[PATCH] reiser4: vfs: add truncate_inode_pages_range()

This patch makes truncate_inode_pages_range from truncate_inode_pages.
truncate_inode_pages became a one-liner call to truncate_inode_pages_range.

Reiser4 needs truncate_inode_pages_ranges because it tries to keep
correspondence between existences of metadata pointing to data pages and pages
to which those metadata point to.  So, when metadata of certain part of file
is removed from filesystem tree, only pages of corresponding range are to be
truncated.

(Needed by the madvise(MADV_REMOVE) patch)

Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a06a84d..92acae9 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -896,6 +896,8 @@
 /* filemap.c */
 extern unsigned long page_unuse(struct page *);
 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);
 
 /* generic vm_area_ops exported for stackable file systems */
 extern struct page *filemap_nopage(struct vm_area_struct *, unsigned long, int *);