Can be fetched from github:
https://github.com/adam900710/linux/tree/refactor_find_free_extent
Which is based on v4.19-rc1.
extent-tree.c::find_free_extent() could be one of the most
ill-structured functions, it has at least 6 non-exit tags and jumps
between them.
Refactor it into 4 parts:
1) find_free_extent()
The main entrance, does the main work of block group iteration and
block group selection.
Now this function doesn't care nor handles free extent search by
itself.
2) find_free_extent_clustered()
Do clustered free extent search.
May try to build/re-fill cluster.
3) find_free_extent_unclustered()
Do unclustered free extent search.
May try to fill free space cache.
4) find_free_extent_update_loop()
Do the loop based black magic.
May allocate new chunk.
With this patch, at least we should make find_free_extent() a little
easier to read, and provides the basis for later work on this function.
Current refactor is trying not to touch the original functionality, thus
the helper structure find_free_extent_ctl still contains a lot of
unrelated members.
But it should not change how find_free_extent() works at all.
changelog:
v2:
Split into 4 patches.
Minor comment newline change.
v3:
Mostly cosmetic update.
Rebased to v4.19-rc1
Rename find_free_extent_ctrl to find_free_extent_ctl to keep the
naming scheme the same.
Fix some comment spelling error.
Enhance comment for find_free_extent_unclustered().
Add reviewed-by tag.
v4:
Move the (ins->objectid) check to proper location of the last patch,
so all (!ins->objectid) branches are in the same code block.
Add reviewed-by tags from Josef.
Qu Wenruo (4):
btrfs: Introduce find_free_extent_ctl structure for later rework
btrfs: Refactor clustered extent allocation into
find_free_extent_clustered()
btrfs: Refactor unclustered extent allocation into
find_free_extent_unclustered()
btrfs: Refactor find_free_extent() loops update into
find_free_extent_update_loop()
fs/btrfs/extent-tree.c | 704 ++++++++++++++++++++++++-----------------
1 file changed, 406 insertions(+), 298 deletions(-)
--
2.19.1
