From 04937d94156d63d7f6249416b82ac810f0218219 Mon Sep 17 00:00:00 2001 From: Heinz Mauelshagen Date: Fri, 23 May 2014 14:10:01 -0400 Subject: [PATCH] dm cache: always split discards on cache block boundaries commit f1daa838e861ae1a0fb7cd9721a21258430fcc8c upstream. 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 Acked-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Greg Kroah-Hartman --- drivers/md/dm-cache-target.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 9306e0b..c0ad90d 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -2195,6 +2195,8 @@ 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); -- 2.7.4