resize_rootfs: Resize underlying luks device as well if possible

usr/bin/resize_rootfs

@@ -26,6 +26,13 @@ read rootdev _rootmnt _rootfs _opts unused <<EOF
 ${out}
 EOF
 
+# Check if rootfs is on a luks device and resize that if possible
+if [ -x /sbin/dmsetup ] && [ -x /sbin/cryptsetup ]; then
+	if [ -n "$(dmsetup status --target crypt ${rootdev})" ]; then
+		cryptsetup resize "${rootdev}"
+	fi
+fi
+
 set +e
 out=$(resize2fs "${rootdev}" 2>&1)
 set -e