From: Logan Gunthorpe <logang@deltatee.com>
To: Sagi Grimberg <sagi@grimberg.me>,
Stephen Bates <sbates@raithlin.com>,
Hannes Reinecke <hare@suse.de>,
"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
"linux-nvme@lists.infradead.org" <linux-nvme@lists.infradead.org>,
"linux-block@vger.kernel.org" <linux-block@vger.kernel.org>,
"linux-fsdevel@vger.kernel.org" <linux-fsdevel@vger.kernel.org>
Cc: Christoph Hellwig <hch@lst.de>, Keith Busch <kbusch@kernel.org>,
Jens Axboe <axboe@fb.com>,
Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
Max Gurtovoy <maxg@mellanox.com>
Subject: Re: [PATCH v6 00/16] nvmet: add target passthru commands support
Date: Mon, 29 Jul 2019 10:17:10 -0600 [thread overview]
Message-ID: <f4e551fe-f081-26d2-5a6a-46f826640189@deltatee.com> (raw)
In-Reply-To: <322df1b1-dbba-2018-44da-c108336f8d55@grimberg.me>
On 2019-07-29 10:15 a.m., Sagi Grimberg wrote:
>
>>> This is different from multipath on say a multi-controller PCI device
>>> and trying to expose both those controllers through passthru. this is
>>> where the problems we are discussing come up.
>>
>> I *think* there is some confusion. I *think* Sagi is talking about network multi-path (i.e. the ability for the host to connect to a controller on the target via two different network paths that fail-over as needed). I *think* Logan is talking about multi-port PCIe NVMe devices that allow namespaces to be accessed via more than one controller over PCIe (dual-port NVMe SSDs being the most obvious example of this today).
>
> Yes, I was referring to fabrics multipathing which is somewhat
> orthogonal to the backend pci multipathing (unless I'm missing
> something).
Yes, so if we focus on the fabrics multipathing, the only issue I see is
that only one controller can be connected to a passthru target (I
believe this was at your request) so two paths simply cannot exist to
begin with. I can easily remove that restriction.
Logan
prev parent reply other threads:[~2019-07-29 16:17 UTC|newest]
Thread overview: 61+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-07-25 17:23 [PATCH v6 00/16] nvmet: add target passthru commands support Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 01/16] chardev: factor out cdev_lookup() helper Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 02/16] chardev: introduce cdev_get_by_path() Logan Gunthorpe
2019-07-25 17:40 ` Greg Kroah-Hartman
2019-07-25 17:53 ` Logan Gunthorpe
2019-07-25 17:58 ` Matthew Wilcox
2019-07-25 18:08 ` Logan Gunthorpe
2019-07-25 18:08 ` Greg Kroah-Hartman
2019-07-25 18:14 ` Logan Gunthorpe
2019-07-25 18:27 ` Greg Kroah-Hartman
2019-07-25 18:36 ` Logan Gunthorpe
2019-07-25 19:02 ` Sagi Grimberg
2019-07-25 19:34 ` Greg Kroah-Hartman
2019-07-25 19:37 ` Sagi Grimberg
2019-07-25 19:43 ` Greg Kroah-Hartman
2019-07-25 19:45 ` Sagi Grimberg
2019-07-25 19:43 ` Sagi Grimberg
2019-07-25 19:41 ` Logan Gunthorpe
2019-07-25 19:00 ` Matthew Wilcox
2019-07-25 19:05 ` Sagi Grimberg
2019-07-25 19:11 ` Matthew Wilcox
2019-07-25 19:24 ` Logan Gunthorpe
2019-07-25 19:26 ` Matthew Wilcox
2019-07-25 19:31 ` Logan Gunthorpe
2019-07-25 23:55 ` Al Viro
2019-07-26 4:29 ` Sagi Grimberg
2019-07-26 7:13 ` Greg Kroah-Hartman
2019-07-26 15:46 ` Logan Gunthorpe
2019-07-25 19:31 ` Sagi Grimberg
2019-07-25 18:10 ` Greg Kroah-Hartman
2019-07-25 18:16 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 03/16] chardev: export cdev_put() Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 04/16] nvme-core: introduce nvme_get_by_path() Logan Gunthorpe
2019-07-25 17:50 ` Matthew Wilcox
2019-07-25 17:54 ` Logan Gunthorpe
2019-07-25 19:58 ` Keith Busch
2019-07-25 20:12 ` Sagi Grimberg
2019-07-25 20:28 ` Logan Gunthorpe
2019-07-25 20:31 ` Keith Busch
2019-07-25 20:37 ` Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 05/16] nvme-core: export existing ctrl and ns interfaces Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 06/16] nvmet: add return value to nvmet_add_async_event() Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 07/16] nvmet: make nvmet_copy_ns_identifier() non-static Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 08/16] nvmet-passthru: update KConfig with config passthru option Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 09/16] nvmet-passthru: add passthru code to process commands Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 10/16] nvmet-passthru: add enable/disable helpers Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 11/16] nvmet-core: allow one host per passthru-ctrl Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 12/16] nvmet-core: don't check the data len for pt-ctrl Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 13/16] nvmet-configfs: introduce passthru configfs interface Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 14/16] block: don't check blk_rq_is_passthrough() in blk_do_io_stat() Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 15/16] block: call blk_account_io_start() in blk_execute_rq_nowait() Logan Gunthorpe
2019-07-25 17:23 ` [PATCH v6 16/16] nvmet-passthru: support block accounting Logan Gunthorpe
2019-07-26 6:23 ` [PATCH v6 00/16] nvmet: add target passthru commands support Hannes Reinecke
2019-07-26 17:07 ` Logan Gunthorpe
2019-07-26 22:21 ` Sagi Grimberg
2019-07-26 22:37 ` Logan Gunthorpe
2019-07-26 23:13 ` Sagi Grimberg
2019-07-27 0:09 ` Logan Gunthorpe
2019-07-27 0:50 ` Stephen Bates
2019-07-29 16:15 ` Sagi Grimberg
2019-07-29 16:17 ` Logan Gunthorpe [this message]
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