Re: [PATCH v4 25/25] cachefiles: Switch to wait_page_key

[Christoph Hellwig]

On Fri, Mar 05, 2021 at 04:19:01AM +0000, Matthew Wilcox (Oracle) wrote:
> Cachefiles was relying on wait_page_key and wait_bit_key being the
> same layout, which is fragile.  Now that wait_page_key is exposed in
> the pagemap.h header, we can remove that fragility.  Also switch it
> to use the folio directly instead of the page.

Yikes.  That fix itself is something that should go into mainline ASAP as
it fixes a massive landmine instead of mixing it up with the folio
conversion.