[PATCH RFC v3 06/15] md/raid0: convert raid0_handle_discard() to use bio_submit_split_bioset()

[Yu Kuai <yukuai1@huaweicloud.com>]

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 disordered split IO by converting bio to
underlying disks before submit_bio_noacct(), with the respect
md_submit_bio() already split 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>
---
 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..99f7839b4e96 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