Bug 1409950

Description of problem:

according https://bugzilla.redhat.com/show_bug.cgi?id=1406885#c18
'''
nfsd: opt in to labeled nfs per export

I believe the attached is all we need for the (upstream) kernel, but it will also need an nfs-utils patch and some testing.  Changelog:

    nfsd: opt in to labeled nfs per export
    
    Currently turning on NFSv4.2 results in 4.2 clients suddenly seeing the
    individual file labels as they're set on the server.  This is not what
    they've previously seen, and not appropriate in may cases.  (In
    particular, if clients have heterogenous security policies then one
    client's labels may not even make sense to another.)  Labeled NFS should
    be opted in only in those cases when the administrator knows it makes
    sense.
    
    It's helpful to be able to turn 4.2 on by default, and otherwise the
    protocol upgrade seems free of regressions.  So, default labeled NFS to
    off and provide an export flag to reenable it.
    
    Users wanting labeled NFS support on an export will henceforth need to:
    
            - make sure 4.2 support is enabled on client and server (as
              before), and
            - upgrade the server nfs-utils to a version supporting the new
              "security_label" export flag.
            - set that "security_label" flag on the export.
    
    This is commit may be seen as a regression to anyone currently depending
    on security labels.  We believe those cases are currently rare.
'''

Version-Release number of selected component (if applicable):
RHEL-7.4

How reproducible:
1


Actual results:
no security_label option

Expected results:
add security_label option

Additional info:
  see https://bugzilla.redhat.com/show_bug.cgi?id=1406885