Subject: [PATCH 32/43] virtio-net: correctly transmit XDP buff after linearizing

From: Jason Wang <[email-masked]>
Date: Tue, 22 May 2018 11:44:29 +0800

[ Upstream commit 5d458a13dd59d04b4d6658a6d5b94d42732b15ae ]

We should not go for the error path after successfully transmitting a
XDP buffer after linearizing. Since the error path may try to pop and
drop next packet and increase the drop counters. Fixing this by simply
drop the refcnt of original page and go for xmit path.

Fixes: 72979a6c3590 ("virtio_net: xdp, add slowpath case for non contiguous buffers")
Cc: John Fastabend <[email-masked]>
Acked-by: Michael S. Tsirkin <[email-masked]>
Signed-off-by: Jason Wang <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 drivers/net/virtio_net.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 16b0c7db431b..8db684c70162 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -775,7 +775,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 			}
 			*xdp_xmit = true;
 			if (unlikely(xdp_page != page))
-				goto err_xdp;
+				put_page(page);
 			rcu_read_unlock();
 			goto xdp_xmit;
 		case XDP_REDIRECT:
-- 
2.17.1