linux-kernel - Re: [RFC PATCH 2/3] fat: add renameat2 RENAME

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Message-ID: <6b5e584a-6d08-afc5-d503-7ef830ee1165@redhat.com>
Date:   Mon, 23 May 2022 17:35:41 +0200
From:   Javier Martinez Canillas <javierm@...hat.com>
To:     OGAWA Hirofumi <hirofumi@...l.parknet.co.jp>
Cc:     linux-kernel@...r.kernel.org, Colin Walters <walters@...bum.org>,
        Peter Jones <pjones@...hat.com>,
        Alexander Larsson <alexl@...hat.com>,
        Alberto Ruiz <aruiz@...hat.com>,
        Christian Kellner <ckellner@...hat.com>,
        Lennart Poettering <lennart@...ttering.net>,
        Chung-Chiang Cheng <cccheng@...ology.com>
Subject: Re: [RFC PATCH 2/3] fat: add renameat2 RENAME_EXCHANGE flag support

Hello OGAWA,

Thanks a lot for your feedback.

On 5/22/22 19:42, OGAWA Hirofumi wrote:
> Javier Martinez Canillas <javierm@...hat.com> writes:
> 
>> The renameat2 RENAME_EXCHANGE flag allows to atomically exchange two paths
>> but is currently not supported by the Linux vfat filesystem driver.
>>
>> Add a vfat_rename_exchange() helper function that implements this support.
>>
>> The super block lock is acquired during the operation to ensure atomicity,
>> and in the error path actions made are reversed also with the mutex held,
>> making the whole operation transactional.
> 
> I'm not fully reviewed yet though (write order and race), basically
> looks like good.
> 

Thanks for looking at the patch. I agree with all your remarks and will
address them in v2. Please let me know once you have reviewed if is OK
from a write order and race point of view.

-- 
Best regards,

Javier Martinez Canillas
Linux Engineering
Red Hat