[PATCH] Drivers: hv: vmbus: fix error return code in vmbus_connect()

[KY Srinivasan]

> -----Original Message-----
> From: Wei Yongjun [mailto:weiyj.lk at gmail.com]
> Sent: Wednesday, September 11, 2013 5:26 PM
> To: KY Srinivasan
> Cc: Haiyang Zhang; yongjun_wei at trendmicro.com.cn;
> devel at linuxdriverproject.org; linux-kernel at vger.kernel.org
> Subject: Re: [PATCH] Drivers: hv: vmbus: fix error return code in
> vmbus_connect()
> 
> On 09/12/2013 04:03 AM, KY Srinivasan wrote:
> >
> >> -----Original Message-----
> >> From: Wei Yongjun [mailto:weiyj.lk at gmail.com]
> >> Sent: Wednesday, September 11, 2013 4:20 AM
> >> To: KY Srinivasan; Haiyang Zhang
> >> Cc: yongjun_wei at trendmicro.com.cn; devel at linuxdriverproject.org; linux-
> >> kernel at vger.kernel.org
> >> Subject: [PATCH] Drivers: hv: vmbus: fix error return code in vmbus_connect()
> >>
> >> From: Wei Yongjun <yongjun_wei at trendmicro.com.cn>
> >>
> >> Fix to return -EINVAL in the version check error handling
> >> case instead of 0, as done elsewhere in this function.
> > The return will not be zero in this case. If you look at the function
> > vmbus_negotiate_version(), in case the host refuses the version, the
> > return value will be set to -ECONNREFUSED
> 
> look at the code:
> 
>  196         do {
>  197                 ret = vmbus_negotiate_version(msginfo, version);
>  198                 if (ret)
>  199                         goto cleanup;
>  200
>  201                 if (vmbus_connection.conn_state == CONNECTED)
>  202                         break;
>  203
>  204                 version = vmbus_get_next_version(version);
>  205         } while (version != VERSION_INVAL);
>  206
>  207         if (version == VERSION_INVAL)
>  208                 goto cleanup;
> 
> if function vmbus_negotiate_version() return error, the code
> will goto cleanup.
> 
> If 'version == VERSION_INVAL' is true, I think we tried all
> of the VERSION_WS2008/VERSION_WIN7/VERSION_WIN8, but still
> can not get the connection.

When you try a given version, vmbus_negotiate_version() returns an error code
if the host does not support that version. Hence, in this code you will not be able to
run on anything prior to ws2012. I have already sent in a patch to fix that - if we timeout
only then we jump to cleanup. In any event, if we tried all versions and none was acceptable
to the host, we would return the value from vmbus_negotiate_version().

K. Y
> 
> 
> 
>