From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jan Kara Subject: Re: [PATCH] ext4: Fixed corruption when online resizing a fs with 1K block size Date: Wed, 8 May 2013 15:58:25 +0200 Message-ID: <20130508135825.GA3810@quack.suse.cz> References: <1367856367-15924-1-git-send-email-maarten@treewalker.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Theodore Ts'o , Andreas Dilger , linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org To: Maarten ter Huurne Return-path: Content-Disposition: inline In-Reply-To: <1367856367-15924-1-git-send-email-maarten@treewalker.org> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Mon 06-05-13 18:06:07, Maarten ter Huurne wrote: > Subtracting the number of the first data block places the superblock > backups one block too early, corrupting the file system. When the block > size is larger than 1K, the first data block is 0, so the subtraction > has no effect and no corruption occurs. Looking where mke2fs places backup super blocks you are right. You can add: Reviewed-by: Jan Kara Honza > > Signed-off-by: Maarten ter Huurne > --- > fs/ext4/resize.c | 4 +--- > 1 file changed, 1 insertion(+), 3 deletions(-) > > diff --git a/fs/ext4/resize.c b/fs/ext4/resize.c > index c169477..116c80d 100644 > --- a/fs/ext4/resize.c > +++ b/fs/ext4/resize.c > @@ -1654,12 +1654,10 @@ errout: > err = err2; > > if (!err) { > - ext4_fsblk_t first_block; > - first_block = ext4_group_first_block_no(sb, 0); > if (test_opt(sb, DEBUG)) > printk(KERN_DEBUG "EXT4-fs: extended group to %llu " > "blocks\n", ext4_blocks_count(es)); > - update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr - first_block, > + update_backups(sb, EXT4_SB(sb)->s_sbh->b_blocknr, > (char *)es, sizeof(struct ext4_super_block), 0); > } > return err; > -- > 1.7.10.4 > > -- > 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 -- Jan Kara SUSE Labs, CR