From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261962AbUBZPdQ (ORCPT ); Thu, 26 Feb 2004 10:33:16 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262074AbUBZPdP (ORCPT ); Thu, 26 Feb 2004 10:33:15 -0500 Received: from ns.virtualhost.dk ([195.184.98.160]:33471 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S261962AbUBZPdL (ORCPT ); Thu, 26 Feb 2004 10:33:11 -0500 Date: Thu, 26 Feb 2004 16:33:07 +0100 From: Jens Axboe To: Christophe Saout Cc: LKML , Andrew Morton Subject: Re: [PATCH] fix small highmem bio bounce bvec handling glitch Message-ID: <20040226153307.GS7580@suse.de> References: <1077807966.10397.2.camel@leto.cs.pocnet.net> <20040226151026.GQ7580@suse.de> <1077809433.10397.11.camel@leto.cs.pocnet.net> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1077809433.10397.11.camel@leto.cs.pocnet.net> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Feb 26 2004, Christophe Saout wrote: > Am Do, den 26.02.2004 schrieb Jens Axboe um 16:10: > > > > --- linux.orig/mm/highmem.c 2004-01-21 19:08:45.000000000 +0100 > > > +++ linux/mm/highmem.c 2004-02-26 15:47:14.574722576 +0100 > > > @@ -294,7 +294,12 @@ > > > if (tovec->bv_page == fromvec->bv_page) > > > continue; > > > > > > - vfrom = page_address(fromvec->bv_page) + fromvec->bv_offset; > > > + /* > > > + * fromvec->bv_offset and fromvec->bv_len might have been > > > + * modified by the block layer, so use the original copy, > > > + * bounce_copy_vec already uses tovec->bv_len > > > + */ > > > + vfrom = page_address(fromvec->bv_page) + tovec->bv_offset; > > > > > > bounce_copy_vec(tovec, vfrom); > > > > Irk yes, that's is pretty nasty, I really wish we could avoid screwing > > with vec entries > > What about a bio->bi_bvec_done field? That'd work. Suparna originally suggested bio->bi_voffset (iirc) as a current offset. It just doesn't feel completely right... > > (it's pretty obscure for bio clones, too)... > > Yes, I noticed that dm-crypt also does the same mistake for reads. I'm > going to change it too (easily accomplished). Great. -- Jens Axboe