autopart: add package

The 'autopart' package is intended for devices with rather large
block device storage (ie. SATA or MMC).
It automatically allocates the free space on the block device used
for booting into an LVM2 physical volume.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

utils/autopart/Makefile

@@ -0,0 +1,40 @@
+include $(TOPDIR)/rules.mk
+
+PKG_NAME:=autopart
+PKG_VERSION:=0.1
+PKG_RELEASE:=$(AUTORELEASE)
+
+PKG_MAINTAINER:=Daniel Golle <daniel@makrotopia.org>
+PKG_LICENSE:=GPL-2.0-or-later
+
+include $(INCLUDE_DIR)/package.mk
+
+define Package/autopart
+  SECTION:=utils
+  CATEGORY:=Utilities
+  SUBMENU:=Disc
+  TITLE:=Automatically initialize LVM partition
+  DEPENDS:=+lvm2 +partx-utils +sfdisk
+  PKGARCH=all
+endef
+
+define Package/autopart/description
+ Automatically allocate the GPT partition for LVM and initialize it
+ on first boot.
+endef
+
+define Build/Prepare
+endef
+
+define Build/Configure
+endef
+
+define Build/Compile
+endef
+
+define Package/autopart/install
+	$(INSTALL_DIR) $(1)/etc/uci-defaults
+	$(INSTALL_BIN) ./files/autopart $(1)/etc/uci-defaults/30-autopart
+endef
+
+$(eval $(call BuildPackage,autopart))

utils/autopart/files/autopart

@@ -0,0 +1,77 @@
+#!/bin/sh
+
+. /lib/functions.sh
+. /lib/upgrade/common.sh
+
+OWRT_VOLUMES=owrt-volumes
+
+part_fixup() {
+	echo "write" | sfdisk --force -q -w never $1
+}
+
+get_free_area() {
+	local found=
+	sfdisk -q -F "$1" 2>/dev/null | while read start end sectors size; do
+		case $start in
+		*"Unpartitioned"* | *"Units:"* | *"Sector"* | *"Start"* )
+			continue
+			;;
+		[0-9]*)
+			case "$size" in
+				*"M")
+					[ "${size%%M}" -lt 100 ] && continue
+					;;
+				*"G" | *"T")
+					;;
+				*"k" | *"b")
+					continue
+					;;
+			esac
+			[ "$found" ] || echo "start=$start, size=$((end - start))"
+			found=1
+			;;
+		esac
+	done
+}
+
+create_lvm_part() {
+	local disk=$1
+	local freepart
+
+	freepart="$(get_free_area $disk)"
+	if [ "$freepart" ]; then
+		echo "$freepart, type=lvm, name=$OWRT_VOLUMES" | sfdisk --force -w never -a $disk
+		partx -a $disk 1>/dev/null 2>/dev/null || true
+		return 0
+	else
+		return 1
+	fi
+}
+
+lvm_init() {
+	lvm pvcreate -f $1
+	lvm vgcreate "$2" $1
+	lvm vgs
+}
+
+autopart_init() {
+	local diskdev
+	local lvmpart
+	local diskserial
+
+	export_bootdevice && export_partdevice diskdev 0
+
+	[ "$diskdev" ] || return
+
+	[ -e "/sys/class/block/$diskdev/device/serial" ] && diskserial=$(cat /sys/class/block/$diskdev/device/serial)
+
+	part_fixup /dev/$diskdev
+	create_lvm_part /dev/$diskdev || return
+	lvmpart=$(get_partition_by_name $diskdev $OWRT_VOLUMES)
+
+	[ "$lvmpart" ] || return
+	lvm_init /dev/$lvmpart "${OWRT_VOLUMES}${diskserial}"
+}
+
+autopart_init
+exit 0