Message-ID: <4BB61F19.2000403@oracle.com>
Date: Fri, 02 Apr 2010 12:45:13 -0400
From: Chuck Lever <chuck.lever@oracle.com>
To: Tom Tucker <tom@opengridcomputing.com>
CC: "J. Bruce Fields" <bfields@fieldses.org>,
        Linux NFS Mailing List <linux-nfs@vger.kernel.org>,
        "linux-rdma@vger.kernel.org" <linux-rdma@vger.kernel.org>
Subject: Re: [PATCH,RFC] nfsd: Make INET6 transport creation failure an informational
 message
References: <4BB522CF.60503@opengridcomputing.com>
In-Reply-To: <4BB522CF.60503@opengridcomputing.com>
Content-Type: text/plain; charset=utf-8; format=flowed
Sender: linux-nfs-owner@vger.kernel.org
MIME-Version: 1.0

Hi Tom-

On 04/01/2010 06:48 PM, Tom Tucker wrote:
> Hi Bruce/Chuck,
>
> RDMA Transports are currently broken in 2.6.34 because they don't have a
> V4ONLY setsockopt. So what happens is that when write_ports attempts to
> create the PF_INET6 transport it fails because the port is already in
> use. There is discussion on linux-rdma about how to fix this, but in the
> interim and perhaps indefinitely, I propose the following:
>
> Tom
>
> nfsd: Make INET6 transport creation failure an informational message
>
> The write_ports code will fail both the INET4 and INET6 transport
> creation if
> the transport returns an error when PF_INET6 is specified. Some transports
> that do not support INET6 return an error other than EAFNOSUPPORT.

That's the real bug.  Any reason the RDMA RPC transport can't return 
EAFNOSUPPORT in this case?

> We
> should
> allow communication on INET4 even if INET6 is not yet supported or fails
> for some reason.

Yes, that's why EAFNOSUPPORT is ignored in __write_ports().  People 
complain when they see messages like this, even if the result is a 
working configuration.

> Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
> ---
>
> fs/nfsd/nfsctl.c | 6 ++++--
> 1 files changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
> index 0f0e77f..934b624 100644
> --- a/fs/nfsd/nfsctl.c
> +++ b/fs/nfsd/nfsctl.c
> @@ -1008,8 +1008,10 @@ static ssize_t __write_ports_addxprt(char *buf)
>
> err = svc_create_xprt(nfsd_serv, transport,
> PF_INET6, port, SVC_SOCK_ANONYMOUS);
> - if (err < 0 && err != -EAFNOSUPPORT)
> - goto out_close;
> + if (err < 0)
> + printk(KERN_INFO "nfsd: Error creating PF_INET6 listener "
> + "for transport '%s'\n", transport);
> +
> return 0;
> out_close:
> xprt = svc_find_xprt(nfsd_serv, transport, PF_INET, port);
>


-- 
chuck[dot]lever[at]oracle[dot]com