[Btrfs-devel] Anyone working on xattr support?

[Chris Mason]

On Tue, 31 Jul 2007 13:09:19 +1000
Jacob Zimmermann <jzimm at runbox.com> wrote:

> G'day,
> 
> There is apparently no xattr support in btrfs yet, so I'm interested
> in helping with that. 

There isn't any xattr code yet, but it is a planned feature.

> 
> I did not see any concrete information about this in the Btrfs Design
> document either, so has anyone already started working on an
> implementation or thinking about how it should be done, to avoid
> duplicating efforts?

Basically, the idea for xattrs is to add directory items to files,
where the xattr itself will be inlined in the directory item (small
xattrs) or pointed to by a key in the directory item (large xattrs).
For the large xattr case, it would actually point to an inode that
would work just like a normal file.

There are a small number of disk format changes required for this, but
my timeline is to start hammering out xattrs by the end of September.
By then I should have enospc and key range locking done in the btree.

You're welcome to dive in and code, the first step would be to make
some code that added directory items to files and was able to
add/remove empty xattrs.

-chris