virtio: make add_buf return capacity remaining
This API change means that virtio_net can tell how much capacity
remains for buffers. It's necessarily fuzzy, since
VIRTIO_RING_F_INDIRECT_DESC means we can fit any number of descriptors
in one, *if* we can kmalloc.
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Dinesh Subhraveti <dineshs@us.ibm.com>
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 32266fb..fbf04a5 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -320,7 +320,7 @@
skb_queue_head(&vi->recv, skb);
err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, num, skb);
- if (err) {
+ if (err < 0) {
skb_unlink(skb, &vi->recv);
trim_pages(vi, skb);
kfree_skb(skb);
@@ -373,7 +373,7 @@
skb_queue_head(&vi->recv, skb);
err = vi->rvq->vq_ops->add_buf(vi->rvq, sg, 0, 1, skb);
- if (err) {
+ if (err < 0) {
skb_unlink(skb, &vi->recv);
kfree_skb(skb);
break;
@@ -527,7 +527,7 @@
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 && !vi->free_in_tasklet)
+ if (err >= 0 && !vi->free_in_tasklet)
mod_timer(&vi->xmit_free_timer, jiffies + (HZ/10));
return err;
@@ -538,7 +538,7 @@
struct virtnet_info *vi = (void *)data;
netif_tx_lock_bh(vi->dev);
- if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) == 0) {
+ if (vi->last_xmit_skb && xmit_skb(vi, vi->last_xmit_skb) >= 0) {
vi->svq->vq_ops->kick(vi->svq);
vi->last_xmit_skb = NULL;
}
@@ -557,7 +557,7 @@
/* If we has a buffer left over from last time, send it now. */
if (unlikely(vi->last_xmit_skb) &&
- xmit_skb(vi, vi->last_xmit_skb) != 0)
+ xmit_skb(vi, vi->last_xmit_skb) < 0)
goto stop_queue;
vi->last_xmit_skb = NULL;
@@ -565,7 +565,7 @@
/* Put new one in send queue and do transmit */
if (likely(skb)) {
__skb_queue_head(&vi->send, skb);
- if (xmit_skb(vi, skb) != 0) {
+ if (xmit_skb(vi, skb) < 0) {
vi->last_xmit_skb = skb;
skb = NULL;
goto stop_queue;
@@ -668,7 +668,7 @@
sg_set_buf(&sg[i + 1], sg_virt(s), s->length);
sg_set_buf(&sg[out + in - 1], &status, sizeof(status));
- BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi));
+ BUG_ON(vi->cvq->vq_ops->add_buf(vi->cvq, sg, out, in, vi) < 0);
vi->cvq->vq_ops->kick(vi->cvq);