[PATCH] ovs: clear skb->tstamp in forwarding path

From: kaixi.fan <redacted>

fq qdisc requires tstamp to be cleared in the forwarding path. Now ovs
doesn't clear skb->tstamp. We encountered a problem with linux
version 5.4.56 and ovs version 2.14.1, and packets failed to
dequeue from qdisc when fq qdisc was attached to ovs port.

Signed-off-by: kaixi.fan <redacted>
Signed-off-by: xiexiaohui <redacted>
Reviewed-by: Cong Wang <redacted>
---
 net/openvswitch/vport.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
index 88deb5b41429..cf2ce5812489 100644
--- a/net/openvswitch/vport.c
+++ b/net/openvswitch/vport.c

@@ -507,6 +507,7 @@ void ovs_vport_send(struct vport *vport, struct sk_buff *skb, u8 mac_proto)
 	}
 
 	skb->dev = vport->dev;
+	skb->tstamp = 0;
 	vport->ops->send(skb);
 	return;
 

-- 
2.20.1

On 8/18/21 4:22 AM, fankaixi.li@bytedance.com wrote:

From: kaixi.fan <redacted>

fq qdisc requires tstamp to be cleared in the forwarding path. Now ovs
doesn't clear skb->tstamp. We encountered a problem with linux
version 5.4.56 and ovs version 2.14.1, and packets failed to
dequeue from qdisc when fq qdisc was attached to ovs port.

Fixes: fb420d5d91c1 ("tcp/fq: move back to CLOCK_MONOTONIC")

This is more precise than " version 5.4.56 and ovs version ..."

Thanks.

Hello:

This patch was applied to netdev/net.git (refs/heads/master):

On Wed, 18 Aug 2021 10:22:15 +0800 you wrote:

From: kaixi.fan <redacted>

fq qdisc requires tstamp to be cleared in the forwarding path. Now ovs
doesn't clear skb->tstamp. We encountered a problem with linux
version 5.4.56 and ovs version 2.14.1, and packets failed to
dequeue from qdisc when fq qdisc was attached to ovs port.

[...]

Here is the summary with links:
  - ovs: clear skb->tstamp in forwarding path
    https://git.kernel.org/netdev/net/c/01634047bf0d

You are awesome, thank you!
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Eric Dumazet [off-list ref] 于2021年8月18日周三 下午5:32写道：

On 8/18/21 4:22 AM, fankaixi.li@bytedance.com wrote:

quoted

From: kaixi.fan <redacted>

fq qdisc requires tstamp to be cleared in the forwarding path. Now ovs
doesn't clear skb->tstamp. We encountered a problem with linux
version 5.4.56 and ovs version 2.14.1, and packets failed to
dequeue from qdisc when fq qdisc was attached to ovs port.

Fixes: fb420d5d91c1 ("tcp/fq: move back to CLOCK_MONOTONIC")

This is more precise than " version 5.4.56 and ovs version ..."

Thanks.

quoted

Signed-off-by: kaixi.fan <redacted>
Signed-off-by: xiexiaohui <redacted>
Reviewed-by: Cong Wang <redacted>
---
 net/openvswitch/vport.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/net/openvswitch/vport.c b/net/openvswitch/vport.c
index 88deb5b41429..cf2ce5812489 100644
--- a/net/openvswitch/vport.c
+++ b/net/openvswitch/vport.c

@@ -507,6 +507,7 @@ void ovs_vport_send(struct vport *vport, struct sk_buff *skb, u8 mac_proto)
      }

      skb->dev = vport->dev;
+     skb->tstamp = 0;
      vport->ops->send(skb);
      return;

Hi Eric Dumazet,

Yes and many thanks.