Re: [PATCH] Avoid null-pointer access in w1/slaves/w1_therm

[David Fries]

On Sat, Mar 14, 2015 at 11:55:16PM +0300, Evgeniy Polyakov wrote:
> Hi David
> 
> 12.03.2015, 03:54, "David Fries" <david@xxxxxxxxx>:
> > Would that be removing all four refcnt, w1_slave, w1_master,
> > w1_family, w1_cb_block, or just some of them?  It sounds good to me,
> > if that had bugs there would be much more than just the w1 system
> > relying on it.  I don't know enough about that system or have the time
> > to code up that change.
> >
> > I can take another look at and post the reference counting w1_therm
> > fix instead of the mutex version as a near term work around until that
> > is available if you want.
> 
> Please cook up a quick fix for this problem - this bug really hurts people.
> And then we will discuss how 'ideal' life cycle should look

Done, I don't like it, I'm not sure anyone else will either, but I'm
no longer crashing in testing, so that's an improvement.  My
"production" system doesn't use w1_therm, so I only see these bugs in
development testing it.  I've come to the conclusion that in the face
of a slave vanishing, w1_therm can't avoid all the race conditions, so
the real fix must be elsewhere.