__page_ref_mod_and_return
__page_ref_mod_and_return(&folio->page, -nr, ret);
__page_ref_mod_and_return(page, 1, ret);
__page_ref_mod_and_return(page, -1, ret);
extern void __page_ref_mod_and_return(struct page *page, int v, int ret);
EXPORT_SYMBOL(__page_ref_mod_and_return);