Re: [PATCH v2 6/7] NFS: direct-io: convert to FOLL_PIN pages

From: Christoph Hellwig
Date: Tue Sep 06 2022 - 02:50:15 EST


On Tue, Aug 30, 2022 at 09:18:42PM -0700, John Hubbard wrote:
static void nfs_direct_release_pages(struct iov_iter *iter, struct page **pages,
unsigned int npages)
> {
> - unsigned int i;
> - for (i = 0; i < npages; i++)
> - put_page(pages[i]);
> + if (user_backed_iter(iter) || iov_iter_is_bvec(iter))
> + dio_w_unpin_user_pages(pages, npages);
> + else
> + release_pages(pages, npages);

Instead of having this magic in all kinds of places, we need a helper
that takes the page array, npages and iter->type and does the right
thing.