Re: [PATCH container v9 05/10] allow pending mount point changes if storage is gone

[Fiona Ebner <f.ebner@proxmox.com>]

Am 29.06.26 um 4:06 PM schrieb Michael Köppl:
> Previously, applying a pending removal of an unused volume whose
> backing storage was already removed would fail with "unable to apply
> pending change unusedN", leaving a dangling reference that could never
> be cleaned up.
> 
> Guard the volume deletion in vmconfig_apply_pending and
> vmconfig_hotplug_pending with a check to ensure that the storage
> exists. If the storage is gone, drop the entry with a warning instead of
> trying to free a volume that no longer exists.
> 
> Apply the same check when a detached mount point is turned into an
> 'unusedN' entry, so a volume on a removed storage is not re-added as a
> dangling unused entry, matching VM behavior.
> 
> Signed-off-by: Michael Köppl <m.koeppl@proxmox.com>
> ---
>  src/PVE/LXC/Config.pm | 43 ++++++++++++++++++++++++++++++++++---------
>  1 file changed, 34 insertions(+), 9 deletions(-)
> 
> diff --git a/src/PVE/LXC/Config.pm b/src/PVE/LXC/Config.pm
> index c8098538..a3dd3a1a 100644
> --- a/src/PVE/LXC/Config.pm
> +++ b/src/PVE/LXC/Config.pm

Missing import for PVE::RESTEnvironment.

> @@ -1663,8 +1663,14 @@ sub vmconfig_hotplug_pending {
>                  # pass
>              } elsif ($opt =~ m/^unused(\d+)$/) {
>                  my $volid = $class->parse_volume($opt, $conf->{$opt})->{volume};
> -                PVE::LXC::delete_mountpoint_volume($storecfg, $vmid, $volid)
> -                    if !$class->is_volume_in_use($conf, $volid, 1, 1);
> +                my ($storeid) = PVE::Storage::parse_volume_id($volid);
> +                if (PVE::Storage::storage_config($storecfg, $storeid, 1)) {
> +                    PVE::LXC::delete_mountpoint_volume($storecfg, $vmid, $volid)
> +                        if !$class->is_volume_in_use($conf, $volid, 1, 1);
> +                } else {
> +                    PVE::RESTEnvironment::log_warn(
> +                        "storage '$storeid' no longer exists, unused volume '$volid' will be removed");
> +                }

Style nit: should we add a helper for readability/to reduce bloat and
repetition?

I'm thinking about something like

with_checked_volid($opt, $conf->{opt}, sub {
    my ($volid) = @_;
    PVE::LXC::delete_mountpoint_volume($storecfg, $vmid, $volid)
        if !$class->is_volume_in_use($conf, $volid, 1, 1);
});

where the helper does the parsing of the volume and volid, logs the
warning and returns if the storage does not exist and calls the
passed-in sub if it does exist.