[Natty] SRU: CIFS mount blocks suspend/hibernate

[Seth Forshee]

On Wed, Nov 09, 2011 at 05:43:54PM +0100, Stefan Bader wrote:
> On 09.11.2011 17:11, Chris J Arges wrote:
> > SRU Justification:
> > 
> > Impact:
> > If a cifs share is mounted in ubuntu-natty and we try to suspend cifsd
> > prevents the laptop from suspending.
> > 
> > Fix:
> > Apply f06ac72e929115f2772c29727152ba0832d641e4 cherry picked from
> > upstream commit (this is already in ubuntu-oneric) to ubuntu-natty linux
> > kernel.
> > This small patch allows the laptop to suspend even if a cifs share is
> > mounted.
> > 
> > Testcase:
> > Boot ubuntu-natty. Mount cifs share. Suspend or Hibernate. (This will
> > not work.)
> > Boot ubuntu-natty with cifs patch applied. Mount cifs share. Suspend or
> > Hibernate. (This works.)
> > 
> > 
> > 
> > 
> > 
> > 
> The patch looks to be consistent with the upstream patch. However there seemed
> to have been a few follow-ups (of which the last one looks a bit worrying):
> 
> * [CIFS] Fixup trivial checkpatch warning
> * Fix build break when freezer not configured
> * PM / Freezer: Reimplement wait_event_freezekillable using
>   freezer_do_not_count/freezer_count

I was looking at this too.  It looks to me like the cherry picked patch
shouldn't fix the problem without also picking up 2792065 "PM / Freezer:
Make fake_signal_wake_up() wake TASK_KILLABLE tasks too" (although to my
understanding it has been verified to fix the problem, so I'm a bit
confused on that point). 2792065 is later reverted though.

It seems to me that it would be a good idea to additionally pick up
6f35c4a "PM / Freezer: Reimplement wait_event_freezekillable using
freezer_do_not_count/freezer_count" to get to the solution that's now
upstream, and probably e0c8ea1 "Fix build break when freezer not
configured" as well since it's trivial and fixes a potential build
failure.