[PATCH] read_mapping_page for address space

Add read_mapping_page() which is used for callers that pass
mapping->a_ops->readpage as the filler for read_cache_page.  This removes
some duplication from filesystem code.

Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/fs/namei.c b/fs/namei.c
index 184fe4ac..bb4a3e4 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -2577,8 +2577,7 @@
 {
 	struct page * page;
 	struct address_space *mapping = dentry->d_inode->i_mapping;
-	page = read_cache_page(mapping, 0, (filler_t *)mapping->a_ops->readpage,
-				NULL);
+	page = read_mapping_page(mapping, 0, NULL);
 	if (IS_ERR(page))
 		goto sync_fail;
 	wait_on_page_locked(page);