Regarding bug 1243591 and aufs issue with file lifecycle

[Andy Whitcroft]

On Mon, Nov 04, 2013 at 02:51:24PM +0100, Wojciech Kocjan wrote:
> Hi,
> 
> I have submitted a bug for Ubuntu that it does not apply the
> aufs3-map.patch (the bug is here: https://bugs.launchpad.net/bugs/1243591).
> Joseph Salisbury has recommended me to contact the mailing list to describe
> the problem in more details.
> 
> I have originally been in contact with the aufs author and the discussion
> related to the issue can be found here:
> 
> http://sourceforge.net/mailarchive/forum.php?thread_name=17716.1382529737%40jrobl&forum_name=aufs-users
> 
> The outcome of the discussion is that aufs was never fully tested without
> the patch, and as an outcome of the discussion and subsequent checking,
> aufs now requires applying the patch to work properly.
> 
> The patch itself can be found here:
> 
> http://sourceforge.net/p/aufs/aufs3-standalone/ci/aufs3.2/tree/aufs3-mmap.patch

Gah that is a pretty nasty looking patch, affecting core vm structures
(making them bigger).  From what I can tell the underly bug is making
/proc/$$/maps contains incorrect filenames?  Is that right?  Which in
your case makes a binary which carries its own .so inside itself and
which pukes it out into a file for use, break, double gah.

I personally would need to be convinced that there is no regression
potential performance wise from this change at the very least before I
could see it being acceptable.  This is a bit of a specialist "use case"
which is being affected.

-apw