From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752811Ab0CCHaS (ORCPT ); Wed, 3 Mar 2010 02:30:18 -0500 Received: from 0122700014.0.fullrate.dk ([95.166.99.235]:45342 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752257Ab0CCHaQ (ORCPT ); Wed, 3 Mar 2010 02:30:16 -0500 Date: Wed, 3 Mar 2010 08:30:14 +0100 From: Jens Axboe To: Dmitry Monakhov Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/2] blkdev: fix merge_bvec_fn return value checks Message-ID: <20100303073014.GE5768@kernel.dk> References: <1267292113-12900-1-git-send-email-dmonakhov@openvz.org> <20100228184634.GI5768@kernel.dk> <874okyf4iw.fsf@openvz.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <874okyf4iw.fsf@openvz.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Mar 03 2010, Dmitry Monakhov wrote: > Jens Axboe writes: > > > On Sat, Feb 27 2010, Dmitry Monakhov wrote: > >> merge_bvec_fn() returns bvec->bv_len on success. So we have to check > >> against this value. But in case of fs_optimization merge we compare > >> with wrong value. This patch must be included in > >> b428cd6da7e6559aca69aa2e3a526037d3f20403 > >> But accidentally i've forgot to add this in the initial patch. > >> To make things straight let's replace all such checks. > >> In fact this makes code easy to understand. > > > > Agree, applied. > Ohh.. as you already know this patch break dm-layer. Sorry. > This is because dm->merge may return more than requested. So correct > check must test against less what requested. Correct patch attached. Have you tested this with dm and md (ie actual users of the merge_bvec functionality) this time? -- Jens Axboe