Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760128AbZDAMZV (ORCPT ); Wed, 1 Apr 2009 08:25:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1764058AbZDAMYi (ORCPT ); Wed, 1 Apr 2009 08:24:38 -0400 Received: from brick.kernel.dk ([93.163.65.50]:54312 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1764072AbZDAMYh (ORCPT ); Wed, 1 Apr 2009 08:24:37 -0400 Date: Wed, 1 Apr 2009 14:24:35 +0200 From: Jens Axboe To: FUJITA Tomonori Cc: tj@kernel.org, bharrosh@panasas.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/8] block: fix SG_IO vector request data length handling Message-ID: <20090401122434.GE5178@kernel.dk> References: <1238583884-13517-3-git-send-email-tj@kernel.org> <20090401204716N.fujita.tomonori@lab.ntt.co.jp> <20090401115058.GD5178@kernel.dk> <20090401211851Y.fujita.tomonori@lab.ntt.co.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090401211851Y.fujita.tomonori@lab.ntt.co.jp> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1548 Lines: 42 On Wed, Apr 01 2009, FUJITA Tomonori wrote: > On Wed, 1 Apr 2009 13:50:58 +0200 > Jens Axboe wrote: > > > On Wed, Apr 01 2009, FUJITA Tomonori wrote: > > > On Wed, 1 Apr 2009 20:04:38 +0900 > > > Tejun Heo wrote: > > > > > > > Impact: fix SG_IO behavior such that it matches the documentation > > > > > > > > SG_IO howto says that if ->dxfer_len and sum of iovec disagress, the > > > > shorter one wins. However, the current implementation returns -EINVAL > > > > for such cases. Trim iovc if it's longer than ->dxfer_len. > > > > > > Is that description about sg's SG_IO? > > > > The more important question is what sg.c actually does, that's more > > important than the documentation. > > Do you think that Doug is a person who makes such mistake? ;) > > Seems that sg worked as the howto says. But I think that I broke it > when I converted sg to use the block layer. I'll fix it soon. OK > About this patch, as we know, there are lots of subtle differences > between sg's SG_IO and the block's. I'm not sure that it's a good idea > to change the behavior of the block's SG_IO. Depends on what it is. For something like this where the alternative is returning -EINVAL and the patch makes it work, we definitely should just do it. -- 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/