public inbox for netdev@vger.kernel.org 
 help / color / mirror / Atom feed

From: Huang Qiang <h.huangqiang@huawei•com>
To: <davem@davemloft•net>, <glommer@parallels•com>
Cc: <netdev@vger•kernel.org>, <containers@lists•linux-foundation.org>,
	<yangzhenzhang@huawei•com>
Subject: [PATCH] netns: correctly use per-netns ipv4 sysctl_tcp_mem
Date: Mon, 9 Jul 2012 14:05:09 +0800	[thread overview]
Message-ID: <4FFA7495.5070702@huawei.com> (raw)

From: Yang Zhenzhang <yangzhenzhang@huawei•com>

Now, kernel allows each net namespace to independently set up its levels
for tcp memory pressure thresholds.

But it seems there is a bug, as using the following steps:

[root@host socket]# lxc-start -n test -f config /bin/bash
[root@net-test socket]# ip route add default via 192.168.58.2
[root@net-test socket]# echo 0 0 0 > /proc/sys/net/ipv4/tcp_mem
[root@net-test socket]# scp root@192•168.58.174:/home/tcp_mem_test .

and it still can transport the "tcp_mem_test" file which we hope it
would not.

It's because inet_init() (net/ipv4/af_inet.c)initialize the
tcp_prot.sysctl_mem:
tcp_prot.sysctl_mem = init_net.ipv4.sysctl_tcp_mem;

So when the protocal is TCP, sk->sk_prot->sysctl_mem(following code)
always use the ipv4 sysctl_tcp_mem of init_net namespace rather than
it's own net namespace.
This patch simply set "prot" equal to net->ipv4.sysctl_tcp_mem when
the protocol type is TCP.

Signed-off-by: Yang Zhenzhang <yangzhenzhang@huawei•com>
---
 include/net/sock.h |    6 ++++++
 1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/include/net/sock.h b/include/net/sock.h
index 4a45216..b62a8d9 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -59,6 +59,7 @@
 #include <linux/static_key.h>
 #include <linux/aio.h>
 #include <linux/sched.h>
+#include <linux/in.h>

 #include <linux/filter.h>
 #include <linux/rculist_nulls.h>
@@ -1062,7 +1063,12 @@ static inline void sk_enter_memory_pressure(struct sock *sk)

 static inline long sk_prot_mem_limits(const struct sock *sk, int index)
 {
+	struct net *net = sock_net(sk);
 	long *prot = sk->sk_prot->sysctl_mem;
+	
+	if (sk->protocol == IPPROTO_TCP)
+		prot = net->ipv4.sysctl_tcp_mem;
+
 	if (mem_cgroup_sockets_enabled && sk->sk_cgrp)
 		prot = sk->sk_cgrp->sysctl_mem;
 	return prot[index];
-- 
1.7.1

next             reply	other threads:[~2012-07-09  6:08 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2012-07-09  6:05 Huang Qiang [this message]
     [not found] ` <4FFA7495.5070702-hv44wF8Li93QT0dZR+AlfA@public.gmane.org>
2012-07-09 22:21   ` [PATCH] netns: correctly use per-netns ipv4 sysctl_tcp_mem David Miller
     [not found]     ` <20120709.152100.571089964662155300.davem-fT/PcQaiUtIeIZ0/mPfg9Q@public.gmane.org>
2012-07-20 22:22       ` Glauber Costa

find likely ancestor, descendant, or conflicting patches for this message:
( dfblob:4a45216 dfblob:b62a8d9 )
 OR (
bs:"[PATCH] netns: correctly use per-netns ipv4 sysctl_tcp_mem" )
	(help)

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=4FFA7495.5070702@huawei.com \
    --to=h.huangqiang@huawei$(echo .)com \
    --cc=containers@lists$(echo .)linux-foundation.org \
    --cc=davem@davemloft$(echo .)net \
    --cc=glommer@parallels$(echo .)com \
    --cc=netdev@vger$(echo .)kernel.org \
    --cc=yangzhenzhang@huawei$(echo .)com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox