QCOW2_INPLACE
l2tab &= ~QCOW2_INPLACE;
*inplace = !!(cluster & QCOW2_INPLACE);
cluster &= ~QCOW2_INPLACE;
if (l2tab == 0 || (l2tab & QCOW2_INPLACE) == 0) {
orig = l2tab & ~QCOW2_INPLACE;
disk->l1[l1off] = l2tab | QCOW2_INPLACE;
l2tab &= ~QCOW2_INPLACE;
buf = htobe64(cluster | QCOW2_INPLACE);
off &= ~QCOW2_INPLACE;