Re: [PATCH 0/1] devpts: use dynamic_dname() to generate proc name

Christian Brauner
2017-08-16T22:28:47Z

On Wed, Aug 16, 2017 at 11:45 PM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
> On Wed, Aug 16, 2017 at 2:37 PM, Christian Brauner
> <christian.brauner@canonical.com> wrote:
>>> And Christian, if you can beat on this, that would be good.
>>
>> Yes, I can pound on this nicely with liblxc. We have patch
>> ( https://github.com/lxc/lxc/pull/1728 ) up for review that
>> allocates pty fds from private devpts mounts in different namespaces
>> and sends those fds around between different namespaces.
>
> Good. Testing that this works with different pts filesystems in
> different places is exactly the kind of thing I'd like to see. I only
> tested with my single pts filesystem that is mounted at /dev/pts, and
> making sure it works when there are multiple mounts and in different
> places is exactly the kind of testing this should get.

I'm compiling a kernel now and depending on how good the in-flight
wifi is I try to test this right away and answer here if that helps. If the
in-flight wifi sucks it might take me until tomorrow.

>
> For example, if some namespace has it's pty's in _its_ /dev/pts/
> hierarchy, and you then pass such a pty to somebody else that either
> doesn't have that pts mount at all, or has it visible somewhere
> entirely different, the result should now be something else than that
> "/dev/pts/n" path.
>
> But it would be good to just test this in general too, and make sure I
> didn't screw up some reference count or something. The patch *looks*
> obviously correct, but ...
>
> Linus