1 files changed, 4 insertions, 7 deletions

diff --git a/mm/migrate.c b/mm/migrate.c
index 576c25eeb1ca..367272d04423 100644
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -172,17 +172,14 @@ static void remove_anon_migration_ptes(struct page *old, struct page *new)
 {
         struct anon_vma *anon_vma;
         struct vm_area_struct *vma;
-        unsigned long mapping;
-
-        mapping = (unsigned long)new->mapping;
-
-        if (!mapping || (mapping & PAGE_MAPPING_ANON) == 0)
-                return;
 
         /*
          * We hold the mmap_sem lock. So no need to call page_lock_anon_vma.
          */
-        anon_vma = (struct anon_vma *) (mapping - PAGE_MAPPING_ANON);
+        anon_vma = page_anon_vma(new);
+        if (!anon_vma)
+                return;
+
         spin_lock(&anon_vma->lock);
 
         list_for_each_entry(vma, &anon_vma->head, anon_vma_node)