On Fri, Aug 21, 2020 at 09:20:58PM -0700, John Hubbard wrote: > Add a new BIO_FOLL_PIN flag to struct bio, whose "short int" flags field > was full, thuse triggering an expansion of the field from 16, to 32 > bits. This allows for a nice assertion in bio_release_pages(), that the > bio page release mechanism matches the page acquisition mechanism. > > Set BIO_FOLL_PIN whenever pin_user_pages_fast() is used, and check for > BIO_FOLL_PIN before using unpin_user_page(). When would the flag not be set when BIO_NO_PAGE_REF is not set? Also I don't think we can't just expand the flags field, but I can send a series to kill off two flags.
