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[68.160.176.52]) by smtp.gmail.com with ESMTPSA id b14sm426205qtk.44.2022.02.22.11.16.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Feb 2022 11:16:14 -0800 (PST) Date: Tue, 22 Feb 2022 14:16:13 -0500 From: Mike Snitzer To: Christoph Hellwig Cc: Brian Geffon , Alasdair Kergon , dm-devel@redhat.com, LKML Subject: Re: dm: introduce a DM_ENFORCE_OPEN_COUNT flag. Message-ID: References: <20220125002025.GA21887@agk-cloud1.hosts.prod.upshift.rdu2.redhat.com> <20220126192234.572058-1-bgeffon@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 02 2022 at 9:42P -0500, Christoph Hellwig wrote: > Withmy block hat on: nak to this. No block driver has any business at > all rejecting "too many openers". In fact any opener but the first of > a partition is already not counted as an opener, and I plan to complete > hide the open count from the device driver. I agree that this proposal exposes controls to userspace that simply shouldn't be meaningful given the arbitrary nature of openers. And preventing openers can result in a race where systemd or some other service opens before the intended primary consumer of the device. Seriously brittle and even if finely tuned to have a suitable value for some niche usecase like android: an absolute hack. Sorry, not interested in taking this. 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[68.160.176.52]) by smtp.gmail.com with ESMTPSA id b14sm426205qtk.44.2022.02.22.11.16.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Feb 2022 11:16:14 -0800 (PST) Date: Tue, 22 Feb 2022 14:16:13 -0500 From: Mike Snitzer To: Christoph Hellwig Message-ID: References: <20220125002025.GA21887@agk-cloud1.hosts.prod.upshift.rdu2.redhat.com> <20220126192234.572058-1-bgeffon@google.com> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.85 on 10.11.54.8 X-loop: dm-devel@redhat.com Cc: dm-devel@redhat.com, Brian Geffon , Alasdair Kergon , LKML Subject: Re: [dm-devel] dm: introduce a DM_ENFORCE_OPEN_COUNT flag. X-BeenThere: dm-devel@redhat.com X-Mailman-Version: 2.1.12 Precedence: junk List-Id: device-mapper development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: dm-devel-bounces@redhat.com Errors-To: dm-devel-bounces@redhat.com X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=dm-devel-bounces@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Disposition: inline Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit On Wed, Feb 02 2022 at 9:42P -0500, Christoph Hellwig wrote: > Withmy block hat on: nak to this. No block driver has any business at > all rejecting "too many openers". In fact any opener but the first of > a partition is already not counted as an opener, and I plan to complete > hide the open count from the device driver. I agree that this proposal exposes controls to userspace that simply shouldn't be meaningful given the arbitrary nature of openers. And preventing openers can result in a race where systemd or some other service opens before the intended primary consumer of the device. Seriously brittle and even if finely tuned to have a suitable value for some niche usecase like android: an absolute hack. Sorry, not interested in taking this. -- dm-devel mailing list dm-devel@redhat.com https://listman.redhat.com/mailman/listinfo/dm-devel