From: Andreas Dilger Subject: Re: [PATCH] ext4: fix ext4_init_block_bitmap() for metablock block group Date: Mon, 16 Jun 2008 13:19:02 -0600 Message-ID: <20080616191902.GU3726@webber.adilger.int> References: <20080615142455.GA3502@localhost.localdomain> <20080616051859.GK3726@webber.adilger.int> <20080616141016.GA19080@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7BIT Cc: linux-ext4@vger.kernel.org, Andrew Morton , Stephen Tweedie , adilger@clusterfs.com, Mingming Cao , Theodore Tso To: Akinobu Mita Return-path: Received: from sca-es-mail-1.Sun.COM ([192.18.43.132]:61395 "EHLO sca-es-mail-1.sun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752651AbYFPTTM (ORCPT ); Mon, 16 Jun 2008 15:19:12 -0400 Received: from fe-sfbay-10.sun.com ([192.18.43.129]) by sca-es-mail-1.sun.com (8.13.7+Sun/8.12.9) with ESMTP id m5GJJBd1024324 for ; Mon, 16 Jun 2008 12:19:11 -0700 (PDT) Received: from conversion-daemon.fe-sfbay-10.sun.com by fe-sfbay-10.sun.com (Sun Java System Messaging Server 6.2-8.04 (built Feb 28 2007)) id <0K2K00501LGQ6400@fe-sfbay-10.sun.com> (original mail from adilger@sun.com) for linux-ext4@vger.kernel.org; Mon, 16 Jun 2008 12:19:11 -0700 (PDT) In-reply-to: <20080616141016.GA19080@localhost.localdomain> Content-disposition: inline Sender: linux-ext4-owner@vger.kernel.org List-ID: On Jun 16, 2008 23:10 +0900, Akinobu Mita wrote: > Looks good to me. But I'd like to divide into the change into simple > bugfix and cleanup patch in order to clarify the each change. > > Here is a bugfix only patch. > > From: Akinobu Mita > Subject: ext4: fix ext4_init_block_bitmap() for metablock block group > > When meta_bg feature is enabled and s_first_meta_bg != 0, > ext4_init_block_bitmap() miscalculates the number of block used by > the group descriptor table (0 or 1 for metablock block group) > > group_rel in the original code should be calculated by: > > group_rel = block_group % EXT4_DESC_PER_BLOCK(sb); > > No need to subtract s_first_meta_bg from brock_group. > It will be equivalent what ext4_bg_num_gdb_meta() does > > Signed-off-by: Akinobu Mita > Cc: Andrew Morton > Cc: Stephen Tweedie > Cc: adilger@clusterfs.com > Cc: Mingming Cao > Cc: Theodore Tso Acked-by: Andreas Dilger > --- > fs/ext4/balloc.c | 5 ++--- > 1 file changed, 2 insertions(+), 3 deletions(-) > > Index: 2.6-git/fs/ext4/balloc.c > =================================================================== > --- 2.6-git.orig/fs/ext4/balloc.c > +++ 2.6-git/fs/ext4/balloc.c > @@ -121,9 +121,8 @@ unsigned ext4_init_block_bitmap(struct s > le16_to_cpu(sbi->s_es->s_reserved_gdt_blocks); > } > } else { /* For META_BG_BLOCK_GROUPS */ > - int group_rel = (block_group - > - le32_to_cpu(sbi->s_es->s_first_meta_bg)) % > - EXT4_DESC_PER_BLOCK(sb); > + int group_rel = block_group % EXT4_DESC_PER_BLOCK(sb); > + > if (group_rel == 0 || group_rel == 1 || > (group_rel == EXT4_DESC_PER_BLOCK(sb) - 1)) > bit_max += 1; Cheers, Andreas -- Andreas Dilger Sr. Staff Engineer, Lustre Group Sun Microsystems of Canada, Inc.