return -EINVAL;
disk = get_gendisk(MKDEV(major, minor), &part);
- if (!disk || part)
+ if (!disk)
return -EINVAL;
+ if (part) {
+ put_disk(disk);
+ return -EINVAL;
+ }
rcu_read_lock();
spin_lock_irq(disk->queue->queue_lock);
{
lockdep_assert_held(q->queue_lock);
+ /*
+ * @q could be exiting and already have destroyed all blkgs as
+ * indicated by NULL root_blkg. If so, don't confuse policies.
+ */
+ if (!q->root_blkg)
+ return;
+
/*
* @q could be exiting and already have destroyed all blkgs as
* indicated by NULL root_blkg. If so, don't confuse policies.