Re: [PATCH v7 3/8] fsdax: Replace mmap entry in case of CoW

[Shiyang Ruan]

On 2021/8/23 20:57, Christoph Hellwig wrote:
> On Thu, Aug 19, 2021 at 03:54:01PM -0700, Dan Williams wrote:
> > static void *dax_insert_entry(struct xa_state *xas, struct vm_fault *vmf,
> >                                const struct iomap_iter *iter, void
> > *entry, pfn_t pfn,
> >                                unsigned long flags)
> >
> >
> > >   {
> > > +       struct address_space *mapping = vmf->vma->vm_file->f_mapping;
> > >          void *new_entry = dax_make_entry(pfn, flags);
> > > +       bool dirty = insert_flags & DAX_IF_DIRTY;
> > > +       bool cow = insert_flags & DAX_IF_COW;
> >
> > ...and then calculate these flags from the source data. I'm just
> > reacting to "yet more flags".
>
> Except for the overly long line above that seems like a good idea.
> The iomap_iter didn't exist for most of the time this patch has been
> around.

So should I reuse the iter->flags to pass the insert_flags? (left shift 
it to higher bits)

--
Thanks,
Ruan.