Merge tag 'xfs-4.16-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs fixes from Darrick Wong:

 - Fix some iomap locking problems

 - Don't allocate cow blocks when we're zeroing file data

* tag 'xfs-4.16-fixes-3' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: don't block on the ilock for RWF_NOWAIT
  xfs: don't start out with the exclusive ilock for direct I/O
  xfs: don't allocate COW blocks for zeroing holes or unwritten extents