Merge tag 'ceph-for-7.1-rc5' of https://github.com/ceph/ceph-client

Pull ceph fix from Ilya Dryomov:
 "A fix for an 'rbd unmap' race condition which popped up on a
  production setup where many RBD devices are frequently mapped and
  unmapped, marked for stable"

* tag 'ceph-for-7.1-rc5' of https://github.com/ceph/ceph-client:
  rbd: eliminate a race in lock_dwork draining on unmap

Author: torvalds

drivers/block/rbd.c

@@ -4565,24 +4565,12 @@ static int rbd_register_watch(struct rbd_device *rbd_dev)
 	return ret;
 }
 
-static void cancel_tasks_sync(struct rbd_device *rbd_dev)
-{
-	dout("%s rbd_dev %p\n", __func__, rbd_dev);
-
-	cancel_work_sync(&rbd_dev->acquired_lock_work);
-	cancel_work_sync(&rbd_dev->released_lock_work);
-	cancel_delayed_work_sync(&rbd_dev->lock_dwork);
-	cancel_work_sync(&rbd_dev->unlock_work);
-}
-
 /*
  * header_rwsem must not be held to avoid a deadlock with
  * rbd_dev_refresh() when flushing notifies.
  */
 static void rbd_unregister_watch(struct rbd_device *rbd_dev)
 {
-	cancel_tasks_sync(rbd_dev);
-
 	mutex_lock(&rbd_dev->watch_mutex);
 	if (rbd_dev->watch_state == RBD_WATCH_STATE_REGISTERED)
 		__rbd_unregister_watch(rbd_dev);
@@ -6548,10 +6536,18 @@ static int rbd_add_parse_args(const char *buf,
 
 static void rbd_dev_image_unlock(struct rbd_device *rbd_dev)
 {
+	dout("%s rbd_dev %p\n", __func__, rbd_dev);
+
+	disable_delayed_work_sync(&rbd_dev->lock_dwork);
+	disable_work_sync(&rbd_dev->unlock_work);
+
 	down_write(&rbd_dev->lock_rwsem);
 	if (__rbd_is_lock_owner(rbd_dev))
 		__rbd_release_lock(rbd_dev);
 	up_write(&rbd_dev->lock_rwsem);
+
+	flush_work(&rbd_dev->acquired_lock_work);
+	flush_work(&rbd_dev->released_lock_work);
 }
 
 /*