[PATCH 04/17] block: simplify blk_mq_plug

Christoph Hellwig
2022-07-04T12:45:24Z

Drop the unused q argument, and invert the check to move the exception
into a branch and the regular path as the normal return.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
block/blk-core.c | 2 +-
block/blk-merge.c | 2 +-
block/blk-mq.c | 2 +-
block/blk-mq.h | 18 ++++++++----------
4 files changed, 11 insertions(+), 13 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 6bcca0b686de4..bc16e9bae2dc4 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -719,7 +719,7 @@ void submit_bio_noacct(struct bio *bio)

might_sleep();

- plug = blk_mq_plug(q, bio);
+ plug = blk_mq_plug(bio);
if (plug && plug->nowait)
bio->bi_opf |= REQ_NOWAIT;

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 0f5f42ebd0bb0..5abf5aa5a5f0e 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -1051,7 +1051,7 @@ bool blk_attempt_plug_merge(struct request_queue *q, struct bio *bio,
struct blk_plug *plug;
struct request *rq;

- plug = blk_mq_plug(q, bio);
+ plug = blk_mq_plug(bio);
if (!plug || rq_list_empty(plug->mq_list))
return false;

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 15c7c5c4ad222..dc714dff73001 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -2804,7 +2804,7 @@ static void bio_set_ioprio(struct bio *bio)
void blk_mq_submit_bio(struct bio *bio)
{
struct request_queue *q = bdev_get_queue(bio->bi_bdev);
- struct blk_plug *plug = blk_mq_plug(q, bio);
+ struct blk_plug *plug = blk_mq_plug(bio);
const int is_sync = op_is_sync(bio->bi_opf);
struct request *rq;
unsigned int nr_segs = 1;
diff --git a/block/blk-mq.h b/block/blk-mq.h
index 31d75a83a562d..1cc0b17d69229 100644
--- a/block/blk-mq.h
+++ b/block/blk-mq.h
@@ -294,7 +294,6 @@ static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)

/*
* blk_mq_plug() - Get caller context plug
- * @q: request queue
* @bio : the bio being submitted by the caller context
*
* Plugging, by design, may delay the insertion of BIOs into the elevator in
@@ -305,23 +304,22 @@ static inline void blk_mq_clear_mq_map(struct blk_mq_queue_map *qmap)
* order. While this is not a problem with regular block devices, this ordering
* change can cause write BIO failures with zoned block devices as these
* require sequential write patterns to zones. Prevent this from happening by
- * ignoring the plug state of a BIO issuing context if the target request queue
- * is for a zoned block device and the BIO to plug is a write operation.
+ * ignoring the plug state of a BIO issuing context if is for a zoned block
+ 8 device and the BIO to plug is a write operation.
*
* Return current->plug if the bio can be plugged and NULL otherwise
*/
-static inline struct blk_plug *blk_mq_plug(struct request_queue *q,
- struct bio *bio)
+static inline struct blk_plug *blk_mq_plug( struct bio *bio)
{
+ /* Zoned block device write operation case: do not plug the BIO */
+ if (bdev_is_zoned(bio->bi_bdev) && op_is_write(bio_op(bio)))
+ return NULL;
+
/*
* For regular block devices or read operations, use the context plug
* which may be NULL if blk_start_plug() was not executed.
*/
- if (!bdev_is_zoned(bio->bi_bdev) || !op_is_write(bio_op(bio)))
- return current->plug;
-
- /* Zoned block device write operation case: do not plug the BIO */
- return NULL;
+ return current->plug;
}

/* Free all requests on the list */
--
2.30.2