ext3: revert "ext3: wait on all pending commits in ext3_sync_fs"

This reverts commit c87591b7.

Since journal_start_commit() is now fixed to return 1 when we started a
transaction commit, there's some transaction waiting to be committed or
there's a transaction already committing, we don't need to call
ext3_force_commit() in ext3_sync_fs().  Furthermore ext3_force_commit()
can unnecessarily create sync transaction which is expensive so it's
worthwhile to remove it when we can.

Cc: Eric Sandeen <sandeen@redhat.com>
Cc: <linux-ext4@vger.kernel.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

fs/ext3/super.c

@@ -2428,12 +2428,13 @@ static void ext3_write_super (struct super_block * sb)
 
 static int ext3_sync_fs(struct super_block *sb, int wait)
 {
+	tid_t target;
+
 	sb->s_dirt = 0;
+	if (journal_start_commit(EXT3_SB(sb)->s_journal, &target)) {
 		if (wait)
-		ext3_force_commit(sb);
-	else
-		journal_start_commit(EXT3_SB(sb)->s_journal, NULL);
-
+			log_wait_commit(EXT3_SB(sb)->s_journal, target);
+	}
 	return 0;
 }