extern unsigned long do_brk(unsigned long, unsigned long);
-/* filemap.c */
-extern unsigned long page_unuse(struct page *);
+/* truncate.c */
extern void truncate_inode_pages(struct address_space *, loff_t);
extern void truncate_inode_pages_range(struct address_space *,
loff_t lstart, loff_t lend);