MNTK_UNMOUNTF
if (vp->v_mount->mnt_kern_flag & MNTK_UNMOUNTF) {
mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
mp->mnt_kern_flag |= MNTK_UNMOUNTF;
mp->mnt_kern_flag &= ~(MNTK_UNMOUNT | MNTK_UNMOUNTF);
if (info->vp->v_mount->mnt_kern_flag & MNTK_UNMOUNTF) {
if (nmp->nm_mountp->mnt_kern_flag & MNTK_UNMOUNTF)