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Date:   Mon, 23 May 2022 22:34:25 -0700
From:   Christoph Hellwig <hch@infradead.org>
To:     Eric Wheeler <bcache@lists.ewheeler.net>
Cc:     Coly Li <colyli@suse.de>,
        Adriano Silva <adriano_da_silva@yahoo.com.br>,
        Bcache Linux <linux-bcache@vger.kernel.org>,
        Matthias Ferdinand <bcache@mfedv.net>,
        linux-block@vger.kernel.org
Subject: Re: [RFC] Add sysctl option to drop disk flushes in bcache? (was:
 Bcache in writes direct with fsync)
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... wait.

Can someone explain what this is all about?  Devices with power fail
protection will advertise that (using VWC flag in NVMe for example) and
we will never send flushes.  So anything that explicitly disables
flushed will generally cause data corruption.