David Hildenbrand wrote:
>
> > -static inline unsigned long dax_folio_share_put(struct folio *folio)
> > +static inline unsigned long dax_folio_put(struct folio *folio)
> > {
> > - return --folio->page.share;
> > + unsigned long ref;
> > + int order, i;
> > +
> > + if (!dax_folio_is_shared(folio))
> > + ref = 0;
> > + else
> > + ref = --folio->share;
> > +
>
> It would still be good to learn how this non-atomic update here is safe
> (@Dan?), but that's independent of this series.
Apologies, I missed this question earlier.
All these manipulations are happening under xas_lock_irq() for @entry
where each @entry is 1:1 correlated with a folio. So concurrent attempts
to associate/disassociate a reflinked block in a file should synchronize
there.
> Staring at it, I would have thought we have to us an atomic_t here.
>
> Acked-by: David Hildenbrand <david@xxxxxxxxxx>
Thanks for taking a look!
