[linux-yocto] [PATCH 4/8] mm: softdirty: don't forget to save file map softdiry bit on unmap

[Yang Shi]

From: Cyrill Gorcunov <gorcunov at openvz.org>

commit b43790eedd31e9535b89bbfa45793919e9504c34 upstream

pte_file_mksoft_dirty operates with argument passed by a value and
returns modified result thus we need to assign @ptfile here, otherwise
itis a no-op which may lead to loss of the softdirty bit.

Signed-off-by: Cyrill Gorcunov <gorcunov at openvz.org>
Cc: Pavel Emelyanov <xemul at parallels.com>
Cc: Hugh Dickins <hughd at google.com>
Signed-off-by: Andrew Morton <akpm at linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>
Signed-off-by: Yang Shi <yang.shi at windriver.com>
---
 mm/rmap.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/rmap.c b/mm/rmap.c
index cdbd312..d6eeae8 100644
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1351,7 +1351,7 @@ static int try_to_unmap_cluster(unsigned long cursor, unsigned int *mapcount,
 		if (page->index != linear_page_index(vma, address)) {
 			pte_t ptfile = pgoff_to_pte(page->index);
 			if (pte_soft_dirty(pteval))
-				pte_file_mksoft_dirty(ptfile);
+				ptfile = pte_file_mksoft_dirty(ptfile);
 			set_pte_at(mm, address, pte, ptfile);
 		}
 
-- 
2.0.2