[PATCH 3.17 014/319] net: fix saving TX flow hash in sock for outgoing connections

From: Greg Kroah-Hartman
Date: Tue Nov 11 2014 - 20:20:08 EST


3.17-stable review patch. If anyone has any objections, please let me know.

------------------

From: Sathya Perla <sathya.perla@xxxxxxxxxx>

[ Upstream commit 9e7ceb060754f134231f68cb29d5db31419fe1ed ]

The commit "net: Save TX flow hash in sock and set in skbuf on xmit"
introduced the inet_set_txhash() and ip6_set_txhash() routines to calculate
and record flow hash(sk_txhash) in the socket structure. sk_txhash is used
to set skb->hash which is used to spread flows across multiple TXQs.

But, the above routines are invoked before the source port of the connection
is created. Because of this all outgoing connections that just differ in the
source port get hashed into the same TXQ.

This patch fixes this problem for IPv4/6 by invoking the the above routines
after the source port is available for the socket.

Fixes: b73c3d0e4("net: Save TX flow hash in sock and set in skbuf on xmit")

Signed-off-by: Sathya Perla <sathya.perla@xxxxxxxxxx>
Acked-by: Eric Dumazet <edumazet@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
net/ipv4/tcp_ipv4.c | 4 ++--
net/ipv6/tcp_ipv6.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)

--- a/net/ipv4/tcp_ipv4.c
+++ b/net/ipv4/tcp_ipv4.c
@@ -208,8 +208,6 @@ int tcp_v4_connect(struct sock *sk, stru
inet->inet_dport = usin->sin_port;
inet->inet_daddr = daddr;

- inet_set_txhash(sk);
-
inet_csk(sk)->icsk_ext_hdr_len = 0;
if (inet_opt)
inet_csk(sk)->icsk_ext_hdr_len = inet_opt->opt.optlen;
@@ -226,6 +224,8 @@ int tcp_v4_connect(struct sock *sk, stru
if (err)
goto failure;

+ inet_set_txhash(sk);
+
rt = ip_route_newports(fl4, rt, orig_sport, orig_dport,
inet->inet_sport, inet->inet_dport, sk);
if (IS_ERR(rt)) {
--- a/net/ipv6/tcp_ipv6.c
+++ b/net/ipv6/tcp_ipv6.c
@@ -198,8 +198,6 @@ static int tcp_v6_connect(struct sock *s
sk->sk_v6_daddr = usin->sin6_addr;
np->flow_label = fl6.flowlabel;

- ip6_set_txhash(sk);
-
/*
* TCP over IPv4
*/
@@ -295,6 +293,8 @@ static int tcp_v6_connect(struct sock *s
if (err)
goto late_failure;

+ ip6_set_txhash(sk);
+
if (!tp->write_seq && likely(!tp->repair))
tp->write_seq = secure_tcpv6_sequence_number(np->saddr.s6_addr32,
sk->sk_v6_daddr.s6_addr32,


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