From 9153df7405ae04c1b0466de720e0a685cfea1a3a Mon Sep 17 00:00:00 2001 From: Joe Thornber Date: Mon, 31 Aug 2015 18:20:08 +0100 Subject: [PATCH] dm cache: fix leaking of deferred bio prison cells There were two cases where dm_cell_visit_release() was being called, which removes the cell from the prison's rbtree, but the callers didn't also return the cell to the mempool. Fix this by having them call free_prison_cell(). This leak manifested as the 'kmalloc-96' slab growing until OOM. Fixes: 651f5fa2a3 ("dm cache: defer whole cells") Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Cc: stable@vger.kernel.org # 4.1+ --- drivers/md/dm-cache-target.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/drivers/md/dm-cache-target.c b/drivers/md/dm-cache-target.c index 8cef66b33243..2f60cbf404e5 100644 --- a/drivers/md/dm-cache-target.c +++ b/drivers/md/dm-cache-target.c @@ -1730,6 +1730,8 @@ static void remap_cell_to_origin_clear_discard(struct cache *cache, remap_to_origin(cache, bio); issue(cache, bio); } + + free_prison_cell(cache, cell); } static void remap_cell_to_cache_dirty(struct cache *cache, struct dm_bio_prison_cell *cell, @@ -1764,6 +1766,8 @@ static void remap_cell_to_cache_dirty(struct cache *cache, struct dm_bio_prison_ remap_to_cache(cache, bio, cblock); issue(cache, bio); } + + free_prison_cell(cache, cell); } /*----------------------------------------------------------------*/