From: Gu Zheng Subject: [PATCH] net: add a pre-check of net_ns in sk_change_net() Date: Mon, 10 Mar 2014 09:57:34 +0800 Message-ID: <531D1C0E.6010507@cn.fujitsu.com> References: <5319A3C2.8080001@cn.fujitsu.com> <20140309.190941.472588800498066811.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org To: David Miller Return-path: In-Reply-To: <20140309.190941.472588800498066811.davem@davemloft.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org 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 --- include/net/sock.h | 8 ++++++-- 1 files changed, 6 insertions(+), 2 deletions(-) diff --git a/include/net/sock.h b/include/net/sock.h index 5c3f7c3..9678569 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) -- 1.7.7