mm: postpone migrated page mapping reset

Postpone resetting page->mapping until the final remove_migration_ptes().
Otherwise the expression PageAnon(migration_entry_to_page(entry)) does not
work.

Signed-off-by: Konstantin Khlebnikov <khlebnikov@openvz.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 1 insertions, 1 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 9871a56d82c..df141f60289 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -445,7 +445,6 @@ void migrate_page_copy(struct page *newpage, struct page *page)
         ClearPageSwapCache(page);
         ClearPagePrivate(page);
         set_page_private(page, 0);
-        page->mapping = NULL;
 
         /*
          * If any waiters have accumulated on the new page then
@@ -667,6 +666,7 @@ static int move_to_new_page(struct page *newpage, struct page *page,
         } else {
                 if (remap_swapcache)
                         remove_migration_ptes(page, newpage);
+                page->mapping = NULL;
         }
 
         unlock_page(newpage);