On 2018年05月21日 22:59, Michael S. Tsirkin wrote:
On Mon, May 21, 2018 at 04:35:05PM +0800, Jason Wang wrote:If we successfully linearize the packets, num_buf were set to zero which was wrong since we now have only 1 buffer to be used for e.g in the error path of receive_mergeable(). Zero num_buf will lead the code try to pop the buffers of next packet and drop it. Fixing this by set num_buf to 1 if we successfully linearize the packet. Fixes: 4941d472bf95 ("virtio-net: do not reset during XDP set") Signed-off-by: Jason Wang <[email protected]> --- drivers/net/virtio_net.c | 1 + 1 file changed, 1 insertion(+) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 6260d65..165a922 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -722,6 +722,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, &len); if (!xdp_page) goto err_xdp; + num_buf = 1;So this is tweaked here for the benefit of err_skb below. That's confusing and we won't remember to change it if we change the error handling. How about fixing the error path? - while (--num_buf) { + while (num_buf-- > 1) { Seems more robust to me.
Looks good, will do this in V2. Thanks
offset = VIRTIO_XDP_HEADROOM; } else { xdp_page = page; -- 2.7.4
