[PATCH 12/16] nfsd4: make readonly access depend on pseudoflavor

[Neil Brown]

On Friday May 18, bfields at fieldses.org wrote:
> From: J. Bruce Fields <bfields at citi.umich.edu>
> 
> Allow readonly access to vary depending on the pseudoflavor, using the
> flag passed with each pseudoflavor in the export downcall.  The rest of
                                                              ^^^^^^^^^^^
> the flags are ignored for now, though some day we might also allow id
  ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> squashing to vary based on the flavor.

This begs the question:  Should we allow those flags to be set.

i.e. if a per-pseudoflavour flag is set that we don't support,
should we just return an error so that the admin knows that their
configuration is not supported.
And how do you tell if a flag is set or not...
Maybe we should complain if the per-pseudoflavour flags are different
to the export-wide flags on any bit other than readonly?

Different id squashing?  Maybe, but it would be awkward to squash to a
different id.  I suspect there would be no call for that.  But having
different values for the allsquash and rootsquash flags might make
sense one day.

NeilBrown