Commit 891fced6 authored by Christoph Hellwig's avatar Christoph Hellwig Committed by Jens Axboe
Browse files

dm: simplify the single bio fast path in __send_duplicate_bios 



Most targets just need a single flush bio.  Open code that case in
__send_duplicate_bios without the need to add the bio to a list.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarMike Snitzer <snitzer@redhat.com>
Link: https://lore.kernel.org/r/20220202160109.108149-9-hch@lst.de


Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 1d1068ce

drivers/md/dm.c

+14 −12
Original line number Diff line number Diff line
@@ -1241,15 +1241,6 @@ static void alloc_multiple_bios(struct bio_list *blist, struct clone_info *ci, 
	struct bio *bio;

	int try;



	if (!num_bios)

		return;



	if (num_bios == 1) {

		bio = alloc_tio(ci, ti, 0, len, GFP_NOIO);

		bio_list_add(blist, bio);

		return;

	}



	for (try = 0; try < 2; try++) {

		int bio_nr;
@@ -1279,13 +1270,24 @@ static void __send_duplicate_bios(struct clone_info *ci, struct dm_target *ti, 
	struct bio_list blist = BIO_EMPTY_LIST;

	struct bio *clone;



	switch (num_bios) {

	case 0:

		break;

	case 1:

		clone = alloc_tio(ci, ti, 0, len, GFP_NOIO);

		if (len)

			bio_setup_sector(clone, ci->sector, *len);

		__map_bio(clone);

		break;

	default:

		alloc_multiple_bios(&blist, ci, ti, num_bios, len);



		while ((clone = bio_list_pop(&blist))) {

			if (len)

				bio_setup_sector(clone, ci->sector, *len);

			__map_bio(clone);

		}

		break;

	}

}



static int __send_empty_flush(struct clone_info *ci)