NAK: user namespace delta for raring?

[Eric W. Biederman]

Serge Hallyn <serge.hallyn at canonical.com> writes:

> Quoting Tim Gardner (tim.gardner at canonical.com):
>> On 01/16/2013 04:21 PM, Serge Hallyn wrote:
>> >Hi,
>> >
>> >The bulk of Eric's user namespace patches were accepted into 3.8.
>> >The remainder are mainly updates to devpts and some kuid fixups for
>> >various filesystems.  A raring tree with those patches pushed on
>> >top is at
>> >
>> >http://kernel.ubuntu.com/git?p=serge/quantal-userns.git;a=summary
>> >
>> >Most of the additional patches come from Eric's tree, though a
>> >few are fixups for Ubuntu delta, plus a patch of mine to allow
>> >tmpfs mounts in user namespaces.
>> >
>> >With that kernel, I can run lxc containers in private user
>> >namespaces.
>> >
>> >Would it be possible to carry these patches as an Ubuntu delta
>> >in raring?
>> >
>> >thanks,
>> >-serge
>> >
>> 
>> I'm quite reluctant to carry these patches. I think they need a
>> bunch of maintainer approvals yet, and definitely some bake time in
>> linux-next (if they haven't already). I'd be a lot more willing to
>> consider them as cherry-picks or backports from the 3.9 merge. What
>> you are proposing appears to have deep and substantive internal
>> behavioural changes that will be extremely difficult for anyone on
>> my team to debug in the event of error.
>
> That's too bad, but thanks.
>
> (The patches with subject 'userns: Convert <...>' are not deep
> substantive changes, but the devpts ones are, and without those
> we still wouldn't have enough to use user namespace with ubuntu
> system containers.)

I will start a final review and pushing these things into linux-next
shortly.  Certainly a lot of my filesystem conversion to kuid and kgid
patches need to be broken up into smaller patches so it is clear they
are simple and obviously correct.

To help me prioritize things are there any of the remaining filesystem
that I have patches for that Ubunutu does not build?  Perhaps you don't
care about xfs?

The basic devpts change is about like the tmptfs change a single line.

The tricky part with devpts is figuring where to modify userspace so
that /dev/pts is mounted with the newinstance options in a container
isn't it?  Since udev doesn't create device nodes not creating making
/dev/ptmx a symlink to /dev/pts/ptmx should not be a problem.  Serge are
there useful containers you can build that can use the newinstance
mount option of /dev/pts?

I don't plan to drop any of my work in my queue but if we router around
some of the parts that need lots of reivew that would be great.

Eric