dmu_buf_init_user
extern inline void dmu_buf_init_user(dmu_buf_user_t *dbu,
dmu_buf_init_user(&dnc->dnc_dbu, NULL,
dmu_buf_init_user(&ds->ds_dbu, dsl_dataset_evict_sync,
dmu_buf_init_user(&dd->dd_dbu, NULL, dsl_dir_evict_async,
dmu_buf_init_user(&handle->sa_dbu, sa_evict_sync, NULL,
dmu_buf_init_user(&l->l_dbu, zap_leaf_evict_sync, NULL, &l->l_dbuf);
dmu_buf_init_user(&l->l_dbu, zap_leaf_evict_sync, NULL, &l->l_dbuf);
dmu_buf_init_user(&zap->zap_dbu, zap_evict_sync, NULL, &zap->zap_dbuf);