elevator_set_none() is called when deleting disk, in which queue has been
un-registered, and elevator switch can't happen any more.
So if q->elevator is NULL, it is not necessary to freeze queue and drain
IO any more.
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
---
block/elevator.c | 10 ++++++++++
1 file changed, 10 insertions(+)
diff --git a/block/elevator.c b/block/elevator.c
index e1386b84a415..35f4de749dcd 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -754,8 +754,18 @@ void elevator_set_none(struct request_queue *q)
.name = "none",
.quiesce_queue = true,
};
+ bool need_change;
int err;
+ WARN_ON_ONCE(blk_queue_registered(q));
+
+ /* queue has been unregisted, elevator can't be switched anymore */
+ mutex_lock(&q->elevator_lock);
+ need_change = !!q->elevator;
+ mutex_unlock(&q->elevator_lock);
+ if (!need_change)
+ return;
+
err = elevator_change(q, &ctx);
if (err < 0)
pr_warn("%s: set none elevator failed %d\n", __func__, err);
--
2.47.0
