diff --git a/src/mds/CInode.h b/src/mds/CInode.h
index 6eb396d3673..140353d45b9 100644
--- a/src/mds/CInode.h
+++ b/src/mds/CInode.h
@@ -71,6 +71,10 @@ struct default_file_layout {
 
   ceph_file_layout layout;
 
+  default_file_layout() {
+    memset(&layout, 0, sizeof(layout));
+  }
+
   void encode(bufferlist &bl) const {
     __u8 struct_v = 1;
     ::encode(struct_v, bl);