six locks: six_lock_readers_add()

This moves a helper out of the bcachefs code that shouldn't have been
there, since it touches six lock internals.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>

fs/bcachefs/btree_locking.c

@@ -24,16 +24,6 @@ void bch2_assert_btree_nodes_not_locked(void)
 
 /* Btree node locking: */
 
-static inline void six_lock_readers_add(struct six_lock *lock, int nr)
-{
-	if (lock->readers)
-		this_cpu_add(*lock->readers, nr);
-	else if (nr > 0)
-		atomic64_add(__SIX_VAL(read_lock, nr), &lock->state.counter);
-	else
-		atomic64_sub(__SIX_VAL(read_lock, -nr), &lock->state.counter);
-}
-
 struct six_lock_count bch2_btree_node_lock_counts(struct btree_trans *trans,
 						  struct btree_path *skip,
 						  struct btree_bkey_cached_common *b,

fs/bcachefs/six.c

@@ -40,6 +40,8 @@ struct six_lock_vals {
 	enum six_lock_type	unlock_wakeup;
 };
 
+#define __SIX_VAL(field, _v)	(((union six_lock_state) { .field = _v }).v)
+
 #define __SIX_LOCK_HELD_read	__SIX_VAL(read_lock, ~0)
 #define __SIX_LOCK_HELD_intent	__SIX_VAL(intent_lock, ~0)
 #define __SIX_LOCK_HELD_write	__SIX_VAL(seq, 1)
@@ -847,3 +849,14 @@ struct six_lock_count six_lock_counts(struct six_lock *lock)
 	return ret;
 }
 EXPORT_SYMBOL_GPL(six_lock_counts);
+
+void six_lock_readers_add(struct six_lock *lock, int nr)
+{
+	if (lock->readers)
+		this_cpu_add(*lock->readers, nr);
+	else if (nr > 0)
+		atomic64_add(__SIX_VAL(read_lock, nr), &lock->state.counter);
+	else
+		atomic64_sub(__SIX_VAL(read_lock, -nr), &lock->state.counter);
+}
+EXPORT_SYMBOL_GPL(six_lock_readers_add);

fs/bcachefs/six.h

@@ -152,8 +152,6 @@ do {									\
 	__six_lock_init((lock), #lock, &__key);				\
 } while (0)
 
-#define __SIX_VAL(field, _v)	(((union six_lock_state) { .field = _v }).v)
-
 #define __SIX_LOCK(type)						\
 bool six_trylock_ip_##type(struct six_lock *, unsigned long);		\
 bool six_relock_ip_##type(struct six_lock *, u32, unsigned long);	\
@@ -258,5 +256,6 @@ struct six_lock_count {
 };
 
 struct six_lock_count six_lock_counts(struct six_lock *);
+void six_lock_readers_add(struct six_lock *, int);
 
 #endif /* _LINUX_SIX_H */