UBIFS: do not commit twice

VFS calls '->sync_fs()' twice - first time with @wait = 0, second
time with @wait = 1. As a result, we may commit and synchronize
write-buffers twice. Avoid doing this by returning immediatelly if
@wait = 0.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/fs/ubifs/super.c b/fs/ubifs/super.c
index 89556ee72518..a7fc97f4d9de 100644
--- a/fs/ubifs/super.c
+++ b/fs/ubifs/super.c
@@ -432,18 +432,19 @@ 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   = wait ? WB_SYNC_ALL : WB_SYNC_NONE,
+                .sync_mode   = WB_SYNC_ALL,
                 .range_start = 0,
                 .range_end   = LLONG_MAX,
                 .nr_to_write = LONG_MAX,
         };
 
         /*
-         * Note by akpm about WB_SYNC_NONE used above: zero @wait is just an
-         * advisory thing to help the file system shove lots of data into the
-         * queues. If some gets missed then it'll be picked up on the second
+         * 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;