From: Andreas Dilger Subject: Re: [PATCH] UPDATED2: types fixup for mballoc Date: Thu, 3 Jan 2008 13:35:46 -0700 Message-ID: <20080103203546.GM3351@webber.adilger.int> References: <473CCEB8.5060201@redhat.com> <473D2147.9030504@redhat.com> <477BEDAC.1030802@redhat.com> <20080103191733.GJ3351@webber.adilger.int> <477D3678.7020203@redhat.com> <477D4152.4020901@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, Alex Tomas To: Eric Sandeen Return-path: Received: from mail.clusterfs.com ([74.0.229.162]:57043 "EHLO mail.clusterfs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751622AbYACUfs (ORCPT ); Thu, 3 Jan 2008 15:35:48 -0500 Content-Disposition: inline In-Reply-To: <477D4152.4020901@redhat.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: On Jan 03, 2008 14:10 -0600, Eric Sandeen wrote: > @@ -1732,17 +1735,19 @@ static void ext4_mb_scan_aligned(struct > + /* find first stripe-aligned block in group */ > + a = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb) > + le32_to_cpu(sbi->s_es->s_first_data_block); > + a += sbi->s_stripe - 1; Why not just have "+ sbi->s_stipe - 1" on the previous line, instead of "+="? Also minor coding style nit: the "+" is normally at the end of the previous line instead of at the start of the next line, so: /* find first stripe-aligned block in group */ a = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb) + le32_to_cpu(sbi->s_es->s_first_data_block) + sbi->s_stripe - 1; > + a = (a * sbi->s_stripe) - le32_to_cpu(sbi->s_es->s_first_data_block); > + i = do_div(a, EXT4_BLOCKS_PER_GROUP(sb)); I guess this doesn't stricly need to be a modulus either, because we know which group this will be in and can just subtract the start. You can just do: /* find first stripe-aligned block in this group */ group_start = e4b->bd_group * EXT4_BLOCKS_PER_GROUP(sb) +; le32_to_cpu(sbi->s_es->s_first_data_block); a = group_start + sbi->s_stripe - 1; do_div(a, sbi->s_stripe); a = (a * sbi->s_stripe) - group_start; Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc.