linux-kernel - Re: [PATCH RFC 4/7] md/raid10: convert read/write to use bio_submit

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [day] [month] [year] [list]

Message-ID: <fe595b6a-8653-d1aa-0ae3-af559107ac5d@huaweicloud.com>
Date: Tue, 26 Aug 2025 17:14:05 +0800
From: Yu Kuai <yukuai1@...weicloud.com>
To: Christoph Hellwig <hch@...radead.org>, Yu Kuai <yukuai1@...weicloud.com>
Cc: colyli@...nel.org, hare@...e.de, tieren@...as.com, axboe@...nel.dk,
 tj@...nel.org, josef@...icpanda.com, song@...nel.org,
 akpm@...ux-foundation.org, neil@...wn.name, linux-block@...r.kernel.org,
 linux-kernel@...r.kernel.org, cgroups@...r.kernel.org,
 linux-raid@...r.kernel.org, yi.zhang@...wei.com, yangerkun@...wei.com,
 johnny.chenyi@...wei.com, John Garry <john.g.garry@...cle.com>,
 "yukuai (C)" <yukuai3@...wei.com>
Subject: Re: [PATCH RFC 4/7] md/raid10: convert read/write to use
 bio_submit_split()

Hi,

在 2025/08/26 15:55, Christoph Hellwig 写道:
> On Tue, Aug 26, 2025 at 09:13:41AM +0800, Yu Kuai wrote:
>>> The NULL return should only happen for REQ_NOWAIT here, so maybe
>>> give R10BIO_Returned a more descriptive name?  Also please document
>>> the flag in the header.
>>
>> And also atomic write here, if bio has to split due to badblocks here.
>> The flag is refer to raid1. I can add cocument for both raid1 and raid10
>> in this case.
> 
> Umm, that's actually a red flag.  If a device guarantees atomic behavior
> it can't just fail it.  So I think REQ_ATOMIC should be disallowed
> for md raid with bad block tracking.
> 

I agree that do not look good, however, John explained while adding this
that user should retry and fallback without REQ_ATOMIC to make things
work as usual.

Thanks,
Kuai

>>
> 
> .
>