FAILED: patch "[PATCH] md: fix mssing blktrace bio split events" failed to apply to 6.12-stable tree

FAILED: patch "[PATCH] md: fix mssing blktrace bio split events" failed to apply to 6.12-stable tree

[gregkh]

The patch below does not apply to the 6.12-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-6.12.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 '2025101606-eggshell-static-9bca@gregkh' --subject-prefix 'PATCH 6.12.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;
 	}

[PATCH 6.12.y 1/4] md/raid0: Handle bio_split() errors

[Sasha Levin]

From: John Garry <john.g.garry@oracle.com>

[ Upstream commit 74538fdac3e85aae55eb4ed786478ed2384cb85d ]

Add proper bio_split() error handling. For any error, set bi_status, end
the bio, and return.

Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20241111112150.3756529-5-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: 22f166218f73 ("md: fix mssing blktrace bio split events")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/md/raid0.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 31bea72bcb01a..67ec633d27e26 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -464,6 +464,12 @@ static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
 		struct bio *split = bio_split(bio,
 			zone->zone_end - bio->bi_iter.bi_sector, GFP_NOIO,
 			&mddev->bio_set);
+
+		if (IS_ERR(split)) {
+			bio->bi_status = errno_to_blk_status(PTR_ERR(split));
+			bio_endio(bio);
+			return;
+		}
 		bio_chain(split, bio);
 		submit_bio_noacct(bio);
 		bio = split;
@@ -606,6 +612,12 @@ static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
 	if (sectors < bio_sectors(bio)) {
 		struct bio *split = bio_split(bio, sectors, GFP_NOIO,
 					      &mddev->bio_set);
+
+		if (IS_ERR(split)) {
+			bio->bi_status = errno_to_blk_status(PTR_ERR(split));
+			bio_endio(bio);
+			return true;
+		}
 		bio_chain(split, bio);
 		raid0_map_submit_bio(mddev, bio);
 		bio = split;
-- 
2.51.0

[PATCH 6.12.y 2/4] md/raid1: Handle bio_split() errors

[Sasha Levin]

From: John Garry <john.g.garry@oracle.com>

[ Upstream commit b1a7ad8b5c4fa28325ee7b369a2d545d3e16ccde ]

Add proper bio_split() error handling. For any error, call
raid_end_bio_io() and return.

For the case of an in the write path, we need to undo the increment in
the rdev pending count and NULLify the r1_bio->bios[] pointers.

For read path failure, we need to undo rdev pending count increment from
the earlier read_balance() call.

Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20241111112150.3756529-6-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: 22f166218f73 ("md: fix mssing blktrace bio split events")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/md/raid1.c | 33 +++++++++++++++++++++++++++++++--
 1 file changed, 31 insertions(+), 2 deletions(-)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index faccf7344ef93..31081d9e94025 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1317,7 +1317,7 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
 	struct raid1_info *mirror;
 	struct bio *read_bio;
 	int max_sectors;
-	int rdisk;
+	int rdisk, error;
 	bool r1bio_existed = !!r1_bio;
 
 	/*
@@ -1378,6 +1378,11 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
 	if (max_sectors < bio_sectors(bio)) {
 		struct bio *split = bio_split(bio, max_sectors,
 					      gfp, &conf->bio_split);
+
+		if (IS_ERR(split)) {
+			error = PTR_ERR(split);
+			goto err_handle;
+		}
 		bio_chain(split, bio);
 		submit_bio_noacct(bio);
 		bio = split;
@@ -1404,6 +1409,13 @@ static void raid1_read_request(struct mddev *mddev, struct bio *bio,
 	read_bio->bi_private = r1_bio;
 	mddev_trace_remap(mddev, read_bio, r1_bio->sector);
 	submit_bio_noacct(read_bio);
+	return;
+
+err_handle:
+	atomic_dec(&mirror->rdev->nr_pending);
+	bio->bi_status = errno_to_blk_status(error);
+	set_bit(R1BIO_Uptodate, &r1_bio->state);
+	raid_end_bio_io(r1_bio);
 }
 
 static void raid1_write_request(struct mddev *mddev, struct bio *bio,
@@ -1411,7 +1423,7 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
 {
 	struct r1conf *conf = mddev->private;
 	struct r1bio *r1_bio;
-	int i, disks;
+	int i, disks, k, error;
 	unsigned long flags;
 	struct md_rdev *blocked_rdev;
 	int first_clone;
@@ -1557,6 +1569,11 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
 	if (max_sectors < bio_sectors(bio)) {
 		struct bio *split = bio_split(bio, max_sectors,
 					      GFP_NOIO, &conf->bio_split);
+
+		if (IS_ERR(split)) {
+			error = PTR_ERR(split);
+			goto err_handle;
+		}
 		bio_chain(split, bio);
 		submit_bio_noacct(bio);
 		bio = split;
@@ -1640,6 +1657,18 @@ static void raid1_write_request(struct mddev *mddev, struct bio *bio,
 
 	/* In case raid1d snuck in to freeze_array */
 	wake_up_barrier(conf);
+	return;
+err_handle:
+	for (k = 0; k < i; k++) {
+		if (r1_bio->bios[k]) {
+			rdev_dec_pending(conf->mirrors[k].rdev, mddev);
+			r1_bio->bios[k] = NULL;
+		}
+	}
+
+	bio->bi_status = errno_to_blk_status(error);
+	set_bit(R1BIO_Uptodate, &r1_bio->state);
+	raid_end_bio_io(r1_bio);
 }
 
 static bool raid1_make_request(struct mddev *mddev, struct bio *bio)
-- 
2.51.0

[PATCH 6.12.y 3/4] md/raid10: Handle bio_split() errors

[Sasha Levin]

From: John Garry <john.g.garry@oracle.com>

[ Upstream commit 4cf58d9529097328b669e3c8693ed21e3a041903 ]

Add proper bio_split() error handling. For any error, call
raid_end_bio_io() and return. Except for discard, where we end the bio
directly.

Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: John Garry <john.g.garry@oracle.com>
Link: https://lore.kernel.org/r/20241111112150.3756529-7-john.g.garry@oracle.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Stable-dep-of: 22f166218f73 ("md: fix mssing blktrace bio split events")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/md/raid10.c | 47 ++++++++++++++++++++++++++++++++++++++++++++-
 1 file changed, 46 insertions(+), 1 deletion(-)

diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 6579bbb6a39a5..d02bd096824c8 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1153,6 +1153,7 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio,
 	int slot = r10_bio->read_slot;
 	struct md_rdev *err_rdev = NULL;
 	gfp_t gfp = GFP_NOIO;
+	int error;
 
 	if (slot >= 0 && r10_bio->devs[slot].rdev) {
 		/*
@@ -1203,6 +1204,10 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio,
 	if (max_sectors < bio_sectors(bio)) {
 		struct bio *split = bio_split(bio, max_sectors,
 					      gfp, &conf->bio_split);
+		if (IS_ERR(split)) {
+			error = PTR_ERR(split);
+			goto err_handle;
+		}
 		bio_chain(split, bio);
 		allow_barrier(conf);
 		submit_bio_noacct(bio);
@@ -1233,6 +1238,11 @@ static void raid10_read_request(struct mddev *mddev, struct bio *bio,
 	mddev_trace_remap(mddev, read_bio, r10_bio->sector);
 	submit_bio_noacct(read_bio);
 	return;
+err_handle:
+	atomic_dec(&rdev->nr_pending);
+	bio->bi_status = errno_to_blk_status(error);
+	set_bit(R10BIO_Uptodate, &r10_bio->state);
+	raid_end_bio_io(r10_bio);
 }
 
 static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio,
@@ -1341,9 +1351,10 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
 				 struct r10bio *r10_bio)
 {
 	struct r10conf *conf = mddev->private;
-	int i;
+	int i, k;
 	sector_t sectors;
 	int max_sectors;
+	int error;
 
 	if ((mddev_is_clustered(mddev) &&
 	     md_cluster_ops->area_resyncing(mddev, WRITE,
@@ -1469,6 +1480,10 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
 	if (r10_bio->sectors < bio_sectors(bio)) {
 		struct bio *split = bio_split(bio, r10_bio->sectors,
 					      GFP_NOIO, &conf->bio_split);
+		if (IS_ERR(split)) {
+			error = PTR_ERR(split);
+			goto err_handle;
+		}
 		bio_chain(split, bio);
 		allow_barrier(conf);
 		submit_bio_noacct(bio);
@@ -1488,6 +1503,26 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
 			raid10_write_one_disk(mddev, r10_bio, bio, true, i);
 	}
 	one_write_done(r10_bio);
+	return;
+err_handle:
+	for (k = 0;  k < i; k++) {
+		int d = r10_bio->devs[k].devnum;
+		struct md_rdev *rdev = conf->mirrors[d].rdev;
+		struct md_rdev *rrdev = conf->mirrors[d].replacement;
+
+		if (r10_bio->devs[k].bio) {
+			rdev_dec_pending(rdev, mddev);
+			r10_bio->devs[k].bio = NULL;
+		}
+		if (r10_bio->devs[k].repl_bio) {
+			rdev_dec_pending(rrdev, mddev);
+			r10_bio->devs[k].repl_bio = NULL;
+		}
+	}
+
+	bio->bi_status = errno_to_blk_status(error);
+	set_bit(R10BIO_Uptodate, &r10_bio->state);
+	raid_end_bio_io(r10_bio);
 }
 
 static void __make_request(struct mddev *mddev, struct bio *bio, int sectors)
@@ -1629,6 +1664,11 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
 	if (remainder) {
 		split_size = stripe_size - remainder;
 		split = bio_split(bio, split_size, GFP_NOIO, &conf->bio_split);
+		if (IS_ERR(split)) {
+			bio->bi_status = errno_to_blk_status(PTR_ERR(split));
+			bio_endio(bio);
+			return 0;
+		}
 		bio_chain(split, bio);
 		allow_barrier(conf);
 		/* Resend the fist split part */
@@ -1639,6 +1679,11 @@ static int raid10_handle_discard(struct mddev *mddev, struct bio *bio)
 	if (remainder) {
 		split_size = bio_sectors(bio) - remainder;
 		split = bio_split(bio, split_size, GFP_NOIO, &conf->bio_split);
+		if (IS_ERR(split)) {
+			bio->bi_status = errno_to_blk_status(PTR_ERR(split));
+			bio_endio(bio);
+			return 0;
+		}
 		bio_chain(split, bio);
 		allow_barrier(conf);
 		/* Resend the second split part */
-- 
2.51.0

[PATCH 6.12.y 4/4] md: fix mssing blktrace bio split events

[Sasha Levin]

From: Yu Kuai <yukuai3@huawei.com>

[ Upstream commit 22f166218f7313e8fe2d19213b5f4b3265f8c39e ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/md/md-linear.c | 1 +
 drivers/md/raid0.c     | 4 ++++
 drivers/md/raid1.c     | 4 ++++
 drivers/md/raid10.c    | 8 ++++++++
 drivers/md/raid5.c     | 2 ++
 5 files changed, 19 insertions(+)

diff --git a/drivers/md/md-linear.c b/drivers/md/md-linear.c
index 369aed044b409..d733ebee624b7 100644
--- a/drivers/md/md-linear.c
+++ b/drivers/md/md-linear.c
@@ -267,6 +267,7 @@ 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 67ec633d27e26..db1ab214250f9 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -470,7 +470,9 @@ 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;
@@ -618,7 +620,9 @@ 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 31081d9e94025..4c6b1bd6da9bb 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -1383,7 +1383,9 @@ 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;
@@ -1574,7 +1576,9 @@ 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 d02bd096824c8..b0062ad9b1d95 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1208,7 +1208,9 @@ 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);
@@ -1484,7 +1486,9 @@ 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);
@@ -1669,7 +1673,9 @@ 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);
@@ -1684,7 +1690,9 @@ 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 39e7596e78c0b..4fae8ade24090 100644
--- a/drivers/md/raid5.c
+++ b/drivers/md/raid5.c
@@ -5484,8 +5484,10 @@ 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;
 	}
-- 
2.51.0