HDFS-5847. Merging r1567812 from trunk to branch-2

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1568562 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -210,6 +210,8 @@ Release 2.4.0 - UNRELEASED
     HDFS-5915. Refactor FSImageFormatProtobuf to simplify cross section reads.
     (Haohui Mai via cnauroth)
 
+    HDFS-5847. Consolidate INodeReference into a separate section. (jing9)
+
 Release 2.3.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES

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

@@ -43,9 +43,6 @@ import org.apache.hadoop.hdfs.server.namenode.FsImageProto.FileSummary;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.FilesUnderConstructionSection.FileUnderConstructionEntry;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.INodeDirectorySection;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.INodeSection;
-import org.apache.hadoop.hdfs.server.namenode.INodeReference.DstReference;
-import org.apache.hadoop.hdfs.server.namenode.INodeReference.WithCount;
-import org.apache.hadoop.hdfs.server.namenode.INodeReference.WithName;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot;
 import org.apache.hadoop.hdfs.util.ReadOnlyList;
 
@@ -69,25 +66,6 @@ public final class FSImageFormatPBINode {
           new FsPermission(perm));
     }
 
-    public static INodeReference loadINodeReference(
-        INodeSection.INodeReference r, FSDirectory dir) throws IOException {
-      long referredId = r.getReferredId();
-      INode referred = dir.getInode(referredId);
-      WithCount withCount = (WithCount) referred.getParentReference();
-      if (withCount == null) {
-        withCount = new INodeReference.WithCount(null, referred);
-      }
-      final INodeReference ref;
-      if (r.hasDstSnapshotId()) { // DstReference
-        ref = new INodeReference.DstReference(null, withCount,
-            r.getDstSnapshotId());
-      } else {
-        ref = new INodeReference.WithName(null, withCount, r.getName()
-            .toByteArray(), r.getLastSnapshotId());
-      }
-      return ref;
-    }
-
     public static INodeDirectory loadINodeDirectory(INodeSection.INode n,
         final String[] stringTable) {
       assert n.getType() == INodeSection.INode.Type.DIRECTORY;
@@ -126,6 +104,8 @@ public final class FSImageFormatPBINode {
     }
 
     void loadINodeDirectorySection(InputStream in) throws IOException {
+      final List<INodeReference> refList = parent.getLoaderContext()
+          .getRefList();
       while (true) {
         INodeDirectorySection.DirEntry e = INodeDirectorySection.DirEntry
             .parseDelimitedFrom(in);
@@ -138,20 +118,13 @@ public final class FSImageFormatPBINode {
           INode child = dir.getInode(id);
           addToParent(p, child);
         }
-        for (int i = 0; i < e.getNumOfRef(); i++) {
-          INodeReference ref = loadINodeReference(in);
+        for (int refId : e.getRefChildrenList()) {
+          INodeReference ref = refList.get(refId);
           addToParent(p, ref);
         }
       }
     }
 
-    private INodeReference loadINodeReference(InputStream in)
-        throws IOException {
-      INodeSection.INodeReference ref = INodeSection.INodeReference
-          .parseDelimitedFrom(in);
-      return loadINodeReference(ref, dir);
-    }
-
     void loadINodeSection(InputStream in) throws IOException {
       INodeSection s = INodeSection.parseDelimitedFrom(in);
       fsn.resetLastInodeId(s.getLastInodeId());
@@ -306,19 +279,6 @@ public final class FSImageFormatPBINode {
       return b;
     }
 
-    public static INodeSection.INodeReference.Builder buildINodeReference(
-        INodeReference ref) throws IOException {
-      INodeSection.INodeReference.Builder rb = INodeSection.INodeReference
-          .newBuilder().setReferredId(ref.getId());
-      if (ref instanceof WithName) {
-        rb.setLastSnapshotId(((WithName) ref).getLastSnapshotId()).setName(
-            ByteString.copyFrom(ref.getLocalNameBytes()));
-      } else if (ref instanceof DstReference) {
-        rb.setDstSnapshotId(((DstReference) ref).getDstSnapshotId());
-      }
-      return rb;
-    }
-
     private final FSNamesystem fsn;
     private final FileSummary.Builder summary;
     private final SaveNamespaceContext context;
@@ -334,6 +294,8 @@ public final class FSImageFormatPBINode {
     void serializeINodeDirectorySection(OutputStream out) throws IOException {
       Iterator<INodeWithAdditionalFields> iter = fsn.getFSDirectory()
           .getINodeMap().getMapIterator();
+      final ArrayList<INodeReference> refList = parent.getSaverContext()
+          .getRefList();
       int i = 0;
       while (iter.hasNext()) {
         INodeWithAdditionalFields n = iter.next();
@@ -346,21 +308,16 @@ public final class FSImageFormatPBINode {
         if (children.size() > 0) {
           INodeDirectorySection.DirEntry.Builder b = INodeDirectorySection.
               DirEntry.newBuilder().setParent(n.getId());
-          List<INodeReference> refs = new ArrayList<INodeReference>();
           for (INode inode : children) {
             if (!inode.isReference()) {
               b.addChildren(inode.getId());
             } else {
-              refs.add(inode.asReference());
+              refList.add(inode.asReference());
+              b.addRefChildren(refList.size() - 1);
             }
           }
-          b.setNumOfRef(refs.size());
           INodeDirectorySection.DirEntry e = b.build();
           e.writeDelimitedTo(out);
-          for (INodeReference ref : refs) {
-            INodeSection.INodeReference.Builder rb = buildINodeReference(ref);
-            rb.build().writeDelimitedTo(out);
-          }
         }
 
         ++i;

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

@@ -75,10 +75,15 @@ public final class FSImageFormatProtobuf {
 
   public static final class LoaderContext {
     private String[] stringTable;
+    private final ArrayList<INodeReference> refList = Lists.newArrayList();
 
     public String[] getStringTable() {
       return stringTable;
     }
+
+    public ArrayList<INodeReference> getRefList() {
+      return refList;
+    }
   }
 
   public static final class SaverContext {
@@ -112,10 +117,15 @@ public final class FSImageFormatProtobuf {
       }
     }
     private final DeduplicationMap<String> stringMap = DeduplicationMap.newMap();
+    private final ArrayList<INodeReference> refList = Lists.newArrayList();
 
     public DeduplicationMap<String> getStringMap() {
       return stringMap;
     }
+
+    public ArrayList<INodeReference> getRefList() {
+      return refList;
+    }
   }
 
   public static final class Loader implements FSImageFormat.AbstractLoader {
@@ -123,7 +133,6 @@ public final class FSImageFormatProtobuf {
     private final Configuration conf;
     private final FSNamesystem fsn;
     private final LoaderContext ctx;
-
     /** The MD5 sum of the loaded file */
     private MD5Hash imgDigest;
     /** The transaction ID of the last edit represented by the loaded file */
@@ -226,6 +235,9 @@ public final class FSImageFormatProtobuf {
           inodeLoader.loadINodeSection(in);
         }
           break;
+        case INODE_REFRENCE:
+          snapshotLoader.loadINodeReferenceSection(in);
+          break;
         case INODE_DIR:
           inodeLoader.loadINodeDirectorySection(in);
           break;
@@ -313,9 +325,10 @@ public final class FSImageFormatProtobuf {
   }
 
   public static final class Saver {
+    public static final int CHECK_CANCEL_INTERVAL = 4096;
+
     private final SaveNamespaceContext context;
     private final SaverContext saverContext;
-
     private long currentOffset = FSImageUtil.MAGIC_HEADER.length;
     private MD5Hash savedDigest;
 
@@ -324,7 +337,6 @@ public final class FSImageFormatProtobuf {
     private OutputStream sectionOutputStream;
     private CompressionCodec codec;
     private OutputStream underlyingOutputStream;
-    public static final int CHECK_CANCEL_INTERVAL = 4096;
 
     Saver(SaveNamespaceContext context) {
       this.context = context;
@@ -400,6 +412,7 @@ public final class FSImageFormatProtobuf {
 
       snapshotSaver.serializeSnapshotSection(sectionOutputStream);
       snapshotSaver.serializeSnapshotDiffSection(sectionOutputStream);
+      snapshotSaver.serializeINodeReferenceSection(sectionOutputStream);
     }
 
     private void saveInternal(FileOutputStream fout,
@@ -535,6 +548,7 @@ public final class FSImageFormatProtobuf {
     NS_INFO("NS_INFO"),
     STRING_TABLE("STRING_TABLE"),
     INODE("INODE"),
+    INODE_REFRENCE("INODE_REFRENCE"),
     SNAPSHOT("SNAPSHOT"),
     INODE_DIR("INODE_DIR"),
     FILES_UNDERCONSTRUCTION("FILES_UNDERCONSTRUCTION"),

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

@@ -18,12 +18,10 @@
 package org.apache.hadoop.hdfs.server.namenode.snapshot;
 
 import static org.apache.hadoop.hdfs.server.namenode.FSImageFormatPBINode.Loader.loadINodeDirectory;
-import static org.apache.hadoop.hdfs.server.namenode.FSImageFormatPBINode.Loader.loadINodeReference;
 import static org.apache.hadoop.hdfs.server.namenode.FSImageFormatPBINode.Loader.loadPermission;
 import static org.apache.hadoop.hdfs.server.namenode.FSImageFormatPBINode.Loader.updateBlocksMap;
 import static org.apache.hadoop.hdfs.server.namenode.FSImageFormatPBINode.Saver.buildINodeDirectory;
 import static org.apache.hadoop.hdfs.server.namenode.FSImageFormatPBINode.Saver.buildINodeFile;
-import static org.apache.hadoop.hdfs.server.namenode.FSImageFormatPBINode.Saver.buildINodeReference;
 
 import java.io.IOException;
 import java.io.InputStream;
@@ -40,8 +38,10 @@ import org.apache.hadoop.classification.InterfaceAudience;
 import org.apache.hadoop.fs.permission.PermissionStatus;
 import org.apache.hadoop.hdfs.server.namenode.FSDirectory;
 import org.apache.hadoop.hdfs.server.namenode.FSImageFormatProtobuf;
+import org.apache.hadoop.hdfs.server.namenode.FSImageFormatProtobuf.SectionName;
 import org.apache.hadoop.hdfs.server.namenode.FSNamesystem;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.FileSummary;
+import org.apache.hadoop.hdfs.server.namenode.FsImageProto.INodeReferenceSection;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.INodeSection;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.SnapshotDiffSection;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.SnapshotDiffSection.CreatedListEntry;
@@ -54,6 +54,9 @@ import org.apache.hadoop.hdfs.server.namenode.INodeFile;
 import org.apache.hadoop.hdfs.server.namenode.INodeFileAttributes;
 import org.apache.hadoop.hdfs.server.namenode.INodeMap;
 import org.apache.hadoop.hdfs.server.namenode.INodeReference;
+import org.apache.hadoop.hdfs.server.namenode.INodeReference.DstReference;
+import org.apache.hadoop.hdfs.server.namenode.INodeReference.WithCount;
+import org.apache.hadoop.hdfs.server.namenode.INodeReference.WithName;
 import org.apache.hadoop.hdfs.server.namenode.INodeWithAdditionalFields;
 import org.apache.hadoop.hdfs.server.namenode.SaveNamespaceContext;
 import org.apache.hadoop.hdfs.server.namenode.snapshot.DirectoryWithSnapshotFeature.DirectoryDiff;
@@ -75,7 +78,6 @@ public class FSImageFormatPBSnapshot {
     private final FSImageFormatProtobuf.Loader parent;
     private final Map<Integer, Snapshot> snapshotMap;
 
-
     public Loader(FSNamesystem fsn, FSImageFormatProtobuf.Loader parent) {
       this.fsn = fsn;
       this.fsDir = fsn.getFSDirectory();
@@ -83,6 +85,43 @@ public class FSImageFormatPBSnapshot {
       this.parent = parent;
     }
 
+    /**
+     * The sequence of the ref node in refList must be strictly the same with
+     * the sequence in fsimage
+     */
+    public void loadINodeReferenceSection(InputStream in) throws IOException {
+      final List<INodeReference> refList = parent.getLoaderContext()
+          .getRefList();
+      while (true) {
+        INodeReferenceSection.INodeReference e = INodeReferenceSection
+            .INodeReference.parseDelimitedFrom(in);
+        if (e == null) {
+          break;
+        }
+        INodeReference ref = loadINodeReference(e);
+        refList.add(ref);
+      }
+    }
+
+    private INodeReference loadINodeReference(
+        INodeReferenceSection.INodeReference r) throws IOException {
+      long referredId = r.getReferredId();
+      INode referred = fsDir.getInode(referredId);
+      WithCount withCount = (WithCount) referred.getParentReference();
+      if (withCount == null) {
+        withCount = new INodeReference.WithCount(null, referred);
+      }
+      final INodeReference ref;
+      if (r.hasDstSnapshotId()) { // DstReference
+        ref = new INodeReference.DstReference(null, withCount,
+            r.getDstSnapshotId());
+      } else {
+        ref = new INodeReference.WithName(null, withCount, r.getName()
+            .toByteArray(), r.getLastSnapshotId());
+      }
+      return ref;
+    }
+
     /**
      * Load the snapshots section from fsimage. Also convert snapshottable
      * directories into {@link INodeDirectorySnapshottable}.
@@ -131,6 +170,8 @@ public class FSImageFormatPBSnapshot {
      * Load the snapshot diff section from fsimage.
      */
     public void loadSnapshotDiffSection(InputStream in) throws IOException {
+      final List<INodeReference> refList = parent.getLoaderContext()
+          .getRefList();
       while (true) {
         SnapshotDiffSection.DiffEntry entry = SnapshotDiffSection.DiffEntry
             .parseDelimitedFrom(in);
@@ -145,7 +186,8 @@ public class FSImageFormatPBSnapshot {
           loadFileDiffList(in, inode.asFile(), entry.getNumOfDiff());
           break;
         case DIRECTORYDIFF:
-          loadDirectoryDiffList(in, inode.asDirectory(), entry.getNumOfDiff());
+          loadDirectoryDiffList(in, inode.asDirectory(), entry.getNumOfDiff(),
+              refList);
           break;
         }
       }
@@ -199,13 +241,13 @@ public class FSImageFormatPBSnapshot {
 
     /**
      * Load the deleted list in a DirectoryDiff
-     * @param totalSize the total size of the deleted list
-     * @param deletedNodes non-reference inodes in the deleted list. These
-     *        inodes' ids are directly recorded in protobuf
      */
-    private List<INode> loadDeletedList(InputStream in, INodeDirectory dir,
-        int refNum, List<Long> deletedNodes) throws IOException {
-      List<INode> dlist = new ArrayList<INode>(refNum + deletedNodes.size());
+    private List<INode> loadDeletedList(final List<INodeReference> refList,
+        InputStream in, INodeDirectory dir, List<Long> deletedNodes,
+        List<Integer> deletedRefNodes)
+        throws IOException {
+      List<INode> dlist = new ArrayList<INode>(deletedRefNodes.size()
+          + deletedNodes.size());
       // load non-reference inodes
       for (long deletedId : deletedNodes) {
         INode deleted = fsDir.getInode(deletedId);
@@ -213,13 +255,12 @@ public class FSImageFormatPBSnapshot {
         addToDeletedList(deleted, dir);
       }
       // load reference nodes in the deleted list
-      for (int r = 0; r < refNum; r++) {
-        INodeSection.INodeReference ref = INodeSection.INodeReference
-            .parseDelimitedFrom(in);
-        INodeReference refNode = loadINodeReference(ref, fsDir);
-        dlist.add(refNode);
-        addToDeletedList(refNode, dir);
+      for (int refId : deletedRefNodes) {
+        INodeReference deletedRef = refList.get(refId);
+        dlist.add(deletedRef);
+        addToDeletedList(deletedRef, dir);
       }
+
       Collections.sort(dlist, new Comparator<INode>() {
         @Override
         public int compare(INode n1, INode n2) {
@@ -231,7 +272,7 @@ public class FSImageFormatPBSnapshot {
 
     /** Load DirectoryDiff list for a directory with snapshot feature */
     private void loadDirectoryDiffList(InputStream in, INodeDirectory dir,
-        int size) throws IOException {
+        int size, final List<INodeReference> refList) throws IOException {
       if (!dir.isWithSnapshot()) {
         dir.addSnapshotFeature(null);
       }
@@ -247,7 +288,7 @@ public class FSImageFormatPBSnapshot {
         INodeDirectoryAttributes copy = null;
         if (useRoot) {
           copy = snapshot.getRoot();
-        }else if (diffInPb.hasSnapshotCopy()) {
+        } else if (diffInPb.hasSnapshotCopy()) {
           INodeSection.INodeDirectory dirCopyInPb = diffInPb.getSnapshotCopy();
           final byte[] name = diffInPb.getName().toByteArray();
           PermissionStatus permission = loadPermission(
@@ -265,8 +306,8 @@ public class FSImageFormatPBSnapshot {
         List<INode> clist = loadCreatedList(in, dir,
             diffInPb.getCreatedListSize());
         // load deleted list
-        List<INode> dlist = loadDeletedList(in, dir,
-            diffInPb.getNumOfDeletedRef(), diffInPb.getDeletedINodeList());
+        List<INode> dlist = loadDeletedList(refList, in, dir,
+            diffInPb.getDeletedINodeList(), diffInPb.getDeletedINodeRefList());
         // create the directory diff
         DirectoryDiff diff = new DirectoryDiff(snapshotId, copy, null,
             childrenSize, clist, dlist, useRoot);
@@ -285,7 +326,8 @@ public class FSImageFormatPBSnapshot {
     private final SaveNamespaceContext context;
 
     public Saver(FSImageFormatProtobuf.Saver parent,
-        FileSummary.Builder headers, SaveNamespaceContext context, FSNamesystem fsn) {
+        FileSummary.Builder headers, SaveNamespaceContext context,
+        FSNamesystem fsn) {
       this.parent = parent;
       this.headers = headers;
       this.context = context;
@@ -330,12 +372,42 @@ public class FSImageFormatPBSnapshot {
       parent.commitSection(headers, FSImageFormatProtobuf.SectionName.SNAPSHOT);
     }
 
+    /**
+     * This can only be called after serializing both INode_Dir and SnapshotDiff
+     */
+    public void serializeINodeReferenceSection(OutputStream out)
+        throws IOException {
+      final List<INodeReference> refList = parent.getSaverContext()
+          .getRefList();
+      for (INodeReference ref : refList) {
+        INodeReferenceSection.INodeReference.Builder rb = buildINodeReference(ref);
+        rb.build().writeDelimitedTo(out);
+      }
+      parent.commitSection(headers, SectionName.INODE_REFRENCE);
+    }
+
+    private INodeReferenceSection.INodeReference.Builder buildINodeReference(
+        INodeReference ref) throws IOException {
+      INodeReferenceSection.INodeReference.Builder rb =
+          INodeReferenceSection.INodeReference.newBuilder().
+            setReferredId(ref.getId());
+      if (ref instanceof WithName) {
+        rb.setLastSnapshotId(((WithName) ref).getLastSnapshotId()).setName(
+            ByteString.copyFrom(ref.getLocalNameBytes()));
+      } else if (ref instanceof DstReference) {
+        rb.setDstSnapshotId(((DstReference) ref).getDstSnapshotId());
+      }
+      return rb;
+    }
+
     /**
      * save all the snapshot diff to fsimage
      */
     public void serializeSnapshotDiffSection(OutputStream out)
         throws IOException {
       INodeMap inodesMap = fsn.getFSDirectory().getINodeMap();
+      final List<INodeReference> refList = parent.getSaverContext()
+          .getRefList();
       int i = 0;
       Iterator<INodeWithAdditionalFields> iter = inodesMap.getMapIterator();
       while (iter.hasNext()) {
@@ -343,7 +415,7 @@ public class FSImageFormatPBSnapshot {
         if (inode.isFile()) {
           serializeFileDiffList(inode.asFile(), out);
         } else if (inode.isDirectory()) {
-          serializeDirDiffList(inode.asDirectory(), out);
+          serializeDirDiffList(inode.asDirectory(), refList, out);
         }
         ++i;
         if (i % FSImageFormatProtobuf.Saver.CHECK_CANCEL_INTERVAL == 0) {
@@ -378,22 +450,18 @@ public class FSImageFormatPBSnapshot {
       }
     }
 
-    private void saveCreatedDeletedList(List<INode> created,
-        List<INodeReference> deletedRefs, OutputStream out) throws IOException {
+    private void saveCreatedList(List<INode> created, OutputStream out)
+        throws IOException {
       // local names of the created list member
       for (INode c : created) {
         SnapshotDiffSection.CreatedListEntry.newBuilder()
             .setName(ByteString.copyFrom(c.getLocalNameBytes())).build()
             .writeDelimitedTo(out);
       }
-      // reference nodes in deleted list
-      for (INodeReference ref : deletedRefs) {
-        INodeSection.INodeReference.Builder rb = buildINodeReference(ref);
-        rb.build().writeDelimitedTo(out);
-      }
     }
 
-    private void serializeDirDiffList(INodeDirectory dir, OutputStream out)
+    private void serializeDirDiffList(INodeDirectory dir,
+        final List<INodeReference> refList, OutputStream out)
         throws IOException {
       DirectoryWithSnapshotFeature sf = dir.getDirectoryWithSnapshotFeature();
       if (sf != null) {
@@ -419,17 +487,16 @@ public class FSImageFormatPBSnapshot {
               .getList(ListType.CREATED);
           db.setCreatedListSize(created.size());
           List<INode> deleted = diff.getChildrenDiff().getList(ListType.DELETED);
-          List<INodeReference> refs = new ArrayList<INodeReference>();
           for (INode d : deleted) {
             if (d.isReference()) {
-              refs.add(d.asReference());
+              refList.add(d.asReference());
+              db.addDeletedINodeRef(refList.size() - 1);
             } else {
               db.addDeletedINode(d.getId());
             }
           }
-          db.setNumOfDeletedRef(refs.size());
           db.build().writeDelimitedTo(out);
-          saveCreatedDeletedList(created, refs, out);
+          saveCreatedList(created, out);
         }
       }
     }

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/LsrPBImage.java

@@ -36,6 +36,7 @@ import org.apache.hadoop.hdfs.server.namenode.FSImageFormatProtobuf.SectionName;
 import org.apache.hadoop.hdfs.server.namenode.FSImageUtil;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.FileSummary;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.INodeDirectorySection;
+import org.apache.hadoop.hdfs.server.namenode.FsImageProto.INodeReferenceSection;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.INodeSection;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.INodeSection.INode;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.INodeSection.INodeDirectory;
@@ -79,6 +80,7 @@ final class LsrPBImage {
   private String[] stringTable;
   private HashMap<Long, INodeSection.INode> inodes = Maps.newHashMap();
   private HashMap<Long, long[]> dirmap = Maps.newHashMap();
+  private ArrayList<INodeReferenceSection.INodeReference> refList = Lists.newArrayList();
 
   public LsrPBImage(Configuration conf, PrintWriter out) {
     this.conf = conf;
@@ -125,6 +127,9 @@ final class LsrPBImage {
         case INODE:
           loadINodeSection(is);
           break;
+        case INODE_REFRENCE:
+          loadINodeReferenceSection(is);
+          break;
         case INODE_DIR:
           loadINodeDirectorySection(is);
           break;
@@ -202,14 +207,26 @@ final class LsrPBImage {
       if (e == null) {
         break;
       }
-      long[] l = new long[e.getChildrenCount()];
-      for (int i = 0; i < l.length; ++i) {
+      long[] l = new long[e.getChildrenCount() + e.getRefChildrenCount()];
+      for (int i = 0; i < e.getChildrenCount(); ++i) {
         l[i] = e.getChildren(i);
       }
+      for (int i = e.getChildrenCount(); i < l.length; i++) {
+        int refId = e.getRefChildren(i - e.getChildrenCount());
+        l[i] = refList.get(refId).getReferredId();
+      }
       dirmap.put(e.getParent(), l);
-      for (int i = 0; i < e.getNumOfRef(); i++) {
-        INodeSection.INodeReference.parseDelimitedFrom(in);
+    }
+  }
+
+  private void loadINodeReferenceSection(InputStream in) throws IOException {
+    while (true) {
+      INodeReferenceSection.INodeReference e = INodeReferenceSection
+          .INodeReference.parseDelimitedFrom(in);
+      if (e == null) {
+        break;
       }
+      refList.add(e);
     }
   }
 

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/offlineImageViewer/PBImageXmlWriter.java

@@ -43,6 +43,7 @@ import org.apache.hadoop.hdfs.server.namenode.FsImageProto.INodeDirectorySection
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.INodeSection;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.INodeSection.INodeDirectory;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.INodeSection.INodeSymlink;
+import org.apache.hadoop.hdfs.server.namenode.FsImageProto.INodeReferenceSection;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.NameSystemSection;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.SecretManagerSection;
 import org.apache.hadoop.hdfs.server.namenode.FsImageProto.SnapshotDiffSection;
@@ -132,6 +133,9 @@ public final class PBImageXmlWriter {
         case INODE:
           dumpINodeSection(is);
           break;
+        case INODE_REFRENCE:
+          dumpINodeReferenceSection(is);
+          break;
         case INODE_DIR:
           dumpINodeDirectorySection(is);
           break;
@@ -227,18 +231,27 @@ public final class PBImageXmlWriter {
       for (long id : e.getChildrenList()) {
         o("inode", id);
       }
-      for (int i = 0; i < e.getNumOfRef(); i++) {
-        INodeSection.INodeReference r = INodeSection.INodeReference
-            .parseDelimitedFrom(in);
-        dumpINodeReference(r);
-
+      for (int refId : e.getRefChildrenList()) {
+        o("inodereference-index", refId);
       }
       out.print("</directory>\n");
     }
     out.print("</INodeDirectorySection>\n");
   }
 
-  private void dumpINodeReference(INodeSection.INodeReference r) {
+  private void dumpINodeReferenceSection(InputStream in) throws IOException {
+    out.print("<INodeReferenceSection>");
+    while (true) {
+      INodeReferenceSection.INodeReference e = INodeReferenceSection
+          .INodeReference.parseDelimitedFrom(in);
+      if (e == null) {
+        break;
+      }
+      dumpINodeReference(e);
+    }
+  }
+
+  private void dumpINodeReference(INodeReferenceSection.INodeReference r) {
     out.print("<ref>");
     o("referredId", r.getReferredId()).o("name", r.getName().toStringUtf8())
         .o("dstSnapshotId", r.getDstSnapshotId())
@@ -362,10 +375,15 @@ public final class PBImageXmlWriter {
             o("name", ce.getName().toStringUtf8());
             out.print("</created>\n");
           }
-          for (int j = 0; j < d.getNumOfDeletedRef(); ++j) {
-            INodeSection.INodeReference r = INodeSection.INodeReference
-                .parseDelimitedFrom(in);
-            dumpINodeReference(r);
+          for (long did : d.getDeletedINodeList()) {
+            out.print("<deleted>");
+            o("inode", did);
+            out.print("</deleted>\n");
+          }
+          for (int dRefid : d.getDeletedINodeRefList()) {
+            out.print("<deleted>");
+            o("inodereference-index", dRefid);
+            out.print("</deleted>\n");
           }
           out.print("</dirdiff>\n");
         }

hadoop-hdfs-project/hadoop-hdfs/src/main/proto/fsimage.proto

@@ -112,17 +112,6 @@ message INodeSection {
     optional bytes target = 2;
   }
 
-  message INodeReference {
-    // id of the referred inode
-    optional uint64 referredId = 1;
-    // local name recorded in WithName
-    optional bytes name = 2;
-    // recorded in DstReference
-    optional uint32 dstSnapshotId = 3;
-    // recorded in WithName
-    optional uint32 lastSnapshotId = 4;
-  }
-
   message INode {
     enum Type {
       FILE = 1;
@@ -163,13 +152,28 @@ message FilesUnderConstructionSection {
 message INodeDirectorySection {
   message DirEntry {
     optional uint64 parent = 1;
+    // children that are not reference nodes
     repeated uint64 children = 2 [packed = true];
-    optional uint64 numOfRef = 3;
-    // repeated INodeReference...
+    // children that are reference nodes, each element is a reference node id
+    repeated uint32 refChildren = 3 [packed = true];
   }
   // repeated DirEntry, ended at the boundary of the section.
 }
 
+message INodeReferenceSection {
+  message INodeReference {
+    // id of the referred inode
+    optional uint64 referredId = 1;
+    // local name recorded in WithName
+    optional bytes name = 2;
+    // recorded in DstReference
+    optional uint32 dstSnapshotId = 3;
+    // recorded in WithName
+    optional uint32 lastSnapshotId = 4;
+  }
+  // repeated INodeReference...
+}
+
 /**
  * This section records the information about snapshot
  * NAME: SNAPSHOT
@@ -204,10 +208,10 @@ message SnapshotDiffSection {
     optional bytes name = 4;
     optional INodeSection.INodeDirectory snapshotCopy = 5;
     optional uint32 createdListSize = 6;
-    optional uint32 numOfDeletedRef = 7; // number of reference nodes in deleted list
-    repeated uint64 deletedINode = 8 [packed = true]; // id of deleted inode
+    repeated uint64 deletedINode = 7 [packed = true]; // id of deleted inodes
+    // id of reference nodes in the deleted list
+    repeated uint32 deletedINodeRef = 8 [packed = true];
     // repeated CreatedListEntry (size is specified by createdListSize)
-    // repeated INodeReference (reference inodes in deleted list)
   }
 
   message FileDiff {