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 BC075C433DB for ; Tue, 9 Mar 2021 11:31:27 +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 022CB65259 for ; Tue, 9 Mar 2021 11:31:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 022CB65259 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=6mNMuVdNovsinOfAzcIjBBZ3aldl9/MNB4b3dAckv+A=; b=IhokN3hgnM1kU3giHySIzhvyf PgAa4XhA17wJIiuUYqr2QbRy43UEkLit318Bsg9DEe7ZiIF4B3M9/oBls1jmxqg/oBVgzPhXvGSiH mM2wAJ1NOL3PpZlCxMKSwjLf91cewYLXiPp+6qbKk4YrLP2vNBB4Ii2fsYxqFE3F2hb4yek1JCmy8 G5zncbAtQjIt/OGGCREm7CDI7jmDFbq+GcYhPer9t3O9k4EMsGz6Z3vQkT64HtR58ytyfPnzlsirL RrshnXZYaCvzor9pXv/f2L7SMFhGDcT2f8wqWHLuK5iVHcs8gLNi9Zh69rqN9sm0NxUjNn8+BbLfK f5rfF7iRA==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lJaZz-004KEE-LY; Tue, 09 Mar 2021 11:31:11 +0000 Received: from verein.lst.de ([213.95.11.211]) by desiato.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lJaZt-004KD2-Vj for linux-nvme@lists.infradead.org; Tue, 09 Mar 2021 11:31:08 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 3625868B05; Tue, 9 Mar 2021 12:31:03 +0100 (CET) Date: Tue, 9 Mar 2021 12:31:03 +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: <20210309113103.GA9233@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> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210303100212.e43jgjvuomgybmy2@mpHalley.localdomain> 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_113106_248004_6FD38036 X-CRM114-Status: GOOD ( 19.82 ) 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 Wed, Mar 03, 2021 at 11:02:12AM +0100, Javier Gonz=E1lez wrote: >> Ignoring some of the deprecated historic mistakes I think the policy >> should be: >> >> - admin commands that often are controller specific should usually >> go to a controller-specific device, the existing /dev/nvmeX >> devices >> - I/O commands and admin command that do specific a nsid should go >> through a per-namespace node that is multipath aware and not >> controller specific > > Sounds good. > > The current implementation re-routes IOCTLs to the char device through > the existing bdev IOCTLs, so I believe we follow this policy already. We > basically default to current behavior. > > And I assume that for legacy, namespace IOCTLs to the controller will > still be routed to the namespace (assuming a single namespace). > >> Which also makes me wonder about patch 2 in the series that seems >> somewhat dangerous. Can we clearly state the policy implemented? > > Patch 2 is the one that exposes the existing logic for multipath. How do > you think we should do it instead? So trying to follow the code: - nvme_cdev_fops implements file operations that directly on a nvme_ns, so they are path specific - we allow opening them even for a hidden controller - there does not seem to be a char device node for ns_head at all. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme