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From:   OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
To:     Javier Martinez Canillas <javierm@redhat.com>
Cc:     linux-kernel@vger.kernel.org,
        Lennart Poettering <lennart@poettering.net>,
        Colin Walters <walters@verbum.org>,
        Peter Jones <pjones@redhat.com>,
        Alberto Ruiz <aruiz@redhat.com>,
        Christian Kellner <ckellner@redhat.com>,
        Chung-Chiang Cheng <cccheng@synology.com>,
        Muhammad Usama Anjum <usama.anjum@collabora.com>,
        Alexander Larsson <alexl@redhat.com>
Subject: Re: [PATCH v4 3/4] fat: add renameat2 RENAME_EXCHANGE flag support
References: <20220601173204.1372569-1-javierm@redhat.com>
        <20220601173204.1372569-4-javierm@redhat.com>
Date:   Wed, 08 Jun 2022 23:33:54 +0900
In-Reply-To: <20220601173204.1372569-4-javierm@redhat.com> (Javier Martinez
        Canillas's message of "Wed, 1 Jun 2022 19:32:03 +0200")
Message-ID: <87h74vteb1.fsf@mail.parknet.co.jp>
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Javier Martinez Canillas <javierm@redhat.com> writes:

> +	/* update ".." directory entry info */
> +	if (old_dotdot_de) {
> +		err = vfat_update_dotdot_de(new_dir, old_inode, old_dotdot_bh,
> +					    old_dotdot_de);
> +		if (err)
> +			goto error_old_dotdot;
> +		drop_nlink(old_dir);
> +		inc_nlink(new_dir);
> +	}
> +
> +	if (new_dotdot_de) {
> +		err = vfat_update_dotdot_de(old_dir, new_inode, new_dotdot_bh,
> +					    new_dotdot_de);
> +		if (err)
> +			goto error_new_dotdot;
> +		drop_nlink(new_dir);
> +		inc_nlink(old_dir);
> +	}

Probably, we should change the nlink only if both of dotdot update are
succeed and different file type. Otherwise, we would have to revert the
nlink change on error path (and can remove unnecessary update as bonus).

Thanks.
-- 
OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>