Re: [PATCH v14 092/138] iomap: Convert to_iomap_page to take a folio

Darrick J. Wong
2021-07-15T21:09:09Z

On Thu, Jul 15, 2021 at 04:36:18AM +0100, Matthew Wilcox (Oracle) wrote:
> The big comment about only using a head page can go away now that
> it takes a folio argument.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>

Looks decent to me,
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

> ---
> fs/iomap/buffered-io.c | 35 +++++++++++++++++------------------
> 1 file changed, 17 insertions(+), 18 deletions(-)
>
> diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
> index 41da4f14c00b..cd5c2f24cb7e 100644
> --- a/fs/iomap/buffered-io.c
> +++ b/fs/iomap/buffered-io.c
> @@ -22,8 +22,8 @@
> #include "../internal.h"
>
> /*
> - * Structure allocated for each page or THP when block size < page size
> - * to track sub-page uptodate status and I/O completions.
> + * Structure allocated for each folio when block size < folio size
> + * to track sub-folio uptodate status and I/O completions.
> */
> struct iomap_page {
> atomic_t read_bytes_pending;
> @@ -32,17 +32,10 @@ struct iomap_page {
> unsigned long uptodate[];
> };
>
> -static inline struct iomap_page *to_iomap_page(struct page *page)
> +static inline struct iomap_page *to_iomap_page(struct folio *folio)
> {
> - /*
> - * per-block data is stored in the head page. Callers should
> - * not be dealing with tail pages (and if they are, they can
> - * call thp_head() first.
> - */
> - VM_BUG_ON_PGFLAGS(PageTail(page), page);
> -
> - if (page_has_private(page))
> - return (struct iomap_page *)page_private(page);
> + if (folio_test_private(folio))
> + return folio_get_private(folio);
> return NULL;
> }
>
> @@ -51,7 +44,8 @@ static struct bio_set iomap_ioend_bioset;
> static struct iomap_page *
> iomap_page_create(struct inode *inode, struct page *page)
> {
> - struct iomap_page *iop = to_iomap_page(page);
> + struct folio *folio = page_folio(page);
> + struct iomap_page *iop = to_iomap_page(folio);
> unsigned int nr_blocks = i_blocks_per_page(inode, page);
>
> if (iop || nr_blocks <= 1)
> @@ -144,7 +138,8 @@ iomap_adjust_read_range(struct inode *inode, struct iomap_page *iop,
> static void
> iomap_iop_set_range_uptodate(struct page *page, unsigned off, unsigned len)
> {
> - struct iomap_page *iop = to_iomap_page(page);
> + struct folio *folio = page_folio(page);
> + struct iomap_page *iop = to_iomap_page(folio);
> struct inode *inode = page->mapping->host;
> unsigned first = off >> inode->i_blkbits;
> unsigned last = (off + len - 1) >> inode->i_blkbits;
> @@ -173,7 +168,8 @@ static void
> iomap_read_page_end_io(struct bio_vec *bvec, int error)
> {
> struct page *page = bvec->bv_page;
> - struct iomap_page *iop = to_iomap_page(page);
> + struct folio *folio = page_folio(page);
> + struct iomap_page *iop = to_iomap_page(folio);
>
> if (unlikely(error)) {
> ClearPageUptodate(page);
> @@ -433,7 +429,8 @@ int
> iomap_is_partially_uptodate(struct page *page, unsigned long from,
> unsigned long count)
> {
> - struct iomap_page *iop = to_iomap_page(page);
> + struct folio *folio = page_folio(page);
> + struct iomap_page *iop = to_iomap_page(folio);
> struct inode *inode = page->mapping->host;
> unsigned len, first, last;
> unsigned i;
> @@ -1011,7 +1008,8 @@ static void
> iomap_finish_page_writeback(struct inode *inode, struct page *page,
> int error, unsigned int len)
> {
> - struct iomap_page *iop = to_iomap_page(page);
> + struct folio *folio = page_folio(page);
> + struct iomap_page *iop = to_iomap_page(folio);
>
> if (error) {
> SetPageError(page);
> @@ -1304,7 +1302,8 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc,
> struct writeback_control *wbc, struct inode *inode,
> struct page *page, u64 end_offset)
> {
> - struct iomap_page *iop = to_iomap_page(page);
> + struct folio *folio = page_folio(page);
> + struct iomap_page *iop = to_iomap_page(folio);
> struct iomap_ioend *ioend, *next;
> unsigned len = i_blocksize(inode);
> u64 file_offset; /* file offset of page */
> --
> 2.30.2
>