'Prepares list of eligible files to be deleted from cache.'

def _shortlist_del_eligible_files(self, share, old_files):

    file_list = []
    (vserver, exp_volume) = self._get_vserver_and_exp_vol(volume_id=None, share=share)
    for old_file in old_files:
        path = ('/vol/%s/%s' % (exp_volume, old_file))
        u_bytes = self.zapi_client.get_file_usage(path, vserver)
        file_list.append((old_file, u_bytes))
    LOG.debug('Shortlisted    files    eligible    for    deletion:    %s', file_list)
    return file_list
