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From: Nicolas Dichtel <nicolas.dichtel@6wind•com>
To: "Eric W. Biederman" <ebiederm@xmission•com>
Cc: netdev@vger•kernel.org, davem@davemloft•net
Subject: Re: [PATCH net-next 1/4] netns: don't clear nsid too early on removal
Date: Fri, 03 Apr 2015 11:56:09 +0200	[thread overview]
Message-ID: <551E63B9.9050208@6wind.com> (raw)
In-Reply-To: <877ftus6rj.fsf@x220.int.ebiederm.org>

Le 02/04/2015 20:51, Eric W. Biederman a écrit :
[snip]
>
> There should be no network sockets and thus no in flight rtnl traffic at
> the time cleanup_net is metioned so I don't see how this patch fixes
> the mentioned commit.
Yes and no.
Yes, there is no network sockets into this netns, *but* modules build
netlink messages because they don't know if there are listeners or not.

>
> I have a second issue with the fact that the code is unnecessarily
> quadratic.  We should keep a list of the issues netns ids and just
> revoke them instead of walking the whole network namespaces.
>
> I strongly suspect that this change makes it possible to create a
> network device whose bottom is in a network namespace we are destroying
> after we have destroyed all of the network devices in that namespace and
> otherwise cleaned up.   Beyond that I can not reason about this patch
> because it opens up a huge number of races.
Ok, you're probably right.
I will send an update.

  reply	other threads:[~2015-04-03  9:56 UTC|newest]

Thread overview: 21+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-04-01 12:49 [PATCH net-next 0/4] netns: enhance netlink interface for nsid Nicolas Dichtel
2015-04-01 12:49 ` [PATCH net-next 1/4] netns: don't clear nsid too early on removal Nicolas Dichtel
2015-04-02 18:51   ` Eric W. Biederman
2015-04-03  9:56     ` Nicolas Dichtel [this message]
2015-04-03 10:02       ` [PATCH net 1/2] Revert "netns: don't clear nsid too early on removal" Nicolas Dichtel
2015-04-03 10:02         ` [PATCH net 2/2] netns: don't allocate an id for dead netns Nicolas Dichtel
2015-04-03 16:36           ` David Miller
2015-04-05  8:39             ` Nicolas Dichtel
2015-04-05 20:34               ` David Miller
2015-04-07  9:36                 ` Nicolas Dichtel
2015-04-03 16:36         ` [PATCH net 1/2] Revert "netns: don't clear nsid too early on removal" David Miller
2015-04-01 12:49 ` [PATCH net-next 2/4] netns: minor cleanup in rtnl_net_getid() Nicolas Dichtel
2015-04-01 12:49 ` [PATCH net-next 3/4] netns: notify netns id events Nicolas Dichtel
2015-04-01 12:49 ` [PATCH net-next 4/4] netns: allow to dump netns ids Nicolas Dichtel
2015-04-01 16:54 ` [PATCH net-next 0/4] netns: enhance netlink interface for nsid Cong Wang
2015-04-02  8:52   ` Nicolas Dichtel
2015-04-07  9:51 ` [PATCH net-next v2 0/3] " Nicolas Dichtel
2015-04-07  9:51   ` [PATCH net-next v2 1/3] netns: minor cleanup in rtnl_net_getid() Nicolas Dichtel
2015-04-07  9:51   ` [PATCH net-next v2 2/3] netns: notify netns id events Nicolas Dichtel
2015-04-07  9:51   ` [PATCH net-next v2 3/3] netns: allow to dump netns ids Nicolas Dichtel
2015-04-07 21:30   ` [PATCH net-next v2 0/3] netns: enhance netlink interface for nsid David Miller

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