+ mm-vmscan-simplify-the-folio-refcount-check-in-pageout-fix.patch added to mm-new branch

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

The patch titled
     Subject: mm-vmscan-simplify-the-folio-refcount-check-in-pageout-fix
has been added to the -mm mm-new branch.  Its filename is
     mm-vmscan-simplify-the-folio-refcount-check-in-pageout-fix.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-vmscan-simplify-the-folio-refcount-check-in-pageout-fix.patch

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

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
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fixup patches in mm-new.

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------------------------------------------------------
From: Baolin Wang <baolin.wang@linux.alibaba.com>
Subject: mm-vmscan-simplify-the-folio-refcount-check-in-pageout-fix
Date: Mon, 22 Sep 2025 14:02:28 +0800

remove warning and comment, per Hugh

Link: https://lkml.kernel.org/r/392a9ca3-31ac-4447-bd44-3c656d63e4ca@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/vmscan.c |   10 +---------
 1 file changed, 1 insertion(+), 9 deletions(-)

--- a/mm/vmscan.c~mm-vmscan-simplify-the-folio-refcount-check-in-pageout-fix
+++ a/mm/vmscan.c
@@ -689,16 +689,8 @@ static pageout_t pageout(struct folio *f
 	 * A freeable shmem or swapcache folio is referenced only by the
 	 * caller that isolated the folio and the page cache.
 	 */
-	if (folio_ref_count(folio) != 1 + folio_nr_pages(folio))
+	if (folio_ref_count(folio) != 1 + folio_nr_pages(folio) || !mapping)
 		return PAGE_KEEP;
-	if (!mapping) {
-		/*
-		 * We should no longer have dirty folios with clean buffers and
-		 * a NULL mapping. However, let's be careful for now.
-		 */
-		VM_WARN_ON_FOLIO(true, folio);
-		return PAGE_KEEP;
-	}
 
 	if (!shmem_mapping(mapping) && !folio_test_anon(folio))
 		return PAGE_ACTIVATE;
_

Patches currently in -mm which might be from baolin.wang@linux.alibaba.com are

mm-vmscan-remove-folio_test_private-check-in-pageout.patch
mm-vmscan-simplify-the-folio-refcount-check-in-pageout.patch
mm-vmscan-simplify-the-folio-refcount-check-in-pageout-fix.patch