#!/bin/bash

# ******************************************
# Resize Linux ext4 partition to fill sdcard
# ******************************************

if [ "$(id -u)" != "0" ]; then
	echo "Script must be run as root !"
	exit 0
fi

sdcard="/dev/mmcblk0"
echo ""

fdisk -l $sdcard | grep $sdcard
echo ""

_btrfs=`mount | grep -o btrfs`

fat=`fdisk -l $sdcard | grep FAT16`
if [ "${fat}" = "" ]; then
  partno="1"
else
  partno="2"
fi
sdcard_part=`fdisk -l $sdcard | grep Linux | awk '{print $1}'`
sdcard_sect=`fdisk -l $sdcard | grep "Disk $sdcard" | awk '{print $7}'`
if [ "${sdcard_sect}" = "" ]; then
    sdcard_sect=`fdisk -l $sdcard | grep total | awk '{print $8}'`
fi
sdcard_end=$(expr $sdcard_sect - 1024)

part_start=`fdisk -l $sdcard | grep Linux | awk '{print $2}'`
part_end=`fdisk -l $sdcard | grep Linux | awk '{print $3}'`

echo "  Max block: $sdcard_end"
echo "   Part end: $part_end"
echo " Part start: $part_start"
echo "   Part num: $partno"
if [ ! "${_btrfs}" = "" ]; then
    echo " btrfs part: yes"
    _resize="btrfs filesystem resize max / &&"
else
    _resize="resize2fs ${sdcard_part} &&"
fi
echo ""
if [ $part_end -ge $sdcard_end ]; then
    echo "Partition allready maximum size !"
    rm /usr/local/bin/fs_resize_warning > /dev/null 2>&1
    exit 0
fi

echo -n "WARNING: Do you want to resize \"$sdcard_part\" (y/N)?  "
read -n 1 ANSWER
if [ ! "${ANSWER}" = "y" ] ; then
    echo ""
    echo "Canceled.."
    exit 0
fi
echo ""

# RESIZE PARTITION

if [ "${partno}" = "1" ] ; then
  echo -e "p\nd\nn\np\n$partno\n$part_start\n$sdcard_end\np\nw" | fdisk ${sdcard} > /dev/null 2>&1
else
  echo -e "p\nd\n$partno\nn\np\n$partno\n$part_start\n$sdcard_end\np\nw" | fdisk ${sdcard} > /dev/null 2>&1
fi

echo "PARTITION RESIZED."

#/etc/init.d/resize2fs_once
cat > /etc/init.d/resize2fs_once << _EOF_
#!/bin/sh
### BEGIN INIT INFO
# Provides: resize2fs_once
# Required-Start: \$local_fs \$remote_fs \$network \$syslog
# Required-Stop:
# Default-Start: 2 3 4 5 S
# Default-Stop:
# Short-Description: Resize the root filesystem to fill partition
# Description:
### END INIT INFO
. /lib/lsb/init-functions
case "\$1" in
start)
log_daemon_msg "Starting resize2fs_once" &&
$_resize
rm /etc/init.d/resize2fs_once &&
update-rc.d resize2fs_once remove &&
log_end_msg \$?
;;
*)
echo "Usage: \$0 start" >&2
exit 3
;;
esac
_EOF_

chmod +x /etc/init.d/resize2fs_once > /dev/null 2>&1

update-rc.d resize2fs_once defaults > /dev/null 2>&1
if [ $? -ne 0 ]; then
    echo "ERROR, run: sudo /etc/int.d/resize2fs_once start  AFTER REBOOT!"
    exit 0
fi

REBOOT=1
echo "*********************************************"
echo "Rootfs Extended. Please REBOOT to take effect"
echo "*********************************************"
echo ""

rm /usr/local/bin/fs_resize_warning > /dev/null 2>&1