RE: [PATCH 1/3] nfsd: use __fput_sync() to avoid delayed closing of files.

[David Laight]

...
> > PS: put it that way - I can buy "nfsd is doing that only to regular
> > files and not on an arbitrary filesystem, at that; having the thread
> > wait on that sucker is not going to cause too much trouble"; I do *not*
> > buy turning it into a thing usable outside of a very narrow set of
> > circumstances.
> >
> 
> Can you say more about "not on an arbitrary filesystem" ?
> I guess you means that procfs and/or sysfs might be problematic as may
> similar virtual filesystems (nfsd maybe).

Can nfs export an ext4 fs that is on a loopback mount on a file
that is remotely nfs (or other) mounted?

As soon as you get loops like that you might find that fput() starts
being problematic.

I'm also sure I remember that nfs wasn't supposed to respond to a write
until it had issued the actual disk write - but maybe no one do that
any more because it really is too slow.
(Especially if the 'disk' is a USB stick.)

	David

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