From 2ca3a929382f11574fe115526ce889ee92eb53ac Mon Sep 17 00:00:00 2001
From: Baolin Wang <baolin.wang@linux.alibaba.com>
Date: Mon, 12 Aug 2024 15:42:08 +0800
Subject: [PATCH] mm: shmem: drop folio reference count using 'nr_pages' in
 shmem_delete_from_page_cache()

To support large folio swapin/swapout for shmem in the following patches,
drop the folio's reference count by the number of pages contained in the
folio when a shmem folio is deleted from shmem pagecache after adding into
swap cache.

Link: https://lkml.kernel.org/r/b371eadb27f42fc51261c51008fbb9a334985b4c.1723434324.git.baolin.wang@linux.alibaba.com
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Daniel Gomez <da.gomez@samsung.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Pankaj Raghav <p.raghav@samsung.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
 mm/shmem.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/shmem.c b/mm/shmem.c
index 635827fd9e77..2123043c7d85 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -851,7 +851,7 @@ static void shmem_delete_from_page_cache(struct folio *folio, void *radswap)
 	__lruvec_stat_mod_folio(folio, NR_FILE_PAGES, -nr);
 	__lruvec_stat_mod_folio(folio, NR_SHMEM, -nr);
 	xa_unlock_irq(&mapping->i_pages);
-	folio_put(folio);
+	folio_put_refs(folio, nr);
 	BUG_ON(error);
 }
 
-- 
2.49.0