From: Wu, Josh <Josh.wu@atmel.com>
Date: Wed, 24 Jul 2013 09:55:30 +0000 (+0800)
Subject: fs: fat: don't call disk_write with zero sector num
X-Git-Tag: v2013.10-rc3~24
X-Git-Url: https://git.librecmc.org/?a=commitdiff_plain;h=6b8f185faf29db302a20f584cc54253667535f08;p=oweals%2Fu-boot.git

fs: fat: don't call disk_write with zero sector num

In the set_cluster() function, it will convert the buffer size to sector
numbers. Then call disk_write() to write by sector.
For remaining buffer, the size is less than a sector, call disk_write()
again to write them in one sector.

But if the total buffer size is less then one sector, the original code
will call disk_write() with zero sector number. It is unnecessary.
So this patch fix this. Now it will not call disk_write() if total buffer size
is less than one sector.

Signed-off-by: Josh Wu <josh.wu@atmel.com>
---

diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index b78026a81f..b7a21e05bf 100644
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -552,9 +552,11 @@ set_cluster(fsdata *mydata, __u32 clustnum, __u8 *buffer,
 
 	debug("clustnum: %d, startsect: %d\n", clustnum, startsect);
 
-	if (disk_write(startsect, size / mydata->sect_size, buffer) < 0) {
-		debug("Error writing data\n");
-		return -1;
+	if ((size / mydata->sect_size) > 0) {
+		if (disk_write(startsect, size / mydata->sect_size, buffer) < 0) {
+			debug("Error writing data\n");
+			return -1;
+		}
 	}
 
 	if (size % mydata->sect_size) {