docs: def tuned(name, **kwargs):
      '''
      Manage options of block device
  
      name
          The name of the block device
  
      opts:
        - read-ahead
            Read-ahead buffer size
  
        - filesystem-read-ahead
            Filesystem Read-ahead buffer size
  
        - read-only
            Set Read-Only
  
        - read-write
            Set Read-Write
      '''
  
      ret = {'changes': {},
             'comment': '',
             'name': name,
             'result': True}
  
      kwarg_map = {'read-ahead': 'getra',
                   'filesystem-read-ahead': 'getfra',
                   'read-only': 'getro',
                   'read-write': 'getro'}
  
      if not __salt__['file.is_blkdev']:
          ret['comment'] = ('Changes to {0} cannot be applied. '
                            'Not a block device. ').format(name)
      elif __opts__['test']:
          ret['comment'] = 'Changes to {0} will be applied '.format(name)
          ret['result'] = None
          return ret
      else:
          current = __salt__['disk.dump'](name)
          changes = __salt__['disk.tune'](name, **kwargs)
          changeset = {}
          for key in kwargs:
              if key in kwarg_map:
                  switch = kwarg_map[key]
                  if current[switch] != changes[switch]:
                      if isinstance(kwargs[key], bool):
                          old = (current[switch] == '1')
                          new = (changes[switch] == '1')
                      else:
                          old = current[switch]
                          new = changes[switch]
                      if key == 'read-write':
                          old = not old
                          new = not new
                      changeset[key] = 'Changed from {0} to {1}'.format(old, new)
          if changes:
              if changeset:
                  ret['comment'] = ('Block device {0} '
                                    'successfully modified ').format(name)
                  ret['changes'] = changeset
              else:
                  ret['comment'] = 'Block device {0} already in correct state'.format(name)
          else:
              ret['comment'] = 'Failed to modify block device {0}'.format(name)
              ret['result'] = False
      return ret