Re: [PATCH v2 44/46] mm/filemap: Convert mapping_get_entry to return a folio

From: Christoph Hellwig
Date: Mon Jun 28 2021 - 02:09:50 EST


On Fri, Jun 25, 2021 at 04:29:47AM +0100, Matthew Wilcox wrote:
> > > - * Return: The head page or shadow entry, %NULL if nothing is found.
> > > + * Return: The folio, swap or shadow entry, %NULL if nothing is found.
> >
> > This (old and new) reads a little weird, given that it returns a
> > struct folio, even if that happens to be a magic entry.
>
> Yeah. How about this?
>
> - * Return: The head page or shadow entry, %NULL if nothing is found.
> + * Return: The folio, swap or shadow entry, %NULL if nothing is found.
> */
> -static struct page *mapping_get_entry(struct address_space *mapping,
> - pgoff_t index)
> +static void *mapping_get_entry(struct address_space *mapping, pgoff_t index)
> {
>
> I still use a struct folio in mapping_get_entry(), but this means that
> pagecache_get_page() doesn't change in this patch.

Much better, thanks.