HDFS-16271. RBF: NullPointerException when setQuota through routers with quota disabled. Contributed by Chengwei Wang.

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/Quota.java

@@ -80,6 +80,9 @@ public class Quota {
    */
   public void setQuota(String path, long namespaceQuota, long storagespaceQuota,
       StorageType type, boolean checkMountEntry) throws IOException {
+    if (!router.isQuotaEnabled()) {
+      throw new IOException("The quota system is disabled in Router.");
+    }
     if (checkMountEntry && isMountEntry(path)) {
       throw new AccessControlException(
           "Permission denied: " + RouterRpcServer.getRemoteUser()
@@ -101,9 +104,6 @@ public class Quota {
       long namespaceQuota, long storagespaceQuota, StorageType type)
       throws IOException {
     rpcServer.checkOperation(OperationCategory.WRITE);
-    if (!router.isQuotaEnabled()) {
-      throw new IOException("The quota system is disabled in Router.");
-    }
 
     // Set quota for current path and its children mount table path.
     if (locations == null) {

hadoop-hdfs-project/hadoop-hdfs-rbf/src/test/java/org/apache/hadoop/hdfs/server/federation/router/TestDisableRouterQuota.java

@@ -70,15 +70,21 @@ public class TestDisableRouterQuota {
   public void testSetQuota() throws Exception {
     long nsQuota = 1024;
     long ssQuota = 1024;
+    Quota quotaModule = router.getRpcServer().getQuotaModule();
 
-    try {
-      Quota quotaModule = router.getRpcServer().getQuotaModule();
-      quotaModule.setQuota("/test", nsQuota, ssQuota, null, false);
-      fail("The setQuota call should fail.");
-    } catch (IOException ioe) {
-      GenericTestUtils.assertExceptionContains(
-          "The quota system is disabled in Router.", ioe);
-    }
+    // don't checkMountEntry called by RouterAdminServer#synchronizeQuota
+    LambdaTestUtils.intercept(
+        IOException.class,
+        "The quota system is disabled in Router.",
+        "The setQuota call should fail.",
+        () -> quotaModule.setQuota("/test", nsQuota, ssQuota, null, false));
+
+    // do checkMountEntry called by RouterClientProtocol#setQuota
+    LambdaTestUtils.intercept(
+        IOException.class,
+        "The quota system is disabled in Router.",
+        "The setQuota call should fail.",
+        () -> quotaModule.setQuota("/test", nsQuota, ssQuota, null, true));
   }
 
   @Test