Merge branch 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md...

Pull MD updates from Song:

"Non-urgent fixes:
   md: don't update recovery_cp when curr_resync is ACTIVE
   md: Free writes_pending in md_stop

 Performance optimization:
   md: Change active_io to percpu"

* 'md-next' of https://git.kernel.org/pub/scm/linux/kernel/git/song/md:
  md: use MD_RESYNC_* whenever possible
  md: Free writes_pending in md_stop
  md: Change active_io to percpu
  md: Factor out is_md_suspended helper
  md: don't update recovery_cp when curr_resync is ACTIVE