From: Christoph Hellwig <hch@lst.de>
To: Damien Le Moal <Damien.LeMoal@wdc.com>
Cc: Christoph Hellwig <hch@lst.de>,
Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
"sagi@grimberg.me" <sagi@grimberg.me>
Subject: Re: [PATCH V9 4/9] nvmet: add ZBD over ZNS backend support
Date: Mon, 18 Jan 2021 19:25:15 +0100 [thread overview]
Message-ID: <20210118182515.GC11082@lst.de> (raw)
In-Reply-To: <BL0PR04MB65145CE93F2AAF66158A3D71E7AA0@BL0PR04MB6514.namprd04.prod.outlook.com>
On Tue, Jan 12, 2021 at 07:52:27AM +0000, Damien Le Moal wrote:
> >
> > I do not understand the logic here, given that NVMe does not have
> > conventional zones.
>
> 512e SAS & SATA SMR drives (512B logical, 4K physical) are a big thing, and for
> these, all writes in sequential zones must be 4K aligned. So I suggested to
> Chaitanya to simply use the physical block size as the LBA size for the target
> to avoid weird IO errors that would not make sense in ZNS/NVMe world (e.g. 512B
> aligned write requests failing).
But in NVMe the physical block size exposes the atomic write unit, which
could be way too large. Іf we want to do this cleanly we need to expose
a minimum sequential zone write alignment value in the block layer.
WARNING: multiple messages have this Message-ID (diff)
From: Christoph Hellwig <hch@lst.de>
To: Damien Le Moal <Damien.LeMoal@wdc.com>
Cc: "linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
Christoph Hellwig <hch@lst.de>,
Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
"sagi@grimberg.me" <sagi@grimberg.me>
Subject: Re: [PATCH V9 4/9] nvmet: add ZBD over ZNS backend support
Date: Mon, 18 Jan 2021 19:25:15 +0100 [thread overview]
Message-ID: <20210118182515.GC11082@lst.de> (raw)
In-Reply-To: <BL0PR04MB65145CE93F2AAF66158A3D71E7AA0@BL0PR04MB6514.namprd04.prod.outlook.com>
On Tue, Jan 12, 2021 at 07:52:27AM +0000, Damien Le Moal wrote:
> >
> > I do not understand the logic here, given that NVMe does not have
> > conventional zones.
>
> 512e SAS & SATA SMR drives (512B logical, 4K physical) are a big thing, and for
> these, all writes in sequential zones must be 4K aligned. So I suggested to
> Chaitanya to simply use the physical block size as the LBA size for the target
> to avoid weird IO errors that would not make sense in ZNS/NVMe world (e.g. 512B
> aligned write requests failing).
But in NVMe the physical block size exposes the atomic write unit, which
could be way too large. Іf we want to do this cleanly we need to expose
a minimum sequential zone write alignment value in the block layer.
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Linux-nvme mailing list
Linux-nvme@lists.infradead.org
http://lists.infradead.org/mailman/listinfo/linux-nvme
next prev parent reply other threads:[~2021-01-18 18:26 UTC|newest]
Thread overview: 98+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-12 4:26 [PATCH V9 0/9] nvmet: add ZBD backend support Chaitanya Kulkarni
2021-01-12 4:26 ` Chaitanya Kulkarni
2021-01-12 4:26 ` [PATCH V9 1/9] block: export bio_add_hw_pages() Chaitanya Kulkarni
2021-01-12 4:26 ` Chaitanya Kulkarni
2021-01-12 5:40 ` Damien Le Moal
2021-01-12 5:40 ` Damien Le Moal
2021-01-12 7:24 ` Christoph Hellwig
2021-01-12 7:24 ` Christoph Hellwig
2021-01-13 1:20 ` Chaitanya Kulkarni
2021-01-13 1:20 ` Chaitanya Kulkarni
2021-01-12 4:26 ` [PATCH V9 2/9] nvmet: add lba to sect conversion helpers Chaitanya Kulkarni
2021-01-12 4:26 ` Chaitanya Kulkarni
2021-01-12 5:08 ` Damien Le Moal
2021-01-12 5:08 ` Damien Le Moal
2021-01-18 18:19 ` Christoph Hellwig
2021-01-18 18:19 ` Christoph Hellwig
2021-01-12 4:26 ` [PATCH V9 3/9] nvmet: add NVM command set identifier support Chaitanya Kulkarni
2021-01-12 4:26 ` Chaitanya Kulkarni
2021-01-12 7:27 ` Christoph Hellwig
2021-01-12 7:27 ` Christoph Hellwig
2021-01-13 4:16 ` Chaitanya Kulkarni
2021-01-13 4:16 ` Chaitanya Kulkarni
2021-01-18 18:21 ` Christoph Hellwig
2021-01-18 18:21 ` Christoph Hellwig
2021-01-12 4:26 ` [PATCH V9 4/9] nvmet: add ZBD over ZNS backend support Chaitanya Kulkarni
2021-01-12 4:26 ` Chaitanya Kulkarni
2021-01-12 5:32 ` Damien Le Moal
2021-01-12 5:32 ` Damien Le Moal
2021-01-12 6:11 ` Chaitanya Kulkarni
2021-01-12 6:11 ` Chaitanya Kulkarni
2021-01-12 6:31 ` Damien Le Moal
2021-01-12 6:31 ` Damien Le Moal
2021-01-12 7:48 ` Christoph Hellwig
2021-01-12 7:48 ` Christoph Hellwig
2021-01-12 7:52 ` Damien Le Moal
2021-01-12 7:52 ` Damien Le Moal
2021-01-18 18:25 ` Christoph Hellwig [this message]
2021-01-18 18:25 ` Christoph Hellwig
2021-01-19 0:02 ` Damien Le Moal
2021-01-19 0:02 ` Damien Le Moal
2021-01-19 4:28 ` Damien Le Moal
2021-01-19 4:28 ` Damien Le Moal
2021-01-19 6:15 ` hch
2021-01-19 6:15 ` hch
2021-01-13 4:57 ` Chaitanya Kulkarni
2021-01-13 4:57 ` Chaitanya Kulkarni
2021-01-18 18:27 ` Christoph Hellwig
2021-01-18 18:27 ` Christoph Hellwig
2021-01-12 4:26 ` [PATCH V9 5/9] nvmet: add bio get helper for different backends Chaitanya Kulkarni
2021-01-12 4:26 ` Chaitanya Kulkarni
2021-01-12 5:37 ` Damien Le Moal
2021-01-12 5:37 ` Damien Le Moal
2021-01-12 5:55 ` Chaitanya Kulkarni
2021-01-12 5:55 ` Chaitanya Kulkarni
2021-01-12 7:33 ` Christoph Hellwig
2021-01-12 7:33 ` Christoph Hellwig
2021-01-13 5:03 ` Chaitanya Kulkarni
2021-01-13 5:03 ` Chaitanya Kulkarni
2021-01-18 18:28 ` Christoph Hellwig
2021-01-18 18:28 ` Christoph Hellwig
2021-01-19 4:57 ` Chaitanya Kulkarni
2021-01-19 4:57 ` Chaitanya Kulkarni
2021-01-12 4:26 ` [PATCH V9 6/9] nvmet: add bio init " Chaitanya Kulkarni
2021-01-12 4:26 ` Chaitanya Kulkarni
2021-01-12 5:40 ` Damien Le Moal
2021-01-12 5:40 ` Damien Le Moal
2021-01-12 5:57 ` Chaitanya Kulkarni
2021-01-12 5:57 ` Chaitanya Kulkarni
2021-01-12 6:27 ` Damien Le Moal
2021-01-12 6:27 ` Damien Le Moal
2021-01-12 7:33 ` Christoph Hellwig
2021-01-12 7:33 ` Christoph Hellwig
2021-01-13 5:04 ` Chaitanya Kulkarni
2021-01-13 5:04 ` Chaitanya Kulkarni
2021-01-18 18:33 ` Christoph Hellwig
2021-01-18 18:33 ` Christoph Hellwig
2021-01-12 4:26 ` [PATCH V9 7/9] nvmet: add bio put " Chaitanya Kulkarni
2021-01-12 4:26 ` Chaitanya Kulkarni
2021-01-12 4:26 ` [PATCH V9 8/9] nvmet: add common I/O length check helper Chaitanya Kulkarni
2021-01-12 4:26 ` Chaitanya Kulkarni
2021-01-12 7:35 ` Christoph Hellwig
2021-01-12 7:35 ` Christoph Hellwig
2021-01-13 5:07 ` Chaitanya Kulkarni
2021-01-13 5:07 ` Chaitanya Kulkarni
2021-01-18 18:34 ` Christoph Hellwig
2021-01-18 18:34 ` Christoph Hellwig
2021-01-12 4:26 ` [PATCH V9 9/9] nvmet: call nvmet_bio_done() for zone append Chaitanya Kulkarni
2021-01-12 4:26 ` Chaitanya Kulkarni
2021-01-12 7:36 ` Christoph Hellwig
2021-01-12 7:36 ` Christoph Hellwig
2021-01-13 5:13 ` Chaitanya Kulkarni
2021-01-13 5:13 ` Chaitanya Kulkarni
2021-01-12 6:12 ` [PATCH V9 0/9] nvmet: add ZBD backend support Chaitanya Kulkarni
2021-01-12 6:12 ` Chaitanya Kulkarni
2021-02-10 22:42 ` Chaitanya Kulkarni
2021-02-10 22:42 ` Chaitanya Kulkarni
2021-02-11 7:20 ` hch
2021-02-11 7:20 ` hch
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