Messages in this thread | | | Date | Thu, 10 Apr 2008 11:44:36 -0500 | From | "Serge E. Hallyn" <> | Subject | Re: [RFC][PATCH 0/7] Clone PTS namespace |
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Quoting Eric W. Biederman (ebiederm@xmission.com): > On Wed, 2008-04-09 at 20:59 -0500, Serge E. Hallyn wrote: > > > Feh, so of course sysfs would have the most interactions for a device > > namespace, but now we have pty, network, and user namespace all needing > > some sort of sysfs solution. For a quickfix for > > CONFIG_USER_SCHED+CONFIG_USER_NS, I just moved /sys/kernel/uids/<uid> > > to /sys/kernel/uids/<userns_address>/<uid>. But what would be a *good* > > general solution? > > > > ln -s /sys /proc/self/sys? > > LOL > > In /proc I prefer the /proc/self approach because we can do it and it is > just much easier to setup and use. (Plus we have weird problems if we > try and capture more then the pid namespace). > > For other filesystems the only really viable option is to capture > namespaces at mount time, as we are doing for devpts and proc with > respect to the pid namespace. > > For the network namespace where it is very much more then a single > directory with symlinks from physical devices pointing at logical > network interfaces. > > My last effort in that area was ok'd by Tejun lightly tested by a few > others and misplaced by gregkh so I don't think we have a real problem > with resurrecting those patches cleaning them up a bit and merging them. > > The biggest gotcha with sysfs is that the VFS locking for the dcache > is in the wrong order for distributed filesystems, where we would like > to make the change atomically on the server and them make the change in > the local cache. Or in this case the sysfs internal data structures. > The truly nasty case is supporting rename (as sysfs does) as the VFS > is not at all happy if you just punt and shoot down the dentries and > instantiate new ones. > > I'm hoping to be able to get back at this in the week or so as things > settle down from my move. My last patches should be in my proof of > concept network namespace tree, if they don't show up elsewhere. > > It isn't my perception that we have a design problem rather, we just > need to move an important piece of code in a subtle and moderately > uninteresting direction for it's primary maintainer. > > Further what I did for the network namespace should easily handle the > uid/gid namespace and should be a good starting place for a general > device namespace.
Agreed. What's the git url and which branch do i use for your proof of concept tree? I'll do the userns patch on top of that. I assume Suka will do the same for ptys?
thanks, -serge
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