Re: [PATCH 14/31] libext2fs: Fix ext2fs_open2() truncation of the superblock parameter

Theodore Ts'o
2013-10-08T15:59:22Z

On Mon, Sep 30, 2013 at 06:28:12PM -0700, Darrick J. Wong wrote:
> Since it's possible for very large filesystems to store backup superblocks at
> very large (> 2^32) block numbers, we need to be able to handle the case of a
> caller directing us to read one of these high-numbered backups.
>
> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>

Hmm... This is technically true, but I'm wondering how much we should
care. In practice, users almost always use the first couple of backup
superblocks. I could imagine a situation with a RAID array where the
first disk(s) were trashed, so we needed to use a backup superblock
beyond 2**32, but it's a bit unlikely.

If there was some other reason why we needed to add a new ext2fs_open3
variant, it would certainly be a good thing to fix. But I'm wondering
if it's worth adding a new interface just for this.

Is there perhaps any other extensions to ext2fs_open() that we might
want to make, either now or in the future?

Regards,

- Ted