if (!pfn_valid(page_to_pfn(page)) || PageReserved(page)) return; 
BUG_ON(!pfn_valid(page_to_pfn(page))); 
void page_add_file_rmap(struct page *page){	BUG_ON(PageAnon(page));	if (!pfn_valid(page_to_pfn(page)) || PageReserved(page))		return;	if (atomic_inc_and_test(&page->_mapcount))		inc_page_state(nr_mapped);}
10457	/local/tlutelli/issta_data/temp/c/2005_temp/2005/10457/b5810039a54e5babf428e9a1e89fc1940fabff11/rmap.c/buggy/mm/rmap.c