reiserfs: Fix locking BUG during mount failure

Commit 1cc3c933190ea54cd4a1cd3141d8db1f6fc46c1c (reiserfs: kill-the-BKL)
introduced a bug in the mount failure case.

The error label releases the lock before calling journal_release_error,
but it requires that the lock be held. do_journal_release unlocks and
retakes it. When it releases it without it held, we trigger a BUG().

The error_alloc label skips the unlock since the lock isn't held yet
but none of the other conditions that are clean up exist yet either.

This patch returns immediately after the kzalloc failure and moves
the reiserfs_write_unlock after the journal_release_error call.

This was reported in https://bugzilla.novell.com/show_bug.cgi?id=591807

Reported-by:  Thomas Siedentopf <thomas.siedentopf@novell.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Cc: Thomas Siedentopf <thomas.siedentopf@novell.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: 2.6.33.x <stable@kernel.org>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>

diff --git a/fs/reiserfs/super.c b/fs/reiserfs/super.c
index 04bf5d791bdad8b9fea4c6eecc6d7772035d7144..ab190511bc182236c0e34bf70977516957a16816 100644 (file)
--- a/fs/reiserfs/super.c
+++ b/fs/reiserfs/super.c
@@ -1618,10 +1618,8 @@ static int reiserfs_fill_super(struct super_block *s, void *data, int silent)
        save_mount_options(s, data);
 
        sbi = kzalloc(sizeof(struct reiserfs_sb_info), GFP_KERNEL);
-       if (!sbi) {
-               errval = -ENOMEM;
-               goto error_alloc;
-       }
+       if (!sbi)
+               return -ENOMEM;
        s->s_fs_info = sbi;
        /* Set default values for options: non-aggressive tails, RO on errors */
        REISERFS_SB(s)->s_mount_opt |= (1 << REISERFS_SMALLTAIL);
@@ -1878,12 +1876,12 @@ static int reiserfs_fill_super(struct super_block *s, void *data, int silent)
        return (0);
 
 error:
-       reiserfs_write_unlock(s);
-error_alloc:
        if (jinit_done) {       /* kill the commit thread, free journal ram */
                journal_release_error(NULL, s);
        }
 
+       reiserfs_write_unlock(s);
+
        reiserfs_free_bitmap_cache(s);
        if (SB_BUFFER_WITH_SB(s))
                brelse(SB_BUFFER_WITH_SB(s));