locks: Cleanup lm_compare_owner and lm_owner_key

After the update to use nlm_lockowners for the NLM server, there are no
more users of lm_compare_owner and lm_owner_key.

Signed-off-by: Benjamin Coddington <[e-mail]>
Signed-off-by: J. Bruce Fields <[e-mail]>

Documentation/filesystems/Locking

···
 
 ----------------------- lock_manager_operations ---------------------------
 prototypes:
-	int (*lm_compare_owner)(struct file_lock *, struct file_lock *);
-	unsigned long (*lm_owner_key)(struct file_lock *);
 	void (*lm_notify)(struct file_lock *);  /* unblock callback */
 	int (*lm_grant)(struct file_lock *, struct file_lock *, int);
 	void (*lm_break)(struct file_lock *); /* break_lease callback */
···
 locking rules:
 
 			inode->i_lock	blocked_lock_lock	may block
-lm_compare_owner:	yes[1]		maybe			no
-lm_owner_key		yes[1]		yes			no
 lm_notify:		yes		yes			no
 lm_grant:		no		no			no
 lm_break:		yes		no			no
 lm_change		yes		no			no
-
-[1]:	->lm_compare_owner and ->lm_owner_key are generally called with
-*an* inode->i_lock held. It may not be the i_lock of the inode
-associated with either file_lock argument! This is the case with deadlock
-detection, since the code has to chase down the owners of locks that may
-be entirely unrelated to the one on which the lock is being acquired.
-For deadlock detection however, the blocked_lock_lock is also held. The
-fact that these locks are held ensures that the file_locks do not
-disappear out from under you while doing the comparison or generating an
-owner key.
 
 --------------------------- buffer_head -----------------------------------
 prototypes:

fs/locks.c

···
  */
 static int posix_same_owner(struct file_lock *fl1, struct file_lock *fl2)
 {
-	if (fl1->fl_lmops && fl1->fl_lmops->lm_compare_owner)
-		return fl2->fl_lmops == fl1->fl_lmops &&
-			fl1->fl_lmops->lm_compare_owner(fl1, fl2);
 	return fl1->fl_owner == fl2->fl_owner;
 }
 
···
 static unsigned long
 posix_owner_key(struct file_lock *fl)
 {
-	if (fl->fl_lmops && fl->fl_lmops->lm_owner_key)
-		return fl->fl_lmops->lm_owner_key(fl);
 	return (unsigned long)fl->fl_owner;
 }
 

include/linux/fs.h

···
 };
 
 struct lock_manager_operations {
-	int (*lm_compare_owner)(struct file_lock *, struct file_lock *);
-	unsigned long (*lm_owner_key)(struct file_lock *);
 	fl_owner_t (*lm_get_owner)(fl_owner_t);
 	void (*lm_put_owner)(fl_owner_t);
 	void (*lm_notify)(struct file_lock *);	/* unblock callback */