- Provide unionfs_add_writecount() which passes the writecount to the
lower or upper vnode as appropriate.
- In unionfs VOP_RECLAIM() implementation, annulate unionfs
writecounts from upper or lower vnode. It is not clear that it is
always correct to remove the all references from either lower or
upper vnode, but we currently do not track which vnode get how many
refs anyway.
Reported and tested by: t_uemura@macome.co.jp
MFC after: 1 week
Sponsored by: The FreeBSD Foundation