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

[Christoph Hellwig]

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.