HDFS-14299. ViewFs: Correct error message for read only operations. Contributed by hu xiaodong.

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

@@ -80,9 +80,9 @@ public class ViewFileSystem extends FileSystem {
 
   static AccessControlException readOnlyMountTable(final String operation,
       final String p) {
-    return new AccessControlException( 
-        "InternalDir of ViewFileSystem is readonly; operation=" + operation + 
-        "Path=" + p);
+    return new AccessControlException(
+        "InternalDir of ViewFileSystem is readonly, operation " + operation +
+            " not permitted on path " + p + ".");
   }
   static AccessControlException readOnlyMountTable(final String operation,
       final Path p) {

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

@@ -162,9 +162,9 @@ public class ViewFs extends AbstractFileSystem {
 
   static AccessControlException readOnlyMountTable(final String operation,
       final String p) {
-    return new AccessControlException( 
-        "InternalDir of ViewFileSystem is readonly; operation=" + operation + 
-        "Path=" + p);
+    return new AccessControlException(
+        "InternalDir of ViewFileSystem is readonly, operation " + operation +
+            " not permitted on path " + p + ".");
   }
   static AccessControlException readOnlyMountTable(final String operation,
       final Path p) {