Re: [PATCH 2/4] fscache: Fix race in fscache_op_complete() due to split atomic_sub & read

[David Howells]

Andrea Parri <andrea.parri@xxxxxxxxxxxxxxxxxxxx> wrote:

> > > > Fix this by using atomic_sub_return() instead of two calls.
> > > 
> > > Seems a case for atomic_sub_return_relaxed()... why not?
> > 
> > Ummm...  In that case, should it be atomic_sub_return_release()?
> 
> Hard to tell for me: your diff./changelog is all I know about fs-cache
> ... (and this suggests -no-, given that atomic_sub() and atomic_read()
> provide no ordering...); good question though. ;-)

Yeah, that doesn't mean that it shouldn't be stricter than 'relaxed'.  It's
kind of like an unlock/release operation, so I think 'release' is probably the
minimum requirement.

David