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Subject: Re: device namespaces
To:     "Eric W. Biederman" <ebiederm@xmission.com>,
        Christian Brauner <christian.brauner@ubuntu.com>
Cc:     Hannes Reinecke <hare@suse.de>, gregkh@linuxfoundation.org,
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From:   "Enrico Weigelt, metux IT consult" <lkml@metux.net>
Message-ID: <c504a8c6-73f8-b45c-6d6b-6f5a1300ab3a@metux.net>
Date:   Mon, 14 Jun 2021 09:49:22 +0200
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On 11.06.21 20:14, Eric W. Biederman wrote:

Hi,

> I favor none of the virtual devices showing up in sysfs.  Maybe existing
> userspace needs the devices in sysfs, but if the solution is simply to
> skip sysfs for virtual devices that is much simpler.

Sorry for being a little bit confused, but by virtual devices you mean
things like pty's or all the other stuff we already see under
/sys/device/virtual ?

I'm yet unsure what the better way is. If we're just talking about pty's
specifically, I maybe could live with threating them like "special sort
of pipes", but I guess that would require some extra magic.

If I'm not mistaken, the whole sysfs stuff is automatically handled
device classes and bus'es - seems that tty's are also class devs.

How would you skip the virtual devices from sysfs ? Adding some filter
into sysfs that looks at the device class (or some flag within it) ?

--mtx

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Enrico Weigelt, metux IT consult
Free software and Linux embedded engineering
info@metux.net -- +49-151-27565287