UDF_ISO_VRS_SIZE
max_sectors = UDF_ISO_VRS_SIZE / 2048;
ret = pread(dev_fd, buffer, UDF_ISO_VRS_SIZE, rpos);
if (ok && ((uint32_t) ret != UDF_ISO_VRS_SIZE)) {
buffer = malloc(UDF_ISO_VRS_SIZE, M_TEMP, M_WAITOK);
max_sectors = UDF_ISO_VRS_SIZE / sector_size;
memset(buffer, 0, UDF_ISO_VRS_SIZE);