Revert "HDFS-11696. Fix warnings from Spotbugs in hadoop-hdfs. Contributed by Yiqun Lin."

This reverts commit 89a8edc0149e3f31a5ade9a0927c4b6332cf6b1a.

 Conflicts:
	hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/tools/DFSAdmin.java

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

@@ -2883,12 +2883,9 @@ public class DFSClient implements java.io.Closeable, RemotePeerFactory,
     }
     synchronized (DFSClient.class) {
       if (STRIPED_READ_THREAD_POOL == null) {
-        // Only after thread pool is fully constructed then save it to
-        // volatile field.
-        ThreadPoolExecutor threadPool = DFSUtilClient.getThreadPoolExecutor(1,
+        STRIPED_READ_THREAD_POOL = DFSUtilClient.getThreadPoolExecutor(1,
             numThreads, 60, "StripedRead-", true);
-        threadPool.allowCoreThreadTimeOut(true);
-        STRIPED_READ_THREAD_POOL = threadPool;
+        STRIPED_READ_THREAD_POOL.allowCoreThreadTimeOut(true);
       }
     }
   }

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

@@ -101,9 +101,8 @@ public final class SlowDiskReports {
     }
 
     boolean areEqual;
-    for (Map.Entry<String, Map<DiskOp, Double>> entry : this.slowDisks
-        .entrySet()) {
-      if (!entry.getValue().equals(that.slowDisks.get(entry.getKey()))) {
+    for (String disk : this.slowDisks.keySet()) {
+      if (!this.slowDisks.get(disk).equals(that.slowDisks.get(disk))) {
         return false;
       }
     }

hadoop-hdfs-project/hadoop-hdfs/dev-support/findbugsExcludeFile.xml

@@ -252,9 +252,4 @@
         <Class name="org.apache.hadoop.hdfs.server.datanode.checker.AbstractFuture" />
         <Bug pattern="NS_DANGEROUS_NON_SHORT_CIRCUIT" />
     </Match>
-    <Match>
-        <Class name="org.apache.hadoop.hdfs.server.namenode.NNUpgradeUtil$1" />
-        <Method name="visitFile" />
-        <Bug pattern="NP_NULL_ON_SOME_PATH_FROM_RETURN_VALUE" />
-    </Match>
  </FindBugsFilter>

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/qjournal/server/JournalNode.java

@@ -299,18 +299,14 @@ public class JournalNode implements Tool, Configurable, JournalNodeMXBean {
         return file.isDirectory();
       }
     });
-
-    if (journalDirs != null) {
-      for (File journalDir : journalDirs) {
-        String jid = journalDir.getName();
-        if (!status.containsKey(jid)) {
-          Map<String, String> jMap = new HashMap<String, String>();
-          jMap.put("Formatted", "true");
-          status.put(jid, jMap);
-        }
+    for (File journalDir : journalDirs) {
+      String jid = journalDir.getName();
+      if (!status.containsKey(jid)) {
+        Map<String, String> jMap = new HashMap<String, String>();
+        jMap.put("Formatted", "true");
+        status.put(jid, jMap);
       }
     }
-
     return JSON.toString(status);
   }
   

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

@@ -188,10 +188,8 @@ public interface HdfsServerConstants {
         return NamenodeRole.NAMENODE;
       }
     }
-
+    
     public void setClusterId(String cid) {
-      Preconditions.checkState(this == UPGRADE || this == UPGRADEONLY
-          || this == FORMAT);
       clusterId = cid;
     }
 
@@ -216,7 +214,6 @@ public interface HdfsServerConstants {
     }
 
     public void setForce(int force) {
-      Preconditions.checkState(this == RECOVER);
       this.force = force;
     }
     
@@ -229,7 +226,6 @@ public interface HdfsServerConstants {
     }
     
     public void setForceFormat(boolean force) {
-      Preconditions.checkState(this == FORMAT);
       isForceFormat = force;
     }
     
@@ -238,7 +234,6 @@ public interface HdfsServerConstants {
     }
     
     public void setInteractiveFormat(boolean interactive) {
-      Preconditions.checkState(this == FORMAT);
       isInteractiveFormat = interactive;
     }
     

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

@@ -1336,14 +1336,10 @@ public class DataStorage extends Storage {
           return name.startsWith(BLOCK_SUBDIR_PREFIX);
         }
       });
-
-    if (otherNames != null) {
-      for (int i = 0; i < otherNames.length; i++) {
-        linkBlocksHelper(new File(from, otherNames[i]),
-            new File(to, otherNames[i]), oldLV, hl, upgradeToIdBasedLayout,
-            blockRoot, idBasedLayoutSingleLinks);
-      }
-    }
+    for(int i = 0; i < otherNames.length; i++)
+      linkBlocksHelper(new File(from, otherNames[i]),
+          new File(to, otherNames[i]), oldLV, hl, upgradeToIdBasedLayout,
+          blockRoot, idBasedLayoutSingleLinks);
   }
 
   /**

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

@@ -255,27 +255,24 @@ public class NNStorageRetentionManager {
     });
 
     // Check whether there is any work to do.
-    if (filesInStorage != null
-        && filesInStorage.length <= numCheckpointsToRetain) {
+    if (filesInStorage.length <= numCheckpointsToRetain) {
       return;
     }
 
     // Create a sorted list of txids from the file names.
     TreeSet<Long> sortedTxIds = new TreeSet<Long>();
-    if (filesInStorage != null) {
-      for (String fName : filesInStorage) {
-        // Extract the transaction id from the file name.
-        long fTxId;
-        try {
-          fTxId = Long.parseLong(fName.substring(oivImagePrefix.length() + 1));
-        } catch (NumberFormatException nfe) {
-          // This should not happen since we have already filtered it.
-          // Log and continue.
-          LOG.warn("Invalid file name. Skipping " + fName);
-          continue;
-        }
-        sortedTxIds.add(Long.valueOf(fTxId));
+    for (String fName : filesInStorage) {
+      // Extract the transaction id from the file name.
+      long fTxId;
+      try {
+        fTxId = Long.parseLong(fName.substring(oivImagePrefix.length() + 1));
+      } catch (NumberFormatException nfe) {
+        // This should not happen since we have already filtered it.
+        // Log and continue.
+        LOG.warn("Invalid file name. Skipping " + fName);
+        continue;
       }
+      sortedTxIds.add(Long.valueOf(fTxId));
     }
 
     int numFilesToDelete = sortedTxIds.size() - numCheckpointsToRetain;

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

@@ -1977,7 +1977,7 @@ public class DFSAdmin extends FsShell {
         return exitCode;
       }
     } else if ("-report".equals(cmd)) {
-      if (argv.length > 6) {
+      if (argv.length < 1) {
         printUsage(cmd);
         return exitCode;
       }
@@ -2007,7 +2007,7 @@ public class DFSAdmin extends FsShell {
         return exitCode;
       }
     } else if (RollingUpgradeCommand.matches(cmd)) {
-      if (argv.length > 2) {
+      if (argv.length < 1 || argv.length > 2) {
         printUsage(cmd);
         return exitCode;
       }
@@ -2082,7 +2082,7 @@ public class DFSAdmin extends FsShell {
         return exitCode;
       }
     } else if ("-triggerBlockReport".equals(cmd)) {
-      if ((argv.length != 2) && (argv.length != 3)) {
+      if (argv.length < 1) {
         printUsage(cmd);
         return exitCode;
       }

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

@@ -722,13 +722,9 @@ class ImageLoaderCurrent implements ImageLoader {
       if (supportSnapshot && supportInodeId) {
         dirNodeMap.put(inodeId, pathName);
       }
-
-      v.visit(ImageElement.NS_QUOTA, in.readLong());
-      if (NameNodeLayoutVersion.supports(Feature.DISKSPACE_QUOTA,
-          imageVersion)) {
-        v.visit(ImageElement.DS_QUOTA, in.readLong());
-      }
-
+      v.visit(ImageElement.NS_QUOTA, numBlocks == -1 ? in.readLong() : -1);
+      if (NameNodeLayoutVersion.supports(Feature.DISKSPACE_QUOTA, imageVersion))
+        v.visit(ImageElement.DS_QUOTA, numBlocks == -1 ? in.readLong() : -1);
       if (supportSnapshot) {
         boolean snapshottable = in.readBoolean();
         if (!snapshottable) {