MIME-Version: 1.0
From:   Marc Dionne <marc.c.dionne@gmail.com>
Date:   Thu, 14 Mar 2019 16:32:17 -0300
Message-ID: <CAB9dFduu5_UDP_G-QXiYCYMPoytMOJQJ5OxXB02rGtbfMXO5BQ@mail.gmail.com>
Subject: Hanging nfs mount - bisected to merge commit 06b5fc3ad94e
To:     linux-nfs@vger.kernel.org,
        Trond Myklebust <trond.myklebust@hammerspace.com>,
        Anna Schumaker <anna.schumaker@netapp.com>
Content-Type: text/plain; charset="UTF-8"
Sender: linux-nfs-owner@vger.kernel.org
Precedence: bulk

I have an odd nfs issue with the current mainline kernel, where a
mount hangs and eventually times out when attempting a mount with nfs
version 4 and that is not offered by the server.  With prior kernels
it fails quickly with "mount.nfs: Protocol not supported".

To reproduce, I have rpc.nfsd start with "-N 4", then try to mount
something local with -o nfsvers=4, for instance:
  $ mount -t nfs -o nfsvers=4 localhost:/s /mnt

I bisected the behaviour down to commit 06b5fc3ad94e ("Merge tag
'nfs-rdma-for-5.1-1' of
git://git.linux-nfs.org/projects/anna/linux-nfs").  It's a merge
commit, but one that has quite a bit of conflict resolution.  I also
verified that the 2 parent commits of the merge (5085607d2091 and
2c94b8eca1a2) both behave as old kernels did.

Thanks
Marc