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=-5.6 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 C07B6C433E0 for ; Fri, 5 Feb 2021 09:40:52 +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 2EF2964FAB for ; Fri, 5 Feb 2021 09:40:52 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2EF2964FAB 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=fjDh5N3EEzCyZEa+afgQ4CA9ouqB2MfSeh/7VFdkXnc=; b=kKHX0EUI2iRcFAPvZdYF73Jla EZcVARoIm9/M6VUoFd3sIK0IlvuOBA83ipF7Yw+id5CM1SyQzpNGnl/Yte0ANDB73uPf1zuHeUbmB Zr55n7ROYdPNt5L0u4ZYGjQ4xvcVAjRV48D6K5FQmIYAnZ+3/gqDJ/s0uufqwaVY2TqT/1b1j9P6j ZN7b64GQquWCx7wIN1lTWxaER5fXDPpACNCsjV0YWcDsF4TgLInC0MVD4Plxj1qaoSuBOpbDR+oTU ou/XZKa7XK/A0XRRPHZw9Pgh1uXP07HXekJEjSp2JZM78vdpZ4wtWgBlrKb0V5kKU8fuPtFDTdD3V vZD3hN6Qw==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1l7xbb-0003PV-Ve; Fri, 05 Feb 2021 09:40:48 +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 1l7xbZ-0003OB-He for linux-nvme@lists.infradead.org; Fri, 05 Feb 2021 09:40:46 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 5ACA068AFE; Fri, 5 Feb 2021 10:40:43 +0100 (CET) Date: Fri, 5 Feb 2021 10:40:43 +0100 From: Christoph Hellwig To: Hannes Reinecke Subject: Re: [PATCH] nvmet: per-host namespaces masking Message-ID: <20210205094043.GA2694@lst.de> References: <20210205092926.64161-1-hare@suse.de> <20210205093237.GA2066@lst.de> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: 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-20210205_044045_704188_35BAFE5F X-CRM114-Status: UNSURE ( 9.92 ) X-CRM114-Notice: Please train this message. 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: Chaitanya Kulkarni , linux-nvme@lists.infradead.org, Christoph Hellwig , Keith Busch , Sagi Grimberg 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, Feb 05, 2021 at 10:38:41AM +0100, Hannes Reinecke wrote: > On 2/5/21 10:32 AM, Christoph Hellwig wrote: >> On Fri, Feb 05, 2021 at 10:29:26AM +0100, Hannes Reinecke wrote: >>> Implement per-host namespaces masking, allowing to expose >>> different namespaces to different hosts connecting to the >>> same subsystem. >>> The original method of adding host nqns to the subsystem >>> takes precedence over the per-host namespace masking. >> >> Why do you want to expose a single subsystem to multiple hosts? This >> creates all kinds of covert channels better avoided. >> > But the alternative is a subsystem per host. > Which leads to a proliferation of subsystems on the target. Yes, that was the choice we had in mind when writing the code. The subsystems are very cheap as they don't require any resources except for some fairly small memory allocations. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme