mount

#!/bin/bash
ROOT=$1
IMAGE=
if [ -z "$ROOT" ]; then
echo "no root is specified"
exit 1
fi

function attach(){
	ROOT=$1
	if [ -f $ROOT ]; then
		IMAGE="$ROOT"
		if [ ! -S /var/lock/qemu-nbd-nbd0 ]; then
			qemu-nbd -c /dev/nbd0 $IMAGE
			mount /dev/nbd0p1 /mnt/gentoo
		fi
		ROOT=/mnt/gentoo
	fi
	VERB="mount -o bind"
	$VERB /dev/ $ROOT/dev     
	$VERB /proc/ $ROOT/proc
	$VERB /sys/ $ROOT/sys 
	$VERB /usr/portage/distfiles/ $ROOT/usr/portage/distfiles
	echo 'mounted'
}

function detach(){
#if mount | grep $ROOT/dev > /dev/null; then
	VERB="umount -l"
	echo 'umounting'
	$VERB $ROOT/dev
	$VERB $ROOT/proc
	$VERB $ROOT/sys
	$VERB $ROOT/usr/portage/distfiles
	if [ ! -z "$IMAGE" ]; then
		if [ -S /var/lock/qemu-nbd-nbd0 ]; then
			umount /mnt/gentoo
			qemu-nbd -d /dev/nbd0
		fi
	fi
}

attach $ROOT
echo "Entering chroot $ROOT"
chroot $ROOT
echo "Exiting chroot $ROOT"
detach $ROOT