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

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 <redacted>

Krzysiek