Merge branch 'layoutfixes'

Merge branch 'layoutfixes'

* layoutfixes:
  NFSv4.1/pnfs: Remove redundant wakeup in pnfs_send_layoutreturn()
  NFSv4.1/pnfs: Remove redundant check in pnfs_layoutgets_blocked()
  NFSv4.1/pnfs: Remove redundant lo->plh_block_lgets in layoutreturn
  NFSv4.1/pnfs: Don't prevent layoutgets when doing return-on-close
  NFSv4.1/pnfs: Fix serialisation of layout return and layoutget
  NFSv4.1/pnfs: Remove redundant checks in pnfs_layoutgets_blocked()
  pNFS: Tighten up locking around DS commit buckets