The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
To reproduce the conflict and resubmit, you may use the following commands:
git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.4.y git checkout FETCH_HEAD git cherry-pick -x 22f166218f7313e8fe2d19213b5f4b3265f8c39e # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025101608-magnitude-earthworm-fcee@gregkh' --subject-prefix 'PATCH 5.4.y' HEAD^..
Possible dependencies:
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From 22f166218f7313e8fe2d19213b5f4b3265f8c39e Mon Sep 17 00:00:00 2001 From: Yu Kuai yukuai3@huawei.com Date: Wed, 10 Sep 2025 14:30:44 +0800 Subject: [PATCH] md: fix mssing blktrace bio split events
If bio is split by internal handling like chunksize or badblocks, the corresponding trace_block_split() is missing, resulting in blktrace inability to catch BIO split events and making it harder to analyze the BIO sequence.
Cc: stable@vger.kernel.org Fixes: 4b1faf931650 ("block: Kill bio_pair_split()") Signed-off-by: Yu Kuai yukuai3@huawei.com Reviewed-by: Damien Le Moal dlemoal@kernel.org Reviewed-by: Christoph Hellwig hch@lst.de Signed-off-by: Jens Axboe axboe@kernel.dk
diff --git a/drivers/md/md-linear.c b/drivers/md/md-linear.c index 5d9b08115375..59d7963c7843 100644 --- a/drivers/md/md-linear.c +++ b/drivers/md/md-linear.c @@ -266,6 +266,7 @@ static bool linear_make_request(struct mddev *mddev, struct bio *bio) }
bio_chain(split, bio); + trace_block_split(split, bio->bi_iter.bi_sector); submit_bio_noacct(bio); bio = split; } diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c index f1d8811a542a..1ba7d0c090f7 100644 --- a/drivers/md/raid0.c +++ b/drivers/md/raid0.c @@ -472,7 +472,9 @@ static void raid0_handle_discard(struct mddev *mddev, struct bio *bio) bio_endio(bio); return; } + bio_chain(split, bio); + trace_block_split(split, bio->bi_iter.bi_sector); submit_bio_noacct(bio); bio = split; end = zone->zone_end; @@ -620,7 +622,9 @@ static bool raid0_make_request(struct mddev *mddev, struct bio *bio) bio_endio(bio); return true; } + bio_chain(split, bio); + trace_block_split(split, bio->bi_iter.bi_sector); raid0_map_submit_bio(mddev, bio); bio = split; } diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c index f096f4d0fca7..64a1e0b47e87 100644 --- a/drivers/md/raid1.c +++ b/drivers/md/raid1.c @@ -1384,7 +1384,9 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio, error = PTR_ERR(split); goto err_handle; } + bio_chain(split, bio); + trace_block_split(split, bio->bi_iter.bi_sector); submit_bio_noacct(bio); bio = split; r1_bio->master_bio = bio; @@ -1616,7 +1618,9 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio, error = PTR_ERR(split); goto err_handle; } + bio_chain(split, bio); + trace_block_split(split, bio->bi_iter.bi_sector); submit_bio_noacct(bio); bio = split; r1_bio->master_bio = bio; diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c index 312e8a0e93e7..3d7b24d6b4eb 100644 --- a/drivers/md/raid10.c +++ b/drivers/md/raid10.c @@ -1209,7 +1209,9 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio, error = PTR_ERR(split); goto err_handle; } + bio_chain(split, bio); + trace_block_split(split, bio->bi_iter.bi_sector); allow_barrier(conf); submit_bio_noacct(bio); wait_barrier(conf, false); @@ -1495,7 +1497,9 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio, error = PTR_ERR(split); goto err_handle; } + bio_chain(split, bio); + trace_block_split(split, bio->bi_iter.bi_sector); allow_barrier(conf); submit_bio_noacct(bio); wait_barrier(conf, false); @@ -1679,7 +1683,9 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio) bio_endio(bio); return 0; } + bio_chain(split, bio); + trace_block_split(split, bio->bi_iter.bi_sector); allow_barrier(conf); /* Resend the fist split part */ submit_bio_noacct(split); @@ -1694,7 +1700,9 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio) bio_endio(bio); return 0; } + bio_chain(split, bio); + trace_block_split(split, bio->bi_iter.bi_sector); allow_barrier(conf); /* Resend the second split part */ submit_bio_noacct(bio); diff --git a/drivers/md/raid5.c b/drivers/md/raid5.c index 5112658ef5f6..96a6d63b3d62 100644 --- a/drivers/md/raid5.c +++ b/drivers/md/raid5.c @@ -5493,8 +5493,10 @@ static struct bio *chunk_aligned_read(struct mddev *mddev, struct bio *raid_bio)
if (sectors < bio_sectors(raid_bio)) { struct r5conf *conf = mddev->private; + split = bio_split(raid_bio, sectors, GFP_NOIO, &conf->bio_split); bio_chain(split, raid_bio); + trace_block_split(split, raid_bio->bi_iter.bi_sector); submit_bio_noacct(raid_bio); raid_bio = split; }