On Sat, Oct 16, 2021 at 07:37:40PM -0600, Jens Axboe wrote:

 
 static inline void blk_mq_sched_requeue_request(struct request *rq)
 {
+	if (rq->rq_flags & RQF_ELV) {
+		struct request_queue *q = rq->q;
+		struct elevator_queue *e = q->elevator;
 
+		if ((rq->rq_flags & RQF_ELVPRIV) && e->type->ops.requeue_request)
+			e->type->ops.requeue_request(rq);
+	}

I think we can just kill of RQF_ELVPRIV now.  It is equivalent to
RQF_ELV for !op_is_flush requests.