rbd: rename RBD_LOCK_STATE_RELEASING and releasing_wait

... to RBD_LOCK_STATE_QUIESCING and quiescing_wait to recognize that
this state and the associated completion are backing rbd_quiesce_lock(),
which isn't specific to releasing the lock.

While exclusive lock does get quiesced before it's released, it also
gets quiesced before an attempt to update the cookie is made and there
the lock is not released as long as ceph_cls_set_cookie() succeeds.
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Dongsheng Yang <dongsheng.yang@easystack.cn>

drivers/block/rbd.c

@@ -362,7 +362,7 @@ enum rbd_watch_state {
 enum rbd_lock_state {
 	RBD_LOCK_STATE_UNLOCKED,
 	RBD_LOCK_STATE_LOCKED,
-	RBD_LOCK_STATE_RELEASING,
+	RBD_LOCK_STATE_QUIESCING,
 };
 
 /* WatchNotify::ClientId */
@@ -422,7 +422,7 @@ struct rbd_device {
 	struct list_head	running_list;
 	struct completion	acquire_wait;
 	int			acquire_err;
-	struct completion	releasing_wait;
+	struct completion	quiescing_wait;
 
 	spinlock_t		object_map_lock;
 	u8			*object_map;
@@ -525,7 +525,7 @@ static bool __rbd_is_lock_owner(struct rbd_device *rbd_dev)
 	lockdep_assert_held(&rbd_dev->lock_rwsem);
 
 	return rbd_dev->lock_state == RBD_LOCK_STATE_LOCKED ||
-	       rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING;
+	       rbd_dev->lock_state == RBD_LOCK_STATE_QUIESCING;
 }
 
 static bool rbd_is_lock_owner(struct rbd_device *rbd_dev)
@@ -3458,12 +3458,12 @@ static void rbd_lock_del_request(struct rbd_img_request *img_req)
 	spin_lock(&rbd_dev->lock_lists_lock);
 	if (!list_empty(&img_req->lock_item)) {
 		list_del_init(&img_req->lock_item);
-		need_wakeup = (rbd_dev->lock_state == RBD_LOCK_STATE_RELEASING &&
+		need_wakeup = (rbd_dev->lock_state == RBD_LOCK_STATE_QUIESCING &&
 			       list_empty(&rbd_dev->running_list));
 	}
 	spin_unlock(&rbd_dev->lock_lists_lock);
 	if (need_wakeup)
-		complete(&rbd_dev->releasing_wait);
+		complete(&rbd_dev->quiescing_wait);
 }
 
 static int rbd_img_exclusive_lock(struct rbd_img_request *img_req)
@@ -4181,16 +4181,16 @@ static bool rbd_quiesce_lock(struct rbd_device *rbd_dev)
 	/*
 	 * Ensure that all in-flight IO is flushed.
 	 */
-	rbd_dev->lock_state = RBD_LOCK_STATE_RELEASING;
-	rbd_assert(!completion_done(&rbd_dev->releasing_wait));
+	rbd_dev->lock_state = RBD_LOCK_STATE_QUIESCING;
+	rbd_assert(!completion_done(&rbd_dev->quiescing_wait));
 	if (list_empty(&rbd_dev->running_list))
 		return true;
 
 	up_write(&rbd_dev->lock_rwsem);
-	wait_for_completion(&rbd_dev->releasing_wait);
+	wait_for_completion(&rbd_dev->quiescing_wait);
 
 	down_write(&rbd_dev->lock_rwsem);
-	if (rbd_dev->lock_state != RBD_LOCK_STATE_RELEASING)
+	if (rbd_dev->lock_state != RBD_LOCK_STATE_QUIESCING)
 		return false;
 
 	rbd_assert(list_empty(&rbd_dev->running_list));
@@ -5383,7 +5383,7 @@ static struct rbd_device *__rbd_dev_create(struct rbd_spec *spec)
 	INIT_LIST_HEAD(&rbd_dev->acquiring_list);
 	INIT_LIST_HEAD(&rbd_dev->running_list);
 	init_completion(&rbd_dev->acquire_wait);
-	init_completion(&rbd_dev->releasing_wait);
+	init_completion(&rbd_dev->quiescing_wait);
 
 	spin_lock_init(&rbd_dev->object_map_lock);