The following patches provide an interface to the lease subsystem in the
current VFS locking code.  NFSv4 delegations and Samba op-locks share most
architecture features.  The version 4 NFS server delegation implementation
should use leases to co-ordinate behavior between local, Samba, and NFS
access.


The main design points are

- Seperate the fcntl interface from the file_lock FL_LEASE processing in
  fcntl_setlease, creating __setlease() called by fcntl_setlease()

- Add new lock_manager callbacks to enable lease properties to be set,
  leases to be broken, and leases to be cleaned up: with default callbacks
  preserving the current fcntl_setlease properties.

- Add a new interface, setlease() which also calls __setlease(), and
  remove_lease() for kernel lease managers (e.g.  the v4 NFS server)


This patch:

Add a lock manager copy lock callback to locks_copy_lock() so that nfsd can
set lease properties.
Signed-off-by: Andy Adamson <andros@citi.umich.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>