From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jens Axboe Subject: Re: [PATCH 4/6] virtio block driver Date: Thu, 20 Sep 2007 14:27:13 +0200 Message-ID: <20070920122713.GK2367@kernel.dk> References: <1190289808.7262.223.camel@localhost.localdomain> <1190290140.7262.228.camel@localhost.localdomain> <1190290369.7262.231.camel@localhost.localdomain> <1190290495.7262.235.camel@localhost.localdomain> <1190290606.7262.239.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: kvm-devel , lguest , virtualization To: Rusty Russell Return-path: Content-Disposition: inline In-Reply-To: <1190290606.7262.239.camel-bi+AKbBUZKY6gyzm1THtWbp2dZbC/Bob@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Errors-To: kvm-devel-bounces-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Id: kvm.vger.kernel.org On Thu, Sep 20 2007, Rusty Russell wrote: > The block driver uses scatter-gather lists with sg[0] being the > request information (struct virtio_blk_outhdr) with the type, sector > and inbuf id. The next N sg entries are the bio itself, then the last > sg is the status byte. Whether the N entries are in or out depends on > whether it's a read or a write. > > We accept the normal (SCSI) ioctls: they get handed through to the other > side which can then handle it or reply that it's unsupported. It's > not clear that this actually works in general, since I don't know > if blk_pc_request() requests have an accurate rq_data_dir(). They should, if they imply a data transfer. > Although we try to reply -ENOTTY on unsupported commands, the block > layer in its infinite wisdom suppressed the error so ioctl(fd, > CDROMEJECT) returns success to userspace. How about ever submitting a patch for that, instead of just repeatedly complaining about it? -- Jens Axboe ------------------------------------------------------------------------- This SF.net email is sponsored by: Microsoft Defy all challenges. Microsoft(R) Visual Studio 2005. http://clk.atdmt.com/MRT/go/vse0120000070mrt/direct/01/