Re: [PATCH v11 13/33] mm/filemap: Add folio_index(), folio_file_page() and folio_contains()

[Matthew Wilcox]

On Wed, Jun 16, 2021 at 11:03:23AM +0100, David Howells wrote:
> Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> wrote:
> 
> > folio_index() is the equivalent of page_index() for folios.
> > folio_file_page() is the equivalent of find_subpage().
> > folio_contains() is the equivalent of thp_contains().
> > 
> > No changes to generated code.
> > 
> > Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> > Reviewed-by: Christoph Hellwig <hch@xxxxxx>
> > Acked-by: Jeff Layton <jlayton@xxxxxxxxxx>
> > Acked-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
> > Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
> > Reviewed-by: William Kucharski <william.kucharski@xxxxxxxxxx>
> 
> folio_subpage() might be a better name than folio_file_page().

I want it to be clear that you can't call this for folios which
aren't part of a file.  For example, anonymous memory.