From a2eda5de55c7176a345b3a1e0d5a45b5773455c7 Mon Sep 17 00:00:00 2001
From: Maksym Telychko <maksym.telychko@globallogic.com>
Date: Thu, 16 Apr 2020 16:48:25 +0300
Subject: Revert "MTX-3262 mpower lockfile rewrite for libmts-io compatibility"

This reverts commit f4b78a288c9e5c2a7a05d71b9bbe9e5fc26f2a63.
---
 src/atcmd.c | 12 +++++++----
 src/utils.c | 72 ++++++++++++++++++++++++++++---------------------------------
 src/utils.h |  8 +------
 3 files changed, 42 insertions(+), 50 deletions(-)

diff --git a/src/atcmd.c b/src/atcmd.c
index eab4210..97fd34b 100644
--- a/src/atcmd.c
+++ b/src/atcmd.c
@@ -1471,7 +1471,7 @@ static int sms_atcmd_init(int fd)
 	return 0;
 }
 
-static struct Lock *lock_file;
+static char *lock_path;
 
 int sms_device_close(int fd)
 {
@@ -1479,7 +1479,11 @@ int sms_device_close(int fd)
 
 	ret = tty_close(fd);
 
-	lock_file = device_unlock(lock_file);
+	if (lock_path) {
+		unlink(lock_path);
+		free(lock_path);
+		lock_path = NULL;
+	}
 
 	return ret;
 }
@@ -1494,8 +1498,8 @@ int sms_device_open(void)
 		return -1;
 	}
 
-	lock_file = device_lock(Global.core.device);
-	if (!lock_file) {
+	lock_path = device_lock(Global.core.device);
+	if (!lock_path) {
 		sms_device_close(fd);
 		return -1;
 	}
diff --git a/src/utils.c b/src/utils.c
index e7d6b69..b93634c 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -33,7 +33,6 @@
 #include <fcntl.h>
 #include <string.h>
 #include <linux/limits.h>
-#include <sys/file.h>
 
 #include "utils.h"
 #include "log.h"
@@ -249,49 +248,44 @@ char *shell_path_expand(const char *path)
 
 #define MAX_TRY 10
 
-struct Lock *device_lock(const char *path)
+char *device_lock(const char *path)
 {
-	struct Lock *result = (struct Lock*)calloc(1, sizeof(struct Lock));
-	if (result == NULL) {
+	int tmp;
+	char *name = basename(path);
+	int fd;
+	char str[32];
+	char *lock;
+	unsigned char num_try=0;
+
+	tmp = asprintf(&lock, "/var/lock/LCK..%s", name);
+	if (tmp < 0) {
 		log_error("out of memory");
 		return NULL;
 	}
 
-	if (asprintf(&result->path, "/var/lock/LCK..%s", basename(path)) < 0) {
-		log_error("out of memory");
-		return NULL;
-	}
-
-	result->fd = open(result->path, O_CREAT | O_RDWR, 0644);
-	if (result->fd >= 0) {
-		unsigned char num_try = 0;
-		while (1) {
-			int lockErr = flock(result->fd, LOCK_EX | LOCK_NB);
-			if (lockErr == 0) {
-				return result;
-			} else if (errno != EWOULDBLOCK) {
-				break;
-			}
-			if (num_try++>=MAX_TRY) {
-				//something locks device too long
-				break;
-			}
-			usleep(100000ul);//100ms
-		}
-		log_error("failed to create %s: %m", result->path);
-		device_unlock(result);
-	}
-	return NULL;
-}
-
-struct Lock *device_unlock(struct Lock *lock)
-{
-	if (lock) {
-		close(lock->fd);
-		free(lock->path);
-		free(lock);
-	}
-	return NULL;
+	do{
+	  fd = open(lock, O_CREAT | O_WRONLY | O_TRUNC | O_EXCL, 0644);
+	  if (fd > 0) {
+	    break;
+	  }else{
+	    log_error("%i number of trying to create %s: %m",num_try+1,lock);
+	  };
+	  if(num_try++>=MAX_TRY){
+		  //something locks device too long
+		  log_error("failed to create %s: %m", lock);
+		  free(lock);
+		  return NULL;
+	  }
+	  usleep(100000ul);//100ms
+	}while(1);
+
+	snprintf(str, sizeof(str), "%10d\n", getpid());
+
+	full_write(fd, str, strlen(str));
+
+	close(fd);
+
+	return lock;
 }
 
 int indexOfChar(const char *array, int len, char character)
diff --git a/src/utils.h b/src/utils.h
index eb9d5bc..04a71b6 100644
--- a/src/utils.h
+++ b/src/utils.h
@@ -30,18 +30,12 @@ enum {
 	USER_YESNO_YES = 1,
 };
 
-struct Lock {
-    char *path;
-    int fd;
-};
-
 int user_yesno(int def, const char *fmt, ...);
 int systemf(const char *fmt, ...);
 FILE *popenf(const char *mode, const char *fmt, ...);
 char *shell_path_expand(const char *path);
 
-struct Lock *device_lock(const char *path);
-struct Lock *device_unlock(struct Lock *lock);
+char *device_lock(const char *path);
 
 int indexOfChar(const char *array, int len, char character);
 
-- 
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