Re: [PATCH v2 0/7] convert most filesystems to pin_user_pages_fast()

[Christoph Hellwig]

On Tue, Aug 30, 2022 at 09:18:36PM -0700, John Hubbard wrote:
> The conversion is temporarily guarded by
> CONFIG_BLK_USE_PIN_USER_PAGES_FOR_DIO. In the future (not part of this
> series), when we are certain that all filesystems have converted their
> Direct IO paths to FOLL_PIN, then we can do the final step, which is to
> get rid of CONFIG_BLK_USE_PIN_USER_PAGES_FOR_DIO and search-and-replace
> the dio_w_*() functions with their final names (see bvec.h changes).

What is the the point of these wrappers?  We should be able to
convert one caller at a time in an entirely safe way.