[CRIU] [RFC][PATCH 0/3] Proposal for native (w/o plugins) support for external bind mounts v2

[Pavel Emelyanov]

On 06/06/2014 03:21 PM, Andrew Vagin wrote:

[snip]

>>>> Does it make sense?
>>>
>>> I'm not sure that I understand you. Look at this:
>>>
>>> I just want to show mountinfo for a real docket CT.
>>>
>>> $ cat /proc/1554/mountinfo

[snip]

>>> 112 102 0:12 /7 /dev/console rw,nosuid,noexec,relatime - devpts devpts rw,gid=5,mode=620,ptmxmode=000
>>>
>>> So we have two types of bind-mounts:
>>> * /var/lib/docker/containers/CTID
>>> * /dev/console, /etc/resolv.conf
>>>
>>> and the option should be able to handle all these cases...
>>>
>>> For example:
>>>
>>> on dump:
>>> --ext-mount s:/var/lib/docker/containers/37192b3177f945beb4a92e182638652b35fa71b14ae5b11072e4bfe22e21d280/=CTPATH
>>> 	all source subpath is replaced on CTPATH
>>
>> There's no such thing as "source subpath". If /var/lib is not directory on /, but
>> a mountpoint, criu would only see the /docker/containers/ID/... paths in mountinfo.
> 
> I know this and in this case you will need to say
> --ext-mount s:/docker/containers/37192b3177f945beb4a92e182638652b35fa71b14ae5b11072e4bfe22e21d280/=CTPATH
> 
> or criu can cut "/var/lib" and compare a device number to be sure that a
> bind-mount belons to the specified path.

Now I don't get the idea :)

Let's imagine we have /a/a being a mountpoint and we bind mount /a/a/a/a/a/a into container.
We tell to criu on dump that --ext-mount s:/a/a/a/a=A. What should it do?

Thanks,
Pavel