Re: A NFS, xfs, reflink and rmapbt story

["J. Bruce Fields" <bfields@fieldses.org>]

On Sun, Feb 16, 2020 at 04:28:51PM +0800, Murphy Zhou wrote:
> Hi Bruce,
> 
> On Mon, Jan 27, 2020 at 05:36:31PM -0500, J. Bruce Fields wrote:
> > On Thu, Jan 23, 2020 at 05:10:19PM -0800, Darrick J. Wong wrote:
> > > On Thu, Jan 23, 2020 at 04:32:17PM +0800, Murphy Zhou wrote:
> > > > Hi,
> > > > 
> > > > Deleting the files left by generic/175 costs too much time when testing
> > > > on NFSv4.2 exporting xfs with rmapbt=1.
> > > > 
> > > > "./check -nfs generic/175 generic/176" should reproduce it.
> > > > 
> > > > My test bed is a 16c8G vm.
> > > 
> > > What kind of storage?
> > > 
> > > > NFSv4.2  rmapbt=1   24h+
> > > 
> > > <URK> Wow.  I wonder what about NFS makes us so slow now?  Synchronous
> > > transactions on the inactivation?  (speculates wildly at the end of the
> > > workday)
> > > 
> > > I'll have a look in the morning.  It might take me a while to remember
> > > how to set up NFS42 :)
> > 
> > It may just be the default on a recent enough distro.
> > 
> > Though I'd be a little surprised if this behavior is specific to the
> > protocol version.
> 
> Can NFS client or server know the file has reflinked part ? Is there
> any thing like a flag or a bit tracking this?

Not that I'm aware of.

--b.