Re: [PATCH v2 3/3] pppoatm: protect against freeing of vcc

From: Krzysztof Mazur
Date: Fri Nov 30 2012 - 12:00:03 EST


On Fri, Nov 30, 2012 at 04:23:46PM +0000, David Woodhouse wrote:
>
> +static void br2684_release_cb(struct atm_vcc *atmvcc)
> +{
> + struct br2684_vcc *brvcc = BR2684_VCC(atmvcc);
> +
> + /*
> + * A race with br2684_xmit_vcc() might cause a spurious wakeup just
> + * after that function *stops* the queue, and qspace might actually
> + * go negative before the queue stops again. We cope with that.
> + */

We cannot race with br2684_xmit_vcc() because both br2684_xmit_vcc()
and br2684_release_cb() are called with locked sk->sk_lock.slock.

> + if (atomic_read(&brvcc->qspace) > 0)
> + netif_wake_queue(brvcc->device);
> +
> + if (brvcc->old_release_cb)
> + brvcc->old_release_cb(atmvcc);
> +}

Except that comment, the patch looks good:

Acked-by: Krzysztof Mazur <krzysiek@xxxxxxxxxxxx>

Krzysiek
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