HADOOP-18110. ViewFileSystem: Add Support for Localized Trash Root

Fixes #3956

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

@@ -132,4 +132,10 @@ public interface Constants {
   Class<? extends MountTableConfigLoader>
       DEFAULT_MOUNT_TABLE_CONFIG_LOADER_IMPL =
       HCFSMountTableConfigLoader.class;
+
+  /**
+   * Enable ViewFileSystem to return a trashRoot which is local to mount point.
+   */
+  String CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH = "fs.viewfs.mount.point.local.trash";
+  boolean CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH_DEFAULT = false;
 }

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

@@ -25,6 +25,8 @@ import static org.apache.hadoop.fs.viewfs.Constants.CONFIG_VIEWFS_IGNORE_PORT_IN
 import static org.apache.hadoop.fs.viewfs.Constants.CONFIG_VIEWFS_MOUNT_LINKS_AS_SYMLINKS;
 import static org.apache.hadoop.fs.viewfs.Constants.CONFIG_VIEWFS_MOUNT_LINKS_AS_SYMLINKS_DEFAULT;
 import static org.apache.hadoop.fs.viewfs.Constants.PERMISSION_555;
+import static org.apache.hadoop.fs.viewfs.Constants.CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH;
+import static org.apache.hadoop.fs.viewfs.Constants.CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH_DEFAULT;
 
 import java.util.function.Function;
 import java.io.FileNotFoundException;
@@ -1130,16 +1132,49 @@ public class ViewFileSystem extends FileSystem {
    * Get the trash root directory for current user when the path
    * specified is deleted.
    *
+   * If CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH is not set, return
+   * the default trash root from targetFS.
+   *
+   * When CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH is set to true,
+   * 1) If path p is in fallback FS or from the same mount point as the default
+   *    trash root for targetFS, return the default trash root for targetFS.
+   * 2) else, return a trash root in the mounted targetFS
+   *    (/mntpoint/.Trash/{user})
+   *
    * @param path the trash root of the path to be determined.
    * @return the trash root path.
    */
   @Override
   public Path getTrashRoot(Path path) {
+    boolean useMountPointLocalTrash =
+        config.getBoolean(CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH,
+            CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH_DEFAULT);
+
     try {
       InodeTree.ResolveResult<FileSystem> res =
           fsState.resolve(getUriPath(path), true);
-      return res.targetFileSystem.getTrashRoot(res.remainingPath);
-    } catch (Exception e) {
+
+      Path trashRoot = res.targetFileSystem.getTrashRoot(res.remainingPath);
+      if (!useMountPointLocalTrash) {
+        return trashRoot;
+      } else {
+        // Path p is either in a mount point or in the fallback FS
+
+        if (ROOT_PATH.equals(new Path(res.resolvedPath))
+            || trashRoot.toUri().getPath().startsWith(res.resolvedPath)) {
+          // Path p is in the fallback FS or targetFileSystem.trashRoot is in
+          // the same mount point as Path p
+          return trashRoot;
+        } else {
+          // targetFileSystem.trashRoot is in a different mount point from
+          // Path p. Return the trash root for the mount point.
+          Path mountPointRoot =
+              res.targetFileSystem.getFileStatus(new Path("/")).getPath();
+          return new Path(mountPointRoot,
+              TRASH_PREFIX + "/" + ugi.getShortUserName());
+        }
+      }
+    } catch (IOException | IllegalArgumentException e) {
       throw new NotInMountpointException(path, "getTrashRoot");
     }
   }
@@ -1156,6 +1191,62 @@ public class ViewFileSystem extends FileSystem {
     for (FileSystem fs : getChildFileSystems()) {
       trashRoots.addAll(fs.getTrashRoots(allUsers));
     }
+
+    // Add trash dirs for each mount point
+    boolean useMountPointLocalTrash =
+        config.getBoolean(CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH,
+            CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH_DEFAULT);
+    if (useMountPointLocalTrash) {
+
+      Set<Path> currentTrashPaths = new HashSet<>();
+      for (FileStatus file : trashRoots) {
+        currentTrashPaths.add(file.getPath());
+      }
+
+      MountPoint[] mountPoints = getMountPoints();
+      try {
+        for (int i = 0; i < mountPoints.length; i++) {
+          Path trashRoot = makeQualified(
+              new Path(mountPoints[i].mountedOnPath + "/" + TRASH_PREFIX));
+
+          // Continue if trashRoot does not exist for this filesystem
+          if (!exists(trashRoot)) {
+            continue;
+          }
+
+          InodeTree.ResolveResult<FileSystem> res =
+              fsState.resolve(getUriPath(trashRoot), true);
+
+          if (!allUsers) {
+            Path userTrash =
+                new Path("/" + TRASH_PREFIX + "/" + ugi.getShortUserName());
+            try {
+              FileStatus file = res.targetFileSystem.getFileStatus(userTrash);
+              if (!currentTrashPaths.contains(file.getPath())) {
+                trashRoots.add(file);
+                currentTrashPaths.add(file.getPath());
+              }
+            } catch (FileNotFoundException ignored) {
+            }
+          } else {
+            FileStatus[] targetFsTrashRoots =
+                res.targetFileSystem.listStatus(new Path("/" + TRASH_PREFIX));
+            for (FileStatus file : targetFsTrashRoots) {
+              // skip if we already include it in currentTrashPaths
+              if (currentTrashPaths.contains(file.getPath())) {
+                continue;
+              }
+
+              trashRoots.add(file);
+              currentTrashPaths.add(file.getPath());
+            }
+          }
+        }
+      } catch (IOException e) {
+        LOG.warn("Exception in get all trash roots", e);
+      }
+    }
+
     return trashRoots;
   }
 

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

@@ -69,6 +69,8 @@ import org.slf4j.LoggerFactory;
 import static org.apache.hadoop.fs.FileSystemTestHelper.*;
 import static org.apache.hadoop.fs.viewfs.Constants.CONFIG_VIEWFS_ENABLE_INNER_CACHE;
 import static org.apache.hadoop.fs.viewfs.Constants.PERMISSION_555;
+import static org.apache.hadoop.fs.viewfs.Constants.CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH;
+import static org.apache.hadoop.fs.FileSystem.TRASH_PREFIX;
 
 import org.junit.After;
 import org.junit.Assert;
@@ -1102,6 +1104,160 @@ abstract public class ViewFileSystemBaseTest {
     Assert.assertTrue("", fsView.getTrashRoots(true).size() > 0);
   }
 
+  /**
+   * Test the localized trash root for getTrashRoot.
+   */
+  @Test
+  public void testTrashRootLocalizedTrash() throws IOException {
+    UserGroupInformation ugi = UserGroupInformation.getCurrentUser();
+    Configuration conf2 = new Configuration(conf);
+    conf2.setBoolean(CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH, true);
+    ConfigUtil.addLinkFallback(conf2, targetTestRoot.toUri());
+    FileSystem fsView2 = FileSystem.get(FsConstants.VIEWFS_URI, conf2);
+
+    // Case 1: path p not in the default FS.
+    // Return a trash root within the mount point.
+    Path dataTestPath = new Path("/data/dir/file");
+    Path dataTrashRoot = new Path(targetTestRoot,
+        "data/" + TRASH_PREFIX + "/" + ugi.getShortUserName());
+    Assert.assertEquals(dataTrashRoot, fsView2.getTrashRoot(dataTestPath));
+
+    // Case 2: path p not found in mount table, fall back to the default FS
+    // Return a trash root in user home dir
+    Path nonExistentPath = new Path("/nonExistentDir/nonExistentFile");
+    Path userTrashRoot = new Path(fsTarget.getHomeDirectory(), TRASH_PREFIX);
+    Assert.assertEquals(userTrashRoot, fsView2.getTrashRoot(nonExistentPath));
+
+    // Case 3: turn off the CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH flag.
+    // Return a trash root in user home dir.
+    conf2.setBoolean(CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH, false);
+    fsView2 = FileSystem.get(FsConstants.VIEWFS_URI, conf2);
+    Assert.assertEquals(userTrashRoot, fsView2.getTrashRoot(dataTestPath));
+
+    // Case 4: viewFS without fallback. Expect exception for a nonExistent path
+    conf2 = new Configuration(conf);
+    fsView2 = FileSystem.get(FsConstants.VIEWFS_URI, conf2);
+    try {
+      fsView2.getTrashRoot(nonExistentPath);
+    } catch (NotInMountpointException ignored) {
+    }
+
+    // Case 5: path p is in the same mount point as targetFS.getTrashRoot().
+    // Return targetFS.getTrashRoot()
+    // Use a new Configuration object, so that we can start with an empty
+    // mount table. This would avoid a conflict between the /user link in
+    // setupMountPoints() and homeDir we will need to setup for this test.
+    // default homeDir for hdfs is /user/.
+    Configuration conf3 = ViewFileSystemTestSetup.createConfig();
+    Path homeDir = fsTarget.getHomeDirectory();
+    String homeParentDir = homeDir.getParent().toUri().getPath();
+    conf3.setBoolean(CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH, true);
+    ConfigUtil.addLink(conf3, homeParentDir,
+        new Path(targetTestRoot, homeParentDir).toUri());
+    Path homeTestPath = new Path(homeDir.toUri().getPath(), "testuser/file");
+    FileSystem fsView3 = FileSystem.get(FsConstants.VIEWFS_URI, conf3);
+    Assert.assertEquals(userTrashRoot, fsView3.getTrashRoot(homeTestPath));
+  }
+
+  /**
+   * A mocked FileSystem which returns a deep trash dir.
+   */
+  static class MockTrashRootFS extends MockFileSystem {
+    public static final Path TRASH =
+        new Path("/mnt/very/deep/deep/trash/dir/.Trash");
+
+    @Override
+    public Path getTrashRoot(Path path) {
+      return TRASH;
+    }
+  }
+
+  /**
+   * Test a trash root that is inside a mount point for getTrashRoot
+   */
+  @Test
+  public void testTrashRootDeepTrashDir() throws IOException {
+
+    Configuration conf2 = ViewFileSystemTestSetup.createConfig();
+    conf2.setBoolean(CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH, true);
+    conf2.setClass("fs.mocktrashfs.impl", MockTrashRootFS.class,
+        FileSystem.class);
+    ConfigUtil.addLink(conf2, "/mnt", URI.create("mocktrashfs://mnt/path"));
+    Path testPath = new Path(MockTrashRootFS.TRASH, "projs/proj");
+    FileSystem fsView2 = FileSystem.get(FsConstants.VIEWFS_URI, conf2);
+    Assert.assertEquals(MockTrashRootFS.TRASH, fsView2.getTrashRoot(testPath));
+  }
+
+  /**
+   * Test localized trash roots in getTrashRoots() for all users.
+   */
+  @Test
+  public void testTrashRootsAllUsers() throws IOException {
+    Configuration conf2 = new Configuration(conf);
+    conf2.setBoolean(CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH, true);
+    FileSystem fsView2 = FileSystem.get(FsConstants.VIEWFS_URI, conf2);
+
+    // Case 1: verify correct trash roots from fsView and fsView2
+    int beforeTrashRootNum = fsView.getTrashRoots(true).size();
+    int beforeTrashRootNum2 = fsView2.getTrashRoots(true).size();
+    Assert.assertEquals(beforeTrashRootNum, beforeTrashRootNum2);
+
+    fsView.mkdirs(new Path("/data/" + TRASH_PREFIX + "/user1"));
+    fsView.mkdirs(new Path("/data/" + TRASH_PREFIX + "/user2"));
+    fsView.mkdirs(new Path("/user/" + TRASH_PREFIX + "/user3"));
+    fsView.mkdirs(new Path("/user/" + TRASH_PREFIX + "/user4"));
+    fsView.mkdirs(new Path("/user2/" + TRASH_PREFIX + "/user5"));
+    int afterTrashRootsNum = fsView.getTrashRoots(true).size();
+    int afterTrashRootsNum2 = fsView2.getTrashRoots(true).size();
+    Assert.assertEquals(beforeTrashRootNum, afterTrashRootsNum);
+    Assert.assertEquals(beforeTrashRootNum2 + 5, afterTrashRootsNum2);
+
+    // Case 2: per-user mount point
+    fsTarget.mkdirs(new Path(targetTestRoot, "Users/userA/.Trash/userA"));
+    Configuration conf3 = new Configuration(conf2);
+    ConfigUtil.addLink(conf3, "/Users/userA",
+        new Path(targetTestRoot, "Users/userA").toUri());
+    FileSystem fsView3 = FileSystem.get(FsConstants.VIEWFS_URI, conf3);
+    int trashRootsNum3 = fsView3.getTrashRoots(true).size();
+    Assert.assertEquals(afterTrashRootsNum2 + 1, trashRootsNum3);
+
+    // Case 3: single /Users mount point for all users
+    fsTarget.mkdirs(new Path(targetTestRoot, "Users/.Trash/user1"));
+    fsTarget.mkdirs(new Path(targetTestRoot, "Users/.Trash/user2"));
+    Configuration conf4 = new Configuration(conf2);
+    ConfigUtil.addLink(conf4, "/Users",
+        new Path(targetTestRoot, "Users").toUri());
+    FileSystem fsView4 = FileSystem.get(FsConstants.VIEWFS_URI, conf4);
+    int trashRootsNum4 = fsView4.getTrashRoots(true).size();
+    Assert.assertEquals(afterTrashRootsNum2 + 2, trashRootsNum4);
+  }
+
+  /**
+   * Test localized trash roots in getTrashRoots() for current user.
+   */
+  @Test
+  public void testTrashRootsCurrentUser() throws IOException {
+    String currentUser =
+        UserGroupInformation.getCurrentUser().getShortUserName();
+    Configuration conf2 = new Configuration(conf);
+    conf2.setBoolean(CONFIG_VIEWFS_MOUNT_POINT_LOCAL_TRASH, true);
+    FileSystem fsView2 = FileSystem.get(FsConstants.VIEWFS_URI, conf2);
+
+    int beforeTrashRootNum = fsView.getTrashRoots(false).size();
+    int beforeTrashRootNum2 = fsView2.getTrashRoots(false).size();
+    Assert.assertEquals(beforeTrashRootNum, beforeTrashRootNum2);
+
+    fsView.mkdirs(new Path("/data/" + TRASH_PREFIX + "/" + currentUser));
+    fsView.mkdirs(new Path("/data/" + TRASH_PREFIX + "/user2"));
+    fsView.mkdirs(new Path("/user/" + TRASH_PREFIX + "/" + currentUser));
+    fsView.mkdirs(new Path("/user/" + TRASH_PREFIX + "/user4"));
+    fsView.mkdirs(new Path("/user2/" + TRASH_PREFIX + "/user5"));
+    int afterTrashRootsNum = fsView.getTrashRoots(false).size();
+    int afterTrashRootsNum2 = fsView2.getTrashRoots(false).size();
+    Assert.assertEquals(beforeTrashRootNum, afterTrashRootsNum);
+    Assert.assertEquals(beforeTrashRootNum2 + 2, afterTrashRootsNum2);
+  }
+
   @Test(expected = NotInMountpointException.class)
   public void testViewFileSystemUtil() throws Exception {
     Configuration newConf = new Configuration(conf);