HDFS-12884. BlockUnderConstructionFeature.truncateBlock should be of type BlockInfo. Contributed by chencan.

(cherry picked from commit 8d898ab25f1c2032a07c9bbd96ba3d0c4eb5be87)
(cherry picked from commit 21db4e9efe9ff634c905aa32667d9dbb203b3699)

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

@@ -60,7 +60,7 @@ public class BlockUnderConstructionFeature {
   /**
    * The block source to use in the event of copy-on-write truncate.
    */
-  private Block truncateBlock;
+  private BlockInfo truncateBlock;
 
   public BlockUnderConstructionFeature(Block blk,
       BlockUCState state, DatanodeStorageInfo[] targets, BlockType blockType) {
@@ -193,11 +193,11 @@ public class BlockUnderConstructionFeature {
   }
 
   /** Get recover block */
-  public Block getTruncateBlock() {
+  public BlockInfo getTruncateBlock() {
     return truncateBlock;
   }
 
-  public void setTruncateBlock(Block recoveryBlock) {
+  public void setTruncateBlock(BlockInfo recoveryBlock) {
     this.truncateBlock = recoveryBlock;
   }
 

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

@@ -104,7 +104,7 @@ final class FSDirTruncateOp {
       final BlockInfo last = file.getLastBlock();
       if (last != null && last.getBlockUCState()
           == BlockUCState.UNDER_RECOVERY) {
-        final Block truncatedBlock = last.getUnderConstructionFeature()
+        final BlockInfo truncatedBlock = last.getUnderConstructionFeature()
             .getTruncateBlock();
         if (truncatedBlock != null) {
           final long truncateLength = file.computeFileSize(false, false)
@@ -259,7 +259,8 @@ final class FSDirTruncateOp {
       oldBlock = file.getLastBlock();
       assert !oldBlock.isComplete() : "oldBlock should be under construction";
       BlockUnderConstructionFeature uc = oldBlock.getUnderConstructionFeature();
-      uc.setTruncateBlock(new Block(oldBlock));
+      uc.setTruncateBlock(new BlockInfoContiguous(oldBlock,
+          oldBlock.getReplication()));
       uc.getTruncateBlock().setNumBytes(oldBlock.getNumBytes() - lastBlockDelta);
       uc.getTruncateBlock().setGenerationStamp(newBlock.getGenerationStamp());
       truncatedBlockUC = oldBlock;

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

@@ -3376,7 +3376,7 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
       BlockUnderConstructionFeature uc =
           lastBlock.getUnderConstructionFeature();
       // determine if last block was intended to be truncated
-      Block recoveryBlock = uc.getTruncateBlock();
+      BlockInfo recoveryBlock = uc.getTruncateBlock();
       boolean truncateRecovery = recoveryBlock != null;
       boolean copyOnTruncate = truncateRecovery &&
           recoveryBlock.getBlockId() != lastBlock.getBlockId();

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

@@ -33,7 +33,6 @@ import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.fs.permission.PermissionStatus;
 import org.apache.hadoop.hdfs.DFSUtilClient;
-import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockStoragePolicySuite;
@@ -1054,12 +1053,11 @@ public abstract class INode implements INodeAttributes, Diff.Element<byte[]> {
       if(uc == null) {
         return;
       }
-      Block truncateBlock = uc.getTruncateBlock();
+      BlockInfo truncateBlock = uc.getTruncateBlock();
       if(truncateBlock == null || truncateBlock.equals(toDelete)) {
         return;
       }
-      assert truncateBlock instanceof BlockInfo : "should be BlockInfo";
-      addDeleteBlock((BlockInfo) truncateBlock);
+      addDeleteBlock(truncateBlock);
     }
 
     public void addUpdateReplicationFactor(BlockInfo block, short targetRepl) {

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

@@ -17,7 +17,6 @@
  */
 package org.apache.hadoop.hdfs.server.namenode.snapshot;
 
-import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfo;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoContiguous;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants;
@@ -129,7 +128,7 @@ public class FileDiffList extends
     }
     // Check if last block is part of truncate recovery
     BlockInfo lastBlock = file.getLastBlock();
-    Block dontRemoveBlock = null;
+    BlockInfo dontRemoveBlock = null;
     if (lastBlock != null && lastBlock.getBlockUCState().equals(
         HdfsServerConstants.BlockUCState.UNDER_RECOVERY)) {
       dontRemoveBlock = lastBlock.getUnderConstructionFeature()