Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Message-ID: <d6a6b309-285a-16ff-6563-1b21380b3a85@suse.de>
Date:   Fri, 5 May 2023 07:28:17 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101
 Thunderbird/102.10.1
Subject: Re: [RFC PATCH 00/11] Rust null block driver
Content-Language: en-US
To:     Bart Van Assche <bvanassche@acm.org>,
        Andreas Hindborg <nmi@metaspace.dk>
Cc:     Jens Axboe <axboe@kernel.dk>, Christoph Hellwig <hch@lst.de>,
        Keith Busch <kbusch@kernel.org>,
        Damien Le Moal <Damien.LeMoal@wdc.com>,
        lsf-pc@lists.linux-foundation.org, rust-for-linux@vger.kernel.org,
        linux-block@vger.kernel.org, Matthew Wilcox <willy@infradead.org>,
        Miguel Ojeda <ojeda@kernel.org>,
        Alex Gaynor <alex.gaynor@gmail.com>,
        Wedson Almeida Filho <wedsonaf@gmail.com>,
        Boqun Feng <boqun.feng@gmail.com>, Gary Guo <gary@garyguo.net>,
        =?UTF-8?Q?Bj=c3=b6rn_Roy_Baron?= <bjorn3_gh@protonmail.com>,
        Benno Lossin <benno.lossin@proton.me>,
        open list <linux-kernel@vger.kernel.org>, gost.dev@samsung.com
References: <20230503090708.2524310-1-nmi@metaspace.dk>
 <da7b815d-3da8-38e5-9b25-b9cfb6878293@acm.org> <87jzxot0jk.fsf@metaspace.dk>
 <b9a1c1b2-3baa-2cad-31ae-8b14e4ee5709@acm.org>
From:   Hannes Reinecke <hare@suse.de>
In-Reply-To: <b9a1c1b2-3baa-2cad-31ae-8b14e4ee5709@acm.org>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 8bit
Precedence: bulk

On 5/4/23 20:36, Bart Van Assche wrote:
> On 5/4/23 11:15, Andreas Hindborg wrote:
>> If it is still unclear to you why this effort was started, please do let
>> me know and I shall try to clarify further :)
> 
> It seems like I was too polite in my previous email. What I meant is that
> rewriting code is useful if it provides a clear advantage to the users of
> a driver. For null_blk, the users are kernel developers. The code that has
> been posted is the start of a rewrite of the null_blk driver. The benefits
> of this rewrite (making low-level memory errors less likely) do not 
> outweigh
> the risks that this effort will introduce functional or performance 
> regressions.
> 
I have to disagree here. While the null_blk driver in itself is 
certainly not _that_ useful, it does provide a good sounding board if 
all the design principles of the linux block layer can be adequately 
expressed in Rust.

And by posting this driver you just proved that, and we all have a 
better understanding what would be needed to convert old or create new 
drivers.

But I guess we'll have a longer discussion at LSF :-)

Cheers,

Hannes
-- 
Dr. Hannes Reinecke                Kernel Storage Architect
hare@suse.de                              +49 911 74053 688
SUSE Software Solutions GmbH, Maxfeldstr. 5, 90409 Nürnberg
HRB 36809 (AG Nürnberg), Geschäftsführer: Ivo Totev, Andrew
Myers, Andrew McDonald, Martje Boudien Moerman