Re: RFC - tree quotas for Linux (2.4.12, ext2)

[James Sutherland]

On Wed, 24 Oct 2001, Rik van Riel wrote:
> On Wed, 24 Oct 2001, James Sutherland wrote:
>
> > Yep, you're right: you'd need to ascend the target directory tree,
> > increasing the cumulative size all the way up, then do the move and
> > decrement the old location's totals in the same way. All wrapped up in a
> > transaction (on journalled FSs) or have fsck rebuild the totals on a dirty
> > mount. Fairly clean and painless on a JFS,
>
> It's only clean and painless when you have infinite journal
> space. When your filesystem's journal isn't big enough to
> keep track of all the quota updates from an arbitrarily deep
> directory tree, you're in big trouble.

Good point. You should be able to do it in constant space, though:
identify the directory being modified, and the "height" to which you have
ascended so far. That'll allow you to back out or redo the transaction
later, which is enough I think?

James.