HDFS-15515: mkdirs on fallback should throw IOE out instead of suppre…

…ssing and returning false (apache#2205)

* HDFS-15515: mkdirs on fallback should throw IOE out instead of suppressing and returning false

* Used LambdaTestUtils#intercept in test

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

@@ -1421,7 +1421,7 @@ public FsStatus getStatus(Path p) throws IOException {
 
     @Override
     public boolean mkdirs(Path dir, FsPermission permission)
-        throws AccessControlException, FileAlreadyExistsException {
+        throws IOException {
       if (theInternalDir.isRoot() && dir == null) {
         throw new FileAlreadyExistsException("/ already exits");
       }
@@ -1451,16 +1451,15 @@ public boolean mkdirs(Path dir, FsPermission permission)
                     .append(linkedFallbackFs.getUri());
             LOG.debug(msg.toString(), e);
           }
-          return false;
+          throw e;
         }
       }
 
       throw readOnlyMountTable("mkdirs",  dir);
     }
 
     @Override
-    public boolean mkdirs(Path dir)
-        throws AccessControlException, FileAlreadyExistsException {
+    public boolean mkdirs(Path dir) throws IOException {
       return mkdirs(dir, null);
     }
 

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/fs/viewfs/TestViewFileSystemLinkFallback.java

@@ -17,6 +17,7 @@
  */
 package org.apache.hadoop.fs.viewfs;
 
+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.assertNotNull;
@@ -759,7 +760,9 @@ public void testMkdirsShouldReturnFalseWhenFallbackFSNotAvailable()
       cluster.shutdownNameNodes(); // Stopping fallback server
       // /user1/test1 does not exist in mount internal dir tree, it would
       // attempt to create in fallback.
-      assertFalse(vfs.mkdirs(nextLevelToInternalDir));
+      intercept(IOException.class, () -> {
+        vfs.mkdirs(nextLevelToInternalDir);
+      });
       cluster.restartNameNodes();
       // should return true succeed when fallback fs is back to normal.
       assertTrue(vfs.mkdirs(nextLevelToInternalDir));