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

Mingming Cao
2006-06-13T00:29:05Z

On Sun, 2006-06-11 at 14:39 +1000, Neil Brown wrote:
> On Saturday June 10, jeff@garzik.org wrote:
> > Theodore Tso wrote:
> > > So you you would be in OK of a model where we copy fs/ext3 to
> > > "fs/ext4", and do development there which would merged rapidly into
> > > mainline so that people who want to participate in testing can use
> > > ext3dev, while people who want stability can use ext3 --- and at some
> > > point, we remove the old ext3 entirely and let fs/ext4 register itself
> > > as both the ext3 and ext4 filesystem, and at some point in the future,
> > > remove the ext3 name entirely?
> >
> > Yep, and in addition I would argue that you can take the opportunity to
> > make ext4 default to extents-enabled, and some similar behavior changes
> > (dir_index default?). The existence of both ext3 and ext4 means you can
> > be more aggressive in turning on stuff, IMO.
> >
> > Jeff
>
> I'm wondering what all this has to say about general principles of
> sub-project development with the Linux kernel.
>
> There is a strong tradition of software projects having a 'stable'
> branch and a 'development' branch, and having both available and both
> receiving bug fixes (at least) so that users can choose what best
> suits their needs.
>
> Due to the (quite appropriate) lack of a stable API for kernel
> modules, it isn't really practical (and definitely isn't encouraged)
> to distribute kernel-modules separately. This seems to suggest that
> if we want a 'stable' and a 'devel' branch of a project, both branches
> need to be distributed as part of the same kernel tree.
>
> Apart from ext2/3 - and maybe reiserfs - there doesn't seem to be much
> evidence of this happening. Why is that?
>
> - is -mm enough? It seems to be enough for small updates, but
> doesn't seem to be enough for more major projects. How long
> have the ext3 patches been in -mm?? (I cannot actually seem
> to find them there at all)
>

To clarify, the first 4 patches of the series are bug fixes for both 32
bit ext3 (with current on-disk layout) and 48 bit ext3(extents based),
they are in mm tree now. The rest of the patches 5-13 to support 48 bit
ext3 based on extents are not in mm tree.