HADOOP-9212. Potential deadlock in FileSystem.Cache/IPC/UGI.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1433879 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -554,6 +554,8 @@ Release 2.0.3-alpha - Unreleased
 
     HADOOP-8816. HTTP Error 413 full HEAD if using kerberos authentication. 
     (moritzmoeller via tucu)
+    
+    HADOOP-9212. Potential deadlock in FileSystem.Cache/IPC/UGI. (tomwhite)
 
 Release 2.0.2-alpha - 2012-09-07 
 

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/Credentials.java

@@ -18,10 +18,13 @@
 
 package org.apache.hadoop.security;
 
+import java.io.BufferedInputStream;
 import java.io.DataInput;
 import java.io.DataInputStream;
 import java.io.DataOutput;
 import java.io.DataOutputStream;
+import java.io.File;
+import java.io.FileInputStream;
 import java.io.IOException;
 import java.util.Arrays;
 import java.util.Collection;
@@ -148,8 +151,32 @@ public class Credentials implements Writable {
       in.close();
       return credentials;
     } catch(IOException ioe) {
-      IOUtils.cleanup(LOG, in);
       throw new IOException("Exception reading " + filename, ioe);
+    } finally {
+      IOUtils.cleanup(LOG, in);
+    }
+  }
+
+  /**
+   * Convenience method for reading a token storage file, and loading the Tokens
+   * therein in the passed UGI
+   * @param filename
+   * @param conf
+   * @throws IOException
+   */
+  public static Credentials readTokenStorageFile(File filename, Configuration conf)
+      throws IOException {
+    DataInputStream in = null;
+    Credentials credentials = new Credentials();
+    try {
+      in = new DataInputStream(new BufferedInputStream(
+          new FileInputStream(filename)));
+      credentials.readTokenStorageStream(in);
+      return credentials;
+    } catch(IOException ioe) {
+      throw new IOException("Exception reading " + filename, ioe);
+    } finally {
+      IOUtils.cleanup(LOG, in);
     }
   }
   

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/security/UserGroupInformation.java

@@ -20,6 +20,7 @@ package org.apache.hadoop.security;
 import static org.apache.hadoop.fs.CommonConfigurationKeys.HADOOP_KERBEROS_MIN_SECONDS_BEFORE_RELOGIN;
 import static org.apache.hadoop.fs.CommonConfigurationKeys.HADOOP_KERBEROS_MIN_SECONDS_BEFORE_RELOGIN_DEFAULT;
 
+import java.io.File;
 import java.io.IOException;
 import java.lang.reflect.UndeclaredThrowableException;
 import java.security.AccessControlContext;
@@ -656,10 +657,11 @@ public class UserGroupInformation {
 
         String fileLocation = System.getenv(HADOOP_TOKEN_FILE_LOCATION);
         if (fileLocation != null) {
-          // load the token storage file and put all of the tokens into the
+          // Load the token storage file and put all of the tokens into the
-          // user.
+          // user. Don't use the FileSystem API for reading since it has a lock
+          // cycle (HADOOP-9212).
           Credentials cred = Credentials.readTokenStorageFile(
-              new Path("file:///" + fileLocation), conf);
+              new File(fileLocation), conf);
           loginUser.addCredentials(cred);
         }
         loginUser.spawnAutoRenewalThreadForUserCreds();