From: Andreas Dilger Subject: Re: [PATCH] e2fsck: Let end_blk to be the maximum value of u32. Date: Thu, 17 May 2012 01:12:57 -0600 Message-ID: References: <1337158225-4627-1-git-send-email-tm@tao.ma> Mime-Version: 1.0 (Apple Message framework v1084) Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 8BIT Cc: linux-ext4@vger.kernel.org, Theodore Ts'o To: Tao Ma Return-path: Received: from idcmail-mo1so.shaw.ca ([24.71.223.10]:20800 "EHLO idcmail-mo1so.shaw.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1761032Ab2EQHNE convert rfc822-to-8bit (ORCPT ); Thu, 17 May 2012 03:13:04 -0400 In-Reply-To: <1337158225-4627-1-git-send-email-tm@tao.ma> Sender: linux-ext4-owner@vger.kernel.org List-ID: On 2012-05-16, at 2:50 AM, Tao Ma wrote: > Now we can use fallocate to create a large file while keep the size > to be small. It will cause the e2fsck complain about it. The test > script is simple and I have pasted it here. We had previously added the EXT4_EOFBLOCKS_FL to distinguish the case between "corrupt i_size should be extended to match i_blocks" and "valid fallocate case of blocks allocated beyond i_size". This was removed recently, but I didn't really understand the reason why it was removed. Cheers, Andreas > DEVICE=/dev/sdb1 > mount -t ext4 $DEVICE /mnt/ext4 > for((i=0;i<10;i++))do fallocate -n -o $[$i*8192] -l 4096 /mnt/ext4/a;done > umount $DEVICE > e2fsck -fn $DEVICE > > The error message will be like this: > e2fsck 1.42.3 (14-May-2012) > Pass 1: Checking inodes, blocks, and sizes > Inode 12 has zero length extent > (invalid logical block 0, physical block 32775) > Clear? no > > Inode 12, i_blocks is 88, should be 0. Fix? no > > Pass 2: Checking directory structure > Pass 3: Checking directory connectivity > Pass 4: Checking reference counts > Pass 5: Checking group summary information > Block bitmap differences: -(8231--8232) -(32770--32778) > Fix? no > > Now actually the end_blk can be any value which is less than > u32, so make end_blk be the maximum value of u32. > > Cc: Theodore Ts'o > Signed-off-by: Tao Ma > --- > lib/ext2fs/extent.c | 4 +--- > 1 files changed, 1 insertions(+), 3 deletions(-) > > diff --git a/lib/ext2fs/extent.c b/lib/ext2fs/extent.c > index eb096d6..e2815c2 100644 > --- a/lib/ext2fs/extent.c > +++ b/lib/ext2fs/extent.c > @@ -253,9 +253,7 @@ extern errcode_t ext2fs_extent_open2(ext2_filsys fs, ext2_ino_t ino, > ext2fs_le16_to_cpu(eh->eh_entries); > handle->path[0].max_entries = ext2fs_le16_to_cpu(eh->eh_max); > handle->path[0].curr = 0; > - handle->path[0].end_blk = > - (EXT2_I_SIZE(handle->inode) + fs->blocksize - 1) >> > - EXT2_BLOCK_SIZE_BITS(fs->super); > + handle->path[0].end_blk = ((((unsigned long long) 1) << 32) - 1); > handle->path[0].visit_num = 1; > handle->level = 0; > handle->magic = EXT2_ET_MAGIC_EXTENT_HANDLE; > -- > 1.7.1 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html Cheers, Andreas