[Ocfs2-devel] [PATCH 0/10] Make ocfs2_extent_tree a first-class object

[Joel Becker]

The new xattr code introduced a great abstraction, ocfs2_extent_tree.
However, it's hidden in alloc.c.  Tao said he wanted to keep it there,
but I think it works great as a first-class object.

Callers into alloc.c can just fill in an ocfs2_extent_tree with the
appropriate ocfs2_get_*_extent_tree() function, then pass it to all
alloc.c functions.  Those functions no longer need individual root_bh,
root_el, et_type, or void*private arguments.  People filling in dinode
extent trees don't even need to pass NULL for that private.

The series first adds structure prefixes to ocfs2_extent_tree and
ocfs2_extent_tree_operations.  Next, it turns 'private' into 'object',
calculating object as bh->b_data if it was NULL.  Third, we calculate
the other fields (root_el, max_leaf_extents) in operations rather than
if blocks.  Finally, we remove the et_type, the if block, and start
using extent trees as first class objects.

Check out the last patch, which is really the payoff, to see what I'm
going for.

Joel