dm: remove unused 'num_write_bios' target interface
No DM target provides num_write_bios and none has since dm-cache's
brief use in 2013.
Having the possibility of num_write_bios > 1 complicates bio
allocation. So remove the interface and assume there is only one bio
needed.
If a target ever needs more, it must provide a suitable bioset and
allocate itself based on its particular needs.
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index 07dec8e..2480c6a 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -1319,32 +1319,22 @@ static int __send_empty_flush(struct clone_info *ci)
}
static int __clone_and_map_data_bio(struct clone_info *ci, struct dm_target *ti,
- sector_t sector, unsigned *len)
+ sector_t sector, unsigned *len)
{
struct bio *bio = ci->bio;
struct dm_target_io *tio;
- unsigned target_bio_nr;
- unsigned num_target_bios = 1;
- int r = 0;
+ int r;
- /*
- * Does the target want to receive duplicate copies of the bio?
- */
- if (bio_data_dir(bio) == WRITE && ti->num_write_bios)
- num_target_bios = ti->num_write_bios(ti, bio);
-
- for (target_bio_nr = 0; target_bio_nr < num_target_bios; target_bio_nr++) {
- tio = alloc_tio(ci, ti, target_bio_nr);
- tio->len_ptr = len;
- r = clone_bio(tio, bio, sector, *len);
- if (r < 0) {
- free_tio(tio);
- break;
- }
- __map_bio(tio);
+ tio = alloc_tio(ci, ti, 0);
+ tio->len_ptr = len;
+ r = clone_bio(tio, bio, sector, *len);
+ if (r < 0) {
+ free_tio(tio);
+ return r;
}
+ __map_bio(tio);
- return r;
+ return 0;
}
typedef unsigned (*get_num_bios_fn)(struct dm_target *ti);