blk-mq: don't special case flush inserts for blk-mq-sched

The current request insertion machinery works just fine for
directly inserting flushes, so no need to special case
this anymore.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>

block/blk-mq.c

@@ -1434,12 +1434,11 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 	cookie = request_to_qc_t(data.hctx, rq);
 
 	if (unlikely(is_flush_fua)) {
-		blk_mq_put_ctx(data.ctx);
+		if (q->elevator)
+			goto elv_insert;
 		blk_mq_bio_to_request(rq, bio);
-		blk_mq_get_driver_tag(rq, NULL, true);
 		blk_insert_flush(rq);
-		blk_mq_run_hw_queue(data.hctx, true);
-		goto done;
+		goto run_queue;
 	}
 
 	plug = current->plug;
@@ -1489,6 +1488,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 	}
 
 	if (q->elevator) {
+elv_insert:
 		blk_mq_put_ctx(data.ctx);
 		blk_mq_bio_to_request(rq, bio);
 		blk_mq_sched_insert_request(rq, false, true,
@@ -1502,6 +1502,7 @@ static blk_qc_t blk_mq_make_request(struct request_queue *q, struct bio *bio)
 		 * latter allows for merging opportunities and more efficient
 		 * dispatching.
 		 */
+run_queue:
 		blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua);
 	}
 	blk_mq_put_ctx(data.ctx);
@@ -1557,12 +1558,11 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
 	cookie = request_to_qc_t(data.hctx, rq);
 
 	if (unlikely(is_flush_fua)) {
-		blk_mq_put_ctx(data.ctx);
+		if (q->elevator)
+			goto elv_insert;
 		blk_mq_bio_to_request(rq, bio);
-		blk_mq_get_driver_tag(rq, NULL, true);
 		blk_insert_flush(rq);
-		blk_mq_run_hw_queue(data.hctx, true);
-		goto done;
+		goto run_queue;
 	}
 
 	/*
@@ -1600,6 +1600,7 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
 	}
 
 	if (q->elevator) {
+elv_insert:
 		blk_mq_put_ctx(data.ctx);
 		blk_mq_bio_to_request(rq, bio);
 		blk_mq_sched_insert_request(rq, false, true,
@@ -1613,6 +1614,7 @@ static blk_qc_t blk_sq_make_request(struct request_queue *q, struct bio *bio)
 		 * latter allows for merging opportunities and more efficient
 		 * dispatching.
 		 */
+run_queue:
 		blk_mq_run_hw_queue(data.hctx, !is_sync || is_flush_fua);
 	}