ocfs2/dlm: solve a BUG when deref failed in dlm_drop_lockres_ref (309e9191) · Commits · 戴 / test

We found a BUG situation that lockres is migrated during deref described below. To solve the BUG, we could purge lockres directly when other node says I did not have a ref. Additionally, we'd better purge lockres if master goes down, as no one will response deref done. Node 1 Node 2(old master) Node3(new master) dlm_purge_lockres send deref to N2 leave domain migrate lockres to N3 finish migration send do assert master to N1 receive do assert msg form N3, but can not find lockres because DROPPING_REF is set, so the owner is still N2. receive deref from N1 and response -EINVAL because lockres is migrated BUG when receive -EINVAL in dlm_drop_lockres_ref Fixes: ("ocfs2/dlm: return in progress if master can not clear the refmap bit right now") Link: http://lkml.kernel.org/r/57845103.3070406@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> Reviewed-by:

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> Signed-off-by:

Linus Torvalds <torvalds@linux-foundation.org>

fs/ocfs2/dlm/dlmmaster.c

+6 −3

Original line number	Diff line number	Diff line
		@@ -2276,9 +2276,12 @@ int dlm_drop_lockres_ref(struct dlm_ctxt dlm, struct dlm_lock_resource res)
		mlog(ML_ERROR, "%s: res %.*s, DEREF to node %u got %d\n",
		dlm->name, namelen, lockname, res->owner, r);
		dlm_print_one_lock_resource(res);
		if (r == -ENOMEM)
		BUG();
		}
		return ret ? ret : r;
		} else
		ret = r;

		return ret;
		}

		int dlm_deref_lockres_handler(struct o2net_msg msg, u32 len, void data,

fs/ocfs2/dlm/dlmthread.c

+11 −2

Original line number	Diff line number	Diff line
		@@ -175,6 +175,15 @@ static void dlm_purge_lockres(struct dlm_ctxt *dlm,
		res->lockname.len, res->lockname.name, master);

		if (!master) {
		if (res->state & DLM_LOCK_RES_DROPPING_REF) {
		mlog(ML_NOTICE, "%s: res %.*s already in "
		"DLM_LOCK_RES_DROPPING_REF state\n",
		dlm->name, res->lockname.len,
		res->lockname.name);
		spin_unlock(&res->spinlock);
		return;
		}

		res->state \|= DLM_LOCK_RES_DROPPING_REF;
		/* drop spinlock... retake below */
		spin_unlock(&res->spinlock);
		@@ -203,8 +212,8 @@ static void dlm_purge_lockres(struct dlm_ctxt *dlm,
		dlm->purge_count--;
		}

		if (!master && ret != 0) {
		mlog(0, "%s: deref %.*s in progress or master goes down\n",
		if (!master && ret == DLM_DEREF_RESPONSE_INPROG) {
		mlog(0, "%s: deref %.*s in progress\n",
		dlm->name, res->lockname.len, res->lockname.name);
		spin_unlock(&res->spinlock);
		return;

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