Re: [PATCH 2/2] Enable v4 mounts when either "nfsvers=4" or "vers=4" option are set (vers-02)

[Steve Dickson <SteveD@redhat.com>]

On 08/26/2009 12:35 PM, Chuck Lever wrote: 
> On Aug 26, 2009, at 11:07 AM, Steve Dickson wrote:
>>> I think that would be a much better approach.  If nfs4 goes away
>>> someday, for example, it will be completely transparent to the mount
>>> command if we've already pushed "-t nfs, vers=4" conversion into the
>>> kernel.
>> Well when/if that day comes, we can easily pull the patches from the
>> mount
>> command.
> 
> You know it's never that easy.  The mount command has to keep legacy
> logic for older kernels.  I'm just saying that the less the mount
> command has to worry about what kernel version is running, the cleaner
> the mount command will be.
Well with this patch, since we are only concentrating on text mounts,
we are already breaking with the tradition of keeping legacy logic... 
And again as long as the nfs4 file system exists this approach will work... 
 
> 
>>> We are pushing all of the details of NFS mounting into the kernel
>>> anyway, over time.
>> Which I've never been a fan of... Again it's much easier change user
>> level code (and more people can do it) than kernel code... especially
>> with things of this nature...
> 
> People can continue to change the mount command all they want.  In fact
> the user space text-based option parsing code is pretty darn flexible as
> it is now.
Yes... the user space parsing code is very well written... 

> 
> I don't think we're denying that your proposal is expedient.  The
> question I think is where we want to be in the long run, 
NFS v4 as the default protocol version followed by NFS V4.1 becoming the
default protocol version. 

> and if your proposed method to handle -t nfs -o vers=4 will make 
> it more complicated to get there.
No. I'm proposing a simple shorthand patch that will make mounting nfs4
file systems easier in hope of moving the technology forward by making 
it more accessible... What I believe you are proposing is architecture
change to hide the fact nfs and nfs4 are separate file systems... 

But in the end, if we do the simple shorthand patch (making the technology 
available today) or the major architecture change (making the technology
available the distant future) with both approaches 'mount -o v4' 
will do the exact same thing... 

I for moving the technology today... 

steved.