Re: [PATCH 1/3] quota: Add a new quotactl command Q_XGETQSTATV

[Jan Kara <jack@suse.cz>]

On Tue 20-08-13 23:43:57, Christoph Hellwig wrote:
> Sorry for being late to the game, but I don not like the in-kernel
> interface here at all.  Given that Q_XGETQSTATV is a strict superset
> of Q_XGETQSTAT there is no need for the second method - just always
> fill out the larger in-kernel structure and only copy the smaller
> information to userspace for the Q_XGETSTAT case.  That keeps the amount
> of code required in the implementations of the methods low and follows
> the model used elsewhere in the kernel (e.g. stat and statfs)
  Well, the trouble is with gquota vs pquota - previously we report in
qs_gquota field either group quotas or project quotas depending on what is
turned on. Generic quota code doesn't know this so xfs get_xstatev() would
have to recognize whether it is being called from the old Q_XGETSTAT
quotactl or from the new Q_XGETSTATV quotactl to know where to fill in
project quotas. And at that point you somewhat loose the elegancy of using
one interface - we could set qs_version to some special value so that
.get_xstatev() recognizes this and does the magic but that doesn't seem very
different from the extra call...

Some duplication could be certainly avoided within XFS itself.

								Honza
-- 
Jan Kara <jack@suse.cz>
SUSE Labs, CR