There is a check for q->tag_set in the front of elevator_get_default, and there should be a check here too. Signed-off-by: Peng Hao <flyingpeng@xxxxxxxxxxx> --- block/elevator.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/block/elevator.c b/block/elevator.c index 1f39f6e8ebb9..b7d0bead680c 100644 --- a/block/elevator.c +++ b/block/elevator.c @@ -636,7 +636,7 @@ static struct elevator_type *elevator_get_default(struct request_queue *q) if (q->tag_set && q->tag_set->flags & BLK_MQ_F_NO_SCHED_BY_DEFAULT) return NULL; - if (q->nr_hw_queues != 1 && + if (q->nr_hw_queues != 1 && q->tag_set && !blk_mq_is_shared_tags(q->tag_set->flags)) return NULL; -- 2.27.0
