virtio_net: skb_orphan() and nf_reset() in xmit path.
The complex transmit free logic was introduced to avoid hangs on
removing the ip_conntrack module and also because drivers aren't
generally supposed to keep stale skbs for unbounded times.
After some debate, it was decided that while doing skb_orphan()
generally is a rat's nest, we can do it in this driver. Following
patches take advantage of this.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 5c498d2..dc4c687 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -528,8 +528,12 @@
num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
- if (err >= 0 && !vi->free_in_tasklet)
+ if (err >= 0 && !vi->free_in_tasklet) {
+ /* Don't wait up for transmitted skbs to be freed. */
+ skb_orphan(skb);
+ nf_reset(skb);
mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
+ }
return err;
}