[PATCH] mm: make filemap_nopage use NOPAGE_SIGBUS

Don't open-code NOPAGE_SIGBUS.
Signed-off-by: Adam Litke <agl@us.ibm.com>
Acked-by: Hugh Dickins <hugh@veritas.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

mm/filemap.c

@@ -1471,7 +1471,7 @@ struct page *filemap_nopage(struct vm_area_struct *area,
 	 * accessible..
 	 */
 	if (area->vm_mm == current->mm)
-		return NULL;
+		return NOPAGE_SIGBUS;
 	/* Fall through to the non-read-ahead case */
 no_cached_page:
 	/*
@@ -1496,7 +1496,7 @@ struct page *filemap_nopage(struct vm_area_struct *area,
 	 */
 	if (error == -ENOMEM)
 		return NOPAGE_OOM;
-	return NULL;
+	return NOPAGE_SIGBUS;
 
 page_not_uptodate:
 	if (!did_readaround) {
@@ -1565,7 +1565,7 @@ struct page *filemap_nopage(struct vm_area_struct *area,
 	 */
 	shrink_readahead_size_eio(file, ra);
 	page_cache_release(page);
-	return NULL;
+	return NOPAGE_SIGBUS;
 }
 EXPORT_SYMBOL(filemap_nopage);