[PATCH] blk-mq: remove the BLK_MQ_REQ_INTERNAL flag

[PATCH] blk-mq: remove the BLK_MQ_REQ_INTERNAL flag

[Christoph Hellwig]

Just check for a non-NULL elevator directly to make the code more clear.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-mq-tag.c     |  4 ++--
 block/blk-mq.c         | 10 +++-------
 block/blk-mq.h         |  2 +-
 include/linux/blk-mq.h |  2 --
 4 files changed, 6 insertions(+), 12 deletions(-)

diff --git a/block/blk-mq-tag.c b/block/blk-mq-tag.c
index ae722f8b13fb2c..281367b0452764 100644
--- a/block/blk-mq-tag.c
+++ b/block/blk-mq-tag.c
@@ -90,9 +90,9 @@ static inline bool hctx_may_queue(struct blk_mq_hw_ctx *hctx,
 static int __blk_mq_get_tag(struct blk_mq_alloc_data *data,
 			    struct sbitmap_queue *bt)
 {
-	if (!(data->flags & BLK_MQ_REQ_INTERNAL) &&
-	    !hctx_may_queue(data->hctx, bt))
+	if (!data->q->elevator && !hctx_may_queue(data->hctx, bt))
 		return BLK_MQ_NO_TAG;
+
 	if (data->shallow_depth)
 		return __sbitmap_queue_get_shallow(bt, data->shallow_depth);
 	else
diff --git a/block/blk-mq.c b/block/blk-mq.c
index b8738b3c6d06a2..2e1d7b435e9a91 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -279,7 +279,7 @@ static struct request *blk_mq_rq_ctx_init(struct blk_mq_alloc_data *data,
 	struct request *rq = tags->static_rqs[tag];
 	req_flags_t rq_flags = 0;
 
-	if (data->flags & BLK_MQ_REQ_INTERNAL) {
+	if (data->q->elevator) {
 		rq->tag = BLK_MQ_NO_TAG;
 		rq->internal_tag = tag;
 	} else {
@@ -364,8 +364,6 @@ static struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data)
 		data->flags |= BLK_MQ_REQ_NOWAIT;
 
 	if (e) {
-		data->flags |= BLK_MQ_REQ_INTERNAL;
-
 		/*
 		 * Flush requests are special and go directly to the
 		 * dispatch list. Don't include reserved tags in the
@@ -380,7 +378,7 @@ static struct request *__blk_mq_alloc_request(struct blk_mq_alloc_data *data)
 retry:
 	data->ctx = blk_mq_get_ctx(q);
 	data->hctx = blk_mq_map_queue(q, data->cmd_flags, data->ctx);
-	if (!(data->flags & BLK_MQ_REQ_INTERNAL))
+	if (!e)
 		blk_mq_tag_busy(data->hctx);
 
 	/*
@@ -476,9 +474,7 @@ struct request *blk_mq_alloc_request_hctx(struct request_queue *q,
 	cpu = cpumask_first_and(data.hctx->cpumask, cpu_online_mask);
 	data.ctx = __blk_mq_get_ctx(q, cpu);
 
-	if (q->elevator)
-		data.flags |= BLK_MQ_REQ_INTERNAL;
-	else
+	if (!q->elevator)
 		blk_mq_tag_busy(data.hctx);
 
 	ret = -EWOULDBLOCK;
diff --git a/block/blk-mq.h b/block/blk-mq.h
index b3ce0f3a2ad2a7..c6330335767ce9 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -159,7 +159,7 @@ struct blk_mq_alloc_data {
 
 static inline struct blk_mq_tags *blk_mq_tags_from_data(struct blk_mq_alloc_data *data)
 {
-	if (data->flags & BLK_MQ_REQ_INTERNAL)
+	if (data->q->elevator)
 		return data->hctx->sched_tags;
 
 	return data->hctx->tags;
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index 1641ec6cd7e551..8986e88a986b14 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -447,8 +447,6 @@ enum {
 	BLK_MQ_REQ_NOWAIT	= (__force blk_mq_req_flags_t)(1 << 0),
 	/* allocate from reserved pool */
 	BLK_MQ_REQ_RESERVED	= (__force blk_mq_req_flags_t)(1 << 1),
-	/* allocate internal/sched tag */
-	BLK_MQ_REQ_INTERNAL	= (__force blk_mq_req_flags_t)(1 << 2),
 	/* set RQF_PREEMPT */
 	BLK_MQ_REQ_PREEMPT	= (__force blk_mq_req_flags_t)(1 << 3),
 };
-- 
2.26.2

Re: [PATCH] blk-mq: remove the BLK_MQ_REQ_INTERNAL flag

[Jens Axboe]

On 6/29/20 9:08 AM, Christoph Hellwig wrote:
> Just check for a non-NULL elevator directly to make the code more clear.

Applied, thanks.

-- 
Jens Axboe