Index: oak-segment/src/main/java/org/apache/jackrabbit/oak/plugins/segment/file/FileAccess.java
===================================================================
--- oak-segment/src/main/java/org/apache/jackrabbit/oak/plugins/segment/file/FileAccess.java	(revision 1740460)
+++ oak-segment/src/main/java/org/apache/jackrabbit/oak/plugins/segment/file/FileAccess.java	(working copy)
@@ -45,9 +45,12 @@
      */
     static class Mapped extends FileAccess {
 
-        private final MappedByteBuffer buffer;
+        private final RandomAccessFile file;
 
+        private MappedByteBuffer buffer;
+
         Mapped(RandomAccessFile file) throws IOException {
+            this.file = file;
             this.buffer = file.getChannel().map(READ_ONLY, 0, file.length());
         }
 
@@ -70,7 +73,9 @@
         }
 
         @Override
-        public void close() {
+        public void close() throws IOException {
+            buffer = null;
+            file.close();
         }
 
     }