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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 05A11C433DB for ; Tue, 9 Mar 2021 12:43:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C5C036525D for ; Tue, 9 Mar 2021 12:43:29 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230468AbhCIMm5 (ORCPT ); Tue, 9 Mar 2021 07:42:57 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35154 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231139AbhCIMm0 (ORCPT ); Tue, 9 Mar 2021 07:42:26 -0500 Received: from mail-wm1-x330.google.com (mail-wm1-x330.google.com [IPv6:2a00:1450:4864:20::330]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 3FD07C06174A for ; Tue, 9 Mar 2021 04:42:26 -0800 (PST) Received: by mail-wm1-x330.google.com with SMTP id 124-20020a1c00820000b029010b871409cfso5917117wma.4 for ; Tue, 09 Mar 2021 04:42:26 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=javigon-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:content-transfer-encoding:in-reply-to; bh=yQ9Tmm2gIeDEXy/XW+0pX8KjL1wB8WvlsRUFdFPh2n4=; b=AQqxydTa7hr/fy+3OfSd0FUs8oA+OYYms1kHhyS6B4WaVovEwShZee+UEmzPV0ezAf OpHA0SAgP5/Kaiuq/53Hlwskd3/i2HlzdoaQDTiHFAAC9EwPuaE9QGufDJg1l448+uV7 AOExI7iSEScVhuKtx+yPv2FuQy/oqvrvxAZ/Aa9M0M1tYf17+3DljC4OuWIfwRW+zCyL 3Nh30feQK8bN1GLGfPsPguFyWPgLQYdljdIV59PBKzM2zqY7op4tYv+N7BIa1VzDEkzi ew7Cq6kaCsqrVtoddCTSDe+Vzb8knpReGtiAfdIAVRSmeIX3syKBKrJwPlhQsTMIYQFy HL5A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:content-transfer-encoding :in-reply-to; bh=yQ9Tmm2gIeDEXy/XW+0pX8KjL1wB8WvlsRUFdFPh2n4=; b=cnrZRHuFwbTp89g7b1qVsaqroZHvYaVJhukgZniLkOARAR7bJwm5I8W45hncZ2HXru 7b2bMkpDsqG3+PR64z5fqIaJTybXQDgjl8FdjTQvqhdtfZFQliSIi0IbUInYu0QadKhc rDQXSlg379SNKlTVQvuZP/01elx6ZIK0Z7EsMDOo3eVR9gmeLO29ysWAMiGLpC+V2b3N fFEt6yl5/0ELzxaFAKdc6uU0BbkhBG4zYr5vQPsy2rgkEWis+RYqoNc4BEVNZlZ6cubT tJsWYdcVvd8FjijbPPm4coR62/7NBhFGNKBpaznLJ1BX3mNeh19dpNU+NttxkvrNgHQy MG7w== X-Gm-Message-State: AOAM530ylM9MR5jF1I3e+Eonttd31ZuRFjN4oHbqpmsqtb/ZavXneI+P yHn5jAlyM0uhggGESFBBCpajEg== X-Google-Smtp-Source: ABdhPJzT5v9Q8cRmtdG3cuTjJZWrMzv00SusH5ZrPUPYuSE3lKxZ50rCN6bpW7sEfq34HrhqEEZ+ew== X-Received: by 2002:a05:600c:198f:: with SMTP id t15mr3873457wmq.8.1615293744941; Tue, 09 Mar 2021 04:42:24 -0800 (PST) Received: from localhost ([194.62.217.57]) by smtp.gmail.com with ESMTPSA id v18sm21351788wrf.41.2021.03.09.04.42.23 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 09 Mar 2021 04:42:23 -0800 (PST) Date: Tue, 9 Mar 2021 13:42:23 +0100 From: Javier =?utf-8?B?R29uesOhbGV6?= To: Christoph Hellwig Cc: 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: <20210309124104.uowad6bd4vlcthmw@mpHalley.local> 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> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20210309113103.GA9233@lst.de> Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 09.03.2021 12:31, Christoph Hellwig wrote: >On Wed, Mar 03, 2021 at 11:02:12AM +0100, Javier González 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 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? 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Tue, 09 Mar 2021 04:42:23 -0800 (PST) Date: Tue, 9 Mar 2021 13:42:23 +0100 From: Javier =?utf-8?B?R29uesOhbGV6?= To: Christoph Hellwig Cc: 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: <20210309124104.uowad6bd4vlcthmw@mpHalley.local> 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> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210309113103.GA9233@lst.de> X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20210309_124226_460515_275F20BC X-CRM114-Status: GOOD ( 19.96 ) 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-Transfer-Encoding: base64 Content-Type: text/plain; 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