{ The purpose of this request is to fetch PVAs of pages that could not be
{ written to disk because of disk parity errors or device malfunctions.
{
{   MMP$FETCH_PVA_UNWRITTEN_PAGES (SEGMENT_P, STARTING_PVA, PVA_LIST,
{               LIST_OVERFLOW, STATUS);
{
{
{   SEGMENT_P: (input) This parameter is used to identify the segment. The
{           segment is specified by the segment number of this parameter.
{   STARTING_PVA: (input) This parameter is used to specify the starting
{           address for scanning for unwritten pages. If the value of
{           this parameter is NIL the scan starts with the beginning of
{           the segment. If the value is not NIL the scan starts with the
{           first page following the page specified by this parameter.
{   PVA_LIST: (output) This parameter contains the array of PVAs that could
{           not be written to disk. If the size of the array is larger than
{           the number of unwritten PVAs, the unused entries will be set
{           to NIL. If the size of the array is less than the number of
{           unwritten pages, the array will contain PVAs of unwritten pages
{           starting with the first unwritten page following the page
{           specified by the <starting_pva> and continuing with as many
{           consecutive unwritten pages as will fit in the array.
{    LIST_OVERFLOW: (output) This parameter specifies a boolean variable
{           which indicates if more unwritten pages exist than could
{           be returned in the <pva_list>.
{    STATUS: (status) This parameter specifies request status.
{           The possible error codes are:
{                 mme$invalid_pva
{                 mme$ref_to_unrecovered_file
{                 mme$no_matching_offset
{                 mme$stack_overflow_on_push
{

