Re: [nfsv4] xattr model in draft-naik-nfsv4-xattrs-01?

[Manoj Naik <[e-mail]>]

"J. Bruce Fields" <[e-mail]> wrote on 10/04/2014 06:12:20 PM:

> From: "J. Bruce Fields" <[e-mail]>
> To: Manoj Naik/Almaden/IBM@IBMUS
> Cc: Christoph Hellwig <[e-mail]>, [e-mail]
> Date: 10/04/2014 06:12 PM
> Subject: Re: [nfsv4] xattr model in draft-naik-nfsv4-xattrs-01?
>
> On Sat, Oct 04, 2014 at 01:34:04PM -0700, Manoj Naik wrote:
> > Christoph Hellwig <[e-mail]> wrote on 10/04/2014 09:17:50 AM:
> > > On the GETXATTR side you conflate the LISTXATTR operation with
GETXATTR,
> > > as well as adding a new bulk get one that isn't present in any OS API
> > > I know.  Both the argument and return structures are basically
entirely
> > > different for the different cases.
> >
> > Agree that GETXATTR includes what is traditionally provided by
listxattr()
> > call. The idea was to limit the number of new operations provided to
two -
> > GETXATTR and SETXATTR. But if there is consensus, we don't have an
issue
> > with adding a LISTXATTR instead.
> >
> > I think the ability to get/set all xattrs of a given file
> > (getallxattrs/setallxattrs?) is useful, especially for backup/restore
> > programs. Granted that there isn't an OS API that exposes this, but
perhaps
> > there should be one? I know some backup utilities that work directly
with a
> > filesystem API to do this. Especially over NFS, I believe a single RPC
that
> > accomplishes this may be desirable. I know somebody on the list or at
the
> > IETF meeting asked for this specifically too.
>
> What does this allow you to do that you can't do by sending multiple
> RPCs, or a single RPC with multiple getxattr/setxattr ops.

You could certainly do this with multiple ops, but not with a single
COMPOUND. See SETXATTR4_REPLACE_ALL in Section 5.3.3.3.

Manoj.

>
> --b.
>