locks: plumb a "priv" pointer into the setlease routines

In later patches, we're going to add a new lock_manager_operation to
finish setting up the lease while still holding the i_lock.  To do
this, we'll need to pass a little bit of info in the fcntl setlease
case (primarily an fasync structure). Plumb the extra pointer into
there in advance of that.

We declare this pointer as a void ** to make it clear that this is
private info, and that the caller isn't required to set this unless
the lm_setup specifically requires it.

Signed-off-by: Jeff Layton <jlayton@primarydata.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>

fs/libfs.c

@@ -1081,12 +1081,14 @@ EXPORT_SYMBOL(alloc_anon_inode);
  * @filp: file pointer
  * @arg: type of lease to obtain
  * @flp: new lease supplied for insertion
+ * @priv: private data for lm_setup operation
  *
  * Generic helper for filesystems that do not wish to allow leases to be set.
  * All arguments are ignored and it just returns -EINVAL.
  */
 int
-simple_nosetlease(struct file *filp, long arg, struct file_lock **flp)
+simple_nosetlease(struct file *filp, long arg, struct file_lock **flp,
+		  void **priv)
 {
 	return -EINVAL;
 }