dm_cache_policy_unregister
dm_cache_policy_unregister(&cleaner_policy_type);
dm_cache_policy_unregister(&mq_policy_type);
dm_cache_policy_unregister(&smq_policy_type);
dm_cache_policy_unregister(&cleaner_policy_type);
dm_cache_policy_unregister(&smq_policy_type);
dm_cache_policy_unregister(&mq_policy_type);
dm_cache_policy_unregister(&default_policy_type);
EXPORT_SYMBOL_GPL(dm_cache_policy_unregister);
void dm_cache_policy_unregister(struct dm_cache_policy_type *type);