On Mon, Jul 17, 2023 at 09:25:58PM +0800, Peng Zhang wrote:
> +++ b/mm/page_io.c
> @@ -406,19 +406,19 @@ static void sio_read_complete(struct kiocb *iocb, long ret)
>
> if (ret == sio->len) {
> for (p = 0; p < sio->pages; p++) {
> - struct page *page = sio->bvec[p].bv_page;
> + struct folio *folio = page_folio(sio->bvec[p].bv_page);
>
> - SetPageUptodate(page);
> - unlock_page(page);
> + folio_mark_uptodate(folio);
> + folio_unlock(folio);
> }
I'm kind of shocked this works today. Usually bvecs coalesce adjacent
pages into a single entry, so you need to use a real iterator like
bio_for_each_folio_all() to extract individual pages from a bvec.
Maybe the sio bvec is constructed inefficiently.
I think Kent had some bvec folio iterators in progress?
> count_vm_events(PSWPIN, sio->pages);
> } else {
> for (p = 0; p < sio->pages; p++) {
> - struct page *page = sio->bvec[p].bv_page;
> + struct folio *folio = page_folio(sio->bvec[p].bv_page);
>
> - SetPageError(page);
> - ClearPageUptodate(page);
> - unlock_page(page);
> + folio_set_error(folio);
> + folio_clear_uptodate(folio);
> + folio_unlock(folio);
Similar questions to the last patch -- who checks the error flag on this
page/folio, and isn't the folio already !uptodate?
> }
> pr_alert_ratelimited("Read-error on swap-device\n");
> }
> --
> 2.25.1
>
