From: David Miller <davem@davemloft.net>
To: den@sw.ru
Cc: dlezcano@fr.ibm.com, netdev@vger.kernel.org, xemul@openvz.org,
ebiederm@xmission.com, containers@lists.osdl.org,
yoshfuji@linux-ipv6.org, benjamin.thery@bull.net
Subject: Re: [patch 1/1][NETNS][IPV6] protect addrconf from loopback registration
Date: Mon, 12 Nov 2007 14:24:55 -0800 (PST) [thread overview]
Message-ID: <20071112.142455.73541417.davem@davemloft.net> (raw)
In-Reply-To: <473883FF.5010505@sw.ru>
From: "Denis V. Lunev" <den@sw.ru>
Date: Mon, 12 Nov 2007 19:49:03 +0300
> Unregister for a loopback in !init_net is a _valid_ operation and should
> be clean, i.e. without kludges in the path. This is the only way to
> check the ref-counting.
For ipv6 the stack really wants to pin down the loopback
device because we need a valid inet6_dev object to reference
at all times in order to simplify the per-device SNMP
statistic bumping.
When a non-loopback device goes down, we point any existing
references to that device's idev to the loopback one instead.
I really consider taking down the loopback device to be
an invalid operation at least how things are implemented
currently.
There was a suggestion to have a "dummy" device that takes the
place of "point dangling idev refs to loopback's one". But
some people get upset when statistical events get lost, and
rightly so. Such a dummy device would either need to be
invisible to the user, or show up and be utterly confusing.
next prev parent reply other threads:[~2007-11-12 22:24 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20071112151953.052335971@mai.toulouse-stg.fr.ibm.com>
2007-11-12 15:19 ` [patch 1/1][NETNS][IPV6] protect addrconf from loopback registration Daniel Lezcano
2007-11-12 16:05 ` Denis V. Lunev
2007-11-12 16:11 ` Daniel Lezcano
2007-11-12 16:49 ` Denis V. Lunev
2007-11-12 16:59 ` Eric W. Biederman
2007-11-12 22:24 ` David Miller [this message]
2007-11-13 12:59 ` Eric W. Biederman
[not found] ` <473879C3.5020301-3ImXcnM4P+0@public.gmane.org>
2007-11-12 16:51 ` Eric W. Biederman
2007-11-12 17:01 ` Daniel Lezcano
2007-11-12 19:50 ` Eric W. Biederman
2007-11-13 1:52 ` YOSHIFUJI Hideaki / 吉藤英明
2007-11-13 13:11 ` Eric W. Biederman
2007-11-13 10:55 ` Daniel Lezcano
2007-11-12 21:00 ` Denis V. Lunev
2007-11-12 16:40 ` Eric W. Biederman
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