Subject: [PATCH] openvswitch: orphan frags on local receive

From: Qin Chuanyu <[email-masked]>
Date: Mon, 24 Feb 2014 21:15:12 +0800

with vhost tx zero_copy, guest nic might get hang when host reserving
skb in socket queue delivered by guest, the case has been solved in
tun, it also been needed by openvswitch. This could easily happened
when a LAST_ACK state tcp occuring between guest and host.

Signed-off-by: Chuanyu Qin <[email-masked]>
---
  net/openvswitch/vport-internal_dev.c |    3 +++
  net/openvswitch/vport.c              |    1 +
  2 files changed, 4 insertions(+), 0 deletions(-)

diff --git a/net/openvswitch/vport-internal_dev.c 
b/net/openvswitch/vport-internal_dev.c
index 729c687..adb25e2 100644
--- a/net/openvswitch/vport-internal_dev.c
+++ b/net/openvswitch/vport-internal_dev.c
@@ -212,6 +212,9 @@ static int internal_dev_recv(struct vport *vport, 
struct sk_buff *skb)
  	struct net_device *netdev = netdev_vport_priv(vport)->dev;
  	int len;

+	if (unlikely(skb_orphan_frags(skb, GFP_ATOMIC)))
+		return -NET_RX_DROP;
+
  	len = skb->len;

  	skb_dst_drop(skb);
diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
index 208dd9a..04172d6 100644
--- a/net/openvswitch/vport.c
+++ b/net/openvswitch/vport.c
@@ -383,6 +383,7 @@ int ovs_vport_send(struct vport *vport, struct 
sk_buff *skb)
  		u64_stats_update_end(&stats->syncp);
  	} else if (sent < 0) {
  		ovs_vport_record_error(vport, VPORT_E_TX_ERROR);
+		skb_tx_error(skb);
  		kfree_skb(skb);
  	} else
  		ovs_vport_record_error(vport, VPORT_E_TX_DROPPED);
-- 
1.7.3.1.msysgit.0