I have a document showing how to set ACLs in hadoop but it has a pre-requisite of setting the following policy. but this policy is missing from my HDP 2.5 ?
set the "dfs.namenode.acls.enabled" to true (HDFS configs).
Read below very good article about HDFS Acls:
As mentioned by @bhagan, Acls are turned off by default. You would need to enable them by setting dfs.namenode.acls.enabled=true in hdfs-site