blk-mq: move blk_mq_flush_plug_list

Move blk_mq_flush_plug_list and blk_mq_plug_issue_direct down in blk-mq.c
to prepare for marking blk_mq_request_issue_directly static without the
need of a forward declaration.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Link: https://lore.kernel.org/r/20211117061404.331732-5-hch@lst.deSigned-off-by: Jens Axboe <axboe@kernel.dk>

block/blk-mq.c

@@ -2309,98 +2309,6 @@ static void blk_mq_commit_rqs(struct blk_mq_hw_ctx *hctx, int *queued,
 	*queued = 0;
 }
 
-static void blk_mq_plug_issue_direct(struct blk_plug *plug, bool from_schedule)
-{
-	struct blk_mq_hw_ctx *hctx = NULL;
-	struct request *rq;
-	int queued = 0;
-	int errors = 0;
-
-	while ((rq = rq_list_pop(&plug->mq_list))) {
-		bool last = rq_list_empty(plug->mq_list);
-		blk_status_t ret;
-
-		if (hctx != rq->mq_hctx) {
-			if (hctx)
-				blk_mq_commit_rqs(hctx, &queued, from_schedule);
-			hctx = rq->mq_hctx;
-		}
-
-		ret = blk_mq_request_issue_directly(rq, last);
-		switch (ret) {
-		case BLK_STS_OK:
-			queued++;
-			break;
-		case BLK_STS_RESOURCE:
-		case BLK_STS_DEV_RESOURCE:
-			blk_mq_request_bypass_insert(rq, false, last);
-			blk_mq_commit_rqs(hctx, &queued, from_schedule);
-			return;
-		default:
-			blk_mq_end_request(rq, ret);
-			errors++;
-			break;
-		}
-	}
-
-	/*
-	 * If we didn't flush the entire list, we could have told the driver
-	 * there was more coming, but that turned out to be a lie.
-	 */
-	if (errors)
-		blk_mq_commit_rqs(hctx, &queued, from_schedule);
-}
-
-void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
-{
-	struct blk_mq_hw_ctx *this_hctx;
-	struct blk_mq_ctx *this_ctx;
-	unsigned int depth;
-	LIST_HEAD(list);
-
-	if (rq_list_empty(plug->mq_list))
-		return;
-	plug->rq_count = 0;
-
-	if (!plug->multiple_queues && !plug->has_elevator && !from_schedule) {
-		blk_mq_plug_issue_direct(plug, false);
-		if (rq_list_empty(plug->mq_list))
-			return;
-	}
-
-	this_hctx = NULL;
-	this_ctx = NULL;
-	depth = 0;
-	do {
-		struct request *rq;
-
-		rq = rq_list_pop(&plug->mq_list);
-
-		if (!this_hctx) {
-			this_hctx = rq->mq_hctx;
-			this_ctx = rq->mq_ctx;
-		} else if (this_hctx != rq->mq_hctx || this_ctx != rq->mq_ctx) {
-			trace_block_unplug(this_hctx->queue, depth,
-						!from_schedule);
-			blk_mq_sched_insert_requests(this_hctx, this_ctx,
-						&list, from_schedule);
-			depth = 0;
-			this_hctx = rq->mq_hctx;
-			this_ctx = rq->mq_ctx;
-
-		}
-
-		list_add(&rq->queuelist, &list);
-		depth++;
-	} while (!rq_list_empty(plug->mq_list));
-
-	if (!list_empty(&list)) {
-		trace_block_unplug(this_hctx->queue, depth, !from_schedule);
-		blk_mq_sched_insert_requests(this_hctx, this_ctx, &list,
-						from_schedule);
-	}
-}
-
 static void blk_mq_bio_to_request(struct request *rq, struct bio *bio,
 		unsigned int nr_segs)
 {
@@ -2540,6 +2448,98 @@ blk_status_t blk_mq_request_issue_directly(struct request *rq, bool last)
 	return ret;
 }
 
+static void blk_mq_plug_issue_direct(struct blk_plug *plug, bool from_schedule)
+{
+	struct blk_mq_hw_ctx *hctx = NULL;
+	struct request *rq;
+	int queued = 0;
+	int errors = 0;
+
+	while ((rq = rq_list_pop(&plug->mq_list))) {
+		bool last = rq_list_empty(plug->mq_list);
+		blk_status_t ret;
+
+		if (hctx != rq->mq_hctx) {
+			if (hctx)
+				blk_mq_commit_rqs(hctx, &queued, from_schedule);
+			hctx = rq->mq_hctx;
+		}
+
+		ret = blk_mq_request_issue_directly(rq, last);
+		switch (ret) {
+		case BLK_STS_OK:
+			queued++;
+			break;
+		case BLK_STS_RESOURCE:
+		case BLK_STS_DEV_RESOURCE:
+			blk_mq_request_bypass_insert(rq, false, last);
+			blk_mq_commit_rqs(hctx, &queued, from_schedule);
+			return;
+		default:
+			blk_mq_end_request(rq, ret);
+			errors++;
+			break;
+		}
+	}
+
+	/*
+	 * If we didn't flush the entire list, we could have told the driver
+	 * there was more coming, but that turned out to be a lie.
+	 */
+	if (errors)
+		blk_mq_commit_rqs(hctx, &queued, from_schedule);
+}
+
+void blk_mq_flush_plug_list(struct blk_plug *plug, bool from_schedule)
+{
+	struct blk_mq_hw_ctx *this_hctx;
+	struct blk_mq_ctx *this_ctx;
+	unsigned int depth;
+	LIST_HEAD(list);
+
+	if (rq_list_empty(plug->mq_list))
+		return;
+	plug->rq_count = 0;
+
+	if (!plug->multiple_queues && !plug->has_elevator && !from_schedule) {
+		blk_mq_plug_issue_direct(plug, false);
+		if (rq_list_empty(plug->mq_list))
+			return;
+	}
+
+	this_hctx = NULL;
+	this_ctx = NULL;
+	depth = 0;
+	do {
+		struct request *rq;
+
+		rq = rq_list_pop(&plug->mq_list);
+
+		if (!this_hctx) {
+			this_hctx = rq->mq_hctx;
+			this_ctx = rq->mq_ctx;
+		} else if (this_hctx != rq->mq_hctx || this_ctx != rq->mq_ctx) {
+			trace_block_unplug(this_hctx->queue, depth,
+						!from_schedule);
+			blk_mq_sched_insert_requests(this_hctx, this_ctx,
+						&list, from_schedule);
+			depth = 0;
+			this_hctx = rq->mq_hctx;
+			this_ctx = rq->mq_ctx;
+
+		}
+
+		list_add(&rq->queuelist, &list);
+		depth++;
+	} while (!rq_list_empty(plug->mq_list));
+
+	if (!list_empty(&list)) {
+		trace_block_unplug(this_hctx->queue, depth, !from_schedule);
+		blk_mq_sched_insert_requests(this_hctx, this_ctx, &list,
+						from_schedule);
+	}
+}
+
 void blk_mq_try_issue_list_directly(struct blk_mq_hw_ctx *hctx,
 		struct list_head *list)
 {