@@ -1175,6 +1175,9 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
if (!xdp_page)
goto err_xdp;
offset = VIRTIO_XDP_HEADROOM;
+
+ put_page(page);
+ page = xdp_page;
} else if (unlikely(headroom < virtnet_get_headroom(vi))) {
xdp_room = SKB_DATA_ALIGN(VIRTIO_XDP_HEADROOM +
sizeof(struct skb_shared_info));
@@ -1189,6 +1192,9 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
page_address(page) + offset, len);
frame_sz = PAGE_SIZE;
offset = VIRTIO_XDP_HEADROOM;
+
+ put_page(page);
+ page = xdp_page;
} else {
xdp_page = page;
}
@@ -1208,8 +1214,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
if (unlikely(!head_skb))
goto err_xdp_frags;
- if (unlikely(xdp_page != page))
- put_page(page);
rcu_read_unlock();
return head_skb;
case XDP_TX:
@@ -1227,8 +1231,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
goto err_xdp_frags;
}
*xdp_xmit |= VIRTIO_XDP_TX;
- if (unlikely(xdp_page != page))
- put_page(page);
rcu_read_unlock();
goto xdp_xmit;
case XDP_REDIRECT:
@@ -1237,8 +1239,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
if (err)
goto err_xdp_frags;
*xdp_xmit |= VIRTIO_XDP_REDIR;
- if (unlikely(xdp_page != page))
- put_page(page);
rcu_read_unlock();
goto xdp_xmit;
default:
@@ -1251,9 +1251,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
goto err_xdp_frags;
}
err_xdp_frags:
- if (unlikely(xdp_page != page))
- __free_pages(xdp_page, 0);
-
if (xdp_buff_has_frags(&xdp)) {
shinfo = xdp_get_shared_info_from_buff(&xdp);
for (i = 0; i < shinfo->nr_frags; i++) {
In the xdp implementation of virtio-net mergeable, it always checks whether two page is used and a page is selected to release. This is complicated for the processing of action, and be careful. In the entire process, we have such principles: * If xdp_page is used (PASS, TX, Redirect), then we release the old page. * If it is a drop case, we will release two. The old page obtained from buf is release inside err_xdp, and xdp_page needs be relased by us. But in fact, when we allocate a new page, we can release the old page immediately. Then just one is using, we just need to release the new page for drop case. On the drop path, err_xdp will release the variable "page", so we only need to let "page" point to the new xdp_page in advance. Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com> --- drivers/net/virtio_net.c | 15 ++++++--------- 1 file changed, 6 insertions(+), 9 deletions(-)