[CRIU] [PATCH 0/2] C/R of mandatory mountpoints

[Dmitry Safonov]

On 07/21/2016 05:11 PM, Dmitry Safonov wrote:
> On 07/21/2016 04:56 PM, Pavel Emelyanov wrote:
>> On 07/12/2016 05:51 PM, Dmitry Safonov wrote:
>>> Support mandatory mounted mountpoints with excluseive locks.
>>
>> I doubt one patch is enough :)
>
> Thanks, I would like to write more patches :)
>
>> Consider we restore a mand-mounted sb, we mount it with MS_MANDLOCK, then
>> restore a file lock on it, then try to open this file for some other
>> reason.
>> The criu restore would block (or abort with error).
>
> Ok, I will look where such situations may happen on restore.
> And could you tell where do you expect this can happen?

And a little note:
It looks like, exclusive mandatory locs allow to open file afaics -- I
found it while was writing test for that, and only rw will be blocked
(or return error).
So, CRIU should open and read()/write() to such file on restore.

>> So either we somehow make full support for mandlocks, or (since we know
>> the problem exists) explicitly abort dumping these guys.
>
> Hmm, do you think, we should not?
> I mean, yep, mount part is already complicated, so only by that reason?