Re: [PATCH v5 4/9] iov_iter: Add a function to extract a page list from an iterator

From: Christoph Hellwig
Date: Fri Jan 13 2023 - 00:28:29 EST


On Thu, Jan 12, 2023 at 09:15:50PM +0000, Al Viro wrote:
> This cleanup_mode thing is wrong. It's literally a trivial
> function of ->user_backed and ->data_source - we don't
> even need to look at the ->type.
>
> Separate it into an inline helper and be done with that;
> don't carry it all over the place.
>
> It's really "if not user-backed => 0, otherwise it's FOLL_PIN or FOLL_GET,
> depending upon the direction".

That would defintively clean up the bio code as well..