Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Yafang Shao <laoar.shao@gmail.com>
To:     edumazet@google.com, davem@davemloft.net
Cc:     netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Yafang Shao <laoar.shao@gmail.com>
Subject: [PATCH v2 net-next] inet: do not set backlog if listen fails
Date:   Sun,  7 Oct 2018 21:36:45 +0800
Message-Id: <1538919405-3093-1-git-send-email-laoar.shao@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

We don't need to set the backlog if listen fails.
The sk_max_ack_backlog will be set in the caller inet_listen() and
dccp_listen_start() if inet_csk_listen_start() return without error.
So just remove this line to avoid this unnecessary operation.

Regarding sk_ack_backlog, we have to set it before a TCP/DCCP socket is
ready to accept new flows to avoid race, because dccp and tcp have lockless
listeners

Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
---
 net/ipv4/inet_connection_sock.c | 1 -
 1 file changed, 1 deletion(-)

diff --git a/net/ipv4/inet_connection_sock.c b/net/ipv4/inet_connection_sock.c
index dfd5009..cdd5c95 100644
--- a/net/ipv4/inet_connection_sock.c
+++ b/net/ipv4/inet_connection_sock.c
@@ -871,7 +871,6 @@ int inet_csk_listen_start(struct sock *sk, int backlog)
 
 	reqsk_queue_alloc(&icsk->icsk_accept_queue);
 
-	sk->sk_max_ack_backlog = backlog;
 	sk->sk_ack_backlog = 0;
 	inet_csk_delack_init(sk);
 
-- 
1.8.3.1