Hi Vinay, The behavior you described is correct according to the POSIX ACL model. The reason for this is that once a file has an ACL, its group permission bits are then used as the mask entry, which filters the permissions applied to named user entries, named group entries, and the unnamed group entry. A subsequent setPermission doesn't change the group entry. Instead, it changes the mask. Our docs describe this in more detail here:
http://hadoop.apache.org/docs/r2.5.2/hadoop-project-dist/hadoop-hdfs/HdfsPermissionsGuide.html#ACLs_Access_Control_Lists I know you've seen this doc, but I'm linking it for the benefit of others reading the thread. On HDFS-4685, the design doc and its references provide more rationale for how the mask works. In your example, running hdfs dfs -setfacl -m group:group2:r-x also has a side effect of updating the mask entry to the union of permissions on all named user entries, named group entries, and the unnamed group entry. This explains why the operations in your example aren't commutative, and swapping steps 2 and 3 gives a different result. You can always override the automatic mask calculation by providing it explicitly in setfacl commands, i.e. hdfs dfs -setfacl -m group:group2:r-x,mask::---. Chris Nauroth Hortonworks http://hortonworks.com/ On Tue, Nov 11, 2014 at 10:28 AM, Vinayakumar B <vinayakum...@apache.org> wrote: > Hi, > > Here is the scenario. > > 1. owner : *user1, *ownerGroup: *group1* > *2. /dir *have permissions set 700 (rwx------) using setPermission(). > 3. Now another Named group ACL has been set to allow access to another > group > group:*group2:r-x* > 4. Now, when */dir is *accessed from a user belongs to *group2, *Its > success. > > 5. But, the steps #2 and #3 are inter-changed, i.e. setPermission (700) > later, then dir is not given access for a user belongs to *group2.* > > This is same as linux behaviour. But ideally, access should be given, > regardless of the order of setting acl and setting permission. > > Any thoughts on this? > > Regards, > Vinay > -- CONFIDENTIALITY NOTICE NOTICE: This message is intended for the use of the individual or entity to which it is addressed and may contain information that is confidential, privileged and exempt from disclosure under applicable law. If the reader of this message is not the intended recipient, you are hereby notified that any printing, copying, dissemination, distribution, disclosure or forwarding of this communication is strictly prohibited. If you have received this communication in error, please contact the sender immediately and delete it from your system. Thank You.
