[PATCH for-6.18/block 07/16] md/raid0: convert raid0_handle_discard() to use bio_submit_split_bioset()

Yu Kuai
2025-09-05T07:15:59Z

From: Yu Kuai <yukuai3@huawei.com>

Unify bio split code, and prepare to fix disordered split IO

Noted commit 319ff40a5427 ("md/raid0: Fix performance regression for large
sequential writes") already fix reordered split IO by remapping bio to
underlying disks before resubmitting it, with the respect
md_submit_bio() already split it by sectors, and raid0_make_request()
will split at most once for unaligned IO. This is a bit hacky and we'll
convert this to solution in general later.

Signed-off-by: Yu Kuai <yukuai3@huawei.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
drivers/md/raid0.c | 19 ++++++-------------
1 file changed, 6 insertions(+), 13 deletions(-)

diff --git a/drivers/md/raid0.c b/drivers/md/raid0.c
index 1ba7d0c090f7..ca08ec2e1f27 100644
--- a/drivers/md/raid0.c
+++ b/drivers/md/raid0.c
@@ -463,23 +463,16 @@ static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
zone = find_zone(conf, &start);

if (bio_end_sector(bio) > zone->zone_end) {
- 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);
+ bio = bio_submit_split_bioset(bio,
+ zone->zone_end - bio->bi_iter.bi_sector,
+ &mddev->bio_set);
+ if (!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;
- } else
+ } else {
end = bio_end_sector(bio);
+ }

orig_end = end;
if (zone != conf->strip_zone)
--
2.39.2