HDFS-13359. DataXceiver hung due to the lock in FsDatasetImpl#getBlockInputStream. Contributed by Yiqun Lin.

linyiqun · jojochuang · commit 8a77a224c734 · 2019-08-09T18:40:28.000-07:00
Signed-off-by: Wei-Chiu Chuang &lt;weichiu@apache.org&gt;
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
@@ -794,7 +794,7 @@ public InputStream getBlockInputStream(ExtendedBlock b,
       long seekOffset) throws IOException {
 
     ReplicaInfo info;
-    synchronized(this) {
+    try (AutoCloseableLock lock = datasetLock.acquire()) {
       info = volumeMap.get(b.getBlockPoolId(), b.getLocalBlock());
     }
 

Original file line number	Diff line number	Diff line change
`@@ -794,7 +794,7 @@ public InputStream getBlockInputStream(ExtendedBlock b,`
`794`	`794`	`long seekOffset) throws IOException {`
`795`	`795`
`796`	`796`	`ReplicaInfo info;`
`797`		`- synchronized(this) {`
	`797`	`+ try (AutoCloseableLock lock = datasetLock.acquire()) {`
`798`	`798`	`info = volumeMap.get(b.getBlockPoolId(), b.getLocalBlock());`
`799`	`799`	`}`
`800`	`800`