On 10/29/2009 11:17 AM, Steve Dickson wrote:
On 10/28/2009 03:05 PM, Roland McGrath wrote:
> It sounds like you are saying that there is no way to export the same
> host filesystems with the same client-perceived names under v4 as was
> being done before under v[23]. Is that really true?
With Pre-F12 servers... Yeah...
The V4 protocol requires a 'pseudo root' to be defined. Other servers simply
make '/' the pseudo root which allows all exports just to work with all
versions.
The Linux server have the feature of being able to define the pseudo root with
the use of the 'fsid=0' export option. A feature none of the other servers
have.
Except that when the other servers create a pseudo root, they don't
*also* expose that pseudo root. I'm fairly strongly of the opinion that
our NFS server should do the same thing: don't expose the pseudo root as
an actual mount.
Unfortunately, there was no forethought as to what happens when a
pseudo root is not defined, until recently... Patches in both the
F-12 kernel and rpc.mountd now dynamically allocate a pseudo root
when one is not defined... Basically meaning '/' becomes the pseudo
root when there is no fsid=0 export option.
And does this explicitly export the / filesystem? I would certainly
hope not as that could surprise the hell out of an admin when his /
filesystem is now exposed when it didn't use to be.
>
> My old /etc/exports is:
>
> /mirror *(ro,insecure,sync,mp,all_squash)
>
> So clients mount server:/mirror to see my /mirror directory's contents.
> No other /foo directory is exported or visible at all to clients, and
> that's how it should stay.
>
> How do I get the same results for v4 clients?
Use a F-12 server or added the '/ *(ro,fsid=0)' export entry like:
/ *(ro,fsid=0)
/mirror *(ro,insecure,sync,mp,all_squash)
I'm perfectly fine with adding the entry to the exports file, but I
think the fsid=0 export entry should be a non-functioning entry other
than setting the pseudo root. As you've described it so far, it also
happens to be a live export and I think that's wrong and should be fixed.
--
Doug Ledford <dledford(a)redhat.com>
GPG KeyID: CFBFF194
http://people.redhat.com/dledford
Infiniband specific RPMs available at
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