From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-4.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 51DEEC433E0 for ; Tue, 16 Feb 2021 17:58:07 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id EEDFD64E08 for ; Tue, 16 Feb 2021 17:58:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org EEDFD64E08 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=yRGEBgDf0LvUW/grOLOrvUB+ZT+IgvRzyXmUOHjy+AA=; b=DSAkQILoD57OT/1eD5B13M6y9 xu+6PdBEqkmyqBQ9M/GpZxMn4WFnRL9l4rMSPNXtuXDYqlGaOpQhPcLOY+2uXbD9EgbqdEpI90d5r vxkaQT7torB2HBjnFi61Rfyi4nvEQi7ybJBDngcmKuA4IwhVAEmADNpTah0SpmJTcsR6iG0MbOSwN cSawOMoEyV9+M1fgmifCe0UbE2W45gG5ERdscxRop5aLmSbDIiDqyp/jqSspfJaDzoQfY2ShNd1Kx +uod3YZBXPjK9wK4zxDEIDJWwp5Xp6M+tYtD+GFkktjzPfI+0WhzevT24UsBF3Efkhu7P/fGV5CLW D4PlPw4oQ==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1lC4bJ-0003iK-Iy; Tue, 16 Feb 2021 17:57:29 +0000 Received: from mail.kernel.org ([198.145.29.99]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1lC4bH-0003hr-5B for linux-nvme@lists.infradead.org; Tue, 16 Feb 2021 17:57:27 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 5263E64E08; Tue, 16 Feb 2021 17:57:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1613498246; bh=ZGL6S+PEuOVL2+Q2ycW+xwsR7E7EX/tF6Peg4VISIss=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NNZ1cY1HrcUDp1O7+YOj6i/XU5zUkDyM7XGENWynyw1z+RpkWHwX8mHkYpeS2yXGI U/0oxcnu0AEuJUN8tHsMFRNzhruCOYr60G1j2VO3L6KDTpUrByOEcM81RBazBjtZFv me7a05xx0zum1USVRVNS5uu6PFqGAlXsClEOTnQy0ttLOWPP71iUxyUv9qA5HslkGw LvJ/5XuUYRQfkrWn4yllhwtWZefie9erVMjlNc13bpxRMTqcCTsdyy2lOP6iU26IqK jZfRjRtbhTY+9X0DgA19dZ/fbDO46PDfvIPhLahAAYvtItDdzT2zh1bsk0KE9lXTDS GWUUbc0FI+LEA== Date: Tue, 16 Feb 2021 09:57:22 -0800 From: Keith Busch To: Minwoo Im Subject: Re: [PATCH] nvme: introduce passthrough ioctl for multipath Message-ID: <20210216175722.GC2708768@dhcp-10-100-145-180.wdc.com> References: <20210214110126.24023-1-minwoo.im.dev@gmail.com> <20210214110126.24023-2-minwoo.im.dev@gmail.com> <20210215170233.GA2707454@dhcp-10-100-145-180.wdc.com> <20210216095147.GA2601@localhost.localdomain> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210216095147.GA2601@localhost.localdomain> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210216_125727_268702_657D46E1 X-CRM114-Status: GOOD ( 22.09 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Jens Axboe , Christoph Hellwig , linux-nvme@lists.infradead.org, Sagi Grimberg Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Tue, Feb 16, 2021 at 06:51:47PM +0900, Minwoo Im wrote: > On 21-02-15 09:02:33, Keith Busch wrote: > > On Sun, Feb 14, 2021 at 08:01:25PM +0900, Minwoo Im wrote: > > > We don't allow NVME_IOCTL_IO_CMD ioctl in case that a controller has > > > multiple namespaces attached. Also, I/O request to the controller > > > character device has not been recommended and deprecated because we have > > > block device to I/O with where the multipath consideration is taken. > > > > > > Once kernel decided a path to I/O for a namespace based on the I/O > > > policy of a NVMe subsystem, userspace is not allowed to choose a path to > > > I/O. If a path is broken(inaccessible state in ANA), then it will not > > > try to I/O to that path. > > > > > > This patch introduced NVME_IOCTL_MPATH_IO command for controller > > > device(e.g., /dev/nvme0) to support multipath I/O passthrough for > > > userspace. Regardless driver's path decision, userspace can target a > > > namespace to I/O. In this case, `cmd.nsid` will be used to find out the > > > namespace instance target which is hidden(e.g., nvmeXcYnZ). > > > > IO commands are not allowed through the character handle with the > > existing ioctls. A new ioctl doesn't make it okay. If it was okay, then > > we could just remove the limitation in the current ones. > > Thanks for your feedback, Keith. If you don't mind, may I ask why it's > been entirely unsafe and deprecated in the exsiting > ioctl(NVME_IOCTL_IO_CMD)? I've seen a patch bfd8947194b2 ("nvme: fixes > for NVME_IOCTL_IO_CMD on the char device), but have no idea why it's > been really depreacted :) A container could read data from namespaces assigned to a different container. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme