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Message-ID: <f2f29f97-5994-37f9-c922-31158c1c1b9a@opensource.wdc.com>
Date:   Thu, 28 Jul 2022 10:52:22 +0900
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Subject: Re: [PATCH v8 00/11] support non power of 2 zoned device
Content-Language: en-US
To:     Bart Van Assche <bvanassche@acm.org>,
        Pankaj Raghav <p.raghav@samsung.com>, hch@lst.de,
        axboe@kernel.dk, snitzer@kernel.org, Johannes.Thumshirn@wdc.com
Cc:     matias.bjorling@wdc.com, gost.dev@samsung.com,
        linux-kernel@vger.kernel.org, hare@suse.de,
        linux-block@vger.kernel.org, pankydev8@gmail.com,
        jaegeuk@kernel.org, dm-devel@redhat.com,
        linux-nvme@lists.infradead.org
References: <CGME20220727162246eucas1p1a758799f13d36ba99d30bf92cc5e2754@eucas1p1.samsung.com>
 <20220727162245.209794-1-p.raghav@samsung.com>
 <51255650-ddc2-4f3d-52e5-14007b9ff538@acm.org>
From:   Damien Le Moal <damien.lemoal@opensource.wdc.com>
Organization: Western Digital Research
In-Reply-To: <51255650-ddc2-4f3d-52e5-14007b9ff538@acm.org>
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On 7/28/22 08:19, Bart Van Assche wrote:
> On 7/27/22 09:22, Pankaj Raghav wrote:
>> This series adds support to npo2 zoned devices in the block and nvme
>> layer and a new **dm target** is added: dm-po2z-target. This new
>> target will be initially used for filesystems such as btrfs and
>> f2fs that does not have native npo2 zone support.
> 
> Should any SCSI changes be included in this patch series? From sd_zbc.c:
> 
> 	if (!is_power_of_2(zone_blocks)) {
> 		sd_printk(KERN_ERR, sdkp,
> 			  "Zone size %llu is not a power of two.\n",
> 			  zone_blocks);
> 		return -EINVAL;
> 	}

There are no non-power of 2 SMR drives on the market and no plans to have
any as far as I know. Users want power of 2 zone size. So I think it is
better to leave sd_zbc & scsi_debug as is for now.

> 
> Thanks,
> 
> Bart.


-- 
Damien Le Moal
Western Digital Research