HDFS-6068. Disallow snapshot names that are also invalid directory names. Contributed by sathish

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/trunk@1579004 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -415,6 +415,9 @@ Release 2.4.0 - UNRELEASED
     HDFS-6090. Use MiniDFSCluster.Builder instead of deprecated constructors.
     (Akira AJISAKA via jing9)
 
+    HDFS-6068. Disallow snapshot names that are also invalid directory names.
+    (sathish via szetszwo)
+
   OPTIMIZATIONS
 
     HDFS-5790. LeaseManager.findPath is very slow when many leases need recovery

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

@@ -6933,6 +6933,12 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
       if (snapshotName == null || snapshotName.isEmpty()) {
         snapshotName = Snapshot.generateDefaultSnapshotName();
       }
+      if(snapshotName != null){
+        if (!DFSUtil.isValidNameForComponent(snapshotName)) {
+            throw new InvalidPathException("Invalid snapshot name: "
+                + snapshotName);
+        }
+      }
       dir.verifySnapshotName(snapshotName, snapshotRoot);
       dir.writeLock();
       try {

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

@@ -337,12 +337,11 @@ public class TestSnapshot {
       hdfs.createSnapshot(dir, name1);
       fail("Exception expected when an illegal name is given");
     } catch (RemoteException e) {
-      String errorMsg = "\"" + HdfsConstants.DOT_SNAPSHOT_DIR
-          + "\" is a reserved name.";
+      String errorMsg = "Invalid path name Invalid snapshot name: " + name1; 
       GenericTestUtils.assertExceptionContains(errorMsg, e);
     }
     
-    String errorMsg = "Snapshot name cannot contain \"" + Path.SEPARATOR + "\"";
+    
     final String[] badNames = new String[] { "foo" + Path.SEPARATOR,
         Path.SEPARATOR + "foo", Path.SEPARATOR, "foo" + Path.SEPARATOR + "bar" };
     for (String badName : badNames) {
@@ -350,6 +349,7 @@ public class TestSnapshot {
         hdfs.createSnapshot(dir, badName);
         fail("Exception expected when an illegal name is given");
       } catch (RemoteException e) {
+    String errorMsg = "Invalid path name Invalid snapshot name: " + badName ;
         GenericTestUtils.assertExceptionContains(errorMsg, e);
       }
     }