From mboxrd@z Thu Jan 1 00:00:00 1970 From: Christoph Hellwig Subject: Re: [RFC PATCH 01/17] block: make generic_make_request handle arbitrarily sized bios Date: Sat, 27 Dec 2014 07:02:07 -0800 Message-ID: <20141227150207.GC1094@infradead.org> References: <20141223101614.GA13138@infradead.org> <20141223114140.GB15080@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20141223114140.GB15080@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Dongsu Park Cc: Christoph Hellwig , linux-kernel@vger.kernel.org, Jens Axboe , Kent Overstreet , Ming Lin , Al Viro , Ming Lei , Neil Brown , Alasdair Kergon , Mike Snitzer , dm-devel@redhat.com, drbd-dev@lists.linbit.com, Jiri Kosina , Geoff Levand , Jim Paris , Joshua Morris , Philip Kelleher , Minchan Kim , Nitin Gupta , Oleg Drokin , Andreas Dilger List-Id: dm-devel.ids On Tue, Dec 23, 2014 at 12:41:40PM +0100, Dongsu Park wrote: > You mean, checking rq->cmd_type == REQ_TYPE_BLOCK_PC, right? > > I'm wondering about how to check that in blk_queue_split(). > At the moment when blk_queue_split() is called, it's even before a request > is mapped e.g. in blk_sq_make_request(). > Unlike scsi drivers where it's easy to get cmd->rq, blk_queue_split() > doesn't seem to be able to get a request by blk_get_request(). > > Or am I missing something? You're probably missing what I didn't notice either: BLOCK_PC requests are never sent through ->make_request. Consider my comment withdrawn and sorry for the confusion. From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.9]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by mail09.linbit.com (LINBIT Mail Daemon) with ESMTPS id 789D01028A59 for ; Sat, 27 Dec 2014 16:02:19 +0100 (CET) Date: Sat, 27 Dec 2014 07:02:07 -0800 From: Christoph Hellwig To: Dongsu Park Message-ID: <20141227150207.GC1094@infradead.org> References: <20141223101614.GA13138@infradead.org> <20141223114140.GB15080@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20141223114140.GB15080@gmail.com> Cc: Jens Axboe , Oleg Drokin , Nitin Gupta , Mike Snitzer , Ming Lin , Minchan Kim , Neil Brown , Jiri Kosina , Ming Lei , linux-kernel@vger.kernel.org, Jim Paris , Philip Kelleher , Christoph Hellwig , Geoff Levand , Kent Overstreet , Al Viro , Andreas Dilger , dm-devel@redhat.com, Joshua Morris , Alasdair Kergon , drbd-dev@lists.linbit.com Subject: Re: [Drbd-dev] [RFC PATCH 01/17] block: make generic_make_request handle arbitrarily sized bios List-Id: "*Coordination* of development, patches, contributions -- *Questions* \(even to developers\) go to drbd-user, please." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On Tue, Dec 23, 2014 at 12:41:40PM +0100, Dongsu Park wrote: > You mean, checking rq->cmd_type == REQ_TYPE_BLOCK_PC, right? > > I'm wondering about how to check that in blk_queue_split(). > At the moment when blk_queue_split() is called, it's even before a request > is mapped e.g. in blk_sq_make_request(). > Unlike scsi drivers where it's easy to get cmd->rq, blk_queue_split() > doesn't seem to be able to get a request by blk_get_request(). > > Or am I missing something? You're probably missing what I didn't notice either: BLOCK_PC requests are never sent through ->make_request. Consider my comment withdrawn and sorry for the confusion.