Re: [PATCH v14 099/138] iomap: Convert bio completions to use folios

Darrick J. Wong
2021-07-15T21:30:06Z

On Thu, Jul 15, 2021 at 04:36:25AM +0100, Matthew Wilcox (Oracle) wrote:
> Use bio_for_each_folio() to iterate over each folio in the bio
> instead of iterating over each page.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Neat conversion,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
> fs/iomap/buffered-io.c | 46 +++++++++++++++++-------------------------
> 1 file changed, 18 insertions(+), 28 deletions(-)
>
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 707a96e36651..4732298f74e1 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -161,36 +161,29 @@ static void iomap_set_range_uptodate(struct folio *folio,
> folio_mark_uptodate(folio);
> }
>
> -static void
> -iomap_read_page_end_io(struct bio_vec *bvec, int error)
> +static void iomap_finish_folio_read(struct folio *folio, size_t offset,
> + size_t len, int error)
> {
> - struct page *page = bvec->bv_page;
> - struct folio *folio = page_folio(page);
> struct iomap_page *iop = to_iomap_page(folio);
>
> if (unlikely(error)) {
> folio_clear_uptodate(folio);
> folio_set_error(folio);
> } else {
> - size_t off = (page - &folio->page) * PAGE_SIZE +
> - bvec->bv_offset;
> -
> - iomap_set_range_uptodate(folio, iop, off, bvec->bv_len);
> + iomap_set_range_uptodate(folio, iop, offset, len);
> }
>
> - if (!iop || atomic_sub_and_test(bvec->bv_len, &iop->read_bytes_pending))
> + if (!iop || atomic_sub_and_test(len, &iop->read_bytes_pending))
> folio_unlock(folio);
> }
>
> -static void
> -iomap_read_end_io(struct bio *bio)
> +static void iomap_read_end_io(struct bio *bio)
> {
> int error = blk_status_to_errno(bio->bi_status);
> - struct bio_vec *bvec;
> - struct bvec_iter_all iter_all;
> + struct folio_iter fi;
>
> - bio_for_each_segment_all(bvec, bio, iter_all)
> - iomap_read_page_end_io(bvec, error);
> + bio_for_each_folio_all(fi, bio)
> + iomap_finish_folio_read(fi.folio, fi.offset, fi.length, error);
> bio_put(bio);
> }
>
> @@ -1014,23 +1007,21 @@ vm_fault_t iomap_page_mkwrite(struct vm_fault *vmf, const struct iomap_ops *ops)
> }
> EXPORT_SYMBOL_GPL(iomap_page_mkwrite);
>
> -static void
> -iomap_finish_page_writeback(struct inode *inode, struct page *page,
> - int error, unsigned int len)
> +static void iomap_finish_folio_write(struct inode *inode, struct folio *folio,
> + size_t len, int error)
> {
> - struct folio *folio = page_folio(page);
> struct iomap_page *iop = to_iomap_page(folio);
>
> if (error) {
> - SetPageError(page);
> + folio_set_error(folio);
> mapping_set_error(inode->i_mapping, -EIO);
> }
>
> - WARN_ON_ONCE(i_blocks_per_page(inode, page) > 1 && !iop);
> + WARN_ON_ONCE(i_blocks_per_folio(inode, folio) > 1 && !iop);
> WARN_ON_ONCE(iop && atomic_read(&iop->write_bytes_pending) <= 0);
>
> if (!iop || atomic_sub_and_test(len, &iop->write_bytes_pending))
> - end_page_writeback(page);
> + folio_end_writeback(folio);
> }
>
> /*
> @@ -1049,8 +1040,7 @@ iomap_finish_ioend(struct iomap_ioend *ioend, int error)
> bool quiet = bio_flagged(bio, BIO_QUIET);
>
> for (bio = &ioend->io_inline_bio; bio; bio = next) {
> - struct bio_vec *bv;
> - struct bvec_iter_all iter_all;
> + struct folio_iter fi;
>
> /*
> * For the last bio, bi_private points to the ioend, so we
> @@ -1061,10 +1051,10 @@ iomap_finish_ioend(struct iomap_ioend *ioend, int error)
> else
> next = bio->bi_private;
>
> - /* walk each page on bio, ending page IO on them */
> - bio_for_each_segment_all(bv, bio, iter_all)
> - iomap_finish_page_writeback(inode, bv->bv_page, error,
> - bv->bv_len);
> + /* walk all folios in bio, ending page IO on them */
> + bio_for_each_folio_all(fi, bio)
> + iomap_finish_folio_write(inode, fi.folio, fi.length,
> + error);
> bio_put(bio);
> }
> /* The ioend has been freed by bio_put() */
> --
> 2.30.2
>