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/net/9p/trans_virtio.c b/net/9p/trans_virtio.c
index 9bf0b73..53c139d 100644
--- a/net/9p/trans_virtio.c
+++ b/net/9p/trans_virtio.c
@@ -200,7 +200,7 @@
req->status = REQ_STATUS_SENT;
- if (chan->vq->vq_ops->add_buf(chan->vq, chan->sg, out, in, req->tc)) {
+ if (chan->vq->vq_ops->add_buf(chan->vq, chan->sg, out, in, req->tc) < 0) {
P9_DPRINTK(P9_DEBUG_TRANS,
"9p debug: virtio rpc add_buf returned failure");
return -EIO;