[CRIU] [PATCH] vma: don't skip vmas during searching a parent vma

[Pavel Emelyanov]

On 05/13/2014 05:18 PM, Andrew Vagin wrote:
> On Tue, May 13, 2014 at 05:09:14PM +0400, Pavel Emelyanov wrote:
>> On 05/13/2014 04:25 PM, Andrey Vagin wrote:
>>> We stop searching if vma->start is bigger than a required one.
>>> The coursor is set on the last examined vma. When we are searching a
>>> parent vma for the next vma, we start examine vma-s starting from
>>> coursor->next, so we don't examine the vma, which is pointed by cursor.
>>>
>>> This patch replaces list_for_each_entry_continue on list_for_each_entry_from.
>>>
>>> Reported-by: Filipe Brandenburger <filbranden at google.com>
>>> Signed-off-by: Andrey Vagin <avagin at openvz.org>
>>
>> Andrey, the recent 3 patches are great, but can you explain why keeping track
>> of mm-dumpable bit breaks cow and we start requiring these fixes?
> 
> The test reports errors like this:
> 17:14:08.431: 21816: ERR: cow01.c:78: Unable to open file /proc/21817/pagemap (errno = 13 (Permission denied))
> 
> These errors are ignored. cow01 worked fine when it was committed. Then
> we decided to execute tests from a non-root user and the test starts
> reports these error and stop to do something useful.

OK, but as you say -- test worked fine when it was committed. This means we
broke COW at some point after moving tests into non superuser?

> commit 495c8007bcf24cbec542bc715901ca10e9c0d3fa
> Author: Andrew Vagin <avagin at openvz.org>
> Date:   Wed Apr 24 10:46:22 2013 +0400
> 
>     zdtm: execite test cases from a test user
> 
> I'm going to fix test too.
> 
>>
>> Thanks,
>> Pavel
>>
> .
>