HADOOP-6963. In FileUtil.getDU(..), neither include the size of directories nor follow symbolic links. Contributed by Ravi Prakash

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1309994 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -324,6 +324,9 @@ Release 2.0.0 - UNRELEASED
     HADOOP-8243. Security support broken in CLI (manual) failover controller
     (todd)
 
+    HADOOP-6963. In FileUtil.getDU(..), neither include the size of directories
+    nor follow symbolic links.  (Ravi Prakash via szetszwo)
+
   BREAKDOWN OF HADOOP-7454 SUBTASKS
 
     HADOOP-7455. HA: Introduce HA Service Protocol Interface. (suresh)

hadoop-common-project/hadoop-common/pom.xml

@@ -78,6 +78,11 @@
       <artifactId>commons-net</artifactId>
       <scope>compile</scope>
     </dependency>
+    <dependency>
+      <groupId>commons-io</groupId>
+      <artifactId>commons-io</artifactId>
+      <scope>compile</scope>
+    </dependency>
     <dependency>
       <groupId>javax.servlet</groupId>
       <artifactId>servlet-api</artifactId>

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

@@ -483,11 +483,18 @@ public static long getDU(File dir) {
     if (!dir.isDirectory()) {
       return dir.length();
     } else {
-      size = dir.length();
       File[] allFiles = dir.listFiles();
       if(allFiles != null) {
          for (int i = 0; i < allFiles.length; i++) {
-            size = size + getDU(allFiles[i]);
+           boolean isSymLink;
+           try {
+             isSymLink = org.apache.commons.io.FileUtils.isSymlink(allFiles[i]);
+           } catch(IOException ioe) {
+             isSymLink = true;
+           }
+           if(!isSymLink) {
+             size += getDU(allFiles[i]);
+           }
          }
       }
       return size;

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

@@ -93,6 +93,9 @@ private void setupDirs() throws IOException {
     // create files in partitioned directories
     createFile(partitioned, "part-r-00000", "foo");
     createFile(partitioned, "part-r-00001", "bar");
+
+    // create a cycle using symlinks. Cycles should be handled
+    FileUtil.symLink(del.toString(), dir1.toString() + "/cycle");
   }
 
   /**
@@ -458,4 +461,18 @@ private boolean copyMerge(String src, String dst)
 
     return result;
   }
+
+  /**
+   * Test that getDU is able to handle cycles caused due to symbolic links
+   * and that directory sizes are not added to the final calculated size
+   * @throws IOException
+   */
+  @Test
+  public void testGetDU() throws IOException {
+    setupDirs();
+
+    long du = FileUtil.getDU(TEST_DIR);
+    //Only two files (in partitioned) have 4 bytes each
+    Assert.assertEquals(du, 8);
+  }
 }