diff --git a/block/blk-mq.c b/block/blk-mq.c index 33145ba52c96..93d9d60980fb 100644 --- a/block/blk-mq.c +++ b/block/blk-mq.c @@ -2765,15 +2765,20 @@ static inline struct request *blk_mq_get_cached_request(struct request_queue *q, return NULL; } - rq_qos_throttle(q, *bio); - if (blk_mq_get_hctx_type((*bio)->bi_opf) != rq->mq_hctx->type) return NULL; if (op_is_flush(rq->cmd_flags) != op_is_flush((*bio)->bi_opf)) return NULL; - rq->cmd_flags = (*bio)->bi_opf; + /* + * If any qos ->throttle() end up blocking, we will have flushed the + * plug and hence killed the cached_rq list as well. Pop this entry + * before we throttle. + */ plug->cached_rq = rq_list_next(rq); + rq_qos_throttle(q, *bio); + + rq->cmd_flags = (*bio)->bi_opf; INIT_LIST_HEAD(&rq->queuelist); return rq; }