HADOOP-8349. ViewFS doesn't work when the root of a file system is mounted. Contributed by Aaron T. Myers.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1334231 13f79535-47bb-0310-9956-ffa450edef68

hadoop-common-project/hadoop-common/CHANGES.txt

@@ -423,6 +423,8 @@ Release 2.0.0 - UNRELEASED
 
     HADOOP-8355. SPNEGO filter throws/logs exception when authentication fails (tucu)
 
+    HADOOP-8349. ViewFS doesn't work when the root of a file system is mounted. (atm)
+
   BREAKDOWN OF HADOOP-7454 SUBTASKS
 
     HADOOP-7455. HA: Introduce HA Service Protocol Interface. (suresh)

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/AbstractFileSystem.java

@@ -346,7 +346,7 @@ public abstract class AbstractFileSystem {
             path);
       } else {
         throw new InvalidPathException(
-            "Path without scheme with non-null autorhrity:" + path);
+            "Path without scheme with non-null authority:" + path);
       }
     }
     String thisScheme = this.getUri().getScheme();

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/Path.java

@@ -223,6 +223,13 @@ public class Path implements Comparable {
      return isUriPathAbsolute();
   }
 
+  /**
+   * @return true if and only if this path represents the root of a file system
+   */
+  public boolean isRoot() {
+    return getParent() == null;
+  }
+
   /** Returns the final component of this path.*/
   public String getName() {
     String path = uri.getPath();

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ChRootedFileSystem.java

@@ -75,7 +75,8 @@ class ChRootedFileSystem extends FilterFileSystem {
   protected Path fullPath(final Path path) {
     super.checkPath(path);
     return path.isAbsolute() ? 
-        new Path(chRootPathPartString + path.toUri().getPath()) :
+        new Path((chRootPathPart.isRoot() ? "" : chRootPathPartString)
+            + path.toUri().getPath()) :
         new Path(chRootPathPartString + workingDir.toUri().getPath(), path);
   }
   
@@ -127,7 +128,7 @@ class ChRootedFileSystem extends FilterFileSystem {
     }
     String pathPart = p.toUri().getPath();
     return (pathPart.length() == chRootPathPartString.length()) ? "" : pathPart
-        .substring(chRootPathPartString.length() + 1);   
+        .substring(chRootPathPartString.length() + (chRootPathPart.isRoot() ? 0 : 1));
   }
   
   @Override

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/fs/viewfs/ChRootedFs.java

@@ -79,7 +79,8 @@ class ChRootedFs extends AbstractFileSystem {
    */
   protected Path fullPath(final Path path) {
     super.checkPath(path);
-    return new Path(chRootPathPartString + path.toUri().getPath());
+    return new Path((chRootPathPart.isRoot() ? "" : chRootPathPartString)
+        + path.toUri().getPath());
   }
   
   public ChRootedFs(final AbstractFileSystem fs, final Path theRoot)
@@ -127,7 +128,8 @@ class ChRootedFs extends AbstractFileSystem {
     }
     String pathPart = p.toUri().getPath();
     return  (pathPart.length() == chRootPathPartString.length()) ?
-        "" : pathPart.substring(chRootPathPartString.length() + 1);   
+        "" : pathPart.substring(chRootPathPartString.length() +
+            (chRootPathPart.isRoot() ? 0 : 1));
   }
   
 

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/ViewFileSystemBaseTest.java

@@ -71,11 +71,8 @@ public class ViewFileSystemBaseTest {
 
   @Before
   public void setUp() throws Exception {
-    targetTestRoot = FileSystemTestHelper.getAbsoluteTestRootPath(fsTarget);
-    // In case previous test was killed before cleanup
-    fsTarget.delete(targetTestRoot, true);
+    initializeTargetTestRoot();
     
-    fsTarget.mkdirs(targetTestRoot);
     // Make  user and data dirs - we creates links to them in the mount table
     fsTarget.mkdirs(new Path(targetTestRoot,"user"));
     fsTarget.mkdirs(new Path(targetTestRoot,"data"));
@@ -99,7 +96,16 @@ public class ViewFileSystemBaseTest {
     fsTarget.delete(FileSystemTestHelper.getTestRootPath(fsTarget), true);
   }
   
+  void initializeTargetTestRoot() throws IOException {
+    targetTestRoot = FileSystemTestHelper.getAbsoluteTestRootPath(fsTarget);
+    // In case previous test was killed before cleanup
+    fsTarget.delete(targetTestRoot, true);
+    
+    fsTarget.mkdirs(targetTestRoot);
+  }
+  
   void setupMountPoints() {
+    ConfigUtil.addLink(conf, "/targetRoot", targetTestRoot.toUri());
     ConfigUtil.addLink(conf, "/user", new Path(targetTestRoot,"user").toUri());
     ConfigUtil.addLink(conf, "/user2", new Path(targetTestRoot,"user").toUri());
     ConfigUtil.addLink(conf, "/data", new Path(targetTestRoot,"data").toUri());
@@ -121,7 +127,7 @@ public class ViewFileSystemBaseTest {
   }
   
   int getExpectedMountPoints() {
-    return 7;
+    return 8;
   }
   
   /**
@@ -166,7 +172,7 @@ public class ViewFileSystemBaseTest {
         }
       }
     }
-    Assert.assertEquals(expectedTokenCount / 2, delTokens.size());
+    Assert.assertEquals((expectedTokenCount + 1) / 2, delTokens.size());
   }
 
   int getExpectedDelegationTokenCountWithCredentials() {
@@ -309,6 +315,16 @@ public class ViewFileSystemBaseTest {
     Assert.assertTrue("Renamed dest should  exist as dir in target",
         fsTarget.isDirectory(new Path(targetTestRoot,"user/dirFooBar")));
     
+    // Make a directory under a directory that's mounted from the root of another FS
+    fsView.mkdirs(new Path("/targetRoot/dirFoo"));
+    Assert.assertTrue(fsView.exists(new Path("/targetRoot/dirFoo")));
+    boolean dirFooPresent = false;
+    for (FileStatus fileStatus : fsView.listStatus(new Path("/targetRoot/"))) {
+      if (fileStatus.getPath().getName().equals("dirFoo")) {
+        dirFooPresent = true;
+      }
+    }
+    Assert.assertTrue(dirFooPresent);
   }
   
   // rename across mount points that point to same target also fail 
@@ -418,7 +434,7 @@ public class ViewFileSystemBaseTest {
   }
   
   int getExpectedDirPaths() {
-    return 6;
+    return 7;
   }
   
   @Test

hadoop-common-project/hadoop-common/src/test/java/org/apache/hadoop/fs/viewfs/ViewFsBaseTest.java

@@ -33,6 +33,7 @@ import org.apache.hadoop.fs.AbstractFileSystem;
 import org.apache.hadoop.fs.BlockLocation;
 import org.apache.hadoop.fs.FileContext;
 import org.apache.hadoop.fs.FileContextTestHelper;
+import org.apache.hadoop.fs.RemoteIterator;
 import org.apache.hadoop.fs.FileContextTestHelper.fileType;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.FsConstants;
@@ -77,12 +78,8 @@ public class ViewFsBaseTest {
 
   @Before
   public void setUp() throws Exception {
-
-    targetTestRoot = FileContextTestHelper.getAbsoluteTestRootPath(fcTarget);
-    // In case previous test was killed before cleanup
-    fcTarget.delete(targetTestRoot, true);
+    initializeTargetTestRoot();
     
-    fcTarget.mkdir(targetTestRoot, FileContext.DEFAULT_PERM, true);
     // Make  user and data dirs - we creates links to them in the mount table
     fcTarget.mkdir(new Path(targetTestRoot,"user"),
         FileContext.DEFAULT_PERM, true);
@@ -100,6 +97,7 @@ public class ViewFsBaseTest {
     
     // Set up the defaultMT in the config with our mount point links
     conf = new Configuration();
+    ConfigUtil.addLink(conf, "/targetRoot", targetTestRoot.toUri());
     ConfigUtil.addLink(conf, "/user",
         new Path(targetTestRoot,"user").toUri());
     ConfigUtil.addLink(conf, "/user2",
@@ -118,6 +116,14 @@ public class ViewFsBaseTest {
     fcView = FileContext.getFileContext(FsConstants.VIEWFS_URI, conf);
     // Also try viewfs://default/    - note authority is name of mount table
   }
+  
+  void initializeTargetTestRoot() throws IOException {
+    targetTestRoot = FileContextTestHelper.getAbsoluteTestRootPath(fcTarget);
+    // In case previous test was killed before cleanup
+    fcTarget.delete(targetTestRoot, true);
+    
+    fcTarget.mkdir(targetTestRoot, FileContext.DEFAULT_PERM, true);
+  }
 
   @After
   public void tearDown() throws Exception {
@@ -128,7 +134,11 @@ public class ViewFsBaseTest {
   public void testGetMountPoints() {
     ViewFs viewfs = (ViewFs) fcView.getDefaultFileSystem();
     MountPoint[] mountPoints = viewfs.getMountPoints();
-    Assert.assertEquals(7, mountPoints.length); 
+    Assert.assertEquals(8, mountPoints.length);
+  }
+  
+  int getExpectedDelegationTokenCount() {
+    return 0;
   }
   
   /**
@@ -140,7 +150,7 @@ public class ViewFsBaseTest {
   public void testGetDelegationTokens() throws IOException {
     List<Token<?>> delTokens = 
         fcView.getDelegationTokens(new Path("/"), "sanjay");
-    Assert.assertEquals(0, delTokens.size()); 
+    Assert.assertEquals(getExpectedDelegationTokenCount(), delTokens.size());
   }
 
   
@@ -281,6 +291,19 @@ public class ViewFsBaseTest {
     Assert.assertTrue("Renamed dest should  exist as dir in target",
         isDir(fcTarget,new Path(targetTestRoot,"user/dirFooBar")));
     
+    // Make a directory under a directory that's mounted from the root of another FS
+    fcView.mkdir(new Path("/targetRoot/dirFoo"), FileContext.DEFAULT_PERM, false);
+    Assert.assertTrue(exists(fcView, new Path("/targetRoot/dirFoo")));
+    boolean dirFooPresent = false;
+    RemoteIterator<FileStatus> dirContents = fcView.listStatus(new Path(
+        "/targetRoot/"));
+    while (dirContents.hasNext()) {
+      FileStatus fileStatus = dirContents.next();
+      if (fileStatus.getPath().getName().equals("dirFoo")) {
+        dirFooPresent = true;
+      }
+    }
+    Assert.assertTrue(dirFooPresent);
   }
   
   // rename across mount points that point to same target also fail 
@@ -358,7 +381,7 @@ public class ViewFsBaseTest {
     
     FileStatus[] dirPaths = fcView.util().listStatus(new Path("/"));
     FileStatus fs;
-    Assert.assertEquals(6, dirPaths.length);
+    Assert.assertEquals(7, dirPaths.length);
     fs = FileContextTestHelper.containsPath(fcView, "/user", dirPaths);
       Assert.assertNotNull(fs);
       Assert.assertTrue("A mount should appear as symlink", fs.isSymlink());

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

@@ -4556,7 +4556,7 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
     if (destinationExisted && dinfo.isDir()) {
       Path spath = new Path(src);
       Path parent = spath.getParent();
-      if (isRoot(parent)) {
+      if (parent.isRoot()) {
         overwrite = parent.toString();
       } else {
         overwrite = parent.toString() + Path.SEPARATOR;
@@ -4569,10 +4569,6 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
 
     leaseManager.changeLease(src, dst, overwrite, replaceBy);
   }
-           
-  private boolean isRoot(Path path) {
-    return path.getParent() == null;
-  }
 
   /**
    * Serializes leases. 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFileSystemAtHdfsRoot.java

@@ -0,0 +1,93 @@
+/**
+ * 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.fs.viewfs;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+
+import javax.security.auth.login.LoginException;
+
+import org.apache.hadoop.conf.Configuration;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.FileSystem;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+
+/**
+ * Make sure that ViewFileSystem works when the root of an FS is mounted to a
+ * ViewFileSystem mount point.
+ */
+public class TestViewFileSystemAtHdfsRoot extends ViewFileSystemBaseTest {
+
+  private static MiniDFSCluster cluster;
+  private static Configuration CONF = new Configuration();
+  private static FileSystem fHdfs;
+  
+  @BeforeClass
+  public static void clusterSetupAtBegining() throws IOException,
+      LoginException, URISyntaxException {
+    SupportsBlocks = true;
+    CONF.setBoolean(
+        DFSConfigKeys.DFS_NAMENODE_DELEGATION_TOKEN_ALWAYS_USE_KEY, true);
+    
+    cluster = new MiniDFSCluster.Builder(CONF)
+      .numDataNodes(2)
+      .build();
+    cluster.waitClusterUp();
+    
+    fHdfs = cluster.getFileSystem();
+  }
+      
+  @AfterClass
+  public static void clusterShutdownAtEnd() throws Exception {
+    cluster.shutdown();   
+  }
+
+  @Before
+  public void setUp() throws Exception {
+    fsTarget = fHdfs;
+    super.setUp();
+  }
+
+  /**
+   * Override this so that we don't set the targetTestRoot to any path under the
+   * root of the FS, and so that we don't try to delete the test dir, but rather
+   * only its contents.
+   */
+  @Override
+  void initializeTargetTestRoot() throws IOException {
+    targetTestRoot = fHdfs.makeQualified(new Path("/"));
+    for (FileStatus status : fHdfs.listStatus(targetTestRoot)) {
+      fHdfs.delete(status.getPath(), true);
+    }
+  }
+
+  @Override
+  int getExpectedDelegationTokenCount() {
+    return 8;
+  }
+
+  @Override
+  int getExpectedDelegationTokenCountWithCredentials() {
+    return 1;
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFileSystemHdfs.java

@@ -105,17 +105,17 @@ public class TestViewFileSystemHdfs extends ViewFileSystemBaseTest {
   // additional mount.
   @Override
   int getExpectedDirPaths() {
-    return 7;
+    return 8;
   }
   
   @Override
   int getExpectedMountPoints() {
-    return 8;
+    return 9;
   }
 
   @Override
   int getExpectedDelegationTokenCount() {
-    return 8;
+    return 9;
   }
 
   @Override

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsAtHdfsRoot.java

@@ -0,0 +1,93 @@
+/**
+ * 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.fs.viewfs;
+
+import java.io.IOException;
+import java.net.URISyntaxException;
+
+import javax.security.auth.login.LoginException;
+
+import org.apache.hadoop.fs.FileContext;
+import org.apache.hadoop.fs.FileStatus;
+import org.apache.hadoop.fs.Path;
+import org.apache.hadoop.fs.RemoteIterator;
+import org.apache.hadoop.hdfs.DFSConfigKeys;
+import org.apache.hadoop.hdfs.HdfsConfiguration;
+import org.apache.hadoop.hdfs.MiniDFSCluster;
+import org.junit.AfterClass;
+import org.junit.Before;
+import org.junit.BeforeClass;
+
+/**
+ * Make sure that ViewFs works when the root of an FS is mounted to a ViewFs
+ * mount point.
+ */
+public class TestViewFsAtHdfsRoot extends ViewFsBaseTest {
+  
+  private static MiniDFSCluster cluster;
+  private static HdfsConfiguration CONF = new HdfsConfiguration();
+  private static FileContext fc;
+  
+  @BeforeClass
+  public static void clusterSetupAtBegining() throws IOException,
+      LoginException, URISyntaxException {
+    SupportsBlocks = true;
+    CONF.setBoolean(
+        DFSConfigKeys.DFS_NAMENODE_DELEGATION_TOKEN_ALWAYS_USE_KEY, true);
+
+    cluster = new MiniDFSCluster.Builder(CONF).numDataNodes(2).build();
+    cluster.waitClusterUp();
+    fc = FileContext.getFileContext(cluster.getURI(0), CONF);
+  }
+
+      
+  @AfterClass
+  public static void ClusterShutdownAtEnd() throws Exception {
+    cluster.shutdown();   
+  }
+
+  @Before
+  public void setUp() throws Exception {
+    // create the test root on local_fs
+    fcTarget = fc;
+    super.setUp();    
+  }
+  
+  /**
+   * Override this so that we don't set the targetTestRoot to any path under the
+   * root of the FS, and so that we don't try to delete the test dir, but rather
+   * only its contents.
+   */
+  @Override
+  void initializeTargetTestRoot() throws IOException {
+    targetTestRoot = fc.makeQualified(new Path("/"));
+    RemoteIterator<FileStatus> dirContents = fc.listStatus(targetTestRoot);
+    while (dirContents.hasNext()) {
+      fc.delete(dirContents.next().getPath(), true);
+    }
+  }
+  
+  /**
+   * This overrides the default implementation since hdfs does have delegation
+   * tokens.
+   */
+  @Override
+  int getExpectedDelegationTokenCount() {
+    return 8;
+  }
+}

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFsHdfs.java

@@ -20,7 +20,6 @@ package org.apache.hadoop.fs.viewfs;
 
 import java.io.IOException;
 import java.net.URISyntaxException;
-import java.util.List;
 
 import javax.security.auth.login.LoginException;
 
@@ -30,20 +29,13 @@ import org.apache.hadoop.hdfs.DFSConfigKeys;
 import org.apache.hadoop.hdfs.HdfsConfiguration;
 import org.apache.hadoop.hdfs.MiniDFSCluster;
 import org.apache.hadoop.security.UserGroupInformation;
-import org.apache.hadoop.security.token.Token;
-
-import org.junit.After;
 import org.junit.AfterClass;
-import org.junit.Assert;
 import org.junit.Before;
 import org.junit.BeforeClass;
-import org.junit.Test;
-
 
 public class TestViewFsHdfs extends ViewFsBaseTest {
 
   private static MiniDFSCluster cluster;
-  private static Path defaultWorkingDirectory;
   private static HdfsConfiguration CONF = new HdfsConfiguration();
   private static FileContext fc;
   
@@ -57,7 +49,7 @@ public class TestViewFsHdfs extends ViewFsBaseTest {
     cluster = new MiniDFSCluster.Builder(CONF).numDataNodes(2).build();
     cluster.waitClusterUp();
     fc = FileContext.getFileContext(cluster.getURI(0), CONF);
-    defaultWorkingDirectory = fc.makeQualified( new Path("/user/" + 
+    Path defaultWorkingDirectory = fc.makeQualified( new Path("/user/" + 
         UserGroupInformation.getCurrentUser().getShortUserName()));
     fc.mkdir(defaultWorkingDirectory, FileContext.DEFAULT_PERM, true);
   }
@@ -73,25 +65,15 @@ public class TestViewFsHdfs extends ViewFsBaseTest {
     // create the test root on local_fs
     fcTarget = fc;
     super.setUp();
-    
-  }
-
-  @After
-  public void tearDown() throws Exception {
-    super.tearDown();
   }
   
-  
-  /*
-   * This overides the default implementation since hdfs does have delegation
+  /**
+   * This overrides the default implementation since hdfs does have delegation
    * tokens.
    */
   @Override
-  @Test
-  public void testGetDelegationTokens() throws IOException {
-    List<Token<?>> delTokens = 
-        fcView.getDelegationTokens(new Path("/"), "sanjay");
-    Assert.assertEquals(7, delTokens.size()); 
+  int getExpectedDelegationTokenCount() {
+    return 8;
   }
  
 }