BUF_HASH_LOCK
(BUF_HASH_LOCK(BUF_HASH_INDEX(hdr->b_spa, &hdr->b_dva, hdr->b_birth)))
kmutex_t *hash_lock = BUF_HASH_LOCK(idx);
kmutex_t *hash_lock = BUF_HASH_LOCK(idx);
ASSERT(MUTEX_HELD(BUF_HASH_LOCK(idx)));