Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759834AbXJDKgk (ORCPT ); Thu, 4 Oct 2007 06:36:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757285AbXJDKgc (ORCPT ); Thu, 4 Oct 2007 06:36:32 -0400 Received: from brick.kernel.dk ([87.55.233.238]:1911 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755796AbXJDKgc (ORCPT ); Thu, 4 Oct 2007 06:36:32 -0400 Date: Thu, 4 Oct 2007 12:38:05 +0200 From: Jens Axboe To: Pierre Ossman Cc: Andrew Morton , Don Mullis , linux-kernel@vger.kernel.org Subject: Re: 2.6.23-rc8-mm2: OOPS in mmc on boot Message-ID: <20071004103805.GB5711@kernel.dk> References: <1191478262.21598.5.camel@dmullis-laptop> <20071003231659.f41df5ed.akpm@linux-foundation.org> <20071004072515.GC5236@kernel.dk> <20071004100154.6093844d@poseidon.drzeus.cx> <20071004080631.GB23808@kernel.dk> <20071004104626.2a219926@poseidon.drzeus.cx> <20071004093014.GE23808@kernel.dk> <20071004122439.0944f3db@poseidon.drzeus.cx> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071004122439.0944f3db@poseidon.drzeus.cx> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1052 Lines: 31 On Thu, Oct 04 2007, Pierre Ossman wrote: > On Thu, 4 Oct 2007 11:30:14 +0200 > Jens Axboe wrote: > > > On Thu, Oct 04 2007, Pierre Ossman wrote: > > > > > > I assume sg_init_one() still can work on an uninitialized sg entry? > > > > Yes, but only if that sg entry is not part of a chained list. > > > > Is that a yes or a no? You said that the ->page field was involved in It's a conditional yes, re-read it :-) > list chaining, so does or doesn't it have to be initialized before a > call to sg_init_one()? That's not the problem. It has to be initialized before calling blk_rq_map_sg(). sg_init_one() will zero the entire sg entry, and that breaks if that particular sg entry is part of a larger sg table AND that sg entry happens to be the chain element. -- 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/