Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1763058Ab3IDQL3 (ORCPT ); Wed, 4 Sep 2013 12:11:29 -0400 Received: from mail-ea0-f170.google.com ([209.85.215.170]:49869 "EHLO mail-ea0-f170.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762951Ab3IDQL0 (ORCPT ); Wed, 4 Sep 2013 12:11:26 -0400 MIME-Version: 1.0 In-Reply-To: <1376078164-23147-1-git-send-email-snitzer@redhat.com> References: <1376078164-23147-1-git-send-email-snitzer@redhat.com> Date: Wed, 4 Sep 2013 09:11:25 -0700 Message-ID: Subject: Re: [PATCH 1/2] Revert "Revert "math64: New div64_u64_rem helper"" From: Anatol Pomozov To: Mike Snitzer Cc: dm-devel@redhat.com, LKML , Mikulas Patocka , Stanislaw Gruszka , Frederic Weisbecker , Ingo Molnar Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 905 Lines: 20 Hi, On Fri, Aug 9, 2013 at 12:56 PM, Mike Snitzer wrote: > This reverts commit f3002134158092178be81339ec5a22ff80e6c308. > > div64_u64_rem was removed because there were no other users. In the light of this discussion https://lkml.org/lkml/2013/8/30/417 we will have more users of div64_u64_rem For example code from ext4_mb_find_by_goal() function uses function do_div() with divisor sbi->s_stripe that has "unsigned long" type. do_div() silently truncates the type to 32bits and do_div() returns incorrect result (or crash if lower 32bits are zero). It should be either replaced with div64_u64_rem() posted here or with just "a % b". -- 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/