HDFS-12885. Add visibility/stability annotations. Contributed by Chris Douglas

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

@@ -16,6 +16,8 @@
  */
 package org.apache.hadoop.hdfs.protocol;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.fs.Path;
 
 import javax.annotation.Nonnull;
@@ -25,6 +27,8 @@ import java.util.Arrays;
  * ProvidedStorageLocation is a location in an external storage system
  * containing the data for a block (~Replica).
  */
+@InterfaceAudience.Private
+@InterfaceStability.Evolving
 public class ProvidedStorageLocation {
   private final Path path;
   private final long offset;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/AliasMapProtocolPB.java

@@ -17,6 +17,7 @@
 package org.apache.hadoop.hdfs.protocolPB;
 
 import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.hdfs.protocol.proto.AliasMapProtocolProtos;
 import org.apache.hadoop.ipc.ProtocolInfo;
 
@@ -30,6 +31,7 @@ import org.apache.hadoop.ipc.ProtocolInfo;
         "org.apache.hadoop.hdfs.server.aliasmap.AliasMapProtocol",
     protocolVersion = 1)
 @InterfaceAudience.Private
+@InterfaceStability.Unstable
 public interface AliasMapProtocolPB extends
     AliasMapProtocolProtos.AliasMapProtocolService.BlockingInterface {
 }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/AliasMapProtocolServerSideTranslatorPB.java

@@ -18,6 +18,8 @@ package org.apache.hadoop.hdfs.protocolPB;
 
 import com.google.protobuf.RpcController;
 import com.google.protobuf.ServiceException;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.ProvidedStorageLocation;
 import org.apache.hadoop.hdfs.protocol.proto.AliasMapProtocolProtos.KeyValueProto;
@@ -40,6 +42,8 @@ import static org.apache.hadoop.hdfs.server.aliasmap.InMemoryAliasMap.*;
  * AliasMapProtocolServerSideTranslatorPB is responsible for translating RPC
  * calls and forwarding them to the internal InMemoryAliasMap.
  */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
 public class AliasMapProtocolServerSideTranslatorPB
     implements AliasMapProtocolPB {
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/protocolPB/InMemoryAliasMapProtocolClientSideTranslatorPB.java

@@ -17,6 +17,8 @@
 package org.apache.hadoop.hdfs.protocolPB;
 
 import com.google.protobuf.ServiceException;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.ProvidedStorageLocation;
@@ -47,6 +49,8 @@ import static org.apache.hadoop.hdfs.protocol.proto.HdfsProtos.*;
  * {@link InMemoryAliasMapProtocol} interface to the RPC server implementing
  * {@link AliasMapProtocolPB}.
  */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
 public class InMemoryAliasMapProtocolClientSideTranslatorPB
     implements InMemoryAliasMapProtocol {
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/aliasmap/InMemoryAliasMap.java

@@ -19,6 +19,8 @@ package org.apache.hadoop.hdfs.server.aliasmap;
 import com.google.common.annotations.VisibleForTesting;
 import com.google.common.collect.Lists;
 import com.google.protobuf.InvalidProtocolBufferException;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configurable;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
@@ -47,6 +49,8 @@ import java.util.Optional;
  * InMemoryAliasMap is an implementation of the InMemoryAliasMapProtocol for
  * use with LevelDB.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public class InMemoryAliasMap implements InMemoryAliasMapProtocol,
     Configurable {
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/aliasmap/InMemoryAliasMapProtocol.java

@@ -16,6 +16,8 @@
  */
 package org.apache.hadoop.hdfs.server.aliasmap;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.ProvidedStorageLocation;
 import org.apache.hadoop.hdfs.server.common.FileRegion;
@@ -30,6 +32,8 @@ import java.util.Optional;
  * provided blocks for an in-memory implementation of the
  * {@link org.apache.hadoop.hdfs.server.common.blockaliasmap.BlockAliasMap}.
  */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
 public interface InMemoryAliasMapProtocol {
 
   /**

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/aliasmap/InMemoryLevelDBAliasMapServer.java

@@ -17,6 +17,8 @@
 package org.apache.hadoop.hdfs.server.aliasmap;
 
 import com.google.protobuf.BlockingService;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.ipc.ProtobufRpcEngine;
 import org.apache.hadoop.security.UserGroupInformation;
 import org.slf4j.Logger;
@@ -42,6 +44,8 @@ import static org.apache.hadoop.hdfs.server.aliasmap.InMemoryAliasMap.CheckedFun
  * InMemoryLevelDBAliasMapServer is the entry point from the Namenode into
  * the {@link InMemoryAliasMap}.
  */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
 public class InMemoryLevelDBAliasMapServer implements InMemoryAliasMapProtocol,
     Configurable, Closeable {
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/ProvidedStorageMap.java

@@ -30,6 +30,8 @@ import java.util.UUID;
 import java.util.concurrent.ConcurrentSkipListMap;
 
 import com.google.common.annotations.VisibleForTesting;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.StorageType;
 import org.apache.hadoop.hdfs.DFSConfigKeys;
@@ -57,6 +59,8 @@ import com.google.protobuf.ByteString;
  * This class allows us to manage and multiplex between storages local to
  * datanodes, and provided storage.
  */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
 public class ProvidedStorageMap {
 
   private static final Logger LOG =

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/common/BlockAlias.java

@@ -17,11 +17,15 @@
  */
 package org.apache.hadoop.hdfs.server.common;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.hdfs.protocol.Block;
 
 /**
  * Interface used to load provided blocks.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
 public interface BlockAlias {
 
   Block getBlock();

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/common/FileRegion.java

@@ -18,6 +18,8 @@
 package org.apache.hadoop.hdfs.server.common;
 
 import org.apache.commons.lang3.tuple.Pair;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.fs.Path;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
@@ -27,6 +29,8 @@ import org.apache.hadoop.hdfs.protocol.ProvidedStorageLocation;
  * This class is used to represent provided blocks that are file regions,
  * i.e., can be described using (path, offset, length).
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public class FileRegion implements BlockAlias {
 
   private final Pair<Block, ProvidedStorageLocation> pair;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/common/blockaliasmap/BlockAliasMap.java

@@ -22,12 +22,16 @@ import java.io.IOException;
 import java.util.Iterator;
 import java.util.Optional;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.server.common.BlockAlias;
 
 /**
  * An abstract class used to read and write block maps for provided blocks.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public abstract class BlockAliasMap<T extends BlockAlias> {
 
   /**

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/common/blockaliasmap/impl/InMemoryLevelDBAliasMapClient.java

@@ -16,6 +16,8 @@
  */
 package org.apache.hadoop.hdfs.server.common.blockaliasmap.impl;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configurable;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.protocol.Block;
@@ -37,6 +39,8 @@ import java.util.Optional;
  * This is used by the Datanode and fs2img to store and retrieve FileRegions
  * based on the given Block.
  */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
 public class InMemoryLevelDBAliasMapClient extends BlockAliasMap<FileRegion>
     implements Configurable {
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/common/blockaliasmap/impl/LevelDBFileRegionAliasMap.java

@@ -24,6 +24,8 @@ import java.util.Iterator;
 import java.util.Map;
 import java.util.Optional;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.iq80.leveldb.DB;
 import org.iq80.leveldb.DBIterator;
 import static org.fusesource.leveldbjni.JniDBFactory.factory;
@@ -45,6 +47,8 @@ import org.slf4j.LoggerFactory;
 /**
  * A LevelDB based implementation of {@link BlockAliasMap}.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public class LevelDBFileRegionAliasMap
       extends BlockAliasMap<FileRegion> implements Configurable {
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/common/blockaliasmap/impl/TextFileRegionAliasMap.java

@@ -34,6 +34,8 @@ import java.util.IdentityHashMap;
 import java.util.NoSuchElementException;
 import java.util.Optional;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configurable;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.LocalFileSystem;
@@ -56,6 +58,8 @@ import com.google.common.annotations.VisibleForTesting;
  * This class is used for block maps stored as text files,
  * with a specified delimiter.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public class TextFileRegionAliasMap
     extends BlockAliasMap<FileRegion> implements Configurable {
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/FinalizedProvidedReplica.java

@@ -19,6 +19,8 @@ package org.apache.hadoop.hdfs.server.datanode;
 
 import java.net.URI;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
@@ -30,6 +32,8 @@ import org.apache.hadoop.hdfs.server.protocol.ReplicaRecoveryInfo;
 /**
  * This class is used for provided replicas that are finalized.
  */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
 public class FinalizedProvidedReplica extends ProvidedReplica {
 
   public FinalizedProvidedReplica(long blockId, URI fileURI,

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/ProvidedReplica.java

@@ -25,6 +25,8 @@ import java.net.URI;
 
 import com.google.common.annotations.VisibleForTesting;
 import org.apache.commons.io.input.BoundedInputStream;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FSDataInputStream;
 import org.apache.hadoop.fs.FileSystem;
@@ -42,6 +44,8 @@ import org.slf4j.LoggerFactory;
 /**
  * This abstract class is used as a base class for provided replicas.
  */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
 public abstract class ProvidedReplica extends ReplicaInfo {
 
   public static final Logger LOG =

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/ProvidedVolumeImpl.java

@@ -28,6 +28,7 @@ import java.util.Map.Entry;
 import java.util.concurrent.ConcurrentHashMap;
 import java.util.concurrent.atomic.AtomicLong;
 
+import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
@@ -65,7 +66,8 @@ import org.apache.hadoop.util.Time;
 /**
  * This class is used to create provided volumes.
  */
-public class ProvidedVolumeImpl extends FsVolumeImpl {
+@InterfaceAudience.Private
+class ProvidedVolumeImpl extends FsVolumeImpl {
 
   /**
    * Get a suffix of the full path, excluding the given prefix.

hadoop-tools/hadoop-fs2img/src/main/java/org/apache/hadoop/hdfs/server/namenode/BlockResolver.java

@@ -20,6 +20,8 @@ package org.apache.hadoop.hdfs.server.namenode;
 import java.util.ArrayList;
 import java.util.List;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos.BlockProto;
 
@@ -27,6 +29,8 @@ import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos.BlockProto;
  * Given an external reference, create a sequence of blocks and associated
  * metadata.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public abstract class BlockResolver {
 
   protected BlockProto buildBlock(long blockId, long bytes) {

hadoop-tools/hadoop-fs2img/src/main/java/org/apache/hadoop/hdfs/server/namenode/FSTreeWalk.java

@@ -23,6 +23,8 @@ import java.util.ArrayList;
 import java.util.Collections;
 import java.util.ConcurrentModificationException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.FileSystem;
@@ -31,6 +33,8 @@ import org.apache.hadoop.fs.Path;
 /**
  * Traversal of an external FileSystem.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public class FSTreeWalk extends TreeWalk {
 
   private final Path root;

hadoop-tools/hadoop-fs2img/src/main/java/org/apache/hadoop/hdfs/server/namenode/FileSystemImage.java

@@ -26,6 +26,8 @@ import org.apache.commons.cli.Option;
 import org.apache.commons.cli.Options;
 import org.apache.commons.cli.ParseException;
 import org.apache.commons.cli.PosixParser;
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
 import org.apache.hadoop.fs.Path;
@@ -37,6 +39,8 @@ import org.apache.hadoop.util.ToolRunner;
 /**
  * Create FSImage from an external namespace.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public class FileSystemImage implements Tool {
 
   private Configuration conf;

hadoop-tools/hadoop-fs2img/src/main/java/org/apache/hadoop/hdfs/server/namenode/FixedBlockMultiReplicaResolver.java

@@ -17,6 +17,8 @@
  */
 package org.apache.hadoop.hdfs.server.namenode;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileStatus;
 
@@ -24,6 +26,8 @@ import org.apache.hadoop.fs.FileStatus;
  * Resolver mapping all files to a configurable, uniform blocksize
  * and replication.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public class FixedBlockMultiReplicaResolver extends FixedBlockResolver {
 
   public static final String REPLICATION =

hadoop-tools/hadoop-fs2img/src/main/java/org/apache/hadoop/hdfs/server/namenode/FixedBlockResolver.java

@@ -21,6 +21,8 @@ import java.util.ArrayList;
 import java.util.List;
 import java.util.concurrent.atomic.AtomicLong;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configurable;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileStatus;
@@ -28,6 +30,8 @@ import org.apache.hadoop.fs.FileStatus;
 /**
  * Resolver mapping all files to a configurable, uniform blocksize.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public class FixedBlockResolver extends BlockResolver implements Configurable {
 
   public static final String BLOCKSIZE =

hadoop-tools/hadoop-fs2img/src/main/java/org/apache/hadoop/hdfs/server/namenode/FsUGIResolver.java

@@ -17,6 +17,9 @@
  */
 package org.apache.hadoop.hdfs.server.namenode;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+
 import java.util.HashSet;
 import java.util.Set;
 
@@ -24,6 +27,8 @@ import java.util.Set;
  * Dynamically assign ids to users/groups as they appear in the external
  * filesystem.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public class FsUGIResolver extends UGIResolver {
 
   private int id;

hadoop-tools/hadoop-fs2img/src/main/java/org/apache/hadoop/hdfs/server/namenode/ImageWriter.java

@@ -38,6 +38,8 @@ import java.util.concurrent.atomic.AtomicLong;
 import com.google.common.base.Charsets;
 import com.google.protobuf.CodedOutputStream;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configurable;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileSystem;
@@ -72,6 +74,8 @@ import static org.apache.hadoop.hdfs.server.namenode.FSImageUtil.MAGIC_HEADER;
  * a valid FSImage/NN storage.
  */
 // TODO: generalize to types beyond FileRegion
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
 public class ImageWriter implements Closeable {
 
   private static final int ONDISK_VERSION = 1;

hadoop-tools/hadoop-fs2img/src/main/java/org/apache/hadoop/hdfs/server/namenode/NullBlockAliasMap.java

@@ -22,6 +22,8 @@ import java.util.Iterator;
 import java.util.NoSuchElementException;
 import java.util.Optional;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.hdfs.protocol.Block;
 import org.apache.hadoop.hdfs.server.common.FileRegion;
 import org.apache.hadoop.hdfs.server.common.blockaliasmap.BlockAliasMap;
@@ -29,6 +31,8 @@ import org.apache.hadoop.hdfs.server.common.blockaliasmap.BlockAliasMap;
 /**
  * Null sink for region information emitted from FSImage.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public class NullBlockAliasMap extends BlockAliasMap<FileRegion> {
 
   @Override

hadoop-tools/hadoop-fs2img/src/main/java/org/apache/hadoop/hdfs/server/namenode/SingleUGIResolver.java

@@ -19,6 +19,8 @@ package org.apache.hadoop.hdfs.server.namenode;
 
 import java.io.IOException;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configurable;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.fs.FileStatus;
@@ -27,6 +29,8 @@ import org.apache.hadoop.security.UserGroupInformation;
 /**
  * Map all owners/groups in external system to a single user in FSImage.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public class SingleUGIResolver extends UGIResolver implements Configurable {
 
   public static final String UID   = "hdfs.image.writer.ugi.single.uid";

hadoop-tools/hadoop-fs2img/src/main/java/org/apache/hadoop/hdfs/server/namenode/TreePath.java

@@ -21,6 +21,8 @@ import java.io.IOException;
 
 import com.google.protobuf.ByteString;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.hdfs.protocol.HdfsConstants;
 import org.apache.hadoop.hdfs.protocol.proto.HdfsProtos.BlockProto;
@@ -37,6 +39,8 @@ import static org.apache.hadoop.hdfs.server.namenode.DirectoryWithQuotaFeature.D
  * Traversal cursor in external filesystem.
  * TODO: generalize, move FS/FileRegion to FSTreePath
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public class TreePath {
   private long id = -1;
   private final long parentId;

hadoop-tools/hadoop-fs2img/src/main/java/org/apache/hadoop/hdfs/server/namenode/TreeWalk.java

@@ -17,6 +17,9 @@
  */
 package org.apache.hadoop.hdfs.server.namenode;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
+
 import java.util.ArrayDeque;
 import java.util.Deque;
 import java.util.Iterator;
@@ -24,6 +27,8 @@ import java.util.Iterator;
 /**
  * Traversal yielding a hierarchical sequence of paths.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public abstract class TreeWalk implements Iterable<TreePath> {
 
   /**

hadoop-tools/hadoop-fs2img/src/main/java/org/apache/hadoop/hdfs/server/namenode/UGIResolver.java

@@ -21,6 +21,8 @@ import java.util.Arrays;
 import java.util.HashMap;
 import java.util.Map;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.permission.FsPermission;
 
@@ -28,6 +30,8 @@ import org.apache.hadoop.fs.permission.FsPermission;
  * Pluggable class for mapping ownership and permissions from an external
  * store to an FSImage.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Unstable
 public abstract class UGIResolver {
 
   static final int USER_STRID_OFFSET = 40;

hadoop-tools/hadoop-fs2img/src/test/java/org/apache/hadoop/hdfs/server/namenode/RandomTreeWalk.java

@@ -24,6 +24,8 @@ import java.util.HashMap;
 import java.util.Map;
 import java.util.Random;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.fs.BlockLocation;
 import org.apache.hadoop.fs.FileStatus;
 import org.apache.hadoop.fs.LocatedFileStatus;
@@ -32,6 +34,8 @@ import org.apache.hadoop.fs.Path;
 /**
  * Random, repeatable hierarchy generator.
  */
+@InterfaceAudience.Private
+@InterfaceStability.Unstable
 public class RandomTreeWalk extends TreeWalk {
 
   private final Path root;