[PATCH 6.1] blk-mq: end the request if getting a keyslot fails

[PATCH 6.1] blk-mq: end the request if getting a keyslot fails

[Eric Biggers]

From: Josef Bacik <josef@toxicpanda.com>

commit e67cb6ed40e7f45912b63d7d575f18dfd2ebc98a upstream.

When blk_crypto_rq_get_keyslot() fails, blk_mq_submit_bio() ends the bio
by hand and frees the request. By then blk_mq_bio_to_request() has done
the IO accounting, which blk_mq_free_request() doesn't undo, so the
in_flight counter never drops and iostat shows a device that is 100%
busy. If the bio went through zone write plugging the zone stays plugged
as well, and every later write to it waits forever.

Use blk_mq_end_request() like the dispatch path does for a request the
driver rejected, after marking it for zone write plugging.

Move the call to blk_zone_write_plug_init_request() before
blk_crypto_rq_get_keyslot() so that it doesn't need to be duplicated.
It doesn't depend on the keyslot.

Fixes: 99dc422335d8 ("block: support to account io_ticks precisely")
Fixes: dd291d77cc90 ("block: Introduce zone write plugging")
Cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20261029200110.1328103-1-ebiggers@kernel.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
[ Backport to 6.1.y: dropped the part related to
  bio_zone_write_plugging(), which doesn't exist on this branch. ]
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
---
 block/blk-mq.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index bc619519dd665..9722b0afdcee3 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3030,9 +3030,7 @@ void blk_mq_submit_bio(struct bio *bio)
 
 	ret = blk_crypto_rq_get_keyslot(rq);
 	if (ret != BLK_STS_OK) {
-		bio->bi_status = ret;
-		bio_endio(bio);
-		blk_mq_free_request(rq);
+		blk_mq_end_request(rq, ret);
 		return;
 	}
 

base-commit: c75b0cf0982c00cddfd88d1acf3872f79b40980c
-- 
2.56.0