btrfs: some small optimizations around space_info locking and cleanups

From: Filipe Manana <fdmanana@suse.com>

Several optimizations to reduce critical sections delimited by a
space_info's spinlock and several cleanups mostly arround space
reservation and flushing. Details in the changelogs.

Filipe Manana (28):
  btrfs: return real error when failing tickets in maybe_fail_all_tickets()
  btrfs: avoid recomputing used space in btrfs_try_granting_tickets()
  btrfs: make btrfs_can_overcommit() return bool instead of int
  btrfs: avoid used space computation when trying to grant tickets
  btrfs: avoid used space computation when reserving space
  btrfs: inline btrfs_space_info_used()
  btrfs: bail out earlier from need_preemptive_reclaim() if we have tickets
  btrfs: increment loop count outside critical section during metadata reclaim
  btrfs: shorten critical section in btrfs_preempt_reclaim_metadata_space()
  btrfs: avoid unnecessary reclaim calculation in priority_reclaim_metadata_space()
  btrfs: assert space_info is locked in steal_from_global_rsv()
  btrfs: assign booleans to global reserve's full field
  btrfs: process ticket outside global reserve critical section
  btrfs: remove double underscore prefix from __reserve_bytes()
  btrfs: reduce space_info critical section in btrfs_chunk_alloc()
  btrfs: reduce block group critical section in btrfs_free_reserved_bytes()
  btrfs: reduce block group critical section in btrfs_add_reserved_bytes()
  btrfs: reduce block group critical section in do_trimming()
  btrfs: reduce block group critical section in pin_down_extent()
  btrfs: use local variable for space_info in pin_down_extent()
  btrfs: remove 'reserved' argument from btrfs_pin_extent()
  btrfs: change 'reserved' argument from pin_down_extent() to bool
  btrfs: reduce block group critical section in unpin_extent_range()
  btrfs: remove pointless label and goto from unpin_extent_range()
  btrfs: add data_race() in btrfs_account_ro_block_groups_free_space()
  btrfs: move ticket wakeup and finalization to remove_ticket()
  btrfs: avoid space_info locking when checking if tickets are served
  btrfs: tag as unlikely fs aborted checks in space flushing code

 fs/btrfs/block-group.c      |  41 +++---
 fs/btrfs/extent-tree.c      |  72 ++++++-----
 fs/btrfs/extent-tree.h      |   3 +-
 fs/btrfs/free-space-cache.c |  20 +--
 fs/btrfs/space-info.c       | 243 +++++++++++++++++++-----------------
 fs/btrfs/space-info.h       |  18 ++-
 6 files changed, 219 insertions(+), 178 deletions(-)

-- 
2.47.2