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Subject: Re: [PATCH 0/3] Enable the setting of a kernel module parameter from
 nfs.conf
To:     Trond Myklebust <trondmy@hammerspace.com>,
        "ajmitchell@redhat.com" <ajmitchell@redhat.com>,
        "chuck.lever@oracle.com" <chuck.lever@oracle.com>
Cc:     "linux-nfs@vger.kernel.org" <linux-nfs@vger.kernel.org>
References: <20210414181040.7108-1-steved@redhat.com>
 <AA442C15-5ED3-4DF5-B23A-9C63429B64BE@oracle.com>
 <5adff402-5636-3153-2d9f-d912d83038fc@RedHat.com>
 <366FA143-AB3E-4320-8329-7EA247ADB22B@oracle.com>
 <bf7a7563989477a30490e3982665f90bdcfa1016.camel@hammerspace.com>
 <ee4bff1c4705ee61f04377bf024fe4bae540d858.camel@hammerspace.com>
From:   Steve Dickson <SteveD@RedHat.com>
Message-ID: <a5b134df-1e62-b877-3eeb-79ab008df636@RedHat.com>
Date:   Sat, 17 Apr 2021 12:33:41 -0400
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Hey!

On 4/15/21 8:40 PM, Trond Myklebust wrote:
> Here is a skeleton example:
> 
> [root@leira rules.d]# cat /etc/udev/rules.d/50-nfs4.rules 
> ACTION=="add" KERNEL=="nfs_client" ATTR{identifier}=="(null)" PROGRAM="/usr/sbin/nfs4_uuid" ATTR{identifier}="%c"
> 
> [root@leira rules.d]# cat /usr/sbin/nfs4_uuid 
> #!/bin/bash
> #
> if [ ! -f /etc/nfs4_uuid ]
> then
> 	uuid="$(uuidgen -r)"
> 	echo -n ${uuid} > /etc/nfs4_uuid
> else
> 	uuid="$(cat /etc/nfs4_uuid)"
> fi
> echo ${uuid}
> 
> 
> Obviously, the /usr/sbin/nfs4_uuid would need to be fleshed out a
> little more to ensure that the file /etc/nfs4_uuid actually contains a
> uuid in the right format, but you get the gist...
> 
> With the above additions, I end up with a repeatable
> 
> [root@leira rules.d]# modprobe nfs4
> [root@leira rules.d]# cat /sys/fs/nfs/net/nfs_client/identifier 
> 7f9f211b-0253-4ef8-a970-b1b0f600af02
> [root@leira rules.d]# cat /etc/nfs4_uuid 
> 7f9f211b-0253-4ef8-a970-b1b0f600af02

I see that this example does populate nfs_client/identifier and
I'm sure we could beef up the mechanism but the may question
is this.... 

How does populating nfs_client/identifier via udev
actually setting the nfs4_unique_id parameter which is used to set
the unique id? I look and i've must have missed it...

If the answer is we need to change the client to look a
the nfs_client/identifier... then we should get rid of the
nfs4_unique_id param all together... 

steved.