From: Pavel Begunkov <asml.silence@gmail.com>
Date: Tue, 19 Oct 2021 22:24:12 +0100
Subject: [PATCH] block: optimise req_bio_endio()
Git-commit: 478eb72b815f33734723867ff236d96afa418d69
Patch-mainline: v5.16-rc1
References: jsc#PED-1183
First, get rid of an extra branch and chain error checks. Also reshuffle
it with bio_advance(), so it goes closer to the final check, with that
the compiler loads rq->rq_flags only once, and also doesn't reload
bio->bi_iter.bi_size if bio_advance() didn't actually advanced the iter.
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Acked-by: Hannes Reinecke <hare@suse.com>
---
block/blk-mq.c | 16 +++++++---------
1 file changed, 7 insertions(+), 9 deletions(-)
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 31d9e612d236..8b05a8f9bb33 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -633,25 +633,23 @@ void blk_mq_free_plug_rqs(struct blk_plug *plug)
static void req_bio_endio(struct request *rq, struct bio *bio,
unsigned int nbytes, blk_status_t error)
{
- if (error)
+ if (unlikely(error)) {
bio->bi_status = error;
-
- if (unlikely(rq->rq_flags & RQF_QUIET))
- bio_set_flag(bio, BIO_QUIET);
-
- bio_advance(bio, nbytes);
-
- if (req_op(rq) == REQ_OP_ZONE_APPEND && error == BLK_STS_OK) {
+ } else if (req_op(rq) == REQ_OP_ZONE_APPEND) {
/*
* Partial zone append completions cannot be supported as the
* BIO fragments may end up not being written sequentially.
*/
- if (bio->bi_iter.bi_size)
+ if (bio->bi_iter.bi_size == nbytes)
bio->bi_status = BLK_STS_IOERR;
else
bio->bi_iter.bi_sector = rq->__sector;
}
+ bio_advance(bio, nbytes);
+
+ if (unlikely(rq->rq_flags & RQF_QUIET))
+ bio_set_flag(bio, BIO_QUIET);
/* don't actually finish bio if it's part of flush sequence */
if (bio->bi_iter.bi_size == 0 && !(rq->rq_flags & RQF_FLUSH_SEQ))
bio_endio(bio);
--
2.35.3