> + folio = page_folio(page);
> +
> + if (!folio_test_large(folio) ||
> + (bio_op(bio) == REQ_OP_ZONE_APPEND)) {
I don't understand why you need this branch. All the arithmetics
below should also work just fine for non-large folios, and there
while the same_page logic in bio_iov_add_zone_append_page probably
needs to be folio-ized first, it should be handled the same way here
as well. bio_iov_add_page should also be moved to take a folio
before the (otherwise nice) changes here.
and of course in the long run we really need a folio version of
pin_user_pages and iov_iter_extract_pages.
