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From:   Richard Weinberger <richard.weinberger@gmail.com>
Date:   Wed, 21 Aug 2019 23:37:30 +0200
Message-ID: <CAFLxGvxr2UMeVa29M9pjLtWMFPz7w6udRV38CRxEF1moyA9_Rw@mail.gmail.com>
Subject: Re: erofs: Question on unused fields in on-disk structs
To:     Gao Xiang <hsiangkao@aol.com>
Cc:     Richard Weinberger <richard@nod.at>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        linux-erofs@lists.ozlabs.org,
        linux-kernel <linux-kernel@vger.kernel.org>
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Gao Xiang,

On Mon, Aug 19, 2019 at 10:45 PM Gao Xiang via Linux-erofs
<linux-erofs@lists.ozlabs.org> wrote:
> > struct erofs_super_block has "checksum" and "features" fields,
> > but they are not used in the source.
> > What is the plan for these?
>
> Yes, both will be used laterly (features is used for compatible
> features, we already have some incompatible features in 5.3).

Good. :-)
I suggest to check the fields being 0 right now.
Otherwise you are in danger that they get burned if an mkfs.erofs does not
initialize the fields.

-- 
Thanks,
//richard