From: ebiederm@xmission•com (Eric W. Biederman)
To: canqun zhang <canqunzhang@gmail•com>
Cc: Gao feng <gaofeng@cn•fujitsu.com>,
netfilter-devel@vger•kernel.org,
"netdev\@vger.kernel.org" <netdev@vger•kernel.org>,
Patrick McHardy <kaber@trash•net>,
pablo@netfilter•org
Subject: Re: [PATCH 01/19] netfilter: move nf_conntrack initialize out of pernet operations
Date: Thu, 27 Dec 2012 20:48:44 -0800 [thread overview]
Message-ID: <87ip7mlr2r.fsf@xmission.com> (raw)
In-Reply-To: <CAFFEFTXT_fkF2pPSxDEEgic80NVWLqBWtFuvs6W9uDUW2aCnqw@mail.gmail.com> (canqun zhang's message of "Fri, 28 Dec 2012 11:52:13 +0800")
canqun zhang <canqunzhang@gmail•com> writes:
> Hi all
> As discussed above,if the host machine create several linux
> containers, there will be several net namespaces.Resources with "nf
> conntrack" are registered or unregistered on the first net
> namespace(init_net),But init_net is not unregistered lastly,so
> cleanuping other net namespaces will triger painic.
> If net namespaces are created with the order of 1,2,...n,they should
> be cleaned with the order of n,...2,1,so in this case init_net will be
> unregistered lastly.
No. Network namespaces in general can be cleaned up in any order.
In particular you should never ever expect to see the order
n,n-1,n-2,...,2,1.
It may make sense to special case init_net in the cleanup order
but I would really rather not.
Now init_net is special and really should never be cleaned up
for non-modular code. So it almost makes sense to special
case init_net.
Does anyone know why Alexy decided to do this only for init_net?
My inclination is that Gao Feng is on the rigt path by just removing
the strange init_net special case and performing the work once
per module load, and once per module unload.
> I fixed it up (see below). I have taken a lot of test!
Thank you.
It is nice to see that we have exposed this mis-assumption.
I am inclined to leave the order of this list as is so that
other assumptions of network namespace unregistration order
are exposed.
Unless there is a truly good reason to perform magic on init_net.
Eric
> diff -r 6a1a258923f5 -r 2667e89e6f50 net/core/net_namespace.c
> --- a/net/core/net_namespace.c Fri Dec 28 11:01:17 2012 +0800
> +++ b/net/core/net_namespace.c Fri Dec 28 11:05:12 2012 +0800
> @@ -450,7 +450,7 @@
>
> list_del(&ops->list);
> for_each_net(net)
> - list_add_tail(&net->exit_list, &net_exit_list);
> + list_add(&net->exit_list, &net_exit_list);
> ops_exit_list(ops, &net_exit_list);
> ops_free_list(ops, &net_exit_lis
>
next prev parent reply other threads:[~2012-12-28 4:49 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-12-28 2:36 [PATCH 01/19] netfilter: move nf_conntrack initialize out of pernet operations Gao feng
2012-12-28 2:36 ` [PATCH 02/19] netfilter: expect: move initial codes out of pernet_operations Gao feng
2012-12-28 2:36 ` [PATCH 03/19] netfilter: acct: " Gao feng
2012-12-28 2:36 ` [PATCH 04/19] netfilter: tstamp: " Gao feng
2012-12-28 2:36 ` [PATCH 05/19] netfilter: ecache: " Gao feng
2012-12-28 2:36 ` [PATCH 06/19] netfilter: timeout: " Gao feng
2012-12-28 2:36 ` [PATCH 07/19] netfilter: helper: " Gao feng
2012-12-28 2:36 ` [PATCH 08/19] netfilter: proto: " Gao feng
2012-12-28 2:36 ` [PATCH 09/19] netfilter: l3proto: prepare reworking l3proto support for netns Gao feng
2012-12-28 2:36 ` [PATCH 10/19] netfilter: ipv4: register ipv4 in module_init Gao feng
2012-12-28 2:36 ` [PATCH 10/19] netfilter: ipv4: register l3proto " Gao feng
2012-12-28 2:36 ` [PATCH 11/19] netfilter: ipv6: register l3proto ipv6 " Gao feng
2012-12-28 2:36 ` [PATCH 12/19] netfilter: l4proto: prepare reworking l4proto support for netns Gao feng
2012-12-28 2:36 ` [PATCH 13/19] netfilter: ipv4: move registration codes out of pernet_operations Gao feng
2012-12-28 2:36 ` [PATCH 14/19] netfilter: ipv6: " Gao feng
2012-12-28 2:36 ` [PATCH 15/19] netfilter: sctp: " Gao feng
2012-12-28 2:36 ` [PATCH 16/19] netfilter: udplite: " Gao feng
2012-12-28 2:36 ` [PATCH 17/19] netfilter: dccp: " Gao feng
2012-12-28 2:36 ` [PATCH 18/19] netfilter: gre: " Gao feng
2012-12-28 2:36 ` [PATCH 19/19] netfilter: gre: fix resource leak when unregister gre proto Gao feng
2013-01-05 3:50 ` Pablo Neira Ayuso
2013-01-07 1:27 ` Gao feng
2013-01-07 2:15 ` Pablo Neira Ayuso
2013-01-07 2:38 ` Pablo Neira Ayuso
2013-01-07 2:59 ` Gao feng
2013-01-07 3:05 ` Gao feng
2013-01-07 3:27 ` Pablo Neira Ayuso
2013-01-07 3:43 ` Gao feng
2012-12-28 3:52 ` [PATCH 01/19] netfilter: move nf_conntrack initialize out of pernet operations canqun zhang
2012-12-28 4:48 ` Eric W. Biederman [this message]
2012-12-28 5:32 ` canqun zhang
2012-12-28 6:00 ` Eric W. Biederman
2012-12-28 11:58 ` Pablo Neira Ayuso
2012-12-28 7:16 ` Gao feng
2012-12-28 8:48 ` canqun zhang
2013-01-10 1:03 ` Gao feng
2013-01-10 16:41 ` Pablo Neira Ayuso
2013-01-11 1:01 ` Gao feng
2013-01-13 15:07 ` Pablo Neira Ayuso
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