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Subject: Re: [PATCH] nvmet: disable direct I/O when unavailable
To:     Johannes Thumshirn <jthumshirn@suse.de>,
        Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
        Christoph Hellwig <hch@lst.de>
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        Linux NVMe Mailinglist <linux-nvme@lists.infradead.org>
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From:   Sagi Grimberg <sagi@grimberg.me>
Message-ID: <71982410-d373-a659-0c0f-8aadf06d1d96@grimberg.me>
Date:   Mon, 25 Feb 2019 13:18:10 -0800
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> Frankly, we have a ton of testing related special cases in the kernel.
> 
> This one is a) simple and small, only 10 LoC, b) far away from the fast
> path or any other place where it could have any impact on legitimate
> users and c) it prints an informal message showing you what happened.
> 
> Sorry but this is a https://xkcd.com/386/ moment.

How about we just fail it with a proper error message and let the
user set buffered_io instead of trying to get smart here...