HDFS-15338. listOpenFiles() should throw InvalidPathException in case of invalid paths. Contributed by Jinglun.

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/DistributedFileSystem.java

@@ -3549,7 +3549,8 @@ public RemoteIterator<OpenFileEntry> listOpenFiles(
 
   public RemoteIterator<OpenFileEntry> listOpenFiles(
       EnumSet<OpenFilesType> openFilesTypes, String path) throws IOException {
-    return dfs.listOpenFiles(openFilesTypes, path);
+    Path absF = fixRelativePart(new Path(path));
+    return dfs.listOpenFiles(openFilesTypes, getPathName(absF));
   }
 
 

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

@@ -1904,6 +1904,7 @@ private void metaSave(PrintWriter out) {
    */
   BatchedListEntries<OpenFileEntry> listOpenFiles(long prevId,
       EnumSet<OpenFilesType> openFilesTypes, String path) throws IOException {
+    INode.checkAbsolutePath(path);
     final String operationName = "listOpenFiles";
     checkSuperuserPrivilege();
     checkOperation(OperationCategory.READ);

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

@@ -806,7 +806,7 @@ static boolean isValidAbsolutePath(final String path){
     return path != null && path.startsWith(Path.SEPARATOR);
   }
 
-  private static void checkAbsolutePath(final String path) {
+  static void checkAbsolutePath(final String path) {
     if (!isValidAbsolutePath(path)) {
       throw new AssertionError("Absolute path required, but got '"
           + path + "'");

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/namenode/TestListOpenFiles.java

@@ -17,6 +17,7 @@
  */
 package org.apache.hadoop.hdfs.server.namenode;
 
+import static org.apache.hadoop.test.LambdaTestUtils.intercept;
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertFalse;
 import static org.junit.Assert.assertTrue;
@@ -295,4 +296,29 @@ public void testListOpenFilesWithFilterPath() throws IOException {
       verifyOpenFiles(openFiles, OpenFilesIterator.FILTER_PATH_DEFAULT);
     }
   }
+
+  @Test
+  public void testListOpenFilesWithInvalidPathServerSide() throws Exception {
+    HashMap<Path, FSDataOutputStream> openFiles = new HashMap<>();
+    openFiles.putAll(
+        DFSTestUtil.createOpenFiles(fs, new Path("/base"), "open-1", 1));
+    verifyOpenFiles(openFiles, EnumSet.of(OpenFilesType.ALL_OPEN_FILES),
+        "/base");
+    intercept(AssertionError.class, "Absolute path required",
+        "Expect InvalidPathException", () -> verifyOpenFiles(new HashMap<>(),
+            EnumSet.of(OpenFilesType.ALL_OPEN_FILES), "hdfs://cluster/base"));
+    while(openFiles.size() > 0) {
+      DFSTestUtil.closeOpenFiles(openFiles, 1);
+      verifyOpenFiles(openFiles);
+    }
+  }
+
+  @Test
+  public void testListOpenFilesWithInvalidPathClientSide() throws Exception {
+    intercept(IllegalArgumentException.class, "Wrong FS",
+        "Expect IllegalArgumentException", () -> fs
+            .listOpenFiles(EnumSet.of(OpenFilesType.ALL_OPEN_FILES),
+                "hdfs://non-cluster/"));
+    fs.listOpenFiles(EnumSet.of(OpenFilesType.ALL_OPEN_FILES), "/path");
+  }
 }