Re: [Ext2-devel] [RFC 0/13] extents and 48bit ext3

Jeff Garzik
2006-06-09T21:56:59Z

H. Peter Anvin wrote:
> Followup to: <4489EAFE.6090303@garzik.org>
> By author: Jeff Garzik <jeff@garzik.org>
> In newsgroup: linux.dev.kernel
>> Theodore Tso wrote:
>>> And I'd also dispute with your "weren't really suited for the original
>>> ext2-style design" comment. Ext2/3 was always designed to be
>>> extensible from the start, and we've successfully added features quite
>>> successfully for quite a while.

>> Although not the only disk format change, extents are a pretty big one.
>> Will this be the last major on-disk format change?

> "Last" is a pretty strong word. Will extents be combined with 64-bit
> block numbers? That's becoming increasingly urgent.

Right, and that proves my point. When you start making major changes
like 32->64 bit block numbers, you should communicate to the user (with
a big blinky "ext4" sign) that his filesystem metadata will change a
lot, not a little. Not to mention that such code will add yet more "if
(new) .. else .." code.

Jeff