From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maarten ter Huurne Subject: [PATCH] ext4: Fixed corruption when online resizing a fs with 1K block size Date: Mon, 6 May 2013 18:06:07 +0200 Message-ID: <1367856367-15924-1-git-send-email-maarten@treewalker.org> Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, Maarten ter Huurne To: "Theodore Ts'o" , Andreas Dilger Return-path: Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org 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. 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