clean_work
struct clean_work *cw = container_of(work, struct clean_work, work);
struct clean_work *work;
INIT_WORK(&cache->clean_work, clean_fn);
flush_work(&cache->clean_work);
struct work_struct clean_work;
struct pcache_cache *cache = container_of(work, struct pcache_cache, clean_work);
queue_work(cache_get_wq(cache), &cache->clean_work);