HADOOP-12119. hadoop fs -expunge does not work for federated namespace (Contributed by J.Andreina)

(cherry picked from commit c815344e2e)

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

@@ -395,6 +395,9 @@ Release 2.8.0 - UNRELEASED
     HADOOP-8151. Error handling in snappy decompressor throws invalid
     exceptions. (Matt Foley via harsh)
 
+    HADOOP-12119. hadoop fs -expunge does not work for federated namespace
+    (J.Andreina via vinayakumarb)
+
 Release 2.7.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES

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

@@ -25,6 +25,7 @@ import java.util.List;
 
 import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.classification.InterfaceStability;
+import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.PathIOException;
 import org.apache.hadoop.fs.PathIsDirectoryException;
 import org.apache.hadoop.fs.PathIsNotDirectoryException;
@@ -195,9 +196,19 @@ class Delete {
     @Override
     protected void processArguments(LinkedList<PathData> args)
     throws IOException {
+      FileSystem[] childFileSystems =
+          FileSystem.get(getConf()).getChildFileSystems();
+      if (null != childFileSystems) {
+        for (FileSystem fs : childFileSystems) {
+          Trash trash = new Trash(fs, getConf());
+          trash.expunge();
+          trash.checkpoint();
+        }
+      } else {
         Trash trash = new Trash(getConf());
         trash.expunge();
         trash.checkpoint();
       }
     }
+  }
 }

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

@@ -594,8 +594,18 @@ public class TestTrash extends TestCase {
     TestLFS() {
       this(new Path(TEST_DIR, "user/test"));
     }
-    TestLFS(Path home) {
-      super();
+    TestLFS(final Path home) {
+      super(new RawLocalFileSystem() {
+        @Override
+        protected Path getInitialWorkingDirectory() {
+          return makeQualified(home);
+        }
+
+        @Override
+        public Path getHomeDirectory() {
+          return makeQualified(home);
+        }
+      });
       this.home = home;
     }
     @Override