#!/bin/sh
set -e

#
# List the soft prerequisites here.  This is a space separated list of
# names, of scripts that are in the same directory as this one, that
# must be run before this one can be.
#
PREREQS=""
case $1 in
    prereqs) echo "$PREREQS"; exit 0;;
esac

. /scripts/functions

# Given the root partition, get the underlying device and partition number
rootpart=$(realpath $ROOT)
rootpart_nr=$(blkid -sPART_ENTRY_NUMBER -o value -p $rootpart)
rootdev="/dev/$(lsblk -no pkname "$rootpart")"

# Check if there's free space on the device (note: we align the first
# partition at 4MB, so there's always at least 3MB free)
free_space="$(sfdisk -qF $rootdev | tail -n1 | grep -v [^0-9]3M)"
if test -z "$free_space"; then
    # Great, we already resized; nothing left to do!
    exit 0
fi

log_begin_msg "$0 resizing $ROOT"

# Unmount for safety
umount "${rootmnt}"

# Expand the partition size to fill the entire device
sfdisk -f $rootdev -N $rootpart_nr <<EOF
,+
EOF

wait_for_udev 5

# Now resize the filesystem
partprobe $rootdev
resize2fs $rootpart

# Remount root
if ! mount -r ${FSTYPE:+-t "${FSTYPE}"} ${ROOTFLAGS} "${ROOT}" "${rootmnt?}"; then
    panic "Failed to mount ${ROOT} as root file system."
fi

log_end_msg