HDDS-2114. Rename does not preserve non-explicitly created interim directories. Contributed by Lokesh Jain & Istvan Fajth.

hadoop-ozone/ozonefs/src/main/java/org/apache/hadoop/fs/ozone/BasicOzoneFileSystem.java

@@ -375,7 +375,11 @@ public class BasicOzoneFileSystem extends FileSystem {
       }
     }
     RenameIterator iterator = new RenameIterator(src, dst);
-    return iterator.iterate();
+    boolean result = iterator.iterate();
+    if (result) {
+      createFakeParentDirectory(src);
+    }
+    return result;
   }
 
   private class DeleteIterator extends OzoneListingIterator {
@@ -460,10 +464,7 @@ public class BasicOzoneFileSystem extends FileSystem {
     if (result) {
       // If this delete operation removes all files/directories from the
       // parent direcotry, then an empty parent directory must be created.
-      Path parent = f.getParent();
-      if (parent != null && !parent.isRoot()) {
-        createFakeDirectoryIfNecessary(parent);
-      }
+      createFakeParentDirectory(f);
     }
 
     return result;
@@ -476,6 +477,19 @@ public class BasicOzoneFileSystem extends FileSystem {
    * @param f path to the fake parent directory
    * @throws IOException
    */
+  private void createFakeParentDirectory(Path f) throws IOException {
+    Path parent = f.getParent();
+    if (parent != null && !parent.isRoot()) {
+      createFakeDirectoryIfNecessary(parent);
+    }
+  }
+
+  /**
+   * Create a fake directory key if it does not already exist.
+   *
+   * @param f path to the fake directory
+   * @throws IOException
+   */
   private void createFakeDirectoryIfNecessary(Path f) throws IOException {
     String key = pathToKey(f);
     if (!key.isEmpty() && !o3Exists(f)) {

hadoop-ozone/ozonefs/src/test/java/org/apache/hadoop/fs/ozone/TestOzoneFileSystem.java

@@ -40,6 +40,7 @@ import org.apache.commons.io.IOUtils;
 import org.junit.After;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertTrue;
 import org.junit.Before;
 import org.junit.Rule;
@@ -264,6 +265,30 @@ public class TestOzoneFileSystem {
         fileStatus2.equals(dir12.toString()));
   }
 
+  @Test
+  public void testNonExplicitlyCreatedPathExistsAfterItsLeafsWereRemoved()
+      throws Exception {
+    Path source = new Path("/source");
+    Path interimPath = new Path(source, "interimPath");
+    Path leafInsideInterimPath = new Path(interimPath, "leaf");
+    Path target = new Path("/target");
+    Path leafInTarget = new Path(target, "leaf");
+
+    fs.mkdirs(source);
+    fs.mkdirs(target);
+    fs.mkdirs(leafInsideInterimPath);
+    assertTrue(fs.rename(leafInsideInterimPath, leafInTarget));
+
+    // after rename listStatus for interimPath should succeed and
+    // interimPath should have no children
+    FileStatus[] statuses = fs.listStatus(interimPath);
+    assertNotNull("liststatus returns a null array", statuses);
+    assertEquals("Statuses array is not empty", 0, statuses.length);
+    FileStatus fileStatus = fs.getFileStatus(interimPath);
+    assertEquals("FileStatus does not point to interimPath",
+        interimPath.getName(), fileStatus.getPath().getName());
+  }
+
   private OzoneKeyDetails getKey(Path keyPath, boolean isDirectory)
       throws IOException, OzoneClientException {
     String key = o3fs.pathToKey(keyPath);