From 50faf9370b0aa357a9d114faafc2327505547928 Mon Sep 17 00:00:00 2001 From: Heinz Mauelshagen <heinzm@redhat.com> 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 <heinzm@redhat.com> Acked-by: Joe Thornber <ejt@redhat.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- 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 1a75869d3a82..677973641d2b 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -1954,6 +1954,8 @@ 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); -- 2.34.1