On Thu, 2019-12-19 at 09:47 +1100, NeilBrown wrote:
> If an NFSv4.1 server doesn't support NFS4_OPEN_CLAIM_DELEG_CUR_FH
> (e.g. Linux 3.0), and a newer NFS client tries to use it to claim
> an open before returning a delegation, the server might return
> NFS4ERR_BADXDR.
> That is what Linux 3.0 does, though the RFC doesn't seem to be
> explicit
> on which flags must be supported, and what error can be returned for
> unsupported flags.

NFS4ERR_BADXDR is defined in RFC5661, section 15.1.1.1 as meaning

"The arguments for this operation do not match those specified in the
XDR definition."

That's clearly not the case here, so I'd chalk this down to a fairly
blatant server bug, at which point it makes no sense to fix it in the
client.

-- 
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@hammerspace.com