From: Christoph Hellwig <hch@lst.de>
Date: Fri, 29 May 2020 15:53:10 +0200
Subject: [PATCH] blk-mq: move more request initialization to
 blk_mq_rq_ctx_init
References: bsc#1175995,jsc#SLE-15608
Git-commit: 7ea4d8a4d683298abd346abf89567774de2fa34a
Patch-mainline: v5.8-rc1

Don't split request initialization between __blk_mq_alloc_request and
blk_mq_rq_ctx_init.  Also remove the op argument as it can be derived
from the blk_mq_alloc_data structure.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
Reviewed-by: Daniel Wagner <dwagner@suse.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
 block/blk-mq.c | 36 +++++++++++++++++++-----------------
 1 file changed, 19 insertions(+), 17 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 74ebab41f7d2..b20ad88d2d70 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -271,7 +271,7 @@ static inline bool blk_mq_need_time_stamp(struct request *rq)
 }
 
 static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
-		unsigned int tag, unsigned int op, u64 alloc_time_ns)
+		unsigned int tag, u64 alloc_time_ns)
 {
 	struct blk_mq_tags *tags = blk_mq_tags_from_data(data);
 	struct request *rq = tags->static_rqs[tag];
@@ -295,7 +295,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
 	rq->mq_ctx = data->ctx;
 	rq->mq_hctx = data->hctx;
 	rq->rq_flags = rq_flags;
-	rq->cmd_flags = op;
+	rq->cmd_flags = data->cmd_flags;
 	if (data->flags & BLK_MQ_REQ_PREEMPT)
 		rq->rq_flags |= RQF_PREEMPT;
 	if (blk_queue_io_stat(data->q))
@@ -327,8 +327,23 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
 	rq->end_io = NULL;
 	rq->end_io_data = NULL;
 
-	data->ctx->rq_dispatched[op_is_sync(op)]++;
+	data->ctx->rq_dispatched[op_is_sync(data->cmd_flags)]++;
 	refcount_set(&rq->ref, 1);
+
+	if (!op_is_flush(data->cmd_flags)) {
+		struct elevator_queue *e = data->q->elevator;
+
+		rq->elv.icq = NULL;
+		if (e && e->type->ops.prepare_request) {
+			if (e->type->icq_cache)
+				blk_mq_sched_assign_ioc(rq);
+
+			e->type->ops.prepare_request(rq);
+			rq->rq_flags |= RQF_ELVPRIV;
+		}
+	}
+
+	data->hctx->queued++;
 	return rq;
 }
 
@@ -336,7 +351,6 @@ static struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data)
 {
 	struct request_queue *q = data->q;
 	struct elevator_queue *e = q->elevator;
-	struct request *rq;
 	unsigned int tag;
 	bool clear_ctx_on_error = false;
 	u64 alloc_time_ns = 0;
@@ -378,19 +392,7 @@ static struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data)
 		return NULL;
 	}
 
-	rq = blk_mq_rq_ctx_init(data, tag, data->cmd_flags, alloc_time_ns);
-	if (!op_is_flush(data->cmd_flags)) {
-		rq->elv.icq = NULL;
-		if (e && e->type->ops.prepare_request) {
-			if (e->type->icq_cache)
-				blk_mq_sched_assign_ioc(rq);
-
-			e->type->ops.prepare_request(rq);
-			rq->rq_flags |= RQF_ELVPRIV;
-		}
-	}
-	data->hctx->queued++;
-	return rq;
+	return blk_mq_rq_ctx_init(data, tag, alloc_time_ns);
 }
 
 struct request *blk_mq_alloc_request(struct request_queue *q, unsigned int op,
-- 
2.16.4