From afa1006a537e1fc1adb5005cbdf4e4d8d9e98b22 Mon Sep 17 00:00:00 2001
From: Inigo Goiri <inigoiri@apache.org>
Date: Tue, 24 Sep 2019 09:58:42 -0700
Subject: [PATCH] HDFS-14843. Double Synchronization in
 BlockReportLeaseManager. Contributed by David Mollitor.

---
 .../server/blockmanagement/BlockReportLeaseManager.java   | 8 ++------
 1 file changed, 2 insertions(+), 6 deletions(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockReportLeaseManager.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockReportLeaseManager.java
index 7db05c7aaa..2a4b6e8455 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockReportLeaseManager.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/blockmanagement/BlockReportLeaseManager.java
@@ -180,12 +180,8 @@ class BlockReportLeaseManager {
   /**
    * Get the next block report lease ID.  Any number is valid except 0.
    */
-  private synchronized long getNextId() {
-    long id;
-    do {
-      id = nextId++;
-    } while (id == 0);
-    return id;
+  private long getNextId() {
+    return ++nextId == 0L ? ++nextId : nextId;
   }
 
   public synchronized void register(DatanodeDescriptor dn) {