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Date: Tue, 9 Jan 2024 07:16:08 +0800
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Subject: Re: nfs-utils&nfsd&autofs not supporting non-2049 TCP port numbers -
 Fwd: showmount -e with custom port number?
To: Jeff Layton <jlayton@kernel.org>,
 Cedric Blancher <cedric.blancher@gmail.com>,
 Linux NFS Mailing List <linux-nfs@vger.kernel.org>
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From: Ian Kent <raven@themaw.net>
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On 8/1/24 22:52, Jeff Layton wrote:
> On Sun, 2024-01-07 at 23:33 +0100, Cedric Blancher wrote:
>> Good evening!
>>
>> Generic issue in all of nfs-utils: None of the utils properly support
>> NFSv4 with non.standard (TCP/2049) port numbers.
>>
>> mount supports it for mounting, but does not show it for listing mounts
>> /proc/mounts does not show the port number either
> mount just gets the mount info from /proc/mounts, which absolutely does
> show a port= option when you use a different port than 2049.
>
>> showmount -e does not support a port number
> showmount talks directly to mountd so you wouldn't usually point it at
> the same port nfs is listening on.  As with most sunrpc based tools, it
> queries rpcbind in order to determine what port to talk to. If you're
> going to use stuff like showmount, then you need to ensure that rpcbind
> is reachable and that the daemons register with it properly.
>
>> autofs does not support non-2049 port numbers
>> nfsd referrals do not support setting non-2049 port numbers
> The same goes for autofs. It just calls /bin/mount. I think (but am not
> sure) that even with NFSv4, when the client can't contact the server on
> port 2049, it'll try to use rpcbind to determine the port.

That is exactly what autofs does, and always has done.


The other thing to be aware of is if you want NFSv4 only you need to tell

autofs that by using the option fstype=nfs4 so that it doesn't try to fall

back to earlier NFS versions and also tries to avoid contacting rpcbind.


Ian

>
> Alternately, if you don't want to deal with rpcbind for mounting, you
> could also specify a hardcoded "port=" mount option in your autofs maps.
>
>
>> ...
>>
>> Could you please make a concentrated effort and allow non-2049 port
>> numbers for NFSv4 mounts, in all of the lifecycle of a NFSv4 mount?
>>  From nfsd, nfsd referrals, client mount/umount, autofs
>> mount/umount+LDAP spec
>>
>> Ced
>>
>> ---------- Forwarded message ---------
>> From: Cedric Blancher <cedric.blancher@gmail.com>
>> Date: Sun, 7 Jan 2024 at 22:32
>> Subject: showmount -e with custom port number?
>> To: Linux NFS Mailing List <linux-nfs@vger.kernel.org>
>>
>>
>> Good evening!
>>
>> How can I get showmount -e to use a non-2049 TCP port number to show
>> mounts on a NFSv4 server?
>>
>> /sbin/showmount -e localhost@30000
>> clnt_create: RPC: Unknown host