Re: radix tree implementation for quota ?

[Ignatios Souvatzis <is%netbsd.org@localhost>]

hi,

On Sun, Nov 28, 2010 at 05:53:59PM +0100, Manuel Bouyer wrote:
> Hello,
> our FFS quota system is pretty outdated and is less and less suitable
> for modern storage (quotacheck is long and can't be avoided). I'm thinking
> about coding a new quota system with would be more closely integrated
> with the filesystem, where quotas would be integrated with filesystem
> metadata (maybe as part of a hidden indode, the same way WAPBL has a
> inode for in-filesystem log). With this, quotas can be checked by fsck_ffs(8)
> at almost 0 cost in time, and it can be covered by WAPBL, completely
> eliminating the need for quotacheck(8) on reboot.

uhm, but our current quota implementation - at least as described by
the 4.3BSD paper - does that, only that the inode isn't hidden...
 
> One open question is how to store quota informations on disk.
> At this time we use one big array indexed by uid or gid. This can
> be very space-consuming

Why? It's a sparse file unless you copy it using cp.

        -is