diff --git a/fs/buffer.c b/fs/buffer.c
index 7ba5838..9819632 100644
--- a/fs/buffer.c
+++ b/fs/buffer.c
@@ -2564,14 +2564,13 @@
 	struct inode *inode = page->mapping->host;
 	struct buffer_head *head = fsdata;
 	struct buffer_head *bh;
+	BUG_ON(fsdata != NULL && page_has_buffers(page));
 
-	if (!PageMappedToDisk(page)) {
-		if (unlikely(copied < len) && !page_has_buffers(page))
-			attach_nobh_buffers(page, head);
-		if (page_has_buffers(page))
-			return generic_write_end(file, mapping, pos, len,
-						copied, page, fsdata);
-	}
+	if (unlikely(copied < len) && !page_has_buffers(page))
+		attach_nobh_buffers(page, head);
+	if (page_has_buffers(page))
+		return generic_write_end(file, mapping, pos, len,
+					copied, page, fsdata);
 
 	SetPageUptodate(page);
 	set_page_dirty(page);