HDFS-8809. HDFS fsck reports under construction blocks as CORRUPT. Contributed by Jing Zhao.

(cherry picked from commit c8bca62718203a1dad9b70d164bdf10cc71b40cd)

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -850,6 +850,8 @@ Release 2.8.0 - UNRELEASED
     HDFS-8922. Link the native_mini_dfs test library with libdl, since IBM Java
     requires it (Ayappan via Colin P. McCabe)
 
+    HDFS-8809. HDFS fsck reports under construction blocks as "CORRUPT". (jing9)
+
 Release 2.7.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

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

@@ -523,6 +523,9 @@ public class NamenodeFsck implements DataEncryptionKeyFactory {
       LocatedBlocks blocks) throws IOException {
     String path = file.getFullName(parent);
     boolean isOpen = blocks.isUnderConstruction();
+    if (isOpen && !showOpenFiles) {
+      return;
+    }
     int missing = 0;
     int corrupt = 0;
     long missize = 0;
@@ -530,8 +533,15 @@ public class NamenodeFsck implements DataEncryptionKeyFactory {
     int misReplicatedPerFile = 0;
     StringBuilder report = new StringBuilder();
     int blockNumber = 0;
+    final LocatedBlock lastBlock = blocks.getLastLocatedBlock();
     for (LocatedBlock lBlk : blocks.getLocatedBlocks()) {
       ExtendedBlock block = lBlk.getBlock();
+      if (!blocks.isLastBlockComplete() && lastBlock != null &&
+          lastBlock.getBlock().equals(block)) {
+        // this is the last block and this is not complete. ignore it since
+        // it is under construction
+        continue;
+      }
       BlockManager bm = namenode.getNamesystem().getBlockManager();
 
       final BlockInfo storedBlock = bm.getStoredBlock(

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

@@ -65,6 +65,7 @@ import org.apache.hadoop.fs.permission.FsPermission;
 import org.apache.hadoop.hdfs.DFSClient;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.DFSInputStream;
+import org.apache.hadoop.hdfs.DFSOutputStream;
 import org.apache.hadoop.hdfs.DFSTestUtil;
 import org.apache.hadoop.hdfs.DFSUtil;
 import org.apache.hadoop.hdfs.DistributedFileSystem;
@@ -601,6 +602,7 @@ public class TestFsck {
         out.write(randomString.getBytes());
         writeCount++;                  
       }
+      ((DFSOutputStream) out.getWrappedStream()).hflush();
       // We expect the filesystem to be HEALTHY and show one open file
       outStr = runFsck(conf, 0, true, topDir);
       System.out.println(outStr);