ocfs2/dlm: Add missing dlm_lock_put()s

Normally locks for remote nodes are freed when that node sends an UNLOCK
message to the master. The master node tags an DLM_UNLOCK_FREE_LOCK action
to do an extra put on the lock at the end.

However, there are times when the master node has to free the locks for the
remote nodes forcibly.

Two cases when this happens are:
1. When the master has migrated the lockres plus all locks to another node.
2. When the master is clearing all the locks of a dead node.

It was in the above two conditions that the dlm was missing the extra put.
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mark.fasheh@oracle.com>

fs/ocfs2/dlm/dlmmaster.c

@@ -2933,6 +2933,9 @@ static void dlm_remove_nonlocal_locks(struct dlm_ctxt *dlm,
 				dlm_lockres_clear_refmap_bit(lock->ml.node, res);
 				list_del_init(&lock->list);
 				dlm_lock_put(lock);
+				/* In a normal unlock, we would have added a
+				 * DLM_UNLOCK_FREE_LOCK action. Force it. */
+				dlm_lock_put(lock);
 			}
 		}
 		queue++;

fs/ocfs2/dlm/dlmrecovery.c

@@ -2130,11 +2130,16 @@ static void dlm_free_dead_locks(struct dlm_ctxt *dlm,
 	assert_spin_locked(&dlm->spinlock);
 	assert_spin_locked(&res->spinlock);
 
+	/* We do two dlm_lock_put(). One for removing from list and the other is
+	 * to force the DLM_UNLOCK_FREE_LOCK action so as to free the locks */
+
 	/* TODO: check pending_asts, pending_basts here */
 	list_for_each_entry_safe(lock, next, &res->granted, list) {
 		if (lock->ml.node == dead_node) {
 			list_del_init(&lock->list);
 			dlm_lock_put(lock);
+			/* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
+			dlm_lock_put(lock);
 			freed++;
 		}
 	}
@@ -2142,6 +2147,8 @@ static void dlm_free_dead_locks(struct dlm_ctxt *dlm,
 		if (lock->ml.node == dead_node) {
 			list_del_init(&lock->list);
 			dlm_lock_put(lock);
+			/* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
+			dlm_lock_put(lock);
 			freed++;
 		}
 	}
@@ -2149,6 +2156,8 @@ static void dlm_free_dead_locks(struct dlm_ctxt *dlm,
 		if (lock->ml.node == dead_node) {
 			list_del_init(&lock->list);
 			dlm_lock_put(lock);
+			/* Can't schedule DLM_UNLOCK_FREE_LOCK - do manually */
+			dlm_lock_put(lock);
 			freed++;
 		}
 	}