ocfs2: revert "ocfs2: fix NULL pointer dereference when dismount and ocfs2rec simultaneously"

75f82eaa502c ("ocfs2: fix NULL pointer dereference when dismount and
ocfs2rec simultaneously") may cause umount hang while shutting down
truncate log.

The situation is as followes:
ocfs2_dismout_volume
-> ocfs2_recovery_exit
  -> free osb->recovery_map
-> ocfs2_truncate_shutdown
  -> lock global bitmap inode
    -> ocfs2_wait_for_recovery
          -> check whether osb->recovery_map->rm_used is zero

Because osb->recovery_map is already freed, rm_used can be any other
values, so it may yield umount hang.

Signed-off-by: joyce.xue <xuejiufei@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 2 insertions, 6 deletions

diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c
index c7a89cea5c5d..ddb662b32447 100644
--- a/fs/ocfs2/super.c
+++ b/fs/ocfs2/super.c
@@ -1925,15 +1925,11 @@ static void ocfs2_dismount_volume(struct super_block *sb, int mnt_err)
 
         ocfs2_shutdown_local_alloc(osb);
 
+        ocfs2_truncate_log_shutdown(osb);
+
         /* This will disable recovery and flush any recovery work. */
         ocfs2_recovery_exit(osb);
 
-        /*
-         * During dismount, when it recovers another node it will call
-         * ocfs2_recover_orphans and queue delayed work osb_truncate_log_wq.
-         */
-        ocfs2_truncate_log_shutdown(osb);
-
         ocfs2_journal_shutdown(osb);
 
         ocfs2_sync_blockdev(sb);