From mboxrd@z Thu Jan  1 00:00:00 1970
From: Rusty Russell <rusty@rustcorp.com.au>
Subject: Re: [PATCH RFC] virtio_net: fix refill related races
Date: Thu, 08 Dec 2011 15:07:29 +1030
Message-ID: <8739cvisqe.fsf@rustcorp.com.au>
References: <20111207152120.GA23417@redhat.com>
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To: Amit Shah <amit.shah@redhat.com>
Cc: netdev@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org, "Michael S. Tsirkin" <mst@redhat.com>
List-Id: virtualization@lists.linuxfoundation.org

On Wed, 7 Dec 2011 17:21:22 +0200, "Michael S. Tsirkin" <mst@redhat.com> wrote:
> Fix theoretical races related to refill work:
> 1. After napi is disabled by ndo_stop, refill work
>    can run and re-enable it.
> 2. Refill can reschedule itself, if this happens
>    it can run after cancel_delayed_work_sync,
>    and will access device after it is destroyed.
> 
> As a solution, add flags to track napi state and
> to disable refill, and toggle them on start, stop
> and remove; check these flags on refill.

Why isn't a "dont-readd" flag sufficient?

Cheers,
Rusty.