return PagePrivate(page) ? (struct metapage *)page->private : NULL; 
return PagePrivate(page) ? (struct metapage *)page_private(page) : NULL; 
static inline struct metapage *page_to_mp(struct page *page, uint offset){	return PagePrivate(page) ? (struct metapage *)page->private : NULL;}
10457	/local/tlutelli/issta_data/temp/c/2005_temp/2005/10457/4c21e2f2441dc5fbb957b030333f5a3f2d02dea7/jfs_metapage.c/buggy/fs/jfs/jfs_metapage.c