Re: RFC: what's in a stable series?

[Christoph Hellwig]

On Thu, Jul 10, 2003 at 01:42:00PM +0100, Alan Cox wrote:
> On Iau, 2003-07-10 at 13:13, Marcelo Tosatti wrote:
> > So Christoph's quota patch does not support vendors "v1" files?
> > 
> > I must be misunderstanding someone.
> 
> There are three species of quota in Linux
> 
> v0	(official old Linux)
> v1	(most 2.4 vendor trees)
> v2	(the 2.5 format)

Umm, no.  You misunderstood.

There's two quota _ondisk_ formats:

v1 old 16bit quota.
v2 new 32bit quota.

2.4 previously only supported v1, 2.5 and 2.4.22-pre4 also support v2.

There's three sys_quotactl ABIs

1) original 16 bit one, supported by all kernels <= 2.4
2) first 32bit one, supported by 2.4-ac any many vendor trees, but never
   in mainline
3) new 32bit one, supported by 2.4.x (x >= 22-pre4) and 2.5

Unfortunately the second one uses the same constants as the old 16bit one
but different structures so there is no way to support both in a single
kernel.