Commit 15cb6f39 authored by Mike Snitzer's avatar Mike Snitzer
Browse files

dm writecache: further writecache_map() cleanup 



Factor out writecache_map_flush() and writecache_map_discard() from
writecache_map(). Also eliminate the various goto labels in
writecache_map().

Signed-off-by: default avatarMike Snitzer <snitzer@redhat.com>
parent 4d020b3a

drivers/md/dm-writecache.c

+43 −32
Original line number Diff line number Diff line
@@ -1447,31 +1447,52 @@ static enum wc_map_op writecache_map_write(struct dm_writecache *wc, struct bio 
	return WC_MAP_SUBMIT;

}



static enum wc_map_op writecache_map_flush(struct dm_writecache *wc, struct bio *bio)

{

	if (writecache_has_error(wc))

		return WC_MAP_ERROR;



	if (WC_MODE_PMEM(wc)) {

		writecache_flush(wc);

		if (writecache_has_error(wc))

			return WC_MAP_ERROR;

		else if (unlikely(wc->cleaner) || unlikely(wc->metadata_only))

			return WC_MAP_REMAP_ORIGIN;

		return WC_MAP_SUBMIT;

	}

	/* SSD: */

	if (dm_bio_get_target_bio_nr(bio))

		return WC_MAP_REMAP_ORIGIN;

	writecache_offload_bio(wc, bio);

	return WC_MAP_RETURN;

}



static enum wc_map_op writecache_map_discard(struct dm_writecache *wc, struct bio *bio)

{

	if (writecache_has_error(wc))

		return WC_MAP_ERROR;



	if (WC_MODE_PMEM(wc)) {

		writecache_discard(wc, bio->bi_iter.bi_sector, bio_end_sector(bio));

		return WC_MAP_REMAP_ORIGIN;

	}

	/* SSD: */

	writecache_offload_bio(wc, bio);

	return WC_MAP_RETURN;

}



static int writecache_map(struct dm_target *ti, struct bio *bio)

{

	struct dm_writecache *wc = ti->private;

	enum wc_map_op map_op = WC_MAP_ERROR;

	enum wc_map_op map_op;



	bio->bi_private = NULL;



	wc_lock(wc);



	if (unlikely(bio->bi_opf & REQ_PREFLUSH)) {

		if (writecache_has_error(wc))

			goto unlock_error;

		if (WC_MODE_PMEM(wc)) {

			writecache_flush(wc);

			if (writecache_has_error(wc))

				goto unlock_error;

			if (unlikely(wc->cleaner) || unlikely(wc->metadata_only))

				goto unlock_remap_origin;

			goto unlock_submit;

		} else {

			if (dm_bio_get_target_bio_nr(bio))

				goto unlock_remap_origin;

			writecache_offload_bio(wc, bio);

			goto unlock_return;

		}

		map_op = writecache_map_flush(wc, bio);

		goto done;

	}



	bio->bi_iter.bi_sector = dm_target_offset(ti, bio->bi_iter.bi_sector);
@@ -1481,29 +1502,22 @@ static int writecache_map(struct dm_target *ti, struct bio *bio) 
		DMERR("I/O is not aligned, sector %llu, size %u, block size %u",

		      (unsigned long long)bio->bi_iter.bi_sector,

		      bio->bi_iter.bi_size, wc->block_size);

		goto unlock_error;

		map_op = WC_MAP_ERROR;

		goto done;

	}



	if (unlikely(bio_op(bio) == REQ_OP_DISCARD)) {

		if (writecache_has_error(wc))

			goto unlock_error;

		if (WC_MODE_PMEM(wc)) {

			writecache_discard(wc, bio->bi_iter.bi_sector, bio_end_sector(bio));

			goto unlock_remap_origin;

		} else {

			writecache_offload_bio(wc, bio);

			goto unlock_return;

		}

		map_op = writecache_map_discard(wc, bio);

		goto done;

	}



	if (bio_data_dir(bio) == READ)

		map_op = writecache_map_read(wc, bio);

	else

		map_op = writecache_map_write(wc, bio);



done:

	switch (map_op) {

	case WC_MAP_REMAP_ORIGIN:

unlock_remap_origin:

		if (likely(wc->pause != 0)) {

			if (bio_op(bio) == REQ_OP_WRITE) {

				dm_iot_io_begin(&wc->iot, 1);
@@ -1515,7 +1529,6 @@ static int writecache_map(struct dm_target *ti, struct bio *bio) 
		return DM_MAPIO_REMAPPED;



	case WC_MAP_REMAP:

unlock_remap:

		/* make sure that writecache_end_io decrements bio_in_progress: */

		bio->bi_private = (void *)1;

		atomic_inc(&wc->bio_in_progress[bio_data_dir(bio)]);
@@ -1523,18 +1536,16 @@ static int writecache_map(struct dm_target *ti, struct bio *bio) 
		return DM_MAPIO_REMAPPED;



	case WC_MAP_SUBMIT:

unlock_submit:

		wc_unlock(wc);

		bio_endio(bio);

		return DM_MAPIO_SUBMITTED;



	case WC_MAP_RETURN:

unlock_return:

		wc_unlock(wc);

		return DM_MAPIO_SUBMITTED;



	case WC_MAP_ERROR:

unlock_error:

	default:

		wc_unlock(wc);

		bio_io_error(bio);

		return DM_MAPIO_SUBMITTED;