HDFS-8355. Erasure Coding: Refactor BlockInfo and BlockInfoUnderConstruction. Contributed by Tsz Wo Nicholas Sze.

hadoop-hdfs-project/hadoop-hdfs/CHANGES-HDFS-EC-7285.txt

@@ -192,3 +192,6 @@
 
     HDFS-8289. Erasure Coding: add ECSchema to HdfsFileStatus. (Yong Zhang via
     jing9)
+
+    HDFS-8355. Erasure Coding: Refactor BlockInfo and BlockInfoUnderConstruction.
+    (Tsz Wo Nicholas Sze via jing9)

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

@@ -17,13 +17,12 @@
  */
 package org.apache.hadoop.hdfs.server.blockmanagement;
 
+import java.util.LinkedList;
+
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
 import org.apache.hadoop.util.LightWeightGSet;
 
-import java.io.IOException;
-import java.util.LinkedList;
-
 /**
  * For a given block (or an erasure coding block group), BlockInfo class
  * maintains 1) the {@link BlockCollection} it is part of, and 2) datanodes
@@ -336,94 +335,4 @@ public LightWeightGSet.LinkedElement getNext() {
   public void setNext(LightWeightGSet.LinkedElement next) {
     this.nextLinkedElement = next;
   }
-
-  static BlockInfo copyOf(BlockInfo b) {
-    if (!b.isStriped()) {
-      return new BlockInfoContiguous((BlockInfoContiguous) b);
-    } else {
-      return new BlockInfoStriped((BlockInfoStriped) b);
-    }
-  }
-
-  static BlockInfo convertToCompleteBlock(BlockInfo blk) throws IOException {
-    if (blk instanceof BlockInfoContiguousUnderConstruction) {
-      return ((BlockInfoContiguousUnderConstruction) blk)
-          .convertToCompleteBlock();
-    } else if (blk instanceof BlockInfoStripedUnderConstruction) {
-      return ((BlockInfoStripedUnderConstruction) blk).convertToCompleteBlock();
-    } else {
-      return blk;
-    }
-  }
-
-  static void commitBlock(BlockInfo blockInfo, Block reported)
-      throws IOException {
-    if (blockInfo instanceof BlockInfoContiguousUnderConstruction) {
-      ((BlockInfoContiguousUnderConstruction) blockInfo).commitBlock(reported);
-    } else if (blockInfo instanceof BlockInfoStripedUnderConstruction) {
-      ((BlockInfoStripedUnderConstruction) blockInfo).commitBlock(reported);
-    }
-  }
-
-  static void addReplica(BlockInfo ucBlock, DatanodeStorageInfo storageInfo,
-      Block reportedBlock, HdfsServerConstants.ReplicaState reportedState) {
-    assert ucBlock instanceof BlockInfoContiguousUnderConstruction ||
-        ucBlock instanceof BlockInfoStripedUnderConstruction;
-    if (ucBlock instanceof BlockInfoContiguousUnderConstruction) {
-      ((BlockInfoContiguousUnderConstruction) ucBlock).addReplicaIfNotPresent(
-          storageInfo, reportedBlock, reportedState);
-    } else { // StripedUC
-      ((BlockInfoStripedUnderConstruction) ucBlock).addReplicaIfNotPresent(
-          storageInfo, reportedBlock, reportedState);
-    }
-  }
-
-  static int getNumExpectedLocations(BlockInfo ucBlock) {
-    assert ucBlock instanceof BlockInfoContiguousUnderConstruction ||
-        ucBlock instanceof BlockInfoStripedUnderConstruction;
-    if (ucBlock instanceof BlockInfoContiguousUnderConstruction) {
-      return ((BlockInfoContiguousUnderConstruction) ucBlock)
-          .getNumExpectedLocations();
-    } else { // StripedUC
-      return ((BlockInfoStripedUnderConstruction) ucBlock)
-          .getNumExpectedLocations();
-    }
-  }
-
-  public static DatanodeStorageInfo[] getExpectedStorageLocations(
-      BlockInfo ucBlock) {
-    assert ucBlock instanceof BlockInfoContiguousUnderConstruction ||
-        ucBlock instanceof BlockInfoStripedUnderConstruction;
-    if (ucBlock instanceof BlockInfoContiguousUnderConstruction) {
-      return ((BlockInfoContiguousUnderConstruction) ucBlock)
-          .getExpectedStorageLocations();
-    } else { // StripedUC
-      return ((BlockInfoStripedUnderConstruction) ucBlock)
-          .getExpectedStorageLocations();
-    }
-  }
-
-  public static void setExpectedLocations(BlockInfo ucBlock,
-      DatanodeStorageInfo[] targets) {
-    assert ucBlock instanceof BlockInfoContiguousUnderConstruction ||
-        ucBlock instanceof BlockInfoStripedUnderConstruction;
-    if (ucBlock instanceof BlockInfoContiguousUnderConstruction) {
-      ((BlockInfoContiguousUnderConstruction) ucBlock)
-          .setExpectedLocations(targets);
-    } else { // StripedUC
-      ((BlockInfoStripedUnderConstruction) ucBlock)
-          .setExpectedLocations(targets);
-    }
-  }
-
-  public static long getBlockRecoveryId(BlockInfo ucBlock) {
-    assert ucBlock instanceof BlockInfoContiguousUnderConstruction ||
-        ucBlock instanceof BlockInfoStripedUnderConstruction;
-    if (ucBlock instanceof BlockInfoContiguousUnderConstruction) {
-      return ((BlockInfoContiguousUnderConstruction) ucBlock)
-          .getBlockRecoveryId();
-    } else { // StripedUC
-      return ((BlockInfoStripedUnderConstruction) ucBlock).getBlockRecoveryId();
-    }
-  }
 }

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

@@ -80,16 +80,8 @@ assert getBlockUCState() != BlockUCState.COMPLETE :
     setExpectedLocations(targets);
   }
 
-  /**
+  @Override
-   * Convert an under construction block to a complete block.
+  public BlockInfoContiguous convertToCompleteBlock() throws IOException {
-   * 
-   * @return BlockInfoContiguous - 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. 
-   */
-  BlockInfoContiguous convertToCompleteBlock() throws IOException {
     assert getBlockUCState() != BlockUCState.COMPLETE :
       "Trying to convert a COMPLETE block";
     return new BlockInfoContiguous(this);
@@ -170,13 +162,8 @@ public void setGenerationStampAndVerifyReplicas(long genStamp) {
     }
   }
 
-  /**
+  @Override
-   * Commit block's length and generation stamp as reported by the client.
+  public void commitBlock(Block block) throws IOException {
-   * Set block state to {@link BlockUCState#COMMITTED}.
-   * @param block - contains client reported block length and generation 
-   * @throws IOException if block ids are inconsistent.
-   */
-  void commitBlock(Block block) throws IOException {
     if(getBlockId() != block.getBlockId())
       throw new IOException("Trying to commit inconsistent block: id = "
           + block.getBlockId() + ", expected id = " + getBlockId());
@@ -235,9 +222,9 @@ public void initializeBlockRecovery(long recoveryId) {
     }
   }
 
-  void addReplicaIfNotPresent(DatanodeStorageInfo storage,
+  @Override
-                     Block block,
+  public void addReplicaIfNotPresent(DatanodeStorageInfo storage,
-                     ReplicaState rState) {
+      Block block, ReplicaState rState) {
     Iterator<ReplicaUnderConstruction> it = replicas.iterator();
     while (it.hasNext()) {
       ReplicaUnderConstruction r = it.next();

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

@@ -73,16 +73,8 @@ assert getBlockUCState() != COMPLETE :
     setExpectedLocations(targets);
   }
 
-  /**
+  @Override
-   * Convert an under construction striped block to a complete striped block.
+  public BlockInfoStriped convertToCompleteBlock() throws IOException {
-   *
-   * @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.
-   */
-  BlockInfoStriped convertToCompleteBlock() throws IOException {
     assert getBlockUCState() != COMPLETE :
       "Trying to convert a COMPLETE block";
     return new BlockInfoStriped(this);
@@ -177,12 +169,8 @@ public void setGenerationStampAndVerifyReplicas(long genStamp) {
     }
   }
 
-  /**
+  @Override
-   * Commit block's length and generation stamp as reported by the client.
+  public void commitBlock(Block block) throws IOException {
-   * Set block state to {@link BlockUCState#COMMITTED}.
-   * @param block - contains client reported block length and generation
-   */
-  void commitBlock(Block block) throws IOException {
     if (getBlockId() != block.getBlockId()) {
       throw new IOException("Trying to commit inconsistent block: id = "
           + block.getBlockId() + ", expected id = " + getBlockId());
@@ -242,8 +230,9 @@ public void initializeBlockRecovery(long recoveryId) {
     }
   }
 
-  void addReplicaIfNotPresent(DatanodeStorageInfo storage, Block reportedBlock,
+  @Override
-      ReplicaState rState) {
+  public void addReplicaIfNotPresent(DatanodeStorageInfo storage,
+      Block reportedBlock, ReplicaState rState) {
     if (replicas == null) {
       replicas = new ReplicaUnderConstruction[1];
       replicas[0] = new ReplicaUnderConstruction(reportedBlock, storage, rState);

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

@@ -17,7 +17,11 @@
  */
 package org.apache.hadoop.hdfs.server.blockmanagement;
 
+import java.io.IOException;
+
 import org.apache.hadoop.hdfs.protocol.Block;
+import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.BlockUCState;
+import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.ReplicaState;
 
 public interface BlockInfoUnderConstruction {
   /**
@@ -54,4 +58,27 @@ public interface BlockInfoUnderConstruction {
    * make it primary.
    */
   public void initializeBlockRecovery(long recoveryId);
+  
+  /** Add the reported replica if it is not already in the replica list. */
+  public void addReplicaIfNotPresent(DatanodeStorageInfo storage,
+      Block reportedBlock, ReplicaState rState);
+
+  /**
+   * Commit block's length and generation stamp as reported by the client.
+   * Set block state to {@link BlockUCState#COMMITTED}.
+   * @param block - contains client reported block length and generation 
+   * @throws IOException if block ids are inconsistent.
+   */
+  public void commitBlock(Block block) throws IOException;
+
+  /**
+   * Convert an under construction block to a complete block.
+   * 
+   * @return 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.
+   */
+  public BlockInfo convertToCompleteBlock() throws IOException;
 }

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

@@ -637,13 +637,19 @@ public boolean hasMinStorage(BlockInfo block, int liveNum) {
    */
   private static boolean commitBlock(final BlockInfo block,
       final Block commitBlock) throws IOException {
-    if (block.getBlockUCState() == BlockUCState.COMMITTED)
+    if (block instanceof BlockInfoUnderConstruction
-      return false;
+        && block.getBlockUCState() != BlockUCState.COMMITTED) {
-    assert block.getNumBytes() <= commitBlock.getNumBytes() :
+      final BlockInfoUnderConstruction uc = (BlockInfoUnderConstruction)block;
-      "commitBlock length is less than the stored one "
+
-      + commitBlock.getNumBytes() + " vs. " + block.getNumBytes();
+      assert block.getNumBytes() <= commitBlock.getNumBytes() :
-    BlockInfo.commitBlock(block, commitBlock);
+        "commitBlock length is less than the stored one "
-    return true;
+        + commitBlock.getNumBytes() + " vs. " + block.getNumBytes();
+
+      uc.commitBlock(commitBlock);
+      return true;
+    }
+
+    return false;
   }
   
   /**
@@ -700,7 +706,10 @@ private BlockInfo completeBlock(final BlockCollection bc,
           "Cannot complete block: block has not been COMMITTED by the client");
     }
 
-    final BlockInfo completeBlock = BlockInfo.convertToCompleteBlock(curBlock);
+    final BlockInfo completeBlock
+        = !(curBlock instanceof BlockInfoUnderConstruction)? curBlock
+            : ((BlockInfoUnderConstruction)curBlock).convertToCompleteBlock();
+
     // replace penultimate block in file
     bc.setBlock(blkIndex, completeBlock);
     
@@ -738,7 +747,9 @@ private BlockInfo completeBlock(final BlockCollection bc,
    */
   public BlockInfo forceCompleteBlock(final BlockCollection bc,
       final BlockInfo block) throws IOException {
-    BlockInfo.commitBlock(block, block);
+    if (block instanceof BlockInfoUnderConstruction) {
+      ((BlockInfoUnderConstruction)block).commitBlock(block);
+    }
     return completeBlock(bc, block, true);
   }
 
@@ -2250,12 +2261,13 @@ private void processFirstBlockReport(
       
       // If block is under construction, add this replica to its list
       if (isBlockUnderConstruction(storedBlock, ucState, reportedState)) {
-        BlockInfo.addReplica(storedBlock, storageInfo, iblk, reportedState);
+        final BlockInfoUnderConstruction uc = (BlockInfoUnderConstruction)storedBlock;
+        uc.addReplicaIfNotPresent(storageInfo, iblk, reportedState);
         // OpenFileBlocks only inside snapshots also will be added to safemode
         // threshold. So we need to update such blocks to safemode
         // refer HDFS-5283
         if (namesystem.isInSnapshot(storedBlock.getBlockCollection())) {
-          int numOfReplicas = BlockInfo.getNumExpectedLocations(storedBlock);
+          int numOfReplicas = uc.getNumExpectedLocations();
           namesystem.incrementSafeBlockCount(numOfReplicas, storedBlock);
         }
         //and fall through to next clause
@@ -2617,7 +2629,8 @@ private boolean isBlockUnderConstruction(BlockInfo storedBlock,
   void addStoredBlockUnderConstruction(StatefulBlockInfo ucBlock,
       DatanodeStorageInfo storageInfo) throws IOException {
     BlockInfo block = ucBlock.storedBlock;
-    BlockInfo.addReplica(block, storageInfo, ucBlock.reportedBlock,
+    final BlockInfoUnderConstruction uc = (BlockInfoUnderConstruction)block;
+    uc.addReplicaIfNotPresent(storageInfo, ucBlock.reportedBlock,
         ucBlock.reportedState);
 
     if (ucBlock.reportedState == ReplicaState.FINALIZED &&
@@ -3945,6 +3958,20 @@ public static LocatedStripedBlock newLocatedStripedBlock(
         null);
   }
 
+  public LocatedBlock newLocatedBlock(ExtendedBlock eb, BlockInfo info,
+      DatanodeStorageInfo[] locs, long offset) throws IOException {
+    final LocatedBlock lb;
+    if (info.isStriped()) {
+      lb = newLocatedStripedBlock(eb, locs,
+          ((BlockInfoStripedUnderConstruction)info).getBlockIndices(),
+          offset, false);
+    } else {
+      lb = newLocatedBlock(eb, locs, offset, false);
+    }
+    setBlockToken(lb, BlockTokenIdentifier.AccessMode.WRITE);
+    return lb;
+  }
+
   /**
    * This class is used internally by {@link this#computeRecoveryWorkForBlocks}
    * to represent a task to recover a block through replication or erasure

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

@@ -17,7 +17,6 @@
  */
 package org.apache.hadoop.hdfs.server.namenode;
 
-import static org.apache.hadoop.crypto.key.KeyProviderCryptoExtension.EncryptedKeyVersion;
 import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.FS_TRASH_INTERVAL_DEFAULT;
 import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.FS_TRASH_INTERVAL_KEY;
 import static org.apache.hadoop.fs.CommonConfigurationKeysPublic.IO_FILE_BUFFER_SIZE_DEFAULT;
@@ -60,9 +59,9 @@
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_EDIT_LOG_AUTOROLL_MULTIPLIER_THRESHOLD_DEFAULT;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_ENABLE_RETRY_CACHE_DEFAULT;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_ENABLE_RETRY_CACHE_KEY;
+import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_INODE_ATTRIBUTES_PROVIDER_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_LAZY_PERSIST_FILE_SCRUB_INTERVAL_SEC;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_LAZY_PERSIST_FILE_SCRUB_INTERVAL_SEC_DEFAULT;
-import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_INODE_ATTRIBUTES_PROVIDER_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_MAX_OBJECTS_DEFAULT;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_MAX_OBJECTS_KEY;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_NAMENODE_NAME_DIR_KEY;
@@ -88,8 +87,8 @@
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_REPLICATION_DEFAULT;
 import static org.apache.hadoop.hdfs.DFSConfigKeys.DFS_REPLICATION_KEY;
 import static org.apache.hadoop.hdfs.server.common.HdfsServerConstants.SECURITY_XATTR_UNREADABLE_BY_SUPERUSER;
-import static org.apache.hadoop.util.Time.now;
 import static org.apache.hadoop.util.Time.monotonicNow;
+import static org.apache.hadoop.util.Time.now;
 
 import java.io.BufferedWriter;
 import java.io.ByteArrayInputStream;
@@ -140,6 +139,7 @@
 import org.apache.hadoop.crypto.CryptoProtocolVersion;
 import org.apache.hadoop.crypto.key.KeyProvider;
 import org.apache.hadoop.crypto.key.KeyProviderCryptoExtension;
+import org.apache.hadoop.crypto.key.KeyProviderCryptoExtension.EncryptedKeyVersion;
 import org.apache.hadoop.fs.BatchedRemoteIterator.BatchedListEntries;
 import org.apache.hadoop.fs.CacheFlag;
 import org.apache.hadoop.fs.ContentSummary;
@@ -152,6 +152,7 @@
 import org.apache.hadoop.fs.InvalidPathException;
 import org.apache.hadoop.fs.Options;
 import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.StorageType;
 import org.apache.hadoop.fs.UnresolvedLinkException;
 import org.apache.hadoop.fs.XAttr;
 import org.apache.hadoop.fs.XAttrSetFlag;
@@ -160,10 +161,8 @@
 import org.apache.hadoop.fs.permission.FsAction;
 import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.fs.permission.PermissionStatus;
-import org.apache.hadoop.fs.StorageType;
 import org.apache.hadoop.ha.HAServiceProtocol.HAServiceState;
 import org.apache.hadoop.ha.ServiceFailedException;
-import org.apache.hadoop.hdfs.protocol.BlockStoragePolicy;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.HAUtil;
@@ -172,6 +171,7 @@
 import org.apache.hadoop.hdfs.XAttrHelper;
 import org.apache.hadoop.hdfs.protocol.AlreadyBeingCreatedException;
 import org.apache.hadoop.hdfs.protocol.Block;
+import org.apache.hadoop.hdfs.protocol.BlockStoragePolicy;
 import org.apache.hadoop.hdfs.protocol.CacheDirectiveEntry;
 import org.apache.hadoop.hdfs.protocol.CacheDirectiveInfo;
 import org.apache.hadoop.hdfs.protocol.CachePoolEntry;
@@ -180,15 +180,15 @@
 import org.apache.hadoop.hdfs.protocol.DatanodeID;
 import org.apache.hadoop.hdfs.protocol.DatanodeInfo;
 import org.apache.hadoop.hdfs.protocol.DirectoryListing;
+import org.apache.hadoop.hdfs.protocol.EncryptionZone;
 import org.apache.hadoop.hdfs.protocol.ErasureCodingInfo;
 import org.apache.hadoop.hdfs.protocol.ErasureCodingZoneInfo;
-import org.apache.hadoop.hdfs.protocol.EncryptionZone;
 import org.apache.hadoop.hdfs.protocol.ExtendedBlock;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
-import org.apache.hadoop.hdfs.protocol.LastBlockWithStatus;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants.DatanodeReportType;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants.SafeModeAction;
 import org.apache.hadoop.hdfs.protocol.HdfsFileStatus;
+import org.apache.hadoop.hdfs.protocol.LastBlockWithStatus;
 import org.apache.hadoop.hdfs.protocol.LocatedBlock;
 import org.apache.hadoop.hdfs.protocol.LocatedBlocks;
 import org.apache.hadoop.hdfs.protocol.LocatedStripedBlock;
@@ -209,7 +209,7 @@
 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.BlockInfoStriped;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
@@ -217,7 +217,6 @@
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeStatistics;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeStorageInfo;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
-import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoStriped;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.BlockUCState;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.NamenodeRole;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.RollingUpgradeStartupOption;
@@ -3799,7 +3798,8 @@ void commitBlockSynchronization(ExtendedBlock oldBlock,
       }
 
       truncatedBlock = iFile.getLastBlock();
-      long recoveryId = BlockInfo.getBlockRecoveryId(truncatedBlock);
+      final BlockInfoUnderConstruction uc = (BlockInfoUnderConstruction)truncatedBlock;
+      final long recoveryId = uc.getBlockRecoveryId();
       copyTruncate = truncatedBlock.getBlockId() != storedBlock.getBlockId();
       if(recoveryId != newgenerationstamp) {
         throw new IOException("The recovery id " + newgenerationstamp