[PATCH] ext3: journal_flush() needs journal_lock_updates()

We need to take journal_lock_updates() while remounting r/o to prevent a new
transaction starting while journal_flush() is running.
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

fs/ext3/super.c

@@ -1875,13 +1875,17 @@ static void ext3_commit_super (struct super_block * sb,
 static void ext3_mark_recovery_complete(struct super_block * sb,
 					struct ext3_super_block * es)
 {
-	journal_flush(EXT3_SB(sb)->s_journal);
+	journal_t *journal = EXT3_SB(sb)->s_journal;
+
+	journal_lock_updates(journal);
+	journal_flush(journal);
 	if (EXT3_HAS_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER) &&
 	    sb->s_flags & MS_RDONLY) {
 		EXT3_CLEAR_INCOMPAT_FEATURE(sb, EXT3_FEATURE_INCOMPAT_RECOVER);
 		sb->s_dirt = 0;
 		ext3_commit_super(sb, es, 1);
 	}
+	journal_unlock_updates(journal);
 }
 
 /*