[PATCH] dm/md dependency tree in sysfs: bd_claim_by_kobject

Adding 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 counterpart of
bd_claim_by_kobject.

Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com>
Cc: Alasdair G Kergon <agk@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>