[PATCH 4.19 104/114] net/dst: do not confirm neighbor for vxlan and geneve pmtu update

From: Greg Kroah-Hartman
Date: Thu Jan 02 2020 - 17:23:35 EST

From: Hangbin Liu <liuhangbin@xxxxxxxxx>

[ 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 <gnault@xxxxxxxxxx>
Tested-by: Guillaume Nault <gnault@xxxxxxxxxx>
Acked-by: David Ahern <dsahern@xxxxxxxxx>
Signed-off-by: Hangbin Liu <liuhangbin@xxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
include/net/dst.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/include/net/dst.h
+++ b/include/net/dst.h
@@ -546,7 +546,7 @@ static inline void skb_tunnel_check_pmtu
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 */