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Message-ID: <79e55dad-7f34-3723-98b0-7c2ef7be9355@redhat.com>
Date:   Mon, 1 Nov 2021 15:10:31 -0400
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Subject: Re: [PATCH 0/1] Enable inter server to server copies on a export
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To:     Bruce Fields <bfields@fieldses.org>,
        Chuck Lever III <chuck.lever@oracle.com>
Cc:     Linux NFS Mailing List <linux-nfs@vger.kernel.org>
References: <20211028144851.644018-1-steved@redhat.com>
 <20211029134534.GA19967@fieldses.org>
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 <20211029164058.GE19967@fieldses.org>
 <65b31c94-54aa-5035-546c-75eb0048ba96@redhat.com>
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 <ce34c1f2-a0ad-fcb0-99fa-a1ccea8abfd7@redhat.com>
 <20211101154046.GA12965@fieldses.org>
 <93DAB7C7-D0BB-48BA-9BFF-2821D88582EA@oracle.com>
 <20211101183916.GA14427@fieldses.org>
From:   Steve Dickson <steved@redhat.com>
In-Reply-To: <20211101183916.GA14427@fieldses.org>
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On 11/1/21 14:39, Bruce Fields wrote:
> On Mon, Nov 01, 2021 at 04:55:45PM +0000, Chuck Lever III wrote:
>>
>>> On Nov 1, 2021, at 11:40 AM, J. Bruce Fields <bfields@fieldses.org> wrote:
>>>
>>> On Mon, Nov 01, 2021 at 11:30:48AM -0400, Steve Dickson wrote:
>>>> Hey!
>>>>
>>>> On 10/29/21 15:14, J. Bruce Fields wrote:
>>>>> On Fri, Oct 29, 2021 at 01:30:36PM -0400, Steve Dickson wrote:
>>>>>> On 10/29/21 12:40, J. Bruce Fields wrote:
>>>>>>> Let's just stick with that for now, and leave it off by default until
>>>>>>> we're sure it's mature enough.  Let's not introduce new configuration to
>>>>>>> work around problems that we haven't really analyzed yet.
>>>>>> How is this going to find problems? At least with the export option
>>>>>> it is documented
>>>>>
>>>>> That sounds fixable.  We need documentation of module parameters anyway.
>>>> Yeah I just took I don't see any documentation of module
>>>> parameters anywhere for any of the modules. But by documentation
>>>> I meant having the feature in the exports(5) manpage.
>>>
>>> I think I'd probably create a new page for sysctls (this isn't the only
>>> one needing documentation), and make sure it's listed in the "SEE ALSO"
>>> section of the other man pages.
>>
>> Aren't sysctls documented under Documentation/ ?
> 
> Sorry, I meant "module parameter".  Anyway, yes, looks like both are
> listed in Documentation/admin-guide/kernel-parameters.txt.
> 
> Might be nice if these were in a man page too somewhere, but maybe
> that's not the most important thing these days.
> 
> --b.
> 
> diff --git a/Documentation/admin-guide/kernel-parameters.txt b/Documentation/admin-guide/kernel-parameters.txt
> index 91ba391f9b32..14bc3f0b0149 100644
> --- a/Documentation/admin-guide/kernel-parameters.txt
> +++ b/Documentation/admin-guide/kernel-parameters.txt
> @@ -3243,6 +3243,19 @@
>   			driver. A non-zero value sets the minimum interval
>   			in seconds between layoutstats transmissions.
>   
> +	nfsd.inter_copy_offload_enable =
> +			[NFSv4.2] When set to 1, the server will support
> +			server-to-server copies for which this server is
> +			the destination of the copy.
> +
> +	nfsd.nfsd4_ssc_umount_timeout =
> +			[NFSv4.2] When used as the destination of a
> +			server-to-server copy, knfsd temporarily mounts
> +			the source server.  It caches the mount in case
> +			it will be needed again, and discards it if not
> +			used for the number of milliseconds specified by
> +			this parameter.
> +
>   	nfsd.nfs4_disable_idmapping=
>   			[NFSv4] When set to the default of '1', the NFSv4
>   			server will return only numeric uids and gids to
> @@ -3250,6 +3263,7 @@
>   			and gids from such clients.  This is intended to ease
>   			migration from NFSv2/v3.
>   
> +
>   	nmi_backtrace.backtrace_idle [KNL]
>   			Dump stacks even of idle CPUs in response to an
>   			NMI stack-backtrace request.
> 
Interesting... I don't see these in the Linus tree I'm looking at [1]
find Documentation/ -type f  | xargs grep -i inter_copy_offload_enable

steved

[1] git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git