[PATCH 2/3] md: Use folio APIs in free_page()

["Matthew Wilcox (Oracle)" <willy@infradead.org>]

Convert the page to a folio.  This removes some of the last uses of a
few page APIs (detach_page_private(), page_buffers()).  Replaces two
calls to compound_head() with one.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
 drivers/md/md-bitmap.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/md/md-bitmap.c b/drivers/md/md-bitmap.c
index 5f1637f974c1..7b42db87d536 100644
--- a/drivers/md/md-bitmap.c
+++ b/drivers/md/md-bitmap.c
@@ -533,19 +533,18 @@ static void write_file_page(struct bitmap *bitmap, struct page *page, int wait)
 
 static void free_buffers(struct page *page)
 {
-	struct buffer_head *bh;
+	struct folio *folio = page_folio(page);
+	struct buffer_head *bh = folio_detach_private(folio);
 
-	if (!PagePrivate(page))
+	if (!bh)
 		return;
 
-	bh = page_buffers(page);
 	while (bh) {
 		struct buffer_head *next = bh->b_this_page;
 		free_buffer_head(bh);
 		bh = next;
 	}
-	detach_page_private(page);
-	put_page(page);
+	folio_put(folio);
 }
 
 /* read a page from a file.
-- 
2.47.3