+ md-remove-the-last-use-of-page_buffers.patch added to mm-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: md: remove the last use of page_buffers()
has been added to the -mm mm-unstable branch.  Its filename is
     md-remove-the-last-use-of-page_buffers.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/md-remove-the-last-use-of-page_buffers.patch

This patch will later appear in the mm-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Subject: md: remove the last use of page_buffers()
Date: Sun, 20 Sep 2026 22:28:11 -0400

Convert the page to a folio and use folio_buffers() instead.  This does
introduce one extra call to compound_head(), but will simplify a later
conversion of md-bitmap to use folios instead of pages.

Link: https://lore.kernel.org/20260920-remove-pg_private-v5-15-bb68b6a21869@nvidia.com
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
---

 drivers/md/md-bitmap.c      |    3 ++-
 include/linux/buffer_head.h |    7 +------
 2 files changed, 3 insertions(+), 7 deletions(-)

--- a/drivers/md/md-bitmap.c~md-remove-the-last-use-of-page_buffers
+++ a/drivers/md/md-bitmap.c
@@ -516,7 +516,8 @@ static void end_bitmap_write(struct bio
 
 static void write_file_page(struct bitmap *bitmap, struct page *page, int wait)
 {
-	struct buffer_head *bh = page_buffers(page);
+	struct folio *folio = page_folio(page);
+	struct buffer_head *bh = folio_buffers(folio);
 
 	while (bh && bh->b_blocknr) {
 		atomic_inc(&bitmap->pending_writes);
--- a/include/linux/buffer_head.h~md-remove-the-last-use-of-page_buffers
+++ a/include/linux/buffer_head.h
@@ -175,12 +175,7 @@ static inline unsigned long bh_offset(co
 	return (unsigned long)(bh)->b_data & (page_size(bh->b_page) - 1);
 }
 
-/* If we *know* page->private refers to buffer_heads */
-#define page_buffers(page)					\
-	({							\
-		BUG_ON(!PagePrivate(page));			\
-		((struct buffer_head *)page_private(page));	\
-	})
+/* If we *know* folio->private refers to buffer_heads */
 #define folio_buffers(folio)		folio_get_private(folio)
 
 void buffer_check_dirty_writeback(struct folio *folio,
_

Patches currently in -mm which might be from willy@infradead.org are

md-use-folio_alloc_buffers.patch
md-use-folio-apis-in-free_page.patch
md-remove-the-last-use-of-page_buffers.patch