diff -Naur linux-2.5.49-mm2/mm/page_walk.c linux-2.5.49-mm2-ioe/mm/page_walk.c
--- linux-2.5.49-mm2/mm/page_walk.c	Wed Nov 27 14:48:33 2002
+++ linux-2.5.49-mm2-ioe/mm/page_walk.c	Wed Nov 27 17:05:35 2002
@@ -116,6 +116,7 @@
 	struct vm_area_struct *vma = pw->vma;
 	int write = pw->vm_flags & (VM_MAYWRITE|VM_WRITE);
 
+	/* follow_page also does all the checking of ptes for us. */
 	while (!(page= follow_page(vma->vm_mm, pw->virt, write))) {
 		int fault;
 
@@ -138,16 +139,7 @@
 		}
 		spin_lock(&vma->vm_mm->page_table_lock);
 	}
-	/* 
-	 * Given a physical address, is there a useful struct page pointing to
-	 * it?  This may become more complex in the future if we start dealing
-	 * with IO-aperture pages for direct-IO.
-	 */
-	if (pfn_valid(page_to_pfn(page)))
-		return page;
-
-	spin_unlock(&vma->vm_mm->page_table_lock);
-	return ERR_PTR(-EFAULT);
+	return page;
 }
 
 /* Setup page walking for the simple and common case. 
@@ -291,7 +283,7 @@
  			pw->page = single_page_walk(pw);
 			if (IS_ERR(pw->page)) {
 				ret = PTR_ERR(pw->page);
-				break;
+				goto out_unlocked;
 			}
 			ret = pw->walker(pw->data);
 			
@@ -304,7 +296,8 @@
  		} while (pw->virt < vma->vm_end);
 		spin_unlock(&pw->mm->page_table_lock);
 	} while (ret == 0);
-
+	
+out_unlocked:
 	/* cleanup after errors */
 	if (ret < 0 && pw->cleaner)
 		pw->cleaner(pw->data);
@@ -393,3 +386,12 @@
 EXPORT_SYMBOL(get_user_pages);
 EXPORT_SYMBOL(get_one_user_page);
 EXPORT_SYMBOL_GPL(walk_user_pages);
+EXPORT_SYMBOL_GPL(setup_simple_page_walk);
+EXPORT_SYMBOL_GPL(setup_sgl_page_walk);
+EXPORT_SYMBOL_GPL(fixup_sgl_walk);
+EXPORT_SYMBOL_GPL(gup_add_pages);
+EXPORT_SYMBOL_GPL(gup_cleanup_pages);
+EXPORT_SYMBOL_GPL(gup_cleanup_pages_kfree);
+EXPORT_SYMBOL_GPL(gup_add_sgls);
+EXPORT_SYMBOL_GPL(gup_cleanup_sgls);
+EXPORT_SYMBOL_GPL(gup_cleanup_sgls_kfree);