From 5812521be0f79583a26e203ac5f23de679cbdd94 Mon Sep 17 00:00:00 2001
From: Gu Zheng <guz.fnst@cn.fujitsu.com>
Date: Mon, 10 Mar 2014 09:57:34 +0800
Subject: [PATCH] net: add a pre-check of net_ns in sk_change_net()
We do not need to switch the net_ns if the target net_ns the same
as the current one, so here we add a pre-check of net_ns to avoid
this as David suggested.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
include/net/sock.h | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/include/net/sock.h b/include/net/sock.h
index 5c3f7c3624aa..967856970a51 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -2252,8 +2252,12 @@ void sock_net_set(struct sock *sk, struct net *net)
*/
static inline void sk_change_net(struct sock *sk, struct net *net)
{
- put_net(sock_net(sk));
- sock_net_set(sk, hold_net(net));
+ struct net *current_net = sock_net(sk);
+
+ if (!net_eq(current_net, net)) {
+ put_net(current_net);
+ sock_net_set(sk, hold_net(net));
+ }
}
static inline struct sock *skb_steal_sock(struct sk_buff *skb)
--
2.34.1