On Wed, Feb 22 2017, Trond Myklebust wrote:

> This patch series was intended as a standalone series. However it now
> aims to fix up a few issues with Neil's initial patch:
>
> 1) When the user turns off all minor versions of NFSv4, then that should
>    be equivalent to turning off NFSv4 support, and so when someone tries
>    to mount, we should return RPC_PROG_MISMATCH.
> 2) Allow the user to use either '4.0' or '4' in order to enable or disable
>    minor version 0. Other minor versions remain enabled/disabled using the
>    '4.x' format.

If I understand you and the code correctly, then this change means that
if I run

   rpc.nfsd -N 4

the nfs server will continue to server v4.1 and v4.2 requests, only v4.0
will be disabled (Assuming a kernel which defaults to serving v4.0, v4.1
and v4.0).

Is that really what we want?

The text in the man page for rpc.nfsd could be read as allowing this
interpretation, though it isn't explicit.
I've always used "NFSv4" to mean any or all for 4.0, 4.1, 4.2, ...

Thanks,
NeilBrown


> 3) Fix up the display of the minor versions so that we don't add '4.0'.
>    Previous kernels have always assumed the '4' means 'minor version 0',
>    so there should be no need to have both.
>
> v2: Make incremental to Neil's patch
>     Fix up display of the version string
>
> Trond Myklebust (2):
>   nfsd: Allow enabling NFSv4.x without also requiring NFSv4.0
>   nfsd: Fix display of the version string
>
>  fs/nfsd/nfsctl.c | 72 ++++++++++++++++++++++++++------------------------------
>  fs/nfsd/nfssvc.c | 14 +++++++++++
>  2 files changed, 48 insertions(+), 38 deletions(-)
>
> -- 
> 2.9.3