HDFS-7853. Erasure coding: extend LocatedBlocks to support reading from striped files. Contributed by Jing Zhao.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/protocol/LocatedBlock.java

@@ -49,14 +49,14 @@ public class LocatedBlock {
   // else false. If block has few corrupt replicas, they are filtered and
   // their locations are not part of this object
   private boolean corrupt;
-  private Token<BlockTokenIdentifier> blockToken = new Token<BlockTokenIdentifier>();
+  private Token<BlockTokenIdentifier> blockToken = new Token<>();
   /**
    * List of cached datanode locations
    */
   private DatanodeInfo[] cachedLocs;
 
   // Used when there are no locations
-  private static final DatanodeInfoWithStorage[] EMPTY_LOCS =
+  static final DatanodeInfoWithStorage[] EMPTY_LOCS =
       new DatanodeInfoWithStorage[0];
 
   public LocatedBlock(ExtendedBlock b, DatanodeInfo[] locs) {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocol/LocatedStripedBlock.java

@@ -0,0 +1,68 @@
+/**
+ * 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
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * 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.protocol;
+
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.fs.StorageType;
+import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeStorageInfo;
+
+import java.util.Arrays;
+
+/**
+ * {@link LocatedBlock} with striped block support. For a striped block, each
+ * datanode storage is associated with a block in the block group. We need to
+ * record the index (in the striped block group) for each of them.
+ */
+@InterfaceAudience.Private
+@InterfaceStability.Evolving
+public class LocatedStripedBlock extends LocatedBlock {
+  private int[] blockIndices;
+
+  public LocatedStripedBlock(ExtendedBlock b, DatanodeInfo[] locs,
+      String[] storageIDs, StorageType[] storageTypes, int[] indices,
+      long startOffset, boolean corrupt, DatanodeInfo[] cachedLocs) {
+    super(b, locs, storageIDs, storageTypes, startOffset, corrupt, cachedLocs);
+    assert indices != null && indices.length == locs.length;
+    this.blockIndices = new int[indices.length];
+    System.arraycopy(indices, 0, blockIndices, 0, indices.length);
+  }
+
+  public LocatedStripedBlock(ExtendedBlock b, DatanodeStorageInfo[] storages,
+      int[] indices, long startOffset, boolean corrupt) {
+    this(b, DatanodeStorageInfo.toDatanodeInfos(storages),
+        DatanodeStorageInfo.toStorageIDs(storages),
+        DatanodeStorageInfo.toStorageTypes(storages), indices,
+        startOffset, corrupt, EMPTY_LOCS);
+  }
+
+  @Override
+  public String toString() {
+    return getClass().getSimpleName() + "{" + getBlock()
+        + "; getBlockSize()=" + getBlockSize()
+        + "; corrupt=" + isCorrupt()
+        + "; offset=" + getStartOffset()
+        + "; locs=" + Arrays.asList(getLocations())
+        + "; indices=" + Arrays.asList(blockIndices)
+        + "}";
+  }
+
+  public int[] getBlockIndices() {
+    return this.blockIndices;
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolServerSideTranslatorPB.java

@@ -419,7 +419,7 @@ public class ClientNamenodeProtocolServerSideTranslatorPB implements
           req.getClientName(), flags);
       AppendResponseProto.Builder builder = AppendResponseProto.newBuilder();
       if (result.getLastBlock() != null) {
-        builder.setBlock(PBHelper.convert(result.getLastBlock()));
+        builder.setBlock(PBHelper.convertLocatedBlock(result.getLastBlock()));
       }
       if (result.getFileStatus() != null) {
         builder.setStat(PBHelper.convert(result.getFileStatus()));
@@ -495,7 +495,7 @@ public class ClientNamenodeProtocolServerSideTranslatorPB implements
           (favor == null || favor.size() == 0) ? null : favor
               .toArray(new String[favor.size()]));
       return AddBlockResponseProto.newBuilder()
-          .setBlock(PBHelper.convert(result)).build();
+          .setBlock(PBHelper.convertLocatedBlock(result)).build();
     } catch (IOException e) {
       throw new ServiceException(e);
     }
@@ -519,7 +519,7 @@ public class ClientNamenodeProtocolServerSideTranslatorPB implements
               new DatanodeInfoProto[excludesList.size()])), 
           req.getNumAdditionalNodes(), req.getClientName());
       return GetAdditionalDatanodeResponseProto.newBuilder().setBlock(
-          PBHelper.convert(result))
+          PBHelper.convertLocatedBlock(result))
           .build();
     } catch (IOException e) {
       throw new ServiceException(e);
@@ -545,8 +545,8 @@ public class ClientNamenodeProtocolServerSideTranslatorPB implements
       ReportBadBlocksRequestProto req) throws ServiceException {
     try {
       List<LocatedBlockProto> bl = req.getBlocksList();
-      server.reportBadBlocks(PBHelper.convertLocatedBlock(
-              bl.toArray(new LocatedBlockProto[bl.size()])));
+      server.reportBadBlocks(PBHelper.convertLocatedBlocks(
+          bl.toArray(new LocatedBlockProto[bl.size()])));
     } catch (IOException e) {
       throw new ServiceException(e);
     }
@@ -950,8 +950,8 @@ public class ClientNamenodeProtocolServerSideTranslatorPB implements
       RpcController controller, UpdateBlockForPipelineRequestProto req)
       throws ServiceException {
     try {
-      LocatedBlockProto result = PBHelper.convert(server
-          .updateBlockForPipeline(PBHelper.convert(req.getBlock()),
+      LocatedBlockProto result = PBHelper.convertLocatedBlock(
+          server.updateBlockForPipeline(PBHelper.convert(req.getBlock()),
               req.getClientName()));
       return UpdateBlockForPipelineResponseProto.newBuilder().setBlock(result)
           .build();

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/ClientNamenodeProtocolTranslatorPB.java

@@ -327,7 +327,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
     try {
       AppendResponseProto res = rpcProxy.append(null, req);
       LocatedBlock lastBlock = res.hasBlock() ? PBHelper
-          .convert(res.getBlock()) : null;
+          .convertLocatedBlockProto(res.getBlock()) : null;
       HdfsFileStatus stat = (res.hasStat()) ? PBHelper.convert(res.getStat())
           : null;
       return new LastBlockWithStatus(lastBlock, stat);
@@ -415,7 +415,8 @@ public class ClientNamenodeProtocolTranslatorPB implements
       req.addAllFavoredNodes(Arrays.asList(favoredNodes));
     }
     try {
-      return PBHelper.convert(rpcProxy.addBlock(null, req.build()).getBlock());
+      return PBHelper.convertLocatedBlockProto(
+          rpcProxy.addBlock(null, req.build()).getBlock());
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
     }
@@ -440,8 +441,8 @@ public class ClientNamenodeProtocolTranslatorPB implements
         .setClientName(clientName)
         .build();
     try {
-      return PBHelper.convert(rpcProxy.getAdditionalDatanode(null, req)
-          .getBlock());
+      return PBHelper.convertLocatedBlockProto(
+          rpcProxy.getAdditionalDatanode(null, req).getBlock());
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);
     }
@@ -468,7 +469,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
   @Override
   public void reportBadBlocks(LocatedBlock[] blocks) throws IOException {
     ReportBadBlocksRequestProto req = ReportBadBlocksRequestProto.newBuilder()
-        .addAllBlocks(Arrays.asList(PBHelper.convertLocatedBlock(blocks)))
+        .addAllBlocks(Arrays.asList(PBHelper.convertLocatedBlocks(blocks)))
         .build();
     try {
       rpcProxy.reportBadBlocks(null, req);
@@ -900,7 +901,7 @@ public class ClientNamenodeProtocolTranslatorPB implements
         .setClientName(clientName)
         .build();
     try {
-      return PBHelper.convert(
+      return PBHelper.convertLocatedBlockProto(
           rpcProxy.updateBlockForPipeline(null, req).getBlock());
     } catch (ServiceException e) {
       throw ProtobufHelper.getRemoteException(e);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/DatanodeProtocolClientSideTranslatorPB.java

@@ -279,7 +279,7 @@ public class DatanodeProtocolClientSideTranslatorPB implements
     ReportBadBlocksRequestProto.Builder builder = ReportBadBlocksRequestProto
         .newBuilder();
     for (int i = 0; i < blocks.length; i++) {
-      builder.addBlocks(i, PBHelper.convert(blocks[i]));
+      builder.addBlocks(i, PBHelper.convertLocatedBlock(blocks[i]));
     }
     ReportBadBlocksRequestProto req = builder.build();
     try {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/DatanodeProtocolServerSideTranslatorPB.java

@@ -258,7 +258,7 @@ public class DatanodeProtocolServerSideTranslatorPB implements
     List<LocatedBlockProto> lbps = request.getBlocksList();
     LocatedBlock [] blocks = new LocatedBlock [lbps.size()];
     for(int i=0; i<lbps.size(); i++) {
-      blocks[i] = PBHelper.convert(lbps.get(i));
+      blocks[i] = PBHelper.convertLocatedBlockProto(lbps.get(i));
     }
     try {
       impl.reportBadBlocks(blocks);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/PBHelper.java

@@ -81,6 +81,7 @@ import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
 import org.apache.hadoop.hdfs.protocol.HdfsLocatedFileStatus;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
+import org.apache.hadoop.hdfs.protocol.LocatedStripedBlock;
 import org.apache.hadoop.hdfs.protocol.RollingUpgradeInfo;
 import org.apache.hadoop.hdfs.protocol.RollingUpgradeStatus;
 import org.apache.hadoop.hdfs.protocol.SnapshotDiffReport;
@@ -626,7 +627,7 @@ public class PBHelper {
     if (b == null) {
       return null;
     }
-    LocatedBlockProto lb = PBHelper.convert((LocatedBlock)b);
+    LocatedBlockProto lb = PBHelper.convertLocatedBlock(b);
     RecoveringBlockProto.Builder builder = RecoveringBlockProto.newBuilder();
     builder.setBlock(lb).setNewGenStamp(b.getNewGenerationStamp());
     if(b.getNewBlock() != null)
@@ -776,7 +777,7 @@ public class PBHelper {
     }
   }
   
-  public static LocatedBlockProto convert(LocatedBlock b) {
+  public static LocatedBlockProto convertLocatedBlock(LocatedBlock b) {
     if (b == null) return null;
     Builder builder = LocatedBlockProto.newBuilder();
     DatanodeInfo[] locs = b.getLocations();
@@ -797,21 +798,27 @@ public class PBHelper {
 
     StorageType[] storageTypes = b.getStorageTypes();
     if (storageTypes != null) {
-      for (int i = 0; i < storageTypes.length; ++i) {
-        builder.addStorageTypes(PBHelper.convertStorageType(storageTypes[i]));
+      for (StorageType storageType : storageTypes) {
+        builder.addStorageTypes(PBHelper.convertStorageType(storageType));
       }
     }
     final String[] storageIDs = b.getStorageIDs();
     if (storageIDs != null) {
       builder.addAllStorageIDs(Arrays.asList(storageIDs));
     }
+    if (b instanceof LocatedStripedBlock) {
+      int[] indices = ((LocatedStripedBlock) b).getBlockIndices();
+      for (int index : indices) {
+        builder.addBlockIndex(index);
+      }
+    }
 
     return builder.setB(PBHelper.convert(b.getBlock()))
         .setBlockToken(PBHelper.convert(b.getBlockToken()))
         .setCorrupt(b.isCorrupt()).setOffset(b.getStartOffset()).build();
   }
   
-  public static LocatedBlock convert(LocatedBlockProto proto) {
+  public static LocatedBlock convertLocatedBlockProto(LocatedBlockProto proto) {
     if (proto == null) return null;
     List<DatanodeInfoProto> locs = proto.getLocsList();
     DatanodeInfo[] targets = new DatanodeInfo[locs.size()];
@@ -831,6 +838,15 @@ public class PBHelper {
       storageIDs = proto.getStorageIDsList().toArray(new String[storageIDsCount]);
     }
 
+    int[] indices = null;
+    final int indexCount = proto.getBlockIndexCount();
+    if (indexCount > 0) {
+      indices = new int[indexCount];
+      for (int i = 0; i < indexCount; i++) {
+        indices[i] = proto.getBlockIndex(i);
+      }
+    }
+
     // Set values from the isCached list, re-using references from loc
     List<DatanodeInfo> cachedLocs = new ArrayList<DatanodeInfo>(locs.size());
     List<Boolean> isCachedList = proto.getIsCachedList();
@@ -840,9 +856,17 @@ public class PBHelper {
       }
     }
 
-    LocatedBlock lb = new LocatedBlock(PBHelper.convert(proto.getB()), targets,
-        storageIDs, storageTypes, proto.getOffset(), proto.getCorrupt(),
-        cachedLocs.toArray(new DatanodeInfo[0]));
+    final LocatedBlock lb;
+    if (indices == null) {
+      lb = new LocatedBlock(PBHelper.convert(proto.getB()), targets, storageIDs,
+          storageTypes, proto.getOffset(), proto.getCorrupt(),
+          cachedLocs.toArray(new DatanodeInfo[cachedLocs.size()]));
+    } else {
+      lb = new LocatedStripedBlock(PBHelper.convert(proto.getB()), targets,
+          storageIDs, storageTypes, indices, proto.getOffset(),
+          proto.getCorrupt(),
+          cachedLocs.toArray(new DatanodeInfo[cachedLocs.size()]));
+    }
     lb.setBlockToken(PBHelper.convert(proto.getBlockToken()));
 
     return lb;
@@ -1258,36 +1282,36 @@ public class PBHelper {
   }
   
   // Located Block Arrays and Lists
-  public static LocatedBlockProto[] convertLocatedBlock(LocatedBlock[] lb) {
+  public static LocatedBlockProto[] convertLocatedBlocks(LocatedBlock[] lb) {
     if (lb == null) return null;
-    return convertLocatedBlock2(Arrays.asList(lb)).toArray(
-        new LocatedBlockProto[lb.length]);
+    return convertLocatedBlocks2(Arrays.asList(lb))
+        .toArray(new LocatedBlockProto[lb.length]);
   }
   
-  public static LocatedBlock[] convertLocatedBlock(LocatedBlockProto[] lb) {
+  public static LocatedBlock[] convertLocatedBlocks(LocatedBlockProto[] lb) {
     if (lb == null) return null;
-    return convertLocatedBlock(Arrays.asList(lb)).toArray(
-        new LocatedBlock[lb.length]);
+    return convertLocatedBlocks(Arrays.asList(lb))
+        .toArray(new LocatedBlock[lb.length]);
   }
   
-  public static List<LocatedBlock> convertLocatedBlock(
+  public static List<LocatedBlock> convertLocatedBlocks(
       List<LocatedBlockProto> lb) {
     if (lb == null) return null;
     final int len = lb.size();
-    List<LocatedBlock> result = 
-        new ArrayList<LocatedBlock>(len);
-    for (int i = 0; i < len; ++i) {
-      result.add(PBHelper.convert(lb.get(i)));
+    List<LocatedBlock> result = new ArrayList<>(len);
+    for (LocatedBlockProto aLb : lb) {
+      result.add(PBHelper.convertLocatedBlockProto(aLb));
     }
     return result;
   }
   
-  public static List<LocatedBlockProto> convertLocatedBlock2(List<LocatedBlock> lb) {
+  public static List<LocatedBlockProto> convertLocatedBlocks2(
+      List<LocatedBlock> lb) {
     if (lb == null) return null;
     final int len = lb.size();
-    List<LocatedBlockProto> result = new ArrayList<LocatedBlockProto>(len);
-    for (int i = 0; i < len; ++i) {
-      result.add(PBHelper.convert(lb.get(i)));
+    List<LocatedBlockProto> result = new ArrayList<>(len);
+    for (LocatedBlock aLb : lb) {
+      result.add(PBHelper.convertLocatedBlock(aLb));
     }
     return result;
   }
@@ -1297,8 +1321,9 @@ public class PBHelper {
   public static LocatedBlocks convert(LocatedBlocksProto lb) {
     return new LocatedBlocks(
         lb.getFileLength(), lb.getUnderConstruction(),
-        PBHelper.convertLocatedBlock(lb.getBlocksList()),
-        lb.hasLastBlock() ? PBHelper.convert(lb.getLastBlock()) : null,
+        PBHelper.convertLocatedBlocks(lb.getBlocksList()),
+        lb.hasLastBlock() ?
+            PBHelper.convertLocatedBlockProto(lb.getLastBlock()) : null,
         lb.getIsLastBlockComplete(),
         lb.hasFileEncryptionInfo() ? convert(lb.getFileEncryptionInfo()) :
             null);
@@ -1311,14 +1336,15 @@ public class PBHelper {
     LocatedBlocksProto.Builder builder = 
         LocatedBlocksProto.newBuilder();
     if (lb.getLastLocatedBlock() != null) {
-      builder.setLastBlock(PBHelper.convert(lb.getLastLocatedBlock()));
+      builder.setLastBlock(
+          PBHelper.convertLocatedBlock(lb.getLastLocatedBlock()));
     }
     if (lb.getFileEncryptionInfo() != null) {
       builder.setFileEncryptionInfo(convert(lb.getFileEncryptionInfo()));
     }
     return builder.setFileLength(lb.getFileLength())
         .setUnderConstruction(lb.isUnderConstruction())
-        .addAllBlocks(PBHelper.convertLocatedBlock2(lb.getLocatedBlocks()))
+        .addAllBlocks(PBHelper.convertLocatedBlocks2(lb.getLocatedBlocks()))
         .setIsLastBlockComplete(lb.isLastBlockComplete()).build();
   }
   

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockInfoStriped.java

@@ -123,6 +123,11 @@ public class BlockInfoStriped extends BlockInfo {
     return -1;
   }
 
+  int getStorageBlockIndex(DatanodeStorageInfo storage) {
+    int i = this.findStorageInfo(storage);
+    return i == -1 ? -1 : indices[i];
+  }
+
   @Override
   boolean removeStorage(DatanodeStorageInfo storage) {
     int dnIndex = findStorageInfoFromEnd(storage);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockInfoStripedUnderConstruction.java

@@ -23,9 +23,6 @@ import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.ReplicaState;
 import org.apache.hadoop.hdfs.server.namenode.NameNode;
 
 import java.io.IOException;
-import java.util.ArrayList;
-import java.util.Iterator;
-import java.util.List;
 
 import static org.apache.hadoop.hdfs.server.common.HdfsServerConstants.BlockUCState.COMPLETE;
 import static org.apache.hadoop.hdfs.server.common.HdfsServerConstants.BlockUCState.UNDER_CONSTRUCTION;
@@ -39,12 +36,8 @@ public class BlockInfoStripedUnderConstruction extends BlockInfoStriped {
 
   /**
    * Block replicas as assigned when the block was allocated.
-   *
-   * TODO: we need to update this attribute, along with the return type of
-   * getExpectedStorageLocations and LocatedBlock. For striped blocks, clients
-   * need to understand the index of each striped block in the block group.
    */
-  private List<ReplicaUnderConstruction> replicas;
+  private ReplicaUnderConstruction[] replicas;
 
   /**
    * The new generation stamp, which this block will have
@@ -75,12 +68,12 @@ public class BlockInfoStripedUnderConstruction extends BlockInfoStriped {
 
   /**
    * Convert an under construction striped block to a complete striped block.
-   * 
+   *
    * @return BlockInfoStriped - a complete block.
-   * @throws IOException if the state of the block 
-   * (the generation stamp and the length) has not been committed by 
-   * the client or it does not have at least a minimal number of replicas 
-   * reported from data-nodes. 
+   * @throws IOException if the state of the block
+   * (the generation stamp and the length) has not been committed by
+   * the client or it does not have at least a minimal number of replicas
+   * reported from data-nodes.
    */
   BlockInfoStriped convertToCompleteBlock() throws IOException {
     assert getBlockUCState() != COMPLETE :
@@ -91,10 +84,13 @@ public class BlockInfoStripedUnderConstruction extends BlockInfoStriped {
   /** Set expected locations */
   public void setExpectedLocations(DatanodeStorageInfo[] targets) {
     int numLocations = targets == null ? 0 : targets.length;
-    this.replicas = new ArrayList<>(numLocations);
+    this.replicas = new ReplicaUnderConstruction[numLocations];
     for(int i = 0; i < numLocations; i++) {
-      replicas.add(new ReplicaUnderConstruction(this, targets[i],
-          ReplicaState.RBW));
+      // when creating a new block we simply sequentially assign block index to
+      // each storage
+      Block blk = new Block(this.getBlockId() + i, this.getGenerationStamp(), 0);
+      replicas[i] = new ReplicaUnderConstruction(blk, targets[i],
+          ReplicaState.RBW);
     }
   }
 
@@ -106,14 +102,24 @@ public class BlockInfoStripedUnderConstruction extends BlockInfoStriped {
     int numLocations = getNumExpectedLocations();
     DatanodeStorageInfo[] storages = new DatanodeStorageInfo[numLocations];
     for (int i = 0; i < numLocations; i++) {
-      storages[i] = replicas.get(i).getExpectedStorageLocation();
+      storages[i] = replicas[i].getExpectedStorageLocation();
     }
     return storages;
   }
 
+  /** @return the index array indicating the block index in each storage */
+  public int[] getBlockIndices() {
+    int numLocations = getNumExpectedLocations();
+    int[] indices = new int[numLocations];
+    for (int i = 0; i < numLocations; i++) {
+      indices[i] = BlockIdManager.getBlockIndex(replicas[i]);
+    }
+    return indices;
+  }
+
   /** Get the number of expected locations */
   public int getNumExpectedLocations() {
-    return replicas == null ? 0 : replicas.size();
+    return replicas == null ? 0 : replicas.length;
   }
 
   /**
@@ -178,7 +184,7 @@ public class BlockInfoStripedUnderConstruction extends BlockInfoStriped {
   public void initializeBlockRecovery(long recoveryId) {
     setBlockUCState(BlockUCState.UNDER_RECOVERY);
     blockRecoveryId = recoveryId;
-    if (replicas == null || replicas.size() == 0) {
+    if (replicas == null || replicas.length == 0) {
       NameNode.blockStateChangeLog.warn("BLOCK*" +
           " BlockInfoUnderConstruction.initLeaseRecovery:" +
           " No blocks found, lease removed.");
@@ -186,28 +192,36 @@ public class BlockInfoStripedUnderConstruction extends BlockInfoStriped {
     // TODO we need to implement different recovery logic here
   }
 
-  void addReplicaIfNotPresent(DatanodeStorageInfo storage, Block block,
+  void addReplicaIfNotPresent(DatanodeStorageInfo storage, Block reportedBlock,
       ReplicaState rState) {
-    Iterator<ReplicaUnderConstruction> it = replicas.iterator();
-    while (it.hasNext()) {
-      ReplicaUnderConstruction r = it.next();
-      DatanodeStorageInfo expectedLocation = r.getExpectedStorageLocation();
-      if (expectedLocation == storage) {
-        // Record the gen stamp from the report
-        r.setGenerationStamp(block.getGenerationStamp());
-        return;
-      } else if (expectedLocation != null &&
-          expectedLocation.getDatanodeDescriptor() ==
-              storage.getDatanodeDescriptor()) {
-        // The Datanode reported that the block is on a different storage
-        // than the one chosen by BlockPlacementPolicy. This can occur as
-        // we allow Datanodes to choose the target storage. Update our
-        // state by removing the stale entry and adding a new one.
-        it.remove();
-        break;
+    if (replicas == null) {
+      replicas = new ReplicaUnderConstruction[1];
+      replicas[0] = new ReplicaUnderConstruction(reportedBlock, storage, rState);
+    } else {
+      for (int i = 0; i < replicas.length; i++) {
+        DatanodeStorageInfo expected = replicas[i].getExpectedStorageLocation();
+        if (expected == storage) {
+          replicas[i].setBlockId(reportedBlock.getBlockId());
+          replicas[i].setGenerationStamp(reportedBlock.getGenerationStamp());
+          return;
+        } else if (expected != null && expected.getDatanodeDescriptor() ==
+            storage.getDatanodeDescriptor()) {
+          // The Datanode reported that the block is on a different storage
+          // than the one chosen by BlockPlacementPolicy. This can occur as
+          // we allow Datanodes to choose the target storage. Update our
+          // state by removing the stale entry and adding a new one.
+          replicas[i] = new ReplicaUnderConstruction(reportedBlock, storage,
+              rState);
+          return;
+        }
       }
+      ReplicaUnderConstruction[] newReplicas =
+          new ReplicaUnderConstruction[replicas.length + 1];
+      System.arraycopy(replicas, 0, newReplicas, 0, replicas.length);
+      newReplicas[newReplicas.length - 1] = new ReplicaUnderConstruction(
+          reportedBlock, storage, rState);
+      replicas = newReplicas;
     }
-    replicas.add(new ReplicaUnderConstruction(block, storage, rState));
   }
 
   @Override
@@ -226,12 +240,11 @@ public class BlockInfoStripedUnderConstruction extends BlockInfoStriped {
   private void appendUCParts(StringBuilder sb) {
     sb.append("{UCState=").append(blockUCState).append(", replicas=[");
     if (replicas != null) {
-      Iterator<ReplicaUnderConstruction> iter = replicas.iterator();
-      if (iter.hasNext()) {
-        iter.next().appendStringTo(sb);
-        while (iter.hasNext()) {
+      int i = 0;
+      for (ReplicaUnderConstruction r : replicas) {
+        r.appendStringTo(sb);
+        if (++i < replicas.length) {
           sb.append(", ");
-          iter.next().appendStringTo(sb);
         }
       }
     }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockManager.java

@@ -55,6 +55,7 @@ import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
 import org.apache.hadoop.fs.FileEncryptionInfo;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
+import org.apache.hadoop.hdfs.protocol.LocatedStripedBlock;
 import org.apache.hadoop.hdfs.protocol.UnregisteredNodeException;
 import org.apache.hadoop.hdfs.security.token.block.BlockTokenIdentifier;
 import org.apache.hadoop.hdfs.security.token.block.BlockTokenSecretManager;
@@ -841,13 +842,24 @@ public class BlockManager {
   }
 
   /** @return a LocatedBlock for the given block */
-  private LocatedBlock createLocatedBlock(final BlockInfo blk,
-      final long pos) throws IOException {
-    if (blk instanceof BlockInfoContiguousUnderConstruction) {
-      if (blk.isComplete()) {
-        throw new IOException(
-            "blk instanceof BlockInfoUnderConstruction && blk.isComplete()"
-            + ", blk=" + blk);
+  private LocatedBlock createLocatedBlock(final BlockInfo blk, final long pos) {
+    if (!blk.isComplete()) {
+      if (blk.isStriped()) {
+        final BlockInfoStripedUnderConstruction uc =
+            (BlockInfoStripedUnderConstruction) blk;
+        final DatanodeStorageInfo[] storages = uc.getExpectedStorageLocations();
+        final ExtendedBlock eb = new ExtendedBlock(namesystem.getBlockPoolId(),
+            blk);
+        return new LocatedStripedBlock(eb, storages, uc.getBlockIndices(), pos,
+            false);
+      } else {
+        assert blk instanceof BlockInfoContiguousUnderConstruction;
+        final BlockInfoContiguousUnderConstruction uc =
+            (BlockInfoContiguousUnderConstruction) blk;
+        final DatanodeStorageInfo[] storages = uc.getExpectedStorageLocations();
+        final ExtendedBlock eb = new ExtendedBlock(namesystem.getBlockPoolId(),
+            blk);
+        return new LocatedBlock(eb, storages, pos, false);
       }
       final BlockInfoContiguousUnderConstruction uc =
           (BlockInfoContiguousUnderConstruction) blk;
@@ -855,7 +867,6 @@ public class BlockManager {
       final ExtendedBlock eb = new ExtendedBlock(namesystem.getBlockPoolId(), blk);
       return newLocatedBlock(eb, storages, pos, false);
     }
-    // TODO support BlockInfoStripedUC
 
     // get block locations
     final int numCorruptNodes = countNodes(blk).corruptReplicas();
@@ -871,13 +882,21 @@ public class BlockManager {
         numCorruptNodes == numNodes;
     final int numMachines = isCorrupt ? numNodes: numNodes - numCorruptNodes;
     final DatanodeStorageInfo[] machines = new DatanodeStorageInfo[numMachines];
-    int j = 0;
+    final int[] blockIndices = blk.isStriped() ? new int[numMachines] : null;
+    int j = 0, i = 0;
     if (numMachines > 0) {
       for(DatanodeStorageInfo storage : blocksMap.getStorages(blk)) {
         final DatanodeDescriptor d = storage.getDatanodeDescriptor();
         final boolean replicaCorrupt = corruptReplicas.isReplicaCorrupt(blk, d);
-        if (isCorrupt || (!replicaCorrupt))
+        if (isCorrupt || (!replicaCorrupt)) {
           machines[j++] = storage;
+          // TODO this can be more efficient
+          if (blockIndices != null) {
+            int index = ((BlockInfoStriped) blk).getStorageBlockIndex(storage);
+            assert index >= 0;
+            blockIndices[i++] = index;
+          }
+        }
       }
     }
     assert j == machines.length :
@@ -887,7 +906,9 @@ public class BlockManager {
       " numCorrupt: " + numCorruptNodes +
       " numCorruptRepls: " + numCorruptReplicas;
     final ExtendedBlock eb = new ExtendedBlock(namesystem.getBlockPoolId(), blk);
-    return newLocatedBlock(eb, machines, pos, isCorrupt);
+    return blockIndices == null ?
+        newLocatedBlock(eb, machines, pos, isCorrupt) :
+        new LocatedStripedBlock(eb, machines, blockIndices, pos, isCorrupt);
   }
 
   /** Create a LocatedBlocks. */
@@ -2501,7 +2522,8 @@ public class BlockManager {
   void addStoredBlockUnderConstruction(StatefulBlockInfo ucBlock,
       DatanodeStorageInfo storageInfo) throws IOException {
     BlockInfo block = ucBlock.storedBlock;
-    BlockInfo.addReplica(block, storageInfo, ucBlock.reportedBlock, ucBlock.reportedState);
+    BlockInfo.addReplica(block, storageInfo, ucBlock.reportedBlock,
+        ucBlock.reportedState);
 
     if (ucBlock.reportedState == ReplicaState.FINALIZED &&
         (block.findStorageInfo(storageInfo) < 0)) {

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeDescriptor.java

@@ -276,7 +276,9 @@ public class DatanodeDescriptor extends DatanodeInfo {
       return storageMap.get(storageID);
     }
   }
-  DatanodeStorageInfo[] getStorageInfos() {
+
+  @VisibleForTesting
+  public DatanodeStorageInfo[] getStorageInfos() {
     synchronized (storageMap) {
       final Collection<DatanodeStorageInfo> storages = storageMap.values();
       return storages.toArray(new DatanodeStorageInfo[storages.size()]);

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/DatanodeStorageInfo.java

@@ -206,6 +206,7 @@ public class DatanodeStorageInfo {
     return getState() == State.FAILED && numBlocks != 0;
   }
 
+  @VisibleForTesting
   public String getStorageID() {
     return storageID;
   }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSImageFormatPBINode.java

@@ -366,16 +366,19 @@ public final class FSImageFormatPBINode {
         INodeSection.FileUnderConstructionFeature uc = f.getFileUC();
         file.toUnderConstruction(uc.getClientName(), uc.getClientMachine());
         BlockInfo lastBlk = file.getLastBlock();
-        // replace the last block of file
-        final BlockInfo ucBlk;
-        if (stripeFeature != null) {
-          BlockInfoStriped striped = (BlockInfoStriped) lastBlk;
-          ucBlk = new BlockInfoStripedUnderConstruction(striped,
-              striped.getDataBlockNum(), striped.getParityBlockNum());
-        } else {
-          ucBlk = new BlockInfoContiguousUnderConstruction(lastBlk, replication);
+        if (lastBlk != null) {
+          // replace the last block of file
+          final BlockInfo ucBlk;
+          if (stripeFeature != null) {
+            BlockInfoStriped striped = (BlockInfoStriped) lastBlk;
+            ucBlk = new BlockInfoStripedUnderConstruction(striped,
+                striped.getDataBlockNum(), striped.getParityBlockNum());
+          } else {
+            ucBlk = new BlockInfoContiguousUnderConstruction(lastBlk,
+                replication);
+          }
+          file.setBlock(file.numBlocks() - 1, ucBlk);
         }
-        file.setBlock(file.numBlocks() - 1, ucBlk);
       }
       return file;
     }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSNamesystem.java

@@ -189,6 +189,7 @@ import org.apache.hadoop.hdfs.protocol.HdfsConstants.SafeModeAction;
 import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
+import org.apache.hadoop.hdfs.protocol.LocatedStripedBlock;
 import org.apache.hadoop.hdfs.protocol.QuotaExceededException;
 import org.apache.hadoop.hdfs.protocol.RecoveryInProgressException;
 import org.apache.hadoop.hdfs.protocol.RollingUpgradeException;
@@ -206,6 +207,7 @@ import org.apache.hadoop.hdfs.server.blockmanagement.BlockIdManager;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguous;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
+import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoStripedUnderConstruction;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeManager;
@@ -1780,8 +1782,14 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
 
     LocatedBlocks blocks = res.blocks;
     if (blocks != null) {
+      List<LocatedBlock> blkList = blocks.getLocatedBlocks();
+      if (blkList == null || blkList.size() == 0 ||
+          blkList.get(0) instanceof LocatedStripedBlock) {
+        // no need to sort locations for striped blocks
+        return blocks;
+      }
       blockManager.getDatanodeManager().sortLocatedBlocks(
-          clientMachine, blocks.getLocatedBlocks());
+          clientMachine, blkList);
 
       // lastBlock is not part of getLocatedBlocks(), might need to sort it too
       LocatedBlock lastBlock = blocks.getLastLocatedBlock();

hadoop-hdfs-project/hadoop-hdfs/src/main/proto/hdfs.proto

@@ -220,6 +220,7 @@ message LocatedBlockProto {
   repeated bool isCached = 6 [packed=true]; // if a location in locs is cached
   repeated StorageTypeProto storageTypes = 7;
   repeated string storageIDs = 8;
+  repeated uint32 blockIndex = 9; // used for striped block to indicate block index for each storage
 }
 
 message DataEncryptionKeyProto {

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/DFSTestUtil.java

@@ -109,7 +109,6 @@ import org.apache.hadoop.hdfs.protocol.proto.DataTransferProtos.BlockOpResponseP
 import org.apache.hadoop.hdfs.security.token.block.BlockTokenIdentifier;
 import org.apache.hadoop.hdfs.security.token.block.ExportedBlockKeys;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguous;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguousUnderConstruction;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManagerTestUtil;
@@ -133,6 +132,10 @@ import org.apache.hadoop.hdfs.server.namenode.ha.ConfiguredFailoverProxyProvider
 import org.apache.hadoop.hdfs.server.protocol.DatanodeRegistration;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeStorage;
 import org.apache.hadoop.hdfs.server.protocol.NamenodeProtocol;
+import org.apache.hadoop.hdfs.server.protocol.ReceivedDeletedBlockInfo;
+import org.apache.hadoop.hdfs.server.protocol.ReceivedDeletedBlockInfo.BlockStatus;
+import org.apache.hadoop.hdfs.server.protocol.StorageBlockReport;
+import org.apache.hadoop.hdfs.server.protocol.StorageReceivedDeletedBlocks;
 import org.apache.hadoop.hdfs.tools.DFSAdmin;
 import org.apache.hadoop.io.IOUtils;
 import org.apache.hadoop.io.nativeio.NativeIO;
@@ -1811,7 +1814,7 @@ public class DFSTestUtil {
     dn.setLastUpdate(Time.now() + offset);
     dn.setLastUpdateMonotonic(Time.monotonicNow() + offset);
   }
-
+  
   /**
    * This method takes a set of block locations and fills the provided buffer
    * with expected bytes based on simulated content from
@@ -1835,4 +1838,12 @@ public class DFSTestUtil {
     }
   }
 
+  public static StorageReceivedDeletedBlocks[] makeReportForReceivedBlock(
+      Block block, BlockStatus blockStatus, DatanodeStorage storage) {
+    ReceivedDeletedBlockInfo[] receivedBlocks = new ReceivedDeletedBlockInfo[1];
+    receivedBlocks[0] = new ReceivedDeletedBlockInfo(block, blockStatus, null);
+    StorageReceivedDeletedBlocks[] reports = new StorageReceivedDeletedBlocks[1];
+    reports[0] = new StorageReceivedDeletedBlocks(storage, receivedBlocks);
+    return reports;
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/protocolPB/TestPBHelper.java

@@ -489,16 +489,16 @@ public class TestPBHelper {
   @Test
   public void testConvertLocatedBlock() {
     LocatedBlock lb = createLocatedBlock();
-    LocatedBlockProto lbProto = PBHelper.convert(lb);
-    LocatedBlock lb2 = PBHelper.convert(lbProto);
+    LocatedBlockProto lbProto = PBHelper.convertLocatedBlock(lb);
+    LocatedBlock lb2 = PBHelper.convertLocatedBlockProto(lbProto);
     compare(lb,lb2);
   }
 
   @Test
   public void testConvertLocatedBlockNoStorageMedia() {
     LocatedBlock lb = createLocatedBlockNoStorageMedia();
-    LocatedBlockProto lbProto = PBHelper.convert(lb);
-    LocatedBlock lb2 = PBHelper.convert(lbProto);
+    LocatedBlockProto lbProto = PBHelper.convertLocatedBlock(lb);
+    LocatedBlock lb2 = PBHelper.convertLocatedBlockProto(lbProto);
     compare(lb,lb2);
   }
 
@@ -508,8 +508,8 @@ public class TestPBHelper {
     for (int i=0;i<3;i++) {
       lbl.add(createLocatedBlock());
     }
-    List<LocatedBlockProto> lbpl = PBHelper.convertLocatedBlock2(lbl);
-    List<LocatedBlock> lbl2 = PBHelper.convertLocatedBlock(lbpl);
+    List<LocatedBlockProto> lbpl = PBHelper.convertLocatedBlocks2(lbl);
+    List<LocatedBlock> lbl2 = PBHelper.convertLocatedBlocks(lbpl);
     assertEquals(lbl.size(), lbl2.size());
     for (int i=0;i<lbl.size();i++) {
       compare(lbl.get(i), lbl2.get(2));
@@ -522,8 +522,8 @@ public class TestPBHelper {
     for (int i=0;i<3;i++) {
       lbl[i] = createLocatedBlock();
     }
-    LocatedBlockProto [] lbpl = PBHelper.convertLocatedBlock(lbl);
-    LocatedBlock [] lbl2 = PBHelper.convertLocatedBlock(lbpl);
+    LocatedBlockProto [] lbpl = PBHelper.convertLocatedBlocks(lbl);
+    LocatedBlock [] lbl2 = PBHelper.convertLocatedBlocks(lbpl);
     assertEquals(lbl.length, lbl2.length);
     for (int i=0;i<lbl.length;i++) {
       compare(lbl[i], lbl2[i]);

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

@@ -227,15 +227,6 @@ public class TestIncrementalBrVariations {
     return new Block(10000000L, 100L, 1048576L);
   }
 
-  private static StorageReceivedDeletedBlocks[] makeReportForReceivedBlock(
-      Block block, DatanodeStorage storage) {
-    ReceivedDeletedBlockInfo[] receivedBlocks = new ReceivedDeletedBlockInfo[1];
-    receivedBlocks[0] = new ReceivedDeletedBlockInfo(block, BlockStatus.RECEIVED_BLOCK, null);
-    StorageReceivedDeletedBlocks[] reports = new StorageReceivedDeletedBlocks[1];
-    reports[0] = new StorageReceivedDeletedBlocks(storage, receivedBlocks);
-    return reports;
-  }
-
   /**
    * Verify that the NameNode can learn about new storages from incremental
    * block reports.
@@ -251,8 +242,9 @@ public class TestIncrementalBrVariations {
     // Generate a report for a fake block on a fake storage.
     final String newStorageUuid = UUID.randomUUID().toString();
     final DatanodeStorage newStorage = new DatanodeStorage(newStorageUuid);
-    StorageReceivedDeletedBlocks[] reports = makeReportForReceivedBlock(
-        getDummyBlock(), newStorage);
+    StorageReceivedDeletedBlocks[] reports = DFSTestUtil.
+        makeReportForReceivedBlock(getDummyBlock(), BlockStatus.RECEIVED_BLOCK,
+            newStorage);
 
     // Send the report to the NN.
     cluster.getNameNodeRpc().blockReceivedAndDeleted(dn0Reg, poolId, reports);

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestAddStripedBlocks.java

@@ -19,18 +19,29 @@ package org.apache.hadoop.hdfs.server.namenode;
 
 import org.apache.hadoop.fs.FSDataOutputStream;
 import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.DFSTestUtil;
 import org.apache.hadoop.hdfs.DistributedFileSystem;
 import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.apache.hadoop.hdfs.protocol.Block;
+import org.apache.hadoop.hdfs.protocol.BlockListAsLongs;
 import org.apache.hadoop.hdfs.protocol.DatanodeID;
+import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
+import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
+import org.apache.hadoop.hdfs.protocol.LocatedStripedBlock;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoStriped;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoStripedUnderConstruction;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeStorageInfo;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
 import org.apache.hadoop.hdfs.server.datanode.DataNode;
+import org.apache.hadoop.hdfs.server.datanode.ReplicaBeingWritten;
+import org.apache.hadoop.hdfs.server.protocol.DatanodeStorage;
+import org.apache.hadoop.hdfs.server.protocol.ReceivedDeletedBlockInfo.BlockStatus;
+import org.apache.hadoop.hdfs.server.protocol.StorageBlockReport;
+import org.apache.hadoop.hdfs.server.protocol.StorageReceivedDeletedBlocks;
 import org.apache.hadoop.io.IOUtils;
 import org.junit.After;
 import org.junit.Assert;
@@ -38,6 +49,9 @@ import org.junit.Before;
 import org.junit.Test;
 
 import java.io.IOException;
+import java.util.ArrayList;
+import java.util.List;
+import java.util.UUID;
 
 import static org.junit.Assert.assertEquals;
 
@@ -143,4 +157,131 @@ public class TestAddStripedBlocks {
     }
     return false;
   }
+
+  @Test
+  public void testGetLocatedStripedBlocks() throws Exception {
+    final Path file = new Path("/file1");
+    // create an empty file
+    FSDataOutputStream out = null;
+    try {
+      out = dfs.create(file, (short) 1);
+
+      FSDirectory fsdir = cluster.getNamesystem().getFSDirectory();
+      INodeFile fileNode = fsdir.getINode4Write(file.toString()).asFile();
+      cluster.getNamesystem().getAdditionalBlock(file.toString(),
+          fileNode.getId(), dfs.getClient().getClientName(), null, null, null);
+      BlockInfoStripedUnderConstruction lastBlk =
+          (BlockInfoStripedUnderConstruction) fileNode.getLastBlock();
+      DatanodeInfo[] expectedDNs = DatanodeStorageInfo
+          .toDatanodeInfos(lastBlk.getExpectedStorageLocations());
+      int[] indices = lastBlk.getBlockIndices();
+
+      LocatedBlocks blks = dfs.getClient().getLocatedBlocks(file.toString(), 0L);
+      Assert.assertEquals(1, blks.locatedBlockCount());
+      LocatedBlock lblk = blks.get(0);
+
+      Assert.assertTrue(lblk instanceof LocatedStripedBlock);
+      DatanodeInfo[] datanodes = lblk.getLocations();
+      int[] blockIndices = ((LocatedStripedBlock) lblk).getBlockIndices();
+      Assert.assertEquals(GROUP_SIZE, datanodes.length);
+      Assert.assertEquals(GROUP_SIZE, blockIndices.length);
+      Assert.assertArrayEquals(indices, blockIndices);
+      Assert.assertArrayEquals(expectedDNs, datanodes);
+    } finally {
+      IOUtils.cleanup(null, out);
+    }
+  }
+
+  /**
+   * Test BlockInfoStripedUnderConstruction#addReplicaIfNotPresent in different
+   * scenarios.
+   */
+  @Test
+  public void testAddUCReplica() throws Exception {
+    final Path file = new Path("/file1");
+    final List<String> storageIDs = new ArrayList<>();
+    // create an empty file
+    FSDataOutputStream out = null;
+    try {
+      out = dfs.create(file, (short) 1);
+
+      // 1. create the UC striped block
+      FSDirectory fsdir = cluster.getNamesystem().getFSDirectory();
+      INodeFile fileNode = fsdir.getINode4Write(file.toString()).asFile();
+      cluster.getNamesystem().getAdditionalBlock(file.toString(),
+          fileNode.getId(), dfs.getClient().getClientName(), null, null, null);
+      BlockInfo lastBlock = fileNode.getLastBlock();
+      BlockInfoStripedUnderConstruction ucBlock =
+          (BlockInfoStripedUnderConstruction) lastBlock;
+
+      DatanodeStorageInfo[] locs = ucBlock.getExpectedStorageLocations();
+      int[] indices = ucBlock.getBlockIndices();
+      Assert.assertEquals(GROUP_SIZE, locs.length);
+      Assert.assertEquals(GROUP_SIZE, indices.length);
+
+      // 2. mimic incremental block reports and make sure the uc-replica list in
+      // the BlockStripedUC is correct
+      int i = 0;
+      for (DataNode dn : cluster.getDataNodes()) {
+        final Block block = new Block(lastBlock.getBlockId() + i++,
+            lastBlock.getGenerationStamp(), 0);
+        DatanodeStorage storage = new DatanodeStorage(UUID.randomUUID().toString());
+        storageIDs.add(storage.getStorageID());
+        StorageReceivedDeletedBlocks[] reports = DFSTestUtil
+            .makeReportForReceivedBlock(block, BlockStatus.RECEIVING_BLOCK,
+                storage);
+        for (StorageReceivedDeletedBlocks report : reports) {
+          cluster.getNamesystem().processIncrementalBlockReport(
+              dn.getDatanodeId(), report);
+        }
+      }
+
+      // make sure lastBlock is correct and the storages have been updated
+      locs = ucBlock.getExpectedStorageLocations();
+      indices = ucBlock.getBlockIndices();
+      Assert.assertEquals(GROUP_SIZE, locs.length);
+      Assert.assertEquals(GROUP_SIZE, indices.length);
+      for (DatanodeStorageInfo newstorage : locs) {
+        Assert.assertTrue(storageIDs.contains(newstorage.getStorageID()));
+      }
+    } finally {
+      IOUtils.cleanup(null, out);
+    }
+
+    // 3. restart the namenode. mimic the full block reports and check the
+    // uc-replica list again
+    cluster.restartNameNode(true);
+    final String bpId = cluster.getNamesystem().getBlockPoolId();
+    INodeFile fileNode = cluster.getNamesystem().getFSDirectory()
+        .getINode4Write(file.toString()).asFile();
+    BlockInfo lastBlock = fileNode.getLastBlock();
+    int i = GROUP_SIZE - 1;
+    for (DataNode dn : cluster.getDataNodes()) {
+      String storageID = storageIDs.get(i);
+      final Block block = new Block(lastBlock.getBlockId() + i--,
+          lastBlock.getGenerationStamp(), 0);
+      DatanodeStorage storage = new DatanodeStorage(storageID);
+      List<ReplicaBeingWritten> blocks = new ArrayList<>();
+      ReplicaBeingWritten replica = new ReplicaBeingWritten(block, null, null,
+          null);
+      blocks.add(replica);
+      BlockListAsLongs bll = new BlockListAsLongs(null, blocks);
+      StorageBlockReport[] reports = {new StorageBlockReport(storage,
+          bll.getBlockListAsLongs())};
+      cluster.getNameNodeRpc().blockReport(dn.getDNRegistrationForBP(bpId),
+          bpId, reports);
+    }
+
+    BlockInfoStripedUnderConstruction ucBlock =
+        (BlockInfoStripedUnderConstruction) lastBlock;
+    DatanodeStorageInfo[] locs = ucBlock.getExpectedStorageLocations();
+    int[] indices = ucBlock.getBlockIndices();
+    Assert.assertEquals(GROUP_SIZE, locs.length);
+    Assert.assertEquals(GROUP_SIZE, indices.length);
+    for (i = 0; i < GROUP_SIZE; i++) {
+      Assert.assertEquals(storageIDs.get(i),
+          locs[GROUP_SIZE - 1 - i].getStorageID());
+      Assert.assertEquals(GROUP_SIZE - i - 1, indices[i]);
+    }
+  }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestFSImage.java

@@ -25,6 +25,8 @@ import java.io.IOException;
 import java.util.EnumSet;
 
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
+import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
+import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.StartupOption;
 import org.junit.Assert;
 
 import org.apache.hadoop.conf.Configuration;
@@ -219,8 +221,7 @@ public class TestFSImage {
         .format(false)
         .manageDataDfsDirs(false)
         .manageNameDfsDirs(false)
-        .waitSafeMode(false)
-        .startupOption(StartupOption.UPGRADE)
+        .waitSafeMode(false).startupOption(StartupOption.UPGRADE)
         .build();
     try {
       FileSystem fs = cluster.getFileSystem();