[PATCH] ocfs2/dlm: fixes

* fix a hang which can occur during shutdown migration
* do not allow nodes to join during recovery
* when restarting lock mastery, do not ignore nodes which come up
* more than one node could become recovery master, fix this
* sleep to allow some time for heartbeat state to catch up to network
* extra debug info for bad recovery state problems
* make DLM_RECO_NODE_DATA_DONE a valid state for non-master recovery nodes
* prune all locks from dead nodes on $RECOVERY lock resources
* do NOT automatically add new nodes to mle nodemaps until they have properly
  joined the domain
* make sure dlm_pick_recovery_master only exits when all nodes have synced
* properly handle dlmunlock errors in dlm_pick_recovery_master
* do not propagate network errors in dlm_send_begin_reco_message
* dead nodes were not being put in the recovery map sometimes, fix this
* dlmunlock was failing to clear the unlock actions on DLM_DENIED
Signed-off-by: Kurt Hackel <kurt.hackel@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

fs/ocfs2/dlm/dlmcommon.h

@@ -657,6 +657,7 @@ void dlm_complete_thread(struct dlm_ctxt *dlm);
 int dlm_launch_recovery_thread(struct dlm_ctxt *dlm);
 void dlm_complete_recovery_thread(struct dlm_ctxt *dlm);
 void dlm_wait_for_recovery(struct dlm_ctxt *dlm);
+int dlm_is_node_dead(struct dlm_ctxt *dlm, u8 node);
 
 void dlm_put(struct dlm_ctxt *dlm);
 struct dlm_ctxt *dlm_grab(struct dlm_ctxt *dlm);

fs/ocfs2/dlm/dlmdomain.c

@@ -573,8 +573,11 @@ static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data)
 	spin_lock(&dlm_domain_lock);
 	dlm = __dlm_lookup_domain_full(query->domain, query->name_len);
 	/* Once the dlm ctxt is marked as leaving then we don't want
-	 * to be put in someone's domain map. */
+	 * to be put in someone's domain map. 
+	 * Also, explicitly disallow joining at certain troublesome
+	 * times (ie. during recovery). */
 	if (dlm && dlm->dlm_state != DLM_CTXT_LEAVING) {
+		int bit = query->node_idx;
 		spin_lock(&dlm->spinlock);
 
 		if (dlm->dlm_state == DLM_CTXT_NEW &&
@@ -586,6 +589,19 @@ static int dlm_query_join_handler(struct o2net_msg *msg, u32 len, void *data)
 		} else if (dlm->joining_node != DLM_LOCK_RES_OWNER_UNKNOWN) {
 			/* Disallow parallel joins. */
 			response = JOIN_DISALLOW;
+		} else if (dlm->reco.state & DLM_RECO_STATE_ACTIVE) {
+			mlog(ML_NOTICE, "node %u trying to join, but recovery "
+			     "is ongoing.\n", bit);
+			response = JOIN_DISALLOW;
+		} else if (test_bit(bit, dlm->recovery_map)) {
+			mlog(ML_NOTICE, "node %u trying to join, but it "
+			     "still needs recovery.\n", bit);
+			response = JOIN_DISALLOW;
+		} else if (test_bit(bit, dlm->domain_map)) {
+			mlog(ML_NOTICE, "node %u trying to join, but it "
+			     "is still in the domain! needs recovery?\n",
+			     bit);
+			response = JOIN_DISALLOW;
 		} else {
 			/* Alright we're fully a part of this domain
 			 * so we keep some state as to who's joining

fs/ocfs2/dlm/dlmmaster.c

@@ -1050,17 +1050,10 @@ static int dlm_restart_lock_mastery(struct dlm_ctxt *dlm,
 	node = dlm_bitmap_diff_iter_next(&bdi, &sc);
 	while (node >= 0) {
 		if (sc == NODE_UP) {
-			/* a node came up.  easy.  might not even need
-			 * to talk to it if its node number is higher
-			 * or if we are already blocked. */
-			mlog(0, "node up! %d\n", node);
-			if (blocked)
-				goto next;
-
-			if (node > dlm->node_num) {
-				mlog(0, "node > this node. skipping.\n");
-				goto next;
-			}
+			/* a node came up.  clear any old vote from
+			 * the response map and set it in the vote map
+			 * then restart the mastery. */
+			mlog(ML_NOTICE, "node %d up while restarting\n", node);
 
 			/* redo the master request, but only for the new node */
 			mlog(0, "sending request to new node\n");
@@ -2005,6 +1998,15 @@ fail:
 				break;
 
 			mlog(0, "timed out during migration\n");
+			/* avoid hang during shutdown when migrating lockres 
+			 * to a node which also goes down */
+			if (dlm_is_node_dead(dlm, target)) {
+				mlog(0, "%s:%.*s: expected migration target %u "
+				     "is no longer up.  restarting.\n",
+				     dlm->name, res->lockname.len,
+				     res->lockname.name, target);
+				ret = -ERESTARTSYS;
+			}
 		}
 		if (ret == -ERESTARTSYS) {
 			/* migration failed, detach and clean up mle */

fs/ocfs2/dlm/dlmunlock.c

@@ -188,6 +188,19 @@ static enum dlm_status dlmunlock_common(struct dlm_ctxt *dlm,
 			actions &= ~(DLM_UNLOCK_REMOVE_LOCK|
 				     DLM_UNLOCK_REGRANT_LOCK|
 				     DLM_UNLOCK_CLEAR_CONVERT_TYPE);
+		} else if (status == DLM_RECOVERING || 
+			   status == DLM_MIGRATING || 
+			   status == DLM_FORWARD) {
+			/* must clear the actions because this unlock
+			 * is about to be retried.  cannot free or do
+			 * any list manipulation. */
+			mlog(0, "%s:%.*s: clearing actions, %s\n",
+			     dlm->name, res->lockname.len,
+			     res->lockname.name,
+			     status==DLM_RECOVERING?"recovering":
+			     (status==DLM_MIGRATING?"migrating":
+			      "forward"));
+			actions = 0;
 		}
 		if (flags & LKM_CANCEL)
 			lock->cancel_pending = 0;