[PATCH v3 11/14] block: Improve zone write request completion handling

[Damien Le Moal <dlemoal@kernel.org>]

blk_zone_complete_request() must be called to handle the completion of a
zone write request handled with zone write plugging. This function is
called from blk_complete_request(), blk_update_request() and also in
blk_mq_submit_bio() error path. Improve this by moving this function
call into blk_mq_finish_request() as all requests are processed with
this function when they complete as well as when they are freed without
being executed. This also improves blk_update_request() used by scsi
devices as these may repeatedly call this function to handle partial
completions.

To be consistent with this change, blk_zone_complete_request() is
renamed to blk_zone_finish_request() and
blk_zone_write_plug_complete_request() is renamed to
blk_zone_write_plug_finish_request().

Signed-off-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
---
 block/blk-mq.c    |  6 ++----
 block/blk-zoned.c | 11 ++++++-----
 block/blk.h       |  8 ++++----
 3 files changed, 12 insertions(+), 13 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 0fae9bd0ecd4..9f677ea85a52 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -691,6 +691,8 @@ static void blk_mq_finish_request(struct request *rq)
 {
 	struct request_queue *q = rq->q;
 
+	blk_zone_finish_request(rq);
+
 	if (rq->rq_flags & RQF_USE_SCHED) {
 		q->elevator->type->ops.finish_request(rq);
 		/*
@@ -828,8 +830,6 @@ static void blk_complete_request(struct request *req)
 		bio = next;
 	} while (bio);
 
-	blk_zone_complete_request(req);
-
 	/*
 	 * Reset counters so that the request stacking driver
 	 * can find how many bytes remain in the request
@@ -940,7 +940,6 @@ bool blk_update_request(struct request *req, blk_status_t error,
 	 * completely done
 	 */
 	if (!req->bio) {
-		blk_zone_complete_request(req);
 		/*
 		 * Reset counters so that the request stacking driver
 		 * can find how many bytes remain in the request
@@ -2996,7 +2995,6 @@ void blk_mq_submit_bio(struct bio *bio)
 	if (ret != BLK_STS_OK) {
 		bio->bi_status = ret;
 		bio_endio(bio);
-		blk_zone_complete_request(rq);
 		blk_mq_free_request(rq);
 		return;
 	}
diff --git a/block/blk-zoned.c b/block/blk-zoned.c
index 1890b6d55d8b..759e85e9167c 100644
--- a/block/blk-zoned.c
+++ b/block/blk-zoned.c
@@ -531,7 +531,7 @@ static inline bool disk_should_remove_zone_wplug(struct gendisk *disk,
 	/*
 	 * Completions of BIOs with blk_zone_write_plug_bio_endio() may
 	 * happen after handling a request completion with
-	 * blk_zone_write_plug_complete_request() (e.g. with split BIOs
+	 * blk_zone_write_plug_finish_request() (e.g. with split BIOs
 	 * that are chained). In such case, disk_zone_wplug_unplug_bio()
 	 * should not attempt to remove the zone write plug until all BIO
 	 * completions are seen. Check by looking at the zone write plug
@@ -921,7 +921,7 @@ void blk_zone_write_plug_init_request(struct request *req)
 
 	/*
 	 * Indicate that completion of this request needs to be handled with
-	 * blk_zone_write_plug_complete_request(), which will drop the reference
+	 * blk_zone_write_plug_finish_request(), which will drop the reference
 	 * on the zone write plug we took above on entry to this function.
 	 */
 	req->rq_flags |= RQF_ZONE_WRITE_PLUGGING;
@@ -1255,7 +1255,7 @@ void blk_zone_write_plug_bio_endio(struct bio *bio)
 	disk_put_zone_wplug(zwplug);
 
 	/*
-	 * For BIO-based devices, blk_zone_write_plug_complete_request()
+	 * For BIO-based devices, blk_zone_write_plug_finish_request()
 	 * is not called. So we need to schedule execution of the next
 	 * plugged BIO here.
 	 */
@@ -1266,11 +1266,12 @@ void blk_zone_write_plug_bio_endio(struct bio *bio)
 	disk_put_zone_wplug(zwplug);
 }
 
-void blk_zone_write_plug_complete_request(struct request *req)
+void blk_zone_write_plug_finish_request(struct request *req)
 {
 	struct gendisk *disk = req->q->disk;
-	struct blk_zone_wplug *zwplug = disk_get_zone_wplug(disk, req->__sector);
+	struct blk_zone_wplug *zwplug;
 
+	zwplug = disk_get_zone_wplug(disk, req->__sector);
 	if (WARN_ON_ONCE(!zwplug))
 		return;
 
diff --git a/block/blk.h b/block/blk.h
index 8a62b861453c..ee4f782d1496 100644
--- a/block/blk.h
+++ b/block/blk.h
@@ -453,11 +453,11 @@ static inline void blk_zone_bio_endio(struct bio *bio)
 		blk_zone_write_plug_bio_endio(bio);
 }
 
-void blk_zone_write_plug_complete_request(struct request *rq);
-static inline void blk_zone_complete_request(struct request *rq)
+void blk_zone_write_plug_finish_request(struct request *rq);
+static inline void blk_zone_finish_request(struct request *rq)
 {
 	if (rq->rq_flags & RQF_ZONE_WRITE_PLUGGING)
-		blk_zone_write_plug_complete_request(rq);
+		blk_zone_write_plug_finish_request(rq);
 }
 int blkdev_report_zones_ioctl(struct block_device *bdev, unsigned int cmd,
 		unsigned long arg);
@@ -491,7 +491,7 @@ static inline void blk_zone_update_request_bio(struct request *rq,
 static inline void blk_zone_bio_endio(struct bio *bio)
 {
 }
-static inline void blk_zone_complete_request(struct request *rq)
+static inline void blk_zone_finish_request(struct request *rq)
 {
 }
 static inline int blkdev_report_zones_ioctl(struct block_device *bdev,
-- 
2.44.0