From 14255786908f991fd2022480fe5575533a3dc7ce Mon Sep 17 00:00:00 2001
From: Vinayakumar B <vinayakumarb@apache.org>
Date: Wed, 20 Jan 2016 21:04:21 +0530
Subject: [PATCH] HDFS-9661. Deadlock in DN.FsDatasetImpl between
 moveBlockAcrossStorage and createRbw (Contributed by ade)

---
 hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt           |  3 +++
 .../server/datanode/fsdataset/impl/FsDatasetImpl.java | 11 +++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
index b051f2f0fb2..e6074bd217b 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
+++ b/hadoop-hdfs-project/hadoop-hdfs/CHANGES.txt
@@ -2646,6 +2646,9 @@ Release 2.7.3 - UNRELEASED
     HDFS-9648. TestStartup.testImageChecksum is broken by HDFS-9569's message
     change. (Wei-Chiu Chuang via Yongjun Zhang)
 
+    HDFS-9661. Deadlock in DN.FsDatasetImpl between moveBlockAcrossStorage and
+    createRbw (ade via vinayakumarb)
+
 Release 2.7.2 - UNRELEASED
 
   INCOMPATIBLE CHANGES
diff --git a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImpl.java b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImpl.java
index 5350974fd7d..cbd412305b3 100644
--- a/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImpl.java
+++ b/hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImpl.java
@@ -936,8 +936,11 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
           + replicaInfo.getVolume().getStorageType());
     }
 
-    try (FsVolumeReference volumeRef = volumes.getNextVolume(
-        targetStorageType, block.getNumBytes())) {
+    FsVolumeReference volumeRef = null;
+    synchronized (this) {
+      volumeRef = volumes.getNextVolume(targetStorageType, block.getNumBytes());
+    }
+    try {
       File oldBlockFile = replicaInfo.getBlockFile();
       File oldMetaFile = replicaInfo.getMetaFile();
       FsVolumeImpl targetVolume = (FsVolumeImpl) volumeRef.getVolume();
@@ -956,6 +959,10 @@ class FsDatasetImpl implements FsDatasetSpi<FsVolumeImpl> {
 
       removeOldReplica(replicaInfo, newReplicaInfo, oldBlockFile, oldMetaFile,
           oldBlockFile.length(), oldMetaFile.length(), block.getBlockPoolId());
+    } finally {
+      if (volumeRef != null) {
+        volumeRef.close();
+      }
     }
 
     // Replace the old block if any to reschedule the scanning.