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From: Keith Busch <kbusch@meta.com>
To: <axboe@kernel.dk>, <hch@lst.de>, <martin.petersen@oracle.com>,
	<linux-block@vger.kernel.org>, <linux-nvme@lists.infradead.org>,
	<linux-scsi@vger.kernel.org>, <sagi@grimberg.me>
Cc: Keith Busch <kbusch@kernel.org>
Subject: [PATCHv4 04/10] blk-integrity: consider entire bio list for merging
Date: Wed, 11 Sep 2024 13:12:34 -0700	[thread overview]
Message-ID: <20240911201240.3982856-5-kbusch@meta.com> (raw)
In-Reply-To: <20240911201240.3982856-1-kbusch@meta.com>

From: Keith Busch <kbusch@kernel.org>

If a bio is merged to a request, the entire bio list is merged, so don't
temporarily detach it from its list when counting segments. In most
cases, bi_next will already be NULL, so detaching is usually a no-op.
But if the bio does have a list, the current code is miscounting the
segments for the resulting merge.

Signed-off-by: Keith Busch <kbusch@kernel.org>
---
 block/blk-integrity.c | 4 ----
 1 file changed, 4 deletions(-)

diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index afd101555d3cb..84065691aaed0 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -134,7 +134,6 @@ bool blk_integrity_merge_bio(struct request_queue *q, struct request *req,
 			     struct bio *bio)
 {
 	int nr_integrity_segs;
-	struct bio *next = bio->bi_next;
 
 	if (blk_integrity_rq(req) == 0 && bio_integrity(bio) == NULL)
 		return true;
@@ -145,10 +144,7 @@ bool blk_integrity_merge_bio(struct request_queue *q, struct request *req,
 	if (bio_integrity(req->bio)->bip_flags != bio_integrity(bio)->bip_flags)
 		return false;
 
-	bio->bi_next = NULL;
 	nr_integrity_segs = blk_rq_count_integrity_sg(q, bio);
-	bio->bi_next = next;
-
 	if (req->nr_integrity_segments + nr_integrity_segs >
 	    q->limits.max_integrity_segments)
 		return false;
-- 
2.43.5


  parent reply	other threads:[~2024-09-11 20:12 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-09-11 20:12 [PATCHv4 00/10] block integrity merging and counting Keith Busch
2024-09-11 20:12 ` [PATCHv4 01/10] blk-mq: unconditional nr_integrity_segments Keith Busch
2024-09-12  7:02   ` Christoph Hellwig
2024-09-13  1:47   ` Martin K. Petersen
2024-09-11 20:12 ` [PATCHv4 02/10] blk-mq: set the nr_integrity_segments from bio Keith Busch
2024-09-13  1:47   ` Martin K. Petersen
2024-09-11 20:12 ` [PATCHv4 03/10] blk-integrity: properly account for segments Keith Busch
2024-09-13  1:48   ` Martin K. Petersen
2024-09-11 20:12 ` Keith Busch [this message]
2024-09-12  7:42   ` [PATCHv4 04/10] blk-integrity: consider entire bio list for merging Christoph Hellwig
2024-09-11 20:12 ` [PATCHv4 05/10] block: provide a request helper for user integrity segments Keith Busch
2024-09-12  7:43   ` Christoph Hellwig
2024-09-13  1:50   ` Martin K. Petersen
2024-09-13 12:33   ` Kanchan Joshi
2024-09-11 20:12 ` [PATCHv4 06/10] block: provide helper for nr_integrity_segments Keith Busch
2024-09-12  7:44   ` Christoph Hellwig
2024-09-13  1:52     ` Martin K. Petersen
2024-09-13 12:35   ` Kanchan Joshi
2024-09-11 20:12 ` [PATCHv4 07/10] scsi: use request helper to get integrity segments Keith Busch
2024-09-13  1:53   ` Martin K. Petersen
2024-09-13 12:35   ` Kanchan Joshi
2024-09-11 20:12 ` [PATCHv4 08/10] nvme-rdma: " Keith Busch
2024-09-13  1:54   ` Martin K. Petersen
2024-09-13 12:37   ` Kanchan Joshi
2024-09-11 20:12 ` [PATCHv4 09/10] block: unexport blk_rq_count_integrity_sg Keith Busch
2024-09-13  1:54   ` Martin K. Petersen
2024-09-11 20:12 ` [PATCHv4 10/10] blk-integrity: improved sg segment mapping Keith Busch
2024-09-11 23:23   ` Keith Busch
2024-09-12  7:46     ` Christoph Hellwig
2024-09-12  7:47   ` Christoph Hellwig
2024-09-13  2:00   ` Martin K. Petersen
2024-09-13  3:45   ` kernel test robot

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