locks: set fl_owner for leases to filp instead of current->files

Like flock locks, leases are owned by the file description. Now that the
i_have_this_lease check in __break_lease is gone, we don't actually use
the fl_owner for leases for anything. So, it's now safe to set this more
appropriately to the same value as the fl_file.

While we're at it, fix up the comments over the fl_owner_t definition
since they're rather out of date.
Signed-off-by: NJeff Layton <jlayton@primarydata.com>

fs/locks.c

@@ -465,7 +465,7 @@ static int lease_init(struct file *filp, long type, struct file_lock *fl)
 	if (assign_type(fl, type) != 0)
 		return -EINVAL;
 
-	fl->fl_owner = current->files;
+	fl->fl_owner = filp;
 	fl->fl_pid = current->tgid;
 
 	fl->fl_file = filp;

include/linux/fs.h

@@ -851,13 +851,7 @@ static inline struct file *get_file(struct file *f)
  */
 #define FILE_LOCK_DEFERRED 1
 
-/*
- * The POSIX file lock owner is determined by
- * the "struct files_struct" in the thread group
- * (or NULL for no owner - BSD locks).
- *
- * Lockd stuffs a "host" pointer into this.
- */
+/* legacy typedef, should eventually be removed */
 typedef void *fl_owner_t;
 
 struct file_lock_operations {