#!/bin/sh

# Check status to see if we are mounted
STATUS=`cat /tmp/overlay/status`
if [ $STATUS -eq 0 ]; then
	echo "Overlayfs not mounted"
	exit 0
fi

# Check if any programs are using overlay files
for dir in /overlay/*; do
	# Check overlay mount points
	if [ -d "${dir}" ]; then
		USINGDIR=`fuser -m ${dir}`
		if [ $? -eq 0 ]; then
			for pid in ${USINGDIR}; do
				if [ -z "$TEXTUSINGFS" ]; then
					TEXTUSINGFS="`ps | grep "$pid" | grep -v grep | awk '{print $5}'`"
				else
					TEXTUSINGFS="$TEXTUSINGFS, `ps | grep "$pid" | grep -v grep | awk '{print $5}'`"
				fi
			done
			PIDUSINGFS="$PIDUSINGFS $USINGDIR"
		fi
	fi
	# Check root mount points
	CHK_ROOT_DIR=`echo ${dir} | sed 's/.*\//\//'`
	if [ -d "${CHK_ROOT_DIR}" ]; then
		USINGDIR=`fuser -m ${CHK_ROOT_DIR}`
		if [ $? -eq 0 ]; then
			for pid in ${USINGDIR}; do
				if [ -z "$TEXTUSINGFS" ]; then
					TEXTUSINGFS="`ps | grep "$pid" | grep -v grep | awk '{print $5}'`"
				else
					TEXTUSINGFS="$TEXTUSINGFS, `ps | grep "$pid" | grep -v grep | awk '{print $5}'`"
				fi
			done
			PIDUSINGFS="$PIDUSINGFS $USINGDIR"
		fi
	fi
done
if [ -n "$PIDUSINGFS" ]; then
	echo "The following programs are using overlayfs:"
	echo "$TEXTUSINGFS"
	read -p "Ok to kill these programs? (Y/n): " CHOICE
	if [ "$CHOICE" == "Y" ] || [ "$CHOICE" == "y" ]; then
		echo "Killing all programs using overlayfs..."
		kill -9 ${PIDUSINGFS}
		if [ $? -ne 0 ]; then
			echo "Problem killing programs, exiting..."
			sleep 2
			exit 1
		fi
	else
		echo "OverlayFS STILL mounted, exiting..."
		sleep 2
		exit 1
	fi
fi

# Unmount overlay dirs in rootfs
for dir in /overlay/*; do
	if [ -d "${dir}" ]; then
		CHK_ROOT_DIR=`echo $dir | sed 's/.*\///'`
		echo "Unmounting overlayfs dir: $CHK_ROOT_DIR"
		umount /${CHK_ROOT_DIR}
	fi
done

# Unmount ext2 image from overlay
echo "Unmounting /overlay dir"
umount /overlay

# Destroy ext2 loop device
LOOPDEV=`cat /tmp/overlay/loopdevice`
echo "Removing loop device $LOOPDEV"
losetup -d ${LOOPDEV}

# Write status
echo 0 > /tmp/overlay/status
echo "" > /tmp/overlay/loopdevice
exit 0