[nfsv4] Re: Interim meeting agenda topics

[Rick Macklem <[e-mail]>]

On Sun, Sep 8, 2024 at 9:34 AM Pali Rohár <[e-mail]> wrote:
>
> On Sunday 08 September 2024 12:05:54 David Noveck wrote:
> > On Fri, Sep 6, 2024, 4:35 PM Rick Macklem <[e-mail]> wrote:
> > > What is left to be resolved / is controversial on the POSIX_ACL draft?
> >
> > Nothing from my point of view.  I don't know of any issues Rick has.   It
> > is reasonable to expect that anyone who does have issues to raise them on
> > the list.   We may need to confirm the non-existence of such issues at the
> > forthcoming interim meeting.  I think we should allocate five minutes for
> > this.
>
> Hello, I have already pointed one issue on the list - problem with mode
> attribute (two meaning modes: NFS4 and POSIX) and its backward/forward
> compatibility on existing NFS4 servers for clients without POSIX ACL
> extension.
I'll admit I just do not understand what you are thinking.
For the proposal, at any one moment in time, a file object on the server
will have, at most, one "true form" ACL. (Where "true form" is the ACL
that is stored for the file object and used to determine access to the file.)

As such, I cannot understand why you would think there are two modes?
(Where "mode" refers to the low order 9 bits of the mode attribute.)

The interaction between setting of the low order 9 bits of mode and the
setting of an ACL is determined by which "true form" the ACL has.

For the weird case where a SETATTR is allowed to set an ACL of the
other "true form" for a file object, the mode bits will be updated the
same way as they would be if that ACL was set for the file object at
any other time (ie. no previous ACL or a previous ACL of the same "true form").

W.r.t. clients that do not support the extension...
These clients might set the mode bits and the effect would be no
different than what occurs now.
--> For a server that uses a "true form" of POSIX draft ACL, that
     ACL might change, just as would happen now. It's just that the client
     cannot actually "see" the ACL.

W.r.t. servers that do not support the extension...
The attributes will not be in the supported_attrs list and any
attempt to GET/SET them should fail.

rick