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,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 104E6C433B4 for ; Mon, 12 Apr 2021 07:45:36 +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 517B660FF0 for ; Mon, 12 Apr 2021 07:45:35 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 517B660FF0 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=32ADs8rxANKcyMyu4mWMBIkGbt8ZaPCZ0EkzyaseFBg=; b=Tt8Ske88snPmT8t1oiiS2AuYx J99ZSZQ3vFY1SrNiaky74Jcg0OorYB80rBXO7Cq0Rs7vJo/3cNRmwySj9Dnf3yUBDFmpXME2/96L5 3TGR9PbWusRZM0EKxmdJ3Atpc6cuL+KQJFG0fSiWWl62ScttAgXJsJEj8btnC/WtegEe9K5psRrgU oW2iEuv1ofXP3ja8O0+FLs6wNB+1uQvBSgi7xEh4ZXE4H80L8VQD9GCwFiFAToUSuzpCcIezBUbnY OQdsUdLOlIJ66CPAKPb8Pfc6GYYr6JDGgy6RAY0QorFHYK72rE+NI/W9m8GRlm8cSxm7+OJFp5W5k CQFaUXnug==; Received: from localhost ([::1] helo=desiato.infradead.org) by desiato.infradead.org with esmtp (Exim 4.94 #2 (Red Hat Linux)) id 1lVrFt-0060uA-Dz; Mon, 12 Apr 2021 07:45:09 +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 1lVrFn-0060tm-2z for linux-nvme@desiato.infradead.org; Mon, 12 Apr 2021 07:45:06 +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=CDMZ74Gid+GOYCUt0krCIOP8he1YJfkbgGjiLM/A8LU=; b=s+F1AAf6ew9XEb/OmdkPz2lfY+ jvo7UxvP7vz5sBLOD4QudOZKeRtml7V4l9sQl14INnqbuPKUgTNairzyrsnuzpdVi7GPOLV+yC0GD Q0iNdVA5+wv0OZ6terUA7hg8JH08PWquem5jbRih9PTWwENX+SfI4udvNes3iMxNmRFAHYXMS3xPM GFUgRAEhFKjira6RvNZMkKWjPM9qRUHzJ+GmIceQw16JEjKHfkI5cFncnbzEXIznEKiBstZ3OOl71 x6ThkrSGYvZYLqMqcEeMvwth/Y6mpLbpupG24ZHvRaUyUNM3irvZQhGDqlBo1q5ad4Vyy6zZo7cUW KU/uEESw==; Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94 #2 (Red Hat Linux)) id 1lVrFk-005w9o-Ib for linux-nvme@lists.infradead.org; Mon, 12 Apr 2021 07:45:01 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id DD5DA68C4E; Mon, 12 Apr 2021 09:44:55 +0200 (CEST) Date: Mon, 12 Apr 2021 09:44:55 +0200 From: Christoph Hellwig To: Minwoo Im Cc: Christoph Hellwig , Keith Busch , Sagi Grimberg , Kanchan Joshi , Javier Gonz??lez , linux-nvme@lists.infradead.org Subject: Re: [PATCH 13/13] nvme: introduce generic per-namespace chardev Message-ID: <20210412074455.GA3653@lst.de> References: <20210408120842.1450092-1-hch@lst.de> <20210408120842.1450092-14-hch@lst.de> <20210409072901.GA2085@localhost> <20210409075415.GA6991@lst.de> <20210409080214.GB2085@localhost> <20210409095205.GA15931@lst.de> <20210409112401.GF2085@localhost> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20210409112401.GF2085@localhost> 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-20210412_004500_780699_634B5B2D X-CRM114-Status: GOOD ( 15.14 ) 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 Fri, Apr 09, 2021 at 08:24:01PM +0900, Minwoo Im wrote: > I think if we don't have a route to the live controller from the > multipath node /dev/ng0n1, how does application figure out controller > node to request admin commands like Identify Namespace before their > own I/O ? > > We have sysfs, but it does not provide every information about the > namespace. Or is there any charming way to find out the live > controller from a head node through sysfs or something that I missed > here ? :) The devie links points to the subsystem, which then points to the controllers: root@testvm:/sys/class/nvme-generic/ng0n1# ls -l device/ total 0 -r--r--r-- 1 root root 4096 Apr 12 07:43 firmware_rev -rw-r--r-- 1 root root 4096 Apr 12 07:44 iopolicy -r--r--r-- 1 root root 4096 Apr 12 07:43 model drwxr-xr-x 3 root root 0 Apr 12 07:43 ng0n1 drwxr-xr-x 3 root root 0 Apr 12 07:43 ng0n2 lrwxrwxrwx 1 root root 0 Apr 12 07:44 nvme0 -> ../../nvme-fabrics/ctl/nvme0 drwxr-xr-x 9 root root 0 Apr 12 07:43 nvme0n1 drwxr-xr-x 9 root root 0 Apr 12 07:43 nvme0n2 lrwxrwxrwx 1 root root 0 Apr 12 07:44 nvme1 -> ../../nvme-fabrics/ctl/nvme1 drwxr-xr-x 2 root root 0 Apr 12 07:44 power -r--r--r-- 1 root root 4096 Apr 12 07:43 serial -r--r--r-- 1 root root 4096 Apr 12 07:44 subsysnqn lrwxrwxrwx 1 root root 0 Apr 12 07:43 subsystem -> ../../../../class/nvme-subsystem -rw-r--r-- 1 root root 4096 Apr 12 07:43 uevent _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme