Re: [PATCH qemu-server 2/3] fix #7743: api: disk import: avoid locking twice when importing from OVA or same VM

[Dominik Csapak <d.csapak@proxmox.com>]

On 6/29/26 2:46 PM, Fiona Ebner wrote:
> When import_from_volid->() is called, the VM configuration of the
> destination VM is already locked. In case the source volume belongs to
> the same VM, there would be a second attempt to lock the config. In
> particular, this also happens when importing from OVA, because the
> source image is first extracted and belongs to the same VM.

the explanation makes sense, and it fixes the issue (works now for POST 
& PUT) but i'm somehow missing the connection here?

AFAIU the reason is that in the async case we lock the config
then fork and then lock again (which does not work)
but in the sync case we lock and later lock again in the
same process so the cached lock in PVE::Tools succeeds?

IMHO the code and rationale is fine here, but i would find it good
to get the actual reason why it failed + why this change
impacts the POST vs PUT case.

Otherwise from the commit message consider this

Reviewed-by: Dominik Csapak <d.csapak@proxmox.com>

> 
> Signed-off-by: Fiona Ebner <f.ebner@proxmox.com>
> ---
>   src/PVE/API2/Qemu.pm | 11 +++++++----
>   1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/src/PVE/API2/Qemu.pm b/src/PVE/API2/Qemu.pm
> index e575d36b..b2a15d96 100644
> --- a/src/PVE/API2/Qemu.pm
> +++ b/src/PVE/API2/Qemu.pm
> @@ -390,10 +390,13 @@ my $import_from_volid = sub {
>       };
>   
>       my $cloned;
> -    if ($running) {
> -        $cloned = PVE::QemuConfig->lock_config_full($src_vmid, 30, $clonefn);
> -    } elsif ($src_vmid) {
> -        $cloned = PVE::QemuConfig->lock_config_shared($src_vmid, 30, $clonefn);
> +    # The config is already locked for the destination.
> +    if ($src_vmid && $src_vmid != $dest_info->{vmid}) {
> +        if ($running) {
> +            $cloned = PVE::QemuConfig->lock_config_full($src_vmid, 30, $clonefn);
> +        } else {
> +            $cloned = PVE::QemuConfig->lock_config_shared($src_vmid, 30, $clonefn);
> +        }
>       } else {
>           $cloned = $clonefn->();
>       }