From: Chuck Lever <chuck.lever@oracle.com>
Subject: Re: [PATCH 2/2] Enable v4 mounts when either "nfsvers=4" or "vers=4"
	option are set (vers-02)
Date: Thu, 27 Aug 2009 13:58:57 -0400
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Cc: Linux NFS Mailing list <linux-nfs@vger.kernel.org>,
	Linux NFSv4 mailing list <nfsv4@linux-nfs.org>
To: Trond Myklebust <trond.myklebust@fys.uio.no>
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On Aug 27, 2009, at 1:48 PM, Trond Myklebust wrote:

> On Thu, 2009-08-27 at 10:14 -0400, Steve Dickson wrote:
>> I say we go with the proposed patch since its simple, architecturally
>> sound, will not cause problems down the road as long as nfs4 remains
>> a standalone file system and its done! Plus I have a patch waiting
>> in the wings that actually does make v4 the first mount that is
>> tried... making v4 the default version...
>
> I do worry that if, at some point, we do get rid of the nfs4  
> filesystem
> alias then we may find ourselves in trouble if we have a large base of
> mount programs out there that translate '-t nfs -overs=4' into '-t
> nfs4'.
>
> I think that if you want to go down this path, you should somehow  
> ensure
> that the resulting program is capable of passing '-t nfs -overs=4'  
> down
> to the kernel (perhaps a configuration file option?).

My impression was that this mount command behavior would be controlled  
with a kernel version switch in mount.nfs, much the same way that we  
already handle switching between text-based and legacy mounting.  That  
won't help with old nfs-utils on new kernels, though.

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