From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joseph Qi Date: Mon, 11 Jul 2016 09:55:06 +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: <57821D09.1040306@huawei.com> References: <57821D09.1040306@huawei.com> Message-ID: <5782FC7A.90208@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 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 > + 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; >