Re: [RFC][PATCH] PM / Sleep: Freeze filesystems during system suspend/hibernation

[Dave Chinner <david@fromorbit.com>]

On Wed, Dec 18, 2013 at 01:01:28AM +0100, Pavel Machek wrote:
> On Wed 2013-12-18 10:31:52, Dave Chinner wrote:
> > On Wed, Dec 18, 2013 at 12:08:43AM +0100, Pavel Machek wrote:
> > > Hi!
> > > 
> > > > >>> Did this patch ever wind up going anywhere?  Fedora has it sitting in
> > > > >>> our tree with a comment that says "rebase" and I don't see it in the
> > > > >>> linux-next tree at all.
> > > > >>>
> > > > >>> Did if fall through the cracks or was it NAKed somewhere?
> > > > >>
> > > > >> No, it wasn't in principle. There were some comments I haven't addressed yet.
> > > > >
> > > > > Dredging up a really old thread, sorry.
> > > > >
> > > > > We're still carrying this patch along in Fedora.  Should we drop it at
> > > > > this point, or is it still eventually going to head upstream?
> > > 
> > > I'd say drop.
> > 
> > I disagree - given the problem it is resolving leads to silent
> > filesystem corruption, this patch should be considered somewhat of a
> > priority to push...
> 
> Umm. Ok, I forgot what it does, really.

It ensures that the filesystem is in an quiescent state both in
memory and on disk, and it cannot be modified in memory or on disk
whilst the suspend image is being generated, or by log recovery
after a resume before the suspended image has been restored.

> So... for few years now suspend corrupts data on XFS? And Fedora has
> the fix but it is not in mainline? That does not sound right...

The issues freezing the filesystem before the suspend image is
created affect every journalled filesystem linux supports, be
it XFS, ext4, reiser, btrfs, etc.

Cheers,

Dave.
-- 
Dave Chinner
david@fromorbit.com