HDFS-17496. DataNode supports more fine-grained dataset lock based on blockid.

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/DFSConfigKeys.java

@@ -1744,6 +1744,10 @@ public class DFSConfigKeys extends CommonConfigurationKeys {
   public static final boolean
       DFS_DATANODE_LOCKMANAGER_TRACE_DEFAULT = false;
 
+  public static final String DFS_DATANODE_DATASET_SUBLOCK_COUNT_KEY =
+      "dfs.datanode.dataset.sublock.count";
+  public static final long DFS_DATANODE_DATASET_SUBLOCK_COUNT_DEFAULT = 1000L;
+
   // dfs.client.retry confs are moved to HdfsClientConfigKeys.Retry
   @Deprecated
   public static final String  DFS_CLIENT_RETRY_POLICY_ENABLED_KEY

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/common/DataNodeLockManager.java

@@ -29,7 +29,8 @@ public interface DataNodeLockManager<T extends AutoCloseDataSetLock> {
    */
   enum LockLevel {
     BLOCK_POOl,
-    VOLUME
+    VOLUME,
+    DIR
   }
 
   /**

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

@@ -94,6 +94,13 @@ private String generateLockName(LockLevel level, String... resources) {
             + resources[0] + "volume lock :" + resources[1]);
       }
       return resources[0] + resources[1];
+    } else if (resources.length == 3 && level == LockLevel.DIR) {
+      if (resources[0] == null || resources[1] == null || resources[2] == null) {
+        throw new IllegalArgumentException("acquire a null dataset lock : "
+            + resources[0] + ",volume lock :" + resources[1]
+        + ",subdir lock :" + resources[2]);
+      }
+      return resources[0] + resources[1] + resources[2];
     } else {
       throw new IllegalArgumentException("lock level do not match resource");
     }
@@ -153,7 +160,7 @@ public DataSetLockManager() {
   public AutoCloseDataSetLock readLock(LockLevel level, String... resources) {
     if (level == LockLevel.BLOCK_POOl) {
       return getReadLock(level, resources[0]);
-    } else {
+    } else if (level == LockLevel.VOLUME){
       AutoCloseDataSetLock bpLock = getReadLock(LockLevel.BLOCK_POOl, resources[0]);
       AutoCloseDataSetLock volLock = getReadLock(level, resources);
       volLock.setParentLock(bpLock);
@@ -162,14 +169,25 @@ public AutoCloseDataSetLock readLock(LockLevel level, String... resources) {
             resources[0]);
       }
       return volLock;
+    } else {
+      AutoCloseDataSetLock bpLock = getReadLock(LockLevel.BLOCK_POOl, resources[0]);
+      AutoCloseDataSetLock volLock = getReadLock(LockLevel.VOLUME, resources[0], resources[1]);
+      volLock.setParentLock(bpLock);
+      AutoCloseDataSetLock dirLock = getReadLock(level, resources);
+      dirLock.setParentLock(volLock);
+      if (openLockTrace) {
+        LOG.debug("Sub lock " + resources[0] + resources[1] + resources[2] + " parent lock " +
+            resources[0] + resources[1]);
+      }
+      return dirLock;
     }
   }
 
   @Override
   public AutoCloseDataSetLock writeLock(LockLevel level, String... resources) {
     if (level == LockLevel.BLOCK_POOl) {
       return getWriteLock(level, resources[0]);
-    } else {
+    } else if (level == LockLevel.VOLUME) {
       AutoCloseDataSetLock bpLock = getReadLock(LockLevel.BLOCK_POOl, resources[0]);
       AutoCloseDataSetLock volLock = getWriteLock(level, resources);
       volLock.setParentLock(bpLock);
@@ -178,6 +196,17 @@ public AutoCloseDataSetLock writeLock(LockLevel level, String... resources) {
             resources[0]);
       }
       return volLock;
+    } else {
+      AutoCloseDataSetLock bpLock = getReadLock(LockLevel.BLOCK_POOl, resources[0]);
+      AutoCloseDataSetLock volLock = getReadLock(LockLevel.VOLUME, resources[0], resources[1]);
+      volLock.setParentLock(bpLock);
+      AutoCloseDataSetLock dirLock = getWriteLock(level, resources);
+      dirLock.setParentLock(volLock);
+      if (openLockTrace) {
+        LOG.debug("Sub lock " + resources[0] + resources[1] + resources[2] + " parent lock " +
+            resources[0] + resources[1]);
+      }
+      return dirLock;
     }
   }
 
@@ -224,8 +253,13 @@ public void addLock(LockLevel level, String... resources) {
     String lockName = generateLockName(level, resources);
     if (level == LockLevel.BLOCK_POOl) {
       lockMap.addLock(lockName, new ReentrantReadWriteLock(isFair));
+    } else if (level == LockLevel.VOLUME) {
+      lockMap.addLock(resources[0], new ReentrantReadWriteLock(isFair));
+      lockMap.addLock(lockName, new ReentrantReadWriteLock(isFair));
     } else {
       lockMap.addLock(resources[0], new ReentrantReadWriteLock(isFair));
+      lockMap.addLock(generateLockName(LockLevel.VOLUME, resources[0], resources[1]),
+          new ReentrantReadWriteLock(isFair));
       lockMap.addLock(lockName, new ReentrantReadWriteLock(isFair));
     }
   }

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

@@ -0,0 +1,36 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.hdfs.server.datanode;
+
+import java.util.List;
+
+/**
+ * This interface is used to generate sub lock name for a blockid.
+ */
+public interface DataSetSubLockStrategy {
+
+  /**
+   * Generate sub lock name for the given blockid.
+   * @param blockid the block id.
+   * @return sub lock name for the input blockid.
+   */
+  String blockIdToSubLock(long blockid);
+
+  List<String> getAllSubLockName();
+}

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

@@ -0,0 +1,53 @@
+/**
+ * Licensed to the Apache Software Foundation (ASF) under one
+ * or more contributor license agreements.  See the NOTICE file
+ * distributed with this work for additional information
+ * regarding copyright ownership.  The ASF licenses this file
+ * to you under the Apache License, Version 2.0 (the
+ * "License"); you may not use this file except in compliance
+ * with the License.  You may obtain a copy of the License at
+ * <p>
+ * http://www.apache.org/licenses/LICENSE-2.0
+ * <p>
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.apache.hadoop.hdfs.server.datanode;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import java.util.ArrayList;
+import java.util.List;
+
+public class ModDataSetSubLockStrategy implements DataSetSubLockStrategy {
+  public static final Logger LOG = LoggerFactory.getLogger(DataSetSubLockStrategy.class);
+
+  private static final String LOCK_NAME_PERFIX = "SubLock";
+  private long modFactor;
+
+  public ModDataSetSubLockStrategy(long mod) {
+    if (mod <= 0) {
+      mod = 1L;
+    }
+    this.modFactor = mod;
+  }
+
+  @Override
+  public String blockIdToSubLock(long blockid) {
+    return LOCK_NAME_PERFIX + (blockid % modFactor);
+  }
+
+  @Override
+  public List<String> getAllSubLockName() {
+    List<String> res = new ArrayList<>();
+    for (long i = 0L; i < modFactor; i++) {
+      res.add(LOCK_NAME_PERFIX + i);
+    }
+    return res;
+  }
+}