Re: [NFS] [PATCH] kNFSD - Allowing rpc.nfsd to setting of the port, transport and version the server will use

["J. Bruce Fields" <bfields@fieldses.org>]

On Fri, Oct 07, 2005 at 12:17:43PM -0400, Steve Dickson wrote:
> Here is a kernel patch that will enable the setting
> of the port knfsd will listens on, the transport knfsd
> will support and which NFS version will be advertised.
> 
> The nfs-utils patch, which is also attached, will added
> the following flags to rpc.nfsd that will enable the kernel
> functionality (Note: These patches are NOT dependent on each
> other. Meaning rpc.nfsd and knfsd will still function correctly
> if one or the other patch do or do not exist):
> 
> 
>    -N  or  --no-nfs-version vers
>         This option can be used to request that rpc.nfsd does not  offer
>         certain  versions of NFS. The current version of rpc.nfsd can
>         support both NFS version 2,3 and the newer version 4.

So the obvious question is what will happen if someone does

	rpc.nfsd -N 3

on a server supporting 2, 3, and 4.

It looks like the code in svc_create() will set pg_lovers to 2 and
pg_hivers to 4 in that case.  So if someone tries to use version 3, the
error they get back will be a somewhat contradictory "sorry, I only
support versions 2 through 4."

It seems to me that it'd be cleaner if the kernel interface only
accepted a range (e.g., "2--4" or "2--3").  Then if someone
attempted the above, they'll get an error back immediately.

Or svc_create could be adjusted to report a more conservative range
("2--2" or "4--4" instead of "2--4").

But I don't have really strong feelings about it.  Maybe we shouldn't
care enough about that case.

--b.