From: Hugh Dickins <hugh@veritas.com>

He who lectures others about hugetlbfs truncation might discover that it's
got screwed by his very own self.  I replaced zap_hugepage_range by
unmap_hugepage_range, overlooking that zap used "len" but unmap "end".

Signed-off-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Index: linux-2.6/fs/hugetlbfs/inode.c
===================================================================
--- linux-2.6.orig/fs/hugetlbfs/inode.c
+++ linux-2.6/fs/hugetlbfs/inode.c
@@ -308,7 +308,6 @@ hugetlb_vmtruncate_list(struct prio_tree
 
 	vma_prio_tree_foreach(vma, &iter, root, h_pgoff, ULONG_MAX) {
 		unsigned long h_vm_pgoff;
-		unsigned long v_length;
 		unsigned long v_offset;
 
 		h_vm_pgoff = vma->vm_pgoff >> (HPAGE_SHIFT - PAGE_SHIFT);
@@ -319,11 +318,8 @@ hugetlb_vmtruncate_list(struct prio_tree
 		if (h_vm_pgoff >= h_pgoff)
 			v_offset = 0;
 
-		v_length = vma->vm_end - vma->vm_start;
-
 		unmap_hugepage_range(vma,
-				vma->vm_start + v_offset,
-				v_length - v_offset);
+				vma->vm_start + v_offset, vma->vm_end);
 	}
 }