HDFS-11591. Block Storage: fix TestCBlockServer test cleanup. Contributed by Xiaoyu Yao

hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/cblock/TestCBlockServer.java

@@ -22,6 +22,7 @@ import org.apache.hadoop.cblock.meta.VolumeInfo;
 import org.apache.hadoop.scm.client.ScmClient;
 import org.apache.hadoop.cblock.util.MockStorageClient;
 import org.apache.hadoop.ozone.OzoneConfiguration;
+import org.junit.AfterClass;
 import org.junit.BeforeClass;
 import org.junit.Test;
 
@@ -47,6 +48,13 @@ public class TestCBlockServer {
     cBlockManager = new CBlockManager(conf, storageClient);
   }
 
+  @AfterClass
+  public static void clean() {
+    cBlockManager.stop();
+    cBlockManager.join();
+    cBlockManager.clean();
+  }
+
   /**
    * Test create volume for different users.
    * @throws Exception