From: Andreas Dilger Subject: Re: ext3: bogus i_mode errors with 2.6.18.1 Date: Sat, 28 Oct 2006 22:24:54 +0800 Message-ID: <20061028142454.GA6182@schatzie.adilger.int> References: <20061023144556.GY22487@skl-net.de> <20061023164416.GM3509@schatzie.adilger.int> <20061023200242.GA5015@schatzie.adilger.int> <20061024091449.GZ22487@skl-net.de> <20061024202716.GX3509@schatzie.adilger.int> <20061025094418.GA22487@skl-net.de> <20061026093613.GM3509@schatzie.adilger.int> <20061026160241.GB12843@skl-net.de> <20061026180133.GN3509@schatzie.adilger.int> <20061027153414.GA6446@skl-net.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Theodore Ts'o , linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, Eric Sandeen Return-path: Received: from mail.clusterfs.com ([206.168.112.78]:62371 "EHLO mail.clusterfs.com") by vger.kernel.org with ESMTP id S1752074AbWJ1OZB (ORCPT ); Sat, 28 Oct 2006 10:25:01 -0400 To: Andre Noll Content-Disposition: inline In-Reply-To: <20061027153414.GA6446@skl-net.de> Sender: linux-ext4-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Oct 27, 2006 17:34 +0200, Andre Noll wrote: > On 12:01, Andreas Dilger wrote: > > Well, since we know at least one bit needs fixing and results in the block > > being written to disk then setting the bits for all of the other metadata > > blocks in this group has no extra IO cost (only a tiny amount of CPU). > > Re-setting the bits if they are already set is not harmful. > > I.e, something like > > int i; > ext3_fsblk_t bit; > unsigned long gdblocks = EXT3_SB(sb)->s_gdb_count; > > for (i = 0, bit = 1; i < gdblocks; i++, bit++) > ext3_set_bit(bit, gdp_bh->b_data); > > Is that correct? Well, it needs to also handle backup superblock, bitmaps, inode table: if (ext3_bg_has_super()) ext3_set_bit(0, gdp_bh->b_data); gdblocks = ext3_bg_num_gdb(sb, group); for (i = 0, bit = 1; i < gdblocks; i++, bit++) /* actually a bit more complex for INCOMPAT_META_BG fs */ ext3_set_bit(i, gdp_bh->b_data); ext3_set_bit(gdp->bg_inode_bitmap % EXT3_BLOCKS_PER_GROUP(sb), ...); ext3_set_bit(gdp->bg_block_bitmap % EXT3_BLOCKS_PER_GROUP(sb), ...); for (i = 0, bit = gdp->bg_inode_table % EXT3_BLOCKS_PER_GROUP(sb); i < EXT3_SB(sb)->s_itb_per_group; i++, bit++) ext3_set_bit(i, gdp_bh->b_data); (or something close to this). Cheers, Andreas -- Andreas Dilger Principal Software Engineer Cluster File Systems, Inc.