On Thu, Jan 26, 2023 at 09:32:12AM +0100, Friedrich Weber wrote:
> The new `overrule-shutdown` parameter is boolean and defaults to 0. If
> it is 1, all active `vzshutdown` tasks by the current user for the same
> CT are aborted before attempting to stop the CT.
> 
> Passing `overrule-shutdown=1` is forbidden for HA resources.
> 
> Signed-off-by: Friedrich Weber <[email protected]>
> ---
>  src/PVE/API2/LXC/Status.pm | 16 ++++++++++++++++
>  1 file changed, 16 insertions(+)
> 
> diff --git a/src/PVE/API2/LXC/Status.pm b/src/PVE/API2/LXC/Status.pm
> index f7e3128..d1d67f4 100644
> --- a/src/PVE/API2/LXC/Status.pm
> +++ b/src/PVE/API2/LXC/Status.pm
> @@ -221,6 +221,12 @@ __PACKAGE__->register_method({
>           node => get_standard_option('pve-node'),
>           vmid => get_standard_option('pve-vmid', { completion => 
> \&PVE::LXC::complete_ctid_running }),
>           skiplock => get_standard_option('skiplock'),
> +         'overrule-shutdown' => {
> +             description => "Abort any active 'vzshutdown' task by the 
> current user for this CT before stopping",
> +             optional => 1,
> +             type => 'boolean',
> +             default => 0,
> +         }
>       },
>      },
>      returns => {
> @@ -238,10 +244,15 @@ __PACKAGE__->register_method({
>       raise_param_exc({ skiplock => "Only root may use this option." })
>           if $skiplock && $authuser ne 'root@pam';
>  
> +     my $overrule_shutdown = extract_param($param, 'overrule-shutdown');
> +
>       die "CT $vmid not running\n" if !PVE::LXC::check_running($vmid);
>  
>       if (PVE::HA::Config::vm_is_ha_managed($vmid) && $rpcenv->{type} ne 
> 'ha') {
>  
> +         raise_param_exc({ 'overrule-shutdown' => "Not applicable for HA 
> resources." })
> +             if $overrule_shutdown;
> +
>           my $hacmd = sub {
>               my $upid = shift;
>  
> @@ -272,6 +283,11 @@ __PACKAGE__->register_method({
>               return $rpcenv->fork_worker('vzstop', $vmid, $authuser, 
> $realcmd);
>           };
>  
> +         if ($overrule_shutdown) {
> +             my $overruled_tasks = 
> PVE::GuestHelpers::overrule_tasks('vzshutdown', $authuser, $vmid);
> +             syslog('info', "overruled vzshutdown tasks: " . join(", ", 
> $overruled_tasks->@*) . "\n");
> +         };
> +

^ So this part is fine (mostly¹)

>           return PVE::LXC::Config->lock_config($vmid, $lockcmd);

^ Here we lock first, then fork the worker, then do `vm_stop` with the
config lock inherited.

This means that creating multiple shutdown tasks before using one with
override=true could cause the override task to cancel the *first* ongoing
shutdown task, then move on to the `lock_config` call - in the meantime
a second shutdown task acquires this very lock and performs another
long-running shutdown, causing the `override` parameter to be
ineffective.

We should switch the ordering here: first fork the worker, then lock.
(¹ And your new chunk would go into the worker as well)

Unless I'm missing something, but AFAICT the current ordering there is
rather ... bad :-)


_______________________________________________
pve-devel mailing list
[email protected]
https://lists.proxmox.com/cgi-bin/mailman/listinfo/pve-devel

Reply via email to