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=-5.2 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 8EAA8C00A89 for ; Mon, 2 Nov 2020 18:59:04 +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 BD21B2225E for ; Mon, 2 Nov 2020 18:59:03 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="Z4Q00yr4" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org BD21B2225E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de 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=oG5iL9C+A6Bu7HRO/T6T9COuCK18OczCp7QViPsQkwU=; b=Z4Q00yr49ipNfPF8Wl3E/OQ/d LLV0/h2FZC4eoMxrtntN6jcu60YwqkgSWABlxjgjtzik5VqZhFnyMkbQnoWeNJcxeKKc1oRQet4q8 R/fDQzzf6RS7DFODYHYHsVpUnNjk07UCE8E7ig9d5Sqh2VpYjVfzB0OxjcIpcRn6W32vodlLR7JFr mBflWAJMZpGp7FcD3UDYzLHxQvaZsgnKlMizbWJCaQc3QkYy7lVDxIiW/HwmMo/3B2FVpdT4/VFS6 AEGqGUBFdKTbjt0/pbGSC2eHlTXXP5Tt4Z+xx8CCQ+NWRMpzvsviR8+qcNboNCPhRuG7akfggEMxi CS2BjOg7g==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1kZf2e-0004oV-RX; Mon, 02 Nov 2020 18:58:56 +0000 Received: from verein.lst.de ([213.95.11.211]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1kZf2c-0004nR-6w for linux-nvme@lists.infradead.org; Mon, 02 Nov 2020 18:58:54 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 6CCF268B05; Mon, 2 Nov 2020 19:58:51 +0100 (CET) Date: Mon, 2 Nov 2020 19:58:51 +0100 From: "hch@lst.de" To: Keith Busch Subject: Re: [PATCH V2] nvme: report capacity 0 for non supported ZNS SSDs Message-ID: <20201102185851.GA21349@lst.de> References: <0916865d50c640e3aa95dc542f3986b9@CAMSVWEXC01.scsc.local> <20201102180836.GC20182@lst.de> <20201102183355.GB1970293@dhcp-10-100-145-180.wdc.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20201102183355.GB1970293@dhcp-10-100-145-180.wdc.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20201102_135854_384352_67AF6604 X-CRM114-Status: GOOD ( 11.94 ) 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: "axboe@kernel.dk" , "Niklas.Cassel@wdc.com" , "javier@javigon.com" , "sagi@grimberg.me" , "joshi.k@samsung.com" , "Klaus B. Jensen" , "linux-nvme@lists.infradead.org" , "linux-block@vger.kernel.org" , Javier Gonzalez , "hch@lst.de" 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 Mon, Nov 02, 2020 at 10:33:55AM -0800, Keith Busch wrote: > I can see this going one of two ways: > > a) Set up the existing controller character device with a generic > disk-less request_queue to the IO queues accepting IO commands to > arbitrary NSIDs. > > b) Each namespace that can't be supported gets their own character > device. > > I'm leaning toward option "a". While it doesn't create handles to unique > namespaces, it has more resilience to potentially future changes. And I > recall the target side had a potential use for that, too. The problem with a) is that it can't be used to give users or groups access to just one namespaces, so it causes a real access control nightmare. The problem with b) is that now applications will break when we add support for new command sets or features. I think c) Each namespace gets its own character device, period. is the only sensible option. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme