linux-block.vger.kernel.org archive mirror
 help / color / mirror / Atom feed
From: Sagi Grimberg <sagi@grimberg.me>
To: Max Gurtovoy <maxg@mellanox.com>,
	Logan Gunthorpe <logang@deltatee.com>,
	linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org,
	linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org
Cc: Chaitanya Kulkarni <Chaitanya.Kulkarni@wdc.com>,
	Stephen Bates <sbates@raithlin.com>, Jens Axboe <axboe@fb.com>,
	Keith Busch <kbusch@kernel.org>, Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH v7 08/14] nvmet-core: allow one host per passthru-ctrl
Date: Thu, 22 Aug 2019 10:41:09 -0700	[thread overview]
Message-ID: <24e2ddd0-4b2a-8092-cf91-df8c0fb482e5@grimberg.me> (raw)
In-Reply-To: <b352c7f1-2629-e72f-9c85-785e0cf7c2c1@mellanox.com>


>>> I don't understand why we don't limit a regular ctrl to single access 
>>> and we do it for the PT ctrl.
>>>
>>> I guess the block layer helps to sync between multiple access in 
>>> parallel but we can do it as well.
>>>
>>> Also, let's say you limit the access to this subsystem to 1 user, the 
>>> bdev is still accessibly for local user and also you can create a 
>>> different subsystem that will use this device (PT and non-PT ctrl).
>>>
>>> Sagi,
>>>
>>> can you explain the trouble you meant and how this limitation solve it ?
>>
>> Its different to emulate the controller with all its admin
>> commands vs. passing it through to the nvme device.. (think of format 
>> nvm)
>>
>>
>>
> we don't need to support format command for PT ctrl as we don't support 
> other commands such create_sq/cq.

That is just an example, basically every command that we are not aware
of we simply passthru to the drive without knowing the implications
on a multi-host environment..

  reply	other threads:[~2019-08-22 17:41 UTC|newest]

Thread overview: 34+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-08-01 23:44 [PATCH v7 00/14] nvmet: add target passthru commands support Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 01/14] nvme-core: introduce nvme_ctrl_get_by_path() Logan Gunthorpe
2019-08-14 14:20   ` Max Gurtovoy
2019-08-15 11:46   ` Max Gurtovoy
2019-08-15 15:59     ` Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 02/14] nvme-core: export existing ctrl and ns interfaces Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 03/14] nvmet: add return value to nvmet_add_async_event() Logan Gunthorpe
2019-08-14 14:26   ` Max Gurtovoy
2019-08-14 16:59     ` Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 04/14] nvmet: make nvmet_copy_ns_identifier() non-static Logan Gunthorpe
2019-08-14 14:29   ` Max Gurtovoy
2019-08-15  7:15     ` Chaitanya Kulkarni
2019-08-01 23:45 ` [PATCH v7 05/14] nvmet-passthru: update KConfig with config passthru option Logan Gunthorpe
2019-08-14 14:31   ` Max Gurtovoy
2019-08-01 23:45 ` [PATCH v7 06/14] nvmet-passthru: add passthru code to process commands Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 07/14] nvmet-passthru: add enable/disable helpers Logan Gunthorpe
2019-08-15 12:20   ` Max Gurtovoy
2019-08-15 16:02     ` Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 08/14] nvmet-core: allow one host per passthru-ctrl Logan Gunthorpe
2019-08-15 12:36   ` Max Gurtovoy
2019-08-15 16:06     ` Logan Gunthorpe
2019-08-18 10:33       ` Max Gurtovoy
2019-08-22  0:09         ` Sagi Grimberg
2019-08-22  8:50           ` Max Gurtovoy
2019-08-22 17:41             ` Sagi Grimberg [this message]
2019-08-22 19:17               ` Sagi Grimberg
2019-08-22 19:41                 ` Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 09/14] nvmet-core: don't check the data len for pt-ctrl Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 10/14] nvmet-tcp: don't check data_len in nvmet_tcp_map_data() Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 11/14] nvmet-configfs: introduce passthru configfs interface Logan Gunthorpe
2019-08-15 12:46   ` Max Gurtovoy
2019-08-01 23:45 ` [PATCH v7 12/14] block: don't check blk_rq_is_passthrough() in blk_do_io_stat() Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 13/14] block: call blk_account_io_start() in blk_execute_rq_nowait() Logan Gunthorpe
2019-08-01 23:45 ` [PATCH v7 14/14] nvmet-passthru: support block accounting Logan Gunthorpe

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=24e2ddd0-4b2a-8092-cf91-df8c0fb482e5@grimberg.me \
    --to=sagi@grimberg.me \
    --cc=Chaitanya.Kulkarni@wdc.com \
    --cc=axboe@fb.com \
    --cc=hch@lst.de \
    --cc=kbusch@kernel.org \
    --cc=linux-block@vger.kernel.org \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-nvme@lists.infradead.org \
    --cc=logang@deltatee.com \
    --cc=maxg@mellanox.com \
    --cc=sbates@raithlin.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).