#!/bin/sh
#
# Copyright 2026 Colin Percival
#
# SPDX-License-Identifier: BSD-2-Clause
#
# PROVIDE: growfs_postboot
# KEYWORD: nostart

# Triggered by /etc/devd/growfs_postboot.conf: When a disk grows, enlarge the
# final partition to fill the available space (if the disk is partitioned) or
# enlarge the UFS filesystem or ZFS zpool (if in use for one of those).  Note
# that in the common case of "a disk is partitioned and one of the partitions
# contains a filesystem" this script is invoked twice -- the repartitioning
# done on the first call generates a new devd event which triggers the second
# invocation.
#
# Enable by setting
# growfs_postboot_enable=YES
# in /etc/rc.conf.  Note that on systems with growfs_enable=YES, it will often
# be necessary to set growfs_swap_size=0 in order to disable swap creation;
# otherwise the "final partition" is the swap space, not the filesystem and
# growing the disk will not cause the most likely desired results.

. /etc/rc.subr

name="growfs_postboot"
desc="automatically grow file systems during runtime"
rcvar="growfs_postboot_enable"
start_cmd="growfs_postboot_start"

disktype() {
	sysctl -n kern.geom.conftxt | awk -v dev="$1" '
	BEGIN {
		partitioned=0
		indev=0
	}
	{
		if (dev == $3) {
			indev=1
			devlevel=$1
		} else if (devlevel >= $1) {
			indev=0
		} else if (indev == 1) {
			if ($2 == "PART") {
				partitioned=1
			}
		}
	}
	END {
		if (partitioned == 1) {
			print "partitioned"
		} else {
			print "unpartitioned"
		}
	}'
}

growpart() {
	# Run 'gpart recover' if GPT
	if gpart list "$1" | grep -qi 'scheme: GPT'; then
		gpart recover "$1" || true
	fi

	# Find the index of the last partition; note that we need to compare
	# the starting sectors in case partitions are not numbered sensibly.
	idx=$(gpart backup "$1" | awk '
		NR == 1 { next }
		$3 + 0 > start { start = $3 + 0; idx = $1 }
		END { print idx }')
	if [ -z "$idx" ]; then
		echo "Error finding final partition of $1"
		return 1
	fi

	# Expand that partition
	gpart resize -i "$idx" "$1"
}

growfilesystem() {
	case $(fstyp -u "/dev/$1" 2>/dev/null) in
	ufs)	growfs -y "/dev/$1"
		;;
	zfs)	zpool list -H -o name |
		    while read -r pool; do
			zpool list -vH -o name "$pool" |
			    grep "^[[:space:]]" |
			    while read -r dev; do
				if [ "$dev" = "$1" ]; then
					zpool online -e "$pool" "$1"
				fi
			    done
		    done
		;;
	"")	# Nothing to grow here
		;;
	*)	echo "Don't know how to grow filesystem on /dev/$1"
		;;
	esac
}

growfs_postboot_start() {
	# Run either growpart or growfilesystem depending on whether this is
	# something which is partitioned or not.
	case $(disktype "$1") in
	partitioned)
		growpart "$1"
		;;
	unpartitioned)
		growfilesystem "$1"
		;;
	esac
}

load_rc_config $name
run_rc_command "$@"