From 449b668ce0b9069fcaafa6344c7f10fa2ba9632e Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Fri, 31 Mar 2017 10:09:45 -0400 Subject: [PATCH] dm cache: set/clear the cache core's dirty_bitset when loading mappings When loading metadata make sure to set/clear the dirty bits in the cache core's dirty_bitset as well as the policy. Otherwise the cache core is unaware that any blocks were dirty when the cache was last shutdown. A very serious side-effect being that the cleaner policy would therefore never be tasked with writing back dirty data from a cache that was in writeback mode (e.g. when switching from smq policy to cleaner policy when decommissioning a writeback cache). This fixes a serious data corruption bug associated with writeback mode. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer --- drivers/md/dm-cache-target.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index b7de289..6e747fc 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -2960,6 +2960,12 @@ static int load_mapping(void *context, dm_oblock_t oblock, dm_cblock_t cblock, int r; struct cache *cache = context; + if (dirty) { + set_bit(from_cblock(cblock), cache->dirty_bitset); + atomic_inc(&cache->nr_dirty); + } else + clear_bit(from_cblock(cblock), cache->dirty_bitset); + r = policy_load_mapping(cache->policy, oblock, cblock, dirty, hint, hint_valid); if (r) return r; -- 2.7.4