From 729cb3aefe71d7f728c7edea78ce7f268a1fdecb Mon Sep 17 00:00:00 2001
From: Weiwei Yang <wwei@apache.org>
Date: Thu, 4 Jul 2019 09:37:24 +0800
Subject: [PATCH] HDFS-12748. NameNode memory leak when accessing webhdfs
 GETHOMEDIRECTORY. Contributed by Weiwei Yang.

---
 .../org/apache/hadoop/hdfs/DFSUtilClient.java | 20 +++++++++++++++++++
 .../hadoop/hdfs/DistributedFileSystem.java    |  8 +-------
 .../web/resources/NamenodeWebHdfsMethods.java |  5 ++---
 3 files changed, 23 insertions(+), 10 deletions(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSUtilClient.java b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSUtilClient.java
index 77cb73831d..795ddfb379 100644
--- a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSUtilClient.java
+++ b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DFSUtilClient.java
@@ -994,4 +994,24 @@ public static Path makePathFromFileId(long fileId) {
     return new Path(sb.toString());
   }
 
+  /**
+   * Returns current user home directory under a home directory prefix.
+   * The home directory prefix can be defined by
+   * {@link HdfsClientConfigKeys#DFS_USER_HOME_DIR_PREFIX_KEY}.
+   * User info is obtained from given {@link UserGroupInformation}.
+   * @param conf configuration
+   * @param ugi {@link UserGroupInformation} of current user.
+   * @return the home directory of current user.
+   */
+  public static Path getHomeDirectory(Configuration conf,
+      UserGroupInformation ugi) {
+    String userHomePrefix = HdfsClientConfigKeys
+        .DFS_USER_HOME_DIR_PREFIX_DEFAULT;
+    if (conf != null) {
+      userHomePrefix = conf.get(
+          HdfsClientConfigKeys.DFS_USER_HOME_DIR_PREFIX_KEY,
+          HdfsClientConfigKeys.DFS_USER_HOME_DIR_PREFIX_DEFAULT);
+    }
+    return new Path(userHomePrefix + "/" + ugi.getShortUserName());
+  }
 }
diff --git a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java
index 7956d8eda9..111b23b0ef 100644
--- a/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java
+++ b/hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java
@@ -132,8 +132,6 @@ public class DistributedFileSystem extends FileSystem
     implements KeyProviderTokenIssuer {
   private Path workingDir;
   private URI uri;
-  private String homeDirPrefix =
-      HdfsClientConfigKeys.DFS_USER_HOME_DIR_PREFIX_DEFAULT;
 
   DFSClient dfs;
   private boolean verifyChecksum = true;
@@ -169,9 +167,6 @@ public void initialize(URI uri, Configuration conf) throws IOException {
     if (host == null) {
       throw new IOException("Incomplete HDFS URI, no host: "+ uri);
     }
-    homeDirPrefix = conf.get(
-        HdfsClientConfigKeys.DFS_USER_HOME_DIR_PREFIX_KEY,
-        HdfsClientConfigKeys.DFS_USER_HOME_DIR_PREFIX_DEFAULT);
 
     this.dfs = new DFSClient(uri, conf, statistics);
     this.uri = URI.create(uri.getScheme()+"://"+uri.getAuthority());
@@ -214,8 +209,7 @@ public void setWorkingDirectory(Path dir) {
 
   @Override
   public Path getHomeDirectory() {
-    return makeQualified(new Path(homeDirPrefix + "/"
-        + dfs.ugi.getShortUserName()));
+    return makeQualified(DFSUtilClient.getHomeDirectory(getConf(), dfs.ugi));
   }
 
   /**
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/web/resources/NamenodeWebHdfsMethods.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/web/resources/NamenodeWebHdfsMethods.java
index 1e8d1a5a00..ddaf0e9c6f 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/web/resources/NamenodeWebHdfsMethods.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/web/resources/NamenodeWebHdfsMethods.java
@@ -1205,9 +1205,8 @@ protected Response get(
       return Response.ok(js).type(MediaType.APPLICATION_JSON).build();
     }
     case GETHOMEDIRECTORY: {
-      final String js = JsonUtil.toJsonString("Path",
-          FileSystem.get(conf != null ? conf : new Configuration())
-              .getHomeDirectory().toUri().getPath());
+      String userHome = DFSUtilClient.getHomeDirectory(conf, ugi).toString();
+      final String js = JsonUtil.toJsonString("Path", userHome);
       return Response.ok(js).type(MediaType.APPLICATION_JSON).build();
     }
     case GETACLSTATUS: {