HDFS-6753. Initialize checkDisk when DirectoryScanner not able to get files list for scanning (Contributed by J.Andreina)

(cherry picked from commit 4f75b15628a76881efc39054612dc128e23d27be)

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

@@ -741,6 +741,9 @@ Release 2.7.0 - UNRELEASED
     HDFS-7774. Unresolved symbols error while compiling HDFS on Windows 7/32 bit.
     (Kiran Kumar M R via cnauroth)
 
+    HDFS-6753. Initialize checkDisk when DirectoryScanner not able to get
+    files list for scanning (J.Andreina via vinayakumarb)
+
     BREAKDOWN OF HDFS-7584 SUBTASKS AND RELATED JIRAS
 
       HDFS-7720. Quota by Storage Type API, tools and ClientNameNode

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

@@ -822,7 +822,7 @@ public class DataNode extends ReconfigurableBase
       reason = "verifcation is not supported by SimulatedFSDataset";
     } 
     if (reason == null) {
-      directoryScanner = new DirectoryScanner(data, conf);
+      directoryScanner = new DirectoryScanner(this, data, conf);
       directoryScanner.start();
     } else {
       LOG.info("Periodic Directory Tree Verification scan is disabled because " +

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

@@ -63,6 +63,7 @@ public class DirectoryScanner implements Runnable {
   private final long scanPeriodMsecs;
   private volatile boolean shouldRun = false;
   private boolean retainDiffs = false;
+  private final DataNode datanode;
 
   final ScanInfoPerBlockPool diffs = new ScanInfoPerBlockPool();
   final Map<String, Stats> stats = new HashMap<String, Stats>();
@@ -308,7 +309,8 @@ public class DirectoryScanner implements Runnable {
     }
   }
 
-  DirectoryScanner(FsDatasetSpi<?> dataset, Configuration conf) {
+  DirectoryScanner(DataNode datanode, FsDatasetSpi<?> dataset, Configuration conf) {
+    this.datanode = datanode;
     this.dataset = dataset;
     int interval = conf.getInt(DFSConfigKeys.DFS_DATANODE_DIRECTORYSCAN_INTERVAL_KEY,
         DFSConfigKeys.DFS_DATANODE_DIRECTORYSCAN_INTERVAL_DEFAULT);
@@ -547,7 +549,7 @@ public class DirectoryScanner implements Runnable {
     for (int i = 0; i < volumes.size(); i++) {
       if (isValid(dataset, volumes.get(i))) {
         ReportCompiler reportCompiler =
-          new ReportCompiler(volumes.get(i));
+          new ReportCompiler(datanode,volumes.get(i));
         Future<ScanInfoPerBlockPool> result = 
           reportCompileThreadPool.submit(reportCompiler);
         compilersInProgress.put(i, result);
@@ -585,8 +587,10 @@ public class DirectoryScanner implements Runnable {
   private static class ReportCompiler 
   implements Callable<ScanInfoPerBlockPool> {
     private final FsVolumeSpi volume;
+    private final DataNode datanode;
 
-    public ReportCompiler(FsVolumeSpi volume) {
+    public ReportCompiler(DataNode datanode, FsVolumeSpi volume) {
+      this.datanode = datanode;
       this.volume = volume;
     }
 
@@ -611,6 +615,8 @@ public class DirectoryScanner implements Runnable {
         files = FileUtil.listFiles(dir);
       } catch (IOException ioe) {
         LOG.warn("Exception occured while compiling report: ", ioe);
+        // Initiate a check on disk failure.
+        datanode.checkDiskErrorAsync();
         // Ignore this directory and proceed.
         return report;
       }

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

@@ -299,10 +299,11 @@ public class TestDirectoryScanner {
         .build();
     try {
       cluster.waitActive();
+      DataNode dataNode = cluster.getDataNodes().get(0);
       bpid = cluster.getNamesystem().getBlockPoolId();
       fds = DataNodeTestUtils.getFSDataset(cluster.getDataNodes().get(0));
       client = cluster.getFileSystem().getClient();
-      scanner = new DirectoryScanner(fds, CONF);
+      scanner = new DirectoryScanner(dataNode, fds, CONF);
       scanner.setRetainDiffs(true);
       FsDatasetTestUtil.stopLazyWriter(cluster.getDataNodes().get(0));
 
@@ -340,9 +341,10 @@ public class TestDirectoryScanner {
     try {
       cluster.waitActive();
       bpid = cluster.getNamesystem().getBlockPoolId();
+      DataNode dataNode = cluster.getDataNodes().get(0);
       fds = DataNodeTestUtils.getFSDataset(cluster.getDataNodes().get(0));
       client = cluster.getFileSystem().getClient();
-      scanner = new DirectoryScanner(fds, CONF);
+      scanner = new DirectoryScanner(dataNode, fds, CONF);
       scanner.setRetainDiffs(true);
       FsDatasetTestUtil.stopLazyWriter(cluster.getDataNodes().get(0));
 
@@ -389,7 +391,8 @@ public class TestDirectoryScanner {
       client = cluster.getFileSystem().getClient();
       CONF.setInt(DFSConfigKeys.DFS_DATANODE_DIRECTORYSCAN_THREADS_KEY,
                   parallelism);
-      scanner = new DirectoryScanner(fds, CONF);
+      DataNode dataNode = cluster.getDataNodes().get(0);
+      scanner = new DirectoryScanner(dataNode, fds, CONF);
       scanner.setRetainDiffs(true);
 
       // Add files with 100 blocks