Re: [ANNOUNCE] bcachefs!

Kent Overstreet
2015-07-24T19:16:04Z

On Tue, Jul 21, 2015 at 10:11:11PM -0700, Ming Lin wrote:
> On Fri, Jul 17, 2015 at 10:21 PM, Ming Lin <mlin@kernel.org> wrote:
> > On Fri, 2015-07-17 at 19:10 -0700, Kent Overstreet wrote:
> >> BTW - probably the most valuable thing you could help out with is the
> >> documentation, in particular the guide:
> >> http://bcache.evilpiepirate.org/BcacheGuide/
> >>
> >> Can you read through (at least some of) that, and tell me what's useful and what
> >> needs clarifying? And tell me what you'd like to see added to the guide next -
> >> I'll try and work on documentation over the next two weeks, since I probably
> >> won't be able to do much real coding with my test machines offline.
> >
> > Yes, I'll read through that.
>
> Would you add some example to explain how the extents/inodes/dirents are stored
> in the btree on disk?

Can you be more specific? Like how inodes/dirents map to keys in the btree, or
how it all ends up on disk?

The inodes/dirents code is pretty short, I'd look at inode.c and dirent.c

> I'm reading the debug code in drivers/md/bcache/debug.c.
> It seems helpful to learn about the internal btree structure.

Are you interested in more the format of the btree node itself, on disk? Like
struct btree_node, struct btree_node_entry, struct bset, and the packing?

I could try and elaborate on that in the guide, give me some specific questions
to cover if you've got any