[PATCH v2 0/7] btrfs: allocator perf improvements

[Boris Burkov <boris@bur.io>]

Working on the bugs to do with large fs-es and unused block groups

https://lore.kernel.org/linux-btrfs/20260916230447.GA1706558@zen.localdomain/T/#t
and
https://lore.kernel.org/linux-btrfs/cover.1790641111.git.boris@bur.io/T/#t

revealed some low hanging fruit in allocation performance for very large
mostly full fs-es. The gist is to try to skip unnecessary operations per block
group which adds up with 10s of thousands of obviously skippable block
groups. Running 20k fallocates in a loop on a sparse file fs improved from
~40s to ~7s.

Changelog:
v2:
- removed data_rwsem and delalloc_bytes from block_group and find_free_extent()


Boris Burkov (7):
  btrfs: skip unhelpful size class relaxing allocation loops
  btrfs: don't take block group references in find_free_extent()
  btrfs: remove redundant checks in find_free_extent() hint path
  btrfs: factor the find_free_extent() block group skip into a helper
  btrfs: find_free_extent checks full block groups unlocked
  btrfs: find_free_extent checks size class unlocked
  btrfs: remove block_group data_rwsem and delalloc_bytes

 fs/btrfs/block-group.c |  12 +--
 fs/btrfs/block-group.h |  13 +---
 fs/btrfs/direct-io.c   |   4 +-
 fs/btrfs/extent-tree.c | 166 +++++++++++++++++------------------------
 fs/btrfs/extent-tree.h |   9 ++-
 fs/btrfs/inode.c       |  36 +++------
 fs/btrfs/relocation.c  |  16 ++--
 fs/btrfs/space-info.c  |   5 +-
 8 files changed, 100 insertions(+), 161 deletions(-)

-- 
2.56.0