dmu_read_by_dnode
int dmu_read_by_dnode(dnode_t *dn, uint64_t offset, uint64_t size, void *buf,
error = dmu_read_by_dnode(zv->zv_dn, offset, size, buf,
if (wr_state == WR_COPIED && dmu_read_by_dnode(zv->zv_dn,