MNTK_QUICKHALT
if (halting && (mp->mnt_kern_flag & MNTK_QUICKHALT)) {
mp->mnt_kern_flag |= MNTK_QUICKHALT; /* no teardown needed on halt */
mp->mnt_kern_flag |= MNTK_QUICKHALT; /* no teardown needed on halt */
mp->mnt_kern_flag |= MNTK_QUICKHALT; /* no teardown needed on halt */