This patch is part of dm/md dependency tree in sysfs.

This adds bd_claim_by_kobject() function which takes kobject as
additional signature of holder device and creates sysfs symlinks
between holder device and claimed device.
bd_release_from_kobject() is a counter part of bd_claim_by_kobject.

Thanks,
-- 
Jun'ichi Nomura, NEC Solutions (America), Inc.