[PATCH 4/6] ext3: fix data integrity for ext4_sync_fs

[Dmitry Monakhov <dmonakhov@openvz.org>]

Inode's data or non journaled quota may be written w/o jounral so we must
send a barrier at the end of ext3_sync_fs. But it can be skipped if journal
commit will do it for us.

changes from v1:
 skip barrier for async mode

Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
---
 fs/ext3/super.c |   12 ++++++++----
 1 files changed, 8 insertions(+), 4 deletions(-)

diff --git a/fs/ext3/super.c b/fs/ext3/super.c
index fb5120a..c8a4e17 100644
--- a/fs/ext3/super.c
+++ b/fs/ext3/super.c
@@ -2521,6 +2521,7 @@ int ext3_force_commit(struct super_block *sb)
 static int ext3_sync_fs(struct super_block *sb, int wait)
 {
 	tid_t target;
+	int ret = 0;
 
 	trace_ext3_sync_fs(sb, wait);
 	/*
@@ -2528,11 +2529,14 @@ static int ext3_sync_fs(struct super_block *sb, int wait)
 	 * no dirty dquots
 	 */
 	dquot_writeback_dquots(sb, -1);
-	if (journal_start_commit(EXT3_SB(sb)->s_journal, &target)) {
-		if (wait)
-			log_wait_commit(EXT3_SB(sb)->s_journal, target);
+	if (wait) {
+		if (journal_start_commit(EXT3_SB(sb)->s_journal, &target))
+			ret = log_wait_commit(EXT3_SB(sb)->s_journal, target);
+		else
+			ret = blkdev_issue_flush(sb->s_bdev, GFP_KERNEL, NULL);
 	}
-	return 0;
+
+	return ret;
 }
 
 /*
-- 
1.7.1