Xue jiufei
2014-May-22 12:14 UTC
[Ocfs2-devel] [PATCH] ocfs2/dlm: Do not purge lockres that is queued for assert master
When workqueue is delayed, it may occured that a lockres is purged
while it is still queued for master assert. it may trigger BUS() 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 at huawei.com>
---
fs/ocfs2/dlm/dlmcommon.h | 4 ++++
fs/ocfs2/dlm/dlmmaster.c | 43 ++++++++++++++++++++++++++++++++++++++++++-
fs/ocfs2/dlm/dlmrecovery.c | 3 ++-
fs/ocfs2/dlm/dlmthread.c | 11 +++++++----
4 files changed, 55 insertions(+), 6 deletions(-)
diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index e051776..fa2bd21 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -332,6 +332,7 @@ struct dlm_lock_resource
u16 state;
char lvb[DLM_LVB_LEN];
unsigned int inflight_locks;
+ unsigned int inflight_assert_workers;
unsigned long refmap[BITS_TO_LONGS(O2NM_MAX_NODES)];
};
@@ -911,6 +912,9 @@ void dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
void dlm_lockres_grab_inflight_ref(struct dlm_ctxt *dlm,
struct dlm_lock_resource *res);
+void __dlm_lockres_grab_inflight_worker(struct dlm_ctxt *dlm,
+ struct dlm_lock_resource *res);
+
void dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock);
void dlm_queue_bast(struct dlm_ctxt *dlm, struct dlm_lock *lock);
void __dlm_queue_ast(struct dlm_ctxt *dlm, struct dlm_lock *lock);
diff --git a/fs/ocfs2/dlm/dlmmaster.c b/fs/ocfs2/dlm/dlmmaster.c
index af3f7aa..65f0e12 100644
--- a/fs/ocfs2/dlm/dlmmaster.c
+++ b/fs/ocfs2/dlm/dlmmaster.c
@@ -577,6 +577,7 @@ static void dlm_init_lockres(struct dlm_ctxt *dlm,
atomic_set(&res->asts_reserved, 0);
res->migration_pending = 0;
res->inflight_locks = 0;
+ res->inflight_assert_workers = 0;
res->dlm = dlm;
@@ -679,6 +680,43 @@ void dlm_lockres_drop_inflight_ref(struct dlm_ctxt *dlm,
wake_up(&res->wq);
}
+void __dlm_lockres_grab_inflight_worker(struct dlm_ctxt *dlm,
+ struct dlm_lock_resource *res)
+{
+ assert_spin_locked(&res->spinlock);
+ res->inflight_assert_workers++;
+ mlog(0, "%s:%.*s: inflight assert worker++: now %u\n",
+ dlm->name, res->lockname.len, res->lockname.name,
+ res->inflight_assert_workers);
+}
+
+void dlm_lockres_grab_inflight_worker(struct dlm_ctxt *dlm,
+ struct dlm_lock_resource *res)
+{
+ spin_lock(&res->spinlock);
+ __dlm_lockres_grab_inflight_worker(dlm, res);
+ spin_unlock(&res->spinlock);
+}
+
+void __dlm_lockres_drop_inflight_worker(struct dlm_ctxt *dlm,
+ struct dlm_lock_resource *res)
+{
+ assert_spin_locked(&res->spinlock);
+ BUG_ON(res->inflight_assert_workers == 0);
+ res->inflight_assert_workers--;
+ mlog(0, "%s:%.*s: inflight assert worker--: now %u\n",
+ dlm->name, res->lockname.len, res->lockname.name,
+ res->inflight_assert_workers);
+}
+
+void dlm_lockres_drop_inflight_worker(struct dlm_ctxt *dlm,
+ struct dlm_lock_resource *res)
+{
+ spin_lock(&res->spinlock);
+ __dlm_lockres_drop_inflight_worker(dlm, res);
+ spin_unlock(&res->spinlock);
+}
+
/*
* lookup a lock resource by name.
* may already exist in the hashtable.
@@ -1599,7 +1637,8 @@ send_response:
mlog(ML_ERROR, "failed to dispatch assert master work\n");
response = DLM_MASTER_RESP_ERROR;
dlm_lockres_put(res);
- }
+ } else
+ dlm_lockres_grab_inflight_worker(dlm, res);
} else {
if (res)
dlm_lockres_put(res);
@@ -2114,6 +2153,8 @@ static void dlm_assert_master_worker(struct dlm_work_item
*item, void *data)
dlm_lockres_release_ast(dlm, res);
put:
+ dlm_lockres_drop_inflight_worker(dlm, res);
+
dlm_lockres_put(res);
mlog(0, "finished with dlm_assert_master_worker\n");
diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
index 5de0194..45067fa 100644
--- a/fs/ocfs2/dlm/dlmrecovery.c
+++ b/fs/ocfs2/dlm/dlmrecovery.c
@@ -1708,7 +1708,8 @@ int dlm_master_requery_handler(struct o2net_msg *msg, u32
len, void *data,
mlog_errno(-ENOMEM);
/* retry!? */
BUG();
- }
+ } else
+ __dlm_lockres_grab_inflight_worker(dlm, res);
} else /* put.. incase we are not the master */
dlm_lockres_put(res);
spin_unlock(&res->spinlock);
diff --git a/fs/ocfs2/dlm/dlmthread.c b/fs/ocfs2/dlm/dlmthread.c
index 9db869d..f68bd4e 100644
--- a/fs/ocfs2/dlm/dlmthread.c
+++ b/fs/ocfs2/dlm/dlmthread.c
@@ -259,11 +259,14 @@ static void dlm_run_purge_list(struct dlm_ctxt *dlm,
* 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(&dlm->purge_list, &lockres->purge);
spin_unlock(&lockres->spinlock);
continue;
--
1.8.3.4