ocfs2/dlm: call dlm_lockres_put without resource spinlock
authoralex chen <alex.chen@huawei.com>
Thu, 9 Oct 2014 22:25:00 +0000 (15:25 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Fri, 10 Oct 2014 02:25:47 +0000 (22:25 -0400)
dlm_lockres_put() should be called without &res->spinlock, otherwise a
deadlock case may happen.

spin_lock(&res->spinlock)
...
dlm_lockres_put
  ->dlm_lockres_release
    ->dlm_print_one_lock_resource
      ->spin_lock(&res->spinlock)

Signed-off-by: Alex Chen <alex.chen@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
fs/ocfs2/dlm/dlmrecovery.c

index 45067faf5695d54d74af0933c8ea403ec4f1a5b3..3365839d29716f101759c6dc86355393ee7c3ab4 100644 (file)
@@ -1710,9 +1710,12 @@ int dlm_master_requery_handler(struct o2net_msg *msg, u32 len, void *data,
                                BUG();
                        } else
                                __dlm_lockres_grab_inflight_worker(dlm, res);
-               } else /* put.. incase we are not the master */
+                       spin_unlock(&res->spinlock);
+               } else {
+                       /* put.. incase we are not the master */
+                       spin_unlock(&res->spinlock);
                        dlm_lockres_put(res);
-               spin_unlock(&res->spinlock);
+               }
        }
        spin_unlock(&dlm->spinlock);