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 <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org # 4.1+
This commit is contained in:
Joe Thornber 2015-08-31 18:20:08 +01:00 committed by Mike Snitzer
parent f15f4d7200
commit 9153df7405

View File

@ -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);
}
/*----------------------------------------------------------------*/