Contributed by Toshihiro Suzuki. (cherry picked from commit 545a0a147c5256c44911ba57b4898e01d786d836) Conflicts: hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/TestFsDatasetImpl.java
Contributed by Toshihiro Suzuki. (cherry picked from commit 545a0a147c5256c44911ba57b4898e01d786d836) Conflicts: hadoop-hdfs-project/hadoop-hdfs/src/test/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/TestFsDatasetImpl.java