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 01:22 PM, Chuck Lever wrote:
>>> 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...
> 
> Nope, we're proposing doing the simple method in the kernel instead of
> in the mount command.
> 
My apologize then... I was misinterpreting what you guys were suggesting..
(email sometimes causes that... :-\ )

I don't think the -o v4 translation will be as easy as a 
"simple method in the kernel" and it surely will not be as simple 
and unintrusive as the patch I'm proposing.... Here is why... 

>From an Linux  architecture standpoint the mount command *always*
know what file system its mounting. There not been a precedence set
where mount, mounts one file system which turns into mounting a
different file system. Meaning there is no kernel support for
nfs_get_sb() to all of sudden decide to roll back the system call
and jump into nfs4_get_sb() (or vice a versa depending on which is the 
default).

Of course we could set that precedence and quit frank we would have
to. I'm not totally against that, although other in the kernel community
might be...  

But there is no way that re-architecturing of kernel will as simple
and straightforward as following the Linux standard architecture of
having mount, mount the correct file system.

steved.