[nfsv4] Asking for details about OPEN_DOWNGRADE

[J. Bruce Fields]

On Fri, Jun 13, 2008 at 01:29:55PM -0700, Mike Mackovitch wrote:
> On Fri, Jun 13, 2008 at 02:52:51PM -0400, Trond Myklebust wrote:
> > On Fri, 2008-06-13 at 10:33 -0700, Mike Mackovitch wrote:
> > > On Fri, Jun 13, 2008 at 10:03:29AM -0700, eric kustarz wrote:
> > > >
> > > > On Jun 13, 2008, at 9:49 AM, Mike Mackovitch wrote:
> > > >
> > > >> On Fri, Jun 13, 2008 at 08:01:03AM -0400, Trond Myklebust wrote:
> > > >>> IOW: you cannot just do
> > > >>>
> > > >>>        OPEN(OPEN4_SHARE_ACCESS_BOTH|OPEN4_SHARE_DENY_NONE)
> > > >>>        OPEN_DOWNGRADE(OPEN4_SHARE_ACCESS_READ|OPEN4_SHARE_DENY_NONE) = NFS4ERR_INVAL
> > > >>
> > > >> This works fine on Solaris server - and the Solaris client
> > > >> even behaves exactly this way.
> > > >
> > > > Yeah, we've got some bugs to fix in this area:
> > > > NFSv4 client can send a bogus OPEN_DOWNGRADE
> > > > http://bugs.opensolaris.org/view_bug.do?bug_id=4877567
> > > >
> > > > NFSv4 server should deny bogus OPEN_DOWNGRADE
> > > > http://bugs.opensolaris.org/view_bug.do?bug_id=4877573
> > > 
> > > Hmmm...if that's really the agreed upon behavior, I must say it's quite
> > > a shame that nobody bothered to fix the spec - not even in NFSv4.1.
> > 
> > How should it be 'fixed' in your opinion?
> 
> By explicitly specifying that the behavior described above should not
> be allowed.  It is clear that the spec is NOT clear about that....
> otherwise, the spec wouldn't be getting "misinterpreted" by many people.
> 
> The text in the OPEN and OPEN_DOWNGRADE descriptions, as well as "Open
> Upgrade and Downgrade" sections, leads me (and others) to believe that
> the server only keeps one "OR"ed-together status for that owner and
> thus sending multiple, redundant OPEN requests (for that owner) was
> unnecessary.

The text of rfc 3530 ("exactly equal to the union of...") doesn't seem
ambiguous to me.

--b.

> 
> (Well, that and a VFS implementation that doesn't pass a
> directory/filename pair to its OPEN call. [grrr])
> 
> --macko
> _______________________________________________
> NFSv4 mailing list
> NFSv4 at linux-nfs.org
> http://linux-nfs.org/cgi-bin/mailman/listinfo/nfsv4