[PATCH net-next 6/8] virtio_net: auto release xdp shinfo

[Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>]

virtnet_build_xdp_buff_mrg() and virtnet_xdp_handler() auto
release xdp shinfo then the caller no need to careful the xdp shinfo.

Signed-off-by: Xuan Zhuo <xuanzhuo@xxxxxxxxxxxxxxxxx>
---
 drivers/net/virtio_net.c | 29 +++++++++++++++++------------
 1 file changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index a3f2bcb3db27..136131a7868a 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -833,14 +833,14 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
 		stats->xdp_tx++;
 		xdpf = xdp_convert_buff_to_frame(xdp);
 		if (unlikely(!xdpf))
-			return VIRTNET_XDP_RES_DROP;
+			goto drop;
 
 		err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
 		if (unlikely(!err)) {
 			xdp_return_frame_rx_napi(xdpf);
 		} else if (unlikely(err < 0)) {
 			trace_xdp_exception(dev, xdp_prog, act);
-			return VIRTNET_XDP_RES_DROP;
+			goto drop;
 		}
 
 		*xdp_xmit |= VIRTIO_XDP_TX;
@@ -850,7 +850,7 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
 		stats->xdp_redirects++;
 		err = xdp_do_redirect(dev, xdp, xdp_prog);
 		if (err)
-			return VIRTNET_XDP_RES_DROP;
+			goto drop;
 
 		*xdp_xmit |= VIRTIO_XDP_REDIR;
 		return VIRTNET_XDP_RES_CONSUMED;
@@ -862,8 +862,12 @@ static int virtnet_xdp_handler(struct bpf_prog *xdp_prog, struct xdp_buff *xdp,
 		trace_xdp_exception(dev, xdp_prog, act);
 		fallthrough;
 	case XDP_DROP:
-		return VIRTNET_XDP_RES_DROP;
+		goto drop;
 	}
+
+drop:
+	put_xdp_frags(xdp);
+	return VIRTNET_XDP_RES_DROP;
 }
 
 static unsigned int virtnet_get_headroom(struct virtnet_info *vi)
@@ -1199,7 +1203,7 @@ static int virtnet_build_xdp_buff_mrg(struct net_device *dev,
 				 dev->name, *num_buf,
 				 virtio16_to_cpu(vi->vdev, hdr->num_buffers));
 			dev->stats.rx_length_errors++;
-			return -EINVAL;
+			goto err;
 		}
 
 		stats->bytes += len;
@@ -1218,7 +1222,7 @@ static int virtnet_build_xdp_buff_mrg(struct net_device *dev,
 			pr_debug("%s: rx error: len %u exceeds truesize %lu\n",
 				 dev->name, len, (unsigned long)(truesize - room));
 			dev->stats.rx_length_errors++;
-			return -EINVAL;
+			goto err;
 		}
 
 		frag = &shinfo->frags[shinfo->nr_frags++];
@@ -1233,6 +1237,10 @@ static int virtnet_build_xdp_buff_mrg(struct net_device *dev,
 
 	*xdp_frags_truesize = xdp_frags_truesz;
 	return 0;
+
+err:
+	put_xdp_frags(xdp);
+	return -EINVAL;
 }
 
 static void *mergeable_xdp_prepare(struct virtnet_info *vi,
@@ -1361,7 +1369,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 		err = virtnet_build_xdp_buff_mrg(dev, vi, rq, &xdp, data, len, frame_sz,
 						 &num_buf, &xdp_frags_truesz, stats);
 		if (unlikely(err))
-			goto err_xdp_frags;
+			goto err_xdp;
 
 		act = virtnet_xdp_handler(xdp_prog, &xdp, dev, xdp_xmit, stats);
 
@@ -1369,7 +1377,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 		case VIRTNET_XDP_RES_PASS:
 			head_skb = build_skb_from_xdp_buff(dev, vi, &xdp, xdp_frags_truesz);
 			if (unlikely(!head_skb))
-				goto err_xdp_frags;
+				goto err_xdp;
 
 			rcu_read_unlock();
 			return head_skb;
@@ -1379,11 +1387,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 			goto xdp_xmit;
 
 		case VIRTNET_XDP_RES_DROP:
-			goto err_xdp_frags;
+			goto err_xdp;
 		}
-err_xdp_frags:
-		put_xdp_frags(&xdp);
-		goto err_xdp;
 	}
 	rcu_read_unlock();
 
-- 
2.32.0.3.g01195cf9f