HDFS-6718. Remove EncryptionZoneManager lock. (wang)

git-svn-id: https://svn.apache.org/repos/asf/hadoop/common/branches/fs-encryption@1612439 13f79535-47bb-0310-9956-ffa450edef68

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

@@ -52,6 +52,8 @@ fs-encryption (Unreleased)
     HDFS-6716. Update usage of KeyProviderCryptoExtension APIs on NameNode.
     (wang)
 
+    HDFS-6718. Remove EncryptionZoneManager lock. (wang)
+
   OPTIMIZATIONS
 
   BUG FIXES

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

@@ -60,35 +60,6 @@ public class EncryptionZoneManager {
 
   }
 
-  /**
-   * Protects the <tt>encryptionZones</tt> map and its contents.
-   */
-  private final ReentrantReadWriteLock lock;
-
-  private void readLock() {
-    lock.readLock().lock();
-  }
-
-  private void readUnlock() {
-    lock.readLock().unlock();
-  }
-
-  private void writeLock() {
-    lock.writeLock().lock();
-  }
-
-  private void writeUnlock() {
-    lock.writeLock().unlock();
-  }
-
-  public boolean hasWriteLock() {
-    return lock.isWriteLockedByCurrentThread();
-  }
-
-  public boolean hasReadLock() {
-    return lock.getReadHoldCount() > 0 || hasWriteLock();
-  }
-
   private final Map<Long, EncryptionZoneInt> encryptionZones;
   private final FSDirectory dir;
   private final KeyProvider provider;
@@ -101,7 +72,6 @@ public class EncryptionZoneManager {
   public EncryptionZoneManager(FSDirectory dir, KeyProvider provider) {
     this.dir = dir;
     this.provider = provider;
-    lock = new ReentrantReadWriteLock();
     encryptionZones = new HashMap<Long, EncryptionZoneInt>();
   }
 
@@ -116,12 +86,7 @@ public class EncryptionZoneManager {
   void addEncryptionZone(Long inodeId, String keyId) {
     assert dir.hasWriteLock();
     final EncryptionZoneInt ez = new EncryptionZoneInt(inodeId, keyId);
-    writeLock();
-    try {
     encryptionZones.put(inodeId, ez);
-    } finally {
-      writeUnlock();
-    }
   }
 
   /**
@@ -131,12 +96,7 @@ public class EncryptionZoneManager {
    */
   void removeEncryptionZone(Long inodeId) {
     assert dir.hasWriteLock();
-    writeLock();
-    try {
     encryptionZones.remove(inodeId);
-    } finally {
-      writeUnlock();
-    }
   }
 
   /**
@@ -147,12 +107,7 @@ public class EncryptionZoneManager {
   boolean isInAnEZ(INodesInPath iip)
       throws UnresolvedLinkException, SnapshotAccessControlException {
     assert dir.hasReadLock();
-    readLock();
-    try {
     return (getEncryptionZoneForPath(iip) != null);
-    } finally {
-      readUnlock();
-    }
   }
 
   /**
@@ -172,16 +127,12 @@ public class EncryptionZoneManager {
    * Called while holding the FSDirectory lock.
    */
   String getKeyName(final INodesInPath iip) {
-    readLock();
+    assert dir.hasReadLock();
-    try {
     EncryptionZoneInt ezi = getEncryptionZoneForPath(iip);
     if (ezi == null) {
       return null;
     }
     return ezi.getKeyName();
-    } finally {
-      readUnlock();
-    }
   }
 
   /**
@@ -191,7 +142,7 @@ public class EncryptionZoneManager {
    * Must be called while holding the manager lock.
    */
   private EncryptionZoneInt getEncryptionZoneForPath(INodesInPath iip) {
-    assert hasReadLock();
+    assert dir.hasReadLock();
     Preconditions.checkNotNull(iip);
     final INode[] inodes = iip.getINodes();
     for (int i = inodes.length - 1; i >= 0; i--) {
@@ -220,8 +171,6 @@ public class EncryptionZoneManager {
   void checkMoveValidity(INodesInPath srcIIP, INodesInPath dstIIP, String src)
       throws IOException {
     assert dir.hasReadLock();
-    readLock();
-    try {
     final EncryptionZoneInt srcEZI = getEncryptionZoneForPath(srcIIP);
     final EncryptionZoneInt dstEZI = getEncryptionZoneForPath(dstIIP);
     final boolean srcInEZ = (srcEZI != null);
@@ -253,9 +202,6 @@ public class EncryptionZoneManager {
         throw new IOException(sb.toString());
       }
     }
-    } finally {
-      readUnlock();
-    }
   }
 
   /**
@@ -266,8 +212,6 @@ public class EncryptionZoneManager {
   XAttr createEncryptionZone(String src, String keyId, KeyVersion keyVersion)
       throws IOException {
     assert dir.hasWriteLock();
-    writeLock();
-    try {
     if (dir.isNonEmptyDirectory(src)) {
       throw new IOException(
           "Attempt to create an encryption zone for a non-empty directory.");
@@ -291,9 +235,6 @@ public class EncryptionZoneManager {
     // Re-get the new encryption zone add the latest key version
     ezi = getEncryptionZoneForPath(srcIIP);
     return keyIdXAttr;
-    } finally {
-      writeUnlock();
-    }
   }
 
   /**
@@ -303,16 +244,11 @@ public class EncryptionZoneManager {
    */
   List<EncryptionZone> listEncryptionZones() throws IOException {
     assert dir.hasReadLock();
-    readLock();
-    try {
     final List<EncryptionZone> ret =
         Lists.newArrayListWithExpectedSize(encryptionZones.size());
     for (EncryptionZoneInt ezi : encryptionZones.values()) {
       ret.add(new EncryptionZone(getFullPathName(ezi), ezi.getKeyName()));
     }
     return ret;
-    } finally {
-      readUnlock();
-    }
   }
 }