Subject: [PATCH 15/23] net/dst: do not confirm neighbor for vxlan and geneve pmtu update

From: Hangbin Liu <[email-masked]>
Date: Sun, 22 Dec 2019 10:51:16 +0800

[ Upstream commit f081042d128a0c7acbd67611def62e1b52e2d294 ]

When do IPv6 tunnel PMTU update and calls __ip6_rt_update_pmtu() in the end,
we should not call dst_confirm_neigh() as there is no two-way communication.

So disable the neigh confirm for vxlan and geneve pmtu update.

v5: No change.
v4: No change.
v3: Do not remove dst_confirm_neigh, but add a new bool parameter in
    dst_ops.update_pmtu to control whether we should do neighbor confirm.
    Also split the big patch to small ones for each area.
v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu.

Fixes: a93bf0ff4490 ("vxlan: update skb dst pmtu on tx path")
Fixes: 52a589d51f10 ("geneve: update skb dst pmtu on tx path")
Reviewed-by: Guillaume Nault <[email-masked]>
Tested-by: Guillaume Nault <[email-masked]>
Acked-by: David Ahern <[email-masked]>
Signed-off-by: Hangbin Liu <[email-masked]>
Signed-off-by: David S. Miller <[email-masked]>
---
 include/net/dst.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/net/dst.h b/include/net/dst.h
index c886c45ba286..35ae45fa0758 100644
--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -546,7 +546,7 @@ static inline void skb_tunnel_check_pmtu(struct sk_buff *skb,
 	u32 encap_mtu = dst_mtu(encap_dst);
 
 	if (skb->len > encap_mtu - headroom)
-		skb_dst_update_pmtu(skb, encap_mtu - headroom);
+		skb_dst_update_pmtu_no_confirm(skb, encap_mtu - headroom);
 }
 
 #endif /* _NET_DST_H */
-- 
2.20.1