repartition: Update partitions in EFI load options

When the ESP partition ID is regenerated, any EFI load options
referencing the old partition ID become invalid. While shim's fallback
will generate a new load option on the next boot, a downstream patch is
needed to make sure the invalid option is removed.

Rather than having shim cleanup this situation, update the load options
at the time the partition UUID is changed. Since both the old and new
UUIDs are known, eos-update-efi-uuid can update only the affected load
options without changing or deleting load options that aren't affected
by the UUID change.

Note that this runs eos-update-efi-uuid in verbose mode, which is pretty
noisy. When we have confidence this is doing the right thing, we can
drop the -v option.

https://phabricator.endlessm.com/T31604

dracut/repartition/endless-repartition.sh

@@ -103,6 +103,12 @@ else
   marker=$(sfdisk --force --part-attrs $root_disk $partno)
 fi
 
+# Read the ESP's current UUID so we can update load options below.
+orig_esp_uuid=
+if [ "$pt_label" = "gpt" ]; then
+  orig_esp_uuid=$(sfdisk --force --part-uuid $root_disk 1)
+fi
+
 case "$marker" in
   *GUID:55* | dd)
     ;;
@@ -199,6 +205,15 @@ udevadm settle
 
 [ "$ret" != "0" ] && exit 0
 
+# Read the ESP's new UUID and update any invalidated load options.
+new_esp_uuid=
+if [ "$pt_label" = "gpt" ]; then
+  new_esp_uuid=$(sfdisk --force --part-uuid $root_disk 1)
+fi
+if [ -d /sys/firmware/efi ] && [ -n "$orig_esp_uuid" ] && [ -n "$new_esp_uuid" ]; then
+  eos-update-efi-uuid -v "$orig_esp_uuid" "$new_esp_uuid"
+fi
+
 # Loop devices need a prod
 if [ -n "$using_loop" ]; then
   partx --update --verbose $root_disk
@@ -214,8 +229,7 @@ udevadm settle
 # If we're an sd-booting image we need to fix-up the copy of the
 # ESP UUID that sd-boot gave us so systemd mounts the ESP
 esp_var=$(echo /sys/firmware/efi/efivars/LoaderDevicePartUUID*)
-if [ -f "${esp_var}" ]; then
-  new_esp_uuid=$(sfdisk $root_disk --part-uuid 1)
+if [ -f "${esp_var}" ] && [ -n "${new_esp_uuid}" ]; then
   #We need to start with 0x06 0x00 0x00 0x00 and end with 0x00 0x00
   #iconv will add the extra 0s
   # Shell gotcha - \06\00 works... until ${new_esp_uuid} starts with a decimal digit.

dracut/repartition/module-setup.sh

@@ -10,6 +10,7 @@ depends() {
 }
 
 install() {
+  dracut_install eos-update-efi-uuid
   dracut_install sfdisk
   dracut_install blockdev
   dracut_install readlink