Merge branch 'apache:trunk' into YARN-11326

Author: slfan1989

hadoop-common-project/hadoop-auth/pom.xml

@@ -110,20 +110,8 @@
           <groupId>org.bouncycastle</groupId>
           <artifactId>bcprov-jdk15on</artifactId>
         </exclusion>
-        <!-- HACK.  Transitive dependency for nimbus-jose-jwt.  Needed for
-        packaging.  Please re-check this version when updating
-        nimbus-jose-jwt.  Please read HADOOP-14903 for more details.
-        -->
-        <exclusion>
-          <groupId>net.minidev</groupId>
-          <artifactId>json-smart</artifactId>
-        </exclusion>
       </exclusions>
     </dependency>
-    <dependency>
-      <groupId>net.minidev</groupId>
-      <artifactId>json-smart</artifactId>
-    </dependency>
     <dependency>
       <groupId>org.apache.zookeeper</groupId>
       <artifactId>zookeeper</artifactId>

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

@@ -2147,6 +2147,19 @@ FsServerDefaults decodeResponse(Map<?, ?> json) throws IOException {
     }.run();
   }
 
+  @Override
+  public Path getLinkTarget(Path f) throws IOException {
+    statistics.incrementReadOps(1);
+    storageStatistics.incrementOpCounter(OpType.GET_LINK_TARGET);
+    final HttpOpParam.Op op = GetOpParam.Op.GETLINKTARGET;
+    return new FsPathResponseRunner<Path>(op, f) {
+      @Override
+      Path decodeResponse(Map<?, ?> json) {
+        return new Path((String) json.get(Path.class.getSimpleName()));
+      }
+    }.run();
+  }
+
   @VisibleForTesting
   InetSocketAddress[] getResolvedNNAddr() {
     return nnAddrs;

hadoop-hdfs-project/hadoop-hdfs-client/src/main/java/org/apache/hadoop/hdfs/web/resources/GetOpParam.java

@@ -64,6 +64,7 @@ public enum Op implements HttpOpParam.Op {
     GETSNAPSHOTDIFF(false, HttpURLConnection.HTTP_OK),
     GETSNAPSHOTDIFFLISTING(false, HttpURLConnection.HTTP_OK),
     GETSNAPSHOTTABLEDIRECTORYLIST(false, HttpURLConnection.HTTP_OK),
+    GETLINKTARGET(false, HttpURLConnection.HTTP_OK),
     GETSNAPSHOTLIST(false, HttpURLConnection.HTTP_OK);
 
     final boolean redirect;

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/resolver/MountTableResolver.java

@@ -678,11 +678,16 @@ private List<MountTable> getTreeValues(final String path, boolean reverse) {
    * @return Size of the cache.
    * @throws IOException If the cache is not initialized.
    */
-  protected long getCacheSize() throws IOException{
-    if (this.locationCache != null) {
-      return this.locationCache.size();
+  protected long getCacheSize() throws IOException {
+    this.readLock.lock();
+    try {
+      if (this.locationCache != null) {
+        return this.locationCache.size();
+      }
+      throw new IOException("localCache is null");
+    } finally {
+      this.readLock.unlock();
     }
-    throw new IOException("localCache is null");
   }
 
   @VisibleForTesting

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/router/RouterWebHdfsMethods.java

@@ -385,6 +385,7 @@ protected Response get(
       case GETXATTRS:
       case LISTXATTRS:
       case CHECKACCESS:
+      case GETLINKTARGET:
       {
         return super.get(ugi, delegation, username, doAsUser, fullpath, op,
             offset, length, renewer, bufferSize, xattrNames, xattrEncoding,

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/store/driver/StateStoreDriver.java

@@ -20,6 +20,8 @@
 import java.net.InetAddress;
 import java.util.Collection;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.conf.Configuration;
 import org.apache.hadoop.hdfs.server.federation.metrics.StateStoreMetrics;
 import org.apache.hadoop.hdfs.server.federation.store.StateStoreService;
@@ -35,6 +37,8 @@
  * provider. Driver implementations will extend this class and implement some of
  * the default methods.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
 public abstract class StateStoreDriver implements StateStoreRecordOperations {
 
   private static final Logger LOG =

hadoop-hdfs-project/hadoop-hdfs-rbf/src/main/java/org/apache/hadoop/hdfs/server/federation/store/driver/impl/StateStoreBaseImpl.java

@@ -23,6 +23,8 @@
 import java.util.ArrayList;
 import java.util.List;
 
+import org.apache.hadoop.classification.InterfaceAudience;
+import org.apache.hadoop.classification.InterfaceStability;
 import org.apache.hadoop.hdfs.server.federation.store.StateStoreUtils;
 import org.apache.hadoop.hdfs.server.federation.store.driver.StateStoreDriver;
 import org.apache.hadoop.hdfs.server.federation.store.records.BaseRecord;
@@ -39,6 +41,8 @@
  * optimization, such as custom get/put/remove queries, depending on the
  * capabilities of the data store.
  */
+@InterfaceAudience.Public
+@InterfaceStability.Evolving
 public abstract class StateStoreBaseImpl extends StateStoreDriver {
 
   @Override