From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753332AbbAVPti (ORCPT ); Thu, 22 Jan 2015 10:49:38 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:41260 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750888AbbAVPtf (ORCPT ); Thu, 22 Jan 2015 10:49:35 -0500 Date: Thu, 22 Jan 2015 07:49:30 -0800 From: Christoph Hellwig To: Keith Busch Cc: Christoph Hellwig , Yan Liu , Matthew Wilcox , 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 Message-ID: <20150122154930.GA28027@infradead.org> References: <1421886503-25276-1-git-send-email-yan@purestorage.com> <20150122084517.GA2093@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.23 (2014-03-12) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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.