The patch titled
Subject: ocfs2/dlm: disable BUG_ON when DLM_LOCK_RES_DROPPING_REF is cleared before dlm_deref_lockres_done_handler
has been added to the -mm tree. Its filename is
ocfs2-dlm-disable-bug_on-when-dlm_lock_res_dropping_ref-is-cleared-before-dlm_deref_lockres_done_handler.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/ocfs2-dlm-disable-bug_on-when-dlm_lock_res_dropping_ref-is-cleared-before-dlm_deref_lockres_done_handler.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/ocfs2-dlm-disable-bug_on-when-dlm_lock_res_dropping_ref-is-cleared-before-dlm_deref_lockres_done_handler.patch
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------------------------------------------------------
From: piaojun <piaojun@xxxxxxxxxx>
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));
Fixes: 60d663cb5273 ("ocfs2/dlm: add DEREF_DONE message")
Link: http://lkml.kernel.org/r/57845055.9080702@xxxxxxxxxx
Signed-off-by: Jun Piao <piaojun@xxxxxxxxxx>
Reviewed-by: Joseph Qi <joseph.qi@xxxxxxxxxx>
Reviewed-by: Jiufei Xue <xuejiufei@xxxxxxxxxx>
Cc: Mark Fasheh <mfasheh@xxxxxxx>
Cc: Joel Becker <jlbec@xxxxxxxxxxxx>
Cc: Junxiao Bi <junxiao.bi@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
fs/ocfs2/dlm/dlmmaster.c | 14 +++++++++++++-
1 file changed, 13 insertions(+), 1 deletion(-)
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);
@@ -2457,6 +2467,8 @@ int dlm_deref_lockres_done_handler(struc
ret = 0;
+ ret = 0;
+
done:
dlm_put(dlm);
return ret;
_
Patches currently in -mm which might be from piaojun@xxxxxxxxxx are
ocfs2-dlm-disable-bug_on-when-dlm_lock_res_dropping_ref-is-cleared-before-dlm_deref_lockres_done_handler.patch
ocfs2-dlm-solve-a-bug-when-deref-failed-in-dlm_drop_lockres_ref.patch
ocfs2-dlm-continue-to-purge-recovery-lockres-when-recovery-master-goes-down.patch
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