Re: NFS Caching broken in 4.19.37

[Anton Ivanov]

On 21/02/2021 14:37, Bruce Fields wrote:
> On Sun, Feb 21, 2021 at 11:38:51AM +0000, Anton Ivanov wrote:
> > On 21/02/2021 09:13, Salvatore Bonaccorso wrote:
> > > On Sat, Feb 20, 2021 at 08:16:26PM +0000, Chuck Lever wrote:
> > > > Confirming you are varying client-side kernels. Should the Linux
> > > > NFS client maintainers be Cc'd?
> > > Ok, agreed. Let's add them as well. NFS client maintainers any ideas
> > > on how to trackle this?
> > This is not observed with Debian backports 5.10 package
> >
> > uname -a
> > Linux madding 5.10.0-0.bpo.3-amd64 #1 SMP Debian 5.10.13-1~bpo10+1
> > (2021-02-11) x86_64 GNU/Linux
> I'm still unclear: when you say you tested a certain kernel: are you
> varying the client-side kernel version, or the server side, or both at
> once?

Client side. This seems to be an entirely client side issue.

A variety of kernels on the clients starting from 4.9 and up to 5.10 
using 4.19 servers. I have observed it on a 4.9 client versus 4.9 server 
earlier.

4.9 fails, 4.19 fails, 5.2 fails, 5.4 fails, 5.10 works.

At present the server is at 4.19.67 in all tests.

Linux jain 4.19.0-6-amd64 #1 SMP Debian 4.19.67-2+deb10u2 (2019-11-11) 
x86_64 GNU/Linux

I can set-up a couple of alternative servers during the week, but so far 
everything is pointing towards a client fs cache issue, not a server one.

Brgds,

> --b.

--
Anton R. Ivanov
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https://www.cambridgegreys.com/