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Date:   Wed, 19 Jul 2023 12:51:39 +0200
From:   Kai Tomerius <kai@tomerius.de>
To:     Theodore Ts'o <tytso@mit.edu>
Cc:     "Alan C. Assis" <acassis@gmail.com>,
        =?iso-8859-1?Q?Bj=F8rn?= Forsman <bjorn.forsman@gmail.com>,
        linux-embedded@vger.kernel.org,
        Ext4 Developers List <linux-ext4@vger.kernel.org>,
        dm-devel@redhat.com
Subject: Re: File system robustness
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> In answer to Kai's original question, the setup that was described
> should be fine --- assuming high quality hardware.

I wonder how to judge that ... it's an eMMC supposedly complying to
some JEDEC standard, so it *should* be ok.

> ... if power is cut suddenly, the data used by the Flash
> Translation Layer can be corrupted, in which case data written months
> or years ago (not just recent data) could be lost.

At least I haven't observed anything like that up to now.

But on another aspect: how about the interaction between dm-integrity
and ext4? Sure, they each have their own journal, and they're
independent layers. Is there anything that could go wrong, say a block
that can't be recovered in the dm-integrity layer, causing ext4 to run
into trouble, e.g., an I/O error that prevents ext4 from mounting?

I assume tne answer is "No", but can I be sure?

Thx
regards
Kai