On Sat, Mar 13, 2021 at 12:37:16PM -0800, Andrew Morton wrote: > On Fri, 5 Mar 2021 04:18:45 +0000 "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> wrote: > > folio_index() is the equivalent of page_index() for folios. folio_page() > > finds the page in a folio for a page cache index. folio_contains() > > tells you whether a folio contains a particular page cache index. > > > > copy-paste changelog into each function's covering comment? Certainly. > > +static inline struct page *folio_page(struct folio *folio, pgoff_t index) > > +{ > > + index -= folio_index(folio); > > + VM_BUG_ON_FOLIO(index >= folio_nr_pages(folio), folio); > > + return &folio->page + index; > > +} > > One would expect folio_page() to be the reverse of page_folio(), only > it isn't anything like that. It is ... but only for files. So maybe folio_file_page()?