From 6ca792edc13c409e8d4eb9001e048264c6a2eb64 Mon Sep 17 00:00:00 2001 From: Maarten ter Huurne Date: Mon, 1 Jul 2013 08:12:08 -0400 Subject: [PATCH] ext4: fix corruption when online resizing a fs with 1K block size 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 Signed-off-by: "Theodore Ts'o" Reviewed-by: Jan Kara CC: stable@vger.kernel.org --- 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 707095b924d9..c5adbb318a90 100644 --- a/fs/ext4/resize.c +++ b/fs/ext4/resize.c @@ -1660,12 +1660,10 @@ static int ext4_group_extend_no_check(struct super_block *sb, 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;