* [Ocfs2-devel] [patch 3/5] ocfs2/dlm: disable BUG_ON when DLM_LOCK_RES_DROPPING_REF is cleared before dlm_deref_lockres_done_handler
@ 2016-07-28 21:06 akpm at linux-foundation.org
2016-07-28 22:01 ` Mark Fasheh
0 siblings, 1 reply; 2+ messages in thread
From: akpm at linux-foundation.org @ 2016-07-28 21:06 UTC (permalink / raw)
To: ocfs2-devel
From: piaojun <piaojun@huawei.com>
Subject: ocfs2/dlm: disable BUG_ON when DLM_LOCK_RES_DROPPING_REF is cleared before dlm_deref_lockres_done_handler
We found a BUG situation in which DLM_LOCK_RES_DROPPING_REF is cleared
unexpected that described below. To solve the bug, we disable the BUG_ON
and purge lockres in dlm_do_local_recovery_cleanup.
Node 1 Node 2(master)
dlm_purge_lockres
dlm_deref_lockres_handler
DLM_LOCK_RES_SETREF_INPROG is set
response DLM_DEREF_RESPONSE_INPROG
receive DLM_DEREF_RESPONSE_INPROG
stop puring in dlm_purge_lockres
and wait for DLM_DEREF_RESPONSE_DONE
dispatch dlm_deref_lockres_worker
response DLM_DEREF_RESPONSE_DONE
receive DLM_DEREF_RESPONSE_DONE and
prepare to purge lockres
Node 2 goes down
find Node2 down and do local
clean up for Node2:
dlm_do_local_recovery_cleanup
-> clear DLM_LOCK_RES_DROPPING_REF
when purging lockres, BUG_ON happens
because DLM_LOCK_RES_DROPPING_REF is clear:
dlm_deref_lockres_done_handler
->BUG_ON(!(res->state & DLM_LOCK_RES_DROPPING_REF));
[akpm at linux-foundation.org: fix duplicated write to `ret']
Fixes: 60d663cb5273 ("ocfs2/dlm: add DEREF_DONE message")
Link: http://lkml.kernel.org/r/57845055.9080702 at huawei.com
Signed-off-by: Jun Piao <piaojun@huawei.com>
Reviewed-by: Joseph Qi <joseph.qi@huawei.com>
Reviewed-by: Jiufei Xue <xuejiufei@huawei.com>
Cc: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
fs/ocfs2/dlm/dlmmaster.c | 13 +++++++++++--
1 file changed, 11 insertions(+), 2 deletions(-)
diff -puN fs/ocfs2/dlm/dlmmaster.c~ocfs2-dlm-disable-bug_on-when-dlm_lock_res_dropping_ref-is-cleared-before-dlm_deref_lockres_done_handler fs/ocfs2/dlm/dlmmaster.c
--- a/fs/ocfs2/dlm/dlmmaster.c~ocfs2-dlm-disable-bug_on-when-dlm_lock_res_dropping_ref-is-cleared-before-dlm_deref_lockres_done_handler
+++ a/fs/ocfs2/dlm/dlmmaster.c
@@ -2416,7 +2416,17 @@ int dlm_deref_lockres_done_handler(struc
}
spin_lock(&res->spinlock);
- BUG_ON(!(res->state & DLM_LOCK_RES_DROPPING_REF));
+ if (!(res->state & DLM_LOCK_RES_DROPPING_REF)) {
+ spin_unlock(&res->spinlock);
+ spin_unlock(&dlm->spinlock);
+ mlog(ML_NOTICE, "%s:%.*s: node %u sends deref done "
+ "but it is already derefed!\n", dlm->name,
+ res->lockname.len, res->lockname.name, node);
+ dlm_lockres_put(res);
+ ret = 0;
+ goto done;
+ }
+
if (!list_empty(&res->purge)) {
mlog(0, "%s: Removing res %.*s from purgelist\n",
dlm->name, res->lockname.len, res->lockname.name);
@@ -2456,7 +2466,6 @@ int dlm_deref_lockres_done_handler(struc
spin_unlock(&dlm->spinlock);
ret = 0;
-
done:
dlm_put(dlm);
return ret;
_
^ permalink raw reply [flat|nested] 2+ messages in thread
* [Ocfs2-devel] [patch 3/5] ocfs2/dlm: disable BUG_ON when DLM_LOCK_RES_DROPPING_REF is cleared before dlm_deref_lockres_done_handler
2016-07-28 21:06 [Ocfs2-devel] [patch 3/5] ocfs2/dlm: disable BUG_ON when DLM_LOCK_RES_DROPPING_REF is cleared before dlm_deref_lockres_done_handler akpm at linux-foundation.org
@ 2016-07-28 22:01 ` Mark Fasheh
0 siblings, 0 replies; 2+ messages in thread
From: Mark Fasheh @ 2016-07-28 22:01 UTC (permalink / raw)
To: ocfs2-devel
On Thu, Jul 28, 2016 at 02:06:02PM -0700, Andrew Morton wrote:
> From: piaojun <piaojun@huawei.com>
> Subject: ocfs2/dlm: disable BUG_ON when DLM_LOCK_RES_DROPPING_REF is cleared before dlm_deref_lockres_done_handler
>
> We found a BUG situation in which DLM_LOCK_RES_DROPPING_REF is cleared
> unexpected that described below. To solve the bug, we disable the BUG_ON
> and purge lockres in dlm_do_local_recovery_cleanup.
>
> Node 1 Node 2(master)
> dlm_purge_lockres
> dlm_deref_lockres_handler
>
> DLM_LOCK_RES_SETREF_INPROG is set
> response DLM_DEREF_RESPONSE_INPROG
>
> receive DLM_DEREF_RESPONSE_INPROG
> stop puring in dlm_purge_lockres
> and wait for DLM_DEREF_RESPONSE_DONE
>
> dispatch dlm_deref_lockres_worker
> response DLM_DEREF_RESPONSE_DONE
>
> receive DLM_DEREF_RESPONSE_DONE and
> prepare to purge lockres
>
> Node 2 goes down
>
> find Node2 down and do local
> clean up for Node2:
> dlm_do_local_recovery_cleanup
> -> clear DLM_LOCK_RES_DROPPING_REF
>
> when purging lockres, BUG_ON happens
> because DLM_LOCK_RES_DROPPING_REF is clear:
> dlm_deref_lockres_done_handler
> ->BUG_ON(!(res->state & DLM_LOCK_RES_DROPPING_REF));
Thanks Piaojun,
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
--Mark
--
Mark Fasheh
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2016-07-28 21:06 [Ocfs2-devel] [patch 3/5] ocfs2/dlm: disable BUG_ON when DLM_LOCK_RES_DROPPING_REF is cleared before dlm_deref_lockres_done_handler akpm at linux-foundation.org
2016-07-28 22:01 ` Mark Fasheh
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