On Wed, 2018-08-08 at 07:36 -0400, Scott Mayhew wrote:
> According to commit d3635ff07e8 ("nfsd: fix configuration of
> supported
> minor versions"), it should be possible to use either '4.0' or '4' to
> enable or disable minor version 0.
>
> Currently, writing '+4' to /proc/fs/nfsd/versions has no effect
> unless
> no minor versions are enabled. That leaves rpc.nfsd without an easy
> way to re-enable v4.0, since that's what it does when invoked with
> '-V 4.0'.
>
> Fixes: d3635ff07e8 ("nfsd: fix configuration of supported minor
> versions")
> Signed-off-by: Scott Mayhew <smayhew@xxxxxxxxxx>
> ---
> fs/nfsd/nfsctl.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
> index d107b4426f7e..b3f9f9233953 100644
> --- a/fs/nfsd/nfsctl.c
> +++ b/fs/nfsd/nfsctl.c
> @@ -614,6 +614,14 @@ static ssize_t __write_versions(struct file
> *file, char *buf, size_t size)
> minor = 0;
> while (nfsd_minorversion(minor,
> cmd) >= 0)
> minor++;
> + } else if (cmd == NFSD_SET) {
> + /*
> + * We have +4 but there are
> already some minors
> + * enabled. We must ensure 4.0
> gets enabled,
> + * since it could be a request
> from rpc.nfsd.
> + */
> + if (nfsd_minorversion(0, cmd) <
> 0)
> + return -EINVAL;
> }
> break;
> default:
This breaks the intention behind that patch, which was to ensure that
+4 must _not_ automatically enable 4.0...
Instead, you use +/-4.0 to enable/disable 4.0, just like you use +/-4.1
to enable/disable 4.1, +/-4.2 to enable/disable 4.2, etc, etc...
The special value +/-4 exists in order allow you to disable/enable v4
altogether. i.e. '-4' acts as a mask to turn off v4.x for all values of
x. '+4' will enable v4.x for those values of x which have been
explicitly set.
--
Trond Myklebust
CTO, Hammerspace Inc
4300 El Camino Real, Suite 105
Los Altos, CA 94022
www.hammer.space
��.n��������+%������w��{.n�����{��w��� jg��� �����ݢj����G���� ���j:+v���w�m������w�������h�����٥
