[PATCH][INET 1/2]: Drop the inet_inherit_port() call.

[PATCH][INET 1/2]: Drop the inet_inherit_port() call.

[Pavel Emelyanov]

As I can see from the code, two places (tcp_v6_syn_recv_sock and
dccp_v6_request_recv_sock) that call this one already run with
BHs disabled, so it's safe to call __inet_inherit_port there.

Besides (in case I missed smth with code review) the calltrace
tcp_v6_syn_recv_sock
 `- tcp_v4_syn_recv_sock
     `- __inet_inherit_port
and the similar for DCCP are valid, but assumes BHs to be disabled.

Signed-off-by: Pavel Emelyanov <xemul@openvz.org>

---
 include/net/inet_hashtables.h |    7 -------
 net/dccp/ipv6.c               |    2 +-
 net/ipv6/tcp_ipv6.c           |    2 +-
 3 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/include/net/inet_hashtables.h b/include/net/inet_hashtables.h
index 5525227..5ec91d8 100644
--- a/include/net/inet_hashtables.h
+++ b/include/net/inet_hashtables.h
@@ -235,13 +235,6 @@ static inline void __inet_inherit_port(struct sock *sk, struct sock *child)
 	spin_unlock(&head->lock);
 }
 
-static inline void inet_inherit_port(struct sock *sk, struct sock *child)
-{
-	local_bh_disable();
-	__inet_inherit_port(sk, child);
-	local_bh_enable();
-}
-
 extern void inet_put_port(struct sock *sk);
 
 extern void inet_listen_wlock(struct inet_hashinfo *hashinfo);
diff --git a/net/dccp/ipv6.c b/net/dccp/ipv6.c
index f8371c7..9b1129b 100644
--- a/net/dccp/ipv6.c
+++ b/net/dccp/ipv6.c
@@ -625,7 +625,7 @@ static struct sock *dccp_v6_request_recv_sock(struct sock *sk,
 	newinet->daddr = newinet->saddr = newinet->rcv_saddr = LOOPBACK4_IPV6;
 
 	__inet6_hash(newsk);
-	inet_inherit_port(sk, newsk);
+	__inet_inherit_port(sk, newsk);
 
 	return newsk;
 
diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c
index 231c4dd..715965f 100644
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -1534,7 +1534,7 @@ static struct sock * tcp_v6_syn_recv_sock(struct sock *sk, struct sk_buff *skb,
 #endif
 
 	__inet6_hash(newsk);
-	inet_inherit_port(sk, newsk);
+	__inet_inherit_port(sk, newsk);
 
 	return newsk;
 
-- 
1.5.3.4

Re: [PATCH][INET 1/2]: Drop the inet_inherit_port() call.

[David Miller]

From: Pavel Emelyanov <xemul@openvz.org>
Date: Thu, 17 Apr 2008 19:59:38 +0400

> As I can see from the code, two places (tcp_v6_syn_recv_sock and
> dccp_v6_request_recv_sock) that call this one already run with
> BHs disabled, so it's safe to call __inet_inherit_port there.
> 
> Besides (in case I missed smth with code review) the calltrace
> tcp_v6_syn_recv_sock
>  `- tcp_v4_syn_recv_sock
>      `- __inet_inherit_port
> and the similar for DCCP are valid, but assumes BHs to be disabled.
> 
> Signed-off-by: Pavel Emelyanov <xemul@openvz.org>

I agree with you analysis, all of these sites have BH disabled,
patch applied.