SD_FAILFAST
if ((un->un_resvd_status & SD_FAILFAST) != 0) {
un->un_resvd_status |= SD_FAILFAST;
un->un_resvd_status &= ~SD_FAILFAST;
if ((un->un_resvd_status & SD_FAILFAST) == 0) {
((un->un_resvd_status & SD_FAILFAST) == 0)) {
if ((un->un_resvd_status & SD_FAILFAST) &&