Make the datactl command more robust (#1059)

* Make the datactl command more robust

Validate target disk (partition) size to avoid a copy attempt which will
fail. If e2image operation fails, make sure the leftover copy is not
regonized as data partition.

* Fix hassos-data service device unit dependencies

buildroot-external/rootfs-overlay/usr/bin/datactl

@@ -9,6 +9,11 @@ set -e
 DATA_DEVICE_CHILD="$(findmnt --noheadings --output=source /mnt/data)"
 DATA_DEVICE_ROOT="/dev/$(lsblk -no pkname "${DATA_DEVICE_CHILD}")"
 
+if [ "${DATA_DEVICE_ROOT}" = "" ]; then
+    echo "[ERROR] Data disk device not found!"
+    exit 1
+fi
+
 # Move command
 if [ "${1}" = "move" ] && [ -e "${2}" ]; then
     NEW_DEVICE_ROOT="${2}"
@@ -39,8 +44,20 @@ if [ "${1}" = "move" ] && [ -e "${2}" ]; then
         -u "0:a52a4597-fa3a-4851-aefd-2fbe9f849079" \
         "${NEW_DEVICE_ROOT}"
 
+    # Since we create a new partition table etc. we are guaranteed the target
+    # partition is partition 1
+    NEW_DEVICE_PART_SIZE=$(cat "/sys/class/block/$(basename "${NEW_DEVICE_ROOT}")1/size")
+    OLD_DEVICE_PART_SIZE=$(cat "/sys/class/block/$(basename "${DATA_DEVICE_CHILD}")/size")
+
+    if [ "${NEW_DEVICE_PART_SIZE}" -lt "${OLD_DEVICE_PART_SIZE}" ]; then
+        echo "[INFO] Target device too small!"
+        sgdisk --zap-all "${NEW_DEVICE_ROOT}"
+        exit 1
+    fi
+
     touch "/mnt/overlay/move-data"
     cat << EOF
+
 Disk ${NEW_DEVICE_ROOT} has been prepared to be used as data drive and the data
 move has been scheduled for the next reboot. Please reboot the device now and
 make sure to leave the disk connected to the system from now on.

buildroot-external/rootfs-overlay/usr/lib/systemd/system/hassos-data.service

@@ -3,9 +3,9 @@ Description=Home Assistant OS data partition migration
 DefaultDependencies=no
 RefuseManualStart=true
 RefuseManualStop=true
-Requires=mnt-overlay.mount dev-disk-by\x2dlabel-hassos\x2ddata.device dev-disk-by\x2dpartlabel-hassos\x2ddata\x2dexternal.service
+Requires=mnt-overlay.mount dev-disk-by\x2dlabel-hassos\x2ddata.device dev-disk-by\x2dpartlabel-hassos\x2ddata\x2dexternal.device
 Wants=hassos-expand.service
-After=mnt-overlay.mount dev-disk-by\x2dlabel-hassos\x2ddata.device systemd-fsck@dev-disk-by\x2dlabel-hassos\x2ddata.service dev-disk-by\x2dpartlabel-hassos\x2ddata\x2dexternal.service
+After=mnt-overlay.mount dev-disk-by\x2dlabel-hassos\x2ddata.device systemd-fsck@dev-disk-by\x2dlabel-hassos\x2ddata.service dev-disk-by\x2dpartlabel-hassos\x2ddata\x2dexternal.device
 Before=hassos-expand.service
 ConditionPathExists=/mnt/overlay/move-data
 

buildroot-external/rootfs-overlay/usr/libexec/hassos-data

@@ -10,9 +10,18 @@ OLD_DEVICE_CHILD="$(readlink -f "/dev/disk/by-label/hassos-data")"
 # Rely on systemd-udev symlinks to find external data partition by partlabel
 NEW_DEVICE_CHILD="$(readlink -f "/dev/disk/by-partlabel/hassos-data-external")"
 
+NEW_DEVICE_PART_SIZE=$(cat "/sys/class/block/$(basename "${NEW_DEVICE_CHILD}")/size")
+OLD_DEVICE_PART_SIZE=$(cat "/sys/class/block/$(basename "${OLD_DEVICE_CHILD}")/size")
+if [ "${NEW_DEVICE_PART_SIZE}" -lt "${OLD_DEVICE_PART_SIZE}" ]; then
+    echo "[INFO] Target device too small!"
+    exit 1
+fi
+
 echo "[INFO] Moving data from ${OLD_DEVICE_CHILD} to ${NEW_DEVICE_CHILD}"
 if ! e2image -ra -p "${OLD_DEVICE_CHILD}" "${NEW_DEVICE_CHILD}"; then
     echo "[ERROR] Copying data partition to external device failed!"
+    # Rename partition to make sure HAOS does not try to mount a failed copy attempt.
+    e2label "${NEW_DEVICE_CHILD}" hassos-data-failed || true
     exit 1
 fi