Commit 6ca792ed authored Jul 01, 2013 by Maarten ter Huurne Committed by Theodore Ts'o Jul 01, 2013

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 <maarten@treewalker.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
CC: stable@vger.kernel.org

parent 03b40e34

fs/ext4/resize.c

+1 −3

Original line number	Diff line number	Diff line
		@@ -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;

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