On Mon, Oct 14, 2013 at 05:56:35PM +0800, Jason Wang wrote:
> We used to schedule the refill work unconditionally after changing the
> number of queues. This may lead an issue if the device is not
> up. Since we only try to cancel the work in ndo_stop(), this may cause
> the refill work still work after removing the device. Fix this by only
> schedule the work when device is up.
> 
> The bug were introduce by commit 9b9cd8024a2882e896c65222aa421d461354e3f2.
> (virtio-net: fix the race between channels setting and refill)
> 
> Cc: Rusty Russell <ru...@rustcorp.com.au>
> Cc: Michael S. Tsirkin <m...@redhat.com>
> Signed-off-by: Jason Wang <jasow...@redhat.com>

It bothers me that we look at the flag without any
locks here.
I think we'll need to take the rtnl lock at least
on restore.

> ---
> The patch were need for 3.10 and above.
> ---
>  drivers/net/virtio_net.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index c4bc1cc..92f0096 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -938,7 +938,9 @@ static int virtnet_set_queues(struct virtnet_info *vi, 
> u16 queue_pairs)
>               return -EINVAL;
>       } else {
>               vi->curr_queue_pairs = queue_pairs;
> -             schedule_delayed_work(&vi->refill, 0);
> +             /* virtnet_open() will refill when device is going to up. */
> +             if (dev->flags & IFF_UP)
> +                     schedule_delayed_work(&vi->refill, 0);
>       }
>  
>       return 0;
> -- 
> 1.8.1.2
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