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 <[email protected]>

Reviewed-by Alex Chen <[email protected]>

Reviewed-by Yiwen Jiang <[email protected]>

Acked-by Changwei Ge <[email protected]>

---
  fs/ocfs2/dlm/dlmcommon.h   |  1 +
  fs/ocfs2/dlm/dlmdomain.c   | 14 ++++++++++++++
  fs/ocfs2/dlm/dlmrecovery.c | 13 ++++++++++---
  3 files changed, 25 insertions(+), 3 deletions(-)

fs/ocfs2/dlm/dlmcommon.h +1 -0

index e9f3705..999ab7d 100644
@@ -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)];

fs/ocfs2/dlm/dlmdomain.c +14 -0

index e1fea14..98a8f56 100644
@@ -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;
 

fs/ocfs2/dlm/dlmrecovery.c +10 -3

index 74407c6..c4cf682 100644
@@ -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 +455,13 @@ 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);
+		spin_unlock(&dlm->spinlock);
+		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 +496,13 @@ 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;