Commit d41e077a authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm: refactor dm_split_and_process_bio a bit 



Remove needless branching and indentation. Leaves code to catch
malformed op_is_zone_mgmt bios (they shouldn't have a payload).

Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarMikulas Patocka <mpatocka@redhat.com>
Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 66bdaa43

drivers/md/dm.c

+28 −26
Original line number Diff line number Diff line
@@ -1394,7 +1394,13 @@ static void init_clone_info(struct clone_info *ci, struct mapped_device *md, 
{

	ci->map = map;

	ci->io = alloc_io(md, bio);

	ci->bio = bio;

	ci->sector = bio->bi_iter.bi_sector;

	ci->sector_count = bio_sectors(bio);



	/* Shouldn't happen but sector_count was being set to 0 so... */

	if (WARN_ON_ONCE(op_is_zone_mgmt(bio_op(bio)) && ci->sector_count))

		ci->sector_count = 0;

}



/*
@@ -1404,6 +1410,7 @@ static void dm_split_and_process_bio(struct mapped_device *md, 
				     struct dm_table *map, struct bio *bio)

{

	struct clone_info ci;

	struct bio *b;

	int error = 0;



	init_clone_info(&ci, md, map, bio);
@@ -1411,34 +1418,29 @@ static void dm_split_and_process_bio(struct mapped_device *md, 
	if (bio->bi_opf & REQ_PREFLUSH) {

		error = __send_empty_flush(&ci);

		/* dm_io_dec_pending submits any data associated with flush */

	} else if (op_is_zone_mgmt(bio_op(bio))) {

		ci.bio = bio;

		ci.sector_count = 0;

		error = __split_and_process_bio(&ci);

	} else {

		ci.bio = bio;

		ci.sector_count = bio_sectors(bio);

		goto out;

	}



	error = __split_and_process_bio(&ci);

		if (ci.sector_count && !error) {

	if (error || !ci.sector_count)

		goto out;



	/*

			 * Remainder must be passed to submit_bio_noacct()

			 * so that it gets handled *after* bios already submitted

			 * have been completely processed.

			 * We take a clone of the original to store in

			 * ci.io->orig_bio to be used by dm_end_io_acct() and for

			 * dm_io_dec_pending() to use for completion handling.

	 * Remainder must be passed to submit_bio_noacct() so it gets handled

	 * *after* bios already submitted have been completely processed.

	 * We take a clone of the original to store in ci.io->orig_bio to be

	 * used by dm_end_io_acct() and for dm_io_dec_pending() to use for

	 * completion handling.

	 */

			struct bio *b = bio_split(bio, bio_sectors(bio) - ci.sector_count,

	b = bio_split(bio, bio_sectors(bio) - ci.sector_count,

		      GFP_NOIO, &md->queue->bio_split);

	ci.io->orig_bio = b;



	bio_chain(b, bio);

	trace_block_split(b, bio->bi_iter.bi_sector);

	submit_bio_noacct(bio);

		}

	}

out:

	dm_start_io_acct(ci.io);



	/* drop the extra reference count */

	dm_io_dec_pending(ci.io, errno_to_blk_status(error));

}