piaojun
2017-Nov-01 01:14 UTC
[Ocfs2-devel] [PATCH] ocfs2/dlm: wait for dlm recovery done when migrating all lockres
wait for dlm recovery done when migrating all lockres in case of new
lockres to be left after leaving dlm domain.
NodeA NodeB NodeC
umount and migrate
all lockres
node down
do recovery for NodeB
and collect a new lockres
form other live nodes
leave domain but the
new lockres remains
mount and join domain
request for the owner
of the new lockres, but
all the other nodes said
'NO', so NodeC decide
to
the owner, and send do
assert msg to other nodes.
other nodes receive the msg
and found two masters exist.
at last cause BUG in
dlm_assert_master_handler()
-->BUG();
Fixes: bc9838c4d44a ("dlm: allow dlm do recovery during shutdown")
Signed-off-by: Jun Piao <piaojun at huawei.com>
Reviewed-by: Alex Chen <alex.chen at huawei.com>
Reviewed-by: Yiwen Jiang <jiangyiwen at huawei.com>
---
fs/ocfs2/dlm/dlmcommon.h | 1 +
fs/ocfs2/dlm/dlmdomain.c | 14 ++++++++++++++
fs/ocfs2/dlm/dlmrecovery.c | 12 +++++++++---
3 files changed, 24 insertions(+), 3 deletions(-)
diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h
index e9f3705..999ab7d 100644
--- a/fs/ocfs2/dlm/dlmcommon.h
+++ b/fs/ocfs2/dlm/dlmcommon.h
@@ -140,6 +140,7 @@ struct dlm_ctxt
u8 node_num;
u32 key;
u8 joining_node;
+ u8 migrate_done; /* set to 1 means node has migrated all lockres */
wait_queue_head_t dlm_join_events;
unsigned long live_nodes_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
unsigned long domain_map[BITS_TO_LONGS(O2NM_MAX_NODES)];
diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c
index e1fea14..98a8f56 100644
--- a/fs/ocfs2/dlm/dlmdomain.c
+++ b/fs/ocfs2/dlm/dlmdomain.c
@@ -461,6 +461,18 @@ static int dlm_migrate_all_locks(struct dlm_ctxt *dlm)
cond_resched_lock(&dlm->spinlock);
num += n;
}
+
+ if (!num) {
+ if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
+ mlog(0, "%s: perhaps there are more lock resources need to "
+ "be migrated after dlm recovery\n", dlm->name);
+ ret = -EAGAIN;
+ } else {
+ mlog(0, "%s: we won't do dlm recovery after migrating all
lockres",
+ dlm->name);
+ dlm->migrate_done = 1;
+ }
+ }
spin_unlock(&dlm->spinlock);
wake_up(&dlm->dlm_thread_wq);
@@ -2052,6 +2064,8 @@ static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain,
dlm->joining_node = DLM_LOCK_RES_OWNER_UNKNOWN;
init_waitqueue_head(&dlm->dlm_join_events);
+ dlm->migrate_done = 0;
+
dlm->reco.new_master = O2NM_INVALID_NODE_NUM;
dlm->reco.dead_node = O2NM_INVALID_NODE_NUM;
diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c
index 74407c6..3106332 100644
--- a/fs/ocfs2/dlm/dlmrecovery.c
+++ b/fs/ocfs2/dlm/dlmrecovery.c
@@ -423,12 +423,11 @@ void dlm_wait_for_recovery(struct dlm_ctxt *dlm)
static void dlm_begin_recovery(struct dlm_ctxt *dlm)
{
- spin_lock(&dlm->spinlock);
+ assert_spin_locked(&dlm->spinlock);
BUG_ON(dlm->reco.state & DLM_RECO_STATE_ACTIVE);
printk(KERN_NOTICE "o2dlm: Begin recovery on domain %s for node
%u\n",
dlm->name, dlm->reco.dead_node);
dlm->reco.state |= DLM_RECO_STATE_ACTIVE;
- spin_unlock(&dlm->spinlock);
}
static void dlm_end_recovery(struct dlm_ctxt *dlm)
@@ -456,6 +455,12 @@ static int dlm_do_recovery(struct dlm_ctxt *dlm)
spin_lock(&dlm->spinlock);
+ if (dlm->migrate_done) {
+ mlog(0, "%s: no need do recovery after migrating all lockres\n",
+ dlm->name);
+ return 0;
+ }
+
/* check to see if the new master has died */
if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM &&
test_bit(dlm->reco.new_master, dlm->recovery_map)) {
@@ -490,12 +495,13 @@ static int dlm_do_recovery(struct dlm_ctxt *dlm)
mlog(0, "%s(%d):recovery thread found node %u in the recovery
map!\n",
dlm->name, task_pid_nr(dlm->dlm_reco_thread_task),
dlm->reco.dead_node);
- spin_unlock(&dlm->spinlock);
/* take write barrier */
/* (stops the list reshuffling thread, proxy ast handling) */
dlm_begin_recovery(dlm);
+ spin_unlock(&dlm->spinlock);
+
if (dlm->reco.new_master == dlm->node_num)
goto master_here;
--
Changwei Ge
2017-Nov-01 02:47 UTC
[Ocfs2-devel] [PATCH] ocfs2/dlm: wait for dlm recovery done when migrating all lockres
Hi Jun, Thanks for reporting. I am very interesting in this issue. But, first of all, I want to make this issue clear, so that I might be able to provide some comments. On 2017/11/1 9:16, piaojun wrote:> wait for dlm recovery done when migrating all lockres in case of new > lockres to be left after leaving dlm domain.What do you mean by 'a new lock resource to be left after leaving domain'? It means we leak a dlm lock resource if below situation happens.> > NodeA NodeB NodeC > > umount and migrate > all lockres > > node down > > do recovery for NodeB > and collect a new lockres > form other live nodesYou mean a lock resource whose owner was NodeB is just migrated from other cluster member nodes?> > leave domain but the > new lockres remains > > mount and join domain > > request for the owner > of the new lockres, but > all the other nodes said > 'NO', so NodeC decide to > the owner, and send do > assert msg to other nodes. > > other nodes receive the msg > and found two masters exist. > at last cause BUG in > dlm_assert_master_handler() > -->BUG();If this issue truly exists, can we take some efforts in dlm_exit_domain_handler? Or perhaps we should kick dlm's work queue before migrating all lock resources.> > Fixes: bc9838c4d44a ("dlm: allow dlm do recovery during shutdown") > > Signed-off-by: Jun Piao <piaojun at huawei.com> > Reviewed-by: Alex Chen <alex.chen at huawei.com> > Reviewed-by: Yiwen Jiang <jiangyiwen at huawei.com> > --- > fs/ocfs2/dlm/dlmcommon.h | 1 + > fs/ocfs2/dlm/dlmdomain.c | 14 ++++++++++++++ > fs/ocfs2/dlm/dlmrecovery.c | 12 +++++++++--- > 3 files changed, 24 insertions(+), 3 deletions(-) > > diff --git a/fs/ocfs2/dlm/dlmcommon.h b/fs/ocfs2/dlm/dlmcommon.h > index e9f3705..999ab7d 100644 > --- a/fs/ocfs2/dlm/dlmcommon.h > +++ b/fs/ocfs2/dlm/dlmcommon.h > @@ -140,6 +140,7 @@ struct dlm_ctxt > u8 node_num; > u32 key; > u8 joining_node; > + u8 migrate_done; /* set to 1 means node has migrated all lockres */ > wait_queue_head_t dlm_join_events; > unsigned long live_nodes_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; > unsigned long domain_map[BITS_TO_LONGS(O2NM_MAX_NODES)]; > diff --git a/fs/ocfs2/dlm/dlmdomain.c b/fs/ocfs2/dlm/dlmdomain.c > index e1fea14..98a8f56 100644 > --- a/fs/ocfs2/dlm/dlmdomain.c > +++ b/fs/ocfs2/dlm/dlmdomain.c > @@ -461,6 +461,18 @@ static int dlm_migrate_all_locks(struct dlm_ctxt *dlm) > cond_resched_lock(&dlm->spinlock); > num += n; > } > + > + if (!num) { > + if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) { > + mlog(0, "%s: perhaps there are more lock resources need to " > + "be migrated after dlm recovery\n", dlm->name);If dlm is mark with DLM_RECO_STATE_ACTIVE, then a lock resource must already be marked with DLM_LOCK_RES_RECOVERING which can't be migrated. So code will goto redo_bucket in function dlm_migrate_all_locks. So I don't understand why a judgement is added here?> + ret = -EAGAIN; > + } else { > + mlog(0, "%s: we won't do dlm recovery after migrating all lockres", > + dlm->name); > + dlm->migrate_done = 1; > + } > + } > spin_unlock(&dlm->spinlock); > wake_up(&dlm->dlm_thread_wq); > > @@ -2052,6 +2064,8 @@ static struct dlm_ctxt *dlm_alloc_ctxt(const char *domain, > dlm->joining_node = DLM_LOCK_RES_OWNER_UNKNOWN; > init_waitqueue_head(&dlm->dlm_join_events); > > + dlm->migrate_done = 0; > + > dlm->reco.new_master = O2NM_INVALID_NODE_NUM; > dlm->reco.dead_node = O2NM_INVALID_NODE_NUM; > > diff --git a/fs/ocfs2/dlm/dlmrecovery.c b/fs/ocfs2/dlm/dlmrecovery.c > index 74407c6..3106332 100644 > --- a/fs/ocfs2/dlm/dlmrecovery.c > +++ b/fs/ocfs2/dlm/dlmrecovery.c > @@ -423,12 +423,11 @@ void dlm_wait_for_recovery(struct dlm_ctxt *dlm) > > static void dlm_begin_recovery(struct dlm_ctxt *dlm) > { > - spin_lock(&dlm->spinlock); > + assert_spin_locked(&dlm->spinlock); > BUG_ON(dlm->reco.state & DLM_RECO_STATE_ACTIVE); > printk(KERN_NOTICE "o2dlm: Begin recovery on domain %s for node %u\n", > dlm->name, dlm->reco.dead_node); > dlm->reco.state |= DLM_RECO_STATE_ACTIVE; > - spin_unlock(&dlm->spinlock); > } > > static void dlm_end_recovery(struct dlm_ctxt *dlm) > @@ -456,6 +455,12 @@ static int dlm_do_recovery(struct dlm_ctxt *dlm) > > spin_lock(&dlm->spinlock); > > + if (dlm->migrate_done) { > + mlog(0, "%s: no need do recovery after migrating all lockres\n", > + dlm->name);Don't we need unlock above spin_lock before return? And if we just return here, how dlm lock resource can clear its REDISCOVERING flag. I suppose this may cause cluster hang. And I cc this to ocfs2 maintainers. Thanks, Changwei> + return 0; > + } > + > /* check to see if the new master has died */ > if (dlm->reco.new_master != O2NM_INVALID_NODE_NUM && > test_bit(dlm->reco.new_master, dlm->recovery_map)) { > @@ -490,12 +495,13 @@ static int dlm_do_recovery(struct dlm_ctxt *dlm) > mlog(0, "%s(%d):recovery thread found node %u in the recovery map!\n", > dlm->name, task_pid_nr(dlm->dlm_reco_thread_task), > dlm->reco.dead_node); > - spin_unlock(&dlm->spinlock); > > /* take write barrier */ > /* (stops the list reshuffling thread, proxy ast handling) */ > dlm_begin_recovery(dlm); > > + spin_unlock(&dlm->spinlock); > + > if (dlm->reco.new_master == dlm->node_num) > goto master_here; >