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Date:   Thu, 17 Feb 2022 21:29:39 +0100 (CET)
From:   Richard Weinberger <richard@nod.at>
To:     bfields <bfields@fieldses.org>
Cc:     linux-nfs <linux-nfs@vger.kernel.org>, david <david@sigma-star.at>,
        luis turcitu <luis.turcitu@appsbroker.com>,
        david young <david.young@appsbroker.com>,
        david oberhollenzer <david.oberhollenzer@sigma-star.at>,
        trond myklebust <trond.myklebust@hammerspace.com>,
        anna schumaker <anna.schumaker@netapp.com>,
        chris chilvers <chris.chilvers@appsbroker.com>
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Subject: Re: [RFC PATCH 0/6] nfs-utils: Improving NFS re-exports
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----- Ursprüngliche Mail -----
> Von: "bfields" <bfields@fieldses.org>
>> 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.
> 
> I understand that.  But, then if a client comes in with a matching
> filehandle, mountd should be able to look up the filesystem and trigger
> a new mount, right?

This does not match what I saw in my experiments. The handle machted only
when the subvolume was mounted before.
But I understand now your point, in theory it should work.
I'll investigate into this.

Thanks,
//richard