[PATCH net-next] hyperv: Move state setting for link query

[Haiyang Zhang]

> -----Original Message-----
> From: Jason Wang [mailto:jasowang at redhat.com]
> Sent: Monday, March 3, 2014 10:10 PM
> To: Haiyang Zhang; davem at davemloft.net; netdev at vger.kernel.org
> Cc: KY Srinivasan; olaf at aepfle.de; linux-kernel at vger.kernel.org; driverdev-
> devel at linuxdriverproject.org
> Subject: Re: [PATCH net-next] hyperv: Move state setting for link query
> 
> On 03/04/2014 07:54 AM, Haiyang Zhang wrote:
> > It moves the state setting for query into rndis_filter_receive_response().
> > All callbacks including query-complete and status-callback are
> > synchronized by channel->inbound_lock. This prevents pentential race
> between them.
> 
> This still looks racy to me. The problem is workqueue is not synchronized with
> those here.
> 
> Consider the following case in netvsc_link_change():
> 
>     if (rdev->link_state) {
>     ... receive interrupt ...
>     rndis_filter_receice_response() which changes rdev->link_state
>     ...
>         netif_carrier_off()
>     }
> 
> And also it need to schedule a work otherwise the link status is out of sync.

I will update this patch to schedule a work by the end of probe function.

Thanks,
- Haiyang