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

Jeff Garzik
2006-06-09T17:50:15Z

Matthew Wilcox wrote:
> On Fri, Jun 09, 2006 at 10:30:06AM -0700, Linus Torvalds wrote:
>> And I'm not saying that just because it's a filesystem, and people get
>> upset if they lose data. No, I'm saying it because from a maintenance
>> standpoint, such a filesystem has almost zero cost.
>
> One of the costs (and I'm not disagreeing with your main point;
> I think forking ext3 to ext4 at this point is reasonable), is that
> bugfixes applied to one don't necessarily get applied to the other.
> I found some recently between ext2 and ext3, and submitted those, but I
> only audited one file. There's lots more to look at and I just haven't
> found the time recently. Going to three variations is a lot more work
> for auditing, and it might be worth splitting some bits which genuinely
> are the same into common code.

With extents and 48bit, you have multiple code paths to audit, regardless.

If applied to ext3, you have to audit

fs/ext3/*.c:
if (extents)
...
else
...

as opposed to

fs/ext3/*.c:
... non-extent code
fs/ext4/*.c:
... extent code