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=-5.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 E4D96C433B4 for ; Tue, 20 Apr 2021 18:58:48 +0000 (UTC) Received: from desiato.infradead.org (desiato.infradead.org [90.155.92.199]) (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 7C57A613DF for ; Tue, 20 Apr 2021 18:58:48 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7C57A613DF 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=desiato.20200630; h=Sender:Content-Transfer-Encoding :Content-Type:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:Cc: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=wp15bxwVV/kPgkXTlvHevV+SvOPgqctDzCILF7oB2a4=; b=Lwclzc+l2k0JdFtGeyQZJMbp3 d8la6VFnH1wa96f4AkxkLbqmj3dPFNORdhSzRzMKUc+yfeIc2QjH7aHqkKkt+EFpLChlkbqFJgady WEwwvpSgvZMlVkykI7ZY5bCQl5WBQkihpyCJykT29X9im5ixYyQQqjOBzGJBhf1yki/kH804tot8g Zy3zAu93NJ9UxzcZBOIf0hFksWOeHiDOJHBO5KselMWOlzaOISBBgINYuVy0hXYZ88RCxUeRYeXIk ovuDABkO7eC0pQKTLn/0B5rJXiulSnr01iHSAbXvFKXG5EPSworWVJwZo5QLm1Tp0lPI0mjS71z1a 1+fXpAf0g==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lYvZr-00Ctut-LY; Tue, 20 Apr 2021 18:58:27 +0000 Received: from bombadil.infradead.org ([2607:7c80:54:e::133]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lYvZo-00CtuC-1E for linux-nvme@desiato.infradead.org; Tue, 20 Apr 2021 18:58:24 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=j2WJRaoQA2xwDMkUpR7MBfDMEtD1QrokqwGMQQM0Uik=; b=H7SlOfVruk031WLfS+81elHlsQ IWJuqciV6idwif9zjhkCbY1Wj4D/NF/sXAFF5eWQuRvdNeLB+K4+JyIvYEpEFEo/fCwuy04KxQbmU XU5MSj8H8cO3CkJbDlTHbPIuEKdKKk+e4cLok/4GWkhvceDVs5InKj230RLn1p7V4YsuFcm0qhAGO OyBNhAknGqeklKz4RVdhJMzhSCZZWnTu1edh64psXKijkASgpVuYHVLi4Z98Lf082VAvR3aBaIafZ +VRLkZcPGE20IGO9TGex/6MGFIiCN8vGSBY5zYKzo4esNgonPCxF1NY322emBIiSUxBZmgSOFitwz jrAuCG/Q==; Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lYvZl-00CMcA-IG for linux-nvme@lists.infradead.org; Tue, 20 Apr 2021 18:58:22 +0000 Received: by mail.kernel.org (Postfix) with ESMTPSA id 319C0613E0; Tue, 20 Apr 2021 18:58:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1618945101; bh=CmxcKRDOcWn/9RRZ+lWQ/GFD6BnvgK9nfFsGnbBsH8M=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NN4Na2coxLgkaDrHYuk9k05wVDNGGxcQ+DH7LDfmNPA04u4RLhrpKeCth+omWxmXx pAAUSxlPlzuTQgIGOtoHv27x9ucRwgDGrCOsAMu1XwfvF6Ffrj+iyIcPTX9XxxgFEl JeHClTU2rCVv7wxFc4/79Z5FfGjaVs/UfjiJsDfhSbrw7MZieTVAvOSe9UO0W6tH5u oHls00nN+vBu630c903gfeKnqaw1tXxQ1opXbUy54A+vnOBmgVPzFuY1hZjKX0h3e4 lEhRK3pFVAei0d0iQyt7d6NrcFGs95/54IdAwL0EoREv7NMgRT6bz28+qie2AKYMI9 uY7nJDkGu2Myg== Date: Wed, 21 Apr 2021 03:58:13 +0900 From: Keith Busch To: Kanchan Joshi Cc: Christoph Hellwig , Minwoo Im , Sagi Grimberg , Javier Gonz??lez , linux-nvme@lists.infradead.org Subject: Re: [PATCH] nvme: introduce generic per-namespace chardev Message-ID: <20210420185813.GA18432@redsun51.ssa.fujisawa.hgst.com> References: <20210420100746.2801722-1-hch@lst.de> <20210420100746.2801722-2-hch@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210420_115821_661761_02E5B2F9 X-CRM114-Status: GOOD ( 16.40 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , 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, Apr 20, 2021 at 11:43:51PM +0530, Kanchan Joshi wrote: > On Tue, Apr 20, 2021 at 3:37 PM Christoph Hellwig wrote: > > > > From: Minwoo Im > > > > Userspace has not been allowed to I/O to device that's failed to > > be initialized. This patch introduces generic per-namespace character > > device to allow userspace to I/O regardless the block device is there or > > not. > > When an application uses this interface to issue passthrough IO, it > needs to know the lba size (at least) to form the command correctly. > But determining lba size would require an admin ioctl. > Do you see there is a way to go about this issue? You'd have to look up the parent controller and issue the command through that. If your application doesn't have permissions to open the controller, then it wouldn't work. So I guess all applications that can open generic namespaces would need access to the controller handle. But if you do that, then is there a point to this indirection anymore? I have to agree, the ability to query your namespaces settings through the namespace's handle really does simplify things... _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme