Re: [Qemu-devel] [PATCH] qga-win: VSS: Handle VSS_E_PROVIDER_ALREADY_REGISTERED error

[Sameeh Jubran]

On Wed, Nov 29, 2017 at 1:17 AM, Michael Roth <address@hidden>
wrote:

> Quoting Sameeh Jubran (2017-11-22 05:30:14)
> > From: Sameeh Jubran <address@hidden>
> >
> > We can get VSS_E_PROVIDER_ALREADY_REGISTERED error if for some
> > reason the uninstall of qemu-ga didn't complete successfully.
> > In this case we can try to unregister the component service
> > and attempt to register it again.
> >
> > Signed-off-by: Sameeh Jubran <address@hidden>
>
> This might be reasonable either way, but I'm concerned with why the
> uninstall of the VSS provider is failing in the first place. Are
> you seeing this issue with uninstall->install of the MSI package?
>
> If so there's 2 cases I've noticed with that:
>
> a) the VSS_E_PROVIDER_ALREADY_REGISTERED issue when you do the install,
>    which currently requires you to run qemu-ga -s vss-uninstall separately
>    and then retrying. This one would get fixed with this patch
> b) the DllRegisterServer call just hangs indefinitely. This one wouldn't
>    get fixed with this patch and it seems to be the one I see more often on
>    Windows 7
>
> I don't yet know the root cause, but both issues seem to have gone away for
> me with this patch:
>
> diff --git a/qga/installer/qemu-ga.wxs b/qga/installer/qemu-ga.wxs
> index 5af11627f8..c76b7a39c5 100644
> --- a/qga/installer/qemu-ga.wxs
> +++ b/qga/installer/qemu-ga.wxs
> @@ -81,7 +81,7 @@
>                Arguments="-d"
>                >
>              </ServiceInstall>
> -            <ServiceControl Id="StartService" Start="install" Stop="both"
> Remove="uninstall" Name="QEMU-GA" Wait="no" />
> +            <ServiceControl Id="StartService" Start="install" Stop="both"
> Remove="uninstall" Name="QEMU-GA" Wait="yes" />
>            </Component>
>            <?ifdef var.InstallVss?>
>            <Component Id="qga_vss_dll" Guid="{CB19C453-FABB-4BB1-
> ABAB-6B74F687BFBB}">
>
> Does this help in your case as well?
>
Yes it does, thanks!

>
> > ---
> >  qga/vss-win32/install.cpp | 9 +++++++++
> >  1 file changed, 9 insertions(+)
> >
> > diff --git a/qga/vss-win32/install.cpp b/qga/vss-win32/install.cpp
> > index 51838eeb26..e7bc5e1d9d 100644
> > --- a/qga/vss-win32/install.cpp
> > +++ b/qga/vss-win32/install.cpp
> > @@ -443,6 +443,15 @@ STDAPI DllRegisterServer(void)
> >                                       VSS_PROV_SOFTWARE,
> >                                       const_cast<WCHAR*>(QGA_
> PROVIDER_VERSION),
> >                                       g_gProviderVersion);
> > +    if (hr == (long int) VSS_E_PROVIDER_ALREADY_REGISTERED) {
> > +        DllUnregisterServer();
> > +        hr = pVssAdmin->RegisterProvider(g_gProviderId,
> CLSID_QGAVSSProvider,
> > +                                     const_cast<WCHAR *
> >(QGA_PROVIDER_LNAME),
> > +                                     VSS_PROV_SOFTWARE,
> > +                                     const_cast<WCHAR *
> >(QGA_PROVIDER_VERSION),
> > +                                     g_gProviderVersion);
> > +    }
> > +
> >      if (FAILED(hr)) {
> >          errmsg_dialog(hr, "RegisterProvider failed");
> >      }
> > --
> > 2.13.6
> >
>
>


-- 
Respectfully,
*Sameeh Jubran*
*Linkedin <https://il.linkedin.com/pub/sameeh-jubran/87/747/a8a>*
*Software Engineer @ Daynix <http://www.daynix.com>.*