dm cache: always split discards on cache block boundaries

The DM cache target cannot cope with discards that span multiple cache
blocks, so each discard bio that spans more than one cache block must
get split by the DM core.

Signed-off-by: Heinz Mauelshagen <heinzm@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # v3.9+
This commit is contained in:
Heinz Mauelshagen 2014-05-23 14:10:01 -04:00 committed by Mike Snitzer
parent 80c578930c
commit f1daa838e8

View File

@ -2178,6 +2178,8 @@ static int cache_create(struct cache_args *ca, struct cache **result)
ti->num_discard_bios = 1;
ti->discards_supported = true;
ti->discard_zeroes_data_unsupported = true;
/* Discard bios must be split on a block boundary */
ti->split_discard_bios = true;
cache->features = ca->features;
ti->per_bio_data_size = get_per_bio_data_size(cache);