On Wed, Jun 05, 2024 at 02:54:54PM +0530, Kundan Kumar wrote:
> @@ -1214,27 +1214,27 @@ static int bio_iov_add_page(struct bio *bio, struct page *page,
>
> if (bio->bi_vcnt > 0 &&
> bvec_try_merge_page(&bio->bi_io_vec[bio->bi_vcnt - 1],
> - page, len, offset, &same_page)) {
> + &folio->page, len, offset, &same_page)) {
Let's make that folio_page(folio, 0)
> +static int bio_iov_add_zone_append_folio(struct bio *bio, struct folio *folio,
> unsigned int len, unsigned int offset)
> {
> struct request_queue *q = bdev_get_queue(bio->bi_bdev);
> bool same_page = false;
>
> - if (bio_add_hw_page(q, bio, page, len, offset,
> + if (bio_add_hw_page(q, bio, &folio->page, len, offset,
Likewise.
> @@ -1301,15 +1301,49 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
>
> for (left = size, i = 0; left > 0; left -= len, i++) {
> struct page *page = pages[i];
> + struct folio *folio = page_folio(page);
> +
> + /* Calculate the offset of page in folio */
> + folio_offset = (folio_page_idx(folio, page) << PAGE_SHIFT) +
> + offset;
No it doesn't. I'd drop the comment entirely, but if you must have a
comment, it turns the page offset into a folio offset.
> + len = min_t(size_t, (folio_size(folio) - folio_offset), left);
> +
> + num_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE);
> +
> + if (num_pages > 1) {
> + ssize_t bytes = left;
> + size_t contig_sz = min_t(size_t, PAGE_SIZE - offset,
> + bytes);
> +
> + /*
> + * Check if pages are contiguous and belong to the
> + * same folio.
> + */
You do like writing obvious comments, don't you?
> + for (j = i + 1; j < i + num_pages; j++) {
> + size_t next = min_t(size_t, PAGE_SIZE, bytes);
> +
> + if (page_folio(pages[j]) != folio ||
> + pages[j] != pages[j - 1] + 1) {
> + break;
> + }
> + contig_sz += next;
> + bytes -= next;
> + }
> + num_pages = j - i;
> + len = contig_sz;
> + }
