Subject: Re: Variant symlink filesystem
To: Cole <cole@opteqint.net>
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Cc: LKML <linux-kernel@vger.kernel.org>
From: Richard Weinberger <richard@nod.at>
Message-ID: <56E327FF.1010103@nod.at>
Date: Fri, 11 Mar 2016 21:18:07 +0100
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Am 11.03.2016 um 21:15 schrieb Cole:
> On 11 March 2016 at 22:04, Richard Weinberger
> <richard.weinberger@gmail.com> wrote:
>> On Fri, Mar 11, 2016 at 5:20 PM, Cole <cole@opteqint.net> wrote:
>>> Hi,
>>>
>>> I have written a Variant Symlink Filesystem for linux, currently
>>> implemented as a kernel module:
>>> https://github.com/onslauth/varsymfs
>>> The code was written for the 3.x kernel.
>>>
>>> I would like to try to get this included into the linux kernel, and am
>>> willing to hand over all copyright and change the license as needed.
>>> As such, I would like to know what I can do to try to make this
>>> happen.
>>>
>>> If the code quality or standards are not up to par with those of the
>>> linux kernel, or code needs to change due to newer changes introduced
>>> into the kernel, please let me know and I will endeavour to make the
>>> necessary changes.
>>>
>>> Please can you also cc me in any replies, as I am not currently
>>> subscribed to the list.
>>
>> Why does this need to be a kernel filesystem and not a filesystem in
>> userspace (FUSE)?
>> Especially as you are dealing with environment variables which are
>> owned and controlled
>> by userspace.
> 
> The original implementation was in fuse, to prove the concept. However,
> because we are compiling, as well as running programs and reading/writing
> files inside of this path, the performance loss is too great. Therefore we
> moved to this solution.

Before giving up and going to kernelspace you could try improving the root cause of the performance loss. :)
Maybe the kernel interface for finding the env variables can be speeded up.

Thanks,
//richard