diff --git a/include/linux/journal-head.h b/include/linux/journal-head.h
index 423cb6d..c18b46f 100644
--- a/include/linux/journal-head.h
+++ b/include/linux/journal-head.h
@@ -66,6 +66,8 @@
 	 * transaction (if there is one).  Only applies to buffers on a
 	 * transaction's data or metadata journaling list.
 	 * [j_list_lock] [jbd_lock_bh_state()]
+	 * Either of these locks is enough for reading, both are needed for
+	 * changes.
 	 */
 	transaction_t *b_transaction;