diff mbox series

[PATCHv4,03/10] blk-integrity: properly account for segments

Message ID 20240911201240.3982856-4-kbusch@meta.com
State Superseded
Headers show
Series block integrity merging and counting | expand

Commit Message

Keith Busch Sept. 11, 2024, 8:12 p.m. UTC 
From: Keith Busch <kbusch@kernel.org>

Both types of merging when integrity data is used are miscounting the
segments:

Merging two requests wasn't accounting for the new segment count, so add
the "next" segment count to the first on a successful merge to ensure
this value is accurate.

Merging a bio into an existing request was double counting the bio's
segments, even if the merge failed later on. Move the segment accounting
to the end when the merge is successful.

Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Keith Busch <kbusch@kernel.org>
---
 block/blk-integrity.c | 2 --
 block/blk-merge.c     | 4 ++++
 2 files changed, 4 insertions(+), 2 deletions(-)

Comments

Martin K. Petersen Sept. 13, 2024, 1:48 a.m. UTC | #1 
Keith,

> Both types of merging when integrity data is used are miscounting the
> segments:
>
> Merging two requests wasn't accounting for the new segment count, so
> add the "next" segment count to the first on a successful merge to
> ensure this value is accurate.
>
> Merging a bio into an existing request was double counting the bio's
> segments, even if the merge failed later on. Move the segment
> accounting to the end when the merge is successful.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
diff mbox series

Patch

diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index 010decc892eaa..afd101555d3cb 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -153,8 +153,6 @@  bool blk_integrity_merge_bio(struct request_queue *q, struct request *req,
 	    q->limits.max_integrity_segments)
 		return false;
 
-	req->nr_integrity_segments += nr_integrity_segs;
-
 	return true;
 }
 
diff --git a/block/blk-merge.c b/block/blk-merge.c
index 56769c4bcd799..ad763ec313b6a 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -639,6 +639,9 @@  static inline int ll_new_hw_segment(struct request *req, struct bio *bio,
 	 * counters.
 	 */
 	req->nr_phys_segments += nr_phys_segs;
+	if (bio_integrity(bio))
+		req->nr_integrity_segments += blk_rq_count_integrity_sg(req->q,
+									bio);
 	return 1;
 
 no_merge:
@@ -731,6 +734,7 @@  static int ll_merge_requests_fn(struct request_queue *q, struct request *req,
 
 	/* Merge is OK... */
 	req->nr_phys_segments = total_phys_segments;
+	req->nr_integrity_segments += next->nr_integrity_segments;
 	return 1;
 }