From ee8f7fcbe638b07e8d1c3dc98e8be35e56306d05 Mon Sep 17 00:00:00 2001 From: piaojun Date: Tue, 2 Aug 2016 14:02:19 -0700 Subject: ocfs2/dlm: continue to purge recovery lockres when recovery master goes down We found a dlm-blocked situation caused by continuous breakdown of recovery masters described below. To solve this problem, we should purge recovery lock once detecting recovery master goes down. N3 N2 N1(reco master) go down pick up recovery lock and begin recoverying for N2 go down pick up recovery lock failed, then purge it: dlm_purge_lockres ->DROPPING_REF is set send deref to N1 failed, recovery lock is not purged find N1 go down, begin recoverying for N1, but blocked in dlm_do_recovery as DROPPING_REF is set: dlm_do_recovery ->dlm_pick_recovery_master ->dlmlock ->dlm_get_lock_resource ->__dlm_wait_on_lockres_flags(tmpres, DLM_LOCK_RES_DROPPING_REF); Fixes: 8c0343968163 ("ocfs2/dlm: clear DROPPING_REF flag when the master goes down") Link: http://lkml.kernel.org/r/578453AF.8030404@huawei.com Signed-off-by: Jun Piao Reviewed-by: Joseph Qi Reviewed-by: Jiufei Xue Reviewed-by: Mark Fasheh Cc: Joel Becker Cc: Junxiao Bi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ocfs2/dlm/dlmmaster.c | 37 +++---------------------------------- 1 file changed, 3 insertions(+), 34 deletions(-) (limited to 'fs/ocfs2/dlm/dlmmaster.c') diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c index 553d220df406..6ea06f8a7d29 100644 --- a/fs/ocfs2/dlm/dlmmaster.c +++ b/fs/ocfs2/dlm/dlmmaster.c @@ -2425,51 +2425,20 @@ int dlm_deref_lockres_done_handler(struct o2net_msg *msg, u32 len, void *data, 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); - list_del_init(&res->purge); - dlm_lockres_put(res); - dlm->purge_count--; - } - - if (!__dlm_lockres_unused(res)) { - mlog(ML_ERROR, "%s: res %.*s in use after deref\n", - dlm->name, res->lockname.len, res->lockname.name); - __dlm_print_one_lock_resource(res); - BUG(); - } - - __dlm_unhash_lockres(dlm, res); - - spin_lock(&dlm->track_lock); - if (!list_empty(&res->tracking)) - list_del_init(&res->tracking); - else { - mlog(ML_ERROR, "%s: Resource %.*s not on the Tracking list\n", - dlm->name, res->lockname.len, res->lockname.name); - __dlm_print_one_lock_resource(res); - } - spin_unlock(&dlm->track_lock); - - /* lockres is not in the hash now. drop the flag and wake up - * any processes waiting in dlm_get_lock_resource. - */ - res->state &= ~DLM_LOCK_RES_DROPPING_REF; + __dlm_do_purge_lockres(dlm, res); spin_unlock(&res->spinlock); wake_up(&res->wq); - dlm_lockres_put(res); - spin_unlock(&dlm->spinlock); ret = 0; done: + if (res) + dlm_lockres_put(res); dlm_put(dlm); return ret; } -- cgit v1.2.3-59-g8ed1b