On Wed, Jan 08, 2025 at 04:18:42PM +0000, Lorenzo Stoakes wrote: > @@ -280,7 +269,10 @@ static void fb_deferred_io_work(struct work_struct *work) > struct folio *folio = page_folio(pageref->page); > > folio_lock(folio); > - folio_mkclean(folio); > + rmap_wrprotect_file_page(fbdefio->mapping, > + pageref->offset >> PAGE_SHIFT, > + compound_nr(pageref->page), > + page_to_pfn(pageref->page)); > folio_unlock(folio); Why do we need to lock the folio? (since this isn't necessarily a folio) Also, do we need compound_nr() here? I _think_ for defio, the number of pages allocated per object are fixed, so this should be an fbdefio->nr_pages field? (something that's always troubled me about compound_nr() is that it returns 1 for tail pages and the number you actually expect for head pages)
