From: alex chen <alex.chen@huawei.com>
Date: Thu, 9 Oct 2014 22:25:00 +0000 (-0700)
Subject: ocfs2/dlm: call dlm_lockres_put without resource spinlock
X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=9a7e6b5a0ad1a554ca982c555a34ce8086d5b994;p=linux-beck.git

ocfs2/dlm: call dlm_lockres_put without resource spinlock

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>
---

diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
index 45067faf5695..3365839d2971 100644
--- a/fs/ocfs2/dlm/dlmrecovery.c
+++ b/fs/ocfs2/dlm/dlmrecovery.c
@@ -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);