--- old/src/java.base/unix/classes/sun/nio/fs/UnixFileStore.java	2017-08-09 14:53:23.857811150 -0700
+++ new/src/java.base/unix/classes/sun/nio/fs/UnixFileStore.java	2017-08-09 14:53:23.750811149 -0700
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2008, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2008, 2017, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -126,6 +126,12 @@
     }
 
     @Override
+    public long getBlockSize() throws IOException {
+       UnixFileStoreAttributes attrs = readAttributes();
+       return attrs.blockSize();
+    }
+
+    @Override
     public long getUnallocatedSpace() throws IOException {
         UnixFileStoreAttributes attrs = readAttributes();
         return attrs.blockSize() * attrs.freeBlocks();