[CRIU] p.haul: mtouch test "Pre-dump failed"

[Cyrill Gorcunov]

On Sat, Mar 29, 2014 at 10:21:14PM +0400, Pavel Emelyanov wrote:
> On 03/28/2014 06:45 PM, Andrew Vagin wrote:
> > On Fri, Mar 28, 2014 at 02:39:33PM +0100, Oscar Fernández wrote:
> >> Hello Andrew, thanks for your answer.
> >>
> >> I'm using the latest version of CRIU ( https://github.com/xemul/criu ).
> >>
> >> Find attached the logs you ask for.
> >>
> >> Thanks for your help.
> > 
> > Which kernel version do you use?
> > 
> > I found that you problem is reproduced, if a kernel is compiled w/o
> > following commit:
> > 
> > commit 9d05746e7b16d8565dddbe3200faa1e669d23bbf
> > Author: Linus Torvalds <torvalds at linux-foundation.org>
> > Date:   Mon Sep 30 08:35:10 2013 -0700
> > 
> >     vfs: allow O_PATH file descriptors for fstatfs()
> > 
> > 
> > $ git describe 9d05746e7b16d8565dddbe3200faa1e669d23bbf
> > v3.12-rc4-126-g9d05746
> 
> Andrey, Cyrill, would you please find out since what time we require
> this patch. CRIU should work on 3.11 kernel.

Not sure if I understand you properly. The CRIU part where we started
to use O_PATH is

commit 307a5e1027881016eb605dfeb4220909c417eea8
Author: Andrey Vagin <avagin at openvz.org>
Date:   Thu Mar 13 16:16:43 2014 +0400

    pre-dump: avoid sleeping in the open() syscall

note that we may workaround this problem simply reading link
directly from dumpee and the parse it to find if the file
is fsnotify.