HDFS-16241. Standby close reconstruction thread (#3493)

Co-authored-by: zhanghuazong <Zhz@20068867>
(cherry picked from commit 88d8c3d0c88bcec5acca30aadca36b7d65c4237c)

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

@@ -3608,7 +3608,7 @@ public class BlockManager implements BlockStatsMXBean {
   /*
    * Stop the ongoing initialisation of reconstruction queues
    */
-  private void stopReconstructionInitializer() {
+  public void stopReconstructionInitializer() {
     if (reconstructionQueuesInitializer != null) {
       reconstructionQueuesInitializer.interrupt();
       try {

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

@@ -1427,8 +1427,11 @@ public class FSNamesystem implements Namesystem, FSNamesystemMBean,
     LOG.info("Stopping services started for active state");
     writeLock();
     try {
-      if (blockManager != null && blockManager.getSPSManager() != null) {
-        blockManager.getSPSManager().stop();
+      if (blockManager != null) {
+        blockManager.stopReconstructionInitializer();
+        if (blockManager.getSPSManager() != null) {
+          blockManager.getSPSManager().stop();
+        }
       }
       stopSecretManager();
       leaseManager.stopMonitor();