From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: ZBC_IN command translation Date: Wed, 7 Jun 2017 23:55:54 -0700 Message-ID: <20170608065553.GA14568@infradead.org> References: <4b12630e-1add-6a4e-51ab-52417e60d4b2@wdc.com> <20170607090751.GA29487@infradead.org> <20170607132443.GA3501@infradead.org> <8b223c09-81ff-19dd-fe32-63711c79b9cb@wdc.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Received: from bombadil.infradead.org ([65.50.211.133]:37248 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750725AbdFHGzy (ORCPT ); Thu, 8 Jun 2017 02:55:54 -0400 Content-Disposition: inline In-Reply-To: <8b223c09-81ff-19dd-fe32-63711c79b9cb@wdc.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: Damien Le Moal Cc: Christoph Hellwig , linux-ide@vger.kernel.org, Hannes Reinecke , Tejun Heo , Jens Axboe , "Martin K. Petersen" On Thu, Jun 08, 2017 at 09:18:39AM +0900, Damien Le Moal wrote: > So I am limiting support in target to the passthrough SCSI (pscsi) > backstore type (and will also add a user emulation backstore). Fixes > needed in pscsi are rather trivial, but the block layer is not involved > at the highest level as scsi commands are simply passed along through > requests. Hence the ZBC/ZAC translation problem showing up. Bah, don't do that. Passthrough backends are a nightmare in so many ways and I really prefer to not see them spread. > > I could work on completing support for ZBC at the block layer API: > 1) Add REQ_OP_ZONE_OPEN/CLOSE/FINISH, with corresponding > blkdev_issue_xxx functions Or just emulate them. > 2) Add more queue attributes and corresponding files in sysfs for the > zoned block device characteristics > 3) Fix sd.c to support the new REQ_OP_ZONE_xxx > 4) Add corresponding user ioctls for OPEN/CLOSE/FINISH What is the practical use cae for that?