# Local filesystem mounting			-*- shell-script -*-

#
# This script overrides local_mount_root() in /scripts/local
# and mounts root as a read-only filesystem with a temporary (rw)
# overlay filesystem.
#

. /scripts/local

local_mount_root()
{
	echo 'using startos initramfs module'

	local_top
	local_device_setup "${ROOT}" "root file system"
	ROOT="${DEV}"

	# Get the root filesystem type if not set
	if [ -z "${ROOTFSTYPE}" ]; then
		FSTYPE=$(get_fstype "${ROOT}")
	else
		FSTYPE=${ROOTFSTYPE}
	fi

	local_premount

	# CHANGES TO THE ORIGINAL FUNCTION BEGIN HERE
	# N.B. this code still lacks error checking

	modprobe ${FSTYPE}
	checkfs ${ROOT} root "${FSTYPE}"

	echo 'mounting startos'
	mkdir /startos

	ROOTFLAGS="$(echo "${ROOTFLAGS}" | sed 's/subvol=\(next\|current\)//' | sed 's/^-o *$//')"

	if [ "${FSTYPE}" != "unknown" ]; then
		mount -t ${FSTYPE} ${ROOTFLAGS} ${ROOT} /startos
	else
		mount ${ROOTFLAGS} ${ROOT} /startos
	fi

	if [ -d /startos/images ]; then
		if [ -h /startos/config/current.rootfs ] && [ -e /startos/config/current.rootfs ]; then
			image=$(readlink -f /startos/config/current.rootfs)
		else
			image="$(ls -t1 /startos/images/*.rootfs | head -n1)"
		fi
		if ! [ -f "$image" ]; then
			>&2 echo "image $image not available to boot"
			exit 1
		fi
	else
		if [ -f /startos/config/upgrade ] && [ -d /startos/next ]; then
			oldroot=/startos/next
		elif [ -d /startos/current ]; then
			oldroot=/startos/current
		elif [ -d /startos/prev ]; then
			oldroot=/startos/prev
		else
			>&2 echo no StartOS filesystem found
			exit 1
		fi

		mkdir -p /startos/config/overlay/etc
		mv $oldroot/etc/fstab /startos/config/overlay/etc/fstab
		mv $oldroot/etc/machine-id /startos/config/overlay/etc/machine-id
		mv $oldroot/etc/ssh /startos/config/overlay/etc/ssh

		mkdir -p /startos/images
		mv $oldroot /startos/images/legacy.rootfs

		rm -rf /startos/next /startos/current /startos/prev

		ln -rsf /startos/images/old.squashfs /startos/config/current.rootfs
		image=$(readlink -f /startos/config/current.rootfs)
	fi

	mkdir /lower /upper

	if [ -d "$image" ]; then
		mount -r --bind $image /lower
	elif [ -f "$image" ]; then
		modprobe loop
		modprobe squashfs
		mount -r $image /lower
	else
		>&2 echo "not a regular file or directory: $image"
		exit 1
	fi

	modprobe overlay || insmod "/lower/lib/modules/$(uname -r)/kernel/fs/overlayfs/overlay.ko"

	# Mount a tmpfs for the overlay in /upper
	mount -t tmpfs tmpfs /upper
	mkdir /upper/data /upper/work

	mkdir -p /startos/config/overlay

	# Mount the final overlay-root in $rootmnt
	mount -t overlay \
		-olowerdir=/startos/config/overlay:/lower,upperdir=/upper/data,workdir=/upper/work \
		overlay ${rootmnt}

	mkdir -m 750 -p ${rootmnt}/media/startos
	mkdir -p ${rootmnt}/media/startos/config
	mount --bind /startos/config ${rootmnt}/media/startos/config
	mkdir -p ${rootmnt}/media/startos/images
	mount --bind /startos/images ${rootmnt}/media/startos/images
	mkdir -p ${rootmnt}/media/startos/root
	mount -r --bind /startos ${rootmnt}/media/startos/root
	mkdir -p ${rootmnt}/media/startos/current
	mount -r --bind /lower ${rootmnt}/media/startos/current
}