++/**
++ * dbg_old_index_check_init - get information for the next old index check.
++ * @c: UBIFS file-system description object
++ * @zroot: root of the index
++ *
++ * This function records information about the index that will be needed for the
++ * next old index check i.e. 'dbg_check_old_index()'.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int dbg_old_index_check_init(struct ubifs_info *c, struct ubifs_zbranch *zroot)
++{
++	struct ubifs_idx_node *idx;
++	int lnum, offs, len, err = 0;
++	struct ubifs_debug_info *d = c->dbg;
++
++	d->old_zroot = *zroot;
++	lnum = d->old_zroot.lnum;
++	offs = d->old_zroot.offs;
++	len = d->old_zroot.len;
++
++	idx = kmalloc(c->max_idx_node_sz, GFP_NOFS);
++	if (!idx)
++		return -ENOMEM;
++
++	err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
++	if (err)
++		goto out;
++
++	d->old_zroot_level = le16_to_cpu(idx->level);
++	d->old_zroot_sqnum = le64_to_cpu(idx->ch.sqnum);
++out:
++	kfree(idx);
++	return err;
++}
++
++/**
++ * dbg_check_old_index - check the old copy of the index.
++ * @c: UBIFS file-system description object
++ * @zroot: root of the new index
++ *
++ * In order to be able to recover from an unclean unmount, a complete copy of
++ * the index must exist on flash. This is the "old" index. The commit process
++ * must write the "new" index to flash without overwriting or destroying any
++ * part of the old index. This function is run at commit end in order to check
++ * that the old index does indeed exist completely intact.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot)
++{
++	int lnum, offs, len, err = 0, uninitialized_var(last_level), child_cnt;
++	int first = 1, iip;
++	struct ubifs_debug_info *d = c->dbg;
++	union ubifs_key lower_key, upper_key, l_key, u_key;
++	unsigned long long uninitialized_var(last_sqnum);
++	struct ubifs_idx_node *idx;
++	struct list_head list;
++	struct idx_node *i;
++	size_t sz;
++
++	if (!(ubifs_chk_flags & UBIFS_CHK_OLD_IDX))
++		goto out;
++
++	INIT_LIST_HEAD(&list);
++
++	sz = sizeof(struct idx_node) + ubifs_idx_node_sz(c, c->fanout) -
++	     UBIFS_IDX_NODE_SZ;
++
++	/* Start at the old zroot */
++	lnum = d->old_zroot.lnum;
++	offs = d->old_zroot.offs;
++	len = d->old_zroot.len;
++	iip = 0;
++
++	/*
++	 * Traverse the index tree preorder depth-first i.e. do a node and then
++	 * its subtrees from left to right.
++	 */
++	while (1) {
++		struct ubifs_branch *br;
++
++		/* Get the next index node */
++		i = kmalloc(sz, GFP_NOFS);
++		if (!i) {
++			err = -ENOMEM;
++			goto out_free;
++		}
++		i->iip = iip;
++		/* Keep the index nodes on our path in a linked list */
++		list_add_tail(&i->list, &list);
++		/* Read the index node */
++		idx = &i->idx;
++		err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
++		if (err)
++			goto out_free;
++		/* Validate index node */
++		child_cnt = le16_to_cpu(idx->child_cnt);
++		if (child_cnt < 1 || child_cnt > c->fanout) {
++			err = 1;
++			goto out_dump;
++		}
++		if (first) {
++			first = 0;
++			/* Check root level and sqnum */
++			if (le16_to_cpu(idx->level) != d->old_zroot_level) {
++				err = 2;
++				goto out_dump;
++			}
++			if (le64_to_cpu(idx->ch.sqnum) != d->old_zroot_sqnum) {
++				err = 3;
++				goto out_dump;
++			}
++			/* Set last values as though root had a parent */
++			last_level = le16_to_cpu(idx->level) + 1;
++			last_sqnum = le64_to_cpu(idx->ch.sqnum) + 1;
++			key_read(c, ubifs_idx_key(c, idx), &lower_key);
++			highest_ino_key(c, &upper_key, INUM_WATERMARK);
++		}
++		key_copy(c, &upper_key, &i->upper_key);
++		if (le16_to_cpu(idx->level) != last_level - 1) {
++			err = 3;
++			goto out_dump;
++		}
++		/*
++		 * The index is always written bottom up hence a child's sqnum
++		 * is always less than the parents.
++		 */
++		if (le64_to_cpu(idx->ch.sqnum) >= last_sqnum) {
++			err = 4;
++			goto out_dump;
++		}
++		/* Check key range */
++		key_read(c, ubifs_idx_key(c, idx), &l_key);
++		br = ubifs_idx_branch(c, idx, child_cnt - 1);
++		key_read(c, &br->key, &u_key);
++		if (keys_cmp(c, &lower_key, &l_key) > 0) {
++			err = 5;
++			goto out_dump;
++		}
++		if (keys_cmp(c, &upper_key, &u_key) < 0) {
++			err = 6;
++			goto out_dump;
++		}
++		if (keys_cmp(c, &upper_key, &u_key) == 0)
++			if (!is_hash_key(c, &u_key)) {
++				err = 7;
++				goto out_dump;
++			}
++		/* Go to next index node */
++		if (le16_to_cpu(idx->level) == 0) {
++			/* At the bottom, so go up until can go right */
++			while (1) {
++				/* Drop the bottom of the list */
++				list_del(&i->list);
++				kfree(i);
++				/* No more list means we are done */
++				if (list_empty(&list))
++					goto out;
++				/* Look at the new bottom */
++				i = list_entry(list.prev, struct idx_node,
++					       list);
++				idx = &i->idx;
++				/* Can we go right */
++				if (iip + 1 < le16_to_cpu(idx->child_cnt)) {
++					iip = iip + 1;
++					break;
++				} else
++					/* Nope, so go up again */
++					iip = i->iip;
++			}
++		} else
++			/* Go down left */
++			iip = 0;
++		/*
++		 * We have the parent in 'idx' and now we set up for reading the
++		 * child pointed to by slot 'iip'.
++		 */
++		last_level = le16_to_cpu(idx->level);
++		last_sqnum = le64_to_cpu(idx->ch.sqnum);
++		br = ubifs_idx_branch(c, idx, iip);
++		lnum = le32_to_cpu(br->lnum);
++		offs = le32_to_cpu(br->offs);
++		len = le32_to_cpu(br->len);
++		key_read(c, &br->key, &lower_key);
++		if (iip + 1 < le16_to_cpu(idx->child_cnt)) {
++			br = ubifs_idx_branch(c, idx, iip + 1);
++			key_read(c, &br->key, &upper_key);
++		} else
++			key_copy(c, &i->upper_key, &upper_key);
++	}
++out:
++	err = dbg_old_index_check_init(c, zroot);
++	if (err)
++		goto out_free;
++
++	return 0;
++
++out_dump:
++	dbg_err("dumping index node (iip=%d)", i->iip);
++	dbg_dump_node(c, idx);
++	list_del(&i->list);
++	kfree(i);
++	if (!list_empty(&list)) {
++		i = list_entry(list.prev, struct idx_node, list);
++		dbg_err("dumping parent index node");
++		dbg_dump_node(c, &i->idx);
++	}
++out_free:
++	while (!list_empty(&list)) {
++		i = list_entry(list.next, struct idx_node, list);
++		list_del(&i->list);
++		kfree(i);
++	}
++	ubifs_err("failed, error %d", err);
++	if (err > 0)
++		err = -EINVAL;
++	return err;
++}
++
++#endif /* CONFIG_UBIFS_FS_DEBUG */
+diff -Nurd linux-2.6.24.orig/fs/ubifs/compress.c linux-2.6.24/fs/ubifs/compress.c
+--- linux-2.6.24.orig/fs/ubifs/compress.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/compress.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,251 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ * Copyright (C) 2006, 2007 University of Szeged, Hungary
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Adrian Hunter
++ *          Artem Bityutskiy (Битюцкий Артём)
++ *          Zoltan Sogor
++ */
++
++/*
++ * This file provides a single place to access to compression and
++ * decompression.
++ */
++
++#include <linux/crypto.h>
++#include "ubifs.h"
++
++/* Fake description object for the "none" compressor */
++static struct ubifs_compressor none_compr = {
++	.compr_type = UBIFS_COMPR_NONE,
++	.name = "none",
++	.capi_name = "",
++};
++
++#ifdef CONFIG_UBIFS_FS_LZO
++static DEFINE_MUTEX(lzo_mutex);
++
++static struct ubifs_compressor lzo_compr = {
++	.compr_type = UBIFS_COMPR_LZO,
++	.comp_mutex = &lzo_mutex,
++	.name = "lzo",
++	.capi_name = "lzo",
++};
++#else
++static struct ubifs_compressor lzo_compr = {
++	.compr_type = UBIFS_COMPR_LZO,
++	.name = "lzo",
++};
++#endif
++
++#ifdef CONFIG_UBIFS_FS_ZLIB
++static DEFINE_MUTEX(deflate_mutex);
++static DEFINE_MUTEX(inflate_mutex);
++
++static struct ubifs_compressor zlib_compr = {
++	.compr_type = UBIFS_COMPR_ZLIB,
++	.comp_mutex = &deflate_mutex,
++	.decomp_mutex = &inflate_mutex,
++	.name = "zlib",
++	.capi_name = "deflate",
++};
++#else
++static struct ubifs_compressor zlib_compr = {
++	.compr_type = UBIFS_COMPR_ZLIB,
++	.name = "zlib",
++};
++#endif
++
++/* All UBIFS compressors */
++struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT];
++
++/**
++ * ubifs_compress - compress data.
++ * @in_buf: data to compress
++ * @in_len: length of the data to compress
++ * @out_buf: output buffer where compressed data should be stored
++ * @out_len: output buffer length is returned here
++ * @compr_type: type of compression to use on enter, actually used compression
++ *              type on exit
++ *
++ * This function compresses input buffer @in_buf of length @in_len and stores
++ * the result in the output buffer @out_buf and the resulting length in
++ * @out_len. If the input buffer does not compress, it is just copied to the
++ * @out_buf. The same happens if @compr_type is %UBIFS_COMPR_NONE or if
++ * compression error occurred.
++ *
++ * Note, if the input buffer was not compressed, it is copied to the output
++ * buffer and %UBIFS_COMPR_NONE is returned in @compr_type.
++ */
++void ubifs_compress(const void *in_buf, int in_len, void *out_buf, int *out_len,
++		    int *compr_type)
++{
++	int err;
++	struct ubifs_compressor *compr = ubifs_compressors[*compr_type];
++
++	if (*compr_type == UBIFS_COMPR_NONE)
++		goto no_compr;
++
++	/* If the input data is small, do not even try to compress it */
++	if (in_len < UBIFS_MIN_COMPR_LEN)
++		goto no_compr;
++
++	if (compr->comp_mutex)
++		mutex_lock(compr->comp_mutex);
++	err = crypto_comp_compress(compr->cc, in_buf, in_len, out_buf,
++				   (unsigned int *)out_len);
++	if (compr->comp_mutex)
++		mutex_unlock(compr->comp_mutex);
++	if (unlikely(err)) {
++		ubifs_warn("cannot compress %d bytes, compressor %s, "
++			   "error %d, leave data uncompressed",
++			   in_len, compr->name, err);
++		 goto no_compr;
++	}
++
++	/*
++	 * If the data compressed only slightly, it is better to leave it
++	 * uncompressed to improve read speed.
++	 */
++	if (in_len - *out_len < UBIFS_MIN_COMPRESS_DIFF)
++		goto no_compr;
++
++	return;
++
++no_compr:
++	memcpy(out_buf, in_buf, in_len);
++	*out_len = in_len;
++	*compr_type = UBIFS_COMPR_NONE;
++}
++
++/**
++ * ubifs_decompress - decompress data.
++ * @in_buf: data to decompress
++ * @in_len: length of the data to decompress
++ * @out_buf: output buffer where decompressed data should
++ * @out_len: output length is returned here
++ * @compr_type: type of compression
++ *
++ * This function decompresses data from buffer @in_buf into buffer @out_buf.
++ * The length of the uncompressed data is returned in @out_len. This functions
++ * returns %0 on success or a negative error code on failure.
++ */
++int ubifs_decompress(const void *in_buf, int in_len, void *out_buf,
++		     int *out_len, int compr_type)
++{
++	int err;
++	struct ubifs_compressor *compr;
++
++	if (unlikely(compr_type < 0 || compr_type >= UBIFS_COMPR_TYPES_CNT)) {
++		ubifs_err("invalid compression type %d", compr_type);
++		return -EINVAL;
++	}
++
++	compr = ubifs_compressors[compr_type];
++
++	if (unlikely(!compr->capi_name)) {
++		ubifs_err("%s compression is not compiled in", compr->name);
++		return -EINVAL;
++	}
++
++	if (compr_type == UBIFS_COMPR_NONE) {
++		memcpy(out_buf, in_buf, in_len);
++		*out_len = in_len;
++		return 0;
++	}
++
++	if (compr->decomp_mutex)
++		mutex_lock(compr->decomp_mutex);
++	err = crypto_comp_decompress(compr->cc, in_buf, in_len, out_buf,
++				     (unsigned int *)out_len);
++	if (compr->decomp_mutex)
++		mutex_unlock(compr->decomp_mutex);
++	if (err)
++		ubifs_err("cannot decompress %d bytes, compressor %s, "
++			  "error %d", in_len, compr->name, err);
++
++	return err;
++}
++
++/**
++ * compr_init - initialize a compressor.
++ * @compr: compressor description object
++ *
++ * This function initializes the requested compressor and returns zero in case
++ * of success or a negative error code in case of failure.
++ */
++static int __init compr_init(struct ubifs_compressor *compr)
++{
++	if (compr->capi_name) {
++		compr->cc = crypto_alloc_comp(compr->capi_name, 0, 0);
++		if (IS_ERR(compr->cc)) {
++			ubifs_err("cannot initialize compressor %s, error %ld",
++				  compr->name, PTR_ERR(compr->cc));
++			return PTR_ERR(compr->cc);
++		}
++	}
++
++	ubifs_compressors[compr->compr_type] = compr;
++	return 0;
++}
++
++/**
++ * compr_exit - de-initialize a compressor.
++ * @compr: compressor description object
++ */
++static void compr_exit(struct ubifs_compressor *compr)
++{
++	if (compr->capi_name)
++		crypto_free_comp(compr->cc);
++	return;
++}
++
++/**
++ * ubifs_compressors_init - initialize UBIFS compressors.
++ *
++ * This function initializes the compressor which were compiled in. Returns
++ * zero in case of success and a negative error code in case of failure.
++ */
++int __init ubifs_compressors_init(void)
++{
++	int err;
++
++	err = compr_init(&lzo_compr);
++	if (err)
++		return err;
++
++	err = compr_init(&zlib_compr);
++	if (err)
++		goto out_lzo;
++
++	ubifs_compressors[UBIFS_COMPR_NONE] = &none_compr;
++	return 0;
++
++out_lzo:
++	compr_exit(&lzo_compr);
++	return err;
++}
++
++/**
++ * ubifs_compressors_exit - de-initialize UBIFS compressors.
++ */
++void ubifs_compressors_exit(void)
++{
++	compr_exit(&lzo_compr);
++	compr_exit(&zlib_compr);
++}
+diff -Nurd linux-2.6.24.orig/fs/ubifs/debug.c linux-2.6.24/fs/ubifs/debug.c
+--- linux-2.6.24.orig/fs/ubifs/debug.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/debug.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,2603 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++/*
++ * This file implements most of the debugging stuff which is compiled in only
++ * when it is enabled. But some debugging check functions are implemented in
++ * corresponding subsystem, just because they are closely related and utilize
++ * various local functions of those subsystems.
++ */
++
++#define UBIFS_DBG_PRESERVE_UBI
++
++#include "ubifs.h"
++#include <linux/module.h>
++#include <linux/moduleparam.h>
++#include <linux/debugfs.h>
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++
++DEFINE_SPINLOCK(dbg_lock);
++
++static char dbg_key_buf0[128];
++static char dbg_key_buf1[128];
++
++unsigned int ubifs_msg_flags = UBIFS_MSG_FLAGS_DEFAULT;
++unsigned int ubifs_chk_flags = UBIFS_CHK_FLAGS_DEFAULT;
++unsigned int ubifs_tst_flags;
++
++module_param_named(debug_msgs, ubifs_msg_flags, uint, S_IRUGO | S_IWUSR);
++module_param_named(debug_chks, ubifs_chk_flags, uint, S_IRUGO | S_IWUSR);
++module_param_named(debug_tsts, ubifs_tst_flags, uint, S_IRUGO | S_IWUSR);
++
++MODULE_PARM_DESC(debug_msgs, "Debug message type flags");
++MODULE_PARM_DESC(debug_chks, "Debug check flags");
++MODULE_PARM_DESC(debug_tsts, "Debug special test flags");
++
++static const char *get_key_fmt(int fmt)
++{
++	switch (fmt) {
++	case UBIFS_SIMPLE_KEY_FMT:
++		return "simple";
++	default:
++		return "unknown/invalid format";
++	}
++}
++
++static const char *get_key_hash(int hash)
++{
++	switch (hash) {
++	case UBIFS_KEY_HASH_R5:
++		return "R5";
++	case UBIFS_KEY_HASH_TEST:
++		return "test";
++	default:
++		return "unknown/invalid name hash";
++	}
++}
++
++static const char *get_key_type(int type)
++{
++	switch (type) {
++	case UBIFS_INO_KEY:
++		return "inode";
++	case UBIFS_DENT_KEY:
++		return "direntry";
++	case UBIFS_XENT_KEY:
++		return "xentry";
++	case UBIFS_DATA_KEY:
++		return "data";
++	case UBIFS_TRUN_KEY:
++		return "truncate";
++	default:
++		return "unknown/invalid key";
++	}
++}
++
++static void sprintf_key(const struct ubifs_info *c, const union ubifs_key *key,
++			char *buffer)
++{
++	char *p = buffer;
++	int type = key_type(c, key);
++
++	if (c->key_fmt == UBIFS_SIMPLE_KEY_FMT) {
++		switch (type) {
++		case UBIFS_INO_KEY:
++			sprintf(p, "(%lu, %s)", (unsigned long)key_inum(c, key),
++			       get_key_type(type));
++			break;
++		case UBIFS_DENT_KEY:
++		case UBIFS_XENT_KEY:
++			sprintf(p, "(%lu, %s, %#08x)",
++				(unsigned long)key_inum(c, key),
++				get_key_type(type), key_hash(c, key));
++			break;
++		case UBIFS_DATA_KEY:
++			sprintf(p, "(%lu, %s, %u)",
++				(unsigned long)key_inum(c, key),
++				get_key_type(type), key_block(c, key));
++			break;
++		case UBIFS_TRUN_KEY:
++			sprintf(p, "(%lu, %s)",
++				(unsigned long)key_inum(c, key),
++				get_key_type(type));
++			break;
++		default:
++			sprintf(p, "(bad key type: %#08x, %#08x)",
++				key->u32[0], key->u32[1]);
++		}
++	} else
++		sprintf(p, "bad key format %d", c->key_fmt);
++}
++
++const char *dbg_key_str0(const struct ubifs_info *c, const union ubifs_key *key)
++{
++	/* dbg_lock must be held */
++	sprintf_key(c, key, dbg_key_buf0);
++	return dbg_key_buf0;
++}
++
++const char *dbg_key_str1(const struct ubifs_info *c, const union ubifs_key *key)
++{
++	/* dbg_lock must be held */
++	sprintf_key(c, key, dbg_key_buf1);
++	return dbg_key_buf1;
++}
++
++const char *dbg_ntype(int type)
++{
++	switch (type) {
++	case UBIFS_PAD_NODE:
++		return "padding node";
++	case UBIFS_SB_NODE:
++		return "superblock node";
++	case UBIFS_MST_NODE:
++		return "master node";
++	case UBIFS_REF_NODE:
++		return "reference node";
++	case UBIFS_INO_NODE:
++		return "inode node";
++	case UBIFS_DENT_NODE:
++		return "direntry node";
++	case UBIFS_XENT_NODE:
++		return "xentry node";
++	case UBIFS_DATA_NODE:
++		return "data node";
++	case UBIFS_TRUN_NODE:
++		return "truncate node";
++	case UBIFS_IDX_NODE:
++		return "indexing node";
++	case UBIFS_CS_NODE:
++		return "commit start node";
++	case UBIFS_ORPH_NODE:
++		return "orphan node";
++	default:
++		return "unknown node";
++	}
++}
++
++static const char *dbg_gtype(int type)
++{
++	switch (type) {
++	case UBIFS_NO_NODE_GROUP:
++		return "no node group";
++	case UBIFS_IN_NODE_GROUP:
++		return "in node group";
++	case UBIFS_LAST_OF_NODE_GROUP:
++		return "last of node group";
++	default:
++		return "unknown";
++	}
++}
++
++const char *dbg_cstate(int cmt_state)
++{
++	switch (cmt_state) {
++	case COMMIT_RESTING:
++		return "commit resting";
++	case COMMIT_BACKGROUND:
++		return "background commit requested";
++	case COMMIT_REQUIRED:
++		return "commit required";
++	case COMMIT_RUNNING_BACKGROUND:
++		return "BACKGROUND commit running";
++	case COMMIT_RUNNING_REQUIRED:
++		return "commit running and required";
++	case COMMIT_BROKEN:
++		return "broken commit";
++	default:
++		return "unknown commit state";
++	}
++}
++
++static void dump_ch(const struct ubifs_ch *ch)
++{
++	printk(KERN_DEBUG "\tmagic          %#x\n", le32_to_cpu(ch->magic));
++	printk(KERN_DEBUG "\tcrc            %#x\n", le32_to_cpu(ch->crc));
++	printk(KERN_DEBUG "\tnode_type      %d (%s)\n", ch->node_type,
++	       dbg_ntype(ch->node_type));
++	printk(KERN_DEBUG "\tgroup_type     %d (%s)\n", ch->group_type,
++	       dbg_gtype(ch->group_type));
++	printk(KERN_DEBUG "\tsqnum          %llu\n",
++	       (unsigned long long)le64_to_cpu(ch->sqnum));
++	printk(KERN_DEBUG "\tlen            %u\n", le32_to_cpu(ch->len));
++}
++
++void dbg_dump_inode(const struct ubifs_info *c, const struct inode *inode)
++{
++	const struct ubifs_inode *ui = ubifs_inode(inode);
++
++	printk(KERN_DEBUG "Dump in-memory inode:");
++	printk(KERN_DEBUG "\tinode          %lu\n", inode->i_ino);
++	printk(KERN_DEBUG "\tsize           %llu\n",
++	       (unsigned long long)i_size_read(inode));
++	printk(KERN_DEBUG "\tnlink          %u\n", inode->i_nlink);
++	printk(KERN_DEBUG "\tuid            %u\n", (unsigned int)inode->i_uid);
++	printk(KERN_DEBUG "\tgid            %u\n", (unsigned int)inode->i_gid);
++	printk(KERN_DEBUG "\tatime          %u.%u\n",
++	       (unsigned int)inode->i_atime.tv_sec,
++	       (unsigned int)inode->i_atime.tv_nsec);
++	printk(KERN_DEBUG "\tmtime          %u.%u\n",
++	       (unsigned int)inode->i_mtime.tv_sec,
++	       (unsigned int)inode->i_mtime.tv_nsec);
++	printk(KERN_DEBUG "\tctime          %u.%u\n",
++	       (unsigned int)inode->i_ctime.tv_sec,
++	       (unsigned int)inode->i_ctime.tv_nsec);
++	printk(KERN_DEBUG "\tcreat_sqnum    %llu\n", ui->creat_sqnum);
++	printk(KERN_DEBUG "\txattr_size     %u\n", ui->xattr_size);
++	printk(KERN_DEBUG "\txattr_cnt      %u\n", ui->xattr_cnt);
++	printk(KERN_DEBUG "\txattr_names    %u\n", ui->xattr_names);
++	printk(KERN_DEBUG "\tdirty          %u\n", ui->dirty);
++	printk(KERN_DEBUG "\txattr          %u\n", ui->xattr);
++	printk(KERN_DEBUG "\tbulk_read      %u\n", ui->xattr);
++	printk(KERN_DEBUG "\tsynced_i_size  %llu\n",
++	       (unsigned long long)ui->synced_i_size);
++	printk(KERN_DEBUG "\tui_size        %llu\n",
++	       (unsigned long long)ui->ui_size);
++	printk(KERN_DEBUG "\tflags          %d\n", ui->flags);
++	printk(KERN_DEBUG "\tcompr_type     %d\n", ui->compr_type);
++	printk(KERN_DEBUG "\tlast_page_read %lu\n", ui->last_page_read);
++	printk(KERN_DEBUG "\tread_in_a_row  %lu\n", ui->read_in_a_row);
++	printk(KERN_DEBUG "\tdata_len       %d\n", ui->data_len);
++}
++
++void dbg_dump_node(const struct ubifs_info *c, const void *node)
++{
++	int i, n;
++	union ubifs_key key;
++	const struct ubifs_ch *ch = node;
++
++	if (dbg_failure_mode)
++		return;
++
++	/* If the magic is incorrect, just hexdump the first bytes */
++	if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC) {
++		printk(KERN_DEBUG "Not a node, first %zu bytes:", UBIFS_CH_SZ);
++		print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 1,
++			       (void *)node, UBIFS_CH_SZ, 1);
++		return;
++	}
++
++	spin_lock(&dbg_lock);
++	dump_ch(node);
++
++	switch (ch->node_type) {
++	case UBIFS_PAD_NODE:
++	{
++		const struct ubifs_pad_node *pad = node;
++
++		printk(KERN_DEBUG "\tpad_len        %u\n",
++		       le32_to_cpu(pad->pad_len));
++		break;
++	}
++	case UBIFS_SB_NODE:
++	{
++		const struct ubifs_sb_node *sup = node;
++		unsigned int sup_flags = le32_to_cpu(sup->flags);
++
++		printk(KERN_DEBUG "\tkey_hash       %d (%s)\n",
++		       (int)sup->key_hash, get_key_hash(sup->key_hash));
++		printk(KERN_DEBUG "\tkey_fmt        %d (%s)\n",
++		       (int)sup->key_fmt, get_key_fmt(sup->key_fmt));
++		printk(KERN_DEBUG "\tflags          %#x\n", sup_flags);
++		printk(KERN_DEBUG "\t  big_lpt      %u\n",
++		       !!(sup_flags & UBIFS_FLG_BIGLPT));
++		printk(KERN_DEBUG "\tmin_io_size    %u\n",
++		       le32_to_cpu(sup->min_io_size));
++		printk(KERN_DEBUG "\tleb_size       %u\n",
++		       le32_to_cpu(sup->leb_size));
++		printk(KERN_DEBUG "\tleb_cnt        %u\n",
++		       le32_to_cpu(sup->leb_cnt));
++		printk(KERN_DEBUG "\tmax_leb_cnt    %u\n",
++		       le32_to_cpu(sup->max_leb_cnt));
++		printk(KERN_DEBUG "\tmax_bud_bytes  %llu\n",
++		       (unsigned long long)le64_to_cpu(sup->max_bud_bytes));
++		printk(KERN_DEBUG "\tlog_lebs       %u\n",
++		       le32_to_cpu(sup->log_lebs));
++		printk(KERN_DEBUG "\tlpt_lebs       %u\n",
++		       le32_to_cpu(sup->lpt_lebs));
++		printk(KERN_DEBUG "\torph_lebs      %u\n",
++		       le32_to_cpu(sup->orph_lebs));
++		printk(KERN_DEBUG "\tjhead_cnt      %u\n",
++		       le32_to_cpu(sup->jhead_cnt));
++		printk(KERN_DEBUG "\tfanout         %u\n",
++		       le32_to_cpu(sup->fanout));
++		printk(KERN_DEBUG "\tlsave_cnt      %u\n",
++		       le32_to_cpu(sup->lsave_cnt));
++		printk(KERN_DEBUG "\tdefault_compr  %u\n",
++		       (int)le16_to_cpu(sup->default_compr));
++		printk(KERN_DEBUG "\trp_size        %llu\n",
++		       (unsigned long long)le64_to_cpu(sup->rp_size));
++		printk(KERN_DEBUG "\trp_uid         %u\n",
++		       le32_to_cpu(sup->rp_uid));
++		printk(KERN_DEBUG "\trp_gid         %u\n",
++		       le32_to_cpu(sup->rp_gid));
++		printk(KERN_DEBUG "\tfmt_version    %u\n",
++		       le32_to_cpu(sup->fmt_version));
++		printk(KERN_DEBUG "\ttime_gran      %u\n",
++		       le32_to_cpu(sup->time_gran));
++		printk(KERN_DEBUG "\tUUID           %02X%02X%02X%02X-%02X%02X"
++		       "-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X\n",
++		       sup->uuid[0], sup->uuid[1], sup->uuid[2], sup->uuid[3],
++		       sup->uuid[4], sup->uuid[5], sup->uuid[6], sup->uuid[7],
++		       sup->uuid[8], sup->uuid[9], sup->uuid[10], sup->uuid[11],
++		       sup->uuid[12], sup->uuid[13], sup->uuid[14],
++		       sup->uuid[15]);
++		break;
++	}
++	case UBIFS_MST_NODE:
++	{
++		const struct ubifs_mst_node *mst = node;
++
++		printk(KERN_DEBUG "\thighest_inum   %llu\n",
++		       (unsigned long long)le64_to_cpu(mst->highest_inum));
++		printk(KERN_DEBUG "\tcommit number  %llu\n",
++		       (unsigned long long)le64_to_cpu(mst->cmt_no));
++		printk(KERN_DEBUG "\tflags          %#x\n",
++		       le32_to_cpu(mst->flags));
++		printk(KERN_DEBUG "\tlog_lnum       %u\n",
++		       le32_to_cpu(mst->log_lnum));
++		printk(KERN_DEBUG "\troot_lnum      %u\n",
++		       le32_to_cpu(mst->root_lnum));
++		printk(KERN_DEBUG "\troot_offs      %u\n",
++		       le32_to_cpu(mst->root_offs));
++		printk(KERN_DEBUG "\troot_len       %u\n",
++		       le32_to_cpu(mst->root_len));
++		printk(KERN_DEBUG "\tgc_lnum        %u\n",
++		       le32_to_cpu(mst->gc_lnum));
++		printk(KERN_DEBUG "\tihead_lnum     %u\n",
++		       le32_to_cpu(mst->ihead_lnum));
++		printk(KERN_DEBUG "\tihead_offs     %u\n",
++		       le32_to_cpu(mst->ihead_offs));
++		printk(KERN_DEBUG "\tindex_size     %llu\n",
++		       (unsigned long long)le64_to_cpu(mst->index_size));
++		printk(KERN_DEBUG "\tlpt_lnum       %u\n",
++		       le32_to_cpu(mst->lpt_lnum));
++		printk(KERN_DEBUG "\tlpt_offs       %u\n",
++		       le32_to_cpu(mst->lpt_offs));
++		printk(KERN_DEBUG "\tnhead_lnum     %u\n",
++		       le32_to_cpu(mst->nhead_lnum));
++		printk(KERN_DEBUG "\tnhead_offs     %u\n",
++		       le32_to_cpu(mst->nhead_offs));
++		printk(KERN_DEBUG "\tltab_lnum      %u\n",
++		       le32_to_cpu(mst->ltab_lnum));
++		printk(KERN_DEBUG "\tltab_offs      %u\n",
++		       le32_to_cpu(mst->ltab_offs));
++		printk(KERN_DEBUG "\tlsave_lnum     %u\n",
++		       le32_to_cpu(mst->lsave_lnum));
++		printk(KERN_DEBUG "\tlsave_offs     %u\n",
++		       le32_to_cpu(mst->lsave_offs));
++		printk(KERN_DEBUG "\tlscan_lnum     %u\n",
++		       le32_to_cpu(mst->lscan_lnum));
++		printk(KERN_DEBUG "\tleb_cnt        %u\n",
++		       le32_to_cpu(mst->leb_cnt));
++		printk(KERN_DEBUG "\tempty_lebs     %u\n",
++		       le32_to_cpu(mst->empty_lebs));
++		printk(KERN_DEBUG "\tidx_lebs       %u\n",
++		       le32_to_cpu(mst->idx_lebs));
++		printk(KERN_DEBUG "\ttotal_free     %llu\n",
++		       (unsigned long long)le64_to_cpu(mst->total_free));
++		printk(KERN_DEBUG "\ttotal_dirty    %llu\n",
++		       (unsigned long long)le64_to_cpu(mst->total_dirty));
++		printk(KERN_DEBUG "\ttotal_used     %llu\n",
++		       (unsigned long long)le64_to_cpu(mst->total_used));
++		printk(KERN_DEBUG "\ttotal_dead     %llu\n",
++		       (unsigned long long)le64_to_cpu(mst->total_dead));
++		printk(KERN_DEBUG "\ttotal_dark     %llu\n",
++		       (unsigned long long)le64_to_cpu(mst->total_dark));
++		break;
++	}
++	case UBIFS_REF_NODE:
++	{
++		const struct ubifs_ref_node *ref = node;
++
++		printk(KERN_DEBUG "\tlnum           %u\n",
++		       le32_to_cpu(ref->lnum));
++		printk(KERN_DEBUG "\toffs           %u\n",
++		       le32_to_cpu(ref->offs));
++		printk(KERN_DEBUG "\tjhead          %u\n",
++		       le32_to_cpu(ref->jhead));
++		break;
++	}
++	case UBIFS_INO_NODE:
++	{
++		const struct ubifs_ino_node *ino = node;
++
++		key_read(c, &ino->key, &key);
++		printk(KERN_DEBUG "\tkey            %s\n", DBGKEY(&key));
++		printk(KERN_DEBUG "\tcreat_sqnum    %llu\n",
++		       (unsigned long long)le64_to_cpu(ino->creat_sqnum));
++		printk(KERN_DEBUG "\tsize           %llu\n",
++		       (unsigned long long)le64_to_cpu(ino->size));
++		printk(KERN_DEBUG "\tnlink          %u\n",
++		       le32_to_cpu(ino->nlink));
++		printk(KERN_DEBUG "\tatime          %lld.%u\n",
++		       (long long)le64_to_cpu(ino->atime_sec),
++		       le32_to_cpu(ino->atime_nsec));
++		printk(KERN_DEBUG "\tmtime          %lld.%u\n",
++		       (long long)le64_to_cpu(ino->mtime_sec),
++		       le32_to_cpu(ino->mtime_nsec));
++		printk(KERN_DEBUG "\tctime          %lld.%u\n",
++		       (long long)le64_to_cpu(ino->ctime_sec),
++		       le32_to_cpu(ino->ctime_nsec));
++		printk(KERN_DEBUG "\tuid            %u\n",
++		       le32_to_cpu(ino->uid));
++		printk(KERN_DEBUG "\tgid            %u\n",
++		       le32_to_cpu(ino->gid));
++		printk(KERN_DEBUG "\tmode           %u\n",
++		       le32_to_cpu(ino->mode));
++		printk(KERN_DEBUG "\tflags          %#x\n",
++		       le32_to_cpu(ino->flags));
++		printk(KERN_DEBUG "\txattr_cnt      %u\n",
++		       le32_to_cpu(ino->xattr_cnt));
++		printk(KERN_DEBUG "\txattr_size     %u\n",
++		       le32_to_cpu(ino->xattr_size));
++		printk(KERN_DEBUG "\txattr_names    %u\n",
++		       le32_to_cpu(ino->xattr_names));
++		printk(KERN_DEBUG "\tcompr_type     %#x\n",
++		       (int)le16_to_cpu(ino->compr_type));
++		printk(KERN_DEBUG "\tdata len       %u\n",
++		       le32_to_cpu(ino->data_len));
++		break;
++	}
++	case UBIFS_DENT_NODE:
++	case UBIFS_XENT_NODE:
++	{
++		const struct ubifs_dent_node *dent = node;
++		int nlen = le16_to_cpu(dent->nlen);
++
++		key_read(c, &dent->key, &key);
++		printk(KERN_DEBUG "\tkey            %s\n", DBGKEY(&key));
++		printk(KERN_DEBUG "\tinum           %llu\n",
++		       (unsigned long long)le64_to_cpu(dent->inum));
++		printk(KERN_DEBUG "\ttype           %d\n", (int)dent->type);
++		printk(KERN_DEBUG "\tnlen           %d\n", nlen);
++		printk(KERN_DEBUG "\tname           ");
++
++		if (nlen > UBIFS_MAX_NLEN)
++			printk(KERN_DEBUG "(bad name length, not printing, "
++					  "bad or corrupted node)");
++		else {
++			for (i = 0; i < nlen && dent->name[i]; i++)
++				printk("%c", dent->name[i]);
++		}
++		printk("\n");
++
++		break;
++	}
++	case UBIFS_DATA_NODE:
++	{
++		const struct ubifs_data_node *dn = node;
++		int dlen = le32_to_cpu(ch->len) - UBIFS_DATA_NODE_SZ;
++
++		key_read(c, &dn->key, &key);
++		printk(KERN_DEBUG "\tkey            %s\n", DBGKEY(&key));
++		printk(KERN_DEBUG "\tsize           %u\n",
++		       le32_to_cpu(dn->size));
++		printk(KERN_DEBUG "\tcompr_typ      %d\n",
++		       (int)le16_to_cpu(dn->compr_type));
++		printk(KERN_DEBUG "\tdata size      %d\n",
++		       dlen);
++		printk(KERN_DEBUG "\tdata:\n");
++		print_hex_dump(KERN_DEBUG, "\t", DUMP_PREFIX_OFFSET, 32, 1,
++			       (void *)&dn->data, dlen, 0);
++		break;
++	}
++	case UBIFS_TRUN_NODE:
++	{
++		const struct ubifs_trun_node *trun = node;
++
++		printk(KERN_DEBUG "\tinum           %u\n",
++		       le32_to_cpu(trun->inum));
++		printk(KERN_DEBUG "\told_size       %llu\n",
++		       (unsigned long long)le64_to_cpu(trun->old_size));
++		printk(KERN_DEBUG "\tnew_size       %llu\n",
++		       (unsigned long long)le64_to_cpu(trun->new_size));
++		break;
++	}
++	case UBIFS_IDX_NODE:
++	{
++		const struct ubifs_idx_node *idx = node;
++
++		n = le16_to_cpu(idx->child_cnt);
++		printk(KERN_DEBUG "\tchild_cnt      %d\n", n);
++		printk(KERN_DEBUG "\tlevel          %d\n",
++		       (int)le16_to_cpu(idx->level));
++		printk(KERN_DEBUG "\tBranches:\n");
++
++		for (i = 0; i < n && i < c->fanout - 1; i++) {
++			const struct ubifs_branch *br;
++
++			br = ubifs_idx_branch(c, idx, i);
++			key_read(c, &br->key, &key);
++			printk(KERN_DEBUG "\t%d: LEB %d:%d len %d key %s\n",
++			       i, le32_to_cpu(br->lnum), le32_to_cpu(br->offs),
++			       le32_to_cpu(br->len), DBGKEY(&key));
++		}
++		break;
++	}
++	case UBIFS_CS_NODE:
++		break;
++	case UBIFS_ORPH_NODE:
++	{
++		const struct ubifs_orph_node *orph = node;
++
++		printk(KERN_DEBUG "\tcommit number  %llu\n",
++		       (unsigned long long)
++				le64_to_cpu(orph->cmt_no) & LLONG_MAX);
++		printk(KERN_DEBUG "\tlast node flag %llu\n",
++		       (unsigned long long)(le64_to_cpu(orph->cmt_no)) >> 63);
++		n = (le32_to_cpu(ch->len) - UBIFS_ORPH_NODE_SZ) >> 3;
++		printk(KERN_DEBUG "\t%d orphan inode numbers:\n", n);
++		for (i = 0; i < n; i++)
++			printk(KERN_DEBUG "\t  ino %llu\n",
++			       (unsigned long long)le64_to_cpu(orph->inos[i]));
++		break;
++	}
++	default:
++		printk(KERN_DEBUG "node type %d was not recognized\n",
++		       (int)ch->node_type);
++	}
++	spin_unlock(&dbg_lock);
++}
++
++void dbg_dump_budget_req(const struct ubifs_budget_req *req)
++{
++	spin_lock(&dbg_lock);
++	printk(KERN_DEBUG "Budgeting request: new_ino %d, dirtied_ino %d\n",
++	       req->new_ino, req->dirtied_ino);
++	printk(KERN_DEBUG "\tnew_ino_d  %d, dirtied_ino_d %d\n",
++	       req->new_ino_d, req->dirtied_ino_d);
++	printk(KERN_DEBUG "\tnew_page    %d, dirtied_page %d\n",
++	       req->new_page, req->dirtied_page);
++	printk(KERN_DEBUG "\tnew_dent    %d, mod_dent     %d\n",
++	       req->new_dent, req->mod_dent);
++	printk(KERN_DEBUG "\tidx_growth  %d\n", req->idx_growth);
++	printk(KERN_DEBUG "\tdata_growth %d dd_growth     %d\n",
++	       req->data_growth, req->dd_growth);
++	spin_unlock(&dbg_lock);
++}
++
++void dbg_dump_lstats(const struct ubifs_lp_stats *lst)
++{
++	spin_lock(&dbg_lock);
++	printk(KERN_DEBUG "(pid %d) Lprops statistics: empty_lebs %d, "
++	       "idx_lebs  %d\n", current->pid, lst->empty_lebs, lst->idx_lebs);
++	printk(KERN_DEBUG "\ttaken_empty_lebs %d, total_free %lld, "
++	       "total_dirty %lld\n", lst->taken_empty_lebs, lst->total_free,
++	       lst->total_dirty);
++	printk(KERN_DEBUG "\ttotal_used %lld, total_dark %lld, "
++	       "total_dead %lld\n", lst->total_used, lst->total_dark,
++	       lst->total_dead);
++	spin_unlock(&dbg_lock);
++}
++
++void dbg_dump_budg(struct ubifs_info *c)
++{
++	int i;
++	struct rb_node *rb;
++	struct ubifs_bud *bud;
++	struct ubifs_gced_idx_leb *idx_gc;
++	long long available, outstanding, free;
++
++	ubifs_assert(spin_is_locked(&c->space_lock));
++	spin_lock(&dbg_lock);
++	printk(KERN_DEBUG "(pid %d) Budgeting info: budg_data_growth %lld, "
++	       "budg_dd_growth %lld, budg_idx_growth %lld\n", current->pid,
++	       c->budg_data_growth, c->budg_dd_growth, c->budg_idx_growth);
++	printk(KERN_DEBUG "\tdata budget sum %lld, total budget sum %lld, "
++	       "freeable_cnt %d\n", c->budg_data_growth + c->budg_dd_growth,
++	       c->budg_data_growth + c->budg_dd_growth + c->budg_idx_growth,
++	       c->freeable_cnt);
++	printk(KERN_DEBUG "\tmin_idx_lebs %d, old_idx_sz %lld, "
++	       "calc_idx_sz %lld, idx_gc_cnt %d\n", c->min_idx_lebs,
++	       c->old_idx_sz, c->calc_idx_sz, c->idx_gc_cnt);
++	printk(KERN_DEBUG "\tdirty_pg_cnt %ld, dirty_zn_cnt %ld, "
++	       "clean_zn_cnt %ld\n", atomic_long_read(&c->dirty_pg_cnt),
++	       atomic_long_read(&c->dirty_zn_cnt),
++	       atomic_long_read(&c->clean_zn_cnt));
++	printk(KERN_DEBUG "\tdark_wm %d, dead_wm %d, max_idx_node_sz %d\n",
++	       c->dark_wm, c->dead_wm, c->max_idx_node_sz);
++	printk(KERN_DEBUG "\tgc_lnum %d, ihead_lnum %d\n",
++	       c->gc_lnum, c->ihead_lnum);
++	/* If we are in R/O mode, journal heads do not exist */
++	if (c->jheads)
++		for (i = 0; i < c->jhead_cnt; i++)
++			printk(KERN_DEBUG "\tjhead %d\t LEB %d\n",
++			       c->jheads[i].wbuf.jhead, c->jheads[i].wbuf.lnum);
++	for (rb = rb_first(&c->buds); rb; rb = rb_next(rb)) {
++		bud = rb_entry(rb, struct ubifs_bud, rb);
++		printk(KERN_DEBUG "\tbud LEB %d\n", bud->lnum);
++	}
++	list_for_each_entry(bud, &c->old_buds, list)
++		printk(KERN_DEBUG "\told bud LEB %d\n", bud->lnum);
++	list_for_each_entry(idx_gc, &c->idx_gc, list)
++		printk(KERN_DEBUG "\tGC'ed idx LEB %d unmap %d\n",
++		       idx_gc->lnum, idx_gc->unmap);
++	printk(KERN_DEBUG "\tcommit state %d\n", c->cmt_state);
++
++	/* Print budgeting predictions */
++	available = ubifs_calc_available(c, c->min_idx_lebs);
++	outstanding = c->budg_data_growth + c->budg_dd_growth;
++	free = ubifs_get_free_space_nolock(c);
++	printk(KERN_DEBUG "Budgeting predictions:\n");
++	printk(KERN_DEBUG "\tavailable: %lld, outstanding %lld, free %lld\n",
++	       available, outstanding, free);
++	spin_unlock(&dbg_lock);
++}
++
++void dbg_dump_lprop(const struct ubifs_info *c, const struct ubifs_lprops *lp)
++{
++	printk(KERN_DEBUG "LEB %d lprops: free %d, dirty %d (used %d), "
++	       "flags %#x\n", lp->lnum, lp->free, lp->dirty,
++	       c->leb_size - lp->free - lp->dirty, lp->flags);
++}
++
++void dbg_dump_lprops(struct ubifs_info *c)
++{
++	int lnum, err;
++	struct ubifs_lprops lp;
++	struct ubifs_lp_stats lst;
++
++	printk(KERN_DEBUG "(pid %d) start dumping LEB properties\n",
++	       current->pid);
++	ubifs_get_lp_stats(c, &lst);
++	dbg_dump_lstats(&lst);
++
++	for (lnum = c->main_first; lnum < c->leb_cnt; lnum++) {
++		err = ubifs_read_one_lp(c, lnum, &lp);
++		if (err)
++			ubifs_err("cannot read lprops for LEB %d", lnum);
++
++		dbg_dump_lprop(c, &lp);
++	}
++	printk(KERN_DEBUG "(pid %d) finish dumping LEB properties\n",
++	       current->pid);
++}
++
++void dbg_dump_lpt_info(struct ubifs_info *c)
++{
++	int i;
++
++	spin_lock(&dbg_lock);
++	printk(KERN_DEBUG "(pid %d) dumping LPT information\n", current->pid);
++	printk(KERN_DEBUG "\tlpt_sz:        %lld\n", c->lpt_sz);
++	printk(KERN_DEBUG "\tpnode_sz:      %d\n", c->pnode_sz);
++	printk(KERN_DEBUG "\tnnode_sz:      %d\n", c->nnode_sz);
++	printk(KERN_DEBUG "\tltab_sz:       %d\n", c->ltab_sz);
++	printk(KERN_DEBUG "\tlsave_sz:      %d\n", c->lsave_sz);
++	printk(KERN_DEBUG "\tbig_lpt:       %d\n", c->big_lpt);
++	printk(KERN_DEBUG "\tlpt_hght:      %d\n", c->lpt_hght);
++	printk(KERN_DEBUG "\tpnode_cnt:     %d\n", c->pnode_cnt);
++	printk(KERN_DEBUG "\tnnode_cnt:     %d\n", c->nnode_cnt);
++	printk(KERN_DEBUG "\tdirty_pn_cnt:  %d\n", c->dirty_pn_cnt);
++	printk(KERN_DEBUG "\tdirty_nn_cnt:  %d\n", c->dirty_nn_cnt);
++	printk(KERN_DEBUG "\tlsave_cnt:     %d\n", c->lsave_cnt);
++	printk(KERN_DEBUG "\tspace_bits:    %d\n", c->space_bits);
++	printk(KERN_DEBUG "\tlpt_lnum_bits: %d\n", c->lpt_lnum_bits);
++	printk(KERN_DEBUG "\tlpt_offs_bits: %d\n", c->lpt_offs_bits);
++	printk(KERN_DEBUG "\tlpt_spc_bits:  %d\n", c->lpt_spc_bits);
++	printk(KERN_DEBUG "\tpcnt_bits:     %d\n", c->pcnt_bits);
++	printk(KERN_DEBUG "\tlnum_bits:     %d\n", c->lnum_bits);
++	printk(KERN_DEBUG "\tLPT root is at %d:%d\n", c->lpt_lnum, c->lpt_offs);
++	printk(KERN_DEBUG "\tLPT head is at %d:%d\n",
++	       c->nhead_lnum, c->nhead_offs);
++	printk(KERN_DEBUG "\tLPT ltab is at %d:%d\n",
++	       c->ltab_lnum, c->ltab_offs);
++	if (c->big_lpt)
++		printk(KERN_DEBUG "\tLPT lsave is at %d:%d\n",
++		       c->lsave_lnum, c->lsave_offs);
++	for (i = 0; i < c->lpt_lebs; i++)
++		printk(KERN_DEBUG "\tLPT LEB %d free %d dirty %d tgc %d "
++		       "cmt %d\n", i + c->lpt_first, c->ltab[i].free,
++		       c->ltab[i].dirty, c->ltab[i].tgc, c->ltab[i].cmt);
++	spin_unlock(&dbg_lock);
++}
++
++void dbg_dump_leb(const struct ubifs_info *c, int lnum)
++{
++	struct ubifs_scan_leb *sleb;
++	struct ubifs_scan_node *snod;
++
++	if (dbg_failure_mode)
++		return;
++
++	printk(KERN_DEBUG "(pid %d) start dumping LEB %d\n",
++	       current->pid, lnum);
++	sleb = ubifs_scan(c, lnum, 0, c->dbg->buf);
++	if (IS_ERR(sleb)) {
++		ubifs_err("scan error %d", (int)PTR_ERR(sleb));
++		return;
++	}
++
++	printk(KERN_DEBUG "LEB %d has %d nodes ending at %d\n", lnum,
++	       sleb->nodes_cnt, sleb->endpt);
++
++	list_for_each_entry(snod, &sleb->nodes, list) {
++		cond_resched();
++		printk(KERN_DEBUG "Dumping node at LEB %d:%d len %d\n", lnum,
++		       snod->offs, snod->len);
++		dbg_dump_node(c, snod->node);
++	}
++
++	printk(KERN_DEBUG "(pid %d) finish dumping LEB %d\n",
++	       current->pid, lnum);
++	ubifs_scan_destroy(sleb);
++	return;
++}
++
++void dbg_dump_znode(const struct ubifs_info *c,
++		    const struct ubifs_znode *znode)
++{
++	int n;
++	const struct ubifs_zbranch *zbr;
++
++	spin_lock(&dbg_lock);
++	if (znode->parent)
++		zbr = &znode->parent->zbranch[znode->iip];
++	else
++		zbr = &c->zroot;
++
++	printk(KERN_DEBUG "znode %p, LEB %d:%d len %d parent %p iip %d level %d"
++	       " child_cnt %d flags %lx\n", znode, zbr->lnum, zbr->offs,
++	       zbr->len, znode->parent, znode->iip, znode->level,
++	       znode->child_cnt, znode->flags);
++
++	if (znode->child_cnt <= 0 || znode->child_cnt > c->fanout) {
++		spin_unlock(&dbg_lock);
++		return;
++	}
++
++	printk(KERN_DEBUG "zbranches:\n");
++	for (n = 0; n < znode->child_cnt; n++) {
++		zbr = &znode->zbranch[n];
++		if (znode->level > 0)
++			printk(KERN_DEBUG "\t%d: znode %p LEB %d:%d len %d key "
++					  "%s\n", n, zbr->znode, zbr->lnum,
++					  zbr->offs, zbr->len,
++					  DBGKEY(&zbr->key));
++		else
++			printk(KERN_DEBUG "\t%d: LNC %p LEB %d:%d len %d key "
++					  "%s\n", n, zbr->znode, zbr->lnum,
++					  zbr->offs, zbr->len,
++					  DBGKEY(&zbr->key));
++	}
++	spin_unlock(&dbg_lock);
++}
++
++void dbg_dump_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat)
++{
++	int i;
++
++	printk(KERN_DEBUG "(pid %d) start dumping heap cat %d (%d elements)\n",
++	       current->pid, cat, heap->cnt);
++	for (i = 0; i < heap->cnt; i++) {
++		struct ubifs_lprops *lprops = heap->arr[i];
++
++		printk(KERN_DEBUG "\t%d. LEB %d hpos %d free %d dirty %d "
++		       "flags %d\n", i, lprops->lnum, lprops->hpos,
++		       lprops->free, lprops->dirty, lprops->flags);
++	}
++	printk(KERN_DEBUG "(pid %d) finish dumping heap\n", current->pid);
++}
++
++void dbg_dump_pnode(struct ubifs_info *c, struct ubifs_pnode *pnode,
++		    struct ubifs_nnode *parent, int iip)
++{
++	int i;
++
++	printk(KERN_DEBUG "(pid %d) dumping pnode:\n", current->pid);
++	printk(KERN_DEBUG "\taddress %zx parent %zx cnext %zx\n",
++	       (size_t)pnode, (size_t)parent, (size_t)pnode->cnext);
++	printk(KERN_DEBUG "\tflags %lu iip %d level %d num %d\n",
++	       pnode->flags, iip, pnode->level, pnode->num);
++	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++		struct ubifs_lprops *lp = &pnode->lprops[i];
++
++		printk(KERN_DEBUG "\t%d: free %d dirty %d flags %d lnum %d\n",
++		       i, lp->free, lp->dirty, lp->flags, lp->lnum);
++	}
++}
++
++void dbg_dump_tnc(struct ubifs_info *c)
++{
++	struct ubifs_znode *znode;
++	int level;
++
++	printk(KERN_DEBUG "\n");
++	printk(KERN_DEBUG "(pid %d) start dumping TNC tree\n", current->pid);
++	znode = ubifs_tnc_levelorder_next(c->zroot.znode, NULL);
++	level = znode->level;
++	printk(KERN_DEBUG "== Level %d ==\n", level);
++	while (znode) {
++		if (level != znode->level) {
++			level = znode->level;
++			printk(KERN_DEBUG "== Level %d ==\n", level);
++		}
++		dbg_dump_znode(c, znode);
++		znode = ubifs_tnc_levelorder_next(c->zroot.znode, znode);
++	}
++	printk(KERN_DEBUG "(pid %d) finish dumping TNC tree\n", current->pid);
++}
++
++static int dump_znode(struct ubifs_info *c, struct ubifs_znode *znode,
++		      void *priv)
++{
++	dbg_dump_znode(c, znode);
++	return 0;
++}
++
++/**
++ * dbg_dump_index - dump the on-flash index.
++ * @c: UBIFS file-system description object
++ *
++ * This function dumps whole UBIFS indexing B-tree, unlike 'dbg_dump_tnc()'
++ * which dumps only in-memory znodes and does not read znodes which from flash.
++ */
++void dbg_dump_index(struct ubifs_info *c)
++{
++	dbg_walk_index(c, NULL, dump_znode, NULL);
++}
++
++/**
++ * dbg_save_space_info - save information about flash space.
++ * @c: UBIFS file-system description object
++ *
++ * This function saves information about UBIFS free space, dirty space, etc, in
++ * order to check it later.
++ */
++void dbg_save_space_info(struct ubifs_info *c)
++{
++	struct ubifs_debug_info *d = c->dbg;
++
++	ubifs_get_lp_stats(c, &d->saved_lst);
++
++	spin_lock(&c->space_lock);
++	d->saved_free = ubifs_get_free_space_nolock(c);
++	spin_unlock(&c->space_lock);
++}
++
++/**
++ * dbg_check_space_info - check flash space information.
++ * @c: UBIFS file-system description object
++ *
++ * This function compares current flash space information with the information
++ * which was saved when the 'dbg_save_space_info()' function was called.
++ * Returns zero if the information has not changed, and %-EINVAL it it has
++ * changed.
++ */
++int dbg_check_space_info(struct ubifs_info *c)
++{
++	struct ubifs_debug_info *d = c->dbg;
++	struct ubifs_lp_stats lst;
++	long long avail, free;
++
++	spin_lock(&c->space_lock);
++	avail = ubifs_calc_available(c, c->min_idx_lebs);
++	spin_unlock(&c->space_lock);
++	free = ubifs_get_free_space(c);
++
++	if (free != d->saved_free) {
++		ubifs_err("free space changed from %lld to %lld",
++			  d->saved_free, free);
++		goto out;
++	}
++
++	return 0;
++
++out:
++	ubifs_msg("saved lprops statistics dump");
++	dbg_dump_lstats(&d->saved_lst);
++	ubifs_get_lp_stats(c, &lst);
++	ubifs_msg("current lprops statistics dump");
++	dbg_dump_lstats(&d->saved_lst);
++	spin_lock(&c->space_lock);
++	dbg_dump_budg(c);
++	spin_unlock(&c->space_lock);
++	dump_stack();
++	return -EINVAL;
++}
++
++/**
++ * dbg_check_synced_i_size - check synchronized inode size.
++ * @inode: inode to check
++ *
++ * If inode is clean, synchronized inode size has to be equivalent to current
++ * inode size. This function has to be called only for locked inodes (@i_mutex
++ * has to be locked). Returns %0 if synchronized inode size if correct, and
++ * %-EINVAL if not.
++ */
++int dbg_check_synced_i_size(struct inode *inode)
++{
++	int err = 0;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++
++	if (!(ubifs_chk_flags & UBIFS_CHK_GEN))
++		return 0;
++	if (!S_ISREG(inode->i_mode))
++		return 0;
++
++	mutex_lock(&ui->ui_mutex);
++	spin_lock(&ui->ui_lock);
++	if (ui->ui_size != ui->synced_i_size && !ui->dirty) {
++		ubifs_err("ui_size is %lld, synced_i_size is %lld, but inode "
++			  "is clean", ui->ui_size, ui->synced_i_size);
++		ubifs_err("i_ino %lu, i_mode %#x, i_size %lld", inode->i_ino,
++			  inode->i_mode, i_size_read(inode));
++		dbg_dump_stack();
++		err = -EINVAL;
++	}
++	spin_unlock(&ui->ui_lock);
++	mutex_unlock(&ui->ui_mutex);
++	return err;
++}
++
++/*
++ * dbg_check_dir - check directory inode size and link count.
++ * @c: UBIFS file-system description object
++ * @dir: the directory to calculate size for
++ * @size: the result is returned here
++ *
++ * This function makes sure that directory size and link count are correct.
++ * Returns zero in case of success and a negative error code in case of
++ * failure.
++ *
++ * Note, it is good idea to make sure the @dir->i_mutex is locked before
++ * calling this function.
++ */
++int dbg_check_dir_size(struct ubifs_info *c, const struct inode *dir)
++{
++	unsigned int nlink = 2;
++	union ubifs_key key;
++	struct ubifs_dent_node *dent, *pdent = NULL;
++	struct qstr nm = { .name = NULL };
++	loff_t size = UBIFS_INO_NODE_SZ;
++
++	if (!(ubifs_chk_flags & UBIFS_CHK_GEN))
++		return 0;
++
++	if (!S_ISDIR(dir->i_mode))
++		return 0;
++
++	lowest_dent_key(c, &key, dir->i_ino);
++	while (1) {
++		int err;
++
++		dent = ubifs_tnc_next_ent(c, &key, &nm);
++		if (IS_ERR(dent)) {
++			err = PTR_ERR(dent);
++			if (err == -ENOENT)
++				break;
++			return err;
++		}
++
++		nm.name = dent->name;
++		nm.len = le16_to_cpu(dent->nlen);
++		size += CALC_DENT_SIZE(nm.len);
++		if (dent->type == UBIFS_ITYPE_DIR)
++			nlink += 1;
++		kfree(pdent);
++		pdent = dent;
++		key_read(c, &dent->key, &key);
++	}
++	kfree(pdent);
++
++	if (i_size_read(dir) != size) {
++		ubifs_err("directory inode %lu has size %llu, "
++			  "but calculated size is %llu", dir->i_ino,
++			  (unsigned long long)i_size_read(dir),
++			  (unsigned long long)size);
++		dump_stack();
++		return -EINVAL;
++	}
++	if (dir->i_nlink != nlink) {
++		ubifs_err("directory inode %lu has nlink %u, but calculated "
++			  "nlink is %u", dir->i_ino, dir->i_nlink, nlink);
++		dump_stack();
++		return -EINVAL;
++	}
++
++	return 0;
++}
++
++/**
++ * dbg_check_key_order - make sure that colliding keys are properly ordered.
++ * @c: UBIFS file-system description object
++ * @zbr1: first zbranch
++ * @zbr2: following zbranch
++ *
++ * In UBIFS indexing B-tree colliding keys has to be sorted in binary order of
++ * names of the direntries/xentries which are referred by the keys. This
++ * function reads direntries/xentries referred by @zbr1 and @zbr2 and makes
++ * sure the name of direntry/xentry referred by @zbr1 is less than
++ * direntry/xentry referred by @zbr2. Returns zero if this is true, %1 if not,
++ * and a negative error code in case of failure.
++ */
++static int dbg_check_key_order(struct ubifs_info *c, struct ubifs_zbranch *zbr1,
++			       struct ubifs_zbranch *zbr2)
++{
++	int err, nlen1, nlen2, cmp;
++	struct ubifs_dent_node *dent1, *dent2;
++	union ubifs_key key;
++
++	ubifs_assert(!keys_cmp(c, &zbr1->key, &zbr2->key));
++	dent1 = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
++	if (!dent1)
++		return -ENOMEM;
++	dent2 = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
++	if (!dent2) {
++		err = -ENOMEM;
++		goto out_free;
++	}
++
++	err = ubifs_tnc_read_node(c, zbr1, dent1);
++	if (err)
++		goto out_free;
++	err = ubifs_validate_entry(c, dent1);
++	if (err)
++		goto out_free;
++
++	err = ubifs_tnc_read_node(c, zbr2, dent2);
++	if (err)
++		goto out_free;
++	err = ubifs_validate_entry(c, dent2);
++	if (err)
++		goto out_free;
++
++	/* Make sure node keys are the same as in zbranch */
++	err = 1;
++	key_read(c, &dent1->key, &key);
++	if (keys_cmp(c, &zbr1->key, &key)) {
++		dbg_err("1st entry at %d:%d has key %s", zbr1->lnum,
++			zbr1->offs, DBGKEY(&key));
++		dbg_err("but it should have key %s according to tnc",
++			DBGKEY(&zbr1->key));
++		dbg_dump_node(c, dent1);
++		goto out_free;
++	}
++
++	key_read(c, &dent2->key, &key);
++	if (keys_cmp(c, &zbr2->key, &key)) {
++		dbg_err("2nd entry at %d:%d has key %s", zbr1->lnum,
++			zbr1->offs, DBGKEY(&key));
++		dbg_err("but it should have key %s according to tnc",
++			DBGKEY(&zbr2->key));
++		dbg_dump_node(c, dent2);
++		goto out_free;
++	}
++
++	nlen1 = le16_to_cpu(dent1->nlen);
++	nlen2 = le16_to_cpu(dent2->nlen);
++
++	cmp = memcmp(dent1->name, dent2->name, min_t(int, nlen1, nlen2));
++	if (cmp < 0 || (cmp == 0 && nlen1 < nlen2)) {
++		err = 0;
++		goto out_free;
++	}
++	if (cmp == 0 && nlen1 == nlen2)
++		dbg_err("2 xent/dent nodes with the same name");
++	else
++		dbg_err("bad order of colliding key %s",
++			DBGKEY(&key));
++
++	ubifs_msg("first node at %d:%d\n", zbr1->lnum, zbr1->offs);
++	dbg_dump_node(c, dent1);
++	ubifs_msg("second node at %d:%d\n", zbr2->lnum, zbr2->offs);
++	dbg_dump_node(c, dent2);
++
++out_free:
++	kfree(dent2);
++	kfree(dent1);
++	return err;
++}
++
++/**
++ * dbg_check_znode - check if znode is all right.
++ * @c: UBIFS file-system description object
++ * @zbr: zbranch which points to this znode
++ *
++ * This function makes sure that znode referred to by @zbr is all right.
++ * Returns zero if it is, and %-EINVAL if it is not.
++ */
++static int dbg_check_znode(struct ubifs_info *c, struct ubifs_zbranch *zbr)
++{
++	struct ubifs_znode *znode = zbr->znode;
++	struct ubifs_znode *zp = znode->parent;
++	int n, err, cmp;
++
++	if (znode->child_cnt <= 0 || znode->child_cnt > c->fanout) {
++		err = 1;
++		goto out;
++	}
++	if (znode->level < 0) {
++		err = 2;
++		goto out;
++	}
++	if (znode->iip < 0 || znode->iip >= c->fanout) {
++		err = 3;
++		goto out;
++	}
++
++	if (zbr->len == 0)
++		/* Only dirty zbranch may have no on-flash nodes */
++		if (!ubifs_zn_dirty(znode)) {
++			err = 4;
++			goto out;
++		}
++
++	if (ubifs_zn_dirty(znode)) {
++		/*
++		 * If znode is dirty, its parent has to be dirty as well. The
++		 * order of the operation is important, so we have to have
++		 * memory barriers.
++		 */
++		smp_mb();
++		if (zp && !ubifs_zn_dirty(zp)) {
++			/*
++			 * The dirty flag is atomic and is cleared outside the
++			 * TNC mutex, so znode's dirty flag may now have
++			 * been cleared. The child is always cleared before the
++			 * parent, so we just need to check again.
++			 */
++			smp_mb();
++			if (ubifs_zn_dirty(znode)) {
++				err = 5;
++				goto out;
++			}
++		}
++	}
++
++	if (zp) {
++		const union ubifs_key *min, *max;
++
++		if (znode->level != zp->level - 1) {
++			err = 6;
++			goto out;
++		}
++
++		/* Make sure the 'parent' pointer in our znode is correct */
++		err = ubifs_search_zbranch(c, zp, &zbr->key, &n);
++		if (!err) {
++			/* This zbranch does not exist in the parent */
++			err = 7;
++			goto out;
++		}
++
++		if (znode->iip >= zp->child_cnt) {
++			err = 8;
++			goto out;
++		}
++
++		if (znode->iip != n) {
++			/* This may happen only in case of collisions */
++			if (keys_cmp(c, &zp->zbranch[n].key,
++				     &zp->zbranch[znode->iip].key)) {
++				err = 9;
++				goto out;
++			}
++			n = znode->iip;
++		}
++
++		/*
++		 * Make sure that the first key in our znode is greater than or
++		 * equal to the key in the pointing zbranch.
++		 */
++		min = &zbr->key;
++		cmp = keys_cmp(c, min, &znode->zbranch[0].key);
++		if (cmp == 1) {
++			err = 10;
++			goto out;
++		}
++
++		if (n + 1 < zp->child_cnt) {
++			max = &zp->zbranch[n + 1].key;
++
++			/*
++			 * Make sure the last key in our znode is less or
++			 * equivalent than the the key in zbranch which goes
++			 * after our pointing zbranch.
++			 */
++			cmp = keys_cmp(c, max,
++				&znode->zbranch[znode->child_cnt - 1].key);
++			if (cmp == -1) {
++				err = 11;
++				goto out;
++			}
++		}
++	} else {
++		/* This may only be root znode */
++		if (zbr != &c->zroot) {
++			err = 12;
++			goto out;
++		}
++	}
++
++	/*
++	 * Make sure that next key is greater or equivalent then the previous
++	 * one.
++	 */
++	for (n = 1; n < znode->child_cnt; n++) {
++		cmp = keys_cmp(c, &znode->zbranch[n - 1].key,
++			       &znode->zbranch[n].key);
++		if (cmp > 0) {
++			err = 13;
++			goto out;
++		}
++		if (cmp == 0) {
++			/* This can only be keys with colliding hash */
++			if (!is_hash_key(c, &znode->zbranch[n].key)) {
++				err = 14;
++				goto out;
++			}
++
++			if (znode->level != 0 || c->replaying)
++				continue;
++
++			/*
++			 * Colliding keys should follow binary order of
++			 * corresponding xentry/dentry names.
++			 */
++			err = dbg_check_key_order(c, &znode->zbranch[n - 1],
++						  &znode->zbranch[n]);
++			if (err < 0)
++				return err;
++			if (err) {
++				err = 15;
++				goto out;
++			}
++		}
++	}
++
++	for (n = 0; n < znode->child_cnt; n++) {
++		if (!znode->zbranch[n].znode &&
++		    (znode->zbranch[n].lnum == 0 ||
++		     znode->zbranch[n].len == 0)) {
++			err = 16;
++			goto out;
++		}
++
++		if (znode->zbranch[n].lnum != 0 &&
++		    znode->zbranch[n].len == 0) {
++			err = 17;
++			goto out;
++		}
++
++		if (znode->zbranch[n].lnum == 0 &&
++		    znode->zbranch[n].len != 0) {
++			err = 18;
++			goto out;
++		}
++
++		if (znode->zbranch[n].lnum == 0 &&
++		    znode->zbranch[n].offs != 0) {
++			err = 19;
++			goto out;
++		}
++
++		if (znode->level != 0 && znode->zbranch[n].znode)
++			if (znode->zbranch[n].znode->parent != znode) {
++				err = 20;
++				goto out;
++			}
++	}
++
++	return 0;
++
++out:
++	ubifs_err("failed, error %d", err);
++	ubifs_msg("dump of the znode");
++	dbg_dump_znode(c, znode);
++	if (zp) {
++		ubifs_msg("dump of the parent znode");
++		dbg_dump_znode(c, zp);
++	}
++	dump_stack();
++	return -EINVAL;
++}
++
++/**
++ * dbg_check_tnc - check TNC tree.
++ * @c: UBIFS file-system description object
++ * @extra: do extra checks that are possible at start commit
++ *
++ * This function traverses whole TNC tree and checks every znode. Returns zero
++ * if everything is all right and %-EINVAL if something is wrong with TNC.
++ */
++int dbg_check_tnc(struct ubifs_info *c, int extra)
++{
++	struct ubifs_znode *znode;
++	long clean_cnt = 0, dirty_cnt = 0;
++	int err, last;
++
++	if (!(ubifs_chk_flags & UBIFS_CHK_TNC))
++		return 0;
++
++	ubifs_assert(mutex_is_locked(&c->tnc_mutex));
++	if (!c->zroot.znode)
++		return 0;
++
++	znode = ubifs_tnc_postorder_first(c->zroot.znode);
++	while (1) {
++		struct ubifs_znode *prev;
++		struct ubifs_zbranch *zbr;
++
++		if (!znode->parent)
++			zbr = &c->zroot;
++		else
++			zbr = &znode->parent->zbranch[znode->iip];
++
++		err = dbg_check_znode(c, zbr);
++		if (err)
++			return err;
++
++		if (extra) {
++			if (ubifs_zn_dirty(znode))
++				dirty_cnt += 1;
++			else
++				clean_cnt += 1;
++		}
++
++		prev = znode;
++		znode = ubifs_tnc_postorder_next(znode);
++		if (!znode)
++			break;
++
++		/*
++		 * If the last key of this znode is equivalent to the first key
++		 * of the next znode (collision), then check order of the keys.
++		 */
++		last = prev->child_cnt - 1;
++		if (prev->level == 0 && znode->level == 0 && !c->replaying &&
++		    !keys_cmp(c, &prev->zbranch[last].key,
++			      &znode->zbranch[0].key)) {
++			err = dbg_check_key_order(c, &prev->zbranch[last],
++						  &znode->zbranch[0]);
++			if (err < 0)
++				return err;
++			if (err) {
++				ubifs_msg("first znode");
++				dbg_dump_znode(c, prev);
++				ubifs_msg("second znode");
++				dbg_dump_znode(c, znode);
++				return -EINVAL;
++			}
++		}
++	}
++
++	if (extra) {
++		if (clean_cnt != atomic_long_read(&c->clean_zn_cnt)) {
++			ubifs_err("incorrect clean_zn_cnt %ld, calculated %ld",
++				  atomic_long_read(&c->clean_zn_cnt),
++				  clean_cnt);
++			return -EINVAL;
++		}
++		if (dirty_cnt != atomic_long_read(&c->dirty_zn_cnt)) {
++			ubifs_err("incorrect dirty_zn_cnt %ld, calculated %ld",
++				  atomic_long_read(&c->dirty_zn_cnt),
++				  dirty_cnt);
++			return -EINVAL;
++		}
++	}
++
++	return 0;
++}
++
++/**
++ * dbg_walk_index - walk the on-flash index.
++ * @c: UBIFS file-system description object
++ * @leaf_cb: called for each leaf node
++ * @znode_cb: called for each indexing node
++ * @priv: private data which is passed to callbacks
++ *
++ * This function walks the UBIFS index and calls the @leaf_cb for each leaf
++ * node and @znode_cb for each indexing node. Returns zero in case of success
++ * and a negative error code in case of failure.
++ *
++ * It would be better if this function removed every znode it pulled to into
++ * the TNC, so that the behavior more closely matched the non-debugging
++ * behavior.
++ */
++int dbg_walk_index(struct ubifs_info *c, dbg_leaf_callback leaf_cb,
++		   dbg_znode_callback znode_cb, void *priv)
++{
++	int err;
++	struct ubifs_zbranch *zbr;
++	struct ubifs_znode *znode, *child;
++
++	mutex_lock(&c->tnc_mutex);
++	/* If the root indexing node is not in TNC - pull it */
++	if (!c->zroot.znode) {
++		c->zroot.znode = ubifs_load_znode(c, &c->zroot, NULL, 0);
++		if (IS_ERR(c->zroot.znode)) {
++			err = PTR_ERR(c->zroot.znode);
++			c->zroot.znode = NULL;
++			goto out_unlock;
++		}
++	}
++
++	/*
++	 * We are going to traverse the indexing tree in the postorder manner.
++	 * Go down and find the leftmost indexing node where we are going to
++	 * start from.
++	 */
++	znode = c->zroot.znode;
++	while (znode->level > 0) {
++		zbr = &znode->zbranch[0];
++		child = zbr->znode;
++		if (!child) {
++			child = ubifs_load_znode(c, zbr, znode, 0);
++			if (IS_ERR(child)) {
++				err = PTR_ERR(child);
++				goto out_unlock;
++			}
++			zbr->znode = child;
++		}
++
++		znode = child;
++	}
++
++	/* Iterate over all indexing nodes */
++	while (1) {
++		int idx;
++
++		cond_resched();
++
++		if (znode_cb) {
++			err = znode_cb(c, znode, priv);
++			if (err) {
++				ubifs_err("znode checking function returned "
++					  "error %d", err);
++				dbg_dump_znode(c, znode);
++				goto out_dump;
++			}
++		}
++		if (leaf_cb && znode->level == 0) {
++			for (idx = 0; idx < znode->child_cnt; idx++) {
++				zbr = &znode->zbranch[idx];
++				err = leaf_cb(c, zbr, priv);
++				if (err) {
++					ubifs_err("leaf checking function "
++						  "returned error %d, for leaf "
++						  "at LEB %d:%d",
++						  err, zbr->lnum, zbr->offs);
++					goto out_dump;
++				}
++			}
++		}
++
++		if (!znode->parent)
++			break;
++
++		idx = znode->iip + 1;
++		znode = znode->parent;
++		if (idx < znode->child_cnt) {
++			/* Switch to the next index in the parent */
++			zbr = &znode->zbranch[idx];
++			child = zbr->znode;
++			if (!child) {
++				child = ubifs_load_znode(c, zbr, znode, idx);
++				if (IS_ERR(child)) {
++					err = PTR_ERR(child);
++					goto out_unlock;
++				}
++				zbr->znode = child;
++			}
++			znode = child;
++		} else
++			/*
++			 * This is the last child, switch to the parent and
++			 * continue.
++			 */
++			continue;
++
++		/* Go to the lowest leftmost znode in the new sub-tree */
++		while (znode->level > 0) {
++			zbr = &znode->zbranch[0];
++			child = zbr->znode;
++			if (!child) {
++				child = ubifs_load_znode(c, zbr, znode, 0);
++				if (IS_ERR(child)) {
++					err = PTR_ERR(child);
++					goto out_unlock;
++				}
++				zbr->znode = child;
++			}
++			znode = child;
++		}
++	}
++
++	mutex_unlock(&c->tnc_mutex);
++	return 0;
++
++out_dump:
++	if (znode->parent)
++		zbr = &znode->parent->zbranch[znode->iip];
++	else
++		zbr = &c->zroot;
++	ubifs_msg("dump of znode at LEB %d:%d", zbr->lnum, zbr->offs);
++	dbg_dump_znode(c, znode);
++out_unlock:
++	mutex_unlock(&c->tnc_mutex);
++	return err;
++}
++
++/**
++ * add_size - add znode size to partially calculated index size.
++ * @c: UBIFS file-system description object
++ * @znode: znode to add size for
++ * @priv: partially calculated index size
++ *
++ * This is a helper function for 'dbg_check_idx_size()' which is called for
++ * every indexing node and adds its size to the 'long long' variable pointed to
++ * by @priv.
++ */
++static int add_size(struct ubifs_info *c, struct ubifs_znode *znode, void *priv)
++{
++	long long *idx_size = priv;
++	int add;
++
++	add = ubifs_idx_node_sz(c, znode->child_cnt);
++	add = ALIGN(add, 8);
++	*idx_size += add;
++	return 0;
++}
++
++/**
++ * dbg_check_idx_size - check index size.
++ * @c: UBIFS file-system description object
++ * @idx_size: size to check
++ *
++ * This function walks the UBIFS index, calculates its size and checks that the
++ * size is equivalent to @idx_size. Returns zero in case of success and a
++ * negative error code in case of failure.
++ */
++int dbg_check_idx_size(struct ubifs_info *c, long long idx_size)
++{
++	int err;
++	long long calc = 0;
++
++	if (!(ubifs_chk_flags & UBIFS_CHK_IDX_SZ))
++		return 0;
++
++	err = dbg_walk_index(c, NULL, add_size, &calc);
++	if (err) {
++		ubifs_err("error %d while walking the index", err);
++		return err;
++	}
++
++	if (calc != idx_size) {
++		ubifs_err("index size check failed: calculated size is %lld, "
++			  "should be %lld", calc, idx_size);
++		dump_stack();
++		return -EINVAL;
++	}
++
++	return 0;
++}
++
++/**
++ * struct fsck_inode - information about an inode used when checking the file-system.
++ * @rb: link in the RB-tree of inodes
++ * @inum: inode number
++ * @mode: inode type, permissions, etc
++ * @nlink: inode link count
++ * @xattr_cnt: count of extended attributes
++ * @references: how many directory/xattr entries refer this inode (calculated
++ *              while walking the index)
++ * @calc_cnt: for directory inode count of child directories
++ * @size: inode size (read from on-flash inode)
++ * @xattr_sz: summary size of all extended attributes (read from on-flash
++ *            inode)
++ * @calc_sz: for directories calculated directory size
++ * @calc_xcnt: count of extended attributes
++ * @calc_xsz: calculated summary size of all extended attributes
++ * @xattr_nms: sum of lengths of all extended attribute names belonging to this
++ *             inode (read from on-flash inode)
++ * @calc_xnms: calculated sum of lengths of all extended attribute names
++ */
++struct fsck_inode {
++	struct rb_node rb;
++	ino_t inum;
++	umode_t mode;
++	unsigned int nlink;
++	unsigned int xattr_cnt;
++	int references;
++	int calc_cnt;
++	long long size;
++	unsigned int xattr_sz;
++	long long calc_sz;
++	long long calc_xcnt;
++	long long calc_xsz;
++	unsigned int xattr_nms;
++	long long calc_xnms;
++};
++
++/**
++ * struct fsck_data - private FS checking information.
++ * @inodes: RB-tree of all inodes (contains @struct fsck_inode objects)
++ */
++struct fsck_data {
++	struct rb_root inodes;
++};
++
++/**
++ * add_inode - add inode information to RB-tree of inodes.
++ * @c: UBIFS file-system description object
++ * @fsckd: FS checking information
++ * @ino: raw UBIFS inode to add
++ *
++ * This is a helper function for 'check_leaf()' which adds information about
++ * inode @ino to the RB-tree of inodes. Returns inode information pointer in
++ * case of success and a negative error code in case of failure.
++ */
++static struct fsck_inode *add_inode(struct ubifs_info *c,
++				    struct fsck_data *fsckd,
++				    struct ubifs_ino_node *ino)
++{
++	struct rb_node **p, *parent = NULL;
++	struct fsck_inode *fscki;
++	ino_t inum = key_inum_flash(c, &ino->key);
++
++	p = &fsckd->inodes.rb_node;
++	while (*p) {
++		parent = *p;
++		fscki = rb_entry(parent, struct fsck_inode, rb);
++		if (inum < fscki->inum)
++			p = &(*p)->rb_left;
++		else if (inum > fscki->inum)
++			p = &(*p)->rb_right;
++		else
++			return fscki;
++	}
++
++        if (inum > c->highest_inum) {
++		ubifs_err("too high inode number, max. is %lu",
++			  (unsigned long)c->highest_inum);
++		return ERR_PTR(-EINVAL);
++        }
++
++	fscki = kzalloc(sizeof(struct fsck_inode), GFP_NOFS);
++	if (!fscki)
++		return ERR_PTR(-ENOMEM);
++
++	fscki->inum = inum;
++	fscki->nlink = le32_to_cpu(ino->nlink);
++	fscki->size = le64_to_cpu(ino->size);
++	fscki->xattr_cnt = le32_to_cpu(ino->xattr_cnt);
++	fscki->xattr_sz = le32_to_cpu(ino->xattr_size);
++	fscki->xattr_nms = le32_to_cpu(ino->xattr_names);
++	fscki->mode = le32_to_cpu(ino->mode);
++	if (S_ISDIR(fscki->mode)) {
++		fscki->calc_sz = UBIFS_INO_NODE_SZ;
++		fscki->calc_cnt = 2;
++	}
++	rb_link_node(&fscki->rb, parent, p);
++	rb_insert_color(&fscki->rb, &fsckd->inodes);
++	return fscki;
++}
++
++/**
++ * search_inode - search inode in the RB-tree of inodes.
++ * @fsckd: FS checking information
++ * @inum: inode number to search
++ *
++ * This is a helper function for 'check_leaf()' which searches inode @inum in
++ * the RB-tree of inodes and returns an inode information pointer or %NULL if
++ * the inode was not found.
++ */
++static struct fsck_inode *search_inode(struct fsck_data *fsckd, ino_t inum)
++{
++	struct rb_node *p;
++	struct fsck_inode *fscki;
++
++	p = fsckd->inodes.rb_node;
++	while (p) {
++		fscki = rb_entry(p, struct fsck_inode, rb);
++		if (inum < fscki->inum)
++			p = p->rb_left;
++		else if (inum > fscki->inum)
++			p = p->rb_right;
++		else
++			return fscki;
++	}
++	return NULL;
++}
++
++/**
++ * read_add_inode - read inode node and add it to RB-tree of inodes.
++ * @c: UBIFS file-system description object
++ * @fsckd: FS checking information
++ * @inum: inode number to read
++ *
++ * This is a helper function for 'check_leaf()' which finds inode node @inum in
++ * the index, reads it, and adds it to the RB-tree of inodes. Returns inode
++ * information pointer in case of success and a negative error code in case of
++ * failure.
++ */
++static struct fsck_inode *read_add_inode(struct ubifs_info *c,
++					 struct fsck_data *fsckd, ino_t inum)
++{
++	int n, err;
++	union ubifs_key key;
++	struct ubifs_znode *znode;
++	struct ubifs_zbranch *zbr;
++	struct ubifs_ino_node *ino;
++	struct fsck_inode *fscki;
++
++	fscki = search_inode(fsckd, inum);
++	if (fscki)
++		return fscki;
++
++	ino_key_init(c, &key, inum);
++	err = ubifs_lookup_level0(c, &key, &znode, &n);
++	if (!err) {
++		ubifs_err("inode %lu not found in index", (unsigned long)inum);
++		return ERR_PTR(-ENOENT);
++	} else if (err < 0) {
++		ubifs_err("error %d while looking up inode %lu",
++			  err, (unsigned long)inum);
++		return ERR_PTR(err);
++	}
++
++	zbr = &znode->zbranch[n];
++	if (zbr->len < UBIFS_INO_NODE_SZ) {
++		ubifs_err("bad node %lu node length %d",
++			  (unsigned long)inum, zbr->len);
++		return ERR_PTR(-EINVAL);
++	}
++
++	ino = kmalloc(zbr->len, GFP_NOFS);
++	if (!ino)
++		return ERR_PTR(-ENOMEM);
++
++	err = ubifs_tnc_read_node(c, zbr, ino);
++	if (err) {
++		ubifs_err("cannot read inode node at LEB %d:%d, error %d",
++			  zbr->lnum, zbr->offs, err);
++		kfree(ino);
++		return ERR_PTR(err);
++	}
++
++	fscki = add_inode(c, fsckd, ino);
++	kfree(ino);
++	if (IS_ERR(fscki)) {
++		ubifs_err("error %ld while adding inode %lu node",
++			  PTR_ERR(fscki), (unsigned long)inum);
++		return fscki;
++	}
++
++	return fscki;
++}
++
++/**
++ * check_leaf - check leaf node.
++ * @c: UBIFS file-system description object
++ * @zbr: zbranch of the leaf node to check
++ * @priv: FS checking information
++ *
++ * This is a helper function for 'dbg_check_filesystem()' which is called for
++ * every single leaf node while walking the indexing tree. It checks that the
++ * leaf node referred from the indexing tree exists, has correct CRC, and does
++ * some other basic validation. This function is also responsible for building
++ * an RB-tree of inodes - it adds all inodes into the RB-tree. It also
++ * calculates reference count, size, etc for each inode in order to later
++ * compare them to the information stored inside the inodes and detect possible
++ * inconsistencies. Returns zero in case of success and a negative error code
++ * in case of failure.
++ */
++static int check_leaf(struct ubifs_info *c, struct ubifs_zbranch *zbr,
++		      void *priv)
++{
++	ino_t inum;
++	void *node;
++	int err, type = key_type(c, &zbr->key);
++	struct fsck_inode *fscki;
++
++	if (zbr->len < UBIFS_CH_SZ) {
++		ubifs_err("bad leaf length %d (LEB %d:%d)",
++			  zbr->len, zbr->lnum, zbr->offs);
++		return -EINVAL;
++	}
++
++	node = kmalloc(zbr->len, GFP_NOFS);
++	if (!node)
++		return -ENOMEM;
++
++	err = ubifs_tnc_read_node(c, zbr, node);
++	if (err) {
++		ubifs_err("cannot read leaf node at LEB %d:%d, error %d",
++			  zbr->lnum, zbr->offs, err);
++		goto out_free;
++	}
++
++	/* If this is an inode node, add it to RB-tree of inodes */
++	if (type == UBIFS_INO_KEY) {
++		fscki = add_inode(c, priv, node);
++		if (IS_ERR(fscki)) {
++			err = PTR_ERR(fscki);
++			ubifs_err("error %d while adding inode node", err);
++			goto out_dump;
++		}
++		goto out;
++	}
++
++	if (type != UBIFS_DENT_KEY && type != UBIFS_XENT_KEY &&
++	    type != UBIFS_DATA_KEY) {
++		ubifs_err("unexpected node type %d at LEB %d:%d",
++			  type, zbr->lnum, zbr->offs);
++		err = -EINVAL;
++		goto out_free;
++	}
++
++	if (type == UBIFS_DATA_KEY) {
++		long long blk_offs;
++		struct ubifs_data_node *dn = node;
++
++		/*
++		 * Search the inode node this data node belongs to and insert
++		 * it to the RB-tree of inodes.
++		 */
++		inum = key_inum_flash(c, &dn->key);
++		fscki = read_add_inode(c, priv, inum);
++		if (IS_ERR(fscki)) {
++			err = PTR_ERR(fscki);
++			ubifs_err("error %d while processing data node and "
++				  "trying to find inode node %lu",
++				  err, (unsigned long)inum);
++			goto out_dump;
++		}
++
++		/* Make sure the data node is within inode size */
++		blk_offs = key_block_flash(c, &dn->key);
++		blk_offs <<= UBIFS_BLOCK_SHIFT;
++		blk_offs += le32_to_cpu(dn->size);
++		if (blk_offs > fscki->size) {
++			ubifs_err("data node at LEB %d:%d is not within inode "
++				  "size %lld", zbr->lnum, zbr->offs,
++				  fscki->size);
++			err = -EINVAL;
++			goto out_dump;
++		}
++	} else {
++		int nlen;
++		struct ubifs_dent_node *dent = node;
++		struct fsck_inode *fscki1;
++
++		err = ubifs_validate_entry(c, dent);
++		if (err)
++			goto out_dump;
++
++		/*
++		 * Search the inode node this entry refers to and the parent
++		 * inode node and insert them to the RB-tree of inodes.
++		 */
++		inum = le64_to_cpu(dent->inum);
++		fscki = read_add_inode(c, priv, inum);
++		if (IS_ERR(fscki)) {
++			err = PTR_ERR(fscki);
++			ubifs_err("error %d while processing entry node and "
++				  "trying to find inode node %lu",
++				  err, (unsigned long)inum);
++			goto out_dump;
++		}
++
++		/* Count how many direntries or xentries refers this inode */
++		fscki->references += 1;
++
++		inum = key_inum_flash(c, &dent->key);
++		fscki1 = read_add_inode(c, priv, inum);
++		if (IS_ERR(fscki1)) {
++			err = PTR_ERR(fscki);
++			ubifs_err("error %d while processing entry node and "
++				  "trying to find parent inode node %lu",
++				  err, (unsigned long)inum);
++			goto out_dump;
++		}
++
++		nlen = le16_to_cpu(dent->nlen);
++		if (type == UBIFS_XENT_KEY) {
++			fscki1->calc_xcnt += 1;
++			fscki1->calc_xsz += CALC_DENT_SIZE(nlen);
++			fscki1->calc_xsz += CALC_XATTR_BYTES(fscki->size);
++			fscki1->calc_xnms += nlen;
++		} else {
++			fscki1->calc_sz += CALC_DENT_SIZE(nlen);
++			if (dent->type == UBIFS_ITYPE_DIR)
++				fscki1->calc_cnt += 1;
++		}
++	}
++
++out:
++	kfree(node);
++	return 0;
++
++out_dump:
++	ubifs_msg("dump of node at LEB %d:%d", zbr->lnum, zbr->offs);
++	dbg_dump_node(c, node);
++out_free:
++	kfree(node);
++	return err;
++}
++
++/**
++ * free_inodes - free RB-tree of inodes.
++ * @fsckd: FS checking information
++ */
++static void free_inodes(struct fsck_data *fsckd)
++{
++	struct rb_node *this = fsckd->inodes.rb_node;
++	struct fsck_inode *fscki;
++
++	while (this) {
++		if (this->rb_left)
++			this = this->rb_left;
++		else if (this->rb_right)
++			this = this->rb_right;
++		else {
++			fscki = rb_entry(this, struct fsck_inode, rb);
++			this = rb_parent(this);
++			if (this) {
++				if (this->rb_left == &fscki->rb)
++					this->rb_left = NULL;
++				else
++					this->rb_right = NULL;
++			}
++			kfree(fscki);
++		}
++	}
++}
++
++/**
++ * check_inodes - checks all inodes.
++ * @c: UBIFS file-system description object
++ * @fsckd: FS checking information
++ *
++ * This is a helper function for 'dbg_check_filesystem()' which walks the
++ * RB-tree of inodes after the index scan has been finished, and checks that
++ * inode nlink, size, etc are correct. Returns zero if inodes are fine,
++ * %-EINVAL if not, and a negative error code in case of failure.
++ */
++static int check_inodes(struct ubifs_info *c, struct fsck_data *fsckd)
++{
++	int n, err;
++	union ubifs_key key;
++	struct ubifs_znode *znode;
++	struct ubifs_zbranch *zbr;
++	struct ubifs_ino_node *ino;
++	struct fsck_inode *fscki;
++	struct rb_node *this = rb_first(&fsckd->inodes);
++
++	while (this) {
++		fscki = rb_entry(this, struct fsck_inode, rb);
++		this = rb_next(this);
++
++		if (S_ISDIR(fscki->mode)) {
++			/*
++			 * Directories have to have exactly one reference (they
++			 * cannot have hardlinks), although root inode is an
++			 * exception.
++			 */
++			if (fscki->inum != UBIFS_ROOT_INO &&
++			    fscki->references != 1) {
++				ubifs_err("directory inode %lu has %d "
++					  "direntries which refer it, but "
++					  "should be 1",
++					  (unsigned long)fscki->inum,
++					  fscki->references);
++				goto out_dump;
++			}
++			if (fscki->inum == UBIFS_ROOT_INO &&
++			    fscki->references != 0) {
++				ubifs_err("root inode %lu has non-zero (%d) "
++					  "direntries which refer it",
++					  (unsigned long)fscki->inum,
++					  fscki->references);
++				goto out_dump;
++			}
++			if (fscki->calc_sz != fscki->size) {
++				ubifs_err("directory inode %lu size is %lld, "
++					  "but calculated size is %lld",
++					  (unsigned long)fscki->inum,
++					  fscki->size, fscki->calc_sz);
++				goto out_dump;
++			}
++			if (fscki->calc_cnt != fscki->nlink) {
++				ubifs_err("directory inode %lu nlink is %d, "
++					  "but calculated nlink is %d",
++					  (unsigned long)fscki->inum,
++					  fscki->nlink, fscki->calc_cnt);
++				goto out_dump;
++			}
++		} else {
++			if (fscki->references != fscki->nlink) {
++				ubifs_err("inode %lu nlink is %d, but "
++					  "calculated nlink is %d",
++					  (unsigned long)fscki->inum,
++					  fscki->nlink, fscki->references);
++				goto out_dump;
++			}
++		}
++		if (fscki->xattr_sz != fscki->calc_xsz) {
++			ubifs_err("inode %lu has xattr size %u, but "
++				  "calculated size is %lld",
++				  (unsigned long)fscki->inum, fscki->xattr_sz,
++				  fscki->calc_xsz);
++			goto out_dump;
++		}
++		if (fscki->xattr_cnt != fscki->calc_xcnt) {
++			ubifs_err("inode %lu has %u xattrs, but "
++				  "calculated count is %lld",
++				  (unsigned long)fscki->inum,
++				  fscki->xattr_cnt, fscki->calc_xcnt);
++			goto out_dump;
++		}
++		if (fscki->xattr_nms != fscki->calc_xnms) {
++			ubifs_err("inode %lu has xattr names' size %u, but "
++				  "calculated names' size is %lld",
++				  (unsigned long)fscki->inum, fscki->xattr_nms,
++				  fscki->calc_xnms);
++			goto out_dump;
++		}
++	}
++
++	return 0;
++
++out_dump:
++	/* Read the bad inode and dump it */
++	ino_key_init(c, &key, fscki->inum);
++	err = ubifs_lookup_level0(c, &key, &znode, &n);
++	if (!err) {
++		ubifs_err("inode %lu not found in index",
++			  (unsigned long)fscki->inum);
++		return -ENOENT;
++	} else if (err < 0) {
++		ubifs_err("error %d while looking up inode %lu",
++			  err, (unsigned long)fscki->inum);
++		return err;
++	}
++
++	zbr = &znode->zbranch[n];
++	ino = kmalloc(zbr->len, GFP_NOFS);
++	if (!ino)
++		return -ENOMEM;
++
++	err = ubifs_tnc_read_node(c, zbr, ino);
++	if (err) {
++		ubifs_err("cannot read inode node at LEB %d:%d, error %d",
++			  zbr->lnum, zbr->offs, err);
++		kfree(ino);
++		return err;
++	}
++
++	ubifs_msg("dump of the inode %lu sitting in LEB %d:%d",
++		  (unsigned long)fscki->inum, zbr->lnum, zbr->offs);
++	dbg_dump_node(c, ino);
++	kfree(ino);
++	return -EINVAL;
++}
++
++/**
++ * dbg_check_filesystem - check the file-system.
++ * @c: UBIFS file-system description object
++ *
++ * This function checks the file system, namely:
++ * o makes sure that all leaf nodes exist and their CRCs are correct;
++ * o makes sure inode nlink, size, xattr size/count are correct (for all
++ *   inodes).
++ *
++ * The function reads whole indexing tree and all nodes, so it is pretty
++ * heavy-weight. Returns zero if the file-system is consistent, %-EINVAL if
++ * not, and a negative error code in case of failure.
++ */
++int dbg_check_filesystem(struct ubifs_info *c)
++{
++	int err;
++	struct fsck_data fsckd;
++
++	if (!(ubifs_chk_flags & UBIFS_CHK_FS))
++		return 0;
++
++	fsckd.inodes = RB_ROOT;
++	err = dbg_walk_index(c, check_leaf, NULL, &fsckd);
++	if (err)
++		goto out_free;
++
++	err = check_inodes(c, &fsckd);
++	if (err)
++		goto out_free;
++
++	free_inodes(&fsckd);
++	return 0;
++
++out_free:
++	ubifs_err("file-system check failed with error %d", err);
++	dump_stack();
++	free_inodes(&fsckd);
++	return err;
++}
++
++static int invocation_cnt;
++
++int dbg_force_in_the_gaps(void)
++{
++	if (!dbg_force_in_the_gaps_enabled)
++		return 0;
++	/* Force in-the-gaps every 8th commit */
++	return !((invocation_cnt++) & 0x7);
++}
++
++/* Failure mode for recovery testing */
++
++#define chance(n, d) (simple_rand() <= (n) * 32768LL / (d))
++
++struct failure_mode_info {
++	struct list_head list;
++	struct ubifs_info *c;
++};
++
++static LIST_HEAD(fmi_list);
++static DEFINE_SPINLOCK(fmi_lock);
++
++static unsigned int next;
++
++static int simple_rand(void)
++{
++	if (next == 0)
++		next = current->pid;
++	next = next * 1103515245 + 12345;
++	return (next >> 16) & 32767;
++}
++
++static void failure_mode_init(struct ubifs_info *c)
++{
++	struct failure_mode_info *fmi;
++
++	fmi = kmalloc(sizeof(struct failure_mode_info), GFP_NOFS);
++	if (!fmi) {
++		ubifs_err("Failed to register failure mode - no memory");
++		return;
++	}
++	fmi->c = c;
++	spin_lock(&fmi_lock);
++	list_add_tail(&fmi->list, &fmi_list);
++	spin_unlock(&fmi_lock);
++}
++
++static void failure_mode_exit(struct ubifs_info *c)
++{
++	struct failure_mode_info *fmi, *tmp;
++
++	spin_lock(&fmi_lock);
++	list_for_each_entry_safe(fmi, tmp, &fmi_list, list)
++		if (fmi->c == c) {
++			list_del(&fmi->list);
++			kfree(fmi);
++		}
++	spin_unlock(&fmi_lock);
++}
++
++static struct ubifs_info *dbg_find_info(struct ubi_volume_desc *desc)
++{
++	struct failure_mode_info *fmi;
++
++	spin_lock(&fmi_lock);
++	list_for_each_entry(fmi, &fmi_list, list)
++		if (fmi->c->ubi == desc) {
++			struct ubifs_info *c = fmi->c;
++
++			spin_unlock(&fmi_lock);
++			return c;
++		}
++	spin_unlock(&fmi_lock);
++	return NULL;
++}
++
++static int in_failure_mode(struct ubi_volume_desc *desc)
++{
++	struct ubifs_info *c = dbg_find_info(desc);
++
++	if (c && dbg_failure_mode)
++		return c->dbg->failure_mode;
++	return 0;
++}
++
++static int do_fail(struct ubi_volume_desc *desc, int lnum, int write)
++{
++	struct ubifs_info *c = dbg_find_info(desc);
++	struct ubifs_debug_info *d;
++
++	if (!c || !dbg_failure_mode)
++		return 0;
++	d = c->dbg;
++	if (d->failure_mode)
++		return 1;
++	if (!d->fail_cnt) {
++		/* First call - decide delay to failure */
++		if (chance(1, 2)) {
++			unsigned int delay = 1 << (simple_rand() >> 11);
++
++			if (chance(1, 2)) {
++				d->fail_delay = 1;
++				d->fail_timeout = jiffies +
++						  msecs_to_jiffies(delay);
++				dbg_rcvry("failing after %ums", delay);
++			} else {
++				d->fail_delay = 2;
++				d->fail_cnt_max = delay;
++				dbg_rcvry("failing after %u calls", delay);
++			}
++		}
++		d->fail_cnt += 1;
++	}
++	/* Determine if failure delay has expired */
++	if (d->fail_delay == 1) {
++		if (time_before(jiffies, d->fail_timeout))
++			return 0;
++	} else if (d->fail_delay == 2)
++		if (d->fail_cnt++ < d->fail_cnt_max)
++			return 0;
++	if (lnum == UBIFS_SB_LNUM) {
++		if (write) {
++			if (chance(1, 2))
++				return 0;
++		} else if (chance(19, 20))
++			return 0;
++		dbg_rcvry("failing in super block LEB %d", lnum);
++	} else if (lnum == UBIFS_MST_LNUM || lnum == UBIFS_MST_LNUM + 1) {
++		if (chance(19, 20))
++			return 0;
++		dbg_rcvry("failing in master LEB %d", lnum);
++	} else if (lnum >= UBIFS_LOG_LNUM && lnum <= c->log_last) {
++		if (write) {
++			if (chance(99, 100))
++				return 0;
++		} else if (chance(399, 400))
++			return 0;
++		dbg_rcvry("failing in log LEB %d", lnum);
++	} else if (lnum >= c->lpt_first && lnum <= c->lpt_last) {
++		if (write) {
++			if (chance(7, 8))
++				return 0;
++		} else if (chance(19, 20))
++			return 0;
++		dbg_rcvry("failing in LPT LEB %d", lnum);
++	} else if (lnum >= c->orph_first && lnum <= c->orph_last) {
++		if (write) {
++			if (chance(1, 2))
++				return 0;
++		} else if (chance(9, 10))
++			return 0;
++		dbg_rcvry("failing in orphan LEB %d", lnum);
++	} else if (lnum == c->ihead_lnum) {
++		if (chance(99, 100))
++			return 0;
++		dbg_rcvry("failing in index head LEB %d", lnum);
++	} else if (c->jheads && lnum == c->jheads[GCHD].wbuf.lnum) {
++		if (chance(9, 10))
++			return 0;
++		dbg_rcvry("failing in GC head LEB %d", lnum);
++	} else if (write && !RB_EMPTY_ROOT(&c->buds) &&
++		   !ubifs_search_bud(c, lnum)) {
++		if (chance(19, 20))
++			return 0;
++		dbg_rcvry("failing in non-bud LEB %d", lnum);
++	} else if (c->cmt_state == COMMIT_RUNNING_BACKGROUND ||
++		   c->cmt_state == COMMIT_RUNNING_REQUIRED) {
++		if (chance(999, 1000))
++			return 0;
++		dbg_rcvry("failing in bud LEB %d commit running", lnum);
++	} else {
++		if (chance(9999, 10000))
++			return 0;
++		dbg_rcvry("failing in bud LEB %d commit not running", lnum);
++	}
++	ubifs_err("*** SETTING FAILURE MODE ON (LEB %d) ***", lnum);
++	d->failure_mode = 1;
++	dump_stack();
++	return 1;
++}
++
++static void cut_data(const void *buf, int len)
++{
++	int flen, i;
++	unsigned char *p = (void *)buf;
++
++	flen = (len * (long long)simple_rand()) >> 15;
++	for (i = flen; i < len; i++)
++		p[i] = 0xff;
++}
++
++int dbg_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
++		 int len, int check)
++{
++	if (in_failure_mode(desc))
++		return -EIO;
++	return ubi_leb_read(desc, lnum, buf, offset, len, check);
++}
++
++int dbg_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
++		  int offset, int len, int dtype)
++{
++	int err, failing;
++
++	if (in_failure_mode(desc))
++		return -EIO;
++	failing = do_fail(desc, lnum, 1);
++	if (failing)
++		cut_data(buf, len);
++	err = ubi_leb_write(desc, lnum, buf, offset, len, dtype);
++	if (err)
++		return err;
++	if (failing)
++		return -EIO;
++	return 0;
++}
++
++int dbg_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
++		   int len, int dtype)
++{
++	int err;
++
++	if (do_fail(desc, lnum, 1))
++		return -EIO;
++	err = ubi_leb_change(desc, lnum, buf, len, dtype);
++	if (err)
++		return err;
++	if (do_fail(desc, lnum, 1))
++		return -EIO;
++	return 0;
++}
++
++int dbg_leb_erase(struct ubi_volume_desc *desc, int lnum)
++{
++	int err;
++
++	if (do_fail(desc, lnum, 0))
++		return -EIO;
++	err = ubi_leb_erase(desc, lnum);
++	if (err)
++		return err;
++	if (do_fail(desc, lnum, 0))
++		return -EIO;
++	return 0;
++}
++
++int dbg_leb_unmap(struct ubi_volume_desc *desc, int lnum)
++{
++	int err;
++
++	if (do_fail(desc, lnum, 0))
++		return -EIO;
++	err = ubi_leb_unmap(desc, lnum);
++	if (err)
++		return err;
++	if (do_fail(desc, lnum, 0))
++		return -EIO;
++	return 0;
++}
++
++int dbg_is_mapped(struct ubi_volume_desc *desc, int lnum)
++{
++	if (in_failure_mode(desc))
++		return -EIO;
++	return ubi_is_mapped(desc, lnum);
++}
++
++int dbg_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype)
++{
++	int err;
++
++	if (do_fail(desc, lnum, 0))
++		return -EIO;
++	err = ubi_leb_map(desc, lnum, dtype);
++	if (err)
++		return err;
++	if (do_fail(desc, lnum, 0))
++		return -EIO;
++	return 0;
++}
++
++/**
++ * ubifs_debugging_init - initialize UBIFS debugging.
++ * @c: UBIFS file-system description object
++ *
++ * This function initializes debugging-related data for the file system.
++ * Returns zero in case of success and a negative error code in case of
++ * failure.
++ */
++int ubifs_debugging_init(struct ubifs_info *c)
++{
++	c->dbg = kzalloc(sizeof(struct ubifs_debug_info), GFP_KERNEL);
++	if (!c->dbg)
++		return -ENOMEM;
++
++	c->dbg->buf = vmalloc(c->leb_size);
++	if (!c->dbg->buf)
++		goto out;
++
++	failure_mode_init(c);
++	return 0;
++
++out:
++	kfree(c->dbg);
++	return -ENOMEM;
++}
++
++/**
++ * ubifs_debugging_exit - free debugging data.
++ * @c: UBIFS file-system description object
++ */
++void ubifs_debugging_exit(struct ubifs_info *c)
++{
++	failure_mode_exit(c);
++	vfree(c->dbg->buf);
++	kfree(c->dbg);
++}
++
++/*
++ * Root directory for UBIFS stuff in debugfs. Contains sub-directories which
++ * contain the stuff specific to particular file-system mounts.
++ */
++static struct dentry *dfs_rootdir;
++
++/**
++ * dbg_debugfs_init - initialize debugfs file-system.
++ *
++ * UBIFS uses debugfs file-system to expose various debugging knobs to
++ * user-space. This function creates "ubifs" directory in the debugfs
++ * file-system. Returns zero in case of success and a negative error code in
++ * case of failure.
++ */
++int dbg_debugfs_init(void)
++{
++	dfs_rootdir = debugfs_create_dir("ubifs", NULL);
++	if (IS_ERR(dfs_rootdir)) {
++		int err = PTR_ERR(dfs_rootdir);
++		ubifs_err("cannot create \"ubifs\" debugfs directory, "
++			  "error %d\n", err);
++		return err;
++	}
++
++	return 0;
++}
++
++/**
++ * dbg_debugfs_exit - remove the "ubifs" directory from debugfs file-system.
++ */
++void dbg_debugfs_exit(void)
++{
++	debugfs_remove(dfs_rootdir);
++}
++
++static int open_debugfs_file(struct inode *inode, struct file *file)
++{
++	file->private_data = inode->i_private;
++	return 0;
++}
++
++static ssize_t write_debugfs_file(struct file *file, const char __user *buf,
++				  size_t count, loff_t *ppos)
++{
++	struct ubifs_info *c = file->private_data;
++	struct ubifs_debug_info *d = c->dbg;
++
++	if (file->f_path.dentry == d->dfs_dump_lprops)
++		dbg_dump_lprops(c);
++	else if (file->f_path.dentry == d->dfs_dump_budg) {
++		spin_lock(&c->space_lock);
++		dbg_dump_budg(c);
++		spin_unlock(&c->space_lock);
++	} else if (file->f_path.dentry == d->dfs_dump_tnc) {
++		mutex_lock(&c->tnc_mutex);
++		dbg_dump_tnc(c);
++		mutex_unlock(&c->tnc_mutex);
++	} else
++		return -EINVAL;
++
++	*ppos += count;
++	return count;
++}
++
++static const struct file_operations dfs_fops = {
++	.open = open_debugfs_file,
++	.write = write_debugfs_file,
++	.owner = THIS_MODULE,
++};
++
++/**
++ * dbg_debugfs_init_fs - initialize debugfs for UBIFS instance.
++ * @c: UBIFS file-system description object
++ *
++ * This function creates all debugfs files for this instance of UBIFS. Returns
++ * zero in case of success and a negative error code in case of failure.
++ *
++ * Note, the only reason we have not merged this function with the
++ * 'ubifs_debugging_init()' function is because it is better to initialize
++ * debugfs interfaces at the very end of the mount process, and remove them at
++ * the very beginning of the mount process.
++ */
++int dbg_debugfs_init_fs(struct ubifs_info *c)
++{
++	int err;
++	const char *fname;
++	struct dentry *dent;
++	struct ubifs_debug_info *d = c->dbg;
++
++	sprintf(d->dfs_dir_name, "ubi%d_%d", c->vi.ubi_num, c->vi.vol_id);
++	d->dfs_dir = debugfs_create_dir(d->dfs_dir_name, dfs_rootdir);
++	if (IS_ERR(d->dfs_dir)) {
++		err = PTR_ERR(d->dfs_dir);
++		ubifs_err("cannot create \"%s\" debugfs directory, error %d\n",
++			  d->dfs_dir_name, err);
++		goto out;
++	}
++
++	fname = "dump_lprops";
++	dent = debugfs_create_file(fname, S_IWUGO, d->dfs_dir, c, &dfs_fops);
++	if (IS_ERR(dent))
++		goto out_remove;
++	d->dfs_dump_lprops = dent;
++
++	fname = "dump_budg";
++	dent = debugfs_create_file(fname, S_IWUGO, d->dfs_dir, c, &dfs_fops);
++	if (IS_ERR(dent))
++		goto out_remove;
++	d->dfs_dump_budg = dent;
++
++	fname = "dump_tnc";
++	dent = debugfs_create_file(fname, S_IWUGO, d->dfs_dir, c, &dfs_fops);
++	if (IS_ERR(dent))
++		goto out_remove;
++	d->dfs_dump_tnc = dent;
++
++	return 0;
++
++out_remove:
++	err = PTR_ERR(dent);
++	ubifs_err("cannot create \"%s\" debugfs directory, error %d\n",
++		  fname, err);
++	if (d->dfs_dump_tnc)
++		debugfs_remove(d->dfs_dump_tnc);
++	if (d->dfs_dump_budg)
++		debugfs_remove(d->dfs_dump_budg);
++	if (d->dfs_dump_lprops)
++		debugfs_remove(d->dfs_dump_lprops);
++	debugfs_remove(d->dfs_dir);
++out:
++	return err;
++}
++
++/**
++ * dbg_debugfs_exit_fs - remove all debugfs files.
++ * @c: UBIFS file-system description object
++ */
++void dbg_debugfs_exit_fs(struct ubifs_info *c)
++{
++	struct ubifs_debug_info *d = c->dbg;
++
++	debugfs_remove(d->dfs_dump_tnc);
++	debugfs_remove(d->dfs_dump_budg);
++	debugfs_remove(d->dfs_dump_lprops);
++	debugfs_remove(d->dfs_dir);
++}
++
++#endif /* CONFIG_UBIFS_FS_DEBUG */
+diff -Nurd linux-2.6.24.orig/fs/ubifs/debug.h linux-2.6.24/fs/ubifs/debug.h
+--- linux-2.6.24.orig/fs/ubifs/debug.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/debug.h	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,486 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++#ifndef __UBIFS_DEBUG_H__
++#define __UBIFS_DEBUG_H__
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++
++/**
++ * ubifs_debug_info - per-FS debugging information.
++ * @buf: a buffer of LEB size, used for various purposes
++ * @old_zroot: old index root - used by 'dbg_check_old_index()'
++ * @old_zroot_level: old index root level - used by 'dbg_check_old_index()'
++ * @old_zroot_sqnum: old index root sqnum - used by 'dbg_check_old_index()'
++ * @failure_mode: failure mode for recovery testing
++ * @fail_delay: 0=>don't delay, 1=>delay a time, 2=>delay a number of calls
++ * @fail_timeout: time in jiffies when delay of failure mode expires
++ * @fail_cnt: current number of calls to failure mode I/O functions
++ * @fail_cnt_max: number of calls by which to delay failure mode
++ * @chk_lpt_sz: used by LPT tree size checker
++ * @chk_lpt_sz2: used by LPT tree size checker
++ * @chk_lpt_wastage: used by LPT tree size checker
++ * @chk_lpt_lebs: used by LPT tree size checker
++ * @new_nhead_offs: used by LPT tree size checker
++ * @new_ihead_lnum: used by debugging to check @c->ihead_lnum
++ * @new_ihead_offs: used by debugging to check @c->ihead_offs
++ *
++ * @saved_lst: saved lprops statistics (used by 'dbg_save_space_info()')
++ * @saved_free: saved free space (used by 'dbg_save_space_info()')
++ *
++ * dfs_dir_name: name of debugfs directory containing this file-system's files
++ * dfs_dir: direntry object of the file-system debugfs directory
++ * dfs_dump_lprops: "dump lprops" debugfs knob
++ * dfs_dump_budg: "dump budgeting information" debugfs knob
++ * dfs_dump_tnc: "dump TNC" debugfs knob
++ */
++struct ubifs_debug_info {
++	void *buf;
++	struct ubifs_zbranch old_zroot;
++	int old_zroot_level;
++	unsigned long long old_zroot_sqnum;
++	int failure_mode;
++	int fail_delay;
++	unsigned long fail_timeout;
++	unsigned int fail_cnt;
++	unsigned int fail_cnt_max;
++	long long chk_lpt_sz;
++	long long chk_lpt_sz2;
++	long long chk_lpt_wastage;
++	int chk_lpt_lebs;
++	int new_nhead_offs;
++	int new_ihead_lnum;
++	int new_ihead_offs;
++
++	struct ubifs_lp_stats saved_lst;
++	long long saved_free;
++
++	char dfs_dir_name[100];
++	struct dentry *dfs_dir;
++	struct dentry *dfs_dump_lprops;
++	struct dentry *dfs_dump_budg;
++	struct dentry *dfs_dump_tnc;
++};
++
++#define ubifs_assert(expr) do {                                                \
++	if (unlikely(!(expr))) {                                               \
++		printk(KERN_CRIT "UBIFS assert failed in %s at %u (pid %d)\n", \
++		       __func__, __LINE__, current->pid);                      \
++		dbg_dump_stack();                                              \
++	}                                                                      \
++} while (0)
++
++#define ubifs_assert_cmt_locked(c) do {                                        \
++	if (unlikely(down_write_trylock(&(c)->commit_sem))) {                  \
++		up_write(&(c)->commit_sem);                                    \
++		printk(KERN_CRIT "commit lock is not locked!\n");              \
++		ubifs_assert(0);                                               \
++	}                                                                      \
++} while (0)
++
++#define dbg_dump_stack() do {                                                  \
++	if (!dbg_failure_mode)                                                 \
++		dump_stack();                                                  \
++} while (0)
++
++/* Generic debugging messages */
++#define dbg_msg(fmt, ...) do {                                                 \
++	spin_lock(&dbg_lock);                                                  \
++	printk(KERN_DEBUG "UBIFS DBG (pid %d): %s: " fmt "\n", current->pid,   \
++	       __func__, ##__VA_ARGS__);                                       \
++	spin_unlock(&dbg_lock);                                                \
++} while (0)
++
++#define dbg_do_msg(typ, fmt, ...) do {                                         \
++	if (ubifs_msg_flags & typ)                                             \
++		dbg_msg(fmt, ##__VA_ARGS__);                                   \
++} while (0)
++
++#define dbg_err(fmt, ...) do {                                                 \
++	spin_lock(&dbg_lock);                                                  \
++	ubifs_err(fmt, ##__VA_ARGS__);                                         \
++	spin_unlock(&dbg_lock);                                                \
++} while (0)
++
++const char *dbg_key_str0(const struct ubifs_info *c,
++			 const union ubifs_key *key);
++const char *dbg_key_str1(const struct ubifs_info *c,
++			 const union ubifs_key *key);
++
++/*
++ * DBGKEY macros require @dbg_lock to be held, which it is in the dbg message
++ * macros.
++ */
++#define DBGKEY(key) dbg_key_str0(c, (key))
++#define DBGKEY1(key) dbg_key_str1(c, (key))
++
++/* General messages */
++#define dbg_gen(fmt, ...)   dbg_do_msg(UBIFS_MSG_GEN, fmt, ##__VA_ARGS__)
++
++/* Additional journal messages */
++#define dbg_jnl(fmt, ...)   dbg_do_msg(UBIFS_MSG_JNL, fmt, ##__VA_ARGS__)
++
++/* Additional TNC messages */
++#define dbg_tnc(fmt, ...)   dbg_do_msg(UBIFS_MSG_TNC, fmt, ##__VA_ARGS__)
++
++/* Additional lprops messages */
++#define dbg_lp(fmt, ...)    dbg_do_msg(UBIFS_MSG_LP, fmt, ##__VA_ARGS__)
++
++/* Additional LEB find messages */
++#define dbg_find(fmt, ...)  dbg_do_msg(UBIFS_MSG_FIND, fmt, ##__VA_ARGS__)
++
++/* Additional mount messages */
++#define dbg_mnt(fmt, ...)   dbg_do_msg(UBIFS_MSG_MNT, fmt, ##__VA_ARGS__)
++
++/* Additional I/O messages */
++#define dbg_io(fmt, ...)    dbg_do_msg(UBIFS_MSG_IO, fmt, ##__VA_ARGS__)
++
++/* Additional commit messages */
++#define dbg_cmt(fmt, ...)   dbg_do_msg(UBIFS_MSG_CMT, fmt, ##__VA_ARGS__)
++
++/* Additional budgeting messages */
++#define dbg_budg(fmt, ...)  dbg_do_msg(UBIFS_MSG_BUDG, fmt, ##__VA_ARGS__)
++
++/* Additional log messages */
++#define dbg_log(fmt, ...)   dbg_do_msg(UBIFS_MSG_LOG, fmt, ##__VA_ARGS__)
++
++/* Additional gc messages */
++#define dbg_gc(fmt, ...)    dbg_do_msg(UBIFS_MSG_GC, fmt, ##__VA_ARGS__)
++
++/* Additional scan messages */
++#define dbg_scan(fmt, ...)  dbg_do_msg(UBIFS_MSG_SCAN, fmt, ##__VA_ARGS__)
++
++/* Additional recovery messages */
++#define dbg_rcvry(fmt, ...) dbg_do_msg(UBIFS_MSG_RCVRY, fmt, ##__VA_ARGS__)
++
++/*
++ * Debugging message type flags (must match msg_type_names in debug.c).
++ *
++ * UBIFS_MSG_GEN: general messages
++ * UBIFS_MSG_JNL: journal messages
++ * UBIFS_MSG_MNT: mount messages
++ * UBIFS_MSG_CMT: commit messages
++ * UBIFS_MSG_FIND: LEB find messages
++ * UBIFS_MSG_BUDG: budgeting messages
++ * UBIFS_MSG_GC: garbage collection messages
++ * UBIFS_MSG_TNC: TNC messages
++ * UBIFS_MSG_LP: lprops messages
++ * UBIFS_MSG_IO: I/O messages
++ * UBIFS_MSG_LOG: log messages
++ * UBIFS_MSG_SCAN: scan messages
++ * UBIFS_MSG_RCVRY: recovery messages
++ */
++enum {
++	UBIFS_MSG_GEN   = 0x1,
++	UBIFS_MSG_JNL   = 0x2,
++	UBIFS_MSG_MNT   = 0x4,
++	UBIFS_MSG_CMT   = 0x8,
++	UBIFS_MSG_FIND  = 0x10,
++	UBIFS_MSG_BUDG  = 0x20,
++	UBIFS_MSG_GC    = 0x40,
++	UBIFS_MSG_TNC   = 0x80,
++	UBIFS_MSG_LP    = 0x100,
++	UBIFS_MSG_IO    = 0x200,
++	UBIFS_MSG_LOG   = 0x400,
++	UBIFS_MSG_SCAN  = 0x800,
++	UBIFS_MSG_RCVRY = 0x1000,
++};
++
++/* Debugging message type flags for each default debug message level */
++#define UBIFS_MSG_LVL_0 0
++#define UBIFS_MSG_LVL_1 0x1
++#define UBIFS_MSG_LVL_2 0x7f
++#define UBIFS_MSG_LVL_3 0xffff
++
++/*
++ * Debugging check flags (must match chk_names in debug.c).
++ *
++ * UBIFS_CHK_GEN: general checks
++ * UBIFS_CHK_TNC: check TNC
++ * UBIFS_CHK_IDX_SZ: check index size
++ * UBIFS_CHK_ORPH: check orphans
++ * UBIFS_CHK_OLD_IDX: check the old index
++ * UBIFS_CHK_LPROPS: check lprops
++ * UBIFS_CHK_FS: check the file-system
++ */
++enum {
++	UBIFS_CHK_GEN     = 0x1,
++	UBIFS_CHK_TNC     = 0x2,
++	UBIFS_CHK_IDX_SZ  = 0x4,
++	UBIFS_CHK_ORPH    = 0x8,
++	UBIFS_CHK_OLD_IDX = 0x10,
++	UBIFS_CHK_LPROPS  = 0x20,
++	UBIFS_CHK_FS      = 0x40,
++};
++
++/*
++ * Special testing flags (must match tst_names in debug.c).
++ *
++ * UBIFS_TST_FORCE_IN_THE_GAPS: force the use of in-the-gaps method
++ * UBIFS_TST_RCVRY: failure mode for recovery testing
++ */
++enum {
++	UBIFS_TST_FORCE_IN_THE_GAPS = 0x2,
++	UBIFS_TST_RCVRY             = 0x4,
++};
++
++#if CONFIG_UBIFS_FS_DEBUG_MSG_LVL == 1
++#define UBIFS_MSG_FLAGS_DEFAULT UBIFS_MSG_LVL_1
++#elif CONFIG_UBIFS_FS_DEBUG_MSG_LVL == 2
++#define UBIFS_MSG_FLAGS_DEFAULT UBIFS_MSG_LVL_2
++#elif CONFIG_UBIFS_FS_DEBUG_MSG_LVL == 3
++#define UBIFS_MSG_FLAGS_DEFAULT UBIFS_MSG_LVL_3
++#else
++#define UBIFS_MSG_FLAGS_DEFAULT UBIFS_MSG_LVL_0
++#endif
++
++#ifdef CONFIG_UBIFS_FS_DEBUG_CHKS
++#define UBIFS_CHK_FLAGS_DEFAULT 0xffffffff
++#else
++#define UBIFS_CHK_FLAGS_DEFAULT 0
++#endif
++
++extern spinlock_t dbg_lock;
++
++extern unsigned int ubifs_msg_flags;
++extern unsigned int ubifs_chk_flags;
++extern unsigned int ubifs_tst_flags;
++
++int ubifs_debugging_init(struct ubifs_info *c);
++void ubifs_debugging_exit(struct ubifs_info *c);
++
++/* Dump functions */
++const char *dbg_ntype(int type);
++const char *dbg_cstate(int cmt_state);
++const char *dbg_get_key_dump(const struct ubifs_info *c,
++			     const union ubifs_key *key);
++void dbg_dump_inode(const struct ubifs_info *c, const struct inode *inode);
++void dbg_dump_node(const struct ubifs_info *c, const void *node);
++void dbg_dump_lpt_node(const struct ubifs_info *c, void *node, int lnum,
++		       int offs);
++void dbg_dump_budget_req(const struct ubifs_budget_req *req);
++void dbg_dump_lstats(const struct ubifs_lp_stats *lst);
++void dbg_dump_budg(struct ubifs_info *c);
++void dbg_dump_lprop(const struct ubifs_info *c, const struct ubifs_lprops *lp);
++void dbg_dump_lprops(struct ubifs_info *c);
++void dbg_dump_lpt_info(struct ubifs_info *c);
++void dbg_dump_leb(const struct ubifs_info *c, int lnum);
++void dbg_dump_znode(const struct ubifs_info *c,
++		    const struct ubifs_znode *znode);
++void dbg_dump_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat);
++void dbg_dump_pnode(struct ubifs_info *c, struct ubifs_pnode *pnode,
++		    struct ubifs_nnode *parent, int iip);
++void dbg_dump_tnc(struct ubifs_info *c);
++void dbg_dump_index(struct ubifs_info *c);
++void dbg_dump_lpt_lebs(const struct ubifs_info *c);
++
++/* Checking helper functions */
++typedef int (*dbg_leaf_callback)(struct ubifs_info *c,
++				 struct ubifs_zbranch *zbr, void *priv);
++typedef int (*dbg_znode_callback)(struct ubifs_info *c,
++				  struct ubifs_znode *znode, void *priv);
++int dbg_walk_index(struct ubifs_info *c, dbg_leaf_callback leaf_cb,
++		   dbg_znode_callback znode_cb, void *priv);
++
++/* Checking functions */
++void dbg_save_space_info(struct ubifs_info *c);
++int dbg_check_space_info(struct ubifs_info *c);
++int dbg_check_lprops(struct ubifs_info *c);
++int dbg_old_index_check_init(struct ubifs_info *c, struct ubifs_zbranch *zroot);
++int dbg_check_old_index(struct ubifs_info *c, struct ubifs_zbranch *zroot);
++int dbg_check_cats(struct ubifs_info *c);
++int dbg_check_ltab(struct ubifs_info *c);
++int dbg_chk_lpt_free_spc(struct ubifs_info *c);
++int dbg_chk_lpt_sz(struct ubifs_info *c, int action, int len);
++int dbg_check_synced_i_size(struct inode *inode);
++int dbg_check_dir_size(struct ubifs_info *c, const struct inode *dir);
++int dbg_check_tnc(struct ubifs_info *c, int extra);
++int dbg_check_idx_size(struct ubifs_info *c, long long idx_size);
++int dbg_check_filesystem(struct ubifs_info *c);
++void dbg_check_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat,
++		    int add_pos);
++int dbg_check_lprops(struct ubifs_info *c);
++int dbg_check_lpt_nodes(struct ubifs_info *c, struct ubifs_cnode *cnode,
++			int row, int col);
++
++/* Force the use of in-the-gaps method for testing */
++
++#define dbg_force_in_the_gaps_enabled \
++	(ubifs_tst_flags & UBIFS_TST_FORCE_IN_THE_GAPS)
++
++int dbg_force_in_the_gaps(void);
++
++/* Failure mode for recovery testing */
++
++#define dbg_failure_mode (ubifs_tst_flags & UBIFS_TST_RCVRY)
++
++#ifndef UBIFS_DBG_PRESERVE_UBI
++
++#define ubi_leb_read   dbg_leb_read
++#define ubi_leb_write  dbg_leb_write
++#define ubi_leb_change dbg_leb_change
++#define ubi_leb_erase  dbg_leb_erase
++#define ubi_leb_unmap  dbg_leb_unmap
++#define ubi_is_mapped  dbg_is_mapped
++#define ubi_leb_map    dbg_leb_map
++
++#endif
++
++int dbg_leb_read(struct ubi_volume_desc *desc, int lnum, char *buf, int offset,
++		 int len, int check);
++int dbg_leb_write(struct ubi_volume_desc *desc, int lnum, const void *buf,
++		  int offset, int len, int dtype);
++int dbg_leb_change(struct ubi_volume_desc *desc, int lnum, const void *buf,
++		   int len, int dtype);
++int dbg_leb_erase(struct ubi_volume_desc *desc, int lnum);
++int dbg_leb_unmap(struct ubi_volume_desc *desc, int lnum);
++int dbg_is_mapped(struct ubi_volume_desc *desc, int lnum);
++int dbg_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype);
++
++static inline int dbg_read(struct ubi_volume_desc *desc, int lnum, char *buf,
++			   int offset, int len)
++{
++	return dbg_leb_read(desc, lnum, buf, offset, len, 0);
++}
++
++static inline int dbg_write(struct ubi_volume_desc *desc, int lnum,
++			    const void *buf, int offset, int len)
++{
++	return dbg_leb_write(desc, lnum, buf, offset, len, UBI_UNKNOWN);
++}
++
++static inline int dbg_change(struct ubi_volume_desc *desc, int lnum,
++				    const void *buf, int len)
++{
++	return dbg_leb_change(desc, lnum, buf, len, UBI_UNKNOWN);
++}
++
++/* Debugfs-related stuff */
++int dbg_debugfs_init(void);
++void dbg_debugfs_exit(void);
++int dbg_debugfs_init_fs(struct ubifs_info *c);
++void dbg_debugfs_exit_fs(struct ubifs_info *c);
++
++#else /* !CONFIG_UBIFS_FS_DEBUG */
++
++/* Use "if (0)" to make compiler check arguments even if debugging is off */
++#define ubifs_assert(expr)  do {                                               \
++	if (0 && (expr))                                                       \
++		printk(KERN_CRIT "UBIFS assert failed in %s at %u (pid %d)\n", \
++		       __func__, __LINE__, current->pid);                      \
++} while (0)
++
++#define dbg_err(fmt, ...)   do {                                               \
++	if (0)                                                                 \
++		ubifs_err(fmt, ##__VA_ARGS__);                                 \
++} while (0)
++
++#define dbg_msg(fmt, ...) do {                                                 \
++	if (0)                                                                 \
++		printk(KERN_DEBUG "UBIFS DBG (pid %d): %s: " fmt "\n",         \
++		       current->pid, __func__, ##__VA_ARGS__);                 \
++} while (0)
++
++#define dbg_dump_stack()
++#define ubifs_assert_cmt_locked(c)
++
++#define dbg_gen(fmt, ...)   dbg_msg(fmt, ##__VA_ARGS__)
++#define dbg_jnl(fmt, ...)   dbg_msg(fmt, ##__VA_ARGS__)
++#define dbg_tnc(fmt, ...)   dbg_msg(fmt, ##__VA_ARGS__)
++#define dbg_lp(fmt, ...)    dbg_msg(fmt, ##__VA_ARGS__)
++#define dbg_find(fmt, ...)  dbg_msg(fmt, ##__VA_ARGS__)
++#define dbg_mnt(fmt, ...)   dbg_msg(fmt, ##__VA_ARGS__)
++#define dbg_io(fmt, ...)    dbg_msg(fmt, ##__VA_ARGS__)
++#define dbg_cmt(fmt, ...)   dbg_msg(fmt, ##__VA_ARGS__)
++#define dbg_budg(fmt, ...)  dbg_msg(fmt, ##__VA_ARGS__)
++#define dbg_log(fmt, ...)   dbg_msg(fmt, ##__VA_ARGS__)
++#define dbg_gc(fmt, ...)    dbg_msg(fmt, ##__VA_ARGS__)
++#define dbg_scan(fmt, ...)  dbg_msg(fmt, ##__VA_ARGS__)
++#define dbg_rcvry(fmt, ...) dbg_msg(fmt, ##__VA_ARGS__)
++
++#define DBGKEY(key)  ((char *)(key))
++#define DBGKEY1(key) ((char *)(key))
++
++#define ubifs_debugging_init(c)                0
++#define ubifs_debugging_exit(c)                ({})
++
++#define dbg_ntype(type)                        ""
++#define dbg_cstate(cmt_state)                  ""
++#define dbg_get_key_dump(c, key)               ({})
++#define dbg_dump_inode(c, inode)               ({})
++#define dbg_dump_node(c, node)                 ({})
++#define dbg_dump_lpt_node(c, node, lnum, offs) ({})
++#define dbg_dump_budget_req(req)               ({})
++#define dbg_dump_lstats(lst)                   ({})
++#define dbg_dump_budg(c)                       ({})
++#define dbg_dump_lprop(c, lp)                  ({})
++#define dbg_dump_lprops(c)                     ({})
++#define dbg_dump_lpt_info(c)                   ({})
++#define dbg_dump_leb(c, lnum)                  ({})
++#define dbg_dump_znode(c, znode)               ({})
++#define dbg_dump_heap(c, heap, cat)            ({})
++#define dbg_dump_pnode(c, pnode, parent, iip)  ({})
++#define dbg_dump_tnc(c)                        ({})
++#define dbg_dump_index(c)                      ({})
++#define dbg_dump_lpt_lebs(c)                   ({})
++
++#define dbg_walk_index(c, leaf_cb, znode_cb, priv) 0
++#define dbg_old_index_check_init(c, zroot)         0
++#define dbg_save_space_info(c)                     ({})
++#define dbg_check_space_info(c)                    0
++#define dbg_check_old_index(c, zroot)              0
++#define dbg_check_cats(c)                          0
++#define dbg_check_ltab(c)                          0
++#define dbg_chk_lpt_free_spc(c)                    0
++#define dbg_chk_lpt_sz(c, action, len)             0
++#define dbg_check_synced_i_size(inode)             0
++#define dbg_check_dir_size(c, dir)                 0
++#define dbg_check_tnc(c, x)                        0
++#define dbg_check_idx_size(c, idx_size)            0
++#define dbg_check_filesystem(c)                    0
++#define dbg_check_heap(c, heap, cat, add_pos)      ({})
++#define dbg_check_lprops(c)                        0
++#define dbg_check_lpt_nodes(c, cnode, row, col)    0
++#define dbg_force_in_the_gaps_enabled              0
++#define dbg_force_in_the_gaps()                    0
++#define dbg_failure_mode                           0
++
++#define dbg_debugfs_init()                         0
++#define dbg_debugfs_exit()
++#define dbg_debugfs_init_fs(c)                     0
++#define dbg_debugfs_exit_fs(c)                     0
++
++#endif /* !CONFIG_UBIFS_FS_DEBUG */
++
++/*
++ * Some compatibility stuff goes here.
++ */
++
++#include <asm/div64.h>
++
++static inline uint64_t div_u64(uint64_t dividend, uint64_t divisor)
++{
++	do_div(dividend, divisor);
++	return dividend;
++}
++
++#endif /* !__UBIFS_DEBUG_H__ */
+diff -Nurd linux-2.6.24.orig/fs/ubifs/dir.c linux-2.6.24/fs/ubifs/dir.c
+--- linux-2.6.24.orig/fs/ubifs/dir.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/dir.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,1215 @@
++/* * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ * Copyright (C) 2006, 2007 University of Szeged, Hungary
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ *          Zoltan Sogor
++ */
++
++/*
++ * This file implements directory operations.
++ *
++ * All FS operations in this file allocate budget before writing anything to the
++ * media. If they fail to allocate it, the error is returned. The only
++ * exceptions are 'ubifs_unlink()' and 'ubifs_rmdir()' which keep working even
++ * if they unable to allocate the budget, because deletion %-ENOSPC failure is
++ * not what users are usually ready to get. UBIFS budgeting subsystem has some
++ * space reserved for these purposes.
++ *
++ * All operations in this file write all inodes which they change straight
++ * away, instead of marking them dirty. For example, 'ubifs_link()' changes
++ * @i_size of the parent inode and writes the parent inode together with the
++ * target inode. This was done to simplify file-system recovery which would
++ * otherwise be very difficult to do. The only exception is rename which marks
++ * the re-named inode dirty (because its @i_ctime is updated) but does not
++ * write it, but just marks it as dirty.
++ */
++
++#include "ubifs.h"
++
++/**
++ * inherit_flags - inherit flags of the parent inode.
++ * @dir: parent inode
++ * @mode: new inode mode flags
++ *
++ * This is a helper function for 'ubifs_new_inode()' which inherits flag of the
++ * parent directory inode @dir. UBIFS inodes inherit the following flags:
++ * o %UBIFS_COMPR_FL, which is useful to switch compression on/of on
++ *   sub-directory basis;
++ * o %UBIFS_SYNC_FL - useful for the same reasons;
++ * o %UBIFS_DIRSYNC_FL - similar, but relevant only to directories.
++ *
++ * This function returns the inherited flags.
++ */
++static int inherit_flags(const struct inode *dir, int mode)
++{
++	int flags;
++	const struct ubifs_inode *ui = ubifs_inode(dir);
++
++	if (!S_ISDIR(dir->i_mode))
++		/*
++		 * The parent is not a directory, which means that an extended
++		 * attribute inode is being created. No flags.
++		 */
++		return 0;
++
++	flags = ui->flags & (UBIFS_COMPR_FL | UBIFS_SYNC_FL | UBIFS_DIRSYNC_FL);
++	if (!S_ISDIR(mode))
++		/* The "DIRSYNC" flag only applies to directories */
++		flags &= ~UBIFS_DIRSYNC_FL;
++	return flags;
++}
++
++/**
++ * ubifs_new_inode - allocate new UBIFS inode object.
++ * @c: UBIFS file-system description object
++ * @dir: parent directory inode
++ * @mode: inode mode flags
++ *
++ * This function finds an unused inode number, allocates new inode and
++ * initializes it. Returns new inode in case of success and an error code in
++ * case of failure.
++ */
++struct inode *ubifs_new_inode(struct ubifs_info *c, const struct inode *dir,
++			      int mode)
++{
++	struct inode *inode;
++	struct ubifs_inode *ui;
++
++	inode = new_inode(c->vfs_sb);
++	ui = ubifs_inode(inode);
++	if (!inode)
++		return ERR_PTR(-ENOMEM);
++
++	/*
++	 * Set 'S_NOCMTIME' to prevent VFS form updating [mc]time of inodes and
++	 * marking them dirty in file write path (see 'file_update_time()').
++	 * UBIFS has to fully control "clean <-> dirty" transitions of inodes
++	 * to make budgeting work.
++	 */
++	inode->i_flags |= (S_NOCMTIME);
++
++	inode->i_uid = current->fsuid;
++	if (dir->i_mode & S_ISGID) {
++		inode->i_gid = dir->i_gid;
++		if (S_ISDIR(mode))
++			mode |= S_ISGID;
++	} else
++		inode->i_gid = current->fsgid;
++	inode->i_mode = mode;
++	inode->i_mtime = inode->i_atime = inode->i_ctime =
++			 ubifs_current_time(inode);
++	inode->i_mapping->nrpages = 0;
++	/* Disable readahead */
++	inode->i_mapping->backing_dev_info = &c->bdi;
++
++	switch (mode & S_IFMT) {
++	case S_IFREG:
++		inode->i_mapping->a_ops = &ubifs_file_address_operations;
++		inode->i_op = &ubifs_file_inode_operations;
++		inode->i_fop = &ubifs_file_operations;
++		break;
++	case S_IFDIR:
++		inode->i_op  = &ubifs_dir_inode_operations;
++		inode->i_fop = &ubifs_dir_operations;
++		inode->i_size = ui->ui_size = UBIFS_INO_NODE_SZ;
++		break;
++	case S_IFLNK:
++		inode->i_op = &ubifs_symlink_inode_operations;
++		break;
++	case S_IFSOCK:
++	case S_IFIFO:
++	case S_IFBLK:
++	case S_IFCHR:
++		inode->i_op  = &ubifs_file_inode_operations;
++		break;
++	default:
++		BUG();
++	}
++
++	ui->flags = inherit_flags(dir, mode);
++	ubifs_set_inode_flags(inode);
++	if (S_ISREG(mode))
++		ui->compr_type = c->default_compr;
++	else
++		ui->compr_type = UBIFS_COMPR_NONE;
++	ui->synced_i_size = 0;
++
++	spin_lock(&c->cnt_lock);
++	/* Inode number overflow is currently not supported */
++	if (c->highest_inum >= INUM_WARN_WATERMARK) {
++		if (c->highest_inum >= INUM_WATERMARK) {
++			spin_unlock(&c->cnt_lock);
++			ubifs_err("out of inode numbers");
++			make_bad_inode(inode);
++			iput(inode);
++			return ERR_PTR(-EINVAL);
++		}
++		ubifs_warn("running out of inode numbers (current %lu, max %d)",
++			   (unsigned long)c->highest_inum, INUM_WATERMARK);
++	}
++
++	inode->i_ino = ++c->highest_inum;
++	/*
++	 * The creation sequence number remains with this inode for its
++	 * lifetime. All nodes for this inode have a greater sequence number,
++	 * and so it is possible to distinguish obsolete nodes belonging to a
++	 * previous incarnation of the same inode number - for example, for the
++	 * purpose of rebuilding the index.
++	 */
++	ui->creat_sqnum = ++c->max_sqnum;
++	spin_unlock(&c->cnt_lock);
++	return inode;
++}
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++
++static int dbg_check_name(struct ubifs_dent_node *dent, struct qstr *nm)
++{
++	if (!(ubifs_chk_flags & UBIFS_CHK_GEN))
++		return 0;
++	if (le16_to_cpu(dent->nlen) != nm->len)
++		return -EINVAL;
++	if (memcmp(dent->name, nm->name, nm->len))
++		return -EINVAL;
++	return 0;
++}
++
++#else
++
++#define dbg_check_name(dent, nm) 0
++
++#endif
++
++static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
++				   struct nameidata *nd)
++{
++	int err;
++	union ubifs_key key;
++	struct inode *inode = NULL;
++	struct ubifs_dent_node *dent;
++	struct ubifs_info *c = dir->i_sb->s_fs_info;
++
++	dbg_gen("'%.*s' in dir ino %lu",
++		dentry->d_name.len, dentry->d_name.name, dir->i_ino);
++
++	if (dentry->d_name.len > UBIFS_MAX_NLEN)
++		return ERR_PTR(-ENAMETOOLONG);
++
++	dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
++	if (!dent)
++		return ERR_PTR(-ENOMEM);
++
++	dent_key_init(c, &key, dir->i_ino, &dentry->d_name);
++
++	err = ubifs_tnc_lookup_nm(c, &key, dent, &dentry->d_name);
++	if (err) {
++		/*
++		 * Do not hash the direntry if parent 'i_nlink' is zero, because
++		 * this has side-effects - '->delete_inode()' call will not be
++		 * called for the parent orphan inode, because 'd_count' of its
++		 * direntry will stay 1 (it'll be negative direntry I guess)
++		 * and prevent 'iput_final()' until the dentry is destroyed due
++		 * to unmount or memory pressure.
++		 */
++		if (err == -ENOENT && dir->i_nlink != 0) {
++			dbg_gen("not found");
++			goto done;
++		}
++		goto out;
++	}
++
++	if (dbg_check_name(dent, &dentry->d_name)) {
++		err = -EINVAL;
++		goto out;
++	}
++
++	inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum));
++	if (IS_ERR(inode)) {
++		/*
++		 * This should not happen. Probably the file-system needs
++		 * checking.
++		 */
++		err = PTR_ERR(inode);
++		ubifs_err("dead directory entry '%.*s', error %d",
++			  dentry->d_name.len, dentry->d_name.name, err);
++		ubifs_ro_mode(c, err);
++		goto out;
++	}
++
++done:
++	kfree(dent);
++	return d_splice_alias(inode, dentry);
++
++out:
++	kfree(dent);
++	return ERR_PTR(err);
++}
++
++static int ubifs_create(struct inode *dir, struct dentry *dentry, int mode,
++			struct nameidata *nd)
++{
++	struct inode *inode;
++	struct ubifs_info *c = dir->i_sb->s_fs_info;
++	int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
++	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
++					.dirtied_ino = 1 };
++	struct ubifs_inode *dir_ui = ubifs_inode(dir);
++
++	/*
++	 * Budget request settings: new inode, new direntry, changing the
++	 * parent directory inode.
++	 */
++
++	dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
++		dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
++
++	err = ubifs_budget_space(c, &req);
++	if (err)
++		return err;
++
++	inode = ubifs_new_inode(c, dir, mode);
++	if (IS_ERR(inode)) {
++		err = PTR_ERR(inode);
++		goto out_budg;
++	}
++
++	mutex_lock(&dir_ui->ui_mutex);
++	dir->i_size += sz_change;
++	dir_ui->ui_size = dir->i_size;
++	dir->i_mtime = dir->i_ctime = inode->i_ctime;
++	err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
++	if (err)
++		goto out_cancel;
++	mutex_unlock(&dir_ui->ui_mutex);
++
++	ubifs_release_budget(c, &req);
++	insert_inode_hash(inode);
++	d_instantiate(dentry, inode);
++	return 0;
++
++out_cancel:
++	dir->i_size -= sz_change;
++	dir_ui->ui_size = dir->i_size;
++	mutex_unlock(&dir_ui->ui_mutex);
++	make_bad_inode(inode);
++	iput(inode);
++out_budg:
++	ubifs_release_budget(c, &req);
++	ubifs_err("cannot create regular file, error %d", err);
++	return err;
++}
++
++/**
++ * vfs_dent_type - get VFS directory entry type.
++ * @type: UBIFS directory entry type
++ *
++ * This function converts UBIFS directory entry type into VFS directory entry
++ * type.
++ */
++static unsigned int vfs_dent_type(uint8_t type)
++{
++	switch (type) {
++	case UBIFS_ITYPE_REG:
++		return DT_REG;
++	case UBIFS_ITYPE_DIR:
++		return DT_DIR;
++	case UBIFS_ITYPE_LNK:
++		return DT_LNK;
++	case UBIFS_ITYPE_BLK:
++		return DT_BLK;
++	case UBIFS_ITYPE_CHR:
++		return DT_CHR;
++	case UBIFS_ITYPE_FIFO:
++		return DT_FIFO;
++	case UBIFS_ITYPE_SOCK:
++		return DT_SOCK;
++	default:
++		BUG();
++	}
++	return 0;
++}
++
++/*
++ * The classical Unix view for directory is that it is a linear array of
++ * (name, inode number) entries. Linux/VFS assumes this model as well.
++ * Particularly, 'readdir()' call wants us to return a directory entry offset
++ * which later may be used to continue 'readdir()'ing the directory or to
++ * 'seek()' to that specific direntry. Obviously UBIFS does not really fit this
++ * model because directory entries are identified by keys, which may collide.
++ *
++ * UBIFS uses directory entry hash value for directory offsets, so
++ * 'seekdir()'/'telldir()' may not always work because of possible key
++ * collisions. But UBIFS guarantees that consecutive 'readdir()' calls work
++ * properly by means of saving full directory entry name in the private field
++ * of the file description object.
++ *
++ * This means that UBIFS cannot support NFS which requires full
++ * 'seekdir()'/'telldir()' support.
++ */
++static int ubifs_readdir(struct file *file, void *dirent, filldir_t filldir)
++{
++	int err, over = 0;
++	struct qstr nm;
++	union ubifs_key key;
++	struct ubifs_dent_node *dent;
++	struct inode *dir = file->f_path.dentry->d_inode;
++	struct ubifs_info *c = dir->i_sb->s_fs_info;
++
++	dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, file->f_pos);
++
++	if (file->f_pos > UBIFS_S_KEY_HASH_MASK || file->f_pos == 2)
++		/*
++		 * The directory was seek'ed to a senseless position or there
++		 * are no more entries.
++		 */
++		return 0;
++
++	/* File positions 0 and 1 correspond to "." and ".." */
++	if (file->f_pos == 0) {
++		ubifs_assert(!file->private_data);
++		over = filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR);
++		if (over)
++			return 0;
++		file->f_pos = 1;
++	}
++
++	if (file->f_pos == 1) {
++		ubifs_assert(!file->private_data);
++		over = filldir(dirent, "..", 2, 1,
++			       parent_ino(file->f_path.dentry), DT_DIR);
++		if (over)
++			return 0;
++
++		/* Find the first entry in TNC and save it */
++		lowest_dent_key(c, &key, dir->i_ino);
++		nm.name = NULL;
++		dent = ubifs_tnc_next_ent(c, &key, &nm);
++		if (IS_ERR(dent)) {
++			err = PTR_ERR(dent);
++			goto out;
++		}
++
++		file->f_pos = key_hash_flash(c, &dent->key);
++		file->private_data = dent;
++	}
++
++	dent = file->private_data;
++	if (!dent) {
++		/*
++		 * The directory was seek'ed to and is now readdir'ed.
++		 * Find the entry corresponding to @file->f_pos or the
++		 * closest one.
++		 */
++		dent_key_init_hash(c, &key, dir->i_ino, file->f_pos);
++		nm.name = NULL;
++		dent = ubifs_tnc_next_ent(c, &key, &nm);
++		if (IS_ERR(dent)) {
++			err = PTR_ERR(dent);
++			goto out;
++		}
++		file->f_pos = key_hash_flash(c, &dent->key);
++		file->private_data = dent;
++	}
++
++	while (1) {
++		dbg_gen("feed '%s', ino %llu, new f_pos %#x",
++			dent->name, (unsigned long long)le64_to_cpu(dent->inum),
++			key_hash_flash(c, &dent->key));
++		ubifs_assert(le64_to_cpu(dent->ch.sqnum) >
++			     ubifs_inode(dir)->creat_sqnum);
++
++		nm.len = le16_to_cpu(dent->nlen);
++		over = filldir(dirent, dent->name, nm.len, file->f_pos,
++			       le64_to_cpu(dent->inum),
++			       vfs_dent_type(dent->type));
++		if (over)
++			return 0;
++
++		/* Switch to the next entry */
++		key_read(c, &dent->key, &key);
++		nm.name = dent->name;
++		dent = ubifs_tnc_next_ent(c, &key, &nm);
++		if (IS_ERR(dent)) {
++			err = PTR_ERR(dent);
++			goto out;
++		}
++
++		kfree(file->private_data);
++		file->f_pos = key_hash_flash(c, &dent->key);
++		file->private_data = dent;
++		cond_resched();
++	}
++
++out:
++	if (err != -ENOENT) {
++		ubifs_err("cannot find next direntry, error %d", err);
++		return err;
++	}
++
++	kfree(file->private_data);
++	file->private_data = NULL;
++	file->f_pos = 2;
++	return 0;
++}
++
++/* If a directory is seeked, we have to free saved readdir() state */
++static loff_t ubifs_dir_llseek(struct file *file, loff_t offset, int origin)
++{
++	kfree(file->private_data);
++	file->private_data = NULL;
++	return generic_file_llseek(file, offset, origin);
++}
++
++/* Free saved readdir() state when the directory is closed */
++static int ubifs_dir_release(struct inode *dir, struct file *file)
++{
++	kfree(file->private_data);
++	file->private_data = NULL;
++	return 0;
++}
++
++/**
++ * lock_2_inodes - a wrapper for locking two UBIFS inodes.
++ * @inode1: first inode
++ * @inode2: second inode
++ *
++ * We do not implement any tricks to guarantee strict lock ordering, because
++ * VFS has already done it for us on the @i_mutex. So this is just a simple
++ * wrapper function.
++ */
++static void lock_2_inodes(struct inode *inode1, struct inode *inode2)
++{
++	mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
++	mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
++}
++
++/**
++ * unlock_2_inodes - a wrapper for unlocking two UBIFS inodes.
++ * @inode1: first inode
++ * @inode2: second inode
++ */
++static void unlock_2_inodes(struct inode *inode1, struct inode *inode2)
++{
++	mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
++	mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
++}
++
++static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
++		      struct dentry *dentry)
++{
++	struct ubifs_info *c = dir->i_sb->s_fs_info;
++	struct inode *inode = old_dentry->d_inode;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++	struct ubifs_inode *dir_ui = ubifs_inode(dir);
++	int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
++	struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 2,
++				.dirtied_ino_d = ALIGN(ui->data_len, 8) };
++
++	/*
++	 * Budget request settings: new direntry, changing the target inode,
++	 * changing the parent inode.
++	 */
++
++	dbg_gen("dent '%.*s' to ino %lu (nlink %d) in dir ino %lu",
++		dentry->d_name.len, dentry->d_name.name, inode->i_ino,
++		inode->i_nlink, dir->i_ino);
++	ubifs_assert(mutex_is_locked(&dir->i_mutex));
++	ubifs_assert(mutex_is_locked(&inode->i_mutex));
++	err = dbg_check_synced_i_size(inode);
++	if (err)
++		return err;
++
++	err = ubifs_budget_space(c, &req);
++	if (err)
++		return err;
++
++	lock_2_inodes(dir, inode);
++	inc_nlink(inode);
++	atomic_inc(&inode->i_count);
++	inode->i_ctime = ubifs_current_time(inode);
++	dir->i_size += sz_change;
++	dir_ui->ui_size = dir->i_size;
++	dir->i_mtime = dir->i_ctime = inode->i_ctime;
++	err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
++	if (err)
++		goto out_cancel;
++	unlock_2_inodes(dir, inode);
++
++	ubifs_release_budget(c, &req);
++	d_instantiate(dentry, inode);
++	return 0;
++
++out_cancel:
++	dir->i_size -= sz_change;
++	dir_ui->ui_size = dir->i_size;
++	drop_nlink(inode);
++	unlock_2_inodes(dir, inode);
++	ubifs_release_budget(c, &req);
++	iput(inode);
++	return err;
++}
++
++static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
++{
++	struct ubifs_info *c = dir->i_sb->s_fs_info;
++	struct inode *inode = dentry->d_inode;
++	struct ubifs_inode *dir_ui = ubifs_inode(dir);
++	int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
++	int err, budgeted = 1;
++	struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
++
++	/*
++	 * Budget request settings: deletion direntry, deletion inode (+1 for
++	 * @dirtied_ino), changing the parent directory inode. If budgeting
++	 * fails, go ahead anyway because we have extra space reserved for
++	 * deletions.
++	 */
++
++	dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu",
++		dentry->d_name.len, dentry->d_name.name, inode->i_ino,
++		inode->i_nlink, dir->i_ino);
++	ubifs_assert(mutex_is_locked(&dir->i_mutex));
++	ubifs_assert(mutex_is_locked(&inode->i_mutex));
++	err = dbg_check_synced_i_size(inode);
++	if (err)
++		return err;
++
++	err = ubifs_budget_space(c, &req);
++	if (err) {
++		if (err != -ENOSPC)
++			return err;
++		budgeted = 0;
++	}
++
++	lock_2_inodes(dir, inode);
++	inode->i_ctime = ubifs_current_time(dir);
++	drop_nlink(inode);
++	dir->i_size -= sz_change;
++	dir_ui->ui_size = dir->i_size;
++	dir->i_mtime = dir->i_ctime = inode->i_ctime;
++	err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
++	if (err)
++		goto out_cancel;
++	unlock_2_inodes(dir, inode);
++
++	if (budgeted)
++		ubifs_release_budget(c, &req);
++	else {
++		/* We've deleted something - clean the "no space" flags */
++		c->nospace = c->nospace_rp = 0;
++		smp_wmb();
++	}
++	return 0;
++
++out_cancel:
++	dir->i_size += sz_change;
++	dir_ui->ui_size = dir->i_size;
++	inc_nlink(inode);
++	unlock_2_inodes(dir, inode);
++	if (budgeted)
++		ubifs_release_budget(c, &req);
++	return err;
++}
++
++/**
++ * check_dir_empty - check if a directory is empty or not.
++ * @c: UBIFS file-system description object
++ * @dir: VFS inode object of the directory to check
++ *
++ * This function checks if directory @dir is empty. Returns zero if the
++ * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
++ * in case of of errors.
++ */
++static int check_dir_empty(struct ubifs_info *c, struct inode *dir)
++{
++	struct qstr nm = { .name = NULL };
++	struct ubifs_dent_node *dent;
++	union ubifs_key key;
++	int err;
++
++	lowest_dent_key(c, &key, dir->i_ino);
++	dent = ubifs_tnc_next_ent(c, &key, &nm);
++	if (IS_ERR(dent)) {
++		err = PTR_ERR(dent);
++		if (err == -ENOENT)
++			err = 0;
++	} else {
++		kfree(dent);
++		err = -ENOTEMPTY;
++	}
++	return err;
++}
++
++static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
++{
++	struct ubifs_info *c = dir->i_sb->s_fs_info;
++	struct inode *inode = dentry->d_inode;
++	int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
++	int err, budgeted = 1;
++	struct ubifs_inode *dir_ui = ubifs_inode(dir);
++	struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 2 };
++
++	/*
++	 * Budget request settings: deletion direntry, deletion inode and
++	 * changing the parent inode. If budgeting fails, go ahead anyway
++	 * because we have extra space reserved for deletions.
++	 */
++
++	dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len,
++		dentry->d_name.name, inode->i_ino, dir->i_ino);
++	ubifs_assert(mutex_is_locked(&dir->i_mutex));
++	ubifs_assert(mutex_is_locked(&inode->i_mutex));
++	err = check_dir_empty(c, dentry->d_inode);
++	if (err)
++		return err;
++
++	err = ubifs_budget_space(c, &req);
++	if (err) {
++		if (err != -ENOSPC)
++			return err;
++		budgeted = 0;
++	}
++
++	lock_2_inodes(dir, inode);
++	inode->i_ctime = ubifs_current_time(dir);
++	clear_nlink(inode);
++	drop_nlink(dir);
++	dir->i_size -= sz_change;
++	dir_ui->ui_size = dir->i_size;
++	dir->i_mtime = dir->i_ctime = inode->i_ctime;
++	err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 1, 0);
++	if (err)
++		goto out_cancel;
++	unlock_2_inodes(dir, inode);
++
++	if (budgeted)
++		ubifs_release_budget(c, &req);
++	else {
++		/* We've deleted something - clean the "no space" flags */
++		c->nospace = c->nospace_rp = 0;
++		smp_wmb();
++	}
++	return 0;
++
++out_cancel:
++	dir->i_size += sz_change;
++	dir_ui->ui_size = dir->i_size;
++	inc_nlink(dir);
++	inc_nlink(inode);
++	inc_nlink(inode);
++	unlock_2_inodes(dir, inode);
++	if (budgeted)
++		ubifs_release_budget(c, &req);
++	return err;
++}
++
++static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
++{
++	struct inode *inode;
++	struct ubifs_inode *dir_ui = ubifs_inode(dir);
++	struct ubifs_info *c = dir->i_sb->s_fs_info;
++	int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
++	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
++
++	/*
++	 * Budget request settings: new inode, new direntry and changing parent
++	 * directory inode.
++	 */
++
++	dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
++		dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
++
++	err = ubifs_budget_space(c, &req);
++	if (err)
++		return err;
++
++	inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
++	if (IS_ERR(inode)) {
++		err = PTR_ERR(inode);
++		goto out_budg;
++	}
++
++	mutex_lock(&dir_ui->ui_mutex);
++	insert_inode_hash(inode);
++	inc_nlink(inode);
++	inc_nlink(dir);
++	dir->i_size += sz_change;
++	dir_ui->ui_size = dir->i_size;
++	dir->i_mtime = dir->i_ctime = inode->i_ctime;
++	err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
++	if (err) {
++		ubifs_err("cannot create directory, error %d", err);
++		goto out_cancel;
++	}
++	mutex_unlock(&dir_ui->ui_mutex);
++
++	ubifs_release_budget(c, &req);
++	d_instantiate(dentry, inode);
++	return 0;
++
++out_cancel:
++	dir->i_size -= sz_change;
++	dir_ui->ui_size = dir->i_size;
++	drop_nlink(dir);
++	mutex_unlock(&dir_ui->ui_mutex);
++	make_bad_inode(inode);
++	iput(inode);
++out_budg:
++	ubifs_release_budget(c, &req);
++	return err;
++}
++
++static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
++		       int mode, dev_t rdev)
++{
++	struct inode *inode;
++	struct ubifs_inode *ui;
++	struct ubifs_inode *dir_ui = ubifs_inode(dir);
++	struct ubifs_info *c = dir->i_sb->s_fs_info;
++	union ubifs_dev_desc *dev = NULL;
++	int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
++	int err, devlen = 0;
++	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
++					.new_ino_d = ALIGN(devlen, 8),
++					.dirtied_ino = 1 };
++
++	/*
++	 * Budget request settings: new inode, new direntry and changing parent
++	 * directory inode.
++	 */
++
++	dbg_gen("dent '%.*s' in dir ino %lu",
++		dentry->d_name.len, dentry->d_name.name, dir->i_ino);
++
++	if (!new_valid_dev(rdev))
++		return -EINVAL;
++
++	if (S_ISBLK(mode) || S_ISCHR(mode)) {
++		dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
++		if (!dev)
++			return -ENOMEM;
++		devlen = ubifs_encode_dev(dev, rdev);
++	}
++
++	err = ubifs_budget_space(c, &req);
++	if (err) {
++		kfree(dev);
++		return err;
++	}
++
++	inode = ubifs_new_inode(c, dir, mode);
++	if (IS_ERR(inode)) {
++		kfree(dev);
++		err = PTR_ERR(inode);
++		goto out_budg;
++	}
++
++	init_special_inode(inode, inode->i_mode, rdev);
++	inode->i_size = ubifs_inode(inode)->ui_size = devlen;
++	ui = ubifs_inode(inode);
++	ui->data = dev;
++	ui->data_len = devlen;
++
++	mutex_lock(&dir_ui->ui_mutex);
++	dir->i_size += sz_change;
++	dir_ui->ui_size = dir->i_size;
++	dir->i_mtime = dir->i_ctime = inode->i_ctime;
++	err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
++	if (err)
++		goto out_cancel;
++	mutex_unlock(&dir_ui->ui_mutex);
++
++	ubifs_release_budget(c, &req);
++	insert_inode_hash(inode);
++	d_instantiate(dentry, inode);
++	return 0;
++
++out_cancel:
++	dir->i_size -= sz_change;
++	dir_ui->ui_size = dir->i_size;
++	mutex_unlock(&dir_ui->ui_mutex);
++	make_bad_inode(inode);
++	iput(inode);
++out_budg:
++	ubifs_release_budget(c, &req);
++	return err;
++}
++
++static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
++			 const char *symname)
++{
++	struct inode *inode;
++	struct ubifs_inode *ui;
++	struct ubifs_inode *dir_ui = ubifs_inode(dir);
++	struct ubifs_info *c = dir->i_sb->s_fs_info;
++	int err, len = strlen(symname);
++	int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
++	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
++					.new_ino_d = ALIGN(len, 8),
++					.dirtied_ino = 1 };
++
++	/*
++	 * Budget request settings: new inode, new direntry and changing parent
++	 * directory inode.
++	 */
++
++	dbg_gen("dent '%.*s', target '%s' in dir ino %lu", dentry->d_name.len,
++		dentry->d_name.name, symname, dir->i_ino);
++
++	if (len > UBIFS_MAX_INO_DATA)
++		return -ENAMETOOLONG;
++
++	err = ubifs_budget_space(c, &req);
++	if (err)
++		return err;
++
++	inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
++	if (IS_ERR(inode)) {
++		err = PTR_ERR(inode);
++		goto out_budg;
++	}
++
++	ui = ubifs_inode(inode);
++	ui->data = kmalloc(len + 1, GFP_NOFS);
++	if (!ui->data) {
++		err = -ENOMEM;
++		goto out_inode;
++	}
++
++	memcpy(ui->data, symname, len);
++	((char *)ui->data)[len] = '\0';
++	/*
++	 * The terminating zero byte is not written to the flash media and it
++	 * is put just to make later in-memory string processing simpler. Thus,
++	 * data length is @len, not @len + %1.
++	 */
++	ui->data_len = len;
++	inode->i_size = ubifs_inode(inode)->ui_size = len;
++
++	mutex_lock(&dir_ui->ui_mutex);
++	dir->i_size += sz_change;
++	dir_ui->ui_size = dir->i_size;
++	dir->i_mtime = dir->i_ctime = inode->i_ctime;
++	err = ubifs_jnl_update(c, dir, &dentry->d_name, inode, 0, 0);
++	if (err)
++		goto out_cancel;
++	mutex_unlock(&dir_ui->ui_mutex);
++
++	ubifs_release_budget(c, &req);
++	insert_inode_hash(inode);
++	d_instantiate(dentry, inode);
++	return 0;
++
++out_cancel:
++	dir->i_size -= sz_change;
++	dir_ui->ui_size = dir->i_size;
++	mutex_unlock(&dir_ui->ui_mutex);
++out_inode:
++	make_bad_inode(inode);
++	iput(inode);
++out_budg:
++	ubifs_release_budget(c, &req);
++	return err;
++}
++
++/**
++ * lock_3_inodes - a wrapper for locking three UBIFS inodes.
++ * @inode1: first inode
++ * @inode2: second inode
++ * @inode3: third inode
++ *
++ * This function is used for 'ubifs_rename()' and @inode1 may be the same as
++ * @inode2 whereas @inode3 may be %NULL.
++ *
++ * We do not implement any tricks to guarantee strict lock ordering, because
++ * VFS has already done it for us on the @i_mutex. So this is just a simple
++ * wrapper function.
++ */
++static void lock_3_inodes(struct inode *inode1, struct inode *inode2,
++			  struct inode *inode3)
++{
++	mutex_lock_nested(&ubifs_inode(inode1)->ui_mutex, WB_MUTEX_1);
++	if (inode2 != inode1)
++		mutex_lock_nested(&ubifs_inode(inode2)->ui_mutex, WB_MUTEX_2);
++	if (inode3)
++		mutex_lock_nested(&ubifs_inode(inode3)->ui_mutex, WB_MUTEX_3);
++}
++
++/**
++ * unlock_3_inodes - a wrapper for unlocking three UBIFS inodes for rename.
++ * @inode1: first inode
++ * @inode2: second inode
++ * @inode3: third inode
++ */
++static void unlock_3_inodes(struct inode *inode1, struct inode *inode2,
++			    struct inode *inode3)
++{
++	if (inode3)
++		mutex_unlock(&ubifs_inode(inode3)->ui_mutex);
++	if (inode1 != inode2)
++		mutex_unlock(&ubifs_inode(inode2)->ui_mutex);
++	mutex_unlock(&ubifs_inode(inode1)->ui_mutex);
++}
++
++static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
++			struct inode *new_dir, struct dentry *new_dentry)
++{
++	struct ubifs_info *c = old_dir->i_sb->s_fs_info;
++	struct inode *old_inode = old_dentry->d_inode;
++	struct inode *new_inode = new_dentry->d_inode;
++	struct ubifs_inode *old_inode_ui = ubifs_inode(old_inode);
++	int err, release, sync = 0, move = (new_dir != old_dir);
++	int is_dir = S_ISDIR(old_inode->i_mode);
++	int unlink = !!new_inode;
++	int new_sz = CALC_DENT_SIZE(new_dentry->d_name.len);
++	int old_sz = CALC_DENT_SIZE(old_dentry->d_name.len);
++	struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1,
++					.dirtied_ino = 3 };
++	struct ubifs_budget_req ino_req = { .dirtied_ino = 1,
++			.dirtied_ino_d = ALIGN(old_inode_ui->data_len, 8) };
++	struct timespec time;
++
++	/*
++	 * Budget request settings: deletion direntry, new direntry, removing
++	 * the old inode, and changing old and new parent directory inodes.
++	 *
++	 * However, this operation also marks the target inode as dirty and
++	 * does not write it, so we allocate budget for the target inode
++	 * separately.
++	 */
++
++	dbg_gen("dent '%.*s' ino %lu in dir ino %lu to dent '%.*s' in "
++		"dir ino %lu", old_dentry->d_name.len, old_dentry->d_name.name,
++		old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len,
++		new_dentry->d_name.name, new_dir->i_ino);
++	ubifs_assert(mutex_is_locked(&old_dir->i_mutex));
++	ubifs_assert(mutex_is_locked(&new_dir->i_mutex));
++	if (unlink)
++		ubifs_assert(mutex_is_locked(&new_inode->i_mutex));
++
++
++	if (unlink && is_dir) {
++		err = check_dir_empty(c, new_inode);
++		if (err)
++			return err;
++	}
++
++	err = ubifs_budget_space(c, &req);
++	if (err)
++		return err;
++	err = ubifs_budget_space(c, &ino_req);
++	if (err) {
++		ubifs_release_budget(c, &req);
++		return err;
++	}
++
++	lock_3_inodes(old_dir, new_dir, new_inode);
++
++	/*
++	 * Like most other Unix systems, set the @i_ctime for inodes on a
++	 * rename.
++	 */
++	time = ubifs_current_time(old_dir);
++	old_inode->i_ctime = time;
++
++	/* We must adjust parent link count when renaming directories */
++	if (is_dir) {
++		if (move) {
++			/*
++			 * @old_dir loses a link because we are moving
++			 * @old_inode to a different directory.
++			 */
++			drop_nlink(old_dir);
++			/*
++			 * @new_dir only gains a link if we are not also
++			 * overwriting an existing directory.
++			 */
++			if (!unlink)
++				inc_nlink(new_dir);
++		} else {
++			/*
++			 * @old_inode is not moving to a different directory,
++			 * but @old_dir still loses a link if we are
++			 * overwriting an existing directory.
++			 */
++			if (unlink)
++				drop_nlink(old_dir);
++		}
++	}
++
++	old_dir->i_size -= old_sz;
++	ubifs_inode(old_dir)->ui_size = old_dir->i_size;
++	old_dir->i_mtime = old_dir->i_ctime = time;
++	new_dir->i_mtime = new_dir->i_ctime = time;
++
++	/*
++	 * And finally, if we unlinked a direntry which happened to have the
++	 * same name as the moved direntry, we have to decrement @i_nlink of
++	 * the unlinked inode and change its ctime.
++	 */
++	if (unlink) {
++		/*
++		 * Directories cannot have hard-links, so if this is a
++		 * directory, decrement its @i_nlink twice because an empty
++		 * directory has @i_nlink 2.
++		 */
++		if (is_dir)
++			drop_nlink(new_inode);
++		new_inode->i_ctime = time;
++		drop_nlink(new_inode);
++	} else {
++		new_dir->i_size += new_sz;
++		ubifs_inode(new_dir)->ui_size = new_dir->i_size;
++	}
++
++	/*
++	 * Do not ask 'ubifs_jnl_rename()' to flush write-buffer if @old_inode
++	 * is dirty, because this will be done later on at the end of
++	 * 'ubifs_rename()'.
++	 */
++	if (IS_SYNC(old_inode)) {
++		sync = IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir);
++		if (unlink && IS_SYNC(new_inode))
++			sync = 1;
++	}
++	err = ubifs_jnl_rename(c, old_dir, old_dentry, new_dir, new_dentry,
++			       sync);
++	if (err)
++		goto out_cancel;
++
++	unlock_3_inodes(old_dir, new_dir, new_inode);
++	ubifs_release_budget(c, &req);
++
++	mutex_lock(&old_inode_ui->ui_mutex);
++	release = old_inode_ui->dirty;
++	mark_inode_dirty_sync(old_inode);
++	mutex_unlock(&old_inode_ui->ui_mutex);
++
++	if (release)
++		ubifs_release_budget(c, &ino_req);
++	if (IS_SYNC(old_inode))
++		err = old_inode->i_sb->s_op->write_inode(old_inode, 1);
++	return err;
++
++out_cancel:
++	if (unlink) {
++		if (is_dir)
++			inc_nlink(new_inode);
++		inc_nlink(new_inode);
++	} else {
++		new_dir->i_size -= new_sz;
++		ubifs_inode(new_dir)->ui_size = new_dir->i_size;
++	}
++	old_dir->i_size += old_sz;
++	ubifs_inode(old_dir)->ui_size = old_dir->i_size;
++	if (is_dir) {
++		if (move) {
++			inc_nlink(old_dir);
++			if (!unlink)
++				drop_nlink(new_dir);
++		} else {
++			if (unlink)
++				inc_nlink(old_dir);
++		}
++	}
++	unlock_3_inodes(old_dir, new_dir, new_inode);
++	ubifs_release_budget(c, &ino_req);
++	ubifs_release_budget(c, &req);
++	return err;
++}
++
++int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
++		  struct kstat *stat)
++{
++	loff_t size;
++	struct inode *inode = dentry->d_inode;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++
++	mutex_lock(&ui->ui_mutex);
++	stat->dev = inode->i_sb->s_dev;
++	stat->ino = inode->i_ino;
++	stat->mode = inode->i_mode;
++	stat->nlink = inode->i_nlink;
++	stat->uid = inode->i_uid;
++	stat->gid = inode->i_gid;
++	stat->rdev = inode->i_rdev;
++	stat->atime = inode->i_atime;
++	stat->mtime = inode->i_mtime;
++	stat->ctime = inode->i_ctime;
++	stat->blksize = UBIFS_BLOCK_SIZE;
++	stat->size = ui->ui_size;
++
++	/*
++	 * Unfortunately, the 'stat()' system call was designed for block
++	 * device based file systems, and it is not appropriate for UBIFS,
++	 * because UBIFS does not have notion of "block". For example, it is
++	 * difficult to tell how many block a directory takes - it actually
++	 * takes less than 300 bytes, but we have to round it to block size,
++	 * which introduces large mistake. This makes utilities like 'du' to
++	 * report completely senseless numbers. This is the reason why UBIFS
++	 * goes the same way as JFFS2 - it reports zero blocks for everything
++	 * but regular files, which makes more sense than reporting completely
++	 * wrong sizes.
++	 */
++	if (S_ISREG(inode->i_mode)) {
++		size = ui->xattr_size;
++		size += stat->size;
++		size = ALIGN(size, UBIFS_BLOCK_SIZE);
++		/*
++		 * Note, user-space expects 512-byte blocks count irrespectively
++		 * of what was reported in @stat->size.
++		 */
++		stat->blocks = size >> 9;
++	} else
++		stat->blocks = 0;
++	mutex_unlock(&ui->ui_mutex);
++	return 0;
++}
++
++const struct inode_operations ubifs_dir_inode_operations = {
++	.lookup      = ubifs_lookup,
++	.create      = ubifs_create,
++	.link        = ubifs_link,
++	.symlink     = ubifs_symlink,
++	.unlink      = ubifs_unlink,
++	.mkdir       = ubifs_mkdir,
++	.rmdir       = ubifs_rmdir,
++	.mknod       = ubifs_mknod,
++	.rename      = ubifs_rename,
++	.setattr     = ubifs_setattr,
++	.getattr     = ubifs_getattr,
++#ifdef CONFIG_UBIFS_FS_XATTR
++	.setxattr    = ubifs_setxattr,
++	.getxattr    = ubifs_getxattr,
++	.listxattr   = ubifs_listxattr,
++	.removexattr = ubifs_removexattr,
++#endif
++};
++
++const struct file_operations ubifs_dir_operations = {
++	.llseek         = ubifs_dir_llseek,
++	.release        = ubifs_dir_release,
++	.read           = generic_read_dir,
++	.readdir        = ubifs_readdir,
++	.fsync          = ubifs_fsync,
++	.unlocked_ioctl = ubifs_ioctl,
++#ifdef CONFIG_COMPAT
++	.compat_ioctl   = ubifs_compat_ioctl,
++#endif
++};
+diff -Nurd linux-2.6.24.orig/fs/ubifs/file.c linux-2.6.24/fs/ubifs/file.c
+--- linux-2.6.24.orig/fs/ubifs/file.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/file.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,1583 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++/*
++ * This file implements VFS file and inode operations of regular files, device
++ * nodes and symlinks as well as address space operations.
++ *
++ * UBIFS uses 2 page flags: PG_private and PG_checked. PG_private is set if the
++ * page is dirty and is used for budgeting purposes - dirty pages should not be
++ * budgeted. The PG_checked flag is set if full budgeting is required for the
++ * page e.g., when it corresponds to a file hole or it is just beyond the file
++ * size. The budgeting is done in 'ubifs_write_begin()', because it is OK to
++ * fail in this function, and the budget is released in 'ubifs_write_end()'. So
++ * the PG_private and PG_checked flags carry the information about how the page
++ * was budgeted, to make it possible to release the budget properly.
++ *
++ * A thing to keep in mind: inode's 'i_mutex' is locked in most VFS operations
++ * we implement. However, this is not true for '->writepage()', which might be
++ * called with 'i_mutex' unlocked. For example, when pdflush is performing
++ * write-back, it calls 'writepage()' with unlocked 'i_mutex', although the
++ * inode has 'I_LOCK' flag in this case. At "normal" work-paths 'i_mutex' is
++ * locked in '->writepage', e.g. in "sys_write -> alloc_pages -> direct reclaim
++ * path'. So, in '->writepage()' we are only guaranteed that the page is
++ * locked.
++ *
++ * Similarly, 'i_mutex' does not have to be locked in readpage(), e.g.,
++ * readahead path does not have it locked ("sys_read -> generic_file_aio_read
++ * -> ondemand_readahead -> readpage"). In case of readahead, 'I_LOCK' flag is
++ * not set as well. However, UBIFS disables readahead.
++ *
++ * This, for example means that there might be 2 concurrent '->writepage()'
++ * calls for the same inode, but different inode dirty pages.
++ */
++
++#include "ubifs.h"
++#include <linux/mount.h>
++
++static int read_block(struct inode *inode, void *addr, unsigned int block,
++		      struct ubifs_data_node *dn)
++{
++	struct ubifs_info *c = inode->i_sb->s_fs_info;
++	int err, len, out_len;
++	union ubifs_key key;
++	unsigned int dlen;
++
++	data_key_init(c, &key, inode->i_ino, block);
++	err = ubifs_tnc_lookup(c, &key, dn);
++	if (err) {
++		if (err == -ENOENT)
++			/* Not found, so it must be a hole */
++			memset(addr, 0, UBIFS_BLOCK_SIZE);
++		return err;
++	}
++
++	ubifs_assert(le64_to_cpu(dn->ch.sqnum) >
++		     ubifs_inode(inode)->creat_sqnum);
++	len = le32_to_cpu(dn->size);
++	if (len <= 0 || len > UBIFS_BLOCK_SIZE)
++		goto dump;
++
++	dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
++	out_len = UBIFS_BLOCK_SIZE;
++	err = ubifs_decompress(&dn->data, dlen, addr, &out_len,
++			       le16_to_cpu(dn->compr_type));
++	if (err || len != out_len)
++		goto dump;
++
++	/*
++	 * Data length can be less than a full block, even for blocks that are
++	 * not the last in the file (e.g., as a result of making a hole and
++	 * appending data). Ensure that the remainder is zeroed out.
++	 */
++	if (len < UBIFS_BLOCK_SIZE)
++		memset(addr + len, 0, UBIFS_BLOCK_SIZE - len);
++
++	return 0;
++
++dump:
++	ubifs_err("bad data node (block %u, inode %lu)",
++		  block, inode->i_ino);
++	dbg_dump_node(c, dn);
++	return -EINVAL;
++}
++
++static int do_readpage(struct page *page)
++{
++	void *addr;
++	int err = 0, i;
++	unsigned int block, beyond;
++	struct ubifs_data_node *dn;
++	struct inode *inode = page->mapping->host;
++	loff_t i_size =  i_size_read(inode);
++
++	dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx",
++		inode->i_ino, page->index, i_size, page->flags);
++	ubifs_assert(!PageChecked(page));
++	ubifs_assert(!PagePrivate(page));
++
++	addr = kmap(page);
++
++	block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
++	beyond = (i_size + UBIFS_BLOCK_SIZE - 1) >> UBIFS_BLOCK_SHIFT;
++	if (block >= beyond) {
++		/* Reading beyond inode */
++		SetPageChecked(page);
++		memset(addr, 0, PAGE_CACHE_SIZE);
++		goto out;
++	}
++
++	dn = kmalloc(UBIFS_MAX_DATA_NODE_SZ, GFP_NOFS);
++	if (!dn) {
++		err = -ENOMEM;
++		goto error;
++	}
++
++	i = 0;
++	while (1) {
++		int ret;
++
++		if (block >= beyond) {
++			/* Reading beyond inode */
++			err = -ENOENT;
++			memset(addr, 0, UBIFS_BLOCK_SIZE);
++		} else {
++			ret = read_block(inode, addr, block, dn);
++			if (ret) {
++				err = ret;
++				if (err != -ENOENT)
++					break;
++			} else if (block + 1 == beyond) {
++				int dlen = le32_to_cpu(dn->size);
++				int ilen = i_size & (UBIFS_BLOCK_SIZE - 1);
++
++				if (ilen && ilen < dlen)
++					memset(addr + ilen, 0, dlen - ilen);
++			}
++		}
++		if (++i >= UBIFS_BLOCKS_PER_PAGE)
++			break;
++		block += 1;
++		addr += UBIFS_BLOCK_SIZE;
++	}
++	if (err) {
++		if (err == -ENOENT) {
++			/* Not found, so it must be a hole */
++			SetPageChecked(page);
++			dbg_gen("hole");
++			goto out_free;
++		}
++		ubifs_err("cannot read page %lu of inode %lu, error %d",
++			  page->index, inode->i_ino, err);
++		goto error;
++	}
++
++out_free:
++	kfree(dn);
++out:
++	SetPageUptodate(page);
++	ClearPageError(page);
++	flush_dcache_page(page);
++	kunmap(page);
++	return 0;
++
++error:
++	kfree(dn);
++	ClearPageUptodate(page);
++	SetPageError(page);
++	flush_dcache_page(page);
++	kunmap(page);
++	return err;
++}
++
++/**
++ * release_new_page_budget - release budget of a new page.
++ * @c: UBIFS file-system description object
++ *
++ * This is a helper function which releases budget corresponding to the budget
++ * of one new page of data.
++ */
++static void release_new_page_budget(struct ubifs_info *c)
++{
++	struct ubifs_budget_req req = { .recalculate = 1, .new_page = 1 };
++
++	ubifs_release_budget(c, &req);
++}
++
++/**
++ * release_existing_page_budget - release budget of an existing page.
++ * @c: UBIFS file-system description object
++ *
++ * This is a helper function which releases budget corresponding to the budget
++ * of changing one one page of data which already exists on the flash media.
++ */
++static void release_existing_page_budget(struct ubifs_info *c)
++{
++	struct ubifs_budget_req req = { .dd_growth = c->page_budget};
++
++	ubifs_release_budget(c, &req);
++}
++
++static int write_begin_slow(struct address_space *mapping,
++			    loff_t pos, unsigned len, struct page **pagep)
++{
++	struct inode *inode = mapping->host;
++	struct ubifs_info *c = inode->i_sb->s_fs_info;
++	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
++	struct ubifs_budget_req req = { .new_page = 1 };
++	int uninitialized_var(err), appending = !!(pos + len > inode->i_size);
++	struct page *page;
++
++	dbg_gen("ino %lu, pos %llu, len %u, i_size %lld",
++		inode->i_ino, pos, len, inode->i_size);
++
++	/*
++	 * At the slow path we have to budget before locking the page, because
++	 * budgeting may force write-back, which would wait on locked pages and
++	 * deadlock if we had the page locked. At this point we do not know
++	 * anything about the page, so assume that this is a new page which is
++	 * written to a hole. This corresponds to largest budget. Later the
++	 * budget will be amended if this is not true.
++	 */
++	if (appending)
++		/* We are appending data, budget for inode change */
++		req.dirtied_ino = 1;
++
++	err = ubifs_budget_space(c, &req);
++	if (unlikely(err))
++		return err;
++
++	page = __grab_cache_page(mapping, index);
++	if (unlikely(!page)) {
++		ubifs_release_budget(c, &req);
++		return -ENOMEM;
++	}
++
++	if (!PageUptodate(page)) {
++		if (!(pos & ~PAGE_CACHE_MASK) && len == PAGE_CACHE_SIZE)
++			SetPageChecked(page);
++		else {
++			err = do_readpage(page);
++			if (err) {
++				unlock_page(page);
++				page_cache_release(page);
++				return err;
++			}
++		}
++
++		SetPageUptodate(page);
++		ClearPageError(page);
++	}
++
++	if (PagePrivate(page))
++		/*
++		 * The page is dirty, which means it was budgeted twice:
++		 *   o first time the budget was allocated by the task which
++		 *     made the page dirty and set the PG_private flag;
++		 *   o and then we budgeted for it for the second time at the
++		 *     very beginning of this function.
++		 *
++		 * So what we have to do is to release the page budget we
++		 * allocated.
++		 */
++		release_new_page_budget(c);
++	else if (!PageChecked(page))
++		/*
++		 * We are changing a page which already exists on the media.
++		 * This means that changing the page does not make the amount
++		 * of indexing information larger, and this part of the budget
++		 * which we have already acquired may be released.
++		 */
++		ubifs_convert_page_budget(c);
++
++	if (appending) {
++		struct ubifs_inode *ui = ubifs_inode(inode);
++
++		/*
++		 * 'ubifs_write_end()' is optimized from the fast-path part of
++		 * 'ubifs_write_begin()' and expects the @ui_mutex to be locked
++		 * if data is appended.
++		 */
++		mutex_lock(&ui->ui_mutex);
++		if (ui->dirty)
++			/*
++			 * The inode is dirty already, so we may free the
++			 * budget we allocated.
++			 */
++			ubifs_release_dirty_inode_budget(c, ui);
++	}
++
++	*pagep = page;
++	return 0;
++}
++
++/**
++ * allocate_budget - allocate budget for 'ubifs_write_begin()'.
++ * @c: UBIFS file-system description object
++ * @page: page to allocate budget for
++ * @ui: UBIFS inode object the page belongs to
++ * @appending: non-zero if the page is appended
++ *
++ * This is a helper function for 'ubifs_write_begin()' which allocates budget
++ * for the operation. The budget is allocated differently depending on whether
++ * this is appending, whether the page is dirty or not, and so on. This
++ * function leaves the @ui->ui_mutex locked in case of appending. Returns zero
++ * in case of success and %-ENOSPC in case of failure.
++ */
++static int allocate_budget(struct ubifs_info *c, struct page *page,
++			   struct ubifs_inode *ui, int appending)
++{
++	struct ubifs_budget_req req = { .fast = 1 };
++
++	if (PagePrivate(page)) {
++		if (!appending)
++			/*
++			 * The page is dirty and we are not appending, which
++			 * means no budget is needed at all.
++			 */
++			return 0;
++
++		mutex_lock(&ui->ui_mutex);
++		if (ui->dirty)
++			/*
++			 * The page is dirty and we are appending, so the inode
++			 * has to be marked as dirty. However, it is already
++			 * dirty, so we do not need any budget. We may return,
++			 * but @ui->ui_mutex hast to be left locked because we
++			 * should prevent write-back from flushing the inode
++			 * and freeing the budget. The lock will be released in
++			 * 'ubifs_write_end()'.
++			 */
++			return 0;
++
++		/*
++		 * The page is dirty, we are appending, the inode is clean, so
++		 * we need to budget the inode change.
++		 */
++		req.dirtied_ino = 1;
++	} else {
++		if (PageChecked(page))
++			/*
++			 * The page corresponds to a hole and does not
++			 * exist on the media. So changing it makes
++			 * make the amount of indexing information
++			 * larger, and we have to budget for a new
++			 * page.
++			 */
++			req.new_page = 1;
++		else
++			/*
++			 * Not a hole, the change will not add any new
++			 * indexing information, budget for page
++			 * change.
++			 */
++			req.dirtied_page = 1;
++
++		if (appending) {
++			mutex_lock(&ui->ui_mutex);
++			if (!ui->dirty)
++				/*
++				 * The inode is clean but we will have to mark
++				 * it as dirty because we are appending. This
++				 * needs a budget.
++				 */
++				req.dirtied_ino = 1;
++		}
++	}
++
++	return ubifs_budget_space(c, &req);
++}
++
++/*
++ * This function is called when a page of data is going to be written. Since
++ * the page of data will not necessarily go to the flash straight away, UBIFS
++ * has to reserve space on the media for it, which is done by means of
++ * budgeting.
++ *
++ * This is the hot-path of the file-system and we are trying to optimize it as
++ * much as possible. For this reasons it is split on 2 parts - slow and fast.
++ *
++ * There many budgeting cases:
++ *     o a new page is appended - we have to budget for a new page and for
++ *       changing the inode; however, if the inode is already dirty, there is
++ *       no need to budget for it;
++ *     o an existing clean page is changed - we have budget for it; if the page
++ *       does not exist on the media (a hole), we have to budget for a new
++ *       page; otherwise, we may budget for changing an existing page; the
++ *       difference between these cases is that changing an existing page does
++ *       not introduce anything new to the FS indexing information, so it does
++ *       not grow, and smaller budget is acquired in this case;
++ *     o an existing dirty page is changed - no need to budget at all, because
++ *       the page budget has been acquired by earlier, when the page has been
++ *       marked dirty.
++ *
++ * UBIFS budgeting sub-system may force write-back if it thinks there is no
++ * space to reserve. This imposes some locking restrictions and makes it
++ * impossible to take into account the above cases, and makes it impossible to
++ * optimize budgeting.
++ *
++ * The solution for this is that the fast path of 'ubifs_write_begin()' assumes
++ * there is a plenty of flash space and the budget will be acquired quickly,
++ * without forcing write-back. The slow path does not make this assumption.
++ */
++static int ubifs_write_begin(struct file *file, struct address_space *mapping,
++			     loff_t pos, unsigned len, unsigned flags,
++			     struct page **pagep, void **fsdata)
++{
++	struct inode *inode = mapping->host;
++	struct ubifs_info *c = inode->i_sb->s_fs_info;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++	pgoff_t index = pos >> PAGE_CACHE_SHIFT;
++	int uninitialized_var(err), appending = !!(pos + len > inode->i_size);
++	struct page *page;
++
++	ubifs_assert(ubifs_inode(inode)->ui_size == inode->i_size);
++
++	if (unlikely(c->ro_media))
++		return -EROFS;
++
++	/* Try out the fast-path part first */
++	page = __grab_cache_page(mapping, index);
++	if (unlikely(!page))
++		return -ENOMEM;
++
++	if (!PageUptodate(page)) {
++		/* The page is not loaded from the flash */
++		if (!(pos & ~PAGE_CACHE_MASK) && len == PAGE_CACHE_SIZE)
++			/*
++			 * We change whole page so no need to load it. But we
++			 * have to set the @PG_checked flag to make the further
++			 * code the page is new. This might be not true, but it
++			 * is better to budget more that to read the page from
++			 * the media.
++			 */
++			SetPageChecked(page);
++		else {
++			err = do_readpage(page);
++			if (err) {
++				unlock_page(page);
++				page_cache_release(page);
++				return err;
++			}
++		}
++
++		SetPageUptodate(page);
++		ClearPageError(page);
++	}
++
++	err = allocate_budget(c, page, ui, appending);
++	if (unlikely(err)) {
++		ubifs_assert(err == -ENOSPC);
++		/*
++		 * Budgeting failed which means it would have to force
++		 * write-back but didn't, because we set the @fast flag in the
++		 * request. Write-back cannot be done now, while we have the
++		 * page locked, because it would deadlock. Unlock and free
++		 * everything and fall-back to slow-path.
++		 */
++		if (appending) {
++			ubifs_assert(mutex_is_locked(&ui->ui_mutex));
++			mutex_unlock(&ui->ui_mutex);
++		}
++		unlock_page(page);
++		page_cache_release(page);
++
++		return write_begin_slow(mapping, pos, len, pagep);
++	}
++
++	/*
++	 * Whee, we aquired budgeting quickly - without involving
++	 * garbage-collection, committing or forceing write-back. We return
++	 * with @ui->ui_mutex locked if we are appending pages, and unlocked
++	 * otherwise. This is an optimization (slightly hacky though).
++	 */
++	*pagep = page;
++	return 0;
++
++}
++
++/**
++ * cancel_budget - cancel budget.
++ * @c: UBIFS file-system description object
++ * @page: page to cancel budget for
++ * @ui: UBIFS inode object the page belongs to
++ * @appending: non-zero if the page is appended
++ *
++ * This is a helper function for a page write operation. It unlocks the
++ * @ui->ui_mutex in case of appending.
++ */
++static void cancel_budget(struct ubifs_info *c, struct page *page,
++			  struct ubifs_inode *ui, int appending)
++{
++	if (appending) {
++		if (!ui->dirty)
++			ubifs_release_dirty_inode_budget(c, ui);
++		mutex_unlock(&ui->ui_mutex);
++	}
++	if (!PagePrivate(page)) {
++		if (PageChecked(page))
++			release_new_page_budget(c);
++		else
++			release_existing_page_budget(c);
++	}
++}
++
++static int ubifs_write_end(struct file *file, struct address_space *mapping,
++			   loff_t pos, unsigned len, unsigned copied,
++			   struct page *page, void *fsdata)
++{
++	struct inode *inode = mapping->host;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++	struct ubifs_info *c = inode->i_sb->s_fs_info;
++	loff_t end_pos = pos + len;
++	int appending = !!(end_pos > inode->i_size);
++
++	dbg_gen("ino %lu, pos %llu, pg %lu, len %u, copied %d, i_size %lld",
++		inode->i_ino, pos, page->index, len, copied, inode->i_size);
++
++	if (unlikely(copied < len && len == PAGE_CACHE_SIZE)) {
++		/*
++		 * VFS copied less data to the page that it intended and
++		 * declared in its '->write_begin()' call via the @len
++		 * argument. If the page was not up-to-date, and @len was
++		 * @PAGE_CACHE_SIZE, the 'ubifs_write_begin()' function did
++		 * not load it from the media (for optimization reasons). This
++		 * means that part of the page contains garbage. So read the
++		 * page now.
++		 */
++		dbg_gen("copied %d instead of %d, read page and repeat",
++			copied, len);
++		cancel_budget(c, page, ui, appending);
++
++		/*
++		 * Return 0 to force VFS to repeat the whole operation, or the
++		 * error code if 'do_readpage()' failes.
++		 */
++		copied = do_readpage(page);
++		goto out;
++	}
++
++	if (!PagePrivate(page)) {
++		SetPagePrivate(page);
++		atomic_long_inc(&c->dirty_pg_cnt);
++		__set_page_dirty_nobuffers(page);
++	}
++
++	if (appending) {
++		i_size_write(inode, end_pos);
++		ui->ui_size = end_pos;
++		/*
++		 * Note, we do not set @I_DIRTY_PAGES (which means that the
++		 * inode has dirty pages), this has been done in
++		 * '__set_page_dirty_nobuffers()'.
++		 */
++		__mark_inode_dirty(inode, I_DIRTY_DATASYNC);
++		ubifs_assert(mutex_is_locked(&ui->ui_mutex));
++		mutex_unlock(&ui->ui_mutex);
++	}
++
++out:
++	unlock_page(page);
++	page_cache_release(page);
++	return copied;
++}
++
++/**
++ * populate_page - copy data nodes into a page for bulk-read.
++ * @c: UBIFS file-system description object
++ * @page: page
++ * @bu: bulk-read information
++ * @n: next zbranch slot
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int populate_page(struct ubifs_info *c, struct page *page,
++			 struct bu_info *bu, int *n)
++{
++	int i = 0, nn = *n, offs = bu->zbranch[0].offs, hole = 0, read = 0;
++	struct inode *inode = page->mapping->host;
++	loff_t i_size = i_size_read(inode);
++	unsigned int page_block;
++	void *addr, *zaddr;
++	pgoff_t end_index;
++
++	dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx",
++		inode->i_ino, page->index, i_size, page->flags);
++
++	addr = zaddr = kmap(page);
++
++	end_index = (i_size - 1) >> PAGE_CACHE_SHIFT;
++	if (!i_size || page->index > end_index) {
++		hole = 1;
++		memset(addr, 0, PAGE_CACHE_SIZE);
++		goto out_hole;
++	}
++
++	page_block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
++	while (1) {
++		int err, len, out_len, dlen;
++
++		if (nn >= bu->cnt) {
++			hole = 1;
++			memset(addr, 0, UBIFS_BLOCK_SIZE);
++		} else if (key_block(c, &bu->zbranch[nn].key) == page_block) {
++			struct ubifs_data_node *dn;
++
++			dn = bu->buf + (bu->zbranch[nn].offs - offs);
++
++			ubifs_assert(le64_to_cpu(dn->ch.sqnum) >
++				     ubifs_inode(inode)->creat_sqnum);
++
++			len = le32_to_cpu(dn->size);
++			if (len <= 0 || len > UBIFS_BLOCK_SIZE)
++				goto out_err;
++
++			dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
++			out_len = UBIFS_BLOCK_SIZE;
++			err = ubifs_decompress(&dn->data, dlen, addr, &out_len,
++					       le16_to_cpu(dn->compr_type));
++			if (err || len != out_len)
++				goto out_err;
++
++			if (len < UBIFS_BLOCK_SIZE)
++				memset(addr + len, 0, UBIFS_BLOCK_SIZE - len);
++
++			nn += 1;
++			read = (i << UBIFS_BLOCK_SHIFT) + len;
++		} else if (key_block(c, &bu->zbranch[nn].key) < page_block) {
++			nn += 1;
++			continue;
++		} else {
++			hole = 1;
++			memset(addr, 0, UBIFS_BLOCK_SIZE);
++		}
++		if (++i >= UBIFS_BLOCKS_PER_PAGE)
++			break;
++		addr += UBIFS_BLOCK_SIZE;
++		page_block += 1;
++	}
++
++	if (end_index == page->index) {
++		int len = i_size & (PAGE_CACHE_SIZE - 1);
++
++		if (len && len < read)
++			memset(zaddr + len, 0, read - len);
++	}
++
++out_hole:
++	if (hole) {
++		SetPageChecked(page);
++		dbg_gen("hole");
++	}
++
++	SetPageUptodate(page);
++	ClearPageError(page);
++	flush_dcache_page(page);
++	kunmap(page);
++	*n = nn;
++	return 0;
++
++out_err:
++	ClearPageUptodate(page);
++	SetPageError(page);
++	flush_dcache_page(page);
++	kunmap(page);
++	ubifs_err("bad data node (block %u, inode %lu)",
++		  page_block, inode->i_ino);
++	return -EINVAL;
++}
++
++/**
++ * ubifs_do_bulk_read - do bulk-read.
++ * @c: UBIFS file-system description object
++ * @bu: bulk-read information
++ * @page1: first page to read
++ *
++ * This function returns %1 if the bulk-read is done, otherwise %0 is returned.
++ */
++static int ubifs_do_bulk_read(struct ubifs_info *c, struct bu_info *bu,
++			      struct page *page1)
++{
++	pgoff_t offset = page1->index, end_index;
++	struct address_space *mapping = page1->mapping;
++	struct inode *inode = mapping->host;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++	int err, page_idx, page_cnt, ret = 0, n = 0;
++	int allocate = bu->buf ? 0 : 1;
++	loff_t isize;
++
++	err = ubifs_tnc_get_bu_keys(c, bu);
++	if (err)
++		goto out_warn;
++
++	if (bu->eof) {
++		/* Turn off bulk-read at the end of the file */
++		ui->read_in_a_row = 1;
++		ui->bulk_read = 0;
++	}
++
++	page_cnt = bu->blk_cnt >> UBIFS_BLOCKS_PER_PAGE_SHIFT;
++	if (!page_cnt) {
++		/*
++		 * This happens when there are multiple blocks per page and the
++		 * blocks for the first page we are looking for, are not
++		 * together. If all the pages were like this, bulk-read would
++		 * reduce performance, so we turn it off for a while.
++		 */
++		goto out_bu_off;
++	}
++
++	if (bu->cnt) {
++		if (allocate) {
++			/*
++			 * Allocate bulk-read buffer depending on how many data
++			 * nodes we are going to read.
++			 */
++			bu->buf_len = bu->zbranch[bu->cnt - 1].offs +
++				      bu->zbranch[bu->cnt - 1].len -
++				      bu->zbranch[0].offs;
++			ubifs_assert(bu->buf_len > 0);
++			ubifs_assert(bu->buf_len <= c->leb_size);
++			bu->buf = kmalloc(bu->buf_len, GFP_NOFS | __GFP_NOWARN);
++			if (!bu->buf)
++				goto out_bu_off;
++		}
++
++		err = ubifs_tnc_bulk_read(c, bu);
++		if (err)
++			goto out_warn;
++	}
++
++	err = populate_page(c, page1, bu, &n);
++	if (err)
++		goto out_warn;
++
++	unlock_page(page1);
++	ret = 1;
++
++	isize = i_size_read(inode);
++	if (isize == 0)
++		goto out_free;
++	end_index = ((isize - 1) >> PAGE_CACHE_SHIFT);
++
++	for (page_idx = 1; page_idx < page_cnt; page_idx++) {
++		pgoff_t page_offset = offset + page_idx;
++		struct page *page;
++
++		if (page_offset > end_index)
++			break;
++		page = find_or_create_page(mapping, page_offset,
++					   GFP_NOFS | __GFP_COLD);
++		if (!page)
++			break;
++		if (!PageUptodate(page))
++			err = populate_page(c, page, bu, &n);
++		unlock_page(page);
++		page_cache_release(page);
++		if (err)
++			break;
++	}
++
++	ui->last_page_read = offset + page_idx - 1;
++
++out_free:
++	if (allocate)
++		kfree(bu->buf);
++	return ret;
++
++out_warn:
++	ubifs_warn("ignoring error %d and skipping bulk-read", err);
++	goto out_free;
++
++out_bu_off:
++	ui->read_in_a_row = ui->bulk_read = 0;
++	goto out_free;
++}
++
++/**
++ * ubifs_bulk_read - determine whether to bulk-read and, if so, do it.
++ * @page: page from which to start bulk-read.
++ *
++ * Some flash media are capable of reading sequentially at faster rates. UBIFS
++ * bulk-read facility is designed to take advantage of that, by reading in one
++ * go consecutive data nodes that are also located consecutively in the same
++ * LEB. This function returns %1 if a bulk-read is done and %0 otherwise.
++ */
++static int ubifs_bulk_read(struct page *page)
++{
++	struct inode *inode = page->mapping->host;
++	struct ubifs_info *c = inode->i_sb->s_fs_info;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++	pgoff_t index = page->index, last_page_read = ui->last_page_read;
++	struct bu_info *bu;
++	int err = 0, allocated = 0;
++
++	ui->last_page_read = index;
++	if (!c->bulk_read)
++		return 0;
++
++	/*
++	 * Bulk-read is protected by @ui->ui_mutex, but it is an optimization,
++	 * so don't bother if we cannot lock the mutex.
++	 */
++	if (!mutex_trylock(&ui->ui_mutex))
++		return 0;
++
++	if (index != last_page_read + 1) {
++		/* Turn off bulk-read if we stop reading sequentially */
++		ui->read_in_a_row = 1;
++		if (ui->bulk_read)
++			ui->bulk_read = 0;
++		goto out_unlock;
++	}
++
++	if (!ui->bulk_read) {
++		ui->read_in_a_row += 1;
++		if (ui->read_in_a_row < 3)
++			goto out_unlock;
++		/* Three reads in a row, so switch on bulk-read */
++		ui->bulk_read = 1;
++	}
++
++	/*
++	 * If possible, try to use pre-allocated bulk-read information, which
++	 * is protected by @c->bu_mutex.
++	 */
++	if (mutex_trylock(&c->bu_mutex))
++		bu = &c->bu;
++	else {
++		bu = kmalloc(sizeof(struct bu_info), GFP_NOFS | __GFP_NOWARN);
++		if (!bu)
++			goto out_unlock;
++
++		bu->buf = NULL;
++		allocated = 1;
++	}
++
++	bu->buf_len = c->max_bu_buf_len;
++	data_key_init(c, &bu->key, inode->i_ino,
++		      page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT);
++	err = ubifs_do_bulk_read(c, bu, page);
++
++	if (!allocated)
++		mutex_unlock(&c->bu_mutex);
++	else
++		kfree(bu);
++
++out_unlock:
++	mutex_unlock(&ui->ui_mutex);
++	return err;
++}
++
++static int ubifs_readpage(struct file *file, struct page *page)
++{
++	if (ubifs_bulk_read(page))
++		return 0;
++	do_readpage(page);
++	unlock_page(page);
++	return 0;
++}
++
++static int do_writepage(struct page *page, int len)
++{
++	int err = 0, i, blen;
++	unsigned int block;
++	void *addr;
++	union ubifs_key key;
++	struct inode *inode = page->mapping->host;
++	struct ubifs_info *c = inode->i_sb->s_fs_info;
++
++#ifdef UBIFS_DEBUG
++	spin_lock(&ui->ui_lock);
++	ubifs_assert(page->index <= ui->synced_i_size << PAGE_CACHE_SIZE);
++	spin_unlock(&ui->ui_lock);
++#endif
++
++	/* Update radix tree tags */
++	set_page_writeback(page);
++
++	addr = kmap(page);
++	block = page->index << UBIFS_BLOCKS_PER_PAGE_SHIFT;
++	i = 0;
++	while (len) {
++		blen = min_t(int, len, UBIFS_BLOCK_SIZE);
++		data_key_init(c, &key, inode->i_ino, block);
++		err = ubifs_jnl_write_data(c, inode, &key, addr, blen);
++		if (err)
++			break;
++		if (++i >= UBIFS_BLOCKS_PER_PAGE)
++			break;
++		block += 1;
++		addr += blen;
++		len -= blen;
++	}
++	if (err) {
++		SetPageError(page);
++		ubifs_err("cannot write page %lu of inode %lu, error %d",
++			  page->index, inode->i_ino, err);
++		ubifs_ro_mode(c, err);
++	}
++
++	ubifs_assert(PagePrivate(page));
++	if (PageChecked(page))
++		release_new_page_budget(c);
++	else
++		release_existing_page_budget(c);
++
++	atomic_long_dec(&c->dirty_pg_cnt);
++	ClearPagePrivate(page);
++	ClearPageChecked(page);
++
++	kunmap(page);
++	unlock_page(page);
++	end_page_writeback(page);
++	return err;
++}
++
++/*
++ * When writing-back dirty inodes, VFS first writes-back pages belonging to the
++ * inode, then the inode itself. For UBIFS this may cause a problem. Consider a
++ * situation when a we have an inode with size 0, then a megabyte of data is
++ * appended to the inode, then write-back starts and flushes some amount of the
++ * dirty pages, the journal becomes full, commit happens and finishes, and then
++ * an unclean reboot happens. When the file system is mounted next time, the
++ * inode size would still be 0, but there would be many pages which are beyond
++ * the inode size, they would be indexed and consume flash space. Because the
++ * journal has been committed, the replay would not be able to detect this
++ * situation and correct the inode size. This means UBIFS would have to scan
++ * whole index and correct all inode sizes, which is long an unacceptable.
++ *
++ * To prevent situations like this, UBIFS writes pages back only if they are
++ * within last synchronized inode size, i.e. the the size which has been
++ * written to the flash media last time. Otherwise, UBIFS forces inode
++ * write-back, thus making sure the on-flash inode contains current inode size,
++ * and then keeps writing pages back.
++ *
++ * Some locking issues explanation. 'ubifs_writepage()' first is called with
++ * the page locked, and it locks @ui_mutex. However, write-back does take inode
++ * @i_mutex, which means other VFS operations may be run on this inode at the
++ * same time. And the problematic one is truncation to smaller size, from where
++ * we have to call 'vmtruncate()', which first changes @inode->i_size, then
++ * drops the truncated pages. And while dropping the pages, it takes the page
++ * lock. This means that 'do_truncation()' cannot call 'vmtruncate()' with
++ * @ui_mutex locked, because it would deadlock with 'ubifs_writepage()'. This
++ * means that @inode->i_size is changed while @ui_mutex is unlocked.
++ *
++ * But in 'ubifs_writepage()' we have to guarantee that we do not write beyond
++ * inode size. How do we do this if @inode->i_size may became smaller while we
++ * are in the middle of 'ubifs_writepage()'? The UBIFS solution is the
++ * @ui->ui_isize "shadow" field which UBIFS uses instead of @inode->i_size
++ * internally and updates it under @ui_mutex.
++ *
++ * Q: why we do not worry that if we race with truncation, we may end up with a
++ * situation when the inode is truncated while we are in the middle of
++ * 'do_writepage()', so we do write beyond inode size?
++ * A: If we are in the middle of 'do_writepage()', truncation would be locked
++ * on the page lock and it would not write the truncated inode node to the
++ * journal before we have finished.
++ */
++static int ubifs_writepage(struct page *page, struct writeback_control *wbc)
++{
++	struct inode *inode = page->mapping->host;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++	loff_t i_size =  i_size_read(inode), synced_i_size;
++	pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
++	int err, len = i_size & (PAGE_CACHE_SIZE - 1);
++	void *kaddr;
++
++	dbg_gen("ino %lu, pg %lu, pg flags %#lx",
++		inode->i_ino, page->index, page->flags);
++	ubifs_assert(PagePrivate(page));
++
++	/* Is the page fully outside @i_size? (truncate in progress) */
++	if (page->index > end_index || (page->index == end_index && !len)) {
++		err = 0;
++		goto out_unlock;
++	}
++
++	spin_lock(&ui->ui_lock);
++	synced_i_size = ui->synced_i_size;
++	spin_unlock(&ui->ui_lock);
++
++	/* Is the page fully inside @i_size? */
++	if (page->index < end_index) {
++		if (page->index >= synced_i_size >> PAGE_CACHE_SHIFT) {
++			err = inode->i_sb->s_op->write_inode(inode, 1);
++			if (err)
++				goto out_unlock;
++			/*
++			 * The inode has been written, but the write-buffer has
++			 * not been synchronized, so in case of an unclean
++			 * reboot we may end up with some pages beyond inode
++			 * size, but they would be in the journal (because
++			 * commit flushes write buffers) and recovery would deal
++			 * with this.
++			 */
++		}
++		return do_writepage(page, PAGE_CACHE_SIZE);
++	}
++
++	/*
++	 * The page straddles @i_size. It must be zeroed out on each and every
++	 * writepage invocation because it may be mmapped. "A file is mapped
++	 * in multiples of the page size. For a file that is not a multiple of
++	 * the page size, the remaining memory is zeroed when mapped, and
++	 * writes to that region are not written out to the file."
++	 */
++	kaddr = kmap_atomic(page, KM_USER0);
++	memset(kaddr + len, 0, PAGE_CACHE_SIZE - len);
++	flush_dcache_page(page);
++	kunmap_atomic(kaddr, KM_USER0);
++
++	if (i_size > synced_i_size) {
++		err = inode->i_sb->s_op->write_inode(inode, 1);
++		if (err)
++			goto out_unlock;
++	}
++
++	return do_writepage(page, len);
++
++out_unlock:
++	unlock_page(page);
++	return err;
++}
++
++/**
++ * do_attr_changes - change inode attributes.
++ * @inode: inode to change attributes for
++ * @attr: describes attributes to change
++ */
++static void do_attr_changes(struct inode *inode, const struct iattr *attr)
++{
++	if (attr->ia_valid & ATTR_UID)
++		inode->i_uid = attr->ia_uid;
++	if (attr->ia_valid & ATTR_GID)
++		inode->i_gid = attr->ia_gid;
++	if (attr->ia_valid & ATTR_ATIME)
++		inode->i_atime = timespec_trunc(attr->ia_atime,
++						inode->i_sb->s_time_gran);
++	if (attr->ia_valid & ATTR_MTIME)
++		inode->i_mtime = timespec_trunc(attr->ia_mtime,
++						inode->i_sb->s_time_gran);
++	if (attr->ia_valid & ATTR_CTIME)
++		inode->i_ctime = timespec_trunc(attr->ia_ctime,
++						inode->i_sb->s_time_gran);
++	if (attr->ia_valid & ATTR_MODE) {
++		umode_t mode = attr->ia_mode;
++
++		if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
++			mode &= ~S_ISGID;
++		inode->i_mode = mode;
++	}
++}
++
++/**
++ * do_truncation - truncate an inode.
++ * @c: UBIFS file-system description object
++ * @inode: inode to truncate
++ * @attr: inode attribute changes description
++ *
++ * This function implements VFS '->setattr()' call when the inode is truncated
++ * to a smaller size. Returns zero in case of success and a negative error code
++ * in case of failure.
++ */
++static int do_truncation(struct ubifs_info *c, struct inode *inode,
++			 const struct iattr *attr)
++{
++	int err;
++	struct ubifs_budget_req req;
++	loff_t old_size = inode->i_size, new_size = attr->ia_size;
++	int offset = new_size & (UBIFS_BLOCK_SIZE - 1), budgeted = 1;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++
++	dbg_gen("ino %lu, size %lld -> %lld", inode->i_ino, old_size, new_size);
++	memset(&req, 0, sizeof(struct ubifs_budget_req));
++
++	/*
++	 * If this is truncation to a smaller size, and we do not truncate on a
++	 * block boundary, budget for changing one data block, because the last
++	 * block will be re-written.
++	 */
++	if (new_size & (UBIFS_BLOCK_SIZE - 1))
++		req.dirtied_page = 1;
++
++	req.dirtied_ino = 1;
++	/* A funny way to budget for truncation node */
++	req.dirtied_ino_d = UBIFS_TRUN_NODE_SZ;
++	err = ubifs_budget_space(c, &req);
++	if (err) {
++		/*
++		 * Treat truncations to zero as deletion and always allow them,
++		 * just like we do for '->unlink()'.
++		 */
++		if (new_size || err != -ENOSPC)
++			return err;
++		budgeted = 0;
++	}
++
++	err = vmtruncate(inode, new_size);
++	if (err)
++		goto out_budg;
++
++	if (offset) {
++		pgoff_t index = new_size >> PAGE_CACHE_SHIFT;
++		struct page *page;
++
++		page = find_lock_page(inode->i_mapping, index);
++		if (page) {
++			if (PageDirty(page)) {
++				/*
++				 * 'ubifs_jnl_truncate()' will try to truncate
++				 * the last data node, but it contains
++				 * out-of-date data because the page is dirty.
++				 * Write the page now, so that
++				 * 'ubifs_jnl_truncate()' will see an already
++				 * truncated (and up to date) data node.
++				 */
++				ubifs_assert(PagePrivate(page));
++
++				clear_page_dirty_for_io(page);
++				if (UBIFS_BLOCKS_PER_PAGE_SHIFT)
++					offset = new_size &
++						 (PAGE_CACHE_SIZE - 1);
++				err = do_writepage(page, offset);
++				page_cache_release(page);
++				if (err)
++					goto out_budg;
++				/*
++				 * We could now tell 'ubifs_jnl_truncate()' not
++				 * to read the last block.
++				 */
++			} else {
++				/*
++				 * We could 'kmap()' the page and pass the data
++				 * to 'ubifs_jnl_truncate()' to save it from
++				 * having to read it.
++				 */
++				unlock_page(page);
++				page_cache_release(page);
++			}
++		}
++	}
++
++	mutex_lock(&ui->ui_mutex);
++	ui->ui_size = inode->i_size;
++	/* Truncation changes inode [mc]time */
++	inode->i_mtime = inode->i_ctime = ubifs_current_time(inode);
++	/* The other attributes may be changed at the same time as well */
++	do_attr_changes(inode, attr);
++
++	err = ubifs_jnl_truncate(c, inode, old_size, new_size);
++	mutex_unlock(&ui->ui_mutex);
++out_budg:
++	if (budgeted)
++		ubifs_release_budget(c, &req);
++	else {
++		c->nospace = c->nospace_rp = 0;
++		smp_wmb();
++	}
++	return err;
++}
++
++/**
++ * do_setattr - change inode attributes.
++ * @c: UBIFS file-system description object
++ * @inode: inode to change attributes for
++ * @attr: inode attribute changes description
++ *
++ * This function implements VFS '->setattr()' call for all cases except
++ * truncations to smaller size. Returns zero in case of success and a negative
++ * error code in case of failure.
++ */
++static int do_setattr(struct ubifs_info *c, struct inode *inode,
++		      const struct iattr *attr)
++{
++	int err, release;
++	loff_t new_size = attr->ia_size;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++	struct ubifs_budget_req req = { .dirtied_ino = 1,
++				.dirtied_ino_d = ALIGN(ui->data_len, 8) };
++
++	err = ubifs_budget_space(c, &req);
++	if (err)
++		return err;
++
++	if (attr->ia_valid & ATTR_SIZE) {
++		dbg_gen("size %lld -> %lld", inode->i_size, new_size);
++		err = vmtruncate(inode, new_size);
++		if (err)
++			goto out;
++	}
++
++	mutex_lock(&ui->ui_mutex);
++	if (attr->ia_valid & ATTR_SIZE) {
++		/* Truncation changes inode [mc]time */
++		inode->i_mtime = inode->i_ctime = ubifs_current_time(inode);
++		/* 'vmtruncate()' changed @i_size, update @ui_size */
++		ui->ui_size = inode->i_size;
++	}
++
++	do_attr_changes(inode, attr);
++
++	release = ui->dirty;
++	if (attr->ia_valid & ATTR_SIZE)
++		/*
++		 * Inode length changed, so we have to make sure
++		 * @I_DIRTY_DATASYNC is set.
++		 */
++		 __mark_inode_dirty(inode, I_DIRTY_SYNC | I_DIRTY_DATASYNC);
++	else
++		mark_inode_dirty_sync(inode);
++	mutex_unlock(&ui->ui_mutex);
++
++	if (release)
++		ubifs_release_budget(c, &req);
++	if (IS_SYNC(inode))
++		err = inode->i_sb->s_op->write_inode(inode, 1);
++	return err;
++
++out:
++	ubifs_release_budget(c, &req);
++	return err;
++}
++
++int ubifs_setattr(struct dentry *dentry, struct iattr *attr)
++{
++	int err;
++	struct inode *inode = dentry->d_inode;
++	struct ubifs_info *c = inode->i_sb->s_fs_info;
++
++	dbg_gen("ino %lu, mode %#x, ia_valid %#x",
++		inode->i_ino, inode->i_mode, attr->ia_valid);
++	err = inode_change_ok(inode, attr);
++	if (err)
++		return err;
++
++	err = dbg_check_synced_i_size(inode);
++	if (err)
++		return err;
++
++	if ((attr->ia_valid & ATTR_SIZE) && attr->ia_size < inode->i_size)
++		/* Truncation to a smaller size */
++		err = do_truncation(c, inode, attr);
++	else
++		err = do_setattr(c, inode, attr);
++
++	return err;
++}
++
++static void ubifs_invalidatepage(struct page *page, unsigned long offset)
++{
++	struct inode *inode = page->mapping->host;
++	struct ubifs_info *c = inode->i_sb->s_fs_info;
++
++	ubifs_assert(PagePrivate(page));
++	if (offset)
++		/* Partial page remains dirty */
++		return;
++
++	if (PageChecked(page))
++		release_new_page_budget(c);
++	else
++		release_existing_page_budget(c);
++
++	atomic_long_dec(&c->dirty_pg_cnt);
++	ClearPagePrivate(page);
++	ClearPageChecked(page);
++}
++
++static void *ubifs_follow_link(struct dentry *dentry, struct nameidata *nd)
++{
++	struct ubifs_inode *ui = ubifs_inode(dentry->d_inode);
++
++	nd_set_link(nd, ui->data);
++	return NULL;
++}
++
++int ubifs_fsync(struct file *file, struct dentry *dentry, int datasync)
++{
++	struct inode *inode = dentry->d_inode;
++	struct ubifs_info *c = inode->i_sb->s_fs_info;
++	int err;
++
++	dbg_gen("syncing inode %lu", inode->i_ino);
++
++	/*
++	 * VFS has already synchronized dirty pages for this inode. Synchronize
++	 * the inode unless this is a 'datasync()' call.
++	 */
++	if (!datasync || (inode->i_state & I_DIRTY_DATASYNC)) {
++		err = inode->i_sb->s_op->write_inode(inode, 1);
++		if (err)
++			return err;
++	}
++
++	/*
++	 * Nodes related to this inode may still sit in a write-buffer. Flush
++	 * them.
++	 */
++	err = ubifs_sync_wbufs_by_inode(c, inode);
++	if (err)
++		return err;
++
++	return 0;
++}
++
++/**
++ * mctime_update_needed - check if mtime or ctime update is needed.
++ * @inode: the inode to do the check for
++ * @now: current time
++ *
++ * This helper function checks if the inode mtime/ctime should be updated or
++ * not. If current values of the time-stamps are within the UBIFS inode time
++ * granularity, they are not updated. This is an optimization.
++ */
++static inline int mctime_update_needed(struct inode *inode,
++				       struct timespec *now)
++{
++	if (!timespec_equal(&inode->i_mtime, now) ||
++	    !timespec_equal(&inode->i_ctime, now))
++		return 1;
++	return 0;
++}
++
++/**
++ * update_ctime - update mtime and ctime of an inode.
++ * @c: UBIFS file-system description object
++ * @inode: inode to update
++ *
++ * This function updates mtime and ctime of the inode if it is not equivalent to
++ * current time. Returns zero in case of success and a negative error code in
++ * case of failure.
++ */
++static int update_mctime(struct ubifs_info *c, struct inode *inode)
++{
++	struct timespec now = ubifs_current_time(inode);
++	struct ubifs_inode *ui = ubifs_inode(inode);
++
++	if (mctime_update_needed(inode, &now)) {
++		int err, release;
++		struct ubifs_budget_req req = { .dirtied_ino = 1,
++				.dirtied_ino_d = ALIGN(ui->data_len, 8) };
++
++		err = ubifs_budget_space(c, &req);
++		if (err)
++			return err;
++
++		mutex_lock(&ui->ui_mutex);
++		inode->i_mtime = inode->i_ctime = ubifs_current_time(inode);
++		release = ui->dirty;
++		mark_inode_dirty_sync(inode);
++		mutex_unlock(&ui->ui_mutex);
++		if (release)
++			ubifs_release_budget(c, &req);
++	}
++
++	return 0;
++}
++
++static ssize_t ubifs_aio_write(struct kiocb *iocb, const struct iovec *iov,
++			       unsigned long nr_segs, loff_t pos)
++{
++	int err;
++	ssize_t ret;
++	struct inode *inode = iocb->ki_filp->f_mapping->host;
++	struct ubifs_info *c = inode->i_sb->s_fs_info;
++
++	err = update_mctime(c, inode);
++	if (err)
++		return err;
++
++	ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
++	if (ret < 0)
++		return ret;
++
++	if (ret > 0 && (IS_SYNC(inode) || iocb->ki_filp->f_flags & O_SYNC)) {
++		err = ubifs_sync_wbufs_by_inode(c, inode);
++		if (err)
++			return err;
++	}
++
++	return ret;
++}
++
++static int ubifs_set_page_dirty(struct page *page)
++{
++	int ret;
++
++	ret = __set_page_dirty_nobuffers(page);
++	/*
++	 * An attempt to dirty a page without budgeting for it - should not
++	 * happen.
++	 */
++	ubifs_assert(ret == 0);
++	return ret;
++}
++
++static int ubifs_releasepage(struct page *page, gfp_t unused_gfp_flags)
++{
++	/*
++	 * An attempt to release a dirty page without budgeting for it - should
++	 * not happen.
++	 */
++	if (PageWriteback(page))
++		return 0;
++	ubifs_assert(PagePrivate(page));
++	ubifs_assert(0);
++	ClearPagePrivate(page);
++	ClearPageChecked(page);
++	return 1;
++}
++
++/*
++ * mmap()d file has taken write protection fault and is being made
++ * writable. UBIFS must ensure page is budgeted for.
++ */
++static int ubifs_vm_page_mkwrite(struct vm_area_struct *vma, struct page *page)
++{
++	struct inode *inode = vma->vm_file->f_path.dentry->d_inode;
++	struct ubifs_info *c = inode->i_sb->s_fs_info;
++	struct timespec now = ubifs_current_time(inode);
++	struct ubifs_budget_req req = { .new_page = 1 };
++	int err, update_time;
++
++	dbg_gen("ino %lu, pg %lu, i_size %lld",	inode->i_ino, page->index,
++		i_size_read(inode));
++	ubifs_assert(!(inode->i_sb->s_flags & MS_RDONLY));
++
++	if (unlikely(c->ro_media))
++		return -EROFS;
++
++	/*
++	 * We have not locked @page so far so we may budget for changing the
++	 * page. Note, we cannot do this after we locked the page, because
++	 * budgeting may cause write-back which would cause deadlock.
++	 *
++	 * At the moment we do not know whether the page is dirty or not, so we
++	 * assume that it is not and budget for a new page. We could look at
++	 * the @PG_private flag and figure this out, but we may race with write
++	 * back and the page state may change by the time we lock it, so this
++	 * would need additional care. We do not bother with this at the
++	 * moment, although it might be good idea to do. Instead, we allocate
++	 * budget for a new page and amend it later on if the page was in fact
++	 * dirty.
++	 *
++	 * The budgeting-related logic of this function is similar to what we
++	 * do in 'ubifs_write_begin()' and 'ubifs_write_end()'. Glance there
++	 * for more comments.
++	 */
++	update_time = mctime_update_needed(inode, &now);
++	if (update_time)
++		/*
++		 * We have to change inode time stamp which requires extra
++		 * budgeting.
++		 */
++		req.dirtied_ino = 1;
++
++	err = ubifs_budget_space(c, &req);
++	if (unlikely(err)) {
++		if (err == -ENOSPC)
++			ubifs_warn("out of space for mmapped file "
++				   "(inode number %lu)", inode->i_ino);
++		return err;
++	}
++
++	lock_page(page);
++	if (unlikely(page->mapping != inode->i_mapping ||
++		     page_offset(page) > i_size_read(inode))) {
++		/* Page got truncated out from underneath us */
++		err = -EINVAL;
++		goto out_unlock;
++	}
++
++	if (PagePrivate(page))
++		release_new_page_budget(c);
++	else {
++		if (!PageChecked(page))
++			ubifs_convert_page_budget(c);
++		SetPagePrivate(page);
++		atomic_long_inc(&c->dirty_pg_cnt);
++		__set_page_dirty_nobuffers(page);
++	}
++
++	if (update_time) {
++		int release;
++		struct ubifs_inode *ui = ubifs_inode(inode);
++
++		mutex_lock(&ui->ui_mutex);
++		inode->i_mtime = inode->i_ctime = ubifs_current_time(inode);
++		release = ui->dirty;
++		mark_inode_dirty_sync(inode);
++		mutex_unlock(&ui->ui_mutex);
++		if (release)
++			ubifs_release_dirty_inode_budget(c, ui);
++	}
++
++	unlock_page(page);
++	return 0;
++
++out_unlock:
++	unlock_page(page);
++	ubifs_release_budget(c, &req);
++	return err;
++}
++
++static struct vm_operations_struct ubifs_file_vm_ops = {
++	.fault        = filemap_fault,
++	.page_mkwrite = ubifs_vm_page_mkwrite,
++};
++
++static int ubifs_file_mmap(struct file *file, struct vm_area_struct *vma)
++{
++	int err;
++
++	/* 'generic_file_mmap()' takes care of NOMMU case */
++	err = generic_file_mmap(file, vma);
++	if (err)
++		return err;
++	vma->vm_ops = &ubifs_file_vm_ops;
++	return 0;
++}
++
++const struct address_space_operations ubifs_file_address_operations = {
++	.readpage       = ubifs_readpage,
++	.writepage      = ubifs_writepage,
++	.write_begin    = ubifs_write_begin,
++	.write_end      = ubifs_write_end,
++	.invalidatepage = ubifs_invalidatepage,
++	.set_page_dirty = ubifs_set_page_dirty,
++	.releasepage    = ubifs_releasepage,
++};
++
++const struct inode_operations ubifs_file_inode_operations = {
++	.setattr     = ubifs_setattr,
++	.getattr     = ubifs_getattr,
++#ifdef CONFIG_UBIFS_FS_XATTR
++	.setxattr    = ubifs_setxattr,
++	.getxattr    = ubifs_getxattr,
++	.listxattr   = ubifs_listxattr,
++	.removexattr = ubifs_removexattr,
++#endif
++};
++
++const struct inode_operations ubifs_symlink_inode_operations = {
++	.readlink    = generic_readlink,
++	.follow_link = ubifs_follow_link,
++	.setattr     = ubifs_setattr,
++	.getattr     = ubifs_getattr,
++};
++
++const struct file_operations ubifs_file_operations = {
++	.llseek         = generic_file_llseek,
++	.read           = do_sync_read,
++	.write          = do_sync_write,
++	.aio_read       = generic_file_aio_read,
++	.aio_write      = ubifs_aio_write,
++	.mmap           = ubifs_file_mmap,
++	.fsync          = ubifs_fsync,
++	.unlocked_ioctl = ubifs_ioctl,
++	.splice_read	= generic_file_splice_read,
++	.splice_write	= generic_file_splice_write,
++#ifdef CONFIG_COMPAT
++	.compat_ioctl   = ubifs_compat_ioctl,
++#endif
++};
+diff -Nurd linux-2.6.24.orig/fs/ubifs/find.c linux-2.6.24/fs/ubifs/find.c
+--- linux-2.6.24.orig/fs/ubifs/find.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/find.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,977 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++/*
++ * This file contains functions for finding LEBs for various purposes e.g.
++ * garbage collection. In general, lprops category heaps and lists are used
++ * for fast access, falling back on scanning the LPT as a last resort.
++ */
++
++#include <linux/sort.h>
++#include "ubifs.h"
++
++/**
++ * struct scan_data - data provided to scan callback functions
++ * @min_space: minimum number of bytes for which to scan
++ * @pick_free: whether it is OK to scan for empty LEBs
++ * @lnum: LEB number found is returned here
++ * @exclude_index: whether to exclude index LEBs
++ */
++struct scan_data {
++	int min_space;
++	int pick_free;
++	int lnum;
++	int exclude_index;
++};
++
++/**
++ * valuable - determine whether LEB properties are valuable.
++ * @c: the UBIFS file-system description object
++ * @lprops: LEB properties
++ *
++ * This function return %1 if the LEB properties should be added to the LEB
++ * properties tree in memory. Otherwise %0 is returned.
++ */
++static int valuable(struct ubifs_info *c, const struct ubifs_lprops *lprops)
++{
++	int n, cat = lprops->flags & LPROPS_CAT_MASK;
++	struct ubifs_lpt_heap *heap;
++
++	switch (cat) {
++	case LPROPS_DIRTY:
++	case LPROPS_DIRTY_IDX:
++	case LPROPS_FREE:
++		heap = &c->lpt_heap[cat - 1];
++		if (heap->cnt < heap->max_cnt)
++			return 1;
++		if (lprops->free + lprops->dirty >= c->dark_wm)
++			return 1;
++		return 0;
++	case LPROPS_EMPTY:
++		n = c->lst.empty_lebs + c->freeable_cnt -
++		    c->lst.taken_empty_lebs;
++		if (n < c->lsave_cnt)
++			return 1;
++		return 0;
++	case LPROPS_FREEABLE:
++		return 1;
++	case LPROPS_FRDI_IDX:
++		return 1;
++	}
++	return 0;
++}
++
++/**
++ * scan_for_dirty_cb - dirty space scan callback.
++ * @c: the UBIFS file-system description object
++ * @lprops: LEB properties to scan
++ * @in_tree: whether the LEB properties are in main memory
++ * @data: information passed to and from the caller of the scan
++ *
++ * This function returns a code that indicates whether the scan should continue
++ * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
++ * in main memory (%LPT_SCAN_ADD), or whether the scan should stop
++ * (%LPT_SCAN_STOP).
++ */
++static int scan_for_dirty_cb(struct ubifs_info *c,
++			     const struct ubifs_lprops *lprops, int in_tree,
++			     struct scan_data *data)
++{
++	int ret = LPT_SCAN_CONTINUE;
++
++	/* Exclude LEBs that are currently in use */
++	if (lprops->flags & LPROPS_TAKEN)
++		return LPT_SCAN_CONTINUE;
++	/* Determine whether to add these LEB properties to the tree */
++	if (!in_tree && valuable(c, lprops))
++		ret |= LPT_SCAN_ADD;
++	/* Exclude LEBs with too little space */
++	if (lprops->free + lprops->dirty < data->min_space)
++		return ret;
++	/* If specified, exclude index LEBs */
++	if (data->exclude_index && lprops->flags & LPROPS_INDEX)
++		return ret;
++	/* If specified, exclude empty or freeable LEBs */
++	if (lprops->free + lprops->dirty == c->leb_size) {
++		if (!data->pick_free)
++			return ret;
++	/* Exclude LEBs with too little dirty space (unless it is empty) */
++	} else if (lprops->dirty < c->dead_wm)
++		return ret;
++	/* Finally we found space */
++	data->lnum = lprops->lnum;
++	return LPT_SCAN_ADD | LPT_SCAN_STOP;
++}
++
++/**
++ * scan_for_dirty - find a data LEB with free space.
++ * @c: the UBIFS file-system description object
++ * @min_space: minimum amount free plus dirty space the returned LEB has to
++ *             have
++ * @pick_free: if it is OK to return a free or freeable LEB
++ * @exclude_index: whether to exclude index LEBs
++ *
++ * This function returns a pointer to the LEB properties found or a negative
++ * error code.
++ */
++static const struct ubifs_lprops *scan_for_dirty(struct ubifs_info *c,
++						 int min_space, int pick_free,
++						 int exclude_index)
++{
++	const struct ubifs_lprops *lprops;
++	struct ubifs_lpt_heap *heap;
++	struct scan_data data;
++	int err, i;
++
++	/* There may be an LEB with enough dirty space on the free heap */
++	heap = &c->lpt_heap[LPROPS_FREE - 1];
++	for (i = 0; i < heap->cnt; i++) {
++		lprops = heap->arr[i];
++		if (lprops->free + lprops->dirty < min_space)
++			continue;
++		if (lprops->dirty < c->dead_wm)
++			continue;
++		return lprops;
++	}
++	/*
++	 * A LEB may have fallen off of the bottom of the dirty heap, and ended
++	 * up as uncategorized even though it has enough dirty space for us now,
++	 * so check the uncategorized list. N.B. neither empty nor freeable LEBs
++	 * can end up as uncategorized because they are kept on lists not
++	 * finite-sized heaps.
++	 */
++	list_for_each_entry(lprops, &c->uncat_list, list) {
++		if (lprops->flags & LPROPS_TAKEN)
++			continue;
++		if (lprops->free + lprops->dirty < min_space)
++			continue;
++		if (exclude_index && (lprops->flags & LPROPS_INDEX))
++			continue;
++		if (lprops->dirty < c->dead_wm)
++			continue;
++		return lprops;
++	}
++	/* We have looked everywhere in main memory, now scan the flash */
++	if (c->pnodes_have >= c->pnode_cnt)
++		/* All pnodes are in memory, so skip scan */
++		return ERR_PTR(-ENOSPC);
++	data.min_space = min_space;
++	data.pick_free = pick_free;
++	data.lnum = -1;
++	data.exclude_index = exclude_index;
++	err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
++				    (ubifs_lpt_scan_callback)scan_for_dirty_cb,
++				    &data);
++	if (err)
++		return ERR_PTR(err);
++	ubifs_assert(data.lnum >= c->main_first && data.lnum < c->leb_cnt);
++	c->lscan_lnum = data.lnum;
++	lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
++	if (IS_ERR(lprops))
++		return lprops;
++	ubifs_assert(lprops->lnum == data.lnum);
++	ubifs_assert(lprops->free + lprops->dirty >= min_space);
++	ubifs_assert(lprops->dirty >= c->dead_wm ||
++		     (pick_free &&
++		      lprops->free + lprops->dirty == c->leb_size));
++	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
++	ubifs_assert(!exclude_index || !(lprops->flags & LPROPS_INDEX));
++	return lprops;
++}
++
++/**
++ * ubifs_find_dirty_leb - find a dirty LEB for the Garbage Collector.
++ * @c: the UBIFS file-system description object
++ * @ret_lp: LEB properties are returned here on exit
++ * @min_space: minimum amount free plus dirty space the returned LEB has to
++ *             have
++ * @pick_free: controls whether it is OK to pick empty or index LEBs
++ *
++ * This function tries to find a dirty logical eraseblock which has at least
++ * @min_space free and dirty space. It prefers to take an LEB from the dirty or
++ * dirty index heap, and it falls-back to LPT scanning if the heaps are empty
++ * or do not have an LEB which satisfies the @min_space criteria.
++ *
++ * Note, LEBs which have less than dead watermark of free + dirty space are
++ * never picked by this function.
++ *
++ * The additional @pick_free argument controls if this function has to return a
++ * free or freeable LEB if one is present. For example, GC must to set it to %1,
++ * when called from the journal space reservation function, because the
++ * appearance of free space may coincide with the loss of enough dirty space
++ * for GC to succeed anyway.
++ *
++ * In contrast, if the Garbage Collector is called from budgeting, it should
++ * just make free space, not return LEBs which are already free or freeable.
++ *
++ * In addition @pick_free is set to %2 by the recovery process in order to
++ * recover gc_lnum in which case an index LEB must not be returned.
++ *
++ * This function returns zero and the LEB properties of found dirty LEB in case
++ * of success, %-ENOSPC if no dirty LEB was found and a negative error code in
++ * case of other failures. The returned LEB is marked as "taken".
++ */
++int ubifs_find_dirty_leb(struct ubifs_info *c, struct ubifs_lprops *ret_lp,
++			 int min_space, int pick_free)
++{
++	int err = 0, sum, exclude_index = pick_free == 2 ? 1 : 0;
++	const struct ubifs_lprops *lp = NULL, *idx_lp = NULL;
++	struct ubifs_lpt_heap *heap, *idx_heap;
++
++	ubifs_get_lprops(c);
++
++	if (pick_free) {
++		int lebs, rsvd_idx_lebs = 0;
++
++		spin_lock(&c->space_lock);
++		lebs = c->lst.empty_lebs + c->idx_gc_cnt;
++		lebs += c->freeable_cnt - c->lst.taken_empty_lebs;
++
++		/*
++		 * Note, the index may consume more LEBs than have been reserved
++		 * for it. It is OK because it might be consolidated by GC.
++		 * But if the index takes fewer LEBs than it is reserved for it,
++		 * this function must avoid picking those reserved LEBs.
++		 */
++		if (c->min_idx_lebs >= c->lst.idx_lebs) {
++			rsvd_idx_lebs = c->min_idx_lebs -  c->lst.idx_lebs;
++			exclude_index = 1;
++		}
++		spin_unlock(&c->space_lock);
++
++		/* Check if there are enough free LEBs for the index */
++		if (rsvd_idx_lebs < lebs) {
++			/* OK, try to find an empty LEB */
++			lp = ubifs_fast_find_empty(c);
++			if (lp)
++				goto found;
++
++			/* Or a freeable LEB */
++			lp = ubifs_fast_find_freeable(c);
++			if (lp)
++				goto found;
++		} else
++			/*
++			 * We cannot pick free/freeable LEBs in the below code.
++			 */
++			pick_free = 0;
++	} else {
++		spin_lock(&c->space_lock);
++		exclude_index = (c->min_idx_lebs >= c->lst.idx_lebs);
++		spin_unlock(&c->space_lock);
++	}
++
++	/* Look on the dirty and dirty index heaps */
++	heap = &c->lpt_heap[LPROPS_DIRTY - 1];
++	idx_heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
++
++	if (idx_heap->cnt && !exclude_index) {
++		idx_lp = idx_heap->arr[0];
++		sum = idx_lp->free + idx_lp->dirty;
++		/*
++		 * Since we reserve thrice as much space for the index than it
++		 * actually takes, it does not make sense to pick indexing LEBs
++		 * with less than, say, half LEB of dirty space. May be half is
++		 * not the optimal boundary - this should be tested and
++		 * checked. This boundary should determine how much we use
++		 * in-the-gaps to consolidate the index comparing to how much
++		 * we use garbage collector to consolidate it. The "half"
++		 * criteria just feels to be fine.
++		 */
++		if (sum < min_space || sum < c->half_leb_size)
++			idx_lp = NULL;
++	}
++
++	if (heap->cnt) {
++		lp = heap->arr[0];
++		if (lp->dirty + lp->free < min_space)
++			lp = NULL;
++	}
++
++	/* Pick the LEB with most space */
++	if (idx_lp && lp) {
++		if (idx_lp->free + idx_lp->dirty >= lp->free + lp->dirty)
++			lp = idx_lp;
++	} else if (idx_lp && !lp)
++		lp = idx_lp;
++
++	if (lp) {
++		ubifs_assert(lp->free + lp->dirty >= c->dead_wm);
++		goto found;
++	}
++
++	/* Did not find a dirty LEB on the dirty heaps, have to scan */
++	dbg_find("scanning LPT for a dirty LEB");
++	lp = scan_for_dirty(c, min_space, pick_free, exclude_index);
++	if (IS_ERR(lp)) {
++		err = PTR_ERR(lp);
++		goto out;
++	}
++	ubifs_assert(lp->dirty >= c->dead_wm ||
++		     (pick_free && lp->free + lp->dirty == c->leb_size));
++
++found:
++	dbg_find("found LEB %d, free %d, dirty %d, flags %#x",
++		 lp->lnum, lp->free, lp->dirty, lp->flags);
++
++	lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
++			     lp->flags | LPROPS_TAKEN, 0);
++	if (IS_ERR(lp)) {
++		err = PTR_ERR(lp);
++		goto out;
++	}
++
++	memcpy(ret_lp, lp, sizeof(struct ubifs_lprops));
++
++out:
++	ubifs_release_lprops(c);
++	return err;
++}
++
++/**
++ * scan_for_free_cb - free space scan callback.
++ * @c: the UBIFS file-system description object
++ * @lprops: LEB properties to scan
++ * @in_tree: whether the LEB properties are in main memory
++ * @data: information passed to and from the caller of the scan
++ *
++ * This function returns a code that indicates whether the scan should continue
++ * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
++ * in main memory (%LPT_SCAN_ADD), or whether the scan should stop
++ * (%LPT_SCAN_STOP).
++ */
++static int scan_for_free_cb(struct ubifs_info *c,
++			    const struct ubifs_lprops *lprops, int in_tree,
++			    struct scan_data *data)
++{
++	int ret = LPT_SCAN_CONTINUE;
++
++	/* Exclude LEBs that are currently in use */
++	if (lprops->flags & LPROPS_TAKEN)
++		return LPT_SCAN_CONTINUE;
++	/* Determine whether to add these LEB properties to the tree */
++	if (!in_tree && valuable(c, lprops))
++		ret |= LPT_SCAN_ADD;
++	/* Exclude index LEBs */
++	if (lprops->flags & LPROPS_INDEX)
++		return ret;
++	/* Exclude LEBs with too little space */
++	if (lprops->free < data->min_space)
++		return ret;
++	/* If specified, exclude empty LEBs */
++	if (!data->pick_free && lprops->free == c->leb_size)
++		return ret;
++	/*
++	 * LEBs that have only free and dirty space must not be allocated
++	 * because they may have been unmapped already or they may have data
++	 * that is obsolete only because of nodes that are still sitting in a
++	 * wbuf.
++	 */
++	if (lprops->free + lprops->dirty == c->leb_size && lprops->dirty > 0)
++		return ret;
++	/* Finally we found space */
++	data->lnum = lprops->lnum;
++	return LPT_SCAN_ADD | LPT_SCAN_STOP;
++}
++
++/**
++ * do_find_free_space - find a data LEB with free space.
++ * @c: the UBIFS file-system description object
++ * @min_space: minimum amount of free space required
++ * @pick_free: whether it is OK to scan for empty LEBs
++ * @squeeze: whether to try to find space in a non-empty LEB first
++ *
++ * This function returns a pointer to the LEB properties found or a negative
++ * error code.
++ */
++static
++const struct ubifs_lprops *do_find_free_space(struct ubifs_info *c,
++					      int min_space, int pick_free,
++					      int squeeze)
++{
++	const struct ubifs_lprops *lprops;
++	struct ubifs_lpt_heap *heap;
++	struct scan_data data;
++	int err, i;
++
++	if (squeeze) {
++		lprops = ubifs_fast_find_free(c);
++		if (lprops && lprops->free >= min_space)
++			return lprops;
++	}
++	if (pick_free) {
++		lprops = ubifs_fast_find_empty(c);
++		if (lprops)
++			return lprops;
++	}
++	if (!squeeze) {
++		lprops = ubifs_fast_find_free(c);
++		if (lprops && lprops->free >= min_space)
++			return lprops;
++	}
++	/* There may be an LEB with enough free space on the dirty heap */
++	heap = &c->lpt_heap[LPROPS_DIRTY - 1];
++	for (i = 0; i < heap->cnt; i++) {
++		lprops = heap->arr[i];
++		if (lprops->free >= min_space)
++			return lprops;
++	}
++	/*
++	 * A LEB may have fallen off of the bottom of the free heap, and ended
++	 * up as uncategorized even though it has enough free space for us now,
++	 * so check the uncategorized list. N.B. neither empty nor freeable LEBs
++	 * can end up as uncategorized because they are kept on lists not
++	 * finite-sized heaps.
++	 */
++	list_for_each_entry(lprops, &c->uncat_list, list) {
++		if (lprops->flags & LPROPS_TAKEN)
++			continue;
++		if (lprops->flags & LPROPS_INDEX)
++			continue;
++		if (lprops->free >= min_space)
++			return lprops;
++	}
++	/* We have looked everywhere in main memory, now scan the flash */
++	if (c->pnodes_have >= c->pnode_cnt)
++		/* All pnodes are in memory, so skip scan */
++		return ERR_PTR(-ENOSPC);
++	data.min_space = min_space;
++	data.pick_free = pick_free;
++	data.lnum = -1;
++	err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
++				    (ubifs_lpt_scan_callback)scan_for_free_cb,
++				    &data);
++	if (err)
++		return ERR_PTR(err);
++	ubifs_assert(data.lnum >= c->main_first && data.lnum < c->leb_cnt);
++	c->lscan_lnum = data.lnum;
++	lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
++	if (IS_ERR(lprops))
++		return lprops;
++	ubifs_assert(lprops->lnum == data.lnum);
++	ubifs_assert(lprops->free >= min_space);
++	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
++	ubifs_assert(!(lprops->flags & LPROPS_INDEX));
++	return lprops;
++}
++
++/**
++ * ubifs_find_free_space - find a data LEB with free space.
++ * @c: the UBIFS file-system description object
++ * @min_space: minimum amount of required free space
++ * @free: contains amount of free space in the LEB on exit
++ * @squeeze: whether to try to find space in a non-empty LEB first
++ *
++ * This function looks for an LEB with at least @min_space bytes of free space.
++ * It tries to find an empty LEB if possible. If no empty LEBs are available,
++ * this function searches for a non-empty data LEB. The returned LEB is marked
++ * as "taken".
++ *
++ * This function returns found LEB number in case of success, %-ENOSPC if it
++ * failed to find a LEB with @min_space bytes of free space and other a negative
++ * error codes in case of failure.
++ */
++int ubifs_find_free_space(struct ubifs_info *c, int min_space, int *free,
++			  int squeeze)
++{
++	const struct ubifs_lprops *lprops;
++	int lebs, rsvd_idx_lebs, pick_free = 0, err, lnum, flags;
++
++	dbg_find("min_space %d", min_space);
++	ubifs_get_lprops(c);
++
++	/* Check if there are enough empty LEBs for commit */
++	spin_lock(&c->space_lock);
++	if (c->min_idx_lebs > c->lst.idx_lebs)
++		rsvd_idx_lebs = c->min_idx_lebs -  c->lst.idx_lebs;
++	else
++		rsvd_idx_lebs = 0;
++	lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt -
++	       c->lst.taken_empty_lebs;
++	if (rsvd_idx_lebs < lebs)
++		/*
++		 * OK to allocate an empty LEB, but we still don't want to go
++		 * looking for one if there aren't any.
++		 */
++		if (c->lst.empty_lebs - c->lst.taken_empty_lebs > 0) {
++			pick_free = 1;
++			/*
++			 * Because we release the space lock, we must account
++			 * for this allocation here. After the LEB properties
++			 * flags have been updated, we subtract one. Note, the
++			 * result of this is that lprops also decreases
++			 * @taken_empty_lebs in 'ubifs_change_lp()', so it is
++			 * off by one for a short period of time which may
++			 * introduce a small disturbance to budgeting
++			 * calculations, but this is harmless because at the
++			 * worst case this would make the budgeting subsystem
++			 * be more pessimistic than needed.
++			 *
++			 * Fundamentally, this is about serialization of the
++			 * budgeting and lprops subsystems. We could make the
++			 * @space_lock a mutex and avoid dropping it before
++			 * calling 'ubifs_change_lp()', but mutex is more
++			 * heavy-weight, and we want budgeting to be as fast as
++			 * possible.
++			 */
++			c->lst.taken_empty_lebs += 1;
++		}
++	spin_unlock(&c->space_lock);
++
++	lprops = do_find_free_space(c, min_space, pick_free, squeeze);
++	if (IS_ERR(lprops)) {
++		err = PTR_ERR(lprops);
++		goto out;
++	}
++
++	lnum = lprops->lnum;
++	flags = lprops->flags | LPROPS_TAKEN;
++
++	lprops = ubifs_change_lp(c, lprops, LPROPS_NC, LPROPS_NC, flags, 0);
++	if (IS_ERR(lprops)) {
++		err = PTR_ERR(lprops);
++		goto out;
++	}
++
++	if (pick_free) {
++		spin_lock(&c->space_lock);
++		c->lst.taken_empty_lebs -= 1;
++		spin_unlock(&c->space_lock);
++	}
++
++	*free = lprops->free;
++	ubifs_release_lprops(c);
++
++	if (*free == c->leb_size) {
++		/*
++		 * Ensure that empty LEBs have been unmapped. They may not have
++		 * been, for example, because of an unclean unmount.  Also
++		 * LEBs that were freeable LEBs (free + dirty == leb_size) will
++		 * not have been unmapped.
++		 */
++		err = ubifs_leb_unmap(c, lnum);
++		if (err)
++			return err;
++	}
++
++	dbg_find("found LEB %d, free %d", lnum, *free);
++	ubifs_assert(*free >= min_space);
++	return lnum;
++
++out:
++	if (pick_free) {
++		spin_lock(&c->space_lock);
++		c->lst.taken_empty_lebs -= 1;
++		spin_unlock(&c->space_lock);
++	}
++	ubifs_release_lprops(c);
++	return err;
++}
++
++/**
++ * scan_for_idx_cb - callback used by the scan for a free LEB for the index.
++ * @c: the UBIFS file-system description object
++ * @lprops: LEB properties to scan
++ * @in_tree: whether the LEB properties are in main memory
++ * @data: information passed to and from the caller of the scan
++ *
++ * This function returns a code that indicates whether the scan should continue
++ * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
++ * in main memory (%LPT_SCAN_ADD), or whether the scan should stop
++ * (%LPT_SCAN_STOP).
++ */
++static int scan_for_idx_cb(struct ubifs_info *c,
++			   const struct ubifs_lprops *lprops, int in_tree,
++			   struct scan_data *data)
++{
++	int ret = LPT_SCAN_CONTINUE;
++
++	/* Exclude LEBs that are currently in use */
++	if (lprops->flags & LPROPS_TAKEN)
++		return LPT_SCAN_CONTINUE;
++	/* Determine whether to add these LEB properties to the tree */
++	if (!in_tree && valuable(c, lprops))
++		ret |= LPT_SCAN_ADD;
++	/* Exclude index LEBS */
++	if (lprops->flags & LPROPS_INDEX)
++		return ret;
++	/* Exclude LEBs that cannot be made empty */
++	if (lprops->free + lprops->dirty != c->leb_size)
++		return ret;
++	/*
++	 * We are allocating for the index so it is safe to allocate LEBs with
++	 * only free and dirty space, because write buffers are sync'd at commit
++	 * start.
++	 */
++	data->lnum = lprops->lnum;
++	return LPT_SCAN_ADD | LPT_SCAN_STOP;
++}
++
++/**
++ * scan_for_leb_for_idx - scan for a free LEB for the index.
++ * @c: the UBIFS file-system description object
++ */
++static const struct ubifs_lprops *scan_for_leb_for_idx(struct ubifs_info *c)
++{
++	struct ubifs_lprops *lprops;
++	struct scan_data data;
++	int err;
++
++	data.lnum = -1;
++	err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
++				    (ubifs_lpt_scan_callback)scan_for_idx_cb,
++				    &data);
++	if (err)
++		return ERR_PTR(err);
++	ubifs_assert(data.lnum >= c->main_first && data.lnum < c->leb_cnt);
++	c->lscan_lnum = data.lnum;
++	lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
++	if (IS_ERR(lprops))
++		return lprops;
++	ubifs_assert(lprops->lnum == data.lnum);
++	ubifs_assert(lprops->free + lprops->dirty == c->leb_size);
++	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
++	ubifs_assert(!(lprops->flags & LPROPS_INDEX));
++	return lprops;
++}
++
++/**
++ * ubifs_find_free_leb_for_idx - find a free LEB for the index.
++ * @c: the UBIFS file-system description object
++ *
++ * This function looks for a free LEB and returns that LEB number. The returned
++ * LEB is marked as "taken", "index".
++ *
++ * Only empty LEBs are allocated. This is for two reasons. First, the commit
++ * calculates the number of LEBs to allocate based on the assumption that they
++ * will be empty. Secondly, free space at the end of an index LEB is not
++ * guaranteed to be empty because it may have been used by the in-the-gaps
++ * method prior to an unclean unmount.
++ *
++ * If no LEB is found %-ENOSPC is returned. For other failures another negative
++ * error code is returned.
++ */
++int ubifs_find_free_leb_for_idx(struct ubifs_info *c)
++{
++	const struct ubifs_lprops *lprops;
++	int lnum = -1, err, flags;
++
++	ubifs_get_lprops(c);
++
++	lprops = ubifs_fast_find_empty(c);
++	if (!lprops) {
++		lprops = ubifs_fast_find_freeable(c);
++		if (!lprops) {
++			ubifs_assert(c->freeable_cnt == 0);
++			if (c->lst.empty_lebs - c->lst.taken_empty_lebs > 0) {
++				lprops = scan_for_leb_for_idx(c);
++				if (IS_ERR(lprops)) {
++					err = PTR_ERR(lprops);
++					goto out;
++				}
++			}
++		}
++	}
++
++	if (!lprops) {
++		err = -ENOSPC;
++		goto out;
++	}
++
++	lnum = lprops->lnum;
++
++	dbg_find("found LEB %d, free %d, dirty %d, flags %#x",
++		 lnum, lprops->free, lprops->dirty, lprops->flags);
++
++	flags = lprops->flags | LPROPS_TAKEN | LPROPS_INDEX;
++	lprops = ubifs_change_lp(c, lprops, c->leb_size, 0, flags, 0);
++	if (IS_ERR(lprops)) {
++		err = PTR_ERR(lprops);
++		goto out;
++	}
++
++	ubifs_release_lprops(c);
++
++	/*
++	 * Ensure that empty LEBs have been unmapped. They may not have been,
++	 * for example, because of an unclean unmount. Also LEBs that were
++	 * freeable LEBs (free + dirty == leb_size) will not have been unmapped.
++	 */
++	err = ubifs_leb_unmap(c, lnum);
++	if (err) {
++		ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
++				    LPROPS_TAKEN | LPROPS_INDEX, 0);
++		return err;
++	}
++
++	return lnum;
++
++out:
++	ubifs_release_lprops(c);
++	return err;
++}
++
++static int cmp_dirty_idx(const struct ubifs_lprops **a,
++			 const struct ubifs_lprops **b)
++{
++	const struct ubifs_lprops *lpa = *a;
++	const struct ubifs_lprops *lpb = *b;
++
++	return lpa->dirty + lpa->free - lpb->dirty - lpb->free;
++}
++
++static void swap_dirty_idx(struct ubifs_lprops **a, struct ubifs_lprops **b,
++			   int size)
++{
++	struct ubifs_lprops *t = *a;
++
++	*a = *b;
++	*b = t;
++}
++
++/**
++ * ubifs_save_dirty_idx_lnums - save an array of the most dirty index LEB nos.
++ * @c: the UBIFS file-system description object
++ *
++ * This function is called each commit to create an array of LEB numbers of
++ * dirty index LEBs sorted in order of dirty and free space.  This is used by
++ * the in-the-gaps method of TNC commit.
++ */
++int ubifs_save_dirty_idx_lnums(struct ubifs_info *c)
++{
++	int i;
++
++	ubifs_get_lprops(c);
++	/* Copy the LPROPS_DIRTY_IDX heap */
++	c->dirty_idx.cnt = c->lpt_heap[LPROPS_DIRTY_IDX - 1].cnt;
++	memcpy(c->dirty_idx.arr, c->lpt_heap[LPROPS_DIRTY_IDX - 1].arr,
++	       sizeof(void *) * c->dirty_idx.cnt);
++	/* Sort it so that the dirtiest is now at the end */
++	sort(c->dirty_idx.arr, c->dirty_idx.cnt, sizeof(void *),
++	     (int (*)(const void *, const void *))cmp_dirty_idx,
++	     (void (*)(void *, void *, int))swap_dirty_idx);
++	dbg_find("found %d dirty index LEBs", c->dirty_idx.cnt);
++	if (c->dirty_idx.cnt)
++		dbg_find("dirtiest index LEB is %d with dirty %d and free %d",
++			 c->dirty_idx.arr[c->dirty_idx.cnt - 1]->lnum,
++			 c->dirty_idx.arr[c->dirty_idx.cnt - 1]->dirty,
++			 c->dirty_idx.arr[c->dirty_idx.cnt - 1]->free);
++	/* Replace the lprops pointers with LEB numbers */
++	for (i = 0; i < c->dirty_idx.cnt; i++)
++		c->dirty_idx.arr[i] = (void *)(size_t)c->dirty_idx.arr[i]->lnum;
++	ubifs_release_lprops(c);
++	return 0;
++}
++
++/**
++ * scan_dirty_idx_cb - callback used by the scan for a dirty index LEB.
++ * @c: the UBIFS file-system description object
++ * @lprops: LEB properties to scan
++ * @in_tree: whether the LEB properties are in main memory
++ * @data: information passed to and from the caller of the scan
++ *
++ * This function returns a code that indicates whether the scan should continue
++ * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
++ * in main memory (%LPT_SCAN_ADD), or whether the scan should stop
++ * (%LPT_SCAN_STOP).
++ */
++static int scan_dirty_idx_cb(struct ubifs_info *c,
++			   const struct ubifs_lprops *lprops, int in_tree,
++			   struct scan_data *data)
++{
++	int ret = LPT_SCAN_CONTINUE;
++
++	/* Exclude LEBs that are currently in use */
++	if (lprops->flags & LPROPS_TAKEN)
++		return LPT_SCAN_CONTINUE;
++	/* Determine whether to add these LEB properties to the tree */
++	if (!in_tree && valuable(c, lprops))
++		ret |= LPT_SCAN_ADD;
++	/* Exclude non-index LEBs */
++	if (!(lprops->flags & LPROPS_INDEX))
++		return ret;
++	/* Exclude LEBs with too little space */
++	if (lprops->free + lprops->dirty < c->min_idx_node_sz)
++		return ret;
++	/* Finally we found space */
++	data->lnum = lprops->lnum;
++	return LPT_SCAN_ADD | LPT_SCAN_STOP;
++}
++
++/**
++ * find_dirty_idx_leb - find a dirty index LEB.
++ * @c: the UBIFS file-system description object
++ *
++ * This function returns LEB number upon success and a negative error code upon
++ * failure.  In particular, -ENOSPC is returned if a dirty index LEB is not
++ * found.
++ *
++ * Note that this function scans the entire LPT but it is called very rarely.
++ */
++static int find_dirty_idx_leb(struct ubifs_info *c)
++{
++	const struct ubifs_lprops *lprops;
++	struct ubifs_lpt_heap *heap;
++	struct scan_data data;
++	int err, i, ret;
++
++	/* Check all structures in memory first */
++	data.lnum = -1;
++	heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
++	for (i = 0; i < heap->cnt; i++) {
++		lprops = heap->arr[i];
++		ret = scan_dirty_idx_cb(c, lprops, 1, &data);
++		if (ret & LPT_SCAN_STOP)
++			goto found;
++	}
++	list_for_each_entry(lprops, &c->frdi_idx_list, list) {
++		ret = scan_dirty_idx_cb(c, lprops, 1, &data);
++		if (ret & LPT_SCAN_STOP)
++			goto found;
++	}
++	list_for_each_entry(lprops, &c->uncat_list, list) {
++		ret = scan_dirty_idx_cb(c, lprops, 1, &data);
++		if (ret & LPT_SCAN_STOP)
++			goto found;
++	}
++	if (c->pnodes_have >= c->pnode_cnt)
++		/* All pnodes are in memory, so skip scan */
++		return -ENOSPC;
++	err = ubifs_lpt_scan_nolock(c, -1, c->lscan_lnum,
++				    (ubifs_lpt_scan_callback)scan_dirty_idx_cb,
++				    &data);
++	if (err)
++		return err;
++found:
++	ubifs_assert(data.lnum >= c->main_first && data.lnum < c->leb_cnt);
++	c->lscan_lnum = data.lnum;
++	lprops = ubifs_lpt_lookup_dirty(c, data.lnum);
++	if (IS_ERR(lprops))
++		return PTR_ERR(lprops);
++	ubifs_assert(lprops->lnum == data.lnum);
++	ubifs_assert(lprops->free + lprops->dirty >= c->min_idx_node_sz);
++	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
++	ubifs_assert((lprops->flags & LPROPS_INDEX));
++
++	dbg_find("found dirty LEB %d, free %d, dirty %d, flags %#x",
++		 lprops->lnum, lprops->free, lprops->dirty, lprops->flags);
++
++	lprops = ubifs_change_lp(c, lprops, LPROPS_NC, LPROPS_NC,
++				 lprops->flags | LPROPS_TAKEN, 0);
++	if (IS_ERR(lprops))
++		return PTR_ERR(lprops);
++
++	return lprops->lnum;
++}
++
++/**
++ * get_idx_gc_leb - try to get a LEB number from trivial GC.
++ * @c: the UBIFS file-system description object
++ */
++static int get_idx_gc_leb(struct ubifs_info *c)
++{
++	const struct ubifs_lprops *lp;
++	int err, lnum;
++
++	err = ubifs_get_idx_gc_leb(c);
++	if (err < 0)
++		return err;
++	lnum = err;
++	/*
++	 * The LEB was due to be unmapped after the commit but
++	 * it is needed now for this commit.
++	 */
++	lp = ubifs_lpt_lookup_dirty(c, lnum);
++	if (IS_ERR(lp))
++		return PTR_ERR(lp);
++	lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
++			     lp->flags | LPROPS_INDEX, -1);
++	if (IS_ERR(lp))
++		return PTR_ERR(lp);
++	dbg_find("LEB %d, dirty %d and free %d flags %#x",
++		 lp->lnum, lp->dirty, lp->free, lp->flags);
++	return lnum;
++}
++
++/**
++ * find_dirtiest_idx_leb - find dirtiest index LEB from dirtiest array.
++ * @c: the UBIFS file-system description object
++ */
++static int find_dirtiest_idx_leb(struct ubifs_info *c)
++{
++	const struct ubifs_lprops *lp;
++	int lnum;
++
++	while (1) {
++		if (!c->dirty_idx.cnt)
++			return -ENOSPC;
++		/* The lprops pointers were replaced by LEB numbers */
++		lnum = (size_t)c->dirty_idx.arr[--c->dirty_idx.cnt];
++		lp = ubifs_lpt_lookup(c, lnum);
++		if (IS_ERR(lp))
++			return PTR_ERR(lp);
++		if ((lp->flags & LPROPS_TAKEN) || !(lp->flags & LPROPS_INDEX))
++			continue;
++		lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
++				     lp->flags | LPROPS_TAKEN, 0);
++		if (IS_ERR(lp))
++			return PTR_ERR(lp);
++		break;
++	}
++	dbg_find("LEB %d, dirty %d and free %d flags %#x", lp->lnum, lp->dirty,
++		 lp->free, lp->flags);
++	ubifs_assert(lp->flags | LPROPS_TAKEN);
++	ubifs_assert(lp->flags | LPROPS_INDEX);
++	return lnum;
++}
++
++/**
++ * ubifs_find_dirty_idx_leb - try to find dirtiest index LEB as at last commit.
++ * @c: the UBIFS file-system description object
++ *
++ * This function attempts to find an untaken index LEB with the most free and
++ * dirty space that can be used without overwriting index nodes that were in the
++ * last index committed.
++ */
++int ubifs_find_dirty_idx_leb(struct ubifs_info *c)
++{
++	int err;
++
++	ubifs_get_lprops(c);
++
++	/*
++	 * We made an array of the dirtiest index LEB numbers as at the start of
++	 * last commit.  Try that array first.
++	 */
++	err = find_dirtiest_idx_leb(c);
++
++	/* Next try scanning the entire LPT */
++	if (err == -ENOSPC)
++		err = find_dirty_idx_leb(c);
++
++	/* Finally take any index LEBs awaiting trivial GC */
++	if (err == -ENOSPC)
++		err = get_idx_gc_leb(c);
++
++	ubifs_release_lprops(c);
++	return err;
++}
+diff -Nurd linux-2.6.24.orig/fs/ubifs/gc.c linux-2.6.24/fs/ubifs/gc.c
+--- linux-2.6.24.orig/fs/ubifs/gc.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/gc.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,869 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Adrian Hunter
++ *          Artem Bityutskiy (Битюцкий Артём)
++ */
++
++/*
++ * This file implements garbage collection. The procedure for garbage collection
++ * is different depending on whether a LEB as an index LEB (contains index
++ * nodes) or not. For non-index LEBs, garbage collection finds a LEB which
++ * contains a lot of dirty space (obsolete nodes), and copies the non-obsolete
++ * nodes to the journal, at which point the garbage-collected LEB is free to be
++ * reused. For index LEBs, garbage collection marks the non-obsolete index nodes
++ * dirty in the TNC, and after the next commit, the garbage-collected LEB is
++ * to be reused. Garbage collection will cause the number of dirty index nodes
++ * to grow, however sufficient space is reserved for the index to ensure the
++ * commit will never run out of space.
++ *
++ * Notes about dead watermark. At current UBIFS implementation we assume that
++ * LEBs which have less than @c->dead_wm bytes of free + dirty space are full
++ * and not worth garbage-collecting. The dead watermark is one min. I/O unit
++ * size, or min. UBIFS node size, depending on what is greater. Indeed, UBIFS
++ * Garbage Collector has to synchronize the GC head's write buffer before
++ * returning, so this is about wasting one min. I/O unit. However, UBIFS GC can
++ * actually reclaim even very small pieces of dirty space by garbage collecting
++ * enough dirty LEBs, but we do not bother doing this at this implementation.
++ *
++ * Notes about dark watermark. The results of GC work depends on how big are
++ * the UBIFS nodes GC deals with. Large nodes make GC waste more space. Indeed,
++ * if GC move data from LEB A to LEB B and nodes in LEB A are large, GC would
++ * have to waste large pieces of free space at the end of LEB B, because nodes
++ * from LEB A would not fit. And the worst situation is when all nodes are of
++ * maximum size. So dark watermark is the amount of free + dirty space in LEB
++ * which are guaranteed to be reclaimable. If LEB has less space, the GC migh
++ * be unable to reclaim it. So, LEBs with free + dirty greater than dark
++ * watermark are "good" LEBs from GC's point of few. The other LEBs are not so
++ * good, and GC takes extra care when moving them.
++ */
++
++#include <linux/pagemap.h>
++#include "ubifs.h"
++
++/*
++ * GC tries to optimize the way it fit nodes to available space, and it sorts
++ * nodes a little. The below constants are watermarks which define "large",
++ * "medium", and "small" nodes.
++ */
++#define MEDIUM_NODE_WM (UBIFS_BLOCK_SIZE / 4)
++#define SMALL_NODE_WM  UBIFS_MAX_DENT_NODE_SZ
++
++/*
++ * GC may need to move more then one LEB to make progress. The below constants
++ * define "soft" and "hard" limits on the number of LEBs the garbage collector
++ * may move.
++ */
++#define SOFT_LEBS_LIMIT 4
++#define HARD_LEBS_LIMIT 32
++
++/**
++ * switch_gc_head - switch the garbage collection journal head.
++ * @c: UBIFS file-system description object
++ * @buf: buffer to write
++ * @len: length of the buffer to write
++ * @lnum: LEB number written is returned here
++ * @offs: offset written is returned here
++ *
++ * This function switch the GC head to the next LEB which is reserved in
++ * @c->gc_lnum. Returns %0 in case of success, %-EAGAIN if commit is required,
++ * and other negative error code in case of failures.
++ */
++static int switch_gc_head(struct ubifs_info *c)
++{
++	int err, gc_lnum = c->gc_lnum;
++	struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;
++
++	ubifs_assert(gc_lnum != -1);
++	dbg_gc("switch GC head from LEB %d:%d to LEB %d (waste %d bytes)",
++	       wbuf->lnum, wbuf->offs + wbuf->used, gc_lnum,
++	       c->leb_size - wbuf->offs - wbuf->used);
++
++	err = ubifs_wbuf_sync_nolock(wbuf);
++	if (err)
++		return err;
++
++	/*
++	 * The GC write-buffer was synchronized, we may safely unmap
++	 * 'c->gc_lnum'.
++	 */
++	err = ubifs_leb_unmap(c, gc_lnum);
++	if (err)
++		return err;
++
++	err = ubifs_add_bud_to_log(c, GCHD, gc_lnum, 0);
++	if (err)
++		return err;
++
++	c->gc_lnum = -1;
++	err = ubifs_wbuf_seek_nolock(wbuf, gc_lnum, 0, UBI_LONGTERM);
++	return err;
++}
++
++/**
++ * joinup - bring data nodes for an inode together.
++ * @c: UBIFS file-system description object
++ * @sleb: describes scanned LEB
++ * @inum: inode number
++ * @blk: block number
++ * @data: list to which to add data nodes
++ *
++ * This function looks at the first few nodes in the scanned LEB @sleb and adds
++ * them to @data if they are data nodes from @inum and have a larger block
++ * number than @blk. This function returns %0 on success and a negative error
++ * code on failure.
++ */
++static int joinup(struct ubifs_info *c, struct ubifs_scan_leb *sleb, ino_t inum,
++		  unsigned int blk, struct list_head *data)
++{
++	int err, cnt = 6, lnum = sleb->lnum, offs;
++	struct ubifs_scan_node *snod, *tmp;
++	union ubifs_key *key;
++
++	list_for_each_entry_safe(snod, tmp, &sleb->nodes, list) {
++		key = &snod->key;
++		if (key_inum(c, key) == inum &&
++		    key_type(c, key) == UBIFS_DATA_KEY &&
++		    key_block(c, key) > blk) {
++			offs = snod->offs;
++			err = ubifs_tnc_has_node(c, key, 0, lnum, offs, 0);
++			if (err < 0)
++				return err;
++			list_del(&snod->list);
++			if (err) {
++				list_add_tail(&snod->list, data);
++				blk = key_block(c, key);
++			} else
++				kfree(snod);
++			cnt = 6;
++		} else if (--cnt == 0)
++			break;
++	}
++	return 0;
++}
++
++/**
++ * move_nodes - move nodes.
++ * @c: UBIFS file-system description object
++ * @sleb: describes nodes to move
++ *
++ * This function moves valid nodes from data LEB described by @sleb to the GC
++ * journal head. The obsolete nodes are dropped.
++ *
++ * When moving nodes we have to deal with classical bin-packing problem: the
++ * space in the current GC journal head LEB and in @c->gc_lnum are the "bins",
++ * where the nodes in the @sleb->nodes list are the elements which should be
++ * fit optimally to the bins. This function uses the "first fit decreasing"
++ * strategy, although it does not really sort the nodes but just split them on
++ * 3 classes - large, medium, and small, so they are roughly sorted.
++ *
++ * This function returns zero in case of success, %-EAGAIN if commit is
++ * required, and other negative error codes in case of other failures.
++ */
++static int move_nodes(struct ubifs_info *c, struct ubifs_scan_leb *sleb)
++{
++	struct ubifs_scan_node *snod, *tmp;
++	struct list_head data, large, medium, small;
++	struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;
++	int avail, err, min = INT_MAX;
++	unsigned int blk = 0;
++	ino_t inum = 0;
++
++	INIT_LIST_HEAD(&data);
++	INIT_LIST_HEAD(&large);
++	INIT_LIST_HEAD(&medium);
++	INIT_LIST_HEAD(&small);
++
++	while (!list_empty(&sleb->nodes)) {
++		struct list_head *lst = sleb->nodes.next;
++
++		snod = list_entry(lst, struct ubifs_scan_node, list);
++
++		ubifs_assert(snod->type != UBIFS_IDX_NODE);
++		ubifs_assert(snod->type != UBIFS_REF_NODE);
++		ubifs_assert(snod->type != UBIFS_CS_NODE);
++
++		err = ubifs_tnc_has_node(c, &snod->key, 0, sleb->lnum,
++					 snod->offs, 0);
++		if (err < 0)
++			goto out;
++
++		list_del(lst);
++		if (!err) {
++			/* The node is obsolete, remove it from the list */
++			kfree(snod);
++			continue;
++		}
++
++		/*
++		 * Sort the list of nodes so that data nodes go first, large
++		 * nodes go second, and small nodes go last.
++		 */
++		if (key_type(c, &snod->key) == UBIFS_DATA_KEY) {
++			if (inum != key_inum(c, &snod->key)) {
++				if (inum) {
++					/*
++					 * Try to move data nodes from the same
++					 * inode together.
++					 */
++					err = joinup(c, sleb, inum, blk, &data);
++					if (err)
++						goto out;
++				}
++				inum = key_inum(c, &snod->key);
++				blk = key_block(c, &snod->key);
++			}
++			list_add_tail(lst, &data);
++		} else if (snod->len > MEDIUM_NODE_WM)
++			list_add_tail(lst, &large);
++		else if (snod->len > SMALL_NODE_WM)
++			list_add_tail(lst, &medium);
++		else
++			list_add_tail(lst, &small);
++
++		/* And find the smallest node */
++		if (snod->len < min)
++			min = snod->len;
++	}
++
++	/*
++	 * Join the tree lists so that we'd have one roughly sorted list
++	 * ('large' will be the head of the joined list).
++	 */
++	list_splice(&data, &large);
++	list_splice(&medium, large.prev);
++	list_splice(&small, large.prev);
++
++	if (wbuf->lnum == -1) {
++		/*
++		 * The GC journal head is not set, because it is the first GC
++		 * invocation since mount.
++		 */
++		err = switch_gc_head(c);
++		if (err)
++			goto out;
++	}
++
++	/* Write nodes to their new location. Use the first-fit strategy */
++	while (1) {
++		avail = c->leb_size - wbuf->offs - wbuf->used;
++		list_for_each_entry_safe(snod, tmp, &large, list) {
++			int new_lnum, new_offs;
++
++			if (avail < min)
++				break;
++
++			if (snod->len > avail)
++				/* This node does not fit */
++				continue;
++
++			cond_resched();
++
++			new_lnum = wbuf->lnum;
++			new_offs = wbuf->offs + wbuf->used;
++			err = ubifs_wbuf_write_nolock(wbuf, snod->node,
++						      snod->len);
++			if (err)
++				goto out;
++			err = ubifs_tnc_replace(c, &snod->key, sleb->lnum,
++						snod->offs, new_lnum, new_offs,
++						snod->len);
++			if (err)
++				goto out;
++
++			avail = c->leb_size - wbuf->offs - wbuf->used;
++			list_del(&snod->list);
++			kfree(snod);
++		}
++
++		if (list_empty(&large))
++			break;
++
++		/*
++		 * Waste the rest of the space in the LEB and switch to the
++		 * next LEB.
++		 */
++		err = switch_gc_head(c);
++		if (err)
++			goto out;
++	}
++
++	return 0;
++
++out:
++	list_for_each_entry_safe(snod, tmp, &large, list) {
++		list_del(&snod->list);
++		kfree(snod);
++	}
++	return err;
++}
++
++/**
++ * gc_sync_wbufs - sync write-buffers for GC.
++ * @c: UBIFS file-system description object
++ *
++ * We must guarantee that obsoleting nodes are on flash. Unfortunately they may
++ * be in a write-buffer instead. That is, a node could be written to a
++ * write-buffer, obsoleting another node in a LEB that is GC'd. If that LEB is
++ * erased before the write-buffer is sync'd and then there is an unclean
++ * unmount, then an existing node is lost. To avoid this, we sync all
++ * write-buffers.
++ *
++ * This function returns %0 on success or a negative error code on failure.
++ */
++static int gc_sync_wbufs(struct ubifs_info *c)
++{
++	int err, i;
++
++	for (i = 0; i < c->jhead_cnt; i++) {
++		if (i == GCHD)
++			continue;
++		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
++		if (err)
++			return err;
++	}
++	return 0;
++}
++
++/**
++ * ubifs_garbage_collect_leb - garbage-collect a logical eraseblock.
++ * @c: UBIFS file-system description object
++ * @lp: describes the LEB to garbage collect
++ *
++ * This function garbage-collects an LEB and returns one of the @LEB_FREED,
++ * @LEB_RETAINED, etc positive codes in case of success, %-EAGAIN if commit is
++ * required, and other negative error codes in case of failures.
++ */
++int ubifs_garbage_collect_leb(struct ubifs_info *c, struct ubifs_lprops *lp)
++{
++	struct ubifs_scan_leb *sleb;
++	struct ubifs_scan_node *snod;
++	struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;
++	int err = 0, lnum = lp->lnum;
++
++	ubifs_assert(c->gc_lnum != -1 || wbuf->offs + wbuf->used == 0 ||
++		     c->need_recovery);
++	ubifs_assert(c->gc_lnum != lnum);
++	ubifs_assert(wbuf->lnum != lnum);
++
++	/*
++	 * We scan the entire LEB even though we only really need to scan up to
++	 * (c->leb_size - lp->free).
++	 */
++	sleb = ubifs_scan(c, lnum, 0, c->sbuf);
++	if (IS_ERR(sleb))
++		return PTR_ERR(sleb);
++
++	ubifs_assert(!list_empty(&sleb->nodes));
++	snod = list_entry(sleb->nodes.next, struct ubifs_scan_node, list);
++
++	if (snod->type == UBIFS_IDX_NODE) {
++		struct ubifs_gced_idx_leb *idx_gc;
++
++		dbg_gc("indexing LEB %d (free %d, dirty %d)",
++		       lnum, lp->free, lp->dirty);
++		list_for_each_entry(snod, &sleb->nodes, list) {
++			struct ubifs_idx_node *idx = snod->node;
++			int level = le16_to_cpu(idx->level);
++
++			ubifs_assert(snod->type == UBIFS_IDX_NODE);
++			key_read(c, ubifs_idx_key(c, idx), &snod->key);
++			err = ubifs_dirty_idx_node(c, &snod->key, level, lnum,
++						   snod->offs);
++			if (err)
++				goto out;
++		}
++
++		idx_gc = kmalloc(sizeof(struct ubifs_gced_idx_leb), GFP_NOFS);
++		if (!idx_gc) {
++			err = -ENOMEM;
++			goto out;
++		}
++
++		idx_gc->lnum = lnum;
++		idx_gc->unmap = 0;
++		list_add(&idx_gc->list, &c->idx_gc);
++
++		/*
++		 * Don't release the LEB until after the next commit, because
++		 * it may contain data which is needed for recovery. So
++		 * although we freed this LEB, it will become usable only after
++		 * the commit.
++		 */
++		err = ubifs_change_one_lp(c, lnum, c->leb_size, 0, 0,
++					  LPROPS_INDEX, 1);
++		if (err)
++			goto out;
++		err = LEB_FREED_IDX;
++	} else {
++		dbg_gc("data LEB %d (free %d, dirty %d)",
++		       lnum, lp->free, lp->dirty);
++
++		err = move_nodes(c, sleb);
++		if (err)
++			goto out_inc_seq;
++
++		err = gc_sync_wbufs(c);
++		if (err)
++			goto out_inc_seq;
++
++		err = ubifs_change_one_lp(c, lnum, c->leb_size, 0, 0, 0, 0);
++		if (err)
++			goto out_inc_seq;
++
++		/* Allow for races with TNC */
++		c->gced_lnum = lnum;
++		smp_wmb();
++		c->gc_seq += 1;
++		smp_wmb();
++
++		if (c->gc_lnum == -1) {
++			c->gc_lnum = lnum;
++			err = LEB_RETAINED;
++		} else {
++			err = ubifs_wbuf_sync_nolock(wbuf);
++			if (err)
++				goto out;
++
++			err = ubifs_leb_unmap(c, lnum);
++			if (err)
++				goto out;
++
++			err = LEB_FREED;
++		}
++	}
++
++out:
++	ubifs_scan_destroy(sleb);
++	return err;
++
++out_inc_seq:
++	/* We may have moved at least some nodes so allow for races with TNC */
++	c->gced_lnum = lnum;
++	smp_wmb();
++	c->gc_seq += 1;
++	smp_wmb();
++	goto out;
++}
++
++/**
++ * ubifs_garbage_collect - UBIFS garbage collector.
++ * @c: UBIFS file-system description object
++ * @anyway: do GC even if there are free LEBs
++ *
++ * This function does out-of-place garbage collection. The return codes are:
++ *   o positive LEB number if the LEB has been freed and may be used;
++ *   o %-EAGAIN if the caller has to run commit;
++ *   o %-ENOSPC if GC failed to make any progress;
++ *   o other negative error codes in case of other errors.
++ *
++ * Garbage collector writes data to the journal when GC'ing data LEBs, and just
++ * marking indexing nodes dirty when GC'ing indexing LEBs. Thus, at some point
++ * commit may be required. But commit cannot be run from inside GC, because the
++ * caller might be holding the commit lock, so %-EAGAIN is returned instead;
++ * And this error code means that the caller has to run commit, and re-run GC
++ * if there is still no free space.
++ *
++ * There are many reasons why this function may return %-EAGAIN:
++ * o the log is full and there is no space to write an LEB reference for
++ *   @c->gc_lnum;
++ * o the journal is too large and exceeds size limitations;
++ * o GC moved indexing LEBs, but they can be used only after the commit;
++ * o the shrinker fails to find clean znodes to free and requests the commit;
++ * o etc.
++ *
++ * Note, if the file-system is close to be full, this function may return
++ * %-EAGAIN infinitely, so the caller has to limit amount of re-invocations of
++ * the function. E.g., this happens if the limits on the journal size are too
++ * tough and GC writes too much to the journal before an LEB is freed. This
++ * might also mean that the journal is too large, and the TNC becomes to big,
++ * so that the shrinker is constantly called, finds not clean znodes to free,
++ * and requests commit. Well, this may also happen if the journal is all right,
++ * but another kernel process consumes too much memory. Anyway, infinite
++ * %-EAGAIN may happen, but in some extreme/misconfiguration cases.
++ */
++int ubifs_garbage_collect(struct ubifs_info *c, int anyway)
++{
++	int i, err, ret, min_space = c->dead_wm;
++	struct ubifs_lprops lp;
++	struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;
++
++	ubifs_assert_cmt_locked(c);
++
++	if (ubifs_gc_should_commit(c))
++		return -EAGAIN;
++
++	mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
++
++	if (c->ro_media) {
++		ret = -EROFS;
++		goto out_unlock;
++	}
++
++	/* We expect the write-buffer to be empty on entry */
++	ubifs_assert(!wbuf->used);
++
++	for (i = 0; ; i++) {
++		int space_before = c->leb_size - wbuf->offs - wbuf->used;
++		int space_after;
++
++		cond_resched();
++
++		/* Give the commit an opportunity to run */
++		if (ubifs_gc_should_commit(c)) {
++			ret = -EAGAIN;
++			break;
++		}
++
++		if (i > SOFT_LEBS_LIMIT && !list_empty(&c->idx_gc)) {
++			/*
++			 * We've done enough iterations. Indexing LEBs were
++			 * moved and will be available after the commit.
++			 */
++			dbg_gc("soft limit, some index LEBs GC'ed, -EAGAIN");
++			ubifs_commit_required(c);
++			ret = -EAGAIN;
++			break;
++		}
++
++		if (i > HARD_LEBS_LIMIT) {
++			/*
++			 * We've moved too many LEBs and have not made
++			 * progress, give up.
++			 */
++			dbg_gc("hard limit, -ENOSPC");
++			ret = -ENOSPC;
++			break;
++		}
++
++		/*
++		 * Empty and freeable LEBs can turn up while we waited for
++		 * the wbuf lock, or while we have been running GC. In that
++		 * case, we should just return one of those instead of
++		 * continuing to GC dirty LEBs. Hence we request
++		 * 'ubifs_find_dirty_leb()' to return an empty LEB if it can.
++		 */
++		ret = ubifs_find_dirty_leb(c, &lp, min_space, anyway ? 0 : 1);
++		if (ret) {
++			if (ret == -ENOSPC)
++				dbg_gc("no more dirty LEBs");
++			break;
++		}
++
++		dbg_gc("found LEB %d: free %d, dirty %d, sum %d "
++		       "(min. space %d)", lp.lnum, lp.free, lp.dirty,
++		       lp.free + lp.dirty, min_space);
++
++		if (lp.free + lp.dirty == c->leb_size) {
++			/* An empty LEB was returned */
++			dbg_gc("LEB %d is free, return it", lp.lnum);
++			/*
++			 * ubifs_find_dirty_leb() doesn't return freeable index
++			 * LEBs.
++			 */
++			ubifs_assert(!(lp.flags & LPROPS_INDEX));
++			if (lp.free != c->leb_size) {
++				/*
++				 * Write buffers must be sync'd before
++				 * unmapping freeable LEBs, because one of them
++				 * may contain data which obsoletes something
++				 * in 'lp.pnum'.
++				 */
++				ret = gc_sync_wbufs(c);
++				if (ret)
++					goto out;
++				ret = ubifs_change_one_lp(c, lp.lnum,
++							  c->leb_size, 0, 0, 0,
++							  0);
++				if (ret)
++					goto out;
++			}
++			ret = ubifs_leb_unmap(c, lp.lnum);
++			if (ret)
++				goto out;
++			ret = lp.lnum;
++			break;
++		}
++
++		space_before = c->leb_size - wbuf->offs - wbuf->used;
++		if (wbuf->lnum == -1)
++			space_before = 0;
++
++		ret = ubifs_garbage_collect_leb(c, &lp);
++		if (ret < 0) {
++			if (ret == -EAGAIN || ret == -ENOSPC) {
++				/*
++				 * These codes are not errors, so we have to
++				 * return the LEB to lprops. But if the
++				 * 'ubifs_return_leb()' function fails, its
++				 * failure code is propagated to the caller
++				 * instead of the original '-EAGAIN' or
++				 * '-ENOSPC'.
++				 */
++				err = ubifs_return_leb(c, lp.lnum);
++				if (err)
++					ret = err;
++				break;
++			}
++			goto out;
++		}
++
++		if (ret == LEB_FREED) {
++			/* An LEB has been freed and is ready for use */
++			dbg_gc("LEB %d freed, return", lp.lnum);
++			ret = lp.lnum;
++			break;
++		}
++
++		if (ret == LEB_FREED_IDX) {
++			/*
++			 * This was an indexing LEB and it cannot be
++			 * immediately used. And instead of requesting the
++			 * commit straight away, we try to garbage collect some
++			 * more.
++			 */
++			dbg_gc("indexing LEB %d freed, continue", lp.lnum);
++			continue;
++		}
++
++		ubifs_assert(ret == LEB_RETAINED);
++		space_after = c->leb_size - wbuf->offs - wbuf->used;
++		dbg_gc("LEB %d retained, freed %d bytes", lp.lnum,
++		       space_after - space_before);
++
++		if (space_after > space_before) {
++			/* GC makes progress, keep working */
++			min_space >>= 1;
++			if (min_space < c->dead_wm)
++				min_space = c->dead_wm;
++			continue;
++		}
++
++		dbg_gc("did not make progress");
++
++		/*
++		 * GC moved an LEB bud have not done any progress. This means
++		 * that the previous GC head LEB contained too few free space
++		 * and the LEB which was GC'ed contained only large nodes which
++		 * did not fit that space.
++		 *
++		 * We can do 2 things:
++		 * 1. pick another LEB in a hope it'll contain a small node
++		 *    which will fit the space we have at the end of current GC
++		 *    head LEB, but there is no guarantee, so we try this out
++		 *    unless we have already been working for too long;
++		 * 2. request an LEB with more dirty space, which will force
++		 *    'ubifs_find_dirty_leb()' to start scanning the lprops
++		 *    table, instead of just picking one from the heap
++		 *    (previously it already picked the dirtiest LEB).
++		 */
++		if (i < SOFT_LEBS_LIMIT) {
++			dbg_gc("try again");
++			continue;
++		}
++
++		min_space <<= 1;
++		if (min_space > c->dark_wm)
++			min_space = c->dark_wm;
++		dbg_gc("set min. space to %d", min_space);
++	}
++
++	if (ret == -ENOSPC && !list_empty(&c->idx_gc)) {
++		dbg_gc("no space, some index LEBs GC'ed, -EAGAIN");
++		ubifs_commit_required(c);
++		ret = -EAGAIN;
++	}
++
++	err = ubifs_wbuf_sync_nolock(wbuf);
++	if (!err)
++		err = ubifs_leb_unmap(c, c->gc_lnum);
++	if (err) {
++		ret = err;
++		goto out;
++	}
++out_unlock:
++	mutex_unlock(&wbuf->io_mutex);
++	return ret;
++
++out:
++	ubifs_assert(ret < 0);
++	ubifs_assert(ret != -ENOSPC && ret != -EAGAIN);
++	ubifs_ro_mode(c, ret);
++	ubifs_wbuf_sync_nolock(wbuf);
++	mutex_unlock(&wbuf->io_mutex);
++	ubifs_return_leb(c, lp.lnum);
++	return ret;
++}
++
++/**
++ * ubifs_gc_start_commit - garbage collection at start of commit.
++ * @c: UBIFS file-system description object
++ *
++ * If a LEB has only dirty and free space, then we may safely unmap it and make
++ * it free.  Note, we cannot do this with indexing LEBs because dirty space may
++ * correspond index nodes that are required for recovery.  In that case, the
++ * LEB cannot be unmapped until after the next commit.
++ *
++ * This function returns %0 upon success and a negative error code upon failure.
++ */
++int ubifs_gc_start_commit(struct ubifs_info *c)
++{
++	struct ubifs_gced_idx_leb *idx_gc;
++	const struct ubifs_lprops *lp;
++	int err = 0, flags;
++
++	ubifs_get_lprops(c);
++
++	/*
++	 * Unmap (non-index) freeable LEBs. Note that recovery requires that all
++	 * wbufs are sync'd before this, which is done in 'do_commit()'.
++	 */
++	while (1) {
++		lp = ubifs_fast_find_freeable(c);
++		if (IS_ERR(lp)) {
++			err = PTR_ERR(lp);
++			goto out;
++		}
++		if (!lp)
++			break;
++		ubifs_assert(!(lp->flags & LPROPS_TAKEN));
++		ubifs_assert(!(lp->flags & LPROPS_INDEX));
++		err = ubifs_leb_unmap(c, lp->lnum);
++		if (err)
++			goto out;
++		lp = ubifs_change_lp(c, lp, c->leb_size, 0, lp->flags, 0);
++		if (IS_ERR(lp)) {
++			err = PTR_ERR(lp);
++			goto out;
++		}
++		ubifs_assert(!(lp->flags & LPROPS_TAKEN));
++		ubifs_assert(!(lp->flags & LPROPS_INDEX));
++	}
++
++	/* Mark GC'd index LEBs OK to unmap after this commit finishes */
++	list_for_each_entry(idx_gc, &c->idx_gc, list)
++		idx_gc->unmap = 1;
++
++	/* Record index freeable LEBs for unmapping after commit */
++	while (1) {
++		lp = ubifs_fast_find_frdi_idx(c);
++		if (IS_ERR(lp)) {
++			err = PTR_ERR(lp);
++			goto out;
++		}
++		if (!lp)
++			break;
++		idx_gc = kmalloc(sizeof(struct ubifs_gced_idx_leb), GFP_NOFS);
++		if (!idx_gc) {
++			err = -ENOMEM;
++			goto out;
++		}
++		ubifs_assert(!(lp->flags & LPROPS_TAKEN));
++		ubifs_assert(lp->flags & LPROPS_INDEX);
++		/* Don't release the LEB until after the next commit */
++		flags = (lp->flags | LPROPS_TAKEN) ^ LPROPS_INDEX;
++		lp = ubifs_change_lp(c, lp, c->leb_size, 0, flags, 1);
++		if (IS_ERR(lp)) {
++			err = PTR_ERR(lp);
++			kfree(idx_gc);
++			goto out;
++		}
++		ubifs_assert(lp->flags & LPROPS_TAKEN);
++		ubifs_assert(!(lp->flags & LPROPS_INDEX));
++		idx_gc->lnum = lp->lnum;
++		idx_gc->unmap = 1;
++		list_add(&idx_gc->list, &c->idx_gc);
++	}
++out:
++	ubifs_release_lprops(c);
++	return err;
++}
++
++/**
++ * ubifs_gc_end_commit - garbage collection at end of commit.
++ * @c: UBIFS file-system description object
++ *
++ * This function completes out-of-place garbage collection of index LEBs.
++ */
++int ubifs_gc_end_commit(struct ubifs_info *c)
++{
++	struct ubifs_gced_idx_leb *idx_gc, *tmp;
++	struct ubifs_wbuf *wbuf;
++	int err = 0;
++
++	wbuf = &c->jheads[GCHD].wbuf;
++	mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
++	list_for_each_entry_safe(idx_gc, tmp, &c->idx_gc, list)
++		if (idx_gc->unmap) {
++			dbg_gc("LEB %d", idx_gc->lnum);
++			err = ubifs_leb_unmap(c, idx_gc->lnum);
++			if (err)
++				goto out;
++			err = ubifs_change_one_lp(c, idx_gc->lnum, LPROPS_NC,
++					  LPROPS_NC, 0, LPROPS_TAKEN, -1);
++			if (err)
++				goto out;
++			list_del(&idx_gc->list);
++			kfree(idx_gc);
++		}
++out:
++	mutex_unlock(&wbuf->io_mutex);
++	return err;
++}
++
++/**
++ * ubifs_destroy_idx_gc - destroy idx_gc list.
++ * @c: UBIFS file-system description object
++ *
++ * This function destroys the @c->idx_gc list. It is called when unmounting
++ * so locks are not needed. Returns zero in case of success and a negative
++ * error code in case of failure.
++ */
++void ubifs_destroy_idx_gc(struct ubifs_info *c)
++{
++	while (!list_empty(&c->idx_gc)) {
++		struct ubifs_gced_idx_leb *idx_gc;
++
++		idx_gc = list_entry(c->idx_gc.next, struct ubifs_gced_idx_leb,
++				    list);
++		c->idx_gc_cnt -= 1;
++		list_del(&idx_gc->list);
++		kfree(idx_gc);
++	}
++}
++
++/**
++ * ubifs_get_idx_gc_leb - get a LEB from GC'd index LEB list.
++ * @c: UBIFS file-system description object
++ *
++ * Called during start commit so locks are not needed.
++ */
++int ubifs_get_idx_gc_leb(struct ubifs_info *c)
++{
++	struct ubifs_gced_idx_leb *idx_gc;
++	int lnum;
++
++	if (list_empty(&c->idx_gc))
++		return -ENOSPC;
++	idx_gc = list_entry(c->idx_gc.next, struct ubifs_gced_idx_leb, list);
++	lnum = idx_gc->lnum;
++	/* c->idx_gc_cnt is updated by the caller when lprops are updated */
++	list_del(&idx_gc->list);
++	kfree(idx_gc);
++	return lnum;
++}
+diff -Nurd linux-2.6.24.orig/fs/ubifs/io.c linux-2.6.24/fs/ubifs/io.c
+--- linux-2.6.24.orig/fs/ubifs/io.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/io.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,940 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ * Copyright (C) 2006, 2007 University of Szeged, Hungary
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ *          Zoltan Sogor
++ */
++
++/*
++ * This file implements UBIFS I/O subsystem which provides various I/O-related
++ * helper functions (reading/writing/checking/validating nodes) and implements
++ * write-buffering support. Write buffers help to save space which otherwise
++ * would have been wasted for padding to the nearest minimal I/O unit boundary.
++ * Instead, data first goes to the write-buffer and is flushed when the
++ * buffer is full or when it is not used for some time (by timer). This is
++ * similar to the mechanism is used by JFFS2.
++ *
++ * Write-buffers are defined by 'struct ubifs_wbuf' objects and protected by
++ * mutexes defined inside these objects. Since sometimes upper-level code
++ * has to lock the write-buffer (e.g. journal space reservation code), many
++ * functions related to write-buffers have "nolock" suffix which means that the
++ * caller has to lock the write-buffer before calling this function.
++ *
++ * UBIFS stores nodes at 64 bit-aligned addresses. If the node length is not
++ * aligned, UBIFS starts the next node from the aligned address, and the padded
++ * bytes may contain any rubbish. In other words, UBIFS does not put padding
++ * bytes in those small gaps. Common headers of nodes store real node lengths,
++ * not aligned lengths. Indexing nodes also store real lengths in branches.
++ *
++ * UBIFS uses padding when it pads to the next min. I/O unit. In this case it
++ * uses padding nodes or padding bytes, if the padding node does not fit.
++ *
++ * All UBIFS nodes are protected by CRC checksums and UBIFS checks all nodes
++ * every time they are read from the flash media.
++ */
++
++#include <linux/crc32.h>
++#include "ubifs.h"
++
++/**
++ * ubifs_ro_mode - switch UBIFS to read read-only mode.
++ * @c: UBIFS file-system description object
++ * @err: error code which is the reason of switching to R/O mode
++ */
++void ubifs_ro_mode(struct ubifs_info *c, int err)
++{
++	if (!c->ro_media) {
++		c->ro_media = 1;
++		c->no_chk_data_crc = 0;
++		ubifs_warn("switched to read-only mode, error %d", err);
++		dbg_dump_stack();
++	}
++}
++
++/**
++ * ubifs_check_node - check node.
++ * @c: UBIFS file-system description object
++ * @buf: node to check
++ * @lnum: logical eraseblock number
++ * @offs: offset within the logical eraseblock
++ * @quiet: print no messages
++ * @must_chk_crc: indicates whether to always check the CRC
++ *
++ * This function checks node magic number and CRC checksum. This function also
++ * validates node length to prevent UBIFS from becoming crazy when an attacker
++ * feeds it a file-system image with incorrect nodes. For example, too large
++ * node length in the common header could cause UBIFS to read memory outside of
++ * allocated buffer when checking the CRC checksum.
++ *
++ * This function may skip data nodes CRC checking if @c->no_chk_data_crc is
++ * true, which is controlled by corresponding UBIFS mount option. However, if
++ * @must_chk_crc is true, then @c->no_chk_data_crc is ignored and CRC is
++ * checked. Similarly, if @c->always_chk_crc is true, @c->no_chk_data_crc is
++ * ignored and CRC is checked.
++ *
++ * This function returns zero in case of success and %-EUCLEAN in case of bad
++ * CRC or magic.
++ */
++int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum,
++		     int offs, int quiet, int must_chk_crc)
++{
++	int err = -EINVAL, type, node_len;
++	uint32_t crc, node_crc, magic;
++	const struct ubifs_ch *ch = buf;
++
++	ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
++	ubifs_assert(!(offs & 7) && offs < c->leb_size);
++
++	magic = le32_to_cpu(ch->magic);
++	if (magic != UBIFS_NODE_MAGIC) {
++		if (!quiet)
++			ubifs_err("bad magic %#08x, expected %#08x",
++				  magic, UBIFS_NODE_MAGIC);
++		err = -EUCLEAN;
++		goto out;
++	}
++
++	type = ch->node_type;
++	if (type < 0 || type >= UBIFS_NODE_TYPES_CNT) {
++		if (!quiet)
++			ubifs_err("bad node type %d", type);
++		goto out;
++	}
++
++	node_len = le32_to_cpu(ch->len);
++	if (node_len + offs > c->leb_size)
++		goto out_len;
++
++	if (c->ranges[type].max_len == 0) {
++		if (node_len != c->ranges[type].len)
++			goto out_len;
++	} else if (node_len < c->ranges[type].min_len ||
++		   node_len > c->ranges[type].max_len)
++		goto out_len;
++
++	if (!must_chk_crc && type == UBIFS_DATA_NODE && !c->always_chk_crc &&
++	     c->no_chk_data_crc)
++		return 0;
++
++	crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8);
++	node_crc = le32_to_cpu(ch->crc);
++	if (crc != node_crc) {
++		if (!quiet)
++			ubifs_err("bad CRC: calculated %#08x, read %#08x",
++				  crc, node_crc);
++		err = -EUCLEAN;
++		goto out;
++	}
++
++	return 0;
++
++out_len:
++	if (!quiet)
++		ubifs_err("bad node length %d", node_len);
++out:
++	if (!quiet) {
++		ubifs_err("bad node at LEB %d:%d", lnum, offs);
++		dbg_dump_node(c, buf);
++		dbg_dump_stack();
++	}
++	return err;
++}
++
++/**
++ * ubifs_pad - pad flash space.
++ * @c: UBIFS file-system description object
++ * @buf: buffer to put padding to
++ * @pad: how many bytes to pad
++ *
++ * The flash media obliges us to write only in chunks of %c->min_io_size and
++ * when we have to write less data we add padding node to the write-buffer and
++ * pad it to the next minimal I/O unit's boundary. Padding nodes help when the
++ * media is being scanned. If the amount of wasted space is not enough to fit a
++ * padding node which takes %UBIFS_PAD_NODE_SZ bytes, we write padding bytes
++ * pattern (%UBIFS_PADDING_BYTE).
++ *
++ * Padding nodes are also used to fill gaps when the "commit-in-gaps" method is
++ * used.
++ */
++void ubifs_pad(const struct ubifs_info *c, void *buf, int pad)
++{
++	uint32_t crc;
++
++	ubifs_assert(pad >= 0 && !(pad & 7));
++
++	if (pad >= UBIFS_PAD_NODE_SZ) {
++		struct ubifs_ch *ch = buf;
++		struct ubifs_pad_node *pad_node = buf;
++
++		ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC);
++		ch->node_type = UBIFS_PAD_NODE;
++		ch->group_type = UBIFS_NO_NODE_GROUP;
++		ch->padding[0] = ch->padding[1] = 0;
++		ch->sqnum = 0;
++		ch->len = cpu_to_le32(UBIFS_PAD_NODE_SZ);
++		pad -= UBIFS_PAD_NODE_SZ;
++		pad_node->pad_len = cpu_to_le32(pad);
++		crc = crc32(UBIFS_CRC32_INIT, buf + 8, UBIFS_PAD_NODE_SZ - 8);
++		ch->crc = cpu_to_le32(crc);
++		memset(buf + UBIFS_PAD_NODE_SZ, 0, pad);
++	} else if (pad > 0)
++		/* Too little space, padding node won't fit */
++		memset(buf, UBIFS_PADDING_BYTE, pad);
++}
++
++/**
++ * next_sqnum - get next sequence number.
++ * @c: UBIFS file-system description object
++ */
++static unsigned long long next_sqnum(struct ubifs_info *c)
++{
++	unsigned long long sqnum;
++
++	spin_lock(&c->cnt_lock);
++	sqnum = ++c->max_sqnum;
++	spin_unlock(&c->cnt_lock);
++
++	if (unlikely(sqnum >= SQNUM_WARN_WATERMARK)) {
++		if (sqnum >= SQNUM_WATERMARK) {
++			ubifs_err("sequence number overflow %llu, end of life",
++				  sqnum);
++			ubifs_ro_mode(c, -EINVAL);
++		}
++		ubifs_warn("running out of sequence numbers, end of life soon");
++	}
++
++	return sqnum;
++}
++
++/**
++ * ubifs_prepare_node - prepare node to be written to flash.
++ * @c: UBIFS file-system description object
++ * @node: the node to pad
++ * @len: node length
++ * @pad: if the buffer has to be padded
++ *
++ * This function prepares node at @node to be written to the media - it
++ * calculates node CRC, fills the common header, and adds proper padding up to
++ * the next minimum I/O unit if @pad is not zero.
++ */
++void ubifs_prepare_node(struct ubifs_info *c, void *node, int len, int pad)
++{
++	uint32_t crc;
++	struct ubifs_ch *ch = node;
++	unsigned long long sqnum = next_sqnum(c);
++
++	ubifs_assert(len >= UBIFS_CH_SZ);
++
++	ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC);
++	ch->len = cpu_to_le32(len);
++	ch->group_type = UBIFS_NO_NODE_GROUP;
++	ch->sqnum = cpu_to_le64(sqnum);
++	ch->padding[0] = ch->padding[1] = 0;
++	crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8);
++	ch->crc = cpu_to_le32(crc);
++
++	if (pad) {
++		len = ALIGN(len, 8);
++		pad = ALIGN(len, c->min_io_size) - len;
++		ubifs_pad(c, node + len, pad);
++	}
++}
++
++/**
++ * ubifs_prep_grp_node - prepare node of a group to be written to flash.
++ * @c: UBIFS file-system description object
++ * @node: the node to pad
++ * @len: node length
++ * @last: indicates the last node of the group
++ *
++ * This function prepares node at @node to be written to the media - it
++ * calculates node CRC and fills the common header.
++ */
++void ubifs_prep_grp_node(struct ubifs_info *c, void *node, int len, int last)
++{
++	uint32_t crc;
++	struct ubifs_ch *ch = node;
++	unsigned long long sqnum = next_sqnum(c);
++
++	ubifs_assert(len >= UBIFS_CH_SZ);
++
++	ch->magic = cpu_to_le32(UBIFS_NODE_MAGIC);
++	ch->len = cpu_to_le32(len);
++	if (last)
++		ch->group_type = UBIFS_LAST_OF_NODE_GROUP;
++	else
++		ch->group_type = UBIFS_IN_NODE_GROUP;
++	ch->sqnum = cpu_to_le64(sqnum);
++	ch->padding[0] = ch->padding[1] = 0;
++	crc = crc32(UBIFS_CRC32_INIT, node + 8, len - 8);
++	ch->crc = cpu_to_le32(crc);
++}
++
++/**
++ * wbuf_timer_callback - write-buffer timer callback function.
++ * @data: timer data (write-buffer descriptor)
++ *
++ * This function is called when the write-buffer timer expires.
++ */
++static void wbuf_timer_callback_nolock(unsigned long data)
++{
++	struct ubifs_wbuf *wbuf = (struct ubifs_wbuf *)data;
++
++	wbuf->need_sync = 1;
++	wbuf->c->need_wbuf_sync = 1;
++	ubifs_wake_up_bgt(wbuf->c);
++}
++
++/**
++ * new_wbuf_timer - start new write-buffer timer.
++ * @wbuf: write-buffer descriptor
++ */
++static void new_wbuf_timer_nolock(struct ubifs_wbuf *wbuf)
++{
++	ubifs_assert(!timer_pending(&wbuf->timer));
++
++	if (!wbuf->timeout)
++		return;
++
++	wbuf->timer.expires = jiffies + wbuf->timeout;
++	add_timer(&wbuf->timer);
++}
++
++/**
++ * cancel_wbuf_timer - cancel write-buffer timer.
++ * @wbuf: write-buffer descriptor
++ */
++static void cancel_wbuf_timer_nolock(struct ubifs_wbuf *wbuf)
++{
++	/*
++	 * If the syncer is waiting for the lock (from the background thread's
++	 * context) and another task is changing write-buffer then the syncing
++	 * should be canceled.
++	 */
++	wbuf->need_sync = 0;
++	del_timer(&wbuf->timer);
++}
++
++/**
++ * ubifs_wbuf_sync_nolock - synchronize write-buffer.
++ * @wbuf: write-buffer to synchronize
++ *
++ * This function synchronizes write-buffer @buf and returns zero in case of
++ * success or a negative error code in case of failure.
++ */
++int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf)
++{
++	struct ubifs_info *c = wbuf->c;
++	int err, dirt;
++
++	cancel_wbuf_timer_nolock(wbuf);
++	if (!wbuf->used || wbuf->lnum == -1)
++		/* Write-buffer is empty or not seeked */
++		return 0;
++
++	dbg_io("LEB %d:%d, %d bytes",
++	       wbuf->lnum, wbuf->offs, wbuf->used);
++	ubifs_assert(!(c->vfs_sb->s_flags & MS_RDONLY));
++	ubifs_assert(!(wbuf->avail & 7));
++	ubifs_assert(wbuf->offs + c->min_io_size <= c->leb_size);
++
++	if (c->ro_media)
++		return -EROFS;
++
++	ubifs_pad(c, wbuf->buf + wbuf->used, wbuf->avail);
++	err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, wbuf->offs,
++			    c->min_io_size, wbuf->dtype);
++	if (err) {
++		ubifs_err("cannot write %d bytes to LEB %d:%d",
++			  c->min_io_size, wbuf->lnum, wbuf->offs);
++		dbg_dump_stack();
++		return err;
++	}
++
++	dirt = wbuf->avail;
++
++	spin_lock(&wbuf->lock);
++	wbuf->offs += c->min_io_size;
++	wbuf->avail = c->min_io_size;
++	wbuf->used = 0;
++	wbuf->next_ino = 0;
++	spin_unlock(&wbuf->lock);
++
++	if (wbuf->sync_callback)
++		err = wbuf->sync_callback(c, wbuf->lnum,
++					  c->leb_size - wbuf->offs, dirt);
++	return err;
++}
++
++/**
++ * ubifs_wbuf_seek_nolock - seek write-buffer.
++ * @wbuf: write-buffer
++ * @lnum: logical eraseblock number to seek to
++ * @offs: logical eraseblock offset to seek to
++ * @dtype: data type
++ *
++ * This function targets the write buffer to logical eraseblock @lnum:@offs.
++ * The write-buffer is synchronized if it is not empty. Returns zero in case of
++ * success and a negative error code in case of failure.
++ */
++int ubifs_wbuf_seek_nolock(struct ubifs_wbuf *wbuf, int lnum, int offs,
++			   int dtype)
++{
++	const struct ubifs_info *c = wbuf->c;
++
++	dbg_io("LEB %d:%d", lnum, offs);
++	ubifs_assert(lnum >= 0 && lnum < c->leb_cnt);
++	ubifs_assert(offs >= 0 && offs <= c->leb_size);
++	ubifs_assert(offs % c->min_io_size == 0 && !(offs & 7));
++	ubifs_assert(lnum != wbuf->lnum);
++
++	if (wbuf->used > 0) {
++		int err = ubifs_wbuf_sync_nolock(wbuf);
++
++		if (err)
++			return err;
++	}
++
++	spin_lock(&wbuf->lock);
++	wbuf->lnum = lnum;
++	wbuf->offs = offs;
++	wbuf->avail = c->min_io_size;
++	wbuf->used = 0;
++	spin_unlock(&wbuf->lock);
++	wbuf->dtype = dtype;
++
++	return 0;
++}
++
++/**
++ * ubifs_bg_wbufs_sync - synchronize write-buffers.
++ * @c: UBIFS file-system description object
++ *
++ * This function is called by background thread to synchronize write-buffers.
++ * Returns zero in case of success and a negative error code in case of
++ * failure.
++ */
++int ubifs_bg_wbufs_sync(struct ubifs_info *c)
++{
++	int err, i;
++
++	if (!c->need_wbuf_sync)
++		return 0;
++	c->need_wbuf_sync = 0;
++
++	if (c->ro_media) {
++		err = -EROFS;
++		goto out_timers;
++	}
++
++	dbg_io("synchronize");
++	for (i = 0; i < c->jhead_cnt; i++) {
++		struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf;
++
++		cond_resched();
++
++		/*
++		 * If the mutex is locked then wbuf is being changed, so
++		 * synchronization is not necessary.
++		 */
++		if (mutex_is_locked(&wbuf->io_mutex))
++			continue;
++
++		mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
++		if (!wbuf->need_sync) {
++			mutex_unlock(&wbuf->io_mutex);
++			continue;
++		}
++
++		err = ubifs_wbuf_sync_nolock(wbuf);
++		mutex_unlock(&wbuf->io_mutex);
++		if (err) {
++			ubifs_err("cannot sync write-buffer, error %d", err);
++			ubifs_ro_mode(c, err);
++			goto out_timers;
++		}
++	}
++
++	return 0;
++
++out_timers:
++	/* Cancel all timers to prevent repeated errors */
++	for (i = 0; i < c->jhead_cnt; i++) {
++		struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf;
++
++		mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
++		cancel_wbuf_timer_nolock(wbuf);
++		mutex_unlock(&wbuf->io_mutex);
++	}
++	return err;
++}
++
++/**
++ * ubifs_wbuf_write_nolock - write data to flash via write-buffer.
++ * @wbuf: write-buffer
++ * @buf: node to write
++ * @len: node length
++ *
++ * This function writes data to flash via write-buffer @wbuf. This means that
++ * the last piece of the node won't reach the flash media immediately if it
++ * does not take whole minimal I/O unit. Instead, the node will sit in RAM
++ * until the write-buffer is synchronized (e.g., by timer).
++ *
++ * This function returns zero in case of success and a negative error code in
++ * case of failure. If the node cannot be written because there is no more
++ * space in this logical eraseblock, %-ENOSPC is returned.
++ */
++int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len)
++{
++	struct ubifs_info *c = wbuf->c;
++	int err, written, n, aligned_len = ALIGN(len, 8), offs;
++
++	dbg_io("%d bytes (%s) to wbuf at LEB %d:%d", len,
++	       dbg_ntype(((struct ubifs_ch *)buf)->node_type), wbuf->lnum,
++	       wbuf->offs + wbuf->used);
++	ubifs_assert(len > 0 && wbuf->lnum >= 0 && wbuf->lnum < c->leb_cnt);
++	ubifs_assert(wbuf->offs >= 0 && wbuf->offs % c->min_io_size == 0);
++	ubifs_assert(!(wbuf->offs & 7) && wbuf->offs <= c->leb_size);
++	ubifs_assert(wbuf->avail > 0 && wbuf->avail <= c->min_io_size);
++	ubifs_assert(mutex_is_locked(&wbuf->io_mutex));
++
++	if (c->leb_size - wbuf->offs - wbuf->used < aligned_len) {
++		err = -ENOSPC;
++		goto out;
++	}
++
++	cancel_wbuf_timer_nolock(wbuf);
++
++	if (c->ro_media)
++		return -EROFS;
++
++	if (aligned_len <= wbuf->avail) {
++		/*
++		 * The node is not very large and fits entirely within
++		 * write-buffer.
++		 */
++		memcpy(wbuf->buf + wbuf->used, buf, len);
++
++		if (aligned_len == wbuf->avail) {
++			dbg_io("flush wbuf to LEB %d:%d", wbuf->lnum,
++				wbuf->offs);
++			err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf,
++					    wbuf->offs, c->min_io_size,
++					    wbuf->dtype);
++			if (err)
++				goto out;
++
++			spin_lock(&wbuf->lock);
++			wbuf->offs += c->min_io_size;
++			wbuf->avail = c->min_io_size;
++			wbuf->used = 0;
++			wbuf->next_ino = 0;
++			spin_unlock(&wbuf->lock);
++		} else {
++			spin_lock(&wbuf->lock);
++			wbuf->avail -= aligned_len;
++			wbuf->used += aligned_len;
++			spin_unlock(&wbuf->lock);
++		}
++
++		goto exit;
++	}
++
++	/*
++	 * The node is large enough and does not fit entirely within current
++	 * minimal I/O unit. We have to fill and flush write-buffer and switch
++	 * to the next min. I/O unit.
++	 */
++	dbg_io("flush wbuf to LEB %d:%d", wbuf->lnum, wbuf->offs);
++	memcpy(wbuf->buf + wbuf->used, buf, wbuf->avail);
++	err = ubi_leb_write(c->ubi, wbuf->lnum, wbuf->buf, wbuf->offs,
++			    c->min_io_size, wbuf->dtype);
++	if (err)
++		goto out;
++
++	offs = wbuf->offs + c->min_io_size;
++	len -= wbuf->avail;
++	aligned_len -= wbuf->avail;
++	written = wbuf->avail;
++
++	/*
++	 * The remaining data may take more whole min. I/O units, so write the
++	 * remains multiple to min. I/O unit size directly to the flash media.
++	 * We align node length to 8-byte boundary because we anyway flash wbuf
++	 * if the remaining space is less than 8 bytes.
++	 */
++	n = aligned_len >> c->min_io_shift;
++	if (n) {
++		n <<= c->min_io_shift;
++		dbg_io("write %d bytes to LEB %d:%d", n, wbuf->lnum, offs);
++		err = ubi_leb_write(c->ubi, wbuf->lnum, buf + written, offs, n,
++				    wbuf->dtype);
++		if (err)
++			goto out;
++		offs += n;
++		aligned_len -= n;
++		len -= n;
++		written += n;
++	}
++
++	spin_lock(&wbuf->lock);
++	if (aligned_len)
++		/*
++		 * And now we have what's left and what does not take whole
++		 * min. I/O unit, so write it to the write-buffer and we are
++		 * done.
++		 */
++		memcpy(wbuf->buf, buf + written, len);
++
++	wbuf->offs = offs;
++	wbuf->used = aligned_len;
++	wbuf->avail = c->min_io_size - aligned_len;
++	wbuf->next_ino = 0;
++	spin_unlock(&wbuf->lock);
++
++exit:
++	if (wbuf->sync_callback) {
++		int free = c->leb_size - wbuf->offs - wbuf->used;
++
++		err = wbuf->sync_callback(c, wbuf->lnum, free, 0);
++		if (err)
++			goto out;
++	}
++
++	if (wbuf->used)
++		new_wbuf_timer_nolock(wbuf);
++
++	return 0;
++
++out:
++	ubifs_err("cannot write %d bytes to LEB %d:%d, error %d",
++		  len, wbuf->lnum, wbuf->offs, err);
++	dbg_dump_node(c, buf);
++	dbg_dump_stack();
++	dbg_dump_leb(c, wbuf->lnum);
++	return err;
++}
++
++/**
++ * ubifs_write_node - write node to the media.
++ * @c: UBIFS file-system description object
++ * @buf: the node to write
++ * @len: node length
++ * @lnum: logical eraseblock number
++ * @offs: offset within the logical eraseblock
++ * @dtype: node life-time hint (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN)
++ *
++ * This function automatically fills node magic number, assigns sequence
++ * number, and calculates node CRC checksum. The length of the @buf buffer has
++ * to be aligned to the minimal I/O unit size. This function automatically
++ * appends padding node and padding bytes if needed. Returns zero in case of
++ * success and a negative error code in case of failure.
++ */
++int ubifs_write_node(struct ubifs_info *c, void *buf, int len, int lnum,
++		     int offs, int dtype)
++{
++	int err, buf_len = ALIGN(len, c->min_io_size);
++
++	dbg_io("LEB %d:%d, %s, length %d (aligned %d)",
++	       lnum, offs, dbg_ntype(((struct ubifs_ch *)buf)->node_type), len,
++	       buf_len);
++	ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
++	ubifs_assert(offs % c->min_io_size == 0 && offs < c->leb_size);
++
++	if (c->ro_media)
++		return -EROFS;
++
++	ubifs_prepare_node(c, buf, len, 1);
++	err = ubi_leb_write(c->ubi, lnum, buf, offs, buf_len, dtype);
++	if (err) {
++		ubifs_err("cannot write %d bytes to LEB %d:%d, error %d",
++			  buf_len, lnum, offs, err);
++		dbg_dump_node(c, buf);
++		dbg_dump_stack();
++	}
++
++	return err;
++}
++
++/**
++ * ubifs_read_node_wbuf - read node from the media or write-buffer.
++ * @wbuf: wbuf to check for un-written data
++ * @buf: buffer to read to
++ * @type: node type
++ * @len: node length
++ * @lnum: logical eraseblock number
++ * @offs: offset within the logical eraseblock
++ *
++ * This function reads a node of known type and length, checks it and stores
++ * in @buf. If the node partially or fully sits in the write-buffer, this
++ * function takes data from the buffer, otherwise it reads the flash media.
++ * Returns zero in case of success, %-EUCLEAN if CRC mismatched and a negative
++ * error code in case of failure.
++ */
++int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len,
++			 int lnum, int offs)
++{
++	const struct ubifs_info *c = wbuf->c;
++	int err, rlen, overlap;
++	struct ubifs_ch *ch = buf;
++
++	dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len);
++	ubifs_assert(wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
++	ubifs_assert(!(offs & 7) && offs < c->leb_size);
++	ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT);
++
++	spin_lock(&wbuf->lock);
++	overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs);
++	if (!overlap) {
++		/* We may safely unlock the write-buffer and read the data */
++		spin_unlock(&wbuf->lock);
++		return ubifs_read_node(c, buf, type, len, lnum, offs);
++	}
++
++	/* Don't read under wbuf */
++	rlen = wbuf->offs - offs;
++	if (rlen < 0)
++		rlen = 0;
++
++	/* Copy the rest from the write-buffer */
++	memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen);
++	spin_unlock(&wbuf->lock);
++
++	if (rlen > 0) {
++		/* Read everything that goes before write-buffer */
++		err = ubi_read(c->ubi, lnum, buf, offs, rlen);
++		if (err && err != -EBADMSG) {
++			ubifs_err("failed to read node %d from LEB %d:%d, "
++				  "error %d", type, lnum, offs, err);
++			dbg_dump_stack();
++			return err;
++		}
++	}
++
++	if (type != ch->node_type) {
++		ubifs_err("bad node type (%d but expected %d)",
++			  ch->node_type, type);
++		goto out;
++	}
++
++	err = ubifs_check_node(c, buf, lnum, offs, 0, 0);
++	if (err) {
++		ubifs_err("expected node type %d", type);
++		return err;
++	}
++
++	rlen = le32_to_cpu(ch->len);
++	if (rlen != len) {
++		ubifs_err("bad node length %d, expected %d", rlen, len);
++		goto out;
++	}
++
++	return 0;
++
++out:
++	ubifs_err("bad node at LEB %d:%d", lnum, offs);
++	dbg_dump_node(c, buf);
++	dbg_dump_stack();
++	return -EINVAL;
++}
++
++/**
++ * ubifs_read_node - read node.
++ * @c: UBIFS file-system description object
++ * @buf: buffer to read to
++ * @type: node type
++ * @len: node length (not aligned)
++ * @lnum: logical eraseblock number
++ * @offs: offset within the logical eraseblock
++ *
++ * This function reads a node of known type and and length, checks it and
++ * stores in @buf. Returns zero in case of success, %-EUCLEAN if CRC mismatched
++ * and a negative error code in case of failure.
++ */
++int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len,
++		    int lnum, int offs)
++{
++	int err, l;
++	struct ubifs_ch *ch = buf;
++
++	dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len);
++	ubifs_assert(lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
++	ubifs_assert(len >= UBIFS_CH_SZ && offs + len <= c->leb_size);
++	ubifs_assert(!(offs & 7) && offs < c->leb_size);
++	ubifs_assert(type >= 0 && type < UBIFS_NODE_TYPES_CNT);
++
++	err = ubi_read(c->ubi, lnum, buf, offs, len);
++	if (err && err != -EBADMSG) {
++		ubifs_err("cannot read node %d from LEB %d:%d, error %d",
++			  type, lnum, offs, err);
++		return err;
++	}
++
++	if (type != ch->node_type) {
++		ubifs_err("bad node type (%d but expected %d)",
++			  ch->node_type, type);
++		goto out;
++	}
++
++	err = ubifs_check_node(c, buf, lnum, offs, 0, 0);
++	if (err) {
++		ubifs_err("expected node type %d", type);
++		return err;
++	}
++
++	l = le32_to_cpu(ch->len);
++	if (l != len) {
++		ubifs_err("bad node length %d, expected %d", l, len);
++		goto out;
++	}
++
++	return 0;
++
++out:
++	ubifs_err("bad node at LEB %d:%d", lnum, offs);
++	dbg_dump_node(c, buf);
++	dbg_dump_stack();
++	return -EINVAL;
++}
++
++/**
++ * ubifs_wbuf_init - initialize write-buffer.
++ * @c: UBIFS file-system description object
++ * @wbuf: write-buffer to initialize
++ *
++ * This function initializes write buffer. Returns zero in case of success
++ * %-ENOMEM in case of failure.
++ */
++int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf)
++{
++	size_t size;
++
++	wbuf->buf = kmalloc(c->min_io_size, GFP_KERNEL);
++	if (!wbuf->buf)
++		return -ENOMEM;
++
++	size = (c->min_io_size / UBIFS_CH_SZ + 1) * sizeof(ino_t);
++	wbuf->inodes = kmalloc(size, GFP_KERNEL);
++	if (!wbuf->inodes) {
++		kfree(wbuf->buf);
++		wbuf->buf = NULL;
++		return -ENOMEM;
++	}
++
++	wbuf->used = 0;
++	wbuf->lnum = wbuf->offs = -1;
++	wbuf->avail = c->min_io_size;
++	wbuf->dtype = UBI_UNKNOWN;
++	wbuf->sync_callback = NULL;
++	mutex_init(&wbuf->io_mutex);
++	spin_lock_init(&wbuf->lock);
++
++	wbuf->c = c;
++	init_timer(&wbuf->timer);
++	wbuf->timer.function = wbuf_timer_callback_nolock;
++	wbuf->timer.data = (unsigned long)wbuf;
++	wbuf->timeout = DEFAULT_WBUF_TIMEOUT;
++	wbuf->next_ino = 0;
++
++	return 0;
++}
++
++/**
++ * ubifs_wbuf_add_ino_nolock - add an inode number into the wbuf inode array.
++ * @wbuf: the write-buffer whereto add
++ * @inum: the inode number
++ *
++ * This function adds an inode number to the inode array of the write-buffer.
++ */
++void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf *wbuf, ino_t inum)
++{
++	if (!wbuf->buf)
++		/* NOR flash or something similar */
++		return;
++
++	spin_lock(&wbuf->lock);
++	if (wbuf->used)
++		wbuf->inodes[wbuf->next_ino++] = inum;
++	spin_unlock(&wbuf->lock);
++}
++
++/**
++ * wbuf_has_ino - returns if the wbuf contains data from the inode.
++ * @wbuf: the write-buffer
++ * @inum: the inode number
++ *
++ * This function returns with %1 if the write-buffer contains some data from the
++ * given inode otherwise it returns with %0.
++ */
++static int wbuf_has_ino(struct ubifs_wbuf *wbuf, ino_t inum)
++{
++	int i, ret = 0;
++
++	spin_lock(&wbuf->lock);
++	for (i = 0; i < wbuf->next_ino; i++)
++		if (inum == wbuf->inodes[i]) {
++			ret = 1;
++			break;
++		}
++	spin_unlock(&wbuf->lock);
++
++	return ret;
++}
++
++/**
++ * ubifs_sync_wbufs_by_inode - synchronize write-buffers for an inode.
++ * @c: UBIFS file-system description object
++ * @inode: inode to synchronize
++ *
++ * This function synchronizes write-buffers which contain nodes belonging to
++ * @inode. Returns zero in case of success and a negative error code in case of
++ * failure.
++ */
++int ubifs_sync_wbufs_by_inode(struct ubifs_info *c, struct inode *inode)
++{
++	int i, err = 0;
++
++	for (i = 0; i < c->jhead_cnt; i++) {
++		struct ubifs_wbuf *wbuf = &c->jheads[i].wbuf;
++
++		if (i == GCHD)
++			/*
++			 * GC head is special, do not look at it. Even if the
++			 * head contains something related to this inode, it is
++			 * a _copy_ of corresponding on-flash node which sits
++			 * somewhere else.
++			 */
++			continue;
++
++		if (!wbuf_has_ino(wbuf, inode->i_ino))
++			continue;
++
++		mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
++		if (wbuf_has_ino(wbuf, inode->i_ino))
++			err = ubifs_wbuf_sync_nolock(wbuf);
++		mutex_unlock(&wbuf->io_mutex);
++
++		if (err) {
++			ubifs_ro_mode(c, err);
++			return err;
++		}
++	}
++	return 0;
++}
+diff -Nurd linux-2.6.24.orig/fs/ubifs/ioctl.c linux-2.6.24/fs/ubifs/ioctl.c
+--- linux-2.6.24.orig/fs/ubifs/ioctl.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/ioctl.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,196 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ * Copyright (C) 2006, 2007 University of Szeged, Hungary
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Zoltan Sogor
++ *          Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++/* This file implements EXT2-compatible extended attribute ioctl() calls */
++
++#include <linux/compat.h>
++#include <linux/smp_lock.h>
++#include "ubifs.h"
++
++/**
++ * ubifs_set_inode_flags - set VFS inode flags.
++ * @inode: VFS inode to set flags for
++ *
++ * This function propagates flags from UBIFS inode object to VFS inode object.
++ */
++void ubifs_set_inode_flags(struct inode *inode)
++{
++	unsigned int flags = ubifs_inode(inode)->flags;
++
++	inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_DIRSYNC);
++	if (flags & UBIFS_SYNC_FL)
++		inode->i_flags |= S_SYNC;
++	if (flags & UBIFS_APPEND_FL)
++		inode->i_flags |= S_APPEND;
++	if (flags & UBIFS_IMMUTABLE_FL)
++		inode->i_flags |= S_IMMUTABLE;
++	if (flags & UBIFS_DIRSYNC_FL)
++		inode->i_flags |= S_DIRSYNC;
++}
++
++/*
++ * ioctl2ubifs - convert ioctl inode flags to UBIFS inode flags.
++ * @ioctl_flags: flags to convert
++ *
++ * This function convert ioctl flags (@FS_COMPR_FL, etc) to UBIFS inode flags
++ * (@UBIFS_COMPR_FL, etc).
++ */
++static int ioctl2ubifs(int ioctl_flags)
++{
++	int ubifs_flags = 0;
++
++	if (ioctl_flags & FS_COMPR_FL)
++		ubifs_flags |= UBIFS_COMPR_FL;
++	if (ioctl_flags & FS_SYNC_FL)
++		ubifs_flags |= UBIFS_SYNC_FL;
++	if (ioctl_flags & FS_APPEND_FL)
++		ubifs_flags |= UBIFS_APPEND_FL;
++	if (ioctl_flags & FS_IMMUTABLE_FL)
++		ubifs_flags |= UBIFS_IMMUTABLE_FL;
++	if (ioctl_flags & FS_DIRSYNC_FL)
++		ubifs_flags |= UBIFS_DIRSYNC_FL;
++
++	return ubifs_flags;
++}
++
++/*
++ * ubifs2ioctl - convert UBIFS inode flags to ioctl inode flags.
++ * @ubifs_flags: flags to convert
++ *
++ * This function convert UBIFS (@UBIFS_COMPR_FL, etc) to ioctl flags
++ * (@FS_COMPR_FL, etc).
++ */
++static int ubifs2ioctl(int ubifs_flags)
++{
++	int ioctl_flags = 0;
++
++	if (ubifs_flags & UBIFS_COMPR_FL)
++		ioctl_flags |= FS_COMPR_FL;
++	if (ubifs_flags & UBIFS_SYNC_FL)
++		ioctl_flags |= FS_SYNC_FL;
++	if (ubifs_flags & UBIFS_APPEND_FL)
++		ioctl_flags |= FS_APPEND_FL;
++	if (ubifs_flags & UBIFS_IMMUTABLE_FL)
++		ioctl_flags |= FS_IMMUTABLE_FL;
++	if (ubifs_flags & UBIFS_DIRSYNC_FL)
++		ioctl_flags |= FS_DIRSYNC_FL;
++
++	return ioctl_flags;
++}
++
++static int setflags(struct inode *inode, int flags)
++{
++	int oldflags, err, release;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++	struct ubifs_info *c = inode->i_sb->s_fs_info;
++	struct ubifs_budget_req req = { .dirtied_ino = 1,
++					.dirtied_ino_d = ui->data_len };
++
++	err = ubifs_budget_space(c, &req);
++	if (err)
++		return err;
++
++	/*
++	 * The IMMUTABLE and APPEND_ONLY flags can only be changed by
++	 * the relevant capability.
++	 */
++	mutex_lock(&ui->ui_mutex);
++	oldflags = ubifs2ioctl(ui->flags);
++	if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
++		if (!capable(CAP_LINUX_IMMUTABLE)) {
++			err = -EPERM;
++			goto out_unlock;
++		}
++	}
++
++	ui->flags = ioctl2ubifs(flags);
++	ubifs_set_inode_flags(inode);
++	inode->i_ctime = ubifs_current_time(inode);
++	release = ui->dirty;
++	mark_inode_dirty_sync(inode);
++	mutex_unlock(&ui->ui_mutex);
++
++	if (release)
++		ubifs_release_budget(c, &req);
++	if (IS_SYNC(inode))
++		err = write_inode_now(inode, 1);
++	return err;
++
++out_unlock:
++	ubifs_err("can't modify inode %lu attributes", inode->i_ino);
++	mutex_unlock(&ui->ui_mutex);
++	ubifs_release_budget(c, &req);
++	return err;
++}
++
++long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
++{
++	int flags;
++	struct inode *inode = file->f_path.dentry->d_inode;
++
++	switch (cmd) {
++	case FS_IOC_GETFLAGS:
++		flags = ubifs2ioctl(ubifs_inode(inode)->flags);
++
++		dbg_gen("get flags: %#x, i_flags %#x", flags, inode->i_flags);
++		return put_user(flags, (int __user *) arg);
++
++	case FS_IOC_SETFLAGS: {
++		if (IS_RDONLY(inode))
++			return -EROFS;
++
++		if (!is_owner_or_cap(inode))
++			return -EACCES;
++
++		if (get_user(flags, (int __user *) arg))
++			return -EFAULT;
++
++		if (!S_ISDIR(inode->i_mode))
++			flags &= ~FS_DIRSYNC_FL;
++
++		dbg_gen("set flags: %#x, i_flags %#x", flags, inode->i_flags);
++		return setflags(inode, flags);
++	}
++
++	default:
++		return -ENOTTY;
++	}
++}
++
++#ifdef CONFIG_COMPAT
++long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
++{
++	switch (cmd) {
++	case FS_IOC32_GETFLAGS:
++		cmd = FS_IOC_GETFLAGS;
++		break;
++	case FS_IOC32_SETFLAGS:
++		cmd = FS_IOC_SETFLAGS;
++		break;
++	default:
++		return -ENOIOCTLCMD;
++	}
++	return ubifs_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
++}
++#endif
+diff -Nurd linux-2.6.24.orig/fs/ubifs/journal.c linux-2.6.24/fs/ubifs/journal.c
+--- linux-2.6.24.orig/fs/ubifs/journal.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/journal.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,1443 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++/*
++ * This file implements UBIFS journal.
++ *
++ * The journal consists of 2 parts - the log and bud LEBs. The log has fixed
++ * length and position, while a bud logical eraseblock is any LEB in the main
++ * area. Buds contain file system data - data nodes, inode nodes, etc. The log
++ * contains only references to buds and some other stuff like commit
++ * start node. The idea is that when we commit the journal, we do
++ * not copy the data, the buds just become indexed. Since after the commit the
++ * nodes in bud eraseblocks become leaf nodes of the file system index tree, we
++ * use term "bud". Analogy is obvious, bud eraseblocks contain nodes which will
++ * become leafs in the future.
++ *
++ * The journal is multi-headed because we want to write data to the journal as
++ * optimally as possible. It is nice to have nodes belonging to the same inode
++ * in one LEB, so we may write data owned by different inodes to different
++ * journal heads, although at present only one data head is used.
++ *
++ * For recovery reasons, the base head contains all inode nodes, all directory
++ * entry nodes and all truncate nodes. This means that the other heads contain
++ * only data nodes.
++ *
++ * Bud LEBs may be half-indexed. For example, if the bud was not full at the
++ * time of commit, the bud is retained to continue to be used in the journal,
++ * even though the "front" of the LEB is now indexed. In that case, the log
++ * reference contains the offset where the bud starts for the purposes of the
++ * journal.
++ *
++ * The journal size has to be limited, because the larger is the journal, the
++ * longer it takes to mount UBIFS (scanning the journal) and the more memory it
++ * takes (indexing in the TNC).
++ *
++ * All the journal write operations like 'ubifs_jnl_update()' here, which write
++ * multiple UBIFS nodes to the journal at one go, are atomic with respect to
++ * unclean reboots. Should the unclean reboot happen, the recovery code drops
++ * all the nodes.
++ */
++
++#include "ubifs.h"
++
++/**
++ * zero_ino_node_unused - zero out unused fields of an on-flash inode node.
++ * @ino: the inode to zero out
++ */
++static inline void zero_ino_node_unused(struct ubifs_ino_node *ino)
++{
++	memset(ino->padding1, 0, 4);
++	memset(ino->padding2, 0, 26);
++}
++
++/**
++ * zero_dent_node_unused - zero out unused fields of an on-flash directory
++ *                         entry node.
++ * @dent: the directory entry to zero out
++ */
++static inline void zero_dent_node_unused(struct ubifs_dent_node *dent)
++{
++	dent->padding1 = 0;
++	memset(dent->padding2, 0, 4);
++}
++
++/**
++ * zero_data_node_unused - zero out unused fields of an on-flash data node.
++ * @data: the data node to zero out
++ */
++static inline void zero_data_node_unused(struct ubifs_data_node *data)
++{
++	memset(data->padding, 0, 2);
++}
++
++/**
++ * zero_trun_node_unused - zero out unused fields of an on-flash truncation
++ *                         node.
++ * @trun: the truncation node to zero out
++ */
++static inline void zero_trun_node_unused(struct ubifs_trun_node *trun)
++{
++	memset(trun->padding, 0, 12);
++}
++
++/**
++ * reserve_space - reserve space in the journal.
++ * @c: UBIFS file-system description object
++ * @jhead: journal head number
++ * @len: node length
++ *
++ * This function reserves space in journal head @head. If the reservation
++ * succeeded, the journal head stays locked and later has to be unlocked using
++ * 'release_head()'. 'write_node()' and 'write_head()' functions also unlock
++ * it. Returns zero in case of success, %-EAGAIN if commit has to be done, and
++ * other negative error codes in case of other failures.
++ */
++static int reserve_space(struct ubifs_info *c, int jhead, int len)
++{
++	int err = 0, err1, retries = 0, avail, lnum, offs, free, squeeze;
++	struct ubifs_wbuf *wbuf = &c->jheads[jhead].wbuf;
++
++	/*
++	 * Typically, the base head has smaller nodes written to it, so it is
++	 * better to try to allocate space at the ends of eraseblocks. This is
++	 * what the squeeze parameter does.
++	 */
++	squeeze = (jhead == BASEHD);
++again:
++	mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
++
++	if (c->ro_media) {
++		err = -EROFS;
++		goto out_unlock;
++	}
++
++	avail = c->leb_size - wbuf->offs - wbuf->used;
++	if (wbuf->lnum != -1 && avail >= len)
++		return 0;
++
++	/*
++	 * Write buffer wasn't seek'ed or there is no enough space - look for an
++	 * LEB with some empty space.
++	 */
++	lnum = ubifs_find_free_space(c, len, &free, squeeze);
++	if (lnum >= 0) {
++		/* Found an LEB, add it to the journal head */
++		offs = c->leb_size - free;
++		err = ubifs_add_bud_to_log(c, jhead, lnum, offs);
++		if (err)
++			goto out_return;
++		/* A new bud was successfully allocated and added to the log */
++		goto out;
++	}
++
++	err = lnum;
++	if (err != -ENOSPC)
++		goto out_unlock;
++
++	/*
++	 * No free space, we have to run garbage collector to make
++	 * some. But the write-buffer mutex has to be unlocked because
++	 * GC also takes it.
++	 */
++	dbg_jnl("no free space  jhead %d, run GC", jhead);
++	mutex_unlock(&wbuf->io_mutex);
++
++	lnum = ubifs_garbage_collect(c, 0);
++	if (lnum < 0) {
++		err = lnum;
++		if (err != -ENOSPC)
++			return err;
++
++		/*
++		 * GC could not make a free LEB. But someone else may
++		 * have allocated new bud for this journal head,
++		 * because we dropped @wbuf->io_mutex, so try once
++		 * again.
++		 */
++		dbg_jnl("GC couldn't make a free LEB for jhead %d", jhead);
++		if (retries++ < 2) {
++			dbg_jnl("retry (%d)", retries);
++			goto again;
++		}
++
++		dbg_jnl("return -ENOSPC");
++		return err;
++	}
++
++	mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
++	dbg_jnl("got LEB %d for jhead %d", lnum, jhead);
++	avail = c->leb_size - wbuf->offs - wbuf->used;
++
++	if (wbuf->lnum != -1 && avail >= len) {
++		/*
++		 * Someone else has switched the journal head and we have
++		 * enough space now. This happens when more then one process is
++		 * trying to write to the same journal head at the same time.
++		 */
++		dbg_jnl("return LEB %d back, already have LEB %d:%d",
++			lnum, wbuf->lnum, wbuf->offs + wbuf->used);
++		err = ubifs_return_leb(c, lnum);
++		if (err)
++			goto out_unlock;
++		return 0;
++	}
++
++	err = ubifs_add_bud_to_log(c, jhead, lnum, 0);
++	if (err)
++		goto out_return;
++	offs = 0;
++
++out:
++	err = ubifs_wbuf_seek_nolock(wbuf, lnum, offs, wbuf->dtype);
++	if (err)
++		goto out_unlock;
++
++	return 0;
++
++out_unlock:
++	mutex_unlock(&wbuf->io_mutex);
++	return err;
++
++out_return:
++	/* An error occurred and the LEB has to be returned to lprops */
++	ubifs_assert(err < 0);
++	err1 = ubifs_return_leb(c, lnum);
++	if (err1 && err == -EAGAIN)
++		/*
++		 * Return original error code only if it is not %-EAGAIN,
++		 * which is not really an error. Otherwise, return the error
++		 * code of 'ubifs_return_leb()'.
++		 */
++		err = err1;
++	mutex_unlock(&wbuf->io_mutex);
++	return err;
++}
++
++/**
++ * write_node - write node to a journal head.
++ * @c: UBIFS file-system description object
++ * @jhead: journal head
++ * @node: node to write
++ * @len: node length
++ * @lnum: LEB number written is returned here
++ * @offs: offset written is returned here
++ *
++ * This function writes a node to reserved space of journal head @jhead.
++ * Returns zero in case of success and a negative error code in case of
++ * failure.
++ */
++static int write_node(struct ubifs_info *c, int jhead, void *node, int len,
++		      int *lnum, int *offs)
++{
++	struct ubifs_wbuf *wbuf = &c->jheads[jhead].wbuf;
++
++	ubifs_assert(jhead != GCHD);
++
++	*lnum = c->jheads[jhead].wbuf.lnum;
++	*offs = c->jheads[jhead].wbuf.offs + c->jheads[jhead].wbuf.used;
++
++	dbg_jnl("jhead %d, LEB %d:%d, len %d", jhead, *lnum, *offs, len);
++	ubifs_prepare_node(c, node, len, 0);
++
++	return ubifs_wbuf_write_nolock(wbuf, node, len);
++}
++
++/**
++ * write_head - write data to a journal head.
++ * @c: UBIFS file-system description object
++ * @jhead: journal head
++ * @buf: buffer to write
++ * @len: length to write
++ * @lnum: LEB number written is returned here
++ * @offs: offset written is returned here
++ * @sync: non-zero if the write-buffer has to by synchronized
++ *
++ * This function is the same as 'write_node()' but it does not assume the
++ * buffer it is writing is a node, so it does not prepare it (which means
++ * initializing common header and calculating CRC).
++ */
++static int write_head(struct ubifs_info *c, int jhead, void *buf, int len,
++		      int *lnum, int *offs, int sync)
++{
++	int err;
++	struct ubifs_wbuf *wbuf = &c->jheads[jhead].wbuf;
++
++	ubifs_assert(jhead != GCHD);
++
++	*lnum = c->jheads[jhead].wbuf.lnum;
++	*offs = c->jheads[jhead].wbuf.offs + c->jheads[jhead].wbuf.used;
++	dbg_jnl("jhead %d, LEB %d:%d, len %d", jhead, *lnum, *offs, len);
++
++	err = ubifs_wbuf_write_nolock(wbuf, buf, len);
++	if (err)
++		return err;
++	if (sync)
++		err = ubifs_wbuf_sync_nolock(wbuf);
++	return err;
++}
++
++/**
++ * make_reservation - reserve journal space.
++ * @c: UBIFS file-system description object
++ * @jhead: journal head
++ * @len: how many bytes to reserve
++ *
++ * This function makes space reservation in journal head @jhead. The function
++ * takes the commit lock and locks the journal head, and the caller has to
++ * unlock the head and finish the reservation with 'finish_reservation()'.
++ * Returns zero in case of success and a negative error code in case of
++ * failure.
++ *
++ * Note, the journal head may be unlocked as soon as the data is written, while
++ * the commit lock has to be released after the data has been added to the
++ * TNC.
++ */
++static int make_reservation(struct ubifs_info *c, int jhead, int len)
++{
++	int err, cmt_retries = 0, nospc_retries = 0;
++
++again:
++	down_read(&c->commit_sem);
++	err = reserve_space(c, jhead, len);
++	if (!err)
++		return 0;
++	up_read(&c->commit_sem);
++
++	if (err == -ENOSPC) {
++		/*
++		 * GC could not make any progress. We should try to commit
++		 * once because it could make some dirty space and GC would
++		 * make progress, so make the error -EAGAIN so that the below
++		 * will commit and re-try.
++		 */
++		if (nospc_retries++ < 2) {
++			dbg_jnl("no space, retry");
++			err = -EAGAIN;
++		}
++
++		/*
++		 * This means that the budgeting is incorrect. We always have
++		 * to be able to write to the media, because all operations are
++		 * budgeted. Deletions are not budgeted, though, but we reserve
++		 * an extra LEB for them.
++		 */
++	}
++
++	if (err != -EAGAIN)
++		goto out;
++
++	/*
++	 * -EAGAIN means that the journal is full or too large, or the above
++	 * code wants to do one commit. Do this and re-try.
++	 */
++	if (cmt_retries > 128) {
++		/*
++		 * This should not happen unless the journal size limitations
++		 * are too tough.
++		 */
++		ubifs_err("stuck in space allocation");
++		err = -ENOSPC;
++		goto out;
++	} else if (cmt_retries > 32)
++		ubifs_warn("too many space allocation re-tries (%d)",
++			   cmt_retries);
++
++	dbg_jnl("-EAGAIN, commit and retry (retried %d times)",
++		cmt_retries);
++	cmt_retries += 1;
++
++	err = ubifs_run_commit(c);
++	if (err)
++		return err;
++	goto again;
++
++out:
++	ubifs_err("cannot reserve %d bytes in jhead %d, error %d",
++		  len, jhead, err);
++	if (err == -ENOSPC) {
++		/* This are some budgeting problems, print useful information */
++		down_write(&c->commit_sem);
++		spin_lock(&c->space_lock);
++		dbg_dump_stack();
++		dbg_dump_budg(c);
++		spin_unlock(&c->space_lock);
++		dbg_dump_lprops(c);
++		cmt_retries = dbg_check_lprops(c);
++		up_write(&c->commit_sem);
++	}
++	return err;
++}
++
++/**
++ * release_head - release a journal head.
++ * @c: UBIFS file-system description object
++ * @jhead: journal head
++ *
++ * This function releases journal head @jhead which was locked by
++ * the 'make_reservation()' function. It has to be called after each successful
++ * 'make_reservation()' invocation.
++ */
++static inline void release_head(struct ubifs_info *c, int jhead)
++{
++	mutex_unlock(&c->jheads[jhead].wbuf.io_mutex);
++}
++
++/**
++ * finish_reservation - finish a reservation.
++ * @c: UBIFS file-system description object
++ *
++ * This function finishes journal space reservation. It must be called after
++ * 'make_reservation()'.
++ */
++static void finish_reservation(struct ubifs_info *c)
++{
++	up_read(&c->commit_sem);
++}
++
++/**
++ * get_dent_type - translate VFS inode mode to UBIFS directory entry type.
++ * @mode: inode mode
++ */
++static int get_dent_type(int mode)
++{
++	switch (mode & S_IFMT) {
++	case S_IFREG:
++		return UBIFS_ITYPE_REG;
++	case S_IFDIR:
++		return UBIFS_ITYPE_DIR;
++	case S_IFLNK:
++		return UBIFS_ITYPE_LNK;
++	case S_IFBLK:
++		return UBIFS_ITYPE_BLK;
++	case S_IFCHR:
++		return UBIFS_ITYPE_CHR;
++	case S_IFIFO:
++		return UBIFS_ITYPE_FIFO;
++	case S_IFSOCK:
++		return UBIFS_ITYPE_SOCK;
++	default:
++		BUG();
++	}
++	return 0;
++}
++
++/**
++ * pack_inode - pack an inode node.
++ * @c: UBIFS file-system description object
++ * @ino: buffer in which to pack inode node
++ * @inode: inode to pack
++ * @last: indicates the last node of the group
++ */
++static void pack_inode(struct ubifs_info *c, struct ubifs_ino_node *ino,
++		       const struct inode *inode, int last)
++{
++	int data_len = 0, last_reference = !inode->i_nlink;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++
++	ino->ch.node_type = UBIFS_INO_NODE;
++	ino_key_init_flash(c, &ino->key, inode->i_ino);
++	ino->creat_sqnum = cpu_to_le64(ui->creat_sqnum);
++	ino->atime_sec  = cpu_to_le64(inode->i_atime.tv_sec);
++	ino->atime_nsec = cpu_to_le32(inode->i_atime.tv_nsec);
++	ino->ctime_sec  = cpu_to_le64(inode->i_ctime.tv_sec);
++	ino->ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
++	ino->mtime_sec  = cpu_to_le64(inode->i_mtime.tv_sec);
++	ino->mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
++	ino->uid   = cpu_to_le32(inode->i_uid);
++	ino->gid   = cpu_to_le32(inode->i_gid);
++	ino->mode  = cpu_to_le32(inode->i_mode);
++	ino->flags = cpu_to_le32(ui->flags);
++	ino->size  = cpu_to_le64(ui->ui_size);
++	ino->nlink = cpu_to_le32(inode->i_nlink);
++	ino->compr_type  = cpu_to_le16(ui->compr_type);
++	ino->data_len    = cpu_to_le32(ui->data_len);
++	ino->xattr_cnt   = cpu_to_le32(ui->xattr_cnt);
++	ino->xattr_size  = cpu_to_le32(ui->xattr_size);
++	ino->xattr_names = cpu_to_le32(ui->xattr_names);
++	zero_ino_node_unused(ino);
++
++	/*
++	 * Drop the attached data if this is a deletion inode, the data is not
++	 * needed anymore.
++	 */
++	if (!last_reference) {
++		memcpy(ino->data, ui->data, ui->data_len);
++		data_len = ui->data_len;
++	}
++
++	ubifs_prep_grp_node(c, ino, UBIFS_INO_NODE_SZ + data_len, last);
++}
++
++/**
++ * mark_inode_clean - mark UBIFS inode as clean.
++ * @c: UBIFS file-system description object
++ * @ui: UBIFS inode to mark as clean
++ *
++ * This helper function marks UBIFS inode @ui as clean by cleaning the
++ * @ui->dirty flag and releasing its budget. Note, VFS may still treat the
++ * inode as dirty and try to write it back, but 'ubifs_write_inode()' would
++ * just do nothing.
++ */
++static void mark_inode_clean(struct ubifs_info *c, struct ubifs_inode *ui)
++{
++	if (ui->dirty)
++		ubifs_release_dirty_inode_budget(c, ui);
++	ui->dirty = 0;
++}
++
++/**
++ * ubifs_jnl_update - update inode.
++ * @c: UBIFS file-system description object
++ * @dir: parent inode or host inode in case of extended attributes
++ * @nm: directory entry name
++ * @inode: inode to update
++ * @deletion: indicates a directory entry deletion i.e unlink or rmdir
++ * @xent: non-zero if the directory entry is an extended attribute entry
++ *
++ * This function updates an inode by writing a directory entry (or extended
++ * attribute entry), the inode itself, and the parent directory inode (or the
++ * host inode) to the journal.
++ *
++ * The function writes the host inode @dir last, which is important in case of
++ * extended attributes. Indeed, then we guarantee that if the host inode gets
++ * synchronized (with 'fsync()'), and the write-buffer it sits in gets flushed,
++ * the extended attribute inode gets flushed too. And this is exactly what the
++ * user expects - synchronizing the host inode synchronizes its extended
++ * attributes. Similarly, this guarantees that if @dir is synchronized, its
++ * directory entry corresponding to @nm gets synchronized too.
++ *
++ * If the inode (@inode) or the parent directory (@dir) are synchronous, this
++ * function synchronizes the write-buffer.
++ *
++ * This function marks the @dir and @inode inodes as clean and returns zero on
++ * success. In case of failure, a negative error code is returned.
++ */
++int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir,
++		     const struct qstr *nm, const struct inode *inode,
++		     int deletion, int xent)
++{
++	int err, dlen, ilen, len, lnum, ino_offs, dent_offs;
++	int aligned_dlen, aligned_ilen, sync = IS_DIRSYNC(dir);
++	int last_reference = !!(deletion && inode->i_nlink == 0);
++	struct ubifs_inode *ui = ubifs_inode(inode);
++	struct ubifs_inode *dir_ui = ubifs_inode(dir);
++	struct ubifs_dent_node *dent;
++	struct ubifs_ino_node *ino;
++	union ubifs_key dent_key, ino_key;
++
++	dbg_jnl("ino %lu, dent '%.*s', data len %d in dir ino %lu",
++		inode->i_ino, nm->len, nm->name, ui->data_len, dir->i_ino);
++	ubifs_assert(dir_ui->data_len == 0);
++	ubifs_assert(mutex_is_locked(&dir_ui->ui_mutex));
++
++	dlen = UBIFS_DENT_NODE_SZ + nm->len + 1;
++	ilen = UBIFS_INO_NODE_SZ;
++
++	/*
++	 * If the last reference to the inode is being deleted, then there is
++	 * no need to attach and write inode data, it is being deleted anyway.
++	 * And if the inode is being deleted, no need to synchronize
++	 * write-buffer even if the inode is synchronous.
++	 */
++	if (!last_reference) {
++		ilen += ui->data_len;
++		sync |= IS_SYNC(inode);
++	}
++
++	aligned_dlen = ALIGN(dlen, 8);
++	aligned_ilen = ALIGN(ilen, 8);
++	len = aligned_dlen + aligned_ilen + UBIFS_INO_NODE_SZ;
++	dent = kmalloc(len, GFP_NOFS);
++	if (!dent)
++		return -ENOMEM;
++
++	/* Make reservation before allocating sequence numbers */
++	err = make_reservation(c, BASEHD, len);
++	if (err)
++		goto out_free;
++
++	if (!xent) {
++		dent->ch.node_type = UBIFS_DENT_NODE;
++		dent_key_init(c, &dent_key, dir->i_ino, nm);
++	} else {
++		dent->ch.node_type = UBIFS_XENT_NODE;
++		xent_key_init(c, &dent_key, dir->i_ino, nm);
++	}
++
++	key_write(c, &dent_key, dent->key);
++	dent->inum = deletion ? 0 : cpu_to_le64(inode->i_ino);
++	dent->type = get_dent_type(inode->i_mode);
++	dent->nlen = cpu_to_le16(nm->len);
++	memcpy(dent->name, nm->name, nm->len);
++	dent->name[nm->len] = '\0';
++	zero_dent_node_unused(dent);
++	ubifs_prep_grp_node(c, dent, dlen, 0);
++
++	ino = (void *)dent + aligned_dlen;
++	pack_inode(c, ino, inode, 0);
++	ino = (void *)ino + aligned_ilen;
++	pack_inode(c, ino, dir, 1);
++
++	if (last_reference) {
++		err = ubifs_add_orphan(c, inode->i_ino);
++		if (err) {
++			release_head(c, BASEHD);
++			goto out_finish;
++		}
++		ui->del_cmtno = c->cmt_no;
++	}
++
++	err = write_head(c, BASEHD, dent, len, &lnum, &dent_offs, sync);
++	if (err)
++		goto out_release;
++	if (!sync) {
++		struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf;
++
++		ubifs_wbuf_add_ino_nolock(wbuf, inode->i_ino);
++		ubifs_wbuf_add_ino_nolock(wbuf, dir->i_ino);
++	}
++	release_head(c, BASEHD);
++	kfree(dent);
++
++	if (deletion) {
++		err = ubifs_tnc_remove_nm(c, &dent_key, nm);
++		if (err)
++			goto out_ro;
++		err = ubifs_add_dirt(c, lnum, dlen);
++	} else
++		err = ubifs_tnc_add_nm(c, &dent_key, lnum, dent_offs, dlen, nm);
++	if (err)
++		goto out_ro;
++
++	/*
++	 * Note, we do not remove the inode from TNC even if the last reference
++	 * to it has just been deleted, because the inode may still be opened.
++	 * Instead, the inode has been added to orphan lists and the orphan
++	 * subsystem will take further care about it.
++	 */
++	ino_key_init(c, &ino_key, inode->i_ino);
++	ino_offs = dent_offs + aligned_dlen;
++	err = ubifs_tnc_add(c, &ino_key, lnum, ino_offs, ilen);
++	if (err)
++		goto out_ro;
++
++	ino_key_init(c, &ino_key, dir->i_ino);
++	ino_offs += aligned_ilen;
++	err = ubifs_tnc_add(c, &ino_key, lnum, ino_offs, UBIFS_INO_NODE_SZ);
++	if (err)
++		goto out_ro;
++
++	finish_reservation(c);
++	spin_lock(&ui->ui_lock);
++	ui->synced_i_size = ui->ui_size;
++	spin_unlock(&ui->ui_lock);
++	mark_inode_clean(c, ui);
++	mark_inode_clean(c, dir_ui);
++	return 0;
++
++out_finish:
++	finish_reservation(c);
++out_free:
++	kfree(dent);
++	return err;
++
++out_release:
++	release_head(c, BASEHD);
++out_ro:
++	ubifs_ro_mode(c, err);
++	if (last_reference)
++		ubifs_delete_orphan(c, inode->i_ino);
++	finish_reservation(c);
++	return err;
++}
++
++/**
++ * ubifs_jnl_write_data - write a data node to the journal.
++ * @c: UBIFS file-system description object
++ * @inode: inode the data node belongs to
++ * @key: node key
++ * @buf: buffer to write
++ * @len: data length (must not exceed %UBIFS_BLOCK_SIZE)
++ *
++ * This function writes a data node to the journal. Returns %0 if the data node
++ * was successfully written, and a negative error code in case of failure.
++ */
++int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode,
++			 const union ubifs_key *key, const void *buf, int len)
++{
++	struct ubifs_data_node *data;
++	int err, lnum, offs, compr_type, out_len;
++	int dlen = UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE * WORST_COMPR_FACTOR;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++
++	dbg_jnl("ino %lu, blk %u, len %d, key %s",
++		(unsigned long)key_inum(c, key), key_block(c, key), len,
++		DBGKEY(key));
++	ubifs_assert(len <= UBIFS_BLOCK_SIZE);
++
++	data = kmalloc(dlen, GFP_NOFS);
++	if (!data)
++		return -ENOMEM;
++
++	data->ch.node_type = UBIFS_DATA_NODE;
++	key_write(c, key, &data->key);
++	data->size = cpu_to_le32(len);
++	zero_data_node_unused(data);
++
++	if (!(ui->flags & UBIFS_COMPR_FL))
++		/* Compression is disabled for this inode */
++		compr_type = UBIFS_COMPR_NONE;
++	else
++		compr_type = ui->compr_type;
++
++	out_len = dlen - UBIFS_DATA_NODE_SZ;
++	ubifs_compress(buf, len, &data->data, &out_len, &compr_type);
++	ubifs_assert(out_len <= UBIFS_BLOCK_SIZE);
++
++	dlen = UBIFS_DATA_NODE_SZ + out_len;
++	data->compr_type = cpu_to_le16(compr_type);
++
++	/* Make reservation before allocating sequence numbers */
++	err = make_reservation(c, DATAHD, dlen);
++	if (err)
++		goto out_free;
++
++	err = write_node(c, DATAHD, data, dlen, &lnum, &offs);
++	if (err)
++		goto out_release;
++	ubifs_wbuf_add_ino_nolock(&c->jheads[DATAHD].wbuf, key_inum(c, key));
++	release_head(c, DATAHD);
++
++	err = ubifs_tnc_add(c, key, lnum, offs, dlen);
++	if (err)
++		goto out_ro;
++
++	finish_reservation(c);
++	kfree(data);
++	return 0;
++
++out_release:
++	release_head(c, DATAHD);
++out_ro:
++	ubifs_ro_mode(c, err);
++	finish_reservation(c);
++out_free:
++	kfree(data);
++	return err;
++}
++
++/**
++ * ubifs_jnl_write_inode - flush inode to the journal.
++ * @c: UBIFS file-system description object
++ * @inode: inode to flush
++ *
++ * This function writes inode @inode to the journal. If the inode is
++ * synchronous, it also synchronizes the write-buffer. Returns zero in case of
++ * success and a negative error code in case of failure.
++ */
++int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode)
++{
++	int err, lnum, offs;
++	struct ubifs_ino_node *ino;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++	int sync = 0, len = UBIFS_INO_NODE_SZ, last_reference = !inode->i_nlink;
++
++	dbg_jnl("ino %lu, nlink %u", inode->i_ino, inode->i_nlink);
++
++	/*
++	 * If the inode is being deleted, do not write the attached data. No
++	 * need to synchronize the write-buffer either.
++	 */
++	if (!last_reference) {
++		len += ui->data_len;
++		sync = IS_SYNC(inode);
++	}
++	ino = kmalloc(len, GFP_NOFS);
++	if (!ino)
++		return -ENOMEM;
++
++	/* Make reservation before allocating sequence numbers */
++	err = make_reservation(c, BASEHD, len);
++	if (err)
++		goto out_free;
++
++	pack_inode(c, ino, inode, 1);
++	err = write_head(c, BASEHD, ino, len, &lnum, &offs, sync);
++	if (err)
++		goto out_release;
++	if (!sync)
++		ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf,
++					  inode->i_ino);
++	release_head(c, BASEHD);
++
++	if (last_reference) {
++		err = ubifs_tnc_remove_ino(c, inode->i_ino);
++		if (err)
++			goto out_ro;
++		ubifs_delete_orphan(c, inode->i_ino);
++		err = ubifs_add_dirt(c, lnum, len);
++	} else {
++		union ubifs_key key;
++
++		ino_key_init(c, &key, inode->i_ino);
++		err = ubifs_tnc_add(c, &key, lnum, offs, len);
++	}
++	if (err)
++		goto out_ro;
++
++	finish_reservation(c);
++	spin_lock(&ui->ui_lock);
++	ui->synced_i_size = ui->ui_size;
++	spin_unlock(&ui->ui_lock);
++	kfree(ino);
++	return 0;
++
++out_release:
++	release_head(c, BASEHD);
++out_ro:
++	ubifs_ro_mode(c, err);
++	finish_reservation(c);
++out_free:
++	kfree(ino);
++	return err;
++}
++
++/**
++ * ubifs_jnl_delete_inode - delete an inode.
++ * @c: UBIFS file-system description object
++ * @inode: inode to delete
++ *
++ * This function deletes inode @inode which includes removing it from orphans,
++ * deleting it from TNC and, in some cases, writing a deletion inode to the
++ * journal.
++ *
++ * When regular file inodes are unlinked or a directory inode is removed, the
++ * 'ubifs_jnl_update()' function writes a corresponding deletion inode and
++ * direntry to the media, and adds the inode to orphans. After this, when the
++ * last reference to this inode has been dropped, this function is called. In
++ * general, it has to write one more deletion inode to the media, because if
++ * a commit happened between 'ubifs_jnl_update()' and
++ * 'ubifs_jnl_delete_inode()', the deletion inode is not in the journal
++ * anymore, and in fact it might not be on the flash anymore, because it might
++ * have been garbage-collected already. And for optimization reasons UBIFS does
++ * not read the orphan area if it has been unmounted cleanly, so it would have
++ * no indication in the journal that there is a deleted inode which has to be
++ * removed from TNC.
++ *
++ * However, if there was no commit between 'ubifs_jnl_update()' and
++ * 'ubifs_jnl_delete_inode()', then there is no need to write the deletion
++ * inode to the media for the second time. And this is quite a typical case.
++ *
++ * This function returns zero in case of success and a negative error code in
++ * case of failure.
++ */
++int ubifs_jnl_delete_inode(struct ubifs_info *c, const struct inode *inode)
++{
++	int err;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++
++	ubifs_assert(inode->i_nlink == 0);
++
++	if (ui->del_cmtno != c->cmt_no)
++		/* A commit happened for sure */
++		return ubifs_jnl_write_inode(c, inode);
++
++	down_read(&c->commit_sem);
++	/*
++	 * Check commit number again, because the first test has been done
++	 * without @c->commit_sem, so a commit might have happened.
++	 */
++	if (ui->del_cmtno != c->cmt_no) {
++		up_read(&c->commit_sem);
++		return ubifs_jnl_write_inode(c, inode);
++	}
++
++	err = ubifs_tnc_remove_ino(c, inode->i_ino);
++	if (err)
++		ubifs_ro_mode(c, err);
++	else
++		ubifs_delete_orphan(c, inode->i_ino);
++	up_read(&c->commit_sem);
++	return err;
++}
++
++/**
++ * ubifs_jnl_rename - rename a directory entry.
++ * @c: UBIFS file-system description object
++ * @old_dir: parent inode of directory entry to rename
++ * @old_dentry: directory entry to rename
++ * @new_dir: parent inode of directory entry to rename
++ * @new_dentry: new directory entry (or directory entry to replace)
++ * @sync: non-zero if the write-buffer has to be synchronized
++ *
++ * This function implements the re-name operation which may involve writing up
++ * to 3 inodes and 2 directory entries. It marks the written inodes as clean
++ * and returns zero on success. In case of failure, a negative error code is
++ * returned.
++ */
++int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
++		     const struct dentry *old_dentry,
++		     const struct inode *new_dir,
++		     const struct dentry *new_dentry, int sync)
++{
++	void *p;
++	union ubifs_key key;
++	struct ubifs_dent_node *dent, *dent2;
++	int err, dlen1, dlen2, ilen, lnum, offs, len;
++	const struct inode *old_inode = old_dentry->d_inode;
++	const struct inode *new_inode = new_dentry->d_inode;
++	int aligned_dlen1, aligned_dlen2, plen = UBIFS_INO_NODE_SZ;
++	int last_reference = !!(new_inode && new_inode->i_nlink == 0);
++	int move = (old_dir != new_dir);
++	struct ubifs_inode *uninitialized_var(new_ui);
++
++	dbg_jnl("dent '%.*s' in dir ino %lu to dent '%.*s' in dir ino %lu",
++		old_dentry->d_name.len, old_dentry->d_name.name,
++		old_dir->i_ino, new_dentry->d_name.len,
++		new_dentry->d_name.name, new_dir->i_ino);
++	ubifs_assert(ubifs_inode(old_dir)->data_len == 0);
++	ubifs_assert(ubifs_inode(new_dir)->data_len == 0);
++	ubifs_assert(mutex_is_locked(&ubifs_inode(old_dir)->ui_mutex));
++	ubifs_assert(mutex_is_locked(&ubifs_inode(new_dir)->ui_mutex));
++
++	dlen1 = UBIFS_DENT_NODE_SZ + new_dentry->d_name.len + 1;
++	dlen2 = UBIFS_DENT_NODE_SZ + old_dentry->d_name.len + 1;
++	if (new_inode) {
++		new_ui = ubifs_inode(new_inode);
++		ubifs_assert(mutex_is_locked(&new_ui->ui_mutex));
++		ilen = UBIFS_INO_NODE_SZ;
++		if (!last_reference)
++			ilen += new_ui->data_len;
++	} else
++		ilen = 0;
++
++	aligned_dlen1 = ALIGN(dlen1, 8);
++	aligned_dlen2 = ALIGN(dlen2, 8);
++	len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + ALIGN(plen, 8);
++	if (old_dir != new_dir)
++		len += plen;
++	dent = kmalloc(len, GFP_NOFS);
++	if (!dent)
++		return -ENOMEM;
++
++	/* Make reservation before allocating sequence numbers */
++	err = make_reservation(c, BASEHD, len);
++	if (err)
++		goto out_free;
++
++	/* Make new dent */
++	dent->ch.node_type = UBIFS_DENT_NODE;
++	dent_key_init_flash(c, &dent->key, new_dir->i_ino, &new_dentry->d_name);
++	dent->inum = cpu_to_le64(old_inode->i_ino);
++	dent->type = get_dent_type(old_inode->i_mode);
++	dent->nlen = cpu_to_le16(new_dentry->d_name.len);
++	memcpy(dent->name, new_dentry->d_name.name, new_dentry->d_name.len);
++	dent->name[new_dentry->d_name.len] = '\0';
++	zero_dent_node_unused(dent);
++	ubifs_prep_grp_node(c, dent, dlen1, 0);
++
++	/* Make deletion dent */
++	dent2 = (void *)dent + aligned_dlen1;
++	dent2->ch.node_type = UBIFS_DENT_NODE;
++	dent_key_init_flash(c, &dent2->key, old_dir->i_ino,
++			    &old_dentry->d_name);
++	dent2->inum = 0;
++	dent2->type = DT_UNKNOWN;
++	dent2->nlen = cpu_to_le16(old_dentry->d_name.len);
++	memcpy(dent2->name, old_dentry->d_name.name, old_dentry->d_name.len);
++	dent2->name[old_dentry->d_name.len] = '\0';
++	zero_dent_node_unused(dent2);
++	ubifs_prep_grp_node(c, dent2, dlen2, 0);
++
++	p = (void *)dent2 + aligned_dlen2;
++	if (new_inode) {
++		pack_inode(c, p, new_inode, 0);
++		p += ALIGN(ilen, 8);
++	}
++
++	if (!move)
++		pack_inode(c, p, old_dir, 1);
++	else {
++		pack_inode(c, p, old_dir, 0);
++		p += ALIGN(plen, 8);
++		pack_inode(c, p, new_dir, 1);
++	}
++
++	if (last_reference) {
++		err = ubifs_add_orphan(c, new_inode->i_ino);
++		if (err) {
++			release_head(c, BASEHD);
++			goto out_finish;
++		}
++		new_ui->del_cmtno = c->cmt_no;
++	}
++
++	err = write_head(c, BASEHD, dent, len, &lnum, &offs, sync);
++	if (err)
++		goto out_release;
++	if (!sync) {
++		struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf;
++
++		ubifs_wbuf_add_ino_nolock(wbuf, new_dir->i_ino);
++		ubifs_wbuf_add_ino_nolock(wbuf, old_dir->i_ino);
++		if (new_inode)
++			ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf,
++						  new_inode->i_ino);
++	}
++	release_head(c, BASEHD);
++
++	dent_key_init(c, &key, new_dir->i_ino, &new_dentry->d_name);
++	err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen1, &new_dentry->d_name);
++	if (err)
++		goto out_ro;
++
++	err = ubifs_add_dirt(c, lnum, dlen2);
++	if (err)
++		goto out_ro;
++
++	dent_key_init(c, &key, old_dir->i_ino, &old_dentry->d_name);
++	err = ubifs_tnc_remove_nm(c, &key, &old_dentry->d_name);
++	if (err)
++		goto out_ro;
++
++	offs += aligned_dlen1 + aligned_dlen2;
++	if (new_inode) {
++		ino_key_init(c, &key, new_inode->i_ino);
++		err = ubifs_tnc_add(c, &key, lnum, offs, ilen);
++		if (err)
++			goto out_ro;
++		offs += ALIGN(ilen, 8);
++	}
++
++	ino_key_init(c, &key, old_dir->i_ino);
++	err = ubifs_tnc_add(c, &key, lnum, offs, plen);
++	if (err)
++		goto out_ro;
++
++	if (old_dir != new_dir) {
++		offs += ALIGN(plen, 8);
++		ino_key_init(c, &key, new_dir->i_ino);
++		err = ubifs_tnc_add(c, &key, lnum, offs, plen);
++		if (err)
++			goto out_ro;
++	}
++
++	finish_reservation(c);
++	if (new_inode) {
++		mark_inode_clean(c, new_ui);
++		spin_lock(&new_ui->ui_lock);
++		new_ui->synced_i_size = new_ui->ui_size;
++		spin_unlock(&new_ui->ui_lock);
++	}
++	mark_inode_clean(c, ubifs_inode(old_dir));
++	if (move)
++		mark_inode_clean(c, ubifs_inode(new_dir));
++	kfree(dent);
++	return 0;
++
++out_release:
++	release_head(c, BASEHD);
++out_ro:
++	ubifs_ro_mode(c, err);
++	if (last_reference)
++		ubifs_delete_orphan(c, new_inode->i_ino);
++out_finish:
++	finish_reservation(c);
++out_free:
++	kfree(dent);
++	return err;
++}
++
++/**
++ * recomp_data_node - re-compress a truncated data node.
++ * @dn: data node to re-compress
++ * @new_len: new length
++ *
++ * This function is used when an inode is truncated and the last data node of
++ * the inode has to be re-compressed and re-written.
++ */
++static int recomp_data_node(struct ubifs_data_node *dn, int *new_len)
++{
++	void *buf;
++	int err, len, compr_type, out_len;
++
++	out_len = le32_to_cpu(dn->size);
++	buf = kmalloc(out_len * WORST_COMPR_FACTOR, GFP_NOFS);
++	if (!buf)
++		return -ENOMEM;
++
++	len = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
++	compr_type = le16_to_cpu(dn->compr_type);
++	err = ubifs_decompress(&dn->data, len, buf, &out_len, compr_type);
++	if (err)
++		goto out;
++
++	ubifs_compress(buf, *new_len, &dn->data, &out_len, &compr_type);
++	ubifs_assert(out_len <= UBIFS_BLOCK_SIZE);
++	dn->compr_type = cpu_to_le16(compr_type);
++	dn->size = cpu_to_le32(*new_len);
++	*new_len = UBIFS_DATA_NODE_SZ + out_len;
++out:
++	kfree(buf);
++	return err;
++}
++
++/**
++ * ubifs_jnl_truncate - update the journal for a truncation.
++ * @c: UBIFS file-system description object
++ * @inode: inode to truncate
++ * @old_size: old size
++ * @new_size: new size
++ *
++ * When the size of a file decreases due to truncation, a truncation node is
++ * written, the journal tree is updated, and the last data block is re-written
++ * if it has been affected. The inode is also updated in order to synchronize
++ * the new inode size.
++ *
++ * This function marks the inode as clean and returns zero on success. In case
++ * of failure, a negative error code is returned.
++ */
++int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode,
++		       loff_t old_size, loff_t new_size)
++{
++	union ubifs_key key, to_key;
++	struct ubifs_ino_node *ino;
++	struct ubifs_trun_node *trun;
++	struct ubifs_data_node *uninitialized_var(dn);
++	int err, dlen, len, lnum, offs, bit, sz, sync = IS_SYNC(inode);
++	struct ubifs_inode *ui = ubifs_inode(inode);
++	ino_t inum = inode->i_ino;
++	unsigned int blk;
++
++	dbg_jnl("ino %lu, size %lld -> %lld",
++		(unsigned long)inum, old_size, new_size);
++	ubifs_assert(!ui->data_len);
++	ubifs_assert(S_ISREG(inode->i_mode));
++	ubifs_assert(mutex_is_locked(&ui->ui_mutex));
++
++	sz = UBIFS_TRUN_NODE_SZ + UBIFS_INO_NODE_SZ +
++	     UBIFS_MAX_DATA_NODE_SZ * WORST_COMPR_FACTOR;
++	ino = kmalloc(sz, GFP_NOFS);
++	if (!ino)
++		return -ENOMEM;
++
++	trun = (void *)ino + UBIFS_INO_NODE_SZ;
++	trun->ch.node_type = UBIFS_TRUN_NODE;
++	trun->inum = cpu_to_le32(inum);
++	trun->old_size = cpu_to_le64(old_size);
++	trun->new_size = cpu_to_le64(new_size);
++	zero_trun_node_unused(trun);
++
++	dlen = new_size & (UBIFS_BLOCK_SIZE - 1);
++	if (dlen) {
++		/* Get last data block so it can be truncated */
++		dn = (void *)trun + UBIFS_TRUN_NODE_SZ;
++		blk = new_size >> UBIFS_BLOCK_SHIFT;
++		data_key_init(c, &key, inum, blk);
++		dbg_jnl("last block key %s", DBGKEY(&key));
++		err = ubifs_tnc_lookup(c, &key, dn);
++		if (err == -ENOENT)
++			dlen = 0; /* Not found (so it is a hole) */
++		else if (err)
++			goto out_free;
++		else {
++			if (le32_to_cpu(dn->size) <= dlen)
++				dlen = 0; /* Nothing to do */
++			else {
++				int compr_type = le16_to_cpu(dn->compr_type);
++
++				if (compr_type != UBIFS_COMPR_NONE) {
++					err = recomp_data_node(dn, &dlen);
++					if (err)
++						goto out_free;
++				} else {
++					dn->size = cpu_to_le32(dlen);
++					dlen += UBIFS_DATA_NODE_SZ;
++				}
++				zero_data_node_unused(dn);
++			}
++		}
++	}
++
++	/* Must make reservation before allocating sequence numbers */
++	len = UBIFS_TRUN_NODE_SZ + UBIFS_INO_NODE_SZ;
++	if (dlen)
++		len += dlen;
++	err = make_reservation(c, BASEHD, len);
++	if (err)
++		goto out_free;
++
++	pack_inode(c, ino, inode, 0);
++	ubifs_prep_grp_node(c, trun, UBIFS_TRUN_NODE_SZ, dlen ? 0 : 1);
++	if (dlen)
++		ubifs_prep_grp_node(c, dn, dlen, 1);
++
++	err = write_head(c, BASEHD, ino, len, &lnum, &offs, sync);
++	if (err)
++		goto out_release;
++	if (!sync)
++		ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, inum);
++	release_head(c, BASEHD);
++
++	if (dlen) {
++		sz = offs + UBIFS_INO_NODE_SZ + UBIFS_TRUN_NODE_SZ;
++		err = ubifs_tnc_add(c, &key, lnum, sz, dlen);
++		if (err)
++			goto out_ro;
++	}
++
++	ino_key_init(c, &key, inum);
++	err = ubifs_tnc_add(c, &key, lnum, offs, UBIFS_INO_NODE_SZ);
++	if (err)
++		goto out_ro;
++
++	err = ubifs_add_dirt(c, lnum, UBIFS_TRUN_NODE_SZ);
++	if (err)
++		goto out_ro;
++
++	bit = new_size & (UBIFS_BLOCK_SIZE - 1);
++	blk = (new_size >> UBIFS_BLOCK_SHIFT) + (bit ? 1 : 0);
++	data_key_init(c, &key, inum, blk);
++
++	bit = old_size & (UBIFS_BLOCK_SIZE - 1);
++	blk = (old_size >> UBIFS_BLOCK_SHIFT) - (bit ? 0 : 1);
++	data_key_init(c, &to_key, inum, blk);
++
++	err = ubifs_tnc_remove_range(c, &key, &to_key);
++	if (err)
++		goto out_ro;
++
++	finish_reservation(c);
++	spin_lock(&ui->ui_lock);
++	ui->synced_i_size = ui->ui_size;
++	spin_unlock(&ui->ui_lock);
++	mark_inode_clean(c, ui);
++	kfree(ino);
++	return 0;
++
++out_release:
++	release_head(c, BASEHD);
++out_ro:
++	ubifs_ro_mode(c, err);
++	finish_reservation(c);
++out_free:
++	kfree(ino);
++	return err;
++}
++
++#ifdef CONFIG_UBIFS_FS_XATTR
++
++/**
++ * ubifs_jnl_delete_xattr - delete an extended attribute.
++ * @c: UBIFS file-system description object
++ * @host: host inode
++ * @inode: extended attribute inode
++ * @nm: extended attribute entry name
++ *
++ * This function delete an extended attribute which is very similar to
++ * un-linking regular files - it writes a deletion xentry, a deletion inode and
++ * updates the target inode. Returns zero in case of success and a negative
++ * error code in case of failure.
++ */
++int ubifs_jnl_delete_xattr(struct ubifs_info *c, const struct inode *host,
++			   const struct inode *inode, const struct qstr *nm)
++{
++	int err, xlen, hlen, len, lnum, xent_offs, aligned_xlen;
++	struct ubifs_dent_node *xent;
++	struct ubifs_ino_node *ino;
++	union ubifs_key xent_key, key1, key2;
++	int sync = IS_DIRSYNC(host);
++	struct ubifs_inode *host_ui = ubifs_inode(host);
++
++	dbg_jnl("host %lu, xattr ino %lu, name '%s', data len %d",
++		host->i_ino, inode->i_ino, nm->name,
++		ubifs_inode(inode)->data_len);
++	ubifs_assert(inode->i_nlink == 0);
++	ubifs_assert(mutex_is_locked(&host_ui->ui_mutex));
++
++	/*
++	 * Since we are deleting the inode, we do not bother to attach any data
++	 * to it and assume its length is %UBIFS_INO_NODE_SZ.
++	 */
++	xlen = UBIFS_DENT_NODE_SZ + nm->len + 1;
++	aligned_xlen = ALIGN(xlen, 8);
++	hlen = host_ui->data_len + UBIFS_INO_NODE_SZ;
++	len = aligned_xlen + UBIFS_INO_NODE_SZ + ALIGN(hlen, 8);
++
++	xent = kmalloc(len, GFP_NOFS);
++	if (!xent)
++		return -ENOMEM;
++
++	/* Make reservation before allocating sequence numbers */
++	err = make_reservation(c, BASEHD, len);
++	if (err) {
++		kfree(xent);
++		return err;
++	}
++
++	xent->ch.node_type = UBIFS_XENT_NODE;
++	xent_key_init(c, &xent_key, host->i_ino, nm);
++	key_write(c, &xent_key, xent->key);
++	xent->inum = 0;
++	xent->type = get_dent_type(inode->i_mode);
++	xent->nlen = cpu_to_le16(nm->len);
++	memcpy(xent->name, nm->name, nm->len);
++	xent->name[nm->len] = '\0';
++	zero_dent_node_unused(xent);
++	ubifs_prep_grp_node(c, xent, xlen, 0);
++
++	ino = (void *)xent + aligned_xlen;
++	pack_inode(c, ino, inode, 0);
++	ino = (void *)ino + UBIFS_INO_NODE_SZ;
++	pack_inode(c, ino, host, 1);
++
++	err = write_head(c, BASEHD, xent, len, &lnum, &xent_offs, sync);
++	if (!sync && !err)
++		ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, host->i_ino);
++	release_head(c, BASEHD);
++	kfree(xent);
++	if (err)
++		goto out_ro;
++
++	/* Remove the extended attribute entry from TNC */
++	err = ubifs_tnc_remove_nm(c, &xent_key, nm);
++	if (err)
++		goto out_ro;
++	err = ubifs_add_dirt(c, lnum, xlen);
++	if (err)
++		goto out_ro;
++
++	/*
++	 * Remove all nodes belonging to the extended attribute inode from TNC.
++	 * Well, there actually must be only one node - the inode itself.
++	 */
++	lowest_ino_key(c, &key1, inode->i_ino);
++	highest_ino_key(c, &key2, inode->i_ino);
++	err = ubifs_tnc_remove_range(c, &key1, &key2);
++	if (err)
++		goto out_ro;
++	err = ubifs_add_dirt(c, lnum, UBIFS_INO_NODE_SZ);
++	if (err)
++		goto out_ro;
++
++	/* And update TNC with the new host inode position */
++	ino_key_init(c, &key1, host->i_ino);
++	err = ubifs_tnc_add(c, &key1, lnum, xent_offs + len - hlen, hlen);
++	if (err)
++		goto out_ro;
++
++	finish_reservation(c);
++	spin_lock(&host_ui->ui_lock);
++	host_ui->synced_i_size = host_ui->ui_size;
++	spin_unlock(&host_ui->ui_lock);
++	mark_inode_clean(c, host_ui);
++	return 0;
++
++out_ro:
++	ubifs_ro_mode(c, err);
++	finish_reservation(c);
++	return err;
++}
++
++/**
++ * ubifs_jnl_change_xattr - change an extended attribute.
++ * @c: UBIFS file-system description object
++ * @inode: extended attribute inode
++ * @host: host inode
++ *
++ * This function writes the updated version of an extended attribute inode and
++ * the host inode tho the journal (to the base head). The host inode is written
++ * after the extended attribute inode in order to guarantee that the extended
++ * attribute will be flushed when the inode is synchronized by 'fsync()' and
++ * consequently, the write-buffer is synchronized. This function returns zero
++ * in case of success and a negative error code in case of failure.
++ */
++int ubifs_jnl_change_xattr(struct ubifs_info *c, const struct inode *inode,
++			   const struct inode *host)
++{
++	int err, len1, len2, aligned_len, aligned_len1, lnum, offs;
++	struct ubifs_inode *host_ui = ubifs_inode(host);
++	struct ubifs_ino_node *ino;
++	union ubifs_key key;
++	int sync = IS_DIRSYNC(host);
++
++	dbg_jnl("ino %lu, ino %lu", host->i_ino, inode->i_ino);
++	ubifs_assert(host->i_nlink > 0);
++	ubifs_assert(inode->i_nlink > 0);
++	ubifs_assert(mutex_is_locked(&host_ui->ui_mutex));
++
++	len1 = UBIFS_INO_NODE_SZ + host_ui->data_len;
++	len2 = UBIFS_INO_NODE_SZ + ubifs_inode(inode)->data_len;
++	aligned_len1 = ALIGN(len1, 8);
++	aligned_len = aligned_len1 + ALIGN(len2, 8);
++
++	ino = kmalloc(aligned_len, GFP_NOFS);
++	if (!ino)
++		return -ENOMEM;
++
++	/* Make reservation before allocating sequence numbers */
++	err = make_reservation(c, BASEHD, aligned_len);
++	if (err)
++		goto out_free;
++
++	pack_inode(c, ino, host, 0);
++	pack_inode(c, (void *)ino + aligned_len1, inode, 1);
++
++	err = write_head(c, BASEHD, ino, aligned_len, &lnum, &offs, 0);
++	if (!sync && !err) {
++		struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf;
++
++		ubifs_wbuf_add_ino_nolock(wbuf, host->i_ino);
++		ubifs_wbuf_add_ino_nolock(wbuf, inode->i_ino);
++	}
++	release_head(c, BASEHD);
++	if (err)
++		goto out_ro;
++
++	ino_key_init(c, &key, host->i_ino);
++	err = ubifs_tnc_add(c, &key, lnum, offs, len1);
++	if (err)
++		goto out_ro;
++
++	ino_key_init(c, &key, inode->i_ino);
++	err = ubifs_tnc_add(c, &key, lnum, offs + aligned_len1, len2);
++	if (err)
++		goto out_ro;
++
++	finish_reservation(c);
++	spin_lock(&host_ui->ui_lock);
++	host_ui->synced_i_size = host_ui->ui_size;
++	spin_unlock(&host_ui->ui_lock);
++	mark_inode_clean(c, host_ui);
++	kfree(ino);
++	return 0;
++
++out_ro:
++	ubifs_ro_mode(c, err);
++	finish_reservation(c);
++out_free:
++	kfree(ino);
++	return err;
++}
++
++#endif /* CONFIG_UBIFS_FS_XATTR */
+diff -Nurd linux-2.6.24.orig/fs/ubifs/key.h linux-2.6.24/fs/ubifs/key.h
+--- linux-2.6.24.orig/fs/ubifs/key.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/key.h	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,557 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++/*
++ * This header contains various key-related definitions and helper function.
++ * UBIFS allows several key schemes, so we access key fields only via these
++ * helpers. At the moment only one key scheme is supported.
++ *
++ * Simple key scheme
++ * ~~~~~~~~~~~~~~~~~
++ *
++ * Keys are 64-bits long. First 32-bits are inode number (parent inode number
++ * in case of direntry key). Next 3 bits are node type. The last 29 bits are
++ * 4KiB offset in case of inode node, and direntry hash in case of a direntry
++ * node. We use "r5" hash borrowed from reiserfs.
++ */
++
++#ifndef __UBIFS_KEY_H__
++#define __UBIFS_KEY_H__
++
++/**
++ * key_mask_hash - mask a valid hash value.
++ * @val: value to be masked
++ *
++ * We use hash values as offset in directories, so values %0 and %1 are
++ * reserved for "." and "..". %2 is reserved for "end of readdir" marker. This
++ * function makes sure the reserved values are not used.
++ */
++static inline uint32_t key_mask_hash(uint32_t hash)
++{
++	hash &= UBIFS_S_KEY_HASH_MASK;
++	if (unlikely(hash <= 2))
++		hash += 3;
++	return hash;
++}
++
++/**
++ * key_r5_hash - R5 hash function (borrowed from reiserfs).
++ * @s: direntry name
++ * @len: name length
++ */
++static inline uint32_t key_r5_hash(const char *s, int len)
++{
++	uint32_t a = 0;
++	const signed char *str = (const signed char *)s;
++
++	while (*str) {
++		a += *str << 4;
++		a += *str >> 4;
++		a *= 11;
++		str++;
++	}
++
++	return key_mask_hash(a);
++}
++
++/**
++ * key_test_hash - testing hash function.
++ * @str: direntry name
++ * @len: name length
++ */
++static inline uint32_t key_test_hash(const char *str, int len)
++{
++	uint32_t a = 0;
++
++	len = min_t(uint32_t, len, 4);
++	memcpy(&a, str, len);
++	return key_mask_hash(a);
++}
++
++/**
++ * ino_key_init - initialize inode key.
++ * @c: UBIFS file-system description object
++ * @key: key to initialize
++ * @inum: inode number
++ */
++static inline void ino_key_init(const struct ubifs_info *c,
++				union ubifs_key *key, ino_t inum)
++{
++	key->u32[0] = inum;
++	key->u32[1] = UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS;
++}
++
++/**
++ * ino_key_init_flash - initialize on-flash inode key.
++ * @c: UBIFS file-system description object
++ * @k: key to initialize
++ * @inum: inode number
++ */
++static inline void ino_key_init_flash(const struct ubifs_info *c, void *k,
++				      ino_t inum)
++{
++	union ubifs_key *key = k;
++
++	key->j32[0] = cpu_to_le32(inum);
++	key->j32[1] = cpu_to_le32(UBIFS_INO_KEY << UBIFS_S_KEY_BLOCK_BITS);
++	memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
++}
++
++/**
++ * lowest_ino_key - get the lowest possible inode key.
++ * @c: UBIFS file-system description object
++ * @key: key to initialize
++ * @inum: inode number
++ */
++static inline void lowest_ino_key(const struct ubifs_info *c,
++				union ubifs_key *key, ino_t inum)
++{
++	key->u32[0] = inum;
++	key->u32[1] = 0;
++}
++
++/**
++ * highest_ino_key - get the highest possible inode key.
++ * @c: UBIFS file-system description object
++ * @key: key to initialize
++ * @inum: inode number
++ */
++static inline void highest_ino_key(const struct ubifs_info *c,
++				union ubifs_key *key, ino_t inum)
++{
++	key->u32[0] = inum;
++	key->u32[1] = 0xffffffff;
++}
++
++/**
++ * dent_key_init - initialize directory entry key.
++ * @c: UBIFS file-system description object
++ * @key: key to initialize
++ * @inum: parent inode number
++ * @nm: direntry name and length
++ */
++static inline void dent_key_init(const struct ubifs_info *c,
++				 union ubifs_key *key, ino_t inum,
++				 const struct qstr *nm)
++{
++	uint32_t hash = c->key_hash(nm->name, nm->len);
++
++	ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
++	key->u32[0] = inum;
++	key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS);
++}
++
++/**
++ * dent_key_init_hash - initialize directory entry key without re-calculating
++ *                      hash function.
++ * @c: UBIFS file-system description object
++ * @key: key to initialize
++ * @inum: parent inode number
++ * @hash: direntry name hash
++ */
++static inline void dent_key_init_hash(const struct ubifs_info *c,
++				      union ubifs_key *key, ino_t inum,
++				      uint32_t hash)
++{
++	ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
++	key->u32[0] = inum;
++	key->u32[1] = hash | (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS);
++}
++
++/**
++ * dent_key_init_flash - initialize on-flash directory entry key.
++ * @c: UBIFS file-system description object
++ * @k: key to initialize
++ * @inum: parent inode number
++ * @nm: direntry name and length
++ */
++static inline void dent_key_init_flash(const struct ubifs_info *c, void *k,
++				       ino_t inum, const struct qstr *nm)
++{
++	union ubifs_key *key = k;
++	uint32_t hash = c->key_hash(nm->name, nm->len);
++
++	ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
++	key->j32[0] = cpu_to_le32(inum);
++	key->j32[1] = cpu_to_le32(hash |
++				  (UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS));
++	memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
++}
++
++/**
++ * lowest_dent_key - get the lowest possible directory entry key.
++ * @c: UBIFS file-system description object
++ * @key: where to store the lowest key
++ * @inum: parent inode number
++ */
++static inline void lowest_dent_key(const struct ubifs_info *c,
++				   union ubifs_key *key, ino_t inum)
++{
++	key->u32[0] = inum;
++	key->u32[1] = UBIFS_DENT_KEY << UBIFS_S_KEY_HASH_BITS;
++}
++
++/**
++ * xent_key_init - initialize extended attribute entry key.
++ * @c: UBIFS file-system description object
++ * @key: key to initialize
++ * @inum: host inode number
++ * @nm: extended attribute entry name and length
++ */
++static inline void xent_key_init(const struct ubifs_info *c,
++				 union ubifs_key *key, ino_t inum,
++				 const struct qstr *nm)
++{
++	uint32_t hash = c->key_hash(nm->name, nm->len);
++
++	ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
++	key->u32[0] = inum;
++	key->u32[1] = hash | (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS);
++}
++
++/**
++ * xent_key_init_hash - initialize extended attribute entry key without
++ *                      re-calculating hash function.
++ * @c: UBIFS file-system description object
++ * @key: key to initialize
++ * @inum: host inode number
++ * @hash: extended attribute entry name hash
++ */
++static inline void xent_key_init_hash(const struct ubifs_info *c,
++				      union ubifs_key *key, ino_t inum,
++				      uint32_t hash)
++{
++	ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
++	key->u32[0] = inum;
++	key->u32[1] = hash | (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS);
++}
++
++/**
++ * xent_key_init_flash - initialize on-flash extended attribute entry key.
++ * @c: UBIFS file-system description object
++ * @k: key to initialize
++ * @inum: host inode number
++ * @nm: extended attribute entry name and length
++ */
++static inline void xent_key_init_flash(const struct ubifs_info *c, void *k,
++				       ino_t inum, const struct qstr *nm)
++{
++	union ubifs_key *key = k;
++	uint32_t hash = c->key_hash(nm->name, nm->len);
++
++	ubifs_assert(!(hash & ~UBIFS_S_KEY_HASH_MASK));
++	key->j32[0] = cpu_to_le32(inum);
++	key->j32[1] = cpu_to_le32(hash |
++				  (UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS));
++	memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
++}
++
++/**
++ * lowest_xent_key - get the lowest possible extended attribute entry key.
++ * @c: UBIFS file-system description object
++ * @key: where to store the lowest key
++ * @inum: host inode number
++ */
++static inline void lowest_xent_key(const struct ubifs_info *c,
++				   union ubifs_key *key, ino_t inum)
++{
++	key->u32[0] = inum;
++	key->u32[1] = UBIFS_XENT_KEY << UBIFS_S_KEY_HASH_BITS;
++}
++
++/**
++ * data_key_init - initialize data key.
++ * @c: UBIFS file-system description object
++ * @key: key to initialize
++ * @inum: inode number
++ * @block: block number
++ */
++static inline void data_key_init(const struct ubifs_info *c,
++				 union ubifs_key *key, ino_t inum,
++				 unsigned int block)
++{
++	ubifs_assert(!(block & ~UBIFS_S_KEY_BLOCK_MASK));
++	key->u32[0] = inum;
++	key->u32[1] = block | (UBIFS_DATA_KEY << UBIFS_S_KEY_BLOCK_BITS);
++}
++
++/**
++ * data_key_init_flash - initialize on-flash data key.
++ * @c: UBIFS file-system description object
++ * @k: key to initialize
++ * @inum: inode number
++ * @block: block number
++ */
++static inline void data_key_init_flash(const struct ubifs_info *c, void *k,
++				       ino_t inum, unsigned int block)
++{
++	union ubifs_key *key = k;
++
++	ubifs_assert(!(block & ~UBIFS_S_KEY_BLOCK_MASK));
++	key->j32[0] = cpu_to_le32(inum);
++	key->j32[1] = cpu_to_le32(block |
++				  (UBIFS_DATA_KEY << UBIFS_S_KEY_BLOCK_BITS));
++	memset(k + 8, 0, UBIFS_MAX_KEY_LEN - 8);
++}
++
++/**
++ * trun_key_init - initialize truncation node key.
++ * @c: UBIFS file-system description object
++ * @key: key to initialize
++ * @inum: inode number
++ *
++ * Note, UBIFS does not have truncation keys on the media and this function is
++ * only used for purposes of replay.
++ */
++static inline void trun_key_init(const struct ubifs_info *c,
++				 union ubifs_key *key, ino_t inum)
++{
++	key->u32[0] = inum;
++	key->u32[1] = UBIFS_TRUN_KEY << UBIFS_S_KEY_BLOCK_BITS;
++}
++
++/**
++ * key_type - get key type.
++ * @c: UBIFS file-system description object
++ * @key: key to get type of
++ */
++static inline int key_type(const struct ubifs_info *c,
++			   const union ubifs_key *key)
++{
++	return key->u32[1] >> UBIFS_S_KEY_BLOCK_BITS;
++}
++
++/**
++ * key_type_flash - get type of a on-flash formatted key.
++ * @c: UBIFS file-system description object
++ * @k: key to get type of
++ */
++static inline int key_type_flash(const struct ubifs_info *c, const void *k)
++{
++	const union ubifs_key *key = k;
++
++	return le32_to_cpu(key->j32[1]) >> UBIFS_S_KEY_BLOCK_BITS;
++}
++
++/**
++ * key_inum - fetch inode number from key.
++ * @c: UBIFS file-system description object
++ * @k: key to fetch inode number from
++ */
++static inline ino_t key_inum(const struct ubifs_info *c, const void *k)
++{
++	const union ubifs_key *key = k;
++
++	return key->u32[0];
++}
++
++/**
++ * key_inum_flash - fetch inode number from an on-flash formatted key.
++ * @c: UBIFS file-system description object
++ * @k: key to fetch inode number from
++ */
++static inline ino_t key_inum_flash(const struct ubifs_info *c, const void *k)
++{
++	const union ubifs_key *key = k;
++
++	return le32_to_cpu(key->j32[0]);
++}
++
++/**
++ * key_hash - get directory entry hash.
++ * @c: UBIFS file-system description object
++ * @key: the key to get hash from
++ */
++static inline int key_hash(const struct ubifs_info *c,
++			   const union ubifs_key *key)
++{
++	return key->u32[1] & UBIFS_S_KEY_HASH_MASK;
++}
++
++/**
++ * key_hash_flash - get directory entry hash from an on-flash formatted key.
++ * @c: UBIFS file-system description object
++ * @k: the key to get hash from
++ */
++static inline int key_hash_flash(const struct ubifs_info *c, const void *k)
++{
++	const union ubifs_key *key = k;
++
++	return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_HASH_MASK;
++}
++
++/**
++ * key_block - get data block number.
++ * @c: UBIFS file-system description object
++ * @key: the key to get the block number from
++ */
++static inline unsigned int key_block(const struct ubifs_info *c,
++				     const union ubifs_key *key)
++{
++	return key->u32[1] & UBIFS_S_KEY_BLOCK_MASK;
++}
++
++/**
++ * key_block_flash - get data block number from an on-flash formatted key.
++ * @c: UBIFS file-system description object
++ * @k: the key to get the block number from
++ */
++static inline unsigned int key_block_flash(const struct ubifs_info *c,
++					   const void *k)
++{
++	const union ubifs_key *key = k;
++
++	return le32_to_cpu(key->j32[1]) & UBIFS_S_KEY_BLOCK_MASK;
++}
++
++/**
++ * key_read - transform a key to in-memory format.
++ * @c: UBIFS file-system description object
++ * @from: the key to transform
++ * @to: the key to store the result
++ */
++static inline void key_read(const struct ubifs_info *c, const void *from,
++			    union ubifs_key *to)
++{
++	const union ubifs_key *f = from;
++
++	to->u32[0] = le32_to_cpu(f->j32[0]);
++	to->u32[1] = le32_to_cpu(f->j32[1]);
++}
++
++/**
++ * key_write - transform a key from in-memory format.
++ * @c: UBIFS file-system description object
++ * @from: the key to transform
++ * @to: the key to store the result
++ */
++static inline void key_write(const struct ubifs_info *c,
++			     const union ubifs_key *from, void *to)
++{
++	union ubifs_key *t = to;
++
++	t->j32[0] = cpu_to_le32(from->u32[0]);
++	t->j32[1] = cpu_to_le32(from->u32[1]);
++	memset(to + 8, 0, UBIFS_MAX_KEY_LEN - 8);
++}
++
++/**
++ * key_write_idx - transform a key from in-memory format for the index.
++ * @c: UBIFS file-system description object
++ * @from: the key to transform
++ * @to: the key to store the result
++ */
++static inline void key_write_idx(const struct ubifs_info *c,
++				 const union ubifs_key *from, void *to)
++{
++	union ubifs_key *t = to;
++
++	t->j32[0] = cpu_to_le32(from->u32[0]);
++	t->j32[1] = cpu_to_le32(from->u32[1]);
++}
++
++/**
++ * key_copy - copy a key.
++ * @c: UBIFS file-system description object
++ * @from: the key to copy from
++ * @to: the key to copy to
++ */
++static inline void key_copy(const struct ubifs_info *c,
++			    const union ubifs_key *from, union ubifs_key *to)
++{
++	to->u64[0] = from->u64[0];
++}
++
++/**
++ * keys_cmp - compare keys.
++ * @c: UBIFS file-system description object
++ * @key1: the first key to compare
++ * @key2: the second key to compare
++ *
++ * This function compares 2 keys and returns %-1 if @key1 is less than
++ * @key2, %0 if the keys are equivalent and %1 if @key1 is greater than @key2.
++ */
++static inline int keys_cmp(const struct ubifs_info *c,
++			   const union ubifs_key *key1,
++			   const union ubifs_key *key2)
++{
++	if (key1->u32[0] < key2->u32[0])
++		return -1;
++	if (key1->u32[0] > key2->u32[0])
++		return 1;
++	if (key1->u32[1] < key2->u32[1])
++		return -1;
++	if (key1->u32[1] > key2->u32[1])
++		return 1;
++
++	return 0;
++}
++
++/**
++ * keys_eq - determine if keys are equivalent.
++ * @c: UBIFS file-system description object
++ * @key1: the first key to compare
++ * @key2: the second key to compare
++ *
++ * This function compares 2 keys and returns %1 if @key1 is equal to @key2 and
++ * %0 if not.
++ */
++static inline int keys_eq(const struct ubifs_info *c,
++			  const union ubifs_key *key1,
++			  const union ubifs_key *key2)
++{
++	if (key1->u32[0] != key2->u32[0])
++		return 0;
++	if (key1->u32[1] != key2->u32[1])
++		return 0;
++	return 1;
++}
++
++/**
++ * is_hash_key - is a key vulnerable to hash collisions.
++ * @c: UBIFS file-system description object
++ * @key: key
++ *
++ * This function returns %1 if @key is a hashed key or %0 otherwise.
++ */
++static inline int is_hash_key(const struct ubifs_info *c,
++			      const union ubifs_key *key)
++{
++	int type = key_type(c, key);
++
++	return type == UBIFS_DENT_KEY || type == UBIFS_XENT_KEY;
++}
++
++/**
++ * key_max_inode_size - get maximum file size allowed by current key format.
++ * @c: UBIFS file-system description object
++ */
++static inline unsigned long long key_max_inode_size(const struct ubifs_info *c)
++{
++	switch (c->key_fmt) {
++	case UBIFS_SIMPLE_KEY_FMT:
++		return (1ULL << UBIFS_S_KEY_BLOCK_BITS) * UBIFS_BLOCK_SIZE;
++	default:
++		return 0;
++	}
++}
++#endif /* !__UBIFS_KEY_H__ */
+diff -Nurd linux-2.6.24.orig/fs/ubifs/log.c linux-2.6.24/fs/ubifs/log.c
+--- linux-2.6.24.orig/fs/ubifs/log.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/log.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,807 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++/*
++ * This file is a part of UBIFS journal implementation and contains various
++ * functions which manipulate the log. The log is a fixed area on the flash
++ * which does not contain any data but refers to buds. The log is a part of the
++ * journal.
++ */
++
++#include "ubifs.h"
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++static int dbg_check_bud_bytes(struct ubifs_info *c);
++#else
++#define dbg_check_bud_bytes(c) 0
++#endif
++
++/**
++ * ubifs_search_bud - search bud LEB.
++ * @c: UBIFS file-system description object
++ * @lnum: logical eraseblock number to search
++ *
++ * This function searches bud LEB @lnum. Returns bud description object in case
++ * of success and %NULL if there is no bud with this LEB number.
++ */
++struct ubifs_bud *ubifs_search_bud(struct ubifs_info *c, int lnum)
++{
++	struct rb_node *p;
++	struct ubifs_bud *bud;
++
++	spin_lock(&c->buds_lock);
++	p = c->buds.rb_node;
++	while (p) {
++		bud = rb_entry(p, struct ubifs_bud, rb);
++		if (lnum < bud->lnum)
++			p = p->rb_left;
++		else if (lnum > bud->lnum)
++			p = p->rb_right;
++		else {
++			spin_unlock(&c->buds_lock);
++			return bud;
++		}
++	}
++	spin_unlock(&c->buds_lock);
++	return NULL;
++}
++
++/**
++ * ubifs_get_wbuf - get the wbuf associated with a LEB, if there is one.
++ * @c: UBIFS file-system description object
++ * @lnum: logical eraseblock number to search
++ *
++ * This functions returns the wbuf for @lnum or %NULL if there is not one.
++ */
++struct ubifs_wbuf *ubifs_get_wbuf(struct ubifs_info *c, int lnum)
++{
++	struct rb_node *p;
++	struct ubifs_bud *bud;
++	int jhead;
++
++	if (!c->jheads)
++		return NULL;
++
++	spin_lock(&c->buds_lock);
++	p = c->buds.rb_node;
++	while (p) {
++		bud = rb_entry(p, struct ubifs_bud, rb);
++		if (lnum < bud->lnum)
++			p = p->rb_left;
++		else if (lnum > bud->lnum)
++			p = p->rb_right;
++		else {
++			jhead = bud->jhead;
++			spin_unlock(&c->buds_lock);
++			return &c->jheads[jhead].wbuf;
++		}
++	}
++	spin_unlock(&c->buds_lock);
++	return NULL;
++}
++
++/**
++ * next_log_lnum - switch to the next log LEB.
++ * @c: UBIFS file-system description object
++ * @lnum: current log LEB
++ */
++static inline int next_log_lnum(const struct ubifs_info *c, int lnum)
++{
++	lnum += 1;
++	if (lnum > c->log_last)
++		lnum = UBIFS_LOG_LNUM;
++
++	return lnum;
++}
++
++/**
++ * empty_log_bytes - calculate amount of empty space in the log.
++ * @c: UBIFS file-system description object
++ */
++static inline long long empty_log_bytes(const struct ubifs_info *c)
++{
++	long long h, t;
++
++	h = (long long)c->lhead_lnum * c->leb_size + c->lhead_offs;
++	t = (long long)c->ltail_lnum * c->leb_size;
++
++	if (h >= t)
++		return c->log_bytes - h + t;
++	else
++		return t - h;
++}
++
++/**
++ * ubifs_add_bud - add bud LEB to the tree of buds and its journal head list.
++ * @c: UBIFS file-system description object
++ * @bud: the bud to add
++ */
++void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud)
++{
++	struct rb_node **p, *parent = NULL;
++	struct ubifs_bud *b;
++	struct ubifs_jhead *jhead;
++
++	spin_lock(&c->buds_lock);
++	p = &c->buds.rb_node;
++	while (*p) {
++		parent = *p;
++		b = rb_entry(parent, struct ubifs_bud, rb);
++		ubifs_assert(bud->lnum != b->lnum);
++		if (bud->lnum < b->lnum)
++			p = &(*p)->rb_left;
++		else
++			p = &(*p)->rb_right;
++	}
++
++	rb_link_node(&bud->rb, parent, p);
++	rb_insert_color(&bud->rb, &c->buds);
++	if (c->jheads) {
++		jhead = &c->jheads[bud->jhead];
++		list_add_tail(&bud->list, &jhead->buds_list);
++	} else
++		ubifs_assert(c->replaying && (c->vfs_sb->s_flags & MS_RDONLY));
++
++	/*
++	 * Note, although this is a new bud, we anyway account this space now,
++	 * before any data has been written to it, because this is about to
++	 * guarantee fixed mount time, and this bud will anyway be read and
++	 * scanned.
++	 */
++	c->bud_bytes += c->leb_size - bud->start;
++
++	dbg_log("LEB %d:%d, jhead %d, bud_bytes %lld", bud->lnum,
++		bud->start, bud->jhead, c->bud_bytes);
++	spin_unlock(&c->buds_lock);
++}
++
++/**
++ * ubifs_create_buds_lists - create journal head buds lists for remount rw.
++ * @c: UBIFS file-system description object
++ */
++void ubifs_create_buds_lists(struct ubifs_info *c)
++{
++	struct rb_node *p;
++
++	spin_lock(&c->buds_lock);
++	p = rb_first(&c->buds);
++	while (p) {
++		struct ubifs_bud *bud = rb_entry(p, struct ubifs_bud, rb);
++		struct ubifs_jhead *jhead = &c->jheads[bud->jhead];
++
++		list_add_tail(&bud->list, &jhead->buds_list);
++		p = rb_next(p);
++	}
++	spin_unlock(&c->buds_lock);
++}
++
++/**
++ * ubifs_add_bud_to_log - add a new bud to the log.
++ * @c: UBIFS file-system description object
++ * @jhead: journal head the bud belongs to
++ * @lnum: LEB number of the bud
++ * @offs: starting offset of the bud
++ *
++ * This function writes reference node for the new bud LEB @lnum it to the log,
++ * and adds it to the buds tress. It also makes sure that log size does not
++ * exceed the 'c->max_bud_bytes' limit. Returns zero in case of success,
++ * %-EAGAIN if commit is required, and a negative error codes in case of
++ * failure.
++ */
++int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs)
++{
++	int err;
++	struct ubifs_bud *bud;
++	struct ubifs_ref_node *ref;
++
++	bud = kmalloc(sizeof(struct ubifs_bud), GFP_NOFS);
++	if (!bud)
++		return -ENOMEM;
++	ref = kzalloc(c->ref_node_alsz, GFP_NOFS);
++	if (!ref) {
++		kfree(bud);
++		return -ENOMEM;
++	}
++
++	mutex_lock(&c->log_mutex);
++
++	if (c->ro_media) {
++		err = -EROFS;
++		goto out_unlock;
++	}
++
++	/* Make sure we have enough space in the log */
++	if (empty_log_bytes(c) - c->ref_node_alsz < c->min_log_bytes) {
++		dbg_log("not enough log space - %lld, required %d",
++			empty_log_bytes(c), c->min_log_bytes);
++		ubifs_commit_required(c);
++		err = -EAGAIN;
++		goto out_unlock;
++	}
++
++	/*
++	 * Make sure the the amount of space in buds will not exceed
++	 * 'c->max_bud_bytes' limit, because we want to guarantee mount time
++	 * limits.
++	 *
++	 * It is not necessary to hold @c->buds_lock when reading @c->bud_bytes
++	 * because we are holding @c->log_mutex. All @c->bud_bytes take place
++	 * when both @c->log_mutex and @c->bud_bytes are locked.
++	 */
++	if (c->bud_bytes + c->leb_size - offs > c->max_bud_bytes) {
++		dbg_log("bud bytes %lld (%lld max), require commit",
++			c->bud_bytes, c->max_bud_bytes);
++		ubifs_commit_required(c);
++		err = -EAGAIN;
++		goto out_unlock;
++	}
++
++	/*
++	 * If the journal is full enough - start background commit. Note, it is
++	 * OK to read 'c->cmt_state' without spinlock because integer reads
++	 * are atomic in the kernel.
++	 */
++	if (c->bud_bytes >= c->bg_bud_bytes &&
++	    c->cmt_state == COMMIT_RESTING) {
++		dbg_log("bud bytes %lld (%lld max), initiate BG commit",
++			c->bud_bytes, c->max_bud_bytes);
++		ubifs_request_bg_commit(c);
++	}
++
++	bud->lnum = lnum;
++	bud->start = offs;
++	bud->jhead = jhead;
++
++	ref->ch.node_type = UBIFS_REF_NODE;
++	ref->lnum = cpu_to_le32(bud->lnum);
++	ref->offs = cpu_to_le32(bud->start);
++	ref->jhead = cpu_to_le32(jhead);
++
++	if (c->lhead_offs > c->leb_size - c->ref_node_alsz) {
++		c->lhead_lnum = next_log_lnum(c, c->lhead_lnum);
++		c->lhead_offs = 0;
++	}
++
++	if (c->lhead_offs == 0) {
++		/* Must ensure next log LEB has been unmapped */
++		err = ubifs_leb_unmap(c, c->lhead_lnum);
++		if (err)
++			goto out_unlock;
++	}
++
++	if (bud->start == 0) {
++		/*
++		 * Before writing the LEB reference which refers an empty LEB
++		 * to the log, we have to make sure it is mapped, because
++		 * otherwise we'd risk to refer an LEB with garbage in case of
++		 * an unclean reboot, because the target LEB might have been
++		 * unmapped, but not yet physically erased.
++		 */
++		err = ubi_leb_map(c->ubi, bud->lnum, UBI_SHORTTERM);
++		if (err)
++			goto out_unlock;
++	}
++
++	dbg_log("write ref LEB %d:%d",
++		c->lhead_lnum, c->lhead_offs);
++	err = ubifs_write_node(c, ref, UBIFS_REF_NODE_SZ, c->lhead_lnum,
++			       c->lhead_offs, UBI_SHORTTERM);
++	if (err)
++		goto out_unlock;
++
++	c->lhead_offs += c->ref_node_alsz;
++
++	ubifs_add_bud(c, bud);
++
++	mutex_unlock(&c->log_mutex);
++	kfree(ref);
++	return 0;
++
++out_unlock:
++	if (err != -EAGAIN)
++		ubifs_ro_mode(c, err);
++	mutex_unlock(&c->log_mutex);
++	kfree(ref);
++	kfree(bud);
++	return err;
++}
++
++/**
++ * remove_buds - remove used buds.
++ * @c: UBIFS file-system description object
++ *
++ * This function removes use buds from the buds tree. It does not remove the
++ * buds which are pointed to by journal heads.
++ */
++static void remove_buds(struct ubifs_info *c)
++{
++	struct rb_node *p;
++
++	ubifs_assert(list_empty(&c->old_buds));
++	c->cmt_bud_bytes = 0;
++	spin_lock(&c->buds_lock);
++	p = rb_first(&c->buds);
++	while (p) {
++		struct rb_node *p1 = p;
++		struct ubifs_bud *bud;
++		struct ubifs_wbuf *wbuf;
++
++		p = rb_next(p);
++		bud = rb_entry(p1, struct ubifs_bud, rb);
++		wbuf = &c->jheads[bud->jhead].wbuf;
++
++		if (wbuf->lnum == bud->lnum) {
++			/*
++			 * Do not remove buds which are pointed to by journal
++			 * heads (non-closed buds).
++			 */
++			c->cmt_bud_bytes += wbuf->offs - bud->start;
++			dbg_log("preserve %d:%d, jhead %d, bud bytes %d, "
++				"cmt_bud_bytes %lld", bud->lnum, bud->start,
++				bud->jhead, wbuf->offs - bud->start,
++				c->cmt_bud_bytes);
++			bud->start = wbuf->offs;
++		} else {
++			c->cmt_bud_bytes += c->leb_size - bud->start;
++			dbg_log("remove %d:%d, jhead %d, bud bytes %d, "
++				"cmt_bud_bytes %lld", bud->lnum, bud->start,
++				bud->jhead, c->leb_size - bud->start,
++				c->cmt_bud_bytes);
++			rb_erase(p1, &c->buds);
++			list_del(&bud->list);
++			/*
++			 * If the commit does not finish, the recovery will need
++			 * to replay the journal, in which case the old buds
++			 * must be unchanged. Do not release them until post
++			 * commit i.e. do not allow them to be garbage
++			 * collected.
++			 */
++			list_add(&bud->list, &c->old_buds);
++		}
++	}
++	spin_unlock(&c->buds_lock);
++}
++
++/**
++ * ubifs_log_start_commit - start commit.
++ * @c: UBIFS file-system description object
++ * @ltail_lnum: return new log tail LEB number
++ *
++ * The commit operation starts with writing "commit start" node to the log and
++ * reference nodes for all journal heads which will define new journal after
++ * the commit has been finished. The commit start and reference nodes are
++ * written in one go to the nearest empty log LEB (hence, when commit is
++ * finished UBIFS may safely unmap all the previous log LEBs). This function
++ * returns zero in case of success and a negative error code in case of
++ * failure.
++ */
++int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum)
++{
++	void *buf;
++	struct ubifs_cs_node *cs;
++	struct ubifs_ref_node *ref;
++	int err, i, max_len, len;
++
++	err = dbg_check_bud_bytes(c);
++	if (err)
++		return err;
++
++	max_len = UBIFS_CS_NODE_SZ + c->jhead_cnt * UBIFS_REF_NODE_SZ;
++	max_len = ALIGN(max_len, c->min_io_size);
++	buf = cs = kmalloc(max_len, GFP_NOFS);
++	if (!buf)
++		return -ENOMEM;
++
++	cs->ch.node_type = UBIFS_CS_NODE;
++	cs->cmt_no = cpu_to_le64(c->cmt_no);
++	ubifs_prepare_node(c, cs, UBIFS_CS_NODE_SZ, 0);
++
++	/*
++	 * Note, we do not lock 'c->log_mutex' because this is the commit start
++	 * phase and we are exclusively using the log. And we do not lock
++	 * write-buffer because nobody can write to the file-system at this
++	 * phase.
++	 */
++
++	len = UBIFS_CS_NODE_SZ;
++	for (i = 0; i < c->jhead_cnt; i++) {
++		int lnum = c->jheads[i].wbuf.lnum;
++		int offs = c->jheads[i].wbuf.offs;
++
++		if (lnum == -1 || offs == c->leb_size)
++			continue;
++
++		dbg_log("add ref to LEB %d:%d for jhead %d", lnum, offs, i);
++		ref = buf + len;
++		ref->ch.node_type = UBIFS_REF_NODE;
++		ref->lnum = cpu_to_le32(lnum);
++		ref->offs = cpu_to_le32(offs);
++		ref->jhead = cpu_to_le32(i);
++
++		ubifs_prepare_node(c, ref, UBIFS_REF_NODE_SZ, 0);
++		len += UBIFS_REF_NODE_SZ;
++	}
++
++	ubifs_pad(c, buf + len, ALIGN(len, c->min_io_size) - len);
++
++	/* Switch to the next log LEB */
++	if (c->lhead_offs) {
++		c->lhead_lnum = next_log_lnum(c, c->lhead_lnum);
++		c->lhead_offs = 0;
++	}
++
++	if (c->lhead_offs == 0) {
++		/* Must ensure next LEB has been unmapped */
++		err = ubifs_leb_unmap(c, c->lhead_lnum);
++		if (err)
++			goto out;
++	}
++
++	len = ALIGN(len, c->min_io_size);
++	dbg_log("writing commit start at LEB %d:0, len %d", c->lhead_lnum, len);
++	err = ubifs_leb_write(c, c->lhead_lnum, cs, 0, len, UBI_SHORTTERM);
++	if (err)
++		goto out;
++
++	*ltail_lnum = c->lhead_lnum;
++
++	c->lhead_offs += len;
++	if (c->lhead_offs == c->leb_size) {
++		c->lhead_lnum = next_log_lnum(c, c->lhead_lnum);
++		c->lhead_offs = 0;
++	}
++
++	remove_buds(c);
++
++	/*
++	 * We have started the commit and now users may use the rest of the log
++	 * for new writes.
++	 */
++	c->min_log_bytes = 0;
++
++out:
++	kfree(buf);
++	return err;
++}
++
++/**
++ * ubifs_log_end_commit - end commit.
++ * @c: UBIFS file-system description object
++ * @ltail_lnum: new log tail LEB number
++ *
++ * This function is called on when the commit operation was finished. It
++ * moves log tail to new position and unmaps LEBs which contain obsolete data.
++ * Returns zero in case of success and a negative error code in case of
++ * failure.
++ */
++int ubifs_log_end_commit(struct ubifs_info *c, int ltail_lnum)
++{
++	int err;
++
++	/*
++	 * At this phase we have to lock 'c->log_mutex' because UBIFS allows FS
++	 * writes during commit. Its only short "commit" start phase when
++	 * writers are blocked.
++	 */
++	mutex_lock(&c->log_mutex);
++
++	dbg_log("old tail was LEB %d:0, new tail is LEB %d:0",
++		c->ltail_lnum, ltail_lnum);
++
++	c->ltail_lnum = ltail_lnum;
++	/*
++	 * The commit is finished and from now on it must be guaranteed that
++	 * there is always enough space for the next commit.
++	 */
++	c->min_log_bytes = c->leb_size;
++
++	spin_lock(&c->buds_lock);
++	c->bud_bytes -= c->cmt_bud_bytes;
++	spin_unlock(&c->buds_lock);
++
++	err = dbg_check_bud_bytes(c);
++
++	mutex_unlock(&c->log_mutex);
++	return err;
++}
++
++/**
++ * ubifs_log_post_commit - things to do after commit is completed.
++ * @c: UBIFS file-system description object
++ * @old_ltail_lnum: old log tail LEB number
++ *
++ * Release buds only after commit is completed, because they must be unchanged
++ * if recovery is needed.
++ *
++ * Unmap log LEBs only after commit is completed, because they may be needed for
++ * recovery.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int ubifs_log_post_commit(struct ubifs_info *c, int old_ltail_lnum)
++{
++	int lnum, err = 0;
++
++	while (!list_empty(&c->old_buds)) {
++		struct ubifs_bud *bud;
++
++		bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
++		err = ubifs_return_leb(c, bud->lnum);
++		if (err)
++			return err;
++		list_del(&bud->list);
++		kfree(bud);
++	}
++	mutex_lock(&c->log_mutex);
++	for (lnum = old_ltail_lnum; lnum != c->ltail_lnum;
++	     lnum = next_log_lnum(c, lnum)) {
++		dbg_log("unmap log LEB %d", lnum);
++		err = ubifs_leb_unmap(c, lnum);
++		if (err)
++			goto out;
++	}
++out:
++	mutex_unlock(&c->log_mutex);
++	return err;
++}
++
++/**
++ * struct done_ref - references that have been done.
++ * @rb: rb-tree node
++ * @lnum: LEB number
++ */
++struct done_ref {
++	struct rb_node rb;
++	int lnum;
++};
++
++/**
++ * done_already - determine if a reference has been done already.
++ * @done_tree: rb-tree to store references that have been done
++ * @lnum: LEB number of reference
++ *
++ * This function returns %1 if the reference has been done, %0 if not, otherwise
++ * a negative error code is returned.
++ */
++static int done_already(struct rb_root *done_tree, int lnum)
++{
++	struct rb_node **p = &done_tree->rb_node, *parent = NULL;
++	struct done_ref *dr;
++
++	while (*p) {
++		parent = *p;
++		dr = rb_entry(parent, struct done_ref, rb);
++		if (lnum < dr->lnum)
++			p = &(*p)->rb_left;
++		else if (lnum > dr->lnum)
++			p = &(*p)->rb_right;
++		else
++			return 1;
++	}
++
++	dr = kzalloc(sizeof(struct done_ref), GFP_NOFS);
++	if (!dr)
++		return -ENOMEM;
++
++	dr->lnum = lnum;
++
++	rb_link_node(&dr->rb, parent, p);
++	rb_insert_color(&dr->rb, done_tree);
++
++	return 0;
++}
++
++/**
++ * destroy_done_tree - destroy the done tree.
++ * @done_tree: done tree to destroy
++ */
++static void destroy_done_tree(struct rb_root *done_tree)
++{
++	struct rb_node *this = done_tree->rb_node;
++	struct done_ref *dr;
++
++	while (this) {
++		if (this->rb_left) {
++			this = this->rb_left;
++			continue;
++		} else if (this->rb_right) {
++			this = this->rb_right;
++			continue;
++		}
++		dr = rb_entry(this, struct done_ref, rb);
++		this = rb_parent(this);
++		if (this) {
++			if (this->rb_left == &dr->rb)
++				this->rb_left = NULL;
++			else
++				this->rb_right = NULL;
++		}
++		kfree(dr);
++	}
++}
++
++/**
++ * add_node - add a node to the consolidated log.
++ * @c: UBIFS file-system description object
++ * @buf: buffer to which to add
++ * @lnum: LEB number to which to write is passed and returned here
++ * @offs: offset to where to write is passed and returned here
++ * @node: node to add
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int add_node(struct ubifs_info *c, void *buf, int *lnum, int *offs,
++		    void *node)
++{
++	struct ubifs_ch *ch = node;
++	int len = le32_to_cpu(ch->len), remains = c->leb_size - *offs;
++
++	if (len > remains) {
++		int sz = ALIGN(*offs, c->min_io_size), err;
++
++		ubifs_pad(c, buf + *offs, sz - *offs);
++		err = ubifs_leb_change(c, *lnum, buf, sz, UBI_SHORTTERM);
++		if (err)
++			return err;
++		*lnum = next_log_lnum(c, *lnum);
++		*offs = 0;
++	}
++	memcpy(buf + *offs, node, len);
++	*offs += ALIGN(len, 8);
++	return 0;
++}
++
++/**
++ * ubifs_consolidate_log - consolidate the log.
++ * @c: UBIFS file-system description object
++ *
++ * Repeated failed commits could cause the log to be full, but at least 1 LEB is
++ * needed for commit. This function rewrites the reference nodes in the log
++ * omitting duplicates, and failed CS nodes, and leaving no gaps.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int ubifs_consolidate_log(struct ubifs_info *c)
++{
++	struct ubifs_scan_leb *sleb;
++	struct ubifs_scan_node *snod;
++	struct rb_root done_tree = RB_ROOT;
++	int lnum, err, first = 1, write_lnum, offs = 0;
++	void *buf;
++
++	dbg_rcvry("log tail LEB %d, log head LEB %d", c->ltail_lnum,
++		  c->lhead_lnum);
++	buf = vmalloc(c->leb_size);
++	if (!buf)
++		return -ENOMEM;
++	lnum = c->ltail_lnum;
++	write_lnum = lnum;
++	while (1) {
++		sleb = ubifs_scan(c, lnum, 0, c->sbuf);
++		if (IS_ERR(sleb)) {
++			err = PTR_ERR(sleb);
++			goto out_free;
++		}
++		list_for_each_entry(snod, &sleb->nodes, list) {
++			switch (snod->type) {
++			case UBIFS_REF_NODE: {
++				struct ubifs_ref_node *ref = snod->node;
++				int ref_lnum = le32_to_cpu(ref->lnum);
++
++				err = done_already(&done_tree, ref_lnum);
++				if (err < 0)
++					goto out_scan;
++				if (err != 1) {
++					err = add_node(c, buf, &write_lnum,
++						       &offs, snod->node);
++					if (err)
++						goto out_scan;
++				}
++				break;
++			}
++			case UBIFS_CS_NODE:
++				if (!first)
++					break;
++				err = add_node(c, buf, &write_lnum, &offs,
++					       snod->node);
++				if (err)
++					goto out_scan;
++				first = 0;
++				break;
++			}
++		}
++		ubifs_scan_destroy(sleb);
++		if (lnum == c->lhead_lnum)
++			break;
++		lnum = next_log_lnum(c, lnum);
++	}
++	if (offs) {
++		int sz = ALIGN(offs, c->min_io_size);
++
++		ubifs_pad(c, buf + offs, sz - offs);
++		err = ubifs_leb_change(c, write_lnum, buf, sz, UBI_SHORTTERM);
++		if (err)
++			goto out_free;
++		offs = ALIGN(offs, c->min_io_size);
++	}
++	destroy_done_tree(&done_tree);
++	vfree(buf);
++	if (write_lnum == c->lhead_lnum) {
++		ubifs_err("log is too full");
++		return -EINVAL;
++	}
++	/* Unmap remaining LEBs */
++	lnum = write_lnum;
++	do {
++		lnum = next_log_lnum(c, lnum);
++		err = ubifs_leb_unmap(c, lnum);
++		if (err)
++			return err;
++	} while (lnum != c->lhead_lnum);
++	c->lhead_lnum = write_lnum;
++	c->lhead_offs = offs;
++	dbg_rcvry("new log head at %d:%d", c->lhead_lnum, c->lhead_offs);
++	return 0;
++
++out_scan:
++	ubifs_scan_destroy(sleb);
++out_free:
++	destroy_done_tree(&done_tree);
++	vfree(buf);
++	return err;
++}
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++
++/**
++ * dbg_check_bud_bytes - make sure bud bytes calculation are all right.
++ * @c: UBIFS file-system description object
++ *
++ * This function makes sure the amount of flash space used by closed buds
++ * ('c->bud_bytes' is correct). Returns zero in case of success and %-EINVAL in
++ * case of failure.
++ */
++static int dbg_check_bud_bytes(struct ubifs_info *c)
++{
++	int i, err = 0;
++	struct ubifs_bud *bud;
++	long long bud_bytes = 0;
++
++	if (!(ubifs_chk_flags & UBIFS_CHK_GEN))
++		return 0;
++
++	spin_lock(&c->buds_lock);
++	for (i = 0; i < c->jhead_cnt; i++)
++		list_for_each_entry(bud, &c->jheads[i].buds_list, list)
++			bud_bytes += c->leb_size - bud->start;
++
++	if (c->bud_bytes != bud_bytes) {
++		ubifs_err("bad bud_bytes %lld, calculated %lld",
++			  c->bud_bytes, bud_bytes);
++		err = -EINVAL;
++	}
++	spin_unlock(&c->buds_lock);
++
++	return err;
++}
++
++#endif /* CONFIG_UBIFS_FS_DEBUG */
+diff -Nurd linux-2.6.24.orig/fs/ubifs/lprops.c linux-2.6.24/fs/ubifs/lprops.c
+--- linux-2.6.24.orig/fs/ubifs/lprops.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/lprops.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,1333 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Adrian Hunter
++ *          Artem Bityutskiy (Битюцкий Артём)
++ */
++
++/*
++ * This file implements the functions that access LEB properties and their
++ * categories. LEBs are categorized based on the needs of UBIFS, and the
++ * categories are stored as either heaps or lists to provide a fast way of
++ * finding a LEB in a particular category. For example, UBIFS may need to find
++ * an empty LEB for the journal, or a very dirty LEB for garbage collection.
++ */
++
++#include "ubifs.h"
++
++/**
++ * get_heap_comp_val - get the LEB properties value for heap comparisons.
++ * @lprops: LEB properties
++ * @cat: LEB category
++ */
++static int get_heap_comp_val(struct ubifs_lprops *lprops, int cat)
++{
++	switch (cat) {
++	case LPROPS_FREE:
++		return lprops->free;
++	case LPROPS_DIRTY_IDX:
++		return lprops->free + lprops->dirty;
++	default:
++		return lprops->dirty;
++	}
++}
++
++/**
++ * move_up_lpt_heap - move a new heap entry up as far as possible.
++ * @c: UBIFS file-system description object
++ * @heap: LEB category heap
++ * @lprops: LEB properties to move
++ * @cat: LEB category
++ *
++ * New entries to a heap are added at the bottom and then moved up until the
++ * parent's value is greater.  In the case of LPT's category heaps, the value
++ * is either the amount of free space or the amount of dirty space, depending
++ * on the category.
++ */
++static void move_up_lpt_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap,
++			     struct ubifs_lprops *lprops, int cat)
++{
++	int val1, val2, hpos;
++
++	hpos = lprops->hpos;
++	if (!hpos)
++		return; /* Already top of the heap */
++	val1 = get_heap_comp_val(lprops, cat);
++	/* Compare to parent and, if greater, move up the heap */
++	do {
++		int ppos = (hpos - 1) / 2;
++
++		val2 = get_heap_comp_val(heap->arr[ppos], cat);
++		if (val2 >= val1)
++			return;
++		/* Greater than parent so move up */
++		heap->arr[ppos]->hpos = hpos;
++		heap->arr[hpos] = heap->arr[ppos];
++		heap->arr[ppos] = lprops;
++		lprops->hpos = ppos;
++		hpos = ppos;
++	} while (hpos);
++}
++
++/**
++ * adjust_lpt_heap - move a changed heap entry up or down the heap.
++ * @c: UBIFS file-system description object
++ * @heap: LEB category heap
++ * @lprops: LEB properties to move
++ * @hpos: heap position of @lprops
++ * @cat: LEB category
++ *
++ * Changed entries in a heap are moved up or down until the parent's value is
++ * greater.  In the case of LPT's category heaps, the value is either the amount
++ * of free space or the amount of dirty space, depending on the category.
++ */
++static void adjust_lpt_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap,
++			    struct ubifs_lprops *lprops, int hpos, int cat)
++{
++	int val1, val2, val3, cpos;
++
++	val1 = get_heap_comp_val(lprops, cat);
++	/* Compare to parent and, if greater than parent, move up the heap */
++	if (hpos) {
++		int ppos = (hpos - 1) / 2;
++
++		val2 = get_heap_comp_val(heap->arr[ppos], cat);
++		if (val1 > val2) {
++			/* Greater than parent so move up */
++			while (1) {
++				heap->arr[ppos]->hpos = hpos;
++				heap->arr[hpos] = heap->arr[ppos];
++				heap->arr[ppos] = lprops;
++				lprops->hpos = ppos;
++				hpos = ppos;
++				if (!hpos)
++					return;
++				ppos = (hpos - 1) / 2;
++				val2 = get_heap_comp_val(heap->arr[ppos], cat);
++				if (val1 <= val2)
++					return;
++				/* Still greater than parent so keep going */
++			}
++		}
++	}
++
++	/* Not greater than parent, so compare to children */
++	while (1) {
++		/* Compare to left child */
++		cpos = hpos * 2 + 1;
++		if (cpos >= heap->cnt)
++			return;
++		val2 = get_heap_comp_val(heap->arr[cpos], cat);
++		if (val1 < val2) {
++			/* Less than left child, so promote biggest child */
++			if (cpos + 1 < heap->cnt) {
++				val3 = get_heap_comp_val(heap->arr[cpos + 1],
++							 cat);
++				if (val3 > val2)
++					cpos += 1; /* Right child is bigger */
++			}
++			heap->arr[cpos]->hpos = hpos;
++			heap->arr[hpos] = heap->arr[cpos];
++			heap->arr[cpos] = lprops;
++			lprops->hpos = cpos;
++			hpos = cpos;
++			continue;
++		}
++		/* Compare to right child */
++		cpos += 1;
++		if (cpos >= heap->cnt)
++			return;
++		val3 = get_heap_comp_val(heap->arr[cpos], cat);
++		if (val1 < val3) {
++			/* Less than right child, so promote right child */
++			heap->arr[cpos]->hpos = hpos;
++			heap->arr[hpos] = heap->arr[cpos];
++			heap->arr[cpos] = lprops;
++			lprops->hpos = cpos;
++			hpos = cpos;
++			continue;
++		}
++		return;
++	}
++}
++
++/**
++ * add_to_lpt_heap - add LEB properties to a LEB category heap.
++ * @c: UBIFS file-system description object
++ * @lprops: LEB properties to add
++ * @cat: LEB category
++ *
++ * This function returns %1 if @lprops is added to the heap for LEB category
++ * @cat, otherwise %0 is returned because the heap is full.
++ */
++static int add_to_lpt_heap(struct ubifs_info *c, struct ubifs_lprops *lprops,
++			   int cat)
++{
++	struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1];
++
++	if (heap->cnt >= heap->max_cnt) {
++		const int b = LPT_HEAP_SZ / 2 - 1;
++		int cpos, val1, val2;
++
++		/* Compare to some other LEB on the bottom of heap */
++		/* Pick a position kind of randomly */
++		cpos = (((size_t)lprops >> 4) & b) + b;
++		ubifs_assert(cpos >= b);
++		ubifs_assert(cpos < LPT_HEAP_SZ);
++		ubifs_assert(cpos < heap->cnt);
++
++		val1 = get_heap_comp_val(lprops, cat);
++		val2 = get_heap_comp_val(heap->arr[cpos], cat);
++		if (val1 > val2) {
++			struct ubifs_lprops *lp;
++
++			lp = heap->arr[cpos];
++			lp->flags &= ~LPROPS_CAT_MASK;
++			lp->flags |= LPROPS_UNCAT;
++			list_add(&lp->list, &c->uncat_list);
++			lprops->hpos = cpos;
++			heap->arr[cpos] = lprops;
++			move_up_lpt_heap(c, heap, lprops, cat);
++			dbg_check_heap(c, heap, cat, lprops->hpos);
++			return 1; /* Added to heap */
++		}
++		dbg_check_heap(c, heap, cat, -1);
++		return 0; /* Not added to heap */
++	} else {
++		lprops->hpos = heap->cnt++;
++		heap->arr[lprops->hpos] = lprops;
++		move_up_lpt_heap(c, heap, lprops, cat);
++		dbg_check_heap(c, heap, cat, lprops->hpos);
++		return 1; /* Added to heap */
++	}
++}
++
++/**
++ * remove_from_lpt_heap - remove LEB properties from a LEB category heap.
++ * @c: UBIFS file-system description object
++ * @lprops: LEB properties to remove
++ * @cat: LEB category
++ */
++static void remove_from_lpt_heap(struct ubifs_info *c,
++				 struct ubifs_lprops *lprops, int cat)
++{
++	struct ubifs_lpt_heap *heap;
++	int hpos = lprops->hpos;
++
++	heap = &c->lpt_heap[cat - 1];
++	ubifs_assert(hpos >= 0 && hpos < heap->cnt);
++	ubifs_assert(heap->arr[hpos] == lprops);
++	heap->cnt -= 1;
++	if (hpos < heap->cnt) {
++		heap->arr[hpos] = heap->arr[heap->cnt];
++		heap->arr[hpos]->hpos = hpos;
++		adjust_lpt_heap(c, heap, heap->arr[hpos], hpos, cat);
++	}
++	dbg_check_heap(c, heap, cat, -1);
++}
++
++/**
++ * lpt_heap_replace - replace lprops in a category heap.
++ * @c: UBIFS file-system description object
++ * @old_lprops: LEB properties to replace
++ * @new_lprops: LEB properties with which to replace
++ * @cat: LEB category
++ *
++ * During commit it is sometimes necessary to copy a pnode (see dirty_cow_pnode)
++ * and the lprops that the pnode contains.  When that happens, references in
++ * the category heaps to those lprops must be updated to point to the new
++ * lprops.  This function does that.
++ */
++static void lpt_heap_replace(struct ubifs_info *c,
++			     struct ubifs_lprops *old_lprops,
++			     struct ubifs_lprops *new_lprops, int cat)
++{
++	struct ubifs_lpt_heap *heap;
++	int hpos = new_lprops->hpos;
++
++	heap = &c->lpt_heap[cat - 1];
++	heap->arr[hpos] = new_lprops;
++}
++
++/**
++ * ubifs_add_to_cat - add LEB properties to a category list or heap.
++ * @c: UBIFS file-system description object
++ * @lprops: LEB properties to add
++ * @cat: LEB category to which to add
++ *
++ * LEB properties are categorized to enable fast find operations.
++ */
++void ubifs_add_to_cat(struct ubifs_info *c, struct ubifs_lprops *lprops,
++		      int cat)
++{
++	switch (cat) {
++	case LPROPS_DIRTY:
++	case LPROPS_DIRTY_IDX:
++	case LPROPS_FREE:
++		if (add_to_lpt_heap(c, lprops, cat))
++			break;
++		/* No more room on heap so make it uncategorized */
++		cat = LPROPS_UNCAT;
++		/* Fall through */
++	case LPROPS_UNCAT:
++		list_add(&lprops->list, &c->uncat_list);
++		break;
++	case LPROPS_EMPTY:
++		list_add(&lprops->list, &c->empty_list);
++		break;
++	case LPROPS_FREEABLE:
++		list_add(&lprops->list, &c->freeable_list);
++		c->freeable_cnt += 1;
++		break;
++	case LPROPS_FRDI_IDX:
++		list_add(&lprops->list, &c->frdi_idx_list);
++		break;
++	default:
++		ubifs_assert(0);
++	}
++	lprops->flags &= ~LPROPS_CAT_MASK;
++	lprops->flags |= cat;
++}
++
++/**
++ * ubifs_remove_from_cat - remove LEB properties from a category list or heap.
++ * @c: UBIFS file-system description object
++ * @lprops: LEB properties to remove
++ * @cat: LEB category from which to remove
++ *
++ * LEB properties are categorized to enable fast find operations.
++ */
++static void ubifs_remove_from_cat(struct ubifs_info *c,
++				  struct ubifs_lprops *lprops, int cat)
++{
++	switch (cat) {
++	case LPROPS_DIRTY:
++	case LPROPS_DIRTY_IDX:
++	case LPROPS_FREE:
++		remove_from_lpt_heap(c, lprops, cat);
++		break;
++	case LPROPS_FREEABLE:
++		c->freeable_cnt -= 1;
++		ubifs_assert(c->freeable_cnt >= 0);
++		/* Fall through */
++	case LPROPS_UNCAT:
++	case LPROPS_EMPTY:
++	case LPROPS_FRDI_IDX:
++		ubifs_assert(!list_empty(&lprops->list));
++		list_del(&lprops->list);
++		break;
++	default:
++		ubifs_assert(0);
++	}
++}
++
++/**
++ * ubifs_replace_cat - replace lprops in a category list or heap.
++ * @c: UBIFS file-system description object
++ * @old_lprops: LEB properties to replace
++ * @new_lprops: LEB properties with which to replace
++ *
++ * During commit it is sometimes necessary to copy a pnode (see dirty_cow_pnode)
++ * and the lprops that the pnode contains. When that happens, references in
++ * category lists and heaps must be replaced. This function does that.
++ */
++void ubifs_replace_cat(struct ubifs_info *c, struct ubifs_lprops *old_lprops,
++		       struct ubifs_lprops *new_lprops)
++{
++	int cat;
++
++	cat = new_lprops->flags & LPROPS_CAT_MASK;
++	switch (cat) {
++	case LPROPS_DIRTY:
++	case LPROPS_DIRTY_IDX:
++	case LPROPS_FREE:
++		lpt_heap_replace(c, old_lprops, new_lprops, cat);
++		break;
++	case LPROPS_UNCAT:
++	case LPROPS_EMPTY:
++	case LPROPS_FREEABLE:
++	case LPROPS_FRDI_IDX:
++		list_replace(&old_lprops->list, &new_lprops->list);
++		break;
++	default:
++		ubifs_assert(0);
++	}
++}
++
++/**
++ * ubifs_ensure_cat - ensure LEB properties are categorized.
++ * @c: UBIFS file-system description object
++ * @lprops: LEB properties
++ *
++ * A LEB may have fallen off of the bottom of a heap, and ended up as
++ * uncategorized even though it has enough space for us now. If that is the case
++ * this function will put the LEB back onto a heap.
++ */
++void ubifs_ensure_cat(struct ubifs_info *c, struct ubifs_lprops *lprops)
++{
++	int cat = lprops->flags & LPROPS_CAT_MASK;
++
++	if (cat != LPROPS_UNCAT)
++		return;
++	cat = ubifs_categorize_lprops(c, lprops);
++	if (cat == LPROPS_UNCAT)
++		return;
++	ubifs_remove_from_cat(c, lprops, LPROPS_UNCAT);
++	ubifs_add_to_cat(c, lprops, cat);
++}
++
++/**
++ * ubifs_categorize_lprops - categorize LEB properties.
++ * @c: UBIFS file-system description object
++ * @lprops: LEB properties to categorize
++ *
++ * LEB properties are categorized to enable fast find operations. This function
++ * returns the LEB category to which the LEB properties belong. Note however
++ * that if the LEB category is stored as a heap and the heap is full, the
++ * LEB properties may have their category changed to %LPROPS_UNCAT.
++ */
++int ubifs_categorize_lprops(const struct ubifs_info *c,
++			    const struct ubifs_lprops *lprops)
++{
++	if (lprops->flags & LPROPS_TAKEN)
++		return LPROPS_UNCAT;
++
++	if (lprops->free == c->leb_size) {
++		ubifs_assert(!(lprops->flags & LPROPS_INDEX));
++		return LPROPS_EMPTY;
++	}
++
++	if (lprops->free + lprops->dirty == c->leb_size) {
++		if (lprops->flags & LPROPS_INDEX)
++			return LPROPS_FRDI_IDX;
++		else
++			return LPROPS_FREEABLE;
++	}
++
++	if (lprops->flags & LPROPS_INDEX) {
++		if (lprops->dirty + lprops->free >= c->min_idx_node_sz)
++			return LPROPS_DIRTY_IDX;
++	} else {
++		if (lprops->dirty >= c->dead_wm &&
++		    lprops->dirty > lprops->free)
++			return LPROPS_DIRTY;
++		if (lprops->free > 0)
++			return LPROPS_FREE;
++	}
++
++	return LPROPS_UNCAT;
++}
++
++/**
++ * change_category - change LEB properties category.
++ * @c: UBIFS file-system description object
++ * @lprops: LEB properties to recategorize
++ *
++ * LEB properties are categorized to enable fast find operations. When the LEB
++ * properties change they must be recategorized.
++ */
++static void change_category(struct ubifs_info *c, struct ubifs_lprops *lprops)
++{
++	int old_cat = lprops->flags & LPROPS_CAT_MASK;
++	int new_cat = ubifs_categorize_lprops(c, lprops);
++
++	if (old_cat == new_cat) {
++		struct ubifs_lpt_heap *heap = &c->lpt_heap[new_cat - 1];
++
++		/* lprops on a heap now must be moved up or down */
++		if (new_cat < 1 || new_cat > LPROPS_HEAP_CNT)
++			return; /* Not on a heap */
++		heap = &c->lpt_heap[new_cat - 1];
++		adjust_lpt_heap(c, heap, lprops, lprops->hpos, new_cat);
++	} else {
++		ubifs_remove_from_cat(c, lprops, old_cat);
++		ubifs_add_to_cat(c, lprops, new_cat);
++	}
++}
++
++/**
++ * calc_dark - calculate LEB dark space size.
++ * @c: the UBIFS file-system description object
++ * @spc: amount of free and dirty space in the LEB
++ *
++ * This function calculates amount of dark space in an LEB which has @spc bytes
++ * of free and dirty space. Returns the calculations result.
++ *
++ * Dark space is the space which is not always usable - it depends on which
++ * nodes are written in which order. E.g., if an LEB has only 512 free bytes,
++ * it is dark space, because it cannot fit a large data node. So UBIFS cannot
++ * count on this LEB and treat these 512 bytes as usable because it is not true
++ * if, for example, only big chunks of uncompressible data will be written to
++ * the FS.
++ */
++static int calc_dark(struct ubifs_info *c, int spc)
++{
++	ubifs_assert(!(spc & 7));
++
++	if (spc < c->dark_wm)
++		return spc;
++
++	/*
++	 * If we have slightly more space then the dark space watermark, we can
++	 * anyway safely assume it we'll be able to write a node of the
++	 * smallest size there.
++	 */
++	if (spc - c->dark_wm < MIN_WRITE_SZ)
++		return spc - MIN_WRITE_SZ;
++
++	return c->dark_wm;
++}
++
++/**
++ * is_lprops_dirty - determine if LEB properties are dirty.
++ * @c: the UBIFS file-system description object
++ * @lprops: LEB properties to test
++ */
++static int is_lprops_dirty(struct ubifs_info *c, struct ubifs_lprops *lprops)
++{
++	struct ubifs_pnode *pnode;
++	int pos;
++
++	pos = (lprops->lnum - c->main_first) & (UBIFS_LPT_FANOUT - 1);
++	pnode = (struct ubifs_pnode *)container_of(lprops - pos,
++						   struct ubifs_pnode,
++						   lprops[0]);
++	return !test_bit(COW_ZNODE, &pnode->flags) &&
++	       test_bit(DIRTY_CNODE, &pnode->flags);
++}
++
++/**
++ * ubifs_change_lp - change LEB properties.
++ * @c: the UBIFS file-system description object
++ * @lp: LEB properties to change
++ * @free: new free space amount
++ * @dirty: new dirty space amount
++ * @flags: new flags
++ * @idx_gc_cnt: change to the count of idx_gc list
++ *
++ * This function changes LEB properties (@free, @dirty or @flag). However, the
++ * property which has the %LPROPS_NC value is not changed. Returns a pointer to
++ * the updated LEB properties on success and a negative error code on failure.
++ *
++ * Note, the LEB properties may have had to be copied (due to COW) and
++ * consequently the pointer returned may not be the same as the pointer
++ * passed.
++ */
++const struct ubifs_lprops *ubifs_change_lp(struct ubifs_info *c,
++					   const struct ubifs_lprops *lp,
++					   int free, int dirty, int flags,
++					   int idx_gc_cnt)
++{
++	/*
++	 * This is the only function that is allowed to change lprops, so we
++	 * discard the const qualifier.
++	 */
++	struct ubifs_lprops *lprops = (struct ubifs_lprops *)lp;
++
++	dbg_lp("LEB %d, free %d, dirty %d, flags %d",
++	       lprops->lnum, free, dirty, flags);
++
++	ubifs_assert(mutex_is_locked(&c->lp_mutex));
++	ubifs_assert(c->lst.empty_lebs >= 0 &&
++		     c->lst.empty_lebs <= c->main_lebs);
++	ubifs_assert(c->freeable_cnt >= 0);
++	ubifs_assert(c->freeable_cnt <= c->main_lebs);
++	ubifs_assert(c->lst.taken_empty_lebs >= 0);
++	ubifs_assert(c->lst.taken_empty_lebs <= c->lst.empty_lebs);
++	ubifs_assert(!(c->lst.total_free & 7) && !(c->lst.total_dirty & 7));
++	ubifs_assert(!(c->lst.total_dead & 7) && !(c->lst.total_dark & 7));
++	ubifs_assert(!(c->lst.total_used & 7));
++	ubifs_assert(free == LPROPS_NC || free >= 0);
++	ubifs_assert(dirty == LPROPS_NC || dirty >= 0);
++
++	if (!is_lprops_dirty(c, lprops)) {
++		lprops = ubifs_lpt_lookup_dirty(c, lprops->lnum);
++		if (IS_ERR(lprops))
++			return lprops;
++	} else
++		ubifs_assert(lprops == ubifs_lpt_lookup_dirty(c, lprops->lnum));
++
++	ubifs_assert(!(lprops->free & 7) && !(lprops->dirty & 7));
++
++	spin_lock(&c->space_lock);
++	if ((lprops->flags & LPROPS_TAKEN) && lprops->free == c->leb_size)
++		c->lst.taken_empty_lebs -= 1;
++
++	if (!(lprops->flags & LPROPS_INDEX)) {
++		int old_spc;
++
++		old_spc = lprops->free + lprops->dirty;
++		if (old_spc < c->dead_wm)
++			c->lst.total_dead -= old_spc;
++		else
++			c->lst.total_dark -= calc_dark(c, old_spc);
++
++		c->lst.total_used -= c->leb_size - old_spc;
++	}
++
++	if (free != LPROPS_NC) {
++		free = ALIGN(free, 8);
++		c->lst.total_free += free - lprops->free;
++
++		/* Increase or decrease empty LEBs counter if needed */
++		if (free == c->leb_size) {
++			if (lprops->free != c->leb_size)
++				c->lst.empty_lebs += 1;
++		} else if (lprops->free == c->leb_size)
++			c->lst.empty_lebs -= 1;
++		lprops->free = free;
++	}
++
++	if (dirty != LPROPS_NC) {
++		dirty = ALIGN(dirty, 8);
++		c->lst.total_dirty += dirty - lprops->dirty;
++		lprops->dirty = dirty;
++	}
++
++	if (flags != LPROPS_NC) {
++		/* Take care about indexing LEBs counter if needed */
++		if ((lprops->flags & LPROPS_INDEX)) {
++			if (!(flags & LPROPS_INDEX))
++				c->lst.idx_lebs -= 1;
++		} else if (flags & LPROPS_INDEX)
++			c->lst.idx_lebs += 1;
++		lprops->flags = flags;
++	}
++
++	if (!(lprops->flags & LPROPS_INDEX)) {
++		int new_spc;
++
++		new_spc = lprops->free + lprops->dirty;
++		if (new_spc < c->dead_wm)
++			c->lst.total_dead += new_spc;
++		else
++			c->lst.total_dark += calc_dark(c, new_spc);
++
++		c->lst.total_used += c->leb_size - new_spc;
++	}
++
++	if ((lprops->flags & LPROPS_TAKEN) && lprops->free == c->leb_size)
++		c->lst.taken_empty_lebs += 1;
++
++	change_category(c, lprops);
++	c->idx_gc_cnt += idx_gc_cnt;
++	spin_unlock(&c->space_lock);
++	return lprops;
++}
++
++/**
++ * ubifs_get_lp_stats - get lprops statistics.
++ * @c: UBIFS file-system description object
++ * @st: return statistics
++ */
++void ubifs_get_lp_stats(struct ubifs_info *c, struct ubifs_lp_stats *lst)
++{
++	spin_lock(&c->space_lock);
++	memcpy(lst, &c->lst, sizeof(struct ubifs_lp_stats));
++	spin_unlock(&c->space_lock);
++}
++
++/**
++ * ubifs_change_one_lp - change LEB properties.
++ * @c: the UBIFS file-system description object
++ * @lnum: LEB to change properties for
++ * @free: amount of free space
++ * @dirty: amount of dirty space
++ * @flags_set: flags to set
++ * @flags_clean: flags to clean
++ * @idx_gc_cnt: change to the count of idx_gc list
++ *
++ * This function changes properties of LEB @lnum. It is a helper wrapper over
++ * 'ubifs_change_lp()' which hides lprops get/release. The arguments are the
++ * same as in case of 'ubifs_change_lp()'. Returns zero in case of success and
++ * a negative error code in case of failure.
++ */
++int ubifs_change_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
++			int flags_set, int flags_clean, int idx_gc_cnt)
++{
++	int err = 0, flags;
++	const struct ubifs_lprops *lp;
++
++	ubifs_get_lprops(c);
++
++	lp = ubifs_lpt_lookup_dirty(c, lnum);
++	if (IS_ERR(lp)) {
++		err = PTR_ERR(lp);
++		goto out;
++	}
++
++	flags = (lp->flags | flags_set) & ~flags_clean;
++	lp = ubifs_change_lp(c, lp, free, dirty, flags, idx_gc_cnt);
++	if (IS_ERR(lp))
++		err = PTR_ERR(lp);
++
++out:
++	ubifs_release_lprops(c);
++	if (err)
++		ubifs_err("cannot change properties of LEB %d, error %d",
++			  lnum, err);
++	return err;
++}
++
++/**
++ * ubifs_update_one_lp - update LEB properties.
++ * @c: the UBIFS file-system description object
++ * @lnum: LEB to change properties for
++ * @free: amount of free space
++ * @dirty: amount of dirty space to add
++ * @flags_set: flags to set
++ * @flags_clean: flags to clean
++ *
++ * This function is the same as 'ubifs_change_one_lp()' but @dirty is added to
++ * current dirty space, not substitutes it.
++ */
++int ubifs_update_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
++			int flags_set, int flags_clean)
++{
++	int err = 0, flags;
++	const struct ubifs_lprops *lp;
++
++	ubifs_get_lprops(c);
++
++	lp = ubifs_lpt_lookup_dirty(c, lnum);
++	if (IS_ERR(lp)) {
++		err = PTR_ERR(lp);
++		goto out;
++	}
++
++	flags = (lp->flags | flags_set) & ~flags_clean;
++	lp = ubifs_change_lp(c, lp, free, lp->dirty + dirty, flags, 0);
++	if (IS_ERR(lp))
++		err = PTR_ERR(lp);
++
++out:
++	ubifs_release_lprops(c);
++	if (err)
++		ubifs_err("cannot update properties of LEB %d, error %d",
++			  lnum, err);
++	return err;
++}
++
++/**
++ * ubifs_read_one_lp - read LEB properties.
++ * @c: the UBIFS file-system description object
++ * @lnum: LEB to read properties for
++ * @lp: where to store read properties
++ *
++ * This helper function reads properties of a LEB @lnum and stores them in @lp.
++ * Returns zero in case of success and a negative error code in case of
++ * failure.
++ */
++int ubifs_read_one_lp(struct ubifs_info *c, int lnum, struct ubifs_lprops *lp)
++{
++	int err = 0;
++	const struct ubifs_lprops *lpp;
++
++	ubifs_get_lprops(c);
++
++	lpp = ubifs_lpt_lookup(c, lnum);
++	if (IS_ERR(lpp)) {
++		err = PTR_ERR(lpp);
++		ubifs_err("cannot read properties of LEB %d, error %d",
++			  lnum, err);
++		goto out;
++	}
++
++	memcpy(lp, lpp, sizeof(struct ubifs_lprops));
++
++out:
++	ubifs_release_lprops(c);
++	return err;
++}
++
++/**
++ * ubifs_fast_find_free - try to find a LEB with free space quickly.
++ * @c: the UBIFS file-system description object
++ *
++ * This function returns LEB properties for a LEB with free space or %NULL if
++ * the function is unable to find a LEB quickly.
++ */
++const struct ubifs_lprops *ubifs_fast_find_free(struct ubifs_info *c)
++{
++	struct ubifs_lprops *lprops;
++	struct ubifs_lpt_heap *heap;
++
++	ubifs_assert(mutex_is_locked(&c->lp_mutex));
++
++	heap = &c->lpt_heap[LPROPS_FREE - 1];
++	if (heap->cnt == 0)
++		return NULL;
++
++	lprops = heap->arr[0];
++	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
++	ubifs_assert(!(lprops->flags & LPROPS_INDEX));
++	return lprops;
++}
++
++/**
++ * ubifs_fast_find_empty - try to find an empty LEB quickly.
++ * @c: the UBIFS file-system description object
++ *
++ * This function returns LEB properties for an empty LEB or %NULL if the
++ * function is unable to find an empty LEB quickly.
++ */
++const struct ubifs_lprops *ubifs_fast_find_empty(struct ubifs_info *c)
++{
++	struct ubifs_lprops *lprops;
++
++	ubifs_assert(mutex_is_locked(&c->lp_mutex));
++
++	if (list_empty(&c->empty_list))
++		return NULL;
++
++	lprops = list_entry(c->empty_list.next, struct ubifs_lprops, list);
++	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
++	ubifs_assert(!(lprops->flags & LPROPS_INDEX));
++	ubifs_assert(lprops->free == c->leb_size);
++	return lprops;
++}
++
++/**
++ * ubifs_fast_find_freeable - try to find a freeable LEB quickly.
++ * @c: the UBIFS file-system description object
++ *
++ * This function returns LEB properties for a freeable LEB or %NULL if the
++ * function is unable to find a freeable LEB quickly.
++ */
++const struct ubifs_lprops *ubifs_fast_find_freeable(struct ubifs_info *c)
++{
++	struct ubifs_lprops *lprops;
++
++	ubifs_assert(mutex_is_locked(&c->lp_mutex));
++
++	if (list_empty(&c->freeable_list))
++		return NULL;
++
++	lprops = list_entry(c->freeable_list.next, struct ubifs_lprops, list);
++	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
++	ubifs_assert(!(lprops->flags & LPROPS_INDEX));
++	ubifs_assert(lprops->free + lprops->dirty == c->leb_size);
++	ubifs_assert(c->freeable_cnt > 0);
++	return lprops;
++}
++
++/**
++ * ubifs_fast_find_frdi_idx - try to find a freeable index LEB quickly.
++ * @c: the UBIFS file-system description object
++ *
++ * This function returns LEB properties for a freeable index LEB or %NULL if the
++ * function is unable to find a freeable index LEB quickly.
++ */
++const struct ubifs_lprops *ubifs_fast_find_frdi_idx(struct ubifs_info *c)
++{
++	struct ubifs_lprops *lprops;
++
++	ubifs_assert(mutex_is_locked(&c->lp_mutex));
++
++	if (list_empty(&c->frdi_idx_list))
++		return NULL;
++
++	lprops = list_entry(c->frdi_idx_list.next, struct ubifs_lprops, list);
++	ubifs_assert(!(lprops->flags & LPROPS_TAKEN));
++	ubifs_assert((lprops->flags & LPROPS_INDEX));
++	ubifs_assert(lprops->free + lprops->dirty == c->leb_size);
++	return lprops;
++}
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++
++/**
++ * dbg_check_cats - check category heaps and lists.
++ * @c: UBIFS file-system description object
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int dbg_check_cats(struct ubifs_info *c)
++{
++	struct ubifs_lprops *lprops;
++	struct list_head *pos;
++	int i, cat;
++
++	if (!(ubifs_chk_flags & (UBIFS_CHK_GEN | UBIFS_CHK_LPROPS)))
++		return 0;
++
++	list_for_each_entry(lprops, &c->empty_list, list) {
++		if (lprops->free != c->leb_size) {
++			ubifs_err("non-empty LEB %d on empty list "
++				  "(free %d dirty %d flags %d)", lprops->lnum,
++				  lprops->free, lprops->dirty, lprops->flags);
++			return -EINVAL;
++		}
++		if (lprops->flags & LPROPS_TAKEN) {
++			ubifs_err("taken LEB %d on empty list "
++				  "(free %d dirty %d flags %d)", lprops->lnum,
++				  lprops->free, lprops->dirty, lprops->flags);
++			return -EINVAL;
++		}
++	}
++
++	i = 0;
++	list_for_each_entry(lprops, &c->freeable_list, list) {
++		if (lprops->free + lprops->dirty != c->leb_size) {
++			ubifs_err("non-freeable LEB %d on freeable list "
++				  "(free %d dirty %d flags %d)", lprops->lnum,
++				  lprops->free, lprops->dirty, lprops->flags);
++			return -EINVAL;
++		}
++		if (lprops->flags & LPROPS_TAKEN) {
++			ubifs_err("taken LEB %d on freeable list "
++				  "(free %d dirty %d flags %d)", lprops->lnum,
++				  lprops->free, lprops->dirty, lprops->flags);
++			return -EINVAL;
++		}
++		i += 1;
++	}
++	if (i != c->freeable_cnt) {
++		ubifs_err("freeable list count %d expected %d", i,
++			  c->freeable_cnt);
++		return -EINVAL;
++	}
++
++	i = 0;
++	list_for_each(pos, &c->idx_gc)
++		i += 1;
++	if (i != c->idx_gc_cnt) {
++		ubifs_err("idx_gc list count %d expected %d", i,
++			  c->idx_gc_cnt);
++		return -EINVAL;
++	}
++
++	list_for_each_entry(lprops, &c->frdi_idx_list, list) {
++		if (lprops->free + lprops->dirty != c->leb_size) {
++			ubifs_err("non-freeable LEB %d on frdi_idx list "
++				  "(free %d dirty %d flags %d)", lprops->lnum,
++				  lprops->free, lprops->dirty, lprops->flags);
++			return -EINVAL;
++		}
++		if (lprops->flags & LPROPS_TAKEN) {
++			ubifs_err("taken LEB %d on frdi_idx list "
++				  "(free %d dirty %d flags %d)", lprops->lnum,
++				  lprops->free, lprops->dirty, lprops->flags);
++			return -EINVAL;
++		}
++		if (!(lprops->flags & LPROPS_INDEX)) {
++			ubifs_err("non-index LEB %d on frdi_idx list "
++				  "(free %d dirty %d flags %d)", lprops->lnum,
++				  lprops->free, lprops->dirty, lprops->flags);
++			return -EINVAL;
++		}
++	}
++
++	for (cat = 1; cat <= LPROPS_HEAP_CNT; cat++) {
++		struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1];
++
++		for (i = 0; i < heap->cnt; i++) {
++			lprops = heap->arr[i];
++			if (!lprops) {
++				ubifs_err("null ptr in LPT heap cat %d", cat);
++				return -EINVAL;
++			}
++			if (lprops->hpos != i) {
++				ubifs_err("bad ptr in LPT heap cat %d", cat);
++				return -EINVAL;
++			}
++			if (lprops->flags & LPROPS_TAKEN) {
++				ubifs_err("taken LEB in LPT heap cat %d", cat);
++				return -EINVAL;
++			}
++		}
++	}
++
++	return 0;
++}
++
++void dbg_check_heap(struct ubifs_info *c, struct ubifs_lpt_heap *heap, int cat,
++		    int add_pos)
++{
++	int i = 0, j, err = 0;
++
++	if (!(ubifs_chk_flags & (UBIFS_CHK_GEN | UBIFS_CHK_LPROPS)))
++		return;
++
++	for (i = 0; i < heap->cnt; i++) {
++		struct ubifs_lprops *lprops = heap->arr[i];
++		struct ubifs_lprops *lp;
++
++		if (i != add_pos)
++			if ((lprops->flags & LPROPS_CAT_MASK) != cat) {
++				err = 1;
++				goto out;
++			}
++		if (lprops->hpos != i) {
++			err = 2;
++			goto out;
++		}
++		lp = ubifs_lpt_lookup(c, lprops->lnum);
++		if (IS_ERR(lp)) {
++			err = 3;
++			goto out;
++		}
++		if (lprops != lp) {
++			dbg_msg("lprops %zx lp %zx lprops->lnum %d lp->lnum %d",
++				(size_t)lprops, (size_t)lp, lprops->lnum,
++				lp->lnum);
++			err = 4;
++			goto out;
++		}
++		for (j = 0; j < i; j++) {
++			lp = heap->arr[j];
++			if (lp == lprops) {
++				err = 5;
++				goto out;
++			}
++			if (lp->lnum == lprops->lnum) {
++				err = 6;
++				goto out;
++			}
++		}
++	}
++out:
++	if (err) {
++		dbg_msg("failed cat %d hpos %d err %d", cat, i, err);
++		dbg_dump_stack();
++		dbg_dump_heap(c, heap, cat);
++	}
++}
++
++/**
++ * struct scan_check_data - data provided to scan callback function.
++ * @lst: LEB properties statistics
++ * @err: error code
++ */
++struct scan_check_data {
++	struct ubifs_lp_stats lst;
++	int err;
++};
++
++/**
++ * scan_check_cb - scan callback.
++ * @c: the UBIFS file-system description object
++ * @lp: LEB properties to scan
++ * @in_tree: whether the LEB properties are in main memory
++ * @data: information passed to and from the caller of the scan
++ *
++ * This function returns a code that indicates whether the scan should continue
++ * (%LPT_SCAN_CONTINUE), whether the LEB properties should be added to the tree
++ * in main memory (%LPT_SCAN_ADD), or whether the scan should stop
++ * (%LPT_SCAN_STOP).
++ */
++static int scan_check_cb(struct ubifs_info *c,
++			 const struct ubifs_lprops *lp, int in_tree,
++			 struct scan_check_data *data)
++{
++	struct ubifs_scan_leb *sleb;
++	struct ubifs_scan_node *snod;
++	struct ubifs_lp_stats *lst = &data->lst;
++	int cat, lnum = lp->lnum, is_idx = 0, used = 0, free, dirty;
++
++	cat = lp->flags & LPROPS_CAT_MASK;
++	if (cat != LPROPS_UNCAT) {
++		cat = ubifs_categorize_lprops(c, lp);
++		if (cat != (lp->flags & LPROPS_CAT_MASK)) {
++			ubifs_err("bad LEB category %d expected %d",
++				  (lp->flags & LPROPS_CAT_MASK), cat);
++			goto out;
++		}
++	}
++
++	/* Check lp is on its category list (if it has one) */
++	if (in_tree) {
++		struct list_head *list = NULL;
++
++		switch (cat) {
++		case LPROPS_EMPTY:
++			list = &c->empty_list;
++			break;
++		case LPROPS_FREEABLE:
++			list = &c->freeable_list;
++			break;
++		case LPROPS_FRDI_IDX:
++			list = &c->frdi_idx_list;
++			break;
++		case LPROPS_UNCAT:
++			list = &c->uncat_list;
++			break;
++		}
++		if (list) {
++			struct ubifs_lprops *lprops;
++			int found = 0;
++
++			list_for_each_entry(lprops, list, list) {
++				if (lprops == lp) {
++					found = 1;
++					break;
++				}
++			}
++			if (!found) {
++				ubifs_err("bad LPT list (category %d)", cat);
++				goto out;
++			}
++		}
++	}
++
++	/* Check lp is on its category heap (if it has one) */
++	if (in_tree && cat > 0 && cat <= LPROPS_HEAP_CNT) {
++		struct ubifs_lpt_heap *heap = &c->lpt_heap[cat - 1];
++
++		if ((lp->hpos != -1 && heap->arr[lp->hpos]->lnum != lnum) ||
++		    lp != heap->arr[lp->hpos]) {
++			ubifs_err("bad LPT heap (category %d)", cat);
++			goto out;
++		}
++	}
++
++	sleb = ubifs_scan(c, lnum, 0, c->dbg->buf);
++	if (IS_ERR(sleb)) {
++		/*
++		 * After an unclean unmount, empty and freeable LEBs
++		 * may contain garbage.
++		 */
++		if (lp->free == c->leb_size) {
++			ubifs_err("scan errors were in empty LEB "
++				  "- continuing checking");
++			lst->empty_lebs += 1;
++			lst->total_free += c->leb_size;
++			lst->total_dark += calc_dark(c, c->leb_size);
++			return LPT_SCAN_CONTINUE;
++		}
++
++		if (lp->free + lp->dirty == c->leb_size &&
++		    !(lp->flags & LPROPS_INDEX)) {
++			ubifs_err("scan errors were in freeable LEB "
++				  "- continuing checking");
++			lst->total_free  += lp->free;
++			lst->total_dirty += lp->dirty;
++			lst->total_dark  +=  calc_dark(c, c->leb_size);
++			return LPT_SCAN_CONTINUE;
++		}
++		data->err = PTR_ERR(sleb);
++		return LPT_SCAN_STOP;
++	}
++
++	is_idx = -1;
++	list_for_each_entry(snod, &sleb->nodes, list) {
++		int found, level = 0;
++
++		cond_resched();
++
++		if (is_idx == -1)
++			is_idx = (snod->type == UBIFS_IDX_NODE) ? 1 : 0;
++
++		if (is_idx && snod->type != UBIFS_IDX_NODE) {
++			ubifs_err("indexing node in data LEB %d:%d",
++				  lnum, snod->offs);
++			goto out_destroy;
++		}
++
++		if (snod->type == UBIFS_IDX_NODE) {
++			struct ubifs_idx_node *idx = snod->node;
++
++			key_read(c, ubifs_idx_key(c, idx), &snod->key);
++			level = le16_to_cpu(idx->level);
++		}
++
++		found = ubifs_tnc_has_node(c, &snod->key, level, lnum,
++					   snod->offs, is_idx);
++		if (found) {
++			if (found < 0)
++				goto out_destroy;
++			used += ALIGN(snod->len, 8);
++		}
++	}
++
++	free = c->leb_size - sleb->endpt;
++	dirty = sleb->endpt - used;
++
++	if (free > c->leb_size || free < 0 || dirty > c->leb_size ||
++	    dirty < 0) {
++		ubifs_err("bad calculated accounting for LEB %d: "
++			  "free %d, dirty %d", lnum, free, dirty);
++		goto out_destroy;
++	}
++
++	if (lp->free + lp->dirty == c->leb_size &&
++	    free + dirty == c->leb_size)
++		if ((is_idx && !(lp->flags & LPROPS_INDEX)) ||
++		    (!is_idx && free == c->leb_size) ||
++		    lp->free == c->leb_size) {
++			/*
++			 * Empty or freeable LEBs could contain index
++			 * nodes from an uncompleted commit due to an
++			 * unclean unmount. Or they could be empty for
++			 * the same reason. Or it may simply not have been
++			 * unmapped.
++			 */
++			free = lp->free;
++			dirty = lp->dirty;
++			is_idx = 0;
++		    }
++
++	if (is_idx && lp->free + lp->dirty == free + dirty &&
++	    lnum != c->ihead_lnum) {
++		/*
++		 * After an unclean unmount, an index LEB could have a different
++		 * amount of free space than the value recorded by lprops. That
++		 * is because the in-the-gaps method may use free space or
++		 * create free space (as a side-effect of using ubi_leb_change
++		 * and not writing the whole LEB). The incorrect free space
++		 * value is not a problem because the index is only ever
++		 * allocated empty LEBs, so there will never be an attempt to
++		 * write to the free space at the end of an index LEB - except
++		 * by the in-the-gaps method for which it is not a problem.
++		 */
++		free = lp->free;
++		dirty = lp->dirty;
++	}
++
++	if (lp->free != free || lp->dirty != dirty)
++		goto out_print;
++
++	if (is_idx && !(lp->flags & LPROPS_INDEX)) {
++		if (free == c->leb_size)
++			/* Free but not unmapped LEB, it's fine */
++			is_idx = 0;
++		else {
++			ubifs_err("indexing node without indexing "
++				  "flag");
++			goto out_print;
++		}
++	}
++
++	if (!is_idx && (lp->flags & LPROPS_INDEX)) {
++		ubifs_err("data node with indexing flag");
++		goto out_print;
++	}
++
++	if (free == c->leb_size)
++		lst->empty_lebs += 1;
++
++	if (is_idx)
++		lst->idx_lebs += 1;
++
++	if (!(lp->flags & LPROPS_INDEX))
++		lst->total_used += c->leb_size - free - dirty;
++	lst->total_free += free;
++	lst->total_dirty += dirty;
++
++	if (!(lp->flags & LPROPS_INDEX)) {
++		int spc = free + dirty;
++
++		if (spc < c->dead_wm)
++			lst->total_dead += spc;
++		else
++			lst->total_dark += calc_dark(c, spc);
++	}
++
++	ubifs_scan_destroy(sleb);
++	return LPT_SCAN_CONTINUE;
++
++out_print:
++	ubifs_err("bad accounting of LEB %d: free %d, dirty %d flags %#x, "
++		  "should be free %d, dirty %d",
++		  lnum, lp->free, lp->dirty, lp->flags, free, dirty);
++	dbg_dump_leb(c, lnum);
++out_destroy:
++	ubifs_scan_destroy(sleb);
++out:
++	data->err = -EINVAL;
++	return LPT_SCAN_STOP;
++}
++
++/**
++ * dbg_check_lprops - check all LEB properties.
++ * @c: UBIFS file-system description object
++ *
++ * This function checks all LEB properties and makes sure they are all correct.
++ * It returns zero if everything is fine, %-EINVAL if there is an inconsistency
++ * and other negative error codes in case of other errors. This function is
++ * called while the file system is locked (because of commit start), so no
++ * additional locking is required. Note that locking the LPT mutex would cause
++ * a circular lock dependency with the TNC mutex.
++ */
++int dbg_check_lprops(struct ubifs_info *c)
++{
++	int i, err;
++	struct scan_check_data data;
++	struct ubifs_lp_stats *lst = &data.lst;
++
++	if (!(ubifs_chk_flags & UBIFS_CHK_LPROPS))
++		return 0;
++
++	/*
++	 * As we are going to scan the media, the write buffers have to be
++	 * synchronized.
++	 */
++	for (i = 0; i < c->jhead_cnt; i++) {
++		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
++		if (err)
++			return err;
++	}
++
++	memset(lst, 0, sizeof(struct ubifs_lp_stats));
++
++	data.err = 0;
++	err = ubifs_lpt_scan_nolock(c, c->main_first, c->leb_cnt - 1,
++				    (ubifs_lpt_scan_callback)scan_check_cb,
++				    &data);
++	if (err && err != -ENOSPC)
++		goto out;
++	if (data.err) {
++		err = data.err;
++		goto out;
++	}
++
++	if (lst->empty_lebs != c->lst.empty_lebs ||
++	    lst->idx_lebs != c->lst.idx_lebs ||
++	    lst->total_free != c->lst.total_free ||
++	    lst->total_dirty != c->lst.total_dirty ||
++	    lst->total_used != c->lst.total_used) {
++		ubifs_err("bad overall accounting");
++		ubifs_err("calculated: empty_lebs %d, idx_lebs %d, "
++			  "total_free %lld, total_dirty %lld, total_used %lld",
++			  lst->empty_lebs, lst->idx_lebs, lst->total_free,
++			  lst->total_dirty, lst->total_used);
++		ubifs_err("read from lprops: empty_lebs %d, idx_lebs %d, "
++			  "total_free %lld, total_dirty %lld, total_used %lld",
++			  c->lst.empty_lebs, c->lst.idx_lebs, c->lst.total_free,
++			  c->lst.total_dirty, c->lst.total_used);
++		err = -EINVAL;
++		goto out;
++	}
++
++	if (lst->total_dead != c->lst.total_dead ||
++	    lst->total_dark != c->lst.total_dark) {
++		ubifs_err("bad dead/dark space accounting");
++		ubifs_err("calculated: total_dead %lld, total_dark %lld",
++			  lst->total_dead, lst->total_dark);
++		ubifs_err("read from lprops: total_dead %lld, total_dark %lld",
++			  c->lst.total_dead, c->lst.total_dark);
++		err = -EINVAL;
++		goto out;
++	}
++
++	err = dbg_check_cats(c);
++out:
++	return err;
++}
++
++#endif /* CONFIG_UBIFS_FS_DEBUG */
+diff -Nurd linux-2.6.24.orig/fs/ubifs/lpt.c linux-2.6.24/fs/ubifs/lpt.c
+--- linux-2.6.24.orig/fs/ubifs/lpt.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/lpt.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,2271 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Adrian Hunter
++ *          Artem Bityutskiy (Битюцкий Артём)
++ */
++
++/*
++ * This file implements the LEB properties tree (LPT) area. The LPT area
++ * contains the LEB properties tree, a table of LPT area eraseblocks (ltab), and
++ * (for the "big" model) a table of saved LEB numbers (lsave). The LPT area sits
++ * between the log and the orphan area.
++ *
++ * The LPT area is like a miniature self-contained file system. It is required
++ * that it never runs out of space, is fast to access and update, and scales
++ * logarithmically. The LEB properties tree is implemented as a wandering tree
++ * much like the TNC, and the LPT area has its own garbage collection.
++ *
++ * The LPT has two slightly different forms called the "small model" and the
++ * "big model". The small model is used when the entire LEB properties table
++ * can be written into a single eraseblock. In that case, garbage collection
++ * consists of just writing the whole table, which therefore makes all other
++ * eraseblocks reusable. In the case of the big model, dirty eraseblocks are
++ * selected for garbage collection, which consists of marking the clean nodes in
++ * that LEB as dirty, and then only the dirty nodes are written out. Also, in
++ * the case of the big model, a table of LEB numbers is saved so that the entire
++ * LPT does not to be scanned looking for empty eraseblocks when UBIFS is first
++ * mounted.
++ */
++
++#include "ubifs.h"
++#include <linux/crc16.h>
++
++/**
++ * do_calc_lpt_geom - calculate sizes for the LPT area.
++ * @c: the UBIFS file-system description object
++ *
++ * Calculate the sizes of LPT bit fields, nodes, and tree, based on the
++ * properties of the flash and whether LPT is "big" (c->big_lpt).
++ */
++static void do_calc_lpt_geom(struct ubifs_info *c)
++{
++	int i, n, bits, per_leb_wastage, max_pnode_cnt;
++	long long sz, tot_wastage;
++
++	n = c->main_lebs + c->max_leb_cnt - c->leb_cnt;
++	max_pnode_cnt = DIV_ROUND_UP(n, UBIFS_LPT_FANOUT);
++
++	c->lpt_hght = 1;
++	n = UBIFS_LPT_FANOUT;
++	while (n < max_pnode_cnt) {
++		c->lpt_hght += 1;
++		n <<= UBIFS_LPT_FANOUT_SHIFT;
++	}
++
++	c->pnode_cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
++
++	n = DIV_ROUND_UP(c->pnode_cnt, UBIFS_LPT_FANOUT);
++	c->nnode_cnt = n;
++	for (i = 1; i < c->lpt_hght; i++) {
++		n = DIV_ROUND_UP(n, UBIFS_LPT_FANOUT);
++		c->nnode_cnt += n;
++	}
++
++	c->space_bits = fls(c->leb_size) - 3;
++	c->lpt_lnum_bits = fls(c->lpt_lebs);
++	c->lpt_offs_bits = fls(c->leb_size - 1);
++	c->lpt_spc_bits = fls(c->leb_size);
++
++	n = DIV_ROUND_UP(c->max_leb_cnt, UBIFS_LPT_FANOUT);
++	c->pcnt_bits = fls(n - 1);
++
++	c->lnum_bits = fls(c->max_leb_cnt - 1);
++
++	bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
++	       (c->big_lpt ? c->pcnt_bits : 0) +
++	       (c->space_bits * 2 + 1) * UBIFS_LPT_FANOUT;
++	c->pnode_sz = (bits + 7) / 8;
++
++	bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
++	       (c->big_lpt ? c->pcnt_bits : 0) +
++	       (c->lpt_lnum_bits + c->lpt_offs_bits) * UBIFS_LPT_FANOUT;
++	c->nnode_sz = (bits + 7) / 8;
++
++	bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
++	       c->lpt_lebs * c->lpt_spc_bits * 2;
++	c->ltab_sz = (bits + 7) / 8;
++
++	bits = UBIFS_LPT_CRC_BITS + UBIFS_LPT_TYPE_BITS +
++	       c->lnum_bits * c->lsave_cnt;
++	c->lsave_sz = (bits + 7) / 8;
++
++	/* Calculate the minimum LPT size */
++	c->lpt_sz = (long long)c->pnode_cnt * c->pnode_sz;
++	c->lpt_sz += (long long)c->nnode_cnt * c->nnode_sz;
++	c->lpt_sz += c->ltab_sz;
++	if (c->big_lpt)
++		c->lpt_sz += c->lsave_sz;
++
++	/* Add wastage */
++	sz = c->lpt_sz;
++	per_leb_wastage = max_t(int, c->pnode_sz, c->nnode_sz);
++	sz += per_leb_wastage;
++	tot_wastage = per_leb_wastage;
++	while (sz > c->leb_size) {
++		sz += per_leb_wastage;
++		sz -= c->leb_size;
++		tot_wastage += per_leb_wastage;
++	}
++	tot_wastage += ALIGN(sz, c->min_io_size) - sz;
++	c->lpt_sz += tot_wastage;
++}
++
++/**
++ * ubifs_calc_lpt_geom - calculate and check sizes for the LPT area.
++ * @c: the UBIFS file-system description object
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int ubifs_calc_lpt_geom(struct ubifs_info *c)
++{
++	int lebs_needed;
++	long long sz;
++
++	do_calc_lpt_geom(c);
++
++	/* Verify that lpt_lebs is big enough */
++	sz = c->lpt_sz * 2; /* Must have at least 2 times the size */
++	lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size);
++	if (lebs_needed > c->lpt_lebs) {
++		ubifs_err("too few LPT LEBs");
++		return -EINVAL;
++	}
++
++	/* Verify that ltab fits in a single LEB (since ltab is a single node */
++	if (c->ltab_sz > c->leb_size) {
++		ubifs_err("LPT ltab too big");
++		return -EINVAL;
++	}
++
++	c->check_lpt_free = c->big_lpt;
++	return 0;
++}
++
++/**
++ * calc_dflt_lpt_geom - calculate default LPT geometry.
++ * @c: the UBIFS file-system description object
++ * @main_lebs: number of main area LEBs is passed and returned here
++ * @big_lpt: whether the LPT area is "big" is returned here
++ *
++ * The size of the LPT area depends on parameters that themselves are dependent
++ * on the size of the LPT area. This function, successively recalculates the LPT
++ * area geometry until the parameters and resultant geometry are consistent.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int calc_dflt_lpt_geom(struct ubifs_info *c, int *main_lebs,
++			      int *big_lpt)
++{
++	int i, lebs_needed;
++	long long sz;
++
++	/* Start by assuming the minimum number of LPT LEBs */
++	c->lpt_lebs = UBIFS_MIN_LPT_LEBS;
++	c->main_lebs = *main_lebs - c->lpt_lebs;
++	if (c->main_lebs <= 0)
++		return -EINVAL;
++
++	/* And assume we will use the small LPT model */
++	c->big_lpt = 0;
++
++	/*
++	 * Calculate the geometry based on assumptions above and then see if it
++	 * makes sense
++	 */
++	do_calc_lpt_geom(c);
++
++	/* Small LPT model must have lpt_sz < leb_size */
++	if (c->lpt_sz > c->leb_size) {
++		/* Nope, so try again using big LPT model */
++		c->big_lpt = 1;
++		do_calc_lpt_geom(c);
++	}
++
++	/* Now check there are enough LPT LEBs */
++	for (i = 0; i < 64 ; i++) {
++		sz = c->lpt_sz * 4; /* Allow 4 times the size */
++		lebs_needed = div_u64(sz + c->leb_size - 1, c->leb_size);
++		if (lebs_needed > c->lpt_lebs) {
++			/* Not enough LPT LEBs so try again with more */
++			c->lpt_lebs = lebs_needed;
++			c->main_lebs = *main_lebs - c->lpt_lebs;
++			if (c->main_lebs <= 0)
++				return -EINVAL;
++			do_calc_lpt_geom(c);
++			continue;
++		}
++		if (c->ltab_sz > c->leb_size) {
++			ubifs_err("LPT ltab too big");
++			return -EINVAL;
++		}
++		*main_lebs = c->main_lebs;
++		*big_lpt = c->big_lpt;
++		return 0;
++	}
++	return -EINVAL;
++}
++
++/**
++ * pack_bits - pack bit fields end-to-end.
++ * @addr: address at which to pack (passed and next address returned)
++ * @pos: bit position at which to pack (passed and next position returned)
++ * @val: value to pack
++ * @nrbits: number of bits of value to pack (1-32)
++ */
++static void pack_bits(uint8_t **addr, int *pos, uint32_t val, int nrbits)
++{
++	uint8_t *p = *addr;
++	int b = *pos;
++
++	ubifs_assert(nrbits > 0);
++	ubifs_assert(nrbits <= 32);
++	ubifs_assert(*pos >= 0);
++	ubifs_assert(*pos < 8);
++	ubifs_assert((val >> nrbits) == 0 || nrbits == 32);
++	if (b) {
++		*p |= ((uint8_t)val) << b;
++		nrbits += b;
++		if (nrbits > 8) {
++			*++p = (uint8_t)(val >>= (8 - b));
++			if (nrbits > 16) {
++				*++p = (uint8_t)(val >>= 8);
++				if (nrbits > 24) {
++					*++p = (uint8_t)(val >>= 8);
++					if (nrbits > 32)
++						*++p = (uint8_t)(val >>= 8);
++				}
++			}
++		}
++	} else {
++		*p = (uint8_t)val;
++		if (nrbits > 8) {
++			*++p = (uint8_t)(val >>= 8);
++			if (nrbits > 16) {
++				*++p = (uint8_t)(val >>= 8);
++				if (nrbits > 24)
++					*++p = (uint8_t)(val >>= 8);
++			}
++		}
++	}
++	b = nrbits & 7;
++	if (b == 0)
++		p++;
++	*addr = p;
++	*pos = b;
++}
++
++/**
++ * ubifs_unpack_bits - unpack bit fields.
++ * @addr: address at which to unpack (passed and next address returned)
++ * @pos: bit position at which to unpack (passed and next position returned)
++ * @nrbits: number of bits of value to unpack (1-32)
++ *
++ * This functions returns the value unpacked.
++ */
++uint32_t ubifs_unpack_bits(uint8_t **addr, int *pos, int nrbits)
++{
++	const int k = 32 - nrbits;
++	uint8_t *p = *addr;
++	int b = *pos;
++	uint32_t uninitialized_var(val);
++	const int bytes = (nrbits + b + 7) >> 3;
++
++	ubifs_assert(nrbits > 0);
++	ubifs_assert(nrbits <= 32);
++	ubifs_assert(*pos >= 0);
++	ubifs_assert(*pos < 8);
++	if (b) {
++		switch (bytes) {
++		case 2:
++			val = p[1];
++			break;
++		case 3:
++			val = p[1] | ((uint32_t)p[2] << 8);
++			break;
++		case 4:
++			val = p[1] | ((uint32_t)p[2] << 8) |
++				     ((uint32_t)p[3] << 16);
++			break;
++		case 5:
++			val = p[1] | ((uint32_t)p[2] << 8) |
++				     ((uint32_t)p[3] << 16) |
++				     ((uint32_t)p[4] << 24);
++		}
++		val <<= (8 - b);
++		val |= *p >> b;
++		nrbits += b;
++	} else {
++		switch (bytes) {
++		case 1:
++			val = p[0];
++			break;
++		case 2:
++			val = p[0] | ((uint32_t)p[1] << 8);
++			break;
++		case 3:
++			val = p[0] | ((uint32_t)p[1] << 8) |
++				     ((uint32_t)p[2] << 16);
++			break;
++		case 4:
++			val = p[0] | ((uint32_t)p[1] << 8) |
++				     ((uint32_t)p[2] << 16) |
++				     ((uint32_t)p[3] << 24);
++			break;
++		}
++	}
++	val <<= k;
++	val >>= k;
++	b = nrbits & 7;
++	p += nrbits >> 3;
++	*addr = p;
++	*pos = b;
++	ubifs_assert((val >> nrbits) == 0 || nrbits - b == 32);
++	return val;
++}
++
++/**
++ * ubifs_pack_pnode - pack all the bit fields of a pnode.
++ * @c: UBIFS file-system description object
++ * @buf: buffer into which to pack
++ * @pnode: pnode to pack
++ */
++void ubifs_pack_pnode(struct ubifs_info *c, void *buf,
++		      struct ubifs_pnode *pnode)
++{
++	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
++	int i, pos = 0;
++	uint16_t crc;
++
++	pack_bits(&addr, &pos, UBIFS_LPT_PNODE, UBIFS_LPT_TYPE_BITS);
++	if (c->big_lpt)
++		pack_bits(&addr, &pos, pnode->num, c->pcnt_bits);
++	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++		pack_bits(&addr, &pos, pnode->lprops[i].free >> 3,
++			  c->space_bits);
++		pack_bits(&addr, &pos, pnode->lprops[i].dirty >> 3,
++			  c->space_bits);
++		if (pnode->lprops[i].flags & LPROPS_INDEX)
++			pack_bits(&addr, &pos, 1, 1);
++		else
++			pack_bits(&addr, &pos, 0, 1);
++	}
++	crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
++		    c->pnode_sz - UBIFS_LPT_CRC_BYTES);
++	addr = buf;
++	pos = 0;
++	pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
++}
++
++/**
++ * ubifs_pack_nnode - pack all the bit fields of a nnode.
++ * @c: UBIFS file-system description object
++ * @buf: buffer into which to pack
++ * @nnode: nnode to pack
++ */
++void ubifs_pack_nnode(struct ubifs_info *c, void *buf,
++		      struct ubifs_nnode *nnode)
++{
++	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
++	int i, pos = 0;
++	uint16_t crc;
++
++	pack_bits(&addr, &pos, UBIFS_LPT_NNODE, UBIFS_LPT_TYPE_BITS);
++	if (c->big_lpt)
++		pack_bits(&addr, &pos, nnode->num, c->pcnt_bits);
++	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++		int lnum = nnode->nbranch[i].lnum;
++
++		if (lnum == 0)
++			lnum = c->lpt_last + 1;
++		pack_bits(&addr, &pos, lnum - c->lpt_first, c->lpt_lnum_bits);
++		pack_bits(&addr, &pos, nnode->nbranch[i].offs,
++			  c->lpt_offs_bits);
++	}
++	crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
++		    c->nnode_sz - UBIFS_LPT_CRC_BYTES);
++	addr = buf;
++	pos = 0;
++	pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
++}
++
++/**
++ * ubifs_pack_ltab - pack the LPT's own lprops table.
++ * @c: UBIFS file-system description object
++ * @buf: buffer into which to pack
++ * @ltab: LPT's own lprops table to pack
++ */
++void ubifs_pack_ltab(struct ubifs_info *c, void *buf,
++		     struct ubifs_lpt_lprops *ltab)
++{
++	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
++	int i, pos = 0;
++	uint16_t crc;
++
++	pack_bits(&addr, &pos, UBIFS_LPT_LTAB, UBIFS_LPT_TYPE_BITS);
++	for (i = 0; i < c->lpt_lebs; i++) {
++		pack_bits(&addr, &pos, ltab[i].free, c->lpt_spc_bits);
++		pack_bits(&addr, &pos, ltab[i].dirty, c->lpt_spc_bits);
++	}
++	crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
++		    c->ltab_sz - UBIFS_LPT_CRC_BYTES);
++	addr = buf;
++	pos = 0;
++	pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
++}
++
++/**
++ * ubifs_pack_lsave - pack the LPT's save table.
++ * @c: UBIFS file-system description object
++ * @buf: buffer into which to pack
++ * @lsave: LPT's save table to pack
++ */
++void ubifs_pack_lsave(struct ubifs_info *c, void *buf, int *lsave)
++{
++	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
++	int i, pos = 0;
++	uint16_t crc;
++
++	pack_bits(&addr, &pos, UBIFS_LPT_LSAVE, UBIFS_LPT_TYPE_BITS);
++	for (i = 0; i < c->lsave_cnt; i++)
++		pack_bits(&addr, &pos, lsave[i], c->lnum_bits);
++	crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
++		    c->lsave_sz - UBIFS_LPT_CRC_BYTES);
++	addr = buf;
++	pos = 0;
++	pack_bits(&addr, &pos, crc, UBIFS_LPT_CRC_BITS);
++}
++
++/**
++ * ubifs_add_lpt_dirt - add dirty space to LPT LEB properties.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number to which to add dirty space
++ * @dirty: amount of dirty space to add
++ */
++void ubifs_add_lpt_dirt(struct ubifs_info *c, int lnum, int dirty)
++{
++	if (!dirty || !lnum)
++		return;
++	dbg_lp("LEB %d add %d to %d",
++	       lnum, dirty, c->ltab[lnum - c->lpt_first].dirty);
++	ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
++	c->ltab[lnum - c->lpt_first].dirty += dirty;
++}
++
++/**
++ * set_ltab - set LPT LEB properties.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number
++ * @free: amount of free space
++ * @dirty: amount of dirty space
++ */
++static void set_ltab(struct ubifs_info *c, int lnum, int free, int dirty)
++{
++	dbg_lp("LEB %d free %d dirty %d to %d %d",
++	       lnum, c->ltab[lnum - c->lpt_first].free,
++	       c->ltab[lnum - c->lpt_first].dirty, free, dirty);
++	ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
++	c->ltab[lnum - c->lpt_first].free = free;
++	c->ltab[lnum - c->lpt_first].dirty = dirty;
++}
++
++/**
++ * ubifs_add_nnode_dirt - add dirty space to LPT LEB properties.
++ * @c: UBIFS file-system description object
++ * @nnode: nnode for which to add dirt
++ */
++void ubifs_add_nnode_dirt(struct ubifs_info *c, struct ubifs_nnode *nnode)
++{
++	struct ubifs_nnode *np = nnode->parent;
++
++	if (np)
++		ubifs_add_lpt_dirt(c, np->nbranch[nnode->iip].lnum,
++				   c->nnode_sz);
++	else {
++		ubifs_add_lpt_dirt(c, c->lpt_lnum, c->nnode_sz);
++		if (!(c->lpt_drty_flgs & LTAB_DIRTY)) {
++			c->lpt_drty_flgs |= LTAB_DIRTY;
++			ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz);
++		}
++	}
++}
++
++/**
++ * add_pnode_dirt - add dirty space to LPT LEB properties.
++ * @c: UBIFS file-system description object
++ * @pnode: pnode for which to add dirt
++ */
++static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode)
++{
++	ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum,
++			   c->pnode_sz);
++}
++
++/**
++ * calc_nnode_num - calculate nnode number.
++ * @row: the row in the tree (root is zero)
++ * @col: the column in the row (leftmost is zero)
++ *
++ * The nnode number is a number that uniquely identifies a nnode and can be used
++ * easily to traverse the tree from the root to that nnode.
++ *
++ * This function calculates and returns the nnode number for the nnode at @row
++ * and @col.
++ */
++static int calc_nnode_num(int row, int col)
++{
++	int num, bits;
++
++	num = 1;
++	while (row--) {
++		bits = (col & (UBIFS_LPT_FANOUT - 1));
++		col >>= UBIFS_LPT_FANOUT_SHIFT;
++		num <<= UBIFS_LPT_FANOUT_SHIFT;
++		num |= bits;
++	}
++	return num;
++}
++
++/**
++ * calc_nnode_num_from_parent - calculate nnode number.
++ * @c: UBIFS file-system description object
++ * @parent: parent nnode
++ * @iip: index in parent
++ *
++ * The nnode number is a number that uniquely identifies a nnode and can be used
++ * easily to traverse the tree from the root to that nnode.
++ *
++ * This function calculates and returns the nnode number based on the parent's
++ * nnode number and the index in parent.
++ */
++static int calc_nnode_num_from_parent(const struct ubifs_info *c,
++				      struct ubifs_nnode *parent, int iip)
++{
++	int num, shft;
++
++	if (!parent)
++		return 1;
++	shft = (c->lpt_hght - parent->level) * UBIFS_LPT_FANOUT_SHIFT;
++	num = parent->num ^ (1 << shft);
++	num |= (UBIFS_LPT_FANOUT + iip) << shft;
++	return num;
++}
++
++/**
++ * calc_pnode_num_from_parent - calculate pnode number.
++ * @c: UBIFS file-system description object
++ * @parent: parent nnode
++ * @iip: index in parent
++ *
++ * The pnode number is a number that uniquely identifies a pnode and can be used
++ * easily to traverse the tree from the root to that pnode.
++ *
++ * This function calculates and returns the pnode number based on the parent's
++ * nnode number and the index in parent.
++ */
++static int calc_pnode_num_from_parent(const struct ubifs_info *c,
++				      struct ubifs_nnode *parent, int iip)
++{
++	int i, n = c->lpt_hght - 1, pnum = parent->num, num = 0;
++
++	for (i = 0; i < n; i++) {
++		num <<= UBIFS_LPT_FANOUT_SHIFT;
++		num |= pnum & (UBIFS_LPT_FANOUT - 1);
++		pnum >>= UBIFS_LPT_FANOUT_SHIFT;
++	}
++	num <<= UBIFS_LPT_FANOUT_SHIFT;
++	num |= iip;
++	return num;
++}
++
++/**
++ * ubifs_create_dflt_lpt - create default LPT.
++ * @c: UBIFS file-system description object
++ * @main_lebs: number of main area LEBs is passed and returned here
++ * @lpt_first: LEB number of first LPT LEB
++ * @lpt_lebs: number of LEBs for LPT is passed and returned here
++ * @big_lpt: use big LPT model is passed and returned here
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
++			  int *lpt_lebs, int *big_lpt)
++{
++	int lnum, err = 0, node_sz, iopos, i, j, cnt, len, alen, row;
++	int blnum, boffs, bsz, bcnt;
++	struct ubifs_pnode *pnode = NULL;
++	struct ubifs_nnode *nnode = NULL;
++	void *buf = NULL, *p;
++	struct ubifs_lpt_lprops *ltab = NULL;
++	int *lsave = NULL;
++
++	err = calc_dflt_lpt_geom(c, main_lebs, big_lpt);
++	if (err)
++		return err;
++	*lpt_lebs = c->lpt_lebs;
++
++	/* Needed by 'ubifs_pack_nnode()' and 'set_ltab()' */
++	c->lpt_first = lpt_first;
++	/* Needed by 'set_ltab()' */
++	c->lpt_last = lpt_first + c->lpt_lebs - 1;
++	/* Needed by 'ubifs_pack_lsave()' */
++	c->main_first = c->leb_cnt - *main_lebs;
++
++	lsave = kmalloc(sizeof(int) * c->lsave_cnt, GFP_KERNEL);
++	pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_KERNEL);
++	nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_KERNEL);
++	buf = vmalloc(c->leb_size);
++	ltab = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
++	if (!pnode || !nnode || !buf || !ltab || !lsave) {
++		err = -ENOMEM;
++		goto out;
++	}
++
++	ubifs_assert(!c->ltab);
++	c->ltab = ltab; /* Needed by set_ltab */
++
++	/* Initialize LPT's own lprops */
++	for (i = 0; i < c->lpt_lebs; i++) {
++		ltab[i].free = c->leb_size;
++		ltab[i].dirty = 0;
++		ltab[i].tgc = 0;
++		ltab[i].cmt = 0;
++	}
++
++	lnum = lpt_first;
++	p = buf;
++	/* Number of leaf nodes (pnodes) */
++	cnt = c->pnode_cnt;
++
++	/*
++	 * The first pnode contains the LEB properties for the LEBs that contain
++	 * the root inode node and the root index node of the index tree.
++	 */
++	node_sz = ALIGN(ubifs_idx_node_sz(c, 1), 8);
++	iopos = ALIGN(node_sz, c->min_io_size);
++	pnode->lprops[0].free = c->leb_size - iopos;
++	pnode->lprops[0].dirty = iopos - node_sz;
++	pnode->lprops[0].flags = LPROPS_INDEX;
++
++	node_sz = UBIFS_INO_NODE_SZ;
++	iopos = ALIGN(node_sz, c->min_io_size);
++	pnode->lprops[1].free = c->leb_size - iopos;
++	pnode->lprops[1].dirty = iopos - node_sz;
++
++	for (i = 2; i < UBIFS_LPT_FANOUT; i++)
++		pnode->lprops[i].free = c->leb_size;
++
++	/* Add first pnode */
++	ubifs_pack_pnode(c, p, pnode);
++	p += c->pnode_sz;
++	len = c->pnode_sz;
++	pnode->num += 1;
++
++	/* Reset pnode values for remaining pnodes */
++	pnode->lprops[0].free = c->leb_size;
++	pnode->lprops[0].dirty = 0;
++	pnode->lprops[0].flags = 0;
++
++	pnode->lprops[1].free = c->leb_size;
++	pnode->lprops[1].dirty = 0;
++
++	/*
++	 * To calculate the internal node branches, we keep information about
++	 * the level below.
++	 */
++	blnum = lnum; /* LEB number of level below */
++	boffs = 0; /* Offset of level below */
++	bcnt = cnt; /* Number of nodes in level below */
++	bsz = c->pnode_sz; /* Size of nodes in level below */
++
++	/* Add all remaining pnodes */
++	for (i = 1; i < cnt; i++) {
++		if (len + c->pnode_sz > c->leb_size) {
++			alen = ALIGN(len, c->min_io_size);
++			set_ltab(c, lnum, c->leb_size - alen, alen - len);
++			memset(p, 0xff, alen - len);
++			err = ubi_leb_change(c->ubi, lnum++, buf, alen,
++					     UBI_SHORTTERM);
++			if (err)
++				goto out;
++			p = buf;
++			len = 0;
++		}
++		ubifs_pack_pnode(c, p, pnode);
++		p += c->pnode_sz;
++		len += c->pnode_sz;
++		/*
++		 * pnodes are simply numbered left to right starting at zero,
++		 * which means the pnode number can be used easily to traverse
++		 * down the tree to the corresponding pnode.
++		 */
++		pnode->num += 1;
++	}
++
++	row = 0;
++	for (i = UBIFS_LPT_FANOUT; cnt > i; i <<= UBIFS_LPT_FANOUT_SHIFT)
++		row += 1;
++	/* Add all nnodes, one level at a time */
++	while (1) {
++		/* Number of internal nodes (nnodes) at next level */
++		cnt = DIV_ROUND_UP(cnt, UBIFS_LPT_FANOUT);
++		for (i = 0; i < cnt; i++) {
++			if (len + c->nnode_sz > c->leb_size) {
++				alen = ALIGN(len, c->min_io_size);
++				set_ltab(c, lnum, c->leb_size - alen,
++					    alen - len);
++				memset(p, 0xff, alen - len);
++				err = ubi_leb_change(c->ubi, lnum++, buf, alen,
++						     UBI_SHORTTERM);
++				if (err)
++					goto out;
++				p = buf;
++				len = 0;
++			}
++			/* Only 1 nnode at this level, so it is the root */
++			if (cnt == 1) {
++				c->lpt_lnum = lnum;
++				c->lpt_offs = len;
++			}
++			/* Set branches to the level below */
++			for (j = 0; j < UBIFS_LPT_FANOUT; j++) {
++				if (bcnt) {
++					if (boffs + bsz > c->leb_size) {
++						blnum += 1;
++						boffs = 0;
++					}
++					nnode->nbranch[j].lnum = blnum;
++					nnode->nbranch[j].offs = boffs;
++					boffs += bsz;
++					bcnt--;
++				} else {
++					nnode->nbranch[j].lnum = 0;
++					nnode->nbranch[j].offs = 0;
++				}
++			}
++			nnode->num = calc_nnode_num(row, i);
++			ubifs_pack_nnode(c, p, nnode);
++			p += c->nnode_sz;
++			len += c->nnode_sz;
++		}
++		/* Only 1 nnode at this level, so it is the root */
++		if (cnt == 1)
++			break;
++		/* Update the information about the level below */
++		bcnt = cnt;
++		bsz = c->nnode_sz;
++		row -= 1;
++	}
++
++	if (*big_lpt) {
++		/* Need to add LPT's save table */
++		if (len + c->lsave_sz > c->leb_size) {
++			alen = ALIGN(len, c->min_io_size);
++			set_ltab(c, lnum, c->leb_size - alen, alen - len);
++			memset(p, 0xff, alen - len);
++			err = ubi_leb_change(c->ubi, lnum++, buf, alen,
++					     UBI_SHORTTERM);
++			if (err)
++				goto out;
++			p = buf;
++			len = 0;
++		}
++
++		c->lsave_lnum = lnum;
++		c->lsave_offs = len;
++
++		for (i = 0; i < c->lsave_cnt && i < *main_lebs; i++)
++			lsave[i] = c->main_first + i;
++		for (; i < c->lsave_cnt; i++)
++			lsave[i] = c->main_first;
++
++		ubifs_pack_lsave(c, p, lsave);
++		p += c->lsave_sz;
++		len += c->lsave_sz;
++	}
++
++	/* Need to add LPT's own LEB properties table */
++	if (len + c->ltab_sz > c->leb_size) {
++		alen = ALIGN(len, c->min_io_size);
++		set_ltab(c, lnum, c->leb_size - alen, alen - len);
++		memset(p, 0xff, alen - len);
++		err = ubi_leb_change(c->ubi, lnum++, buf, alen, UBI_SHORTTERM);
++		if (err)
++			goto out;
++		p = buf;
++		len = 0;
++	}
++
++	c->ltab_lnum = lnum;
++	c->ltab_offs = len;
++
++	/* Update ltab before packing it */
++	len += c->ltab_sz;
++	alen = ALIGN(len, c->min_io_size);
++	set_ltab(c, lnum, c->leb_size - alen, alen - len);
++
++	ubifs_pack_ltab(c, p, ltab);
++	p += c->ltab_sz;
++
++	/* Write remaining buffer */
++	memset(p, 0xff, alen - len);
++	err = ubi_leb_change(c->ubi, lnum, buf, alen, UBI_SHORTTERM);
++	if (err)
++		goto out;
++
++	c->nhead_lnum = lnum;
++	c->nhead_offs = ALIGN(len, c->min_io_size);
++
++	dbg_lp("space_bits %d", c->space_bits);
++	dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits);
++	dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits);
++	dbg_lp("lpt_spc_bits %d", c->lpt_spc_bits);
++	dbg_lp("pcnt_bits %d", c->pcnt_bits);
++	dbg_lp("lnum_bits %d", c->lnum_bits);
++	dbg_lp("pnode_sz %d", c->pnode_sz);
++	dbg_lp("nnode_sz %d", c->nnode_sz);
++	dbg_lp("ltab_sz %d", c->ltab_sz);
++	dbg_lp("lsave_sz %d", c->lsave_sz);
++	dbg_lp("lsave_cnt %d", c->lsave_cnt);
++	dbg_lp("lpt_hght %d", c->lpt_hght);
++	dbg_lp("big_lpt %d", c->big_lpt);
++	dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
++	dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
++	dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
++	if (c->big_lpt)
++		dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
++out:
++	c->ltab = NULL;
++	kfree(lsave);
++	vfree(ltab);
++	vfree(buf);
++	kfree(nnode);
++	kfree(pnode);
++	return err;
++}
++
++/**
++ * update_cats - add LEB properties of a pnode to LEB category lists and heaps.
++ * @c: UBIFS file-system description object
++ * @pnode: pnode
++ *
++ * When a pnode is loaded into memory, the LEB properties it contains are added,
++ * by this function, to the LEB category lists and heaps.
++ */
++static void update_cats(struct ubifs_info *c, struct ubifs_pnode *pnode)
++{
++	int i;
++
++	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++		int cat = pnode->lprops[i].flags & LPROPS_CAT_MASK;
++		int lnum = pnode->lprops[i].lnum;
++
++		if (!lnum)
++			return;
++		ubifs_add_to_cat(c, &pnode->lprops[i], cat);
++	}
++}
++
++/**
++ * replace_cats - add LEB properties of a pnode to LEB category lists and heaps.
++ * @c: UBIFS file-system description object
++ * @old_pnode: pnode copied
++ * @new_pnode: pnode copy
++ *
++ * During commit it is sometimes necessary to copy a pnode
++ * (see dirty_cow_pnode).  When that happens, references in
++ * category lists and heaps must be replaced.  This function does that.
++ */
++static void replace_cats(struct ubifs_info *c, struct ubifs_pnode *old_pnode,
++			 struct ubifs_pnode *new_pnode)
++{
++	int i;
++
++	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++		if (!new_pnode->lprops[i].lnum)
++			return;
++		ubifs_replace_cat(c, &old_pnode->lprops[i],
++				  &new_pnode->lprops[i]);
++	}
++}
++
++/**
++ * check_lpt_crc - check LPT node crc is correct.
++ * @c: UBIFS file-system description object
++ * @buf: buffer containing node
++ * @len: length of node
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int check_lpt_crc(void *buf, int len)
++{
++	int pos = 0;
++	uint8_t *addr = buf;
++	uint16_t crc, calc_crc;
++
++	crc = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_CRC_BITS);
++	calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
++			 len - UBIFS_LPT_CRC_BYTES);
++	if (crc != calc_crc) {
++		ubifs_err("invalid crc in LPT node: crc %hx calc %hx", crc,
++			  calc_crc);
++		dbg_dump_stack();
++		return -EINVAL;
++	}
++	return 0;
++}
++
++/**
++ * check_lpt_type - check LPT node type is correct.
++ * @c: UBIFS file-system description object
++ * @addr: address of type bit field is passed and returned updated here
++ * @pos: position of type bit field is passed and returned updated here
++ * @type: expected type
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int check_lpt_type(uint8_t **addr, int *pos, int type)
++{
++	int node_type;
++
++	node_type = ubifs_unpack_bits(addr, pos, UBIFS_LPT_TYPE_BITS);
++	if (node_type != type) {
++		ubifs_err("invalid type (%d) in LPT node type %d", node_type,
++			  type);
++		dbg_dump_stack();
++		return -EINVAL;
++	}
++	return 0;
++}
++
++/**
++ * unpack_pnode - unpack a pnode.
++ * @c: UBIFS file-system description object
++ * @buf: buffer containing packed pnode to unpack
++ * @pnode: pnode structure to fill
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int unpack_pnode(const struct ubifs_info *c, void *buf,
++			struct ubifs_pnode *pnode)
++{
++	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
++	int i, pos = 0, err;
++
++	err = check_lpt_type(&addr, &pos, UBIFS_LPT_PNODE);
++	if (err)
++		return err;
++	if (c->big_lpt)
++		pnode->num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
++	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++		struct ubifs_lprops * const lprops = &pnode->lprops[i];
++
++		lprops->free = ubifs_unpack_bits(&addr, &pos, c->space_bits);
++		lprops->free <<= 3;
++		lprops->dirty = ubifs_unpack_bits(&addr, &pos, c->space_bits);
++		lprops->dirty <<= 3;
++
++		if (ubifs_unpack_bits(&addr, &pos, 1))
++			lprops->flags = LPROPS_INDEX;
++		else
++			lprops->flags = 0;
++		lprops->flags |= ubifs_categorize_lprops(c, lprops);
++	}
++	err = check_lpt_crc(buf, c->pnode_sz);
++	return err;
++}
++
++/**
++ * ubifs_unpack_nnode - unpack a nnode.
++ * @c: UBIFS file-system description object
++ * @buf: buffer containing packed nnode to unpack
++ * @nnode: nnode structure to fill
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int ubifs_unpack_nnode(const struct ubifs_info *c, void *buf,
++		       struct ubifs_nnode *nnode)
++{
++	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
++	int i, pos = 0, err;
++
++	err = check_lpt_type(&addr, &pos, UBIFS_LPT_NNODE);
++	if (err)
++		return err;
++	if (c->big_lpt)
++		nnode->num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
++	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++		int lnum;
++
++		lnum = ubifs_unpack_bits(&addr, &pos, c->lpt_lnum_bits) +
++		       c->lpt_first;
++		if (lnum == c->lpt_last + 1)
++			lnum = 0;
++		nnode->nbranch[i].lnum = lnum;
++		nnode->nbranch[i].offs = ubifs_unpack_bits(&addr, &pos,
++						     c->lpt_offs_bits);
++	}
++	err = check_lpt_crc(buf, c->nnode_sz);
++	return err;
++}
++
++/**
++ * unpack_ltab - unpack the LPT's own lprops table.
++ * @c: UBIFS file-system description object
++ * @buf: buffer from which to unpack
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int unpack_ltab(const struct ubifs_info *c, void *buf)
++{
++	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
++	int i, pos = 0, err;
++
++	err = check_lpt_type(&addr, &pos, UBIFS_LPT_LTAB);
++	if (err)
++		return err;
++	for (i = 0; i < c->lpt_lebs; i++) {
++		int free = ubifs_unpack_bits(&addr, &pos, c->lpt_spc_bits);
++		int dirty = ubifs_unpack_bits(&addr, &pos, c->lpt_spc_bits);
++
++		if (free < 0 || free > c->leb_size || dirty < 0 ||
++		    dirty > c->leb_size || free + dirty > c->leb_size)
++			return -EINVAL;
++
++		c->ltab[i].free = free;
++		c->ltab[i].dirty = dirty;
++		c->ltab[i].tgc = 0;
++		c->ltab[i].cmt = 0;
++	}
++	err = check_lpt_crc(buf, c->ltab_sz);
++	return err;
++}
++
++/**
++ * unpack_lsave - unpack the LPT's save table.
++ * @c: UBIFS file-system description object
++ * @buf: buffer from which to unpack
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int unpack_lsave(const struct ubifs_info *c, void *buf)
++{
++	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
++	int i, pos = 0, err;
++
++	err = check_lpt_type(&addr, &pos, UBIFS_LPT_LSAVE);
++	if (err)
++		return err;
++	for (i = 0; i < c->lsave_cnt; i++) {
++		int lnum = ubifs_unpack_bits(&addr, &pos, c->lnum_bits);
++
++		if (lnum < c->main_first || lnum >= c->leb_cnt)
++			return -EINVAL;
++		c->lsave[i] = lnum;
++	}
++	err = check_lpt_crc(buf, c->lsave_sz);
++	return err;
++}
++
++/**
++ * validate_nnode - validate a nnode.
++ * @c: UBIFS file-system description object
++ * @nnode: nnode to validate
++ * @parent: parent nnode (or NULL for the root nnode)
++ * @iip: index in parent
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int validate_nnode(const struct ubifs_info *c, struct ubifs_nnode *nnode,
++			  struct ubifs_nnode *parent, int iip)
++{
++	int i, lvl, max_offs;
++
++	if (c->big_lpt) {
++		int num = calc_nnode_num_from_parent(c, parent, iip);
++
++		if (nnode->num != num)
++			return -EINVAL;
++	}
++	lvl = parent ? parent->level - 1 : c->lpt_hght;
++	if (lvl < 1)
++		return -EINVAL;
++	if (lvl == 1)
++		max_offs = c->leb_size - c->pnode_sz;
++	else
++		max_offs = c->leb_size - c->nnode_sz;
++	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++		int lnum = nnode->nbranch[i].lnum;
++		int offs = nnode->nbranch[i].offs;
++
++		if (lnum == 0) {
++			if (offs != 0)
++				return -EINVAL;
++			continue;
++		}
++		if (lnum < c->lpt_first || lnum > c->lpt_last)
++			return -EINVAL;
++		if (offs < 0 || offs > max_offs)
++			return -EINVAL;
++	}
++	return 0;
++}
++
++/**
++ * validate_pnode - validate a pnode.
++ * @c: UBIFS file-system description object
++ * @pnode: pnode to validate
++ * @parent: parent nnode
++ * @iip: index in parent
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int validate_pnode(const struct ubifs_info *c, struct ubifs_pnode *pnode,
++			  struct ubifs_nnode *parent, int iip)
++{
++	int i;
++
++	if (c->big_lpt) {
++		int num = calc_pnode_num_from_parent(c, parent, iip);
++
++		if (pnode->num != num)
++			return -EINVAL;
++	}
++	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++		int free = pnode->lprops[i].free;
++		int dirty = pnode->lprops[i].dirty;
++
++		if (free < 0 || free > c->leb_size || free % c->min_io_size ||
++		    (free & 7))
++			return -EINVAL;
++		if (dirty < 0 || dirty > c->leb_size || (dirty & 7))
++			return -EINVAL;
++		if (dirty + free > c->leb_size)
++			return -EINVAL;
++	}
++	return 0;
++}
++
++/**
++ * set_pnode_lnum - set LEB numbers on a pnode.
++ * @c: UBIFS file-system description object
++ * @pnode: pnode to update
++ *
++ * This function calculates the LEB numbers for the LEB properties it contains
++ * based on the pnode number.
++ */
++static void set_pnode_lnum(const struct ubifs_info *c,
++			   struct ubifs_pnode *pnode)
++{
++	int i, lnum;
++
++	lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + c->main_first;
++	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++		if (lnum >= c->leb_cnt)
++			return;
++		pnode->lprops[i].lnum = lnum++;
++	}
++}
++
++/**
++ * ubifs_read_nnode - read a nnode from flash and link it to the tree in memory.
++ * @c: UBIFS file-system description object
++ * @parent: parent nnode (or NULL for the root)
++ * @iip: index in parent
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int ubifs_read_nnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
++{
++	struct ubifs_nbranch *branch = NULL;
++	struct ubifs_nnode *nnode = NULL;
++	void *buf = c->lpt_nod_buf;
++	int err, lnum, offs;
++
++	if (parent) {
++		branch = &parent->nbranch[iip];
++		lnum = branch->lnum;
++		offs = branch->offs;
++	} else {
++		lnum = c->lpt_lnum;
++		offs = c->lpt_offs;
++	}
++	nnode = kzalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
++	if (!nnode) {
++		err = -ENOMEM;
++		goto out;
++	}
++	if (lnum == 0) {
++		/*
++		 * This nnode was not written which just means that the LEB
++		 * properties in the subtree below it describe empty LEBs. We
++		 * make the nnode as though we had read it, which in fact means
++		 * doing almost nothing.
++		 */
++		if (c->big_lpt)
++			nnode->num = calc_nnode_num_from_parent(c, parent, iip);
++	} else {
++		err = ubi_read(c->ubi, lnum, buf, offs, c->nnode_sz);
++		if (err)
++			goto out;
++		err = ubifs_unpack_nnode(c, buf, nnode);
++		if (err)
++			goto out;
++	}
++	err = validate_nnode(c, nnode, parent, iip);
++	if (err)
++		goto out;
++	if (!c->big_lpt)
++		nnode->num = calc_nnode_num_from_parent(c, parent, iip);
++	if (parent) {
++		branch->nnode = nnode;
++		nnode->level = parent->level - 1;
++	} else {
++		c->nroot = nnode;
++		nnode->level = c->lpt_hght;
++	}
++	nnode->parent = parent;
++	nnode->iip = iip;
++	return 0;
++
++out:
++	ubifs_err("error %d reading nnode at %d:%d", err, lnum, offs);
++	kfree(nnode);
++	return err;
++}
++
++/**
++ * read_pnode - read a pnode from flash and link it to the tree in memory.
++ * @c: UBIFS file-system description object
++ * @parent: parent nnode
++ * @iip: index in parent
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int read_pnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip)
++{
++	struct ubifs_nbranch *branch;
++	struct ubifs_pnode *pnode = NULL;
++	void *buf = c->lpt_nod_buf;
++	int err, lnum, offs;
++
++	branch = &parent->nbranch[iip];
++	lnum = branch->lnum;
++	offs = branch->offs;
++	pnode = kzalloc(sizeof(struct ubifs_pnode), GFP_NOFS);
++	if (!pnode) {
++		err = -ENOMEM;
++		goto out;
++	}
++	if (lnum == 0) {
++		/*
++		 * This pnode was not written which just means that the LEB
++		 * properties in it describe empty LEBs. We make the pnode as
++		 * though we had read it.
++		 */
++		int i;
++
++		if (c->big_lpt)
++			pnode->num = calc_pnode_num_from_parent(c, parent, iip);
++		for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++			struct ubifs_lprops * const lprops = &pnode->lprops[i];
++
++			lprops->free = c->leb_size;
++			lprops->flags = ubifs_categorize_lprops(c, lprops);
++		}
++	} else {
++		err = ubi_read(c->ubi, lnum, buf, offs, c->pnode_sz);
++		if (err)
++			goto out;
++		err = unpack_pnode(c, buf, pnode);
++		if (err)
++			goto out;
++	}
++	err = validate_pnode(c, pnode, parent, iip);
++	if (err)
++		goto out;
++	if (!c->big_lpt)
++		pnode->num = calc_pnode_num_from_parent(c, parent, iip);
++	branch->pnode = pnode;
++	pnode->parent = parent;
++	pnode->iip = iip;
++	set_pnode_lnum(c, pnode);
++	c->pnodes_have += 1;
++	return 0;
++
++out:
++	ubifs_err("error %d reading pnode at %d:%d", err, lnum, offs);
++	dbg_dump_pnode(c, pnode, parent, iip);
++	dbg_msg("calc num: %d", calc_pnode_num_from_parent(c, parent, iip));
++	kfree(pnode);
++	return err;
++}
++
++/**
++ * read_ltab - read LPT's own lprops table.
++ * @c: UBIFS file-system description object
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int read_ltab(struct ubifs_info *c)
++{
++	int err;
++	void *buf;
++
++	buf = vmalloc(c->ltab_sz);
++	if (!buf)
++		return -ENOMEM;
++	err = ubi_read(c->ubi, c->ltab_lnum, buf, c->ltab_offs, c->ltab_sz);
++	if (err)
++		goto out;
++	err = unpack_ltab(c, buf);
++out:
++	vfree(buf);
++	return err;
++}
++
++/**
++ * read_lsave - read LPT's save table.
++ * @c: UBIFS file-system description object
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int read_lsave(struct ubifs_info *c)
++{
++	int err, i;
++	void *buf;
++
++	buf = vmalloc(c->lsave_sz);
++	if (!buf)
++		return -ENOMEM;
++	err = ubi_read(c->ubi, c->lsave_lnum, buf, c->lsave_offs, c->lsave_sz);
++	if (err)
++		goto out;
++	err = unpack_lsave(c, buf);
++	if (err)
++		goto out;
++	for (i = 0; i < c->lsave_cnt; i++) {
++		int lnum = c->lsave[i];
++
++		/*
++		 * Due to automatic resizing, the values in the lsave table
++		 * could be beyond the volume size - just ignore them.
++		 */
++		if (lnum >= c->leb_cnt)
++			continue;
++		ubifs_lpt_lookup(c, lnum);
++	}
++out:
++	vfree(buf);
++	return err;
++}
++
++/**
++ * ubifs_get_nnode - get a nnode.
++ * @c: UBIFS file-system description object
++ * @parent: parent nnode (or NULL for the root)
++ * @iip: index in parent
++ *
++ * This function returns a pointer to the nnode on success or a negative error
++ * code on failure.
++ */
++struct ubifs_nnode *ubifs_get_nnode(struct ubifs_info *c,
++				    struct ubifs_nnode *parent, int iip)
++{
++	struct ubifs_nbranch *branch;
++	struct ubifs_nnode *nnode;
++	int err;
++
++	branch = &parent->nbranch[iip];
++	nnode = branch->nnode;
++	if (nnode)
++		return nnode;
++	err = ubifs_read_nnode(c, parent, iip);
++	if (err)
++		return ERR_PTR(err);
++	return branch->nnode;
++}
++
++/**
++ * ubifs_get_pnode - get a pnode.
++ * @c: UBIFS file-system description object
++ * @parent: parent nnode
++ * @iip: index in parent
++ *
++ * This function returns a pointer to the pnode on success or a negative error
++ * code on failure.
++ */
++struct ubifs_pnode *ubifs_get_pnode(struct ubifs_info *c,
++				    struct ubifs_nnode *parent, int iip)
++{
++	struct ubifs_nbranch *branch;
++	struct ubifs_pnode *pnode;
++	int err;
++
++	branch = &parent->nbranch[iip];
++	pnode = branch->pnode;
++	if (pnode)
++		return pnode;
++	err = read_pnode(c, parent, iip);
++	if (err)
++		return ERR_PTR(err);
++	update_cats(c, branch->pnode);
++	return branch->pnode;
++}
++
++/**
++ * ubifs_lpt_lookup - lookup LEB properties in the LPT.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number to lookup
++ *
++ * This function returns a pointer to the LEB properties on success or a
++ * negative error code on failure.
++ */
++struct ubifs_lprops *ubifs_lpt_lookup(struct ubifs_info *c, int lnum)
++{
++	int err, i, h, iip, shft;
++	struct ubifs_nnode *nnode;
++	struct ubifs_pnode *pnode;
++
++	if (!c->nroot) {
++		err = ubifs_read_nnode(c, NULL, 0);
++		if (err)
++			return ERR_PTR(err);
++	}
++	nnode = c->nroot;
++	i = lnum - c->main_first;
++	shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
++	for (h = 1; h < c->lpt_hght; h++) {
++		iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
++		shft -= UBIFS_LPT_FANOUT_SHIFT;
++		nnode = ubifs_get_nnode(c, nnode, iip);
++		if (IS_ERR(nnode))
++			return ERR_PTR(PTR_ERR(nnode));
++	}
++	iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
++	shft -= UBIFS_LPT_FANOUT_SHIFT;
++	pnode = ubifs_get_pnode(c, nnode, iip);
++	if (IS_ERR(pnode))
++		return ERR_PTR(PTR_ERR(pnode));
++	iip = (i & (UBIFS_LPT_FANOUT - 1));
++	dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum,
++	       pnode->lprops[iip].free, pnode->lprops[iip].dirty,
++	       pnode->lprops[iip].flags);
++	return &pnode->lprops[iip];
++}
++
++/**
++ * dirty_cow_nnode - ensure a nnode is not being committed.
++ * @c: UBIFS file-system description object
++ * @nnode: nnode to check
++ *
++ * Returns dirtied nnode on success or negative error code on failure.
++ */
++static struct ubifs_nnode *dirty_cow_nnode(struct ubifs_info *c,
++					   struct ubifs_nnode *nnode)
++{
++	struct ubifs_nnode *n;
++	int i;
++
++	if (!test_bit(COW_CNODE, &nnode->flags)) {
++		/* nnode is not being committed */
++		if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
++			c->dirty_nn_cnt += 1;
++			ubifs_add_nnode_dirt(c, nnode);
++		}
++		return nnode;
++	}
++
++	/* nnode is being committed, so copy it */
++	n = kmalloc(sizeof(struct ubifs_nnode), GFP_NOFS);
++	if (unlikely(!n))
++		return ERR_PTR(-ENOMEM);
++
++	memcpy(n, nnode, sizeof(struct ubifs_nnode));
++	n->cnext = NULL;
++	__set_bit(DIRTY_CNODE, &n->flags);
++	__clear_bit(COW_CNODE, &n->flags);
++
++	/* The children now have new parent */
++	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++		struct ubifs_nbranch *branch = &n->nbranch[i];
++
++		if (branch->cnode)
++			branch->cnode->parent = n;
++	}
++
++	ubifs_assert(!test_bit(OBSOLETE_CNODE, &nnode->flags));
++	__set_bit(OBSOLETE_CNODE, &nnode->flags);
++
++	c->dirty_nn_cnt += 1;
++	ubifs_add_nnode_dirt(c, nnode);
++	if (nnode->parent)
++		nnode->parent->nbranch[n->iip].nnode = n;
++	else
++		c->nroot = n;
++	return n;
++}
++
++/**
++ * dirty_cow_pnode - ensure a pnode is not being committed.
++ * @c: UBIFS file-system description object
++ * @pnode: pnode to check
++ *
++ * Returns dirtied pnode on success or negative error code on failure.
++ */
++static struct ubifs_pnode *dirty_cow_pnode(struct ubifs_info *c,
++					   struct ubifs_pnode *pnode)
++{
++	struct ubifs_pnode *p;
++
++	if (!test_bit(COW_CNODE, &pnode->flags)) {
++		/* pnode is not being committed */
++		if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) {
++			c->dirty_pn_cnt += 1;
++			add_pnode_dirt(c, pnode);
++		}
++		return pnode;
++	}
++
++	/* pnode is being committed, so copy it */
++	p = kmalloc(sizeof(struct ubifs_pnode), GFP_NOFS);
++	if (unlikely(!p))
++		return ERR_PTR(-ENOMEM);
++
++	memcpy(p, pnode, sizeof(struct ubifs_pnode));
++	p->cnext = NULL;
++	__set_bit(DIRTY_CNODE, &p->flags);
++	__clear_bit(COW_CNODE, &p->flags);
++	replace_cats(c, pnode, p);
++
++	ubifs_assert(!test_bit(OBSOLETE_CNODE, &pnode->flags));
++	__set_bit(OBSOLETE_CNODE, &pnode->flags);
++
++	c->dirty_pn_cnt += 1;
++	add_pnode_dirt(c, pnode);
++	pnode->parent->nbranch[p->iip].pnode = p;
++	return p;
++}
++
++/**
++ * ubifs_lpt_lookup_dirty - lookup LEB properties in the LPT.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number to lookup
++ *
++ * This function returns a pointer to the LEB properties on success or a
++ * negative error code on failure.
++ */
++struct ubifs_lprops *ubifs_lpt_lookup_dirty(struct ubifs_info *c, int lnum)
++{
++	int err, i, h, iip, shft;
++	struct ubifs_nnode *nnode;
++	struct ubifs_pnode *pnode;
++
++	if (!c->nroot) {
++		err = ubifs_read_nnode(c, NULL, 0);
++		if (err)
++			return ERR_PTR(err);
++	}
++	nnode = c->nroot;
++	nnode = dirty_cow_nnode(c, nnode);
++	if (IS_ERR(nnode))
++		return ERR_PTR(PTR_ERR(nnode));
++	i = lnum - c->main_first;
++	shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
++	for (h = 1; h < c->lpt_hght; h++) {
++		iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
++		shft -= UBIFS_LPT_FANOUT_SHIFT;
++		nnode = ubifs_get_nnode(c, nnode, iip);
++		if (IS_ERR(nnode))
++			return ERR_PTR(PTR_ERR(nnode));
++		nnode = dirty_cow_nnode(c, nnode);
++		if (IS_ERR(nnode))
++			return ERR_PTR(PTR_ERR(nnode));
++	}
++	iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
++	shft -= UBIFS_LPT_FANOUT_SHIFT;
++	pnode = ubifs_get_pnode(c, nnode, iip);
++	if (IS_ERR(pnode))
++		return ERR_PTR(PTR_ERR(pnode));
++	pnode = dirty_cow_pnode(c, pnode);
++	if (IS_ERR(pnode))
++		return ERR_PTR(PTR_ERR(pnode));
++	iip = (i & (UBIFS_LPT_FANOUT - 1));
++	dbg_lp("LEB %d, free %d, dirty %d, flags %d", lnum,
++	       pnode->lprops[iip].free, pnode->lprops[iip].dirty,
++	       pnode->lprops[iip].flags);
++	ubifs_assert(test_bit(DIRTY_CNODE, &pnode->flags));
++	return &pnode->lprops[iip];
++}
++
++/**
++ * lpt_init_rd - initialize the LPT for reading.
++ * @c: UBIFS file-system description object
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int lpt_init_rd(struct ubifs_info *c)
++{
++	int err, i;
++
++	c->ltab = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
++	if (!c->ltab)
++		return -ENOMEM;
++
++	i = max_t(int, c->nnode_sz, c->pnode_sz);
++	c->lpt_nod_buf = kmalloc(i, GFP_KERNEL);
++	if (!c->lpt_nod_buf)
++		return -ENOMEM;
++
++	for (i = 0; i < LPROPS_HEAP_CNT; i++) {
++		c->lpt_heap[i].arr = kmalloc(sizeof(void *) * LPT_HEAP_SZ,
++					     GFP_KERNEL);
++		if (!c->lpt_heap[i].arr)
++			return -ENOMEM;
++		c->lpt_heap[i].cnt = 0;
++		c->lpt_heap[i].max_cnt = LPT_HEAP_SZ;
++	}
++
++	c->dirty_idx.arr = kmalloc(sizeof(void *) * LPT_HEAP_SZ, GFP_KERNEL);
++	if (!c->dirty_idx.arr)
++		return -ENOMEM;
++	c->dirty_idx.cnt = 0;
++	c->dirty_idx.max_cnt = LPT_HEAP_SZ;
++
++	err = read_ltab(c);
++	if (err)
++		return err;
++
++	dbg_lp("space_bits %d", c->space_bits);
++	dbg_lp("lpt_lnum_bits %d", c->lpt_lnum_bits);
++	dbg_lp("lpt_offs_bits %d", c->lpt_offs_bits);
++	dbg_lp("lpt_spc_bits %d", c->lpt_spc_bits);
++	dbg_lp("pcnt_bits %d", c->pcnt_bits);
++	dbg_lp("lnum_bits %d", c->lnum_bits);
++	dbg_lp("pnode_sz %d", c->pnode_sz);
++	dbg_lp("nnode_sz %d", c->nnode_sz);
++	dbg_lp("ltab_sz %d", c->ltab_sz);
++	dbg_lp("lsave_sz %d", c->lsave_sz);
++	dbg_lp("lsave_cnt %d", c->lsave_cnt);
++	dbg_lp("lpt_hght %d", c->lpt_hght);
++	dbg_lp("big_lpt %d", c->big_lpt);
++	dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
++	dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
++	dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
++	if (c->big_lpt)
++		dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
++
++	return 0;
++}
++
++/**
++ * lpt_init_wr - initialize the LPT for writing.
++ * @c: UBIFS file-system description object
++ *
++ * 'lpt_init_rd()' must have been called already.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int lpt_init_wr(struct ubifs_info *c)
++{
++	int err, i;
++
++	c->ltab_cmt = vmalloc(sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
++	if (!c->ltab_cmt)
++		return -ENOMEM;
++
++	c->lpt_buf = vmalloc(c->leb_size);
++	if (!c->lpt_buf)
++		return -ENOMEM;
++
++	if (c->big_lpt) {
++		c->lsave = kmalloc(sizeof(int) * c->lsave_cnt, GFP_NOFS);
++		if (!c->lsave)
++			return -ENOMEM;
++		err = read_lsave(c);
++		if (err)
++			return err;
++	}
++
++	for (i = 0; i < c->lpt_lebs; i++)
++		if (c->ltab[i].free == c->leb_size) {
++			err = ubifs_leb_unmap(c, i + c->lpt_first);
++			if (err)
++				return err;
++		}
++
++	return 0;
++}
++
++/**
++ * ubifs_lpt_init - initialize the LPT.
++ * @c: UBIFS file-system description object
++ * @rd: whether to initialize lpt for reading
++ * @wr: whether to initialize lpt for writing
++ *
++ * For mounting 'rw', @rd and @wr are both true. For mounting 'ro', @rd is true
++ * and @wr is false. For mounting from 'ro' to 'rw', @rd is false and @wr is
++ * true.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int ubifs_lpt_init(struct ubifs_info *c, int rd, int wr)
++{
++	int err;
++
++	if (rd) {
++		err = lpt_init_rd(c);
++		if (err)
++			return err;
++	}
++
++	if (wr) {
++		err = lpt_init_wr(c);
++		if (err)
++			return err;
++	}
++
++	return 0;
++}
++
++/**
++ * struct lpt_scan_node - somewhere to put nodes while we scan LPT.
++ * @nnode: where to keep a nnode
++ * @pnode: where to keep a pnode
++ * @cnode: where to keep a cnode
++ * @in_tree: is the node in the tree in memory
++ * @ptr.nnode: pointer to the nnode (if it is an nnode) which may be here or in
++ * the tree
++ * @ptr.pnode: ditto for pnode
++ * @ptr.cnode: ditto for cnode
++ */
++struct lpt_scan_node {
++	union {
++		struct ubifs_nnode nnode;
++		struct ubifs_pnode pnode;
++		struct ubifs_cnode cnode;
++	};
++	int in_tree;
++	union {
++		struct ubifs_nnode *nnode;
++		struct ubifs_pnode *pnode;
++		struct ubifs_cnode *cnode;
++	} ptr;
++};
++
++/**
++ * scan_get_nnode - for the scan, get a nnode from either the tree or flash.
++ * @c: the UBIFS file-system description object
++ * @path: where to put the nnode
++ * @parent: parent of the nnode
++ * @iip: index in parent of the nnode
++ *
++ * This function returns a pointer to the nnode on success or a negative error
++ * code on failure.
++ */
++static struct ubifs_nnode *scan_get_nnode(struct ubifs_info *c,
++					  struct lpt_scan_node *path,
++					  struct ubifs_nnode *parent, int iip)
++{
++	struct ubifs_nbranch *branch;
++	struct ubifs_nnode *nnode;
++	void *buf = c->lpt_nod_buf;
++	int err;
++
++	branch = &parent->nbranch[iip];
++	nnode = branch->nnode;
++	if (nnode) {
++		path->in_tree = 1;
++		path->ptr.nnode = nnode;
++		return nnode;
++	}
++	nnode = &path->nnode;
++	path->in_tree = 0;
++	path->ptr.nnode = nnode;
++	memset(nnode, 0, sizeof(struct ubifs_nnode));
++	if (branch->lnum == 0) {
++		/*
++		 * This nnode was not written which just means that the LEB
++		 * properties in the subtree below it describe empty LEBs. We
++		 * make the nnode as though we had read it, which in fact means
++		 * doing almost nothing.
++		 */
++		if (c->big_lpt)
++			nnode->num = calc_nnode_num_from_parent(c, parent, iip);
++	} else {
++		err = ubi_read(c->ubi, branch->lnum, buf, branch->offs,
++			       c->nnode_sz);
++		if (err)
++			return ERR_PTR(err);
++		err = ubifs_unpack_nnode(c, buf, nnode);
++		if (err)
++			return ERR_PTR(err);
++	}
++	err = validate_nnode(c, nnode, parent, iip);
++	if (err)
++		return ERR_PTR(err);
++	if (!c->big_lpt)
++		nnode->num = calc_nnode_num_from_parent(c, parent, iip);
++	nnode->level = parent->level - 1;
++	nnode->parent = parent;
++	nnode->iip = iip;
++	return nnode;
++}
++
++/**
++ * scan_get_pnode - for the scan, get a pnode from either the tree or flash.
++ * @c: the UBIFS file-system description object
++ * @path: where to put the pnode
++ * @parent: parent of the pnode
++ * @iip: index in parent of the pnode
++ *
++ * This function returns a pointer to the pnode on success or a negative error
++ * code on failure.
++ */
++static struct ubifs_pnode *scan_get_pnode(struct ubifs_info *c,
++					  struct lpt_scan_node *path,
++					  struct ubifs_nnode *parent, int iip)
++{
++	struct ubifs_nbranch *branch;
++	struct ubifs_pnode *pnode;
++	void *buf = c->lpt_nod_buf;
++	int err;
++
++	branch = &parent->nbranch[iip];
++	pnode = branch->pnode;
++	if (pnode) {
++		path->in_tree = 1;
++		path->ptr.pnode = pnode;
++		return pnode;
++	}
++	pnode = &path->pnode;
++	path->in_tree = 0;
++	path->ptr.pnode = pnode;
++	memset(pnode, 0, sizeof(struct ubifs_pnode));
++	if (branch->lnum == 0) {
++		/*
++		 * This pnode was not written which just means that the LEB
++		 * properties in it describe empty LEBs. We make the pnode as
++		 * though we had read it.
++		 */
++		int i;
++
++		if (c->big_lpt)
++			pnode->num = calc_pnode_num_from_parent(c, parent, iip);
++		for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++			struct ubifs_lprops * const lprops = &pnode->lprops[i];
++
++			lprops->free = c->leb_size;
++			lprops->flags = ubifs_categorize_lprops(c, lprops);
++		}
++	} else {
++		ubifs_assert(branch->lnum >= c->lpt_first &&
++			     branch->lnum <= c->lpt_last);
++		ubifs_assert(branch->offs >= 0 && branch->offs < c->leb_size);
++		err = ubi_read(c->ubi, branch->lnum, buf, branch->offs,
++			       c->pnode_sz);
++		if (err)
++			return ERR_PTR(err);
++		err = unpack_pnode(c, buf, pnode);
++		if (err)
++			return ERR_PTR(err);
++	}
++	err = validate_pnode(c, pnode, parent, iip);
++	if (err)
++		return ERR_PTR(err);
++	if (!c->big_lpt)
++		pnode->num = calc_pnode_num_from_parent(c, parent, iip);
++	pnode->parent = parent;
++	pnode->iip = iip;
++	set_pnode_lnum(c, pnode);
++	return pnode;
++}
++
++/**
++ * ubifs_lpt_scan_nolock - scan the LPT.
++ * @c: the UBIFS file-system description object
++ * @start_lnum: LEB number from which to start scanning
++ * @end_lnum: LEB number at which to stop scanning
++ * @scan_cb: callback function called for each lprops
++ * @data: data to be passed to the callback function
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int ubifs_lpt_scan_nolock(struct ubifs_info *c, int start_lnum, int end_lnum,
++			  ubifs_lpt_scan_callback scan_cb, void *data)
++{
++	int err = 0, i, h, iip, shft;
++	struct ubifs_nnode *nnode;
++	struct ubifs_pnode *pnode;
++	struct lpt_scan_node *path;
++
++	if (start_lnum == -1) {
++		start_lnum = end_lnum + 1;
++		if (start_lnum >= c->leb_cnt)
++			start_lnum = c->main_first;
++	}
++
++	ubifs_assert(start_lnum >= c->main_first && start_lnum < c->leb_cnt);
++	ubifs_assert(end_lnum >= c->main_first && end_lnum < c->leb_cnt);
++
++	if (!c->nroot) {
++		err = ubifs_read_nnode(c, NULL, 0);
++		if (err)
++			return err;
++	}
++
++	path = kmalloc(sizeof(struct lpt_scan_node) * (c->lpt_hght + 1),
++		       GFP_NOFS);
++	if (!path)
++		return -ENOMEM;
++
++	path[0].ptr.nnode = c->nroot;
++	path[0].in_tree = 1;
++again:
++	/* Descend to the pnode containing start_lnum */
++	nnode = c->nroot;
++	i = start_lnum - c->main_first;
++	shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
++	for (h = 1; h < c->lpt_hght; h++) {
++		iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
++		shft -= UBIFS_LPT_FANOUT_SHIFT;
++		nnode = scan_get_nnode(c, path + h, nnode, iip);
++		if (IS_ERR(nnode)) {
++			err = PTR_ERR(nnode);
++			goto out;
++		}
++	}
++	iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
++	shft -= UBIFS_LPT_FANOUT_SHIFT;
++	pnode = scan_get_pnode(c, path + h, nnode, iip);
++	if (IS_ERR(pnode)) {
++		err = PTR_ERR(pnode);
++		goto out;
++	}
++	iip = (i & (UBIFS_LPT_FANOUT - 1));
++
++	/* Loop for each lprops */
++	while (1) {
++		struct ubifs_lprops *lprops = &pnode->lprops[iip];
++		int ret, lnum = lprops->lnum;
++
++		ret = scan_cb(c, lprops, path[h].in_tree, data);
++		if (ret < 0) {
++			err = ret;
++			goto out;
++		}
++		if (ret & LPT_SCAN_ADD) {
++			/* Add all the nodes in path to the tree in memory */
++			for (h = 1; h < c->lpt_hght; h++) {
++				const size_t sz = sizeof(struct ubifs_nnode);
++				struct ubifs_nnode *parent;
++
++				if (path[h].in_tree)
++					continue;
++				nnode = kmalloc(sz, GFP_NOFS);
++				if (!nnode) {
++					err = -ENOMEM;
++					goto out;
++				}
++				memcpy(nnode, &path[h].nnode, sz);
++				parent = nnode->parent;
++				parent->nbranch[nnode->iip].nnode = nnode;
++				path[h].ptr.nnode = nnode;
++				path[h].in_tree = 1;
++				path[h + 1].cnode.parent = nnode;
++			}
++			if (path[h].in_tree)
++				ubifs_ensure_cat(c, lprops);
++			else {
++				const size_t sz = sizeof(struct ubifs_pnode);
++				struct ubifs_nnode *parent;
++
++				pnode = kmalloc(sz, GFP_NOFS);
++				if (!pnode) {
++					err = -ENOMEM;
++					goto out;
++				}
++				memcpy(pnode, &path[h].pnode, sz);
++				parent = pnode->parent;
++				parent->nbranch[pnode->iip].pnode = pnode;
++				path[h].ptr.pnode = pnode;
++				path[h].in_tree = 1;
++				update_cats(c, pnode);
++				c->pnodes_have += 1;
++			}
++			err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)
++						  c->nroot, 0, 0);
++			if (err)
++				goto out;
++			err = dbg_check_cats(c);
++			if (err)
++				goto out;
++		}
++		if (ret & LPT_SCAN_STOP) {
++			err = 0;
++			break;
++		}
++		/* Get the next lprops */
++		if (lnum == end_lnum) {
++			/*
++			 * We got to the end without finding what we were
++			 * looking for
++			 */
++			err = -ENOSPC;
++			goto out;
++		}
++		if (lnum + 1 >= c->leb_cnt) {
++			/* Wrap-around to the beginning */
++			start_lnum = c->main_first;
++			goto again;
++		}
++		if (iip + 1 < UBIFS_LPT_FANOUT) {
++			/* Next lprops is in the same pnode */
++			iip += 1;
++			continue;
++		}
++		/* We need to get the next pnode. Go up until we can go right */
++		iip = pnode->iip;
++		while (1) {
++			h -= 1;
++			ubifs_assert(h >= 0);
++			nnode = path[h].ptr.nnode;
++			if (iip + 1 < UBIFS_LPT_FANOUT)
++				break;
++			iip = nnode->iip;
++		}
++		/* Go right */
++		iip += 1;
++		/* Descend to the pnode */
++		h += 1;
++		for (; h < c->lpt_hght; h++) {
++			nnode = scan_get_nnode(c, path + h, nnode, iip);
++			if (IS_ERR(nnode)) {
++				err = PTR_ERR(nnode);
++				goto out;
++			}
++			iip = 0;
++		}
++		pnode = scan_get_pnode(c, path + h, nnode, iip);
++		if (IS_ERR(pnode)) {
++			err = PTR_ERR(pnode);
++			goto out;
++		}
++		iip = 0;
++	}
++out:
++	kfree(path);
++	return err;
++}
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++
++/**
++ * dbg_chk_pnode - check a pnode.
++ * @c: the UBIFS file-system description object
++ * @pnode: pnode to check
++ * @col: pnode column
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int dbg_chk_pnode(struct ubifs_info *c, struct ubifs_pnode *pnode,
++			 int col)
++{
++	int i;
++
++	if (pnode->num != col) {
++		dbg_err("pnode num %d expected %d parent num %d iip %d",
++			pnode->num, col, pnode->parent->num, pnode->iip);
++		return -EINVAL;
++	}
++	for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++		struct ubifs_lprops *lp, *lprops = &pnode->lprops[i];
++		int lnum = (pnode->num << UBIFS_LPT_FANOUT_SHIFT) + i +
++			   c->main_first;
++		int found, cat = lprops->flags & LPROPS_CAT_MASK;
++		struct ubifs_lpt_heap *heap;
++		struct list_head *list = NULL;
++
++		if (lnum >= c->leb_cnt)
++			continue;
++		if (lprops->lnum != lnum) {
++			dbg_err("bad LEB number %d expected %d",
++				lprops->lnum, lnum);
++			return -EINVAL;
++		}
++		if (lprops->flags & LPROPS_TAKEN) {
++			if (cat != LPROPS_UNCAT) {
++				dbg_err("LEB %d taken but not uncat %d",
++					lprops->lnum, cat);
++				return -EINVAL;
++			}
++			continue;
++		}
++		if (lprops->flags & LPROPS_INDEX) {
++			switch (cat) {
++			case LPROPS_UNCAT:
++			case LPROPS_DIRTY_IDX:
++			case LPROPS_FRDI_IDX:
++				break;
++			default:
++				dbg_err("LEB %d index but cat %d",
++					lprops->lnum, cat);
++				return -EINVAL;
++			}
++		} else {
++			switch (cat) {
++			case LPROPS_UNCAT:
++			case LPROPS_DIRTY:
++			case LPROPS_FREE:
++			case LPROPS_EMPTY:
++			case LPROPS_FREEABLE:
++				break;
++			default:
++				dbg_err("LEB %d not index but cat %d",
++					lprops->lnum, cat);
++				return -EINVAL;
++			}
++		}
++		switch (cat) {
++		case LPROPS_UNCAT:
++			list = &c->uncat_list;
++			break;
++		case LPROPS_EMPTY:
++			list = &c->empty_list;
++			break;
++		case LPROPS_FREEABLE:
++			list = &c->freeable_list;
++			break;
++		case LPROPS_FRDI_IDX:
++			list = &c->frdi_idx_list;
++			break;
++		}
++		found = 0;
++		switch (cat) {
++		case LPROPS_DIRTY:
++		case LPROPS_DIRTY_IDX:
++		case LPROPS_FREE:
++			heap = &c->lpt_heap[cat - 1];
++			if (lprops->hpos < heap->cnt &&
++			    heap->arr[lprops->hpos] == lprops)
++				found = 1;
++			break;
++		case LPROPS_UNCAT:
++		case LPROPS_EMPTY:
++		case LPROPS_FREEABLE:
++		case LPROPS_FRDI_IDX:
++			list_for_each_entry(lp, list, list)
++				if (lprops == lp) {
++					found = 1;
++					break;
++				}
++			break;
++		}
++		if (!found) {
++			dbg_err("LEB %d cat %d not found in cat heap/list",
++				lprops->lnum, cat);
++			return -EINVAL;
++		}
++		switch (cat) {
++		case LPROPS_EMPTY:
++			if (lprops->free != c->leb_size) {
++				dbg_err("LEB %d cat %d free %d dirty %d",
++					lprops->lnum, cat, lprops->free,
++					lprops->dirty);
++				return -EINVAL;
++			}
++		case LPROPS_FREEABLE:
++		case LPROPS_FRDI_IDX:
++			if (lprops->free + lprops->dirty != c->leb_size) {
++				dbg_err("LEB %d cat %d free %d dirty %d",
++					lprops->lnum, cat, lprops->free,
++					lprops->dirty);
++				return -EINVAL;
++			}
++		}
++	}
++	return 0;
++}
++
++/**
++ * dbg_check_lpt_nodes - check nnodes and pnodes.
++ * @c: the UBIFS file-system description object
++ * @cnode: next cnode (nnode or pnode) to check
++ * @row: row of cnode (root is zero)
++ * @col: column of cnode (leftmost is zero)
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int dbg_check_lpt_nodes(struct ubifs_info *c, struct ubifs_cnode *cnode,
++			int row, int col)
++{
++	struct ubifs_nnode *nnode, *nn;
++	struct ubifs_cnode *cn;
++	int num, iip = 0, err;
++
++	if (!(ubifs_chk_flags & UBIFS_CHK_LPROPS))
++		return 0;
++
++	while (cnode) {
++		ubifs_assert(row >= 0);
++		nnode = cnode->parent;
++		if (cnode->level) {
++			/* cnode is a nnode */
++			num = calc_nnode_num(row, col);
++			if (cnode->num != num) {
++				dbg_err("nnode num %d expected %d "
++					"parent num %d iip %d", cnode->num, num,
++					(nnode ? nnode->num : 0), cnode->iip);
++				return -EINVAL;
++			}
++			nn = (struct ubifs_nnode *)cnode;
++			while (iip < UBIFS_LPT_FANOUT) {
++				cn = nn->nbranch[iip].cnode;
++				if (cn) {
++					/* Go down */
++					row += 1;
++					col <<= UBIFS_LPT_FANOUT_SHIFT;
++					col += iip;
++					iip = 0;
++					cnode = cn;
++					break;
++				}
++				/* Go right */
++				iip += 1;
++			}
++			if (iip < UBIFS_LPT_FANOUT)
++				continue;
++		} else {
++			struct ubifs_pnode *pnode;
++
++			/* cnode is a pnode */
++			pnode = (struct ubifs_pnode *)cnode;
++			err = dbg_chk_pnode(c, pnode, col);
++			if (err)
++				return err;
++		}
++		/* Go up and to the right */
++		row -= 1;
++		col >>= UBIFS_LPT_FANOUT_SHIFT;
++		iip = cnode->iip + 1;
++		cnode = (struct ubifs_cnode *)nnode;
++	}
++	return 0;
++}
++
++#endif /* CONFIG_UBIFS_FS_DEBUG */
+diff -Nurd linux-2.6.24.orig/fs/ubifs/lpt_commit.c linux-2.6.24/fs/ubifs/lpt_commit.c
+--- linux-2.6.24.orig/fs/ubifs/lpt_commit.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/lpt_commit.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,1969 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Adrian Hunter
++ *          Artem Bityutskiy (Битюцкий Артём)
++ */
++
++/*
++ * This file implements commit-related functionality of the LEB properties
++ * subsystem.
++ */
++
++#include <linux/crc16.h>
++#include "ubifs.h"
++
++/**
++ * first_dirty_cnode - find first dirty cnode.
++ * @c: UBIFS file-system description object
++ * @nnode: nnode at which to start
++ *
++ * This function returns the first dirty cnode or %NULL if there is not one.
++ */
++static struct ubifs_cnode *first_dirty_cnode(struct ubifs_nnode *nnode)
++{
++	ubifs_assert(nnode);
++	while (1) {
++		int i, cont = 0;
++
++		for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++			struct ubifs_cnode *cnode;
++
++			cnode = nnode->nbranch[i].cnode;
++			if (cnode &&
++			    test_bit(DIRTY_CNODE, &cnode->flags)) {
++				if (cnode->level == 0)
++					return cnode;
++				nnode = (struct ubifs_nnode *)cnode;
++				cont = 1;
++				break;
++			}
++		}
++		if (!cont)
++			return (struct ubifs_cnode *)nnode;
++	}
++}
++
++/**
++ * next_dirty_cnode - find next dirty cnode.
++ * @cnode: cnode from which to begin searching
++ *
++ * This function returns the next dirty cnode or %NULL if there is not one.
++ */
++static struct ubifs_cnode *next_dirty_cnode(struct ubifs_cnode *cnode)
++{
++	struct ubifs_nnode *nnode;
++	int i;
++
++	ubifs_assert(cnode);
++	nnode = cnode->parent;
++	if (!nnode)
++		return NULL;
++	for (i = cnode->iip + 1; i < UBIFS_LPT_FANOUT; i++) {
++		cnode = nnode->nbranch[i].cnode;
++		if (cnode && test_bit(DIRTY_CNODE, &cnode->flags)) {
++			if (cnode->level == 0)
++				return cnode; /* cnode is a pnode */
++			/* cnode is a nnode */
++			return first_dirty_cnode((struct ubifs_nnode *)cnode);
++		}
++	}
++	return (struct ubifs_cnode *)nnode;
++}
++
++/**
++ * get_cnodes_to_commit - create list of dirty cnodes to commit.
++ * @c: UBIFS file-system description object
++ *
++ * This function returns the number of cnodes to commit.
++ */
++static int get_cnodes_to_commit(struct ubifs_info *c)
++{
++	struct ubifs_cnode *cnode, *cnext;
++	int cnt = 0;
++
++	if (!c->nroot)
++		return 0;
++
++	if (!test_bit(DIRTY_CNODE, &c->nroot->flags))
++		return 0;
++
++	c->lpt_cnext = first_dirty_cnode(c->nroot);
++	cnode = c->lpt_cnext;
++	if (!cnode)
++		return 0;
++	cnt += 1;
++	while (1) {
++		ubifs_assert(!test_bit(COW_ZNODE, &cnode->flags));
++		__set_bit(COW_ZNODE, &cnode->flags);
++		cnext = next_dirty_cnode(cnode);
++		if (!cnext) {
++			cnode->cnext = c->lpt_cnext;
++			break;
++		}
++		cnode->cnext = cnext;
++		cnode = cnext;
++		cnt += 1;
++	}
++	dbg_cmt("committing %d cnodes", cnt);
++	dbg_lp("committing %d cnodes", cnt);
++	ubifs_assert(cnt == c->dirty_nn_cnt + c->dirty_pn_cnt);
++	return cnt;
++}
++
++/**
++ * upd_ltab - update LPT LEB properties.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number
++ * @free: amount of free space
++ * @dirty: amount of dirty space to add
++ */
++static void upd_ltab(struct ubifs_info *c, int lnum, int free, int dirty)
++{
++	dbg_lp("LEB %d free %d dirty %d to %d +%d",
++	       lnum, c->ltab[lnum - c->lpt_first].free,
++	       c->ltab[lnum - c->lpt_first].dirty, free, dirty);
++	ubifs_assert(lnum >= c->lpt_first && lnum <= c->lpt_last);
++	c->ltab[lnum - c->lpt_first].free = free;
++	c->ltab[lnum - c->lpt_first].dirty += dirty;
++}
++
++/**
++ * alloc_lpt_leb - allocate an LPT LEB that is empty.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number is passed and returned here
++ *
++ * This function finds the next empty LEB in the ltab starting from @lnum. If a
++ * an empty LEB is found it is returned in @lnum and the function returns %0.
++ * Otherwise the function returns -ENOSPC.  Note however, that LPT is designed
++ * never to run out of space.
++ */
++static int alloc_lpt_leb(struct ubifs_info *c, int *lnum)
++{
++	int i, n;
++
++	n = *lnum - c->lpt_first + 1;
++	for (i = n; i < c->lpt_lebs; i++) {
++		if (c->ltab[i].tgc || c->ltab[i].cmt)
++			continue;
++		if (c->ltab[i].free == c->leb_size) {
++			c->ltab[i].cmt = 1;
++			*lnum = i + c->lpt_first;
++			return 0;
++		}
++	}
++
++	for (i = 0; i < n; i++) {
++		if (c->ltab[i].tgc || c->ltab[i].cmt)
++			continue;
++		if (c->ltab[i].free == c->leb_size) {
++			c->ltab[i].cmt = 1;
++			*lnum = i + c->lpt_first;
++			return 0;
++		}
++	}
++	return -ENOSPC;
++}
++
++/**
++ * layout_cnodes - layout cnodes for commit.
++ * @c: UBIFS file-system description object
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int layout_cnodes(struct ubifs_info *c)
++{
++	int lnum, offs, len, alen, done_lsave, done_ltab, err;
++	struct ubifs_cnode *cnode;
++
++	err = dbg_chk_lpt_sz(c, 0, 0);
++	if (err)
++		return err;
++	cnode = c->lpt_cnext;
++	if (!cnode)
++		return 0;
++	lnum = c->nhead_lnum;
++	offs = c->nhead_offs;
++	/* Try to place lsave and ltab nicely */
++	done_lsave = !c->big_lpt;
++	done_ltab = 0;
++	if (!done_lsave && offs + c->lsave_sz <= c->leb_size) {
++		done_lsave = 1;
++		c->lsave_lnum = lnum;
++		c->lsave_offs = offs;
++		offs += c->lsave_sz;
++		dbg_chk_lpt_sz(c, 1, c->lsave_sz);
++	}
++
++	if (offs + c->ltab_sz <= c->leb_size) {
++		done_ltab = 1;
++		c->ltab_lnum = lnum;
++		c->ltab_offs = offs;
++		offs += c->ltab_sz;
++		dbg_chk_lpt_sz(c, 1, c->ltab_sz);
++	}
++
++	do {
++		if (cnode->level) {
++			len = c->nnode_sz;
++			c->dirty_nn_cnt -= 1;
++		} else {
++			len = c->pnode_sz;
++			c->dirty_pn_cnt -= 1;
++		}
++		while (offs + len > c->leb_size) {
++			alen = ALIGN(offs, c->min_io_size);
++			upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
++			dbg_chk_lpt_sz(c, 2, alen - offs);
++			err = alloc_lpt_leb(c, &lnum);
++			if (err)
++				goto no_space;
++			offs = 0;
++			ubifs_assert(lnum >= c->lpt_first &&
++				     lnum <= c->lpt_last);
++			/* Try to place lsave and ltab nicely */
++			if (!done_lsave) {
++				done_lsave = 1;
++				c->lsave_lnum = lnum;
++				c->lsave_offs = offs;
++				offs += c->lsave_sz;
++				dbg_chk_lpt_sz(c, 1, c->lsave_sz);
++				continue;
++			}
++			if (!done_ltab) {
++				done_ltab = 1;
++				c->ltab_lnum = lnum;
++				c->ltab_offs = offs;
++				offs += c->ltab_sz;
++				dbg_chk_lpt_sz(c, 1, c->ltab_sz);
++				continue;
++			}
++			break;
++		}
++		if (cnode->parent) {
++			cnode->parent->nbranch[cnode->iip].lnum = lnum;
++			cnode->parent->nbranch[cnode->iip].offs = offs;
++		} else {
++			c->lpt_lnum = lnum;
++			c->lpt_offs = offs;
++		}
++		offs += len;
++		dbg_chk_lpt_sz(c, 1, len);
++		cnode = cnode->cnext;
++	} while (cnode && cnode != c->lpt_cnext);
++
++	/* Make sure to place LPT's save table */
++	if (!done_lsave) {
++		if (offs + c->lsave_sz > c->leb_size) {
++			alen = ALIGN(offs, c->min_io_size);
++			upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
++			dbg_chk_lpt_sz(c, 2, alen - offs);
++			err = alloc_lpt_leb(c, &lnum);
++			if (err)
++				goto no_space;
++			offs = 0;
++			ubifs_assert(lnum >= c->lpt_first &&
++				     lnum <= c->lpt_last);
++		}
++		done_lsave = 1;
++		c->lsave_lnum = lnum;
++		c->lsave_offs = offs;
++		offs += c->lsave_sz;
++		dbg_chk_lpt_sz(c, 1, c->lsave_sz);
++	}
++
++	/* Make sure to place LPT's own lprops table */
++	if (!done_ltab) {
++		if (offs + c->ltab_sz > c->leb_size) {
++			alen = ALIGN(offs, c->min_io_size);
++			upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
++			dbg_chk_lpt_sz(c, 2, alen - offs);
++			err = alloc_lpt_leb(c, &lnum);
++			if (err)
++				goto no_space;
++			offs = 0;
++			ubifs_assert(lnum >= c->lpt_first &&
++				     lnum <= c->lpt_last);
++		}
++		done_ltab = 1;
++		c->ltab_lnum = lnum;
++		c->ltab_offs = offs;
++		offs += c->ltab_sz;
++		dbg_chk_lpt_sz(c, 1, c->ltab_sz);
++	}
++
++	alen = ALIGN(offs, c->min_io_size);
++	upd_ltab(c, lnum, c->leb_size - alen, alen - offs);
++	dbg_chk_lpt_sz(c, 4, alen - offs);
++	err = dbg_chk_lpt_sz(c, 3, alen);
++	if (err)
++		return err;
++	return 0;
++
++no_space:
++	ubifs_err("LPT out of space");
++	dbg_err("LPT out of space at LEB %d:%d needing %d, done_ltab %d, "
++		"done_lsave %d", lnum, offs, len, done_ltab, done_lsave);
++	dbg_dump_lpt_info(c);
++	dbg_dump_lpt_lebs(c);
++	dump_stack();
++	return err;
++}
++
++/**
++ * realloc_lpt_leb - allocate an LPT LEB that is empty.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number is passed and returned here
++ *
++ * This function duplicates exactly the results of the function alloc_lpt_leb.
++ * It is used during end commit to reallocate the same LEB numbers that were
++ * allocated by alloc_lpt_leb during start commit.
++ *
++ * This function finds the next LEB that was allocated by the alloc_lpt_leb
++ * function starting from @lnum. If a LEB is found it is returned in @lnum and
++ * the function returns %0. Otherwise the function returns -ENOSPC.
++ * Note however, that LPT is designed never to run out of space.
++ */
++static int realloc_lpt_leb(struct ubifs_info *c, int *lnum)
++{
++	int i, n;
++
++	n = *lnum - c->lpt_first + 1;
++	for (i = n; i < c->lpt_lebs; i++)
++		if (c->ltab[i].cmt) {
++			c->ltab[i].cmt = 0;
++			*lnum = i + c->lpt_first;
++			return 0;
++		}
++
++	for (i = 0; i < n; i++)
++		if (c->ltab[i].cmt) {
++			c->ltab[i].cmt = 0;
++			*lnum = i + c->lpt_first;
++			return 0;
++		}
++	return -ENOSPC;
++}
++
++/**
++ * write_cnodes - write cnodes for commit.
++ * @c: UBIFS file-system description object
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int write_cnodes(struct ubifs_info *c)
++{
++	int lnum, offs, len, from, err, wlen, alen, done_ltab, done_lsave;
++	struct ubifs_cnode *cnode;
++	void *buf = c->lpt_buf;
++
++	cnode = c->lpt_cnext;
++	if (!cnode)
++		return 0;
++	lnum = c->nhead_lnum;
++	offs = c->nhead_offs;
++	from = offs;
++	/* Ensure empty LEB is unmapped */
++	if (offs == 0) {
++		err = ubifs_leb_unmap(c, lnum);
++		if (err)
++			return err;
++	}
++	/* Try to place lsave and ltab nicely */
++	done_lsave = !c->big_lpt;
++	done_ltab = 0;
++	if (!done_lsave && offs + c->lsave_sz <= c->leb_size) {
++		done_lsave = 1;
++		ubifs_pack_lsave(c, buf + offs, c->lsave);
++		offs += c->lsave_sz;
++		dbg_chk_lpt_sz(c, 1, c->lsave_sz);
++	}
++
++	if (offs + c->ltab_sz <= c->leb_size) {
++		done_ltab = 1;
++		ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
++		offs += c->ltab_sz;
++		dbg_chk_lpt_sz(c, 1, c->ltab_sz);
++	}
++
++	/* Loop for each cnode */
++	do {
++		if (cnode->level)
++			len = c->nnode_sz;
++		else
++			len = c->pnode_sz;
++		while (offs + len > c->leb_size) {
++			wlen = offs - from;
++			if (wlen) {
++				alen = ALIGN(wlen, c->min_io_size);
++				memset(buf + offs, 0xff, alen - wlen);
++				err = ubifs_leb_write(c, lnum, buf + from, from,
++						       alen, UBI_SHORTTERM);
++				if (err)
++					return err;
++				dbg_chk_lpt_sz(c, 4, alen - wlen);
++			}
++			dbg_chk_lpt_sz(c, 2, 0);
++			err = realloc_lpt_leb(c, &lnum);
++			if (err)
++				goto no_space;
++			offs = 0;
++			from = 0;
++			ubifs_assert(lnum >= c->lpt_first &&
++				     lnum <= c->lpt_last);
++			err = ubifs_leb_unmap(c, lnum);
++			if (err)
++				return err;
++			/* Try to place lsave and ltab nicely */
++			if (!done_lsave) {
++				done_lsave = 1;
++				ubifs_pack_lsave(c, buf + offs, c->lsave);
++				offs += c->lsave_sz;
++				dbg_chk_lpt_sz(c, 1, c->lsave_sz);
++				continue;
++			}
++			if (!done_ltab) {
++				done_ltab = 1;
++				ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
++				offs += c->ltab_sz;
++				dbg_chk_lpt_sz(c, 1, c->ltab_sz);
++				continue;
++			}
++			break;
++		}
++		if (cnode->level)
++			ubifs_pack_nnode(c, buf + offs,
++					 (struct ubifs_nnode *)cnode);
++		else
++			ubifs_pack_pnode(c, buf + offs,
++					 (struct ubifs_pnode *)cnode);
++		/*
++		 * The reason for the barriers is the same as in case of TNC.
++		 * See comment in 'write_index()'. 'dirty_cow_nnode()' and
++		 * 'dirty_cow_pnode()' are the functions for which this is
++		 * important.
++		 */
++		clear_bit(DIRTY_CNODE, &cnode->flags);
++		smp_mb__before_clear_bit();
++		clear_bit(COW_ZNODE, &cnode->flags);
++		smp_mb__after_clear_bit();
++		offs += len;
++		dbg_chk_lpt_sz(c, 1, len);
++		cnode = cnode->cnext;
++	} while (cnode && cnode != c->lpt_cnext);
++
++	/* Make sure to place LPT's save table */
++	if (!done_lsave) {
++		if (offs + c->lsave_sz > c->leb_size) {
++			wlen = offs - from;
++			alen = ALIGN(wlen, c->min_io_size);
++			memset(buf + offs, 0xff, alen - wlen);
++			err = ubifs_leb_write(c, lnum, buf + from, from, alen,
++					      UBI_SHORTTERM);
++			if (err)
++				return err;
++			dbg_chk_lpt_sz(c, 2, alen - wlen);
++			err = realloc_lpt_leb(c, &lnum);
++			if (err)
++				goto no_space;
++			offs = 0;
++			ubifs_assert(lnum >= c->lpt_first &&
++				     lnum <= c->lpt_last);
++			err = ubifs_leb_unmap(c, lnum);
++			if (err)
++				return err;
++		}
++		done_lsave = 1;
++		ubifs_pack_lsave(c, buf + offs, c->lsave);
++		offs += c->lsave_sz;
++		dbg_chk_lpt_sz(c, 1, c->lsave_sz);
++	}
++
++	/* Make sure to place LPT's own lprops table */
++	if (!done_ltab) {
++		if (offs + c->ltab_sz > c->leb_size) {
++			wlen = offs - from;
++			alen = ALIGN(wlen, c->min_io_size);
++			memset(buf + offs, 0xff, alen - wlen);
++			err = ubifs_leb_write(c, lnum, buf + from, from, alen,
++					      UBI_SHORTTERM);
++			if (err)
++				return err;
++			dbg_chk_lpt_sz(c, 2, alen - wlen);
++			err = realloc_lpt_leb(c, &lnum);
++			if (err)
++				goto no_space;
++			offs = 0;
++			ubifs_assert(lnum >= c->lpt_first &&
++				     lnum <= c->lpt_last);
++			err = ubifs_leb_unmap(c, lnum);
++			if (err)
++				return err;
++		}
++		done_ltab = 1;
++		ubifs_pack_ltab(c, buf + offs, c->ltab_cmt);
++		offs += c->ltab_sz;
++		dbg_chk_lpt_sz(c, 1, c->ltab_sz);
++	}
++
++	/* Write remaining data in buffer */
++	wlen = offs - from;
++	alen = ALIGN(wlen, c->min_io_size);
++	memset(buf + offs, 0xff, alen - wlen);
++	err = ubifs_leb_write(c, lnum, buf + from, from, alen, UBI_SHORTTERM);
++	if (err)
++		return err;
++
++	dbg_chk_lpt_sz(c, 4, alen - wlen);
++	err = dbg_chk_lpt_sz(c, 3, ALIGN(offs, c->min_io_size));
++	if (err)
++		return err;
++
++	c->nhead_lnum = lnum;
++	c->nhead_offs = ALIGN(offs, c->min_io_size);
++
++	dbg_lp("LPT root is at %d:%d", c->lpt_lnum, c->lpt_offs);
++	dbg_lp("LPT head is at %d:%d", c->nhead_lnum, c->nhead_offs);
++	dbg_lp("LPT ltab is at %d:%d", c->ltab_lnum, c->ltab_offs);
++	if (c->big_lpt)
++		dbg_lp("LPT lsave is at %d:%d", c->lsave_lnum, c->lsave_offs);
++
++	return 0;
++
++no_space:
++	ubifs_err("LPT out of space mismatch");
++	dbg_err("LPT out of space mismatch at LEB %d:%d needing %d, done_ltab "
++		"%d, done_lsave %d", lnum, offs, len, done_ltab, done_lsave);
++	dbg_dump_lpt_info(c);
++	dbg_dump_lpt_lebs(c);
++	dump_stack();
++	return err;
++}
++
++/**
++ * next_pnode_to_dirty - find next pnode to dirty.
++ * @c: UBIFS file-system description object
++ * @pnode: pnode
++ *
++ * This function returns the next pnode to dirty or %NULL if there are no more
++ * pnodes.  Note that pnodes that have never been written (lnum == 0) are
++ * skipped.
++ */
++static struct ubifs_pnode *next_pnode_to_dirty(struct ubifs_info *c,
++					       struct ubifs_pnode *pnode)
++{
++	struct ubifs_nnode *nnode;
++	int iip;
++
++	/* Try to go right */
++	nnode = pnode->parent;
++	for (iip = pnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
++		if (nnode->nbranch[iip].lnum)
++			return ubifs_get_pnode(c, nnode, iip);
++	}
++
++	/* Go up while can't go right */
++	do {
++		iip = nnode->iip + 1;
++		nnode = nnode->parent;
++		if (!nnode)
++			return NULL;
++		for (; iip < UBIFS_LPT_FANOUT; iip++) {
++			if (nnode->nbranch[iip].lnum)
++				break;
++		}
++       } while (iip >= UBIFS_LPT_FANOUT);
++
++	/* Go right */
++	nnode = ubifs_get_nnode(c, nnode, iip);
++	if (IS_ERR(nnode))
++		return (void *)nnode;
++
++	/* Go down to level 1 */
++	while (nnode->level > 1) {
++		for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++) {
++			if (nnode->nbranch[iip].lnum)
++				break;
++		}
++		if (iip >= UBIFS_LPT_FANOUT) {
++			/*
++			 * Should not happen, but we need to keep going
++			 * if it does.
++			 */
++			iip = 0;
++		}
++		nnode = ubifs_get_nnode(c, nnode, iip);
++		if (IS_ERR(nnode))
++			return (void *)nnode;
++	}
++
++	for (iip = 0; iip < UBIFS_LPT_FANOUT; iip++)
++		if (nnode->nbranch[iip].lnum)
++			break;
++	if (iip >= UBIFS_LPT_FANOUT)
++		/* Should not happen, but we need to keep going if it does */
++		iip = 0;
++	return ubifs_get_pnode(c, nnode, iip);
++}
++
++/**
++ * pnode_lookup - lookup a pnode in the LPT.
++ * @c: UBIFS file-system description object
++ * @i: pnode number (0 to main_lebs - 1)
++ *
++ * This function returns a pointer to the pnode on success or a negative
++ * error code on failure.
++ */
++static struct ubifs_pnode *pnode_lookup(struct ubifs_info *c, int i)
++{
++	int err, h, iip, shft;
++	struct ubifs_nnode *nnode;
++
++	if (!c->nroot) {
++		err = ubifs_read_nnode(c, NULL, 0);
++		if (err)
++			return ERR_PTR(err);
++	}
++	i <<= UBIFS_LPT_FANOUT_SHIFT;
++	nnode = c->nroot;
++	shft = c->lpt_hght * UBIFS_LPT_FANOUT_SHIFT;
++	for (h = 1; h < c->lpt_hght; h++) {
++		iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
++		shft -= UBIFS_LPT_FANOUT_SHIFT;
++		nnode = ubifs_get_nnode(c, nnode, iip);
++		if (IS_ERR(nnode))
++			return ERR_PTR(PTR_ERR(nnode));
++	}
++	iip = ((i >> shft) & (UBIFS_LPT_FANOUT - 1));
++	return ubifs_get_pnode(c, nnode, iip);
++}
++
++/**
++ * add_pnode_dirt - add dirty space to LPT LEB properties.
++ * @c: UBIFS file-system description object
++ * @pnode: pnode for which to add dirt
++ */
++static void add_pnode_dirt(struct ubifs_info *c, struct ubifs_pnode *pnode)
++{
++	ubifs_add_lpt_dirt(c, pnode->parent->nbranch[pnode->iip].lnum,
++			   c->pnode_sz);
++}
++
++/**
++ * do_make_pnode_dirty - mark a pnode dirty.
++ * @c: UBIFS file-system description object
++ * @pnode: pnode to mark dirty
++ */
++static void do_make_pnode_dirty(struct ubifs_info *c, struct ubifs_pnode *pnode)
++{
++	/* Assumes cnext list is empty i.e. not called during commit */
++	if (!test_and_set_bit(DIRTY_CNODE, &pnode->flags)) {
++		struct ubifs_nnode *nnode;
++
++		c->dirty_pn_cnt += 1;
++		add_pnode_dirt(c, pnode);
++		/* Mark parent and ancestors dirty too */
++		nnode = pnode->parent;
++		while (nnode) {
++			if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
++				c->dirty_nn_cnt += 1;
++				ubifs_add_nnode_dirt(c, nnode);
++				nnode = nnode->parent;
++			} else
++				break;
++		}
++	}
++}
++
++/**
++ * make_tree_dirty - mark the entire LEB properties tree dirty.
++ * @c: UBIFS file-system description object
++ *
++ * This function is used by the "small" LPT model to cause the entire LEB
++ * properties tree to be written.  The "small" LPT model does not use LPT
++ * garbage collection because it is more efficient to write the entire tree
++ * (because it is small).
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int make_tree_dirty(struct ubifs_info *c)
++{
++	struct ubifs_pnode *pnode;
++
++	pnode = pnode_lookup(c, 0);
++	while (pnode) {
++		do_make_pnode_dirty(c, pnode);
++		pnode = next_pnode_to_dirty(c, pnode);
++		if (IS_ERR(pnode))
++			return PTR_ERR(pnode);
++	}
++	return 0;
++}
++
++/**
++ * need_write_all - determine if the LPT area is running out of free space.
++ * @c: UBIFS file-system description object
++ *
++ * This function returns %1 if the LPT area is running out of free space and %0
++ * if it is not.
++ */
++static int need_write_all(struct ubifs_info *c)
++{
++	long long free = 0;
++	int i;
++
++	for (i = 0; i < c->lpt_lebs; i++) {
++		if (i + c->lpt_first == c->nhead_lnum)
++			free += c->leb_size - c->nhead_offs;
++		else if (c->ltab[i].free == c->leb_size)
++			free += c->leb_size;
++		else if (c->ltab[i].free + c->ltab[i].dirty == c->leb_size)
++			free += c->leb_size;
++	}
++	/* Less than twice the size left */
++	if (free <= c->lpt_sz * 2)
++		return 1;
++	return 0;
++}
++
++/**
++ * lpt_tgc_start - start trivial garbage collection of LPT LEBs.
++ * @c: UBIFS file-system description object
++ *
++ * LPT trivial garbage collection is where a LPT LEB contains only dirty and
++ * free space and so may be reused as soon as the next commit is completed.
++ * This function is called during start commit to mark LPT LEBs for trivial GC.
++ */
++static void lpt_tgc_start(struct ubifs_info *c)
++{
++	int i;
++
++	for (i = 0; i < c->lpt_lebs; i++) {
++		if (i + c->lpt_first == c->nhead_lnum)
++			continue;
++		if (c->ltab[i].dirty > 0 &&
++		    c->ltab[i].free + c->ltab[i].dirty == c->leb_size) {
++			c->ltab[i].tgc = 1;
++			c->ltab[i].free = c->leb_size;
++			c->ltab[i].dirty = 0;
++			dbg_lp("LEB %d", i + c->lpt_first);
++		}
++	}
++}
++
++/**
++ * lpt_tgc_end - end trivial garbage collection of LPT LEBs.
++ * @c: UBIFS file-system description object
++ *
++ * LPT trivial garbage collection is where a LPT LEB contains only dirty and
++ * free space and so may be reused as soon as the next commit is completed.
++ * This function is called after the commit is completed (master node has been
++ * written) and un-maps LPT LEBs that were marked for trivial GC.
++ */
++static int lpt_tgc_end(struct ubifs_info *c)
++{
++	int i, err;
++
++	for (i = 0; i < c->lpt_lebs; i++)
++		if (c->ltab[i].tgc) {
++			err = ubifs_leb_unmap(c, i + c->lpt_first);
++			if (err)
++				return err;
++			c->ltab[i].tgc = 0;
++			dbg_lp("LEB %d", i + c->lpt_first);
++		}
++	return 0;
++}
++
++/**
++ * populate_lsave - fill the lsave array with important LEB numbers.
++ * @c: the UBIFS file-system description object
++ *
++ * This function is only called for the "big" model. It records a small number
++ * of LEB numbers of important LEBs.  Important LEBs are ones that are (from
++ * most important to least important): empty, freeable, freeable index, dirty
++ * index, dirty or free. Upon mount, we read this list of LEB numbers and bring
++ * their pnodes into memory.  That will stop us from having to scan the LPT
++ * straight away. For the "small" model we assume that scanning the LPT is no
++ * big deal.
++ */
++static void populate_lsave(struct ubifs_info *c)
++{
++	struct ubifs_lprops *lprops;
++	struct ubifs_lpt_heap *heap;
++	int i, cnt = 0;
++
++	ubifs_assert(c->big_lpt);
++	if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) {
++		c->lpt_drty_flgs |= LSAVE_DIRTY;
++		ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz);
++	}
++	list_for_each_entry(lprops, &c->empty_list, list) {
++		c->lsave[cnt++] = lprops->lnum;
++		if (cnt >= c->lsave_cnt)
++			return;
++	}
++	list_for_each_entry(lprops, &c->freeable_list, list) {
++		c->lsave[cnt++] = lprops->lnum;
++		if (cnt >= c->lsave_cnt)
++			return;
++	}
++	list_for_each_entry(lprops, &c->frdi_idx_list, list) {
++		c->lsave[cnt++] = lprops->lnum;
++		if (cnt >= c->lsave_cnt)
++			return;
++	}
++	heap = &c->lpt_heap[LPROPS_DIRTY_IDX - 1];
++	for (i = 0; i < heap->cnt; i++) {
++		c->lsave[cnt++] = heap->arr[i]->lnum;
++		if (cnt >= c->lsave_cnt)
++			return;
++	}
++	heap = &c->lpt_heap[LPROPS_DIRTY - 1];
++	for (i = 0; i < heap->cnt; i++) {
++		c->lsave[cnt++] = heap->arr[i]->lnum;
++		if (cnt >= c->lsave_cnt)
++			return;
++	}
++	heap = &c->lpt_heap[LPROPS_FREE - 1];
++	for (i = 0; i < heap->cnt; i++) {
++		c->lsave[cnt++] = heap->arr[i]->lnum;
++		if (cnt >= c->lsave_cnt)
++			return;
++	}
++	/* Fill it up completely */
++	while (cnt < c->lsave_cnt)
++		c->lsave[cnt++] = c->main_first;
++}
++
++/**
++ * nnode_lookup - lookup a nnode in the LPT.
++ * @c: UBIFS file-system description object
++ * @i: nnode number
++ *
++ * This function returns a pointer to the nnode on success or a negative
++ * error code on failure.
++ */
++static struct ubifs_nnode *nnode_lookup(struct ubifs_info *c, int i)
++{
++	int err, iip;
++	struct ubifs_nnode *nnode;
++
++	if (!c->nroot) {
++		err = ubifs_read_nnode(c, NULL, 0);
++		if (err)
++			return ERR_PTR(err);
++	}
++	nnode = c->nroot;
++	while (1) {
++		iip = i & (UBIFS_LPT_FANOUT - 1);
++		i >>= UBIFS_LPT_FANOUT_SHIFT;
++		if (!i)
++			break;
++		nnode = ubifs_get_nnode(c, nnode, iip);
++		if (IS_ERR(nnode))
++			return nnode;
++	}
++	return nnode;
++}
++
++/**
++ * make_nnode_dirty - find a nnode and, if found, make it dirty.
++ * @c: UBIFS file-system description object
++ * @node_num: nnode number of nnode to make dirty
++ * @lnum: LEB number where nnode was written
++ * @offs: offset where nnode was written
++ *
++ * This function is used by LPT garbage collection.  LPT garbage collection is
++ * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
++ * simply involves marking all the nodes in the LEB being garbage-collected as
++ * dirty.  The dirty nodes are written next commit, after which the LEB is free
++ * to be reused.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int make_nnode_dirty(struct ubifs_info *c, int node_num, int lnum,
++			    int offs)
++{
++	struct ubifs_nnode *nnode;
++
++	nnode = nnode_lookup(c, node_num);
++	if (IS_ERR(nnode))
++		return PTR_ERR(nnode);
++	if (nnode->parent) {
++		struct ubifs_nbranch *branch;
++
++		branch = &nnode->parent->nbranch[nnode->iip];
++		if (branch->lnum != lnum || branch->offs != offs)
++			return 0; /* nnode is obsolete */
++	} else if (c->lpt_lnum != lnum || c->lpt_offs != offs)
++			return 0; /* nnode is obsolete */
++	/* Assumes cnext list is empty i.e. not called during commit */
++	if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
++		c->dirty_nn_cnt += 1;
++		ubifs_add_nnode_dirt(c, nnode);
++		/* Mark parent and ancestors dirty too */
++		nnode = nnode->parent;
++		while (nnode) {
++			if (!test_and_set_bit(DIRTY_CNODE, &nnode->flags)) {
++				c->dirty_nn_cnt += 1;
++				ubifs_add_nnode_dirt(c, nnode);
++				nnode = nnode->parent;
++			} else
++				break;
++		}
++	}
++	return 0;
++}
++
++/**
++ * make_pnode_dirty - find a pnode and, if found, make it dirty.
++ * @c: UBIFS file-system description object
++ * @node_num: pnode number of pnode to make dirty
++ * @lnum: LEB number where pnode was written
++ * @offs: offset where pnode was written
++ *
++ * This function is used by LPT garbage collection.  LPT garbage collection is
++ * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
++ * simply involves marking all the nodes in the LEB being garbage-collected as
++ * dirty.  The dirty nodes are written next commit, after which the LEB is free
++ * to be reused.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int make_pnode_dirty(struct ubifs_info *c, int node_num, int lnum,
++			    int offs)
++{
++	struct ubifs_pnode *pnode;
++	struct ubifs_nbranch *branch;
++
++	pnode = pnode_lookup(c, node_num);
++	if (IS_ERR(pnode))
++		return PTR_ERR(pnode);
++	branch = &pnode->parent->nbranch[pnode->iip];
++	if (branch->lnum != lnum || branch->offs != offs)
++		return 0;
++	do_make_pnode_dirty(c, pnode);
++	return 0;
++}
++
++/**
++ * make_ltab_dirty - make ltab node dirty.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number where ltab was written
++ * @offs: offset where ltab was written
++ *
++ * This function is used by LPT garbage collection.  LPT garbage collection is
++ * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
++ * simply involves marking all the nodes in the LEB being garbage-collected as
++ * dirty.  The dirty nodes are written next commit, after which the LEB is free
++ * to be reused.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int make_ltab_dirty(struct ubifs_info *c, int lnum, int offs)
++{
++	if (lnum != c->ltab_lnum || offs != c->ltab_offs)
++		return 0; /* This ltab node is obsolete */
++	if (!(c->lpt_drty_flgs & LTAB_DIRTY)) {
++		c->lpt_drty_flgs |= LTAB_DIRTY;
++		ubifs_add_lpt_dirt(c, c->ltab_lnum, c->ltab_sz);
++	}
++	return 0;
++}
++
++/**
++ * make_lsave_dirty - make lsave node dirty.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number where lsave was written
++ * @offs: offset where lsave was written
++ *
++ * This function is used by LPT garbage collection.  LPT garbage collection is
++ * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
++ * simply involves marking all the nodes in the LEB being garbage-collected as
++ * dirty.  The dirty nodes are written next commit, after which the LEB is free
++ * to be reused.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int make_lsave_dirty(struct ubifs_info *c, int lnum, int offs)
++{
++	if (lnum != c->lsave_lnum || offs != c->lsave_offs)
++		return 0; /* This lsave node is obsolete */
++	if (!(c->lpt_drty_flgs & LSAVE_DIRTY)) {
++		c->lpt_drty_flgs |= LSAVE_DIRTY;
++		ubifs_add_lpt_dirt(c, c->lsave_lnum, c->lsave_sz);
++	}
++	return 0;
++}
++
++/**
++ * make_node_dirty - make node dirty.
++ * @c: UBIFS file-system description object
++ * @node_type: LPT node type
++ * @node_num: node number
++ * @lnum: LEB number where node was written
++ * @offs: offset where node was written
++ *
++ * This function is used by LPT garbage collection.  LPT garbage collection is
++ * used only for the "big" LPT model (c->big_lpt == 1).  Garbage collection
++ * simply involves marking all the nodes in the LEB being garbage-collected as
++ * dirty.  The dirty nodes are written next commit, after which the LEB is free
++ * to be reused.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int make_node_dirty(struct ubifs_info *c, int node_type, int node_num,
++			   int lnum, int offs)
++{
++	switch (node_type) {
++	case UBIFS_LPT_NNODE:
++		return make_nnode_dirty(c, node_num, lnum, offs);
++	case UBIFS_LPT_PNODE:
++		return make_pnode_dirty(c, node_num, lnum, offs);
++	case UBIFS_LPT_LTAB:
++		return make_ltab_dirty(c, lnum, offs);
++	case UBIFS_LPT_LSAVE:
++		return make_lsave_dirty(c, lnum, offs);
++	}
++	return -EINVAL;
++}
++
++/**
++ * get_lpt_node_len - return the length of a node based on its type.
++ * @c: UBIFS file-system description object
++ * @node_type: LPT node type
++ */
++static int get_lpt_node_len(const struct ubifs_info *c, int node_type)
++{
++	switch (node_type) {
++	case UBIFS_LPT_NNODE:
++		return c->nnode_sz;
++	case UBIFS_LPT_PNODE:
++		return c->pnode_sz;
++	case UBIFS_LPT_LTAB:
++		return c->ltab_sz;
++	case UBIFS_LPT_LSAVE:
++		return c->lsave_sz;
++	}
++	return 0;
++}
++
++/**
++ * get_pad_len - return the length of padding in a buffer.
++ * @c: UBIFS file-system description object
++ * @buf: buffer
++ * @len: length of buffer
++ */
++static int get_pad_len(const struct ubifs_info *c, uint8_t *buf, int len)
++{
++	int offs, pad_len;
++
++	if (c->min_io_size == 1)
++		return 0;
++	offs = c->leb_size - len;
++	pad_len = ALIGN(offs, c->min_io_size) - offs;
++	return pad_len;
++}
++
++/**
++ * get_lpt_node_type - return type (and node number) of a node in a buffer.
++ * @c: UBIFS file-system description object
++ * @buf: buffer
++ * @node_num: node number is returned here
++ */
++static int get_lpt_node_type(const struct ubifs_info *c, uint8_t *buf,
++			     int *node_num)
++{
++	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
++	int pos = 0, node_type;
++
++	node_type = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_TYPE_BITS);
++	*node_num = ubifs_unpack_bits(&addr, &pos, c->pcnt_bits);
++	return node_type;
++}
++
++/**
++ * is_a_node - determine if a buffer contains a node.
++ * @c: UBIFS file-system description object
++ * @buf: buffer
++ * @len: length of buffer
++ *
++ * This function returns %1 if the buffer contains a node or %0 if it does not.
++ */
++static int is_a_node(const struct ubifs_info *c, uint8_t *buf, int len)
++{
++	uint8_t *addr = buf + UBIFS_LPT_CRC_BYTES;
++	int pos = 0, node_type, node_len;
++	uint16_t crc, calc_crc;
++
++	if (len < UBIFS_LPT_CRC_BYTES + (UBIFS_LPT_TYPE_BITS + 7) / 8)
++		return 0;
++	node_type = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_TYPE_BITS);
++	if (node_type == UBIFS_LPT_NOT_A_NODE)
++		return 0;
++	node_len = get_lpt_node_len(c, node_type);
++	if (!node_len || node_len > len)
++		return 0;
++	pos = 0;
++	addr = buf;
++	crc = ubifs_unpack_bits(&addr, &pos, UBIFS_LPT_CRC_BITS);
++	calc_crc = crc16(-1, buf + UBIFS_LPT_CRC_BYTES,
++			 node_len - UBIFS_LPT_CRC_BYTES);
++	if (crc != calc_crc)
++		return 0;
++	return 1;
++}
++
++/**
++ * lpt_gc_lnum - garbage collect a LPT LEB.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number to garbage collect
++ *
++ * LPT garbage collection is used only for the "big" LPT model
++ * (c->big_lpt == 1).  Garbage collection simply involves marking all the nodes
++ * in the LEB being garbage-collected as dirty.  The dirty nodes are written
++ * next commit, after which the LEB is free to be reused.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int lpt_gc_lnum(struct ubifs_info *c, int lnum)
++{
++	int err, len = c->leb_size, node_type, node_num, node_len, offs;
++	void *buf = c->lpt_buf;
++
++	dbg_lp("LEB %d", lnum);
++	err = ubi_read(c->ubi, lnum, buf, 0, c->leb_size);
++	if (err) {
++		ubifs_err("cannot read LEB %d, error %d", lnum, err);
++		return err;
++	}
++	while (1) {
++		if (!is_a_node(c, buf, len)) {
++			int pad_len;
++
++			pad_len = get_pad_len(c, buf, len);
++			if (pad_len) {
++				buf += pad_len;
++				len -= pad_len;
++				continue;
++			}
++			return 0;
++		}
++		node_type = get_lpt_node_type(c, buf, &node_num);
++		node_len = get_lpt_node_len(c, node_type);
++		offs = c->leb_size - len;
++		ubifs_assert(node_len != 0);
++		mutex_lock(&c->lp_mutex);
++		err = make_node_dirty(c, node_type, node_num, lnum, offs);
++		mutex_unlock(&c->lp_mutex);
++		if (err)
++			return err;
++		buf += node_len;
++		len -= node_len;
++	}
++	return 0;
++}
++
++/**
++ * lpt_gc - LPT garbage collection.
++ * @c: UBIFS file-system description object
++ *
++ * Select a LPT LEB for LPT garbage collection and call 'lpt_gc_lnum()'.
++ * Returns %0 on success and a negative error code on failure.
++ */
++static int lpt_gc(struct ubifs_info *c)
++{
++	int i, lnum = -1, dirty = 0;
++
++	mutex_lock(&c->lp_mutex);
++	for (i = 0; i < c->lpt_lebs; i++) {
++		ubifs_assert(!c->ltab[i].tgc);
++		if (i + c->lpt_first == c->nhead_lnum ||
++		    c->ltab[i].free + c->ltab[i].dirty == c->leb_size)
++			continue;
++		if (c->ltab[i].dirty > dirty) {
++			dirty = c->ltab[i].dirty;
++			lnum = i + c->lpt_first;
++		}
++	}
++	mutex_unlock(&c->lp_mutex);
++	if (lnum == -1)
++		return -ENOSPC;
++	return lpt_gc_lnum(c, lnum);
++}
++
++/**
++ * ubifs_lpt_start_commit - UBIFS commit starts.
++ * @c: the UBIFS file-system description object
++ *
++ * This function has to be called when UBIFS starts the commit operation.
++ * This function "freezes" all currently dirty LEB properties and does not
++ * change them anymore. Further changes are saved and tracked separately
++ * because they are not part of this commit. This function returns zero in case
++ * of success and a negative error code in case of failure.
++ */
++int ubifs_lpt_start_commit(struct ubifs_info *c)
++{
++	int err, cnt;
++
++	dbg_lp("");
++
++	mutex_lock(&c->lp_mutex);
++	err = dbg_chk_lpt_free_spc(c);
++	if (err)
++		goto out;
++	err = dbg_check_ltab(c);
++	if (err)
++		goto out;
++
++	if (c->check_lpt_free) {
++		/*
++		 * We ensure there is enough free space in
++		 * ubifs_lpt_post_commit() by marking nodes dirty. That
++		 * information is lost when we unmount, so we also need
++		 * to check free space once after mounting also.
++		 */
++		c->check_lpt_free = 0;
++		while (need_write_all(c)) {
++			mutex_unlock(&c->lp_mutex);
++			err = lpt_gc(c);
++			if (err)
++				return err;
++			mutex_lock(&c->lp_mutex);
++		}
++	}
++
++	lpt_tgc_start(c);
++
++	if (!c->dirty_pn_cnt) {
++		dbg_cmt("no cnodes to commit");
++		err = 0;
++		goto out;
++	}
++
++	if (!c->big_lpt && need_write_all(c)) {
++		/* If needed, write everything */
++		err = make_tree_dirty(c);
++		if (err)
++			goto out;
++		lpt_tgc_start(c);
++	}
++
++	if (c->big_lpt)
++		populate_lsave(c);
++
++	cnt = get_cnodes_to_commit(c);
++	ubifs_assert(cnt != 0);
++
++	err = layout_cnodes(c);
++	if (err)
++		goto out;
++
++	/* Copy the LPT's own lprops for end commit to write */
++	memcpy(c->ltab_cmt, c->ltab,
++	       sizeof(struct ubifs_lpt_lprops) * c->lpt_lebs);
++	c->lpt_drty_flgs &= ~(LTAB_DIRTY | LSAVE_DIRTY);
++
++out:
++	mutex_unlock(&c->lp_mutex);
++	return err;
++}
++
++/**
++ * free_obsolete_cnodes - free obsolete cnodes for commit end.
++ * @c: UBIFS file-system description object
++ */
++static void free_obsolete_cnodes(struct ubifs_info *c)
++{
++	struct ubifs_cnode *cnode, *cnext;
++
++	cnext = c->lpt_cnext;
++	if (!cnext)
++		return;
++	do {
++		cnode = cnext;
++		cnext = cnode->cnext;
++		if (test_bit(OBSOLETE_CNODE, &cnode->flags))
++			kfree(cnode);
++		else
++			cnode->cnext = NULL;
++	} while (cnext != c->lpt_cnext);
++	c->lpt_cnext = NULL;
++}
++
++/**
++ * ubifs_lpt_end_commit - finish the commit operation.
++ * @c: the UBIFS file-system description object
++ *
++ * This function has to be called when the commit operation finishes. It
++ * flushes the changes which were "frozen" by 'ubifs_lprops_start_commit()' to
++ * the media. Returns zero in case of success and a negative error code in case
++ * of failure.
++ */
++int ubifs_lpt_end_commit(struct ubifs_info *c)
++{
++	int err;
++
++	dbg_lp("");
++
++	if (!c->lpt_cnext)
++		return 0;
++
++	err = write_cnodes(c);
++	if (err)
++		return err;
++
++	mutex_lock(&c->lp_mutex);
++	free_obsolete_cnodes(c);
++	mutex_unlock(&c->lp_mutex);
++
++	return 0;
++}
++
++/**
++ * ubifs_lpt_post_commit - post commit LPT trivial GC and LPT GC.
++ * @c: UBIFS file-system description object
++ *
++ * LPT trivial GC is completed after a commit. Also LPT GC is done after a
++ * commit for the "big" LPT model.
++ */
++int ubifs_lpt_post_commit(struct ubifs_info *c)
++{
++	int err;
++
++	mutex_lock(&c->lp_mutex);
++	err = lpt_tgc_end(c);
++	if (err)
++		goto out;
++	if (c->big_lpt)
++		while (need_write_all(c)) {
++			mutex_unlock(&c->lp_mutex);
++			err = lpt_gc(c);
++			if (err)
++				return err;
++			mutex_lock(&c->lp_mutex);
++		}
++out:
++	mutex_unlock(&c->lp_mutex);
++	return err;
++}
++
++/**
++ * first_nnode - find the first nnode in memory.
++ * @c: UBIFS file-system description object
++ * @hght: height of tree where nnode found is returned here
++ *
++ * This function returns a pointer to the nnode found or %NULL if no nnode is
++ * found. This function is a helper to 'ubifs_lpt_free()'.
++ */
++static struct ubifs_nnode *first_nnode(struct ubifs_info *c, int *hght)
++{
++	struct ubifs_nnode *nnode;
++	int h, i, found;
++
++	nnode = c->nroot;
++	*hght = 0;
++	if (!nnode)
++		return NULL;
++	for (h = 1; h < c->lpt_hght; h++) {
++		found = 0;
++		for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++			if (nnode->nbranch[i].nnode) {
++				found = 1;
++				nnode = nnode->nbranch[i].nnode;
++				*hght = h;
++				break;
++			}
++		}
++		if (!found)
++			break;
++	}
++	return nnode;
++}
++
++/**
++ * next_nnode - find the next nnode in memory.
++ * @c: UBIFS file-system description object
++ * @nnode: nnode from which to start.
++ * @hght: height of tree where nnode is, is passed and returned here
++ *
++ * This function returns a pointer to the nnode found or %NULL if no nnode is
++ * found. This function is a helper to 'ubifs_lpt_free()'.
++ */
++static struct ubifs_nnode *next_nnode(struct ubifs_info *c,
++				      struct ubifs_nnode *nnode, int *hght)
++{
++	struct ubifs_nnode *parent;
++	int iip, h, i, found;
++
++	parent = nnode->parent;
++	if (!parent)
++		return NULL;
++	if (nnode->iip == UBIFS_LPT_FANOUT - 1) {
++		*hght -= 1;
++		return parent;
++	}
++	for (iip = nnode->iip + 1; iip < UBIFS_LPT_FANOUT; iip++) {
++		nnode = parent->nbranch[iip].nnode;
++		if (nnode)
++			break;
++	}
++	if (!nnode) {
++		*hght -= 1;
++		return parent;
++	}
++	for (h = *hght + 1; h < c->lpt_hght; h++) {
++		found = 0;
++		for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++			if (nnode->nbranch[i].nnode) {
++				found = 1;
++				nnode = nnode->nbranch[i].nnode;
++				*hght = h;
++				break;
++			}
++		}
++		if (!found)
++			break;
++	}
++	return nnode;
++}
++
++/**
++ * ubifs_lpt_free - free resources owned by the LPT.
++ * @c: UBIFS file-system description object
++ * @wr_only: free only resources used for writing
++ */
++void ubifs_lpt_free(struct ubifs_info *c, int wr_only)
++{
++	struct ubifs_nnode *nnode;
++	int i, hght;
++
++	/* Free write-only things first */
++
++	free_obsolete_cnodes(c); /* Leftover from a failed commit */
++
++	vfree(c->ltab_cmt);
++	c->ltab_cmt = NULL;
++	vfree(c->lpt_buf);
++	c->lpt_buf = NULL;
++	kfree(c->lsave);
++	c->lsave = NULL;
++
++	if (wr_only)
++		return;
++
++	/* Now free the rest */
++
++	nnode = first_nnode(c, &hght);
++	while (nnode) {
++		for (i = 0; i < UBIFS_LPT_FANOUT; i++)
++			kfree(nnode->nbranch[i].nnode);
++		nnode = next_nnode(c, nnode, &hght);
++	}
++	for (i = 0; i < LPROPS_HEAP_CNT; i++)
++		kfree(c->lpt_heap[i].arr);
++	kfree(c->dirty_idx.arr);
++	kfree(c->nroot);
++	vfree(c->ltab);
++	kfree(c->lpt_nod_buf);
++}
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++
++/**
++ * dbg_is_all_ff - determine if a buffer contains only 0xFF bytes.
++ * @buf: buffer
++ * @len: buffer length
++ */
++static int dbg_is_all_ff(uint8_t *buf, int len)
++{
++	int i;
++
++	for (i = 0; i < len; i++)
++		if (buf[i] != 0xff)
++			return 0;
++	return 1;
++}
++
++/**
++ * dbg_is_nnode_dirty - determine if a nnode is dirty.
++ * @c: the UBIFS file-system description object
++ * @lnum: LEB number where nnode was written
++ * @offs: offset where nnode was written
++ */
++static int dbg_is_nnode_dirty(struct ubifs_info *c, int lnum, int offs)
++{
++	struct ubifs_nnode *nnode;
++	int hght;
++
++	/* Entire tree is in memory so first_nnode / next_nnode are OK */
++	nnode = first_nnode(c, &hght);
++	for (; nnode; nnode = next_nnode(c, nnode, &hght)) {
++		struct ubifs_nbranch *branch;
++
++		cond_resched();
++		if (nnode->parent) {
++			branch = &nnode->parent->nbranch[nnode->iip];
++			if (branch->lnum != lnum || branch->offs != offs)
++				continue;
++			if (test_bit(DIRTY_CNODE, &nnode->flags))
++				return 1;
++			return 0;
++		} else {
++			if (c->lpt_lnum != lnum || c->lpt_offs != offs)
++				continue;
++			if (test_bit(DIRTY_CNODE, &nnode->flags))
++				return 1;
++			return 0;
++		}
++	}
++	return 1;
++}
++
++/**
++ * dbg_is_pnode_dirty - determine if a pnode is dirty.
++ * @c: the UBIFS file-system description object
++ * @lnum: LEB number where pnode was written
++ * @offs: offset where pnode was written
++ */
++static int dbg_is_pnode_dirty(struct ubifs_info *c, int lnum, int offs)
++{
++	int i, cnt;
++
++	cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
++	for (i = 0; i < cnt; i++) {
++		struct ubifs_pnode *pnode;
++		struct ubifs_nbranch *branch;
++
++		cond_resched();
++		pnode = pnode_lookup(c, i);
++		if (IS_ERR(pnode))
++			return PTR_ERR(pnode);
++		branch = &pnode->parent->nbranch[pnode->iip];
++		if (branch->lnum != lnum || branch->offs != offs)
++			continue;
++		if (test_bit(DIRTY_CNODE, &pnode->flags))
++			return 1;
++		return 0;
++	}
++	return 1;
++}
++
++/**
++ * dbg_is_ltab_dirty - determine if a ltab node is dirty.
++ * @c: the UBIFS file-system description object
++ * @lnum: LEB number where ltab node was written
++ * @offs: offset where ltab node was written
++ */
++static int dbg_is_ltab_dirty(struct ubifs_info *c, int lnum, int offs)
++{
++	if (lnum != c->ltab_lnum || offs != c->ltab_offs)
++		return 1;
++	return (c->lpt_drty_flgs & LTAB_DIRTY) != 0;
++}
++
++/**
++ * dbg_is_lsave_dirty - determine if a lsave node is dirty.
++ * @c: the UBIFS file-system description object
++ * @lnum: LEB number where lsave node was written
++ * @offs: offset where lsave node was written
++ */
++static int dbg_is_lsave_dirty(struct ubifs_info *c, int lnum, int offs)
++{
++	if (lnum != c->lsave_lnum || offs != c->lsave_offs)
++		return 1;
++	return (c->lpt_drty_flgs & LSAVE_DIRTY) != 0;
++}
++
++/**
++ * dbg_is_node_dirty - determine if a node is dirty.
++ * @c: the UBIFS file-system description object
++ * @node_type: node type
++ * @lnum: LEB number where node was written
++ * @offs: offset where node was written
++ */
++static int dbg_is_node_dirty(struct ubifs_info *c, int node_type, int lnum,
++			     int offs)
++{
++	switch (node_type) {
++	case UBIFS_LPT_NNODE:
++		return dbg_is_nnode_dirty(c, lnum, offs);
++	case UBIFS_LPT_PNODE:
++		return dbg_is_pnode_dirty(c, lnum, offs);
++	case UBIFS_LPT_LTAB:
++		return dbg_is_ltab_dirty(c, lnum, offs);
++	case UBIFS_LPT_LSAVE:
++		return dbg_is_lsave_dirty(c, lnum, offs);
++	}
++	return 1;
++}
++
++/**
++ * dbg_check_ltab_lnum - check the ltab for a LPT LEB number.
++ * @c: the UBIFS file-system description object
++ * @lnum: LEB number where node was written
++ * @offs: offset where node was written
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int dbg_check_ltab_lnum(struct ubifs_info *c, int lnum)
++{
++	int err, len = c->leb_size, dirty = 0, node_type, node_num, node_len;
++	int ret;
++	void *buf = c->dbg->buf;
++
++	if (!(ubifs_chk_flags & UBIFS_CHK_LPROPS))
++		return 0;
++
++	dbg_lp("LEB %d", lnum);
++	err = ubi_read(c->ubi, lnum, buf, 0, c->leb_size);
++	if (err) {
++		dbg_msg("ubi_read failed, LEB %d, error %d", lnum, err);
++		return err;
++	}
++	while (1) {
++		if (!is_a_node(c, buf, len)) {
++			int i, pad_len;
++
++			pad_len = get_pad_len(c, buf, len);
++			if (pad_len) {
++				buf += pad_len;
++				len -= pad_len;
++				dirty += pad_len;
++				continue;
++			}
++			if (!dbg_is_all_ff(buf, len)) {
++				dbg_msg("invalid empty space in LEB %d at %d",
++					lnum, c->leb_size - len);
++				err = -EINVAL;
++			}
++			i = lnum - c->lpt_first;
++			if (len != c->ltab[i].free) {
++				dbg_msg("invalid free space in LEB %d "
++					"(free %d, expected %d)",
++					lnum, len, c->ltab[i].free);
++				err = -EINVAL;
++			}
++			if (dirty != c->ltab[i].dirty) {
++				dbg_msg("invalid dirty space in LEB %d "
++					"(dirty %d, expected %d)",
++					lnum, dirty, c->ltab[i].dirty);
++				err = -EINVAL;
++			}
++			return err;
++		}
++		node_type = get_lpt_node_type(c, buf, &node_num);
++		node_len = get_lpt_node_len(c, node_type);
++		ret = dbg_is_node_dirty(c, node_type, lnum, c->leb_size - len);
++		if (ret == 1)
++			dirty += node_len;
++		buf += node_len;
++		len -= node_len;
++	}
++}
++
++/**
++ * dbg_check_ltab - check the free and dirty space in the ltab.
++ * @c: the UBIFS file-system description object
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int dbg_check_ltab(struct ubifs_info *c)
++{
++	int lnum, err, i, cnt;
++
++	if (!(ubifs_chk_flags & UBIFS_CHK_LPROPS))
++		return 0;
++
++	/* Bring the entire tree into memory */
++	cnt = DIV_ROUND_UP(c->main_lebs, UBIFS_LPT_FANOUT);
++	for (i = 0; i < cnt; i++) {
++		struct ubifs_pnode *pnode;
++
++		pnode = pnode_lookup(c, i);
++		if (IS_ERR(pnode))
++			return PTR_ERR(pnode);
++		cond_resched();
++	}
++
++	/* Check nodes */
++	err = dbg_check_lpt_nodes(c, (struct ubifs_cnode *)c->nroot, 0, 0);
++	if (err)
++		return err;
++
++	/* Check each LEB */
++	for (lnum = c->lpt_first; lnum <= c->lpt_last; lnum++) {
++		err = dbg_check_ltab_lnum(c, lnum);
++		if (err) {
++			dbg_err("failed at LEB %d", lnum);
++			return err;
++		}
++	}
++
++	dbg_lp("succeeded");
++	return 0;
++}
++
++/**
++ * dbg_chk_lpt_free_spc - check LPT free space is enough to write entire LPT.
++ * @c: the UBIFS file-system description object
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int dbg_chk_lpt_free_spc(struct ubifs_info *c)
++{
++	long long free = 0;
++	int i;
++
++	if (!(ubifs_chk_flags & UBIFS_CHK_LPROPS))
++		return 0;
++
++	for (i = 0; i < c->lpt_lebs; i++) {
++		if (c->ltab[i].tgc || c->ltab[i].cmt)
++			continue;
++		if (i + c->lpt_first == c->nhead_lnum)
++			free += c->leb_size - c->nhead_offs;
++		else if (c->ltab[i].free == c->leb_size)
++			free += c->leb_size;
++	}
++	if (free < c->lpt_sz) {
++		dbg_err("LPT space error: free %lld lpt_sz %lld",
++			free, c->lpt_sz);
++		dbg_dump_lpt_info(c);
++		dbg_dump_lpt_lebs(c);
++		dump_stack();
++		return -EINVAL;
++	}
++	return 0;
++}
++
++/**
++ * dbg_chk_lpt_sz - check LPT does not write more than LPT size.
++ * @c: the UBIFS file-system description object
++ * @action: action
++ * @len: length written
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int dbg_chk_lpt_sz(struct ubifs_info *c, int action, int len)
++{
++	struct ubifs_debug_info *d = c->dbg;
++	long long chk_lpt_sz, lpt_sz;
++	int err = 0;
++
++	if (!(ubifs_chk_flags & UBIFS_CHK_LPROPS))
++		return 0;
++
++	switch (action) {
++	case 0:
++		d->chk_lpt_sz = 0;
++		d->chk_lpt_sz2 = 0;
++		d->chk_lpt_lebs = 0;
++		d->chk_lpt_wastage = 0;
++		if (c->dirty_pn_cnt > c->pnode_cnt) {
++			dbg_err("dirty pnodes %d exceed max %d",
++				c->dirty_pn_cnt, c->pnode_cnt);
++			err = -EINVAL;
++		}
++		if (c->dirty_nn_cnt > c->nnode_cnt) {
++			dbg_err("dirty nnodes %d exceed max %d",
++				c->dirty_nn_cnt, c->nnode_cnt);
++			err = -EINVAL;
++		}
++		return err;
++	case 1:
++		d->chk_lpt_sz += len;
++		return 0;
++	case 2:
++		d->chk_lpt_sz += len;
++		d->chk_lpt_wastage += len;
++		d->chk_lpt_lebs += 1;
++		return 0;
++	case 3:
++		chk_lpt_sz = c->leb_size;
++		chk_lpt_sz *= d->chk_lpt_lebs;
++		chk_lpt_sz += len - c->nhead_offs;
++		if (d->chk_lpt_sz != chk_lpt_sz) {
++			dbg_err("LPT wrote %lld but space used was %lld",
++				d->chk_lpt_sz, chk_lpt_sz);
++			err = -EINVAL;
++		}
++		if (d->chk_lpt_sz > c->lpt_sz) {
++			dbg_err("LPT wrote %lld but lpt_sz is %lld",
++				d->chk_lpt_sz, c->lpt_sz);
++			err = -EINVAL;
++		}
++		if (d->chk_lpt_sz2 && d->chk_lpt_sz != d->chk_lpt_sz2) {
++			dbg_err("LPT layout size %lld but wrote %lld",
++				d->chk_lpt_sz, d->chk_lpt_sz2);
++			err = -EINVAL;
++		}
++		if (d->chk_lpt_sz2 && d->new_nhead_offs != len) {
++			dbg_err("LPT new nhead offs: expected %d was %d",
++				d->new_nhead_offs, len);
++			err = -EINVAL;
++		}
++		lpt_sz = (long long)c->pnode_cnt * c->pnode_sz;
++		lpt_sz += (long long)c->nnode_cnt * c->nnode_sz;
++		lpt_sz += c->ltab_sz;
++		if (c->big_lpt)
++			lpt_sz += c->lsave_sz;
++		if (d->chk_lpt_sz - d->chk_lpt_wastage > lpt_sz) {
++			dbg_err("LPT chk_lpt_sz %lld + waste %lld exceeds %lld",
++				d->chk_lpt_sz, d->chk_lpt_wastage, lpt_sz);
++			err = -EINVAL;
++		}
++		if (err) {
++			dbg_dump_lpt_info(c);
++			dbg_dump_lpt_lebs(c);
++			dump_stack();
++		}
++		d->chk_lpt_sz2 = d->chk_lpt_sz;
++		d->chk_lpt_sz = 0;
++		d->chk_lpt_wastage = 0;
++		d->chk_lpt_lebs = 0;
++		d->new_nhead_offs = len;
++		return err;
++	case 4:
++		d->chk_lpt_sz += len;
++		d->chk_lpt_wastage += len;
++		return 0;
++	default:
++		return -EINVAL;
++	}
++}
++
++/**
++ * dbg_dump_lpt_leb - dump an LPT LEB.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number to dump
++ *
++ * This function dumps an LEB from LPT area. Nodes in this area are very
++ * different to nodes in the main area (e.g., they do not have common headers,
++ * they do not have 8-byte alignments, etc), so we have a separate function to
++ * dump LPT area LEBs. Note, LPT has to be locked by the caller.
++ */
++static void dump_lpt_leb(const struct ubifs_info *c, int lnum)
++{
++	int err, len = c->leb_size, node_type, node_num, node_len, offs;
++	void *buf = c->dbg->buf;
++
++	printk(KERN_DEBUG "(pid %d) start dumping LEB %d\n",
++	       current->pid, lnum);
++	err = ubi_read(c->ubi, lnum, buf, 0, c->leb_size);
++	if (err) {
++		ubifs_err("cannot read LEB %d, error %d", lnum, err);
++		return;
++	}
++	while (1) {
++		offs = c->leb_size - len;
++		if (!is_a_node(c, buf, len)) {
++			int pad_len;
++
++			pad_len = get_pad_len(c, buf, len);
++			if (pad_len) {
++				printk(KERN_DEBUG "LEB %d:%d, pad %d bytes\n",
++				       lnum, offs, pad_len);
++				buf += pad_len;
++				len -= pad_len;
++				continue;
++			}
++			if (len)
++				printk(KERN_DEBUG "LEB %d:%d, free %d bytes\n",
++				       lnum, offs, len);
++			break;
++		}
++
++		node_type = get_lpt_node_type(c, buf, &node_num);
++		switch (node_type) {
++		case UBIFS_LPT_PNODE:
++		{
++			node_len = c->pnode_sz;
++			if (c->big_lpt)
++				printk(KERN_DEBUG "LEB %d:%d, pnode num %d\n",
++				       lnum, offs, node_num);
++			else
++				printk(KERN_DEBUG "LEB %d:%d, pnode\n",
++				       lnum, offs);
++			break;
++		}
++		case UBIFS_LPT_NNODE:
++		{
++			int i;
++			struct ubifs_nnode nnode;
++
++			node_len = c->nnode_sz;
++			if (c->big_lpt)
++				printk(KERN_DEBUG "LEB %d:%d, nnode num %d, ",
++				       lnum, offs, node_num);
++			else
++				printk(KERN_DEBUG "LEB %d:%d, nnode, ",
++				       lnum, offs);
++			err = ubifs_unpack_nnode(c, buf, &nnode);
++			for (i = 0; i < UBIFS_LPT_FANOUT; i++) {
++				printk("%d:%d", nnode.nbranch[i].lnum,
++				       nnode.nbranch[i].offs);
++				if (i != UBIFS_LPT_FANOUT - 1)
++					printk(", ");
++			}
++			printk("\n");
++			break;
++		}
++		case UBIFS_LPT_LTAB:
++			node_len = c->ltab_sz;
++			printk(KERN_DEBUG "LEB %d:%d, ltab\n",
++			       lnum, offs);
++			break;
++		case UBIFS_LPT_LSAVE:
++			node_len = c->lsave_sz;
++			printk(KERN_DEBUG "LEB %d:%d, lsave len\n", lnum, offs);
++			break;
++		default:
++			ubifs_err("LPT node type %d not recognized", node_type);
++			return;
++		}
++
++		buf += node_len;
++		len -= node_len;
++	}
++
++	printk(KERN_DEBUG "(pid %d) finish dumping LEB %d\n",
++	       current->pid, lnum);
++}
++
++/**
++ * dbg_dump_lpt_lebs - dump LPT lebs.
++ * @c: UBIFS file-system description object
++ *
++ * This function dumps all LPT LEBs. The caller has to make sure the LPT is
++ * locked.
++ */
++void dbg_dump_lpt_lebs(const struct ubifs_info *c)
++{
++	int i;
++
++	printk(KERN_DEBUG "(pid %d) start dumping all LPT LEBs\n",
++	       current->pid);
++	for (i = 0; i < c->lpt_lebs; i++)
++		dump_lpt_leb(c, i + c->lpt_first);
++	printk(KERN_DEBUG "(pid %d) finish dumping all LPT LEBs\n",
++	       current->pid);
++}
++
++#endif /* CONFIG_UBIFS_FS_DEBUG */
+diff -Nurd linux-2.6.24.orig/fs/ubifs/master.c linux-2.6.24/fs/ubifs/master.c
+--- linux-2.6.24.orig/fs/ubifs/master.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/master.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,387 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++/* This file implements reading and writing the master node */
++
++#include "ubifs.h"
++
++/**
++ * scan_for_master - search the valid master node.
++ * @c: UBIFS file-system description object
++ *
++ * This function scans the master node LEBs and search for the latest master
++ * node. Returns zero in case of success and a negative error code in case of
++ * failure.
++ */
++static int scan_for_master(struct ubifs_info *c)
++{
++	struct ubifs_scan_leb *sleb;
++	struct ubifs_scan_node *snod;
++	int lnum, offs = 0, nodes_cnt;
++
++	lnum = UBIFS_MST_LNUM;
++
++	sleb = ubifs_scan(c, lnum, 0, c->sbuf);
++	if (IS_ERR(sleb))
++		return PTR_ERR(sleb);
++	nodes_cnt = sleb->nodes_cnt;
++	if (nodes_cnt > 0) {
++		snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node,
++				  list);
++		if (snod->type != UBIFS_MST_NODE)
++			goto out;
++		memcpy(c->mst_node, snod->node, snod->len);
++		offs = snod->offs;
++	}
++	ubifs_scan_destroy(sleb);
++
++	lnum += 1;
++
++	sleb = ubifs_scan(c, lnum, 0, c->sbuf);
++	if (IS_ERR(sleb))
++		return PTR_ERR(sleb);
++	if (sleb->nodes_cnt != nodes_cnt)
++		goto out;
++	if (!sleb->nodes_cnt)
++		goto out;
++	snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node, list);
++	if (snod->type != UBIFS_MST_NODE)
++		goto out;
++	if (snod->offs != offs)
++		goto out;
++	if (memcmp((void *)c->mst_node + UBIFS_CH_SZ,
++		   (void *)snod->node + UBIFS_CH_SZ,
++		   UBIFS_MST_NODE_SZ - UBIFS_CH_SZ))
++		goto out;
++	c->mst_offs = offs;
++	ubifs_scan_destroy(sleb);
++	return 0;
++
++out:
++	ubifs_scan_destroy(sleb);
++	return -EINVAL;
++}
++
++/**
++ * validate_master - validate master node.
++ * @c: UBIFS file-system description object
++ *
++ * This function validates data which was read from master node. Returns zero
++ * if the data is all right and %-EINVAL if not.
++ */
++static int validate_master(const struct ubifs_info *c)
++{
++	long long main_sz;
++	int err;
++
++	if (c->max_sqnum >= SQNUM_WATERMARK) {
++		err = 1;
++		goto out;
++	}
++
++	if (c->cmt_no >= c->max_sqnum) {
++		err = 2;
++		goto out;
++	}
++
++	if (c->highest_inum >= INUM_WATERMARK) {
++		err = 3;
++		goto out;
++	}
++
++	if (c->lhead_lnum < UBIFS_LOG_LNUM ||
++	    c->lhead_lnum >= UBIFS_LOG_LNUM + c->log_lebs ||
++	    c->lhead_offs < 0 || c->lhead_offs >= c->leb_size ||
++	    c->lhead_offs & (c->min_io_size - 1)) {
++		err = 4;
++		goto out;
++	}
++
++	if (c->zroot.lnum >= c->leb_cnt || c->zroot.lnum < c->main_first ||
++	    c->zroot.offs >= c->leb_size || c->zroot.offs & 7) {
++		err = 5;
++		goto out;
++	}
++
++	if (c->zroot.len < c->ranges[UBIFS_IDX_NODE].min_len ||
++	    c->zroot.len > c->ranges[UBIFS_IDX_NODE].max_len) {
++		err = 6;
++		goto out;
++	}
++
++	if (c->gc_lnum >= c->leb_cnt || c->gc_lnum < c->main_first) {
++		err = 7;
++		goto out;
++	}
++
++	if (c->ihead_lnum >= c->leb_cnt || c->ihead_lnum < c->main_first ||
++	    c->ihead_offs % c->min_io_size || c->ihead_offs < 0 ||
++	    c->ihead_offs > c->leb_size || c->ihead_offs & 7) {
++		err = 8;
++		goto out;
++	}
++
++	main_sz = (long long)c->main_lebs * c->leb_size;
++	if (c->old_idx_sz & 7 || c->old_idx_sz >= main_sz) {
++		err = 9;
++		goto out;
++	}
++
++	if (c->lpt_lnum < c->lpt_first || c->lpt_lnum > c->lpt_last ||
++	    c->lpt_offs < 0 || c->lpt_offs + c->nnode_sz > c->leb_size) {
++		err = 10;
++		goto out;
++	}
++
++	if (c->nhead_lnum < c->lpt_first || c->nhead_lnum > c->lpt_last ||
++	    c->nhead_offs < 0 || c->nhead_offs % c->min_io_size ||
++	    c->nhead_offs > c->leb_size) {
++		err = 11;
++		goto out;
++	}
++
++	if (c->ltab_lnum < c->lpt_first || c->ltab_lnum > c->lpt_last ||
++	    c->ltab_offs < 0 ||
++	    c->ltab_offs + c->ltab_sz > c->leb_size) {
++		err = 12;
++		goto out;
++	}
++
++	if (c->big_lpt && (c->lsave_lnum < c->lpt_first ||
++	    c->lsave_lnum > c->lpt_last || c->lsave_offs < 0 ||
++	    c->lsave_offs + c->lsave_sz > c->leb_size)) {
++		err = 13;
++		goto out;
++	}
++
++	if (c->lscan_lnum < c->main_first || c->lscan_lnum >= c->leb_cnt) {
++		err = 14;
++		goto out;
++	}
++
++	if (c->lst.empty_lebs < 0 || c->lst.empty_lebs > c->main_lebs - 2) {
++		err = 15;
++		goto out;
++	}
++
++	if (c->lst.idx_lebs < 0 || c->lst.idx_lebs > c->main_lebs - 1) {
++		err = 16;
++		goto out;
++	}
++
++	if (c->lst.total_free < 0 || c->lst.total_free > main_sz ||
++	    c->lst.total_free & 7) {
++		err = 17;
++		goto out;
++	}
++
++	if (c->lst.total_dirty < 0 || (c->lst.total_dirty & 7)) {
++		err = 18;
++		goto out;
++	}
++
++	if (c->lst.total_used < 0 || (c->lst.total_used & 7)) {
++		err = 19;
++		goto out;
++	}
++
++	if (c->lst.total_free + c->lst.total_dirty +
++	    c->lst.total_used > main_sz) {
++		err = 20;
++		goto out;
++	}
++
++	if (c->lst.total_dead + c->lst.total_dark +
++	    c->lst.total_used + c->old_idx_sz > main_sz) {
++		err = 21;
++		goto out;
++	}
++
++	if (c->lst.total_dead < 0 ||
++	    c->lst.total_dead > c->lst.total_free + c->lst.total_dirty ||
++	    c->lst.total_dead & 7) {
++		err = 22;
++		goto out;
++	}
++
++	if (c->lst.total_dark < 0 ||
++	    c->lst.total_dark > c->lst.total_free + c->lst.total_dirty ||
++	    c->lst.total_dark & 7) {
++		err = 23;
++		goto out;
++	}
++
++	return 0;
++
++out:
++	ubifs_err("bad master node at offset %d error %d", c->mst_offs, err);
++	dbg_dump_node(c, c->mst_node);
++	return -EINVAL;
++}
++
++/**
++ * ubifs_read_master - read master node.
++ * @c: UBIFS file-system description object
++ *
++ * This function finds and reads the master node during file-system mount. If
++ * the flash is empty, it creates default master node as well. Returns zero in
++ * case of success and a negative error code in case of failure.
++ */
++int ubifs_read_master(struct ubifs_info *c)
++{
++	int err, old_leb_cnt;
++
++	c->mst_node = kzalloc(c->mst_node_alsz, GFP_KERNEL);
++	if (!c->mst_node)
++		return -ENOMEM;
++
++	err = scan_for_master(c);
++	if (err) {
++		err = ubifs_recover_master_node(c);
++		if (err)
++			/*
++			 * Note, we do not free 'c->mst_node' here because the
++			 * unmount routine will take care of this.
++			 */
++			return err;
++	}
++
++	/* Make sure that the recovery flag is clear */
++	c->mst_node->flags &= cpu_to_le32(~UBIFS_MST_RCVRY);
++
++	c->max_sqnum       = le64_to_cpu(c->mst_node->ch.sqnum);
++	c->highest_inum    = le64_to_cpu(c->mst_node->highest_inum);
++	c->cmt_no          = le64_to_cpu(c->mst_node->cmt_no);
++	c->zroot.lnum      = le32_to_cpu(c->mst_node->root_lnum);
++	c->zroot.offs      = le32_to_cpu(c->mst_node->root_offs);
++	c->zroot.len       = le32_to_cpu(c->mst_node->root_len);
++	c->lhead_lnum      = le32_to_cpu(c->mst_node->log_lnum);
++	c->gc_lnum         = le32_to_cpu(c->mst_node->gc_lnum);
++	c->ihead_lnum      = le32_to_cpu(c->mst_node->ihead_lnum);
++	c->ihead_offs      = le32_to_cpu(c->mst_node->ihead_offs);
++	c->old_idx_sz      = le64_to_cpu(c->mst_node->index_size);
++	c->lpt_lnum        = le32_to_cpu(c->mst_node->lpt_lnum);
++	c->lpt_offs        = le32_to_cpu(c->mst_node->lpt_offs);
++	c->nhead_lnum      = le32_to_cpu(c->mst_node->nhead_lnum);
++	c->nhead_offs      = le32_to_cpu(c->mst_node->nhead_offs);
++	c->ltab_lnum       = le32_to_cpu(c->mst_node->ltab_lnum);
++	c->ltab_offs       = le32_to_cpu(c->mst_node->ltab_offs);
++	c->lsave_lnum      = le32_to_cpu(c->mst_node->lsave_lnum);
++	c->lsave_offs      = le32_to_cpu(c->mst_node->lsave_offs);
++	c->lscan_lnum      = le32_to_cpu(c->mst_node->lscan_lnum);
++	c->lst.empty_lebs  = le32_to_cpu(c->mst_node->empty_lebs);
++	c->lst.idx_lebs    = le32_to_cpu(c->mst_node->idx_lebs);
++	old_leb_cnt        = le32_to_cpu(c->mst_node->leb_cnt);
++	c->lst.total_free  = le64_to_cpu(c->mst_node->total_free);
++	c->lst.total_dirty = le64_to_cpu(c->mst_node->total_dirty);
++	c->lst.total_used  = le64_to_cpu(c->mst_node->total_used);
++	c->lst.total_dead  = le64_to_cpu(c->mst_node->total_dead);
++	c->lst.total_dark  = le64_to_cpu(c->mst_node->total_dark);
++
++	c->calc_idx_sz = c->old_idx_sz;
++
++	if (c->mst_node->flags & cpu_to_le32(UBIFS_MST_NO_ORPHS))
++		c->no_orphs = 1;
++
++	if (old_leb_cnt != c->leb_cnt) {
++		/* The file system has been resized */
++		int growth = c->leb_cnt - old_leb_cnt;
++
++		if (c->leb_cnt < old_leb_cnt ||
++		    c->leb_cnt < UBIFS_MIN_LEB_CNT) {
++			ubifs_err("bad leb_cnt on master node");
++			dbg_dump_node(c, c->mst_node);
++			return -EINVAL;
++		}
++
++		dbg_mnt("Auto resizing (master) from %d LEBs to %d LEBs",
++			old_leb_cnt, c->leb_cnt);
++		c->lst.empty_lebs += growth;
++		c->lst.total_free += growth * (long long)c->leb_size;
++		c->lst.total_dark += growth * (long long)c->dark_wm;
++
++		/*
++		 * Reflect changes back onto the master node. N.B. the master
++		 * node gets written immediately whenever mounting (or
++		 * remounting) in read-write mode, so we do not need to write it
++		 * here.
++		 */
++		c->mst_node->leb_cnt = cpu_to_le32(c->leb_cnt);
++		c->mst_node->empty_lebs = cpu_to_le32(c->lst.empty_lebs);
++		c->mst_node->total_free = cpu_to_le64(c->lst.total_free);
++		c->mst_node->total_dark = cpu_to_le64(c->lst.total_dark);
++	}
++
++	err = validate_master(c);
++	if (err)
++		return err;
++
++	err = dbg_old_index_check_init(c, &c->zroot);
++
++	return err;
++}
++
++/**
++ * ubifs_write_master - write master node.
++ * @c: UBIFS file-system description object
++ *
++ * This function writes the master node. The caller has to take the
++ * @c->mst_mutex lock before calling this function. Returns zero in case of
++ * success and a negative error code in case of failure. The master node is
++ * written twice to enable recovery.
++ */
++int ubifs_write_master(struct ubifs_info *c)
++{
++	int err, lnum, offs, len;
++
++	if (c->ro_media)
++		return -EROFS;
++
++	lnum = UBIFS_MST_LNUM;
++	offs = c->mst_offs + c->mst_node_alsz;
++	len = UBIFS_MST_NODE_SZ;
++
++	if (offs + UBIFS_MST_NODE_SZ > c->leb_size) {
++		err = ubifs_leb_unmap(c, lnum);
++		if (err)
++			return err;
++		offs = 0;
++	}
++
++	c->mst_offs = offs;
++	c->mst_node->highest_inum = cpu_to_le64(c->highest_inum);
++
++	err = ubifs_write_node(c, c->mst_node, len, lnum, offs, UBI_SHORTTERM);
++	if (err)
++		return err;
++
++	lnum += 1;
++
++	if (offs == 0) {
++		err = ubifs_leb_unmap(c, lnum);
++		if (err)
++			return err;
++	}
++	err = ubifs_write_node(c, c->mst_node, len, lnum, offs, UBI_SHORTTERM);
++
++	return err;
++}
+diff -Nurd linux-2.6.24.orig/fs/ubifs/misc.h linux-2.6.24/fs/ubifs/misc.h
+--- linux-2.6.24.orig/fs/ubifs/misc.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/misc.h	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,340 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++/*
++ * This file contains miscellaneous helper functions.
++ */
++
++#ifndef __UBIFS_MISC_H__
++#define __UBIFS_MISC_H__
++
++/**
++ * ubifs_zn_dirty - check if znode is dirty.
++ * @znode: znode to check
++ *
++ * This helper function returns %1 if @znode is dirty and %0 otherwise.
++ */
++static inline int ubifs_zn_dirty(const struct ubifs_znode *znode)
++{
++	return !!test_bit(DIRTY_ZNODE, &znode->flags);
++}
++
++/**
++ * ubifs_wake_up_bgt - wake up background thread.
++ * @c: UBIFS file-system description object
++ */
++static inline void ubifs_wake_up_bgt(struct ubifs_info *c)
++{
++	if (c->bgt && !c->need_bgt) {
++		c->need_bgt = 1;
++		wake_up_process(c->bgt);
++	}
++}
++
++/**
++ * ubifs_tnc_find_child - find next child in znode.
++ * @znode: znode to search at
++ * @start: the zbranch index to start at
++ *
++ * This helper function looks for znode child starting at index @start. Returns
++ * the child or %NULL if no children were found.
++ */
++static inline struct ubifs_znode *
++ubifs_tnc_find_child(struct ubifs_znode *znode, int start)
++{
++	while (start < znode->child_cnt) {
++		if (znode->zbranch[start].znode)
++			return znode->zbranch[start].znode;
++		start += 1;
++	}
++
++	return NULL;
++}
++
++/**
++ * ubifs_inode - get UBIFS inode information by VFS 'struct inode' object.
++ * @inode: the VFS 'struct inode' pointer
++ */
++static inline struct ubifs_inode *ubifs_inode(const struct inode *inode)
++{
++	return container_of(inode, struct ubifs_inode, vfs_inode);
++}
++
++/**
++ * ubifs_compr_present - check if compressor was compiled in.
++ * @compr_type: compressor type to check
++ *
++ * This function returns %1 of compressor of type @compr_type is present, and
++ * %0 if not.
++ */
++static inline int ubifs_compr_present(int compr_type)
++{
++	ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
++	return !!ubifs_compressors[compr_type]->capi_name;
++}
++
++/**
++ * ubifs_compr_name - get compressor name string by its type.
++ * @compr_type: compressor type
++ *
++ * This function returns compressor type string.
++ */
++static inline const char *ubifs_compr_name(int compr_type)
++{
++	ubifs_assert(compr_type >= 0 && compr_type < UBIFS_COMPR_TYPES_CNT);
++	return ubifs_compressors[compr_type]->name;
++}
++
++/**
++ * ubifs_wbuf_sync - synchronize write-buffer.
++ * @wbuf: write-buffer to synchronize
++ *
++ * This is the same as as 'ubifs_wbuf_sync_nolock()' but it does not assume
++ * that the write-buffer is already locked.
++ */
++static inline int ubifs_wbuf_sync(struct ubifs_wbuf *wbuf)
++{
++	int err;
++
++	mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
++	err = ubifs_wbuf_sync_nolock(wbuf);
++	mutex_unlock(&wbuf->io_mutex);
++	return err;
++}
++
++/**
++ * ubifs_leb_unmap - unmap an LEB.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number to unmap
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static inline int ubifs_leb_unmap(const struct ubifs_info *c, int lnum)
++{
++	int err;
++
++	if (c->ro_media)
++		return -EROFS;
++	err = ubi_leb_unmap(c->ubi, lnum);
++	if (err) {
++		ubifs_err("unmap LEB %d failed, error %d", lnum, err);
++		return err;
++	}
++
++	return 0;
++}
++
++/**
++ * ubifs_leb_write - write to a LEB.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number to write
++ * @buf: buffer to write from
++ * @offs: offset within LEB to write to
++ * @len: length to write
++ * @dtype: data type
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static inline int ubifs_leb_write(const struct ubifs_info *c, int lnum,
++				  const void *buf, int offs, int len, int dtype)
++{
++	int err;
++
++	if (c->ro_media)
++		return -EROFS;
++	err = ubi_leb_write(c->ubi, lnum, buf, offs, len, dtype);
++	if (err) {
++		ubifs_err("writing %d bytes at %d:%d, error %d",
++			  len, lnum, offs, err);
++		return err;
++	}
++
++	return 0;
++}
++
++/**
++ * ubifs_leb_change - atomic LEB change.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number to write
++ * @buf: buffer to write from
++ * @len: length to write
++ * @dtype: data type
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static inline int ubifs_leb_change(const struct ubifs_info *c, int lnum,
++				   const void *buf, int len, int dtype)
++{
++	int err;
++
++	if (c->ro_media)
++		return -EROFS;
++	err = ubi_leb_change(c->ubi, lnum, buf, len, dtype);
++	if (err) {
++		ubifs_err("changing %d bytes in LEB %d, error %d",
++			  len, lnum, err);
++		return err;
++	}
++
++	return 0;
++}
++
++/**
++ * ubifs_encode_dev - encode device node IDs.
++ * @dev: UBIFS device node information
++ * @rdev: device IDs to encode
++ *
++ * This is a helper function which encodes major/minor numbers of a device node
++ * into UBIFS device node description. We use standard Linux "new" and "huge"
++ * encodings.
++ */
++static inline int ubifs_encode_dev(union ubifs_dev_desc *dev, dev_t rdev)
++{
++	if (new_valid_dev(rdev)) {
++		dev->new = cpu_to_le32(new_encode_dev(rdev));
++		return sizeof(dev->new);
++	} else {
++		dev->huge = cpu_to_le64(huge_encode_dev(rdev));
++		return sizeof(dev->huge);
++	}
++}
++
++/**
++ * ubifs_add_dirt - add dirty space to LEB properties.
++ * @c: the UBIFS file-system description object
++ * @lnum: LEB to add dirty space for
++ * @dirty: dirty space to add
++ *
++ * This is a helper function which increased amount of dirty LEB space. Returns
++ * zero in case of success and a negative error code in case of failure.
++ */
++static inline int ubifs_add_dirt(struct ubifs_info *c, int lnum, int dirty)
++{
++	return ubifs_update_one_lp(c, lnum, LPROPS_NC, dirty, 0, 0);
++}
++
++/**
++ * ubifs_return_leb - return LEB to lprops.
++ * @c: the UBIFS file-system description object
++ * @lnum: LEB to return
++ *
++ * This helper function cleans the "taken" flag of a logical eraseblock in the
++ * lprops. Returns zero in case of success and a negative error code in case of
++ * failure.
++ */
++static inline int ubifs_return_leb(struct ubifs_info *c, int lnum)
++{
++	return ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
++				   LPROPS_TAKEN, 0);
++}
++
++/**
++ * ubifs_idx_node_sz - return index node size.
++ * @c: the UBIFS file-system description object
++ * @child_cnt: number of children of this index node
++ */
++static inline int ubifs_idx_node_sz(const struct ubifs_info *c, int child_cnt)
++{
++	return UBIFS_IDX_NODE_SZ + (UBIFS_BRANCH_SZ + c->key_len) * child_cnt;
++}
++
++/**
++ * ubifs_idx_branch - return pointer to an index branch.
++ * @c: the UBIFS file-system description object
++ * @idx: index node
++ * @bnum: branch number
++ */
++static inline
++struct ubifs_branch *ubifs_idx_branch(const struct ubifs_info *c,
++				      const struct ubifs_idx_node *idx,
++				      int bnum)
++{
++	return (struct ubifs_branch *)((void *)idx->branches +
++				       (UBIFS_BRANCH_SZ + c->key_len) * bnum);
++}
++
++/**
++ * ubifs_idx_key - return pointer to an index key.
++ * @c: the UBIFS file-system description object
++ * @idx: index node
++ */
++static inline void *ubifs_idx_key(const struct ubifs_info *c,
++				  const struct ubifs_idx_node *idx)
++{
++	return (void *)((struct ubifs_branch *)idx->branches)->key;
++}
++
++/**
++ * ubifs_current_time - round current time to time granularity.
++ * @inode: inode
++ */
++static inline struct timespec ubifs_current_time(struct inode *inode)
++{
++	return (inode->i_sb->s_time_gran < NSEC_PER_SEC) ?
++		current_fs_time(inode->i_sb) : CURRENT_TIME_SEC;
++}
++
++/**
++ * ubifs_tnc_lookup - look up a file-system node.
++ * @c: UBIFS file-system description object
++ * @key: node key to lookup
++ * @node: the node is returned here
++ *
++ * This function look up and reads node with key @key. The caller has to make
++ * sure the @node buffer is large enough to fit the node. Returns zero in case
++ * of success, %-ENOENT if the node was not found, and a negative error code in
++ * case of failure.
++ */
++static inline int ubifs_tnc_lookup(struct ubifs_info *c,
++				   const union ubifs_key *key, void *node)
++{
++	return ubifs_tnc_locate(c, key, node, NULL, NULL);
++}
++
++/**
++ * ubifs_get_lprops - get reference to LEB properties.
++ * @c: the UBIFS file-system description object
++ *
++ * This function locks lprops. Lprops have to be unlocked by
++ * 'ubifs_release_lprops()'.
++ */
++static inline void ubifs_get_lprops(struct ubifs_info *c)
++{
++	mutex_lock(&c->lp_mutex);
++}
++
++/**
++ * ubifs_release_lprops - release lprops lock.
++ * @c: the UBIFS file-system description object
++ *
++ * This function has to be called after each 'ubifs_get_lprops()' call to
++ * unlock lprops.
++ */
++static inline void ubifs_release_lprops(struct ubifs_info *c)
++{
++	ubifs_assert(mutex_is_locked(&c->lp_mutex));
++	ubifs_assert(c->lst.empty_lebs >= 0 &&
++		     c->lst.empty_lebs <= c->main_lebs);
++	mutex_unlock(&c->lp_mutex);
++}
++
++#endif /* __UBIFS_MISC_H__ */
+diff -Nurd linux-2.6.24.orig/fs/ubifs/orphan.c linux-2.6.24/fs/ubifs/orphan.c
+--- linux-2.6.24.orig/fs/ubifs/orphan.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/orphan.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,962 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Author: Adrian Hunter
++ */
++
++#include "ubifs.h"
++
++/*
++ * An orphan is an inode number whose inode node has been committed to the index
++ * with a link count of zero. That happens when an open file is deleted
++ * (unlinked) and then a commit is run. In the normal course of events the inode
++ * would be deleted when the file is closed. However in the case of an unclean
++ * unmount, orphans need to be accounted for. After an unclean unmount, the
++ * orphans' inodes must be deleted which means either scanning the entire index
++ * looking for them, or keeping a list on flash somewhere. This unit implements
++ * the latter approach.
++ *
++ * The orphan area is a fixed number of LEBs situated between the LPT area and
++ * the main area. The number of orphan area LEBs is specified when the file
++ * system is created. The minimum number is 1. The size of the orphan area
++ * should be so that it can hold the maximum number of orphans that are expected
++ * to ever exist at one time.
++ *
++ * The number of orphans that can fit in a LEB is:
++ *
++ *         (c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64)
++ *
++ * For example: a 15872 byte LEB can fit 1980 orphans so 1 LEB may be enough.
++ *
++ * Orphans are accumulated in a rb-tree. When an inode's link count drops to
++ * zero, the inode number is added to the rb-tree. It is removed from the tree
++ * when the inode is deleted.  Any new orphans that are in the orphan tree when
++ * the commit is run, are written to the orphan area in 1 or more orphan nodes.
++ * If the orphan area is full, it is consolidated to make space.  There is
++ * always enough space because validation prevents the user from creating more
++ * than the maximum number of orphans allowed.
++ */
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++static int dbg_check_orphans(struct ubifs_info *c);
++#else
++#define dbg_check_orphans(c) 0
++#endif
++
++/**
++ * ubifs_add_orphan - add an orphan.
++ * @c: UBIFS file-system description object
++ * @inum: orphan inode number
++ *
++ * Add an orphan. This function is called when an inodes link count drops to
++ * zero.
++ */
++int ubifs_add_orphan(struct ubifs_info *c, ino_t inum)
++{
++	struct ubifs_orphan *orphan, *o;
++	struct rb_node **p, *parent = NULL;
++
++	orphan = kzalloc(sizeof(struct ubifs_orphan), GFP_NOFS);
++	if (!orphan)
++		return -ENOMEM;
++	orphan->inum = inum;
++	orphan->new = 1;
++
++	spin_lock(&c->orphan_lock);
++	if (c->tot_orphans >= c->max_orphans) {
++		spin_unlock(&c->orphan_lock);
++		kfree(orphan);
++		return -ENFILE;
++	}
++	p = &c->orph_tree.rb_node;
++	while (*p) {
++		parent = *p;
++		o = rb_entry(parent, struct ubifs_orphan, rb);
++		if (inum < o->inum)
++			p = &(*p)->rb_left;
++		else if (inum > o->inum)
++			p = &(*p)->rb_right;
++		else {
++			dbg_err("orphaned twice");
++			spin_unlock(&c->orphan_lock);
++			kfree(orphan);
++			return 0;
++		}
++	}
++	c->tot_orphans += 1;
++	c->new_orphans += 1;
++	rb_link_node(&orphan->rb, parent, p);
++	rb_insert_color(&orphan->rb, &c->orph_tree);
++	list_add_tail(&orphan->list, &c->orph_list);
++	list_add_tail(&orphan->new_list, &c->orph_new);
++	spin_unlock(&c->orphan_lock);
++	dbg_gen("ino %lu", (unsigned long)inum);
++	return 0;
++}
++
++/**
++ * ubifs_delete_orphan - delete an orphan.
++ * @c: UBIFS file-system description object
++ * @inum: orphan inode number
++ *
++ * Delete an orphan. This function is called when an inode is deleted.
++ */
++void ubifs_delete_orphan(struct ubifs_info *c, ino_t inum)
++{
++	struct ubifs_orphan *o;
++	struct rb_node *p;
++
++	spin_lock(&c->orphan_lock);
++	p = c->orph_tree.rb_node;
++	while (p) {
++		o = rb_entry(p, struct ubifs_orphan, rb);
++		if (inum < o->inum)
++			p = p->rb_left;
++		else if (inum > o->inum)
++			p = p->rb_right;
++		else {
++			if (o->dnext) {
++				spin_unlock(&c->orphan_lock);
++				dbg_gen("deleted twice ino %lu",
++					(unsigned long)inum);
++				return;
++			}
++			if (o->cnext) {
++				o->dnext = c->orph_dnext;
++				c->orph_dnext = o;
++				spin_unlock(&c->orphan_lock);
++				dbg_gen("delete later ino %lu",
++					(unsigned long)inum);
++				return;
++			}
++			rb_erase(p, &c->orph_tree);
++			list_del(&o->list);
++			c->tot_orphans -= 1;
++			if (o->new) {
++				list_del(&o->new_list);
++				c->new_orphans -= 1;
++			}
++			spin_unlock(&c->orphan_lock);
++			kfree(o);
++			dbg_gen("inum %lu", (unsigned long)inum);
++			return;
++		}
++	}
++	spin_unlock(&c->orphan_lock);
++	dbg_err("missing orphan ino %lu", (unsigned long)inum);
++	dbg_dump_stack();
++}
++
++/**
++ * ubifs_orphan_start_commit - start commit of orphans.
++ * @c: UBIFS file-system description object
++ *
++ * Start commit of orphans.
++ */
++int ubifs_orphan_start_commit(struct ubifs_info *c)
++{
++	struct ubifs_orphan *orphan, **last;
++
++	spin_lock(&c->orphan_lock);
++	last = &c->orph_cnext;
++	list_for_each_entry(orphan, &c->orph_new, new_list) {
++		ubifs_assert(orphan->new);
++		orphan->new = 0;
++		*last = orphan;
++		last = &orphan->cnext;
++	}
++	*last = orphan->cnext;
++	c->cmt_orphans = c->new_orphans;
++	c->new_orphans = 0;
++	dbg_cmt("%d orphans to commit", c->cmt_orphans);
++	INIT_LIST_HEAD(&c->orph_new);
++	if (c->tot_orphans == 0)
++		c->no_orphs = 1;
++	else
++		c->no_orphs = 0;
++	spin_unlock(&c->orphan_lock);
++	return 0;
++}
++
++/**
++ * avail_orphs - calculate available space.
++ * @c: UBIFS file-system description object
++ *
++ * This function returns the number of orphans that can be written in the
++ * available space.
++ */
++static int avail_orphs(struct ubifs_info *c)
++{
++	int avail_lebs, avail, gap;
++
++	avail_lebs = c->orph_lebs - (c->ohead_lnum - c->orph_first) - 1;
++	avail = avail_lebs *
++	       ((c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64));
++	gap = c->leb_size - c->ohead_offs;
++	if (gap >= UBIFS_ORPH_NODE_SZ + sizeof(__le64))
++		avail += (gap - UBIFS_ORPH_NODE_SZ) / sizeof(__le64);
++	return avail;
++}
++
++/**
++ * tot_avail_orphs - calculate total space.
++ * @c: UBIFS file-system description object
++ *
++ * This function returns the number of orphans that can be written in half
++ * the total space. That leaves half the space for adding new orphans.
++ */
++static int tot_avail_orphs(struct ubifs_info *c)
++{
++	int avail_lebs, avail;
++
++	avail_lebs = c->orph_lebs;
++	avail = avail_lebs *
++	       ((c->leb_size - UBIFS_ORPH_NODE_SZ) / sizeof(__le64));
++	return avail / 2;
++}
++
++/**
++ * do_write_orph_node - write a node to the orphan head.
++ * @c: UBIFS file-system description object
++ * @len: length of node
++ * @atomic: write atomically
++ *
++ * This function writes a node to the orphan head from the orphan buffer. If
++ * %atomic is not zero, then the write is done atomically. On success, %0 is
++ * returned, otherwise a negative error code is returned.
++ */
++static int do_write_orph_node(struct ubifs_info *c, int len, int atomic)
++{
++	int err = 0;
++
++	if (atomic) {
++		ubifs_assert(c->ohead_offs == 0);
++		ubifs_prepare_node(c, c->orph_buf, len, 1);
++		len = ALIGN(len, c->min_io_size);
++		err = ubifs_leb_change(c, c->ohead_lnum, c->orph_buf, len,
++				       UBI_SHORTTERM);
++	} else {
++		if (c->ohead_offs == 0) {
++			/* Ensure LEB has been unmapped */
++			err = ubifs_leb_unmap(c, c->ohead_lnum);
++			if (err)
++				return err;
++		}
++		err = ubifs_write_node(c, c->orph_buf, len, c->ohead_lnum,
++				       c->ohead_offs, UBI_SHORTTERM);
++	}
++	return err;
++}
++
++/**
++ * write_orph_node - write an orphan node.
++ * @c: UBIFS file-system description object
++ * @atomic: write atomically
++ *
++ * This function builds an orphan node from the cnext list and writes it to the
++ * orphan head. On success, %0 is returned, otherwise a negative error code
++ * is returned.
++ */
++static int write_orph_node(struct ubifs_info *c, int atomic)
++{
++	struct ubifs_orphan *orphan, *cnext;
++	struct ubifs_orph_node *orph;
++	int gap, err, len, cnt, i;
++
++	ubifs_assert(c->cmt_orphans > 0);
++	gap = c->leb_size - c->ohead_offs;
++	if (gap < UBIFS_ORPH_NODE_SZ + sizeof(__le64)) {
++		c->ohead_lnum += 1;
++		c->ohead_offs = 0;
++		gap = c->leb_size;
++		if (c->ohead_lnum > c->orph_last) {
++			/*
++			 * We limit the number of orphans so that this should
++			 * never happen.
++			 */
++			ubifs_err("out of space in orphan area");
++			return -EINVAL;
++		}
++	}
++	cnt = (gap - UBIFS_ORPH_NODE_SZ) / sizeof(__le64);
++	if (cnt > c->cmt_orphans)
++		cnt = c->cmt_orphans;
++	len = UBIFS_ORPH_NODE_SZ + cnt * sizeof(__le64);
++	ubifs_assert(c->orph_buf);
++	orph = c->orph_buf;
++	orph->ch.node_type = UBIFS_ORPH_NODE;
++	spin_lock(&c->orphan_lock);
++	cnext = c->orph_cnext;
++	for (i = 0; i < cnt; i++) {
++		orphan = cnext;
++		orph->inos[i] = cpu_to_le64(orphan->inum);
++		cnext = orphan->cnext;
++		orphan->cnext = NULL;
++	}
++	c->orph_cnext = cnext;
++	c->cmt_orphans -= cnt;
++	spin_unlock(&c->orphan_lock);
++	if (c->cmt_orphans)
++		orph->cmt_no = cpu_to_le64(c->cmt_no);
++	else
++		/* Mark the last node of the commit */
++		orph->cmt_no = cpu_to_le64((c->cmt_no) | (1ULL << 63));
++	ubifs_assert(c->ohead_offs + len <= c->leb_size);
++	ubifs_assert(c->ohead_lnum >= c->orph_first);
++	ubifs_assert(c->ohead_lnum <= c->orph_last);
++	err = do_write_orph_node(c, len, atomic);
++	c->ohead_offs += ALIGN(len, c->min_io_size);
++	c->ohead_offs = ALIGN(c->ohead_offs, 8);
++	return err;
++}
++
++/**
++ * write_orph_nodes - write orphan nodes until there are no more to commit.
++ * @c: UBIFS file-system description object
++ * @atomic: write atomically
++ *
++ * This function writes orphan nodes for all the orphans to commit. On success,
++ * %0 is returned, otherwise a negative error code is returned.
++ */
++static int write_orph_nodes(struct ubifs_info *c, int atomic)
++{
++	int err;
++
++	while (c->cmt_orphans > 0) {
++		err = write_orph_node(c, atomic);
++		if (err)
++			return err;
++	}
++	if (atomic) {
++		int lnum;
++
++		/* Unmap any unused LEBs after consolidation */
++		lnum = c->ohead_lnum + 1;
++		for (lnum = c->ohead_lnum + 1; lnum <= c->orph_last; lnum++) {
++			err = ubifs_leb_unmap(c, lnum);
++			if (err)
++				return err;
++		}
++	}
++	return 0;
++}
++
++/**
++ * consolidate - consolidate the orphan area.
++ * @c: UBIFS file-system description object
++ *
++ * This function enables consolidation by putting all the orphans into the list
++ * to commit. The list is in the order that the orphans were added, and the
++ * LEBs are written atomically in order, so at no time can orphans be lost by
++ * an unclean unmount.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int consolidate(struct ubifs_info *c)
++{
++	int tot_avail = tot_avail_orphs(c), err = 0;
++
++	spin_lock(&c->orphan_lock);
++	dbg_cmt("there is space for %d orphans and there are %d",
++		tot_avail, c->tot_orphans);
++	if (c->tot_orphans - c->new_orphans <= tot_avail) {
++		struct ubifs_orphan *orphan, **last;
++		int cnt = 0;
++
++		/* Change the cnext list to include all non-new orphans */
++		last = &c->orph_cnext;
++		list_for_each_entry(orphan, &c->orph_list, list) {
++			if (orphan->new)
++				continue;
++			*last = orphan;
++			last = &orphan->cnext;
++			cnt += 1;
++		}
++		*last = orphan->cnext;
++		ubifs_assert(cnt == c->tot_orphans - c->new_orphans);
++		c->cmt_orphans = cnt;
++		c->ohead_lnum = c->orph_first;
++		c->ohead_offs = 0;
++	} else {
++		/*
++		 * We limit the number of orphans so that this should
++		 * never happen.
++		 */
++		ubifs_err("out of space in orphan area");
++		err = -EINVAL;
++	}
++	spin_unlock(&c->orphan_lock);
++	return err;
++}
++
++/**
++ * commit_orphans - commit orphans.
++ * @c: UBIFS file-system description object
++ *
++ * This function commits orphans to flash. On success, %0 is returned,
++ * otherwise a negative error code is returned.
++ */
++static int commit_orphans(struct ubifs_info *c)
++{
++	int avail, atomic = 0, err;
++
++	ubifs_assert(c->cmt_orphans > 0);
++	avail = avail_orphs(c);
++	if (avail < c->cmt_orphans) {
++		/* Not enough space to write new orphans, so consolidate */
++		err = consolidate(c);
++		if (err)
++			return err;
++		atomic = 1;
++	}
++	err = write_orph_nodes(c, atomic);
++	return err;
++}
++
++/**
++ * erase_deleted - erase the orphans marked for deletion.
++ * @c: UBIFS file-system description object
++ *
++ * During commit, the orphans being committed cannot be deleted, so they are
++ * marked for deletion and deleted by this function. Also, the recovery
++ * adds killed orphans to the deletion list, and therefore they are deleted
++ * here too.
++ */
++static void erase_deleted(struct ubifs_info *c)
++{
++	struct ubifs_orphan *orphan, *dnext;
++
++	spin_lock(&c->orphan_lock);
++	dnext = c->orph_dnext;
++	while (dnext) {
++		orphan = dnext;
++		dnext = orphan->dnext;
++		ubifs_assert(!orphan->new);
++		rb_erase(&orphan->rb, &c->orph_tree);
++		list_del(&orphan->list);
++		c->tot_orphans -= 1;
++		dbg_gen("deleting orphan ino %lu", (unsigned long)orphan->inum);
++		kfree(orphan);
++	}
++	c->orph_dnext = NULL;
++	spin_unlock(&c->orphan_lock);
++}
++
++/**
++ * ubifs_orphan_end_commit - end commit of orphans.
++ * @c: UBIFS file-system description object
++ *
++ * End commit of orphans.
++ */
++int ubifs_orphan_end_commit(struct ubifs_info *c)
++{
++	int err;
++
++	if (c->cmt_orphans != 0) {
++		err = commit_orphans(c);
++		if (err)
++			return err;
++	}
++	erase_deleted(c);
++	err = dbg_check_orphans(c);
++	return err;
++}
++
++/**
++ * ubifs_clear_orphans - erase all LEBs used for orphans.
++ * @c: UBIFS file-system description object
++ *
++ * If recovery is not required, then the orphans from the previous session
++ * are not needed. This function locates the LEBs used to record
++ * orphans, and un-maps them.
++ */
++int ubifs_clear_orphans(struct ubifs_info *c)
++{
++	int lnum, err;
++
++	for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
++		err = ubifs_leb_unmap(c, lnum);
++		if (err)
++			return err;
++	}
++	c->ohead_lnum = c->orph_first;
++	c->ohead_offs = 0;
++	return 0;
++}
++
++/**
++ * insert_dead_orphan - insert an orphan.
++ * @c: UBIFS file-system description object
++ * @inum: orphan inode number
++ *
++ * This function is a helper to the 'do_kill_orphans()' function. The orphan
++ * must be kept until the next commit, so it is added to the rb-tree and the
++ * deletion list.
++ */
++static int insert_dead_orphan(struct ubifs_info *c, ino_t inum)
++{
++	struct ubifs_orphan *orphan, *o;
++	struct rb_node **p, *parent = NULL;
++
++	orphan = kzalloc(sizeof(struct ubifs_orphan), GFP_KERNEL);
++	if (!orphan)
++		return -ENOMEM;
++	orphan->inum = inum;
++
++	p = &c->orph_tree.rb_node;
++	while (*p) {
++		parent = *p;
++		o = rb_entry(parent, struct ubifs_orphan, rb);
++		if (inum < o->inum)
++			p = &(*p)->rb_left;
++		else if (inum > o->inum)
++			p = &(*p)->rb_right;
++		else {
++			/* Already added - no problem */
++			kfree(orphan);
++			return 0;
++		}
++	}
++	c->tot_orphans += 1;
++	rb_link_node(&orphan->rb, parent, p);
++	rb_insert_color(&orphan->rb, &c->orph_tree);
++	list_add_tail(&orphan->list, &c->orph_list);
++	orphan->dnext = c->orph_dnext;
++	c->orph_dnext = orphan;
++	dbg_mnt("ino %lu, new %d, tot %d", (unsigned long)inum,
++		c->new_orphans, c->tot_orphans);
++	return 0;
++}
++
++/**
++ * do_kill_orphans - remove orphan inodes from the index.
++ * @c: UBIFS file-system description object
++ * @sleb: scanned LEB
++ * @last_cmt_no: cmt_no of last orphan node read is passed and returned here
++ * @outofdate: whether the LEB is out of date is returned here
++ * @last_flagged: whether the end orphan node is encountered
++ *
++ * This function is a helper to the 'kill_orphans()' function. It goes through
++ * every orphan node in a LEB and for every inode number recorded, removes
++ * all keys for that inode from the TNC.
++ */
++static int do_kill_orphans(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
++			   unsigned long long *last_cmt_no, int *outofdate,
++			   int *last_flagged)
++{
++	struct ubifs_scan_node *snod;
++	struct ubifs_orph_node *orph;
++	unsigned long long cmt_no;
++	ino_t inum;
++	int i, n, err, first = 1;
++
++	list_for_each_entry(snod, &sleb->nodes, list) {
++		if (snod->type != UBIFS_ORPH_NODE) {
++			ubifs_err("invalid node type %d in orphan area at "
++				  "%d:%d", snod->type, sleb->lnum, snod->offs);
++			dbg_dump_node(c, snod->node);
++			return -EINVAL;
++		}
++
++		orph = snod->node;
++
++		/* Check commit number */
++		cmt_no = le64_to_cpu(orph->cmt_no) & LLONG_MAX;
++		/*
++		 * The commit number on the master node may be less, because
++		 * of a failed commit. If there are several failed commits in a
++		 * row, the commit number written on orphan nodes will continue
++		 * to increase (because the commit number is adjusted here) even
++		 * though the commit number on the master node stays the same
++		 * because the master node has not been re-written.
++		 */
++		if (cmt_no > c->cmt_no)
++			c->cmt_no = cmt_no;
++		if (cmt_no < *last_cmt_no && *last_flagged) {
++			/*
++			 * The last orphan node had a higher commit number and
++			 * was flagged as the last written for that commit
++			 * number. That makes this orphan node, out of date.
++			 */
++			if (!first) {
++				ubifs_err("out of order commit number %llu in "
++					  "orphan node at %d:%d",
++					  cmt_no, sleb->lnum, snod->offs);
++				dbg_dump_node(c, snod->node);
++				return -EINVAL;
++			}
++			dbg_rcvry("out of date LEB %d", sleb->lnum);
++			*outofdate = 1;
++			return 0;
++		}
++
++		if (first)
++			first = 0;
++
++		n = (le32_to_cpu(orph->ch.len) - UBIFS_ORPH_NODE_SZ) >> 3;
++		for (i = 0; i < n; i++) {
++			inum = le64_to_cpu(orph->inos[i]);
++			dbg_rcvry("deleting orphaned inode %lu",
++				  (unsigned long)inum);
++			err = ubifs_tnc_remove_ino(c, inum);
++			if (err)
++				return err;
++			err = insert_dead_orphan(c, inum);
++			if (err)
++				return err;
++		}
++
++		*last_cmt_no = cmt_no;
++		if (le64_to_cpu(orph->cmt_no) & (1ULL << 63)) {
++			dbg_rcvry("last orph node for commit %llu at %d:%d",
++				  cmt_no, sleb->lnum, snod->offs);
++			*last_flagged = 1;
++		} else
++			*last_flagged = 0;
++	}
++
++	return 0;
++}
++
++/**
++ * kill_orphans - remove all orphan inodes from the index.
++ * @c: UBIFS file-system description object
++ *
++ * If recovery is required, then orphan inodes recorded during the previous
++ * session (which ended with an unclean unmount) must be deleted from the index.
++ * This is done by updating the TNC, but since the index is not updated until
++ * the next commit, the LEBs where the orphan information is recorded are not
++ * erased until the next commit.
++ */
++static int kill_orphans(struct ubifs_info *c)
++{
++	unsigned long long last_cmt_no = 0;
++	int lnum, err = 0, outofdate = 0, last_flagged = 0;
++
++	c->ohead_lnum = c->orph_first;
++	c->ohead_offs = 0;
++	/* Check no-orphans flag and skip this if no orphans */
++	if (c->no_orphs) {
++		dbg_rcvry("no orphans");
++		return 0;
++	}
++	/*
++	 * Orph nodes always start at c->orph_first and are written to each
++	 * successive LEB in turn. Generally unused LEBs will have been unmapped
++	 * but may contain out of date orphan nodes if the unmap didn't go
++	 * through. In addition, the last orphan node written for each commit is
++	 * marked (top bit of orph->cmt_no is set to 1). It is possible that
++	 * there are orphan nodes from the next commit (i.e. the commit did not
++	 * complete successfully). In that case, no orphans will have been lost
++	 * due to the way that orphans are written, and any orphans added will
++	 * be valid orphans anyway and so can be deleted.
++	 */
++	for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
++		struct ubifs_scan_leb *sleb;
++
++		dbg_rcvry("LEB %d", lnum);
++		sleb = ubifs_scan(c, lnum, 0, c->sbuf);
++		if (IS_ERR(sleb)) {
++			sleb = ubifs_recover_leb(c, lnum, 0, c->sbuf, 0);
++			if (IS_ERR(sleb)) {
++				err = PTR_ERR(sleb);
++				break;
++			}
++		}
++		err = do_kill_orphans(c, sleb, &last_cmt_no, &outofdate,
++				      &last_flagged);
++		if (err || outofdate) {
++			ubifs_scan_destroy(sleb);
++			break;
++		}
++		if (sleb->endpt) {
++			c->ohead_lnum = lnum;
++			c->ohead_offs = sleb->endpt;
++		}
++		ubifs_scan_destroy(sleb);
++	}
++	return err;
++}
++
++/**
++ * ubifs_mount_orphans - delete orphan inodes and erase LEBs that recorded them.
++ * @c: UBIFS file-system description object
++ * @unclean: indicates recovery from unclean unmount
++ * @read_only: indicates read only mount
++ *
++ * This function is called when mounting to erase orphans from the previous
++ * session. If UBIFS was not unmounted cleanly, then the inodes recorded as
++ * orphans are deleted.
++ */
++int ubifs_mount_orphans(struct ubifs_info *c, int unclean, int read_only)
++{
++	int err = 0;
++
++	c->max_orphans = tot_avail_orphs(c);
++
++	if (!read_only) {
++		c->orph_buf = vmalloc(c->leb_size);
++		if (!c->orph_buf)
++			return -ENOMEM;
++	}
++
++	if (unclean)
++		err = kill_orphans(c);
++	else if (!read_only)
++		err = ubifs_clear_orphans(c);
++
++	return err;
++}
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++
++struct check_orphan {
++	struct rb_node rb;
++	ino_t inum;
++};
++
++struct check_info {
++	unsigned long last_ino;
++	unsigned long tot_inos;
++	unsigned long missing;
++	unsigned long long leaf_cnt;
++	struct ubifs_ino_node *node;
++	struct rb_root root;
++};
++
++static int dbg_find_orphan(struct ubifs_info *c, ino_t inum)
++{
++	struct ubifs_orphan *o;
++	struct rb_node *p;
++
++	spin_lock(&c->orphan_lock);
++	p = c->orph_tree.rb_node;
++	while (p) {
++		o = rb_entry(p, struct ubifs_orphan, rb);
++		if (inum < o->inum)
++			p = p->rb_left;
++		else if (inum > o->inum)
++			p = p->rb_right;
++		else {
++			spin_unlock(&c->orphan_lock);
++			return 1;
++		}
++	}
++	spin_unlock(&c->orphan_lock);
++	return 0;
++}
++
++static int dbg_ins_check_orphan(struct rb_root *root, ino_t inum)
++{
++	struct check_orphan *orphan, *o;
++	struct rb_node **p, *parent = NULL;
++
++	orphan = kzalloc(sizeof(struct check_orphan), GFP_NOFS);
++	if (!orphan)
++		return -ENOMEM;
++	orphan->inum = inum;
++
++	p = &root->rb_node;
++	while (*p) {
++		parent = *p;
++		o = rb_entry(parent, struct check_orphan, rb);
++		if (inum < o->inum)
++			p = &(*p)->rb_left;
++		else if (inum > o->inum)
++			p = &(*p)->rb_right;
++		else {
++			kfree(orphan);
++			return 0;
++		}
++	}
++	rb_link_node(&orphan->rb, parent, p);
++	rb_insert_color(&orphan->rb, root);
++	return 0;
++}
++
++static int dbg_find_check_orphan(struct rb_root *root, ino_t inum)
++{
++	struct check_orphan *o;
++	struct rb_node *p;
++
++	p = root->rb_node;
++	while (p) {
++		o = rb_entry(p, struct check_orphan, rb);
++		if (inum < o->inum)
++			p = p->rb_left;
++		else if (inum > o->inum)
++			p = p->rb_right;
++		else
++			return 1;
++	}
++	return 0;
++}
++
++static void dbg_free_check_tree(struct rb_root *root)
++{
++	struct rb_node *this = root->rb_node;
++	struct check_orphan *o;
++
++	while (this) {
++		if (this->rb_left) {
++			this = this->rb_left;
++			continue;
++		} else if (this->rb_right) {
++			this = this->rb_right;
++			continue;
++		}
++		o = rb_entry(this, struct check_orphan, rb);
++		this = rb_parent(this);
++		if (this) {
++			if (this->rb_left == &o->rb)
++				this->rb_left = NULL;
++			else
++				this->rb_right = NULL;
++		}
++		kfree(o);
++	}
++}
++
++static int dbg_orphan_check(struct ubifs_info *c, struct ubifs_zbranch *zbr,
++			    void *priv)
++{
++	struct check_info *ci = priv;
++	ino_t inum;
++	int err;
++
++	inum = key_inum(c, &zbr->key);
++	if (inum != ci->last_ino) {
++		/* Lowest node type is the inode node, so it comes first */
++		if (key_type(c, &zbr->key) != UBIFS_INO_KEY)
++			ubifs_err("found orphan node ino %lu, type %d",
++				  (unsigned long)inum, key_type(c, &zbr->key));
++		ci->last_ino = inum;
++		ci->tot_inos += 1;
++		err = ubifs_tnc_read_node(c, zbr, ci->node);
++		if (err) {
++			ubifs_err("node read failed, error %d", err);
++			return err;
++		}
++		if (ci->node->nlink == 0)
++			/* Must be recorded as an orphan */
++			if (!dbg_find_check_orphan(&ci->root, inum) &&
++			    !dbg_find_orphan(c, inum)) {
++				ubifs_err("missing orphan, ino %lu",
++					  (unsigned long)inum);
++				ci->missing += 1;
++			}
++	}
++	ci->leaf_cnt += 1;
++	return 0;
++}
++
++static int dbg_read_orphans(struct check_info *ci, struct ubifs_scan_leb *sleb)
++{
++	struct ubifs_scan_node *snod;
++	struct ubifs_orph_node *orph;
++	ino_t inum;
++	int i, n, err;
++
++	list_for_each_entry(snod, &sleb->nodes, list) {
++		cond_resched();
++		if (snod->type != UBIFS_ORPH_NODE)
++			continue;
++		orph = snod->node;
++		n = (le32_to_cpu(orph->ch.len) - UBIFS_ORPH_NODE_SZ) >> 3;
++		for (i = 0; i < n; i++) {
++			inum = le64_to_cpu(orph->inos[i]);
++			err = dbg_ins_check_orphan(&ci->root, inum);
++			if (err)
++				return err;
++		}
++	}
++	return 0;
++}
++
++static int dbg_scan_orphans(struct ubifs_info *c, struct check_info *ci)
++{
++	int lnum, err = 0;
++
++	/* Check no-orphans flag and skip this if no orphans */
++	if (c->no_orphs)
++		return 0;
++
++	for (lnum = c->orph_first; lnum <= c->orph_last; lnum++) {
++		struct ubifs_scan_leb *sleb;
++
++		sleb = ubifs_scan(c, lnum, 0, c->dbg->buf);
++		if (IS_ERR(sleb)) {
++			err = PTR_ERR(sleb);
++			break;
++		}
++
++		err = dbg_read_orphans(ci, sleb);
++		ubifs_scan_destroy(sleb);
++		if (err)
++			break;
++	}
++
++	return err;
++}
++
++static int dbg_check_orphans(struct ubifs_info *c)
++{
++	struct check_info ci;
++	int err;
++
++	if (!(ubifs_chk_flags & UBIFS_CHK_ORPH))
++		return 0;
++
++	ci.last_ino = 0;
++	ci.tot_inos = 0;
++	ci.missing  = 0;
++	ci.leaf_cnt = 0;
++	ci.root = RB_ROOT;
++	ci.node = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
++	if (!ci.node) {
++		ubifs_err("out of memory");
++		return -ENOMEM;
++	}
++
++	err = dbg_scan_orphans(c, &ci);
++	if (err)
++		goto out;
++
++	err = dbg_walk_index(c, &dbg_orphan_check, NULL, &ci);
++	if (err) {
++		ubifs_err("cannot scan TNC, error %d", err);
++		goto out;
++	}
++
++	if (ci.missing) {
++		ubifs_err("%lu missing orphan(s)", ci.missing);
++		err = -EINVAL;
++		goto out;
++	}
++
++	dbg_cmt("last inode number is %lu", ci.last_ino);
++	dbg_cmt("total number of inodes is %lu", ci.tot_inos);
++	dbg_cmt("total number of leaf nodes is %llu", ci.leaf_cnt);
++
++out:
++	dbg_free_check_tree(&ci.root);
++	kfree(ci.node);
++	return err;
++}
++
++#endif /* CONFIG_UBIFS_FS_DEBUG */
+diff -Nurd linux-2.6.24.orig/fs/ubifs/recovery.c linux-2.6.24/fs/ubifs/recovery.c
+--- linux-2.6.24.orig/fs/ubifs/recovery.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/recovery.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,1520 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Adrian Hunter
++ *          Artem Bityutskiy (Битюцкий Артём)
++ */
++
++/*
++ * This file implements functions needed to recover from unclean un-mounts.
++ * When UBIFS is mounted, it checks a flag on the master node to determine if
++ * an un-mount was completed sucessfully. If not, the process of mounting
++ * incorparates additional checking and fixing of on-flash data structures.
++ * UBIFS always cleans away all remnants of an unclean un-mount, so that
++ * errors do not accumulate. However UBIFS defers recovery if it is mounted
++ * read-only, and the flash is not modified in that case.
++ */
++
++#include <linux/crc32.h>
++#include "ubifs.h"
++
++/**
++ * is_empty - determine whether a buffer is empty (contains all 0xff).
++ * @buf: buffer to clean
++ * @len: length of buffer
++ *
++ * This function returns %1 if the buffer is empty (contains all 0xff) otherwise
++ * %0 is returned.
++ */
++static int is_empty(void *buf, int len)
++{
++	uint8_t *p = buf;
++	int i;
++
++	for (i = 0; i < len; i++)
++		if (*p++ != 0xff)
++			return 0;
++	return 1;
++}
++
++/**
++ * get_master_node - get the last valid master node allowing for corruption.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number
++ * @pbuf: buffer containing the LEB read, is returned here
++ * @mst: master node, if found, is returned here
++ * @cor: corruption, if found, is returned here
++ *
++ * This function allocates a buffer, reads the LEB into it, and finds and
++ * returns the last valid master node allowing for one area of corruption.
++ * The corrupt area, if there is one, must be consistent with the assumption
++ * that it is the result of an unclean unmount while the master node was being
++ * written. Under those circumstances, it is valid to use the previously written
++ * master node.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int get_master_node(const struct ubifs_info *c, int lnum, void **pbuf,
++			   struct ubifs_mst_node **mst, void **cor)
++{
++	const int sz = c->mst_node_alsz;
++	int err, offs, len;
++	void *sbuf, *buf;
++
++	sbuf = vmalloc(c->leb_size);
++	if (!sbuf)
++		return -ENOMEM;
++
++	err = ubi_read(c->ubi, lnum, sbuf, 0, c->leb_size);
++	if (err && err != -EBADMSG)
++		goto out_free;
++
++	/* Find the first position that is definitely not a node */
++	offs = 0;
++	buf = sbuf;
++	len = c->leb_size;
++	while (offs + UBIFS_MST_NODE_SZ <= c->leb_size) {
++		struct ubifs_ch *ch = buf;
++
++		if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC)
++			break;
++		offs += sz;
++		buf  += sz;
++		len  -= sz;
++	}
++	/* See if there was a valid master node before that */
++	if (offs) {
++		int ret;
++
++		offs -= sz;
++		buf  -= sz;
++		len  += sz;
++		ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1);
++		if (ret != SCANNED_A_NODE && offs) {
++			/* Could have been corruption so check one place back */
++			offs -= sz;
++			buf  -= sz;
++			len  += sz;
++			ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1);
++			if (ret != SCANNED_A_NODE)
++				/*
++				 * We accept only one area of corruption because
++				 * we are assuming that it was caused while
++				 * trying to write a master node.
++				 */
++				goto out_err;
++		}
++		if (ret == SCANNED_A_NODE) {
++			struct ubifs_ch *ch = buf;
++
++			if (ch->node_type != UBIFS_MST_NODE)
++				goto out_err;
++			dbg_rcvry("found a master node at %d:%d", lnum, offs);
++			*mst = buf;
++			offs += sz;
++			buf  += sz;
++			len  -= sz;
++		}
++	}
++	/* Check for corruption */
++	if (offs < c->leb_size) {
++		if (!is_empty(buf, min_t(int, len, sz))) {
++			*cor = buf;
++			dbg_rcvry("found corruption at %d:%d", lnum, offs);
++		}
++		offs += sz;
++		buf  += sz;
++		len  -= sz;
++	}
++	/* Check remaining empty space */
++	if (offs < c->leb_size)
++		if (!is_empty(buf, len))
++			goto out_err;
++	*pbuf = sbuf;
++	return 0;
++
++out_err:
++	err = -EINVAL;
++out_free:
++	vfree(sbuf);
++	*mst = NULL;
++	*cor = NULL;
++	return err;
++}
++
++/**
++ * write_rcvrd_mst_node - write recovered master node.
++ * @c: UBIFS file-system description object
++ * @mst: master node
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int write_rcvrd_mst_node(struct ubifs_info *c,
++				struct ubifs_mst_node *mst)
++{
++	int err = 0, lnum = UBIFS_MST_LNUM, sz = c->mst_node_alsz;
++	__le32 save_flags;
++
++	dbg_rcvry("recovery");
++
++	save_flags = mst->flags;
++	mst->flags |= cpu_to_le32(UBIFS_MST_RCVRY);
++
++	ubifs_prepare_node(c, mst, UBIFS_MST_NODE_SZ, 1);
++	err = ubi_leb_change(c->ubi, lnum, mst, sz, UBI_SHORTTERM);
++	if (err)
++		goto out;
++	err = ubi_leb_change(c->ubi, lnum + 1, mst, sz, UBI_SHORTTERM);
++	if (err)
++		goto out;
++out:
++	mst->flags = save_flags;
++	return err;
++}
++
++/**
++ * ubifs_recover_master_node - recover the master node.
++ * @c: UBIFS file-system description object
++ *
++ * This function recovers the master node from corruption that may occur due to
++ * an unclean unmount.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int ubifs_recover_master_node(struct ubifs_info *c)
++{
++	void *buf1 = NULL, *buf2 = NULL, *cor1 = NULL, *cor2 = NULL;
++	struct ubifs_mst_node *mst1 = NULL, *mst2 = NULL, *mst;
++	const int sz = c->mst_node_alsz;
++	int err, offs1, offs2;
++
++	dbg_rcvry("recovery");
++
++	err = get_master_node(c, UBIFS_MST_LNUM, &buf1, &mst1, &cor1);
++	if (err)
++		goto out_free;
++
++	err = get_master_node(c, UBIFS_MST_LNUM + 1, &buf2, &mst2, &cor2);
++	if (err)
++		goto out_free;
++
++	if (mst1) {
++		offs1 = (void *)mst1 - buf1;
++		if ((le32_to_cpu(mst1->flags) & UBIFS_MST_RCVRY) &&
++		    (offs1 == 0 && !cor1)) {
++			/*
++			 * mst1 was written by recovery at offset 0 with no
++			 * corruption.
++			 */
++			dbg_rcvry("recovery recovery");
++			mst = mst1;
++		} else if (mst2) {
++			offs2 = (void *)mst2 - buf2;
++			if (offs1 == offs2) {
++				/* Same offset, so must be the same */
++				if (memcmp((void *)mst1 + UBIFS_CH_SZ,
++					   (void *)mst2 + UBIFS_CH_SZ,
++					   UBIFS_MST_NODE_SZ - UBIFS_CH_SZ))
++					goto out_err;
++				mst = mst1;
++			} else if (offs2 + sz == offs1) {
++				/* 1st LEB was written, 2nd was not */
++				if (cor1)
++					goto out_err;
++				mst = mst1;
++			} else if (offs1 == 0 && offs2 + sz >= c->leb_size) {
++				/* 1st LEB was unmapped and written, 2nd not */
++				if (cor1)
++					goto out_err;
++				mst = mst1;
++			} else
++				goto out_err;
++		} else {
++			/*
++			 * 2nd LEB was unmapped and about to be written, so
++			 * there must be only one master node in the first LEB
++			 * and no corruption.
++			 */
++			if (offs1 != 0 || cor1)
++				goto out_err;
++			mst = mst1;
++		}
++	} else {
++		if (!mst2)
++			goto out_err;
++		/*
++		 * 1st LEB was unmapped and about to be written, so there must
++		 * be no room left in 2nd LEB.
++		 */
++		offs2 = (void *)mst2 - buf2;
++		if (offs2 + sz + sz <= c->leb_size)
++			goto out_err;
++		mst = mst2;
++	}
++
++	dbg_rcvry("recovered master node from LEB %d",
++		  (mst == mst1 ? UBIFS_MST_LNUM : UBIFS_MST_LNUM + 1));
++
++	memcpy(c->mst_node, mst, UBIFS_MST_NODE_SZ);
++
++	if ((c->vfs_sb->s_flags & MS_RDONLY)) {
++		/* Read-only mode. Keep a copy for switching to rw mode */
++		c->rcvrd_mst_node = kmalloc(sz, GFP_KERNEL);
++		if (!c->rcvrd_mst_node) {
++			err = -ENOMEM;
++			goto out_free;
++		}
++		memcpy(c->rcvrd_mst_node, c->mst_node, UBIFS_MST_NODE_SZ);
++	} else {
++		/* Write the recovered master node */
++		c->max_sqnum = le64_to_cpu(mst->ch.sqnum) - 1;
++		err = write_rcvrd_mst_node(c, c->mst_node);
++		if (err)
++			goto out_free;
++	}
++
++	vfree(buf2);
++	vfree(buf1);
++
++	return 0;
++
++out_err:
++	err = -EINVAL;
++out_free:
++	ubifs_err("failed to recover master node");
++	if (mst1) {
++		dbg_err("dumping first master node");
++		dbg_dump_node(c, mst1);
++	}
++	if (mst2) {
++		dbg_err("dumping second master node");
++		dbg_dump_node(c, mst2);
++	}
++	vfree(buf2);
++	vfree(buf1);
++	return err;
++}
++
++/**
++ * ubifs_write_rcvrd_mst_node - write the recovered master node.
++ * @c: UBIFS file-system description object
++ *
++ * This function writes the master node that was recovered during mounting in
++ * read-only mode and must now be written because we are remounting rw.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int ubifs_write_rcvrd_mst_node(struct ubifs_info *c)
++{
++	int err;
++
++	if (!c->rcvrd_mst_node)
++		return 0;
++	c->rcvrd_mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
++	c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
++	err = write_rcvrd_mst_node(c, c->rcvrd_mst_node);
++	if (err)
++		return err;
++	kfree(c->rcvrd_mst_node);
++	c->rcvrd_mst_node = NULL;
++	return 0;
++}
++
++/**
++ * is_last_write - determine if an offset was in the last write to a LEB.
++ * @c: UBIFS file-system description object
++ * @buf: buffer to check
++ * @offs: offset to check
++ *
++ * This function returns %1 if @offs was in the last write to the LEB whose data
++ * is in @buf, otherwise %0 is returned.  The determination is made by checking
++ * for subsequent empty space starting from the next min_io_size boundary (or a
++ * bit less than the common header size if min_io_size is one).
++ */
++static int is_last_write(const struct ubifs_info *c, void *buf, int offs)
++{
++	int empty_offs;
++	int check_len;
++	uint8_t *p;
++
++	if (c->min_io_size == 1) {
++		check_len = c->leb_size - offs;
++		p = buf + check_len;
++		for (; check_len > 0; check_len--)
++			if (*--p != 0xff)
++				break;
++		/*
++		 * 'check_len' is the size of the corruption which cannot be
++		 * more than the size of 1 node if it was caused by an unclean
++		 * unmount.
++		 */
++		if (check_len > UBIFS_MAX_NODE_SZ)
++			return 0;
++		return 1;
++	}
++
++	/*
++	 * Round up to the next c->min_io_size boundary i.e. 'offs' is in the
++	 * last wbuf written. After that should be empty space.
++	 */
++	empty_offs = ALIGN(offs + 1, c->min_io_size);
++	check_len = c->leb_size - empty_offs;
++	p = buf + empty_offs - offs;
++
++	for (; check_len > 0; check_len--)
++		if (*p++ != 0xff)
++			return 0;
++	return 1;
++}
++
++/**
++ * clean_buf - clean the data from an LEB sitting in a buffer.
++ * @c: UBIFS file-system description object
++ * @buf: buffer to clean
++ * @lnum: LEB number to clean
++ * @offs: offset from which to clean
++ * @len: length of buffer
++ *
++ * This function pads up to the next min_io_size boundary (if there is one) and
++ * sets empty space to all 0xff. @buf, @offs and @len are updated to the next
++ * min_io_size boundary (if there is one).
++ */
++static void clean_buf(const struct ubifs_info *c, void **buf, int lnum,
++		      int *offs, int *len)
++{
++	int empty_offs, pad_len;
++
++	lnum = lnum;
++	dbg_rcvry("cleaning corruption at %d:%d", lnum, *offs);
++
++	if (c->min_io_size == 1) {
++		memset(*buf, 0xff, c->leb_size - *offs);
++		return;
++	}
++
++	ubifs_assert(!(*offs & 7));
++	empty_offs = ALIGN(*offs, c->min_io_size);
++	pad_len = empty_offs - *offs;
++	ubifs_pad(c, *buf, pad_len);
++	*offs += pad_len;
++	*buf += pad_len;
++	*len -= pad_len;
++	memset(*buf, 0xff, c->leb_size - empty_offs);
++}
++
++/**
++ * no_more_nodes - determine if there are no more nodes in a buffer.
++ * @c: UBIFS file-system description object
++ * @buf: buffer to check
++ * @len: length of buffer
++ * @lnum: LEB number of the LEB from which @buf was read
++ * @offs: offset from which @buf was read
++ *
++ * This function scans @buf for more nodes and returns %0 is a node is found and
++ * %1 if no more nodes are found.
++ */
++static int no_more_nodes(const struct ubifs_info *c, void *buf, int len,
++			int lnum, int offs)
++{
++	int skip, next_offs = 0;
++
++	if (len > UBIFS_DATA_NODE_SZ) {
++		struct ubifs_ch *ch = buf;
++		int dlen = le32_to_cpu(ch->len);
++
++		if (ch->node_type == UBIFS_DATA_NODE && dlen >= UBIFS_CH_SZ &&
++		    dlen <= UBIFS_MAX_DATA_NODE_SZ)
++			/* The corrupt node looks like a data node */
++			next_offs = ALIGN(offs + dlen, 8);
++	}
++
++	if (c->min_io_size == 1)
++		skip = 8;
++	else
++		skip = ALIGN(offs + 1, c->min_io_size) - offs;
++
++	offs += skip;
++	buf += skip;
++	len -= skip;
++	while (len > 8) {
++		struct ubifs_ch *ch = buf;
++		uint32_t magic = le32_to_cpu(ch->magic);
++		int ret;
++
++		if (magic == UBIFS_NODE_MAGIC) {
++			ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 1);
++			if (ret == SCANNED_A_NODE || ret > 0) {
++				/*
++				 * There is a small chance this is just data in
++				 * a data node, so check that possibility. e.g.
++				 * this is part of a file that itself contains
++				 * a UBIFS image.
++				 */
++				if (next_offs && offs + le32_to_cpu(ch->len) <=
++				    next_offs)
++					continue;
++				dbg_rcvry("unexpected node at %d:%d", lnum,
++					  offs);
++				return 0;
++			}
++		}
++		offs += 8;
++		buf += 8;
++		len -= 8;
++	}
++	return 1;
++}
++
++/**
++ * fix_unclean_leb - fix an unclean LEB.
++ * @c: UBIFS file-system description object
++ * @sleb: scanned LEB information
++ * @start: offset where scan started
++ */
++static int fix_unclean_leb(struct ubifs_info *c, struct ubifs_scan_leb *sleb,
++			   int start)
++{
++	int lnum = sleb->lnum, endpt = start;
++
++	/* Get the end offset of the last node we are keeping */
++	if (!list_empty(&sleb->nodes)) {
++		struct ubifs_scan_node *snod;
++
++		snod = list_entry(sleb->nodes.prev,
++				  struct ubifs_scan_node, list);
++		endpt = snod->offs + snod->len;
++	}
++
++	if ((c->vfs_sb->s_flags & MS_RDONLY) && !c->remounting_rw) {
++		/* Add to recovery list */
++		struct ubifs_unclean_leb *ucleb;
++
++		dbg_rcvry("need to fix LEB %d start %d endpt %d",
++			  lnum, start, sleb->endpt);
++		ucleb = kzalloc(sizeof(struct ubifs_unclean_leb), GFP_NOFS);
++		if (!ucleb)
++			return -ENOMEM;
++		ucleb->lnum = lnum;
++		ucleb->endpt = endpt;
++		list_add_tail(&ucleb->list, &c->unclean_leb_list);
++	} else {
++		/* Write the fixed LEB back to flash */
++		int err;
++
++		dbg_rcvry("fixing LEB %d start %d endpt %d",
++			  lnum, start, sleb->endpt);
++		if (endpt == 0) {
++			err = ubifs_leb_unmap(c, lnum);
++			if (err)
++				return err;
++		} else {
++			int len = ALIGN(endpt, c->min_io_size);
++
++			if (start) {
++				err = ubi_read(c->ubi, lnum, sleb->buf, 0,
++					       start);
++				if (err)
++					return err;
++			}
++			/* Pad to min_io_size */
++			if (len > endpt) {
++				int pad_len = len - ALIGN(endpt, 8);
++
++				if (pad_len > 0) {
++					void *buf = sleb->buf + len - pad_len;
++
++					ubifs_pad(c, buf, pad_len);
++				}
++			}
++			err = ubi_leb_change(c->ubi, lnum, sleb->buf, len,
++					     UBI_UNKNOWN);
++			if (err)
++				return err;
++		}
++	}
++	return 0;
++}
++
++/**
++ * drop_incomplete_group - drop nodes from an incomplete group.
++ * @sleb: scanned LEB information
++ * @offs: offset of dropped nodes is returned here
++ *
++ * This function returns %1 if nodes are dropped and %0 otherwise.
++ */
++static int drop_incomplete_group(struct ubifs_scan_leb *sleb, int *offs)
++{
++	int dropped = 0;
++
++	while (!list_empty(&sleb->nodes)) {
++		struct ubifs_scan_node *snod;
++		struct ubifs_ch *ch;
++
++		snod = list_entry(sleb->nodes.prev, struct ubifs_scan_node,
++				  list);
++		ch = snod->node;
++		if (ch->group_type != UBIFS_IN_NODE_GROUP)
++			return dropped;
++		dbg_rcvry("dropping node at %d:%d", sleb->lnum, snod->offs);
++		*offs = snod->offs;
++		list_del(&snod->list);
++		kfree(snod);
++		sleb->nodes_cnt -= 1;
++		dropped = 1;
++	}
++	return dropped;
++}
++
++/**
++ * ubifs_recover_leb - scan and recover a LEB.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number
++ * @offs: offset
++ * @sbuf: LEB-sized buffer to use
++ * @grouped: nodes may be grouped for recovery
++ *
++ * This function does a scan of a LEB, but caters for errors that might have
++ * been caused by the unclean unmount from which we are attempting to recover.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum,
++					 int offs, void *sbuf, int grouped)
++{
++	int err, len = c->leb_size - offs, need_clean = 0, quiet = 1;
++	int empty_chkd = 0, start = offs;
++	struct ubifs_scan_leb *sleb;
++	void *buf = sbuf + offs;
++
++	dbg_rcvry("%d:%d", lnum, offs);
++
++	sleb = ubifs_start_scan(c, lnum, offs, sbuf);
++	if (IS_ERR(sleb))
++		return sleb;
++
++	if (sleb->ecc)
++		need_clean = 1;
++
++	while (len >= 8) {
++		int ret;
++
++		dbg_scan("look at LEB %d:%d (%d bytes left)",
++			 lnum, offs, len);
++
++		cond_resched();
++
++		/*
++		 * Scan quietly until there is an error from which we cannot
++		 * recover
++		 */
++		ret = ubifs_scan_a_node(c, buf, len, lnum, offs, quiet);
++
++		if (ret == SCANNED_A_NODE) {
++			/* A valid node, and not a padding node */
++			struct ubifs_ch *ch = buf;
++			int node_len;
++
++			err = ubifs_add_snod(c, sleb, buf, offs);
++			if (err)
++				goto error;
++			node_len = ALIGN(le32_to_cpu(ch->len), 8);
++			offs += node_len;
++			buf += node_len;
++			len -= node_len;
++			continue;
++		}
++
++		if (ret > 0) {
++			/* Padding bytes or a valid padding node */
++			offs += ret;
++			buf += ret;
++			len -= ret;
++			continue;
++		}
++
++		if (ret == SCANNED_EMPTY_SPACE) {
++			if (!is_empty(buf, len)) {
++				if (!is_last_write(c, buf, offs))
++					break;
++				clean_buf(c, &buf, lnum, &offs, &len);
++				need_clean = 1;
++			}
++			empty_chkd = 1;
++			break;
++		}
++
++		if (ret == SCANNED_GARBAGE || ret == SCANNED_A_BAD_PAD_NODE)
++			if (is_last_write(c, buf, offs)) {
++				clean_buf(c, &buf, lnum, &offs, &len);
++				need_clean = 1;
++				empty_chkd = 1;
++				break;
++			}
++
++		if (ret == SCANNED_A_CORRUPT_NODE)
++			if (no_more_nodes(c, buf, len, lnum, offs)) {
++				clean_buf(c, &buf, lnum, &offs, &len);
++				need_clean = 1;
++				empty_chkd = 1;
++				break;
++			}
++
++		if (quiet) {
++			/* Redo the last scan but noisily */
++			quiet = 0;
++			continue;
++		}
++
++		switch (ret) {
++		case SCANNED_GARBAGE:
++			dbg_err("garbage");
++			goto corrupted;
++		case SCANNED_A_CORRUPT_NODE:
++		case SCANNED_A_BAD_PAD_NODE:
++			dbg_err("bad node");
++			goto corrupted;
++		default:
++			dbg_err("unknown");
++			goto corrupted;
++		}
++	}
++
++	if (!empty_chkd && !is_empty(buf, len)) {
++		if (is_last_write(c, buf, offs)) {
++			clean_buf(c, &buf, lnum, &offs, &len);
++			need_clean = 1;
++		} else {
++			ubifs_err("corrupt empty space at LEB %d:%d",
++				  lnum, offs);
++			goto corrupted;
++		}
++	}
++
++	/* Drop nodes from incomplete group */
++	if (grouped && drop_incomplete_group(sleb, &offs)) {
++		buf = sbuf + offs;
++		len = c->leb_size - offs;
++		clean_buf(c, &buf, lnum, &offs, &len);
++		need_clean = 1;
++	}
++
++	if (offs % c->min_io_size) {
++		clean_buf(c, &buf, lnum, &offs, &len);
++		need_clean = 1;
++	}
++
++	ubifs_end_scan(c, sleb, lnum, offs);
++
++	if (need_clean) {
++		err = fix_unclean_leb(c, sleb, start);
++		if (err)
++			goto error;
++	}
++
++	return sleb;
++
++corrupted:
++	ubifs_scanned_corruption(c, lnum, offs, buf);
++	err = -EUCLEAN;
++error:
++	ubifs_err("LEB %d scanning failed", lnum);
++	ubifs_scan_destroy(sleb);
++	return ERR_PTR(err);
++}
++
++/**
++ * get_cs_sqnum - get commit start sequence number.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number of commit start node
++ * @offs: offset of commit start node
++ * @cs_sqnum: commit start sequence number is returned here
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int get_cs_sqnum(struct ubifs_info *c, int lnum, int offs,
++			unsigned long long *cs_sqnum)
++{
++	struct ubifs_cs_node *cs_node = NULL;
++	int err, ret;
++
++	dbg_rcvry("at %d:%d", lnum, offs);
++	cs_node = kmalloc(UBIFS_CS_NODE_SZ, GFP_KERNEL);
++	if (!cs_node)
++		return -ENOMEM;
++	if (c->leb_size - offs < UBIFS_CS_NODE_SZ)
++		goto out_err;
++	err = ubi_read(c->ubi, lnum, (void *)cs_node, offs, UBIFS_CS_NODE_SZ);
++	if (err && err != -EBADMSG)
++		goto out_free;
++	ret = ubifs_scan_a_node(c, cs_node, UBIFS_CS_NODE_SZ, lnum, offs, 0);
++	if (ret != SCANNED_A_NODE) {
++		dbg_err("Not a valid node");
++		goto out_err;
++	}
++	if (cs_node->ch.node_type != UBIFS_CS_NODE) {
++		dbg_err("Node a CS node, type is %d", cs_node->ch.node_type);
++		goto out_err;
++	}
++	if (le64_to_cpu(cs_node->cmt_no) != c->cmt_no) {
++		dbg_err("CS node cmt_no %llu != current cmt_no %llu",
++			(unsigned long long)le64_to_cpu(cs_node->cmt_no),
++			c->cmt_no);
++		goto out_err;
++	}
++	*cs_sqnum = le64_to_cpu(cs_node->ch.sqnum);
++	dbg_rcvry("commit start sqnum %llu", *cs_sqnum);
++	kfree(cs_node);
++	return 0;
++
++out_err:
++	err = -EINVAL;
++out_free:
++	ubifs_err("failed to get CS sqnum");
++	kfree(cs_node);
++	return err;
++}
++
++/**
++ * ubifs_recover_log_leb - scan and recover a log LEB.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number
++ * @offs: offset
++ * @sbuf: LEB-sized buffer to use
++ *
++ * This function does a scan of a LEB, but caters for errors that might have
++ * been caused by the unclean unmount from which we are attempting to recover.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++struct ubifs_scan_leb *ubifs_recover_log_leb(struct ubifs_info *c, int lnum,
++					     int offs, void *sbuf)
++{
++	struct ubifs_scan_leb *sleb;
++	int next_lnum;
++
++	dbg_rcvry("LEB %d", lnum);
++	next_lnum = lnum + 1;
++	if (next_lnum >= UBIFS_LOG_LNUM + c->log_lebs)
++		next_lnum = UBIFS_LOG_LNUM;
++	if (next_lnum != c->ltail_lnum) {
++		/*
++		 * We can only recover at the end of the log, so check that the
++		 * next log LEB is empty or out of date.
++		 */
++		sleb = ubifs_scan(c, next_lnum, 0, sbuf);
++		if (IS_ERR(sleb))
++			return sleb;
++		if (sleb->nodes_cnt) {
++			struct ubifs_scan_node *snod;
++			unsigned long long cs_sqnum = c->cs_sqnum;
++
++			snod = list_entry(sleb->nodes.next,
++					  struct ubifs_scan_node, list);
++			if (cs_sqnum == 0) {
++				int err;
++
++				err = get_cs_sqnum(c, lnum, offs, &cs_sqnum);
++				if (err) {
++					ubifs_scan_destroy(sleb);
++					return ERR_PTR(err);
++				}
++			}
++			if (snod->sqnum > cs_sqnum) {
++				ubifs_err("unrecoverable log corruption "
++					  "in LEB %d", lnum);
++				ubifs_scan_destroy(sleb);
++				return ERR_PTR(-EUCLEAN);
++			}
++		}
++		ubifs_scan_destroy(sleb);
++	}
++	return ubifs_recover_leb(c, lnum, offs, sbuf, 0);
++}
++
++/**
++ * recover_head - recover a head.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number of head to recover
++ * @offs: offset of head to recover
++ * @sbuf: LEB-sized buffer to use
++ *
++ * This function ensures that there is no data on the flash at a head location.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int recover_head(const struct ubifs_info *c, int lnum, int offs,
++			void *sbuf)
++{
++	int len, err, need_clean = 0;
++
++	if (c->min_io_size > 1)
++		len = c->min_io_size;
++	else
++		len = 512;
++	if (offs + len > c->leb_size)
++		len = c->leb_size - offs;
++
++	if (!len)
++		return 0;
++
++	/* Read at the head location and check it is empty flash */
++	err = ubi_read(c->ubi, lnum, sbuf, offs, len);
++	if (err)
++		need_clean = 1;
++	else {
++		uint8_t *p = sbuf;
++
++		while (len--)
++			if (*p++ != 0xff) {
++				need_clean = 1;
++				break;
++			}
++	}
++
++	if (need_clean) {
++		dbg_rcvry("cleaning head at %d:%d", lnum, offs);
++		if (offs == 0)
++			return ubifs_leb_unmap(c, lnum);
++		err = ubi_read(c->ubi, lnum, sbuf, 0, offs);
++		if (err)
++			return err;
++		return ubi_leb_change(c->ubi, lnum, sbuf, offs, UBI_UNKNOWN);
++	}
++
++	return 0;
++}
++
++/**
++ * ubifs_recover_inl_heads - recover index and LPT heads.
++ * @c: UBIFS file-system description object
++ * @sbuf: LEB-sized buffer to use
++ *
++ * This function ensures that there is no data on the flash at the index and
++ * LPT head locations.
++ *
++ * This deals with the recovery of a half-completed journal commit. UBIFS is
++ * careful never to overwrite the last version of the index or the LPT. Because
++ * the index and LPT are wandering trees, data from a half-completed commit will
++ * not be referenced anywhere in UBIFS. The data will be either in LEBs that are
++ * assumed to be empty and will be unmapped anyway before use, or in the index
++ * and LPT heads.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int ubifs_recover_inl_heads(const struct ubifs_info *c, void *sbuf)
++{
++	int err;
++
++	ubifs_assert(!(c->vfs_sb->s_flags & MS_RDONLY) || c->remounting_rw);
++
++	dbg_rcvry("checking index head at %d:%d", c->ihead_lnum, c->ihead_offs);
++	err = recover_head(c, c->ihead_lnum, c->ihead_offs, sbuf);
++	if (err)
++		return err;
++
++	dbg_rcvry("checking LPT head at %d:%d", c->nhead_lnum, c->nhead_offs);
++	err = recover_head(c, c->nhead_lnum, c->nhead_offs, sbuf);
++	if (err)
++		return err;
++
++	return 0;
++}
++
++/**
++ *  clean_an_unclean_leb - read and write a LEB to remove corruption.
++ * @c: UBIFS file-system description object
++ * @ucleb: unclean LEB information
++ * @sbuf: LEB-sized buffer to use
++ *
++ * This function reads a LEB up to a point pre-determined by the mount recovery,
++ * checks the nodes, and writes the result back to the flash, thereby cleaning
++ * off any following corruption, or non-fatal ECC errors.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int clean_an_unclean_leb(const struct ubifs_info *c,
++				struct ubifs_unclean_leb *ucleb, void *sbuf)
++{
++	int err, lnum = ucleb->lnum, offs = 0, len = ucleb->endpt, quiet = 1;
++	void *buf = sbuf;
++
++	dbg_rcvry("LEB %d len %d", lnum, len);
++
++	if (len == 0) {
++		/* Nothing to read, just unmap it */
++		err = ubifs_leb_unmap(c, lnum);
++		if (err)
++			return err;
++		return 0;
++	}
++
++	err = ubi_read(c->ubi, lnum, buf, offs, len);
++	if (err && err != -EBADMSG)
++		return err;
++
++	while (len >= 8) {
++		int ret;
++
++		cond_resched();
++
++		/* Scan quietly until there is an error */
++		ret = ubifs_scan_a_node(c, buf, len, lnum, offs, quiet);
++
++		if (ret == SCANNED_A_NODE) {
++			/* A valid node, and not a padding node */
++			struct ubifs_ch *ch = buf;
++			int node_len;
++
++			node_len = ALIGN(le32_to_cpu(ch->len), 8);
++			offs += node_len;
++			buf += node_len;
++			len -= node_len;
++			continue;
++		}
++
++		if (ret > 0) {
++			/* Padding bytes or a valid padding node */
++			offs += ret;
++			buf += ret;
++			len -= ret;
++			continue;
++		}
++
++		if (ret == SCANNED_EMPTY_SPACE) {
++			ubifs_err("unexpected empty space at %d:%d",
++				  lnum, offs);
++			return -EUCLEAN;
++		}
++
++		if (quiet) {
++			/* Redo the last scan but noisily */
++			quiet = 0;
++			continue;
++		}
++
++		ubifs_scanned_corruption(c, lnum, offs, buf);
++		return -EUCLEAN;
++	}
++
++	/* Pad to min_io_size */
++	len = ALIGN(ucleb->endpt, c->min_io_size);
++	if (len > ucleb->endpt) {
++		int pad_len = len - ALIGN(ucleb->endpt, 8);
++
++		if (pad_len > 0) {
++			buf = c->sbuf + len - pad_len;
++			ubifs_pad(c, buf, pad_len);
++		}
++	}
++
++	/* Write back the LEB atomically */
++	err = ubi_leb_change(c->ubi, lnum, sbuf, len, UBI_UNKNOWN);
++	if (err)
++		return err;
++
++	dbg_rcvry("cleaned LEB %d", lnum);
++
++	return 0;
++}
++
++/**
++ * ubifs_clean_lebs - clean LEBs recovered during read-only mount.
++ * @c: UBIFS file-system description object
++ * @sbuf: LEB-sized buffer to use
++ *
++ * This function cleans a LEB identified during recovery that needs to be
++ * written but was not because UBIFS was mounted read-only. This happens when
++ * remounting to read-write mode.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int ubifs_clean_lebs(const struct ubifs_info *c, void *sbuf)
++{
++	dbg_rcvry("recovery");
++	while (!list_empty(&c->unclean_leb_list)) {
++		struct ubifs_unclean_leb *ucleb;
++		int err;
++
++		ucleb = list_entry(c->unclean_leb_list.next,
++				   struct ubifs_unclean_leb, list);
++		err = clean_an_unclean_leb(c, ucleb, sbuf);
++		if (err)
++			return err;
++		list_del(&ucleb->list);
++		kfree(ucleb);
++	}
++	return 0;
++}
++
++/**
++ * ubifs_rcvry_gc_commit - recover the GC LEB number and run the commit.
++ * @c: UBIFS file-system description object
++ *
++ * Out-of-place garbage collection requires always one empty LEB with which to
++ * start garbage collection. The LEB number is recorded in c->gc_lnum and is
++ * written to the master node on unmounting. In the case of an unclean unmount
++ * the value of gc_lnum recorded in the master node is out of date and cannot
++ * be used. Instead, recovery must allocate an empty LEB for this purpose.
++ * However, there may not be enough empty space, in which case it must be
++ * possible to GC the dirtiest LEB into the GC head LEB.
++ *
++ * This function also runs the commit which causes the TNC updates from
++ * size-recovery and orphans to be written to the flash. That is important to
++ * ensure correct replay order for subsequent mounts.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int ubifs_rcvry_gc_commit(struct ubifs_info *c)
++{
++	struct ubifs_wbuf *wbuf = &c->jheads[GCHD].wbuf;
++	struct ubifs_lprops lp;
++	int lnum, err;
++
++	c->gc_lnum = -1;
++	if (wbuf->lnum == -1) {
++		dbg_rcvry("no GC head LEB");
++		goto find_free;
++	}
++	/*
++	 * See whether the used space in the dirtiest LEB fits in the GC head
++	 * LEB.
++	 */
++	if (wbuf->offs == c->leb_size) {
++		dbg_rcvry("no room in GC head LEB");
++		goto find_free;
++	}
++	err = ubifs_find_dirty_leb(c, &lp, wbuf->offs, 2);
++	if (err) {
++		if (err == -ENOSPC)
++			dbg_err("could not find a dirty LEB");
++		return err;
++	}
++	ubifs_assert(!(lp.flags & LPROPS_INDEX));
++	lnum = lp.lnum;
++	if (lp.free + lp.dirty == c->leb_size) {
++		/* An empty LEB was returned */
++		if (lp.free != c->leb_size) {
++			err = ubifs_change_one_lp(c, lnum, c->leb_size,
++						  0, 0, 0, 0);
++			if (err)
++				return err;
++		}
++		err = ubifs_leb_unmap(c, lnum);
++		if (err)
++			return err;
++		c->gc_lnum = lnum;
++		dbg_rcvry("allocated LEB %d for GC", lnum);
++		/* Run the commit */
++		dbg_rcvry("committing");
++		return ubifs_run_commit(c);
++	}
++	/*
++	 * There was no empty LEB so the used space in the dirtiest LEB must fit
++	 * in the GC head LEB.
++	 */
++	if (lp.free + lp.dirty < wbuf->offs) {
++		dbg_rcvry("LEB %d doesn't fit in GC head LEB %d:%d",
++			  lnum, wbuf->lnum, wbuf->offs);
++		err = ubifs_return_leb(c, lnum);
++		if (err)
++			return err;
++		goto find_free;
++	}
++	/*
++	 * We run the commit before garbage collection otherwise subsequent
++	 * mounts will see the GC and orphan deletion in a different order.
++	 */
++	dbg_rcvry("committing");
++	err = ubifs_run_commit(c);
++	if (err)
++		return err;
++	/*
++	 * The data in the dirtiest LEB fits in the GC head LEB, so do the GC
++	 * - use locking to keep 'ubifs_assert()' happy.
++	 */
++	dbg_rcvry("GC'ing LEB %d", lnum);
++	mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
++	err = ubifs_garbage_collect_leb(c, &lp);
++	if (err >= 0) {
++		int err2 = ubifs_wbuf_sync_nolock(wbuf);
++
++		if (err2)
++			err = err2;
++	}
++	mutex_unlock(&wbuf->io_mutex);
++	if (err < 0) {
++		dbg_err("GC failed, error %d", err);
++		if (err == -EAGAIN)
++			err = -EINVAL;
++		return err;
++	}
++	if (err != LEB_RETAINED) {
++		dbg_err("GC returned %d", err);
++		return -EINVAL;
++	}
++	err = ubifs_leb_unmap(c, c->gc_lnum);
++	if (err)
++		return err;
++	dbg_rcvry("allocated LEB %d for GC", lnum);
++	return 0;
++
++find_free:
++	/*
++	 * There is no GC head LEB or the free space in the GC head LEB is too
++	 * small. Allocate gc_lnum by calling 'ubifs_find_free_leb_for_idx()' so
++	 * GC is not run.
++	 */
++	lnum = ubifs_find_free_leb_for_idx(c);
++	if (lnum < 0) {
++		dbg_err("could not find an empty LEB");
++		return lnum;
++	}
++	/* And reset the index flag */
++	err = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
++				  LPROPS_INDEX, 0);
++	if (err)
++		return err;
++	c->gc_lnum = lnum;
++	dbg_rcvry("allocated LEB %d for GC", lnum);
++	/* Run the commit */
++	dbg_rcvry("committing");
++	return ubifs_run_commit(c);
++}
++
++/**
++ * struct size_entry - inode size information for recovery.
++ * @rb: link in the RB-tree of sizes
++ * @inum: inode number
++ * @i_size: size on inode
++ * @d_size: maximum size based on data nodes
++ * @exists: indicates whether the inode exists
++ * @inode: inode if pinned in memory awaiting rw mode to fix it
++ */
++struct size_entry {
++	struct rb_node rb;
++	ino_t inum;
++	loff_t i_size;
++	loff_t d_size;
++	int exists;
++	struct inode *inode;
++};
++
++/**
++ * add_ino - add an entry to the size tree.
++ * @c: UBIFS file-system description object
++ * @inum: inode number
++ * @i_size: size on inode
++ * @d_size: maximum size based on data nodes
++ * @exists: indicates whether the inode exists
++ */
++static int add_ino(struct ubifs_info *c, ino_t inum, loff_t i_size,
++		   loff_t d_size, int exists)
++{
++	struct rb_node **p = &c->size_tree.rb_node, *parent = NULL;
++	struct size_entry *e;
++
++	while (*p) {
++		parent = *p;
++		e = rb_entry(parent, struct size_entry, rb);
++		if (inum < e->inum)
++			p = &(*p)->rb_left;
++		else
++			p = &(*p)->rb_right;
++	}
++
++	e = kzalloc(sizeof(struct size_entry), GFP_KERNEL);
++	if (!e)
++		return -ENOMEM;
++
++	e->inum = inum;
++	e->i_size = i_size;
++	e->d_size = d_size;
++	e->exists = exists;
++
++	rb_link_node(&e->rb, parent, p);
++	rb_insert_color(&e->rb, &c->size_tree);
++
++	return 0;
++}
++
++/**
++ * find_ino - find an entry on the size tree.
++ * @c: UBIFS file-system description object
++ * @inum: inode number
++ */
++static struct size_entry *find_ino(struct ubifs_info *c, ino_t inum)
++{
++	struct rb_node *p = c->size_tree.rb_node;
++	struct size_entry *e;
++
++	while (p) {
++		e = rb_entry(p, struct size_entry, rb);
++		if (inum < e->inum)
++			p = p->rb_left;
++		else if (inum > e->inum)
++			p = p->rb_right;
++		else
++			return e;
++	}
++	return NULL;
++}
++
++/**
++ * remove_ino - remove an entry from the size tree.
++ * @c: UBIFS file-system description object
++ * @inum: inode number
++ */
++static void remove_ino(struct ubifs_info *c, ino_t inum)
++{
++	struct size_entry *e = find_ino(c, inum);
++
++	if (!e)
++		return;
++	rb_erase(&e->rb, &c->size_tree);
++	kfree(e);
++}
++
++/**
++ * ubifs_destroy_size_tree - free resources related to the size tree.
++ * @c: UBIFS file-system description object
++ */
++void ubifs_destroy_size_tree(struct ubifs_info *c)
++{
++	struct rb_node *this = c->size_tree.rb_node;
++	struct size_entry *e;
++
++	while (this) {
++		if (this->rb_left) {
++			this = this->rb_left;
++			continue;
++		} else if (this->rb_right) {
++			this = this->rb_right;
++			continue;
++		}
++		e = rb_entry(this, struct size_entry, rb);
++		if (e->inode)
++			iput(e->inode);
++		this = rb_parent(this);
++		if (this) {
++			if (this->rb_left == &e->rb)
++				this->rb_left = NULL;
++			else
++				this->rb_right = NULL;
++		}
++		kfree(e);
++	}
++	c->size_tree = RB_ROOT;
++}
++
++/**
++ * ubifs_recover_size_accum - accumulate inode sizes for recovery.
++ * @c: UBIFS file-system description object
++ * @key: node key
++ * @deletion: node is for a deletion
++ * @new_size: inode size
++ *
++ * This function has two purposes:
++ *     1) to ensure there are no data nodes that fall outside the inode size
++ *     2) to ensure there are no data nodes for inodes that do not exist
++ * To accomplish those purposes, a rb-tree is constructed containing an entry
++ * for each inode number in the journal that has not been deleted, and recording
++ * the size from the inode node, the maximum size of any data node (also altered
++ * by truncations) and a flag indicating a inode number for which no inode node
++ * was present in the journal.
++ *
++ * Note that there is still the possibility that there are data nodes that have
++ * been committed that are beyond the inode size, however the only way to find
++ * them would be to scan the entire index. Alternatively, some provision could
++ * be made to record the size of inodes at the start of commit, which would seem
++ * very cumbersome for a scenario that is quite unlikely and the only negative
++ * consequence of which is wasted space.
++ *
++ * This functions returns %0 on success and a negative error code on failure.
++ */
++int ubifs_recover_size_accum(struct ubifs_info *c, union ubifs_key *key,
++			     int deletion, loff_t new_size)
++{
++	ino_t inum = key_inum(c, key);
++	struct size_entry *e;
++	int err;
++
++	switch (key_type(c, key)) {
++	case UBIFS_INO_KEY:
++		if (deletion)
++			remove_ino(c, inum);
++		else {
++			e = find_ino(c, inum);
++			if (e) {
++				e->i_size = new_size;
++				e->exists = 1;
++			} else {
++				err = add_ino(c, inum, new_size, 0, 1);
++				if (err)
++					return err;
++			}
++		}
++		break;
++	case UBIFS_DATA_KEY:
++		e = find_ino(c, inum);
++		if (e) {
++			if (new_size > e->d_size)
++				e->d_size = new_size;
++		} else {
++			err = add_ino(c, inum, 0, new_size, 0);
++			if (err)
++				return err;
++		}
++		break;
++	case UBIFS_TRUN_KEY:
++		e = find_ino(c, inum);
++		if (e)
++			e->d_size = new_size;
++		break;
++	}
++	return 0;
++}
++
++/**
++ * fix_size_in_place - fix inode size in place on flash.
++ * @c: UBIFS file-system description object
++ * @e: inode size information for recovery
++ */
++static int fix_size_in_place(struct ubifs_info *c, struct size_entry *e)
++{
++	struct ubifs_ino_node *ino = c->sbuf;
++	unsigned char *p;
++	union ubifs_key key;
++	int err, lnum, offs, len;
++	loff_t i_size;
++	uint32_t crc;
++
++	/* Locate the inode node LEB number and offset */
++	ino_key_init(c, &key, e->inum);
++	err = ubifs_tnc_locate(c, &key, ino, &lnum, &offs);
++	if (err)
++		goto out;
++	/*
++	 * If the size recorded on the inode node is greater than the size that
++	 * was calculated from nodes in the journal then don't change the inode.
++	 */
++	i_size = le64_to_cpu(ino->size);
++	if (i_size >= e->d_size)
++		return 0;
++	/* Read the LEB */
++	err = ubi_read(c->ubi, lnum, c->sbuf, 0, c->leb_size);
++	if (err)
++		goto out;
++	/* Change the size field and recalculate the CRC */
++	ino = c->sbuf + offs;
++	ino->size = cpu_to_le64(e->d_size);
++	len = le32_to_cpu(ino->ch.len);
++	crc = crc32(UBIFS_CRC32_INIT, (void *)ino + 8, len - 8);
++	ino->ch.crc = cpu_to_le32(crc);
++	/* Work out where data in the LEB ends and free space begins */
++	p = c->sbuf;
++	len = c->leb_size - 1;
++	while (p[len] == 0xff)
++		len -= 1;
++	len = ALIGN(len + 1, c->min_io_size);
++	/* Atomically write the fixed LEB back again */
++	err = ubi_leb_change(c->ubi, lnum, c->sbuf, len, UBI_UNKNOWN);
++	if (err)
++		goto out;
++	dbg_rcvry("inode %lu at %d:%d size %lld -> %lld ",
++		  (unsigned long)e->inum, lnum, offs, i_size, e->d_size);
++	return 0;
++
++out:
++	ubifs_warn("inode %lu failed to fix size %lld -> %lld error %d",
++		   (unsigned long)e->inum, e->i_size, e->d_size, err);
++	return err;
++}
++
++/**
++ * ubifs_recover_size - recover inode size.
++ * @c: UBIFS file-system description object
++ *
++ * This function attempts to fix inode size discrepancies identified by the
++ * 'ubifs_recover_size_accum()' function.
++ *
++ * This functions returns %0 on success and a negative error code on failure.
++ */
++int ubifs_recover_size(struct ubifs_info *c)
++{
++	struct rb_node *this = rb_first(&c->size_tree);
++
++	while (this) {
++		struct size_entry *e;
++		int err;
++
++		e = rb_entry(this, struct size_entry, rb);
++		if (!e->exists) {
++			union ubifs_key key;
++
++			ino_key_init(c, &key, e->inum);
++			err = ubifs_tnc_lookup(c, &key, c->sbuf);
++			if (err && err != -ENOENT)
++				return err;
++			if (err == -ENOENT) {
++				/* Remove data nodes that have no inode */
++				dbg_rcvry("removing ino %lu",
++					  (unsigned long)e->inum);
++				err = ubifs_tnc_remove_ino(c, e->inum);
++				if (err)
++					return err;
++			} else {
++				struct ubifs_ino_node *ino = c->sbuf;
++
++				e->exists = 1;
++				e->i_size = le64_to_cpu(ino->size);
++			}
++		}
++		if (e->exists && e->i_size < e->d_size) {
++			if (!e->inode && (c->vfs_sb->s_flags & MS_RDONLY)) {
++				/* Fix the inode size and pin it in memory */
++				struct inode *inode;
++
++				inode = ubifs_iget(c->vfs_sb, e->inum);
++				if (IS_ERR(inode))
++					return PTR_ERR(inode);
++				if (inode->i_size < e->d_size) {
++					dbg_rcvry("ino %lu size %lld -> %lld",
++						  (unsigned long)e->inum,
++						  e->d_size, inode->i_size);
++					inode->i_size = e->d_size;
++					ubifs_inode(inode)->ui_size = e->d_size;
++					e->inode = inode;
++					this = rb_next(this);
++					continue;
++				}
++				iput(inode);
++			} else {
++				/* Fix the size in place */
++				err = fix_size_in_place(c, e);
++				if (err)
++					return err;
++				if (e->inode)
++					iput(e->inode);
++			}
++		}
++		this = rb_next(this);
++		rb_erase(&e->rb, &c->size_tree);
++		kfree(e);
++	}
++	return 0;
++}
+diff -Nurd linux-2.6.24.orig/fs/ubifs/replay.c linux-2.6.24/fs/ubifs/replay.c
+--- linux-2.6.24.orig/fs/ubifs/replay.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/replay.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,1084 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Adrian Hunter
++ *          Artem Bityutskiy (Битюцкий Артём)
++ */
++
++/*
++ * This file contains journal replay code. It runs when the file-system is being
++ * mounted and requires no locking.
++ *
++ * The larger is the journal, the longer it takes to scan it, so the longer it
++ * takes to mount UBIFS. This is why the journal has limited size which may be
++ * changed depending on the system requirements. But a larger journal gives
++ * faster I/O speed because it writes the index less frequently. So this is a
++ * trade-off. Also, the journal is indexed by the in-memory index (TNC), so the
++ * larger is the journal, the more memory its index may consume.
++ */
++
++#include "ubifs.h"
++
++/*
++ * Replay flags.
++ *
++ * REPLAY_DELETION: node was deleted
++ * REPLAY_REF: node is a reference node
++ */
++enum {
++	REPLAY_DELETION = 1,
++	REPLAY_REF = 2,
++};
++
++/**
++ * struct replay_entry - replay tree entry.
++ * @lnum: logical eraseblock number of the node
++ * @offs: node offset
++ * @len: node length
++ * @sqnum: node sequence number
++ * @flags: replay flags
++ * @rb: links the replay tree
++ * @key: node key
++ * @nm: directory entry name
++ * @old_size: truncation old size
++ * @new_size: truncation new size
++ * @free: amount of free space in a bud
++ * @dirty: amount of dirty space in a bud from padding and deletion nodes
++ *
++ * UBIFS journal replay must compare node sequence numbers, which means it must
++ * build a tree of node information to insert into the TNC.
++ */
++struct replay_entry {
++	int lnum;
++	int offs;
++	int len;
++	unsigned long long sqnum;
++	int flags;
++	struct rb_node rb;
++	union ubifs_key key;
++	union {
++		struct qstr nm;
++		struct {
++			loff_t old_size;
++			loff_t new_size;
++		};
++		struct {
++			int free;
++			int dirty;
++		};
++	};
++};
++
++/**
++ * struct bud_entry - entry in the list of buds to replay.
++ * @list: next bud in the list
++ * @bud: bud description object
++ * @free: free bytes in the bud
++ * @sqnum: reference node sequence number
++ */
++struct bud_entry {
++	struct list_head list;
++	struct ubifs_bud *bud;
++	int free;
++	unsigned long long sqnum;
++};
++
++/**
++ * set_bud_lprops - set free and dirty space used by a bud.
++ * @c: UBIFS file-system description object
++ * @r: replay entry of bud
++ */
++static int set_bud_lprops(struct ubifs_info *c, struct replay_entry *r)
++{
++	const struct ubifs_lprops *lp;
++	int err = 0, dirty;
++
++	ubifs_get_lprops(c);
++
++	lp = ubifs_lpt_lookup_dirty(c, r->lnum);
++	if (IS_ERR(lp)) {
++		err = PTR_ERR(lp);
++		goto out;
++	}
++
++	dirty = lp->dirty;
++	if (r->offs == 0 && (lp->free != c->leb_size || lp->dirty != 0)) {
++		/*
++		 * The LEB was added to the journal with a starting offset of
++		 * zero which means the LEB must have been empty. The LEB
++		 * property values should be lp->free == c->leb_size and
++		 * lp->dirty == 0, but that is not the case. The reason is that
++		 * the LEB was garbage collected. The garbage collector resets
++		 * the free and dirty space without recording it anywhere except
++		 * lprops, so if there is not a commit then lprops does not have
++		 * that information next time the file system is mounted.
++		 *
++		 * We do not need to adjust free space because the scan has told
++		 * us the exact value which is recorded in the replay entry as
++		 * r->free.
++		 *
++		 * However we do need to subtract from the dirty space the
++		 * amount of space that the garbage collector reclaimed, which
++		 * is the whole LEB minus the amount of space that was free.
++		 */
++		dbg_mnt("bud LEB %d was GC'd (%d free, %d dirty)", r->lnum,
++			lp->free, lp->dirty);
++		dbg_gc("bud LEB %d was GC'd (%d free, %d dirty)", r->lnum,
++			lp->free, lp->dirty);
++		dirty -= c->leb_size - lp->free;
++		/*
++		 * If the replay order was perfect the dirty space would now be
++		 * zero. The order is not perfect because the the journal heads
++		 * race with each other. This is not a problem but is does mean
++		 * that the dirty space may temporarily exceed c->leb_size
++		 * during the replay.
++		 */
++		if (dirty != 0)
++			dbg_msg("LEB %d lp: %d free %d dirty "
++				"replay: %d free %d dirty", r->lnum, lp->free,
++				lp->dirty, r->free, r->dirty);
++	}
++	lp = ubifs_change_lp(c, lp, r->free, dirty + r->dirty,
++			     lp->flags | LPROPS_TAKEN, 0);
++	if (IS_ERR(lp)) {
++		err = PTR_ERR(lp);
++		goto out;
++	}
++out:
++	ubifs_release_lprops(c);
++	return err;
++}
++
++/**
++ * trun_remove_range - apply a replay entry for a truncation to the TNC.
++ * @c: UBIFS file-system description object
++ * @r: replay entry of truncation
++ */
++static int trun_remove_range(struct ubifs_info *c, struct replay_entry *r)
++{
++	unsigned min_blk, max_blk;
++	union ubifs_key min_key, max_key;
++	ino_t ino;
++
++	min_blk = r->new_size / UBIFS_BLOCK_SIZE;
++	if (r->new_size & (UBIFS_BLOCK_SIZE - 1))
++		min_blk += 1;
++
++	max_blk = r->old_size / UBIFS_BLOCK_SIZE;
++	if ((r->old_size & (UBIFS_BLOCK_SIZE - 1)) == 0)
++		max_blk -= 1;
++
++	ino = key_inum(c, &r->key);
++
++	data_key_init(c, &min_key, ino, min_blk);
++	data_key_init(c, &max_key, ino, max_blk);
++
++	return ubifs_tnc_remove_range(c, &min_key, &max_key);
++}
++
++/**
++ * apply_replay_entry - apply a replay entry to the TNC.
++ * @c: UBIFS file-system description object
++ * @r: replay entry to apply
++ *
++ * Apply a replay entry to the TNC.
++ */
++static int apply_replay_entry(struct ubifs_info *c, struct replay_entry *r)
++{
++	int err, deletion = ((r->flags & REPLAY_DELETION) != 0);
++
++	dbg_mnt("LEB %d:%d len %d flgs %d sqnum %llu %s", r->lnum,
++		r->offs, r->len, r->flags, r->sqnum, DBGKEY(&r->key));
++
++	/* Set c->replay_sqnum to help deal with dangling branches. */
++	c->replay_sqnum = r->sqnum;
++
++	if (r->flags & REPLAY_REF)
++		err = set_bud_lprops(c, r);
++	else if (is_hash_key(c, &r->key)) {
++		if (deletion)
++			err = ubifs_tnc_remove_nm(c, &r->key, &r->nm);
++		else
++			err = ubifs_tnc_add_nm(c, &r->key, r->lnum, r->offs,
++					       r->len, &r->nm);
++	} else {
++		if (deletion)
++			switch (key_type(c, &r->key)) {
++			case UBIFS_INO_KEY:
++			{
++				ino_t inum = key_inum(c, &r->key);
++
++				err = ubifs_tnc_remove_ino(c, inum);
++				break;
++			}
++			case UBIFS_TRUN_KEY:
++				err = trun_remove_range(c, r);
++				break;
++			default:
++				err = ubifs_tnc_remove(c, &r->key);
++				break;
++			}
++		else
++			err = ubifs_tnc_add(c, &r->key, r->lnum, r->offs,
++					    r->len);
++		if (err)
++			return err;
++
++		if (c->need_recovery)
++			err = ubifs_recover_size_accum(c, &r->key, deletion,
++						       r->new_size);
++	}
++
++	return err;
++}
++
++/**
++ * destroy_replay_tree - destroy the replay.
++ * @c: UBIFS file-system description object
++ *
++ * Destroy the replay tree.
++ */
++static void destroy_replay_tree(struct ubifs_info *c)
++{
++	struct rb_node *this = c->replay_tree.rb_node;
++	struct replay_entry *r;
++
++	while (this) {
++		if (this->rb_left) {
++			this = this->rb_left;
++			continue;
++		} else if (this->rb_right) {
++			this = this->rb_right;
++			continue;
++		}
++		r = rb_entry(this, struct replay_entry, rb);
++		this = rb_parent(this);
++		if (this) {
++			if (this->rb_left == &r->rb)
++				this->rb_left = NULL;
++			else
++				this->rb_right = NULL;
++		}
++		if (is_hash_key(c, &r->key))
++			kfree(r->nm.name);
++		kfree(r);
++	}
++	c->replay_tree = RB_ROOT;
++}
++
++/**
++ * apply_replay_tree - apply the replay tree to the TNC.
++ * @c: UBIFS file-system description object
++ *
++ * Apply the replay tree.
++ * Returns zero in case of success and a negative error code in case of
++ * failure.
++ */
++static int apply_replay_tree(struct ubifs_info *c)
++{
++	struct rb_node *this = rb_first(&c->replay_tree);
++
++	while (this) {
++		struct replay_entry *r;
++		int err;
++
++		cond_resched();
++
++		r = rb_entry(this, struct replay_entry, rb);
++		err = apply_replay_entry(c, r);
++		if (err)
++			return err;
++		this = rb_next(this);
++	}
++	return 0;
++}
++
++/**
++ * insert_node - insert a node to the replay tree.
++ * @c: UBIFS file-system description object
++ * @lnum: node logical eraseblock number
++ * @offs: node offset
++ * @len: node length
++ * @key: node key
++ * @sqnum: sequence number
++ * @deletion: non-zero if this is a deletion
++ * @used: number of bytes in use in a LEB
++ * @old_size: truncation old size
++ * @new_size: truncation new size
++ *
++ * This function inserts a scanned non-direntry node to the replay tree. The
++ * replay tree is an RB-tree containing @struct replay_entry elements which are
++ * indexed by the sequence number. The replay tree is applied at the very end
++ * of the replay process. Since the tree is sorted in sequence number order,
++ * the older modifications are applied first. This function returns zero in
++ * case of success and a negative error code in case of failure.
++ */
++static int insert_node(struct ubifs_info *c, int lnum, int offs, int len,
++		       union ubifs_key *key, unsigned long long sqnum,
++		       int deletion, int *used, loff_t old_size,
++		       loff_t new_size)
++{
++	struct rb_node **p = &c->replay_tree.rb_node, *parent = NULL;
++	struct replay_entry *r;
++
++	if (key_inum(c, key) >= c->highest_inum)
++		c->highest_inum = key_inum(c, key);
++
++	dbg_mnt("add LEB %d:%d, key %s", lnum, offs, DBGKEY(key));
++	while (*p) {
++		parent = *p;
++		r = rb_entry(parent, struct replay_entry, rb);
++		if (sqnum < r->sqnum) {
++			p = &(*p)->rb_left;
++			continue;
++		} else if (sqnum > r->sqnum) {
++			p = &(*p)->rb_right;
++			continue;
++		}
++		ubifs_err("duplicate sqnum in replay");
++		return -EINVAL;
++	}
++
++	r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL);
++	if (!r)
++		return -ENOMEM;
++
++	if (!deletion)
++		*used += ALIGN(len, 8);
++	r->lnum = lnum;
++	r->offs = offs;
++	r->len = len;
++	r->sqnum = sqnum;
++	r->flags = (deletion ? REPLAY_DELETION : 0);
++	r->old_size = old_size;
++	r->new_size = new_size;
++	key_copy(c, key, &r->key);
++
++	rb_link_node(&r->rb, parent, p);
++	rb_insert_color(&r->rb, &c->replay_tree);
++	return 0;
++}
++
++/**
++ * insert_dent - insert a directory entry node into the replay tree.
++ * @c: UBIFS file-system description object
++ * @lnum: node logical eraseblock number
++ * @offs: node offset
++ * @len: node length
++ * @key: node key
++ * @name: directory entry name
++ * @nlen: directory entry name length
++ * @sqnum: sequence number
++ * @deletion: non-zero if this is a deletion
++ * @used: number of bytes in use in a LEB
++ *
++ * This function inserts a scanned directory entry node to the replay tree.
++ * Returns zero in case of success and a negative error code in case of
++ * failure.
++ *
++ * This function is also used for extended attribute entries because they are
++ * implemented as directory entry nodes.
++ */
++static int insert_dent(struct ubifs_info *c, int lnum, int offs, int len,
++		       union ubifs_key *key, const char *name, int nlen,
++		       unsigned long long sqnum, int deletion, int *used)
++{
++	struct rb_node **p = &c->replay_tree.rb_node, *parent = NULL;
++	struct replay_entry *r;
++	char *nbuf;
++
++	if (key_inum(c, key) >= c->highest_inum)
++		c->highest_inum = key_inum(c, key);
++
++	dbg_mnt("add LEB %d:%d, key %s", lnum, offs, DBGKEY(key));
++	while (*p) {
++		parent = *p;
++		r = rb_entry(parent, struct replay_entry, rb);
++		if (sqnum < r->sqnum) {
++			p = &(*p)->rb_left;
++			continue;
++		}
++		if (sqnum > r->sqnum) {
++			p = &(*p)->rb_right;
++			continue;
++		}
++		ubifs_err("duplicate sqnum in replay");
++		return -EINVAL;
++	}
++
++	r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL);
++	if (!r)
++		return -ENOMEM;
++	nbuf = kmalloc(nlen + 1, GFP_KERNEL);
++	if (!nbuf) {
++		kfree(r);
++		return -ENOMEM;
++	}
++
++	if (!deletion)
++		*used += ALIGN(len, 8);
++	r->lnum = lnum;
++	r->offs = offs;
++	r->len = len;
++	r->sqnum = sqnum;
++	r->nm.len = nlen;
++	memcpy(nbuf, name, nlen);
++	nbuf[nlen] = '\0';
++	r->nm.name = nbuf;
++	r->flags = (deletion ? REPLAY_DELETION : 0);
++	key_copy(c, key, &r->key);
++
++	ubifs_assert(!*p);
++	rb_link_node(&r->rb, parent, p);
++	rb_insert_color(&r->rb, &c->replay_tree);
++	return 0;
++}
++
++/**
++ * ubifs_validate_entry - validate directory or extended attribute entry node.
++ * @c: UBIFS file-system description object
++ * @dent: the node to validate
++ *
++ * This function validates directory or extended attribute entry node @dent.
++ * Returns zero if the node is all right and a %-EINVAL if not.
++ */
++int ubifs_validate_entry(struct ubifs_info *c,
++			 const struct ubifs_dent_node *dent)
++{
++	int key_type = key_type_flash(c, dent->key);
++	int nlen = le16_to_cpu(dent->nlen);
++
++	if (le32_to_cpu(dent->ch.len) != nlen + UBIFS_DENT_NODE_SZ + 1 ||
++	    dent->type >= UBIFS_ITYPES_CNT ||
++	    nlen > UBIFS_MAX_NLEN || dent->name[nlen] != 0 ||
++	    strnlen(dent->name, nlen) != nlen ||
++	    le64_to_cpu(dent->inum) > MAX_INUM) {
++		ubifs_err("bad %s node", key_type == UBIFS_DENT_KEY ?
++			  "directory entry" : "extended attribute entry");
++		return -EINVAL;
++	}
++
++	if (key_type != UBIFS_DENT_KEY && key_type != UBIFS_XENT_KEY) {
++		ubifs_err("bad key type %d", key_type);
++		return -EINVAL;
++	}
++
++	return 0;
++}
++
++/**
++ * replay_bud - replay a bud logical eraseblock.
++ * @c: UBIFS file-system description object
++ * @lnum: bud logical eraseblock number to replay
++ * @offs: bud start offset
++ * @jhead: journal head to which this bud belongs
++ * @free: amount of free space in the bud is returned here
++ * @dirty: amount of dirty space from padding and deletion nodes is returned
++ * here
++ *
++ * This function returns zero in case of success and a negative error code in
++ * case of failure.
++ */
++static int replay_bud(struct ubifs_info *c, int lnum, int offs, int jhead,
++		      int *free, int *dirty)
++{
++	int err = 0, used = 0;
++	struct ubifs_scan_leb *sleb;
++	struct ubifs_scan_node *snod;
++	struct ubifs_bud *bud;
++
++	dbg_mnt("replay bud LEB %d, head %d", lnum, jhead);
++	if (c->need_recovery)
++		sleb = ubifs_recover_leb(c, lnum, offs, c->sbuf, jhead != GCHD);
++	else
++		sleb = ubifs_scan(c, lnum, offs, c->sbuf);
++	if (IS_ERR(sleb))
++		return PTR_ERR(sleb);
++
++	/*
++	 * The bud does not have to start from offset zero - the beginning of
++	 * the 'lnum' LEB may contain previously committed data. One of the
++	 * things we have to do in replay is to correctly update lprops with
++	 * newer information about this LEB.
++	 *
++	 * At this point lprops thinks that this LEB has 'c->leb_size - offs'
++	 * bytes of free space because it only contain information about
++	 * committed data.
++	 *
++	 * But we know that real amount of free space is 'c->leb_size -
++	 * sleb->endpt', and the space in the 'lnum' LEB between 'offs' and
++	 * 'sleb->endpt' is used by bud data. We have to correctly calculate
++	 * how much of these data are dirty and update lprops with this
++	 * information.
++	 *
++	 * The dirt in that LEB region is comprised of padding nodes, deletion
++	 * nodes, truncation nodes and nodes which are obsoleted by subsequent
++	 * nodes in this LEB. So instead of calculating clean space, we
++	 * calculate used space ('used' variable).
++	 */
++
++	list_for_each_entry(snod, &sleb->nodes, list) {
++		int deletion = 0;
++
++		cond_resched();
++
++		if (snod->sqnum >= SQNUM_WATERMARK) {
++			ubifs_err("file system's life ended");
++			goto out_dump;
++		}
++
++		if (snod->sqnum > c->max_sqnum)
++			c->max_sqnum = snod->sqnum;
++
++		switch (snod->type) {
++		case UBIFS_INO_NODE:
++		{
++			struct ubifs_ino_node *ino = snod->node;
++			loff_t new_size = le64_to_cpu(ino->size);
++
++			if (le32_to_cpu(ino->nlink) == 0)
++				deletion = 1;
++			err = insert_node(c, lnum, snod->offs, snod->len,
++					  &snod->key, snod->sqnum, deletion,
++					  &used, 0, new_size);
++			break;
++		}
++		case UBIFS_DATA_NODE:
++		{
++			struct ubifs_data_node *dn = snod->node;
++			loff_t new_size = le32_to_cpu(dn->size) +
++					  key_block(c, &snod->key) *
++					  UBIFS_BLOCK_SIZE;
++
++			err = insert_node(c, lnum, snod->offs, snod->len,
++					  &snod->key, snod->sqnum, deletion,
++					  &used, 0, new_size);
++			break;
++		}
++		case UBIFS_DENT_NODE:
++		case UBIFS_XENT_NODE:
++		{
++			struct ubifs_dent_node *dent = snod->node;
++
++			err = ubifs_validate_entry(c, dent);
++			if (err)
++				goto out_dump;
++
++			err = insert_dent(c, lnum, snod->offs, snod->len,
++					  &snod->key, dent->name,
++					  le16_to_cpu(dent->nlen), snod->sqnum,
++					  !le64_to_cpu(dent->inum), &used);
++			break;
++		}
++		case UBIFS_TRUN_NODE:
++		{
++			struct ubifs_trun_node *trun = snod->node;
++			loff_t old_size = le64_to_cpu(trun->old_size);
++			loff_t new_size = le64_to_cpu(trun->new_size);
++			union ubifs_key key;
++
++			/* Validate truncation node */
++			if (old_size < 0 || old_size > c->max_inode_sz ||
++			    new_size < 0 || new_size > c->max_inode_sz ||
++			    old_size <= new_size) {
++				ubifs_err("bad truncation node");
++				goto out_dump;
++			}
++
++			/*
++			 * Create a fake truncation key just to use the same
++			 * functions which expect nodes to have keys.
++			 */
++			trun_key_init(c, &key, le32_to_cpu(trun->inum));
++			err = insert_node(c, lnum, snod->offs, snod->len,
++					  &key, snod->sqnum, 1, &used,
++					  old_size, new_size);
++			break;
++		}
++		default:
++			ubifs_err("unexpected node type %d in bud LEB %d:%d",
++				  snod->type, lnum, snod->offs);
++			err = -EINVAL;
++			goto out_dump;
++		}
++		if (err)
++			goto out;
++	}
++
++	bud = ubifs_search_bud(c, lnum);
++	if (!bud)
++		BUG();
++
++	ubifs_assert(sleb->endpt - offs >= used);
++	ubifs_assert(sleb->endpt % c->min_io_size == 0);
++
++	if (sleb->endpt + c->min_io_size <= c->leb_size &&
++	    !(c->vfs_sb->s_flags & MS_RDONLY))
++		err = ubifs_wbuf_seek_nolock(&c->jheads[jhead].wbuf, lnum,
++					     sleb->endpt, UBI_SHORTTERM);
++
++	*dirty = sleb->endpt - offs - used;
++	*free = c->leb_size - sleb->endpt;
++
++out:
++	ubifs_scan_destroy(sleb);
++	return err;
++
++out_dump:
++	ubifs_err("bad node is at LEB %d:%d", lnum, snod->offs);
++	dbg_dump_node(c, snod->node);
++	ubifs_scan_destroy(sleb);
++	return -EINVAL;
++}
++
++/**
++ * insert_ref_node - insert a reference node to the replay tree.
++ * @c: UBIFS file-system description object
++ * @lnum: node logical eraseblock number
++ * @offs: node offset
++ * @sqnum: sequence number
++ * @free: amount of free space in bud
++ * @dirty: amount of dirty space from padding and deletion nodes
++ *
++ * This function inserts a reference node to the replay tree and returns zero
++ * in case of success or a negative error code in case of failure.
++ */
++static int insert_ref_node(struct ubifs_info *c, int lnum, int offs,
++			   unsigned long long sqnum, int free, int dirty)
++{
++	struct rb_node **p = &c->replay_tree.rb_node, *parent = NULL;
++	struct replay_entry *r;
++
++	dbg_mnt("add ref LEB %d:%d", lnum, offs);
++	while (*p) {
++		parent = *p;
++		r = rb_entry(parent, struct replay_entry, rb);
++		if (sqnum < r->sqnum) {
++			p = &(*p)->rb_left;
++			continue;
++		} else if (sqnum > r->sqnum) {
++			p = &(*p)->rb_right;
++			continue;
++		}
++		ubifs_err("duplicate sqnum in replay tree");
++		return -EINVAL;
++	}
++
++	r = kzalloc(sizeof(struct replay_entry), GFP_KERNEL);
++	if (!r)
++		return -ENOMEM;
++
++	r->lnum = lnum;
++	r->offs = offs;
++	r->sqnum = sqnum;
++	r->flags = REPLAY_REF;
++	r->free = free;
++	r->dirty = dirty;
++
++	rb_link_node(&r->rb, parent, p);
++	rb_insert_color(&r->rb, &c->replay_tree);
++	return 0;
++}
++
++/**
++ * replay_buds - replay all buds.
++ * @c: UBIFS file-system description object
++ *
++ * This function returns zero in case of success and a negative error code in
++ * case of failure.
++ */
++static int replay_buds(struct ubifs_info *c)
++{
++	struct bud_entry *b;
++	int err, uninitialized_var(free), uninitialized_var(dirty);
++
++	list_for_each_entry(b, &c->replay_buds, list) {
++		err = replay_bud(c, b->bud->lnum, b->bud->start, b->bud->jhead,
++				 &free, &dirty);
++		if (err)
++			return err;
++		err = insert_ref_node(c, b->bud->lnum, b->bud->start, b->sqnum,
++				      free, dirty);
++		if (err)
++			return err;
++	}
++
++	return 0;
++}
++
++/**
++ * destroy_bud_list - destroy the list of buds to replay.
++ * @c: UBIFS file-system description object
++ */
++static void destroy_bud_list(struct ubifs_info *c)
++{
++	struct bud_entry *b;
++
++	while (!list_empty(&c->replay_buds)) {
++		b = list_entry(c->replay_buds.next, struct bud_entry, list);
++		list_del(&b->list);
++		kfree(b);
++	}
++}
++
++/**
++ * add_replay_bud - add a bud to the list of buds to replay.
++ * @c: UBIFS file-system description object
++ * @lnum: bud logical eraseblock number to replay
++ * @offs: bud start offset
++ * @jhead: journal head to which this bud belongs
++ * @sqnum: reference node sequence number
++ *
++ * This function returns zero in case of success and a negative error code in
++ * case of failure.
++ */
++static int add_replay_bud(struct ubifs_info *c, int lnum, int offs, int jhead,
++			  unsigned long long sqnum)
++{
++	struct ubifs_bud *bud;
++	struct bud_entry *b;
++
++	dbg_mnt("add replay bud LEB %d:%d, head %d", lnum, offs, jhead);
++
++	bud = kmalloc(sizeof(struct ubifs_bud), GFP_KERNEL);
++	if (!bud)
++		return -ENOMEM;
++
++	b = kmalloc(sizeof(struct bud_entry), GFP_KERNEL);
++	if (!b) {
++		kfree(bud);
++		return -ENOMEM;
++	}
++
++	bud->lnum = lnum;
++	bud->start = offs;
++	bud->jhead = jhead;
++	ubifs_add_bud(c, bud);
++
++	b->bud = bud;
++	b->sqnum = sqnum;
++	list_add_tail(&b->list, &c->replay_buds);
++
++	return 0;
++}
++
++/**
++ * validate_ref - validate a reference node.
++ * @c: UBIFS file-system description object
++ * @ref: the reference node to validate
++ * @ref_lnum: LEB number of the reference node
++ * @ref_offs: reference node offset
++ *
++ * This function returns %1 if a bud reference already exists for the LEB. %0 is
++ * returned if the reference node is new, otherwise %-EINVAL is returned if
++ * validation failed.
++ */
++static int validate_ref(struct ubifs_info *c, const struct ubifs_ref_node *ref)
++{
++	struct ubifs_bud *bud;
++	int lnum = le32_to_cpu(ref->lnum);
++	unsigned int offs = le32_to_cpu(ref->offs);
++	unsigned int jhead = le32_to_cpu(ref->jhead);
++
++	/*
++	 * ref->offs may point to the end of LEB when the journal head points
++	 * to the end of LEB and we write reference node for it during commit.
++	 * So this is why we require 'offs > c->leb_size'.
++	 */
++	if (jhead >= c->jhead_cnt || lnum >= c->leb_cnt ||
++	    lnum < c->main_first || offs > c->leb_size ||
++	    offs & (c->min_io_size - 1))
++		return -EINVAL;
++
++	/* Make sure we have not already looked at this bud */
++	bud = ubifs_search_bud(c, lnum);
++	if (bud) {
++		if (bud->jhead == jhead && bud->start <= offs)
++			return 1;
++		ubifs_err("bud at LEB %d:%d was already referred", lnum, offs);
++		return -EINVAL;
++	}
++
++	return 0;
++}
++
++/**
++ * replay_log_leb - replay a log logical eraseblock.
++ * @c: UBIFS file-system description object
++ * @lnum: log logical eraseblock to replay
++ * @offs: offset to start replaying from
++ * @sbuf: scan buffer
++ *
++ * This function replays a log LEB and returns zero in case of success, %1 if
++ * this is the last LEB in the log, and a negative error code in case of
++ * failure.
++ */
++static int replay_log_leb(struct ubifs_info *c, int lnum, int offs, void *sbuf)
++{
++	int err;
++	struct ubifs_scan_leb *sleb;
++	struct ubifs_scan_node *snod;
++	const struct ubifs_cs_node *node;
++
++	dbg_mnt("replay log LEB %d:%d", lnum, offs);
++	sleb = ubifs_scan(c, lnum, offs, sbuf);
++	if (IS_ERR(sleb)) {
++		if (c->need_recovery)
++			sleb = ubifs_recover_log_leb(c, lnum, offs, sbuf);
++		if (IS_ERR(sleb))
++			return PTR_ERR(sleb);
++	}
++
++	if (sleb->nodes_cnt == 0) {
++		err = 1;
++		goto out;
++	}
++
++	node = sleb->buf;
++
++	snod = list_entry(sleb->nodes.next, struct ubifs_scan_node, list);
++	if (c->cs_sqnum == 0) {
++		/*
++		 * This is the first log LEB we are looking at, make sure that
++		 * the first node is a commit start node. Also record its
++		 * sequence number so that UBIFS can determine where the log
++		 * ends, because all nodes which were have higher sequence
++		 * numbers.
++		 */
++		if (snod->type != UBIFS_CS_NODE) {
++			dbg_err("first log node at LEB %d:%d is not CS node",
++				lnum, offs);
++			goto out_dump;
++		}
++		if (le64_to_cpu(node->cmt_no) != c->cmt_no) {
++			dbg_err("first CS node at LEB %d:%d has wrong "
++				"commit number %llu expected %llu",
++				lnum, offs,
++				(unsigned long long)le64_to_cpu(node->cmt_no),
++				c->cmt_no);
++			goto out_dump;
++		}
++
++		c->cs_sqnum = le64_to_cpu(node->ch.sqnum);
++		dbg_mnt("commit start sqnum %llu", c->cs_sqnum);
++	}
++
++	if (snod->sqnum < c->cs_sqnum) {
++		/*
++		 * This means that we reached end of log and now
++		 * look to the older log data, which was already
++		 * committed but the eraseblock was not erased (UBIFS
++		 * only un-maps it). So this basically means we have to
++		 * exit with "end of log" code.
++		 */
++		err = 1;
++		goto out;
++	}
++
++	/* Make sure the first node sits at offset zero of the LEB */
++	if (snod->offs != 0) {
++		dbg_err("first node is not at zero offset");
++		goto out_dump;
++	}
++
++	list_for_each_entry(snod, &sleb->nodes, list) {
++
++		cond_resched();
++
++		if (snod->sqnum >= SQNUM_WATERMARK) {
++			ubifs_err("file system's life ended");
++			goto out_dump;
++		}
++
++		if (snod->sqnum < c->cs_sqnum) {
++			dbg_err("bad sqnum %llu, commit sqnum %llu",
++				snod->sqnum, c->cs_sqnum);
++			goto out_dump;
++		}
++
++		if (snod->sqnum > c->max_sqnum)
++			c->max_sqnum = snod->sqnum;
++
++		switch (snod->type) {
++		case UBIFS_REF_NODE: {
++			const struct ubifs_ref_node *ref = snod->node;
++
++			err = validate_ref(c, ref);
++			if (err == 1)
++				break; /* Already have this bud */
++			if (err)
++				goto out_dump;
++
++			err = add_replay_bud(c, le32_to_cpu(ref->lnum),
++					     le32_to_cpu(ref->offs),
++					     le32_to_cpu(ref->jhead),
++					     snod->sqnum);
++			if (err)
++				goto out;
++
++			break;
++		}
++		case UBIFS_CS_NODE:
++			/* Make sure it sits at the beginning of LEB */
++			if (snod->offs != 0) {
++				ubifs_err("unexpected node in log");
++				goto out_dump;
++			}
++			break;
++		default:
++			ubifs_err("unexpected node in log");
++			goto out_dump;
++		}
++	}
++
++	if (sleb->endpt || c->lhead_offs >= c->leb_size) {
++		c->lhead_lnum = lnum;
++		c->lhead_offs = sleb->endpt;
++	}
++
++	err = !sleb->endpt;
++out:
++	ubifs_scan_destroy(sleb);
++	return err;
++
++out_dump:
++	ubifs_err("log error detected while replying the log at LEB %d:%d",
++		  lnum, offs + snod->offs);
++	dbg_dump_node(c, snod->node);
++	ubifs_scan_destroy(sleb);
++	return -EINVAL;
++}
++
++/**
++ * take_ihead - update the status of the index head in lprops to 'taken'.
++ * @c: UBIFS file-system description object
++ *
++ * This function returns the amount of free space in the index head LEB or a
++ * negative error code.
++ */
++static int take_ihead(struct ubifs_info *c)
++{
++	const struct ubifs_lprops *lp;
++	int err, free;
++
++	ubifs_get_lprops(c);
++
++	lp = ubifs_lpt_lookup_dirty(c, c->ihead_lnum);
++	if (IS_ERR(lp)) {
++		err = PTR_ERR(lp);
++		goto out;
++	}
++
++	free = lp->free;
++
++	lp = ubifs_change_lp(c, lp, LPROPS_NC, LPROPS_NC,
++			     lp->flags | LPROPS_TAKEN, 0);
++	if (IS_ERR(lp)) {
++		err = PTR_ERR(lp);
++		goto out;
++	}
++
++	err = free;
++out:
++	ubifs_release_lprops(c);
++	return err;
++}
++
++/**
++ * ubifs_replay_journal - replay journal.
++ * @c: UBIFS file-system description object
++ *
++ * This function scans the journal, replays and cleans it up. It makes sure all
++ * memory data structures related to uncommitted journal are built (dirty TNC
++ * tree, tree of buds, modified lprops, etc).
++ */
++int ubifs_replay_journal(struct ubifs_info *c)
++{
++	int err, i, lnum, offs, free;
++	void *sbuf = NULL;
++
++	BUILD_BUG_ON(UBIFS_TRUN_KEY > 5);
++
++	/* Update the status of the index head in lprops to 'taken' */
++	free = take_ihead(c);
++	if (free < 0)
++		return free; /* Error code */
++
++	if (c->ihead_offs != c->leb_size - free) {
++		ubifs_err("bad index head LEB %d:%d", c->ihead_lnum,
++			  c->ihead_offs);
++		return -EINVAL;
++	}
++
++	sbuf = vmalloc(c->leb_size);
++	if (!sbuf)
++		return -ENOMEM;
++
++	dbg_mnt("start replaying the journal");
++
++	c->replaying = 1;
++
++	lnum = c->ltail_lnum = c->lhead_lnum;
++	offs = c->lhead_offs;
++
++	for (i = 0; i < c->log_lebs; i++, lnum++) {
++		if (lnum >= UBIFS_LOG_LNUM + c->log_lebs) {
++			/*
++			 * The log is logically circular, we reached the last
++			 * LEB, switch to the first one.
++			 */
++			lnum = UBIFS_LOG_LNUM;
++			offs = 0;
++		}
++		err = replay_log_leb(c, lnum, offs, sbuf);
++		if (err == 1)
++			/* We hit the end of the log */
++			break;
++		if (err)
++			goto out;
++		offs = 0;
++	}
++
++	err = replay_buds(c);
++	if (err)
++		goto out;
++
++	err = apply_replay_tree(c);
++	if (err)
++		goto out;
++
++	/*
++	 * UBIFS budgeting calculations use @c->budg_uncommitted_idx variable
++	 * to roughly estimate index growth. Things like @c->min_idx_lebs
++	 * depend on it. This means we have to initialize it to make sure
++	 * budgeting works properly.
++	 */
++	c->budg_uncommitted_idx = atomic_long_read(&c->dirty_zn_cnt);
++	c->budg_uncommitted_idx *= c->max_idx_node_sz;
++
++	ubifs_assert(c->bud_bytes <= c->max_bud_bytes || c->need_recovery);
++	dbg_mnt("finished, log head LEB %d:%d, max_sqnum %llu, "
++		"highest_inum %lu", c->lhead_lnum, c->lhead_offs, c->max_sqnum,
++		(unsigned long)c->highest_inum);
++out:
++	destroy_replay_tree(c);
++	destroy_bud_list(c);
++	vfree(sbuf);
++	c->replaying = 0;
++	return err;
++}
+diff -Nurd linux-2.6.24.orig/fs/ubifs/sb.c linux-2.6.24/fs/ubifs/sb.c
+--- linux-2.6.24.orig/fs/ubifs/sb.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/sb.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,634 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++/*
++ * This file implements UBIFS superblock. The superblock is stored at the first
++ * LEB of the volume and is never changed by UBIFS. Only user-space tools may
++ * change it. The superblock node mostly contains geometry information.
++ */
++
++#include "ubifs.h"
++#include <linux/random.h>
++
++/*
++ * Default journal size in logical eraseblocks as a percent of total
++ * flash size.
++ */
++#define DEFAULT_JNL_PERCENT 5
++
++/* Default maximum journal size in bytes */
++#define DEFAULT_MAX_JNL (32*1024*1024)
++
++/* Default indexing tree fanout */
++#define DEFAULT_FANOUT 8
++
++/* Default number of data journal heads */
++#define DEFAULT_JHEADS_CNT 1
++
++/* Default positions of different LEBs in the main area */
++#define DEFAULT_IDX_LEB  0
++#define DEFAULT_DATA_LEB 1
++#define DEFAULT_GC_LEB   2
++
++/* Default number of LEB numbers in LPT's save table */
++#define DEFAULT_LSAVE_CNT 256
++
++/* Default reserved pool size as a percent of maximum free space */
++#define DEFAULT_RP_PERCENT 5
++
++/* The default maximum size of reserved pool in bytes */
++#define DEFAULT_MAX_RP_SIZE (5*1024*1024)
++
++/* Default UBIFS compressor */
++#define DEFAULT_COMPRESSOR UBIFS_COMPR_LZO
++
++/* Default time granularity in nanoseconds */
++#define DEFAULT_TIME_GRAN 1000000000
++
++/**
++ * create_default_filesystem - format empty UBI volume.
++ * @c: UBIFS file-system description object
++ *
++ * This function creates default empty file-system. Returns zero in case of
++ * success and a negative error code in case of failure.
++ */
++static int create_default_filesystem(struct ubifs_info *c)
++{
++	struct ubifs_sb_node *sup;
++	struct ubifs_mst_node *mst;
++	struct ubifs_idx_node *idx;
++	struct ubifs_branch *br;
++	struct ubifs_ino_node *ino;
++	struct ubifs_cs_node *cs;
++	union ubifs_key key;
++	int err, tmp, jnl_lebs, log_lebs, max_buds, main_lebs, main_first;
++	int lpt_lebs, lpt_first, orph_lebs, big_lpt, ino_waste, sup_flags = 0;
++	int min_leb_cnt = UBIFS_MIN_LEB_CNT;
++	long long tmp64, main_bytes;
++	__le64 tmp_le64;
++
++	/* Some functions called from here depend on the @c->key_len filed */
++	c->key_len = UBIFS_SK_LEN;
++
++	/*
++	 * First of all, we have to calculate default file-system geometry -
++	 * log size, journal size, etc.
++	 */
++	if (c->leb_cnt < 0x7FFFFFFF / DEFAULT_JNL_PERCENT)
++		/* We can first multiply then divide and have no overflow */
++		jnl_lebs = c->leb_cnt * DEFAULT_JNL_PERCENT / 100;
++	else
++		jnl_lebs = (c->leb_cnt / 100) * DEFAULT_JNL_PERCENT;
++
++	if (jnl_lebs < UBIFS_MIN_JNL_LEBS)
++		jnl_lebs = UBIFS_MIN_JNL_LEBS;
++	if (jnl_lebs * c->leb_size > DEFAULT_MAX_JNL)
++		jnl_lebs = DEFAULT_MAX_JNL / c->leb_size;
++
++	/*
++	 * The log should be large enough to fit reference nodes for all bud
++	 * LEBs. Because buds do not have to start from the beginning of LEBs
++	 * (half of the LEB may contain committed data), the log should
++	 * generally be larger, make it twice as large.
++	 */
++	tmp = 2 * (c->ref_node_alsz * jnl_lebs) + c->leb_size - 1;
++	log_lebs = tmp / c->leb_size;
++	/* Plus one LEB reserved for commit */
++	log_lebs += 1;
++	if (c->leb_cnt - min_leb_cnt > 8) {
++		/* And some extra space to allow writes while committing */
++		log_lebs += 1;
++		min_leb_cnt += 1;
++	}
++
++	max_buds = jnl_lebs - log_lebs;
++	if (max_buds < UBIFS_MIN_BUD_LEBS)
++		max_buds = UBIFS_MIN_BUD_LEBS;
++
++	/*
++	 * Orphan nodes are stored in a separate area. One node can store a lot
++	 * of orphan inode numbers, but when new orphan comes we just add a new
++	 * orphan node. At some point the nodes are consolidated into one
++	 * orphan node.
++	 */
++	orph_lebs = UBIFS_MIN_ORPH_LEBS;
++#ifdef CONFIG_UBIFS_FS_DEBUG
++	if (c->leb_cnt - min_leb_cnt > 1)
++		/*
++		 * For debugging purposes it is better to have at least 2
++		 * orphan LEBs, because the orphan subsystem would need to do
++		 * consolidations and would be stressed more.
++		 */
++		orph_lebs += 1;
++#endif
++
++	main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS - log_lebs;
++	main_lebs -= orph_lebs;
++
++	lpt_first = UBIFS_LOG_LNUM + log_lebs;
++	c->lsave_cnt = DEFAULT_LSAVE_CNT;
++	c->max_leb_cnt = c->leb_cnt;
++	err = ubifs_create_dflt_lpt(c, &main_lebs, lpt_first, &lpt_lebs,
++				    &big_lpt);
++	if (err)
++		return err;
++
++	dbg_gen("LEB Properties Tree created (LEBs %d-%d)", lpt_first,
++		lpt_first + lpt_lebs - 1);
++
++	main_first = c->leb_cnt - main_lebs;
++
++	/* Create default superblock */
++	tmp = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
++	sup = kzalloc(tmp, GFP_KERNEL);
++	if (!sup)
++		return -ENOMEM;
++
++	tmp64 = (long long)max_buds * c->leb_size;
++	if (big_lpt)
++		sup_flags |= UBIFS_FLG_BIGLPT;
++
++	sup->ch.node_type  = UBIFS_SB_NODE;
++	sup->key_hash      = UBIFS_KEY_HASH_R5;
++	sup->flags         = cpu_to_le32(sup_flags);
++	sup->min_io_size   = cpu_to_le32(c->min_io_size);
++	sup->leb_size      = cpu_to_le32(c->leb_size);
++	sup->leb_cnt       = cpu_to_le32(c->leb_cnt);
++	sup->max_leb_cnt   = cpu_to_le32(c->max_leb_cnt);
++	sup->max_bud_bytes = cpu_to_le64(tmp64);
++	sup->log_lebs      = cpu_to_le32(log_lebs);
++	sup->lpt_lebs      = cpu_to_le32(lpt_lebs);
++	sup->orph_lebs     = cpu_to_le32(orph_lebs);
++	sup->jhead_cnt     = cpu_to_le32(DEFAULT_JHEADS_CNT);
++	sup->fanout        = cpu_to_le32(DEFAULT_FANOUT);
++	sup->lsave_cnt     = cpu_to_le32(c->lsave_cnt);
++	sup->fmt_version   = cpu_to_le32(UBIFS_FORMAT_VERSION);
++	sup->time_gran     = cpu_to_le32(DEFAULT_TIME_GRAN);
++	if (c->mount_opts.override_compr)
++		sup->default_compr = cpu_to_le16(c->mount_opts.compr_type);
++	else
++		sup->default_compr = cpu_to_le16(UBIFS_COMPR_LZO);
++
++	generate_random_uuid(sup->uuid);
++
++	main_bytes = (long long)main_lebs * c->leb_size;
++	tmp64 = div_u64(main_bytes * DEFAULT_RP_PERCENT, 100);
++	if (tmp64 > DEFAULT_MAX_RP_SIZE)
++		tmp64 = DEFAULT_MAX_RP_SIZE;
++	sup->rp_size = cpu_to_le64(tmp64);
++
++	err = ubifs_write_node(c, sup, UBIFS_SB_NODE_SZ, 0, 0, UBI_LONGTERM);
++	kfree(sup);
++	if (err)
++		return err;
++
++	dbg_gen("default superblock created at LEB 0:0");
++
++	/* Create default master node */
++	mst = kzalloc(c->mst_node_alsz, GFP_KERNEL);
++	if (!mst)
++		return -ENOMEM;
++
++	mst->ch.node_type = UBIFS_MST_NODE;
++	mst->log_lnum     = cpu_to_le32(UBIFS_LOG_LNUM);
++	mst->highest_inum = cpu_to_le64(UBIFS_FIRST_INO);
++	mst->cmt_no       = 0;
++	mst->root_lnum    = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
++	mst->root_offs    = 0;
++	tmp = ubifs_idx_node_sz(c, 1);
++	mst->root_len     = cpu_to_le32(tmp);
++	mst->gc_lnum      = cpu_to_le32(main_first + DEFAULT_GC_LEB);
++	mst->ihead_lnum   = cpu_to_le32(main_first + DEFAULT_IDX_LEB);
++	mst->ihead_offs   = cpu_to_le32(ALIGN(tmp, c->min_io_size));
++	mst->index_size   = cpu_to_le64(ALIGN(tmp, 8));
++	mst->lpt_lnum     = cpu_to_le32(c->lpt_lnum);
++	mst->lpt_offs     = cpu_to_le32(c->lpt_offs);
++	mst->nhead_lnum   = cpu_to_le32(c->nhead_lnum);
++	mst->nhead_offs   = cpu_to_le32(c->nhead_offs);
++	mst->ltab_lnum    = cpu_to_le32(c->ltab_lnum);
++	mst->ltab_offs    = cpu_to_le32(c->ltab_offs);
++	mst->lsave_lnum   = cpu_to_le32(c->lsave_lnum);
++	mst->lsave_offs   = cpu_to_le32(c->lsave_offs);
++	mst->lscan_lnum   = cpu_to_le32(main_first);
++	mst->empty_lebs   = cpu_to_le32(main_lebs - 2);
++	mst->idx_lebs     = cpu_to_le32(1);
++	mst->leb_cnt      = cpu_to_le32(c->leb_cnt);
++
++	/* Calculate lprops statistics */
++	tmp64 = main_bytes;
++	tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
++	tmp64 -= ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
++	mst->total_free = cpu_to_le64(tmp64);
++
++	tmp64 = ALIGN(ubifs_idx_node_sz(c, 1), c->min_io_size);
++	ino_waste = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size) -
++			  UBIFS_INO_NODE_SZ;
++	tmp64 += ino_waste;
++	tmp64 -= ALIGN(ubifs_idx_node_sz(c, 1), 8);
++	mst->total_dirty = cpu_to_le64(tmp64);
++
++	/*  The indexing LEB does not contribute to dark space */
++	tmp64 = (c->main_lebs - 1) * c->dark_wm;
++	mst->total_dark = cpu_to_le64(tmp64);
++
++	mst->total_used = cpu_to_le64(UBIFS_INO_NODE_SZ);
++
++	err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM, 0,
++			       UBI_UNKNOWN);
++	if (err) {
++		kfree(mst);
++		return err;
++	}
++	err = ubifs_write_node(c, mst, UBIFS_MST_NODE_SZ, UBIFS_MST_LNUM + 1, 0,
++			       UBI_UNKNOWN);
++	kfree(mst);
++	if (err)
++		return err;
++
++	dbg_gen("default master node created at LEB %d:0", UBIFS_MST_LNUM);
++
++	/* Create the root indexing node */
++	tmp = ubifs_idx_node_sz(c, 1);
++	idx = kzalloc(ALIGN(tmp, c->min_io_size), GFP_KERNEL);
++	if (!idx)
++		return -ENOMEM;
++
++	c->key_fmt = UBIFS_SIMPLE_KEY_FMT;
++	c->key_hash = key_r5_hash;
++
++	idx->ch.node_type = UBIFS_IDX_NODE;
++	idx->child_cnt = cpu_to_le16(1);
++	ino_key_init(c, &key, UBIFS_ROOT_INO);
++	br = ubifs_idx_branch(c, idx, 0);
++	key_write_idx(c, &key, &br->key);
++	br->lnum = cpu_to_le32(main_first + DEFAULT_DATA_LEB);
++	br->len  = cpu_to_le32(UBIFS_INO_NODE_SZ);
++	err = ubifs_write_node(c, idx, tmp, main_first + DEFAULT_IDX_LEB, 0,
++			       UBI_UNKNOWN);
++	kfree(idx);
++	if (err)
++		return err;
++
++	dbg_gen("default root indexing node created LEB %d:0",
++		main_first + DEFAULT_IDX_LEB);
++
++	/* Create default root inode */
++	tmp = ALIGN(UBIFS_INO_NODE_SZ, c->min_io_size);
++	ino = kzalloc(tmp, GFP_KERNEL);
++	if (!ino)
++		return -ENOMEM;
++
++	ino_key_init_flash(c, &ino->key, UBIFS_ROOT_INO);
++	ino->ch.node_type = UBIFS_INO_NODE;
++	ino->creat_sqnum = cpu_to_le64(++c->max_sqnum);
++	ino->nlink = cpu_to_le32(2);
++	tmp_le64 = cpu_to_le64(CURRENT_TIME_SEC.tv_sec);
++	ino->atime_sec   = tmp_le64;
++	ino->ctime_sec   = tmp_le64;
++	ino->mtime_sec   = tmp_le64;
++	ino->atime_nsec  = 0;
++	ino->ctime_nsec  = 0;
++	ino->mtime_nsec  = 0;
++	ino->mode = cpu_to_le32(S_IFDIR | S_IRUGO | S_IWUSR | S_IXUGO);
++	ino->size = cpu_to_le64(UBIFS_INO_NODE_SZ);
++
++	/* Set compression enabled by default */
++	ino->flags = cpu_to_le32(UBIFS_COMPR_FL);
++
++	err = ubifs_write_node(c, ino, UBIFS_INO_NODE_SZ,
++			       main_first + DEFAULT_DATA_LEB, 0,
++			       UBI_UNKNOWN);
++	kfree(ino);
++	if (err)
++		return err;
++
++	dbg_gen("root inode created at LEB %d:0",
++		main_first + DEFAULT_DATA_LEB);
++
++	/*
++	 * The first node in the log has to be the commit start node. This is
++	 * always the case during normal file-system operation. Write a fake
++	 * commit start node to the log.
++	 */
++	tmp = ALIGN(UBIFS_CS_NODE_SZ, c->min_io_size);
++	cs = kzalloc(tmp, GFP_KERNEL);
++	if (!cs)
++		return -ENOMEM;
++
++	cs->ch.node_type = UBIFS_CS_NODE;
++	err = ubifs_write_node(c, cs, UBIFS_CS_NODE_SZ, UBIFS_LOG_LNUM,
++			       0, UBI_UNKNOWN);
++	kfree(cs);
++
++	ubifs_msg("default file-system created");
++	return 0;
++}
++
++/**
++ * validate_sb - validate superblock node.
++ * @c: UBIFS file-system description object
++ * @sup: superblock node
++ *
++ * This function validates superblock node @sup. Since most of data was read
++ * from the superblock and stored in @c, the function validates fields in @c
++ * instead. Returns zero in case of success and %-EINVAL in case of validation
++ * failure.
++ */
++static int validate_sb(struct ubifs_info *c, struct ubifs_sb_node *sup)
++{
++	long long max_bytes;
++	int err = 1, min_leb_cnt;
++
++	if (!c->key_hash) {
++		err = 2;
++		goto failed;
++	}
++
++	if (sup->key_fmt != UBIFS_SIMPLE_KEY_FMT) {
++		err = 3;
++		goto failed;
++	}
++
++	if (le32_to_cpu(sup->min_io_size) != c->min_io_size) {
++		ubifs_err("min. I/O unit mismatch: %d in superblock, %d real",
++			  le32_to_cpu(sup->min_io_size), c->min_io_size);
++		goto failed;
++	}
++
++	if (le32_to_cpu(sup->leb_size) != c->leb_size) {
++		ubifs_err("LEB size mismatch: %d in superblock, %d real",
++			  le32_to_cpu(sup->leb_size), c->leb_size);
++		goto failed;
++	}
++
++	if (c->log_lebs < UBIFS_MIN_LOG_LEBS ||
++	    c->lpt_lebs < UBIFS_MIN_LPT_LEBS ||
++	    c->orph_lebs < UBIFS_MIN_ORPH_LEBS ||
++	    c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
++		err = 4;
++		goto failed;
++	}
++
++	/*
++	 * Calculate minimum allowed amount of main area LEBs. This is very
++	 * similar to %UBIFS_MIN_LEB_CNT, but we take into account real what we
++	 * have just read from the superblock.
++	 */
++	min_leb_cnt = UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs;
++	min_leb_cnt += c->lpt_lebs + c->orph_lebs + c->jhead_cnt + 6;
++
++	if (c->leb_cnt < min_leb_cnt || c->leb_cnt > c->vi.size) {
++		ubifs_err("bad LEB count: %d in superblock, %d on UBI volume, "
++			  "%d minimum required", c->leb_cnt, c->vi.size,
++			  min_leb_cnt);
++		goto failed;
++	}
++
++	if (c->max_leb_cnt < c->leb_cnt) {
++		ubifs_err("max. LEB count %d less than LEB count %d",
++			  c->max_leb_cnt, c->leb_cnt);
++		goto failed;
++	}
++
++	if (c->main_lebs < UBIFS_MIN_MAIN_LEBS) {
++		err = 7;
++		goto failed;
++	}
++
++	if (c->max_bud_bytes < (long long)c->leb_size * UBIFS_MIN_BUD_LEBS ||
++	    c->max_bud_bytes > (long long)c->leb_size * c->main_lebs) {
++		err = 8;
++		goto failed;
++	}
++
++	if (c->jhead_cnt < NONDATA_JHEADS_CNT + 1 ||
++	    c->jhead_cnt > NONDATA_JHEADS_CNT + UBIFS_MAX_JHEADS) {
++		err = 9;
++		goto failed;
++	}
++
++	if (c->fanout < UBIFS_MIN_FANOUT ||
++	    ubifs_idx_node_sz(c, c->fanout) > c->leb_size) {
++		err = 10;
++		goto failed;
++	}
++
++	if (c->lsave_cnt < 0 || (c->lsave_cnt > DEFAULT_LSAVE_CNT &&
++	    c->lsave_cnt > c->max_leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS -
++	    c->log_lebs - c->lpt_lebs - c->orph_lebs)) {
++		err = 11;
++		goto failed;
++	}
++
++	if (UBIFS_SB_LEBS + UBIFS_MST_LEBS + c->log_lebs + c->lpt_lebs +
++	    c->orph_lebs + c->main_lebs != c->leb_cnt) {
++		err = 12;
++		goto failed;
++	}
++
++	if (c->default_compr < 0 || c->default_compr >= UBIFS_COMPR_TYPES_CNT) {
++		err = 13;
++		goto failed;
++	}
++
++	max_bytes = c->main_lebs * (long long)c->leb_size;
++	if (c->rp_size < 0 || max_bytes < c->rp_size) {
++		err = 14;
++		goto failed;
++	}
++
++	if (le32_to_cpu(sup->time_gran) > 1000000000 ||
++	    le32_to_cpu(sup->time_gran) < 1) {
++		err = 15;
++		goto failed;
++	}
++
++	return 0;
++
++failed:
++	ubifs_err("bad superblock, error %d", err);
++	dbg_dump_node(c, sup);
++	return -EINVAL;
++}
++
++/**
++ * ubifs_read_sb_node - read superblock node.
++ * @c: UBIFS file-system description object
++ *
++ * This function returns a pointer to the superblock node or a negative error
++ * code.
++ */
++struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c)
++{
++	struct ubifs_sb_node *sup;
++	int err;
++
++	sup = kmalloc(ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size), GFP_NOFS);
++	if (!sup)
++		return ERR_PTR(-ENOMEM);
++
++	err = ubifs_read_node(c, sup, UBIFS_SB_NODE, UBIFS_SB_NODE_SZ,
++			      UBIFS_SB_LNUM, 0);
++	if (err) {
++		kfree(sup);
++		return ERR_PTR(err);
++	}
++
++	return sup;
++}
++
++/**
++ * ubifs_write_sb_node - write superblock node.
++ * @c: UBIFS file-system description object
++ * @sup: superblock node read with 'ubifs_read_sb_node()'
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup)
++{
++	int len = ALIGN(UBIFS_SB_NODE_SZ, c->min_io_size);
++
++	ubifs_prepare_node(c, sup, UBIFS_SB_NODE_SZ, 1);
++	return ubifs_leb_change(c, UBIFS_SB_LNUM, sup, len, UBI_LONGTERM);
++}
++
++/**
++ * ubifs_read_superblock - read superblock.
++ * @c: UBIFS file-system description object
++ *
++ * This function finds, reads and checks the superblock. If an empty UBI volume
++ * is being mounted, this function creates default superblock. Returns zero in
++ * case of success, and a negative error code in case of failure.
++ */
++int ubifs_read_superblock(struct ubifs_info *c)
++{
++	int err, sup_flags;
++	struct ubifs_sb_node *sup;
++
++	if (c->empty) {
++		err = create_default_filesystem(c);
++		if (err)
++			return err;
++	}
++
++	sup = ubifs_read_sb_node(c);
++	if (IS_ERR(sup))
++		return PTR_ERR(sup);
++
++	/*
++	 * The software supports all previous versions but not future versions,
++	 * due to the unavailability of time-travelling equipment.
++	 */
++	c->fmt_version = le32_to_cpu(sup->fmt_version);
++	if (c->fmt_version > UBIFS_FORMAT_VERSION) {
++		ubifs_err("on-flash format version is %d, but software only "
++			  "supports up to version %d", c->fmt_version,
++			  UBIFS_FORMAT_VERSION);
++		err = -EINVAL;
++		goto out;
++	}
++
++	if (c->fmt_version < 3) {
++		ubifs_err("on-flash format version %d is not supported",
++			  c->fmt_version);
++		err = -EINVAL;
++		goto out;
++	}
++
++	switch (sup->key_hash) {
++	case UBIFS_KEY_HASH_R5:
++		c->key_hash = key_r5_hash;
++		c->key_hash_type = UBIFS_KEY_HASH_R5;
++		break;
++
++	case UBIFS_KEY_HASH_TEST:
++		c->key_hash = key_test_hash;
++		c->key_hash_type = UBIFS_KEY_HASH_TEST;
++		break;
++	};
++
++	c->key_fmt = sup->key_fmt;
++
++	switch (c->key_fmt) {
++	case UBIFS_SIMPLE_KEY_FMT:
++		c->key_len = UBIFS_SK_LEN;
++		break;
++	default:
++		ubifs_err("unsupported key format");
++		err = -EINVAL;
++		goto out;
++	}
++
++	c->leb_cnt       = le32_to_cpu(sup->leb_cnt);
++	c->max_leb_cnt   = le32_to_cpu(sup->max_leb_cnt);
++	c->max_bud_bytes = le64_to_cpu(sup->max_bud_bytes);
++	c->log_lebs      = le32_to_cpu(sup->log_lebs);
++	c->lpt_lebs      = le32_to_cpu(sup->lpt_lebs);
++	c->orph_lebs     = le32_to_cpu(sup->orph_lebs);
++	c->jhead_cnt     = le32_to_cpu(sup->jhead_cnt) + NONDATA_JHEADS_CNT;
++	c->fanout        = le32_to_cpu(sup->fanout);
++	c->lsave_cnt     = le32_to_cpu(sup->lsave_cnt);
++	c->rp_size       = le64_to_cpu(sup->rp_size);
++	c->rp_uid        = le32_to_cpu(sup->rp_uid);
++	c->rp_gid        = le32_to_cpu(sup->rp_gid);
++	sup_flags        = le32_to_cpu(sup->flags);
++	if (!c->mount_opts.override_compr)
++		c->default_compr = le16_to_cpu(sup->default_compr);
++
++	c->vfs_sb->s_time_gran = le32_to_cpu(sup->time_gran);
++	memcpy(&c->uuid, &sup->uuid, 16);
++	c->big_lpt = !!(sup_flags & UBIFS_FLG_BIGLPT);
++
++	/* Automatically increase file system size to the maximum size */
++	c->old_leb_cnt = c->leb_cnt;
++	if (c->leb_cnt < c->vi.size && c->leb_cnt < c->max_leb_cnt) {
++		c->leb_cnt = min_t(int, c->max_leb_cnt, c->vi.size);
++		if (c->vfs_sb->s_flags & MS_RDONLY)
++			dbg_mnt("Auto resizing (ro) from %d LEBs to %d LEBs",
++				c->old_leb_cnt,	c->leb_cnt);
++		else {
++			dbg_mnt("Auto resizing (sb) from %d LEBs to %d LEBs",
++				c->old_leb_cnt, c->leb_cnt);
++			sup->leb_cnt = cpu_to_le32(c->leb_cnt);
++			err = ubifs_write_sb_node(c, sup);
++			if (err)
++				goto out;
++			c->old_leb_cnt = c->leb_cnt;
++		}
++	}
++
++	c->log_bytes = (long long)c->log_lebs * c->leb_size;
++	c->log_last = UBIFS_LOG_LNUM + c->log_lebs - 1;
++	c->lpt_first = UBIFS_LOG_LNUM + c->log_lebs;
++	c->lpt_last = c->lpt_first + c->lpt_lebs - 1;
++	c->orph_first = c->lpt_last + 1;
++	c->orph_last = c->orph_first + c->orph_lebs - 1;
++	c->main_lebs = c->leb_cnt - UBIFS_SB_LEBS - UBIFS_MST_LEBS;
++	c->main_lebs -= c->log_lebs + c->lpt_lebs + c->orph_lebs;
++	c->main_first = c->leb_cnt - c->main_lebs;
++	c->report_rp_size = ubifs_reported_space(c, c->rp_size);
++
++	err = validate_sb(c, sup);
++out:
++	kfree(sup);
++	return err;
++}
+diff -Nurd linux-2.6.24.orig/fs/ubifs/scan.c linux-2.6.24/fs/ubifs/scan.c
+--- linux-2.6.24.orig/fs/ubifs/scan.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/scan.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,362 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Adrian Hunter
++ *          Artem Bityutskiy (Битюцкий Артём)
++ */
++
++/*
++ * This file implements the scan which is a general-purpose function for
++ * determining what nodes are in an eraseblock. The scan is used to replay the
++ * journal, to do garbage collection. for the TNC in-the-gaps method, and by
++ * debugging functions.
++ */
++
++#include "ubifs.h"
++
++/**
++ * scan_padding_bytes - scan for padding bytes.
++ * @buf: buffer to scan
++ * @len: length of buffer
++ *
++ * This function returns the number of padding bytes on success and
++ * %SCANNED_GARBAGE on failure.
++ */
++static int scan_padding_bytes(void *buf, int len)
++{
++	int pad_len = 0, max_pad_len = min_t(int, UBIFS_PAD_NODE_SZ, len);
++	uint8_t *p = buf;
++
++	dbg_scan("not a node");
++
++	while (pad_len < max_pad_len && *p++ == UBIFS_PADDING_BYTE)
++		pad_len += 1;
++
++	if (!pad_len || (pad_len & 7))
++		return SCANNED_GARBAGE;
++
++	dbg_scan("%d padding bytes", pad_len);
++
++	return pad_len;
++}
++
++/**
++ * ubifs_scan_a_node - scan for a node or padding.
++ * @c: UBIFS file-system description object
++ * @buf: buffer to scan
++ * @len: length of buffer
++ * @lnum: logical eraseblock number
++ * @offs: offset within the logical eraseblock
++ * @quiet: print no messages
++ *
++ * This function returns a scanning code to indicate what was scanned.
++ */
++int ubifs_scan_a_node(const struct ubifs_info *c, void *buf, int len, int lnum,
++		      int offs, int quiet)
++{
++	struct ubifs_ch *ch = buf;
++	uint32_t magic;
++
++	magic = le32_to_cpu(ch->magic);
++
++	if (magic == 0xFFFFFFFF) {
++		dbg_scan("hit empty space");
++		return SCANNED_EMPTY_SPACE;
++	}
++
++	if (magic != UBIFS_NODE_MAGIC)
++		return scan_padding_bytes(buf, len);
++
++	if (len < UBIFS_CH_SZ)
++		return SCANNED_GARBAGE;
++
++	dbg_scan("scanning %s", dbg_ntype(ch->node_type));
++
++	if (ubifs_check_node(c, buf, lnum, offs, quiet, 1))
++		return SCANNED_A_CORRUPT_NODE;
++
++	if (ch->node_type == UBIFS_PAD_NODE) {
++		struct ubifs_pad_node *pad = buf;
++		int pad_len = le32_to_cpu(pad->pad_len);
++		int node_len = le32_to_cpu(ch->len);
++
++		/* Validate the padding node */
++		if (pad_len < 0 ||
++		    offs + node_len + pad_len > c->leb_size) {
++			if (!quiet) {
++				ubifs_err("bad pad node at LEB %d:%d",
++					  lnum, offs);
++				dbg_dump_node(c, pad);
++			}
++			return SCANNED_A_BAD_PAD_NODE;
++		}
++
++		/* Make the node pads to 8-byte boundary */
++		if ((node_len + pad_len) & 7) {
++			if (!quiet) {
++				dbg_err("bad padding length %d - %d",
++					offs, offs + node_len + pad_len);
++			}
++			return SCANNED_A_BAD_PAD_NODE;
++		}
++
++		dbg_scan("%d bytes padded, offset now %d",
++			 pad_len, ALIGN(offs + node_len + pad_len, 8));
++
++		return node_len + pad_len;
++	}
++
++	return SCANNED_A_NODE;
++}
++
++/**
++ * ubifs_start_scan - create LEB scanning information at start of scan.
++ * @c: UBIFS file-system description object
++ * @lnum: logical eraseblock number
++ * @offs: offset to start at (usually zero)
++ * @sbuf: scan buffer (must be c->leb_size)
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++struct ubifs_scan_leb *ubifs_start_scan(const struct ubifs_info *c, int lnum,
++					int offs, void *sbuf)
++{
++	struct ubifs_scan_leb *sleb;
++	int err;
++
++	dbg_scan("scan LEB %d:%d", lnum, offs);
++
++	sleb = kzalloc(sizeof(struct ubifs_scan_leb), GFP_NOFS);
++	if (!sleb)
++		return ERR_PTR(-ENOMEM);
++
++	sleb->lnum = lnum;
++	INIT_LIST_HEAD(&sleb->nodes);
++	sleb->buf = sbuf;
++
++	err = ubi_read(c->ubi, lnum, sbuf + offs, offs, c->leb_size - offs);
++	if (err && err != -EBADMSG) {
++		ubifs_err("cannot read %d bytes from LEB %d:%d,"
++			  " error %d", c->leb_size - offs, lnum, offs, err);
++		kfree(sleb);
++		return ERR_PTR(err);
++	}
++
++	if (err == -EBADMSG)
++		sleb->ecc = 1;
++
++	return sleb;
++}
++
++/**
++ * ubifs_end_scan - update LEB scanning information at end of scan.
++ * @c: UBIFS file-system description object
++ * @sleb: scanning information
++ * @lnum: logical eraseblock number
++ * @offs: offset to start at (usually zero)
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++void ubifs_end_scan(const struct ubifs_info *c, struct ubifs_scan_leb *sleb,
++		    int lnum, int offs)
++{
++	lnum = lnum;
++	dbg_scan("stop scanning LEB %d at offset %d", lnum, offs);
++	ubifs_assert(offs % c->min_io_size == 0);
++
++	sleb->endpt = ALIGN(offs, c->min_io_size);
++}
++
++/**
++ * ubifs_add_snod - add a scanned node to LEB scanning information.
++ * @c: UBIFS file-system description object
++ * @sleb: scanning information
++ * @buf: buffer containing node
++ * @offs: offset of node on flash
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++int ubifs_add_snod(const struct ubifs_info *c, struct ubifs_scan_leb *sleb,
++		   void *buf, int offs)
++{
++	struct ubifs_ch *ch = buf;
++	struct ubifs_ino_node *ino = buf;
++	struct ubifs_scan_node *snod;
++
++	snod = kzalloc(sizeof(struct ubifs_scan_node), GFP_NOFS);
++	if (!snod)
++		return -ENOMEM;
++
++	snod->sqnum = le64_to_cpu(ch->sqnum);
++	snod->type = ch->node_type;
++	snod->offs = offs;
++	snod->len = le32_to_cpu(ch->len);
++	snod->node = buf;
++
++	switch (ch->node_type) {
++	case UBIFS_INO_NODE:
++	case UBIFS_DENT_NODE:
++	case UBIFS_XENT_NODE:
++	case UBIFS_DATA_NODE:
++	case UBIFS_TRUN_NODE:
++		/*
++		 * The key is in the same place in all keyed
++		 * nodes.
++		 */
++		key_read(c, &ino->key, &snod->key);
++		break;
++	}
++	list_add_tail(&snod->list, &sleb->nodes);
++	sleb->nodes_cnt += 1;
++	return 0;
++}
++
++/**
++ * ubifs_scanned_corruption - print information after UBIFS scanned corruption.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number of corruption
++ * @offs: offset of corruption
++ * @buf: buffer containing corruption
++ */
++void ubifs_scanned_corruption(const struct ubifs_info *c, int lnum, int offs,
++			      void *buf)
++{
++	int len;
++
++	ubifs_err("corrupted data at LEB %d:%d", lnum, offs);
++	if (dbg_failure_mode)
++		return;
++	len = c->leb_size - offs;
++	if (len > 4096)
++		len = 4096;
++	dbg_err("first %d bytes from LEB %d:%d", len, lnum, offs);
++	print_hex_dump(KERN_DEBUG, "", DUMP_PREFIX_OFFSET, 32, 4, buf, len, 1);
++}
++
++/**
++ * ubifs_scan - scan a logical eraseblock.
++ * @c: UBIFS file-system description object
++ * @lnum: logical eraseblock number
++ * @offs: offset to start at (usually zero)
++ * @sbuf: scan buffer (must be c->leb_size)
++ *
++ * This function scans LEB number @lnum and returns complete information about
++ * its contents. Returns an error code in case of failure.
++ */
++struct ubifs_scan_leb *ubifs_scan(const struct ubifs_info *c, int lnum,
++				  int offs, void *sbuf)
++{
++	void *buf = sbuf + offs;
++	int err, len = c->leb_size - offs;
++	struct ubifs_scan_leb *sleb;
++
++	sleb = ubifs_start_scan(c, lnum, offs, sbuf);
++	if (IS_ERR(sleb))
++		return sleb;
++
++	while (len >= 8) {
++		struct ubifs_ch *ch = buf;
++		int node_len, ret;
++
++		dbg_scan("look at LEB %d:%d (%d bytes left)",
++			 lnum, offs, len);
++
++		cond_resched();
++
++		ret = ubifs_scan_a_node(c, buf, len, lnum, offs, 0);
++
++		if (ret > 0) {
++			/* Padding bytes or a valid padding node */
++			offs += ret;
++			buf += ret;
++			len -= ret;
++			continue;
++		}
++
++		if (ret == SCANNED_EMPTY_SPACE)
++			/* Empty space is checked later */
++			break;
++
++		switch (ret) {
++		case SCANNED_GARBAGE:
++			dbg_err("garbage");
++			goto corrupted;
++		case SCANNED_A_NODE:
++			break;
++		case SCANNED_A_CORRUPT_NODE:
++		case SCANNED_A_BAD_PAD_NODE:
++			dbg_err("bad node");
++			goto corrupted;
++		default:
++			dbg_err("unknown");
++			goto corrupted;
++		}
++
++		err = ubifs_add_snod(c, sleb, buf, offs);
++		if (err)
++			goto error;
++
++		node_len = ALIGN(le32_to_cpu(ch->len), 8);
++		offs += node_len;
++		buf += node_len;
++		len -= node_len;
++	}
++
++	if (offs % c->min_io_size)
++		goto corrupted;
++
++	ubifs_end_scan(c, sleb, lnum, offs);
++
++	for (; len > 4; offs += 4, buf = buf + 4, len -= 4)
++		if (*(uint32_t *)buf != 0xffffffff)
++			break;
++	for (; len; offs++, buf++, len--)
++		if (*(uint8_t *)buf != 0xff) {
++			ubifs_err("corrupt empty space at LEB %d:%d",
++				  lnum, offs);
++			goto corrupted;
++		}
++
++	return sleb;
++
++corrupted:
++	ubifs_scanned_corruption(c, lnum, offs, buf);
++	err = -EUCLEAN;
++error:
++	ubifs_err("LEB %d scanning failed", lnum);
++	ubifs_scan_destroy(sleb);
++	return ERR_PTR(err);
++}
++
++/**
++ * ubifs_scan_destroy - destroy LEB scanning information.
++ * @sleb: scanning information to free
++ */
++void ubifs_scan_destroy(struct ubifs_scan_leb *sleb)
++{
++	struct ubifs_scan_node *node;
++	struct list_head *head;
++
++	head = &sleb->nodes;
++	while (!list_empty(head)) {
++		node = list_entry(head->next, struct ubifs_scan_node, list);
++		list_del(&node->list);
++		kfree(node);
++	}
++	kfree(sleb);
++}
+diff -Nurd linux-2.6.24.orig/fs/ubifs/shrinker.c linux-2.6.24/fs/ubifs/shrinker.c
+--- linux-2.6.24.orig/fs/ubifs/shrinker.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/shrinker.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,322 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++/*
++ * This file implements UBIFS shrinker which evicts clean znodes from the TNC
++ * tree when Linux VM needs more RAM.
++ *
++ * We do not implement any LRU lists to find oldest znodes to free because it
++ * would add additional overhead to the file system fast paths. So the shrinker
++ * just walks the TNC tree when searching for znodes to free.
++ *
++ * If the root of a TNC sub-tree is clean and old enough, then the children are
++ * also clean and old enough. So the shrinker walks the TNC in level order and
++ * dumps entire sub-trees.
++ *
++ * The age of znodes is just the time-stamp when they were last looked at.
++ * The current shrinker first tries to evict old znodes, then young ones.
++ *
++ * Since the shrinker is global, it has to protect against races with FS
++ * un-mounts, which is done by the 'ubifs_infos_lock' and 'c->umount_mutex'.
++ */
++
++#include "ubifs.h"
++
++/* List of all UBIFS file-system instances */
++LIST_HEAD(ubifs_infos);
++
++/*
++ * We number each shrinker run and record the number on the ubifs_info structure
++ * so that we can easily work out which ubifs_info structures have already been
++ * done by the current run.
++ */
++static unsigned int shrinker_run_no;
++
++/* Protects 'ubifs_infos' list */
++DEFINE_SPINLOCK(ubifs_infos_lock);
++
++/* Global clean znode counter (for all mounted UBIFS instances) */
++atomic_long_t ubifs_clean_zn_cnt;
++
++/**
++ * shrink_tnc - shrink TNC tree.
++ * @c: UBIFS file-system description object
++ * @nr: number of znodes to free
++ * @age: the age of znodes to free
++ * @contention: if any contention, this is set to %1
++ *
++ * This function traverses TNC tree and frees clean znodes. It does not free
++ * clean znodes which younger then @age. Returns number of freed znodes.
++ */
++static int shrink_tnc(struct ubifs_info *c, int nr, int age, int *contention)
++{
++	int total_freed = 0;
++	struct ubifs_znode *znode, *zprev;
++	int time = get_seconds();
++
++	ubifs_assert(mutex_is_locked(&c->umount_mutex));
++	ubifs_assert(mutex_is_locked(&c->tnc_mutex));
++
++	if (!c->zroot.znode || atomic_long_read(&c->clean_zn_cnt) == 0)
++		return 0;
++
++	/*
++	 * Traverse the TNC tree in levelorder manner, so that it is possible
++	 * to destroy large sub-trees. Indeed, if a znode is old, then all its
++	 * children are older or of the same age.
++	 *
++	 * Note, we are holding 'c->tnc_mutex', so we do not have to lock the
++	 * 'c->space_lock' when _reading_ 'c->clean_zn_cnt', because it is
++	 * changed only when the 'c->tnc_mutex' is held.
++	 */
++	zprev = NULL;
++	znode = ubifs_tnc_levelorder_next(c->zroot.znode, NULL);
++	while (znode && total_freed < nr &&
++	       atomic_long_read(&c->clean_zn_cnt) > 0) {
++		int freed;
++
++		/*
++		 * If the znode is clean, but it is in the 'c->cnext' list, this
++		 * means that this znode has just been written to flash as a
++		 * part of commit and was marked clean. They will be removed
++		 * from the list at end commit. We cannot change the list,
++		 * because it is not protected by any mutex (design decision to
++		 * make commit really independent and parallel to main I/O). So
++		 * we just skip these znodes.
++		 *
++		 * Note, the 'clean_zn_cnt' counters are not updated until
++		 * after the commit, so the UBIFS shrinker does not report
++		 * the znodes which are in the 'c->cnext' list as freeable.
++		 *
++		 * Also note, if the root of a sub-tree is not in 'c->cnext',
++		 * then the whole sub-tree is not in 'c->cnext' as well, so it
++		 * is safe to dump whole sub-tree.
++		 */
++
++		if (znode->cnext) {
++			/*
++			 * Very soon these znodes will be removed from the list
++			 * and become freeable.
++			 */
++			*contention = 1;
++		} else if (!ubifs_zn_dirty(znode) &&
++			   abs(time - znode->time) >= age) {
++			if (znode->parent)
++				znode->parent->zbranch[znode->iip].znode = NULL;
++			else
++				c->zroot.znode = NULL;
++
++			freed = ubifs_destroy_tnc_subtree(znode);
++			atomic_long_sub(freed, &ubifs_clean_zn_cnt);
++			atomic_long_sub(freed, &c->clean_zn_cnt);
++			ubifs_assert(atomic_long_read(&c->clean_zn_cnt) >= 0);
++			total_freed += freed;
++			znode = zprev;
++		}
++
++		if (unlikely(!c->zroot.znode))
++			break;
++
++		zprev = znode;
++		znode = ubifs_tnc_levelorder_next(c->zroot.znode, znode);
++		cond_resched();
++	}
++
++	return total_freed;
++}
++
++/**
++ * shrink_tnc_trees - shrink UBIFS TNC trees.
++ * @nr: number of znodes to free
++ * @age: the age of znodes to free
++ * @contention: if any contention, this is set to %1
++ *
++ * This function walks the list of mounted UBIFS file-systems and frees clean
++ * znodes which are older then @age, until at least @nr znodes are freed.
++ * Returns the number of freed znodes.
++ */
++static int shrink_tnc_trees(int nr, int age, int *contention)
++{
++	struct ubifs_info *c;
++	struct list_head *p;
++	unsigned int run_no;
++	int freed = 0;
++
++	spin_lock(&ubifs_infos_lock);
++	do {
++		run_no = ++shrinker_run_no;
++	} while (run_no == 0);
++	/* Iterate over all mounted UBIFS file-systems and try to shrink them */
++	p = ubifs_infos.next;
++	while (p != &ubifs_infos) {
++		c = list_entry(p, struct ubifs_info, infos_list);
++		/*
++		 * We move the ones we do to the end of the list, so we stop
++		 * when we see one we have already done.
++		 */
++		if (c->shrinker_run_no == run_no)
++			break;
++		if (!mutex_trylock(&c->umount_mutex)) {
++			/* Some un-mount is in progress, try next FS */
++			*contention = 1;
++			p = p->next;
++			continue;
++		}
++		/*
++		 * We're holding 'c->umount_mutex', so the file-system won't go
++		 * away.
++		 */
++		if (!mutex_trylock(&c->tnc_mutex)) {
++			mutex_unlock(&c->umount_mutex);
++			*contention = 1;
++			p = p->next;
++			continue;
++		}
++		spin_unlock(&ubifs_infos_lock);
++		/*
++		 * OK, now we have TNC locked, the file-system cannot go away -
++		 * it is safe to reap the cache.
++		 */
++		c->shrinker_run_no = run_no;
++		freed += shrink_tnc(c, nr, age, contention);
++		mutex_unlock(&c->tnc_mutex);
++		spin_lock(&ubifs_infos_lock);
++		/* Get the next list element before we move this one */
++		p = p->next;
++		/*
++		 * Move this one to the end of the list to provide some
++		 * fairness.
++		 */
++		list_del(&c->infos_list);
++		list_add_tail(&c->infos_list, &ubifs_infos);
++		mutex_unlock(&c->umount_mutex);
++		if (freed >= nr)
++			break;
++	}
++	spin_unlock(&ubifs_infos_lock);
++	return freed;
++}
++
++/**
++ * kick_a_thread - kick a background thread to start commit.
++ *
++ * This function kicks a background thread to start background commit. Returns
++ * %-1 if a thread was kicked or there is another reason to assume the memory
++ * will soon be freed or become freeable. If there are no dirty znodes, returns
++ * %0.
++ */
++static int kick_a_thread(void)
++{
++	int i;
++	struct ubifs_info *c;
++
++	/*
++	 * Iterate over all mounted UBIFS file-systems and find out if there is
++	 * already an ongoing commit operation there. If no, then iterate for
++	 * the second time and initiate background commit.
++	 */
++	spin_lock(&ubifs_infos_lock);
++	for (i = 0; i < 2; i++) {
++		list_for_each_entry(c, &ubifs_infos, infos_list) {
++			long dirty_zn_cnt;
++
++			if (!mutex_trylock(&c->umount_mutex)) {
++				/*
++				 * Some un-mount is in progress, it will
++				 * certainly free memory, so just return.
++				 */
++				spin_unlock(&ubifs_infos_lock);
++				return -1;
++			}
++
++			dirty_zn_cnt = atomic_long_read(&c->dirty_zn_cnt);
++
++			if (!dirty_zn_cnt || c->cmt_state == COMMIT_BROKEN ||
++			    c->ro_media) {
++				mutex_unlock(&c->umount_mutex);
++				continue;
++			}
++
++			if (c->cmt_state != COMMIT_RESTING) {
++				spin_unlock(&ubifs_infos_lock);
++				mutex_unlock(&c->umount_mutex);
++				return -1;
++			}
++
++			if (i == 1) {
++				list_del(&c->infos_list);
++				list_add_tail(&c->infos_list, &ubifs_infos);
++				spin_unlock(&ubifs_infos_lock);
++
++				ubifs_request_bg_commit(c);
++				mutex_unlock(&c->umount_mutex);
++				return -1;
++			}
++			mutex_unlock(&c->umount_mutex);
++		}
++	}
++	spin_unlock(&ubifs_infos_lock);
++
++	return 0;
++}
++
++int ubifs_shrinker(int nr, gfp_t gfp_mask)
++{
++	int freed, contention = 0;
++	long clean_zn_cnt = atomic_long_read(&ubifs_clean_zn_cnt);
++
++	if (nr == 0)
++		return clean_zn_cnt;
++
++	if (!clean_zn_cnt) {
++		/*
++		 * No clean znodes, nothing to reap. All we can do in this case
++		 * is to kick background threads to start commit, which will
++		 * probably make clean znodes which, in turn, will be freeable.
++		 * And we return -1 which means will make VM call us again
++		 * later.
++		 */
++		dbg_tnc("no clean znodes, kick a thread");
++		return kick_a_thread();
++	}
++
++	freed = shrink_tnc_trees(nr, OLD_ZNODE_AGE, &contention);
++	if (freed >= nr)
++		goto out;
++
++	dbg_tnc("not enough old znodes, try to free young ones");
++	freed += shrink_tnc_trees(nr - freed, YOUNG_ZNODE_AGE, &contention);
++	if (freed >= nr)
++		goto out;
++
++	dbg_tnc("not enough young znodes, free all");
++	freed += shrink_tnc_trees(nr - freed, 0, &contention);
++
++	if (!freed && contention) {
++		dbg_tnc("freed nothing, but contention");
++		return -1;
++	}
++
++out:
++	dbg_tnc("%d znodes were freed, requested %d", freed, nr);
++	return freed;
++}
+diff -Nurd linux-2.6.24.orig/fs/ubifs/super.c linux-2.6.24/fs/ubifs/super.c
+--- linux-2.6.24.orig/fs/ubifs/super.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/super.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,2192 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++/*
++ * This file implements UBIFS initialization and VFS superblock operations. Some
++ * initialization stuff which is rather large and complex is placed at
++ * corresponding subsystems, but most of it is here.
++ */
++
++#include <linux/init.h>
++#include <linux/slab.h>
++#include <linux/module.h>
++#include <linux/ctype.h>
++#include <linux/kthread.h>
++#include <linux/parser.h>
++#include <linux/seq_file.h>
++#include <linux/mount.h>
++#include <linux/writeback.h>
++#include "ubifs.h"
++
++/*
++ * Maximum amount of memory we may 'kmalloc()' without worrying that we are
++ * allocating too much.
++ */
++#define UBIFS_KMALLOC_OK (128*1024)
++
++/* Slab cache for UBIFS inodes */
++struct kmem_cache *ubifs_inode_slab;
++
++#ifndef UBIFS_COMPAT_NO_SHRINKER
++/* UBIFS TNC shrinker description */
++static struct shrinker ubifs_shrinker_info = {
++	.shrink = ubifs_shrinker,
++	.seeks = DEFAULT_SEEKS,
++};
++#endif
++
++/**
++ * validate_inode - validate inode.
++ * @c: UBIFS file-system description object
++ * @inode: the inode to validate
++ *
++ * This is a helper function for 'ubifs_iget()' which validates various fields
++ * of a newly built inode to make sure they contain sane values and prevent
++ * possible vulnerabilities. Returns zero if the inode is all right and
++ * a non-zero error code if not.
++ */
++static int validate_inode(struct ubifs_info *c, const struct inode *inode)
++{
++	int err;
++	const struct ubifs_inode *ui = ubifs_inode(inode);
++
++	if (inode->i_size > c->max_inode_sz) {
++		ubifs_err("inode is too large (%lld)",
++			  (long long)inode->i_size);
++		return 1;
++	}
++
++	if (ui->compr_type < 0 || ui->compr_type >= UBIFS_COMPR_TYPES_CNT) {
++		ubifs_err("unknown compression type %d", ui->compr_type);
++		return 2;
++	}
++
++	if (ui->xattr_names + ui->xattr_cnt > XATTR_LIST_MAX)
++		return 3;
++
++	if (ui->data_len < 0 || ui->data_len > UBIFS_MAX_INO_DATA)
++		return 4;
++
++	if (ui->xattr && (inode->i_mode & S_IFMT) != S_IFREG)
++		return 5;
++
++	if (!ubifs_compr_present(ui->compr_type)) {
++		ubifs_warn("inode %lu uses '%s' compression, but it was not "
++			   "compiled in", inode->i_ino,
++			   ubifs_compr_name(ui->compr_type));
++	}
++
++	err = dbg_check_dir_size(c, inode);
++	return err;
++}
++
++struct inode *ubifs_iget(struct super_block *sb, unsigned long inum)
++{
++	struct inode *inode;
++
++	inode = iget(sb, inum);
++	if (!inode) {
++		make_bad_inode(inode);
++		return ERR_PTR(-EINVAL);
++	}
++
++	return inode;
++}
++
++void ubifs_read_inode(struct inode *inode)
++{
++	int err;
++	union ubifs_key key;
++	struct ubifs_ino_node *ino;
++	struct ubifs_info *c = inode->i_sb->s_fs_info;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++
++	dbg_gen("inode %lu", inode->i_ino);
++	ubifs_assert(inode->i_state & I_LOCK);
++
++	ino = kmalloc(UBIFS_MAX_INO_NODE_SZ, GFP_NOFS);
++	if (!ino) {
++		err = -ENOMEM;
++		goto out;
++	}
++
++	ino_key_init(c, &key, inode->i_ino);
++
++	err = ubifs_tnc_lookup(c, &key, ino);
++	if (err)
++		goto out_ino;
++
++	inode->i_flags |= (S_NOCMTIME | S_NOATIME);
++	inode->i_nlink = le32_to_cpu(ino->nlink);
++	inode->i_uid   = le32_to_cpu(ino->uid);
++	inode->i_gid   = le32_to_cpu(ino->gid);
++	inode->i_atime.tv_sec  = (int64_t)le64_to_cpu(ino->atime_sec);
++	inode->i_atime.tv_nsec = le32_to_cpu(ino->atime_nsec);
++	inode->i_mtime.tv_sec  = (int64_t)le64_to_cpu(ino->mtime_sec);
++	inode->i_mtime.tv_nsec = le32_to_cpu(ino->mtime_nsec);
++	inode->i_ctime.tv_sec  = (int64_t)le64_to_cpu(ino->ctime_sec);
++	inode->i_ctime.tv_nsec = le32_to_cpu(ino->ctime_nsec);
++	inode->i_mode = le32_to_cpu(ino->mode);
++	inode->i_size = le64_to_cpu(ino->size);
++
++	ui->data_len    = le32_to_cpu(ino->data_len);
++	ui->flags       = le32_to_cpu(ino->flags);
++	ui->compr_type  = le16_to_cpu(ino->compr_type);
++	ui->creat_sqnum = le64_to_cpu(ino->creat_sqnum);
++	ui->xattr_cnt   = le32_to_cpu(ino->xattr_cnt);
++	ui->xattr_size  = le32_to_cpu(ino->xattr_size);
++	ui->xattr_names = le32_to_cpu(ino->xattr_names);
++	ui->synced_i_size = ui->ui_size = inode->i_size;
++
++	ui->xattr = (ui->flags & UBIFS_XATTR_FL) ? 1 : 0;
++
++	err = validate_inode(c, inode);
++	if (err)
++		goto out_invalid;
++
++	/* Disable read-ahead */
++	inode->i_mapping->backing_dev_info = &c->bdi;
++
++	switch (inode->i_mode & S_IFMT) {
++	case S_IFREG:
++		inode->i_mapping->a_ops = &ubifs_file_address_operations;
++		inode->i_op = &ubifs_file_inode_operations;
++		inode->i_fop = &ubifs_file_operations;
++		if (ui->xattr) {
++			ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
++			if (!ui->data) {
++				err = -ENOMEM;
++				goto out_ino;
++			}
++			memcpy(ui->data, ino->data, ui->data_len);
++			((char *)ui->data)[ui->data_len] = '\0';
++		} else if (ui->data_len != 0) {
++			err = 10;
++			goto out_invalid;
++		}
++		break;
++	case S_IFDIR:
++		inode->i_op  = &ubifs_dir_inode_operations;
++		inode->i_fop = &ubifs_dir_operations;
++		if (ui->data_len != 0) {
++			err = 11;
++			goto out_invalid;
++		}
++		break;
++	case S_IFLNK:
++		inode->i_op = &ubifs_symlink_inode_operations;
++		if (ui->data_len <= 0 || ui->data_len > UBIFS_MAX_INO_DATA) {
++			err = 12;
++			goto out_invalid;
++		}
++		ui->data = kmalloc(ui->data_len + 1, GFP_NOFS);
++		if (!ui->data) {
++			err = -ENOMEM;
++			goto out_ino;
++		}
++		memcpy(ui->data, ino->data, ui->data_len);
++		((char *)ui->data)[ui->data_len] = '\0';
++		break;
++	case S_IFBLK:
++	case S_IFCHR:
++	{
++		dev_t rdev;
++		union ubifs_dev_desc *dev;
++
++		ui->data = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
++		if (!ui->data) {
++			err = -ENOMEM;
++			goto out_ino;
++		}
++
++		dev = (union ubifs_dev_desc *)ino->data;
++		if (ui->data_len == sizeof(dev->new))
++			rdev = new_decode_dev(le32_to_cpu(dev->new));
++		else if (ui->data_len == sizeof(dev->huge))
++			rdev = huge_decode_dev(le64_to_cpu(dev->huge));
++		else {
++			err = 13;
++			goto out_invalid;
++		}
++		memcpy(ui->data, ino->data, ui->data_len);
++		inode->i_op = &ubifs_file_inode_operations;
++		init_special_inode(inode, inode->i_mode, rdev);
++		break;
++	}
++	case S_IFSOCK:
++	case S_IFIFO:
++		inode->i_op = &ubifs_file_inode_operations;
++		init_special_inode(inode, inode->i_mode, 0);
++		if (ui->data_len != 0) {
++			err = 14;
++			goto out_invalid;
++		}
++		break;
++	default:
++		err = 15;
++		goto out_invalid;
++	}
++
++	ubifs_set_inode_flags(inode);
++	kfree(ino);
++	return;
++
++out_invalid:
++	ubifs_err("inode %lu validation failed, error %d", inode->i_ino, err);
++	dbg_dump_inode(c, inode);
++	dbg_dump_node(c, ino);
++	err = -EINVAL;
++out_ino:
++	kfree(ino);
++out:
++	ubifs_err("failed to read inode %lu, error %d", inode->i_ino, err);
++	make_bad_inode(inode);
++	return;
++}
++
++static struct inode *ubifs_alloc_inode(struct super_block *sb)
++{
++	struct ubifs_inode *ui;
++
++	ui = kmem_cache_alloc(ubifs_inode_slab, GFP_NOFS);
++	if (!ui)
++		return NULL;
++
++	memset((void *)ui + sizeof(struct inode), 0,
++	       sizeof(struct ubifs_inode) - sizeof(struct inode));
++	mutex_init(&ui->ui_mutex);
++	spin_lock_init(&ui->ui_lock);
++	return &ui->vfs_inode;
++};
++
++static void ubifs_destroy_inode(struct inode *inode)
++{
++	struct ubifs_inode *ui = ubifs_inode(inode);
++
++	kfree(ui->data);
++	kmem_cache_free(ubifs_inode_slab, inode);
++}
++
++/*
++ * Note, Linux write-back code calls this without 'i_mutex'.
++ */
++static int ubifs_write_inode(struct inode *inode, int wait)
++{
++	int err = 0;
++	struct ubifs_info *c = inode->i_sb->s_fs_info;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++
++	ubifs_assert(!ui->xattr);
++	if (is_bad_inode(inode))
++		return 0;
++
++	mutex_lock(&ui->ui_mutex);
++	/*
++	 * Due to races between write-back forced by budgeting
++	 * (see 'sync_some_inodes()') and pdflush write-back, the inode may
++	 * have already been synchronized, do not do this again. This might
++	 * also happen if it was synchronized in an VFS operation, e.g.
++	 * 'ubifs_link()'.
++	 */
++	if (!ui->dirty) {
++		mutex_unlock(&ui->ui_mutex);
++		return 0;
++	}
++
++	/*
++	 * As an optimization, do not write orphan inodes to the media just
++	 * because this is not needed.
++	 */
++	dbg_gen("inode %lu, mode %#x, nlink %u",
++		inode->i_ino, (int)inode->i_mode, inode->i_nlink);
++	if (inode->i_nlink) {
++		err = ubifs_jnl_write_inode(c, inode);
++		if (err)
++			ubifs_err("can't write inode %lu, error %d",
++				  inode->i_ino, err);
++	}
++
++	ui->dirty = 0;
++	mutex_unlock(&ui->ui_mutex);
++	ubifs_release_dirty_inode_budget(c, ui);
++	return err;
++}
++
++static void ubifs_delete_inode(struct inode *inode)
++{
++	int err;
++	struct ubifs_info *c = inode->i_sb->s_fs_info;
++	struct ubifs_inode *ui = ubifs_inode(inode);
++
++	if (ui->xattr)
++		/*
++		 * Extended attribute inode deletions are fully handled in
++		 * 'ubifs_removexattr()'. These inodes are special and have
++		 * limited usage, so there is nothing to do here.
++		 */
++		goto out;
++
++	dbg_gen("inode %lu, mode %#x", inode->i_ino, (int)inode->i_mode);
++	ubifs_assert(!atomic_read(&inode->i_count));
++	ubifs_assert(inode->i_nlink == 0);
++
++	truncate_inode_pages(&inode->i_data, 0);
++	if (is_bad_inode(inode))
++		goto out;
++
++	ui->ui_size = inode->i_size = 0;
++	err = ubifs_jnl_delete_inode(c, inode);
++	if (err)
++		/*
++		 * Worst case we have a lost orphan inode wasting space, so a
++		 * simple error message is OK here.
++		 */
++		ubifs_err("can't delete inode %lu, error %d",
++			  inode->i_ino, err);
++
++out:
++	if (ui->dirty)
++		ubifs_release_dirty_inode_budget(c, ui);
++	clear_inode(inode);
++}
++
++static void ubifs_dirty_inode(struct inode *inode)
++{
++	struct ubifs_inode *ui = ubifs_inode(inode);
++
++	ubifs_assert(mutex_is_locked(&ui->ui_mutex));
++	if (!ui->dirty) {
++		ui->dirty = 1;
++		dbg_gen("inode %lu",  inode->i_ino);
++	}
++}
++
++static int ubifs_statfs(struct dentry *dentry, struct kstatfs *buf)
++{
++	struct ubifs_info *c = dentry->d_sb->s_fs_info;
++	unsigned long long free;
++	__le32 *uuid = (__le32 *)c->uuid;
++
++	free = ubifs_get_free_space(c);
++	dbg_gen("free space %lld bytes (%lld blocks)",
++		free, free >> UBIFS_BLOCK_SHIFT);
++
++	buf->f_type = UBIFS_SUPER_MAGIC;
++	buf->f_bsize = UBIFS_BLOCK_SIZE;
++	buf->f_blocks = c->block_cnt;
++	buf->f_bfree = free >> UBIFS_BLOCK_SHIFT;
++	if (free > c->report_rp_size)
++		buf->f_bavail = (free - c->report_rp_size) >> UBIFS_BLOCK_SHIFT;
++	else
++		buf->f_bavail = 0;
++	buf->f_files = 0;
++	buf->f_ffree = 0;
++	buf->f_namelen = UBIFS_MAX_NLEN;
++	buf->f_fsid.val[0] = le32_to_cpu(uuid[0]) ^ le32_to_cpu(uuid[2]);
++	buf->f_fsid.val[1] = le32_to_cpu(uuid[1]) ^ le32_to_cpu(uuid[3]);
++	ubifs_assert(buf->f_bfree <= c->block_cnt);
++	return 0;
++}
++
++static int ubifs_show_options(struct seq_file *s, struct vfsmount *mnt)
++{
++	struct ubifs_info *c = mnt->mnt_sb->s_fs_info;
++
++	if (c->mount_opts.unmount_mode == 2)
++		seq_printf(s, ",fast_unmount");
++	else if (c->mount_opts.unmount_mode == 1)
++		seq_printf(s, ",norm_unmount");
++
++	if (c->mount_opts.bulk_read == 2)
++		seq_printf(s, ",bulk_read");
++	else if (c->mount_opts.bulk_read == 1)
++		seq_printf(s, ",no_bulk_read");
++
++	if (c->mount_opts.chk_data_crc == 2)
++		seq_printf(s, ",chk_data_crc");
++	else if (c->mount_opts.chk_data_crc == 1)
++		seq_printf(s, ",no_chk_data_crc");
++
++	if (c->mount_opts.override_compr) {
++		seq_printf(s, ",compr=");
++		seq_printf(s, ubifs_compr_name(c->mount_opts.compr_type));
++	}
++
++	return 0;
++}
++
++static int ubifs_sync_fs(struct super_block *sb, int wait)
++{
++	int i, err;
++	struct ubifs_info *c = sb->s_fs_info;
++	struct writeback_control wbc = {
++		.sync_mode   = WB_SYNC_ALL,
++		.range_start = 0,
++		.range_end   = LLONG_MAX,
++		.nr_to_write = LONG_MAX,
++	};
++
++  	/*
++	 * Zero @wait is just an advisory thing to help the file system shove
++	 * lots of data into the queues, and there will be the second
++	 * '->sync_fs()' call, with non-zero @wait.
++	 */
++	if (!wait)
++		return 0;
++
++	if (sb->s_flags & MS_RDONLY)
++		return 0;
++
++	/*
++	 * VFS calls '->sync_fs()' before synchronizing all dirty inodes and
++	 * pages, so synchronize them first, then commit the journal. Strictly
++	 * speaking, it is not necessary to commit the journal here,
++	 * synchronizing write-buffers would be enough. But committing makes
++	 * UBIFS free space predictions much more accurate, so we want to let
++	 * the user be able to get more accurate results of 'statfs()' after
++	 * they synchronize the file system.
++	 */
++	generic_sync_sb_inodes(sb, &wbc);
++
++	/*
++	 * Synchronize write buffers, because 'ubifs_run_commit()' does not
++	 * do this if it waits for an already running commit.
++	 */
++	for (i = 0; i < c->jhead_cnt; i++) {
++		err = ubifs_wbuf_sync(&c->jheads[i].wbuf);
++		if (err)
++			return err;
++	}
++
++	err = ubifs_run_commit(c);
++	if (err)
++		return err;
++
++	return ubi_sync(c->vi.ubi_num);
++}
++
++/**
++ * init_constants_early - initialize UBIFS constants.
++ * @c: UBIFS file-system description object
++ *
++ * This function initialize UBIFS constants which do not need the superblock to
++ * be read. It also checks that the UBI volume satisfies basic UBIFS
++ * requirements. Returns zero in case of success and a negative error code in
++ * case of failure.
++ */
++static int init_constants_early(struct ubifs_info *c)
++{
++	if (c->vi.corrupted) {
++		ubifs_warn("UBI volume is corrupted - read-only mode");
++		c->ro_media = 1;
++	}
++
++	if (c->di.ro_mode) {
++		ubifs_msg("read-only UBI device");
++		c->ro_media = 1;
++	}
++
++	if (c->vi.vol_type == UBI_STATIC_VOLUME) {
++		ubifs_msg("static UBI volume - read-only mode");
++		c->ro_media = 1;
++	}
++
++	c->leb_cnt = c->vi.size;
++	c->leb_size = c->vi.usable_leb_size;
++	c->half_leb_size = c->leb_size / 2;
++	c->min_io_size = c->di.min_io_size;
++	c->min_io_shift = fls(c->min_io_size) - 1;
++
++	if (c->leb_size < UBIFS_MIN_LEB_SZ) {
++		ubifs_err("too small LEBs (%d bytes), min. is %d bytes",
++			  c->leb_size, UBIFS_MIN_LEB_SZ);
++		return -EINVAL;
++	}
++
++	if (c->leb_cnt < UBIFS_MIN_LEB_CNT) {
++		ubifs_err("too few LEBs (%d), min. is %d",
++			  c->leb_cnt, UBIFS_MIN_LEB_CNT);
++		return -EINVAL;
++	}
++
++	if (!is_power_of_2(c->min_io_size)) {
++		ubifs_err("bad min. I/O size %d", c->min_io_size);
++		return -EINVAL;
++	}
++
++	/*
++	 * UBIFS aligns all node to 8-byte boundary, so to make function in
++	 * io.c simpler, assume minimum I/O unit size to be 8 bytes if it is
++	 * less than 8.
++	 */
++	if (c->min_io_size < 8) {
++		c->min_io_size = 8;
++		c->min_io_shift = 3;
++	}
++
++	c->ref_node_alsz = ALIGN(UBIFS_REF_NODE_SZ, c->min_io_size);
++	c->mst_node_alsz = ALIGN(UBIFS_MST_NODE_SZ, c->min_io_size);
++
++	/*
++	 * Initialize node length ranges which are mostly needed for node
++	 * length validation.
++	 */
++	c->ranges[UBIFS_PAD_NODE].len  = UBIFS_PAD_NODE_SZ;
++	c->ranges[UBIFS_SB_NODE].len   = UBIFS_SB_NODE_SZ;
++	c->ranges[UBIFS_MST_NODE].len  = UBIFS_MST_NODE_SZ;
++	c->ranges[UBIFS_REF_NODE].len  = UBIFS_REF_NODE_SZ;
++	c->ranges[UBIFS_TRUN_NODE].len = UBIFS_TRUN_NODE_SZ;
++	c->ranges[UBIFS_CS_NODE].len   = UBIFS_CS_NODE_SZ;
++
++	c->ranges[UBIFS_INO_NODE].min_len  = UBIFS_INO_NODE_SZ;
++	c->ranges[UBIFS_INO_NODE].max_len  = UBIFS_MAX_INO_NODE_SZ;
++	c->ranges[UBIFS_ORPH_NODE].min_len =
++				UBIFS_ORPH_NODE_SZ + sizeof(__le64);
++	c->ranges[UBIFS_ORPH_NODE].max_len = c->leb_size;
++	c->ranges[UBIFS_DENT_NODE].min_len = UBIFS_DENT_NODE_SZ;
++	c->ranges[UBIFS_DENT_NODE].max_len = UBIFS_MAX_DENT_NODE_SZ;
++	c->ranges[UBIFS_XENT_NODE].min_len = UBIFS_XENT_NODE_SZ;
++	c->ranges[UBIFS_XENT_NODE].max_len = UBIFS_MAX_XENT_NODE_SZ;
++	c->ranges[UBIFS_DATA_NODE].min_len = UBIFS_DATA_NODE_SZ;
++	c->ranges[UBIFS_DATA_NODE].max_len = UBIFS_MAX_DATA_NODE_SZ;
++	/*
++	 * Minimum indexing node size is amended later when superblock is
++	 * read and the key length is known.
++	 */
++	c->ranges[UBIFS_IDX_NODE].min_len = UBIFS_IDX_NODE_SZ + UBIFS_BRANCH_SZ;
++	/*
++	 * Maximum indexing node size is amended later when superblock is
++	 * read and the fanout is known.
++	 */
++	c->ranges[UBIFS_IDX_NODE].max_len = INT_MAX;
++
++	/*
++	 * Initialize dead and dark LEB space watermarks. See gc.c for comments
++	 * about these values.
++	 */
++	c->dead_wm = ALIGN(MIN_WRITE_SZ, c->min_io_size);
++	c->dark_wm = ALIGN(UBIFS_MAX_NODE_SZ, c->min_io_size);
++
++	/*
++	 * Calculate how many bytes would be wasted at the end of LEB if it was
++	 * fully filled with data nodes of maximum size. This is used in
++	 * calculations when reporting free space.
++	 */
++	c->leb_overhead = c->leb_size % UBIFS_MAX_DATA_NODE_SZ;
++
++	/* Buffer size for bulk-reads */
++	c->max_bu_buf_len = UBIFS_MAX_BULK_READ * UBIFS_MAX_DATA_NODE_SZ;
++	if (c->max_bu_buf_len > c->leb_size)
++		c->max_bu_buf_len = c->leb_size;
++	return 0;
++}
++
++/**
++ * bud_wbuf_callback - bud LEB write-buffer synchronization call-back.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB the write-buffer was synchronized to
++ * @free: how many free bytes left in this LEB
++ * @pad: how many bytes were padded
++ *
++ * This is a callback function which is called by the I/O unit when the
++ * write-buffer is synchronized. We need this to correctly maintain space
++ * accounting in bud logical eraseblocks. This function returns zero in case of
++ * success and a negative error code in case of failure.
++ *
++ * This function actually belongs to the journal, but we keep it here because
++ * we want to keep it static.
++ */
++static int bud_wbuf_callback(struct ubifs_info *c, int lnum, int free, int pad)
++{
++	return ubifs_update_one_lp(c, lnum, free, pad, 0, 0);
++}
++
++/*
++ * init_constants_sb - initialize UBIFS constants.
++ * @c: UBIFS file-system description object
++ *
++ * This is a helper function which initializes various UBIFS constants after
++ * the superblock has been read. It also checks various UBIFS parameters and
++ * makes sure they are all right. Returns zero in case of success and a
++ * negative error code in case of failure.
++ */
++static int init_constants_sb(struct ubifs_info *c)
++{
++	int tmp, err;
++	long long tmp64;
++
++	c->main_bytes = (long long)c->main_lebs * c->leb_size;
++	c->max_znode_sz = sizeof(struct ubifs_znode) +
++				c->fanout * sizeof(struct ubifs_zbranch);
++
++	tmp = ubifs_idx_node_sz(c, 1);
++	c->ranges[UBIFS_IDX_NODE].min_len = tmp;
++	c->min_idx_node_sz = ALIGN(tmp, 8);
++
++	tmp = ubifs_idx_node_sz(c, c->fanout);
++	c->ranges[UBIFS_IDX_NODE].max_len = tmp;
++	c->max_idx_node_sz = ALIGN(tmp, 8);
++
++	/* Make sure LEB size is large enough to fit full commit */
++	tmp = UBIFS_CS_NODE_SZ + UBIFS_REF_NODE_SZ * c->jhead_cnt;
++	tmp = ALIGN(tmp, c->min_io_size);
++	if (tmp > c->leb_size) {
++		dbg_err("too small LEB size %d, at least %d needed",
++			c->leb_size, tmp);
++		return -EINVAL;
++	}
++
++	/*
++	 * Make sure that the log is large enough to fit reference nodes for
++	 * all buds plus one reserved LEB.
++	 */
++	tmp64 = c->max_bud_bytes + c->leb_size - 1;
++	c->max_bud_cnt = div_u64(tmp64, c->leb_size);
++	tmp = (c->ref_node_alsz * c->max_bud_cnt + c->leb_size - 1);
++	tmp /= c->leb_size;
++	tmp += 1;
++	if (c->log_lebs < tmp) {
++		dbg_err("too small log %d LEBs, required min. %d LEBs",
++			c->log_lebs, tmp);
++		return -EINVAL;
++	}
++
++	/*
++	 * When budgeting we assume worst-case scenarios when the pages are not
++	 * be compressed and direntries are of the maximum size.
++	 *
++	 * Note, data, which may be stored in inodes is budgeted separately, so
++	 * it is not included into 'c->inode_budget'.
++	 */
++	c->page_budget = UBIFS_MAX_DATA_NODE_SZ * UBIFS_BLOCKS_PER_PAGE;
++	c->inode_budget = UBIFS_INO_NODE_SZ;
++	c->dent_budget = UBIFS_MAX_DENT_NODE_SZ;
++
++	/*
++	 * When the amount of flash space used by buds becomes
++	 * 'c->max_bud_bytes', UBIFS just blocks all writers and starts commit.
++	 * The writers are unblocked when the commit is finished. To avoid
++	 * writers to be blocked UBIFS initiates background commit in advance,
++	 * when number of bud bytes becomes above the limit defined below.
++	 */
++	c->bg_bud_bytes = (c->max_bud_bytes * 13) >> 4;
++
++	/*
++	 * Ensure minimum journal size. All the bytes in the journal heads are
++	 * considered to be used, when calculating the current journal usage.
++	 * Consequently, if the journal is too small, UBIFS will treat it as
++	 * always full.
++	 */
++	tmp64 = (long long)(c->jhead_cnt + 1) * c->leb_size + 1;
++	if (c->bg_bud_bytes < tmp64)
++		c->bg_bud_bytes = tmp64;
++	if (c->max_bud_bytes < tmp64 + c->leb_size)
++		c->max_bud_bytes = tmp64 + c->leb_size;
++
++	err = ubifs_calc_lpt_geom(c);
++	if (err)
++		return err;
++
++	return 0;
++}
++
++/*
++ * init_constants_master - initialize UBIFS constants.
++ * @c: UBIFS file-system description object
++ *
++ * This is a helper function which initializes various UBIFS constants after
++ * the master node has been read. It also checks various UBIFS parameters and
++ * makes sure they are all right.
++ */
++static void init_constants_master(struct ubifs_info *c)
++{
++	long long tmp64;
++
++	c->min_idx_lebs = ubifs_calc_min_idx_lebs(c);
++
++	/*
++	 * Calculate total amount of FS blocks. This number is not used
++	 * internally because it does not make much sense for UBIFS, but it is
++	 * necessary to report something for the 'statfs()' call.
++	 *
++	 * Subtract the LEB reserved for GC, the LEB which is reserved for
++	 * deletions, minimum LEBs for the index, and assume only one journal
++	 * head is available.
++	 */
++	tmp64 = c->main_lebs - 1 - 1 - MIN_INDEX_LEBS - c->jhead_cnt + 1;
++	tmp64 *= (long long)c->leb_size - c->leb_overhead;
++	tmp64 = ubifs_reported_space(c, tmp64);
++	c->block_cnt = tmp64 >> UBIFS_BLOCK_SHIFT;
++}
++
++/**
++ * take_gc_lnum - reserve GC LEB.
++ * @c: UBIFS file-system description object
++ *
++ * This function ensures that the LEB reserved for garbage collection is marked
++ * as "taken" in lprops. We also have to set free space to LEB size and dirty
++ * space to zero, because lprops may contain out-of-date information if the
++ * file-system was un-mounted before it has been committed. This function
++ * returns zero in case of success and a negative error code in case of
++ * failure.
++ */
++static int take_gc_lnum(struct ubifs_info *c)
++{
++	int err;
++
++	if (c->gc_lnum == -1) {
++		ubifs_err("no LEB for GC");
++		return -EINVAL;
++	}
++
++	/* And we have to tell lprops that this LEB is taken */
++	err = ubifs_change_one_lp(c, c->gc_lnum, c->leb_size, 0,
++				  LPROPS_TAKEN, 0, 0);
++	return err;
++}
++
++/**
++ * alloc_wbufs - allocate write-buffers.
++ * @c: UBIFS file-system description object
++ *
++ * This helper function allocates and initializes UBIFS write-buffers. Returns
++ * zero in case of success and %-ENOMEM in case of failure.
++ */
++static int alloc_wbufs(struct ubifs_info *c)
++{
++	int i, err;
++
++	c->jheads = kzalloc(c->jhead_cnt * sizeof(struct ubifs_jhead),
++			   GFP_KERNEL);
++	if (!c->jheads)
++		return -ENOMEM;
++
++	/* Initialize journal heads */
++	for (i = 0; i < c->jhead_cnt; i++) {
++		INIT_LIST_HEAD(&c->jheads[i].buds_list);
++		err = ubifs_wbuf_init(c, &c->jheads[i].wbuf);
++		if (err)
++			return err;
++
++		c->jheads[i].wbuf.sync_callback = &bud_wbuf_callback;
++		c->jheads[i].wbuf.jhead = i;
++	}
++
++	c->jheads[BASEHD].wbuf.dtype = UBI_SHORTTERM;
++	/*
++	 * Garbage Collector head likely contains long-term data and
++	 * does not need to be synchronized by timer.
++	 */
++	c->jheads[GCHD].wbuf.dtype = UBI_LONGTERM;
++	c->jheads[GCHD].wbuf.timeout = 0;
++
++	return 0;
++}
++
++/**
++ * free_wbufs - free write-buffers.
++ * @c: UBIFS file-system description object
++ */
++static void free_wbufs(struct ubifs_info *c)
++{
++	int i;
++
++	if (c->jheads) {
++		for (i = 0; i < c->jhead_cnt; i++) {
++			kfree(c->jheads[i].wbuf.buf);
++			kfree(c->jheads[i].wbuf.inodes);
++		}
++		kfree(c->jheads);
++		c->jheads = NULL;
++	}
++}
++
++/**
++ * free_orphans - free orphans.
++ * @c: UBIFS file-system description object
++ */
++static void free_orphans(struct ubifs_info *c)
++{
++	struct ubifs_orphan *orph;
++
++	while (c->orph_dnext) {
++		orph = c->orph_dnext;
++		c->orph_dnext = orph->dnext;
++		list_del(&orph->list);
++		kfree(orph);
++	}
++
++	while (!list_empty(&c->orph_list)) {
++		orph = list_entry(c->orph_list.next, struct ubifs_orphan, list);
++		list_del(&orph->list);
++		kfree(orph);
++		dbg_err("orphan list not empty at unmount");
++	}
++
++	vfree(c->orph_buf);
++	c->orph_buf = NULL;
++}
++
++/**
++ * free_buds - free per-bud objects.
++ * @c: UBIFS file-system description object
++ */
++static void free_buds(struct ubifs_info *c)
++{
++	struct rb_node *this = c->buds.rb_node;
++	struct ubifs_bud *bud;
++
++	while (this) {
++		if (this->rb_left)
++			this = this->rb_left;
++		else if (this->rb_right)
++			this = this->rb_right;
++		else {
++			bud = rb_entry(this, struct ubifs_bud, rb);
++			this = rb_parent(this);
++			if (this) {
++				if (this->rb_left == &bud->rb)
++					this->rb_left = NULL;
++				else
++					this->rb_right = NULL;
++			}
++			kfree(bud);
++		}
++	}
++}
++
++/**
++ * check_volume_empty - check if the UBI volume is empty.
++ * @c: UBIFS file-system description object
++ *
++ * This function checks if the UBIFS volume is empty by looking if its LEBs are
++ * mapped or not. The result of checking is stored in the @c->empty variable.
++ * Returns zero in case of success and a negative error code in case of
++ * failure.
++ */
++static int check_volume_empty(struct ubifs_info *c)
++{
++	int lnum, err;
++
++	c->empty = 1;
++	for (lnum = 0; lnum < c->leb_cnt; lnum++) {
++		err = ubi_is_mapped(c->ubi, lnum);
++		if (unlikely(err < 0))
++			return err;
++		if (err == 1) {
++			c->empty = 0;
++			break;
++		}
++
++		cond_resched();
++	}
++
++	return 0;
++}
++
++/*
++ * UBIFS mount options.
++ *
++ * Opt_fast_unmount: do not run a journal commit before un-mounting
++ * Opt_norm_unmount: run a journal commit before un-mounting
++ * Opt_bulk_read: enable bulk-reads
++ * Opt_no_bulk_read: disable bulk-reads
++ * Opt_chk_data_crc: check CRCs when reading data nodes
++ * Opt_no_chk_data_crc: do not check CRCs when reading data nodes
++ * Opt_override_compr: override default compressor
++ * Opt_err: just end of array marker
++ */
++enum {
++	Opt_fast_unmount,
++	Opt_norm_unmount,
++	Opt_bulk_read,
++	Opt_no_bulk_read,
++	Opt_chk_data_crc,
++	Opt_no_chk_data_crc,
++	Opt_override_compr,
++	Opt_err,
++};
++
++static match_table_t tokens = {
++	{Opt_fast_unmount, "fast_unmount"},
++	{Opt_norm_unmount, "norm_unmount"},
++	{Opt_bulk_read, "bulk_read"},
++	{Opt_no_bulk_read, "no_bulk_read"},
++	{Opt_chk_data_crc, "chk_data_crc"},
++	{Opt_no_chk_data_crc, "no_chk_data_crc"},
++	{Opt_override_compr, "compr=%s"},
++	{Opt_err, NULL},
++};
++
++/**
++ * ubifs_parse_options - parse mount parameters.
++ * @c: UBIFS file-system description object
++ * @options: parameters to parse
++ * @is_remount: non-zero if this is FS re-mount
++ *
++ * This function parses UBIFS mount options and returns zero in case success
++ * and a negative error code in case of failure.
++ */
++static int ubifs_parse_options(struct ubifs_info *c, char *options,
++			       int is_remount)
++{
++	char *p;
++	substring_t args[MAX_OPT_ARGS];
++
++	if (!options)
++		return 0;
++
++	while ((p = strsep(&options, ","))) {
++		int token;
++
++		if (!*p)
++			continue;
++
++		token = match_token(p, tokens, args);
++		switch (token) {
++		/*
++		 * %Opt_fast_unmount and %Opt_norm_unmount options are ignored.
++		 * We accepte them in order to be backware-compatible. But this
++		 * should be removed at some point.
++		 */
++		case Opt_fast_unmount:
++			c->mount_opts.unmount_mode = 2;
++			break;
++		case Opt_norm_unmount:
++			c->mount_opts.unmount_mode = 1;
++			break;
++		case Opt_bulk_read:
++			c->mount_opts.bulk_read = 2;
++			c->bulk_read = 1;
++			break;
++		case Opt_no_bulk_read:
++			c->mount_opts.bulk_read = 1;
++			c->bulk_read = 0;
++			break;
++		case Opt_chk_data_crc:
++			c->mount_opts.chk_data_crc = 2;
++			c->no_chk_data_crc = 0;
++			break;
++		case Opt_no_chk_data_crc:
++			c->mount_opts.chk_data_crc = 1;
++			c->no_chk_data_crc = 1;
++			break;
++		case Opt_override_compr:
++		{
++			char *name = match_strdup(&args[0]);
++
++			if (!name)
++				return -ENOMEM;
++			if (!strcmp(name, "none"))
++				c->mount_opts.compr_type = UBIFS_COMPR_NONE;
++			else if (!strcmp(name, "lzo"))
++				c->mount_opts.compr_type = UBIFS_COMPR_LZO;
++			else if (!strcmp(name, "zlib"))
++				c->mount_opts.compr_type = UBIFS_COMPR_ZLIB;
++			else {
++				ubifs_err("unknown compressor \"%s\"", name);
++				kfree(name);
++				return -EINVAL;
++			}
++			kfree(name);
++			c->mount_opts.override_compr = 1;
++			c->default_compr = c->mount_opts.compr_type;
++			break;
++		}
++		default:
++			ubifs_err("unrecognized mount option \"%s\" "
++				  "or missing value", p);
++			return -EINVAL;
++		}
++	}
++
++	return 0;
++}
++
++/**
++ * destroy_journal - destroy journal data structures.
++ * @c: UBIFS file-system description object
++ *
++ * This function destroys journal data structures including those that may have
++ * been created by recovery functions.
++ */
++static void destroy_journal(struct ubifs_info *c)
++{
++	while (!list_empty(&c->unclean_leb_list)) {
++		struct ubifs_unclean_leb *ucleb;
++
++		ucleb = list_entry(c->unclean_leb_list.next,
++				   struct ubifs_unclean_leb, list);
++		list_del(&ucleb->list);
++		kfree(ucleb);
++	}
++	while (!list_empty(&c->old_buds)) {
++		struct ubifs_bud *bud;
++
++		bud = list_entry(c->old_buds.next, struct ubifs_bud, list);
++		list_del(&bud->list);
++		kfree(bud);
++	}
++	ubifs_destroy_idx_gc(c);
++	ubifs_destroy_size_tree(c);
++	ubifs_tnc_close(c);
++	free_buds(c);
++}
++
++/**
++ * bu_init - initialize bulk-read information.
++ * @c: UBIFS file-system description object
++ */
++static void bu_init(struct ubifs_info *c)
++{
++	ubifs_assert(c->bulk_read == 1);
++
++	if (c->bu.buf)
++		return; /* Already initialized */
++
++again:
++	c->bu.buf = kmalloc(c->max_bu_buf_len, GFP_KERNEL | __GFP_NOWARN);
++	if (!c->bu.buf) {
++		if (c->max_bu_buf_len > UBIFS_KMALLOC_OK) {
++			c->max_bu_buf_len = UBIFS_KMALLOC_OK;
++			goto again;
++		}
++
++		/* Just disable bulk-read */
++		ubifs_warn("Cannot allocate %d bytes of memory for bulk-read, "
++			   "disabling it", c->max_bu_buf_len);
++		c->mount_opts.bulk_read = 1;
++		c->bulk_read = 0;
++		return;
++	}
++}
++
++/**
++ * check_free_space - check if there is enough free space to mount.
++ * @c: UBIFS file-system description object
++ *
++ * This function makes sure UBIFS has enough free space to be mounted in
++ * read/write mode. UBIFS must always have some free space to allow deletions.
++ */
++static int check_free_space(struct ubifs_info *c)
++{
++	ubifs_assert(c->dark_wm > 0);
++	if (c->lst.total_free + c->lst.total_dirty < c->dark_wm) {
++		ubifs_err("insufficient free space to mount in read/write mode");
++		dbg_dump_budg(c);
++		dbg_dump_lprops(c);
++		return -ENOSPC;
++	}
++	return 0;
++}
++
++/**
++ * mount_ubifs - mount UBIFS file-system.
++ * @c: UBIFS file-system description object
++ *
++ * This function mounts UBIFS file system. Returns zero in case of success and
++ * a negative error code in case of failure.
++ *
++ * Note, the function does not de-allocate resources it it fails half way
++ * through, and the caller has to do this instead.
++ */
++static int mount_ubifs(struct ubifs_info *c)
++{
++	struct super_block *sb = c->vfs_sb;
++	int err, mounted_read_only = (sb->s_flags & MS_RDONLY);
++	long long x;
++	size_t sz;
++
++	err = init_constants_early(c);
++	if (err)
++		return err;
++
++	err = ubifs_debugging_init(c);
++	if (err)
++		return err;
++
++	err = check_volume_empty(c);
++	if (err)
++		goto out_free;
++
++	if (c->empty && (mounted_read_only || c->ro_media)) {
++		/*
++		 * This UBI volume is empty, and read-only, or the file system
++		 * is mounted read-only - we cannot format it.
++		 */
++		ubifs_err("can't format empty UBI volume: read-only %s",
++			  c->ro_media ? "UBI volume" : "mount");
++		err = -EROFS;
++		goto out_free;
++	}
++
++	if (c->ro_media && !mounted_read_only) {
++		ubifs_err("cannot mount read-write - read-only media");
++		err = -EROFS;
++		goto out_free;
++	}
++
++	/*
++	 * The requirement for the buffer is that it should fit indexing B-tree
++	 * height amount of integers. We assume the height if the TNC tree will
++	 * never exceed 64.
++	 */
++	err = -ENOMEM;
++	c->bottom_up_buf = kmalloc(BOTTOM_UP_HEIGHT * sizeof(int), GFP_KERNEL);
++	if (!c->bottom_up_buf)
++		goto out_free;
++
++	c->sbuf = vmalloc(c->leb_size);
++	if (!c->sbuf)
++		goto out_free;
++
++	if (!mounted_read_only) {
++		c->ileb_buf = vmalloc(c->leb_size);
++		if (!c->ileb_buf)
++			goto out_free;
++	}
++
++	if (c->bulk_read == 1)
++		bu_init(c);
++
++	/*
++	 * We have to check all CRCs, even for data nodes, when we mount the FS
++	 * (specifically, when we are replaying).
++	 */
++	c->always_chk_crc = 1;
++
++	err = ubifs_read_superblock(c);
++	if (err)
++		goto out_free;
++
++	/*
++	 * Make sure the compressor which is set as default in the superblock
++	 * or overridden by mount options is actually compiled in.
++	 */
++	if (!ubifs_compr_present(c->default_compr)) {
++		ubifs_err("'compressor \"%s\" is not compiled in",
++			  ubifs_compr_name(c->default_compr));
++		goto out_free;
++	}
++
++	err = init_constants_sb(c);
++	if (err)
++		goto out_free;
++
++	sz = ALIGN(c->max_idx_node_sz, c->min_io_size);
++	sz = ALIGN(sz + c->max_idx_node_sz, c->min_io_size);
++	c->cbuf = kmalloc(sz, GFP_NOFS);
++	if (!c->cbuf) {
++		err = -ENOMEM;
++		goto out_free;
++	}
++
++	sprintf(c->bgt_name, BGT_NAME_PATTERN, c->vi.ubi_num, c->vi.vol_id);
++	if (!mounted_read_only) {
++		err = alloc_wbufs(c);
++		if (err)
++			goto out_cbuf;
++
++		/* Create background thread */
++		c->bgt = kthread_create(ubifs_bg_thread, c, c->bgt_name);
++		if (IS_ERR(c->bgt)) {
++			err = PTR_ERR(c->bgt);
++			c->bgt = NULL;
++			ubifs_err("cannot spawn \"%s\", error %d",
++				  c->bgt_name, err);
++			goto out_wbufs;
++		}
++		wake_up_process(c->bgt);
++	}
++
++	err = ubifs_read_master(c);
++	if (err)
++		goto out_master;
++
++	init_constants_master(c);
++
++	if ((c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY)) != 0) {
++		ubifs_msg("recovery needed");
++		c->need_recovery = 1;
++		if (!mounted_read_only) {
++			err = ubifs_recover_inl_heads(c, c->sbuf);
++			if (err)
++				goto out_master;
++		}
++	} else if (!mounted_read_only) {
++		/*
++		 * Set the "dirty" flag so that if we reboot uncleanly we
++		 * will notice this immediately on the next mount.
++		 */
++		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
++		err = ubifs_write_master(c);
++		if (err)
++			goto out_master;
++	}
++
++	err = ubifs_lpt_init(c, 1, !mounted_read_only);
++	if (err)
++		goto out_lpt;
++
++	err = dbg_check_idx_size(c, c->old_idx_sz);
++	if (err)
++		goto out_lpt;
++
++	err = ubifs_replay_journal(c);
++	if (err)
++		goto out_journal;
++
++	err = ubifs_mount_orphans(c, c->need_recovery, mounted_read_only);
++	if (err)
++		goto out_orphans;
++
++	if (!mounted_read_only) {
++		int lnum;
++
++		err = check_free_space(c);
++		if (err)
++			goto out_orphans;
++
++		/* Check for enough log space */
++		lnum = c->lhead_lnum + 1;
++		if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
++			lnum = UBIFS_LOG_LNUM;
++		if (lnum == c->ltail_lnum) {
++			err = ubifs_consolidate_log(c);
++			if (err)
++				goto out_orphans;
++		}
++
++		if (c->need_recovery) {
++			err = ubifs_recover_size(c);
++			if (err)
++				goto out_orphans;
++			err = ubifs_rcvry_gc_commit(c);
++		} else {
++			err = take_gc_lnum(c);
++			if (err)
++				goto out_orphans;
++
++			/*
++			 * GC LEB may contain garbage if there was an unclean
++			 * reboot, and it should be un-mapped.
++			 */
++			err = ubifs_leb_unmap(c, c->gc_lnum);
++			if (err)
++				return err;
++		}
++
++		err = dbg_check_lprops(c);
++		if (err)
++			goto out_orphans;
++	} else if (c->need_recovery) {
++		err = ubifs_recover_size(c);
++		if (err)
++			goto out_orphans;
++	} else {
++		/*
++		 * Even if we mount read-only, we have to set space in GC LEB
++		 * to proper value because this affects UBIFS free space
++		 * reporting. We do not want to have a situation when
++		 * re-mounting from R/O to R/W changes amount of free space.
++		 */
++		err = take_gc_lnum(c);
++		if (err)
++			goto out_orphans;
++	}
++
++	spin_lock(&ubifs_infos_lock);
++	list_add_tail(&c->infos_list, &ubifs_infos);
++	spin_unlock(&ubifs_infos_lock);
++
++	if (c->need_recovery) {
++		if (mounted_read_only)
++			ubifs_msg("recovery deferred");
++		else {
++			c->need_recovery = 0;
++			ubifs_msg("recovery completed");
++			/* GC LEB has to be empty and taken at this point */
++			ubifs_assert(c->lst.taken_empty_lebs == 1);
++		}
++	} else
++		ubifs_assert(c->lst.taken_empty_lebs == 1);
++
++	err = dbg_check_filesystem(c);
++	if (err)
++		goto out_infos;
++
++	err = dbg_debugfs_init_fs(c);
++	if (err)
++		goto out_infos;
++
++	c->always_chk_crc = 0;
++
++	ubifs_msg("mounted UBI device %d, volume %d, name \"%s\"",
++		  c->vi.ubi_num, c->vi.vol_id, c->vi.name);
++	if (mounted_read_only)
++		ubifs_msg("mounted read-only");
++	x = (long long)c->main_lebs * c->leb_size;
++	ubifs_msg("file system size:   %lld bytes (%lld KiB, %lld MiB, %d "
++		  "LEBs)", x, x >> 10, x >> 20, c->main_lebs);
++	x = (long long)c->log_lebs * c->leb_size + c->max_bud_bytes;
++	ubifs_msg("journal size:       %lld bytes (%lld KiB, %lld MiB, %d "
++		  "LEBs)", x, x >> 10, x >> 20, c->log_lebs + c->max_bud_cnt);
++	ubifs_msg("media format:       %d (latest is %d)",
++		  c->fmt_version, UBIFS_FORMAT_VERSION);
++	ubifs_msg("default compressor: %s", ubifs_compr_name(c->default_compr));
++	ubifs_msg("reserved for root:  %llu bytes (%llu KiB)",
++		c->report_rp_size, c->report_rp_size >> 10);
++
++	dbg_msg("compiled on:         " __DATE__ " at " __TIME__);
++	dbg_msg("min. I/O unit size:  %d bytes", c->min_io_size);
++	dbg_msg("LEB size:            %d bytes (%d KiB)",
++		c->leb_size, c->leb_size >> 10);
++	dbg_msg("data journal heads:  %d",
++		c->jhead_cnt - NONDATA_JHEADS_CNT);
++	dbg_msg("UUID:                %02X%02X%02X%02X-%02X%02X"
++	       "-%02X%02X-%02X%02X-%02X%02X%02X%02X%02X%02X",
++	       c->uuid[0], c->uuid[1], c->uuid[2], c->uuid[3],
++	       c->uuid[4], c->uuid[5], c->uuid[6], c->uuid[7],
++	       c->uuid[8], c->uuid[9], c->uuid[10], c->uuid[11],
++	       c->uuid[12], c->uuid[13], c->uuid[14], c->uuid[15]);
++	dbg_msg("big_lpt              %d", c->big_lpt);
++	dbg_msg("log LEBs:            %d (%d - %d)",
++		c->log_lebs, UBIFS_LOG_LNUM, c->log_last);
++	dbg_msg("LPT area LEBs:       %d (%d - %d)",
++		c->lpt_lebs, c->lpt_first, c->lpt_last);
++	dbg_msg("orphan area LEBs:    %d (%d - %d)",
++		c->orph_lebs, c->orph_first, c->orph_last);
++	dbg_msg("main area LEBs:      %d (%d - %d)",
++		c->main_lebs, c->main_first, c->leb_cnt - 1);
++	dbg_msg("index LEBs:          %d", c->lst.idx_lebs);
++	dbg_msg("total index bytes:   %lld (%lld KiB, %lld MiB)",
++		c->old_idx_sz, c->old_idx_sz >> 10, c->old_idx_sz >> 20);
++	dbg_msg("key hash type:       %d", c->key_hash_type);
++	dbg_msg("tree fanout:         %d", c->fanout);
++	dbg_msg("reserved GC LEB:     %d", c->gc_lnum);
++	dbg_msg("first main LEB:      %d", c->main_first);
++	dbg_msg("max. znode size      %d", c->max_znode_sz);
++	dbg_msg("max. index node size %d", c->max_idx_node_sz);
++	dbg_msg("node sizes:          data %zu, inode %zu, dentry %zu",
++		UBIFS_DATA_NODE_SZ, UBIFS_INO_NODE_SZ, UBIFS_DENT_NODE_SZ);
++	dbg_msg("node sizes:          trun %zu, sb %zu, master %zu",
++		UBIFS_TRUN_NODE_SZ, UBIFS_SB_NODE_SZ, UBIFS_MST_NODE_SZ);
++	dbg_msg("node sizes:          ref %zu, cmt. start %zu, orph %zu",
++		UBIFS_REF_NODE_SZ, UBIFS_CS_NODE_SZ, UBIFS_ORPH_NODE_SZ);
++	dbg_msg("max. node sizes:     data %zu, inode %zu dentry %zu",
++	        UBIFS_MAX_DATA_NODE_SZ, UBIFS_MAX_INO_NODE_SZ,
++		UBIFS_MAX_DENT_NODE_SZ);
++	dbg_msg("dead watermark:      %d", c->dead_wm);
++	dbg_msg("dark watermark:      %d", c->dark_wm);
++	dbg_msg("LEB overhead:        %d", c->leb_overhead);
++	x = (long long)c->main_lebs * c->dark_wm;
++	dbg_msg("max. dark space:     %lld (%lld KiB, %lld MiB)",
++		x, x >> 10, x >> 20);
++	dbg_msg("maximum bud bytes:   %lld (%lld KiB, %lld MiB)",
++		c->max_bud_bytes, c->max_bud_bytes >> 10,
++		c->max_bud_bytes >> 20);
++	dbg_msg("BG commit bud bytes: %lld (%lld KiB, %lld MiB)",
++		c->bg_bud_bytes, c->bg_bud_bytes >> 10,
++		c->bg_bud_bytes >> 20);
++	dbg_msg("current bud bytes    %lld (%lld KiB, %lld MiB)",
++		c->bud_bytes, c->bud_bytes >> 10, c->bud_bytes >> 20);
++	dbg_msg("max. seq. number:    %llu", c->max_sqnum);
++	dbg_msg("commit number:       %llu", c->cmt_no);
++
++	return 0;
++
++out_infos:
++	spin_lock(&ubifs_infos_lock);
++	list_del(&c->infos_list);
++	spin_unlock(&ubifs_infos_lock);
++out_orphans:
++	free_orphans(c);
++out_journal:
++	destroy_journal(c);
++out_lpt:
++	ubifs_lpt_free(c, 0);
++out_master:
++	kfree(c->mst_node);
++	kfree(c->rcvrd_mst_node);
++	if (c->bgt)
++		kthread_stop(c->bgt);
++out_wbufs:
++	free_wbufs(c);
++out_cbuf:
++	kfree(c->cbuf);
++out_free:
++	kfree(c->bu.buf);
++	vfree(c->ileb_buf);
++	vfree(c->sbuf);
++	kfree(c->bottom_up_buf);
++	ubifs_debugging_exit(c);
++	return err;
++}
++
++/**
++ * ubifs_umount - un-mount UBIFS file-system.
++ * @c: UBIFS file-system description object
++ *
++ * Note, this function is called to free allocated resourced when un-mounting,
++ * as well as free resources when an error occurred while we were half way
++ * through mounting (error path cleanup function). So it has to make sure the
++ * resource was actually allocated before freeing it.
++ */
++static void ubifs_umount(struct ubifs_info *c)
++{
++	dbg_gen("un-mounting UBI device %d, volume %d", c->vi.ubi_num,
++		c->vi.vol_id);
++
++	dbg_debugfs_exit_fs(c);
++	spin_lock(&ubifs_infos_lock);
++	list_del(&c->infos_list);
++	spin_unlock(&ubifs_infos_lock);
++
++	if (c->bgt)
++		kthread_stop(c->bgt);
++
++	destroy_journal(c);
++	free_wbufs(c);
++	free_orphans(c);
++	ubifs_lpt_free(c, 0);
++
++	kfree(c->cbuf);
++	kfree(c->rcvrd_mst_node);
++	kfree(c->mst_node);
++	kfree(c->bu.buf);
++	vfree(c->ileb_buf);
++	vfree(c->sbuf);
++	kfree(c->bottom_up_buf);
++	ubifs_debugging_exit(c);
++}
++
++/**
++ * ubifs_remount_rw - re-mount in read-write mode.
++ * @c: UBIFS file-system description object
++ *
++ * UBIFS avoids allocating many unnecessary resources when mounted in read-only
++ * mode. This function allocates the needed resources and re-mounts UBIFS in
++ * read-write mode.
++ */
++static int ubifs_remount_rw(struct ubifs_info *c)
++{
++	int err, lnum;
++
++	mutex_lock(&c->umount_mutex);
++	dbg_save_space_info(c);
++	c->remounting_rw = 1;
++	c->always_chk_crc = 1;
++
++	err = check_free_space(c);
++	if (err)
++		goto out;
++
++	if (c->old_leb_cnt != c->leb_cnt) {
++		struct ubifs_sb_node *sup;
++
++		sup = ubifs_read_sb_node(c);
++		if (IS_ERR(sup)) {
++			err = PTR_ERR(sup);
++			goto out;
++		}
++		sup->leb_cnt = cpu_to_le32(c->leb_cnt);
++		err = ubifs_write_sb_node(c, sup);
++		if (err)
++			goto out;
++	}
++
++	if (c->need_recovery) {
++		ubifs_msg("completing deferred recovery");
++		err = ubifs_write_rcvrd_mst_node(c);
++		if (err)
++			goto out;
++		err = ubifs_recover_size(c);
++		if (err)
++			goto out;
++		err = ubifs_clean_lebs(c, c->sbuf);
++		if (err)
++			goto out;
++		err = ubifs_recover_inl_heads(c, c->sbuf);
++		if (err)
++			goto out;
++	} else {
++		/* A readonly mount is not allowed to have orphans */
++		ubifs_assert(c->tot_orphans == 0);
++		err = ubifs_clear_orphans(c);
++		if (err)
++			goto out;
++	}
++
++	if (!(c->mst_node->flags & cpu_to_le32(UBIFS_MST_DIRTY))) {
++		c->mst_node->flags |= cpu_to_le32(UBIFS_MST_DIRTY);
++		err = ubifs_write_master(c);
++		if (err)
++			goto out;
++	}
++
++	c->ileb_buf = vmalloc(c->leb_size);
++	if (!c->ileb_buf) {
++		err = -ENOMEM;
++		goto out;
++	}
++
++	err = ubifs_lpt_init(c, 0, 1);
++	if (err)
++		goto out;
++
++	err = alloc_wbufs(c);
++	if (err)
++		goto out;
++
++	ubifs_create_buds_lists(c);
++
++	/* Create background thread */
++	c->bgt = kthread_create(ubifs_bg_thread, c, c->bgt_name);
++	if (IS_ERR(c->bgt)) {
++		err = PTR_ERR(c->bgt);
++		c->bgt = NULL;
++		ubifs_err("cannot spawn \"%s\", error %d",
++			  c->bgt_name, err);
++		goto out;
++	}
++	wake_up_process(c->bgt);
++
++	c->orph_buf = vmalloc(c->leb_size);
++	if (!c->orph_buf) {
++		err = -ENOMEM;
++		goto out;
++	}
++
++	/* Check for enough log space */
++	lnum = c->lhead_lnum + 1;
++	if (lnum >= UBIFS_LOG_LNUM + c->log_lebs)
++		lnum = UBIFS_LOG_LNUM;
++	if (lnum == c->ltail_lnum) {
++		err = ubifs_consolidate_log(c);
++		if (err)
++			goto out;
++	}
++
++	if (c->need_recovery)
++		err = ubifs_rcvry_gc_commit(c);
++	else
++		err = ubifs_leb_unmap(c, c->gc_lnum);
++	if (err)
++		goto out;
++
++	if (c->need_recovery) {
++		c->need_recovery = 0;
++		ubifs_msg("deferred recovery completed");
++	}
++
++	dbg_gen("re-mounted read-write");
++	c->vfs_sb->s_flags &= ~MS_RDONLY;
++	c->remounting_rw = 0;
++	c->always_chk_crc = 0;
++	err = dbg_check_space_info(c);
++	mutex_unlock(&c->umount_mutex);
++	return err;
++
++out:
++	vfree(c->orph_buf);
++	c->orph_buf = NULL;
++	if (c->bgt) {
++		kthread_stop(c->bgt);
++		c->bgt = NULL;
++	}
++	free_wbufs(c);
++	vfree(c->ileb_buf);
++	c->ileb_buf = NULL;
++	ubifs_lpt_free(c, 1);
++	c->remounting_rw = 0;
++	c->always_chk_crc = 0;
++	mutex_unlock(&c->umount_mutex);
++	return err;
++}
++
++/**
++ * ubifs_remount_ro - re-mount in read-only mode.
++ * @c: UBIFS file-system description object
++ *
++ * We assume VFS has stopped writing. Possibly the background thread could be
++ * running a commit, however kthread_stop will wait in that case.
++ */
++static void ubifs_remount_ro(struct ubifs_info *c)
++{
++	int i, err;
++
++	ubifs_assert(!c->need_recovery);
++	ubifs_assert(!(c->vfs_sb->s_flags & MS_RDONLY));
++
++	mutex_lock(&c->umount_mutex);
++	if (c->bgt) {
++		kthread_stop(c->bgt);
++		c->bgt = NULL;
++	}
++
++	dbg_save_space_info(c);
++
++	for (i = 0; i < c->jhead_cnt; i++) {
++		ubifs_wbuf_sync(&c->jheads[i].wbuf);
++		del_timer_sync(&c->jheads[i].wbuf.timer);
++	}
++
++	c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
++	c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
++	c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
++	err = ubifs_write_master(c);
++	if (err)
++		ubifs_ro_mode(c, err);
++
++	free_wbufs(c);
++	vfree(c->orph_buf);
++	c->orph_buf = NULL;
++	vfree(c->ileb_buf);
++	c->ileb_buf = NULL;
++	ubifs_lpt_free(c, 1);
++	err = dbg_check_space_info(c);
++	if (err)
++		ubifs_ro_mode(c, err);
++	mutex_unlock(&c->umount_mutex);
++}
++
++static void ubifs_put_super(struct super_block *sb)
++{
++	int i;
++	struct ubifs_info *c = sb->s_fs_info;
++
++	ubifs_msg("un-mount UBI device %d, volume %d", c->vi.ubi_num,
++		  c->vi.vol_id);
++	/*
++	 * The following asserts are only valid if there has not been a failure
++	 * of the media. For example, there will be dirty inodes if we failed
++	 * to write them back because of I/O errors.
++	 */
++	ubifs_assert(atomic_long_read(&c->dirty_pg_cnt) == 0);
++	ubifs_assert(c->budg_idx_growth == 0);
++	ubifs_assert(c->budg_dd_growth == 0);
++	ubifs_assert(c->budg_data_growth == 0);
++
++	/*
++	 * The 'c->umount_lock' prevents races between UBIFS memory shrinker
++	 * and file system un-mount. Namely, it prevents the shrinker from
++	 * picking this superblock for shrinking - it will be just skipped if
++	 * the mutex is locked.
++	 */
++	mutex_lock(&c->umount_mutex);
++	if (!(c->vfs_sb->s_flags & MS_RDONLY)) {
++		/*
++		 * First of all kill the background thread to make sure it does
++		 * not interfere with un-mounting and freeing resources.
++		 */
++		if (c->bgt) {
++			kthread_stop(c->bgt);
++			c->bgt = NULL;
++		}
++
++		/* Synchronize write-buffers */
++		if (c->jheads)
++			for (i = 0; i < c->jhead_cnt; i++) {
++				ubifs_wbuf_sync(&c->jheads[i].wbuf);
++				del_timer_sync(&c->jheads[i].wbuf.timer);
++			}
++
++		/*
++		 * On fatal errors c->ro_media is set to 1, in which case we do
++		 * not write the master node.
++		 */
++		if (!c->ro_media) {
++			/*
++			 * We are being cleanly unmounted which means the
++			 * orphans were killed - indicate this in the master
++			 * node. Also save the reserved GC LEB number.
++			 */
++			int err;
++
++			c->mst_node->flags &= ~cpu_to_le32(UBIFS_MST_DIRTY);
++			c->mst_node->flags |= cpu_to_le32(UBIFS_MST_NO_ORPHS);
++			c->mst_node->gc_lnum = cpu_to_le32(c->gc_lnum);
++			err = ubifs_write_master(c);
++			if (err)
++				/*
++				 * Recovery will attempt to fix the master area
++				 * next mount, so we just print a message and
++				 * continue to unmount normally.
++				 */
++				ubifs_err("failed to write master node, "
++					  "error %d", err);
++		}
++	}
++
++	ubifs_umount(c);
++	bdi_destroy(&c->bdi);
++	ubi_close_volume(c->ubi);
++	mutex_unlock(&c->umount_mutex);
++	kfree(c);
++}
++
++static int ubifs_remount_fs(struct super_block *sb, int *flags, char *data)
++{
++	int err;
++	struct ubifs_info *c = sb->s_fs_info;
++
++	dbg_gen("old flags %#lx, new flags %#x", sb->s_flags, *flags);
++
++	err = ubifs_parse_options(c, data, 1);
++	if (err) {
++		ubifs_err("invalid or unknown remount parameter");
++		return err;
++	}
++
++	if ((sb->s_flags & MS_RDONLY) && !(*flags & MS_RDONLY)) {
++		if (c->ro_media) {
++			ubifs_msg("cannot re-mount due to prior errors");
++			return -EROFS;
++		}
++		err = ubifs_remount_rw(c);
++		if (err)
++			return err;
++	} else if (!(sb->s_flags & MS_RDONLY) && (*flags & MS_RDONLY)) {
++		if (c->ro_media) {
++			ubifs_msg("cannot re-mount due to prior errors");
++			return -EROFS;
++		}
++		ubifs_remount_ro(c);
++	}
++
++	if (c->bulk_read == 1)
++		bu_init(c);
++	else {
++		dbg_gen("disable bulk-read");
++		kfree(c->bu.buf);
++		c->bu.buf = NULL;
++	}
++
++	ubifs_assert(c->lst.taken_empty_lebs == 1);
++	return 0;
++}
++
++const struct super_operations ubifs_super_operations = {
++	.read_inode    = ubifs_read_inode,
++	.alloc_inode   = ubifs_alloc_inode,
++	.destroy_inode = ubifs_destroy_inode,
++	.put_super     = ubifs_put_super,
++	.write_inode   = ubifs_write_inode,
++	.delete_inode  = ubifs_delete_inode,
++	.statfs        = ubifs_statfs,
++	.dirty_inode   = ubifs_dirty_inode,
++	.remount_fs    = ubifs_remount_fs,
++	.show_options  = ubifs_show_options,
++	.sync_fs       = ubifs_sync_fs,
++};
++
++/**
++ * open_ubi - parse UBI device name string and open the UBI device.
++ * @name: UBI volume name
++ * @mode: UBI volume open mode
++ *
++ * There are several ways to specify UBI volumes when mounting UBIFS:
++ * o ubiX_Y    - UBI device number X, volume Y;
++ * o ubiY      - UBI device number 0, volume Y;
++ * o ubiX:NAME - mount UBI device X, volume with name NAME;
++ * o ubi:NAME  - mount UBI device 0, volume with name NAME.
++ *
++ * Alternative '!' separator may be used instead of ':' (because some shells
++ * like busybox may interpret ':' as an NFS host name separator). This function
++ * returns ubi volume object in case of success and a negative error code in
++ * case of failure.
++ */
++static struct ubi_volume_desc *open_ubi(const char *name, int mode)
++{
++	int dev, vol;
++	char *endptr;
++
++	if (name[0] != 'u' || name[1] != 'b' || name[2] != 'i')
++		return ERR_PTR(-EINVAL);
++
++	/* ubi:NAME method */
++	if ((name[3] == ':' || name[3] == '!') && name[4] != '\0')
++		return ubi_open_volume_nm(0, name + 4, mode);
++
++	if (!isdigit(name[3]))
++		return ERR_PTR(-EINVAL);
++
++	dev = simple_strtoul(name + 3, &endptr, 0);
++
++	/* ubiY method */
++	if (*endptr == '\0')
++		return ubi_open_volume(0, dev, mode);
++
++	/* ubiX_Y method */
++	if (*endptr == '_' && isdigit(endptr[1])) {
++		vol = simple_strtoul(endptr + 1, &endptr, 0);
++		if (*endptr != '\0')
++			return ERR_PTR(-EINVAL);
++		return ubi_open_volume(dev, vol, mode);
++	}
++
++	/* ubiX:NAME method */
++	if ((*endptr == ':' || *endptr == '!') && endptr[1] != '\0')
++		return ubi_open_volume_nm(dev, ++endptr, mode);
++
++	return ERR_PTR(-EINVAL);
++}
++
++static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
++{
++	struct ubi_volume_desc *ubi = sb->s_fs_info;
++	struct ubifs_info *c;
++	struct inode *root;
++	int err;
++
++	c = kzalloc(sizeof(struct ubifs_info), GFP_KERNEL);
++	if (!c)
++		return -ENOMEM;
++
++	spin_lock_init(&c->cnt_lock);
++	spin_lock_init(&c->cs_lock);
++	spin_lock_init(&c->buds_lock);
++	spin_lock_init(&c->space_lock);
++	spin_lock_init(&c->orphan_lock);
++	init_rwsem(&c->commit_sem);
++	mutex_init(&c->lp_mutex);
++	mutex_init(&c->tnc_mutex);
++	mutex_init(&c->log_mutex);
++	mutex_init(&c->mst_mutex);
++	mutex_init(&c->umount_mutex);
++	mutex_init(&c->bu_mutex);
++	init_waitqueue_head(&c->cmt_wq);
++	c->buds = RB_ROOT;
++	c->old_idx = RB_ROOT;
++	c->size_tree = RB_ROOT;
++	c->orph_tree = RB_ROOT;
++	INIT_LIST_HEAD(&c->infos_list);
++	INIT_LIST_HEAD(&c->idx_gc);
++	INIT_LIST_HEAD(&c->replay_list);
++	INIT_LIST_HEAD(&c->replay_buds);
++	INIT_LIST_HEAD(&c->uncat_list);
++	INIT_LIST_HEAD(&c->empty_list);
++	INIT_LIST_HEAD(&c->freeable_list);
++	INIT_LIST_HEAD(&c->frdi_idx_list);
++	INIT_LIST_HEAD(&c->unclean_leb_list);
++	INIT_LIST_HEAD(&c->old_buds);
++	INIT_LIST_HEAD(&c->orph_list);
++	INIT_LIST_HEAD(&c->orph_new);
++
++	c->highest_inum = UBIFS_FIRST_INO;
++	c->lhead_lnum = c->ltail_lnum = UBIFS_LOG_LNUM;
++
++	ubi_get_volume_info(ubi, &c->vi);
++	ubi_get_device_info(c->vi.ubi_num, &c->di);
++
++	/* Re-open the UBI device in read-write mode */
++	c->ubi = ubi_open_volume(c->vi.ubi_num, c->vi.vol_id, UBI_READWRITE);
++	if (IS_ERR(c->ubi)) {
++		err = PTR_ERR(c->ubi);
++		goto out_free;
++	}
++
++	/*
++	 * UBIFS provides 'backing_dev_info' in order to disable read-ahead. For
++	 * UBIFS, I/O is not deferred, it is done immediately in readpage,
++	 * which means the user would have to wait not just for their own I/O
++	 * but the read-ahead I/O as well i.e. completely pointless.
++	 *
++	 * Read-ahead will be disabled because @c->bdi.ra_pages is 0.
++	 */
++	c->bdi.capabilities = BDI_CAP_MAP_COPY;
++	c->bdi.unplug_io_fn = default_unplug_io_fn;
++	err  = bdi_init(&c->bdi);
++	if (err)
++		goto out_close;
++
++	err = ubifs_parse_options(c, data, 0);
++	if (err)
++		goto out_bdi;
++
++	c->vfs_sb = sb;
++
++	sb->s_fs_info = c;
++	sb->s_magic = UBIFS_SUPER_MAGIC;
++	sb->s_blocksize = UBIFS_BLOCK_SIZE;
++	sb->s_blocksize_bits = UBIFS_BLOCK_SHIFT;
++	sb->s_dev = c->vi.cdev;
++	sb->s_maxbytes = c->max_inode_sz = key_max_inode_size(c);
++	if (c->max_inode_sz > MAX_LFS_FILESIZE)
++		sb->s_maxbytes = c->max_inode_sz = MAX_LFS_FILESIZE;
++	sb->s_op = &ubifs_super_operations;
++
++	mutex_lock(&c->umount_mutex);
++	err = mount_ubifs(c);
++	if (err) {
++		ubifs_assert(err < 0);
++		goto out_unlock;
++	}
++
++	/* Read the root inode */
++	root = ubifs_iget(sb, UBIFS_ROOT_INO);
++	if (IS_ERR(root)) {
++		err = PTR_ERR(root);
++		goto out_umount;
++	}
++
++	sb->s_root = d_alloc_root(root);
++	if (!sb->s_root)
++		goto out_iput;
++
++	mutex_unlock(&c->umount_mutex);
++	return 0;
++
++out_iput:
++	iput(root);
++out_umount:
++	ubifs_umount(c);
++out_unlock:
++	mutex_unlock(&c->umount_mutex);
++out_bdi:
++	bdi_destroy(&c->bdi);
++out_close:
++	ubi_close_volume(c->ubi);
++out_free:
++	kfree(c);
++	return err;
++}
++
++static int sb_test(struct super_block *sb, void *data)
++{
++	dev_t *dev = data;
++
++	return sb->s_dev == *dev;
++}
++
++static int sb_set(struct super_block *sb, void *data)
++{
++	dev_t *dev = data;
++
++	sb->s_dev = *dev;
++	return 0;
++}
++
++static int ubifs_get_sb(struct file_system_type *fs_type, int flags,
++			const char *name, void *data, struct vfsmount *mnt)
++{
++	struct ubi_volume_desc *ubi;
++	struct ubi_volume_info vi;
++	struct super_block *sb;
++	int err;
++
++	dbg_gen("name %s, flags %#x", name, flags);
++
++	/*
++	 * Get UBI device number and volume ID. Mount it read-only so far
++	 * because this might be a new mount point, and UBI allows only one
++	 * read-write user at a time.
++	 */
++	ubi = open_ubi(name, UBI_READONLY);
++	if (IS_ERR(ubi)) {
++		ubifs_err("cannot open \"%s\", error %d",
++			  name, (int)PTR_ERR(ubi));
++		return PTR_ERR(ubi);
++	}
++	ubi_get_volume_info(ubi, &vi);
++
++	dbg_gen("opened ubi%d_%d", vi.ubi_num, vi.vol_id);
++
++	sb = sget(fs_type, &sb_test, &sb_set, &vi.cdev);
++	if (IS_ERR(sb)) {
++		err = PTR_ERR(sb);
++		goto out_close;
++	}
++
++	if (sb->s_root) {
++		/* A new mount point for already mounted UBIFS */
++		dbg_gen("this ubi volume is already mounted");
++		if ((flags ^ sb->s_flags) & MS_RDONLY) {
++			err = -EBUSY;
++			goto out_deact;
++		}
++	} else {
++		sb->s_flags = flags;
++		/*
++		 * Pass 'ubi' to 'fill_super()' in sb->s_fs_info where it is
++		 * replaced by 'c'.
++		 */
++		sb->s_fs_info = ubi;
++		err = ubifs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
++		if (err)
++			goto out_deact;
++		/* We do not support atime */
++		sb->s_flags |= MS_ACTIVE | MS_NOATIME;
++	}
++
++	/* 'fill_super()' opens ubi again so we must close it here */
++	ubi_close_volume(ubi);
++
++	return simple_set_mnt(mnt, sb);
++
++out_deact:
++	up_write(&sb->s_umount);
++	deactivate_super(sb);
++out_close:
++	ubi_close_volume(ubi);
++	return err;
++}
++
++static void ubifs_kill_sb(struct super_block *sb)
++{
++	generic_shutdown_super(sb);
++}
++
++static struct file_system_type ubifs_fs_type = {
++	.name     = "ubifs",
++	.owner    = THIS_MODULE,
++	.get_sb   = ubifs_get_sb,
++	.kill_sb  = ubifs_kill_sb,
++	.fs_flags = FS_REQUIRES_DEV,
++};
++
++/*
++ * Inode slab cache constructor.
++ */
++static void inode_slab_ctor(struct kmem_cache *cachep, void *obj)
++{
++	struct ubifs_inode *ui = obj;
++	inode_init_once(&ui->vfs_inode);
++}
++
++static int __init ubifs_init(void)
++{
++	int err;
++
++	BUILD_BUG_ON(sizeof(struct ubifs_ch) != 24);
++
++	/* Make sure node sizes are 8-byte aligned */
++	BUILD_BUG_ON(UBIFS_CH_SZ        & 7);
++	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  & 7);
++	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ & 7);
++	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ & 7);
++	BUILD_BUG_ON(UBIFS_DATA_NODE_SZ & 7);
++	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ & 7);
++	BUILD_BUG_ON(UBIFS_SB_NODE_SZ   & 7);
++	BUILD_BUG_ON(UBIFS_MST_NODE_SZ  & 7);
++	BUILD_BUG_ON(UBIFS_REF_NODE_SZ  & 7);
++	BUILD_BUG_ON(UBIFS_CS_NODE_SZ   & 7);
++	BUILD_BUG_ON(UBIFS_ORPH_NODE_SZ & 7);
++
++	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ & 7);
++	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ & 7);
++	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ & 7);
++	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  & 7);
++	BUILD_BUG_ON(UBIFS_MAX_NODE_SZ      & 7);
++	BUILD_BUG_ON(MIN_WRITE_SZ           & 7);
++
++	/* Check min. node size */
++	BUILD_BUG_ON(UBIFS_INO_NODE_SZ  < MIN_WRITE_SZ);
++	BUILD_BUG_ON(UBIFS_DENT_NODE_SZ < MIN_WRITE_SZ);
++	BUILD_BUG_ON(UBIFS_XENT_NODE_SZ < MIN_WRITE_SZ);
++	BUILD_BUG_ON(UBIFS_TRUN_NODE_SZ < MIN_WRITE_SZ);
++
++	BUILD_BUG_ON(UBIFS_MAX_DENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
++	BUILD_BUG_ON(UBIFS_MAX_XENT_NODE_SZ > UBIFS_MAX_NODE_SZ);
++	BUILD_BUG_ON(UBIFS_MAX_DATA_NODE_SZ > UBIFS_MAX_NODE_SZ);
++	BUILD_BUG_ON(UBIFS_MAX_INO_NODE_SZ  > UBIFS_MAX_NODE_SZ);
++
++	/* Defined node sizes */
++	BUILD_BUG_ON(UBIFS_SB_NODE_SZ  != 4096);
++	BUILD_BUG_ON(UBIFS_MST_NODE_SZ != 512);
++	BUILD_BUG_ON(UBIFS_INO_NODE_SZ != 160);
++	BUILD_BUG_ON(UBIFS_REF_NODE_SZ != 64);
++
++	/*
++	 * We use 2 bit wide bit-fields to store compression type, which should
++	 * be amended if more compressors are added. The bit-fields are:
++	 * @compr_type in 'struct ubifs_inode', @default_compr in
++	 * 'struct ubifs_info' and @compr_type in 'struct ubifs_mount_opts'.
++	 */
++	BUILD_BUG_ON(UBIFS_COMPR_TYPES_CNT > 4);
++
++	/*
++	 * We require that PAGE_CACHE_SIZE is greater-than-or-equal-to
++	 * UBIFS_BLOCK_SIZE. It is assumed that both are powers of 2.
++	 */
++	if (PAGE_CACHE_SIZE < UBIFS_BLOCK_SIZE) {
++		ubifs_err("VFS page cache size is %u bytes, but UBIFS requires"
++			  " at least 4096 bytes",
++			  (unsigned int)PAGE_CACHE_SIZE);
++		return -EINVAL;
++	}
++
++	err = register_filesystem(&ubifs_fs_type);
++	if (err) {
++		ubifs_err("cannot register file system, error %d", err);
++		return err;
++	}
++
++	err = -ENOMEM;
++	ubifs_inode_slab = kmem_cache_create("ubifs_inode_slab",
++				sizeof(struct ubifs_inode), 0,
++				SLAB_MEM_SPREAD | SLAB_RECLAIM_ACCOUNT,
++				&inode_slab_ctor);
++	if (!ubifs_inode_slab)
++		goto out_reg;
++
++	register_shrinker(&ubifs_shrinker_info);
++
++	err = ubifs_compressors_init();
++	if (err)
++		goto out_shrinker;
++
++	err = dbg_debugfs_init();
++	if (err)
++		goto out_compr;
++
++	return 0;
++
++out_compr:
++	ubifs_compressors_exit();
++out_shrinker:
++	unregister_shrinker(&ubifs_shrinker_info);
++	kmem_cache_destroy(ubifs_inode_slab);
++out_reg:
++	unregister_filesystem(&ubifs_fs_type);
++	return err;
++}
++/* late_initcall to let compressors initialize first */
++late_initcall(ubifs_init);
++
++static void __exit ubifs_exit(void)
++{
++	ubifs_assert(list_empty(&ubifs_infos));
++	ubifs_assert(atomic_long_read(&ubifs_clean_zn_cnt) == 0);
++
++	dbg_debugfs_exit();
++	ubifs_compressors_exit();
++	unregister_shrinker(&ubifs_shrinker_info);
++	kmem_cache_destroy(ubifs_inode_slab);
++	unregister_filesystem(&ubifs_fs_type);
++}
++module_exit(ubifs_exit);
++
++MODULE_LICENSE("GPL");
++MODULE_VERSION(__stringify(UBIFS_VERSION));
++MODULE_AUTHOR("Artem Bityutskiy, Adrian Hunter");
++MODULE_DESCRIPTION("UBIFS - UBI File System");
+diff -Nurd linux-2.6.24.orig/fs/ubifs/tnc.c linux-2.6.24/fs/ubifs/tnc.c
+--- linux-2.6.24.orig/fs/ubifs/tnc.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/tnc.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,3270 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Adrian Hunter
++ *          Artem Bityutskiy (Битюцкий Артём)
++ */
++
++/*
++ * This file implements TNC (Tree Node Cache) which caches indexing nodes of
++ * the UBIFS B-tree.
++ *
++ * At the moment the locking rules of the TNC tree are quite simple and
++ * straightforward. We just have a mutex and lock it when we traverse the
++ * tree. If a znode is not in memory, we read it from flash while still having
++ * the mutex locked.
++ */
++
++#include <linux/crc32.h>
++#include "ubifs.h"
++
++/*
++ * Returned codes of 'matches_name()' and 'fallible_matches_name()' functions.
++ * @NAME_LESS: name corresponding to the first argument is less than second
++ * @NAME_MATCHES: names match
++ * @NAME_GREATER: name corresponding to the second argument is greater than
++ *                first
++ * @NOT_ON_MEDIA: node referred by zbranch does not exist on the media
++ *
++ * These constants were introduce to improve readability.
++ */
++enum {
++	NAME_LESS    = 0,
++	NAME_MATCHES = 1,
++	NAME_GREATER = 2,
++	NOT_ON_MEDIA = 3,
++};
++
++/**
++ * insert_old_idx - record an index node obsoleted since the last commit start.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number of obsoleted index node
++ * @offs: offset of obsoleted index node
++ *
++ * Returns %0 on success, and a negative error code on failure.
++ *
++ * For recovery, there must always be a complete intact version of the index on
++ * flash at all times. That is called the "old index". It is the index as at the
++ * time of the last successful commit. Many of the index nodes in the old index
++ * may be dirty, but they must not be erased until the next successful commit
++ * (at which point that index becomes the old index).
++ *
++ * That means that the garbage collection and the in-the-gaps method of
++ * committing must be able to determine if an index node is in the old index.
++ * Most of the old index nodes can be found by looking up the TNC using the
++ * 'lookup_znode()' function. However, some of the old index nodes may have
++ * been deleted from the current index or may have been changed so much that
++ * they cannot be easily found. In those cases, an entry is added to an RB-tree.
++ * That is what this function does. The RB-tree is ordered by LEB number and
++ * offset because they uniquely identify the old index node.
++ */
++static int insert_old_idx(struct ubifs_info *c, int lnum, int offs)
++{
++	struct ubifs_old_idx *old_idx, *o;
++	struct rb_node **p, *parent = NULL;
++
++	old_idx = kmalloc(sizeof(struct ubifs_old_idx), GFP_NOFS);
++	if (unlikely(!old_idx))
++		return -ENOMEM;
++	old_idx->lnum = lnum;
++	old_idx->offs = offs;
++
++	p = &c->old_idx.rb_node;
++	while (*p) {
++		parent = *p;
++		o = rb_entry(parent, struct ubifs_old_idx, rb);
++		if (lnum < o->lnum)
++			p = &(*p)->rb_left;
++		else if (lnum > o->lnum)
++			p = &(*p)->rb_right;
++		else if (offs < o->offs)
++			p = &(*p)->rb_left;
++		else if (offs > o->offs)
++			p = &(*p)->rb_right;
++		else {
++			ubifs_err("old idx added twice!");
++			kfree(old_idx);
++			return 0;
++		}
++	}
++	rb_link_node(&old_idx->rb, parent, p);
++	rb_insert_color(&old_idx->rb, &c->old_idx);
++	return 0;
++}
++
++/**
++ * insert_old_idx_znode - record a znode obsoleted since last commit start.
++ * @c: UBIFS file-system description object
++ * @znode: znode of obsoleted index node
++ *
++ * Returns %0 on success, and a negative error code on failure.
++ */
++int insert_old_idx_znode(struct ubifs_info *c, struct ubifs_znode *znode)
++{
++	if (znode->parent) {
++		struct ubifs_zbranch *zbr;
++
++		zbr = &znode->parent->zbranch[znode->iip];
++		if (zbr->len)
++			return insert_old_idx(c, zbr->lnum, zbr->offs);
++	} else
++		if (c->zroot.len)
++			return insert_old_idx(c, c->zroot.lnum,
++					      c->zroot.offs);
++	return 0;
++}
++
++/**
++ * ins_clr_old_idx_znode - record a znode obsoleted since last commit start.
++ * @c: UBIFS file-system description object
++ * @znode: znode of obsoleted index node
++ *
++ * Returns %0 on success, and a negative error code on failure.
++ */
++static int ins_clr_old_idx_znode(struct ubifs_info *c,
++				 struct ubifs_znode *znode)
++{
++	int err;
++
++	if (znode->parent) {
++		struct ubifs_zbranch *zbr;
++
++		zbr = &znode->parent->zbranch[znode->iip];
++		if (zbr->len) {
++			err = insert_old_idx(c, zbr->lnum, zbr->offs);
++			if (err)
++				return err;
++			zbr->lnum = 0;
++			zbr->offs = 0;
++			zbr->len = 0;
++		}
++	} else
++		if (c->zroot.len) {
++			err = insert_old_idx(c, c->zroot.lnum, c->zroot.offs);
++			if (err)
++				return err;
++			c->zroot.lnum = 0;
++			c->zroot.offs = 0;
++			c->zroot.len = 0;
++		}
++	return 0;
++}
++
++/**
++ * destroy_old_idx - destroy the old_idx RB-tree.
++ * @c: UBIFS file-system description object
++ *
++ * During start commit, the old_idx RB-tree is used to avoid overwriting index
++ * nodes that were in the index last commit but have since been deleted.  This
++ * is necessary for recovery i.e. the old index must be kept intact until the
++ * new index is successfully written.  The old-idx RB-tree is used for the
++ * in-the-gaps method of writing index nodes and is destroyed every commit.
++ */
++void destroy_old_idx(struct ubifs_info *c)
++{
++	struct rb_node *this = c->old_idx.rb_node;
++	struct ubifs_old_idx *old_idx;
++
++	while (this) {
++		if (this->rb_left) {
++			this = this->rb_left;
++			continue;
++		} else if (this->rb_right) {
++			this = this->rb_right;
++			continue;
++		}
++		old_idx = rb_entry(this, struct ubifs_old_idx, rb);
++		this = rb_parent(this);
++		if (this) {
++			if (this->rb_left == &old_idx->rb)
++				this->rb_left = NULL;
++			else
++				this->rb_right = NULL;
++		}
++		kfree(old_idx);
++	}
++	c->old_idx = RB_ROOT;
++}
++
++/**
++ * copy_znode - copy a dirty znode.
++ * @c: UBIFS file-system description object
++ * @znode: znode to copy
++ *
++ * A dirty znode being committed may not be changed, so it is copied.
++ */
++static struct ubifs_znode *copy_znode(struct ubifs_info *c,
++				      struct ubifs_znode *znode)
++{
++	struct ubifs_znode *zn;
++
++	zn = kmalloc(c->max_znode_sz, GFP_NOFS);
++	if (unlikely(!zn))
++		return ERR_PTR(-ENOMEM);
++
++	memcpy(zn, znode, c->max_znode_sz);
++	zn->cnext = NULL;
++	__set_bit(DIRTY_ZNODE, &zn->flags);
++	__clear_bit(COW_ZNODE, &zn->flags);
++
++	ubifs_assert(!test_bit(OBSOLETE_ZNODE, &znode->flags));
++	__set_bit(OBSOLETE_ZNODE, &znode->flags);
++
++	if (znode->level != 0) {
++		int i;
++		const int n = zn->child_cnt;
++
++		/* The children now have new parent */
++		for (i = 0; i < n; i++) {
++			struct ubifs_zbranch *zbr = &zn->zbranch[i];
++
++			if (zbr->znode)
++				zbr->znode->parent = zn;
++		}
++	}
++
++	atomic_long_inc(&c->dirty_zn_cnt);
++	return zn;
++}
++
++/**
++ * add_idx_dirt - add dirt due to a dirty znode.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number of index node
++ * @dirt: size of index node
++ *
++ * This function updates lprops dirty space and the new size of the index.
++ */
++static int add_idx_dirt(struct ubifs_info *c, int lnum, int dirt)
++{
++	c->calc_idx_sz -= ALIGN(dirt, 8);
++	return ubifs_add_dirt(c, lnum, dirt);
++}
++
++/**
++ * dirty_cow_znode - ensure a znode is not being committed.
++ * @c: UBIFS file-system description object
++ * @zbr: branch of znode to check
++ *
++ * Returns dirtied znode on success or negative error code on failure.
++ */
++static struct ubifs_znode *dirty_cow_znode(struct ubifs_info *c,
++					   struct ubifs_zbranch *zbr)
++{
++	struct ubifs_znode *znode = zbr->znode;
++	struct ubifs_znode *zn;
++	int err;
++
++	if (!test_bit(COW_ZNODE, &znode->flags)) {
++		/* znode is not being committed */
++		if (!test_and_set_bit(DIRTY_ZNODE, &znode->flags)) {
++			atomic_long_inc(&c->dirty_zn_cnt);
++			atomic_long_dec(&c->clean_zn_cnt);
++			atomic_long_dec(&ubifs_clean_zn_cnt);
++			err = add_idx_dirt(c, zbr->lnum, zbr->len);
++			if (unlikely(err))
++				return ERR_PTR(err);
++		}
++		return znode;
++	}
++
++	zn = copy_znode(c, znode);
++	if (IS_ERR(zn))
++		return zn;
++
++	if (zbr->len) {
++		err = insert_old_idx(c, zbr->lnum, zbr->offs);
++		if (unlikely(err))
++			return ERR_PTR(err);
++		err = add_idx_dirt(c, zbr->lnum, zbr->len);
++	} else
++		err = 0;
++
++	zbr->znode = zn;
++	zbr->lnum = 0;
++	zbr->offs = 0;
++	zbr->len = 0;
++
++	if (unlikely(err))
++		return ERR_PTR(err);
++	return zn;
++}
++
++/**
++ * lnc_add - add a leaf node to the leaf node cache.
++ * @c: UBIFS file-system description object
++ * @zbr: zbranch of leaf node
++ * @node: leaf node
++ *
++ * Leaf nodes are non-index nodes directory entry nodes or data nodes. The
++ * purpose of the leaf node cache is to save re-reading the same leaf node over
++ * and over again. Most things are cached by VFS, however the file system must
++ * cache directory entries for readdir and for resolving hash collisions. The
++ * present implementation of the leaf node cache is extremely simple, and
++ * allows for error returns that are not used but that may be needed if a more
++ * complex implementation is created.
++ *
++ * Note, this function does not add the @node object to LNC directly, but
++ * allocates a copy of the object and adds the copy to LNC. The reason for this
++ * is that @node has been allocated outside of the TNC subsystem and will be
++ * used with @c->tnc_mutex unlock upon return from the TNC subsystem. But LNC
++ * may be changed at any time, e.g. freed by the shrinker.
++ */
++static int lnc_add(struct ubifs_info *c, struct ubifs_zbranch *zbr,
++		   const void *node)
++{
++	int err;
++	void *lnc_node;
++	const struct ubifs_dent_node *dent = node;
++
++	ubifs_assert(!zbr->leaf);
++	ubifs_assert(zbr->len != 0);
++	ubifs_assert(is_hash_key(c, &zbr->key));
++
++	err = ubifs_validate_entry(c, dent);
++	if (err) {
++		dbg_dump_stack();
++		dbg_dump_node(c, dent);
++		return err;
++	}
++
++	lnc_node = kmalloc(zbr->len, GFP_NOFS);
++	if (!lnc_node)
++		/* We don't have to have the cache, so no error */
++		return 0;
++
++	memcpy(lnc_node, node, zbr->len);
++	zbr->leaf = lnc_node;
++	return 0;
++}
++
++ /**
++ * lnc_add_directly - add a leaf node to the leaf-node-cache.
++ * @c: UBIFS file-system description object
++ * @zbr: zbranch of leaf node
++ * @node: leaf node
++ *
++ * This function is similar to 'lnc_add()', but it does not create a copy of
++ * @node but inserts @node to TNC directly.
++ */
++static int lnc_add_directly(struct ubifs_info *c, struct ubifs_zbranch *zbr,
++			    void *node)
++{
++	int err;
++
++	ubifs_assert(!zbr->leaf);
++	ubifs_assert(zbr->len != 0);
++
++	err = ubifs_validate_entry(c, node);
++	if (err) {
++		dbg_dump_stack();
++		dbg_dump_node(c, node);
++		return err;
++	}
++
++	zbr->leaf = node;
++	return 0;
++}
++
++/**
++ * lnc_free - remove a leaf node from the leaf node cache.
++ * @zbr: zbranch of leaf node
++ * @node: leaf node
++ */
++static void lnc_free(struct ubifs_zbranch *zbr)
++{
++	if (!zbr->leaf)
++		return;
++	kfree(zbr->leaf);
++	zbr->leaf = NULL;
++}
++
++/**
++ * tnc_read_node_nm - read a "hashed" leaf node.
++ * @c: UBIFS file-system description object
++ * @zbr: key and position of the node
++ * @node: node is returned here
++ *
++ * This function reads a "hashed" node defined by @zbr from the leaf node cache
++ * (in it is there) or from the hash media, in which case the node is also
++ * added to LNC. Returns zero in case of success or a negative negative error
++ * code in case of failure.
++ */
++static int tnc_read_node_nm(struct ubifs_info *c, struct ubifs_zbranch *zbr,
++			    void *node)
++{
++	int err;
++
++	ubifs_assert(is_hash_key(c, &zbr->key));
++
++	if (zbr->leaf) {
++		/* Read from the leaf node cache */
++		ubifs_assert(zbr->len != 0);
++		memcpy(node, zbr->leaf, zbr->len);
++		return 0;
++	}
++
++	err = ubifs_tnc_read_node(c, zbr, node);
++	if (err)
++		return err;
++
++	/* Add the node to the leaf node cache */
++	err = lnc_add(c, zbr, node);
++	return err;
++}
++
++/**
++ * try_read_node - read a node if it is a node.
++ * @c: UBIFS file-system description object
++ * @buf: buffer to read to
++ * @type: node type
++ * @len: node length (not aligned)
++ * @lnum: LEB number of node to read
++ * @offs: offset of node to read
++ *
++ * This function tries to read a node of known type and length, checks it and
++ * stores it in @buf. This function returns %1 if a node is present and %0 if
++ * a node is not present. A negative error code is returned for I/O errors.
++ * This function performs that same function as ubifs_read_node except that
++ * it does not require that there is actually a node present and instead
++ * the return code indicates if a node was read.
++ *
++ * Note, this function does not check CRC of data nodes if @c->no_chk_data_crc
++ * is true (it is controlled by corresponding mount option). However, if
++ * @c->always_chk_crc is true, @c->no_chk_data_crc is ignored and CRC is always
++ * checked.
++ */
++static int try_read_node(const struct ubifs_info *c, void *buf, int type,
++			 int len, int lnum, int offs)
++{
++	int err, node_len;
++	struct ubifs_ch *ch = buf;
++	uint32_t crc, node_crc;
++
++	dbg_io("LEB %d:%d, %s, length %d", lnum, offs, dbg_ntype(type), len);
++
++	err = ubi_read(c->ubi, lnum, buf, offs, len);
++	if (err) {
++		ubifs_err("cannot read node type %d from LEB %d:%d, error %d",
++			  type, lnum, offs, err);
++		return err;
++	}
++
++	if (le32_to_cpu(ch->magic) != UBIFS_NODE_MAGIC)
++		return 0;
++
++	if (ch->node_type != type)
++		return 0;
++
++	node_len = le32_to_cpu(ch->len);
++	if (node_len != len)
++		return 0;
++
++	if (type == UBIFS_DATA_NODE && !c->always_chk_crc && c->no_chk_data_crc)
++		return 1;
++
++	crc = crc32(UBIFS_CRC32_INIT, buf + 8, node_len - 8);
++	node_crc = le32_to_cpu(ch->crc);
++	if (crc != node_crc)
++		return 0;
++
++	return 1;
++}
++
++/**
++ * fallible_read_node - try to read a leaf node.
++ * @c: UBIFS file-system description object
++ * @key:  key of node to read
++ * @zbr:  position of node
++ * @node: node returned
++ *
++ * This function tries to read a node and returns %1 if the node is read, %0
++ * if the node is not present, and a negative error code in the case of error.
++ */
++static int fallible_read_node(struct ubifs_info *c, const union ubifs_key *key,
++			      struct ubifs_zbranch *zbr, void *node)
++{
++	int ret;
++
++	dbg_tnc("LEB %d:%d, key %s", zbr->lnum, zbr->offs, DBGKEY(key));
++
++	ret = try_read_node(c, node, key_type(c, key), zbr->len, zbr->lnum,
++			    zbr->offs);
++	if (ret == 1) {
++		union ubifs_key node_key;
++		struct ubifs_dent_node *dent = node;
++
++		/* All nodes have key in the same place */
++		key_read(c, &dent->key, &node_key);
++		if (keys_cmp(c, key, &node_key) != 0)
++			ret = 0;
++	}
++	if (ret == 0 && c->replaying)
++		dbg_mnt("dangling branch LEB %d:%d len %d, key %s",
++			zbr->lnum, zbr->offs, zbr->len, DBGKEY(key));
++	return ret;
++}
++
++/**
++ * matches_name - determine if a direntry or xattr entry matches a given name.
++ * @c: UBIFS file-system description object
++ * @zbr: zbranch of dent
++ * @nm: name to match
++ *
++ * This function checks if xentry/direntry referred by zbranch @zbr matches name
++ * @nm. Returns %NAME_MATCHES if it does, %NAME_LESS if the name referred by
++ * @zbr is less than @nm, and %NAME_GREATER if it is greater than @nm. In case
++ * of failure, a negative error code is returned.
++ */
++static int matches_name(struct ubifs_info *c, struct ubifs_zbranch *zbr,
++			const struct qstr *nm)
++{
++	struct ubifs_dent_node *dent;
++	int nlen, err;
++
++	/* If possible, match against the dent in the leaf node cache */
++	if (!zbr->leaf) {
++		dent = kmalloc(zbr->len, GFP_NOFS);
++		if (!dent)
++			return -ENOMEM;
++
++		err = ubifs_tnc_read_node(c, zbr, dent);
++		if (err)
++			goto out_free;
++
++		/* Add the node to the leaf node cache */
++		err = lnc_add_directly(c, zbr, dent);
++		if (err)
++			goto out_free;
++	} else
++		dent = zbr->leaf;
++
++	nlen = le16_to_cpu(dent->nlen);
++	err = memcmp(dent->name, nm->name, min_t(int, nlen, nm->len));
++	if (err == 0) {
++		if (nlen == nm->len)
++			return NAME_MATCHES;
++		else if (nlen < nm->len)
++			return NAME_LESS;
++		else
++			return NAME_GREATER;
++	} else if (err < 0)
++		return NAME_LESS;
++	else
++		return NAME_GREATER;
++
++out_free:
++	kfree(dent);
++	return err;
++}
++
++/**
++ * get_znode - get a TNC znode that may not be loaded yet.
++ * @c: UBIFS file-system description object
++ * @znode: parent znode
++ * @n: znode branch slot number
++ *
++ * This function returns the znode or a negative error code.
++ */
++static struct ubifs_znode *get_znode(struct ubifs_info *c,
++				     struct ubifs_znode *znode, int n)
++{
++	struct ubifs_zbranch *zbr;
++
++	zbr = &znode->zbranch[n];
++	if (zbr->znode)
++		znode = zbr->znode;
++	else
++		znode = ubifs_load_znode(c, zbr, znode, n);
++	return znode;
++}
++
++/**
++ * tnc_next - find next TNC entry.
++ * @c: UBIFS file-system description object
++ * @zn: znode is passed and returned here
++ * @n: znode branch slot number is passed and returned here
++ *
++ * This function returns %0 if the next TNC entry is found, %-ENOENT if there is
++ * no next entry, or a negative error code otherwise.
++ */
++static int tnc_next(struct ubifs_info *c, struct ubifs_znode **zn, int *n)
++{
++	struct ubifs_znode *znode = *zn;
++	int nn = *n;
++
++	nn += 1;
++	if (nn < znode->child_cnt) {
++		*n = nn;
++		return 0;
++	}
++	while (1) {
++		struct ubifs_znode *zp;
++
++		zp = znode->parent;
++		if (!zp)
++			return -ENOENT;
++		nn = znode->iip + 1;
++		znode = zp;
++		if (nn < znode->child_cnt) {
++			znode = get_znode(c, znode, nn);
++			if (IS_ERR(znode))
++				return PTR_ERR(znode);
++			while (znode->level != 0) {
++				znode = get_znode(c, znode, 0);
++				if (IS_ERR(znode))
++					return PTR_ERR(znode);
++			}
++			nn = 0;
++			break;
++		}
++	}
++	*zn = znode;
++	*n = nn;
++	return 0;
++}
++
++/**
++ * tnc_prev - find previous TNC entry.
++ * @c: UBIFS file-system description object
++ * @zn: znode is returned here
++ * @n: znode branch slot number is passed and returned here
++ *
++ * This function returns %0 if the previous TNC entry is found, %-ENOENT if
++ * there is no next entry, or a negative error code otherwise.
++ */
++static int tnc_prev(struct ubifs_info *c, struct ubifs_znode **zn, int *n)
++{
++	struct ubifs_znode *znode = *zn;
++	int nn = *n;
++
++	if (nn > 0) {
++		*n = nn - 1;
++		return 0;
++	}
++	while (1) {
++		struct ubifs_znode *zp;
++
++		zp = znode->parent;
++		if (!zp)
++			return -ENOENT;
++		nn = znode->iip - 1;
++		znode = zp;
++		if (nn >= 0) {
++			znode = get_znode(c, znode, nn);
++			if (IS_ERR(znode))
++				return PTR_ERR(znode);
++			while (znode->level != 0) {
++				nn = znode->child_cnt - 1;
++				znode = get_znode(c, znode, nn);
++				if (IS_ERR(znode))
++					return PTR_ERR(znode);
++			}
++			nn = znode->child_cnt - 1;
++			break;
++		}
++	}
++	*zn = znode;
++	*n = nn;
++	return 0;
++}
++
++/**
++ * resolve_collision - resolve a collision.
++ * @c: UBIFS file-system description object
++ * @key: key of a directory or extended attribute entry
++ * @zn: znode is returned here
++ * @n: zbranch number is passed and returned here
++ * @nm: name of the entry
++ *
++ * This function is called for "hashed" keys to make sure that the found key
++ * really corresponds to the looked up node (directory or extended attribute
++ * entry). It returns %1 and sets @zn and @n if the collision is resolved.
++ * %0 is returned if @nm is not found and @zn and @n are set to the previous
++ * entry, i.e. to the entry after which @nm could follow if it were in TNC.
++ * This means that @n may be set to %-1 if the leftmost key in @zn is the
++ * previous one. A negative error code is returned on failures.
++ */
++static int resolve_collision(struct ubifs_info *c, const union ubifs_key *key,
++			     struct ubifs_znode **zn, int *n,
++			     const struct qstr *nm)
++{
++	int err;
++
++	err = matches_name(c, &(*zn)->zbranch[*n], nm);
++	if (unlikely(err < 0))
++		return err;
++	if (err == NAME_MATCHES)
++		return 1;
++
++	if (err == NAME_GREATER) {
++		/* Look left */
++		while (1) {
++			err = tnc_prev(c, zn, n);
++			if (err == -ENOENT) {
++				ubifs_assert(*n == 0);
++				*n = -1;
++				return 0;
++			}
++			if (err < 0)
++				return err;
++			if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) {
++				/*
++				 * We have found the branch after which we would
++				 * like to insert, but inserting in this znode
++				 * may still be wrong. Consider the following 3
++				 * znodes, in the case where we are resolving a
++				 * collision with Key2.
++				 *
++				 *                  znode zp
++				 *            ----------------------
++				 * level 1     |  Key0  |  Key1  |
++				 *            -----------------------
++				 *                 |            |
++				 *       znode za  |            |  znode zb
++				 *          ------------      ------------
++				 * level 0  |  Key0  |        |  Key2  |
++				 *          ------------      ------------
++				 *
++				 * The lookup finds Key2 in znode zb. Lets say
++				 * there is no match and the name is greater so
++				 * we look left. When we find Key0, we end up
++				 * here. If we return now, we will insert into
++				 * znode za at slot n = 1.  But that is invalid
++				 * according to the parent's keys.  Key2 must
++				 * be inserted into znode zb.
++				 *
++				 * Note, this problem is not relevant for the
++				 * case when we go right, because
++				 * 'tnc_insert()' would correct the parent key.
++				 */
++				if (*n == (*zn)->child_cnt - 1) {
++					err = tnc_next(c, zn, n);
++					if (err) {
++						/* Should be impossible */
++						ubifs_assert(0);
++						if (err == -ENOENT)
++							err = -EINVAL;
++						return err;
++					}
++					ubifs_assert(*n == 0);
++					*n = -1;
++				}
++				return 0;
++			}
++			err = matches_name(c, &(*zn)->zbranch[*n], nm);
++			if (err < 0)
++				return err;
++			if (err == NAME_LESS)
++				return 0;
++			if (err == NAME_MATCHES)
++				return 1;
++			ubifs_assert(err == NAME_GREATER);
++		}
++	} else {
++		int nn = *n;
++		struct ubifs_znode *znode = *zn;
++
++		/* Look right */
++		while (1) {
++			err = tnc_next(c, &znode, &nn);
++			if (err == -ENOENT)
++				return 0;
++			if (err < 0)
++				return err;
++			if (keys_cmp(c, &znode->zbranch[nn].key, key))
++				return 0;
++			err = matches_name(c, &znode->zbranch[nn], nm);
++			if (err < 0)
++				return err;
++			if (err == NAME_GREATER)
++				return 0;
++			*zn = znode;
++			*n = nn;
++			if (err == NAME_MATCHES)
++				return 1;
++			ubifs_assert(err == NAME_LESS);
++		}
++	}
++}
++
++/**
++ * fallible_matches_name - determine if a dent matches a given name.
++ * @c: UBIFS file-system description object
++ * @zbr: zbranch of dent
++ * @nm: name to match
++ *
++ * This is a "fallible" version of 'matches_name()' function which does not
++ * panic if the direntry/xentry referred by @zbr does not exist on the media.
++ *
++ * This function checks if xentry/direntry referred by zbranch @zbr matches name
++ * @nm. Returns %NAME_MATCHES it does, %NAME_LESS if the name referred by @zbr
++ * is less than @nm, %NAME_GREATER if it is greater than @nm, and @NOT_ON_MEDIA
++ * if xentry/direntry referred by @zbr does not exist on the media. A negative
++ * error code is returned in case of failure.
++ */
++static int fallible_matches_name(struct ubifs_info *c,
++				 struct ubifs_zbranch *zbr,
++				 const struct qstr *nm)
++{
++	struct ubifs_dent_node *dent;
++	int nlen, err;
++
++	/* If possible, match against the dent in the leaf node cache */
++	if (!zbr->leaf) {
++		dent = kmalloc(zbr->len, GFP_NOFS);
++		if (!dent)
++			return -ENOMEM;
++
++		err = fallible_read_node(c, &zbr->key, zbr, dent);
++		if (err < 0)
++			goto out_free;
++		if (err == 0) {
++			/* The node was not present */
++			err = NOT_ON_MEDIA;
++			goto out_free;
++		}
++		ubifs_assert(err == 1);
++
++		err = lnc_add_directly(c, zbr, dent);
++		if (err)
++			goto out_free;
++	} else
++		dent = zbr->leaf;
++
++	nlen = le16_to_cpu(dent->nlen);
++	err = memcmp(dent->name, nm->name, min_t(int, nlen, nm->len));
++	if (err == 0) {
++		if (nlen == nm->len)
++			return NAME_MATCHES;
++		else if (nlen < nm->len)
++			return NAME_LESS;
++		else
++			return NAME_GREATER;
++	} else if (err < 0)
++		return NAME_LESS;
++	else
++		return NAME_GREATER;
++
++out_free:
++	kfree(dent);
++	return err;
++}
++
++/**
++ * fallible_resolve_collision - resolve a collision even if nodes are missing.
++ * @c: UBIFS file-system description object
++ * @key: key
++ * @zn: znode is returned here
++ * @n: branch number is passed and returned here
++ * @nm: name of directory entry
++ * @adding: indicates caller is adding a key to the TNC
++ *
++ * This is a "fallible" version of the 'resolve_collision()' function which
++ * does not panic if one of the nodes referred to by TNC does not exist on the
++ * media. This may happen when replaying the journal if a deleted node was
++ * Garbage-collected and the commit was not done. A branch that refers to a node
++ * that is not present is called a dangling branch. The following are the return
++ * codes for this function:
++ *  o if @nm was found, %1 is returned and @zn and @n are set to the found
++ *    branch;
++ *  o if we are @adding and @nm was not found, %0 is returned;
++ *  o if we are not @adding and @nm was not found, but a dangling branch was
++ *    found, then %1 is returned and @zn and @n are set to the dangling branch;
++ *  o a negative error code is returned in case of failure.
++ */
++static int fallible_resolve_collision(struct ubifs_info *c,
++				      const union ubifs_key *key,
++				      struct ubifs_znode **zn, int *n,
++				      const struct qstr *nm, int adding)
++{
++	struct ubifs_znode *o_znode = NULL, *znode = *zn;
++	int uninitialized_var(o_n), err, cmp, unsure = 0, nn = *n;
++
++	cmp = fallible_matches_name(c, &znode->zbranch[nn], nm);
++	if (unlikely(cmp < 0))
++		return cmp;
++	if (cmp == NAME_MATCHES)
++		return 1;
++	if (cmp == NOT_ON_MEDIA) {
++		o_znode = znode;
++		o_n = nn;
++		/*
++		 * We are unlucky and hit a dangling branch straight away.
++		 * Now we do not really know where to go to find the needed
++		 * branch - to the left or to the right. Well, let's try left.
++		 */
++		unsure = 1;
++	} else if (!adding)
++		unsure = 1; /* Remove a dangling branch wherever it is */
++
++	if (cmp == NAME_GREATER || unsure) {
++		/* Look left */
++		while (1) {
++			err = tnc_prev(c, zn, n);
++			if (err == -ENOENT) {
++				ubifs_assert(*n == 0);
++				*n = -1;
++				break;
++			}
++			if (err < 0)
++				return err;
++			if (keys_cmp(c, &(*zn)->zbranch[*n].key, key)) {
++				/* See comments in 'resolve_collision()' */
++				if (*n == (*zn)->child_cnt - 1) {
++					err = tnc_next(c, zn, n);
++					if (err) {
++						/* Should be impossible */
++						ubifs_assert(0);
++						if (err == -ENOENT)
++							err = -EINVAL;
++						return err;
++					}
++					ubifs_assert(*n == 0);
++					*n = -1;
++				}
++				break;
++			}
++			err = fallible_matches_name(c, &(*zn)->zbranch[*n], nm);
++			if (err < 0)
++				return err;
++			if (err == NAME_MATCHES)
++				return 1;
++			if (err == NOT_ON_MEDIA) {
++				o_znode = *zn;
++				o_n = *n;
++				continue;
++			}
++			if (!adding)
++				continue;
++			if (err == NAME_LESS)
++				break;
++			else
++				unsure = 0;
++		}
++	}
++
++	if (cmp == NAME_LESS || unsure) {
++		/* Look right */
++		*zn = znode;
++		*n = nn;
++		while (1) {
++			err = tnc_next(c, &znode, &nn);
++			if (err == -ENOENT)
++				break;
++			if (err < 0)
++				return err;
++			if (keys_cmp(c, &znode->zbranch[nn].key, key))
++				break;
++			err = fallible_matches_name(c, &znode->zbranch[nn], nm);
++			if (err < 0)
++				return err;
++			if (err == NAME_GREATER)
++				break;
++			*zn = znode;
++			*n = nn;
++			if (err == NAME_MATCHES)
++				return 1;
++			if (err == NOT_ON_MEDIA) {
++				o_znode = znode;
++				o_n = nn;
++			}
++		}
++	}
++
++	/* Never match a dangling branch when adding */
++	if (adding || !o_znode)
++		return 0;
++
++	dbg_mnt("dangling match LEB %d:%d len %d %s",
++		o_znode->zbranch[o_n].lnum, o_znode->zbranch[o_n].offs,
++		o_znode->zbranch[o_n].len, DBGKEY(key));
++	*zn = o_znode;
++	*n = o_n;
++	return 1;
++}
++
++/**
++ * matches_position - determine if a zbranch matches a given position.
++ * @zbr: zbranch of dent
++ * @lnum: LEB number of dent to match
++ * @offs: offset of dent to match
++ *
++ * This function returns %1 if @lnum:@offs matches, and %0 otherwise.
++ */
++static int matches_position(struct ubifs_zbranch *zbr, int lnum, int offs)
++{
++	if (zbr->lnum == lnum && zbr->offs == offs)
++		return 1;
++	else
++		return 0;
++}
++
++/**
++ * resolve_collision_directly - resolve a collision directly.
++ * @c: UBIFS file-system description object
++ * @key: key of directory entry
++ * @zn: znode is passed and returned here
++ * @n: zbranch number is passed and returned here
++ * @lnum: LEB number of dent node to match
++ * @offs: offset of dent node to match
++ *
++ * This function is used for "hashed" keys to make sure the found directory or
++ * extended attribute entry node is what was looked for. It is used when the
++ * flash address of the right node is known (@lnum:@offs) which makes it much
++ * easier to resolve collisions (no need to read entries and match full
++ * names). This function returns %1 and sets @zn and @n if the collision is
++ * resolved, %0 if @lnum:@offs is not found and @zn and @n are set to the
++ * previous directory entry. Otherwise a negative error code is returned.
++ */
++static int resolve_collision_directly(struct ubifs_info *c,
++				      const union ubifs_key *key,
++				      struct ubifs_znode **zn, int *n,
++				      int lnum, int offs)
++{
++	struct ubifs_znode *znode;
++	int nn, err;
++
++	znode = *zn;
++	nn = *n;
++	if (matches_position(&znode->zbranch[nn], lnum, offs))
++		return 1;
++
++	/* Look left */
++	while (1) {
++		err = tnc_prev(c, &znode, &nn);
++		if (err == -ENOENT)
++			break;
++		if (err < 0)
++			return err;
++		if (keys_cmp(c, &znode->zbranch[nn].key, key))
++			break;
++		if (matches_position(&znode->zbranch[nn], lnum, offs)) {
++			*zn = znode;
++			*n = nn;
++			return 1;
++		}
++	}
++
++	/* Look right */
++	znode = *zn;
++	nn = *n;
++	while (1) {
++		err = tnc_next(c, &znode, &nn);
++		if (err == -ENOENT)
++			return 0;
++		if (err < 0)
++			return err;
++		if (keys_cmp(c, &znode->zbranch[nn].key, key))
++			return 0;
++		*zn = znode;
++		*n = nn;
++		if (matches_position(&znode->zbranch[nn], lnum, offs))
++			return 1;
++	}
++}
++
++/**
++ * dirty_cow_bottom_up - dirty a znode and its ancestors.
++ * @c: UBIFS file-system description object
++ * @znode: znode to dirty
++ *
++ * If we do not have a unique key that resides in a znode, then we cannot
++ * dirty that znode from the top down (i.e. by using lookup_level0_dirty)
++ * This function records the path back to the last dirty ancestor, and then
++ * dirties the znodes on that path.
++ */
++static struct ubifs_znode *dirty_cow_bottom_up(struct ubifs_info *c,
++					       struct ubifs_znode *znode)
++{
++	struct ubifs_znode *zp;
++	int *path = c->bottom_up_buf, p = 0;
++
++	ubifs_assert(c->zroot.znode);
++	ubifs_assert(znode);
++	if (c->zroot.znode->level > BOTTOM_UP_HEIGHT) {
++		kfree(c->bottom_up_buf);
++		c->bottom_up_buf = kmalloc(c->zroot.znode->level * sizeof(int),
++					   GFP_NOFS);
++		if (!c->bottom_up_buf)
++			return ERR_PTR(-ENOMEM);
++		path = c->bottom_up_buf;
++	}
++	if (c->zroot.znode->level) {
++		/* Go up until parent is dirty */
++		while (1) {
++			int n;
++
++			zp = znode->parent;
++			if (!zp)
++				break;
++			n = znode->iip;
++			ubifs_assert(p < c->zroot.znode->level);
++			path[p++] = n;
++			if (!zp->cnext && ubifs_zn_dirty(znode))
++				break;
++			znode = zp;
++		}
++	}
++
++	/* Come back down, dirtying as we go */
++	while (1) {
++		struct ubifs_zbranch *zbr;
++
++		zp = znode->parent;
++		if (zp) {
++			ubifs_assert(path[p - 1] >= 0);
++			ubifs_assert(path[p - 1] < zp->child_cnt);
++			zbr = &zp->zbranch[path[--p]];
++			znode = dirty_cow_znode(c, zbr);
++		} else {
++			ubifs_assert(znode == c->zroot.znode);
++			znode = dirty_cow_znode(c, &c->zroot);
++		}
++		if (IS_ERR(znode) || !p)
++			break;
++		ubifs_assert(path[p - 1] >= 0);
++		ubifs_assert(path[p - 1] < znode->child_cnt);
++		znode = znode->zbranch[path[p - 1]].znode;
++	}
++
++	return znode;
++}
++
++/**
++ * ubifs_lookup_level0 - search for zero-level znode.
++ * @c: UBIFS file-system description object
++ * @key:  key to lookup
++ * @zn: znode is returned here
++ * @n: znode branch slot number is returned here
++ *
++ * This function looks up the TNC tree and search for zero-level znode which
++ * refers key @key. The found zero-level znode is returned in @zn. There are 3
++ * cases:
++ *   o exact match, i.e. the found zero-level znode contains key @key, then %1
++ *     is returned and slot number of the matched branch is stored in @n;
++ *   o not exact match, which means that zero-level znode does not contain
++ *     @key, then %0 is returned and slot number of the closed branch is stored
++ *     in  @n;
++ *   o @key is so small that it is even less than the lowest key of the
++ *     leftmost zero-level node, then %0 is returned and %0 is stored in @n.
++ *
++ * Note, when the TNC tree is traversed, some znodes may be absent, then this
++ * function reads corresponding indexing nodes and inserts them to TNC. In
++ * case of failure, a negative error code is returned.
++ */
++int ubifs_lookup_level0(struct ubifs_info *c, const union ubifs_key *key,
++			struct ubifs_znode **zn, int *n)
++{
++	int err, exact;
++	struct ubifs_znode *znode;
++	unsigned long time = get_seconds();
++
++	dbg_tnc("search key %s", DBGKEY(key));
++
++	znode = c->zroot.znode;
++	if (unlikely(!znode)) {
++		znode = ubifs_load_znode(c, &c->zroot, NULL, 0);
++		if (IS_ERR(znode))
++			return PTR_ERR(znode);
++	}
++
++	znode->time = time;
++
++	while (1) {
++		struct ubifs_zbranch *zbr;
++
++		exact = ubifs_search_zbranch(c, znode, key, n);
++
++		if (znode->level == 0)
++			break;
++
++		if (*n < 0)
++			*n = 0;
++		zbr = &znode->zbranch[*n];
++
++		if (zbr->znode) {
++			znode->time = time;
++			znode = zbr->znode;
++			continue;
++		}
++
++		/* znode is not in TNC cache, load it from the media */
++		znode = ubifs_load_znode(c, zbr, znode, *n);
++		if (IS_ERR(znode))
++			return PTR_ERR(znode);
++	}
++
++	*zn = znode;
++	if (exact || !is_hash_key(c, key) || *n != -1) {
++		dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n);
++		return exact;
++	}
++
++	/*
++	 * Here is a tricky place. We have not found the key and this is a
++	 * "hashed" key, which may collide. The rest of the code deals with
++	 * situations like this:
++	 *
++	 *                  | 3 | 5 |
++	 *                  /       \
++	 *          | 3 | 5 |      | 6 | 7 | (x)
++	 *
++	 * Or more a complex example:
++	 *
++	 *                | 1 | 5 |
++	 *                /       \
++	 *       | 1 | 3 |         | 5 | 8 |
++	 *              \           /
++	 *          | 5 | 5 |   | 6 | 7 | (x)
++	 *
++	 * In the examples, if we are looking for key "5", we may reach nodes
++	 * marked with "(x)". In this case what we have do is to look at the
++	 * left and see if there is "5" key there. If there is, we have to
++	 * return it.
++	 *
++	 * Note, this whole situation is possible because we allow to have
++	 * elements which are equivalent to the next key in the parent in the
++	 * children of current znode. For example, this happens if we split a
++	 * znode like this: | 3 | 5 | 5 | 6 | 7 |, which results in something
++	 * like this:
++	 *                      | 3 | 5 |
++	 *                       /     \
++	 *                | 3 | 5 |   | 5 | 6 | 7 |
++	 *                              ^
++	 * And this becomes what is at the first "picture" after key "5" marked
++	 * with "^" is removed. What could be done is we could prohibit
++	 * splitting in the middle of the colliding sequence. Also, when
++	 * removing the leftmost key, we would have to correct the key of the
++	 * parent node, which would introduce additional complications. Namely,
++	 * if we changed the the leftmost key of the parent znode, the garbage
++	 * collector would be unable to find it (GC is doing this when GC'ing
++	 * indexing LEBs). Although we already have an additional RB-tree where
++	 * we save such changed znodes (see 'ins_clr_old_idx_znode()') until
++	 * after the commit. But anyway, this does not look easy to implement
++	 * so we did not try this.
++	 */
++	err = tnc_prev(c, &znode, n);
++	if (err == -ENOENT) {
++		dbg_tnc("found 0, lvl %d, n -1", znode->level);
++		*n = -1;
++		return 0;
++	}
++	if (unlikely(err < 0))
++		return err;
++	if (keys_cmp(c, key, &znode->zbranch[*n].key)) {
++		dbg_tnc("found 0, lvl %d, n -1", znode->level);
++		*n = -1;
++		return 0;
++	}
++
++	dbg_tnc("found 1, lvl %d, n %d", znode->level, *n);
++	*zn = znode;
++	return 1;
++}
++
++/**
++ * lookup_level0_dirty - search for zero-level znode dirtying.
++ * @c: UBIFS file-system description object
++ * @key:  key to lookup
++ * @zn: znode is returned here
++ * @n: znode branch slot number is returned here
++ *
++ * This function looks up the TNC tree and search for zero-level znode which
++ * refers key @key. The found zero-level znode is returned in @zn. There are 3
++ * cases:
++ *   o exact match, i.e. the found zero-level znode contains key @key, then %1
++ *     is returned and slot number of the matched branch is stored in @n;
++ *   o not exact match, which means that zero-level znode does not contain @key
++ *     then %0 is returned and slot number of the closed branch is stored in
++ *     @n;
++ *   o @key is so small that it is even less than the lowest key of the
++ *     leftmost zero-level node, then %0 is returned and %-1 is stored in @n.
++ *
++ * Additionally all znodes in the path from the root to the located zero-level
++ * znode are marked as dirty.
++ *
++ * Note, when the TNC tree is traversed, some znodes may be absent, then this
++ * function reads corresponding indexing nodes and inserts them to TNC. In
++ * case of failure, a negative error code is returned.
++ */
++static int lookup_level0_dirty(struct ubifs_info *c, const union ubifs_key *key,
++			       struct ubifs_znode **zn, int *n)
++{
++	int err, exact;
++	struct ubifs_znode *znode;
++	unsigned long time = get_seconds();
++
++	dbg_tnc("search and dirty key %s", DBGKEY(key));
++
++	znode = c->zroot.znode;
++	if (unlikely(!znode)) {
++		znode = ubifs_load_znode(c, &c->zroot, NULL, 0);
++		if (IS_ERR(znode))
++			return PTR_ERR(znode);
++	}
++
++	znode = dirty_cow_znode(c, &c->zroot);
++	if (IS_ERR(znode))
++		return PTR_ERR(znode);
++
++	znode->time = time;
++
++	while (1) {
++		struct ubifs_zbranch *zbr;
++
++		exact = ubifs_search_zbranch(c, znode, key, n);
++
++		if (znode->level == 0)
++			break;
++
++		if (*n < 0)
++			*n = 0;
++		zbr = &znode->zbranch[*n];
++
++		if (zbr->znode) {
++			znode->time = time;
++			znode = dirty_cow_znode(c, zbr);
++			if (IS_ERR(znode))
++				return PTR_ERR(znode);
++			continue;
++		}
++
++		/* znode is not in TNC cache, load it from the media */
++		znode = ubifs_load_znode(c, zbr, znode, *n);
++		if (IS_ERR(znode))
++			return PTR_ERR(znode);
++		znode = dirty_cow_znode(c, zbr);
++		if (IS_ERR(znode))
++			return PTR_ERR(znode);
++	}
++
++	*zn = znode;
++	if (exact || !is_hash_key(c, key) || *n != -1) {
++		dbg_tnc("found %d, lvl %d, n %d", exact, znode->level, *n);
++		return exact;
++	}
++
++	/*
++	 * See huge comment at 'lookup_level0_dirty()' what is the rest of the
++	 * code.
++	 */
++	err = tnc_prev(c, &znode, n);
++	if (err == -ENOENT) {
++		*n = -1;
++		dbg_tnc("found 0, lvl %d, n -1", znode->level);
++		return 0;
++	}
++	if (unlikely(err < 0))
++		return err;
++	if (keys_cmp(c, key, &znode->zbranch[*n].key)) {
++		*n = -1;
++		dbg_tnc("found 0, lvl %d, n -1", znode->level);
++		return 0;
++	}
++
++	if (znode->cnext || !ubifs_zn_dirty(znode)) {
++		znode = dirty_cow_bottom_up(c, znode);
++		if (IS_ERR(znode))
++			return PTR_ERR(znode);
++	}
++
++	dbg_tnc("found 1, lvl %d, n %d", znode->level, *n);
++	*zn = znode;
++	return 1;
++}
++
++/**
++ * maybe_leb_gced - determine if a LEB may have been garbage collected.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number
++ * @gc_seq1: garbage collection sequence number
++ *
++ * This function determines if @lnum may have been garbage collected since
++ * sequence number @gc_seq1. If it may have been then %1 is returned, otherwise
++ * %0 is returned.
++ */
++static int maybe_leb_gced(struct ubifs_info *c, int lnum, int gc_seq1)
++{
++	int gc_seq2, gced_lnum;
++
++	gced_lnum = c->gced_lnum;
++	smp_rmb();
++	gc_seq2 = c->gc_seq;
++	/* Same seq means no GC */
++	if (gc_seq1 == gc_seq2)
++		return 0;
++	/* Different by more than 1 means we don't know */
++	if (gc_seq1 + 1 != gc_seq2)
++		return 1;
++	/*
++	 * We have seen the sequence number has increased by 1. Now we need to
++	 * be sure we read the right LEB number, so read it again.
++	 */
++	smp_rmb();
++	if (gced_lnum != c->gced_lnum)
++		return 1;
++	/* Finally we can check lnum */
++	if (gced_lnum == lnum)
++		return 1;
++	return 0;
++}
++
++/**
++ * ubifs_tnc_locate - look up a file-system node and return it and its location.
++ * @c: UBIFS file-system description object
++ * @key: node key to lookup
++ * @node: the node is returned here
++ * @lnum: LEB number is returned here
++ * @offs: offset is returned here
++ *
++ * This function look up and reads node with key @key. The caller has to make
++ * sure the @node buffer is large enough to fit the node. Returns zero in case
++ * of success, %-ENOENT if the node was not found, and a negative error code in
++ * case of failure. The node location can be returned in @lnum and @offs.
++ */
++int ubifs_tnc_locate(struct ubifs_info *c, const union ubifs_key *key,
++		     void *node, int *lnum, int *offs)
++{
++	int found, n, err, safely = 0, gc_seq1;
++	struct ubifs_znode *znode;
++	struct ubifs_zbranch zbr, *zt;
++
++again:
++	mutex_lock(&c->tnc_mutex);
++	found = ubifs_lookup_level0(c, key, &znode, &n);
++	if (!found) {
++		err = -ENOENT;
++		goto out;
++	} else if (found < 0) {
++		err = found;
++		goto out;
++	}
++	zt = &znode->zbranch[n];
++	if (lnum) {
++		*lnum = zt->lnum;
++		*offs = zt->offs;
++	}
++	if (is_hash_key(c, key)) {
++		/*
++		 * In this case the leaf node cache gets used, so we pass the
++		 * address of the zbranch and keep the mutex locked
++		 */
++		err = tnc_read_node_nm(c, zt, node);
++		goto out;
++	}
++	if (safely) {
++		err = ubifs_tnc_read_node(c, zt, node);
++		goto out;
++	}
++	/* Drop the TNC mutex prematurely and race with garbage collection */
++	zbr = znode->zbranch[n];
++	gc_seq1 = c->gc_seq;
++	mutex_unlock(&c->tnc_mutex);
++
++	if (ubifs_get_wbuf(c, zbr.lnum)) {
++		/* We do not GC journal heads */
++		err = ubifs_tnc_read_node(c, &zbr, node);
++		return err;
++	}
++
++	err = fallible_read_node(c, key, &zbr, node);
++	if (err <= 0 || maybe_leb_gced(c, zbr.lnum, gc_seq1)) {
++		/*
++		 * The node may have been GC'ed out from under us so try again
++		 * while keeping the TNC mutex locked.
++		 */
++		safely = 1;
++		goto again;
++	}
++	return 0;
++
++out:
++	mutex_unlock(&c->tnc_mutex);
++	return err;
++}
++
++/**
++ * ubifs_tnc_get_bu_keys - lookup keys for bulk-read.
++ * @c: UBIFS file-system description object
++ * @bu: bulk-read parameters and results
++ *
++ * Lookup consecutive data node keys for the same inode that reside
++ * consecutively in the same LEB. This function returns zero in case of success
++ * and a negative error code in case of failure.
++ *
++ * Note, if the bulk-read buffer length (@bu->buf_len) is known, this function
++ * makes sure bulk-read nodes fit the buffer. Otherwise, this function prepares
++ * maximum possible amount of nodes for bulk-read.
++ */
++int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu)
++{
++	int n, err = 0, lnum = -1, uninitialized_var(offs);
++	int uninitialized_var(len);
++	unsigned int block = key_block(c, &bu->key);
++	struct ubifs_znode *znode;
++
++	bu->cnt = 0;
++	bu->blk_cnt = 0;
++	bu->eof = 0;
++
++	mutex_lock(&c->tnc_mutex);
++	/* Find first key */
++	err = ubifs_lookup_level0(c, &bu->key, &znode, &n);
++	if (err < 0)
++		goto out;
++	if (err) {
++		/* Key found */
++		len = znode->zbranch[n].len;
++		/* The buffer must be big enough for at least 1 node */
++		if (len > bu->buf_len) {
++			err = -EINVAL;
++			goto out;
++		}
++		/* Add this key */
++		bu->zbranch[bu->cnt++] = znode->zbranch[n];
++		bu->blk_cnt += 1;
++		lnum = znode->zbranch[n].lnum;
++		offs = ALIGN(znode->zbranch[n].offs + len, 8);
++	}
++	while (1) {
++		struct ubifs_zbranch *zbr;
++		union ubifs_key *key;
++		unsigned int next_block;
++
++		/* Find next key */
++		err = tnc_next(c, &znode, &n);
++		if (err)
++			goto out;
++		zbr = &znode->zbranch[n];
++		key = &zbr->key;
++		/* See if there is another data key for this file */
++		if (key_inum(c, key) != key_inum(c, &bu->key) ||
++		    key_type(c, key) != UBIFS_DATA_KEY) {
++			err = -ENOENT;
++			goto out;
++		}
++		if (lnum < 0) {
++			/* First key found */
++			lnum = zbr->lnum;
++			offs = ALIGN(zbr->offs + zbr->len, 8);
++			len = zbr->len;
++			if (len > bu->buf_len) {
++				err = -EINVAL;
++				goto out;
++			}
++		} else {
++			/*
++			 * The data nodes must be in consecutive positions in
++			 * the same LEB.
++			 */
++			if (zbr->lnum != lnum || zbr->offs != offs)
++				goto out;
++			offs += ALIGN(zbr->len, 8);
++			len = ALIGN(len, 8) + zbr->len;
++			/* Must not exceed buffer length */
++			if (len > bu->buf_len)
++				goto out;
++		}
++		/* Allow for holes */
++		next_block = key_block(c, key);
++		bu->blk_cnt += (next_block - block - 1);
++		if (bu->blk_cnt >= UBIFS_MAX_BULK_READ)
++			goto out;
++		block = next_block;
++		/* Add this key */
++		bu->zbranch[bu->cnt++] = *zbr;
++		bu->blk_cnt += 1;
++		/* See if we have room for more */
++		if (bu->cnt >= UBIFS_MAX_BULK_READ)
++			goto out;
++		if (bu->blk_cnt >= UBIFS_MAX_BULK_READ)
++			goto out;
++	}
++out:
++	if (err == -ENOENT) {
++		bu->eof = 1;
++		err = 0;
++	}
++	bu->gc_seq = c->gc_seq;
++	mutex_unlock(&c->tnc_mutex);
++	if (err)
++		return err;
++	/*
++	 * An enormous hole could cause bulk-read to encompass too many
++	 * page cache pages, so limit the number here.
++	 */
++	if (bu->blk_cnt > UBIFS_MAX_BULK_READ)
++		bu->blk_cnt = UBIFS_MAX_BULK_READ;
++	/*
++	 * Ensure that bulk-read covers a whole number of page cache
++	 * pages.
++	 */
++	if (UBIFS_BLOCKS_PER_PAGE == 1 ||
++	    !(bu->blk_cnt & (UBIFS_BLOCKS_PER_PAGE - 1)))
++		return 0;
++	if (bu->eof) {
++		/* At the end of file we can round up */
++		bu->blk_cnt += UBIFS_BLOCKS_PER_PAGE - 1;
++		return 0;
++	}
++	/* Exclude data nodes that do not make up a whole page cache page */
++	block = key_block(c, &bu->key) + bu->blk_cnt;
++	block &= ~(UBIFS_BLOCKS_PER_PAGE - 1);
++	while (bu->cnt) {
++		if (key_block(c, &bu->zbranch[bu->cnt - 1].key) < block)
++			break;
++		bu->cnt -= 1;
++	}
++	return 0;
++}
++
++/**
++ * read_wbuf - bulk-read from a LEB with a wbuf.
++ * @wbuf: wbuf that may overlap the read
++ * @buf: buffer into which to read
++ * @len: read length
++ * @lnum: LEB number from which to read
++ * @offs: offset from which to read
++ *
++ * This functions returns %0 on success or a negative error code on failure.
++ */
++static int read_wbuf(struct ubifs_wbuf *wbuf, void *buf, int len, int lnum,
++		     int offs)
++{
++	const struct ubifs_info *c = wbuf->c;
++	int rlen, overlap;
++
++	dbg_io("LEB %d:%d, length %d", lnum, offs, len);
++	ubifs_assert(wbuf && lnum >= 0 && lnum < c->leb_cnt && offs >= 0);
++	ubifs_assert(!(offs & 7) && offs < c->leb_size);
++	ubifs_assert(offs + len <= c->leb_size);
++
++	spin_lock(&wbuf->lock);
++	overlap = (lnum == wbuf->lnum && offs + len > wbuf->offs);
++	if (!overlap) {
++		/* We may safely unlock the write-buffer and read the data */
++		spin_unlock(&wbuf->lock);
++		return ubi_read(c->ubi, lnum, buf, offs, len);
++	}
++
++	/* Don't read under wbuf */
++	rlen = wbuf->offs - offs;
++	if (rlen < 0)
++		rlen = 0;
++
++	/* Copy the rest from the write-buffer */
++	memcpy(buf + rlen, wbuf->buf + offs + rlen - wbuf->offs, len - rlen);
++	spin_unlock(&wbuf->lock);
++
++	if (rlen > 0)
++		/* Read everything that goes before write-buffer */
++		return ubi_read(c->ubi, lnum, buf, offs, rlen);
++
++	return 0;
++}
++
++/**
++ * validate_data_node - validate data nodes for bulk-read.
++ * @c: UBIFS file-system description object
++ * @buf: buffer containing data node to validate
++ * @zbr: zbranch of data node to validate
++ *
++ * This functions returns %0 on success or a negative error code on failure.
++ */
++static int validate_data_node(struct ubifs_info *c, void *buf,
++			      struct ubifs_zbranch *zbr)
++{
++	union ubifs_key key1;
++	struct ubifs_ch *ch = buf;
++	int err, len;
++
++	if (ch->node_type != UBIFS_DATA_NODE) {
++		ubifs_err("bad node type (%d but expected %d)",
++			  ch->node_type, UBIFS_DATA_NODE);
++		goto out_err;
++	}
++
++	err = ubifs_check_node(c, buf, zbr->lnum, zbr->offs, 0, 0);
++	if (err) {
++		ubifs_err("expected node type %d", UBIFS_DATA_NODE);
++		goto out;
++	}
++
++	len = le32_to_cpu(ch->len);
++	if (len != zbr->len) {
++		ubifs_err("bad node length %d, expected %d", len, zbr->len);
++		goto out_err;
++	}
++
++	/* Make sure the key of the read node is correct */
++	key_read(c, buf + UBIFS_KEY_OFFSET, &key1);
++	if (!keys_eq(c, &zbr->key, &key1)) {
++		ubifs_err("bad key in node at LEB %d:%d",
++			  zbr->lnum, zbr->offs);
++		dbg_tnc("looked for key %s found node's key %s",
++			DBGKEY(&zbr->key), DBGKEY1(&key1));
++		goto out_err;
++	}
++
++	return 0;
++
++out_err:
++	err = -EINVAL;
++out:
++	ubifs_err("bad node at LEB %d:%d", zbr->lnum, zbr->offs);
++	dbg_dump_node(c, buf);
++	dbg_dump_stack();
++	return err;
++}
++
++/**
++ * ubifs_tnc_bulk_read - read a number of data nodes in one go.
++ * @c: UBIFS file-system description object
++ * @bu: bulk-read parameters and results
++ *
++ * This functions reads and validates the data nodes that were identified by the
++ * 'ubifs_tnc_get_bu_keys()' function. This functions returns %0 on success,
++ * -EAGAIN to indicate a race with GC, or another negative error code on
++ * failure.
++ */
++int ubifs_tnc_bulk_read(struct ubifs_info *c, struct bu_info *bu)
++{
++	int lnum = bu->zbranch[0].lnum, offs = bu->zbranch[0].offs, len, err, i;
++	struct ubifs_wbuf *wbuf;
++	void *buf;
++
++	len = bu->zbranch[bu->cnt - 1].offs;
++	len += bu->zbranch[bu->cnt - 1].len - offs;
++	if (len > bu->buf_len) {
++		ubifs_err("buffer too small %d vs %d", bu->buf_len, len);
++		return -EINVAL;
++	}
++
++	/* Do the read */
++	wbuf = ubifs_get_wbuf(c, lnum);
++	if (wbuf)
++		err = read_wbuf(wbuf, bu->buf, len, lnum, offs);
++	else
++		err = ubi_read(c->ubi, lnum, bu->buf, offs, len);
++
++	/* Check for a race with GC */
++	if (maybe_leb_gced(c, lnum, bu->gc_seq))
++		return -EAGAIN;
++
++	if (err && err != -EBADMSG) {
++		ubifs_err("failed to read from LEB %d:%d, error %d",
++			  lnum, offs, err);
++		dbg_dump_stack();
++		dbg_tnc("key %s", DBGKEY(&bu->key));
++		return err;
++	}
++
++	/* Validate the nodes read */
++	buf = bu->buf;
++	for (i = 0; i < bu->cnt; i++) {
++		err = validate_data_node(c, buf, &bu->zbranch[i]);
++		if (err)
++			return err;
++		buf = buf + ALIGN(bu->zbranch[i].len, 8);
++	}
++
++	return 0;
++}
++
++/**
++ * do_lookup_nm- look up a "hashed" node.
++ * @c: UBIFS file-system description object
++ * @key: node key to lookup
++ * @node: the node is returned here
++ * @nm: node name
++ *
++ * This function look up and reads a node which contains name hash in the key.
++ * Since the hash may have collisions, there may be many nodes with the same
++ * key, so we have to sequentially look to all of them until the needed one is
++ * found. This function returns zero in case of success, %-ENOENT if the node
++ * was not found, and a negative error code in case of failure.
++ */
++static int do_lookup_nm(struct ubifs_info *c, const union ubifs_key *key,
++			void *node, const struct qstr *nm)
++{
++	int found, n, err;
++	struct ubifs_znode *znode;
++
++	dbg_tnc("name '%.*s' key %s", nm->len, nm->name, DBGKEY(key));
++	mutex_lock(&c->tnc_mutex);
++	found = ubifs_lookup_level0(c, key, &znode, &n);
++	if (!found) {
++		err = -ENOENT;
++		goto out_unlock;
++	} else if (found < 0) {
++		err = found;
++		goto out_unlock;
++	}
++
++	ubifs_assert(n >= 0);
++
++	err = resolve_collision(c, key, &znode, &n, nm);
++	dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n);
++	if (unlikely(err < 0))
++		goto out_unlock;
++	if (err == 0) {
++		err = -ENOENT;
++		goto out_unlock;
++	}
++
++	err = tnc_read_node_nm(c, &znode->zbranch[n], node);
++
++out_unlock:
++	mutex_unlock(&c->tnc_mutex);
++	return err;
++}
++
++/**
++ * ubifs_tnc_lookup_nm - look up a "hashed" node.
++ * @c: UBIFS file-system description object
++ * @key: node key to lookup
++ * @node: the node is returned here
++ * @nm: node name
++ *
++ * This function look up and reads a node which contains name hash in the key.
++ * Since the hash may have collisions, there may be many nodes with the same
++ * key, so we have to sequentially look to all of them until the needed one is
++ * found. This function returns zero in case of success, %-ENOENT if the node
++ * was not found, and a negative error code in case of failure.
++ */
++int ubifs_tnc_lookup_nm(struct ubifs_info *c, const union ubifs_key *key,
++			void *node, const struct qstr *nm)
++{
++	int err, len;
++	const struct ubifs_dent_node *dent = node;
++
++	/*
++	 * We assume that in most of the cases there are no name collisions and
++	 * 'ubifs_tnc_lookup()' returns us the right direntry.
++	 */
++	err = ubifs_tnc_lookup(c, key, node);
++	if (err)
++		return err;
++
++	len = le16_to_cpu(dent->nlen);
++	if (nm->len == len && !memcmp(dent->name, nm->name, len))
++		return 0;
++
++	/*
++	 * Unluckily, there are hash collisions and we have to iterate over
++	 * them look at each direntry with colliding name hash sequentially.
++	 */
++	return do_lookup_nm(c, key, node, nm);
++}
++
++/**
++ * correct_parent_keys - correct parent znodes' keys.
++ * @c: UBIFS file-system description object
++ * @znode: znode to correct parent znodes for
++ *
++ * This is a helper function for 'tnc_insert()'. When the key of the leftmost
++ * zbranch changes, keys of parent znodes have to be corrected. This helper
++ * function is called in such situations and corrects the keys if needed.
++ */
++static void correct_parent_keys(const struct ubifs_info *c,
++				struct ubifs_znode *znode)
++{
++	union ubifs_key *key, *key1;
++
++	ubifs_assert(znode->parent);
++	ubifs_assert(znode->iip == 0);
++
++	key = &znode->zbranch[0].key;
++	key1 = &znode->parent->zbranch[0].key;
++
++	while (keys_cmp(c, key, key1) < 0) {
++		key_copy(c, key, key1);
++		znode = znode->parent;
++		znode->alt = 1;
++		if (!znode->parent || znode->iip)
++			break;
++		key1 = &znode->parent->zbranch[0].key;
++	}
++}
++
++/**
++ * insert_zbranch - insert a zbranch into a znode.
++ * @znode: znode into which to insert
++ * @zbr: zbranch to insert
++ * @n: slot number to insert to
++ *
++ * This is a helper function for 'tnc_insert()'. UBIFS does not allow "gaps" in
++ * znode's array of zbranches and keeps zbranches consolidated, so when a new
++ * zbranch has to be inserted to the @znode->zbranches[]' array at the @n-th
++ * slot, zbranches starting from @n have to be moved right.
++ */
++static void insert_zbranch(struct ubifs_znode *znode,
++			   const struct ubifs_zbranch *zbr, int n)
++{
++	int i;
++
++	ubifs_assert(ubifs_zn_dirty(znode));
++
++	if (znode->level) {
++		for (i = znode->child_cnt; i > n; i--) {
++			znode->zbranch[i] = znode->zbranch[i - 1];
++			if (znode->zbranch[i].znode)
++				znode->zbranch[i].znode->iip = i;
++		}
++		if (zbr->znode)
++			zbr->znode->iip = n;
++	} else
++		for (i = znode->child_cnt; i > n; i--)
++			znode->zbranch[i] = znode->zbranch[i - 1];
++
++	znode->zbranch[n] = *zbr;
++	znode->child_cnt += 1;
++
++	/*
++	 * After inserting at slot zero, the lower bound of the key range of
++	 * this znode may have changed. If this znode is subsequently split
++	 * then the upper bound of the key range may change, and furthermore
++	 * it could change to be lower than the original lower bound. If that
++	 * happens, then it will no longer be possible to find this znode in the
++	 * TNC using the key from the index node on flash. That is bad because
++	 * if it is not found, we will assume it is obsolete and may overwrite
++	 * it. Then if there is an unclean unmount, we will start using the
++	 * old index which will be broken.
++	 *
++	 * So we first mark znodes that have insertions at slot zero, and then
++	 * if they are split we add their lnum/offs to the old_idx tree.
++	 */
++	if (n == 0)
++		znode->alt = 1;
++}
++
++/**
++ * tnc_insert - insert a node into TNC.
++ * @c: UBIFS file-system description object
++ * @znode: znode to insert into
++ * @zbr: branch to insert
++ * @n: slot number to insert new zbranch to
++ *
++ * This function inserts a new node described by @zbr into znode @znode. If
++ * znode does not have a free slot for new zbranch, it is split. Parent znodes
++ * are splat as well if needed. Returns zero in case of success or a negative
++ * error code in case of failure.
++ */
++static int tnc_insert(struct ubifs_info *c, struct ubifs_znode *znode,
++		      struct ubifs_zbranch *zbr, int n)
++{
++	struct ubifs_znode *zn, *zi, *zp;
++	int i, keep, move, appending = 0;
++	union ubifs_key *key = &zbr->key, *key1;
++
++	ubifs_assert(n >= 0 && n <= c->fanout);
++
++	/* Implement naive insert for now */
++again:
++	zp = znode->parent;
++	if (znode->child_cnt < c->fanout) {
++		ubifs_assert(n != c->fanout);
++		dbg_tnc("inserted at %d level %d, key %s", n, znode->level,
++			DBGKEY(key));
++
++		insert_zbranch(znode, zbr, n);
++
++		/* Ensure parent's key is correct */
++		if (n == 0 && zp && znode->iip == 0)
++			correct_parent_keys(c, znode);
++
++		return 0;
++	}
++
++	/*
++	 * Unfortunately, @znode does not have more empty slots and we have to
++	 * split it.
++	 */
++	dbg_tnc("splitting level %d, key %s", znode->level, DBGKEY(key));
++
++	if (znode->alt)
++		/*
++		 * We can no longer be sure of finding this znode by key, so we
++		 * record it in the old_idx tree.
++		 */
++		ins_clr_old_idx_znode(c, znode);
++
++	zn = kzalloc(c->max_znode_sz, GFP_NOFS);
++	if (!zn)
++		return -ENOMEM;
++	zn->parent = zp;
++	zn->level = znode->level;
++
++	/* Decide where to split */
++	if (znode->level == 0 && key_type(c, key) == UBIFS_DATA_KEY) {
++		/* Try not to split consecutive data keys */
++		if (n == c->fanout) {
++			key1 = &znode->zbranch[n - 1].key;
++			if (key_inum(c, key1) == key_inum(c, key) &&
++			    key_type(c, key1) == UBIFS_DATA_KEY)
++				appending = 1;
++		} else
++			goto check_split;
++	} else if (appending && n != c->fanout) {
++		/* Try not to split consecutive data keys */
++		appending = 0;
++check_split:
++		if (n >= (c->fanout + 1) / 2) {
++			key1 = &znode->zbranch[0].key;
++			if (key_inum(c, key1) == key_inum(c, key) &&
++			    key_type(c, key1) == UBIFS_DATA_KEY) {
++				key1 = &znode->zbranch[n].key;
++				if (key_inum(c, key1) != key_inum(c, key) ||
++				    key_type(c, key1) != UBIFS_DATA_KEY) {
++					keep = n;
++					move = c->fanout - keep;
++					zi = znode;
++					goto do_split;
++				}
++			}
++		}
++	}
++
++	if (appending) {
++		keep = c->fanout;
++		move = 0;
++	} else {
++		keep = (c->fanout + 1) / 2;
++		move = c->fanout - keep;
++	}
++
++	/*
++	 * Although we don't at present, we could look at the neighbors and see
++	 * if we can move some zbranches there.
++	 */
++
++	if (n < keep) {
++		/* Insert into existing znode */
++		zi = znode;
++		move += 1;
++		keep -= 1;
++	} else {
++		/* Insert into new znode */
++		zi = zn;
++		n -= keep;
++		/* Re-parent */
++		if (zn->level != 0)
++			zbr->znode->parent = zn;
++	}
++
++do_split:
++
++	__set_bit(DIRTY_ZNODE, &zn->flags);
++	atomic_long_inc(&c->dirty_zn_cnt);
++
++	zn->child_cnt = move;
++	znode->child_cnt = keep;
++
++	dbg_tnc("moving %d, keeping %d", move, keep);
++
++	/* Move zbranch */
++	for (i = 0; i < move; i++) {
++		zn->zbranch[i] = znode->zbranch[keep + i];
++		/* Re-parent */
++		if (zn->level != 0)
++			if (zn->zbranch[i].znode) {
++				zn->zbranch[i].znode->parent = zn;
++				zn->zbranch[i].znode->iip = i;
++			}
++	}
++
++	/* Insert new key and branch */
++	dbg_tnc("inserting at %d level %d, key %s", n, zn->level, DBGKEY(key));
++
++	insert_zbranch(zi, zbr, n);
++
++	/* Insert new znode (produced by spitting) into the parent */
++	if (zp) {
++		if (n == 0 && zi == znode && znode->iip == 0)
++			correct_parent_keys(c, znode);
++
++		/* Locate insertion point */
++		n = znode->iip + 1;
++
++		/* Tail recursion */
++		zbr->key = zn->zbranch[0].key;
++		zbr->znode = zn;
++		zbr->lnum = 0;
++		zbr->offs = 0;
++		zbr->len = 0;
++		znode = zp;
++
++		goto again;
++	}
++
++	/* We have to split root znode */
++	dbg_tnc("creating new zroot at level %d", znode->level + 1);
++
++	zi = kzalloc(c->max_znode_sz, GFP_NOFS);
++	if (!zi)
++		return -ENOMEM;
++
++	zi->child_cnt = 2;
++	zi->level = znode->level + 1;
++
++	__set_bit(DIRTY_ZNODE, &zi->flags);
++	atomic_long_inc(&c->dirty_zn_cnt);
++
++	zi->zbranch[0].key = znode->zbranch[0].key;
++	zi->zbranch[0].znode = znode;
++	zi->zbranch[0].lnum = c->zroot.lnum;
++	zi->zbranch[0].offs = c->zroot.offs;
++	zi->zbranch[0].len = c->zroot.len;
++	zi->zbranch[1].key = zn->zbranch[0].key;
++	zi->zbranch[1].znode = zn;
++
++	c->zroot.lnum = 0;
++	c->zroot.offs = 0;
++	c->zroot.len = 0;
++	c->zroot.znode = zi;
++
++	zn->parent = zi;
++	zn->iip = 1;
++	znode->parent = zi;
++	znode->iip = 0;
++
++	return 0;
++}
++
++/**
++ * ubifs_tnc_add - add a node to TNC.
++ * @c: UBIFS file-system description object
++ * @key: key to add
++ * @lnum: LEB number of node
++ * @offs: node offset
++ * @len: node length
++ *
++ * This function adds a node with key @key to TNC. The node may be new or it may
++ * obsolete some existing one. Returns %0 on success or negative error code on
++ * failure.
++ */
++int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum,
++		  int offs, int len)
++{
++	int found, n, err = 0;
++	struct ubifs_znode *znode;
++
++	mutex_lock(&c->tnc_mutex);
++	dbg_tnc("%d:%d, len %d, key %s", lnum, offs, len, DBGKEY(key));
++	found = lookup_level0_dirty(c, key, &znode, &n);
++	if (!found) {
++		struct ubifs_zbranch zbr;
++
++		zbr.znode = NULL;
++		zbr.lnum = lnum;
++		zbr.offs = offs;
++		zbr.len = len;
++		key_copy(c, key, &zbr.key);
++		err = tnc_insert(c, znode, &zbr, n + 1);
++	} else if (found == 1) {
++		struct ubifs_zbranch *zbr = &znode->zbranch[n];
++
++		lnc_free(zbr);
++		err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
++		zbr->lnum = lnum;
++		zbr->offs = offs;
++		zbr->len = len;
++	} else
++		err = found;
++	if (!err)
++		err = dbg_check_tnc(c, 0);
++	mutex_unlock(&c->tnc_mutex);
++
++	return err;
++}
++
++/**
++ * ubifs_tnc_replace - replace a node in the TNC only if the old node is found.
++ * @c: UBIFS file-system description object
++ * @key: key to add
++ * @old_lnum: LEB number of old node
++ * @old_offs: old node offset
++ * @lnum: LEB number of node
++ * @offs: node offset
++ * @len: node length
++ *
++ * This function replaces a node with key @key in the TNC only if the old node
++ * is found.  This function is called by garbage collection when node are moved.
++ * Returns %0 on success or negative error code on failure.
++ */
++int ubifs_tnc_replace(struct ubifs_info *c, const union ubifs_key *key,
++		      int old_lnum, int old_offs, int lnum, int offs, int len)
++{
++	int found, n, err = 0;
++	struct ubifs_znode *znode;
++
++	mutex_lock(&c->tnc_mutex);
++	dbg_tnc("old LEB %d:%d, new LEB %d:%d, len %d, key %s", old_lnum,
++		old_offs, lnum, offs, len, DBGKEY(key));
++	found = lookup_level0_dirty(c, key, &znode, &n);
++	if (found < 0) {
++		err = found;
++		goto out_unlock;
++	}
++
++	if (found == 1) {
++		struct ubifs_zbranch *zbr = &znode->zbranch[n];
++
++		found = 0;
++		if (zbr->lnum == old_lnum && zbr->offs == old_offs) {
++			lnc_free(zbr);
++			err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
++			if (err)
++				goto out_unlock;
++			zbr->lnum = lnum;
++			zbr->offs = offs;
++			zbr->len = len;
++			found = 1;
++		} else if (is_hash_key(c, key)) {
++			found = resolve_collision_directly(c, key, &znode, &n,
++							   old_lnum, old_offs);
++			dbg_tnc("rc returned %d, znode %p, n %d, LEB %d:%d",
++				found, znode, n, old_lnum, old_offs);
++			if (found < 0) {
++				err = found;
++				goto out_unlock;
++			}
++
++			if (found) {
++				/* Ensure the znode is dirtied */
++				if (znode->cnext || !ubifs_zn_dirty(znode)) {
++					znode = dirty_cow_bottom_up(c, znode);
++					if (IS_ERR(znode)) {
++						err = PTR_ERR(znode);
++						goto out_unlock;
++					}
++				}
++				zbr = &znode->zbranch[n];
++				lnc_free(zbr);
++				err = ubifs_add_dirt(c, zbr->lnum,
++						     zbr->len);
++				if (err)
++					goto out_unlock;
++				zbr->lnum = lnum;
++				zbr->offs = offs;
++				zbr->len = len;
++			}
++		}
++	}
++
++	if (!found)
++		err = ubifs_add_dirt(c, lnum, len);
++
++	if (!err)
++		err = dbg_check_tnc(c, 0);
++
++out_unlock:
++	mutex_unlock(&c->tnc_mutex);
++	return err;
++}
++
++/**
++ * ubifs_tnc_add_nm - add a "hashed" node to TNC.
++ * @c: UBIFS file-system description object
++ * @key: key to add
++ * @lnum: LEB number of node
++ * @offs: node offset
++ * @len: node length
++ * @nm: node name
++ *
++ * This is the same as 'ubifs_tnc_add()' but it should be used with keys which
++ * may have collisions, like directory entry keys.
++ */
++int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key,
++		     int lnum, int offs, int len, const struct qstr *nm)
++{
++	int found, n, err = 0;
++	struct ubifs_znode *znode;
++
++	mutex_lock(&c->tnc_mutex);
++	dbg_tnc("LEB %d:%d, name '%.*s', key %s", lnum, offs, nm->len, nm->name,
++		DBGKEY(key));
++	found = lookup_level0_dirty(c, key, &znode, &n);
++	if (found < 0) {
++		err = found;
++		goto out_unlock;
++	}
++
++	if (found == 1) {
++		if (c->replaying)
++			found = fallible_resolve_collision(c, key, &znode, &n,
++							   nm, 1);
++		else
++			found = resolve_collision(c, key, &znode, &n, nm);
++		dbg_tnc("rc returned %d, znode %p, n %d", found, znode, n);
++		if (found < 0) {
++			err = found;
++			goto out_unlock;
++		}
++
++		/* Ensure the znode is dirtied */
++		if (znode->cnext || !ubifs_zn_dirty(znode)) {
++			znode = dirty_cow_bottom_up(c, znode);
++			if (IS_ERR(znode)) {
++				err = PTR_ERR(znode);
++				goto out_unlock;
++			}
++		}
++
++		if (found == 1) {
++			struct ubifs_zbranch *zbr = &znode->zbranch[n];
++
++			lnc_free(zbr);
++			err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
++			zbr->lnum = lnum;
++			zbr->offs = offs;
++			zbr->len = len;
++			goto out_unlock;
++		}
++	}
++
++	if (!found) {
++		struct ubifs_zbranch zbr;
++
++		zbr.znode = NULL;
++		zbr.lnum = lnum;
++		zbr.offs = offs;
++		zbr.len = len;
++		key_copy(c, key, &zbr.key);
++		err = tnc_insert(c, znode, &zbr, n + 1);
++		if (err)
++			goto out_unlock;
++		if (c->replaying) {
++			/*
++			 * We did not find it in the index so there may be a
++			 * dangling branch still in the index. So we remove it
++			 * by passing 'ubifs_tnc_remove_nm()' the same key but
++			 * an unmatchable name.
++			 */
++			struct qstr noname = { .len = 0, .name = "" };
++
++			err = dbg_check_tnc(c, 0);
++			mutex_unlock(&c->tnc_mutex);
++			if (err)
++				return err;
++			return ubifs_tnc_remove_nm(c, key, &noname);
++		}
++	}
++
++out_unlock:
++	if (!err)
++		err = dbg_check_tnc(c, 0);
++	mutex_unlock(&c->tnc_mutex);
++	return err;
++}
++
++/**
++ * tnc_delete - delete a znode form TNC.
++ * @c: UBIFS file-system description object
++ * @znode: znode to delete from
++ * @n: zbranch slot number to delete
++ *
++ * This function deletes a leaf node from @n-th slot of @znode. Returns zero in
++ * case of success and a negative error code in case of failure.
++ */
++static int tnc_delete(struct ubifs_info *c, struct ubifs_znode *znode, int n)
++{
++	struct ubifs_zbranch *zbr;
++	struct ubifs_znode *zp;
++	int i, err;
++
++	/* Delete without merge for now */
++	ubifs_assert(znode->level == 0);
++	ubifs_assert(n >= 0 && n < c->fanout);
++	dbg_tnc("deleting %s", DBGKEY(&znode->zbranch[n].key));
++
++	zbr = &znode->zbranch[n];
++	lnc_free(zbr);
++
++	err = ubifs_add_dirt(c, zbr->lnum, zbr->len);
++	if (err) {
++		dbg_dump_znode(c, znode);
++		return err;
++	}
++
++	/* We do not "gap" zbranch slots */
++	for (i = n; i < znode->child_cnt - 1; i++)
++		znode->zbranch[i] = znode->zbranch[i + 1];
++	znode->child_cnt -= 1;
++
++	if (znode->child_cnt > 0)
++		return 0;
++
++	/*
++	 * This was the last zbranch, we have to delete this znode from the
++	 * parent.
++	 */
++
++	do {
++		ubifs_assert(!test_bit(OBSOLETE_ZNODE, &znode->flags));
++		ubifs_assert(ubifs_zn_dirty(znode));
++
++		zp = znode->parent;
++		n = znode->iip;
++
++		atomic_long_dec(&c->dirty_zn_cnt);
++
++		err = insert_old_idx_znode(c, znode);
++		if (err)
++			return err;
++
++		if (znode->cnext) {
++			__set_bit(OBSOLETE_ZNODE, &znode->flags);
++			atomic_long_inc(&c->clean_zn_cnt);
++			atomic_long_inc(&ubifs_clean_zn_cnt);
++		} else
++			kfree(znode);
++		znode = zp;
++	} while (znode->child_cnt == 1); /* while removing last child */
++
++	/* Remove from znode, entry n - 1 */
++	znode->child_cnt -= 1;
++	ubifs_assert(znode->level != 0);
++	for (i = n; i < znode->child_cnt; i++) {
++		znode->zbranch[i] = znode->zbranch[i + 1];
++		if (znode->zbranch[i].znode)
++			znode->zbranch[i].znode->iip = i;
++	}
++
++	/*
++	 * If this is the root and it has only 1 child then
++	 * collapse the tree.
++	 */
++	if (!znode->parent) {
++		while (znode->child_cnt == 1 && znode->level != 0) {
++			zp = znode;
++			zbr = &znode->zbranch[0];
++			znode = get_znode(c, znode, 0);
++			if (IS_ERR(znode))
++				return PTR_ERR(znode);
++			znode = dirty_cow_znode(c, zbr);
++			if (IS_ERR(znode))
++				return PTR_ERR(znode);
++			znode->parent = NULL;
++			znode->iip = 0;
++			if (c->zroot.len) {
++				err = insert_old_idx(c, c->zroot.lnum,
++						     c->zroot.offs);
++				if (err)
++					return err;
++			}
++			c->zroot.lnum = zbr->lnum;
++			c->zroot.offs = zbr->offs;
++			c->zroot.len = zbr->len;
++			c->zroot.znode = znode;
++			ubifs_assert(!test_bit(OBSOLETE_ZNODE,
++				     &zp->flags));
++			ubifs_assert(test_bit(DIRTY_ZNODE, &zp->flags));
++			atomic_long_dec(&c->dirty_zn_cnt);
++
++			if (zp->cnext) {
++				__set_bit(OBSOLETE_ZNODE, &zp->flags);
++				atomic_long_inc(&c->clean_zn_cnt);
++				atomic_long_inc(&ubifs_clean_zn_cnt);
++			} else
++				kfree(zp);
++		}
++	}
++
++	return 0;
++}
++
++/**
++ * ubifs_tnc_remove - remove an index entry of a node.
++ * @c: UBIFS file-system description object
++ * @key: key of node
++ *
++ * Returns %0 on success or negative error code on failure.
++ */
++int ubifs_tnc_remove(struct ubifs_info *c, const union ubifs_key *key)
++{
++	int found, n, err = 0;
++	struct ubifs_znode *znode;
++
++	mutex_lock(&c->tnc_mutex);
++	dbg_tnc("key %s", DBGKEY(key));
++	found = lookup_level0_dirty(c, key, &znode, &n);
++	if (found < 0) {
++		err = found;
++		goto out_unlock;
++	}
++	if (found == 1)
++		err = tnc_delete(c, znode, n);
++	if (!err)
++		err = dbg_check_tnc(c, 0);
++
++out_unlock:
++	mutex_unlock(&c->tnc_mutex);
++	return err;
++}
++
++/**
++ * ubifs_tnc_remove_nm - remove an index entry for a "hashed" node.
++ * @c: UBIFS file-system description object
++ * @key: key of node
++ * @nm: directory entry name
++ *
++ * Returns %0 on success or negative error code on failure.
++ */
++int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key,
++			const struct qstr *nm)
++{
++	int n, err;
++	struct ubifs_znode *znode;
++
++	mutex_lock(&c->tnc_mutex);
++	dbg_tnc("%.*s, key %s", nm->len, nm->name, DBGKEY(key));
++	err = lookup_level0_dirty(c, key, &znode, &n);
++	if (err < 0)
++		goto out_unlock;
++
++	if (err) {
++		if (c->replaying)
++			err = fallible_resolve_collision(c, key, &znode, &n,
++							 nm, 0);
++		else
++			err = resolve_collision(c, key, &znode, &n, nm);
++		dbg_tnc("rc returned %d, znode %p, n %d", err, znode, n);
++		if (err < 0)
++			goto out_unlock;
++		if (err) {
++			/* Ensure the znode is dirtied */
++			if (znode->cnext || !ubifs_zn_dirty(znode)) {
++				    znode = dirty_cow_bottom_up(c, znode);
++				    if (IS_ERR(znode)) {
++					    err = PTR_ERR(znode);
++					    goto out_unlock;
++				    }
++			}
++			err = tnc_delete(c, znode, n);
++		}
++	}
++
++out_unlock:
++	if (!err)
++		err = dbg_check_tnc(c, 0);
++	mutex_unlock(&c->tnc_mutex);
++	return err;
++}
++
++/**
++ * key_in_range - determine if a key falls within a range of keys.
++ * @c: UBIFS file-system description object
++ * @key: key to check
++ * @from_key: lowest key in range
++ * @to_key: highest key in range
++ *
++ * This function returns %1 if the key is in range and %0 otherwise.
++ */
++static int key_in_range(struct ubifs_info *c, union ubifs_key *key,
++			union ubifs_key *from_key, union ubifs_key *to_key)
++{
++	if (keys_cmp(c, key, from_key) < 0)
++		return 0;
++	if (keys_cmp(c, key, to_key) > 0)
++		return 0;
++	return 1;
++}
++
++/**
++ * ubifs_tnc_remove_range - remove index entries in range.
++ * @c: UBIFS file-system description object
++ * @from_key: lowest key to remove
++ * @to_key: highest key to remove
++ *
++ * This function removes index entries starting at @from_key and ending at
++ * @to_key.  This function returns zero in case of success and a negative error
++ * code in case of failure.
++ */
++int ubifs_tnc_remove_range(struct ubifs_info *c, union ubifs_key *from_key,
++			   union ubifs_key *to_key)
++{
++	int i, n, k, err = 0;
++	struct ubifs_znode *znode;
++	union ubifs_key *key;
++
++	mutex_lock(&c->tnc_mutex);
++	while (1) {
++		/* Find first level 0 znode that contains keys to remove */
++		err = ubifs_lookup_level0(c, from_key, &znode, &n);
++		if (err < 0)
++			goto out_unlock;
++
++		if (err)
++			key = from_key;
++		else {
++			err = tnc_next(c, &znode, &n);
++			if (err == -ENOENT) {
++				err = 0;
++				goto out_unlock;
++			}
++			if (err < 0)
++				goto out_unlock;
++			key = &znode->zbranch[n].key;
++			if (!key_in_range(c, key, from_key, to_key)) {
++				err = 0;
++				goto out_unlock;
++			}
++		}
++
++		/* Ensure the znode is dirtied */
++		if (znode->cnext || !ubifs_zn_dirty(znode)) {
++			znode = dirty_cow_bottom_up(c, znode);
++			if (IS_ERR(znode)) {
++				err = PTR_ERR(znode);
++				goto out_unlock;
++			}
++		}
++
++		/* Remove all keys in range except the first */
++		for (i = n + 1, k = 0; i < znode->child_cnt; i++, k++) {
++			key = &znode->zbranch[i].key;
++			if (!key_in_range(c, key, from_key, to_key))
++				break;
++			lnc_free(&znode->zbranch[i]);
++			err = ubifs_add_dirt(c, znode->zbranch[i].lnum,
++					     znode->zbranch[i].len);
++			if (err) {
++				dbg_dump_znode(c, znode);
++				goto out_unlock;
++			}
++			dbg_tnc("removing %s", DBGKEY(key));
++		}
++		if (k) {
++			for (i = n + 1 + k; i < znode->child_cnt; i++)
++				znode->zbranch[i - k] = znode->zbranch[i];
++			znode->child_cnt -= k;
++		}
++
++		/* Now delete the first */
++		err = tnc_delete(c, znode, n);
++		if (err)
++			goto out_unlock;
++	}
++
++out_unlock:
++	if (!err)
++		err = dbg_check_tnc(c, 0);
++	mutex_unlock(&c->tnc_mutex);
++	return err;
++}
++
++/**
++ * ubifs_tnc_remove_ino - remove an inode from TNC.
++ * @c: UBIFS file-system description object
++ * @inum: inode number to remove
++ *
++ * This function remove inode @inum and all the extended attributes associated
++ * with the anode from TNC and returns zero in case of success or a negative
++ * error code in case of failure.
++ */
++int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum)
++{
++	union ubifs_key key1, key2;
++	struct ubifs_dent_node *xent, *pxent = NULL;
++	struct qstr nm = { .name = NULL };
++
++	dbg_tnc("ino %lu", (unsigned long)inum);
++
++	/*
++	 * Walk all extended attribute entries and remove them together with
++	 * corresponding extended attribute inodes.
++	 */
++	lowest_xent_key(c, &key1, inum);
++	while (1) {
++		ino_t xattr_inum;
++		int err;
++
++		xent = ubifs_tnc_next_ent(c, &key1, &nm);
++		if (IS_ERR(xent)) {
++			err = PTR_ERR(xent);
++			if (err == -ENOENT)
++				break;
++			return err;
++		}
++
++		xattr_inum = le64_to_cpu(xent->inum);
++		dbg_tnc("xent '%s', ino %lu", xent->name,
++			(unsigned long)xattr_inum);
++
++		nm.name = xent->name;
++		nm.len = le16_to_cpu(xent->nlen);
++		err = ubifs_tnc_remove_nm(c, &key1, &nm);
++		if (err) {
++			kfree(xent);
++			return err;
++		}
++
++		lowest_ino_key(c, &key1, xattr_inum);
++		highest_ino_key(c, &key2, xattr_inum);
++		err = ubifs_tnc_remove_range(c, &key1, &key2);
++		if (err) {
++			kfree(xent);
++			return err;
++		}
++
++		kfree(pxent);
++		pxent = xent;
++		key_read(c, &xent->key, &key1);
++	}
++
++	kfree(pxent);
++	lowest_ino_key(c, &key1, inum);
++	highest_ino_key(c, &key2, inum);
++
++	return ubifs_tnc_remove_range(c, &key1, &key2);
++}
++
++/**
++ * ubifs_tnc_next_ent - walk directory or extended attribute entries.
++ * @c: UBIFS file-system description object
++ * @key: key of last entry
++ * @nm: name of last entry found or %NULL
++ *
++ * This function finds and reads the next directory or extended attribute entry
++ * after the given key (@key) if there is one. @nm is used to resolve
++ * collisions.
++ *
++ * If the name of the current entry is not known and only the key is known,
++ * @nm->name has to be %NULL. In this case the semantics of this function is a
++ * little bit different and it returns the entry corresponding to this key, not
++ * the next one. If the key was not found, the closest "right" entry is
++ * returned.
++ *
++ * If the fist entry has to be found, @key has to contain the lowest possible
++ * key value for this inode and @name has to be %NULL.
++ *
++ * This function returns the found directory or extended attribute entry node
++ * in case of success, %-ENOENT is returned if no entry was found, and a
++ * negative error code is returned in case of failure.
++ */
++struct ubifs_dent_node *ubifs_tnc_next_ent(struct ubifs_info *c,
++					   union ubifs_key *key,
++					   const struct qstr *nm)
++{
++	int n, err, type = key_type(c, key);
++	struct ubifs_znode *znode;
++	struct ubifs_dent_node *dent;
++	struct ubifs_zbranch *zbr;
++	union ubifs_key *dkey;
++
++	dbg_tnc("%s %s", nm->name ? (char *)nm->name : "(lowest)", DBGKEY(key));
++	ubifs_assert(is_hash_key(c, key));
++
++	mutex_lock(&c->tnc_mutex);
++	err = ubifs_lookup_level0(c, key, &znode, &n);
++	if (unlikely(err < 0))
++		goto out_unlock;
++
++	if (nm->name) {
++		if (err) {
++			/* Handle collisions */
++			err = resolve_collision(c, key, &znode, &n, nm);
++			dbg_tnc("rc returned %d, znode %p, n %d",
++				err, znode, n);
++			if (unlikely(err < 0))
++				goto out_unlock;
++		}
++
++		/* Now find next entry */
++		err = tnc_next(c, &znode, &n);
++		if (unlikely(err))
++			goto out_unlock;
++	} else {
++		/*
++		 * The full name of the entry was not given, in which case the
++		 * behavior of this function is a little different and it
++		 * returns current entry, not the next one.
++		 */
++		if (!err) {
++			/*
++			 * However, the given key does not exist in the TNC
++			 * tree and @znode/@n variables contain the closest
++			 * "preceding" element. Switch to the next one.
++			 */
++			err = tnc_next(c, &znode, &n);
++			if (err)
++				goto out_unlock;
++		}
++	}
++
++	zbr = &znode->zbranch[n];
++	dent = kmalloc(zbr->len, GFP_NOFS);
++	if (unlikely(!dent)) {
++		err = -ENOMEM;
++		goto out_unlock;
++	}
++
++	/*
++	 * The above 'tnc_next()' call could lead us to the next inode, check
++	 * this.
++	 */
++	dkey = &zbr->key;
++	if (key_inum(c, dkey) != key_inum(c, key) ||
++	    key_type(c, dkey) != type) {
++		err = -ENOENT;
++		goto out_free;
++	}
++
++	err = tnc_read_node_nm(c, zbr, dent);
++	if (unlikely(err))
++		goto out_free;
++
++	mutex_unlock(&c->tnc_mutex);
++	return dent;
++
++out_free:
++	kfree(dent);
++out_unlock:
++	mutex_unlock(&c->tnc_mutex);
++	return ERR_PTR(err);
++}
++
++/**
++ * tnc_destroy_cnext - destroy left-over obsolete znodes from a failed commit.
++ * @c: UBIFS file-system description object
++ *
++ * Destroy left-over obsolete znodes from a failed commit.
++ */
++static void tnc_destroy_cnext(struct ubifs_info *c)
++{
++	struct ubifs_znode *cnext;
++
++	if (!c->cnext)
++		return;
++	ubifs_assert(c->cmt_state == COMMIT_BROKEN);
++	cnext = c->cnext;
++	do {
++		struct ubifs_znode *znode = cnext;
++
++		cnext = cnext->cnext;
++		if (test_bit(OBSOLETE_ZNODE, &znode->flags))
++			kfree(znode);
++	} while (cnext && cnext != c->cnext);
++}
++
++/**
++ * ubifs_tnc_close - close TNC subsystem and free all related resources.
++ * @c: UBIFS file-system description object
++ */
++void ubifs_tnc_close(struct ubifs_info *c)
++{
++	long clean_freed;
++
++	tnc_destroy_cnext(c);
++	if (c->zroot.znode) {
++		clean_freed = ubifs_destroy_tnc_subtree(c->zroot.znode);
++		atomic_long_sub(clean_freed, &ubifs_clean_zn_cnt);
++	}
++	kfree(c->gap_lebs);
++	kfree(c->ilebs);
++	destroy_old_idx(c);
++}
++
++/**
++ * left_znode - get the znode to the left.
++ * @c: UBIFS file-system description object
++ * @znode: znode
++ *
++ * This function returns a pointer to the znode to the left of @znode or NULL if
++ * there is not one. A negative error code is returned on failure.
++ */
++static struct ubifs_znode *left_znode(struct ubifs_info *c,
++				      struct ubifs_znode *znode)
++{
++	int level = znode->level;
++
++	while (1) {
++		int n = znode->iip - 1;
++
++		/* Go up until we can go left */
++		znode = znode->parent;
++		if (!znode)
++			return NULL;
++		if (n >= 0) {
++			/* Now go down the rightmost branch to 'level' */
++			znode = get_znode(c, znode, n);
++			if (IS_ERR(znode))
++				return znode;
++			while (znode->level != level) {
++				n = znode->child_cnt - 1;
++				znode = get_znode(c, znode, n);
++				if (IS_ERR(znode))
++					return znode;
++			}
++			break;
++		}
++	}
++	return znode;
++}
++
++/**
++ * right_znode - get the znode to the right.
++ * @c: UBIFS file-system description object
++ * @znode: znode
++ *
++ * This function returns a pointer to the znode to the right of @znode or NULL
++ * if there is not one. A negative error code is returned on failure.
++ */
++static struct ubifs_znode *right_znode(struct ubifs_info *c,
++				       struct ubifs_znode *znode)
++{
++	int level = znode->level;
++
++	while (1) {
++		int n = znode->iip + 1;
++
++		/* Go up until we can go right */
++		znode = znode->parent;
++		if (!znode)
++			return NULL;
++		if (n < znode->child_cnt) {
++			/* Now go down the leftmost branch to 'level' */
++			znode = get_znode(c, znode, n);
++			if (IS_ERR(znode))
++				return znode;
++			while (znode->level != level) {
++				znode = get_znode(c, znode, 0);
++				if (IS_ERR(znode))
++					return znode;
++			}
++			break;
++		}
++	}
++	return znode;
++}
++
++/**
++ * lookup_znode - find a particular indexing node from TNC.
++ * @c: UBIFS file-system description object
++ * @key: index node key to lookup
++ * @level: index node level
++ * @lnum: index node LEB number
++ * @offs: index node offset
++ *
++ * This function searches an indexing node by its first key @key and its
++ * address @lnum:@offs. It looks up the indexing tree by pulling all indexing
++ * nodes it traverses to TNC. This function is called fro indexing nodes which
++ * were found on the media by scanning, for example when garbage-collecting or
++ * when doing in-the-gaps commit. This means that the indexing node which is
++ * looked for does not have to have exactly the same leftmost key @key, because
++ * the leftmost key may have been changed, in which case TNC will contain a
++ * dirty znode which still refers the same @lnum:@offs. This function is clever
++ * enough to recognize such indexing nodes.
++ *
++ * Note, if a znode was deleted or changed too much, then this function will
++ * not find it. For situations like this UBIFS has the old index RB-tree
++ * (indexed by @lnum:@offs).
++ *
++ * This function returns a pointer to the znode found or %NULL if it is not
++ * found. A negative error code is returned on failure.
++ */
++static struct ubifs_znode *lookup_znode(struct ubifs_info *c,
++					union ubifs_key *key, int level,
++					int lnum, int offs)
++{
++	struct ubifs_znode *znode, *zn;
++	int n, nn;
++
++	/*
++	 * The arguments have probably been read off flash, so don't assume
++	 * they are valid.
++	 */
++	if (level < 0)
++		return ERR_PTR(-EINVAL);
++
++	/* Get the root znode */
++	znode = c->zroot.znode;
++	if (!znode) {
++		znode = ubifs_load_znode(c, &c->zroot, NULL, 0);
++		if (IS_ERR(znode))
++			return znode;
++	}
++	/* Check if it is the one we are looking for */
++	if (c->zroot.lnum == lnum && c->zroot.offs == offs)
++		return znode;
++	/* Descend to the parent level i.e. (level + 1) */
++	if (level >= znode->level)
++		return NULL;
++	while (1) {
++		ubifs_search_zbranch(c, znode, key, &n);
++		if (n < 0) {
++			/*
++			 * We reached a znode where the leftmost key is greater
++			 * than the key we are searching for. This is the same
++			 * situation as the one described in a huge comment at
++			 * the end of the 'ubifs_lookup_level0()' function. And
++			 * for exactly the same reasons we have to try to look
++			 * left before giving up.
++			 */
++			znode = left_znode(c, znode);
++			if (!znode)
++				return NULL;
++			if (IS_ERR(znode))
++				return znode;
++			ubifs_search_zbranch(c, znode, key, &n);
++			ubifs_assert(n >= 0);
++		}
++		if (znode->level == level + 1)
++			break;
++		znode = get_znode(c, znode, n);
++		if (IS_ERR(znode))
++			return znode;
++	}
++	/* Check if the child is the one we are looking for */
++	if (znode->zbranch[n].lnum == lnum && znode->zbranch[n].offs == offs)
++		return get_znode(c, znode, n);
++	/* If the key is unique, there is nowhere else to look */
++	if (!is_hash_key(c, key))
++		return NULL;
++	/*
++	 * The key is not unique and so may be also in the znodes to either
++	 * side.
++	 */
++	zn = znode;
++	nn = n;
++	/* Look left */
++	while (1) {
++		/* Move one branch to the left */
++		if (n)
++			n -= 1;
++		else {
++			znode = left_znode(c, znode);
++			if (!znode)
++				break;
++			if (IS_ERR(znode))
++				return znode;
++			n = znode->child_cnt - 1;
++		}
++		/* Check it */
++		if (znode->zbranch[n].lnum == lnum &&
++		    znode->zbranch[n].offs == offs)
++			return get_znode(c, znode, n);
++		/* Stop if the key is less than the one we are looking for */
++		if (keys_cmp(c, &znode->zbranch[n].key, key) < 0)
++			break;
++	}
++	/* Back to the middle */
++	znode = zn;
++	n = nn;
++	/* Look right */
++	while (1) {
++		/* Move one branch to the right */
++		if (++n >= znode->child_cnt) {
++			znode = right_znode(c, znode);
++			if (!znode)
++				break;
++			if (IS_ERR(znode))
++				return znode;
++			n = 0;
++		}
++		/* Check it */
++		if (znode->zbranch[n].lnum == lnum &&
++		    znode->zbranch[n].offs == offs)
++			return get_znode(c, znode, n);
++		/* Stop if the key is greater than the one we are looking for */
++		if (keys_cmp(c, &znode->zbranch[n].key, key) > 0)
++			break;
++	}
++	return NULL;
++}
++
++/**
++ * is_idx_node_in_tnc - determine if an index node is in the TNC.
++ * @c: UBIFS file-system description object
++ * @key: key of index node
++ * @level: index node level
++ * @lnum: LEB number of index node
++ * @offs: offset of index node
++ *
++ * This function returns %0 if the index node is not referred to in the TNC, %1
++ * if the index node is referred to in the TNC and the corresponding znode is
++ * dirty, %2 if an index node is referred to in the TNC and the corresponding
++ * znode is clean, and a negative error code in case of failure.
++ *
++ * Note, the @key argument has to be the key of the first child. Also note,
++ * this function relies on the fact that 0:0 is never a valid LEB number and
++ * offset for a main-area node.
++ */
++int is_idx_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, int level,
++		       int lnum, int offs)
++{
++	struct ubifs_znode *znode;
++
++	znode = lookup_znode(c, key, level, lnum, offs);
++	if (!znode)
++		return 0;
++	if (IS_ERR(znode))
++		return PTR_ERR(znode);
++
++	return ubifs_zn_dirty(znode) ? 1 : 2;
++}
++
++/**
++ * is_leaf_node_in_tnc - determine if a non-indexing not is in the TNC.
++ * @c: UBIFS file-system description object
++ * @key: node key
++ * @lnum: node LEB number
++ * @offs: node offset
++ *
++ * This function returns %1 if the node is referred to in the TNC, %0 if it is
++ * not, and a negative error code in case of failure.
++ *
++ * Note, this function relies on the fact that 0:0 is never a valid LEB number
++ * and offset for a main-area node.
++ */
++static int is_leaf_node_in_tnc(struct ubifs_info *c, union ubifs_key *key,
++			       int lnum, int offs)
++{
++	struct ubifs_zbranch *zbr;
++	struct ubifs_znode *znode, *zn;
++	int n, found, err, nn;
++	const int unique = !is_hash_key(c, key);
++
++	found = ubifs_lookup_level0(c, key, &znode, &n);
++	if (found < 0)
++		return found; /* Error code */
++	if (!found)
++		return 0;
++	zbr = &znode->zbranch[n];
++	if (lnum == zbr->lnum && offs == zbr->offs)
++		return 1; /* Found it */
++	if (unique)
++		return 0;
++	/*
++	 * Because the key is not unique, we have to look left
++	 * and right as well
++	 */
++	zn = znode;
++	nn = n;
++	/* Look left */
++	while (1) {
++		err = tnc_prev(c, &znode, &n);
++		if (err == -ENOENT)
++			break;
++		if (err)
++			return err;
++		if (keys_cmp(c, key, &znode->zbranch[n].key))
++			break;
++		zbr = &znode->zbranch[n];
++		if (lnum == zbr->lnum && offs == zbr->offs)
++			return 1; /* Found it */
++	}
++	/* Look right */
++	znode = zn;
++	n = nn;
++	while (1) {
++		err = tnc_next(c, &znode, &n);
++		if (err) {
++			if (err == -ENOENT)
++				return 0;
++			return err;
++		}
++		if (keys_cmp(c, key, &znode->zbranch[n].key))
++			break;
++		zbr = &znode->zbranch[n];
++		if (lnum == zbr->lnum && offs == zbr->offs)
++			return 1; /* Found it */
++	}
++	return 0;
++}
++
++/**
++ * ubifs_tnc_has_node - determine whether a node is in the TNC.
++ * @c: UBIFS file-system description object
++ * @key: node key
++ * @level: index node level (if it is an index node)
++ * @lnum: node LEB number
++ * @offs: node offset
++ * @is_idx: non-zero if the node is an index node
++ *
++ * This function returns %1 if the node is in the TNC, %0 if it is not, and a
++ * negative error code in case of failure. For index nodes, @key has to be the
++ * key of the first child. An index node is considered to be in the TNC only if
++ * the corresponding znode is clean or has not been loaded.
++ */
++int ubifs_tnc_has_node(struct ubifs_info *c, union ubifs_key *key, int level,
++		       int lnum, int offs, int is_idx)
++{
++	int err;
++
++	mutex_lock(&c->tnc_mutex);
++	if (is_idx) {
++		err = is_idx_node_in_tnc(c, key, level, lnum, offs);
++		if (err < 0)
++			goto out_unlock;
++		if (err == 1)
++			/* The index node was found but it was dirty */
++			err = 0;
++		else if (err == 2)
++			/* The index node was found and it was clean */
++			err = 1;
++		else
++			BUG_ON(err != 0);
++	} else
++		err = is_leaf_node_in_tnc(c, key, lnum, offs);
++
++out_unlock:
++	mutex_unlock(&c->tnc_mutex);
++	return err;
++}
++
++/**
++ * ubifs_dirty_idx_node - dirty an index node.
++ * @c: UBIFS file-system description object
++ * @key: index node key
++ * @level: index node level
++ * @lnum: index node LEB number
++ * @offs: index node offset
++ *
++ * This function loads and dirties an index node so that it can be garbage
++ * collected. The @key argument has to be the key of the first child. This
++ * function relies on the fact that 0:0 is never a valid LEB number and offset
++ * for a main-area node. Returns %0 on success and a negative error code on
++ * failure.
++ */
++int ubifs_dirty_idx_node(struct ubifs_info *c, union ubifs_key *key, int level,
++			 int lnum, int offs)
++{
++	struct ubifs_znode *znode;
++	int err = 0;
++
++	mutex_lock(&c->tnc_mutex);
++	znode = lookup_znode(c, key, level, lnum, offs);
++	if (!znode)
++		goto out_unlock;
++	if (IS_ERR(znode)) {
++		err = PTR_ERR(znode);
++		goto out_unlock;
++	}
++	znode = dirty_cow_bottom_up(c, znode);
++	if (IS_ERR(znode)) {
++		err = PTR_ERR(znode);
++		goto out_unlock;
++	}
++
++out_unlock:
++	mutex_unlock(&c->tnc_mutex);
++	return err;
++}
+diff -Nurd linux-2.6.24.orig/fs/ubifs/tnc_commit.c linux-2.6.24/fs/ubifs/tnc_commit.c
+--- linux-2.6.24.orig/fs/ubifs/tnc_commit.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/tnc_commit.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,1105 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Adrian Hunter
++ *          Artem Bityutskiy (Битюцкий Артём)
++ */
++
++/* This file implements TNC functions for committing */
++
++#include "ubifs.h"
++
++/**
++ * make_idx_node - make an index node for fill-the-gaps method of TNC commit.
++ * @c: UBIFS file-system description object
++ * @idx: buffer in which to place new index node
++ * @znode: znode from which to make new index node
++ * @lnum: LEB number where new index node will be written
++ * @offs: offset where new index node will be written
++ * @len: length of new index node
++ */
++static int make_idx_node(struct ubifs_info *c, struct ubifs_idx_node *idx,
++			 struct ubifs_znode *znode, int lnum, int offs, int len)
++{
++	struct ubifs_znode *zp;
++	int i, err;
++
++	/* Make index node */
++	idx->ch.node_type = UBIFS_IDX_NODE;
++	idx->child_cnt = cpu_to_le16(znode->child_cnt);
++	idx->level = cpu_to_le16(znode->level);
++	for (i = 0; i < znode->child_cnt; i++) {
++		struct ubifs_branch *br = ubifs_idx_branch(c, idx, i);
++		struct ubifs_zbranch *zbr = &znode->zbranch[i];
++
++		key_write_idx(c, &zbr->key, &br->key);
++		br->lnum = cpu_to_le32(zbr->lnum);
++		br->offs = cpu_to_le32(zbr->offs);
++		br->len = cpu_to_le32(zbr->len);
++		if (!zbr->lnum || !zbr->len) {
++			ubifs_err("bad ref in znode");
++			dbg_dump_znode(c, znode);
++			if (zbr->znode)
++				dbg_dump_znode(c, zbr->znode);
++		}
++	}
++	ubifs_prepare_node(c, idx, len, 0);
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++	znode->lnum = lnum;
++	znode->offs = offs;
++	znode->len = len;
++#endif
++
++	err = insert_old_idx_znode(c, znode);
++
++	/* Update the parent */
++	zp = znode->parent;
++	if (zp) {
++		struct ubifs_zbranch *zbr;
++
++		zbr = &zp->zbranch[znode->iip];
++		zbr->lnum = lnum;
++		zbr->offs = offs;
++		zbr->len = len;
++	} else {
++		c->zroot.lnum = lnum;
++		c->zroot.offs = offs;
++		c->zroot.len = len;
++	}
++	c->calc_idx_sz += ALIGN(len, 8);
++
++	atomic_long_dec(&c->dirty_zn_cnt);
++
++	ubifs_assert(ubifs_zn_dirty(znode));
++	ubifs_assert(test_bit(COW_ZNODE, &znode->flags));
++
++	__clear_bit(DIRTY_ZNODE, &znode->flags);
++	__clear_bit(COW_ZNODE, &znode->flags);
++
++	return err;
++}
++
++/**
++ * fill_gap - make index nodes in gaps in dirty index LEBs.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number that gap appears in
++ * @gap_start: offset of start of gap
++ * @gap_end: offset of end of gap
++ * @dirt: adds dirty space to this
++ *
++ * This function returns the number of index nodes written into the gap.
++ */
++static int fill_gap(struct ubifs_info *c, int lnum, int gap_start, int gap_end,
++		    int *dirt)
++{
++	int len, gap_remains, gap_pos, written, pad_len;
++
++	ubifs_assert((gap_start & 7) == 0);
++	ubifs_assert((gap_end & 7) == 0);
++	ubifs_assert(gap_end >= gap_start);
++
++	gap_remains = gap_end - gap_start;
++	if (!gap_remains)
++		return 0;
++	gap_pos = gap_start;
++	written = 0;
++	while (c->enext) {
++		len = ubifs_idx_node_sz(c, c->enext->child_cnt);
++		if (len < gap_remains) {
++			struct ubifs_znode *znode = c->enext;
++			const int alen = ALIGN(len, 8);
++			int err;
++
++			ubifs_assert(alen <= gap_remains);
++			err = make_idx_node(c, c->ileb_buf + gap_pos, znode,
++					    lnum, gap_pos, len);
++			if (err)
++				return err;
++			gap_remains -= alen;
++			gap_pos += alen;
++			c->enext = znode->cnext;
++			if (c->enext == c->cnext)
++				c->enext = NULL;
++			written += 1;
++		} else
++			break;
++	}
++	if (gap_end == c->leb_size) {
++		c->ileb_len = ALIGN(gap_pos, c->min_io_size);
++		/* Pad to end of min_io_size */
++		pad_len = c->ileb_len - gap_pos;
++	} else
++		/* Pad to end of gap */
++		pad_len = gap_remains;
++	dbg_gc("LEB %d:%d to %d len %d nodes written %d wasted bytes %d",
++	       lnum, gap_start, gap_end, gap_end - gap_start, written, pad_len);
++	ubifs_pad(c, c->ileb_buf + gap_pos, pad_len);
++	*dirt += pad_len;
++	return written;
++}
++
++/**
++ * find_old_idx - find an index node obsoleted since the last commit start.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB number of obsoleted index node
++ * @offs: offset of obsoleted index node
++ *
++ * Returns %1 if found and %0 otherwise.
++ */
++static int find_old_idx(struct ubifs_info *c, int lnum, int offs)
++{
++	struct ubifs_old_idx *o;
++	struct rb_node *p;
++
++	p = c->old_idx.rb_node;
++	while (p) {
++		o = rb_entry(p, struct ubifs_old_idx, rb);
++		if (lnum < o->lnum)
++			p = p->rb_left;
++		else if (lnum > o->lnum)
++			p = p->rb_right;
++		else if (offs < o->offs)
++			p = p->rb_left;
++		else if (offs > o->offs)
++			p = p->rb_right;
++		else
++			return 1;
++	}
++	return 0;
++}
++
++/**
++ * is_idx_node_in_use - determine if an index node can be overwritten.
++ * @c: UBIFS file-system description object
++ * @key: key of index node
++ * @level: index node level
++ * @lnum: LEB number of index node
++ * @offs: offset of index node
++ *
++ * If @key / @lnum / @offs identify an index node that was not part of the old
++ * index, then this function returns %0 (obsolete).  Else if the index node was
++ * part of the old index but is now dirty %1 is returned, else if it is clean %2
++ * is returned. A negative error code is returned on failure.
++ */
++static int is_idx_node_in_use(struct ubifs_info *c, union ubifs_key *key,
++			      int level, int lnum, int offs)
++{
++	int ret;
++
++	ret = is_idx_node_in_tnc(c, key, level, lnum, offs);
++	if (ret < 0)
++		return ret; /* Error code */
++	if (ret == 0)
++		if (find_old_idx(c, lnum, offs))
++			return 1;
++	return ret;
++}
++
++/**
++ * layout_leb_in_gaps - layout index nodes using in-the-gaps method.
++ * @c: UBIFS file-system description object
++ * @p: return LEB number here
++ *
++ * This function lays out new index nodes for dirty znodes using in-the-gaps
++ * method of TNC commit.
++ * This function merely puts the next znode into the next gap, making no attempt
++ * to try to maximise the number of znodes that fit.
++ * This function returns the number of index nodes written into the gaps, or a
++ * negative error code on failure.
++ */
++static int layout_leb_in_gaps(struct ubifs_info *c, int *p)
++{
++	struct ubifs_scan_leb *sleb;
++	struct ubifs_scan_node *snod;
++	int lnum, dirt = 0, gap_start, gap_end, err, written, tot_written;
++
++	tot_written = 0;
++	/* Get an index LEB with lots of obsolete index nodes */
++	lnum = ubifs_find_dirty_idx_leb(c);
++	if (lnum < 0)
++		/*
++		 * There also may be dirt in the index head that could be
++		 * filled, however we do not check there at present.
++		 */
++		return lnum; /* Error code */
++	*p = lnum;
++	dbg_gc("LEB %d", lnum);
++	/*
++	 * Scan the index LEB.  We use the generic scan for this even though
++	 * it is more comprehensive and less efficient than is needed for this
++	 * purpose.
++	 */
++	sleb = ubifs_scan(c, lnum, 0, c->ileb_buf);
++	c->ileb_len = 0;
++	if (IS_ERR(sleb))
++		return PTR_ERR(sleb);
++	gap_start = 0;
++	list_for_each_entry(snod, &sleb->nodes, list) {
++		struct ubifs_idx_node *idx;
++		int in_use, level;
++
++		ubifs_assert(snod->type == UBIFS_IDX_NODE);
++		idx = snod->node;
++		key_read(c, ubifs_idx_key(c, idx), &snod->key);
++		level = le16_to_cpu(idx->level);
++		/* Determine if the index node is in use (not obsolete) */
++		in_use = is_idx_node_in_use(c, &snod->key, level, lnum,
++					    snod->offs);
++		if (in_use < 0) {
++			ubifs_scan_destroy(sleb);
++			return in_use; /* Error code */
++		}
++		if (in_use) {
++			if (in_use == 1)
++				dirt += ALIGN(snod->len, 8);
++			/*
++			 * The obsolete index nodes form gaps that can be
++			 * overwritten.  This gap has ended because we have
++			 * found an index node that is still in use
++			 * i.e. not obsolete
++			 */
++			gap_end = snod->offs;
++			/* Try to fill gap */
++			written = fill_gap(c, lnum, gap_start, gap_end, &dirt);
++			if (written < 0) {
++				ubifs_scan_destroy(sleb);
++				return written; /* Error code */
++			}
++			tot_written += written;
++			gap_start = ALIGN(snod->offs + snod->len, 8);
++		}
++	}
++	ubifs_scan_destroy(sleb);
++	c->ileb_len = c->leb_size;
++	gap_end = c->leb_size;
++	/* Try to fill gap */
++	written = fill_gap(c, lnum, gap_start, gap_end, &dirt);
++	if (written < 0)
++		return written; /* Error code */
++	tot_written += written;
++	if (tot_written == 0) {
++		struct ubifs_lprops lp;
++
++		dbg_gc("LEB %d wrote %d index nodes", lnum, tot_written);
++		err = ubifs_read_one_lp(c, lnum, &lp);
++		if (err)
++			return err;
++		if (lp.free == c->leb_size) {
++			/*
++			 * We must have snatched this LEB from the idx_gc list
++			 * so we need to correct the free and dirty space.
++			 */
++			err = ubifs_change_one_lp(c, lnum,
++						  c->leb_size - c->ileb_len,
++						  dirt, 0, 0, 0);
++			if (err)
++				return err;
++		}
++		return 0;
++	}
++	err = ubifs_change_one_lp(c, lnum, c->leb_size - c->ileb_len, dirt,
++				  0, 0, 0);
++	if (err)
++		return err;
++	err = ubifs_leb_change(c, lnum, c->ileb_buf, c->ileb_len,
++			       UBI_SHORTTERM);
++	if (err)
++		return err;
++	dbg_gc("LEB %d wrote %d index nodes", lnum, tot_written);
++	return tot_written;
++}
++
++/**
++ * get_leb_cnt - calculate the number of empty LEBs needed to commit.
++ * @c: UBIFS file-system description object
++ * @cnt: number of znodes to commit
++ *
++ * This function returns the number of empty LEBs needed to commit @cnt znodes
++ * to the current index head.  The number is not exact and may be more than
++ * needed.
++ */
++static int get_leb_cnt(struct ubifs_info *c, int cnt)
++{
++	int d;
++
++	/* Assume maximum index node size (i.e. overestimate space needed) */
++	cnt -= (c->leb_size - c->ihead_offs) / c->max_idx_node_sz;
++	if (cnt < 0)
++		cnt = 0;
++	d = c->leb_size / c->max_idx_node_sz;
++	return DIV_ROUND_UP(cnt, d);
++}
++
++/**
++ * layout_in_gaps - in-the-gaps method of committing TNC.
++ * @c: UBIFS file-system description object
++ * @cnt: number of dirty znodes to commit.
++ *
++ * This function lays out new index nodes for dirty znodes using in-the-gaps
++ * method of TNC commit.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int layout_in_gaps(struct ubifs_info *c, int cnt)
++{
++	int err, leb_needed_cnt, written, *p;
++
++	dbg_gc("%d znodes to write", cnt);
++
++	c->gap_lebs = kmalloc(sizeof(int) * (c->lst.idx_lebs + 1), GFP_NOFS);
++	if (!c->gap_lebs)
++		return -ENOMEM;
++
++	p = c->gap_lebs;
++	do {
++		ubifs_assert(p < c->gap_lebs + sizeof(int) * c->lst.idx_lebs);
++		written = layout_leb_in_gaps(c, p);
++		if (written < 0) {
++			err = written;
++			if (err != -ENOSPC) {
++				kfree(c->gap_lebs);
++				c->gap_lebs = NULL;
++				return err;
++			}
++			if (!dbg_force_in_the_gaps_enabled) {
++				/*
++				 * Do not print scary warnings if the debugging
++				 * option which forces in-the-gaps is enabled.
++				 */
++				ubifs_err("out of space");
++				spin_lock(&c->space_lock);
++				dbg_dump_budg(c);
++				spin_unlock(&c->space_lock);
++				dbg_dump_lprops(c);
++			}
++			/* Try to commit anyway */
++			err = 0;
++			break;
++		}
++		p++;
++		cnt -= written;
++		leb_needed_cnt = get_leb_cnt(c, cnt);
++		dbg_gc("%d znodes remaining, need %d LEBs, have %d", cnt,
++		       leb_needed_cnt, c->ileb_cnt);
++	} while (leb_needed_cnt > c->ileb_cnt);
++
++	*p = -1;
++	return 0;
++}
++
++/**
++ * layout_in_empty_space - layout index nodes in empty space.
++ * @c: UBIFS file-system description object
++ *
++ * This function lays out new index nodes for dirty znodes using empty LEBs.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int layout_in_empty_space(struct ubifs_info *c)
++{
++	struct ubifs_znode *znode, *cnext, *zp;
++	int lnum, offs, len, next_len, buf_len, buf_offs, used, avail;
++	int wlen, blen, err;
++
++	cnext = c->enext;
++	if (!cnext)
++		return 0;
++
++	lnum = c->ihead_lnum;
++	buf_offs = c->ihead_offs;
++
++	buf_len = ubifs_idx_node_sz(c, c->fanout);
++	buf_len = ALIGN(buf_len, c->min_io_size);
++	used = 0;
++	avail = buf_len;
++
++	/* Ensure there is enough room for first write */
++	next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
++	if (buf_offs + next_len > c->leb_size)
++		lnum = -1;
++
++	while (1) {
++		znode = cnext;
++
++		len = ubifs_idx_node_sz(c, znode->child_cnt);
++
++		/* Determine the index node position */
++		if (lnum == -1) {
++			if (c->ileb_nxt >= c->ileb_cnt) {
++				ubifs_err("out of space");
++				return -ENOSPC;
++			}
++			lnum = c->ilebs[c->ileb_nxt++];
++			buf_offs = 0;
++			used = 0;
++			avail = buf_len;
++		}
++
++		offs = buf_offs + used;
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++		znode->lnum = lnum;
++		znode->offs = offs;
++		znode->len = len;
++#endif
++
++		/* Update the parent */
++		zp = znode->parent;
++		if (zp) {
++			struct ubifs_zbranch *zbr;
++			int i;
++
++			i = znode->iip;
++			zbr = &zp->zbranch[i];
++			zbr->lnum = lnum;
++			zbr->offs = offs;
++			zbr->len = len;
++		} else {
++			c->zroot.lnum = lnum;
++			c->zroot.offs = offs;
++			c->zroot.len = len;
++		}
++		c->calc_idx_sz += ALIGN(len, 8);
++
++		/*
++		 * Once lprops is updated, we can decrease the dirty znode count
++		 * but it is easier to just do it here.
++		 */
++		atomic_long_dec(&c->dirty_zn_cnt);
++
++		/*
++		 * Calculate the next index node length to see if there is
++		 * enough room for it
++		 */
++		cnext = znode->cnext;
++		if (cnext == c->cnext)
++			next_len = 0;
++		else
++			next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
++
++		if (c->min_io_size == 1) {
++			buf_offs += ALIGN(len, 8);
++			if (next_len) {
++				if (buf_offs + next_len <= c->leb_size)
++					continue;
++				err = ubifs_update_one_lp(c, lnum, 0,
++						c->leb_size - buf_offs, 0, 0);
++				if (err)
++					return err;
++				lnum = -1;
++				continue;
++			}
++			err = ubifs_update_one_lp(c, lnum,
++					c->leb_size - buf_offs, 0, 0, 0);
++			if (err)
++				return err;
++			break;
++		}
++
++		/* Update buffer positions */
++		wlen = used + len;
++		used += ALIGN(len, 8);
++		avail -= ALIGN(len, 8);
++
++		if (next_len != 0 &&
++		    buf_offs + used + next_len <= c->leb_size &&
++		    avail > 0)
++			continue;
++
++		if (avail <= 0 && next_len &&
++		    buf_offs + used + next_len <= c->leb_size)
++			blen = buf_len;
++		else
++			blen = ALIGN(wlen, c->min_io_size);
++
++		/* The buffer is full or there are no more znodes to do */
++		buf_offs += blen;
++		if (next_len) {
++			if (buf_offs + next_len > c->leb_size) {
++				err = ubifs_update_one_lp(c, lnum,
++					c->leb_size - buf_offs, blen - used,
++					0, 0);
++				if (err)
++					return err;
++				lnum = -1;
++			}
++			used -= blen;
++			if (used < 0)
++				used = 0;
++			avail = buf_len - used;
++			continue;
++		}
++		err = ubifs_update_one_lp(c, lnum, c->leb_size - buf_offs,
++					  blen - used, 0, 0);
++		if (err)
++			return err;
++		break;
++	}
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++	c->dbg->new_ihead_lnum = lnum;
++	c->dbg->new_ihead_offs = buf_offs;
++#endif
++
++	return 0;
++}
++
++/**
++ * layout_commit - determine positions of index nodes to commit.
++ * @c: UBIFS file-system description object
++ * @no_space: indicates that insufficient empty LEBs were allocated
++ * @cnt: number of znodes to commit
++ *
++ * Calculate and update the positions of index nodes to commit.  If there were
++ * an insufficient number of empty LEBs allocated, then index nodes are placed
++ * into the gaps created by obsolete index nodes in non-empty index LEBs.  For
++ * this purpose, an obsolete index node is one that was not in the index as at
++ * the end of the last commit.  To write "in-the-gaps" requires that those index
++ * LEBs are updated atomically in-place.
++ */
++static int layout_commit(struct ubifs_info *c, int no_space, int cnt)
++{
++	int err;
++
++	if (no_space) {
++		err = layout_in_gaps(c, cnt);
++		if (err)
++			return err;
++	}
++	err = layout_in_empty_space(c);
++	return err;
++}
++
++/**
++ * find_first_dirty - find first dirty znode.
++ * @znode: znode to begin searching from
++ */
++static struct ubifs_znode *find_first_dirty(struct ubifs_znode *znode)
++{
++	int i, cont;
++
++	if (!znode)
++		return NULL;
++
++	while (1) {
++		if (znode->level == 0) {
++			if (ubifs_zn_dirty(znode))
++				return znode;
++			return NULL;
++		}
++		cont = 0;
++		for (i = 0; i < znode->child_cnt; i++) {
++			struct ubifs_zbranch *zbr = &znode->zbranch[i];
++
++			if (zbr->znode && ubifs_zn_dirty(zbr->znode)) {
++				znode = zbr->znode;
++				cont = 1;
++				break;
++			}
++		}
++		if (!cont) {
++			if (ubifs_zn_dirty(znode))
++				return znode;
++			return NULL;
++		}
++	}
++}
++
++/**
++ * find_next_dirty - find next dirty znode.
++ * @znode: znode to begin searching from
++ */
++static struct ubifs_znode *find_next_dirty(struct ubifs_znode *znode)
++{
++	int n = znode->iip + 1;
++
++	znode = znode->parent;
++	if (!znode)
++		return NULL;
++	for (; n < znode->child_cnt; n++) {
++		struct ubifs_zbranch *zbr = &znode->zbranch[n];
++
++		if (zbr->znode && ubifs_zn_dirty(zbr->znode))
++			return find_first_dirty(zbr->znode);
++	}
++	return znode;
++}
++
++/**
++ * get_znodes_to_commit - create list of dirty znodes to commit.
++ * @c: UBIFS file-system description object
++ *
++ * This function returns the number of znodes to commit.
++ */
++static int get_znodes_to_commit(struct ubifs_info *c)
++{
++	struct ubifs_znode *znode, *cnext;
++	int cnt = 0;
++
++	c->cnext = find_first_dirty(c->zroot.znode);
++	znode = c->enext = c->cnext;
++	if (!znode) {
++		dbg_cmt("no znodes to commit");
++		return 0;
++	}
++	cnt += 1;
++	while (1) {
++		ubifs_assert(!test_bit(COW_ZNODE, &znode->flags));
++		__set_bit(COW_ZNODE, &znode->flags);
++		znode->alt = 0;
++		cnext = find_next_dirty(znode);
++		if (!cnext) {
++			znode->cnext = c->cnext;
++			break;
++		}
++		znode->cnext = cnext;
++		znode = cnext;
++		cnt += 1;
++	}
++	dbg_cmt("committing %d znodes", cnt);
++	ubifs_assert(cnt == atomic_long_read(&c->dirty_zn_cnt));
++	return cnt;
++}
++
++/**
++ * alloc_idx_lebs - allocate empty LEBs to be used to commit.
++ * @c: UBIFS file-system description object
++ * @cnt: number of znodes to commit
++ *
++ * This function returns %-ENOSPC if it cannot allocate a sufficient number of
++ * empty LEBs.  %0 is returned on success, otherwise a negative error code
++ * is returned.
++ */
++static int alloc_idx_lebs(struct ubifs_info *c, int cnt)
++{
++	int i, leb_cnt, lnum;
++
++	c->ileb_cnt = 0;
++	c->ileb_nxt = 0;
++	leb_cnt = get_leb_cnt(c, cnt);
++	dbg_cmt("need about %d empty LEBS for TNC commit", leb_cnt);
++	if (!leb_cnt)
++		return 0;
++	c->ilebs = kmalloc(leb_cnt * sizeof(int), GFP_NOFS);
++	if (!c->ilebs)
++		return -ENOMEM;
++	for (i = 0; i < leb_cnt; i++) {
++		lnum = ubifs_find_free_leb_for_idx(c);
++		if (lnum < 0)
++			return lnum;
++		c->ilebs[c->ileb_cnt++] = lnum;
++		dbg_cmt("LEB %d", lnum);
++	}
++	if (dbg_force_in_the_gaps())
++		return -ENOSPC;
++	return 0;
++}
++
++/**
++ * free_unused_idx_lebs - free unused LEBs that were allocated for the commit.
++ * @c: UBIFS file-system description object
++ *
++ * It is possible that we allocate more empty LEBs for the commit than we need.
++ * This functions frees the surplus.
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int free_unused_idx_lebs(struct ubifs_info *c)
++{
++	int i, err = 0, lnum, er;
++
++	for (i = c->ileb_nxt; i < c->ileb_cnt; i++) {
++		lnum = c->ilebs[i];
++		dbg_cmt("LEB %d", lnum);
++		er = ubifs_change_one_lp(c, lnum, LPROPS_NC, LPROPS_NC, 0,
++					 LPROPS_INDEX | LPROPS_TAKEN, 0);
++		if (!err)
++			err = er;
++	}
++	return err;
++}
++
++/**
++ * free_idx_lebs - free unused LEBs after commit end.
++ * @c: UBIFS file-system description object
++ *
++ * This function returns %0 on success and a negative error code on failure.
++ */
++static int free_idx_lebs(struct ubifs_info *c)
++{
++	int err;
++
++	err = free_unused_idx_lebs(c);
++	kfree(c->ilebs);
++	c->ilebs = NULL;
++	return err;
++}
++
++/**
++ * ubifs_tnc_start_commit - start TNC commit.
++ * @c: UBIFS file-system description object
++ * @zroot: new index root position is returned here
++ *
++ * This function prepares the list of indexing nodes to commit and lays out
++ * their positions on flash. If there is not enough free space it uses the
++ * in-gap commit method. Returns zero in case of success and a negative error
++ * code in case of failure.
++ */
++int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot)
++{
++	int err = 0, cnt;
++
++	mutex_lock(&c->tnc_mutex);
++	err = dbg_check_tnc(c, 1);
++	if (err)
++		goto out;
++	cnt = get_znodes_to_commit(c);
++	if (cnt != 0) {
++		int no_space = 0;
++
++		err = alloc_idx_lebs(c, cnt);
++		if (err == -ENOSPC)
++			no_space = 1;
++		else if (err)
++			goto out_free;
++		err = layout_commit(c, no_space, cnt);
++		if (err)
++			goto out_free;
++		ubifs_assert(atomic_long_read(&c->dirty_zn_cnt) == 0);
++		err = free_unused_idx_lebs(c);
++		if (err)
++			goto out;
++	}
++	destroy_old_idx(c);
++	memcpy(zroot, &c->zroot, sizeof(struct ubifs_zbranch));
++
++	err = ubifs_save_dirty_idx_lnums(c);
++	if (err)
++		goto out;
++
++	spin_lock(&c->space_lock);
++	/*
++	 * Although we have not finished committing yet, update size of the
++	 * committed index ('c->old_idx_sz') and zero out the index growth
++	 * budget. It is OK to do this now, because we've reserved all the
++	 * space which is needed to commit the index, and it is save for the
++	 * budgeting subsystem to assume the index is already committed,
++	 * even though it is not.
++	 */
++	ubifs_assert(c->min_idx_lebs == ubifs_calc_min_idx_lebs(c));
++	c->old_idx_sz = c->calc_idx_sz;
++	c->budg_uncommitted_idx = 0;
++	c->min_idx_lebs = ubifs_calc_min_idx_lebs(c);
++	spin_unlock(&c->space_lock);
++	mutex_unlock(&c->tnc_mutex);
++
++	dbg_cmt("number of index LEBs %d", c->lst.idx_lebs);
++	dbg_cmt("size of index %llu", c->calc_idx_sz);
++	return err;
++
++out_free:
++	free_idx_lebs(c);
++out:
++	mutex_unlock(&c->tnc_mutex);
++	return err;
++}
++
++/**
++ * write_index - write index nodes.
++ * @c: UBIFS file-system description object
++ *
++ * This function writes the index nodes whose positions were laid out in the
++ * layout_in_empty_space function.
++ */
++static int write_index(struct ubifs_info *c)
++{
++	struct ubifs_idx_node *idx;
++	struct ubifs_znode *znode, *cnext;
++	int i, lnum, offs, len, next_len, buf_len, buf_offs, used;
++	int avail, wlen, err, lnum_pos = 0;
++
++	cnext = c->enext;
++	if (!cnext)
++		return 0;
++
++	/*
++	 * Always write index nodes to the index head so that index nodes and
++	 * other types of nodes are never mixed in the same erase block.
++	 */
++	lnum = c->ihead_lnum;
++	buf_offs = c->ihead_offs;
++
++	/* Allocate commit buffer */
++	buf_len = ALIGN(c->max_idx_node_sz, c->min_io_size);
++	used = 0;
++	avail = buf_len;
++
++	/* Ensure there is enough room for first write */
++	next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
++	if (buf_offs + next_len > c->leb_size) {
++		err = ubifs_update_one_lp(c, lnum, LPROPS_NC, 0, 0,
++					  LPROPS_TAKEN);
++		if (err)
++			return err;
++		lnum = -1;
++	}
++
++	while (1) {
++		cond_resched();
++
++		znode = cnext;
++		idx = c->cbuf + used;
++
++		/* Make index node */
++		idx->ch.node_type = UBIFS_IDX_NODE;
++		idx->child_cnt = cpu_to_le16(znode->child_cnt);
++		idx->level = cpu_to_le16(znode->level);
++		for (i = 0; i < znode->child_cnt; i++) {
++			struct ubifs_branch *br = ubifs_idx_branch(c, idx, i);
++			struct ubifs_zbranch *zbr = &znode->zbranch[i];
++
++			key_write_idx(c, &zbr->key, &br->key);
++			br->lnum = cpu_to_le32(zbr->lnum);
++			br->offs = cpu_to_le32(zbr->offs);
++			br->len = cpu_to_le32(zbr->len);
++			if (!zbr->lnum || !zbr->len) {
++				ubifs_err("bad ref in znode");
++				dbg_dump_znode(c, znode);
++				if (zbr->znode)
++					dbg_dump_znode(c, zbr->znode);
++			}
++		}
++		len = ubifs_idx_node_sz(c, znode->child_cnt);
++		ubifs_prepare_node(c, idx, len, 0);
++
++		/* Determine the index node position */
++		if (lnum == -1) {
++			lnum = c->ilebs[lnum_pos++];
++			buf_offs = 0;
++			used = 0;
++			avail = buf_len;
++		}
++		offs = buf_offs + used;
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++		if (lnum != znode->lnum || offs != znode->offs ||
++		    len != znode->len) {
++			ubifs_err("inconsistent znode posn");
++			return -EINVAL;
++		}
++#endif
++
++		/* Grab some stuff from znode while we still can */
++		cnext = znode->cnext;
++
++		ubifs_assert(ubifs_zn_dirty(znode));
++		ubifs_assert(test_bit(COW_ZNODE, &znode->flags));
++
++		/*
++		 * It is important that other threads should see %DIRTY_ZNODE
++		 * flag cleared before %COW_ZNODE. Specifically, it matters in
++		 * the 'dirty_cow_znode()' function. This is the reason for the
++		 * first barrier. Also, we want the bit changes to be seen to
++		 * other threads ASAP, to avoid unnecesarry copying, which is
++		 * the reason for the second barrier.
++		 */
++		clear_bit(DIRTY_ZNODE, &znode->flags);
++		smp_mb__before_clear_bit();
++		clear_bit(COW_ZNODE, &znode->flags);
++		smp_mb__after_clear_bit();
++
++		/* Do not access znode from this point on */
++
++		/* Update buffer positions */
++		wlen = used + len;
++		used += ALIGN(len, 8);
++		avail -= ALIGN(len, 8);
++
++		/*
++		 * Calculate the next index node length to see if there is
++		 * enough room for it
++		 */
++		if (cnext == c->cnext)
++			next_len = 0;
++		else
++			next_len = ubifs_idx_node_sz(c, cnext->child_cnt);
++
++		if (c->min_io_size == 1) {
++			/*
++			 * Write the prepared index node immediately if there is
++			 * no minimum IO size
++			 */
++			err = ubifs_leb_write(c, lnum, c->cbuf, buf_offs,
++					      wlen, UBI_SHORTTERM);
++			if (err)
++				return err;
++			buf_offs += ALIGN(wlen, 8);
++			if (next_len) {
++				used = 0;
++				avail = buf_len;
++				if (buf_offs + next_len > c->leb_size) {
++					err = ubifs_update_one_lp(c, lnum,
++						LPROPS_NC, 0, 0, LPROPS_TAKEN);
++					if (err)
++						return err;
++					lnum = -1;
++				}
++				continue;
++			}
++		} else {
++			int blen, nxt_offs = buf_offs + used + next_len;
++
++			if (next_len && nxt_offs <= c->leb_size) {
++				if (avail > 0)
++					continue;
++				else
++					blen = buf_len;
++			} else {
++				wlen = ALIGN(wlen, 8);
++				blen = ALIGN(wlen, c->min_io_size);
++				ubifs_pad(c, c->cbuf + wlen, blen - wlen);
++			}
++			/*
++			 * The buffer is full or there are no more znodes
++			 * to do
++			 */
++			err = ubifs_leb_write(c, lnum, c->cbuf, buf_offs,
++					      blen, UBI_SHORTTERM);
++			if (err)
++				return err;
++			buf_offs += blen;
++			if (next_len) {
++				if (nxt_offs > c->leb_size) {
++					err = ubifs_update_one_lp(c, lnum,
++						LPROPS_NC, 0, 0, LPROPS_TAKEN);
++					if (err)
++						return err;
++					lnum = -1;
++				}
++				used -= blen;
++				if (used < 0)
++					used = 0;
++				avail = buf_len - used;
++				memmove(c->cbuf, c->cbuf + blen, used);
++				continue;
++			}
++		}
++		break;
++	}
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++	if (lnum != c->dbg->new_ihead_lnum ||
++	    buf_offs != c->dbg->new_ihead_offs) {
++		ubifs_err("inconsistent ihead");
++		return -EINVAL;
++	}
++#endif
++
++	c->ihead_lnum = lnum;
++	c->ihead_offs = buf_offs;
++
++	return 0;
++}
++
++/**
++ * free_obsolete_znodes - free obsolete znodes.
++ * @c: UBIFS file-system description object
++ *
++ * At the end of commit end, obsolete znodes are freed.
++ */
++static void free_obsolete_znodes(struct ubifs_info *c)
++{
++	struct ubifs_znode *znode, *cnext;
++
++	cnext = c->cnext;
++	do {
++		znode = cnext;
++		cnext = znode->cnext;
++		if (test_bit(OBSOLETE_ZNODE, &znode->flags))
++			kfree(znode);
++		else {
++			znode->cnext = NULL;
++			atomic_long_inc(&c->clean_zn_cnt);
++			atomic_long_inc(&ubifs_clean_zn_cnt);
++		}
++	} while (cnext != c->cnext);
++}
++
++/**
++ * return_gap_lebs - return LEBs used by the in-gap commit method.
++ * @c: UBIFS file-system description object
++ *
++ * This function clears the "taken" flag for the LEBs which were used by the
++ * "commit in-the-gaps" method.
++ */
++static int return_gap_lebs(struct ubifs_info *c)
++{
++	int *p, err;
++
++	if (!c->gap_lebs)
++		return 0;
++
++	dbg_cmt("");
++	for (p = c->gap_lebs; *p != -1; p++) {
++		err = ubifs_change_one_lp(c, *p, LPROPS_NC, LPROPS_NC, 0,
++					  LPROPS_TAKEN, 0);
++		if (err)
++			return err;
++	}
++
++	kfree(c->gap_lebs);
++	c->gap_lebs = NULL;
++	return 0;
++}
++
++/**
++ * ubifs_tnc_end_commit - update the TNC for commit end.
++ * @c: UBIFS file-system description object
++ *
++ * Write the dirty znodes.
++ */
++int ubifs_tnc_end_commit(struct ubifs_info *c)
++{
++	int err;
++
++	if (!c->cnext)
++		return 0;
++
++	err = return_gap_lebs(c);
++	if (err)
++		return err;
++
++	err = write_index(c);
++	if (err)
++		return err;
++
++	mutex_lock(&c->tnc_mutex);
++
++	dbg_cmt("TNC height is %d", c->zroot.znode->level + 1);
++
++	free_obsolete_znodes(c);
++
++	c->cnext = NULL;
++	kfree(c->ilebs);
++	c->ilebs = NULL;
++
++	mutex_unlock(&c->tnc_mutex);
++
++	return 0;
++}
+diff -Nurd linux-2.6.24.orig/fs/ubifs/tnc_misc.c linux-2.6.24/fs/ubifs/tnc_misc.c
+--- linux-2.6.24.orig/fs/ubifs/tnc_misc.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/tnc_misc.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,494 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Adrian Hunter
++ *          Artem Bityutskiy (Битюцкий Артём)
++ */
++
++/*
++ * This file contains miscelanious TNC-related functions shared betweend
++ * different files. This file does not form any logically separate TNC
++ * sub-system. The file was created because there is a lot of TNC code and
++ * putting it all in one file would make that file too big and unreadable.
++ */
++
++#include "ubifs.h"
++
++/**
++ * ubifs_tnc_levelorder_next - next TNC tree element in levelorder traversal.
++ * @zr: root of the subtree to traverse
++ * @znode: previous znode
++ *
++ * This function implements levelorder TNC traversal. The LNC is ignored.
++ * Returns the next element or %NULL if @znode is already the last one.
++ */
++struct ubifs_znode *ubifs_tnc_levelorder_next(struct ubifs_znode *zr,
++					      struct ubifs_znode *znode)
++{
++	int level, iip, level_search = 0;
++	struct ubifs_znode *zn;
++
++	ubifs_assert(zr);
++
++	if (unlikely(!znode))
++		return zr;
++
++	if (unlikely(znode == zr)) {
++		if (znode->level == 0)
++			return NULL;
++		return ubifs_tnc_find_child(zr, 0);
++	}
++
++	level = znode->level;
++
++	iip = znode->iip;
++	while (1) {
++		ubifs_assert(znode->level <= zr->level);
++
++		/*
++		 * First walk up until there is a znode with next branch to
++		 * look at.
++		 */
++		while (znode->parent != zr && iip >= znode->parent->child_cnt) {
++			znode = znode->parent;
++			iip = znode->iip;
++		}
++
++		if (unlikely(znode->parent == zr &&
++			     iip >= znode->parent->child_cnt)) {
++			/* This level is done, switch to the lower one */
++			level -= 1;
++			if (level_search || level < 0)
++				/*
++				 * We were already looking for znode at lower
++				 * level ('level_search'). As we are here
++				 * again, it just does not exist. Or all levels
++				 * were finished ('level < 0').
++				 */
++				return NULL;
++
++			level_search = 1;
++			iip = -1;
++			znode = ubifs_tnc_find_child(zr, 0);
++			ubifs_assert(znode);
++		}
++
++		/* Switch to the next index */
++		zn = ubifs_tnc_find_child(znode->parent, iip + 1);
++		if (!zn) {
++			/* No more children to look at, we have walk up */
++			iip = znode->parent->child_cnt;
++			continue;
++		}
++
++		/* Walk back down to the level we came from ('level') */
++		while (zn->level != level) {
++			znode = zn;
++			zn = ubifs_tnc_find_child(zn, 0);
++			if (!zn) {
++				/*
++				 * This path is not too deep so it does not
++				 * reach 'level'. Try next path.
++				 */
++				iip = znode->iip;
++				break;
++			}
++		}
++
++		if (zn) {
++			ubifs_assert(zn->level >= 0);
++			return zn;
++		}
++	}
++}
++
++/**
++ * ubifs_search_zbranch - search znode branch.
++ * @c: UBIFS file-system description object
++ * @znode: znode to search in
++ * @key: key to search for
++ * @n: znode branch slot number is returned here
++ *
++ * This is a helper function which search branch with key @key in @znode using
++ * binary search. The result of the search may be:
++ *   o exact match, then %1 is returned, and the slot number of the branch is
++ *     stored in @n;
++ *   o no exact match, then %0 is returned and the slot number of the left
++ *     closest branch is returned in @n; the slot if all keys in this znode are
++ *     greater than @key, then %-1 is returned in @n.
++ */
++int ubifs_search_zbranch(const struct ubifs_info *c,
++			 const struct ubifs_znode *znode,
++			 const union ubifs_key *key, int *n)
++{
++	int beg = 0, end = znode->child_cnt, uninitialized_var(mid);
++	int uninitialized_var(cmp);
++	const struct ubifs_zbranch *zbr = &znode->zbranch[0];
++
++	ubifs_assert(end > beg);
++
++	while (end > beg) {
++		mid = (beg + end) >> 1;
++		cmp = keys_cmp(c, key, &zbr[mid].key);
++		if (cmp > 0)
++			beg = mid + 1;
++		else if (cmp < 0)
++			end = mid;
++		else {
++			*n = mid;
++			return 1;
++		}
++	}
++
++	*n = end - 1;
++
++	/* The insert point is after *n */
++	ubifs_assert(*n >= -1 && *n < znode->child_cnt);
++	if (*n == -1)
++		ubifs_assert(keys_cmp(c, key, &zbr[0].key) < 0);
++	else
++		ubifs_assert(keys_cmp(c, key, &zbr[*n].key) > 0);
++	if (*n + 1 < znode->child_cnt)
++		ubifs_assert(keys_cmp(c, key, &zbr[*n + 1].key) < 0);
++
++	return 0;
++}
++
++/**
++ * ubifs_tnc_postorder_first - find first znode to do postorder tree traversal.
++ * @znode: znode to start at (root of the sub-tree to traverse)
++ *
++ * Find the lowest leftmost znode in a subtree of the TNC tree. The LNC is
++ * ignored.
++ */
++struct ubifs_znode *ubifs_tnc_postorder_first(struct ubifs_znode *znode)
++{
++	if (unlikely(!znode))
++		return NULL;
++
++	while (znode->level > 0) {
++		struct ubifs_znode *child;
++
++		child = ubifs_tnc_find_child(znode, 0);
++		if (!child)
++			return znode;
++		znode = child;
++	}
++
++	return znode;
++}
++
++/**
++ * ubifs_tnc_postorder_next - next TNC tree element in postorder traversal.
++ * @znode: previous znode
++ *
++ * This function implements postorder TNC traversal. The LNC is ignored.
++ * Returns the next element or %NULL if @znode is already the last one.
++ */
++struct ubifs_znode *ubifs_tnc_postorder_next(struct ubifs_znode *znode)
++{
++	struct ubifs_znode *zn;
++
++	ubifs_assert(znode);
++	if (unlikely(!znode->parent))
++		return NULL;
++
++	/* Switch to the next index in the parent */
++	zn = ubifs_tnc_find_child(znode->parent, znode->iip + 1);
++	if (!zn)
++		/* This is in fact the last child, return parent */
++		return znode->parent;
++
++	/* Go to the first znode in this new subtree */
++	return ubifs_tnc_postorder_first(zn);
++}
++
++/**
++ * ubifs_destroy_tnc_subtree - destroy all znodes connected to a subtree.
++ * @znode: znode defining subtree to destroy
++ *
++ * This function destroys subtree of the TNC tree. Returns number of clean
++ * znodes in the subtree.
++ */
++long ubifs_destroy_tnc_subtree(struct ubifs_znode *znode)
++{
++	struct ubifs_znode *zn = ubifs_tnc_postorder_first(znode);
++	long clean_freed = 0;
++	int n;
++
++	ubifs_assert(zn);
++	while (1) {
++		for (n = 0; n < zn->child_cnt; n++) {
++			if (!zn->zbranch[n].znode)
++				continue;
++
++			if (zn->level > 0 &&
++			    !ubifs_zn_dirty(zn->zbranch[n].znode))
++				clean_freed += 1;
++
++			cond_resched();
++			kfree(zn->zbranch[n].znode);
++		}
++
++		if (zn == znode) {
++			if (!ubifs_zn_dirty(zn))
++				clean_freed += 1;
++			kfree(zn);
++			return clean_freed;
++		}
++
++		zn = ubifs_tnc_postorder_next(zn);
++	}
++}
++
++/**
++ * read_znode - read an indexing node from flash and fill znode.
++ * @c: UBIFS file-system description object
++ * @lnum: LEB of the indexing node to read
++ * @offs: node offset
++ * @len: node length
++ * @znode: znode to read to
++ *
++ * This function reads an indexing node from the flash media and fills znode
++ * with the read data. Returns zero in case of success and a negative error
++ * code in case of failure. The read indexing node is validated and if anything
++ * is wrong with it, this function prints complaint messages and returns
++ * %-EINVAL.
++ */
++static int read_znode(struct ubifs_info *c, int lnum, int offs, int len,
++		      struct ubifs_znode *znode)
++{
++	int i, err, type, cmp;
++	struct ubifs_idx_node *idx;
++
++	idx = kmalloc(c->max_idx_node_sz, GFP_NOFS);
++	if (!idx)
++		return -ENOMEM;
++
++	err = ubifs_read_node(c, idx, UBIFS_IDX_NODE, len, lnum, offs);
++	if (err < 0) {
++		kfree(idx);
++		return err;
++	}
++
++	znode->child_cnt = le16_to_cpu(idx->child_cnt);
++	znode->level = le16_to_cpu(idx->level);
++
++	dbg_tnc("LEB %d:%d, level %d, %d branch",
++		lnum, offs, znode->level, znode->child_cnt);
++
++	if (znode->child_cnt > c->fanout || znode->level > UBIFS_MAX_LEVELS) {
++		dbg_err("current fanout %d, branch count %d",
++			c->fanout, znode->child_cnt);
++		dbg_err("max levels %d, znode level %d",
++			UBIFS_MAX_LEVELS, znode->level);
++		err = 1;
++		goto out_dump;
++	}
++
++	for (i = 0; i < znode->child_cnt; i++) {
++		const struct ubifs_branch *br = ubifs_idx_branch(c, idx, i);
++		struct ubifs_zbranch *zbr = &znode->zbranch[i];
++
++		key_read(c, &br->key, &zbr->key);
++		zbr->lnum = le32_to_cpu(br->lnum);
++		zbr->offs = le32_to_cpu(br->offs);
++		zbr->len  = le32_to_cpu(br->len);
++		zbr->znode = NULL;
++
++		/* Validate branch */
++
++		if (zbr->lnum < c->main_first ||
++		    zbr->lnum >= c->leb_cnt || zbr->offs < 0 ||
++		    zbr->offs + zbr->len > c->leb_size || zbr->offs & 7) {
++			dbg_err("bad branch %d", i);
++			err = 2;
++			goto out_dump;
++		}
++
++		switch (key_type(c, &zbr->key)) {
++		case UBIFS_INO_KEY:
++		case UBIFS_DATA_KEY:
++		case UBIFS_DENT_KEY:
++		case UBIFS_XENT_KEY:
++			break;
++		default:
++			dbg_msg("bad key type at slot %d: %s", i,
++				DBGKEY(&zbr->key));
++			err = 3;
++			goto out_dump;
++		}
++
++		if (znode->level)
++			continue;
++
++		type = key_type(c, &zbr->key);
++		if (c->ranges[type].max_len == 0) {
++			if (zbr->len != c->ranges[type].len) {
++				dbg_err("bad target node (type %d) length (%d)",
++					type, zbr->len);
++				dbg_err("have to be %d", c->ranges[type].len);
++				err = 4;
++				goto out_dump;
++			}
++		} else if (zbr->len < c->ranges[type].min_len ||
++			   zbr->len > c->ranges[type].max_len) {
++			dbg_err("bad target node (type %d) length (%d)",
++				type, zbr->len);
++			dbg_err("have to be in range of %d-%d",
++				c->ranges[type].min_len,
++				c->ranges[type].max_len);
++			err = 5;
++			goto out_dump;
++		}
++	}
++
++	/*
++	 * Ensure that the next key is greater or equivalent to the
++	 * previous one.
++	 */
++	for (i = 0; i < znode->child_cnt - 1; i++) {
++		const union ubifs_key *key1, *key2;
++
++		key1 = &znode->zbranch[i].key;
++		key2 = &znode->zbranch[i + 1].key;
++
++		cmp = keys_cmp(c, key1, key2);
++		if (cmp > 0) {
++			dbg_err("bad key order (keys %d and %d)", i, i + 1);
++			err = 6;
++			goto out_dump;
++		} else if (cmp == 0 && !is_hash_key(c, key1)) {
++			/* These can only be keys with colliding hash */
++			dbg_err("keys %d and %d are not hashed but equivalent",
++				i, i + 1);
++			err = 7;
++			goto out_dump;
++		}
++	}
++
++	kfree(idx);
++	return 0;
++
++out_dump:
++	ubifs_err("bad indexing node at LEB %d:%d, error %d", lnum, offs, err);
++	dbg_dump_node(c, idx);
++	kfree(idx);
++	return -EINVAL;
++}
++
++/**
++ * ubifs_load_znode - load znode to TNC cache.
++ * @c: UBIFS file-system description object
++ * @zbr: znode branch
++ * @parent: znode's parent
++ * @iip: index in parent
++ *
++ * This function loads znode pointed to by @zbr into the TNC cache and
++ * returns pointer to it in case of success and a negative error code in case
++ * of failure.
++ */
++struct ubifs_znode *ubifs_load_znode(struct ubifs_info *c,
++				     struct ubifs_zbranch *zbr,
++				     struct ubifs_znode *parent, int iip)
++{
++	int err;
++	struct ubifs_znode *znode;
++
++	ubifs_assert(!zbr->znode);
++	/*
++	 * A slab cache is not presently used for znodes because the znode size
++	 * depends on the fanout which is stored in the superblock.
++	 */
++	znode = kzalloc(c->max_znode_sz, GFP_NOFS);
++	if (!znode)
++		return ERR_PTR(-ENOMEM);
++
++	err = read_znode(c, zbr->lnum, zbr->offs, zbr->len, znode);
++	if (err)
++		goto out;
++
++	atomic_long_inc(&c->clean_zn_cnt);
++
++	/*
++	 * Increment the global clean znode counter as well. It is OK that
++	 * global and per-FS clean znode counters may be inconsistent for some
++	 * short time (because we might be preempted at this point), the global
++	 * one is only used in shrinker.
++	 */
++	atomic_long_inc(&ubifs_clean_zn_cnt);
++
++	zbr->znode = znode;
++	znode->parent = parent;
++	znode->time = get_seconds();
++	znode->iip = iip;
++
++	return znode;
++
++out:
++	kfree(znode);
++	return ERR_PTR(err);
++}
++
++/**
++ * ubifs_tnc_read_node - read a leaf node from the flash media.
++ * @c: UBIFS file-system description object
++ * @zbr: key and position of the node
++ * @node: node is returned here
++ *
++ * This function reads a node defined by @zbr from the flash media. Returns
++ * zero in case of success or a negative negative error code in case of
++ * failure.
++ */
++int ubifs_tnc_read_node(struct ubifs_info *c, struct ubifs_zbranch *zbr,
++			void *node)
++{
++	union ubifs_key key1, *key = &zbr->key;
++	int err, type = key_type(c, key);
++	struct ubifs_wbuf *wbuf;
++
++	/*
++	 * 'zbr' has to point to on-flash node. The node may sit in a bud and
++	 * may even be in a write buffer, so we have to take care about this.
++	 */
++	wbuf = ubifs_get_wbuf(c, zbr->lnum);
++	if (wbuf)
++		err = ubifs_read_node_wbuf(wbuf, node, type, zbr->len,
++					   zbr->lnum, zbr->offs);
++	else
++		err = ubifs_read_node(c, node, type, zbr->len, zbr->lnum,
++				      zbr->offs);
++
++	if (err) {
++		dbg_tnc("key %s", DBGKEY(key));
++		return err;
++	}
++
++	/* Make sure the key of the read node is correct */
++	key_read(c, node + UBIFS_KEY_OFFSET, &key1);
++	if (!keys_eq(c, key, &key1)) {
++		ubifs_err("bad key in node at LEB %d:%d",
++			  zbr->lnum, zbr->offs);
++		dbg_tnc("looked for key %s found node's key %s",
++			DBGKEY(key), DBGKEY1(&key1));
++		dbg_dump_node(c, node);
++		return -EINVAL;
++	}
++
++	return 0;
++}
+diff -Nurd linux-2.6.24.orig/fs/ubifs/ubifs-media.h linux-2.6.24/fs/ubifs/ubifs-media.h
+--- linux-2.6.24.orig/fs/ubifs/ubifs-media.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/ubifs-media.h	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,751 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++/*
++ * This file describes UBIFS on-flash format and contains definitions of all the
++ * relevant data structures and constants.
++ *
++ * All UBIFS on-flash objects are stored in the form of nodes. All nodes start
++ * with the UBIFS node magic number and have the same common header. Nodes
++ * always sit at 8-byte aligned positions on the media and node header sizes are
++ * also 8-byte aligned (except for the indexing node and the padding node).
++ */
++
++#ifndef __UBIFS_MEDIA_H__
++#define __UBIFS_MEDIA_H__
++
++/* UBIFS node magic number (must not have the padding byte first or last) */
++#define UBIFS_NODE_MAGIC  0x06101831
++
++/* UBIFS on-flash format version */
++#define UBIFS_FORMAT_VERSION 4
++
++/* Minimum logical eraseblock size in bytes */
++#define UBIFS_MIN_LEB_SZ (15*1024)
++
++/* Initial CRC32 value used when calculating CRC checksums */
++#define UBIFS_CRC32_INIT 0xFFFFFFFFU
++
++/*
++ * UBIFS does not try to compress data if its length is less than the below
++ * constant.
++ */
++#define UBIFS_MIN_COMPR_LEN 128
++
++/*
++ * If compressed data length is less than %UBIFS_MIN_COMPRESS_DIFF bytes
++ * shorter than uncompressed data length, UBIFS preferes to leave this data
++ * node uncompress, because it'll be read faster.
++ */
++#define UBIFS_MIN_COMPRESS_DIFF 64
++
++/* Root inode number */
++#define UBIFS_ROOT_INO 1
++
++/* Lowest inode number used for regular inodes (not UBIFS-only internal ones) */
++#define UBIFS_FIRST_INO 64
++
++/*
++ * Maximum file name and extended attribute length (must be a multiple of 8,
++ * minus 1).
++ */
++#define UBIFS_MAX_NLEN 255
++
++/* Maximum number of data journal heads */
++#define UBIFS_MAX_JHEADS 1
++
++/*
++ * Size of UBIFS data block. Note, UBIFS is not a block oriented file-system,
++ * which means that it does not treat the underlying media as consisting of
++ * blocks like in case of hard drives. Do not be confused. UBIFS block is just
++ * the maximum amount of data which one data node can have or which can be
++ * attached to an inode node.
++ */
++#define UBIFS_BLOCK_SIZE  4096
++#define UBIFS_BLOCK_SHIFT 12
++
++/* UBIFS padding byte pattern (must not be first or last byte of node magic) */
++#define UBIFS_PADDING_BYTE 0xCE
++
++/* Maximum possible key length */
++#define UBIFS_MAX_KEY_LEN 16
++
++/* Key length ("simple" format) */
++#define UBIFS_SK_LEN 8
++
++/* Minimum index tree fanout */
++#define UBIFS_MIN_FANOUT 3
++
++/* Maximum number of levels in UBIFS indexing B-tree */
++#define UBIFS_MAX_LEVELS 512
++
++/* Maximum amount of data attached to an inode in bytes */
++#define UBIFS_MAX_INO_DATA UBIFS_BLOCK_SIZE
++
++/* LEB Properties Tree fanout (must be power of 2) and fanout shift */
++#define UBIFS_LPT_FANOUT 4
++#define UBIFS_LPT_FANOUT_SHIFT 2
++
++/* LEB Properties Tree bit field sizes */
++#define UBIFS_LPT_CRC_BITS 16
++#define UBIFS_LPT_CRC_BYTES 2
++#define UBIFS_LPT_TYPE_BITS 4
++
++/* The key is always at the same position in all keyed nodes */
++#define UBIFS_KEY_OFFSET offsetof(struct ubifs_ino_node, key)
++
++/*
++ * LEB Properties Tree node types.
++ *
++ * UBIFS_LPT_PNODE: LPT leaf node (contains LEB properties)
++ * UBIFS_LPT_NNODE: LPT internal node
++ * UBIFS_LPT_LTAB: LPT's own lprops table
++ * UBIFS_LPT_LSAVE: LPT's save table (big model only)
++ * UBIFS_LPT_NODE_CNT: count of LPT node types
++ * UBIFS_LPT_NOT_A_NODE: all ones (15 for 4 bits) is never a valid node type
++ */
++enum {
++	UBIFS_LPT_PNODE,
++	UBIFS_LPT_NNODE,
++	UBIFS_LPT_LTAB,
++	UBIFS_LPT_LSAVE,
++	UBIFS_LPT_NODE_CNT,
++	UBIFS_LPT_NOT_A_NODE = (1 << UBIFS_LPT_TYPE_BITS) - 1,
++};
++
++/*
++ * UBIFS inode types.
++ *
++ * UBIFS_ITYPE_REG: regular file
++ * UBIFS_ITYPE_DIR: directory
++ * UBIFS_ITYPE_LNK: soft link
++ * UBIFS_ITYPE_BLK: block device node
++ * UBIFS_ITYPE_CHR: character device node
++ * UBIFS_ITYPE_FIFO: fifo
++ * UBIFS_ITYPE_SOCK: socket
++ * UBIFS_ITYPES_CNT: count of supported file types
++ */
++enum {
++	UBIFS_ITYPE_REG,
++	UBIFS_ITYPE_DIR,
++	UBIFS_ITYPE_LNK,
++	UBIFS_ITYPE_BLK,
++	UBIFS_ITYPE_CHR,
++	UBIFS_ITYPE_FIFO,
++	UBIFS_ITYPE_SOCK,
++	UBIFS_ITYPES_CNT,
++};
++
++/*
++ * Supported key hash functions.
++ *
++ * UBIFS_KEY_HASH_R5: R5 hash
++ * UBIFS_KEY_HASH_TEST: test hash which just returns first 4 bytes of the name
++ */
++enum {
++	UBIFS_KEY_HASH_R5,
++	UBIFS_KEY_HASH_TEST,
++};
++
++/*
++ * Supported key formats.
++ *
++ * UBIFS_SIMPLE_KEY_FMT: simple key format
++ */
++enum {
++	UBIFS_SIMPLE_KEY_FMT,
++};
++
++/*
++ * The simple key format uses 29 bits for storing UBIFS block number and hash
++ * value.
++ */
++#define UBIFS_S_KEY_BLOCK_BITS 29
++#define UBIFS_S_KEY_BLOCK_MASK 0x1FFFFFFF
++#define UBIFS_S_KEY_HASH_BITS  UBIFS_S_KEY_BLOCK_BITS
++#define UBIFS_S_KEY_HASH_MASK  UBIFS_S_KEY_BLOCK_MASK
++
++/*
++ * Key types.
++ *
++ * UBIFS_INO_KEY: inode node key
++ * UBIFS_DATA_KEY: data node key
++ * UBIFS_DENT_KEY: directory entry node key
++ * UBIFS_XENT_KEY: extended attribute entry key
++ * UBIFS_KEY_TYPES_CNT: number of supported key types
++ */
++enum {
++	UBIFS_INO_KEY,
++	UBIFS_DATA_KEY,
++	UBIFS_DENT_KEY,
++	UBIFS_XENT_KEY,
++	UBIFS_KEY_TYPES_CNT,
++};
++
++/* Count of LEBs reserved for the superblock area */
++#define UBIFS_SB_LEBS 1
++/* Count of LEBs reserved for the master area */
++#define UBIFS_MST_LEBS 2
++
++/* First LEB of the superblock area */
++#define UBIFS_SB_LNUM 0
++/* First LEB of the master area */
++#define UBIFS_MST_LNUM (UBIFS_SB_LNUM + UBIFS_SB_LEBS)
++/* First LEB of the log area */
++#define UBIFS_LOG_LNUM (UBIFS_MST_LNUM + UBIFS_MST_LEBS)
++
++/*
++ * The below constants define the absolute minimum values for various UBIFS
++ * media areas. Many of them actually depend of flash geometry and the FS
++ * configuration (number of journal heads, orphan LEBs, etc). This means that
++ * the smallest volume size which can be used for UBIFS cannot be pre-defined
++ * by these constants. The file-system that meets the below limitation will not
++ * necessarily mount. UBIFS does run-time calculations and validates the FS
++ * size.
++ */
++
++/* Minimum number of logical eraseblocks in the log */
++#define UBIFS_MIN_LOG_LEBS 2
++/* Minimum number of bud logical eraseblocks (one for each head) */
++#define UBIFS_MIN_BUD_LEBS 3
++/* Minimum number of journal logical eraseblocks */
++#define UBIFS_MIN_JNL_LEBS (UBIFS_MIN_LOG_LEBS + UBIFS_MIN_BUD_LEBS)
++/* Minimum number of LPT area logical eraseblocks */
++#define UBIFS_MIN_LPT_LEBS 2
++/* Minimum number of orphan area logical eraseblocks */
++#define UBIFS_MIN_ORPH_LEBS 1
++/*
++ * Minimum number of main area logical eraseblocks (buds, 3 for the index, 1
++ * for GC, 1 for deletions, and at least 1 for committed data).
++ */
++#define UBIFS_MIN_MAIN_LEBS (UBIFS_MIN_BUD_LEBS + 6)
++
++/* Minimum number of logical eraseblocks */
++#define UBIFS_MIN_LEB_CNT (UBIFS_SB_LEBS + UBIFS_MST_LEBS + \
++			   UBIFS_MIN_LOG_LEBS + UBIFS_MIN_LPT_LEBS + \
++			   UBIFS_MIN_ORPH_LEBS + UBIFS_MIN_MAIN_LEBS)
++
++/* Node sizes (N.B. these are guaranteed to be multiples of 8) */
++#define UBIFS_CH_SZ        sizeof(struct ubifs_ch)
++#define UBIFS_INO_NODE_SZ  sizeof(struct ubifs_ino_node)
++#define UBIFS_DATA_NODE_SZ sizeof(struct ubifs_data_node)
++#define UBIFS_DENT_NODE_SZ sizeof(struct ubifs_dent_node)
++#define UBIFS_TRUN_NODE_SZ sizeof(struct ubifs_trun_node)
++#define UBIFS_PAD_NODE_SZ  sizeof(struct ubifs_pad_node)
++#define UBIFS_SB_NODE_SZ   sizeof(struct ubifs_sb_node)
++#define UBIFS_MST_NODE_SZ  sizeof(struct ubifs_mst_node)
++#define UBIFS_REF_NODE_SZ  sizeof(struct ubifs_ref_node)
++#define UBIFS_IDX_NODE_SZ  sizeof(struct ubifs_idx_node)
++#define UBIFS_CS_NODE_SZ   sizeof(struct ubifs_cs_node)
++#define UBIFS_ORPH_NODE_SZ sizeof(struct ubifs_orph_node)
++/* Extended attribute entry nodes are identical to directory entry nodes */
++#define UBIFS_XENT_NODE_SZ UBIFS_DENT_NODE_SZ
++/* Only this does not have to be multiple of 8 bytes */
++#define UBIFS_BRANCH_SZ    sizeof(struct ubifs_branch)
++
++/* Maximum node sizes (N.B. these are guaranteed to be multiples of 8) */
++#define UBIFS_MAX_DATA_NODE_SZ  (UBIFS_DATA_NODE_SZ + UBIFS_BLOCK_SIZE)
++#define UBIFS_MAX_INO_NODE_SZ   (UBIFS_INO_NODE_SZ + UBIFS_MAX_INO_DATA)
++#define UBIFS_MAX_DENT_NODE_SZ  (UBIFS_DENT_NODE_SZ + UBIFS_MAX_NLEN + 1)
++#define UBIFS_MAX_XENT_NODE_SZ  UBIFS_MAX_DENT_NODE_SZ
++
++/* The largest UBIFS node */
++#define UBIFS_MAX_NODE_SZ UBIFS_MAX_INO_NODE_SZ
++
++/*
++ * On-flash inode flags.
++ *
++ * UBIFS_COMPR_FL: use compression for this inode
++ * UBIFS_SYNC_FL:  I/O on this inode has to be synchronous
++ * UBIFS_IMMUTABLE_FL: inode is immutable
++ * UBIFS_APPEND_FL: writes to the inode may only append data
++ * UBIFS_DIRSYNC_FL: I/O on this directory inode has to be synchronous
++ * UBIFS_XATTR_FL: this inode is the inode for an extended attribute value
++ *
++ * Note, these are on-flash flags which correspond to ioctl flags
++ * (@FS_COMPR_FL, etc). They have the same values now, but generally, do not
++ * have to be the same.
++ */
++enum {
++	UBIFS_COMPR_FL     = 0x01,
++	UBIFS_SYNC_FL      = 0x02,
++	UBIFS_IMMUTABLE_FL = 0x04,
++	UBIFS_APPEND_FL    = 0x08,
++	UBIFS_DIRSYNC_FL   = 0x10,
++	UBIFS_XATTR_FL     = 0x20,
++};
++
++/* Inode flag bits used by UBIFS */
++#define UBIFS_FL_MASK 0x0000001F
++
++/*
++ * UBIFS compression types.
++ *
++ * UBIFS_COMPR_NONE: no compression
++ * UBIFS_COMPR_LZO: LZO compression
++ * UBIFS_COMPR_ZLIB: ZLIB compression
++ * UBIFS_COMPR_TYPES_CNT: count of supported compression types
++ */
++enum {
++	UBIFS_COMPR_NONE,
++	UBIFS_COMPR_LZO,
++	UBIFS_COMPR_ZLIB,
++	UBIFS_COMPR_TYPES_CNT,
++};
++
++/*
++ * UBIFS node types.
++ *
++ * UBIFS_INO_NODE: inode node
++ * UBIFS_DATA_NODE: data node
++ * UBIFS_DENT_NODE: directory entry node
++ * UBIFS_XENT_NODE: extended attribute node
++ * UBIFS_TRUN_NODE: truncation node
++ * UBIFS_PAD_NODE: padding node
++ * UBIFS_SB_NODE: superblock node
++ * UBIFS_MST_NODE: master node
++ * UBIFS_REF_NODE: LEB reference node
++ * UBIFS_IDX_NODE: index node
++ * UBIFS_CS_NODE: commit start node
++ * UBIFS_ORPH_NODE: orphan node
++ * UBIFS_NODE_TYPES_CNT: count of supported node types
++ *
++ * Note, we index arrays by these numbers, so keep them low and contiguous.
++ * Node type constants for inodes, direntries and so on have to be the same as
++ * corresponding key type constants.
++ */
++enum {
++	UBIFS_INO_NODE,
++	UBIFS_DATA_NODE,
++	UBIFS_DENT_NODE,
++	UBIFS_XENT_NODE,
++	UBIFS_TRUN_NODE,
++	UBIFS_PAD_NODE,
++	UBIFS_SB_NODE,
++	UBIFS_MST_NODE,
++	UBIFS_REF_NODE,
++	UBIFS_IDX_NODE,
++	UBIFS_CS_NODE,
++	UBIFS_ORPH_NODE,
++	UBIFS_NODE_TYPES_CNT,
++};
++
++/*
++ * Master node flags.
++ *
++ * UBIFS_MST_DIRTY: rebooted uncleanly - master node is dirty
++ * UBIFS_MST_NO_ORPHS: no orphan inodes present
++ * UBIFS_MST_RCVRY: written by recovery
++ */
++enum {
++	UBIFS_MST_DIRTY = 1,
++	UBIFS_MST_NO_ORPHS = 2,
++	UBIFS_MST_RCVRY = 4,
++};
++
++/*
++ * Node group type (used by recovery to recover whole group or none).
++ *
++ * UBIFS_NO_NODE_GROUP: this node is not part of a group
++ * UBIFS_IN_NODE_GROUP: this node is a part of a group
++ * UBIFS_LAST_OF_NODE_GROUP: this node is the last in a group
++ */
++enum {
++	UBIFS_NO_NODE_GROUP = 0,
++	UBIFS_IN_NODE_GROUP,
++	UBIFS_LAST_OF_NODE_GROUP,
++};
++
++/*
++ * Superblock flags.
++ *
++ * UBIFS_FLG_BIGLPT: if "big" LPT model is used if set
++ */
++enum {
++	UBIFS_FLG_BIGLPT = 0x02,
++};
++
++/**
++ * struct ubifs_ch - common header node.
++ * @magic: UBIFS node magic number (%UBIFS_NODE_MAGIC)
++ * @crc: CRC-32 checksum of the node header
++ * @sqnum: sequence number
++ * @len: full node length
++ * @node_type: node type
++ * @group_type: node group type
++ * @padding: reserved for future, zeroes
++ *
++ * Every UBIFS node starts with this common part. If the node has a key, the
++ * key always goes next.
++ */
++struct ubifs_ch {
++	__le32 magic;
++	__le32 crc;
++	__le64 sqnum;
++	__le32 len;
++	__u8 node_type;
++	__u8 group_type;
++	__u8 padding[2];
++} __attribute__ ((packed));
++
++/**
++ * union ubifs_dev_desc - device node descriptor.
++ * @new: new type device descriptor
++ * @huge: huge type device descriptor
++ *
++ * This data structure describes major/minor numbers of a device node. In an
++ * inode is a device node then its data contains an object of this type. UBIFS
++ * uses standard Linux "new" and "huge" device node encodings.
++ */
++union ubifs_dev_desc {
++	__le32 new;
++	__le64 huge;
++} __attribute__ ((packed));
++
++/**
++ * struct ubifs_ino_node - inode node.
++ * @ch: common header
++ * @key: node key
++ * @creat_sqnum: sequence number at time of creation
++ * @size: inode size in bytes (amount of uncompressed data)
++ * @atime_sec: access time seconds
++ * @ctime_sec: creation time seconds
++ * @mtime_sec: modification time seconds
++ * @atime_nsec: access time nanoseconds
++ * @ctime_nsec: creation time nanoseconds
++ * @mtime_nsec: modification time nanoseconds
++ * @nlink: number of hard links
++ * @uid: owner ID
++ * @gid: group ID
++ * @mode: access flags
++ * @flags: per-inode flags (%UBIFS_COMPR_FL, %UBIFS_SYNC_FL, etc)
++ * @data_len: inode data length
++ * @xattr_cnt: count of extended attributes this inode has
++ * @xattr_size: summarized size of all extended attributes in bytes
++ * @padding1: reserved for future, zeroes
++ * @xattr_names: sum of lengths of all extended attribute names belonging to
++ *               this inode
++ * @compr_type: compression type used for this inode
++ * @padding2: reserved for future, zeroes
++ * @data: data attached to the inode
++ *
++ * Note, even though inode compression type is defined by @compr_type, some
++ * nodes of this inode may be compressed with different compressor - this
++ * happens if compression type is changed while the inode already has data
++ * nodes. But @compr_type will be use for further writes to the inode.
++ *
++ * Note, do not forget to amend 'zero_ino_node_unused()' function when changing
++ * the padding fields.
++ */
++struct ubifs_ino_node {
++	struct ubifs_ch ch;
++	__u8 key[UBIFS_MAX_KEY_LEN];
++	__le64 creat_sqnum;
++	__le64 size;
++	__le64 atime_sec;
++	__le64 ctime_sec;
++	__le64 mtime_sec;
++	__le32 atime_nsec;
++	__le32 ctime_nsec;
++	__le32 mtime_nsec;
++	__le32 nlink;
++	__le32 uid;
++	__le32 gid;
++	__le32 mode;
++	__le32 flags;
++	__le32 data_len;
++	__le32 xattr_cnt;
++	__le32 xattr_size;
++	__u8 padding1[4]; /* Watch 'zero_ino_node_unused()' if changing! */
++	__le32 xattr_names;
++	__le16 compr_type;
++	__u8 padding2[26]; /* Watch 'zero_ino_node_unused()' if changing! */
++	__u8 data[];
++} __attribute__ ((packed));
++
++/**
++ * struct ubifs_dent_node - directory entry node.
++ * @ch: common header
++ * @key: node key
++ * @inum: target inode number
++ * @padding1: reserved for future, zeroes
++ * @type: type of the target inode (%UBIFS_ITYPE_REG, %UBIFS_ITYPE_DIR, etc)
++ * @nlen: name length
++ * @padding2: reserved for future, zeroes
++ * @name: zero-terminated name
++ *
++ * Note, do not forget to amend 'zero_dent_node_unused()' function when
++ * changing the padding fields.
++ */
++struct ubifs_dent_node {
++	struct ubifs_ch ch;
++	__u8 key[UBIFS_MAX_KEY_LEN];
++	__le64 inum;
++	__u8 padding1;
++	__u8 type;
++	__le16 nlen;
++	__u8 padding2[4]; /* Watch 'zero_dent_node_unused()' if changing! */
++	__u8 name[];
++} __attribute__ ((packed));
++
++/**
++ * struct ubifs_data_node - data node.
++ * @ch: common header
++ * @key: node key
++ * @size: uncompressed data size in bytes
++ * @compr_type: compression type (%UBIFS_COMPR_NONE, %UBIFS_COMPR_LZO, etc)
++ * @padding: reserved for future, zeroes
++ * @data: data
++ *
++ * Note, do not forget to amend 'zero_data_node_unused()' function when
++ * changing the padding fields.
++ */
++struct ubifs_data_node {
++	struct ubifs_ch ch;
++	__u8 key[UBIFS_MAX_KEY_LEN];
++	__le32 size;
++	__le16 compr_type;
++	__u8 padding[2]; /* Watch 'zero_data_node_unused()' if changing! */
++	__u8 data[];
++} __attribute__ ((packed));
++
++/**
++ * struct ubifs_trun_node - truncation node.
++ * @ch: common header
++ * @inum: truncated inode number
++ * @padding: reserved for future, zeroes
++ * @old_size: size before truncation
++ * @new_size: size after truncation
++ *
++ * This node exists only in the journal and never goes to the main area. Note,
++ * do not forget to amend 'zero_trun_node_unused()' function when changing the
++ * padding fields.
++ */
++struct ubifs_trun_node {
++	struct ubifs_ch ch;
++	__le32 inum;
++	__u8 padding[12]; /* Watch 'zero_trun_node_unused()' if changing! */
++	__le64 old_size;
++	__le64 new_size;
++} __attribute__ ((packed));
++
++/**
++ * struct ubifs_pad_node - padding node.
++ * @ch: common header
++ * @pad_len: how many bytes after this node are unused (because padded)
++ * @padding: reserved for future, zeroes
++ */
++struct ubifs_pad_node {
++	struct ubifs_ch ch;
++	__le32 pad_len;
++} __attribute__ ((packed));
++
++/**
++ * struct ubifs_sb_node - superblock node.
++ * @ch: common header
++ * @padding: reserved for future, zeroes
++ * @key_hash: type of hash function used in keys
++ * @key_fmt: format of the key
++ * @flags: file-system flags (%UBIFS_FLG_BIGLPT, etc)
++ * @min_io_size: minimal input/output unit size
++ * @leb_size: logical eraseblock size in bytes
++ * @leb_cnt: count of LEBs used by file-system
++ * @max_leb_cnt: maximum count of LEBs used by file-system
++ * @max_bud_bytes: maximum amount of data stored in buds
++ * @log_lebs: log size in logical eraseblocks
++ * @lpt_lebs: number of LEBs used for lprops table
++ * @orph_lebs: number of LEBs used for recording orphans
++ * @jhead_cnt: count of journal heads
++ * @fanout: tree fanout (max. number of links per indexing node)
++ * @lsave_cnt: number of LEB numbers in LPT's save table
++ * @fmt_version: UBIFS on-flash format version
++ * @default_compr: default compression
++ * @padding1: reserved for future, zeroes
++ * @rp_uid: reserve pool UID
++ * @rp_gid: reserve pool GID
++ * @rp_size: size of the reserved pool in bytes
++ * @padding2: reserved for future, zeroes
++ * @time_gran: time granularity in nanoseconds
++ * @uuid: UUID generated when the file system image was created
++ */
++struct ubifs_sb_node {
++	struct ubifs_ch ch;
++	__u8 padding[2];
++	__u8 key_hash;
++	__u8 key_fmt;
++	__le32 flags;
++	__le32 min_io_size;
++	__le32 leb_size;
++	__le32 leb_cnt;
++	__le32 max_leb_cnt;
++	__le64 max_bud_bytes;
++	__le32 log_lebs;
++	__le32 lpt_lebs;
++	__le32 orph_lebs;
++	__le32 jhead_cnt;
++	__le32 fanout;
++	__le32 lsave_cnt;
++	__le32 fmt_version;
++	__le16 default_compr;
++	__u8 padding1[2];
++	__le32 rp_uid;
++	__le32 rp_gid;
++	__le64 rp_size;
++	__le32 time_gran;
++	__u8 uuid[16];
++	__u8 padding2[3972];
++} __attribute__ ((packed));
++
++/**
++ * struct ubifs_mst_node - master node.
++ * @ch: common header
++ * @highest_inum: highest inode number in the committed index
++ * @cmt_no: commit number
++ * @flags: various flags (%UBIFS_MST_DIRTY, etc)
++ * @log_lnum: start of the log
++ * @root_lnum: LEB number of the root indexing node
++ * @root_offs: offset within @root_lnum
++ * @root_len: root indexing node length
++ * @gc_lnum: LEB reserved for garbage collection (%-1 value means the LEB was
++ * not reserved and should be reserved on mount)
++ * @ihead_lnum: LEB number of index head
++ * @ihead_offs: offset of index head
++ * @index_size: size of index on flash
++ * @total_free: total free space in bytes
++ * @total_dirty: total dirty space in bytes
++ * @total_used: total used space in bytes (includes only data LEBs)
++ * @total_dead: total dead space in bytes (includes only data LEBs)
++ * @total_dark: total dark space in bytes (includes only data LEBs)
++ * @lpt_lnum: LEB number of LPT root nnode
++ * @lpt_offs: offset of LPT root nnode
++ * @nhead_lnum: LEB number of LPT head
++ * @nhead_offs: offset of LPT head
++ * @ltab_lnum: LEB number of LPT's own lprops table
++ * @ltab_offs: offset of LPT's own lprops table
++ * @lsave_lnum: LEB number of LPT's save table (big model only)
++ * @lsave_offs: offset of LPT's save table (big model only)
++ * @lscan_lnum: LEB number of last LPT scan
++ * @empty_lebs: number of empty logical eraseblocks
++ * @idx_lebs: number of indexing logical eraseblocks
++ * @leb_cnt: count of LEBs used by file-system
++ * @padding: reserved for future, zeroes
++ */
++struct ubifs_mst_node {
++	struct ubifs_ch ch;
++	__le64 highest_inum;
++	__le64 cmt_no;
++	__le32 flags;
++	__le32 log_lnum;
++	__le32 root_lnum;
++	__le32 root_offs;
++	__le32 root_len;
++	__le32 gc_lnum;
++	__le32 ihead_lnum;
++	__le32 ihead_offs;
++	__le64 index_size;
++	__le64 total_free;
++	__le64 total_dirty;
++	__le64 total_used;
++	__le64 total_dead;
++	__le64 total_dark;
++	__le32 lpt_lnum;
++	__le32 lpt_offs;
++	__le32 nhead_lnum;
++	__le32 nhead_offs;
++	__le32 ltab_lnum;
++	__le32 ltab_offs;
++	__le32 lsave_lnum;
++	__le32 lsave_offs;
++	__le32 lscan_lnum;
++	__le32 empty_lebs;
++	__le32 idx_lebs;
++	__le32 leb_cnt;
++	__u8 padding[344];
++} __attribute__ ((packed));
++
++/**
++ * struct ubifs_ref_node - logical eraseblock reference node.
++ * @ch: common header
++ * @lnum: the referred logical eraseblock number
++ * @offs: start offset in the referred LEB
++ * @jhead: journal head number
++ * @padding: reserved for future, zeroes
++ */
++struct ubifs_ref_node {
++	struct ubifs_ch ch;
++	__le32 lnum;
++	__le32 offs;
++	__le32 jhead;
++	__u8 padding[28];
++} __attribute__ ((packed));
++
++/**
++ * struct ubifs_branch - key/reference/length branch
++ * @lnum: LEB number of the target node
++ * @offs: offset within @lnum
++ * @len: target node length
++ * @key: key
++ */
++struct ubifs_branch {
++	__le32 lnum;
++	__le32 offs;
++	__le32 len;
++	__u8 key[];
++} __attribute__ ((packed));
++
++/**
++ * struct ubifs_idx_node - indexing node.
++ * @ch: common header
++ * @child_cnt: number of child index nodes
++ * @level: tree level
++ * @branches: LEB number / offset / length / key branches
++ */
++struct ubifs_idx_node {
++	struct ubifs_ch ch;
++	__le16 child_cnt;
++	__le16 level;
++	__u8 branches[];
++} __attribute__ ((packed));
++
++/**
++ * struct ubifs_cs_node - commit start node.
++ * @ch: common header
++ * @cmt_no: commit number
++ */
++struct ubifs_cs_node {
++	struct ubifs_ch ch;
++	__le64 cmt_no;
++} __attribute__ ((packed));
++
++/**
++ * struct ubifs_orph_node - orphan node.
++ * @ch: common header
++ * @cmt_no: commit number (also top bit is set on the last node of the commit)
++ * @inos: inode numbers of orphans
++ */
++struct ubifs_orph_node {
++	struct ubifs_ch ch;
++	__le64 cmt_no;
++	__le64 inos[];
++} __attribute__ ((packed));
++
++#endif /* __UBIFS_MEDIA_H__ */
+diff -Nurd linux-2.6.24.orig/fs/ubifs/ubifs.h linux-2.6.24/fs/ubifs/ubifs.h
+--- linux-2.6.24.orig/fs/ubifs/ubifs.h	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/ubifs.h	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,1722 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++#ifndef __UBIFS_H__
++#define __UBIFS_H__
++
++#include <asm/div64.h>
++#include <linux/statfs.h>
++#include <linux/fs.h>
++#include <linux/err.h>
++#include <linux/sched.h>
++#include <linux/vmalloc.h>
++#include <linux/spinlock.h>
++#include <linux/mutex.h>
++#include <linux/rwsem.h>
++#include <linux/mtd/ubi.h>
++#include <linux/pagemap.h>
++#include <linux/backing-dev.h>
++#include "ubifs-media.h"
++
++/* Version of this UBIFS implementation */
++#define UBIFS_VERSION 1
++
++/* Normal UBIFS messages */
++#define ubifs_msg(fmt, ...) \
++		printk(KERN_NOTICE "UBIFS: " fmt "\n", ##__VA_ARGS__)
++/* UBIFS error messages */
++#define ubifs_err(fmt, ...)                                                  \
++	printk(KERN_ERR "UBIFS error (pid %d): %s: " fmt "\n", current->pid, \
++	       __func__, ##__VA_ARGS__)
++/* UBIFS warning messages */
++#define ubifs_warn(fmt, ...)                                         \
++	printk(KERN_WARNING "UBIFS warning (pid %d): %s: " fmt "\n", \
++	       current->pid, __func__, ##__VA_ARGS__)
++
++/* UBIFS file system VFS magic number */
++#define UBIFS_SUPER_MAGIC 0x24051905
++
++/* Number of UBIFS blocks per VFS page */
++#define UBIFS_BLOCKS_PER_PAGE (PAGE_CACHE_SIZE / UBIFS_BLOCK_SIZE)
++#define UBIFS_BLOCKS_PER_PAGE_SHIFT (PAGE_CACHE_SHIFT - UBIFS_BLOCK_SHIFT)
++
++/* "File system end of life" sequence number watermark */
++#define SQNUM_WARN_WATERMARK 0xFFFFFFFF00000000ULL
++#define SQNUM_WATERMARK      0xFFFFFFFFFF000000ULL
++
++/*
++ * Minimum amount of LEBs reserved for the index. At present the index needs at
++ * least 2 LEBs: one for the index head and one for in-the-gaps method (which
++ * currently does not cater for the index head and so excludes it from
++ * consideration).
++ */
++#define MIN_INDEX_LEBS 2
++
++/* Minimum amount of data UBIFS writes to the flash */
++#define MIN_WRITE_SZ (UBIFS_DATA_NODE_SZ + 8)
++
++/*
++ * Currently we do not support inode number overlapping and re-using, so this
++ * watermark defines dangerous inode number level. This should be fixed later,
++ * although it is difficult to exceed current limit. Another option is to use
++ * 64-bit inode numbers, but this means more overhead.
++ */
++#define INUM_WARN_WATERMARK 0xFFF00000
++#define INUM_WATERMARK      0xFFFFFF00
++
++/* Largest key size supported in this implementation */
++#define CUR_MAX_KEY_LEN UBIFS_SK_LEN
++
++/* Maximum number of entries in each LPT (LEB category) heap */
++#define LPT_HEAP_SZ 256
++
++/*
++ * Background thread name pattern. The numbers are UBI device and volume
++ * numbers.
++ */
++#define BGT_NAME_PATTERN "ubifs_bgt%d_%d"
++
++/* Default write-buffer synchronization timeout (5 secs) */
++#define DEFAULT_WBUF_TIMEOUT (5 * HZ)
++
++/* Maximum possible inode number (only 32-bit inodes are supported now) */
++#define MAX_INUM 0xFFFFFFFF
++
++/* Number of non-data journal heads */
++#define NONDATA_JHEADS_CNT 2
++
++/* Garbage collector head */
++#define GCHD   0
++/* Base journal head number */
++#define BASEHD 1
++/* First "general purpose" journal head */
++#define DATAHD 2
++
++/* 'No change' value for 'ubifs_change_lp()' */
++#define LPROPS_NC 0x80000001
++
++/*
++ * There is no notion of truncation key because truncation nodes do not exist
++ * in TNC. However, when replaying, it is handy to introduce fake "truncation"
++ * keys for truncation nodes because the code becomes simpler. So we define
++ * %UBIFS_TRUN_KEY type.
++ */
++#define UBIFS_TRUN_KEY UBIFS_KEY_TYPES_CNT
++
++/*
++ * How much a directory entry/extended attribute entry adds to the parent/host
++ * inode.
++ */
++#define CALC_DENT_SIZE(name_len) ALIGN(UBIFS_DENT_NODE_SZ + (name_len) + 1, 8)
++
++/* How much an extended attribute adds to the host inode */
++#define CALC_XATTR_BYTES(data_len) ALIGN(UBIFS_INO_NODE_SZ + (data_len) + 1, 8)
++
++/*
++ * Znodes which were not touched for 'OLD_ZNODE_AGE' seconds are considered
++ * "old", and znode which were touched last 'YOUNG_ZNODE_AGE' seconds ago are
++ * considered "young". This is used by shrinker when selecting znode to trim
++ * off.
++ */
++#define OLD_ZNODE_AGE 20
++#define YOUNG_ZNODE_AGE 5
++
++/*
++ * Some compressors, like LZO, may end up with more data then the input buffer.
++ * So UBIFS always allocates larger output buffer, to be sure the compressor
++ * will not corrupt memory in case of worst case compression.
++ */
++#define WORST_COMPR_FACTOR 2
++
++/* Maximum expected tree height for use by bottom_up_buf */
++#define BOTTOM_UP_HEIGHT 64
++
++/* Maximum number of data nodes to bulk-read */
++#define UBIFS_MAX_BULK_READ 32
++
++/*
++ * Lockdep classes for UBIFS inode @ui_mutex.
++ */
++enum {
++	WB_MUTEX_1 = 0,
++	WB_MUTEX_2 = 1,
++	WB_MUTEX_3 = 2,
++};
++
++/*
++ * Znode flags (actually, bit numbers which store the flags).
++ *
++ * DIRTY_ZNODE: znode is dirty
++ * COW_ZNODE: znode is being committed and a new instance of this znode has to
++ *            be created before changing this znode
++ * OBSOLETE_ZNODE: znode is obsolete, which means it was deleted, but it is
++ *                 still in the commit list and the ongoing commit operation
++ *                 will commit it, and delete this znode after it is done
++ */
++enum {
++	DIRTY_ZNODE    = 0,
++	COW_ZNODE      = 1,
++	OBSOLETE_ZNODE = 2,
++};
++
++/*
++ * Commit states.
++ *
++ * COMMIT_RESTING: commit is not wanted
++ * COMMIT_BACKGROUND: background commit has been requested
++ * COMMIT_REQUIRED: commit is required
++ * COMMIT_RUNNING_BACKGROUND: background commit is running
++ * COMMIT_RUNNING_REQUIRED: commit is running and it is required
++ * COMMIT_BROKEN: commit failed
++ */
++enum {
++	COMMIT_RESTING = 0,
++	COMMIT_BACKGROUND,
++	COMMIT_REQUIRED,
++	COMMIT_RUNNING_BACKGROUND,
++	COMMIT_RUNNING_REQUIRED,
++	COMMIT_BROKEN,
++};
++
++/*
++ * 'ubifs_scan_a_node()' return values.
++ *
++ * SCANNED_GARBAGE:  scanned garbage
++ * SCANNED_EMPTY_SPACE: scanned empty space
++ * SCANNED_A_NODE: scanned a valid node
++ * SCANNED_A_CORRUPT_NODE: scanned a corrupted node
++ * SCANNED_A_BAD_PAD_NODE: scanned a padding node with invalid pad length
++ *
++ * Greater than zero means: 'scanned that number of padding bytes'
++ */
++enum {
++	SCANNED_GARBAGE        = 0,
++	SCANNED_EMPTY_SPACE    = -1,
++	SCANNED_A_NODE         = -2,
++	SCANNED_A_CORRUPT_NODE = -3,
++	SCANNED_A_BAD_PAD_NODE = -4,
++};
++
++/*
++ * LPT cnode flag bits.
++ *
++ * DIRTY_CNODE: cnode is dirty
++ * COW_CNODE: cnode is being committed and must be copied before writing
++ * OBSOLETE_CNODE: cnode is being committed and has been copied (or deleted),
++ * so it can (and must) be freed when the commit is finished
++ */
++enum {
++	DIRTY_CNODE    = 0,
++	COW_CNODE      = 1,
++	OBSOLETE_CNODE = 2,
++};
++
++/*
++ * Dirty flag bits (lpt_drty_flgs) for LPT special nodes.
++ *
++ * LTAB_DIRTY: ltab node is dirty
++ * LSAVE_DIRTY: lsave node is dirty
++ */
++enum {
++	LTAB_DIRTY  = 1,
++	LSAVE_DIRTY = 2,
++};
++
++/*
++ * Return codes used by the garbage collector.
++ * @LEB_FREED: the logical eraseblock was freed and is ready to use
++ * @LEB_FREED_IDX: indexing LEB was freed and can be used only after the commit
++ * @LEB_RETAINED: the logical eraseblock was freed and retained for GC purposes
++ */
++enum {
++	LEB_FREED,
++	LEB_FREED_IDX,
++	LEB_RETAINED,
++};
++
++/**
++ * struct ubifs_old_idx - index node obsoleted since last commit start.
++ * @rb: rb-tree node
++ * @lnum: LEB number of obsoleted index node
++ * @offs: offset of obsoleted index node
++ */
++struct ubifs_old_idx {
++	struct rb_node rb;
++	int lnum;
++	int offs;
++};
++
++/* The below union makes it easier to deal with keys */
++union ubifs_key {
++	uint8_t u8[CUR_MAX_KEY_LEN];
++	uint32_t u32[CUR_MAX_KEY_LEN/4];
++	uint64_t u64[CUR_MAX_KEY_LEN/8];
++	__le32 j32[CUR_MAX_KEY_LEN/4];
++};
++
++/**
++ * struct ubifs_scan_node - UBIFS scanned node information.
++ * @list: list of scanned nodes
++ * @key: key of node scanned (if it has one)
++ * @sqnum: sequence number
++ * @type: type of node scanned
++ * @offs: offset with LEB of node scanned
++ * @len: length of node scanned
++ * @node: raw node
++ */
++struct ubifs_scan_node {
++	struct list_head list;
++	union ubifs_key key;
++	unsigned long long sqnum;
++	int type;
++	int offs;
++	int len;
++	void *node;
++};
++
++/**
++ * struct ubifs_scan_leb - UBIFS scanned LEB information.
++ * @lnum: logical eraseblock number
++ * @nodes_cnt: number of nodes scanned
++ * @nodes: list of struct ubifs_scan_node
++ * @endpt: end point (and therefore the start of empty space)
++ * @ecc: read returned -EBADMSG
++ * @buf: buffer containing entire LEB scanned
++ */
++struct ubifs_scan_leb {
++	int lnum;
++	int nodes_cnt;
++	struct list_head nodes;
++	int endpt;
++	int ecc;
++	void *buf;
++};
++
++/**
++ * struct ubifs_gced_idx_leb - garbage-collected indexing LEB.
++ * @list: list
++ * @lnum: LEB number
++ * @unmap: OK to unmap this LEB
++ *
++ * This data structure is used to temporary store garbage-collected indexing
++ * LEBs - they are not released immediately, but only after the next commit.
++ * This is needed to guarantee recoverability.
++ */
++struct ubifs_gced_idx_leb {
++	struct list_head list;
++	int lnum;
++	int unmap;
++};
++
++/**
++ * struct ubifs_inode - UBIFS in-memory inode description.
++ * @vfs_inode: VFS inode description object
++ * @creat_sqnum: sequence number at time of creation
++ * @del_cmtno: commit number corresponding to the time the inode was deleted,
++ *             protected by @c->commit_sem;
++ * @xattr_size: summarized size of all extended attributes in bytes
++ * @xattr_cnt: count of extended attributes this inode has
++ * @xattr_names: sum of lengths of all extended attribute names belonging to
++ *               this inode
++ * @dirty: non-zero if the inode is dirty
++ * @xattr: non-zero if this is an extended attribute inode
++ * @bulk_read: non-zero if bulk-read should be used
++ * @ui_mutex: serializes inode write-back with the rest of VFS operations,
++ *            serializes "clean <-> dirty" state changes, serializes bulk-read,
++ *            protects @dirty, @bulk_read, @ui_size, and @xattr_size
++ * @ui_lock: protects @synced_i_size
++ * @synced_i_size: synchronized size of inode, i.e. the value of inode size
++ *                 currently stored on the flash; used only for regular file
++ *                 inodes
++ * @ui_size: inode size used by UBIFS when writing to flash
++ * @flags: inode flags (@UBIFS_COMPR_FL, etc)
++ * @compr_type: default compression type used for this inode
++ * @last_page_read: page number of last page read (for bulk read)
++ * @read_in_a_row: number of consecutive pages read in a row (for bulk read)
++ * @data_len: length of the data attached to the inode
++ * @data: inode's data
++ *
++ * @ui_mutex exists for two main reasons. At first it prevents inodes from
++ * being written back while UBIFS changing them, being in the middle of an VFS
++ * operation. This way UBIFS makes sure the inode fields are consistent. For
++ * example, in 'ubifs_rename()' we change 3 inodes simultaneously, and
++ * write-back must not write any of them before we have finished.
++ *
++ * The second reason is budgeting - UBIFS has to budget all operations. If an
++ * operation is going to mark an inode dirty, it has to allocate budget for
++ * this. It cannot just mark it dirty because there is no guarantee there will
++ * be enough flash space to write the inode back later. This means UBIFS has
++ * to have full control over inode "clean <-> dirty" transitions (and pages
++ * actually). But unfortunately, VFS marks inodes dirty in many places, and it
++ * does not ask the file-system if it is allowed to do so (there is a notifier,
++ * but it is not enough), i.e., there is no mechanism to synchronize with this.
++ * So UBIFS has its own inode dirty flag and its own mutex to serialize
++ * "clean <-> dirty" transitions.
++ *
++ * The @synced_i_size field is used to make sure we never write pages which are
++ * beyond last synchronized inode size. See 'ubifs_writepage()' for more
++ * information.
++ *
++ * The @ui_size is a "shadow" variable for @inode->i_size and UBIFS uses
++ * @ui_size instead of @inode->i_size. The reason for this is that UBIFS cannot
++ * make sure @inode->i_size is always changed under @ui_mutex, because it
++ * cannot call 'vmtruncate()' with @ui_mutex locked, because it would deadlock
++ * with 'ubifs_writepage()' (see file.c). All the other inode fields are
++ * changed under @ui_mutex, so they do not need "shadow" fields. Note, one
++ * could consider to rework locking and base it on "shadow" fields.
++ */
++struct ubifs_inode {
++	struct inode vfs_inode;
++	unsigned long long creat_sqnum;
++	unsigned long long del_cmtno;
++	unsigned int xattr_size;
++	unsigned int xattr_cnt;
++	unsigned int xattr_names;
++	unsigned int dirty:1;
++	unsigned int xattr:1;
++	unsigned int bulk_read:1;
++	unsigned int compr_type:2;
++	struct mutex ui_mutex;
++	spinlock_t ui_lock;
++	loff_t synced_i_size;
++	loff_t ui_size;
++	int flags;
++	pgoff_t last_page_read;
++	pgoff_t read_in_a_row;
++	int data_len;
++	void *data;
++};
++
++/**
++ * struct ubifs_unclean_leb - records a LEB recovered under read-only mode.
++ * @list: list
++ * @lnum: LEB number of recovered LEB
++ * @endpt: offset where recovery ended
++ *
++ * This structure records a LEB identified during recovery that needs to be
++ * cleaned but was not because UBIFS was mounted read-only. The information
++ * is used to clean the LEB when remounting to read-write mode.
++ */
++struct ubifs_unclean_leb {
++	struct list_head list;
++	int lnum;
++	int endpt;
++};
++
++/*
++ * LEB properties flags.
++ *
++ * LPROPS_UNCAT: not categorized
++ * LPROPS_DIRTY: dirty > free, dirty >= @c->dead_wm, not index
++ * LPROPS_DIRTY_IDX: dirty + free > @c->min_idx_node_sze and index
++ * LPROPS_FREE: free > 0, dirty < @c->dead_wm, not empty, not index
++ * LPROPS_HEAP_CNT: number of heaps used for storing categorized LEBs
++ * LPROPS_EMPTY: LEB is empty, not taken
++ * LPROPS_FREEABLE: free + dirty == leb_size, not index, not taken
++ * LPROPS_FRDI_IDX: free + dirty == leb_size and index, may be taken
++ * LPROPS_CAT_MASK: mask for the LEB categories above
++ * LPROPS_TAKEN: LEB was taken (this flag is not saved on the media)
++ * LPROPS_INDEX: LEB contains indexing nodes (this flag also exists on flash)
++ */
++enum {
++	LPROPS_UNCAT     =  0,
++	LPROPS_DIRTY     =  1,
++	LPROPS_DIRTY_IDX =  2,
++	LPROPS_FREE      =  3,
++	LPROPS_HEAP_CNT  =  3,
++	LPROPS_EMPTY     =  4,
++	LPROPS_FREEABLE  =  5,
++	LPROPS_FRDI_IDX  =  6,
++	LPROPS_CAT_MASK  = 15,
++	LPROPS_TAKEN     = 16,
++	LPROPS_INDEX     = 32,
++};
++
++/**
++ * struct ubifs_lprops - logical eraseblock properties.
++ * @free: amount of free space in bytes
++ * @dirty: amount of dirty space in bytes
++ * @flags: LEB properties flags (see above)
++ * @lnum: LEB number
++ * @list: list of same-category lprops (for LPROPS_EMPTY and LPROPS_FREEABLE)
++ * @hpos: heap position in heap of same-category lprops (other categories)
++ */
++struct ubifs_lprops {
++	int free;
++	int dirty;
++	int flags;
++	int lnum;
++	union {
++		struct list_head list;
++		int hpos;
++	};
++};
++
++/**
++ * struct ubifs_lpt_lprops - LPT logical eraseblock properties.
++ * @free: amount of free space in bytes
++ * @dirty: amount of dirty space in bytes
++ * @tgc: trivial GC flag (1 => unmap after commit end)
++ * @cmt: commit flag (1 => reserved for commit)
++ */
++struct ubifs_lpt_lprops {
++	int free;
++	int dirty;
++	unsigned tgc:1;
++	unsigned cmt:1;
++};
++
++/**
++ * struct ubifs_lp_stats - statistics of eraseblocks in the main area.
++ * @empty_lebs: number of empty LEBs
++ * @taken_empty_lebs: number of taken LEBs
++ * @idx_lebs: number of indexing LEBs
++ * @total_free: total free space in bytes (includes all LEBs)
++ * @total_dirty: total dirty space in bytes (includes all LEBs)
++ * @total_used: total used space in bytes (does not include index LEBs)
++ * @total_dead: total dead space in bytes (does not include index LEBs)
++ * @total_dark: total dark space in bytes (does not include index LEBs)
++ *
++ * The @taken_empty_lebs field counts the LEBs that are in the transient state
++ * of having been "taken" for use but not yet written to. @taken_empty_lebs is
++ * needed to account correctly for @gc_lnum, otherwise @empty_lebs could be
++ * used by itself (in which case 'unused_lebs' would be a better name). In the
++ * case of @gc_lnum, it is "taken" at mount time or whenever a LEB is retained
++ * by GC, but unlike other empty LEBs that are "taken", it may not be written
++ * straight away (i.e. before the next commit start or unmount), so either
++ * @gc_lnum must be specially accounted for, or the current approach followed
++ * i.e. count it under @taken_empty_lebs.
++ *
++ * @empty_lebs includes @taken_empty_lebs.
++ *
++ * @total_used, @total_dead and @total_dark fields do not account indexing
++ * LEBs.
++ */
++struct ubifs_lp_stats {
++	int empty_lebs;
++	int taken_empty_lebs;
++	int idx_lebs;
++	long long total_free;
++	long long total_dirty;
++	long long total_used;
++	long long total_dead;
++	long long total_dark;
++};
++
++struct ubifs_nnode;
++
++/**
++ * struct ubifs_cnode - LEB Properties Tree common node.
++ * @parent: parent nnode
++ * @cnext: next cnode to commit
++ * @flags: flags (%DIRTY_LPT_NODE or %OBSOLETE_LPT_NODE)
++ * @iip: index in parent
++ * @level: level in the tree (zero for pnodes, greater than zero for nnodes)
++ * @num: node number
++ */
++struct ubifs_cnode {
++	struct ubifs_nnode *parent;
++	struct ubifs_cnode *cnext;
++	unsigned long flags;
++	int iip;
++	int level;
++	int num;
++};
++
++/**
++ * struct ubifs_pnode - LEB Properties Tree leaf node.
++ * @parent: parent nnode
++ * @cnext: next cnode to commit
++ * @flags: flags (%DIRTY_LPT_NODE or %OBSOLETE_LPT_NODE)
++ * @iip: index in parent
++ * @level: level in the tree (always zero for pnodes)
++ * @num: node number
++ * @lprops: LEB properties array
++ */
++struct ubifs_pnode {
++	struct ubifs_nnode *parent;
++	struct ubifs_cnode *cnext;
++	unsigned long flags;
++	int iip;
++	int level;
++	int num;
++	struct ubifs_lprops lprops[UBIFS_LPT_FANOUT];
++};
++
++/**
++ * struct ubifs_nbranch - LEB Properties Tree internal node branch.
++ * @lnum: LEB number of child
++ * @offs: offset of child
++ * @nnode: nnode child
++ * @pnode: pnode child
++ * @cnode: cnode child
++ */
++struct ubifs_nbranch {
++	int lnum;
++	int offs;
++	union {
++		struct ubifs_nnode *nnode;
++		struct ubifs_pnode *pnode;
++		struct ubifs_cnode *cnode;
++	};
++};
++
++/**
++ * struct ubifs_nnode - LEB Properties Tree internal node.
++ * @parent: parent nnode
++ * @cnext: next cnode to commit
++ * @flags: flags (%DIRTY_LPT_NODE or %OBSOLETE_LPT_NODE)
++ * @iip: index in parent
++ * @level: level in the tree (always greater than zero for nnodes)
++ * @num: node number
++ * @nbranch: branches to child nodes
++ */
++struct ubifs_nnode {
++	struct ubifs_nnode *parent;
++	struct ubifs_cnode *cnext;
++	unsigned long flags;
++	int iip;
++	int level;
++	int num;
++	struct ubifs_nbranch nbranch[UBIFS_LPT_FANOUT];
++};
++
++/**
++ * struct ubifs_lpt_heap - heap of categorized lprops.
++ * @arr: heap array
++ * @cnt: number in heap
++ * @max_cnt: maximum number allowed in heap
++ *
++ * There are %LPROPS_HEAP_CNT heaps.
++ */
++struct ubifs_lpt_heap {
++	struct ubifs_lprops **arr;
++	int cnt;
++	int max_cnt;
++};
++
++/*
++ * Return codes for LPT scan callback function.
++ *
++ * LPT_SCAN_CONTINUE: continue scanning
++ * LPT_SCAN_ADD: add the LEB properties scanned to the tree in memory
++ * LPT_SCAN_STOP: stop scanning
++ */
++enum {
++	LPT_SCAN_CONTINUE = 0,
++	LPT_SCAN_ADD = 1,
++	LPT_SCAN_STOP = 2,
++};
++
++struct ubifs_info;
++
++/* Callback used by the 'ubifs_lpt_scan_nolock()' function */
++typedef int (*ubifs_lpt_scan_callback)(struct ubifs_info *c,
++				       const struct ubifs_lprops *lprops,
++				       int in_tree, void *data);
++
++/**
++ * struct ubifs_wbuf - UBIFS write-buffer.
++ * @c: UBIFS file-system description object
++ * @buf: write-buffer (of min. flash I/O unit size)
++ * @lnum: logical eraseblock number the write-buffer points to
++ * @offs: write-buffer offset in this logical eraseblock
++ * @avail: number of bytes available in the write-buffer
++ * @used:  number of used bytes in the write-buffer
++ * @dtype: type of data stored in this LEB (%UBI_LONGTERM, %UBI_SHORTTERM,
++ * %UBI_UNKNOWN)
++ * @jhead: journal head the mutex belongs to (note, needed only to shut lockdep
++ *         up by 'mutex_lock_nested()).
++ * @sync_callback: write-buffer synchronization callback
++ * @io_mutex: serializes write-buffer I/O
++ * @lock: serializes @buf, @lnum, @offs, @avail, @used, @next_ino and @inodes
++ *        fields
++ * @timer: write-buffer timer
++ * @timeout: timer expire interval in jiffies
++ * @need_sync: it is set if its timer expired and needs sync
++ * @next_ino: points to the next position of the following inode number
++ * @inodes: stores the inode numbers of the nodes which are in wbuf
++ *
++ * The write-buffer synchronization callback is called when the write-buffer is
++ * synchronized in order to notify how much space was wasted due to
++ * write-buffer padding and how much free space is left in the LEB.
++ *
++ * Note: the fields @buf, @lnum, @offs, @avail and @used can be read under
++ * spin-lock or mutex because they are written under both mutex and spin-lock.
++ * @buf is appended to under mutex but overwritten under both mutex and
++ * spin-lock. Thus the data between @buf and @buf + @used can be read under
++ * spinlock.
++ */
++struct ubifs_wbuf {
++	struct ubifs_info *c;
++	void *buf;
++	int lnum;
++	int offs;
++	int avail;
++	int used;
++	int dtype;
++	int jhead;
++	int (*sync_callback)(struct ubifs_info *c, int lnum, int free, int pad);
++	struct mutex io_mutex;
++	spinlock_t lock;
++	struct timer_list timer;
++	int timeout;
++	int need_sync;
++	int next_ino;
++	ino_t *inodes;
++};
++
++/**
++ * struct ubifs_bud - bud logical eraseblock.
++ * @lnum: logical eraseblock number
++ * @start: where the (uncommitted) bud data starts
++ * @jhead: journal head number this bud belongs to
++ * @list: link in the list buds belonging to the same journal head
++ * @rb: link in the tree of all buds
++ */
++struct ubifs_bud {
++	int lnum;
++	int start;
++	int jhead;
++	struct list_head list;
++	struct rb_node rb;
++};
++
++/**
++ * struct ubifs_jhead - journal head.
++ * @wbuf: head's write-buffer
++ * @buds_list: list of bud LEBs belonging to this journal head
++ *
++ * Note, the @buds list is protected by the @c->buds_lock.
++ */
++struct ubifs_jhead {
++	struct ubifs_wbuf wbuf;
++	struct list_head buds_list;
++};
++
++/**
++ * struct ubifs_zbranch - key/coordinate/length branch stored in znodes.
++ * @key: key
++ * @znode: znode address in memory
++ * @lnum: LEB number of the target node (indexing node or data node)
++ * @offs: target node offset within @lnum
++ * @len: target node length
++ */
++struct ubifs_zbranch {
++	union ubifs_key key;
++	union {
++		struct ubifs_znode *znode;
++		void *leaf;
++	};
++	int lnum;
++	int offs;
++	int len;
++};
++
++/**
++ * struct ubifs_znode - in-memory representation of an indexing node.
++ * @parent: parent znode or NULL if it is the root
++ * @cnext: next znode to commit
++ * @flags: znode flags (%DIRTY_ZNODE, %COW_ZNODE or %OBSOLETE_ZNODE)
++ * @time: last access time (seconds)
++ * @level: level of the entry in the TNC tree
++ * @child_cnt: count of child znodes
++ * @iip: index in parent's zbranch array
++ * @alt: lower bound of key range has altered i.e. child inserted at slot 0
++ * @lnum: LEB number of the corresponding indexing node
++ * @offs: offset of the corresponding indexing node
++ * @len: length  of the corresponding indexing node
++ * @zbranch: array of znode branches (@c->fanout elements)
++ */
++struct ubifs_znode {
++	struct ubifs_znode *parent;
++	struct ubifs_znode *cnext;
++	unsigned long flags;
++	unsigned long time;
++	int level;
++	int child_cnt;
++	int iip;
++	int alt;
++#ifdef CONFIG_UBIFS_FS_DEBUG
++	int lnum, offs, len;
++#endif
++	struct ubifs_zbranch zbranch[];
++};
++
++/**
++ * struct bu_info - bulk-read information.
++ * @key: first data node key
++ * @zbranch: zbranches of data nodes to bulk read
++ * @buf: buffer to read into
++ * @buf_len: buffer length
++ * @gc_seq: GC sequence number to detect races with GC
++ * @cnt: number of data nodes for bulk read
++ * @blk_cnt: number of data blocks including holes
++ * @oef: end of file reached
++ */
++struct bu_info {
++	union ubifs_key key;
++	struct ubifs_zbranch zbranch[UBIFS_MAX_BULK_READ];
++	void *buf;
++	int buf_len;
++	int gc_seq;
++	int cnt;
++	int blk_cnt;
++	int eof;
++};
++
++/**
++ * struct ubifs_node_range - node length range description data structure.
++ * @len: fixed node length
++ * @min_len: minimum possible node length
++ * @max_len: maximum possible node length
++ *
++ * If @max_len is %0, the node has fixed length @len.
++ */
++struct ubifs_node_range {
++	union {
++		int len;
++		int min_len;
++	};
++	int max_len;
++};
++
++/**
++ * struct ubifs_compressor - UBIFS compressor description structure.
++ * @compr_type: compressor type (%UBIFS_COMPR_LZO, etc)
++ * @cc: cryptoapi compressor handle
++ * @comp_mutex: mutex used during compression
++ * @decomp_mutex: mutex used during decompression
++ * @name: compressor name
++ * @capi_name: cryptoapi compressor name
++ */
++struct ubifs_compressor {
++	int compr_type;
++	struct crypto_comp *cc;
++	struct mutex *comp_mutex;
++	struct mutex *decomp_mutex;
++	const char *name;
++	const char *capi_name;
++};
++
++/**
++ * struct ubifs_budget_req - budget requirements of an operation.
++ *
++ * @fast: non-zero if the budgeting should try to acquire budget quickly and
++ *        should not try to call write-back
++ * @recalculate: non-zero if @idx_growth, @data_growth, and @dd_growth fields
++ *               have to be re-calculated
++ * @new_page: non-zero if the operation adds a new page
++ * @dirtied_page: non-zero if the operation makes a page dirty
++ * @new_dent: non-zero if the operation adds a new directory entry
++ * @mod_dent: non-zero if the operation removes or modifies an existing
++ *            directory entry
++ * @new_ino: non-zero if the operation adds a new inode
++ * @new_ino_d: now much data newly created inode contains
++ * @dirtied_ino: how many inodes the operation makes dirty
++ * @dirtied_ino_d: now much data dirtied inode contains
++ * @idx_growth: how much the index will supposedly grow
++ * @data_growth: how much new data the operation will supposedly add
++ * @dd_growth: how much data that makes other data dirty the operation will
++ *             supposedly add
++ *
++ * @idx_growth, @data_growth and @dd_growth are not used in budget request. The
++ * budgeting subsystem caches index and data growth values there to avoid
++ * re-calculating them when the budget is released. However, if @idx_growth is
++ * %-1, it is calculated by the release function using other fields.
++ *
++ * An inode may contain 4KiB of data at max., thus the widths of @new_ino_d
++ * is 13 bits, and @dirtied_ino_d - 15, because up to 4 inodes may be made
++ * dirty by the re-name operation.
++ *
++ * Note, UBIFS aligns node lengths to 8-bytes boundary, so the requester has to
++ * make sure the amount of inode data which contribute to @new_ino_d and
++ * @dirtied_ino_d fields are aligned.
++ */
++struct ubifs_budget_req {
++	unsigned int fast:1;
++	unsigned int recalculate:1;
++#ifndef UBIFS_DEBUG
++	unsigned int new_page:1;
++	unsigned int dirtied_page:1;
++	unsigned int new_dent:1;
++	unsigned int mod_dent:1;
++	unsigned int new_ino:1;
++	unsigned int new_ino_d:13;
++	unsigned int dirtied_ino:4;
++	unsigned int dirtied_ino_d:15;
++#else
++	/* Not bit-fields to check for overflows */
++	unsigned int new_page;
++	unsigned int dirtied_page;
++	unsigned int new_dent;
++	unsigned int mod_dent;
++	unsigned int new_ino;
++	unsigned int new_ino_d;
++	unsigned int dirtied_ino;
++	unsigned int dirtied_ino_d;
++#endif
++	int idx_growth;
++	int data_growth;
++	int dd_growth;
++};
++
++/**
++ * struct ubifs_orphan - stores the inode number of an orphan.
++ * @rb: rb-tree node of rb-tree of orphans sorted by inode number
++ * @list: list head of list of orphans in order added
++ * @new_list: list head of list of orphans added since the last commit
++ * @cnext: next orphan to commit
++ * @dnext: next orphan to delete
++ * @inum: inode number
++ * @new: %1 => added since the last commit, otherwise %0
++ */
++struct ubifs_orphan {
++	struct rb_node rb;
++	struct list_head list;
++	struct list_head new_list;
++	struct ubifs_orphan *cnext;
++	struct ubifs_orphan *dnext;
++	ino_t inum;
++	int new;
++};
++
++/**
++ * struct ubifs_mount_opts - UBIFS-specific mount options information.
++ * @unmount_mode: selected unmount mode (%0 default, %1 normal, %2 fast)
++ * @bulk_read: enable/disable bulk-reads (%0 default, %1 disabe, %2 enable)
++ * @chk_data_crc: enable/disable CRC data checking when reading data nodes
++ *                (%0 default, %1 disabe, %2 enable)
++ * @override_compr: override default compressor (%0 - do not override and use
++ *                  superblock compressor, %1 - override and use compressor
++ *                  specified in @compr_type)
++ * @compr_type: compressor type to override the superblock compressor with
++ *              (%UBIFS_COMPR_NONE, etc)
++ */
++struct ubifs_mount_opts {
++	unsigned int unmount_mode:2;
++	unsigned int bulk_read:2;
++	unsigned int chk_data_crc:2;
++	unsigned int override_compr:1;
++	unsigned int compr_type:2;
++};
++
++struct ubifs_debug_info;
++
++/**
++ * struct ubifs_info - UBIFS file-system description data structure
++ * (per-superblock).
++ * @vfs_sb: VFS @struct super_block object
++ * @bdi: backing device info object to make VFS happy and disable read-ahead
++ *
++ * @highest_inum: highest used inode number
++ * @max_sqnum: current global sequence number
++ * @cmt_no: commit number of the last successfully completed commit, protected
++ *          by @commit_sem
++ * @cnt_lock: protects @highest_inum and @max_sqnum counters
++ * @fmt_version: UBIFS on-flash format version
++ * @uuid: UUID from super block
++ *
++ * @lhead_lnum: log head logical eraseblock number
++ * @lhead_offs: log head offset
++ * @ltail_lnum: log tail logical eraseblock number (offset is always 0)
++ * @log_mutex: protects the log, @lhead_lnum, @lhead_offs, @ltail_lnum, and
++ *             @bud_bytes
++ * @min_log_bytes: minimum required number of bytes in the log
++ * @cmt_bud_bytes: used during commit to temporarily amount of bytes in
++ *                 committed buds
++ *
++ * @buds: tree of all buds indexed by bud LEB number
++ * @bud_bytes: how many bytes of flash is used by buds
++ * @buds_lock: protects the @buds tree, @bud_bytes, and per-journal head bud
++ *             lists
++ * @jhead_cnt: count of journal heads
++ * @jheads: journal heads (head zero is base head)
++ * @max_bud_bytes: maximum number of bytes allowed in buds
++ * @bg_bud_bytes: number of bud bytes when background commit is initiated
++ * @old_buds: buds to be released after commit ends
++ * @max_bud_cnt: maximum number of buds
++ *
++ * @commit_sem: synchronizes committer with other processes
++ * @cmt_state: commit state
++ * @cs_lock: commit state lock
++ * @cmt_wq: wait queue to sleep on if the log is full and a commit is running
++ *
++ * @big_lpt: flag that LPT is too big to write whole during commit
++ * @no_chk_data_crc: do not check CRCs when reading data nodes (except during
++ *                   recovery)
++ * @bulk_read: enable bulk-reads
++ * @default_compr: default compression algorithm (%UBIFS_COMPR_LZO, etc)
++ *
++ * @tnc_mutex: protects the Tree Node Cache (TNC), @zroot, @cnext, @enext, and
++ *             @calc_idx_sz
++ * @zroot: zbranch which points to the root index node and znode
++ * @cnext: next znode to commit
++ * @enext: next znode to commit to empty space
++ * @gap_lebs: array of LEBs used by the in-gaps commit method
++ * @cbuf: commit buffer
++ * @ileb_buf: buffer for commit in-the-gaps method
++ * @ileb_len: length of data in ileb_buf
++ * @ihead_lnum: LEB number of index head
++ * @ihead_offs: offset of index head
++ * @ilebs: pre-allocated index LEBs
++ * @ileb_cnt: number of pre-allocated index LEBs
++ * @ileb_nxt: next pre-allocated index LEBs
++ * @old_idx: tree of index nodes obsoleted since the last commit start
++ * @bottom_up_buf: a buffer which is used by 'dirty_cow_bottom_up()' in tnc.c
++ *
++ * @mst_node: master node
++ * @mst_offs: offset of valid master node
++ * @mst_mutex: protects the master node area, @mst_node, and @mst_offs
++ *
++ * @max_bu_buf_len: maximum bulk-read buffer length
++ * @bu_mutex: protects the pre-allocated bulk-read buffer and @c->bu
++ * @bu: pre-allocated bulk-read information
++ *
++ * @log_lebs: number of logical eraseblocks in the log
++ * @log_bytes: log size in bytes
++ * @log_last: last LEB of the log
++ * @lpt_lebs: number of LEBs used for lprops table
++ * @lpt_first: first LEB of the lprops table area
++ * @lpt_last: last LEB of the lprops table area
++ * @orph_lebs: number of LEBs used for the orphan area
++ * @orph_first: first LEB of the orphan area
++ * @orph_last: last LEB of the orphan area
++ * @main_lebs: count of LEBs in the main area
++ * @main_first: first LEB of the main area
++ * @main_bytes: main area size in bytes
++ *
++ * @key_hash_type: type of the key hash
++ * @key_hash: direntry key hash function
++ * @key_fmt: key format
++ * @key_len: key length
++ * @fanout: fanout of the index tree (number of links per indexing node)
++ *
++ * @min_io_size: minimal input/output unit size
++ * @min_io_shift: number of bits in @min_io_size minus one
++ * @leb_size: logical eraseblock size in bytes
++ * @half_leb_size: half LEB size
++ * @leb_cnt: count of logical eraseblocks
++ * @max_leb_cnt: maximum count of logical eraseblocks
++ * @old_leb_cnt: count of logical eraseblocks before re-size
++ * @ro_media: the underlying UBI volume is read-only
++ *
++ * @dirty_pg_cnt: number of dirty pages (not used)
++ * @dirty_zn_cnt: number of dirty znodes
++ * @clean_zn_cnt: number of clean znodes
++ *
++ * @budg_idx_growth: amount of bytes budgeted for index growth
++ * @budg_data_growth: amount of bytes budgeted for cached data
++ * @budg_dd_growth: amount of bytes budgeted for cached data that will make
++ *                  other data dirty
++ * @budg_uncommitted_idx: amount of bytes were budgeted for growth of the index,
++ *                        but which still have to be taken into account because
++ *                        the index has not been committed so far
++ * @space_lock: protects @budg_idx_growth, @budg_data_growth, @budg_dd_growth,
++ *              @budg_uncommited_idx, @min_idx_lebs, @old_idx_sz, @lst,
++ *              @nospace, and @nospace_rp;
++ * @min_idx_lebs: minimum number of LEBs required for the index
++ * @old_idx_sz: size of index on flash
++ * @calc_idx_sz: temporary variable which is used to calculate new index size
++ *               (contains accurate new index size at end of TNC commit start)
++ * @lst: lprops statistics
++ * @nospace: non-zero if the file-system does not have flash space (used as
++ *           optimization)
++ * @nospace_rp: the same as @nospace, but additionally means that even reserved
++ *              pool is full
++ *
++ * @page_budget: budget for a page
++ * @inode_budget: budget for an inode
++ * @dent_budget: budget for a directory entry
++ *
++ * @ref_node_alsz: size of the LEB reference node aligned to the min. flash
++ * I/O unit
++ * @mst_node_alsz: master node aligned size
++ * @min_idx_node_sz: minimum indexing node aligned on 8-bytes boundary
++ * @max_idx_node_sz: maximum indexing node aligned on 8-bytes boundary
++ * @max_inode_sz: maximum possible inode size in bytes
++ * @max_znode_sz: size of znode in bytes
++ *
++ * @leb_overhead: how many bytes are wasted in an LEB when it is filled with
++ *                data nodes of maximum size - used in free space reporting
++ * @dead_wm: LEB dead space watermark
++ * @dark_wm: LEB dark space watermark
++ * @block_cnt: count of 4KiB blocks on the FS
++ *
++ * @ranges: UBIFS node length ranges
++ * @ubi: UBI volume descriptor
++ * @di: UBI device information
++ * @vi: UBI volume information
++ *
++ * @orph_tree: rb-tree of orphan inode numbers
++ * @orph_list: list of orphan inode numbers in order added
++ * @orph_new: list of orphan inode numbers added since last commit
++ * @orph_cnext: next orphan to commit
++ * @orph_dnext: next orphan to delete
++ * @orphan_lock: lock for orph_tree and orph_new
++ * @orph_buf: buffer for orphan nodes
++ * @new_orphans: number of orphans since last commit
++ * @cmt_orphans: number of orphans being committed
++ * @tot_orphans: number of orphans in the rb_tree
++ * @max_orphans: maximum number of orphans allowed
++ * @ohead_lnum: orphan head LEB number
++ * @ohead_offs: orphan head offset
++ * @no_orphs: non-zero if there are no orphans
++ *
++ * @bgt: UBIFS background thread
++ * @bgt_name: background thread name
++ * @need_bgt: if background thread should run
++ * @need_wbuf_sync: if write-buffers have to be synchronized
++ *
++ * @gc_lnum: LEB number used for garbage collection
++ * @sbuf: a buffer of LEB size used by GC and replay for scanning
++ * @idx_gc: list of index LEBs that have been garbage collected
++ * @idx_gc_cnt: number of elements on the idx_gc list
++ * @gc_seq: incremented for every non-index LEB garbage collected
++ * @gced_lnum: last non-index LEB that was garbage collected
++ *
++ * @infos_list: links all 'ubifs_info' objects
++ * @umount_mutex: serializes shrinker and un-mount
++ * @shrinker_run_no: shrinker run number
++ *
++ * @space_bits: number of bits needed to record free or dirty space
++ * @lpt_lnum_bits: number of bits needed to record a LEB number in the LPT
++ * @lpt_offs_bits: number of bits needed to record an offset in the LPT
++ * @lpt_spc_bits: number of bits needed to space in the LPT
++ * @pcnt_bits: number of bits needed to record pnode or nnode number
++ * @lnum_bits: number of bits needed to record LEB number
++ * @nnode_sz: size of on-flash nnode
++ * @pnode_sz: size of on-flash pnode
++ * @ltab_sz: size of on-flash LPT lprops table
++ * @lsave_sz: size of on-flash LPT save table
++ * @pnode_cnt: number of pnodes
++ * @nnode_cnt: number of nnodes
++ * @lpt_hght: height of the LPT
++ * @pnodes_have: number of pnodes in memory
++ *
++ * @lp_mutex: protects lprops table and all the other lprops-related fields
++ * @lpt_lnum: LEB number of the root nnode of the LPT
++ * @lpt_offs: offset of the root nnode of the LPT
++ * @nhead_lnum: LEB number of LPT head
++ * @nhead_offs: offset of LPT head
++ * @lpt_drty_flgs: dirty flags for LPT special nodes e.g. ltab
++ * @dirty_nn_cnt: number of dirty nnodes
++ * @dirty_pn_cnt: number of dirty pnodes
++ * @check_lpt_free: flag that indicates LPT GC may be needed
++ * @lpt_sz: LPT size
++ * @lpt_nod_buf: buffer for an on-flash nnode or pnode
++ * @lpt_buf: buffer of LEB size used by LPT
++ * @nroot: address in memory of the root nnode of the LPT
++ * @lpt_cnext: next LPT node to commit
++ * @lpt_heap: array of heaps of categorized lprops
++ * @dirty_idx: a (reverse sorted) copy of the LPROPS_DIRTY_IDX heap as at
++ *             previous commit start
++ * @uncat_list: list of un-categorized LEBs
++ * @empty_list: list of empty LEBs
++ * @freeable_list: list of freeable non-index LEBs (free + dirty == leb_size)
++ * @frdi_idx_list: list of freeable index LEBs (free + dirty == leb_size)
++ * @freeable_cnt: number of freeable LEBs in @freeable_list
++ *
++ * @ltab_lnum: LEB number of LPT's own lprops table
++ * @ltab_offs: offset of LPT's own lprops table
++ * @ltab: LPT's own lprops table
++ * @ltab_cmt: LPT's own lprops table (commit copy)
++ * @lsave_cnt: number of LEB numbers in LPT's save table
++ * @lsave_lnum: LEB number of LPT's save table
++ * @lsave_offs: offset of LPT's save table
++ * @lsave: LPT's save table
++ * @lscan_lnum: LEB number of last LPT scan
++ *
++ * @rp_size: size of the reserved pool in bytes
++ * @report_rp_size: size of the reserved pool reported to user-space
++ * @rp_uid: reserved pool user ID
++ * @rp_gid: reserved pool group ID
++ *
++ * @empty: if the UBI device is empty
++ * @replay_tree: temporary tree used during journal replay
++ * @replay_list: temporary list used during journal replay
++ * @replay_buds: list of buds to replay
++ * @cs_sqnum: sequence number of first node in the log (commit start node)
++ * @replay_sqnum: sequence number of node currently being replayed
++ * @need_recovery: file-system needs recovery
++ * @replaying: set to %1 during journal replay
++ * @unclean_leb_list: LEBs to recover when mounting ro to rw
++ * @rcvrd_mst_node: recovered master node to write when mounting ro to rw
++ * @size_tree: inode size information for recovery
++ * @remounting_rw: set while remounting from ro to rw (sb flags have MS_RDONLY)
++ * @always_chk_crc: always check CRCs (while mounting and remounting rw)
++ * @mount_opts: UBIFS-specific mount options
++ *
++ * @dbg: debugging-related information
++ */
++struct ubifs_info {
++	struct super_block *vfs_sb;
++	struct backing_dev_info bdi;
++
++	ino_t highest_inum;
++	unsigned long long max_sqnum;
++	unsigned long long cmt_no;
++	spinlock_t cnt_lock;
++	int fmt_version;
++	unsigned char uuid[16];
++
++	int lhead_lnum;
++	int lhead_offs;
++	int ltail_lnum;
++	struct mutex log_mutex;
++	int min_log_bytes;
++	long long cmt_bud_bytes;
++
++	struct rb_root buds;
++	long long bud_bytes;
++	spinlock_t buds_lock;
++	int jhead_cnt;
++	struct ubifs_jhead *jheads;
++	long long max_bud_bytes;
++	long long bg_bud_bytes;
++	struct list_head old_buds;
++	int max_bud_cnt;
++
++	struct rw_semaphore commit_sem;
++	int cmt_state;
++	spinlock_t cs_lock;
++	wait_queue_head_t cmt_wq;
++
++	unsigned int big_lpt:1;
++	unsigned int no_chk_data_crc:1;
++	unsigned int bulk_read:1;
++	unsigned int default_compr:2;
++
++	struct mutex tnc_mutex;
++	struct ubifs_zbranch zroot;
++	struct ubifs_znode *cnext;
++	struct ubifs_znode *enext;
++	int *gap_lebs;
++	void *cbuf;
++	void *ileb_buf;
++	int ileb_len;
++	int ihead_lnum;
++	int ihead_offs;
++	int *ilebs;
++	int ileb_cnt;
++	int ileb_nxt;
++	struct rb_root old_idx;
++	int *bottom_up_buf;
++
++	struct ubifs_mst_node *mst_node;
++	int mst_offs;
++	struct mutex mst_mutex;
++
++	int max_bu_buf_len;
++	struct mutex bu_mutex;
++	struct bu_info bu;
++
++	int log_lebs;
++	long long log_bytes;
++	int log_last;
++	int lpt_lebs;
++	int lpt_first;
++	int lpt_last;
++	int orph_lebs;
++	int orph_first;
++	int orph_last;
++	int main_lebs;
++	int main_first;
++	long long main_bytes;
++
++	uint8_t key_hash_type;
++	uint32_t (*key_hash)(const char *str, int len);
++	int key_fmt;
++	int key_len;
++	int fanout;
++
++	int min_io_size;
++	int min_io_shift;
++	int leb_size;
++	int half_leb_size;
++	int leb_cnt;
++	int max_leb_cnt;
++	int old_leb_cnt;
++	int ro_media;
++
++	atomic_long_t dirty_pg_cnt;
++	atomic_long_t dirty_zn_cnt;
++	atomic_long_t clean_zn_cnt;
++
++	long long budg_idx_growth;
++	long long budg_data_growth;
++	long long budg_dd_growth;
++	long long budg_uncommitted_idx;
++	spinlock_t space_lock;
++	int min_idx_lebs;
++	unsigned long long old_idx_sz;
++	unsigned long long calc_idx_sz;
++	struct ubifs_lp_stats lst;
++	unsigned int nospace:1;
++	unsigned int nospace_rp:1;
++
++	int page_budget;
++	int inode_budget;
++	int dent_budget;
++
++	int ref_node_alsz;
++	int mst_node_alsz;
++	int min_idx_node_sz;
++	int max_idx_node_sz;
++	long long max_inode_sz;
++	int max_znode_sz;
++
++	int leb_overhead;
++	int dead_wm;
++	int dark_wm;
++	int block_cnt;
++
++	struct ubifs_node_range ranges[UBIFS_NODE_TYPES_CNT];
++	struct ubi_volume_desc *ubi;
++	struct ubi_device_info di;
++	struct ubi_volume_info vi;
++
++	struct rb_root orph_tree;
++	struct list_head orph_list;
++	struct list_head orph_new;
++	struct ubifs_orphan *orph_cnext;
++	struct ubifs_orphan *orph_dnext;
++	spinlock_t orphan_lock;
++	void *orph_buf;
++	int new_orphans;
++	int cmt_orphans;
++	int tot_orphans;
++	int max_orphans;
++	int ohead_lnum;
++	int ohead_offs;
++	int no_orphs;
++
++	struct task_struct *bgt;
++	char bgt_name[sizeof(BGT_NAME_PATTERN) + 9];
++	int need_bgt;
++	int need_wbuf_sync;
++
++	int gc_lnum;
++	void *sbuf;
++	struct list_head idx_gc;
++	int idx_gc_cnt;
++	int gc_seq;
++	int gced_lnum;
++
++	struct list_head infos_list;
++	struct mutex umount_mutex;
++	unsigned int shrinker_run_no;
++
++	int space_bits;
++	int lpt_lnum_bits;
++	int lpt_offs_bits;
++	int lpt_spc_bits;
++	int pcnt_bits;
++	int lnum_bits;
++	int nnode_sz;
++	int pnode_sz;
++	int ltab_sz;
++	int lsave_sz;
++	int pnode_cnt;
++	int nnode_cnt;
++	int lpt_hght;
++	int pnodes_have;
++
++	struct mutex lp_mutex;
++	int lpt_lnum;
++	int lpt_offs;
++	int nhead_lnum;
++	int nhead_offs;
++	int lpt_drty_flgs;
++	int dirty_nn_cnt;
++	int dirty_pn_cnt;
++	int check_lpt_free;
++	long long lpt_sz;
++	void *lpt_nod_buf;
++	void *lpt_buf;
++	struct ubifs_nnode *nroot;
++	struct ubifs_cnode *lpt_cnext;
++	struct ubifs_lpt_heap lpt_heap[LPROPS_HEAP_CNT];
++	struct ubifs_lpt_heap dirty_idx;
++	struct list_head uncat_list;
++	struct list_head empty_list;
++	struct list_head freeable_list;
++	struct list_head frdi_idx_list;
++	int freeable_cnt;
++
++	int ltab_lnum;
++	int ltab_offs;
++	struct ubifs_lpt_lprops *ltab;
++	struct ubifs_lpt_lprops *ltab_cmt;
++	int lsave_cnt;
++	int lsave_lnum;
++	int lsave_offs;
++	int *lsave;
++	int lscan_lnum;
++
++	long long rp_size;
++	long long report_rp_size;
++	uid_t rp_uid;
++	gid_t rp_gid;
++
++	/* The below fields are used only during mounting and re-mounting */
++	int empty;
++	struct rb_root replay_tree;
++	struct list_head replay_list;
++	struct list_head replay_buds;
++	unsigned long long cs_sqnum;
++	unsigned long long replay_sqnum;
++	int need_recovery;
++	int replaying;
++	struct list_head unclean_leb_list;
++	struct ubifs_mst_node *rcvrd_mst_node;
++	struct rb_root size_tree;
++	int remounting_rw;
++	int always_chk_crc;
++	struct ubifs_mount_opts mount_opts;
++
++#ifdef CONFIG_UBIFS_FS_DEBUG
++	struct ubifs_debug_info *dbg;
++#endif
++};
++
++extern struct list_head ubifs_infos;
++extern spinlock_t ubifs_infos_lock;
++extern atomic_long_t ubifs_clean_zn_cnt;
++extern struct kmem_cache *ubifs_inode_slab;
++extern const struct super_operations ubifs_super_operations;
++extern const struct address_space_operations ubifs_file_address_operations;
++extern const struct file_operations ubifs_file_operations;
++extern const struct inode_operations ubifs_file_inode_operations;
++extern const struct file_operations ubifs_dir_operations;
++extern const struct inode_operations ubifs_dir_inode_operations;
++extern const struct inode_operations ubifs_symlink_inode_operations;
++extern struct backing_dev_info ubifs_backing_dev_info;
++extern struct ubifs_compressor *ubifs_compressors[UBIFS_COMPR_TYPES_CNT];
++
++/* io.c */
++void ubifs_ro_mode(struct ubifs_info *c, int err);
++int ubifs_wbuf_write_nolock(struct ubifs_wbuf *wbuf, void *buf, int len);
++int ubifs_wbuf_seek_nolock(struct ubifs_wbuf *wbuf, int lnum, int offs,
++			   int dtype);
++int ubifs_wbuf_init(struct ubifs_info *c, struct ubifs_wbuf *wbuf);
++int ubifs_read_node(const struct ubifs_info *c, void *buf, int type, int len,
++		    int lnum, int offs);
++int ubifs_read_node_wbuf(struct ubifs_wbuf *wbuf, void *buf, int type, int len,
++			 int lnum, int offs);
++int ubifs_write_node(struct ubifs_info *c, void *node, int len, int lnum,
++		     int offs, int dtype);
++int ubifs_check_node(const struct ubifs_info *c, const void *buf, int lnum,
++		     int offs, int quiet, int must_chk_crc);
++void ubifs_prepare_node(struct ubifs_info *c, void *buf, int len, int pad);
++void ubifs_prep_grp_node(struct ubifs_info *c, void *node, int len, int last);
++int ubifs_io_init(struct ubifs_info *c);
++void ubifs_pad(const struct ubifs_info *c, void *buf, int pad);
++int ubifs_wbuf_sync_nolock(struct ubifs_wbuf *wbuf);
++int ubifs_bg_wbufs_sync(struct ubifs_info *c);
++void ubifs_wbuf_add_ino_nolock(struct ubifs_wbuf *wbuf, ino_t inum);
++int ubifs_sync_wbufs_by_inode(struct ubifs_info *c, struct inode *inode);
++
++/* scan.c */
++struct ubifs_scan_leb *ubifs_scan(const struct ubifs_info *c, int lnum,
++				  int offs, void *sbuf);
++void ubifs_scan_destroy(struct ubifs_scan_leb *sleb);
++int ubifs_scan_a_node(const struct ubifs_info *c, void *buf, int len, int lnum,
++		      int offs, int quiet);
++struct ubifs_scan_leb *ubifs_start_scan(const struct ubifs_info *c, int lnum,
++					int offs, void *sbuf);
++void ubifs_end_scan(const struct ubifs_info *c, struct ubifs_scan_leb *sleb,
++		    int lnum, int offs);
++int ubifs_add_snod(const struct ubifs_info *c, struct ubifs_scan_leb *sleb,
++		   void *buf, int offs);
++void ubifs_scanned_corruption(const struct ubifs_info *c, int lnum, int offs,
++			      void *buf);
++
++/* log.c */
++void ubifs_add_bud(struct ubifs_info *c, struct ubifs_bud *bud);
++void ubifs_create_buds_lists(struct ubifs_info *c);
++int ubifs_add_bud_to_log(struct ubifs_info *c, int jhead, int lnum, int offs);
++struct ubifs_bud *ubifs_search_bud(struct ubifs_info *c, int lnum);
++struct ubifs_wbuf *ubifs_get_wbuf(struct ubifs_info *c, int lnum);
++int ubifs_log_start_commit(struct ubifs_info *c, int *ltail_lnum);
++int ubifs_log_end_commit(struct ubifs_info *c, int new_ltail_lnum);
++int ubifs_log_post_commit(struct ubifs_info *c, int old_ltail_lnum);
++int ubifs_consolidate_log(struct ubifs_info *c);
++
++/* journal.c */
++int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir,
++		     const struct qstr *nm, const struct inode *inode,
++		     int deletion, int xent);
++int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode,
++			 const union ubifs_key *key, const void *buf, int len);
++int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode);
++int ubifs_jnl_delete_inode(struct ubifs_info *c, const struct inode *inode);
++int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
++		     const struct dentry *old_dentry,
++		     const struct inode *new_dir,
++		     const struct dentry *new_dentry, int sync);
++int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode,
++		       loff_t old_size, loff_t new_size);
++int ubifs_jnl_delete_xattr(struct ubifs_info *c, const struct inode *host,
++			   const struct inode *inode, const struct qstr *nm);
++int ubifs_jnl_change_xattr(struct ubifs_info *c, const struct inode *inode1,
++			   const struct inode *inode2);
++
++/* budget.c */
++int ubifs_budget_space(struct ubifs_info *c, struct ubifs_budget_req *req);
++void ubifs_release_budget(struct ubifs_info *c, struct ubifs_budget_req *req);
++void ubifs_release_dirty_inode_budget(struct ubifs_info *c,
++				      struct ubifs_inode *ui);
++int ubifs_budget_inode_op(struct ubifs_info *c, struct inode *inode,
++			  struct ubifs_budget_req *req);
++void ubifs_release_ino_dirty(struct ubifs_info *c, struct inode *inode,
++				struct ubifs_budget_req *req);
++void ubifs_cancel_ino_op(struct ubifs_info *c, struct inode *inode,
++			 struct ubifs_budget_req *req);
++long long ubifs_get_free_space(struct ubifs_info *c);
++long long ubifs_get_free_space_nolock(struct ubifs_info *c);
++int ubifs_calc_min_idx_lebs(struct ubifs_info *c);
++void ubifs_convert_page_budget(struct ubifs_info *c);
++long long ubifs_reported_space(const struct ubifs_info *c, long long free);
++long long ubifs_calc_available(const struct ubifs_info *c, int min_idx_lebs);
++
++/* find.c */
++int ubifs_find_free_space(struct ubifs_info *c, int min_space, int *free,
++			  int squeeze);
++int ubifs_find_free_leb_for_idx(struct ubifs_info *c);
++int ubifs_find_dirty_leb(struct ubifs_info *c, struct ubifs_lprops *ret_lp,
++			 int min_space, int pick_free);
++int ubifs_find_dirty_idx_leb(struct ubifs_info *c);
++int ubifs_save_dirty_idx_lnums(struct ubifs_info *c);
++
++/* tnc.c */
++int ubifs_lookup_level0(struct ubifs_info *c, const union ubifs_key *key,
++			struct ubifs_znode **zn, int *n);
++int ubifs_tnc_lookup_nm(struct ubifs_info *c, const union ubifs_key *key,
++			void *node, const struct qstr *nm);
++int ubifs_tnc_locate(struct ubifs_info *c, const union ubifs_key *key,
++		     void *node, int *lnum, int *offs);
++int ubifs_tnc_add(struct ubifs_info *c, const union ubifs_key *key, int lnum,
++		  int offs, int len);
++int ubifs_tnc_replace(struct ubifs_info *c, const union ubifs_key *key,
++		      int old_lnum, int old_offs, int lnum, int offs, int len);
++int ubifs_tnc_add_nm(struct ubifs_info *c, const union ubifs_key *key,
++		     int lnum, int offs, int len, const struct qstr *nm);
++int ubifs_tnc_remove(struct ubifs_info *c, const union ubifs_key *key);
++int ubifs_tnc_remove_nm(struct ubifs_info *c, const union ubifs_key *key,
++			const struct qstr *nm);
++int ubifs_tnc_remove_range(struct ubifs_info *c, union ubifs_key *from_key,
++			   union ubifs_key *to_key);
++int ubifs_tnc_remove_ino(struct ubifs_info *c, ino_t inum);
++struct ubifs_dent_node *ubifs_tnc_next_ent(struct ubifs_info *c,
++					   union ubifs_key *key,
++					   const struct qstr *nm);
++void ubifs_tnc_close(struct ubifs_info *c);
++int ubifs_tnc_has_node(struct ubifs_info *c, union ubifs_key *key, int level,
++		       int lnum, int offs, int is_idx);
++int ubifs_dirty_idx_node(struct ubifs_info *c, union ubifs_key *key, int level,
++			 int lnum, int offs);
++/* Shared by tnc.c for tnc_commit.c */
++void destroy_old_idx(struct ubifs_info *c);
++int is_idx_node_in_tnc(struct ubifs_info *c, union ubifs_key *key, int level,
++		       int lnum, int offs);
++int insert_old_idx_znode(struct ubifs_info *c, struct ubifs_znode *znode);
++int ubifs_tnc_get_bu_keys(struct ubifs_info *c, struct bu_info *bu);
++int ubifs_tnc_bulk_read(struct ubifs_info *c, struct bu_info *bu);
++
++/* tnc_misc.c */
++struct ubifs_znode *ubifs_tnc_levelorder_next(struct ubifs_znode *zr,
++					      struct ubifs_znode *znode);
++int ubifs_search_zbranch(const struct ubifs_info *c,
++			 const struct ubifs_znode *znode,
++			 const union ubifs_key *key, int *n);
++struct ubifs_znode *ubifs_tnc_postorder_first(struct ubifs_znode *znode);
++struct ubifs_znode *ubifs_tnc_postorder_next(struct ubifs_znode *znode);
++long ubifs_destroy_tnc_subtree(struct ubifs_znode *zr);
++struct ubifs_znode *ubifs_load_znode(struct ubifs_info *c,
++				     struct ubifs_zbranch *zbr,
++				     struct ubifs_znode *parent, int iip);
++int ubifs_tnc_read_node(struct ubifs_info *c, struct ubifs_zbranch *zbr,
++			void *node);
++
++/* tnc_commit.c */
++int ubifs_tnc_start_commit(struct ubifs_info *c, struct ubifs_zbranch *zroot);
++int ubifs_tnc_end_commit(struct ubifs_info *c);
++
++/* shrinker.c */
++int ubifs_shrinker(int nr_to_scan, gfp_t gfp_mask);
++
++/* commit.c */
++int ubifs_bg_thread(void *info);
++void ubifs_commit_required(struct ubifs_info *c);
++void ubifs_request_bg_commit(struct ubifs_info *c);
++int ubifs_run_commit(struct ubifs_info *c);
++void ubifs_recovery_commit(struct ubifs_info *c);
++int ubifs_gc_should_commit(struct ubifs_info *c);
++void ubifs_wait_for_commit(struct ubifs_info *c);
++
++/* master.c */
++int ubifs_read_master(struct ubifs_info *c);
++int ubifs_write_master(struct ubifs_info *c);
++
++/* sb.c */
++int ubifs_read_superblock(struct ubifs_info *c);
++struct ubifs_sb_node *ubifs_read_sb_node(struct ubifs_info *c);
++int ubifs_write_sb_node(struct ubifs_info *c, struct ubifs_sb_node *sup);
++
++/* replay.c */
++int ubifs_validate_entry(struct ubifs_info *c,
++			 const struct ubifs_dent_node *dent);
++int ubifs_replay_journal(struct ubifs_info *c);
++
++/* gc.c */
++int ubifs_garbage_collect(struct ubifs_info *c, int anyway);
++int ubifs_gc_start_commit(struct ubifs_info *c);
++int ubifs_gc_end_commit(struct ubifs_info *c);
++void ubifs_destroy_idx_gc(struct ubifs_info *c);
++int ubifs_get_idx_gc_leb(struct ubifs_info *c);
++int ubifs_garbage_collect_leb(struct ubifs_info *c, struct ubifs_lprops *lp);
++
++/* orphan.c */
++int ubifs_add_orphan(struct ubifs_info *c, ino_t inum);
++void ubifs_delete_orphan(struct ubifs_info *c, ino_t inum);
++int ubifs_orphan_start_commit(struct ubifs_info *c);
++int ubifs_orphan_end_commit(struct ubifs_info *c);
++int ubifs_mount_orphans(struct ubifs_info *c, int unclean, int read_only);
++int ubifs_clear_orphans(struct ubifs_info *c);
++
++/* lpt.c */
++int ubifs_calc_lpt_geom(struct ubifs_info *c);
++int ubifs_create_dflt_lpt(struct ubifs_info *c, int *main_lebs, int lpt_first,
++			  int *lpt_lebs, int *big_lpt);
++int ubifs_lpt_init(struct ubifs_info *c, int rd, int wr);
++struct ubifs_lprops *ubifs_lpt_lookup(struct ubifs_info *c, int lnum);
++struct ubifs_lprops *ubifs_lpt_lookup_dirty(struct ubifs_info *c, int lnum);
++int ubifs_lpt_scan_nolock(struct ubifs_info *c, int start_lnum, int end_lnum,
++			  ubifs_lpt_scan_callback scan_cb, void *data);
++
++/* Shared by lpt.c for lpt_commit.c */
++void ubifs_pack_lsave(struct ubifs_info *c, void *buf, int *lsave);
++void ubifs_pack_ltab(struct ubifs_info *c, void *buf,
++		     struct ubifs_lpt_lprops *ltab);
++void ubifs_pack_pnode(struct ubifs_info *c, void *buf,
++		      struct ubifs_pnode *pnode);
++void ubifs_pack_nnode(struct ubifs_info *c, void *buf,
++		      struct ubifs_nnode *nnode);
++struct ubifs_pnode *ubifs_get_pnode(struct ubifs_info *c,
++				    struct ubifs_nnode *parent, int iip);
++struct ubifs_nnode *ubifs_get_nnode(struct ubifs_info *c,
++				    struct ubifs_nnode *parent, int iip);
++int ubifs_read_nnode(struct ubifs_info *c, struct ubifs_nnode *parent, int iip);
++void ubifs_add_lpt_dirt(struct ubifs_info *c, int lnum, int dirty);
++void ubifs_add_nnode_dirt(struct ubifs_info *c, struct ubifs_nnode *nnode);
++uint32_t ubifs_unpack_bits(uint8_t **addr, int *pos, int nrbits);
++struct ubifs_nnode *ubifs_first_nnode(struct ubifs_info *c, int *hght);
++/* Needed only in debugging code in lpt_commit.c */
++int ubifs_unpack_nnode(const struct ubifs_info *c, void *buf,
++		       struct ubifs_nnode *nnode);
++
++/* lpt_commit.c */
++int ubifs_lpt_start_commit(struct ubifs_info *c);
++int ubifs_lpt_end_commit(struct ubifs_info *c);
++int ubifs_lpt_post_commit(struct ubifs_info *c);
++void ubifs_lpt_free(struct ubifs_info *c, int wr_only);
++
++/* lprops.c */
++const struct ubifs_lprops *ubifs_change_lp(struct ubifs_info *c,
++					   const struct ubifs_lprops *lp,
++					   int free, int dirty, int flags,
++					   int idx_gc_cnt);
++void ubifs_get_lp_stats(struct ubifs_info *c, struct ubifs_lp_stats *lst);
++void ubifs_add_to_cat(struct ubifs_info *c, struct ubifs_lprops *lprops,
++		      int cat);
++void ubifs_replace_cat(struct ubifs_info *c, struct ubifs_lprops *old_lprops,
++		       struct ubifs_lprops *new_lprops);
++void ubifs_ensure_cat(struct ubifs_info *c, struct ubifs_lprops *lprops);
++int ubifs_categorize_lprops(const struct ubifs_info *c,
++			    const struct ubifs_lprops *lprops);
++int ubifs_change_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
++			int flags_set, int flags_clean, int idx_gc_cnt);
++int ubifs_update_one_lp(struct ubifs_info *c, int lnum, int free, int dirty,
++			int flags_set, int flags_clean);
++int ubifs_read_one_lp(struct ubifs_info *c, int lnum, struct ubifs_lprops *lp);
++const struct ubifs_lprops *ubifs_fast_find_free(struct ubifs_info *c);
++const struct ubifs_lprops *ubifs_fast_find_empty(struct ubifs_info *c);
++const struct ubifs_lprops *ubifs_fast_find_freeable(struct ubifs_info *c);
++const struct ubifs_lprops *ubifs_fast_find_frdi_idx(struct ubifs_info *c);
++
++/* file.c */
++int ubifs_fsync(struct file *file, struct dentry *dentry, int datasync);
++int ubifs_setattr(struct dentry *dentry, struct iattr *attr);
++
++/* dir.c */
++struct inode *ubifs_new_inode(struct ubifs_info *c, const struct inode *dir,
++			      int mode);
++int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
++		  struct kstat *stat);
++
++/* xattr.c */
++int ubifs_setxattr(struct dentry *dentry, const char *name,
++		   const void *value, size_t size, int flags);
++ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf,
++		       size_t size);
++ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size);
++int ubifs_removexattr(struct dentry *dentry, const char *name);
++
++/* super.c */
++struct inode *ubifs_iget(struct super_block *sb, unsigned long inum);
++
++/* recovery.c */
++int ubifs_recover_master_node(struct ubifs_info *c);
++int ubifs_write_rcvrd_mst_node(struct ubifs_info *c);
++struct ubifs_scan_leb *ubifs_recover_leb(struct ubifs_info *c, int lnum,
++					 int offs, void *sbuf, int grouped);
++struct ubifs_scan_leb *ubifs_recover_log_leb(struct ubifs_info *c, int lnum,
++					     int offs, void *sbuf);
++int ubifs_recover_inl_heads(const struct ubifs_info *c, void *sbuf);
++int ubifs_clean_lebs(const struct ubifs_info *c, void *sbuf);
++int ubifs_rcvry_gc_commit(struct ubifs_info *c);
++int ubifs_recover_size_accum(struct ubifs_info *c, union ubifs_key *key,
++			     int deletion, loff_t new_size);
++int ubifs_recover_size(struct ubifs_info *c);
++void ubifs_destroy_size_tree(struct ubifs_info *c);
++
++/* ioctl.c */
++long ubifs_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
++void ubifs_set_inode_flags(struct inode *inode);
++#ifdef CONFIG_COMPAT
++long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg);
++#endif
++
++/* compressor.c */
++int __init ubifs_compressors_init(void);
++void ubifs_compressors_exit(void);
++void ubifs_compress(const void *in_buf, int in_len, void *out_buf, int *out_len,
++		    int *compr_type);
++int ubifs_decompress(const void *buf, int len, void *out, int *out_len,
++		     int compr_type);
++
++#include "debug.h"
++#include "misc.h"
++#include "key.h"
++
++#endif /* !__UBIFS_H__ */
+diff -Nurd linux-2.6.24.orig/fs/ubifs/xattr.c linux-2.6.24/fs/ubifs/xattr.c
+--- linux-2.6.24.orig/fs/ubifs/xattr.c	1970-01-01 01:00:00.000000000 +0100
++++ linux-2.6.24/fs/ubifs/xattr.c	2009-04-17 09:49:28.000000000 +0200
+@@ -0,0 +1,571 @@
++/*
++ * This file is part of UBIFS.
++ *
++ * Copyright (C) 2006-2008 Nokia Corporation.
++ *
++ * This program is free software; you can redistribute it and/or modify it
++ * under the terms of the GNU General Public License version 2 as published by
++ * the Free Software Foundation.
++ *
++ * This program is distributed in the hope that it will be useful, but WITHOUT
++ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
++ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
++ * more details.
++ *
++ * You should have received a copy of the GNU General Public License along with
++ * this program; if not, write to the Free Software Foundation, Inc., 51
++ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
++ *
++ * Authors: Artem Bityutskiy (Битюцкий Артём)
++ *          Adrian Hunter
++ */
++
++/*
++ * This file implements UBIFS extended attributes support.
++ *
++ * Extended attributes are implemented as regular inodes with attached data,
++ * which limits extended attribute size to UBIFS block size (4KiB). Names of
++ * extended attributes are described by extended attribute entries (xentries),
++ * which are almost identical to directory entries, but have different key type.
++ *
++ * In other words, the situation with extended attributes is very similar to
++ * directories. Indeed, any inode (but of course not xattr inodes) may have a
++ * number of associated xentries, just like directory inodes have associated
++ * directory entries. Extended attribute entries store the name of the extended
++ * attribute, the host inode number, and the extended attribute inode number.
++ * Similarly, direntries store the name, the parent and the target inode
++ * numbers. Thus, most of the common UBIFS mechanisms may be re-used for
++ * extended attributes.
++ *
++ * The number of extended attributes is not limited, but there is Linux
++ * limitation on the maximum possible size of the list of all extended
++ * attributes associated with an inode (%XATTR_LIST_MAX), so UBIFS makes sure
++ * the sum of all extended attribute names of the inode does not exceed that
++ * limit.
++ *
++ * Extended attributes are synchronous, which means they are written to the
++ * flash media synchronously and there is no write-back for extended attribute
++ * inodes. The extended attribute values are not stored in compressed form on
++ * the media.
++ *
++ * Since extended attributes are represented by regular inodes, they are cached
++ * in the VFS inode cache. The xentries are cached in the LNC cache (see
++ * tnc.c).
++ *
++ * ACL support is not implemented.
++ */
++
++#include <linux/xattr.h>
++#include <linux/posix_acl_xattr.h>
++#include "ubifs.h"
++
++/*
++ * Limit the number of extended attributes per inode so that the total size
++ * (@xattr_size) is guaranteeded to fit in an 'unsigned int'.
++ */
++#define MAX_XATTRS_PER_INODE 65535
++
++/*
++ * Extended attribute type constants.
++ *
++ * USER_XATTR: user extended attribute ("user.*")
++ * TRUSTED_XATTR: trusted extended attribute ("trusted.*)
++ * SECURITY_XATTR: security extended attribute ("security.*")
++ */
++enum {
++	USER_XATTR,
++	TRUSTED_XATTR,
++	SECURITY_XATTR,
++};
++
++static struct inode_operations none_inode_operations;
++static struct address_space_operations none_address_operations;
++static struct file_operations none_file_operations;
++
++/**
++ * create_xattr - create an extended attribute.
++ * @c: UBIFS file-system description object
++ * @host: host inode
++ * @nm: extended attribute name
++ * @value: extended attribute value
++ * @size: size of extended attribute value
++ *
++ * This is a helper function which creates an extended attribute of name @nm
++ * and value @value for inode @host. The host inode is also updated on flash
++ * because the ctime and extended attribute accounting data changes. This
++ * function returns zero in case of success and a negative error code in case
++ * of failure.
++ */
++static int create_xattr(struct ubifs_info *c, struct inode *host,
++			const struct qstr *nm, const void *value, int size)
++{
++	int err;
++	struct inode *inode;
++	struct ubifs_inode *ui, *host_ui = ubifs_inode(host);
++	struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
++				.new_ino_d = ALIGN(size, 8), .dirtied_ino = 1,
++				.dirtied_ino_d = ALIGN(host_ui->data_len, 8) };
++
++	if (host_ui->xattr_cnt >= MAX_XATTRS_PER_INODE)
++		return -ENOSPC;
++	/*
++	 * Linux limits the maximum size of the extended attribute names list
++	 * to %XATTR_LIST_MAX. This means we should not allow creating more
++	 * extended attributes if the name list becomes larger. This limitation
++	 * is artificial for UBIFS, though.
++	 */
++	if (host_ui->xattr_names + host_ui->xattr_cnt +
++					nm->len + 1 > XATTR_LIST_MAX)
++		return -ENOSPC;
++
++	err = ubifs_budget_space(c, &req);
++	if (err)
++		return err;
++
++	inode = ubifs_new_inode(c, host, S_IFREG | S_IRWXUGO);
++	if (IS_ERR(inode)) {
++		err = PTR_ERR(inode);
++		goto out_budg;
++	}
++
++	/* Re-define all operations to be "nothing" */
++	inode->i_mapping->a_ops = &none_address_operations;
++	inode->i_op = &none_inode_operations;
++	inode->i_fop = &none_file_operations;
++
++	inode->i_flags |= S_SYNC | S_NOATIME | S_NOCMTIME | S_NOQUOTA;
++	ui = ubifs_inode(inode);
++	ui->xattr = 1;
++	ui->flags |= UBIFS_XATTR_FL;
++	ui->data = kmalloc(size, GFP_NOFS);
++	if (!ui->data) {
++		err = -ENOMEM;
++		goto out_free;
++	}
++	memcpy(ui->data, value, size);
++	inode->i_size = ui->ui_size = size;
++	ui->data_len = size;
++
++	mutex_lock(&host_ui->ui_mutex);
++	host->i_ctime = ubifs_current_time(host);
++	host_ui->xattr_cnt += 1;
++	host_ui->xattr_size += CALC_DENT_SIZE(nm->len);
++	host_ui->xattr_size += CALC_XATTR_BYTES(size);
++	host_ui->xattr_names += nm->len;
++
++	err = ubifs_jnl_update(c, host, nm, inode, 0, 1);
++	if (err)
++		goto out_cancel;
++	mutex_unlock(&host_ui->ui_mutex);
++
++	ubifs_release_budget(c, &req);
++	insert_inode_hash(inode);
++	iput(inode);
++	return 0;
++
++out_cancel:
++	host_ui->xattr_cnt -= 1;
++	host_ui->xattr_size -= CALC_DENT_SIZE(nm->len);
++	host_ui->xattr_size -= CALC_XATTR_BYTES(size);
++	mutex_unlock(&host_ui->ui_mutex);
++out_free:
++	make_bad_inode(inode);
++	iput(inode);
++out_budg:
++	ubifs_release_budget(c, &req);
++	return err;
++}
++
++/**
++ * change_xattr - change an extended attribute.
++ * @c: UBIFS file-system description object
++ * @host: host inode
++ * @inode: extended attribute inode
++ * @value: extended attribute value
++ * @size: size of extended attribute value
++ *
++ * This helper function changes the value of extended attribute @inode with new
++ * data from @value. Returns zero in case of success and a negative error code
++ * in case of failure.
++ */
++static int change_xattr(struct ubifs_info *c, struct inode *host,
++			struct inode *inode, const void *value, int size)
++{
++	int err;
++	struct ubifs_inode *host_ui = ubifs_inode(host);
++	struct ubifs_inode *ui = ubifs_inode(inode);
++	struct ubifs_budget_req req = { .dirtied_ino = 2,
++		.dirtied_ino_d = ALIGN(size, 8) + ALIGN(host_ui->data_len, 8) };
++
++	ubifs_assert(ui->data_len == inode->i_size);
++	err = ubifs_budget_space(c, &req);
++	if (err)
++		return err;
++
++	kfree(ui->data);
++	ui->data = kmalloc(size, GFP_NOFS);
++	if (!ui->data) {
++		err = -ENOMEM;
++		goto out_free;
++	}
++	memcpy(ui->data, value, size);
++	inode->i_size = ui->ui_size = size;
++	ui->data_len = size;
++
++	mutex_lock(&host_ui->ui_mutex);
++	host->i_ctime = ubifs_current_time(host);
++	host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len);
++	host_ui->xattr_size += CALC_XATTR_BYTES(size);
++
++	/*
++	 * It is important to write the host inode after the xattr inode
++	 * because if the host inode gets synchronized (via 'fsync()'), then
++	 * the extended attribute inode gets synchronized, because it goes
++	 * before the host inode in the write-buffer.
++	 */
++	err = ubifs_jnl_change_xattr(c, inode, host);
++	if (err)
++		goto out_cancel;
++	mutex_unlock(&host_ui->ui_mutex);
++
++	ubifs_release_budget(c, &req);
++	return 0;
++
++out_cancel:
++	host_ui->xattr_size -= CALC_XATTR_BYTES(size);
++	host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len);
++	mutex_unlock(&host_ui->ui_mutex);
++	make_bad_inode(inode);
++out_free:
++	ubifs_release_budget(c, &req);
++	return err;
++}
++
++/**
++ * check_namespace - check extended attribute name-space.
++ * @nm: extended attribute name
++ *
++ * This function makes sure the extended attribute name belongs to one of the
++ * supported extended attribute name-spaces. Returns name-space index in case
++ * of success and a negative error code in case of failure.
++ */
++static int check_namespace(const struct qstr *nm)
++{
++	int type;
++
++	if (nm->len > UBIFS_MAX_NLEN)
++		return -ENAMETOOLONG;
++
++	if (!strncmp(nm->name, XATTR_TRUSTED_PREFIX,
++		     XATTR_TRUSTED_PREFIX_LEN)) {
++		if (nm->name[sizeof(XATTR_TRUSTED_PREFIX) - 1] == '\0')
++			return -EINVAL;
++		type = TRUSTED_XATTR;
++	} else if (!strncmp(nm->name, XATTR_USER_PREFIX,
++				      XATTR_USER_PREFIX_LEN)) {
++		if (nm->name[XATTR_USER_PREFIX_LEN] == '\0')
++			return -EINVAL;
++		type = USER_XATTR;
++	} else if (!strncmp(nm->name, XATTR_SECURITY_PREFIX,
++				     XATTR_SECURITY_PREFIX_LEN)) {
++		if (nm->name[sizeof(XATTR_SECURITY_PREFIX) - 1] == '\0')
++			return -EINVAL;
++		type = SECURITY_XATTR;
++	} else
++		return -EOPNOTSUPP;
++
++	return type;
++}
++
++static struct inode *iget_xattr(struct ubifs_info *c, ino_t inum)
++{
++	struct inode *inode;
++
++	inode = ubifs_iget(c->vfs_sb, inum);
++	if (IS_ERR(inode)) {
++		ubifs_err("dead extended attribute entry, error %d",
++			  (int)PTR_ERR(inode));
++		return inode;
++	}
++	if (ubifs_inode(inode)->xattr)
++		return inode;
++	ubifs_err("corrupt extended attribute entry");
++	iput(inode);
++	return ERR_PTR(-EINVAL);
++}
++
++int ubifs_setxattr(struct dentry *dentry, const char *name,
++		   const void *value, size_t size, int flags)
++{
++	struct inode *inode, *host = dentry->d_inode;
++	struct ubifs_info *c = host->i_sb->s_fs_info;
++	struct qstr nm = { .name = name, .len = strlen(name) };
++	struct ubifs_dent_node *xent;
++	union ubifs_key key;
++	int err, type;
++
++	dbg_gen("xattr '%s', host ino %lu ('%.*s'), size %zd", name,
++		host->i_ino, dentry->d_name.len, dentry->d_name.name, size);
++	ubifs_assert(mutex_is_locked(&host->i_mutex));
++
++	if (size > UBIFS_MAX_INO_DATA)
++		return -ERANGE;
++
++	type = check_namespace(&nm);
++	if (type < 0)
++		return type;
++
++	xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
++	if (!xent)
++		return -ENOMEM;
++
++	/*
++	 * The extended attribute entries are stored in LNC, so multiple
++	 * look-ups do not involve reading the flash.
++	 */
++	xent_key_init(c, &key, host->i_ino, &nm);
++	err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
++	if (err) {
++		if (err != -ENOENT)
++			goto out_free;
++
++		if (flags & XATTR_REPLACE)
++			/* We are asked not to create the xattr */
++			err = -ENODATA;
++		else
++			err = create_xattr(c, host, &nm, value, size);
++		goto out_free;
++	}
++
++	if (flags & XATTR_CREATE) {
++		/* We are asked not to replace the xattr */
++		err = -EEXIST;
++		goto out_free;
++	}
++
++	inode = iget_xattr(c, le64_to_cpu(xent->inum));
++	if (IS_ERR(inode)) {
++		err = PTR_ERR(inode);
++		goto out_free;
++	}
++
++	err = change_xattr(c, host, inode, value, size);
++	iput(inode);
++
++out_free:
++	kfree(xent);
++	return err;
++}
++
++ssize_t ubifs_getxattr(struct dentry *dentry, const char *name, void *buf,
++		       size_t size)
++{
++	struct inode *inode, *host = dentry->d_inode;
++	struct ubifs_info *c = host->i_sb->s_fs_info;
++	struct qstr nm = { .name = name, .len = strlen(name) };
++	struct ubifs_inode *ui;
++	struct ubifs_dent_node *xent;
++	union ubifs_key key;
++	int err;
++
++	dbg_gen("xattr '%s', ino %lu ('%.*s'), buf size %zd", name,
++		host->i_ino, dentry->d_name.len, dentry->d_name.name, size);
++
++	err = check_namespace(&nm);
++	if (err < 0)
++		return err;
++
++	xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
++	if (!xent)
++		return -ENOMEM;
++
++	xent_key_init(c, &key, host->i_ino, &nm);
++	err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
++	if (err) {
++		if (err == -ENOENT)
++			err = -ENODATA;
++		goto out_unlock;
++	}
++
++	inode = iget_xattr(c, le64_to_cpu(xent->inum));
++	if (IS_ERR(inode)) {
++		err = PTR_ERR(inode);
++		goto out_unlock;
++	}
++
++	ui = ubifs_inode(inode);
++	ubifs_assert(inode->i_size == ui->data_len);
++	ubifs_assert(ubifs_inode(host)->xattr_size > ui->data_len);
++
++	if (buf) {
++		/* If @buf is %NULL we are supposed to return the length */
++		if (ui->data_len > size) {
++			dbg_err("buffer size %zd, xattr len %d",
++				size, ui->data_len);
++			err = -ERANGE;
++			goto out_iput;
++		}
++
++		memcpy(buf, ui->data, ui->data_len);
++	}
++	err = ui->data_len;
++
++out_iput:
++	iput(inode);
++out_unlock:
++	kfree(xent);
++	return err;
++}
++
++ssize_t ubifs_listxattr(struct dentry *dentry, char *buffer, size_t size)
++{
++	union ubifs_key key;
++	struct inode *host = dentry->d_inode;
++	struct ubifs_info *c = host->i_sb->s_fs_info;
++	struct ubifs_inode *host_ui = ubifs_inode(host);
++	struct ubifs_dent_node *xent, *pxent = NULL;
++	int err, len, written = 0;
++	struct qstr nm = { .name = NULL };
++
++	dbg_gen("ino %lu ('%.*s'), buffer size %zd", host->i_ino,
++		dentry->d_name.len, dentry->d_name.name, size);
++
++	len = host_ui->xattr_names + host_ui->xattr_cnt;
++	if (!buffer)
++		/*
++		 * We should return the minimum buffer size which will fit a
++		 * null-terminated list of all the extended attribute names.
++		 */
++		return len;
++
++	if (len > size)
++		return -ERANGE;
++
++	lowest_xent_key(c, &key, host->i_ino);
++	while (1) {
++		int type;
++
++		xent = ubifs_tnc_next_ent(c, &key, &nm);
++		if (IS_ERR(xent)) {
++			err = PTR_ERR(xent);
++			break;
++		}
++
++		nm.name = xent->name;
++		nm.len = le16_to_cpu(xent->nlen);
++
++		type = check_namespace(&nm);
++		if (unlikely(type < 0)) {
++			err = type;
++			break;
++		}
++
++		/* Show trusted namespace only for "power" users */
++		if (type != TRUSTED_XATTR || capable(CAP_SYS_ADMIN)) {
++			memcpy(buffer + written, nm.name, nm.len + 1);
++			written += nm.len + 1;
++		}
++
++		kfree(pxent);
++		pxent = xent;
++		key_read(c, &xent->key, &key);
++	}
++
++	kfree(pxent);
++	if (err != -ENOENT) {
++		ubifs_err("cannot find next direntry, error %d", err);
++		return err;
++	}
++
++	ubifs_assert(written <= size);
++	return written;
++}
++
++static int remove_xattr(struct ubifs_info *c, struct inode *host,
++			struct inode *inode, const struct qstr *nm)
++{
++	int err;
++	struct ubifs_inode *host_ui = ubifs_inode(host);
++	struct ubifs_inode *ui = ubifs_inode(inode);
++	struct ubifs_budget_req req = { .dirtied_ino = 2, .mod_dent = 1,
++				.dirtied_ino_d = ALIGN(host_ui->data_len, 8) };
++
++	ubifs_assert(ui->data_len == inode->i_size);
++
++	err = ubifs_budget_space(c, &req);
++	if (err)
++		return err;
++
++	mutex_lock(&host_ui->ui_mutex);
++	host->i_ctime = ubifs_current_time(host);
++	host_ui->xattr_cnt -= 1;
++	host_ui->xattr_size -= CALC_DENT_SIZE(nm->len);
++	host_ui->xattr_size -= CALC_XATTR_BYTES(ui->data_len);
++	host_ui->xattr_names -= nm->len;
++
++	err = ubifs_jnl_delete_xattr(c, host, inode, nm);
++	if (err)
++		goto out_cancel;
++	mutex_unlock(&host_ui->ui_mutex);
++
++	ubifs_release_budget(c, &req);
++	return 0;
++
++out_cancel:
++	host_ui->xattr_cnt += 1;
++	host_ui->xattr_size += CALC_DENT_SIZE(nm->len);
++	host_ui->xattr_size += CALC_XATTR_BYTES(ui->data_len);
++	mutex_unlock(&host_ui->ui_mutex);
++	ubifs_release_budget(c, &req);
++	make_bad_inode(inode);
++	return err;
++}
++
++int ubifs_removexattr(struct dentry *dentry, const char *name)
++{
++	struct inode *inode, *host = dentry->d_inode;
++	struct ubifs_info *c = host->i_sb->s_fs_info;
++	struct qstr nm = { .name = name, .len = strlen(name) };
++	struct ubifs_dent_node *xent;
++	union ubifs_key key;
++	int err;
++
++	dbg_gen("xattr '%s', ino %lu ('%.*s')", name,
++		host->i_ino, dentry->d_name.len, dentry->d_name.name);
++	ubifs_assert(mutex_is_locked(&host->i_mutex));
++
++	err = check_namespace(&nm);
++	if (err < 0)
++		return err;
++
++	xent = kmalloc(UBIFS_MAX_XENT_NODE_SZ, GFP_NOFS);
++	if (!xent)
++		return -ENOMEM;
++
++	xent_key_init(c, &key, host->i_ino, &nm);
++	err = ubifs_tnc_lookup_nm(c, &key, xent, &nm);
++	if (err) {
++		if (err == -ENOENT)
++			err = -ENODATA;
++		goto out_free;
++	}
++
++	inode = iget_xattr(c, le64_to_cpu(xent->inum));
++	if (IS_ERR(inode)) {
++		err = PTR_ERR(inode);
++		goto out_free;
++	}
++
++	ubifs_assert(inode->i_nlink == 1);
++	inode->i_nlink = 0;
++	err = remove_xattr(c, host, inode, &nm);
++	if (err)
++		inode->i_nlink = 1;
++
++	/* If @i_nlink is 0, 'iput()' will delete the inode */
++	iput(inode);
++
++out_free:
++	kfree(xent);
++	return err;
++}
+diff -Nurd linux-2.6.24.orig/include/linux/fs.h linux-2.6.24/include/linux/fs.h
+--- linux-2.6.24.orig/include/linux/fs.h	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/include/linux/fs.h	2009-04-17 09:49:28.000000000 +0200
+@@ -1672,6 +1672,8 @@
+ extern int invalidate_inode_pages2(struct address_space *mapping);
+ extern int invalidate_inode_pages2_range(struct address_space *mapping,
+ 					 pgoff_t start, pgoff_t end);
++extern void generic_sync_sb_inodes(struct super_block *sb,
++				struct writeback_control *wbc);
+ extern int write_inode_now(struct inode *, int);
+ extern int filemap_fdatawrite(struct address_space *);
+ extern int filemap_flush(struct address_space *);
+diff -Nurd linux-2.6.24.orig/include/linux/mtd/ubi.h linux-2.6.24/include/linux/mtd/ubi.h
+--- linux-2.6.24.orig/include/linux/mtd/ubi.h	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/include/linux/mtd/ubi.h	2009-04-17 09:49:28.000000000 +0200
+@@ -26,23 +26,6 @@
+ #include <mtd/ubi-user.h>
+ 
+ /*
+- * UBI data type hint constants.
+- *
+- * UBI_LONGTERM: long-term data
+- * UBI_SHORTTERM: short-term data
+- * UBI_UNKNOWN: data persistence is unknown
+- *
+- * These constants are used when data is written to UBI volumes in order to
+- * help the UBI wear-leveling unit to find more appropriate physical
+- * eraseblocks.
+- */
+-enum {
+-	UBI_LONGTERM = 1,
+-	UBI_SHORTTERM,
+-	UBI_UNKNOWN
+-};
+-
+-/*
+  * enum ubi_open_mode - UBI volume open mode constants.
+  *
+  * UBI_READONLY: read-only mode
+@@ -62,13 +45,13 @@
+  * @size: how many physical eraseblocks are reserved for this volume
+  * @used_bytes: how many bytes of data this volume contains
+  * @used_ebs: how many physical eraseblocks of this volume actually contain any
+- * data
++ *            data
+  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
+  * @corrupted: non-zero if the volume is corrupted (static volumes only)
+  * @upd_marker: non-zero if the volume has update marker set
+  * @alignment: volume alignment
+  * @usable_leb_size: how many bytes are available in logical eraseblocks of
+- * this volume
++ *                   this volume
+  * @name_len: volume name length
+  * @name: volume name
+  * @cdev: UBI volume character device major and minor numbers
+@@ -167,7 +150,9 @@
+ 		   int len, int dtype);
+ int ubi_leb_erase(struct ubi_volume_desc *desc, int lnum);
+ int ubi_leb_unmap(struct ubi_volume_desc *desc, int lnum);
++int ubi_leb_map(struct ubi_volume_desc *desc, int lnum, int dtype);
+ int ubi_is_mapped(struct ubi_volume_desc *desc, int lnum);
++int ubi_sync(int ubi_num);
+ 
+ /*
+  * This function is the same as the 'ubi_leb_read()' function, but it does not
+diff -Nurd linux-2.6.24.orig/include/mtd/Kbuild linux-2.6.24/include/mtd/Kbuild
+--- linux-2.6.24.orig/include/mtd/Kbuild	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/include/mtd/Kbuild	2009-04-17 09:49:28.000000000 +0200
+@@ -3,5 +3,4 @@
+ header-y += mtd-abi.h
+ header-y += mtd-user.h
+ header-y += nftl-user.h
+-header-y += ubi-header.h
+ header-y += ubi-user.h
+diff -Nurd linux-2.6.24.orig/include/mtd/ubi-user.h linux-2.6.24/include/mtd/ubi-user.h
+--- linux-2.6.24.orig/include/mtd/ubi-user.h	2009-04-17 09:45:11.000000000 +0200
++++ linux-2.6.24/include/mtd/ubi-user.h	2009-04-17 09:49:28.000000000 +0200
+@@ -22,33 +22,55 @@
+ #define __UBI_USER_H__
+ 
+ /*
++ * UBI device creation (the same as MTD device attachment)
++ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
++ *
++ * MTD devices may be attached using %UBI_IOCATT ioctl command of the UBI
++ * control device. The caller has to properly fill and pass
++ * &struct ubi_attach_req object - UBI will attach the MTD device specified in
++ * the request and return the newly created UBI device number as the ioctl
++ * return value.
++ *
++ * UBI device deletion (the same as MTD device detachment)
++ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
++ *
++ * An UBI device maybe deleted with %UBI_IOCDET ioctl command of the UBI
++ * control device.
++ *
+  * UBI volume creation
+  * ~~~~~~~~~~~~~~~~~~~
+  *
+- * UBI volumes are created via the %UBI_IOCMKVOL IOCTL command of UBI character
++ * UBI volumes are created via the %UBI_IOCMKVOL ioctl command of UBI character
+  * device. A &struct ubi_mkvol_req object has to be properly filled and a
+- * pointer to it has to be passed to the IOCTL.
++ * pointer to it has to be passed to the ioctl.
+  *
+  * UBI volume deletion
+  * ~~~~~~~~~~~~~~~~~~~
+  *
+- * To delete a volume, the %UBI_IOCRMVOL IOCTL command of the UBI character
++ * To delete a volume, the %UBI_IOCRMVOL ioctl command of the UBI character
+  * device should be used. A pointer to the 32-bit volume ID hast to be passed
+- * to the IOCTL.
++ * to the ioctl.
+  *
+  * UBI volume re-size
+  * ~~~~~~~~~~~~~~~~~~
+  *
+- * To re-size a volume, the %UBI_IOCRSVOL IOCTL command of the UBI character
++ * To re-size a volume, the %UBI_IOCRSVOL ioctl command of the UBI character
+  * device should be used. A &struct ubi_rsvol_req object has to be properly
+- * filled and a pointer to it has to be passed to the IOCTL.
++ * filled and a pointer to it has to be passed to the ioctl.
++ *
++ * UBI volumes re-name
++ * ~~~~~~~~~~~~~~~~~~~
++ *
++ * To re-name several volumes atomically at one go, the %UBI_IOCRNVOL command
++ * of the UBI character device should be used. A &struct ubi_rnvol_req object
++ * has to be properly filled and a pointer to it has to be passed to the ioctl.
+  *
+  * UBI volume update
+  * ~~~~~~~~~~~~~~~~~
+  *
+- * Volume update should be done via the %UBI_IOCVOLUP IOCTL command of the
++ * Volume update should be done via the %UBI_IOCVOLUP ioctl command of the
+  * corresponding UBI volume character device. A pointer to a 64-bit update
+- * size should be passed to the IOCTL. After then, UBI expects user to write
++ * size should be passed to the ioctl. After this, UBI expects user to write
+  * this number of bytes to the volume character device. The update is finished
+  * when the claimed number of bytes is passed. So, the volume update sequence
+  * is something like:
+@@ -57,19 +79,65 @@
+  * ioctl(fd, UBI_IOCVOLUP, &image_size);
+  * write(fd, buf, image_size);
+  * close(fd);
++ *
++ * Logical eraseblock erase
++ * ~~~~~~~~~~~~~~~~~~~~~~~~
++ *
++ * To erase a logical eraseblock, the %UBI_IOCEBER ioctl command of the
++ * corresponding UBI volume character device should be used. This command
++ * unmaps the requested logical eraseblock, makes sure the corresponding
++ * physical eraseblock is successfully erased, and returns.
++ *
++ * Atomic logical eraseblock change
++ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
++ *
++ * Atomic logical eraseblock change operation is called using the %UBI_IOCEBCH
++ * ioctl command of the corresponding UBI volume character device. A pointer to
++ * a &struct ubi_leb_change_req object has to be passed to the ioctl. Then the
++ * user is expected to write the requested amount of bytes (similarly to what
++ * should be done in case of the "volume update" ioctl).
++ *
++ * Logical eraseblock map
++ * ~~~~~~~~~~~~~~~~~~~~~
++ *
++ * To map a logical eraseblock to a physical eraseblock, the %UBI_IOCEBMAP
++ * ioctl command should be used. A pointer to a &struct ubi_map_req object is
++ * expected to be passed. The ioctl maps the requested logical eraseblock to
++ * a physical eraseblock and returns.  Only non-mapped logical eraseblocks can
++ * be mapped. If the logical eraseblock specified in the request is already
++ * mapped to a physical eraseblock, the ioctl fails and returns error.
++ *
++ * Logical eraseblock unmap
++ * ~~~~~~~~~~~~~~~~~~~~~~~~
++ *
++ * To unmap a logical eraseblock to a physical eraseblock, the %UBI_IOCEBUNMAP
++ * ioctl command should be used. The ioctl unmaps the logical eraseblocks,
++ * schedules corresponding physical eraseblock for erasure, and returns. Unlike
++ * the "LEB erase" command, it does not wait for the physical eraseblock being
++ * erased. Note, the side effect of this is that if an unclean reboot happens
++ * after the unmap ioctl returns, you may find the LEB mapped again to the same
++ * physical eraseblock after the UBI is run again.
++ *
++ * Check if logical eraseblock is mapped
++ * ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
++ *
++ * To check if a logical eraseblock is mapped to a physical eraseblock, the
++ * %UBI_IOCEBISMAP ioctl command should be used. It returns %0 if the LEB is
++ * not mapped, and %1 if it is mapped.
+  */
+ 
+ /*
+- * When a new volume is created, users may either specify the volume number they
+- * want to create or to let UBI automatically assign a volume number using this
+- * constant.
++ * When a new UBI volume or UBI device is created, users may either specify the
++ * volume/device number they want to create or to let UBI automatically assign
++ * the number using these constants.
+  */
+ #define UBI_VOL_NUM_AUTO (-1)
++#define UBI_DEV_NUM_AUTO (-1)
+ 
+ /* Maximum volume name length */
+ #define UBI_MAX_VOLUME_NAME 127
+ 
+-/* IOCTL commands of UBI character devices */
++/* ioctl commands of UBI character devices */
+ 
+ #define UBI_IOC_MAGIC 'o'
+ 
+@@ -79,15 +147,57 @@
+ #define UBI_IOCRMVOL _IOW(UBI_IOC_MAGIC, 1, int32_t)
+ /* Re-size an UBI volume */
+ #define UBI_IOCRSVOL _IOW(UBI_IOC_MAGIC, 2, struct ubi_rsvol_req)
++/* Re-name volumes */
++#define UBI_IOCRNVOL _IOW(UBI_IOC_MAGIC, 3, struct ubi_rnvol_req)
+ 
+-/* IOCTL commands of UBI volume character devices */
++/* ioctl commands of the UBI control character device */
++
++#define UBI_CTRL_IOC_MAGIC 'o'
++
++/* Attach an MTD device */
++#define UBI_IOCATT _IOW(UBI_CTRL_IOC_MAGIC, 64, struct ubi_attach_req)
++/* Detach an MTD device */
++#define UBI_IOCDET _IOW(UBI_CTRL_IOC_MAGIC, 65, int32_t)
++
++/* ioctl commands of UBI volume character devices */
+ 
+ #define UBI_VOL_IOC_MAGIC 'O'
+ 
+ /* Start UBI volume update */
+ #define UBI_IOCVOLUP _IOW(UBI_VOL_IOC_MAGIC, 0, int64_t)
+-/* An eraseblock erasure command, used for debugging, disabled by default */
++/* LEB erasure command, used for debugging, disabled by default */
+ #define UBI_IOCEBER _IOW(UBI_VOL_IOC_MAGIC, 1, int32_t)
++/* Atomic LEB change command */
++#define UBI_IOCEBCH _IOW(UBI_VOL_IOC_MAGIC, 2, int32_t)
++/* Map LEB command */
++#define UBI_IOCEBMAP _IOW(UBI_VOL_IOC_MAGIC, 3, struct ubi_map_req)
++/* Unmap LEB command */
++#define UBI_IOCEBUNMAP _IOW(UBI_VOL_IOC_MAGIC, 4, int32_t)
++/* Check if LEB is mapped command */
++#define UBI_IOCEBISMAP _IOR(UBI_VOL_IOC_MAGIC, 5, int32_t)
++
++/* Maximum MTD device name length supported by UBI */
++#define MAX_UBI_MTD_NAME_LEN 127
++
++/* Maximum amount of UBI volumes that can be re-named at one go */
++#define UBI_MAX_RNVOL 32
++
++/*
++ * UBI data type hint constants.
++ *
++ * UBI_LONGTERM: long-term data
++ * UBI_SHORTTERM: short-term data
++ * UBI_UNKNOWN: data persistence is unknown
++ *
++ * These constants are used when data is written to UBI volumes in order to
++ * help the UBI wear-leveling unit to find more appropriate physical
++ * eraseblocks.
++ */
++enum {
++	UBI_LONGTERM  = 1,
++	UBI_SHORTTERM = 2,
++	UBI_UNKNOWN   = 3,
++};
+ 
+ /*
+  * UBI volume type constants.
+@@ -97,22 +207,58 @@
+  */
+ enum {
+ 	UBI_DYNAMIC_VOLUME = 3,
+-	UBI_STATIC_VOLUME = 4
++	UBI_STATIC_VOLUME  = 4,
++};
++
++/**
++ * struct ubi_attach_req - attach MTD device request.
++ * @ubi_num: UBI device number to create
++ * @mtd_num: MTD device number to attach
++ * @vid_hdr_offset: VID header offset (use defaults if %0)
++ * @padding: reserved for future, not used, has to be zeroed
++ *
++ * This data structure is used to specify MTD device UBI has to attach and the
++ * parameters it has to use. The number which should be assigned to the new UBI
++ * device is passed in @ubi_num. UBI may automatically assign the number if
++ * @UBI_DEV_NUM_AUTO is passed. In this case, the device number is returned in
++ * @ubi_num.
++ *
++ * Most applications should pass %0 in @vid_hdr_offset to make UBI use default
++ * offset of the VID header within physical eraseblocks. The default offset is
++ * the next min. I/O unit after the EC header. For example, it will be offset
++ * 512 in case of a 512 bytes page NAND flash with no sub-page support. Or
++ * it will be 512 in case of a 2KiB page NAND flash with 4 512-byte sub-pages.
++ *
++ * But in rare cases, if this optimizes things, the VID header may be placed to
++ * a different offset. For example, the boot-loader might do things faster if
++ * the VID header sits at the end of the first 2KiB NAND page with 4 sub-pages.
++ * As the boot-loader would not normally need to read EC headers (unless it
++ * needs UBI in RW mode), it might be faster to calculate ECC. This is weird
++ * example, but it real-life example. So, in this example, @vid_hdr_offer would
++ * be 2KiB-64 bytes = 1984. Note, that this position is not even 512-bytes
++ * aligned, which is OK, as UBI is clever enough to realize this is 4th
++ * sub-page of the first page and add needed padding.
++ */
++struct ubi_attach_req {
++	int32_t ubi_num;
++	int32_t mtd_num;
++	int32_t vid_hdr_offset;
++	int8_t padding[12];
+ };
+ 
+ /**
+  * struct ubi_mkvol_req - volume description data structure used in
+- * volume creation requests.
++ *                        volume creation requests.
+  * @vol_id: volume number
+  * @alignment: volume alignment
+  * @bytes: volume size in bytes
+  * @vol_type: volume type (%UBI_DYNAMIC_VOLUME or %UBI_STATIC_VOLUME)
+- * @padding1: reserved for future, not used
++ * @padding1: reserved for future, not used, has to be zeroed
+  * @name_len: volume name length
+- * @padding2: reserved for future, not used
++ * @padding2: reserved for future, not used, has to be zeroed
+  * @name: volume name
+  *
+- * This structure is used by userspace programs when creating new volumes. The
++ * This structure is used by user-space programs when creating new volumes. The
+  * @used_bytes field is only necessary when creating static volumes.
+  *
+  * The @alignment field specifies the required alignment of the volume logical
+@@ -139,7 +285,7 @@
+ 	int8_t padding1;
+ 	int16_t name_len;
+ 	int8_t padding2[4];
+-	char name[UBI_MAX_VOLUME_NAME+1];
++	char name[UBI_MAX_VOLUME_NAME + 1];
+ } __attribute__ ((packed));
+ 
+ /**
+@@ -158,4 +304,73 @@
+ 	int32_t vol_id;
+ } __attribute__ ((packed));
+ 
++/**
++ * struct ubi_rnvol_req - volumes re-name request.
++ * @count: count of volumes to re-name
++ * @padding1:  reserved for future, not used, has to be zeroed
++ * @vol_id: ID of the volume to re-name
++ * @name_len: name length
++ * @padding2:  reserved for future, not used, has to be zeroed
++ * @name: new volume name
++ *
++ * UBI allows to re-name up to %32 volumes at one go. The count of volumes to
++ * re-name is specified in the @count field. The ID of the volumes to re-name
++ * and the new names are specified in the @vol_id and @name fields.
++ *
++ * The UBI volume re-name operation is atomic, which means that should power cut
++ * happen, the volumes will have either old name or new name. So the possible
++ * use-cases of this command is atomic upgrade. Indeed, to upgrade, say, volumes
++ * A and B one may create temporary volumes %A1 and %B1 with the new contents,
++ * then atomically re-name A1->A and B1->B, in which case old %A and %B will
++ * be removed.
++ *
++ * If it is not desirable to remove old A and B, the re-name request has to
++ * contain 4 entries: A1->A, A->A1, B1->B, B->B1, in which case old A1 and B1
++ * become A and B, and old A and B will become A1 and B1.
++ *
++ * It is also OK to request: A1->A, A1->X, B1->B, B->Y, in which case old A1
++ * and B1 become A and B, and old A and B become X and Y.
++ *
++ * In other words, in case of re-naming into an existing volume name, the
++ * existing volume is removed, unless it is re-named as well at the same
++ * re-name request.
++ */
++struct ubi_rnvol_req {
++	int32_t count;
++	int8_t padding1[12];
++	struct {
++		int32_t vol_id;
++		int16_t name_len;
++		int8_t  padding2[2];
++		char    name[UBI_MAX_VOLUME_NAME + 1];
++	} ents[UBI_MAX_RNVOL];
++} __attribute__ ((packed));
++
++/**
++ * struct ubi_leb_change_req - a data structure used in atomic LEB change
++ *                             requests.
++ * @lnum: logical eraseblock number to change
++ * @bytes: how many bytes will be written to the logical eraseblock
++ * @dtype: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN)
++ * @padding: reserved for future, not used, has to be zeroed
++ */
++struct ubi_leb_change_req {
++	int32_t lnum;
++	int32_t bytes;
++	int8_t  dtype;
++	int8_t  padding[7];
++} __attribute__ ((packed));
++
++/**
++ * struct ubi_map_req - a data structure used in map LEB requests.
++ * @lnum: logical eraseblock number to unmap
++ * @dtype: data type (%UBI_LONGTERM, %UBI_SHORTTERM, %UBI_UNKNOWN)
++ * @padding: reserved for future, not used, has to be zeroed
++ */
++struct ubi_map_req {
++	int32_t lnum;
++	int8_t  dtype;
++	int8_t  padding[3];
++} __attribute__ ((packed));
++
+ #endif /* __UBI_USER_H__ */