svn merge -c 1166466 from trunk for HDFS-2223.

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-0.23-PB@1228662 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -1,5 +1,14 @@
 Hadoop HDFS Change Log
 
+Release 0.23-PB - Unreleased
+
+  OPTIMIZATIONS
+
+    HDFS-2018. Move all journal stream management code into one place.
+               (Ivan Kelly via jitendra)
+
+    HDFS-2223. Untangle depencencies between NN components (todd)
+
 Release 0.23.1 - UNRELEASED
 
   INCOMPATIBLE CHANGES
@@ -82,9 +91,6 @@ Release 0.23.1 - UNRELEASED
     for a client on the same node as the block file.  (Andrew Purtell,
     Suresh Srinivas and Jitendra Nath Pandey via szetszwo)
 
-    HDFS-2018. Move all journal stream management code into one place.
-               (Ivan Kelly via jitendra)
-
   BUG FIXES
 
     HDFS-2541. For a sufficiently large value of blocks, the DN Scanner 

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

@@ -81,6 +81,8 @@ public class BackupImage extends FSImage {
    */
   private boolean stopApplyingEditsOnNextRoll = false;
   
+  private FSNamesystem namesystem;
+
   /**
    * Construct a backup image.
    * @param conf Configuration
@@ -92,6 +94,10 @@ public class BackupImage extends FSImage {
     bnState = BNState.DROP_UNTIL_NEXT_ROLL;
   }
   
+  void setNamesystem(FSNamesystem fsn) {
+    this.namesystem = fsn;
+  }
+
   /**
    * Analyze backup storage directories for consistency.<br>
    * Recover from incomplete checkpoints if required.<br>
@@ -139,7 +145,7 @@ public class BackupImage extends FSImage {
    * and create empty edits.
    */
   void saveCheckpoint() throws IOException {
-    saveNamespace();
+    saveNamespace(namesystem);
   }
 
   /**
@@ -222,7 +228,7 @@ public class BackupImage extends FSImage {
       }
       lastAppliedTxId += numTxns;
       
-      getFSNamesystem().dir.updateCountForINodeWithQuota(); // inefficient!
+      namesystem.dir.updateCountForINodeWithQuota(); // inefficient!
     } finally {
       backupInputStream.clear();
     }
@@ -271,7 +277,7 @@ public class BackupImage extends FSImage {
           editStreams.add(s);
         }
       }
-      loadEdits(editStreams);
+      loadEdits(editStreams, namesystem);
     }
     
     // now, need to load the in-progress file

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

@@ -123,6 +123,7 @@ public class BackupNode extends NameNode {
   protected void loadNamesystem(Configuration conf) throws IOException {
     BackupImage bnImage = new BackupImage(conf);
     this.namesystem = new FSNamesystem(conf, bnImage);
+    bnImage.setNamesystem(namesystem);
     bnImage.recoverCreateRead();
   }
 

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

@@ -224,7 +224,7 @@ class Checkpointer extends Daemon {
         
         LOG.info("Loading image with txid " + sig.mostRecentCheckpointTxId);
         File file = bnStorage.findImageFile(sig.mostRecentCheckpointTxId);
-        bnImage.reloadFromImageFile(file);
+        bnImage.reloadFromImageFile(file, backupNode.getNamesystem());
       }
       
       lastApplied = bnImage.getLastAppliedTxId();
@@ -238,11 +238,11 @@ class Checkpointer extends Daemon {
             backupNode.nnHttpAddress, log, bnStorage);
       }
   
-      rollForwardByApplyingLogs(manifest, bnImage);
+      rollForwardByApplyingLogs(manifest, bnImage, backupNode.getNamesystem());
     }
 
     long txid = bnImage.getLastAppliedTxId();
-    bnImage.saveFSImageInAllDirs(txid);
+    bnImage.saveFSImageInAllDirs(backupNode.getNamesystem(), txid);
     bnStorage.writeAll();
 
     if(cpCmd.needToReturnImage()) {
@@ -272,7 +272,8 @@ class Checkpointer extends Daemon {
 
   static void rollForwardByApplyingLogs(
       RemoteEditLogManifest manifest,
-      FSImage dstImage) throws IOException {
+      FSImage dstImage,
+      FSNamesystem dstNamesystem) throws IOException {
     NNStorage dstStorage = dstImage.getStorage();
   
     List<EditLogInputStream> editsStreams = Lists.newArrayList();    
@@ -286,6 +287,6 @@ class Checkpointer extends Daemon {
     }
     LOG.info("Checkpointer about to load edits from " +
         editsStreams.size() + " stream(s).");
-    dstImage.loadEdits(editsStreams);
+    dstImage.loadEdits(editsStreams, dstNamesystem);
   }
 }

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

@@ -57,9 +57,10 @@ import org.apache.hadoop.hdfs.server.blockmanagement.BlockInfoUnderConstruction;
 import org.apache.hadoop.hdfs.server.blockmanagement.BlockManager;
 import org.apache.hadoop.hdfs.server.blockmanagement.DatanodeDescriptor;
 import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.BlockUCState;
-import org.apache.hadoop.hdfs.server.common.HdfsServerConstants.StartupOption;
 import org.apache.hadoop.hdfs.util.ByteArray;
 
+import com.google.common.base.Preconditions;
+
 /*************************************************
  * FSDirectory stores the filesystem directory state.
  * It handles writing/loading values to disk, and logging
@@ -73,6 +74,7 @@ public class FSDirectory implements Closeable {
 
   INodeDirectoryWithQuota rootDir;
   FSImage fsImage;  
+  private final FSNamesystem namesystem;
   private volatile boolean ready = false;
   private static final long UNKNOWN_DISK_SPACE = -1;
   private final int maxComponentLength;
@@ -114,15 +116,9 @@ public class FSDirectory implements Closeable {
    */
   private final NameCache<ByteArray> nameCache;
 
-  /** Access an existing dfs name directory. */
-  FSDirectory(FSNamesystem ns, Configuration conf) throws IOException {
-    this(new FSImage(conf), ns, conf);
-  }
-
   FSDirectory(FSImage fsImage, FSNamesystem ns, Configuration conf) {
     this.dirLock = new ReentrantReadWriteLock(true); // fair
     this.cond = dirLock.writeLock().newCondition();
-    fsImage.setFSNamesystem(ns);
     rootDir = new INodeDirectoryWithQuota(INodeDirectory.ROOT_NAME,
         ns.createFsOwnerPermissions(new FsPermission((short)0755)),
         Integer.MAX_VALUE, UNKNOWN_DISK_SPACE);
@@ -146,10 +142,11 @@ public class FSDirectory implements Closeable {
     NameNode.LOG.info("Caching file names occuring more than " + threshold
         + " times ");
     nameCache = new NameCache<ByteArray>(threshold);
+    namesystem = ns;
   }
     
   private FSNamesystem getFSNamesystem() {
-    return fsImage.getFSNamesystem();
+    return namesystem;
   }
 
   private BlockManager getBlockManager() {
@@ -157,33 +154,11 @@ public class FSDirectory implements Closeable {
   }
 
   /**
-   * Load the filesystem image into memory.
+   * Notify that loading of this FSDirectory is complete, and
-   *
+   * it is ready for use 
-   * @param startOpt Startup type as specified by the user.
-   * @throws IOException If image or editlog cannot be read.
    */
-  void loadFSImage(StartupOption startOpt) 
+  void imageLoadComplete() {
-      throws IOException {
+    Preconditions.checkState(!ready, "FSDirectory already loaded");
-    // format before starting up if requested
-    if (startOpt == StartupOption.FORMAT) {
-      fsImage.format(fsImage.getStorage().determineClusterId());// reuse current id
-
-      startOpt = StartupOption.REGULAR;
-    }
-    boolean success = false;
-    try {
-      if (fsImage.recoverTransitionRead(startOpt)) {
-        fsImage.saveNamespace();
-      }
-      fsImage.openEditLog();
-      
-      fsImage.setCheckpointDirectories(null, null);
-      success = true;
-    } finally {
-      if (!success) {
-        fsImage.close();
-      }
-    }
     writeLock();
     try {
       setReady(true);

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

@@ -70,7 +70,6 @@ import com.google.common.collect.Lists;
 public class FSImage implements Closeable {
   protected static final Log LOG = LogFactory.getLog(FSImage.class.getName());
 
-  protected FSNamesystem namesystem = null;
   protected FSEditLog editLog = null;
   private boolean isUpgradeFinalized = false;
 
@@ -82,38 +81,20 @@ public class FSImage implements Closeable {
    */
   protected long lastAppliedTxId = 0;
 
-  /**
-   * URIs for importing an image from a checkpoint. In the default case,
-   * URIs will represent directories. 
-   */
-  private Collection<URI> checkpointDirs;
-  private Collection<URI> checkpointEditsDirs;
-
   final private Configuration conf;
 
   private final NNStorageRetentionManager archivalManager; 
 
-  /**
-   * Construct an FSImage.
-   * @param conf Configuration
-   * @see #FSImage(Configuration conf, FSNamesystem ns, 
-   *               Collection imageDirs, Collection editsDirs) 
-   * @throws IOException if default directories are invalid.
-   */
-  public FSImage(Configuration conf) throws IOException {
-    this(conf, (FSNamesystem)null);
-  }
 
   /**
    * Construct an FSImage
    * @param conf Configuration
-   * @param ns The FSNamesystem using this image.
+   * @see #FSImage(Configuration conf, 
-   * @see #FSImage(Configuration conf, FSNamesystem ns, 
    *               Collection imageDirs, Collection editsDirs) 
    * @throws IOException if default directories are invalid.
    */
-  private FSImage(Configuration conf, FSNamesystem ns) throws IOException {
+  protected FSImage(Configuration conf) throws IOException {
-    this(conf, ns,
+    this(conf,
          FSNamesystem.getNamespaceDirs(conf),
          FSNamesystem.getNamespaceEditsDirs(conf));
   }
@@ -124,17 +105,14 @@ public class FSImage implements Closeable {
    * Setup storage and initialize the edit log.
    *
    * @param conf Configuration
-   * @param ns The FSNamesystem using this image.
    * @param imageDirs Directories the image can be stored in.
    * @param editsDirs Directories the editlog can be stored in.
    * @throws IOException if directories are invalid.
    */
-  protected FSImage(Configuration conf, FSNamesystem ns,
+  protected FSImage(Configuration conf,
                     Collection<URI> imageDirs, Collection<URI> editsDirs)
       throws IOException {
     this.conf = conf;
-    setCheckpointDirectories(FSImage.getCheckpointDirs(conf, null),
-                             FSImage.getCheckpointEditsDirs(conf, null));
 
     storage = new NNStorage(conf, imageDirs, editsDirs);
     if(conf.getBoolean(DFSConfigKeys.DFS_NAMENODE_NAME_DIR_RESTORE_KEY,
@@ -143,31 +121,18 @@ public class FSImage implements Closeable {
     }
 
     this.editLog = new FSEditLog(storage);
-    setFSNamesystem(ns);
     
     archivalManager = new NNStorageRetentionManager(conf, storage, editLog);
   }
  
-  protected FSNamesystem getFSNamesystem() {
+  void format(FSNamesystem fsn, String clusterId) throws IOException {
-    return namesystem;
+    long fileCount = fsn.getTotalFiles();
-  }
+    // Expect 1 file, which is the root inode
-
+    Preconditions.checkState(fileCount == 1,
-  void setFSNamesystem(FSNamesystem ns) {
+        "FSImage.format should be called with an uninitialized namesystem, has " +
-    namesystem = ns;
+        fileCount + " files");
-    if (ns != null) {
-      storage.setUpgradeManager(ns.upgradeManager);
-    }
-  }
- 
-  void setCheckpointDirectories(Collection<URI> dirs,
-                                Collection<URI> editsDirs) {
-    checkpointDirs = dirs;
-    checkpointEditsDirs = editsDirs;
-  }
-  
-  void format(String clusterId) throws IOException {
     storage.format(clusterId);
-    saveFSImageInAllDirs(0);    
+    saveFSImageInAllDirs(fsn, 0);
   }
   
   /**
@@ -179,7 +144,7 @@ public class FSImage implements Closeable {
    * @throws IOException
    * @return true if the image needs to be saved or false otherwise
    */
-  boolean recoverTransitionRead(StartupOption startOpt)
+  boolean recoverTransitionRead(StartupOption startOpt, FSNamesystem target)
       throws IOException {
     assert startOpt != StartupOption.FORMAT : 
       "NameNode formatting should be performed before reading the image";
@@ -187,21 +152,14 @@ public class FSImage implements Closeable {
     Collection<URI> imageDirs = storage.getImageDirectories();
     Collection<URI> editsDirs = storage.getEditsDirectories();
 
+
     // none of the data dirs exist
     if((imageDirs.size() == 0 || editsDirs.size() == 0) 
                              && startOpt != StartupOption.IMPORT)  
       throw new IOException(
           "All specified directories are not accessible or do not exist.");
     
-    if(startOpt == StartupOption.IMPORT 
+    storage.setUpgradeManager(target.upgradeManager);
-        && (checkpointDirs == null || checkpointDirs.isEmpty()))
-      throw new IOException("Cannot import image from a checkpoint. "
-                            + "\"dfs.namenode.checkpoint.dir\" is not set." );
-
-    if(startOpt == StartupOption.IMPORT 
-        && (checkpointEditsDirs == null || checkpointEditsDirs.isEmpty()))
-      throw new IOException("Cannot import image from a checkpoint. "
-                            + "\"dfs.namenode.checkpoint.dir\" is not set." );
     
     // 1. For each data directory calculate its state and 
     // check whether all is consistent before transitioning.
@@ -261,10 +219,10 @@ public class FSImage implements Closeable {
     // 3. Do transitions
     switch(startOpt) {
     case UPGRADE:
-      doUpgrade();
+      doUpgrade(target);
       return false; // upgrade saved image already
     case IMPORT:
-      doImportCheckpoint();
+      doImportCheckpoint(target);
       return false; // import checkpoint saved image already
     case ROLLBACK:
       doRollback();
@@ -273,7 +231,7 @@ public class FSImage implements Closeable {
       // just load the image
     }
     
-    return loadFSImage();
+    return loadFSImage(target);
   }
   
   /**
@@ -324,11 +282,11 @@ public class FSImage implements Closeable {
     return isFormatted;
   }
 
-  private void doUpgrade() throws IOException {
+  private void doUpgrade(FSNamesystem target) throws IOException {
     if(storage.getDistributedUpgradeState()) {
       // only distributed upgrade need to continue
       // don't do version upgrade
-      this.loadFSImage();
+      this.loadFSImage(target);
       storage.initializeDistributedUpgrade();
       return;
     }
@@ -343,7 +301,7 @@ public class FSImage implements Closeable {
     }
 
     // load the latest image
-    this.loadFSImage();
+    this.loadFSImage(target);
 
     // Do upgrade for each directory
     long oldCTime = storage.getCTime();
@@ -385,7 +343,7 @@ public class FSImage implements Closeable {
     storage.reportErrorsOnDirectories(errorSDs);
     errorSDs.clear();
 
-    saveFSImageInAllDirs(editLog.getLastWrittenTxId());
+    saveFSImageInAllDirs(target, editLog.getLastWrittenTxId());
 
     for (Iterator<StorageDirectory> it = storage.dirIterator(); it.hasNext();) {
       StorageDirectory sd = it.next();
@@ -422,7 +380,7 @@ public class FSImage implements Closeable {
     // a previous fs states in at least one of the storage directories.
     // Directories that don't have previous state do not rollback
     boolean canRollback = false;
-    FSImage prevState = new FSImage(conf, getFSNamesystem());
+    FSImage prevState = new FSImage(conf);
     prevState.getStorage().layoutVersion = HdfsConstants.LAYOUT_VERSION;
     for (Iterator<StorageDirectory> it = storage.dirIterator(); it.hasNext();) {
       StorageDirectory sd = it.next();
@@ -504,19 +462,32 @@ public class FSImage implements Closeable {
 
   /**
    * Load image from a checkpoint directory and save it into the current one.
+   * @param target the NameSystem to import into
    * @throws IOException
    */
-  void doImportCheckpoint() throws IOException {
+  void doImportCheckpoint(FSNamesystem target) throws IOException {
-    FSNamesystem fsNamesys = getFSNamesystem();
+    Collection<URI> checkpointDirs =
-    FSImage ckptImage = new FSImage(conf, fsNamesys,
+      FSImage.getCheckpointDirs(conf, null);
+    Collection<URI> checkpointEditsDirs =
+      FSImage.getCheckpointEditsDirs(conf, null);
+
+    if (checkpointDirs == null || checkpointDirs.isEmpty()) {
+      throw new IOException("Cannot import image from a checkpoint. "
+                            + "\"dfs.namenode.checkpoint.dir\" is not set." );
+    }
+    
+    if (checkpointEditsDirs == null || checkpointEditsDirs.isEmpty()) {
+      throw new IOException("Cannot import image from a checkpoint. "
+                            + "\"dfs.namenode.checkpoint.dir\" is not set." );
+    }
+
+    FSImage realImage = target.getFSImage();
+    FSImage ckptImage = new FSImage(conf, 
                                     checkpointDirs, checkpointEditsDirs);
-    // replace real image with the checkpoint image
+    target.dir.fsImage = ckptImage;
-    FSImage realImage = fsNamesys.getFSImage();
-    assert realImage == this;
-    fsNamesys.dir.fsImage = ckptImage;
     // load from the checkpoint dirs
     try {
-      ckptImage.recoverTransitionRead(StartupOption.REGULAR);
+      ckptImage.recoverTransitionRead(StartupOption.REGULAR, target);
     } finally {
       ckptImage.close();
     }
@@ -524,10 +495,11 @@ public class FSImage implements Closeable {
     realImage.getStorage().setStorageInfo(ckptImage.getStorage());
     realImage.getEditLog().setNextTxId(ckptImage.getEditLog().getLastWrittenTxId()+1);
 
-    fsNamesys.dir.fsImage = realImage;
+    target.dir.fsImage = realImage;
     realImage.getStorage().setBlockPoolID(ckptImage.getBlockPoolID());
+
     // and save it but keep the same checkpointTime
-    saveNamespace();
+    saveNamespace(target);
     getStorage().writeAll();
   }
 
@@ -558,11 +530,11 @@ public class FSImage implements Closeable {
    * Toss the current image and namesystem, reloading from the specified
    * file.
    */
-  void reloadFromImageFile(File file) throws IOException {
+  void reloadFromImageFile(File file, FSNamesystem target) throws IOException {
-    namesystem.dir.reset();
+    target.dir.reset();
 
     LOG.debug("Reloading namespace from " + file);
-    loadFSImage(file);
+    loadFSImage(file, target);
   }
 
   /**
@@ -580,7 +552,7 @@ public class FSImage implements Closeable {
    * @return whether the image should be saved
    * @throws IOException
    */
-  boolean loadFSImage() throws IOException {
+  boolean loadFSImage(FSNamesystem target) throws IOException {
     FSImageStorageInspector inspector = storage.readAndInspectDirs();
     
     isUpgradeFinalized = inspector.isUpgradeFinalized();
@@ -615,7 +587,7 @@ public class FSImage implements Closeable {
                                  getLayoutVersion())) {
         // For txid-based layout, we should have a .md5 file
         // next to the image file
-        loadFSImage(imageFile.getFile());
+        loadFSImage(imageFile.getFile(), target);
       } else if (LayoutVersion.supports(Feature.FSIMAGE_CHECKSUM,
                                         getLayoutVersion())) {
         // In 0.22, we have the checksum stored in the VERSION file.
@@ -627,17 +599,17 @@ public class FSImage implements Closeable {
               NNStorage.DEPRECATED_MESSAGE_DIGEST_PROPERTY +
               " not set for storage directory " + sdForProperties.getRoot());
         }
-        loadFSImage(imageFile.getFile(), new MD5Hash(md5));
+        loadFSImage(imageFile.getFile(), new MD5Hash(md5), target);
       } else {
         // We don't have any record of the md5sum
-        loadFSImage(imageFile.getFile(), null);
+        loadFSImage(imageFile.getFile(), null, target);
       }
     } catch (IOException ioe) {
       FSEditLog.closeAllStreams(editStreams);
       throw new IOException("Failed to load image from " + imageFile, ioe);
     }
     
-    long numLoaded = loadEdits(editStreams);
+    long numLoaded = loadEdits(editStreams, target);
     needToSave |= needsResaveBasedOnStaleCheckpoint(imageFile.getFile(),
                                                     numLoaded);
     
@@ -671,14 +643,15 @@ public class FSImage implements Closeable {
    * Load the specified list of edit files into the image.
    * @return the number of transactions loaded
    */
-  protected long loadEdits(Iterable<EditLogInputStream> editStreams) throws IOException {
+  protected long loadEdits(Iterable<EditLogInputStream> editStreams,
+                           FSNamesystem target) throws IOException {
     LOG.debug("About to load edits:\n  " + Joiner.on("\n  ").join(editStreams));
 
     long startingTxId = getLastAppliedTxId() + 1;
     int numLoaded = 0;
 
     try {    
-      FSEditLogLoader loader = new FSEditLogLoader(namesystem);
+      FSEditLogLoader loader = new FSEditLogLoader(target);
       
       // Load latest edits
       for (EditLogInputStream editIn : editStreams) {
@@ -693,7 +666,7 @@ public class FSImage implements Closeable {
     }
 
     // update the counts
-    getFSNamesystem().dir.updateCountForINodeWithQuota();    
+    target.dir.updateCountForINodeWithQuota();    
     return numLoaded;
   }
 
@@ -702,13 +675,14 @@ public class FSImage implements Closeable {
    * Load the image namespace from the given image file, verifying
    * it against the MD5 sum stored in its associated .md5 file.
    */
-  private void loadFSImage(File imageFile) throws IOException {
+  private void loadFSImage(File imageFile, FSNamesystem target)
+      throws IOException {
     MD5Hash expectedMD5 = MD5FileUtils.readStoredMd5ForFile(imageFile);
     if (expectedMD5 == null) {
       throw new IOException("No MD5 file found corresponding to image file "
           + imageFile);
     }
-    loadFSImage(imageFile, expectedMD5);
+    loadFSImage(imageFile, expectedMD5, target);
   }
   
   /**
@@ -716,11 +690,12 @@ public class FSImage implements Closeable {
    * filenames and blocks.  Return whether we should
    * "re-save" and consolidate the edit-logs
    */
-  private void loadFSImage(File curFile, MD5Hash expectedMd5) throws IOException {
+  private void loadFSImage(File curFile, MD5Hash expectedMd5,
+      FSNamesystem target) throws IOException {
     FSImageFormat.Loader loader = new FSImageFormat.Loader(
-        conf, getFSNamesystem());
+        conf, target);
     loader.load(curFile);
-    namesystem.setBlockPoolId(this.getBlockPoolID());
+    target.setBlockPoolId(this.getBlockPoolID());
 
     // Check that the image digest we loaded matches up with what
     // we expected
@@ -741,13 +716,14 @@ public class FSImage implements Closeable {
   /**
    * Save the contents of the FS image to the file.
    */
-  void saveFSImage(StorageDirectory sd, long txid) throws IOException {
+  void saveFSImage(FSNamesystem source, StorageDirectory sd, long txid)
+      throws IOException {
     File newFile = NNStorage.getStorageFile(sd, NameNodeFile.IMAGE_NEW, txid);
     File dstFile = NNStorage.getStorageFile(sd, NameNodeFile.IMAGE, txid);
     
     FSImageFormat.Saver saver = new FSImageFormat.Saver();
     FSImageCompression compression = FSImageCompression.createCompression(conf);
-    saver.save(newFile, txid, getFSNamesystem(), compression);
+    saver.save(newFile, txid, source, compression);
     
     MD5FileUtils.saveMD5File(dstFile, saver.getSavedDigest());
     storage.setMostRecentCheckpointTxId(txid);
@@ -768,8 +744,11 @@ public class FSImage implements Closeable {
     private StorageDirectory sd;
     private List<StorageDirectory> errorSDs;
     private final long txid;
+    private final FSNamesystem source;
     
-    FSImageSaver(StorageDirectory sd, List<StorageDirectory> errorSDs, long txid) {
+    FSImageSaver(FSNamesystem source, StorageDirectory sd,
+        List<StorageDirectory> errorSDs, long txid) {
+      this.source = source;
       this.sd = sd;
       this.errorSDs = errorSDs;
       this.txid = txid;
@@ -777,7 +756,7 @@ public class FSImage implements Closeable {
     
     public void run() {
       try {
-        saveFSImage(sd, txid);
+        saveFSImage(source, sd, txid);
       } catch (Throwable t) {
         LOG.error("Unable to save image for " + sd.getRoot(), t);
         errorSDs.add(sd);
@@ -806,7 +785,7 @@ public class FSImage implements Closeable {
    * Save the contents of the FS image to a new image file in each of the
    * current storage directories.
    */
-  void saveNamespace() throws IOException {
+  void saveNamespace(FSNamesystem source) throws IOException {
     assert editLog != null : "editLog must be initialized";
     storage.attemptRestoreRemovedStorage();
 
@@ -817,7 +796,7 @@ public class FSImage implements Closeable {
     }
     long imageTxId = editLog.getLastWrittenTxId();
     try {
-      saveFSImageInAllDirs(imageTxId);
+      saveFSImageInAllDirs(source, imageTxId);
       storage.writeAll();
     } finally {
       if (editLogWasOpen) {
@@ -829,7 +808,8 @@ public class FSImage implements Closeable {
     
   }
   
-  protected void saveFSImageInAllDirs(long txid) throws IOException {
+  protected void saveFSImageInAllDirs(FSNamesystem source, long txid)
+      throws IOException {
     if (storage.getNumStorageDirs(NameNodeDirType.IMAGE) == 0) {
       throw new IOException("No image directories available!");
     }
@@ -842,7 +822,7 @@ public class FSImage implements Closeable {
     for (Iterator<StorageDirectory> it
            = storage.dirIterator(NameNodeDirType.IMAGE); it.hasNext();) {
       StorageDirectory sd = it.next();
-      FSImageSaver saver = new FSImageSaver(sd, errorSDs, txid);
+      FSImageSaver saver = new FSImageSaver(source, sd, errorSDs, txid);
       Thread saveThread = new Thread(saver, saver.toString());
       saveThreads.add(saveThread);
       saveThread.start();

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

@@ -556,8 +556,13 @@ class FSImageFormat {
       DataOutputStream out = new DataOutputStream(fos);
       try {
         out.writeInt(HdfsConstants.LAYOUT_VERSION);
-        out.writeInt(sourceNamesystem.getFSImage()
+        // We use the non-locked version of getNamespaceInfo here since
-                     .getStorage().getNamespaceID()); // TODO bad dependency
+        // the coordinating thread of saveNamespace already has read-locked
+        // the namespace for us. If we attempt to take another readlock
+        // from the actual saver thread, there's a potential of a
+        // fairness-related deadlock. See the comments on HDFS-2223.
+        out.writeInt(sourceNamesystem.unprotectedGetNamespaceInfo()
+            .getNamespaceID());
         out.writeLong(fsDir.rootDir.numItemsInTree());
         out.writeLong(sourceNamesystem.getGenerationStamp());
         out.writeLong(txid);

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

@@ -171,6 +171,8 @@ import org.apache.hadoop.util.StringUtils;
 import org.apache.hadoop.util.VersionInfo;
 import org.mortbay.util.ajax.JSON;
 
+import com.google.common.base.Preconditions;
+
 /***************************************************
  * FSNamesystem does the actual bookkeeping work for the
  * DataNode.
@@ -293,12 +295,43 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
   // lock to protect FSNamesystem.
   private ReentrantReadWriteLock fsLock;
 
+  
   /**
-   * FSNamesystem constructor.
+   * Instantiates an FSNamesystem loaded from the image and edits
+   * directories specified in the passed Configuration.
+   * 
+   * @param conf the Configuration which specifies the storage directories
+   *             from which to load
+   * @return an FSNamesystem which contains the loaded namespace
+   * @throws IOException if loading fails
    */
-  FSNamesystem(Configuration conf) throws IOException {
+  public static FSNamesystem loadFromDisk(Configuration conf) throws IOException {
+    FSImage fsImage = new FSImage(conf);
+    FSNamesystem namesystem = new FSNamesystem(conf, fsImage);
+
+    long loadStart = now();
+    StartupOption startOpt = NameNode.getStartupOption(conf);
+    namesystem.loadFSImage(startOpt, fsImage);
+    long timeTakenToLoadFSImage = now() - loadStart;
+    LOG.info("Finished loading FSImage in " + timeTakenToLoadFSImage + " msecs");
+    NameNode.getNameNodeMetrics().setFsImageLoadTime(
+                              (int) timeTakenToLoadFSImage);
+    return namesystem;
+  }
+
+  /**
+   * Create an FSNamesystem associated with the specified image.
+   * 
+   * Note that this does not load any data off of disk -- if you would
+   * like that behavior, use {@link #loadFromDisk(Configuration)}
+
+   * @param fnImage The FSImage to associate with
+   * @param conf configuration
+   * @throws IOException on bad configuration
+   */
+  FSNamesystem(Configuration conf, FSImage fsImage) throws IOException {
     try {
-      initialize(conf, null);
+      initialize(conf, fsImage);
     } catch(IOException e) {
       LOG.error(getClass().getSimpleName() + " initialization failed.", e);
       close();
@@ -314,29 +347,41 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
     resourceRecheckInterval = conf.getLong(
         DFS_NAMENODE_RESOURCE_CHECK_INTERVAL_KEY,
         DFS_NAMENODE_RESOURCE_CHECK_INTERVAL_DEFAULT);
-    nnResourceChecker = new NameNodeResourceChecker(conf);
-    checkAvailableResources();
     this.systemStart = now();
     this.blockManager = new BlockManager(this, this, conf);
     this.datanodeStatistics = blockManager.getDatanodeManager().getDatanodeStatistics();
     this.fsLock = new ReentrantReadWriteLock(true); // fair locking
     setConfigurationParameters(conf);
     dtSecretManager = createDelegationTokenSecretManager(conf);
-    this.registerMBean(); // register the MBean for the FSNamesystemState
-    if(fsImage == null) {
-      this.dir = new FSDirectory(this, conf);
-      StartupOption startOpt = NameNode.getStartupOption(conf);
-      this.dir.loadFSImage(startOpt);
-      long timeTakenToLoadFSImage = now() - systemStart;
-      LOG.info("Finished loading FSImage in " + timeTakenToLoadFSImage + " msecs");
-      NameNode.getNameNodeMetrics().setFsImageLoadTime(
-                                (int) timeTakenToLoadFSImage);
-    } else {
     this.dir = new FSDirectory(fsImage, this, conf);
-    }
     this.safeMode = new SafeModeInfo(conf);
   }
 
+  void loadFSImage(StartupOption startOpt, FSImage fsImage)
+      throws IOException {
+    // format before starting up if requested
+    if (startOpt == StartupOption.FORMAT) {
+      
+      fsImage.format(this, fsImage.getStorage().determineClusterId());// reuse current id
+
+      startOpt = StartupOption.REGULAR;
+    }
+    boolean success = false;
+    try {
+      if (fsImage.recoverTransitionRead(startOpt, this)) {
+        fsImage.saveNamespace(this);
+      }
+      fsImage.openEditLog();
+      
+      success = true;
+    } finally {
+      if (!success) {
+        fsImage.close();
+      }
+    }
+    dir.imageLoadComplete();
+  }
+
   void activateSecretManager() throws IOException {
     if (dtSecretManager != null) {
       dtSecretManager.startThreads();
@@ -347,8 +392,13 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
    * Activate FSNamesystem daemons.
    */
   void activate(Configuration conf) throws IOException {
+    this.registerMBean(); // register the MBean for the FSNamesystemState
+
     writeLock();
     try {
+      nnResourceChecker = new NameNodeResourceChecker(conf);
+      checkAvailableResources();
+
       setBlockTotal();
       blockManager.activate(conf);
 
@@ -431,37 +481,6 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
     return hasReadLock() || hasWriteLock();
   }
 
-  /**
-   * dirs is a list of directories where the filesystem directory state 
-   * is stored
-   */
-  FSNamesystem(FSImage fsImage, Configuration conf) throws IOException {
-    this.fsLock = new ReentrantReadWriteLock(true);
-    this.blockManager = new BlockManager(this, this, conf);
-    setConfigurationParameters(conf);
-    this.dir = new FSDirectory(fsImage, this, conf);
-    dtSecretManager = createDelegationTokenSecretManager(conf);
-  }
-
-  /**
-   * Create FSNamesystem for {@link BackupNode}.
-   * Should do everything that would be done for the NameNode,
-   * except for loading the image.
-   * 
-   * @param bnImage {@link BackupImage}
-   * @param conf configuration
-   * @throws IOException
-   */
-  FSNamesystem(Configuration conf, BackupImage bnImage) throws IOException {
-    try {
-      initialize(conf, bnImage);
-    } catch(IOException e) {
-      LOG.error(getClass().getSimpleName() + " initialization failed.", e);
-      close();
-      throw e;
-    }
-  }
-
   /**
    * Initializes some of the members from configuration
    */
@@ -510,13 +529,20 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
   NamespaceInfo getNamespaceInfo() {
     readLock();
     try {
+      return unprotectedGetNamespaceInfo();
+    } finally {
+      readUnlock();
+    }
+  }
+
+  /**
+   * Version of {@see #getNamespaceInfo()} that is not protected by a lock.
+   */
+  NamespaceInfo unprotectedGetNamespaceInfo() {
     return new NamespaceInfo(dir.fsImage.getStorage().getNamespaceID(),
         getClusterId(), getBlockPoolId(),
         dir.fsImage.getStorage().getCTime(),
         upgradeManager.getUpgradeVersion());
-    } finally {
-      readUnlock();
-    }
   }
 
   /**
@@ -2569,6 +2595,8 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
    * @throws IOException
    */
   private void checkAvailableResources() throws IOException {
+    Preconditions.checkState(nnResourceChecker != null,
+        "nnResourceChecker not initialized");
     hasResourcesAvailable = nnResourceChecker.hasAvailableDiskSpace();
   }
 
@@ -2729,7 +2757,7 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
         throw new IOException("Safe mode should be turned ON " +
                               "in order to create namespace image.");
       }
-      getFSImage().saveNamespace();
+      getFSImage().saveNamespace(this);
       LOG.info("New namespace image has been created.");
     } finally {
       readUnlock();

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

@@ -295,7 +295,7 @@ public class NameNode {
   }
 
   protected void loadNamesystem(Configuration conf) throws IOException {
-    this.namesystem = new FSNamesystem(conf);
+    this.namesystem = FSNamesystem.loadFromDisk(conf);
   }
 
   NamenodeRegistration getRegistration() {
@@ -601,16 +601,16 @@ public class NameNode {
     }
     System.out.println("Formatting using clusterid: " + clusterId);
     
-    FSImage fsImage = new FSImage(conf, null, dirsToFormat, editDirsToFormat);
+    FSImage fsImage = new FSImage(conf, dirsToFormat, editDirsToFormat);
-    FSNamesystem nsys = new FSNamesystem(fsImage, conf);
+    FSNamesystem fsn = new FSNamesystem(conf, fsImage);
-    nsys.dir.fsImage.format(clusterId);
+    fsImage.format(fsn, clusterId);
     return false;
   }
 
   private static boolean finalize(Configuration conf,
                                boolean isConfirmationNeeded
                                ) throws IOException {
-    FSNamesystem nsys = new FSNamesystem(new FSImage(conf), conf);
+    FSNamesystem nsys = new FSNamesystem(conf, new FSImage(conf));
     System.err.print(
         "\"finalize\" will remove the previous state of the files system.\n"
         + "Recent upgrade will become permanent.\n"

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

@@ -124,6 +124,8 @@ public class SecondaryNameNode implements Runnable {
   /** checkpoint once every this many transactions, regardless of time */
   private long checkpointTxnCount;
 
+  private FSNamesystem namesystem;
+
 
   /** {@inheritDoc} */
   public String toString() {
@@ -228,6 +230,8 @@ public class SecondaryNameNode implements Runnable {
     checkpointImage = new CheckpointStorage(conf, checkpointDirs, checkpointEditsDirs);
     checkpointImage.recoverCreate(commandLineOpts.shouldFormat());
     
+    namesystem = new FSNamesystem(conf, checkpointImage);
+
     // Initialize other scheduling parameters from the configuration
     checkpointCheckPeriod = conf.getLong(
         DFS_NAMENODE_CHECKPOINT_CHECK_PERIOD_KEY,
@@ -527,7 +531,7 @@ public class SecondaryNameNode implements Runnable {
 
     boolean loadImage = downloadCheckpointFiles(
         fsName, checkpointImage, sig, manifest);   // Fetch fsimage and edits
-    doMerge(sig, manifest, loadImage, checkpointImage);
+    doMerge(sig, manifest, loadImage, checkpointImage, namesystem);
     
     //
     // Upload the new image into the NameNode. Then tell the Namenode
@@ -757,8 +761,7 @@ public class SecondaryNameNode implements Runnable {
     CheckpointStorage(Configuration conf, 
                       Collection<URI> imageDirs,
                       Collection<URI> editsDirs) throws IOException {
-      super(conf, (FSNamesystem)null, imageDirs, editsDirs);
+      super(conf, imageDirs, editsDirs);
-      setFSNamesystem(new FSNamesystem(this, conf));
       
       // the 2NN never writes edits -- it only downloads them. So
       // we shouldn't have any editLog instance. Setting to null
@@ -844,7 +847,8 @@ public class SecondaryNameNode implements Runnable {
     
   static void doMerge(
       CheckpointSignature sig, RemoteEditLogManifest manifest,
-      boolean loadImage, FSImage dstImage) throws IOException {   
+      boolean loadImage, FSImage dstImage, FSNamesystem dstNamesystem)
+      throws IOException {   
     NNStorage dstStorage = dstImage.getStorage();
     
     dstStorage.setStorageInfo(sig);
@@ -855,11 +859,11 @@ public class SecondaryNameNode implements Runnable {
             sig.mostRecentCheckpointTxId + " even though it should have " +
             "just been downloaded");
       }
-      dstImage.reloadFromImageFile(file);
+      dstImage.reloadFromImageFile(file, dstNamesystem);
     }
     
-    Checkpointer.rollForwardByApplyingLogs(manifest, dstImage);
+    Checkpointer.rollForwardByApplyingLogs(manifest, dstImage, dstNamesystem);
-    dstImage.saveFSImageInAllDirs(dstImage.getLastAppliedTxId());
+    dstImage.saveFSImageInAllDirs(dstNamesystem, dstImage.getLastAppliedTxId());
     dstStorage.writeAll();
   }
 }

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/common/TestDistributedUpgrade.java

@@ -34,6 +34,7 @@ import org.apache.hadoop.hdfs.server.namenode.UpgradeObjectNamenode;
 import org.apache.hadoop.hdfs.server.protocol.DatanodeProtocol;
 import org.apache.hadoop.hdfs.server.protocol.UpgradeCommand;
 import org.apache.hadoop.hdfs.tools.DFSAdmin;
+import org.apache.hadoop.test.GenericTestUtils;
 
 import org.junit.Test;
 import static org.junit.Assert.*;
@@ -61,7 +62,8 @@ public class TestDistributedUpgrade {
    * Attempts to start a NameNode with the given operation.  Starting
    * the NameNode should throw an exception.
    */
-  void startNameNodeShouldFail(StartupOption operation) {
+  void startNameNodeShouldFail(StartupOption operation,
+      String exceptionSubstring) {
     try {
       //cluster = new MiniDFSCluster.Builder(conf).numDataNodes(0).startupOption(operation).build(); // should fail
       // we set manage dirs to true as NN has to start from untar'ed image with 
@@ -73,8 +75,8 @@ public class TestDistributedUpgrade {
                                               .build(); // should fail
       throw new AssertionError("NameNode should have failed to start");
     } catch (Exception expected) {
-      expected = null;
+      GenericTestUtils.assertExceptionContains(
-      // expected
+          exceptionSubstring, expected);
     }
   }
   
@@ -117,7 +119,7 @@ public class TestDistributedUpgrade {
     conf.setInt(DFSConfigKeys.DFS_DATANODE_SCAN_PERIOD_HOURS_KEY, -1); // block scanning off
 
     log("NameNode start in regular mode when dustributed upgrade is required", numDirs);
-    startNameNodeShouldFail(StartupOption.REGULAR);
+    startNameNodeShouldFail(StartupOption.REGULAR, "contains an old layout version");
 
     log("Start NameNode only distributed upgrade", numDirs);
     // cluster = new MiniDFSCluster.Builder(conf).numDataNodes(0).format(false)
@@ -130,10 +132,12 @@ public class TestDistributedUpgrade {
     cluster.shutdown();
 
     log("NameNode start in regular mode when dustributed upgrade has been started", numDirs);
-    startNameNodeShouldFail(StartupOption.REGULAR);
+    startNameNodeShouldFail(StartupOption.REGULAR,
+        "Previous distributed upgrade was not completed");
 
     log("NameNode rollback to the old version that require a dustributed upgrade", numDirs);
-    startNameNodeShouldFail(StartupOption.ROLLBACK);
+    startNameNodeShouldFail(StartupOption.ROLLBACK,
+        "Cannot rollback to storage version -7 using this version");
 
     log("Normal distributed upgrade for the cluster", numDirs);
     cluster = new MiniDFSCluster.Builder(conf)

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

@@ -1216,7 +1216,7 @@ public class TestCheckpoint extends TestCase {
       CheckpointStorage spyImage1 = spyOnSecondaryImage(secondary1);
       DelayAnswer delayer = new DelayAnswer(LOG);
       Mockito.doAnswer(delayer).when(spyImage1)
-        .saveFSImageInAllDirs(Mockito.anyLong());
+        .saveFSImageInAllDirs(Mockito.<FSNamesystem>any(), Mockito.anyLong());
 
       // Set up a thread to do a checkpoint from the first 2NN
       DoCheckpointThread checkpointThread = new DoCheckpointThread(secondary1);

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

@@ -48,7 +48,7 @@ public class TestClusterId {
     // see if cluster id not empty.
     Collection<URI> dirsToFormat = FSNamesystem.getNamespaceDirs(config);
     Collection<URI> editsToFormat = new ArrayList<URI>(0);
-    FSImage fsImage = new FSImage(config, null, dirsToFormat, editsToFormat);
+    FSImage fsImage = new FSImage(config, dirsToFormat, editsToFormat);
     
     Iterator<StorageDirectory> sdit = 
       fsImage.getStorage().dirIterator(NNStorage.NameNodeDirType.IMAGE);

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

@@ -350,7 +350,7 @@ public class TestEditLogRace {
     Configuration conf = getConf();
     NameNode.initMetrics(conf, NamenodeRole.NAMENODE);
     DFSTestUtil.formatNameNode(conf);
-    final FSNamesystem namesystem = new FSNamesystem(conf);
+    final FSNamesystem namesystem = FSNamesystem.loadFromDisk(conf);
 
     try {
       FSImage fsimage = namesystem.getFSImage();
@@ -448,7 +448,7 @@ public class TestEditLogRace {
     Configuration conf = getConf();
     NameNode.initMetrics(conf, NamenodeRole.NAMENODE);
     DFSTestUtil.formatNameNode(conf);
-    final FSNamesystem namesystem = new FSNamesystem(conf);
+    final FSNamesystem namesystem = FSNamesystem.loadFromDisk(conf);
 
     try {
       FSImage fsimage = namesystem.getFSImage();

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

@@ -79,7 +79,7 @@ public class TestSaveNamespace {
 
     public Void answer(InvocationOnMock invocation) throws Throwable {
       Object[] args = invocation.getArguments();
-      StorageDirectory sd = (StorageDirectory)args[0];
+      StorageDirectory sd = (StorageDirectory)args[1];
 
       if (count++ == 1) {
         LOG.info("Injecting fault for sd: " + sd);
@@ -106,7 +106,7 @@ public class TestSaveNamespace {
     Configuration conf = getConf();
     NameNode.initMetrics(conf, NamenodeRole.NAMENODE);
     DFSTestUtil.formatNameNode(conf);
-    FSNamesystem fsn = new FSNamesystem(conf);
+    FSNamesystem fsn = FSNamesystem.loadFromDisk(conf);
 
     // Replace the FSImage with a spy
     FSImage originalImage = fsn.dir.fsImage;
@@ -124,19 +124,22 @@ public class TestSaveNamespace {
     case SAVE_SECOND_FSIMAGE_RTE:
       // The spy throws a RuntimeException when writing to the second directory
       doAnswer(new FaultySaveImage(true)).
-        when(spyImage).saveFSImage((StorageDirectory)anyObject(), anyLong());
+        when(spyImage).saveFSImage(Mockito.eq(fsn),
+            (StorageDirectory)anyObject(), anyLong());
       shouldFail = false;
       break;
     case SAVE_SECOND_FSIMAGE_IOE:
       // The spy throws an IOException when writing to the second directory
       doAnswer(new FaultySaveImage(false)).
-        when(spyImage).saveFSImage((StorageDirectory)anyObject(), anyLong());
+        when(spyImage).saveFSImage(Mockito.eq(fsn),
+            (StorageDirectory)anyObject(), anyLong());
       shouldFail = false;
       break;
     case SAVE_ALL_FSIMAGES:
       // The spy throws IOException in all directories
       doThrow(new RuntimeException("Injected")).
-        when(spyImage).saveFSImage((StorageDirectory)anyObject(), anyLong());
+        when(spyImage).saveFSImage(Mockito.eq(fsn),
+            (StorageDirectory)anyObject(), anyLong());
       shouldFail = true;
       break;
     case WRITE_STORAGE_ALL:
@@ -184,7 +187,7 @@ public class TestSaveNamespace {
 
       // Start a new namesystem, which should be able to recover
       // the namespace from the previous incarnation.
-      fsn = new FSNamesystem(conf);
+      fsn = FSNamesystem.loadFromDisk(conf);
 
       // Make sure the image loaded including our edits.
       checkEditExists(fsn, 1);
@@ -209,7 +212,7 @@ public class TestSaveNamespace {
 
     NameNode.initMetrics(conf, NamenodeRole.NAMENODE);
     DFSTestUtil.formatNameNode(conf);
-    FSNamesystem fsn = new FSNamesystem(conf);
+    FSNamesystem fsn = FSNamesystem.loadFromDisk(conf);
 
     // Replace the FSImage with a spy
     FSImage originalImage = fsn.dir.fsImage;
@@ -263,7 +266,7 @@ public class TestSaveNamespace {
       // Start a new namesystem, which should be able to recover
       // the namespace from the previous incarnation.
       LOG.info("Loading new FSmage from disk.");
-      fsn = new FSNamesystem(conf);
+      fsn = FSNamesystem.loadFromDisk(conf);
 
       // Make sure the image loaded including our edit.
       LOG.info("Checking reloaded image.");
@@ -344,7 +347,7 @@ public class TestSaveNamespace {
     Configuration conf = getConf();
     NameNode.initMetrics(conf, NamenodeRole.NAMENODE);
     DFSTestUtil.formatNameNode(conf);
-    FSNamesystem fsn = new FSNamesystem(conf);
+    FSNamesystem fsn = FSNamesystem.loadFromDisk(conf);
 
     // Replace the FSImage with a spy
     final FSImage originalImage = fsn.dir.fsImage;
@@ -360,7 +363,8 @@ public class TestSaveNamespace {
         FSNamesystem.getNamespaceEditsDirs(conf));
 
     doThrow(new IOException("Injected fault: saveFSImage")).
-      when(spyImage).saveFSImage((StorageDirectory)anyObject(),
+      when(spyImage).saveFSImage(
+          Mockito.eq(fsn), (StorageDirectory)anyObject(),
           Mockito.anyLong());
 
     try {
@@ -390,7 +394,7 @@ public class TestSaveNamespace {
 
       // Start a new namesystem, which should be able to recover
       // the namespace from the previous incarnation.
-      fsn = new FSNamesystem(conf);
+      fsn = FSNamesystem.loadFromDisk(conf);
 
       // Make sure the image loaded including our edits.
       checkEditExists(fsn, 1);
@@ -406,7 +410,7 @@ public class TestSaveNamespace {
     Configuration conf = getConf();
     NameNode.initMetrics(conf, NamenodeRole.NAMENODE);
     DFSTestUtil.formatNameNode(conf);
-    FSNamesystem fsn = new FSNamesystem(conf);
+    FSNamesystem fsn = FSNamesystem.loadFromDisk(conf);
 
     try {
       doAnEdit(fsn, 1);
@@ -425,7 +429,7 @@ public class TestSaveNamespace {
 
       // Start a new namesystem, which should be able to recover
       // the namespace from the previous incarnation.
-      fsn = new FSNamesystem(conf);
+      fsn = FSNamesystem.loadFromDisk(conf);
 
       // Make sure the image loaded including our edits.
       checkEditExists(fsn, 1);
@@ -442,7 +446,7 @@ public class TestSaveNamespace {
     Configuration conf = getConf();
     NameNode.initMetrics(conf, NamenodeRole.NAMENODE);
     DFSTestUtil.formatNameNode(conf);
-    FSNamesystem fsn = new FSNamesystem(conf);
+    FSNamesystem fsn = FSNamesystem.loadFromDisk(conf);
 
     try {
       // We have a BEGIN_LOG_SEGMENT txn to start
@@ -464,7 +468,7 @@ public class TestSaveNamespace {
       assertEquals(5, fsn.getEditLog().getLastWrittenTxId());
       fsn = null;
       
-      fsn = new FSNamesystem(conf);
+      fsn = FSNamesystem.loadFromDisk(conf);
       // 1 more txn to start new segment on restart
       assertEquals(6, fsn.getEditLog().getLastWrittenTxId());
       

hadoop-hdfs-project/hadoop-hdfs/src/test/unit/org/apache/hadoop/hdfs/server/namenode/TestNNLeaseRecovery.java

@@ -84,7 +84,7 @@ public class TestNNLeaseRecovery {
     FileSystem.setDefaultUri(conf, "hdfs://localhost:0");
     conf.set(DFSConfigKeys.DFS_NAMENODE_HTTP_ADDRESS_KEY, "0.0.0.0:0");
     DFSTestUtil.formatNameNode(conf);
-    fsn = spy(new FSNamesystem(conf));
+    fsn = spy(FSNamesystem.loadFromDisk(conf));
   }
 
   /**
@@ -428,7 +428,6 @@ public class TestNNLeaseRecovery {
                             
     when(fsn.getFSImage()).thenReturn(fsImage);
     when(fsn.getFSImage().getEditLog()).thenReturn(editLog);
-    fsn.getFSImage().setFSNamesystem(fsn);
     
     switch (fileBlocksNumber) {
       case 0: