Re: [PATCH v8 07/10] block: Switch to pinning pages.

[Christoph Hellwig]

On Tue, Jan 24, 2023 at 02:47:51PM +0000, David Howells wrote:
> > > +static inline void bio_set_cleanup_mode(struct bio *bio, struct iov_iter *iter)
> > > +{
> > > +	unsigned int cleanup_mode = iov_iter_extract_mode(iter);
> > > +
> > > +	if (cleanup_mode & FOLL_GET)
> > > +		bio_set_flag(bio, BIO_PAGE_REFFED);
> > > +	if (cleanup_mode & FOLL_PIN)
> > > +		bio_set_flag(bio, BIO_PAGE_PINNED);
> > 
> > Can FOLL_GET ever happen?
> 
> Yes - unless patches 8 and 9 are merged.  I had them as one, but Christoph
> split them up.

It can't.  Per your latest branch:

#define iov_iter_extract_mode(iter) (user_backed_iter(iter) ? FOLL_PIN : 0)