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Date:   Tue, 18 Aug 2020 20:13:08 +0200
From:   Javier Gonzalez <javier@javigon.com>
To:     Keith Busch <kbusch@kernel.org>
Cc:     Christoph Hellwig <hch@lst.de>,
        Kanchan Joshi <joshi.k@samsung.com>, Damien.LeMoal@wdc.com,
        axboe@kernel.dk, sagi@grimberg.me, linux-nvme@lists.infradead.org,
        linux-kernel@vger.kernel.org, johannes.thumshirn@wdc.com,
        Nitesh Shetty <nj.shetty@samsung.com>,
        SelvaKumar S <selvakuma.s1@samsung.com>
Subject: Re: [PATCH 2/2] nvme: add emulation for zone-append
Message-ID: <20200818181308.7g3xom4lxwuoogev@MacBook-Pro.localdomain>
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 <20200818052936.10995-3-joshi.k@samsung.com>
 <20200818071249.GB2544@lst.de>
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 <20200818165811.GA2979311@dhcp-10-100-145-180.wdl.wdc.com>
 <20200818172912.e54klrofz3tfhxhj@MacBook-Pro.localdomain>
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On 18.08.2020 10:39, Keith Busch wrote:
>On Tue, Aug 18, 2020 at 07:29:12PM +0200, Javier Gonzalez wrote:
>> On 18.08.2020 09:58, Keith Busch wrote:
>> > On Tue, Aug 18, 2020 at 11:50:33AM +0200, Javier Gonzalez wrote:
>> > > a number of customers are requiring the use of normal writes, which we
>> > > want to support.
>> >
>> > A device that supports append is completely usable for those customers,
>> > too. There's no need to create divergence in this driver.
>>
>> Not really. You know as well as I do that some features are disabled for
>> a particular SSD model on customer requirements. Generic models
>> implementing append can submit both I/Os, but those that remove append
>> are left out.
>
>You are only supporting my point: if your device supports append, you
>get to work in every ZNS use case, otherwise you only get to work in a
>subset.

There are several devices. Some of them enable append and some do not. I
would like to support the later too.