From mboxrd@z Thu Jan 1 00:00:00 1970 From: piaojun Date: Mon, 11 Jul 2016 10:17:00 +0800 Subject: [Ocfs2-devel] ocfs2/dlm: disable BUG_ON when DLM_LOCK_RES_DROPPING_REF, is cleared before dlm_deref_lockres_done_handler In-Reply-To: <5782FC7A.90208@huawei.com> References: <57821D09.1040306@huawei.com> <5782FC7A.90208@huawei.com> Message-ID: <5783019C.7030203@huawei.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ocfs2-devel@oss.oracle.com On 2016-7-11 9:55, Joseph Qi wrote: > Hi Jun, > > On 2016/7/10 18:01, piaojun wrote: >> 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") >> Signed-off-by: Jun Piao >> --- >> fs/ocfs2/dlm/dlmmaster.c | 13 ++++++++++++- >> 1 file changed, 12 insertions(+), 1 deletion(-) >> >> diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c >> index 9aed6e2..f72e7ae 100644 >> --- a/fs/ocfs2/dlm/dlmmaster.c >> +++ b/fs/ocfs2/dlm/dlmmaster.c >> @@ -2416,7 +2416,16 @@ int dlm_deref_lockres_done_handler(struct o2net_msg *msg, u32 len, void *data, >> } >> >> 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); > So we treat this case as normal? > If so, we'd better return 0 other than -EINVAL. > > Thanks, > Joseph > Good suggestion, I will fix this problem in the following [PATCH v2]. Thanks, Jun Piao >> + goto done; >> + } >> + >> if (!list_empty(&res->purge)) { >> mlog(0, "%s: Removing res %.*s from purgelist\n", >> dlm->name, res->lockname.len, res->lockname.name); >> @@ -2455,6 +2464,8 @@ int dlm_deref_lockres_done_handler(struct o2net_msg *msg, u32 len, void *data, >> >> spin_unlock(&dlm->spinlock); >> >> + ret = 0; >> + >> done: >> dlm_put(dlm); >> return ret; >> > > > > . >