HDFS-5124. Merge change r1516672 from branch-2.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2.1-beta@1516673 13f79535-47bb-0310-9956-ffa450edef68

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -99,6 +99,9 @@ Release 2.1.1-beta - UNRELEASED
     HDFS-4594. WebHDFS open sets Content-Length header to what is specified by
     length parameter rather than how much data is actually returned. (cnauroth)
 
+    HDFS-5124. DelegationTokenSecretManager#retrievePassword can cause deadlock 
+    in NameNode. (Daryn Sharp via jing9)
+
 Release 2.1.0-beta - 2013-08-22
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/security/token/delegation/DelegationTokenSecretManager.java

@@ -82,7 +82,7 @@ public class DelegationTokenSecretManager
   }
   
   @Override
-  public synchronized byte[] retrievePassword(
+  public byte[] retrievePassword(
       DelegationTokenIdentifier identifier) throws InvalidToken {
     try {
       // this check introduces inconsistency in the authentication to a
@@ -91,7 +91,7 @@ public class DelegationTokenSecretManager
       // different in that a standby may be behind and thus not yet know
       // of all tokens issued by the active NN.  the following check does
       // not allow ANY token auth, however it should allow known tokens in
-      checkAvailableForRead();
+      namesystem.checkOperation(OperationCategory.READ);
     } catch (StandbyException se) {
       // FIXME: this is a hack to get around changing method signatures by
       // tunneling a non-InvalidToken exception as the cause which the
@@ -103,17 +103,6 @@ public class DelegationTokenSecretManager
     return super.retrievePassword(identifier);
   }
   
-  @Override //SecretManager
-  public void checkAvailableForRead() throws StandbyException {
-    namesystem.checkOperation(OperationCategory.READ);
-    namesystem.readLock();
-    try {
-      namesystem.checkOperation(OperationCategory.READ);
-    } finally {
-      namesystem.readUnlock();
-    }
-  }
-
   /**
    * Returns expiry time of a token given its identifier.
    *