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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,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 89E5EC433E0 for ; Tue, 9 Mar 2021 15:06:32 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 443BE65253 for ; Tue, 9 Mar 2021 15:06:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230490AbhCIPGA (ORCPT ); Tue, 9 Mar 2021 10:06:00 -0500 Received: from verein.lst.de ([213.95.11.211]:60578 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230147AbhCIPFd (ORCPT ); Tue, 9 Mar 2021 10:05:33 -0500 Received: by verein.lst.de (Postfix, from userid 2407) id 2C9B168B05; Tue, 9 Mar 2021 16:05:31 +0100 (CET) Date: Tue, 9 Mar 2021 16:05:31 +0100 From: Christoph Hellwig To: Javier =?iso-8859-1?Q?Gonz=E1lez?= Cc: Christoph Hellwig , linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, kbusch@kernel.org, sagi@grimberg.me, minwoo.im.dev@gmail.com Subject: Re: [PATCH V6 1/2] nvme: enable char device per namespace Message-ID: <20210309150531.GA15052@lst.de> References: <20210301192452.16770-1-javier.gonz@samsung.com> <20210301192452.16770-2-javier.gonz@samsung.com> <20210303091022.GA12784@lst.de> <20210303100212.e43jgjvuomgybmy2@mpHalley.localdomain> <20210309113103.GA9233@lst.de> <20210309124104.uowad6bd4vlcthmw@mpHalley.local> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210309124104.uowad6bd4vlcthmw@mpHalley.local> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On Tue, Mar 09, 2021 at 01:42:23PM +0100, Javier González wrote: >> - nvme_cdev_fops implements file operations that directly on a nvme_ns, >> so they are path specific > > This is correct. > >> - we allow opening them even for a hidden controller > > This is also correct. > >> - there does not seem to be a char device node for ns_head at all. > > Also correct. > > We tried to keep it simple in the first iteration. Am I understanding > that you see necessary to have per ns_head char devices? That would be my understanding of "multipath support" for this character device, yes. Especially as hiding the individual char devices for the hidden controllers once they are initially exposed would be an ABI break. 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,HEADER_FROM_DIFFERENT_DOMAINS,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 89486C433DB for ; Tue, 9 Mar 2021 15:05:48 +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 0243765243 for ; Tue, 9 Mar 2021 15:05:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 0243765243 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=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=M4DYVL3gl10XqFnDDFBn7KrDj/i31rWp5Sn65HtZLBc=; b=RilPJnYUE/g7eH76GjGUfsgcL oXdJvuUbhoeTC/TpWad4W2lLGCCRhoGrhBNnrGfPh9aCZOvyTitra6jImwT5+4M4MhMsMCS5M1NsV SN+jb1grEmTA076JqonburmP7vSJ2Eu1tUNzfSjp9vxpYmpstwmsHUmeQy6cQTsORYNq+CP3m/a6o cfpsNPMcw3AoRBzkONjpryRwOu3hP8gsII8ndFGY1+5gTSzAc3UGG+nnZdplrd9UEe7bBZ6H7Lwcj PUJeJAyAkTLN3q69zMoMHWOAtQ8+m9b3DjV3zy80FOWT8pJhObJ2rwK70E9g1PkPeE9FytIVVDeI9 3I88hFRXw==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lJdvV-004ubb-BF; Tue, 09 Mar 2021 15:05:37 +0000 Received: from verein.lst.de ([213.95.11.211]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lJdvR-004uat-HL for linux-nvme@lists.infradead.org; Tue, 09 Mar 2021 15:05:35 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 2C9B168B05; Tue, 9 Mar 2021 16:05:31 +0100 (CET) Date: Tue, 9 Mar 2021 16:05:31 +0100 From: Christoph Hellwig To: Javier =?iso-8859-1?Q?Gonz=E1lez?= Cc: Christoph Hellwig , linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, kbusch@kernel.org, sagi@grimberg.me, minwoo.im.dev@gmail.com Subject: Re: [PATCH V6 1/2] nvme: enable char device per namespace Message-ID: <20210309150531.GA15052@lst.de> References: <20210301192452.16770-1-javier.gonz@samsung.com> <20210301192452.16770-2-javier.gonz@samsung.com> <20210303091022.GA12784@lst.de> <20210303100212.e43jgjvuomgybmy2@mpHalley.localdomain> <20210309113103.GA9233@lst.de> <20210309124104.uowad6bd4vlcthmw@mpHalley.local> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210309124104.uowad6bd4vlcthmw@mpHalley.local> 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-20210309_150533_760061_27254C82 X-CRM114-Status: GOOD ( 15.15 ) 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="iso-8859-1" Content-Transfer-Encoding: quoted-printable Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Tue, Mar 09, 2021 at 01:42:23PM +0100, Javier Gonz=E1lez wrote: >> - nvme_cdev_fops implements file operations that directly on a nvme_ns, >> so they are path specific > > This is correct. > >> - we allow opening them even for a hidden controller > > This is also correct. > >> - there does not seem to be a char device node for ns_head at all. > > Also correct. > > We tried to keep it simple in the first iteration. Am I understanding > that you see necessary to have per ns_head char devices? That would be my understanding of "multipath support" for this character device, yes. Especially as hiding the individual char devices for the hidden controllers once they are initially exposed would be an ABI break. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme