xfs
[Top] [All Lists]

Re: mmap vs mtime in 2.6.26 and up

To: Ferenc Wagner <wferi@xxxxxxx>
Subject: Re: mmap vs mtime in 2.6.26 and up
From: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Date: Mon, 18 May 2009 07:43:05 -0400
Cc: Ray Lee <ray-lk@xxxxxxxxxxxxx>, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>, Peter Staubach <staubach@xxxxxxxxxx>, Miklos Szeredi <mszeredi@xxxxxxx>, xfs@xxxxxxxxxxx, linux-kernel@xxxxxxxxxxxxxxx
In-reply-to: <20090515165054.GA11439@xxxxxxxxxxxxx>
User-agent: Mutt/1.5.18 (2008-05-17)
On Fri, May 15, 2009 at 12:50:54PM -0400, Christoph Hellwig wrote:
> On Fri, May 15, 2009 at 06:40:29PM +0200, Ferenc Wagner wrote:
> > Thanks for the analysis.  Unfortunately I don't nearly know enough to
> > work on this issue, but would like to track it as it affects our
> > backup system.  So, shouldn't #2645 be reopened again?
> 
> Yes, definitively as the current "fix" is incorrected.  I'll try to cook
> up a correct version once I get some time.

Doing this correctly in the framework of the current codee is
unfortunately not so easy, as calling ->setattr requires taking i_mutex
which we can't in the pagefaul path.

To fix this properly we need to actually update the timestamps during
msync and co as done by the patches from Miklos:

        http://lkml.org/lkml/2007/2/28/166

and Peter:

        http://lkml.org/lkml/2006/5/31/176

----- End forwarded message -----

<Prev in Thread] Current Thread [Next in Thread>