Date:   Fri, 15 Mar 2019 12:01:05 -0700
From:   Jakub Kicinski <jakub.kicinski@netronome.com>
To:     Trond Myklebust <trond.myklebust@hammerspace.com>
Cc:     linux-nfs@vger.kernel.org,
        Anna Schumaker <anna.schumaker@netapp.com>
Subject: Re: mount.nfs: Protocol error after upgrade to linux/master
Message-ID: <20190315120105.5541ad46@cakuba.netronome.com>
In-Reply-To: <20190315110555.0807d015@cakuba.netronome.com>
References: <20190315110555.0807d015@cakuba.netronome.com>
Organization: Netronome Systems, Ltd.
MIME-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Sender: linux-nfs-owner@vger.kernel.org
Precedence: bulk

On Fri, 15 Mar 2019 11:05:55 -0700, Jakub Kicinski wrote:
> Hi,
> 
> I just upgraded from:
> 
> commit a3b1933d34d5bb26d7503752e3528315a9e28339 (net)
> Merge: c6873d18cb4a 24319258660a
> Author: David S. Miller <davem@davemloft.net>
> Date:   Mon Mar 11 16:22:49 2019 -0700
> 
> to
> 
> commit 3b319ee220a8795406852a897299dbdfc1b09911
> Merge: 9352ca585b2a b6e88119f1ed
> Author: Linus Torvalds <torvalds@linux-foundation.org>
> Date:   Thu Mar 14 10:48:14 2019 -0700
> 
> and I'm seeing:
> 
> # mount /home/
> mount.nfs: Protocol error
> 
> No errors in dmesg, please let me know if it's a known problem or what
> other info could be of use.

Hm.. I tried to bisect but reverting to that commit doesn't help.  

Looks like the server responds with:

  ICMP parameter problem - octet 22, length 80

pointing at some IP options (type 134)...