Comment 5 for bug 1853981

I think that "blk-mq: honor IO scheduler for multiqueue devices" is broken in disco because it misses the following commit:

commit 970d168de636ddac8221cbd4a11d7678943e7379
blk-mq: simplify blk_mq_make_request()

Move the blk_mq_bio_to_request() call in front of the if-statement.

Either this has to be picked before the mq change or there must be a call to blk_mq_bio_to_request(rq, bio) before calling blk_mq_sched_insert_request(rq, false, true, true):

                }

                blk_add_rq_to_plug(plug, rq);
+ } else if (q->elevator) {
+ blk_mq_bio_to_request(rq, bio);
+ blk_mq_sched_insert_request(rq, false, true, true);
        } else if (plug && !blk_queue_nomerges(q)) {
                blk_mq_bio_to_request(rq, bio);