HDFS-10682. Replace FsDatasetImpl object lock with a separate lock object. (Contributed by Chen Liang)

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

@@ -46,6 +46,7 @@ import org.apache.hadoop.io.LongWritable;
 import org.apache.hadoop.io.ReadaheadPool.ReadaheadRequest;
 import org.apache.hadoop.io.nativeio.NativeIO;
 import org.apache.hadoop.net.SocketOutputStream;
+import org.apache.hadoop.util.AutoCloseableLock;
 import org.apache.hadoop.util.DataChecksum;
 import org.apache.htrace.core.Sampler;
 import org.apache.htrace.core.TraceScope;
@@ -240,7 +241,7 @@ class BlockSender implements java.io.Closeable {
       
       final Replica replica;
       final long replicaVisibleLength;
-      synchronized(datanode.data) { 
+      try(AutoCloseableLock lock = datanode.data.acquireDatasetLock()) {
         replica = getReplica(block, datanode);
         replicaVisibleLength = replica.getVisibleLength();
       }

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

@@ -196,6 +196,7 @@ import org.apache.hadoop.tracing.TraceAdminProtocolPB;
 import org.apache.hadoop.tracing.TraceAdminProtocolServerSideTranslatorPB;
 import org.apache.hadoop.tracing.TraceUtils;
 import org.apache.hadoop.tracing.TracerConfigurationManager;
+import org.apache.hadoop.util.AutoCloseableLock;
 import org.apache.hadoop.util.Daemon;
 import org.apache.hadoop.util.DiskChecker;
 import org.apache.hadoop.util.DiskChecker.DiskErrorException;
@@ -2817,7 +2818,7 @@ public class DataNode extends ReconfigurableBase
     final BlockConstructionStage stage;
 
     //get replica information
-    synchronized(data) {
+    try(AutoCloseableLock lock = data.acquireDatasetLock()) {
       Block storedBlock = data.getStoredBlock(b.getBlockPoolId(),
           b.getBlockId());
       if (null == storedBlock) {

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

@@ -43,6 +43,7 @@ import org.apache.commons.logging.LogFactory;
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileUtil;
+import org.apache.hadoop.util.AutoCloseableLock;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
@@ -581,7 +582,7 @@ public class DirectoryScanner implements Runnable {
     Map<String, ScanInfo[]> diskReport = getDiskReport();
 
     // Hold FSDataset lock to prevent further changes to the block map
-    synchronized(dataset) {
+    try(AutoCloseableLock lock = dataset.acquireDatasetLock()) {
       for (Entry<String, ScanInfo[]> entry : diskReport.entrySet()) {
         String bpid = entry.getKey();
         ScanInfo[] blockpoolReport = entry.getValue();

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

@@ -60,6 +60,7 @@ import org.apache.hadoop.hdfs.server.protocol.NamespaceInfo;
 import org.apache.hadoop.hdfs.server.protocol.ReplicaRecoveryInfo;
 import org.apache.hadoop.hdfs.server.protocol.StorageReport;
 import org.apache.hadoop.hdfs.server.protocol.VolumeFailureSummary;
+import org.apache.hadoop.util.AutoCloseableLock;
 import org.apache.hadoop.util.ReflectionUtils;
 
 /**
@@ -641,4 +642,9 @@ public interface FsDatasetSpi<V extends FsVolumeSpi> extends FSDatasetMBean {
    * Confirm whether the block is deleting
    */
   boolean isDeletingBlock(String bpid, long blockId);
+
+  /**
+   * Acquire the lock of the dataset.
+   */
+  AutoCloseableLock acquireDatasetLock();
 }

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

@@ -56,6 +56,7 @@ import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeReference;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.FsVolumeSpi;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeStorage;
 import org.apache.hadoop.io.IOUtils;
+import org.apache.hadoop.util.AutoCloseableLock;
 import org.apache.hadoop.util.CloseableReferenceCount;
 import org.apache.hadoop.util.DiskChecker.DiskErrorException;
 import org.apache.hadoop.util.StringUtils;
@@ -303,7 +304,7 @@ public class FsVolumeImpl implements FsVolumeSpi {
 
   private void decDfsUsedAndNumBlocks(String bpid, long value,
                                       boolean blockFileDeleted) {
-    synchronized(dataset) {
+    try(AutoCloseableLock lock = dataset.acquireDatasetLock()) {
       BlockPoolSlice bp = bpSlices.get(bpid);
       if (bp != null) {
         bp.decDfsUsed(value);
@@ -315,7 +316,7 @@ public class FsVolumeImpl implements FsVolumeSpi {
   }
 
   void incDfsUsedAndNumBlocks(String bpid, long value) {
-    synchronized (dataset) {
+    try(AutoCloseableLock lock = dataset.acquireDatasetLock()) {
       BlockPoolSlice bp = bpSlices.get(bpid);
       if (bp != null) {
         bp.incDfsUsed(value);
@@ -325,7 +326,7 @@ public class FsVolumeImpl implements FsVolumeSpi {
   }
 
   void incDfsUsed(String bpid, long value) {
-    synchronized(dataset) {
+    try(AutoCloseableLock lock = dataset.acquireDatasetLock()) {
       BlockPoolSlice bp = bpSlices.get(bpid);
       if (bp != null) {
         bp.incDfsUsed(value);
@@ -336,7 +337,7 @@ public class FsVolumeImpl implements FsVolumeSpi {
   @VisibleForTesting
   public long getDfsUsed() throws IOException {
     long dfsUsed = 0;
-    synchronized(dataset) {
+    try(AutoCloseableLock lock = dataset.acquireDatasetLock()) {
       for(BlockPoolSlice s : bpSlices.values()) {
         dfsUsed += s.getDfsUsed();
       }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/SimulatedFSDataset.java

@@ -62,6 +62,7 @@ import org.apache.hadoop.hdfs.server.protocol.VolumeFailureSummary;
 import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.metrics2.MetricsCollector;
 import org.apache.hadoop.metrics2.util.MBeans;
+import org.apache.hadoop.util.AutoCloseableLock;
 import org.apache.hadoop.util.DataChecksum;
 
 /**
@@ -113,6 +114,8 @@ public class SimulatedFSDataset implements FsDatasetSpi<FsVolumeSpi> {
       "dfs.datanode.simulateddatastorage.state";
   private static final DatanodeStorage.State DEFAULT_STATE =
       DatanodeStorage.State.NORMAL;
+
+  private final AutoCloseableLock datasetLock;
   
   static final byte[] nullCrcFileData;
   static {
@@ -550,6 +553,7 @@ public class SimulatedFSDataset implements FsDatasetSpi<FsVolumeSpi> {
         conf.getLong(CONFIG_PROPERTY_CAPACITY, DEFAULT_CAPACITY),
         conf.getEnum(CONFIG_PROPERTY_STATE, DEFAULT_STATE));
     this.volume = new SimulatedVolume(this.storage);
+    this.datasetLock = new AutoCloseableLock();
   }
 
   public synchronized void injectBlocks(String bpid,
@@ -1365,5 +1369,10 @@ public class SimulatedFSDataset implements FsDatasetSpi<FsVolumeSpi> {
   public boolean isDeletingBlock(String bpid, long blockId) {
     throw new UnsupportedOperationException();
   }
+
+  @Override
+  public AutoCloseableLock acquireDatasetLock() {
+    return datasetLock.acquire();
+  }
 }
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestBlockRecovery.java

@@ -85,6 +85,7 @@ import org.apache.hadoop.hdfs.server.protocol.ReplicaRecoveryInfo;
 import org.apache.hadoop.hdfs.server.protocol.StorageReport;
 import org.apache.hadoop.hdfs.server.protocol.VolumeFailureSummary;
 import org.apache.hadoop.test.GenericTestUtils;
+import org.apache.hadoop.util.AutoCloseableLock;
 import org.apache.hadoop.util.DataChecksum;
 import org.apache.hadoop.util.Time;
 import org.apache.log4j.Level;
@@ -693,7 +694,7 @@ public class TestBlockRecovery {
             final RecoveringBlock recoveringBlock = new RecoveringBlock(
                 block.getBlock(), locations, block.getBlock()
                     .getGenerationStamp() + 1);
-            synchronized (dataNode.data) {
+            try(AutoCloseableLock lock = dataNode.data.acquireDatasetLock()) {
               Thread.sleep(2000);
               dataNode.initReplicaRecovery(recoveringBlock);
             }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/TestDirectoryScanner.java

@@ -60,6 +60,7 @@ import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.FsDatasetTestUtil;
 import org.apache.hadoop.hdfs.server.datanode.fsdataset.impl.LazyPersistTestCase;
 import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.test.GenericTestUtils;
+import org.apache.hadoop.util.AutoCloseableLock;
 import org.apache.hadoop.util.Time;
 import org.junit.Before;
 import org.junit.Test;
@@ -109,7 +110,7 @@ public class TestDirectoryScanner {
 
   /** Truncate a block file */
   private long truncateBlockFile() throws IOException {
-    synchronized (fds) {
+    try(AutoCloseableLock lock = fds.acquireDatasetLock()) {
       for (ReplicaInfo b : FsDatasetTestUtil.getReplicas(fds, bpid)) {
         File f = b.getBlockFile();
         File mf = b.getMetaFile();
@@ -134,7 +135,7 @@ public class TestDirectoryScanner {
 
   /** Delete a block file */
   private long deleteBlockFile() {
-    synchronized(fds) {
+    try(AutoCloseableLock lock = fds.acquireDatasetLock()) {
       for (ReplicaInfo b : FsDatasetTestUtil.getReplicas(fds, bpid)) {
         File f = b.getBlockFile();
         File mf = b.getMetaFile();
@@ -150,7 +151,7 @@ public class TestDirectoryScanner {
 
   /** Delete block meta file */
   private long deleteMetaFile() {
-    synchronized(fds) {
+    try(AutoCloseableLock lock = fds.acquireDatasetLock()) {
       for (ReplicaInfo b : FsDatasetTestUtil.getReplicas(fds, bpid)) {
         File file = b.getMetaFile();
         // Delete a metadata file
@@ -169,7 +170,7 @@ public class TestDirectoryScanner {
    * @throws IOException
    */
   private void duplicateBlock(long blockId) throws IOException {
-    synchronized (fds) {
+    try(AutoCloseableLock lock = fds.acquireDatasetLock()) {
       ReplicaInfo b = FsDatasetTestUtil.fetchReplicaInfo(fds, bpid, blockId);
       try (FsDatasetSpi.FsVolumeReferences volumes =
           fds.getFsVolumeReferences()) {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/extdataset/ExternalDatasetImpl.java

@@ -43,6 +43,7 @@ import org.apache.hadoop.hdfs.server.protocol.ReplicaRecoveryInfo;
 import org.apache.hadoop.hdfs.server.protocol.StorageReport;
 import org.apache.hadoop.hdfs.server.protocol.VolumeFailureSummary;
 import org.apache.hadoop.metrics2.MetricsCollector;
+import org.apache.hadoop.util.AutoCloseableLock;
 
 public class ExternalDatasetImpl implements FsDatasetSpi<ExternalVolumeImpl> {
 
@@ -448,4 +449,9 @@ public class ExternalDatasetImpl implements FsDatasetSpi<ExternalVolumeImpl> {
   public boolean isDeletingBlock(String bpid, long blockId) {
     return false;
   }
+
+  @Override
+  public AutoCloseableLock acquireDatasetLock() {
+    return null;
+  }
 }