[libvirt] [PATCH] vz: fixed race in vzDomainAttach/DettachDevice

[Mikhail Feoktistov]

On 18.08.2016 14:57, Olga Krishtal wrote:
> While dettaching/attaching device in OpenStack, nova
> calls vzDomainDettachDevice twice, because the update of the internal
> configuration of the ct comes a bit latter than the update event.
> As the result, we suffer from the second call to dettach the same device.
>
> Signed-off-by: Olga Krishtal <okrishtal at virtuozzo.com>
> ---
>   src/vz/vz_sdk.c | 12 ++++++++++++
>   1 file changed, 12 insertions(+)
>
> diff --git a/src/vz/vz_sdk.c b/src/vz/vz_sdk.c
> index 68dd5b5..9fbf968 100644
> --- a/src/vz/vz_sdk.c
> +++ b/src/vz/vz_sdk.c
> @@ -3594,6 +3594,12 @@ prlsdkAttachDevice(vzDriverPtr driver,
>           return -1;
>       }
>   
> +    if (prlsdkUpdateDomain(driver, dom) < 0) {
> +        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> +                        _("Failed to save new config"));
> +        return -1;
> +    }
> +
I suggest to call prlsdkUpdateDomain from vzDomainDetachDeviceFlags and
vzDomainAttachDeviceFlags.

Example for vzDomainAttachDeviceFlags():

     if (vzEnsureDomainExists(dom) < 0)
         goto cleanup;

     if (prlsdkAttachDevice(driver, dom, dev) < 0)
         goto cleanup;

+    if (prlsdkUpdateDomain(driver, dom) < 0)
  +       goto cleanup;

     ret = 0;
  cleanup:
     virDomainDeviceDefFree(dev);
     if (job)
         vzDomainObjEndJob(dom);


>       job = PrlVm_CommitEx(privdom->sdkdom, PVCF_DETACH_HDD_BUNDLE);
>       if (PRL_FAILED(waitDomainJob(job, dom)))
>           return -1;
> @@ -3661,6 +3667,12 @@ prlsdkDetachDevice(vzDriverPtr driver,
>           goto cleanup;
>       }
>   
> +    if (prlsdkUpdateDomain(driver, dom) < 0) {
> +        virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
> +                        _("Failed to save new config"));
> +        goto cleanup;
> +    }
> +
>       job = PrlVm_CommitEx(privdom->sdkdom, PVCF_DETACH_HDD_BUNDLE);
>       if (PRL_FAILED(waitDomainJob(job, dom)))
>           goto cleanup;