#!/bin/sh
PATH=/bin:/usr/bin:/sbin:/usr/sbin
SYSTEM_MNT=/opt
SYS_BLK_DIR=/sys/class/block
MODULES_MNT=/usr/lib/modules

mkdir -p /dev /sys /proc
mount -o nosuid,strictatime,mode=755 -t devtmpfs devtmpfs /dev
mount -o nosuid,noexec,nodev -t sysfs sysfs /sys
mount -o nosuid,noexec,nodev -t proc proc /proc

#Find devices with label or partlabel
ROOTFS=`/sbin/blkid -L rootfs`
if [ x$ROOTFS = "x" ]
then
    ROOTFS=`/sbin/blkid -t PARTLABEL=rootfs -o device`
fi

MODULES=`/sbin/blkid -L modules`
if [ x$MODULES = "x" ]
then
    MODULES=`/sbin/blkid -t PARTLABEL=module -o device`
fi

DATAFS=`/sbin/blkid -L system-data`
if [ x$DATAFS = "x" ]
then
    DATAFS=`/sbin/blkid -t PARTLABEL=system-data -o device`
fi

#Fsck, resize, mount devices
if [ x$ROOTFS = "x" ]
then
    echo "Warning : There is no rootfs partition."
else
    /usr/bin/mount -o remount,ro $ROOTFS
fi

if [ x$MODULES = "x" ]
then
    echo "Warning : There is no modules partition."
else
    /sbin/resize2fs -f $MODULES
    /sbin/fsck -y $MODULES
    /bin/mount $MODULES $MODULES_MNT
fi

if [ x$DATAFS = "x" ]
then
    echo "Warning : There is no system-data partition."
else
    /usr/bin/mount | grep "$DATAFS " > /dev/null

    if [ $? = "0" ]
    then
        /usr/bin/umount -l "$DATAFS"
    fi
    /sbin/fsck -y $DATAFS
    /sbin/resize2fs -f $DATAFS
    /usr/bin/mount $DATAFS $SYSTEM_MNT
fi

mkdir -p /opt/.overlayfs_upper
mkdir -p /opt/.overlayfs_work
mount -t overlay overlay -o ro,lowerdir=/,upperdir=/opt/.overlayfs_upper,workdir=/opt/.overlayfs_work /.overlayfs_merged
mount --make-private /
mount -M /opt  /.overlayfs_merged/opt
mount -M /sys  /.overlayfs_merged/sys
mount -M /proc /.overlayfs_merged/proc
mount -M /dev  /.overlayfs_merged/dev
mount -M /usr/lib/modules  /.overlayfs_merged/usr/lib/modules
/sbin/pivot_root /.overlayfs_merged /.overlayfs_merged/.rootfs_old
mount --make-shared /

INIT=/usr/lib/systemd/systemd
if [ $$ = 1 ]; then
        [ "$INIT" ] && exec "$INIT" "$@"
fi

echo "======================================================================"
echo "[/sbin/init] WARNING!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!"
echo "This Message should never be printed. ($INIT execution failure?)"
echo "======================================================================"
exec /bin/sh