ocfs2/dlm: do not purge lockres that is queued for assert master
When workqueue is delayed, it may occur that a lockres is purged while it
is still queued for master assert. it may trigger BUG() as follows.
N1 N2
dlm_get_lockres()
->dlm_do_master_requery
is the master of lockres,
so queue assert_master work
dlm_thread() start running
and purge the lockres
dlm_assert_master_worker()
send assert master message
to other nodes
receiving the assert_master
message, set master to N2
dlmlock_remote() send create_lock message to N2, but receive DLM_IVLOCKID,
if it is RECOVERY lockres, it triggers the BUG().
Another BUG() is triggered when N3 become the new master and send
assert_master to N1, N1 will trigger the BUG() because owner doesn't
match. So we should not purge lockres when it is queued for assert
master.
Signed-off-by: joyce.xue <xuejiufei@huawei.com>
Reviewed-by: Mark Fasheh <mfasheh@suse.de>
Cc: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/ocfs2/dlm/dlmthread.c b/fs/ocfs2/dlm/dlmthread.c
index cf53a82..69aac6f 100644
--- a/fs/ocfs2/dlm/dlmthread.c
+++ b/fs/ocfs2/dlm/dlmthread.c
@@ -259,11 +259,14 @@
* refs on it. */
unused = __dlm_lockres_unused(lockres);
if (!unused ||
- (lockres->state & DLM_LOCK_RES_MIGRATING)) {
+ (lockres->state & DLM_LOCK_RES_MIGRATING) ||
+ (lockres->inflight_assert_workers != 0)) {
mlog(0, "%s: res %.*s is in use or being remastered, "
- "used %d, state %d\n", dlm->name,
- lockres->lockname.len, lockres->lockname.name,
- !unused, lockres->state);
+ "used %d, state %d, assert master workers %u\n",
+ dlm->name, lockres->lockname.len,
+ lockres->lockname.name,
+ !unused, lockres->state,
+ lockres->inflight_assert_workers);
list_move_tail(&lockres->purge, &dlm->purge_list);
spin_unlock(&lockres->spinlock);
continue;