Ocfs2 devel - Jun 2014 - [PATCH V2] ocfs2/dlm: fix misuse of list_move_tail() in dlm_run_purge_list()

When a lockres in purge list but is still in use, it should be moved to
the tail of purge list. dlm_thread will continue to check next lockres
in purge list. However, code list_move_tail(&dlm->purge_list,
&lockres->purge) will do *no* movements, so dlm_thread will purge the
same lockres in this loop again and again. If it is in use for a long
time, other lockres will not be processed.

Signed-off-by: Yiwen Jiang <jiangyiwen at huawei.com>
Signed-off-by: joyce.xue <xuejiufei at huawei.com>
---
 fs/ocfs2/dlm/dlmthread.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/ocfs2/dlm/dlmthread.c b/fs/ocfs2/dlm/dlmthread.c
index 9db869d..cf53a82 100644
--- a/fs/ocfs2/dlm/dlmthread.c
+++ b/fs/ocfs2/dlm/dlmthread.c
@@ -264,7 +264,7 @@ static void dlm_run_purge_list(struct dlm_ctxt *dlm,
 			     "used %d, state %d\n", dlm->name,
 			     lockres->lockname.len, lockres->lockname.name,
 			     !unused, lockres->state);
-			list_move_tail(&dlm->purge_list, &lockres->purge);
+			list_move_tail(&lockres->purge, &dlm->purge_list);
 			spin_unlock(&lockres->spinlock);
 			continue;
 		}
-- 
1.8.3.4

On Fri, Jun 13, 2014 at 03:41:59PM +0800, Xue jiufei
wrote:
> When a lockres in purge list but is still in use, it should be moved to
> the tail of purge list. dlm_thread will continue to check next lockres
> in purge list. However, code list_move_tail(&dlm->purge_list,
> &lockres->purge) will do *no* movements, so dlm_thread will purge
the
> same lockres in this loop again and again. If it is in use for a long
> time, other lockres will not be processed.
> 
> Signed-off-by: Yiwen Jiang <jiangyiwen at huawei.com>
> Signed-off-by: joyce.xue <xuejiufei at huawei.com>
Oh didn't realize, this must be the fixed version of the patch? It
might've
been nice to label it V2 or something. Anyway, thanks for this. Please
ignore my previous mail.

Reviewed-by: Mark Fasheh <mfasheh at suse.de>

--
Mark Fasheh