[merged mm-stable] writeback-move-the-folio_prepare_writeback-loop-out-of-write_cache_pages.patch removed from -mm tree

[Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>]

The quilt patch titled
     Subject: writeback: move the folio_prepare_writeback loop out of write_cache_pages()
has been removed from the -mm tree.  Its filename was
     writeback-move-the-folio_prepare_writeback-loop-out-of-write_cache_pages.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>
Subject: writeback: move the folio_prepare_writeback loop out of write_cache_pages()
Date: Thu, 15 Feb 2024 07:36:47 +0100

Move the loop for should-we-write-this-folio to writeback_get_folio.

[hch@xxxxxx: fold loop into existing helper instead of a separate one per Jan]
Link: https://lkml.kernel.org/r/20240215063649.2164017-13-hch@xxxxxx
Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
Signed-off-by: Christoph Hellwig <hch@xxxxxx>
Reviewed-by: Brian Foster <bfoster@xxxxxxxxxx>
Reviewed-by: Jan Kara <jack@xxxxxxx>
Acked-by: Dave Chinner <dchinner@xxxxxxxxxx>
Cc: Christian Brauner <brauner@xxxxxxxxxx>
Cc: David Howells <dhowells@xxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 mm/page-writeback.c |   18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

--- a/mm/page-writeback.c~writeback-move-the-folio_prepare_writeback-loop-out-of-write_cache_pages
+++ a/mm/page-writeback.c
@@ -2411,6 +2411,7 @@ static struct folio *writeback_get_folio
 {
 	struct folio *folio;
 
+retry:
 	folio = folio_batch_next(&wbc->fbatch);
 	if (!folio) {
 		folio_batch_release(&wbc->fbatch);
@@ -2418,8 +2419,17 @@ static struct folio *writeback_get_folio
 		filemap_get_folios_tag(mapping, &wbc->index, wbc_end(wbc),
 				wbc_to_tag(wbc), &wbc->fbatch);
 		folio = folio_batch_next(&wbc->fbatch);
+		if (!folio)
+			return NULL;
+	}
+
+	folio_lock(folio);
+	if (unlikely(!folio_prepare_writeback(mapping, wbc, folio))) {
+		folio_unlock(folio);
+		goto retry;
 	}
 
+	trace_wbc_writepage(wbc, inode_to_bdi(mapping->host));
 	return folio;
 }
 
@@ -2480,14 +2490,6 @@ int write_cache_pages(struct address_spa
 		if (!folio)
 			break;
 
-		folio_lock(folio);
-		if (!folio_prepare_writeback(mapping, wbc, folio)) {
-			folio_unlock(folio);
-			continue;
-		}
-
-		trace_wbc_writepage(wbc, inode_to_bdi(mapping->host));
-
 		error = writepage(folio, wbc, data);
 		wbc->nr_to_write -= folio_nr_pages(folio);
 
_

Patches currently in -mm which might be from willy@xxxxxxxxxxxxx are