From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [dm-devel] [PATCH 3/6] sd: implement the Persistent Reservation API Date: Thu, 15 Oct 2015 17:32:27 +0200 Message-ID: <20151015153227.GA3536@lst.de> References: <1444911052-9423-1-git-send-email-hch@lst.de> <1444911052-9423-4-git-send-email-hch@lst.de> <561FC6AA.3080508@sandisk.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <561FC6AA.3080508-XdAiOPVOjttBDgjK7y7TUQ@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Bart Van Assche Cc: device-mapper development , axboe-b10kYP2dOMg@public.gmane.org, linux-scsi-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nvme-IAPFreCvJWM7uuMidbF8XUB+6BGkLq7r@public.gmane.org, keith.busch-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org List-Id: dm-devel.ids On Thu, Oct 15, 2015 at 08:30:50AM -0700, Bart Van Assche wrote: > Can you explain why this functionality has been added to the sd driver > instead of the SCSI core ? Aren't persistent reservations a concept that > applies to all SCSI device types ? In theory it does. In practice it's only used by disks/arrays and tapes, and as tapes don't have a struct block_device this isn't going to be useful for them. From mboxrd@z Thu Jan 1 00:00:00 1970 From: hch@lst.de (Christoph Hellwig) Date: Thu, 15 Oct 2015 17:32:27 +0200 Subject: [dm-devel] [PATCH 3/6] sd: implement the Persistent Reservation API In-Reply-To: <561FC6AA.3080508@sandisk.com> References: <1444911052-9423-1-git-send-email-hch@lst.de> <1444911052-9423-4-git-send-email-hch@lst.de> <561FC6AA.3080508@sandisk.com> Message-ID: <20151015153227.GA3536@lst.de> On Thu, Oct 15, 2015@08:30:50AM -0700, Bart Van Assche wrote: > Can you explain why this functionality has been added to the sd driver > instead of the SCSI core ? Aren't persistent reservations a concept that > applies to all SCSI device types ? In theory it does. In practice it's only used by disks/arrays and tapes, and as tapes don't have a struct block_device this isn't going to be useful for them. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753425AbbJOPca (ORCPT ); Thu, 15 Oct 2015 11:32:30 -0400 Received: from verein.lst.de ([213.95.11.211]:39225 "EHLO newverein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751889AbbJOPc3 (ORCPT ); Thu, 15 Oct 2015 11:32:29 -0400 Date: Thu, 15 Oct 2015 17:32:27 +0200 From: Christoph Hellwig To: Bart Van Assche Cc: device-mapper development , axboe@fb.com, linux-scsi@vger.kernel.org, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, keith.busch@intel.com Subject: Re: [dm-devel] [PATCH 3/6] sd: implement the Persistent Reservation API Message-ID: <20151015153227.GA3536@lst.de> References: <1444911052-9423-1-git-send-email-hch@lst.de> <1444911052-9423-4-git-send-email-hch@lst.de> <561FC6AA.3080508@sandisk.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <561FC6AA.3080508@sandisk.com> User-Agent: Mutt/1.5.17 (2007-11-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Oct 15, 2015 at 08:30:50AM -0700, Bart Van Assche wrote: > Can you explain why this functionality has been added to the sd driver > instead of the SCSI core ? Aren't persistent reservations a concept that > applies to all SCSI device types ? In theory it does. In practice it's only used by disks/arrays and tapes, and as tapes don't have a struct block_device this isn't going to be useful for them.