# 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 embassy 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}"

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

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

	echo 'mounting embassyfs'

	mkdir /embassyfs

	mount --move ${rootmnt} /embassyfs

	if ! [ -d /embassyfs/current ] && [ -d /embassyfs/prev ]; then
		mv /embassyfs/prev /embassyfs/current
	fi

	if ! [ -d /embassyfs/current ]; then
		mkdir /embassyfs/current
		for FILE in $(ls /embassyfs); do
			if [ "$FILE" != current ]; then
				mv /embassyfs/$FILE /embassyfs/current/
			fi
		done
	fi

	mkdir -p /embassyfs/config

	if [ -f /embassyfs/config/upgrade ] && [ -d /embassyfs/next ]; then
		mv /embassyfs/current /embassyfs/prev
		mv /embassyfs/next /embassyfs/current
		rm /embassyfs/config/upgrade
	fi

	if ! [ -d /embassyfs/next ]; then
		if [ -d /embassyfs/prev ]; then
			mv /embassyfs/prev /embassyfs/next
		else
			mkdir /embassyfs/next
		fi
	fi

	mkdir /lower /upper

	mount -r --bind /embassyfs/current /lower

	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

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

	mkdir -p ${rootmnt}/media/embassy/config
	mount --bind /embassyfs/config ${rootmnt}/media/embassy/config
	mkdir -p ${rootmnt}/media/embassy/next
	mount --bind /embassyfs/next ${rootmnt}/media/embassy/next
	mkdir -p ${rootmnt}/media/embassy/embassyfs
	mount -r --bind /embassyfs ${rootmnt}/media/embassy/embassyfs
}