Re: [RFC PATCH 0/6] nfs-utils: Improving NFS re-exports

[Richard Weinberger <richard@nod.at>]

----- Ursprüngliche Mail -----
> Von: "bfields" <bfields@fieldses.org>
>> Which one do you prefer?
>> "predefined-fsidnum" should be the safest one to start.
> 
> I don't know!  I'll have to do some more reading and think about it.

No need to worry, take your time.
 
>> > Setting the timeout to 0 doesn't help with re-export server reboots.
>> > After a reboot is another case where we could end up in a situation
>> > where a client hands us a filehandle for a filesystem that isn't mounted
>> > yet.
>> > 
>> > I think you want to keep a path with each entry in the database.  When
>> > mountd gets a request for a filesystem it hasn't seen before, it stats
>> > that path, which should trigger the automounts.
>> 
>> I have implemented that already. This feature is part of this series. :-)
> 
> Oh, good, got it.  It'll take me some time to catch up.

The reason why setting the timeout to 0 is still needed is because
when mountd uncovers a subvolume but no client uses it a filehandle,
it is not locked and can be unmounted later.
Only when nfsd sees a matching filehandle the reference counter will
be increased and umounting is no longer possible.

Thanks,
//richard