pgoff_t index; 
void page_add_anon_rmap(struct page *page,	struct vm_area_struct *vma, unsigned long address){	BUG_ON(PageReserved(page));	inc_mm_counter(vma->vm_mm, anon_rss);	if (atomic_inc_and_test(&page->_mapcount)) {		struct anon_vma *anon_vma = vma->anon_vma;		pgoff_t index;		BUG_ON(!anon_vma);		anon_vma = (void *) anon_vma + PAGE_MAPPING_ANON;		page->mapping = (struct address_space *) anon_vma;		index = (address - vma->vm_start) >> PAGE_SHIFT;		index += vma->vm_pgoff;		index >>= PAGE_CACHE_SHIFT - PAGE_SHIFT;		page->index = index;		inc_page_state(nr_mapped);	}	/* else checking page index and mapping is racy */}
10457	/local/tlutelli/issta_data/temp/c/2005_temp/2005/10457/4d7670e0f649f9e6e6ea6c8bb9f52441fa00f92b/rmap.c/buggy/mm/rmap.c