[dm-devel] Re: [PATCH 2.6.19 5/5] fs: freeze_bdev with semaphore not mutex

[Pavel Machek]

Hi!

> > > Well, it looks like the interactions with dm add quite a bit of
> > > complexity here.
> > 
> > What about just fixing xfs (thou shall not write to disk when kernel
> > threads are frozen), and getting rid of blockdev freezing?
> 
> Well, first I must admit you were absolutely right being suspicious with
> respect to this stuff.

(OTOH your patch found real bugs in suspend.c, so...)

> OTOH I have no idea _how_ we can tell xfs that the processes have been
> frozen.  Should we introduce a global flag for that or something?

I guess XFS should just do all the writes from process context, and
refuse any writing when its threads are frozen... I actually still
believe it is doing the right thing, because you can't really write to
disk from timer.
								Pavel
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