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 Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id DC7CFC433F5 for ; Tue, 15 Mar 2022 08:46:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=2MaRY3FhQHvwy+duMTt4bpFbWvl+JrvIe5naHSiNFjo=; b=hC9IzqE4bCqOvKXrCKa5Vf4BEl bQY+AdeTV36Q6MaB29PIzSBO6tk28ONrqovKF4jzGAnZBuEr22/CYOJyBCUGzCq4ZTDIVbOfCcH7N K0MXPgnJUFCuSjsV7GzQbLoFKCMb7iA3qaTfwG+8WnKEyqHm0S2IlfTKWUnWMWen8HChsqCN/VFyl 2W51nXGeF2k49Lrn2fkDYV25MYlnZDG+8NmgNvu5Q5NYpRVgrYDnKMDMFjyB6U+ZOreqoXJhnDHP0 EEj8ndmcZZwkaejOibV8CjPW+rQjSQJsi584xmlUs5Hr/pQ6DKIVa0/X+j5rPDvYY9qWy5Ic2H2UX x+ec94IQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nU2or-008LNc-AO; Tue, 15 Mar 2022 08:46:17 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nU2oo-008LLx-3y for linux-nvme@lists.infradead.org; Tue, 15 Mar 2022 08:46:15 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 5183D68AA6; Tue, 15 Mar 2022 09:46:11 +0100 (CET) Date: Tue, 15 Mar 2022 09:46:11 +0100 From: "hch@lst.de" To: Sagi Grimberg Cc: "hch@lst.de" , Sungup Moon , "kbusch@kernel.org" , "axboe@fb.com" , "linux-nvme@lists.infradead.org" , "linux-kernel@vger.kernel.org" Subject: Re: [PATCH v2] driver/nvme/host: Support duplicated nsid for the private ns Message-ID: <20220315084611.GA3961@lst.de> References: <20220314110545epcms2p4a227eac7c4652445050e70ee2350635d@epcms2p4> <20220315071230.GA2069@lst.de> <20220315071926.GA2137@lst.de> <20220315084035.GA3834@lst.de> <6ac83f8b-01e6-5394-0570-023ac6b1a71d@grimberg.me> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6ac83f8b-01e6-5394-0570-023ac6b1a71d@grimberg.me> 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-20220315_014614_357049_9F44807D X-CRM114-Status: GOOD ( 11.37 ) 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: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Tue, Mar 15, 2022 at 10:42:56AM +0200, Sagi Grimberg wrote: >>>> + * We also do this for private namespaces as the namespace sharing flag >>>> + * could change after a rescan. >>> >>> What happens in this case? we now have non-unique shared namespaces? >> >> The non-uniqueue NSIDs can only happen for private namespaces. > > But what happens if this changes upon a rescan as you commented? Well, it can't change to shared as the nsids are non-unique. If we want to be paranoid we could add a sanity check for that, but then again there are a bunch of other things where we could be more paranoid.