Hi Yi,
can you try the patch below? This changes the teardown code to not
re-enable writeback tracking when we're shutting the queue down, which
is what I suspect is on the ->callbacks list.
diff --git a/block/elevator.c b/block/elevator.c
index ff45d8388f487..bb5c6ee4546cd 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -523,8 +523,6 @@ void elv_unregister_queue(struct request_queue *q)
kobject_del(&e->kobj);
e->registered = 0;
- /* Re-enable throttling in case elevator disabled it */
- wbt_enable_default(q);
}
}
@@ -591,8 +589,11 @@ int elevator_switch_mq(struct request_queue *q,
lockdep_assert_held(&q->sysfs_lock);
if (q->elevator) {
- if (q->elevator->registered)
+ if (q->elevator->registered) {
elv_unregister_queue(q);
+ /* Re-enable throttling in case elevator disabled it */
+ wbt_enable_default(q);
+ }
ioc_clear_queue(q);
elevator_exit(q, q->elevator);
