Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Tue, 15 Oct 2002 05:30:33 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Tue, 15 Oct 2002 05:30:33 -0400 Received: from ns.virtualhost.dk ([195.184.98.160]:13445 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id ; Tue, 15 Oct 2002 05:30:31 -0400 Date: Tue, 15 Oct 2002 11:36:08 +0200 From: Jens Axboe To: Joe Thornber Cc: Austin Gonyou , linux-lvm@sistina.com, Alan Cox , Linux Kernel Mailing List Subject: Re: [linux-lvm] Re: [PATCH] 2.5 version of device mapper submission Message-ID: <20021015093608.GF5294@suse.de> References: <1034453946.15067.22.camel@irongate.swansea.linux.org.uk> <1034614756.29775.5.camel@UberGeek.coremetrics.com> <20021014175608.GA14963@fib011235813.fsnet.co.uk> <20021015082152.GA4827@suse.de> <20021015093244.GA3782@fib011235813.fsnet.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20021015093244.GA3782@fib011235813.fsnet.co.uk> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1504 Lines: 40 On Tue, Oct 15 2002, Joe Thornber wrote: > On Tue, Oct 15, 2002 at 10:21:52AM +0200, Jens Axboe wrote: > > On Mon, Oct 14 2002, Joe Thornber wrote: > > > 10.patch > > > [Device-mapper] > > > Add call to blk_queue_bounce() at the beginning of the request function. > > > > What on earth for? I also see that you are setting BLK_BOUNCE_HIGH as > > the bounce limit unconditionally for your queue. Puzzled. > > This is just me stupidly copying loop.c, already found out it doesn't > work. Please ignore. Well it should work, but dm never ever wants to bounce any data on its own. That should only happen at the target queue, if at all. > > When does dm even have to touch the data in the bio? > > Tell me; if I'm splitting a bio using bio_clone, and then map the bio > to a driver that calls blk_queue_bounce. How can I avoid the > > BUG_ON((*bio_orig)->bi_idx); > > triggering ? Or is bio_clone not to be used anymore ? (btw, do you have a complete patch against a recent kernel?) Bouncing has just never been used with a cloned bio, so there might be a corner case or two that needs to be fixed up. But walk me through your request handling, please. It seems you are always allocating a clone_info and bio clone for io? -- Jens Axboe - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/