HDFS-9851. NameNode throws NPE when setPermission is called on a path that does not exist. Contributed by Brahma Reddy Battula.

hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt

@@ -129,6 +129,9 @@ Release 2.7.3 - UNRELEASED
     HDFS-9766. TestDataNodeMetrics#testDataNodeTimeSpend fails intermittently.
     (Xiao Chen via aajisaka)
 
+    HDFS-9851. NameNode throws NPE when setPermission is called on a path that
+    does not exist. (Brahma Reddy Battula via aajisaka)
+
 Release 2.7.2 - 2016-01-25
 
   INCOMPATIBLE CHANGES

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirXAttrOp.java

@@ -32,6 +32,7 @@ import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos;
 import org.apache.hadoop.hdfs.protocolPB.PBHelper;
 import org.apache.hadoop.security.AccessControlException;
 
+import java.io.FileNotFoundException;
 import java.io.IOException;
 import java.util.EnumSet;
 import java.util.List;
@@ -396,7 +397,7 @@ class FSDirXAttrOp {
   private static void checkXAttrChangeAccess(
       FSDirectory fsd, INodesInPath iip, XAttr xAttr,
       FSPermissionChecker pc)
-      throws AccessControlException {
+      throws AccessControlException, FileNotFoundException {
     if (fsd.isPermissionEnabled() && xAttr.getNameSpace() == XAttr.NameSpace
         .USER) {
       final INode inode = iip.getLastINode();

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSDirectory.java

@@ -1673,7 +1673,11 @@ public class FSDirectory implements Closeable {
   }
 
   void checkOwner(FSPermissionChecker pc, INodesInPath iip)
-      throws AccessControlException {
+      throws AccessControlException, FileNotFoundException {
+    if (iip.getLastINode() == null) {
+      throw new FileNotFoundException(
+          "Directory/File does not exist " + iip.getPath());
+    }
     checkPermission(pc, iip, true, null, null, null, null);
   }
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/security/TestPermission.java

@@ -20,6 +20,7 @@ package org.apache.hadoop.security;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
+import static org.junit.Assert.fail;
 
 import java.io.IOException;
 import java.util.Random;
@@ -50,6 +51,7 @@ public class TestPermission {
   final private static Path CHILD_DIR2 = new Path(ROOT_PATH, "child2");
   final private static Path CHILD_FILE1 = new Path(ROOT_PATH, "file1");
   final private static Path CHILD_FILE2 = new Path(ROOT_PATH, "file2");
+  final private static Path CHILD_FILE3 = new Path(ROOT_PATH, "file3");
 
   final private static int FILE_LEN = 100;
   final private static Random RAN = new Random();
@@ -257,6 +259,18 @@ public class TestPermission {
       final Path RENAME_PATH = new Path("/foo/bar");
       userfs.mkdirs(RENAME_PATH);
       assertTrue(canRename(userfs, RENAME_PATH, CHILD_DIR1));
+      // test permissions on files that do not exist
+      assertFalse(userfs.exists(CHILD_FILE3));
+      try {
+        userfs.setOwner(CHILD_FILE3, "foo", "bar");
+        fail("setOwner should fail for non-exist file");
+      } catch (java.io.FileNotFoundException ignored) {
+      }
+      try {
+        userfs.setPermission(CHILD_FILE3, new FsPermission((short) 0777));
+        fail("setPermission should fail for non-exist file");
+      } catch (java.io.FileNotFoundException ignored) {
+      }
     } finally {
       cluster.shutdown();
     }