UDF_FID_SIZE
if (ds->off + UDF_FID_SIZE > ds->size ||
ds->off + letoh16(fid->l_iu) + fid->l_fi + UDF_FID_SIZE > ds->size){
if (frag_size < UDF_FID_SIZE)
UDF_FID_SIZE - frag_size);
total_fid_size = UDF_FID_SIZE + letoh16(fid->l_iu) + fid->l_fi;
total_fid_size = letoh16(fid->l_iu) + fid->l_fi + UDF_FID_SIZE;