Re: [PATCH] netns: Coexist with the sysfs limitations

From: Eric W. Biederman
Date: Thu Oct 23 2008 - 11:44:52 EST

Benjamin Thery <benjamin.thery@xxxxxxxx> writes:

> Serge E. Hallyn wrote:
>> Quoting Eric W. Biederman (ebiederm@xxxxxxxxxxxx):
>>> To make testing of the network namespace simpler allow
>>> the network namespace code and the sysfs code to be
>>> compiled and run at the same time. To do this only
>>> virtual devices are allowed in the additional network
>>> namespaces and those virtual devices are not placed
>>> in the kobject tree.
>>> Since virtual devices don't actually do anything interesting
>>> hardware wise that needs device management there should
>>> be no loss in keeping them out of the kobject tree and
>>> by implication sysfs. The gain in ease of testing
>>> and code coverage should be significant.
>>> I.e. people running distributions that make it next to
>>> impossible to boot without sysfs should at be able to
>>> boot a test kernel now.
>>> Plus no ABIs are harmed with this patch.
>>> Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
>> Duh.
>> Tested-by: Serge Hallyn <serue@xxxxxxxxxx>
>> Acked-by: Serge Hallyn <serue@xxxxxxxxxx>
> Oh, this patch is short, clean, and the limitation introduced isn't too
> annoying for testing netns right now.
> At least, my proposal provoked some reactions :)


> BTW, there's a second limitation with your patch:
> we can't rename the net devices in the additional network namespaces.
> In net/core/dev.c, dev_change_name() fails: call to device_rename() return an
> (expected) -EINVAL error.
> Maybe we should add a test on the net to only call it in init_net?

Yes. Good catch.

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