HDFS-10828. Fix usage of FsDatasetImpl object lock in ReplicaMap. (Arpit Agarwal)

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/BlockPoolSlice.java

@@ -54,6 +54,7 @@ import org.apache.hadoop.hdfs.server.datanode.ReplicaBeingWritten;
 import org.apache.hadoop.hdfs.server.datanode.ReplicaWaitingToBeRecovered;
 import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.io.nativeio.NativeIO;
+import org.apache.hadoop.util.AutoCloseableLock;
 import org.apache.hadoop.util.DataChecksum;
 import org.apache.hadoop.util.DiskChecker;
 import org.apache.hadoop.util.DiskChecker.DiskErrorException;
@@ -740,7 +741,7 @@ class BlockPoolSlice {
 
   private boolean readReplicasFromCache(ReplicaMap volumeMap,
       final RamDiskReplicaTracker lazyWriteReplicaMap) {
-    ReplicaMap tmpReplicaMap = new ReplicaMap(this);
+    ReplicaMap tmpReplicaMap = new ReplicaMap(new AutoCloseableLock());
     File replicaFile = new File(currentDir, REPLICA_CACHE_FILE);
     // Check whether the file exists or not.
     if (!replicaFile.exists()) {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImpl.java

@@ -271,7 +271,8 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
   private boolean blockPinningEnabled;
   private final int maxDataLength;
 
-  private final AutoCloseableLock datasetLock;
+  @VisibleForTesting
+  final AutoCloseableLock datasetLock;
   private final Condition datasetLockCondition;
   
   /**
@@ -313,7 +314,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     }
 
     storageMap = new ConcurrentHashMap<String, DatanodeStorage>();
-    volumeMap = new ReplicaMap(this);
+    volumeMap = new ReplicaMap(datasetLock);
     ramDiskReplicaTracker = RamDiskReplicaTracker.getInstance(conf, this);
 
     @SuppressWarnings("unchecked")
@@ -434,7 +435,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     FsVolumeImpl fsVolume = new FsVolumeImpl(
         this, sd.getStorageUuid(), dir, this.conf, storageType);
     FsVolumeReference ref = fsVolume.obtainReference();
-    ReplicaMap tempVolumeMap = new ReplicaMap(this);
+    ReplicaMap tempVolumeMap = new ReplicaMap(datasetLock);
     fsVolume.getVolumeMap(tempVolumeMap, ramDiskReplicaTracker);
 
     activateVolume(tempVolumeMap, sd, storageType, ref);
@@ -468,7 +469,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
     StorageType storageType = location.getStorageType();
     final FsVolumeImpl fsVolume =
         createFsVolume(sd.getStorageUuid(), sd.getCurrentDir(), storageType);
-    final ReplicaMap tempVolumeMap = new ReplicaMap(fsVolume);
+    final ReplicaMap tempVolumeMap = new ReplicaMap(new AutoCloseableLock());
     ArrayList<IOException> exceptions = Lists.newArrayList();
 
     for (final NamespaceInfo nsInfo : nsInfos) {
@@ -2474,7 +2475,7 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
       Block block, long recoveryId, long xceiverStopTimeout) throws IOException {
     while (true) {
       try {
-        synchronized (map.getMutex()) {
+        try (AutoCloseableLock lock = map.getLock().acquire()) {
           return initReplicaRecoveryImpl(bpid, map, block, recoveryId);
         }
       } catch (MustStopExistingWriter e) {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/ReplicaMap.java

@@ -25,28 +25,29 @@ import org.apache.hadoop.HadoopIllegalArgumentException;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.server.datanode.ReplicaInfo;
 import org.apache.hadoop.util.LightWeightResizableGSet;
+import org.apache.hadoop.util.AutoCloseableLock;
 
 /**
  * Maintains the replica map. 
  */
 class ReplicaMap {
-  // Object using which this class is synchronized
+  // Lock object to synchronize this instance.
-  private final Object mutex;
+  private final AutoCloseableLock lock;
   
   // Map of block pool Id to another map of block Id to ReplicaInfo.
   private final Map<String, LightWeightResizableGSet<Block, ReplicaInfo>> map =
     new HashMap<String, LightWeightResizableGSet<Block, ReplicaInfo>>();
 
-  ReplicaMap(Object mutex) {
+  ReplicaMap(AutoCloseableLock lock) {
-    if (mutex == null) {
+    if (lock == null) {
       throw new HadoopIllegalArgumentException(
-          "Object to synchronize on cannot be null");
+          "Lock to synchronize on cannot be null");
     }
-    this.mutex = mutex;
+    this.lock = lock;
   }
   
   String[] getBlockPoolList() {
-    synchronized(mutex) {
+    try (AutoCloseableLock l = lock.acquire()) {
       return map.keySet().toArray(new String[map.keySet().size()]);   
     }
   }
@@ -91,7 +92,7 @@ class ReplicaMap {
    */
   ReplicaInfo get(String bpid, long blockId) {
     checkBlockPool(bpid);
-    synchronized(mutex) {
+    try (AutoCloseableLock l = lock.acquire()) {
       LightWeightResizableGSet<Block, ReplicaInfo> m = map.get(bpid);
       return m != null ? m.get(new Block(blockId)) : null;
     }
@@ -108,7 +109,7 @@ class ReplicaMap {
   ReplicaInfo add(String bpid, ReplicaInfo replicaInfo) {
     checkBlockPool(bpid);
     checkBlock(replicaInfo);
-    synchronized(mutex) {
+    try (AutoCloseableLock l = lock.acquire()) {
       LightWeightResizableGSet<Block, ReplicaInfo> m = map.get(bpid);
       if (m == null) {
         // Add an entry for block pool if it does not exist already
@@ -137,7 +138,7 @@ class ReplicaMap {
   ReplicaInfo remove(String bpid, Block block) {
     checkBlockPool(bpid);
     checkBlock(block);
-    synchronized(mutex) {
+    try (AutoCloseableLock l = lock.acquire()) {
       LightWeightResizableGSet<Block, ReplicaInfo> m = map.get(bpid);
       if (m != null) {
         ReplicaInfo replicaInfo = m.get(block);
@@ -159,7 +160,7 @@ class ReplicaMap {
    */
   ReplicaInfo remove(String bpid, long blockId) {
     checkBlockPool(bpid);
-    synchronized(mutex) {
+    try (AutoCloseableLock l = lock.acquire()) {
       LightWeightResizableGSet<Block, ReplicaInfo> m = map.get(bpid);
       if (m != null) {
         return m.remove(new Block(blockId));
@@ -175,7 +176,7 @@ class ReplicaMap {
    */
   int size(String bpid) {
     LightWeightResizableGSet<Block, ReplicaInfo> m = null;
-    synchronized(mutex) {
+    try (AutoCloseableLock l = lock.acquire()) {
       m = map.get(bpid);
       return m != null ? m.size() : 0;
     }
@@ -184,9 +185,9 @@ class ReplicaMap {
   /**
    * Get a collection of the replicas for given block pool
    * This method is <b>not synchronized</b>. It needs to be synchronized
-   * externally using the mutex, both for getting the replicas
+   * externally using the lock, both for getting the replicas
    * values from the map and iterating over it. Mutex can be accessed using
-   * {@link #getMutext()} method.
+   * {@link #getLock()} method.
    * 
    * @param bpid block pool id
    * @return a collection of the replicas belonging to the block pool
@@ -199,7 +200,7 @@ class ReplicaMap {
 
   void initBlockPool(String bpid) {
     checkBlockPool(bpid);
-    synchronized(mutex) {
+    try (AutoCloseableLock l = lock.acquire()) {
       LightWeightResizableGSet<Block, ReplicaInfo> m = map.get(bpid);
       if (m == null) {
         // Add an entry for block pool if it does not exist already
@@ -211,16 +212,16 @@ class ReplicaMap {
   
   void cleanUpBlockPool(String bpid) {
     checkBlockPool(bpid);
-    synchronized(mutex) {
+    try (AutoCloseableLock l = lock.acquire()) {
       map.remove(bpid);
     }
   }
   
   /**
-   * Give access to mutex used for synchronizing ReplicasMap
+   * Get the lock object used for synchronizing ReplicasMap
-   * @return object used as lock
+   * @return lock object
    */
-  Object getMutex() {
+  AutoCloseableLock getLock() {
-    return mutex;
+    return lock;
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/TestInterDatanodeProtocol.java

@@ -58,6 +58,7 @@ import org.apache.hadoop.io.Writable;
 import org.apache.hadoop.ipc.RPC;
 import org.apache.hadoop.ipc.Server;
 import org.apache.hadoop.net.NetUtils;
+import org.apache.hadoop.util.AutoCloseableLock;
 import org.junit.Assert;
 import org.junit.Test;
 
@@ -234,7 +235,7 @@ public class TestInterDatanodeProtocol {
     final long firstblockid = 10000L;
     final long gs = 7777L;
     final long length = 22L;
-    final ReplicaMap map = new ReplicaMap(this);
+    final ReplicaMap map = new ReplicaMap(new AutoCloseableLock());
     String bpid = "BP-TEST";
     final Block[] blocks = new Block[5];
     for(int i = 0; i < blocks.length; i++) {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/TestReplicaMap.java

@@ -23,6 +23,7 @@ import static org.junit.Assert.fail;
 
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.server.datanode.FinalizedReplica;
+import org.apache.hadoop.util.AutoCloseableLock;
 import org.junit.Before;
 import org.junit.Test;
 
@@ -30,7 +31,7 @@ import org.junit.Test;
  * Unit test for ReplicasMap class
  */
 public class TestReplicaMap {
-  private final ReplicaMap map = new ReplicaMap(TestReplicaMap.class);
+  private final ReplicaMap map = new ReplicaMap(new AutoCloseableLock());
   private final String bpid = "BP-TEST";
   private final  Block block = new Block(1234, 1234, 1234);
   

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/TestWriteToReplica.java

@@ -42,6 +42,7 @@ import org.apache.hadoop.hdfs.server.datanode.ReplicaNotFoundException;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsDatasetSpi;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi;
 import org.apache.hadoop.hdfs.server.namenode.NameNode;
+import org.apache.hadoop.util.AutoCloseableLock;
 import org.apache.hadoop.util.DiskChecker.DiskOutOfSpaceException;
 import org.junit.Assert;
 import org.junit.Test;
@@ -534,7 +535,7 @@ public class TestWriteToReplica {
           bpList.size() == 2);
       
       createReplicas(bpList, volumes, cluster.getFsDatasetTestUtils(dn));
-      ReplicaMap oldReplicaMap = new ReplicaMap(this);
+      ReplicaMap oldReplicaMap = new ReplicaMap(new AutoCloseableLock());
       oldReplicaMap.addAll(dataSet.volumeMap);
 
       cluster.restartDataNode(0);