[PATCH] expand-on-first-boot: Switch from resize2fs to systemd-growfs

[Tobias Schmidl <tobiasschmidl@siemens.com>]

We want to be more versatile in our approach of resizing the root
partition. Therefore we switch from resize2fs to systemd-growfs (on
systems with systemd-growfs).

This allows for ext4, btrfs, xfs, and dm-crypt partitions to be resized.

Signed-off-by: Tobias Schmidl <tobiasschmidl@siemens.com>
---
 .../files/expand-last-partition.sh                | 15 +++++++++++++--
 1 file changed, 13 insertions(+), 2 deletions(-)

diff --git a/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh b/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
index bb371e9..f0dc66d 100755
--- a/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
+++ b/meta/recipes-support/expand-on-first-boot/files/expand-last-partition.sh
@@ -3,7 +3,7 @@
 # Resize last partition to full medium size
 #
 # This software is a part of ISAR.
-# Copyright (c) Siemens AG, 2018
+# Copyright (c) Siemens AG, 2018-2022
 #
 # SPDX-License-Identifier: MIT
 
@@ -45,4 +45,15 @@ partx -u "${LAST_PART}"
 # when using systemd mount units.
 export EXT2FS_NO_MTAB_OK=1
 
-resize2fs "${LAST_PART}"
+# If we are on a systemd system, we call systemd-growfs, otherwise resize2fs
+if [ -x /lib/systemd/systemd-growfs ]; then
+	MOUNT_POINT=$(findmnt "${LAST_PART}" -o target -n)
+	if [ -z "$MOUNT_POINT" ]; then
+		echo "Cannot find mount point for ${LAST_PART}"
+		exit 1
+	fi
+	mount "${MOUNT_POINT}" || true
+	/lib/systemd/systemd-growfs "${MOUNT_POINT}"
+else
+	resize2fs "${LAST_PART}"
+fi
-- 
2.36.1