[CRIU] Sync TODO-s for mount.c work

[Tycho Andersen]

Hi Oleg,

On Wed, Apr 22, 2015 at 9:35 AM, Oleg Nesterov <oleg at redhat.com> wrote:
> On 04/22, Tycho Andersen wrote:
>>
>> In this case you have to use --ext-mount-map KEY:VAL as in the good
>> old days before --ext-mount-map auto.
>
> I _suspected_ this ;) Thanks.
>
> OK, before I dive into the sources, could you please tell me what
> should I pass as KEY:VAL pair? (I didn't read this code yet and I
> am not sure if I can understand it, at least quickly).

Looking at your mountinfo, I'm not sure you can dump this process. The
problem is e.g.:

36 34 253:1 / / rw,relatime shared:7 master:1 - xfs
/dev/mapper/rhel_ibm--x3650m4--02--vm--02-root
rw,seclabel,attr2,inode64,noquota

This is not a bind mount, but it has external sharing according to the
rest of your mountinfo (there is no "shared:1" anywhere). There is no
way to tell criu (currently) to allow mounts that aren't bind mounts
to have sharing. I guess this configuration is the result of something
like:

unshare(CLONE_NEWNS)
mount(NULL, "/", NULL, MS_PRIVATE, NULL)

so all criu needs to do is learn how to do that and it should be ok.

Tycho

>
> Oleg.
>