bfq_choose_req
return bfq_choose_req(bfqd, next, prev, blk_rq_pos(last));
next_rq = bfq_choose_req(bfqd, bfqq->next_rq, rq, bfqd->last_position);
next_rq = bfq_choose_req(bfqd, bfqq->next_rq, req,