HDFS-5372. In FSNamesystem, hasReadLock() returns false if the current thread holds the write lock (Contributed by Vinay)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/branch-2@1543029 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -288,6 +288,9 @@ Release 2.2.1 - UNRELEASED
     HDFS-5519. COMMIT handler should update the commit status after sync
     (brandonli)
 
+    HDFS-5372. In FSNamesystem, hasReadLock() returns false if the current 
+    thread holds the write lock (Vinaykumar B via umamahesh)
+
 Release 2.2.0 - 2013-10-13
 
   INCOMPATIBLE CHANGES

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

@@ -817,7 +817,7 @@ public class BlockManager {
       final boolean isFileUnderConstruction, final long offset,
       final long length, final boolean needBlockToken, final boolean inSnapshot)
       throws IOException {
-    assert namesystem.hasReadOrWriteLock();
+    assert namesystem.hasReadLock();
     if (blocks == null) {
       return null;
     } else if (blocks.length == 0) {

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

@@ -1265,11 +1265,7 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
   }
   @Override
   public boolean hasReadLock() {
-    return this.fsLock.getReadHoldCount() > 0;
+    return this.fsLock.getReadHoldCount() > 0 || hasWriteLock();
-  }
-  @Override
-  public boolean hasReadOrWriteLock() {
-    return hasReadLock() || hasWriteLock();
   }
 
   public int getReadHoldCount() {
@@ -2006,7 +2002,7 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
    */
   private void verifyParentDir(String src) throws FileNotFoundException,
       ParentNotDirectoryException, UnresolvedLinkException {
-    assert hasReadOrWriteLock();
+    assert hasReadLock();
     Path parent = new Path(src).getParent();
     if (parent != null) {
       final INode parentNode = dir.getINode(parent.toString());
@@ -2613,7 +2609,7 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
                                 ExtendedBlock previous,
                                 LocatedBlock[] onRetryBlock)
           throws IOException  {
-    assert hasReadOrWriteLock();
+    assert hasReadLock();
 
     checkBlock(previous);
     onRetryBlock[0] = null;
@@ -2810,7 +2806,7 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
   private INodeFileUnderConstruction checkLease(String src, long fileId,
       String holder, INode inode) throws LeaseExpiredException,
       FileNotFoundException {
-    assert hasReadOrWriteLock();
+    assert hasReadLock();
     if (inode == null || !inode.isFile()) {
       Lease lease = leaseManager.getLease(holder);
       throw new LeaseExpiredException(
@@ -3769,7 +3765,7 @@ public class FSNamesystem implements Namesystem, FSClusterStats,
   
   @Override
   public boolean isInSnapshot(BlockInfoUnderConstruction blockUC) {
-    assert hasReadOrWriteLock();
+    assert hasReadLock();
     final BlockCollection bc = blockUC.getBlockCollection();
     if (bc == null || !(bc instanceof INodeFileUnderConstruction)) {
       return false;

hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/util/RwLock.java

@@ -39,7 +39,4 @@ public interface RwLock {
 
   /** Check if the current thread holds write lock. */
   public boolean hasWriteLock();
-
-  /** Check if the current thread holds read or write lock. */
-  public boolean hasReadOrWriteLock();
 }