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From: Christoph Hellwig <hch@infradead.org>
To: Keith Busch <keith.busch@intel.com>
Cc: Christoph Hellwig <hch@infradead.org>,
	Yan Liu <yan@purestorage.com>,
	Matthew Wilcox <willy@linux.intel.com>,
	linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org
Subject: Re: [PATCH 1/1] NVMe: Do not take nsid while a passthrough IO command is being issued via a block device file descriptor
Date: Thu, 22 Jan 2015 07:49:30 -0800	[thread overview]
Message-ID: <20150122154930.GA28027@infradead.org> (raw)
In-Reply-To: <alpine.LNX.2.00.1501221430040.15481@localhost.lm.intel.com>

On Thu, Jan 22, 2015 at 03:21:28PM +0000, Keith Busch wrote:
> The case I considered was the "hidden" attribute in the NVMe LBA Range
> Type feature. It only indicates the storage should be hidden from the OS
> for general use, but the host may still use it for special purposes. In
> truth, the driver doesn't handle the hidden attribute very well and it
> doesn't seem like a well thought out feature in the spec anyway.

At least for Linux we should simply ignore that attribute.

> But if you really need to restrict namespace access, shouldn't that be
> enforced on the target side with reservations or similar mechanism?

Think for example about containers where we give eah container access
to a single nvme namespace, including container root access.  Here you
don't really want container A to be able to submit I/O for another
container.  A similar case exists for virtualization where we had
problems with SCSI passthrough from guests.

WARNING: multiple messages have this Message-ID (diff)
From: hch@infradead.org (Christoph Hellwig)
Subject: [PATCH 1/1] NVMe: Do not take nsid while a passthrough IO command is being issued via a block device file descriptor
Date: Thu, 22 Jan 2015 07:49:30 -0800	[thread overview]
Message-ID: <20150122154930.GA28027@infradead.org> (raw)
In-Reply-To: <alpine.LNX.2.00.1501221430040.15481@localhost.lm.intel.com>

On Thu, Jan 22, 2015@03:21:28PM +0000, Keith Busch wrote:
> The case I considered was the "hidden" attribute in the NVMe LBA Range
> Type feature. It only indicates the storage should be hidden from the OS
> for general use, but the host may still use it for special purposes. In
> truth, the driver doesn't handle the hidden attribute very well and it
> doesn't seem like a well thought out feature in the spec anyway.

At least for Linux we should simply ignore that attribute.

> But if you really need to restrict namespace access, shouldn't that be
> enforced on the target side with reservations or similar mechanism?

Think for example about containers where we give eah container access
to a single nvme namespace, including container root access.  Here you
don't really want container A to be able to submit I/O for another
container.  A similar case exists for virtualization where we had
problems with SCSI passthrough from guests.

  reply	other threads:[~2015-01-22 15:49 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-01-22  0:28 [PATCH 1/1] NVMe: Do not take nsid while a passthrough IO command is being issued via a block device file descriptor Yan Liu
2015-01-22  0:28 ` Yan Liu
2015-01-22  0:47 ` Keith Busch
2015-01-22  0:47   ` Keith Busch
2015-01-22  8:45   ` Christoph Hellwig
2015-01-22  8:45     ` Christoph Hellwig
2015-01-22 15:21     ` Keith Busch
2015-01-22 15:21       ` Keith Busch
2015-01-22 15:49       ` Christoph Hellwig [this message]
2015-01-22 15:49         ` Christoph Hellwig
2015-01-22 16:58         ` Keith Busch
2015-01-22 16:58           ` Keith Busch
     [not found]   ` <CADMsRTZjajAj682a5FH-AmpphoQ4vw5QxqnJiGEQ+Jg_f7TvoA@mail.gmail.com>
2015-01-22 14:22     ` Keith Busch
2015-01-22 14:22       ` Keith Busch
2015-01-23  0:02 Yan Liu
2015-01-23  0:02 ` Yan Liu
2015-01-23  7:57 ` Christoph Hellwig
2015-01-23  7:57   ` Christoph Hellwig
2015-01-23 16:22   ` Keith Busch
2015-01-23 16:22     ` Keith Busch
2015-01-23 17:27     ` Christoph Hellwig
2015-01-23 17:27       ` Christoph Hellwig
2015-01-23 17:50       ` Keith Busch
2015-01-23 17:50         ` Keith Busch
2015-01-25 14:41         ` Christoph Hellwig
2015-01-25 14:41           ` Christoph Hellwig
2015-01-23 23:57 Yan Liu
2015-01-23 23:57 ` Yan Liu
2015-01-25 14:59 ` Christoph Hellwig
2015-01-25 14:59   ` Christoph Hellwig
2015-01-26 18:02   ` Keith Busch
2015-01-26 18:02     ` Keith Busch

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