diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index a275da5786a..f4b0da19e2b 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -27,6 +27,8 @@ Release 2.0.3-alpha - Unreleased
 
     HDFS-3924. Multi-byte id in HdfsVolumeId. (Andrew Wang via atm)
 
+    HDFS-3936. MiniDFSCluster shutdown races with BlocksMap usage. (eli)
+
 Release 2.0.2-alpha - 2012-09-07 
   
   INCOMPATIBLE CHANGES
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlocksMap.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlocksMap.java
index e6b503781ac..ef21dc3a332 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlocksMap.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlocksMap.java
@@ -94,7 +94,7 @@ class BlocksMap {
   }
 
   void close() {
-    blocks = null;
+    // Empty blocks once GSet#clear is implemented (HDFS-3940)
   }
 
   BlockCollection getBlockCollection(Block b) {
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSClientRetries.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSClientRetries.java
index c89d9f68513..35b8a13d57a 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSClientRetries.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/TestDFSClientRetries.java
@@ -778,7 +778,7 @@ public class TestDFSClientRetries {
   }
 
   /** Test client retry with namenode restarting. */
-  @Test
+  @Test(timeout=300000)
   public void testNamenodeRestart() throws Exception {
     namenodeRestartTest(new Configuration(), false);
   }
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestWebHDFS.java b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestWebHDFS.java
index 8d9f1ea0d3b..969ad5c1fb9 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestWebHDFS.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/web/TestWebHDFS.java
@@ -80,7 +80,7 @@ public class TestWebHDFS {
     }
   }
 
-  @Test
+  @Test(timeout=300000)
   public void testLargeFile() throws Exception {
     largeFileTest(200L << 20); //200MB file length
   }
@@ -202,7 +202,7 @@ public class TestWebHDFS {
   }
 
   /** Test client retry with namenode restarting. */
-  @Test
+  @Test(timeout=300000)
   public void testNamenodeRestart() throws Exception {
     ((Log4JLogger)NamenodeWebHdfsMethods.LOG).getLogger().setLevel(Level.ALL);
     final Configuration conf = WebHdfsTestUtil.createConf();