From 9bf46441ad86da901c902bf78df2d213cc601185 Mon Sep 17 00:00:00 2001
From: David Hildenbrand <david@redhat.com>
Date: Wed, 29 May 2024 13:19:03 +0200
Subject: [PATCH] mm/filemap: reinitialize folio->_mapcount directly

Let's get rid of the page_mapcount_reset() call and simply reinitialize
folio->_mapcount directly.

Link: https://lkml.kernel.org/r/20240529111904.2069608-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org>	[zram/zsmalloc workloads]
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport (IBM) <rppt@kernel.org>
Cc: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/filemap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index 876cc64aadd7..ea2d44fcd326 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -177,7 +177,7 @@ static void filemap_unaccount_folio(struct address_space *mapping,
 				 * and we'd rather not leak it: if we're wrong,
 				 * another bad page check should catch it later.
 				 */
-				page_mapcount_reset(&folio->page);
+				atomic_set(&folio->_mapcount, -1);
 				folio_ref_sub(folio, mapcount);
 			}
 		}