On Mon, Oct 17, 2022 at 01:51:18PM -0700, Dan Williams wrote: > > A good design is that nothing has a struct folio * unless it can also > > prove it has a non-zero refcount on it, and that is simply impossible > > for any caller at this point. > > I agree that's a good design, and I think it is a bug to make this > request on anything but a zero-refcount folio, but plumbing pgmap > offsets to replace pfn_to_page() would require dax_direct_access() to > shift from a pfn lookup to a pgmap + offset lookup. That is fair for this series, but maybe the other pgmap users shouldn't be converted to use this style of API? Jason
