[PATCH 0/3] Use generic percpu counters in XFS V2

[Dave Chinner]

This series replaces the XFS per-cpu superblock counters with
generic per-cpu counters. It adds a specialised operation to the
generic counter implementation and then switches the XFS percpu
superblock counters over to use the generic percpu counter
implementation. The result is several hundred lines of complex code
removed from XFS.

Version 2:
- use wrappers for percpu_counter_add_unless_lt() to allow custom
  batch sizes to be used.
- removed xfs_icsb_*() wrappers from percpu counters.
- cleaned up split of xfs_icsb_modify_counters().