[PATCH 5.11 031/210] nds32: flush_dcache_page: use page_mapping_file to avoid races with swapoff

Greg Kroah-Hartman
2021-04-12T09:22:23Z

From: Mike Rapoport <rppt@linux.ibm.com>

commit a3a8833dffb7e7329c2586b8bfc531adb503f123 upstream.

Commit cb9f753a3731 ("mm: fix races between swapoff and flush dcache")
updated flush_dcache_page implementations on several architectures to
use page_mapping_file() in order to avoid races between page_mapping()
and swapoff().

This update missed arch/nds32 and there is a possibility of a race
there.

Replace page_mapping() with page_mapping_file() in nds32 implementation
of flush_dcache_page().

Link: https://lkml.kernel.org/r/20210330175126.26500-1-rppt@kernel.org
Fixes: cb9f753a3731 ("mm: fix races between swapoff and flush dcache")
Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: Greentime Hu <green.hu@gmail.com>
Cc: Huang Ying <ying.huang@intel.com>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Vincent Chen <deanbo422@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
arch/nds32/mm/cacheflush.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/nds32/mm/cacheflush.c
+++ b/arch/nds32/mm/cacheflush.c
@@ -238,7 +238,7 @@ void flush_dcache_page(struct page *page
{
struct address_space *mapping;

- mapping = page_mapping(page);
+ mapping = page_mapping_file(page);
if (mapping && !mapping_mapped(mapping))
set_bit(PG_dcache_dirty, &page->flags);
else {