#!/bin/bash
set +e
DESTDIR="$1"
if [[ $UID -ne 0 ]] ; then
    echo "You must be root!"
    exit 1
fi
if [[ -b "$1" ]] ; then
    DESTDIR=$(mktemp -d)
    mount "$1" "$DESTDIR"
fi
shift
if [[ "$DESTDIR" == "" ||  ! -f "$DESTDIR/etc/os-release" ]] ; then
    echo "Target filesystem is invalid: $DESTDIR"
    exit 1
fi
mount --bind /dev "$DESTDIR/dev"
mount --bind /run  "$DESTDIR/run"
mount --bind /media  "$DESTDIR/media"
mount -t devpts devpts "$DESTDIR/dev/pts"
mount -t sysfs sysfs "$DESTDIR/sys"
mount -t proc proc "$DESTDIR/proc"
mount -t tmpfs tmpfs  "$DESTDIR/dev/shm"
mount --bind /tmp "$DESTDIR/tmp"
#if [[ -d /sys/firmware/efi/ ]] ; then
#    mount -t efivarfs efivarfs  "$DESTDIR/sys/firmware/efi/efivars"
#fi
#cat /etc/resolv.conf > $DESTDIR/etc/resolv.conf
#SHELL=/bin/bash unshare --fork --pid chroot "$DESTDIR" "$@"
#exit
# 下面的因为有问题，不使用
#if [[ -d /sys/firmware/efi/ ]] ; then
#    while umount "$DESTDIR/sys/firmware/efi/efivars" 2>/dev/null ; do : ;done
#fi
#for dir in dev/pts dev/shm dev sys proc run media ; do
#    while umount "$DESTDIR/$dir" 2>/dev/null; do : ;done
#done
#umount -lf "$DESTDIR"  2>/dev/null