The check style issues reported in the build can be ignored..
./hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImpl.java:1: File length is 3,107 lines (max allowed is 2,000).
The file was already more than 2000 line earlier to this patch. So, this can be ignored.
./hadoop-hdfs-project/hadoop-hdfs/src/main/java/org/apache/hadoop/hdfs/server/datanode/fsdataset/impl/FsDatasetImpl.java:2563:16: Variable 'reservedSpaceForRBW' must be private and have accessor methods.
All other fields usedSpace,freeSpace, reservedSpace in VolumeInfo are declared in the same fashion with out accessor menthods for some reason. I think we can ignore this also.