Re: 14.1 NFS / mountd : -alldirs not working as expected

On Thu, Nov 21, 2024 at 1:56 PM Michael Proto <mike@jellydonut.org> wrote:
>
> On Thu, Nov 21, 2024 at 7:11 AM Rick Macklem <rick.macklem@gmail.com> wrote:
> >
> > On Wed, Nov 20, 2024 at 8:01 PM Michael Proto <mike@jellydonut.org> wrote:
> > >
> > > Hello all,
> > >
> > > Running into an issue with a 14.1 server that I think is a bug, though
> > > it may be me not interpreting documentation correctly so I wanted to
> > > ask here.
> > =alldirs simply means that any directory within the server file system
> > can be mounted. So, yes, everything up to the root dir can be mounted.
> >
> > Normally, the directory for such an exports line would be the root directory
> > of the file system, but I doubt mountd actually enforces that, since the export
> > line is for "all directories" in the file system.
> >
> > >
> > > Using NFSv3, with FreeBSD 14.1 as the NFS server. Based on what I see
> > > in exports(5), if I want to export conditional mounts (IE filesystem
> > > paths that are intermittently mounted locally on server)
> > No idea what you mean by "intermittently mounted locally"?
> > (An export will be for whatever file system is mounted for the directory
> > at the time mountd is started or updates exports when a SIGHUP is
> > sent to it.)
> >
> > Exporting a file system that is not always mounted on the server is
> > a very bad idea imho. It would be much better to add the exports(5)
> > line after the file system is mounted and remove it before the file
> > system is unmounted, if you need to export a file system not always
> > mounted.
> >
>
> Agreed, for the rare circumstances where I use this the playbook has
> always been to update /etc/exports before and after any (un)mounting,
> just interested if mountd would programmatically enforce it for the
> hopefully-rare time such steps are overlooked. Seeing that error in
> the mountd.c code gave me hope mountd itself could assist there,
> regardless I have other ways of achieving the same result.
I suppose a new exports option that says "only do the export if the
directory path is the root of a file system" might be useful.

I'll stick it on my todo list, rick

>
> Appreciate the response.
>
>
> -Michael Proto