overlayfs is for UBI file systems

1 files changed, 119 insertions, 0 deletions

diff --git a/recipes-core/multitech/overlayfs-init-ubi/overlayfs.init b/recipes-core/multitech/overlayfs-init-ubi/overlayfs.init
new file mode 100644
index 0000000..72a6217
--- /dev/null
+++ b/recipes-core/multitech/overlayfs-init-ubi/overlayfs.init
@@ -0,0 +1,119 @@
+#!/bin/bash
+# To turn on systemd debug:
+# setenv bootargs "systemd.log_level=debug console=ttymxc0,115200 ubi.mtd=nandubi root=ubi0:rootfs rootfstype=ubifs ro
+# rootflags=chk_data_crc mtdparts=gpmi-nand:4m(nandboot),-(nandubi)"
+
+# Command to erase user data file system
+# Modified for ubifs, secure boot (no U-Boot access)
+
+MNT_USER="/mnt/user"
+OVERLAY="$MNT_USER/overlay"
+WORKDIR="$MNT_USER/work"
+UPPERDIR="$MNT_USER/upper"
+LOWERDIR="/"
+USER_ORIG="$UPPERDIR/orig"
+USER_PARTITION="ubi0:user-data"
+DO_ERASE_USERDATA_FILE="/mnt/user/.persistent/mts_do_erase_userdata"
+DO_CLEAR_USERDATA_FILE="/mnt/user/.persistent/mts_do_clear_userdata"
+
+pid=$$
+prefix="<3>overlayrootfs-generator[${pid}]: "
+loginfo()  { echo "${prefix}$@" >/dev/kmsg ; }
+logpipe() { cat <(echo -n "${prefix}") - >/dev/kmsg ; }
+
+mnt_user() {
+    mkdir -p $MNT_USER
+    mount -t ubifs $USER_PARTITION $MNT_USER
+}
+
+fs="/run /dev /proc /sys /sys/kernel/security /dev/shm /dev/pts /run /sys/fs/cgroup /sys/fs/cgroup/unified
+ /sys/fs/cgroup/systemd /sys/fs/cgroup/devices /sys/fs/cgroup/freezer /sys/fs/cgroup/pids /sys/fs/cgroup/memory
+ /dev/mqueue /sys/kernel/debug /tmp /sys/fs/fuse/connections /sys/kernel/config /var/volatile"
+ 
+my_switch_root() {
+    NEW_ROOT=$1
+    echo mountinfo >&2
+    cat /proc/mounts >&2
+    mount --make-rprivate /
+    for f in $fs ; do
+        mount -o noatime,move --bind $f $NEW_ROOT/$f
+    done
+    /sbin/pivot_root $NEW_ROOT $NEW_ROOT/orig
+}
+
+# remove old hidden and non-hidden files and folders
+do_remove_old() {
+    shopt -s dotglob
+    rm -rf $MNT_USER/*.old
+    shopt -u dotglob
+}
+
+# select files for deletion
+do_select_old() {
+    if [[ -f $DO_ERASE_USERDATA_FILE ]]; then
+        # when "erase user data" is requested - mark all hidden and non-hidden files for deletion
+        shopt -s dotglob
+        trap  "shopt -u dotglob" RETURN
+        loginfo "Erasing user data"
+    else
+        # when "clear user data" is requested - mark all non-hidden files for deletion
+        loginfo "Clearing user data"
+    fi
+
+    for FILE_PATH in "$MNT_USER"/*; do
+        FILE_NAME=$(basename "$FILE_PATH")
+        # rename all files and folders that exist in /mnt/user
+        mv "$FILE_PATH" "$MNT_USER/$FILE_NAME.old"
+    done
+}
+
+do_rw_mount() {
+    loginfo "Starting RW overlayfs"
+    mount -t tmpfs inittemp /mnt
+    mnt_user
+
+    do_remove_old
+    if [[ -f $DO_CLEAR_USERDATA_FILE ]] || [[ -f $DO_ERASE_USERDATA_FILE ]] ; then
+        do_select_old
+        do_remove_old
+        rm -f $DO_CLEAR_USERDATA_FILE 
+    fi
+
+    mkdir -p $UPPERDIR $WORKDIR $OVERLAY $USER_ORIG ${MNT_USER}/.persistent
+    loginfo "Mounting..."
+    set -x
+    mount -o noatime,lowerdir=$LOWERDIR,upperdir=$UPPERDIR,workdir=$WORKDIR,rw -t overlay overlay $OVERLAY
+    loginfo "JAK: What does overlay look like in /proc/mounts?"
+    cat /proc/mounts | grep overlay | logpipe
+
+    mkdir -p ${OVERLAY}/var/persistent
+
+    mount --bind ${MNT_USER}/.persistent ${OVERLAY}/var/persistent
+    loginfo "Switch root to $OVERLAY"
+    my_switch_root $OVERLAY
+    cat /proc/mounts | grep overlay >&2
+    mount -o remount,rw /
+    cat /proc/mounts | grep overlay | logpipe
+    cat /proc/mounts | grep tmp | logpipe
+    umount -l /tmp
+    umount -l /var/volatile
+    cgroupmnts=$(sed -r -e 's/[^[:space:]]*[[:space:]]//'  -e 's/[[:space:]]+.*//g' /proc/mounts | grep '^/orig')
+    for mp in ${cgroupmnts} ; do
+        if [[ $mp != /orig ]] ; then
+            umount -l $mp
+        fi
+    done
+}
+
+do_start() {
+    do_rw_mount
+}
+
+case $1 in
+start)
+    do_start
+;;
+*)
+    echo "Usage: $0 {start}"
+;;
+esac