factory-reset-lvm

#!/bin/sh
#
# Factory reset tool for LVM based Sailfish OS filesystems.
#
# Copyright (C) 2015 Jolla Ltd.
# Contact: Kalle Jokiniemi <kalle.jokiniemi@jolla.com>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; version 2
# of the License.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

# Parameters:
# $1 -> Root size in MB
# $2 -> Reserve space for later use in MB

ROOTDEV="/dev/sailfish/root"
HOMEDEV="/dev/sailfish/home"
NAME=$0

flash_script()
{
cat << 'EOF'
#!/bin/sh
for SCRIPT in /var/lib/platform-updates/* ; do
	if [ -x $SCRIPT ]; then
		echo "$SCRIPT ... "
		$SCRIPT && echo "OK" || echo "FAILED"
	fi
done
EOF
}

flash_firmwares()
{
	if test -z $1; then
		echo "$NAME: No mount point given" > /dev/kmsg
		exit 1
	fi
	mount -t tmpfs tmpfs $1/tmp
	mount -t devtmpfs devtmpfs $1/dev
	mount -t proc proc $1/proc
	flash_script > $1/tmp/flash-firmwares
	chmod 755 $1/tmp/flash-firmwares
	chroot $1 /tmp/flash-firmwares
	umount $1/tmp $1/dev $1/proc
}

if test -z $1 || ! test $1 -ge 0; then
	echo "$NAME: Please pass root size in MB as parameter!" > /dev/kmsg
	exit 1
fi

if test -z $2 || ! test $2 -ge 0; then
	echo "$NAME: Please pass reserve size in MB as parameter!" > /dev/kmsg
	exit 1
fi

ROOT_SIZE=$1
RESERVE_KB=$(expr $2 \* 1024)

echo "$NAME: Starting factory reset.." > /dev/kmsg

PHYSDEV=$(find-mmc-bypartlabel "sailfish")
if test $? != "0"; then
	echo "$NAME: Error: could not find sailfish partition" > /dev/kmsg
	exit 1
fi

FIMAGE_DEV_PATH=$(find-mmc-bypartlabel "fimage")
if test $? != "0"; then
	echo "$NAME: Error: could not find fimage partition" > /dev/kmsg
	exit 1
fi

echo "$NAME: fimage partition in $FIMAGE_DEV_PATH" > /dev/kmsg

FIMAGE_MOUNT=$(mktemp -d)
if ! mount "$FIMAGE_DEV_PATH" "$FIMAGE_MOUNT"; then
	echo "$NAME: Error, could not mount fimage for factory reset!" > /dev/kmsg
	rmdir $FIMAGE_MOUNT
	exit 1
fi

MOUNT_POINT=$(mktemp -d)

# Clean up old LVM if it happens to exist
lvm vgchange -a n
lvm vgremove -y sailfish
lvm pvremove -y $PHYSDEV

# Create the LVM setup
if ! lvm pvcreate $PHYSDEV; then
	echo "$NAME: Error, could create LVM physical device for $PHYSDEV" > /dev/kmsg
	exit 1
fi

# If the PV exists, creating VG should never fail
lvm vgcreate sailfish $PHYSDEV

# Checking for errors to maybe catch wrong root size parameter
if ! lvm lvcreate -L "$ROOT_SIZE"M --name root sailfish; then
	echo "$NAME: Error, could create root LV" > /dev/kmsg
	exit 1
fi


# Calculate home size
FREE_EXTENTS=$(lvm vgdisplay sailfish -c | cut -d ":" -f 16)
EXTENT_SIZE=$(lvm vgdisplay sailfish -c | cut -d ":" -f 13)
FREE_KB=$(expr $FREE_EXTENTS \* $EXTENT_SIZE)
HOME_SIZE=$(expr $FREE_KB - $RESERVE_KB)

# Check for too big reserve (not enough room left for home) case (1024kB * 64 = 64MB)
if test $HOME_SIZE -le 65536; then
	echo "$NAME: Error: too big reserve, not enough space for home" > /dev/kmsg
	exit 1
fi

# Create home LV
lvm lvcreate -L "$HOME_SIZE"K --name home sailfish

# Create filesystems
mkfs.ext4 $ROOTDEV
mkfs.ext4 $HOMEDEV

# Start restoring Sailfish OS from the factory images
mount $ROOTDEV $MOUNT_POINT
mkdir -p $MOUNT_POINT/home
mount $HOMEDEV $MOUNT_POINT/home
TEMPMOUNT=$(mktemp -d)
# Find the biggest versioned Sailfish folder and use that
SAILFISH_FIMAGE=$(ls -d $FIMAGE_MOUNT/Sailfish* | tail -1)

if test -z $SAILFISH_FIMAGE; then
	echo "$NAME: Error: Could not find a recovery image folder!" > /dev/kmsg
	exit 1
fi

if ! test -f $SAILFISH_FIMAGE/sailfish_root.squashfs.img; then
	echo "$NAME: Error: cannot find sailfish root recovery image!" > /dev/kmsg
	exit 1
fi

if ! test -f $SAILFISH_FIMAGE/sailfish_home.squashfs.img; then
	echo "$NAME: Error: cannot find sailfish home recovery image!" > /dev/kmsg
	exit 1
fi

mount -t squashfs -o loop $SAILFISH_FIMAGE/sailfish_root.squashfs.img $TEMPMOUNT
cp -a $TEMPMOUNT/* $MOUNT_POINT
sync
umount $TEMPMOUNT
mount -t squashfs -o loop $SAILFISH_FIMAGE/sailfish_home.squashfs.img $TEMPMOUNT
cp -a $TEMPMOUNT/* $MOUNT_POINT/home
sync
umount $TEMPMOUNT
rmdir $TEMPMOUNT

# Flash firmwares from the resetted root
flash_firmwares $MOUNT_POINT

# Clean up
umount $MOUNT_POINT/home
umount $MOUNT_POINT
rmdir $MOUNT_POINT

umount $FIMAGE_MOUNT
rmdir $FIMAGE_MOUNT