md/raid0: Factor out helper for mapping and submitting a bio

Factor out helper function for mapping and submitting a bio out of
raid0_make_request(). We will use it later for submitting both parts of
a split bio.

Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Yu Kuai <yukuai3@huawei.com>
Link: https://lore.kernel.org/r/20230814092720.3931-1-jack@suse.cz
Signed-off-by: Song Liu <song@kernel.org>

drivers/md/raid0.c

@@ -545,68 +545,35 @@ static void raid0_handle_discard(struct mddev *mddev, struct bio *bio)
 	bio_endio(bio);
 }
 
-static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
+static void raid0_map_submit_bio(struct mddev *mddev, struct bio *bio)
 {
 	struct r0conf *conf = mddev->private;
 	struct strip_zone *zone;
 	struct md_rdev *tmp_dev;
-	sector_t bio_sector;
-	sector_t sector;
-	sector_t orig_sector;
-	unsigned chunk_sects;
-	unsigned sectors;
-
-	if (unlikely(bio->bi_opf & REQ_PREFLUSH)
-	    && md_flush_request(mddev, bio))
-		return true;
-
-	if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
-		raid0_handle_discard(mddev, bio);
-		return true;
-	}
-
-	bio_sector = bio->bi_iter.bi_sector;
-	sector = bio_sector;
-	chunk_sects = mddev->chunk_sectors;
-
-	sectors = chunk_sects -
-		(likely(is_power_of_2(chunk_sects))
-		 ? (sector & (chunk_sects-1))
-		 : sector_div(sector, chunk_sects));
-
-	/* Restore due to sector_div */
-	sector = bio_sector;
-
-	if (sectors < bio_sectors(bio)) {
-		struct bio *split = bio_split(bio, sectors, GFP_NOIO,
-					      &mddev->bio_set);
-		bio_chain(split, bio);
-		submit_bio_noacct(bio);
-		bio = split;
-	}
+	sector_t bio_sector = bio->bi_iter.bi_sector;
+	sector_t sector = bio_sector;
 
 	if (bio->bi_pool != &mddev->bio_set)
 		md_account_bio(mddev, &bio);
 
-	orig_sector = sector;
 	zone = find_zone(mddev->private, &sector);
 	switch (conf->layout) {
 	case RAID0_ORIG_LAYOUT:
-		tmp_dev = map_sector(mddev, zone, orig_sector, &sector);
+		tmp_dev = map_sector(mddev, zone, bio_sector, &sector);
 		break;
 	case RAID0_ALT_MULTIZONE_LAYOUT:
 		tmp_dev = map_sector(mddev, zone, sector, &sector);
 		break;
 	default:
 		WARN(1, "md/raid0:%s: Invalid layout\n", mdname(mddev));
 		bio_io_error(bio);
-		return true;
+		return;
 	}
 
 	if (unlikely(is_rdev_broken(tmp_dev))) {
 		bio_io_error(bio);
 		md_error(mddev, tmp_dev);
-		return true;
+		return;
 	}
 
 	bio_set_dev(bio, tmp_dev->bdev);
@@ -618,6 +585,40 @@ static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
 				      bio_sector);
 	mddev_check_write_zeroes(mddev, bio);
 	submit_bio_noacct(bio);
+}
+
+static bool raid0_make_request(struct mddev *mddev, struct bio *bio)
+{
+	sector_t sector;
+	unsigned chunk_sects;
+	unsigned sectors;
+
+	if (unlikely(bio->bi_opf & REQ_PREFLUSH)
+	    && md_flush_request(mddev, bio))
+		return true;
+
+	if (unlikely((bio_op(bio) == REQ_OP_DISCARD))) {
+		raid0_handle_discard(mddev, bio);
+		return true;
+	}
+
+	sector = bio->bi_iter.bi_sector;
+	chunk_sects = mddev->chunk_sectors;
+
+	sectors = chunk_sects -
+		(likely(is_power_of_2(chunk_sects))
+		 ? (sector & (chunk_sects-1))
+		 : sector_div(sector, chunk_sects));
+
+	if (sectors < bio_sectors(bio)) {
+		struct bio *split = bio_split(bio, sectors, GFP_NOIO,
+					      &mddev->bio_set);
+		bio_chain(split, bio);
+		submit_bio_noacct(bio);
+		bio = split;
+	}
+
+	raid0_map_submit_bio(mddev, bio);
 	return true;
 }