HDFS-4274. BlockPoolSliceScanner does not close verification log during shutdown. Contributed by Chris Nauroth

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1432318 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -399,6 +399,9 @@ Release 2.0.3-alpha - Unreleased
     HDFS-4328. TestLargeBlock#testLargeBlockSize is timing out. (Chris Nauroth
     via atm)
 
+    HDFS-4274. BlockPoolSliceScanner does not close verification log during
+    shutdown. (Chris Nauroth via suresh)
+
   BREAKDOWN OF HDFS-3077 SUBTASKS
 
     HDFS-3077. Quorum-based protocol for reading and writing edit logs.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/BlockPoolSliceScanner.java

@@ -603,6 +603,15 @@ class BlockPoolSliceScanner {
     }
   }
 
+  /**
+   * Shuts down this BlockPoolSliceScanner and releases any internal resources.
+   */
+  void shutdown() {
+    if (verificationLog != null) {
+      verificationLog.close();
+    }
+  }
+  
   private void scan() {
     if (LOG.isDebugEnabled()) {
       LOG.debug("Starting to scan blockpool: " + blockPoolId);
@@ -610,7 +619,8 @@ class BlockPoolSliceScanner {
     try {
       adjustThrottler();
         
-      while (datanode.shouldRun && !Thread.interrupted()
+      while (datanode.shouldRun
+          && !datanode.blockScanner.blockScannerThread.isInterrupted()
           && datanode.isBPServiceAlive(blockPoolId)) {
         long now = Time.now();
         synchronized (this) {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/DataBlockScanner.java

@@ -100,6 +100,11 @@ public class DataBlockScanner implements Runnable {
       }
       bpScanner.scanBlockPoolSlice();
     }
+
+    // Call shutdown for each allocated BlockPoolSliceScanner.
+    for (BlockPoolSliceScanner bpss: blockPoolScannerMap.values()) {
+      bpss.shutdown();
+    }
   }
 
   // Wait for at least one block pool to be up
@@ -232,12 +237,24 @@ public class DataBlockScanner implements Runnable {
     }
   }
   
-  public synchronized void shutdown() {
+  public void shutdown() {
+    synchronized (this) {
       if (blockScannerThread != null) {
         blockScannerThread.interrupt();
       }
     }
 
+    // We cannot join within the synchronized block, because it would create a
+    // deadlock situation.  blockScannerThread calls other synchronized methods.
+    if (blockScannerThread != null) {
+      try {
+        blockScannerThread.join();
+      } catch (InterruptedException e) {
+        // shutting down anyway
+      }
+    }
+  }
+
   public synchronized void addBlockPool(String blockPoolId) {
     if (blockPoolScannerMap.get(blockPoolId) != null) {
       return;