From: Maarten ter Huurne Date: Mon, 1 Jul 2013 12:12:08 +0000 (-0400) Subject: ext4: fix corruption when online resizing a fs with 1K block size X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=6ca792edc13c409e8d4eb9001e048264c6a2eb64;p=linux-beck.git 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 --- 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 @@ 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;