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authorRusty Russell <rusty@rustcorp.com.au>2008-02-04 23:50:07 -0500
committerRusty Russell <rusty@rustcorp.com.au>2008-02-04 23:50:08 +1100
commit2cb9c6bafc58cf4066cb15f0ac6989a1015a02cc (patch)
tree5a81ecc2d80724054d2b8f5679a58e1d42e9322a /drivers
parenta48bd8f67003c342e147309a331f656a5e75a5e4 (diff)
virtio: free transmit skbs when notified, not on next xmit.
This fixes a potential dangling xmit problem. We also suppress refill interrupts until we need them. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/virtio_net.c25
1 files changed, 19 insertions, 6 deletions
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index bd4d26a36ea..a61c176607f 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -56,11 +56,13 @@ static inline void vnet_hdr_to_sg(struct scatterlist *sg, struct sk_buff *skb)
sg_init_one(sg, skb_vnet_hdr(skb), sizeof(struct virtio_net_hdr));
}
-static void skb_xmit_done(struct virtqueue *rvq)
+static void skb_xmit_done(struct virtqueue *svq)
{
- struct virtnet_info *vi = rvq->vdev->priv;
+ struct virtnet_info *vi = svq->vdev->priv;
- /* In case we were waiting for output buffers. */
+ /* Suppress further interrupts. */
+ svq->vq_ops->disable_cb(svq);
+ /* We were waiting for more output buffers. */
netif_wake_queue(vi->dev);
}
@@ -232,8 +234,6 @@ static int start_xmit(struct sk_buff *skb, struct net_device *dev)
pr_debug("%s: xmit %p %s\n", dev->name, skb, print_mac(mac, dest));
- free_old_xmit_skbs(vi);
-
/* Encode metadata header at front. */
hdr = skb_vnet_hdr(skb);
if (skb->ip_summed == CHECKSUM_PARTIAL) {
@@ -266,11 +266,24 @@ static int start_xmit(struct sk_buff *skb, struct net_device *dev)
vnet_hdr_to_sg(sg, skb);
num = skb_to_sgvec(skb, sg+1, 0, skb->len) + 1;
__skb_queue_head(&vi->send, skb);
+
+again:
+ /* Free up any pending old buffers before queueing new ones. */
+ free_old_xmit_skbs(vi);
err = vi->svq->vq_ops->add_buf(vi->svq, sg, num, 0, skb);
if (err) {
pr_debug("%s: virtio not prepared to send\n", dev->name);
- skb_unlink(skb, &vi->send);
netif_stop_queue(dev);
+
+ /* Activate callback for using skbs: if this fails it
+ * means some were used in the meantime. */
+ if (unlikely(!vi->svq->vq_ops->enable_cb(vi->svq))) {
+ printk("Unlikely: restart svq failed\n");
+ netif_start_queue(dev);
+ goto again;
+ }
+ __skb_unlink(skb, &vi->send);
+
return NETDEV_TX_BUSY;
}
vi->svq->vq_ops->kick(vi->svq);