f2fs: fix incorrect parsing with option string

Previously 'background_gc={on***,off***}' is being parsed as correct option,
with this patch we cloud fix the trivial bug in mount process.

Change log from v1:
 o need to check length of parameter suggested by Jaegeuk Kim.

Signed-off-by: Chao Yu <chao2.yu@samsung.com>
Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 057a3efb2487..dbe402b1a4b7 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -258,9 +258,9 @@ static int parse_options(struct super_block *sb, char *options)
 
                         if (!name)
                                 return -ENOMEM;
-                        if (!strncmp(name, "on", 2))
+                        if (strlen(name) == 2 && !strncmp(name, "on", 2))
                                 set_opt(sbi, BG_GC);
-                        else if (!strncmp(name, "off", 3))
+                        else if (strlen(name) == 3 && !strncmp(name, "off", 3))
                                 clear_opt(sbi, BG_GC);
                         else {
                                 kfree(name);