[v15,03/17] iomap: Convert to_iomap_page to take a folio

Commit Message

Matthew Wilcox (Oracle) July 19, 2021, 6:39 p.m. UTC

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) <[e-mail]>
Reviewed-by: Darrick J. Wong <[e-mail]>
---
 fs/iomap/buffered-io.c | 32 +++++++++++++++-----------------
 1 file changed, 15 insertions(+), 17 deletions(-)

Comments

Christoph Hellwig July 20, 2021, 6:49 a.m. UTC | #1

On Mon, Jul 19, 2021 at 07:39:47PM +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) <[e-mail]>
> Reviewed-by: Darrick J. Wong <[e-mail]>

Looks good,

Reviewed-by: Christoph Hellwig <[e-mail]>

(all the iomap work is going to cause heavy clashes with the iomap_iter
work, but they should be mostly context, not really functional).

Patch

diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c
index 87ccb3438bec..d4870a2691f9 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);
@@ -435,7 +431,8 @@  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;
@@ -1012,7 +1009,8 @@  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);