Date: Mon, 17 Feb 2014 17:19:00 -0500
From: "J. Bruce Fields" <bfields@fieldses.org>
To: Weng Meiling <wengmeiling.weng@huawei.com>
Cc: Stanislav Kinsbursky <skinsbursky@parallels.com>, greg@kroah.com,
        linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org,
        devel@openvz.org
Subject: Re: [PATCH] nfsd: check passed socket's net matches NFSd
 superblock's one
Message-ID: <20140217221900.GA8401@fieldses.org>
References: <20131230142339.16166.28243.stgit@localhost.localdomain>
 <20140103222226.GD5164@fieldses.org>
 <52FEC818.7030604@huawei.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
In-Reply-To: <52FEC818.7030604@huawei.com>
Sender: linux-nfs-owner@vger.kernel.org

On Sat, Feb 15, 2014 at 09:51:20AM +0800, Weng Meiling wrote:
> Hi Bruce,
> 
> The upstream has merged your git tree for-3.14, but there is no this patch?
> Do you forget this patch?

Apologies, I'm not sure what happened.

Looking back at it....  The patch causes all my pynfs reboot recovery
tests to fail.  They're just doing a "systemctl restart
nfs-server.service", and "systemctl status nfs-server.service" shows in
part

	ExecStart=/usr/sbin/rpc.nfsd $RPCNFSDARGS $RPCNFSDCOUNT (code=exited, status=1/FAILURE)

So the patch is causing rpc.nfsd to fail?  No network namespaces should
be involved.  

I haven't investigated any further.

--b.

> 
> Thanks!
> Weng Meiling
> 
> 
> On 2014/1/4 6:22, J. Bruce Fields wrote:
> > On Mon, Dec 30, 2013 at 05:23:59PM +0300, Stanislav Kinsbursky wrote:
> >> There could be a case, when NFSd file system is mounted in network, different
> >> to socket's one, like below:
> >>
> >> "ip netns exec" creates new network and mount namespace, which duplicates NFSd
> >> mount point, created in init_net context. And thus NFS server stop in nested
> >> network context leads to RPCBIND client destruction in init_net.
> >> Then, on NFSd start in nested network context, rpc.nfsd process creates socket
> >> in nested net and passes it into "write_ports", which leads to RPCBIND sockets
> >> creation in init_net context because of the same reason (NFSd monut point was
> >> created in init_net context). An attempt to register passed socket in nested
> >> net leads to panic, because no RPCBIND client present in nexted network
> >> namespace.
> > 
> > So it's the attempt to use a NULL ->rpcb_local_clnt4?
> > 
> > Interesting, thanks--applying with a minor fix to logged message.
> > 
> > --b.
> > 
> 
> 
>