#ifdef CONFIG_MMU
+static inline struct anon_vma *page_anon_vma(struct page *page)
+{
+ if (((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) !=
+ PAGE_MAPPING_ANON)
+ return NULL;
+ return page_rmapping(page);
+}
+
static inline void anon_vma_lock(struct vm_area_struct *vma)
{
struct anon_vma *anon_vma = vma->anon_vma;