On Wed, Jun 16, 2021 at 11:30:46AM +0100, David Howells wrote: > Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> wrote: > > > + struct page *page = &folio->page; > > Isn't that a layering violation? Should it be something like: > > struct page *page = folio_head(); > > or: > > struct page *page = folio_subpage(0); It's not a layering violation, but it is bad style. It indicates the function is incompletely converted to folios and probably isn't actually folio-safe. After about a dozen more commits, it's possible to finish the conversion in afs_page_mkwrite(), and I do so here: https://git.infradead.org/users/willy/pagecache.git/commitdiff/f49f546f4ad83c8a6fec861af5f9d0825b850abc It's still not 100% clean as afs_page_dirty() expects a head|base page instead of a folio, so there's more cleanup required. Also trace_afs_page_dirty() continues to take a page instead of a folio, but that tends to not actually be a problem.
