[PATCH pve-manager 1/1] pve8to9: warn about an unmounted ESP

[Samuel Rufinatscha <s.rufinatscha@proxmox.com>]

A UEFI system may fail to boot after upgrading from PVE 8 to PVE 9
if its EFI System Partition (ESP) was not mounted at /boot/efi during
the GRUB update.

Warn if /boot/efi is not mounted on a UEFI system. Ask the user to
mount it before upgrading and to make sure it mounts at boot. Skip
systems managed by proxmox-boot-tool, which mounts the ESPs itself.

Link: https://bugzilla.proxmox.com/show_bug.cgi?id=7958
Signed-off-by: Samuel Rufinatscha <s.rufinatscha@proxmox.com>
---
 PVE/CLI/pve8to9.pm | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/PVE/CLI/pve8to9.pm b/PVE/CLI/pve8to9.pm
index cf0f2f69..0c15cda9 100644
--- a/PVE/CLI/pve8to9.pm
+++ b/PVE/CLI/pve8to9.pm
@@ -21,6 +21,7 @@ use PVE::Jobs;
 use PVE::JSONSchema;
 use PVE::Network;
 use PVE::NodeConfig;
+use PVE::ProcFSTools;
 use PVE::RPCEnvironment;
 use PVE::Storage;
 use PVE::Storage::Plugin;
@@ -1624,6 +1625,15 @@ sub check_bootloader {
             }
         }
     } else {
+        if (!PVE::ProcFSTools::is_mounted('/boot/efi')) {
+            log_warn(
+                "System booted in UEFI mode but the EFI System Partition (ESP) is not mounted at"
+                    . " /boot/efi. Mount it at /boot/efi before upgrading and ensure it mounts"
+                    . " automatically at boot (e.g. via /etc/fstab), otherwise GRUB updates may leave"
+                    . " the system unbootable."
+            );
+            $boot_ok = 0;
+        }
         if (!-f "/usr/share/doc/grub-efi-amd64/changelog.Debian.gz") {
             log_warn("System booted in uefi mode but grub-efi-amd64 meta-package not installed,"
                 . " new grub versions will not be installed to /boot/efi! Install grub-efi-amd64."
-- 
2.47.3