Index: oak-lucene/src/main/java/org/apache/jackrabbit/oak/plugins/index/lucene/OakDirectory.java
===================================================================
--- oak-lucene/src/main/java/org/apache/jackrabbit/oak/plugins/index/lucene/OakDirectory.java	(revision 1675332)
+++ oak-lucene/src/main/java/org/apache/jackrabbit/oak/plugins/index/lucene/OakDirectory.java	(working copy)
@@ -23,6 +23,7 @@
 import java.io.IOException;
 import java.io.InputStream;
 import java.util.Collection;
+import java.util.Iterator;
 import java.util.List;
 
 import com.google.common.primitives.Ints;
@@ -30,6 +31,7 @@
 import org.apache.jackrabbit.oak.api.PropertyState;
 import org.apache.jackrabbit.oak.api.Type;
 import org.apache.jackrabbit.oak.spi.state.NodeBuilder;
+import org.apache.lucene.store.AlreadyClosedException;
 import org.apache.lucene.store.Directory;
 import org.apache.lucene.store.IOContext;
 import org.apache.lucene.store.IndexInput;
@@ -37,6 +39,7 @@
 import org.apache.lucene.store.Lock;
 import org.apache.lucene.store.LockFactory;
 import org.apache.lucene.store.NoLockFactory;
+import org.apache.lucene.util.WeakIdentityMap;
 
 import static com.google.common.base.Preconditions.checkElementIndex;
 import static com.google.common.base.Preconditions.checkNotNull;
@@ -329,29 +332,41 @@
     private static class OakIndexInput extends IndexInput {
 
         private final OakIndexFile file;
+        private boolean isClone = false;
+        private final WeakIdentityMap<OakIndexInput, Boolean> clones;
 
         public OakIndexInput(String name, NodeBuilder file) {
             super(name);
             this.file = new OakIndexFile(name, file);
+            clones = WeakIdentityMap.newConcurrentHashMap();
         }
 
         private OakIndexInput(OakIndexInput that) {
             super(that.toString());
             this.file = new OakIndexFile(that.file);
+            clones = null;
         }
 
         @Override
         public OakIndexInput clone() {
-            return new OakIndexInput(this);
+            // TODO : shouldn't we use super#clone ?
+            OakIndexInput clonedIndexInput = new OakIndexInput(this);
+            clonedIndexInput.isClone = true;
+            if (clones != null) {
+                clones.put(clonedIndexInput, Boolean.TRUE);
+            }
+            return clonedIndexInput;
         }
 
         @Override
         public void readBytes(byte[] b, int o, int n) throws IOException {
+            checkNotClosed();
             file.readBytes(b, o, n);
         }
 
         @Override
         public byte readByte() throws IOException {
+            checkNotClosed();
             byte[] b = new byte[1];
             readBytes(b, 0, 1);
             return b[0];
@@ -359,16 +374,19 @@
 
         @Override
         public void seek(long pos) throws IOException {
+            checkNotClosed();
             file.seek(pos);
         }
 
         @Override
         public long length() {
+            checkNotClosed();
             return file.length;
         }
 
         @Override
         public long getFilePointer() {
+            checkNotClosed();
             return file.position;
         }
 
@@ -376,8 +394,22 @@
         public void close() {
             file.blob = null;
             file.data = null;
+
+            if (clones != null) {
+                for (Iterator<OakIndexInput> it = clones.keyIterator(); it.hasNext();) {
+                    final OakIndexInput clone = it.next();
+                    assert clone.isClone;
+                    clone.close();
+                }
+            }
         }
 
+        private void checkNotClosed() {
+            if (file.blob == null && file.data == null) {
+                throw new AlreadyClosedException("Already closed: " + this);
+            }
+        }
+
     }
 
     private final class OakIndexOutput extends IndexOutput {