Subject: [PATCH net-next v2] ipv6: remove useless spin_lock/spin_unlock

From: Duan Jiong <[email-masked]>
Date: Wed, 3 Dec 2014 10:29:40 +0800

xchg is atomic, so there is no necessary to use spin_lock/spin_unlock
to protect it. At last, remove the redundant
opt = xchg(&inet6_sk(sk)->opt, opt); statement.

Signed-off-by: Duan Jiong <[email-masked]>
---
v2: remove the redundant opt = xchg(&inet6_sk(sk)->opt, opt); statement.

 net/ipv6/ipv6_sockglue.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/net/ipv6/ipv6_sockglue.c b/net/ipv6/ipv6_sockglue.c
index e1a9583..66980d8 100644
--- a/net/ipv6/ipv6_sockglue.c
+++ b/net/ipv6/ipv6_sockglue.c
@@ -110,12 +110,8 @@ struct ipv6_txoptions *ipv6_update_options(struct sock *sk,
 			icsk->icsk_ext_hdr_len = opt->opt_flen + opt->opt_nflen;
 			icsk->icsk_sync_mss(sk, icsk->icsk_pmtu_cookie);
 		}
-		opt = xchg(&inet6_sk(sk)->opt, opt);
-	} else {
-		spin_lock(&sk->sk_dst_lock);
-		opt = xchg(&inet6_sk(sk)->opt, opt);
-		spin_unlock(&sk->sk_dst_lock);
 	}
+	opt = xchg(&inet6_sk(sk)->opt, opt);
 	sk_dst_reset(sk);
 
 	return opt;
-- 
1.8.3.1