dprintf_dnode
dprintf_dnode(dn, "start=%llu end=%llu\n", start_blkid, end_blkid);
dprintf_dnode(dn, "blkid=%llu nblks=%llu txg=%llu\n",
dprintf_dnode(dn, "dn=%p dnp=%p used=%llu delta=%lld\n",