diff --git a/mars_trans_logger.c b/mars_trans_logger.c
index cd859fd5..928c3a6d 100644
--- a/mars_trans_logger.c
+++ b/mars_trans_logger.c
@@ -829,7 +829,7 @@ void pos_complete(struct trans_logger_mref_aspect *orig_mref_a)
 
 	tmp = &orig_mref_a->pos_head;
 
-	traced_lock(&brick->pos_lock, flags);
+	traced_lock(&log_input->pos_lock, flags);
 	// am I the first member? (means "youngest" list entry)
 	if (tmp == log_input->pos_list.next) {
 		if (unlikely(!log_input)) {
@@ -856,7 +856,7 @@ void pos_complete(struct trans_logger_mref_aspect *orig_mref_a)
 	}
 	list_del_init(tmp);
 	atomic_dec(&brick->pos_count);
-	traced_unlock(&brick->pos_lock, flags);
+	traced_unlock(&log_input->pos_lock, flags);
 err:;
 }
 
@@ -1369,7 +1369,7 @@ bool phase1_startio(struct trans_logger_mref_aspect *orig_mref_a)
 	}
 	orig_mref_a->log_pos = logst->log_pos + logst->offset;
 
-	traced_lock(&brick->pos_lock, flags);
+	traced_lock(&input->pos_lock, flags);
 #if 1
 	if (!list_empty(&input->pos_list)) {
 		struct trans_logger_mref_aspect *last_mref_a;
@@ -1381,7 +1381,7 @@ bool phase1_startio(struct trans_logger_mref_aspect *orig_mref_a)
 #endif
 	list_add_tail(&orig_mref_a->pos_head, &input->pos_list);
 	atomic_inc(&brick->pos_count);
-	traced_unlock(&brick->pos_lock, flags);
+	traced_unlock(&input->pos_lock, flags);
 
 	qq_inc_flying(&brick->q_phase1);
 	return true;
@@ -2565,7 +2565,6 @@ int trans_logger_brick_construct(struct trans_logger_brick *brick)
 		INIT_LIST_HEAD(&start->hash_anchor);
 	}
 	atomic_set(&brick->hash_count, 0);
-	spin_lock_init(&brick->pos_lock);
 	spin_lock_init(&brick->replay_lock);
 	INIT_LIST_HEAD(&brick->replay_list);
 	init_waitqueue_head(&brick->worker_event);
@@ -2606,6 +2605,7 @@ int trans_logger_output_construct(struct trans_logger_output *output)
 static noinline
 int trans_logger_input_construct(struct trans_logger_input *input)
 {
+	spin_lock_init(&input->pos_lock);
 	INIT_LIST_HEAD(&input->pos_list);
 	return 0;
 }
diff --git a/mars_trans_logger.h b/mars_trans_logger.h
index 0f8d8009..e0001268 100644
--- a/mars_trans_logger.h
+++ b/mars_trans_logger.h
@@ -131,7 +131,6 @@ struct trans_logger_brick {
 	int replay_code;    // replay errors (if any)
 	// private
 	loff_t old_margin;
-	spinlock_t pos_lock;
 	spinlock_t replay_lock;
 	struct list_head replay_list;
 	struct task_struct *thread;
@@ -193,6 +192,7 @@ struct trans_logger_input {
 	// private
 	struct generic_object_layout sub_layout;
 	struct log_status logst;
+	spinlock_t pos_lock;
 	struct list_head pos_list;
 };
 
diff --git a/sy_old/mars_light.c b/sy_old/mars_light.c
index 37d3df9d..3017e523 100644
--- a/sy_old/mars_light.c
+++ b/sy_old/mars_light.c
@@ -1946,7 +1946,7 @@ void _rotate_trans(struct mars_rotate *rot)
 		struct trans_logger_input *trans_input = trans_brick->inputs[old_nr];
 		if (!trans_input->connect) {
 			MARS_DBG("ignoring unused input %d\n", old_nr);
-		} else if (trans_input->replay_min_pos == trans_input->replay_max_pos) {
+		} else if (trans_input->replay_min_pos == trans_input->replay_max_pos && list_empty(&trans_input->pos_list)) {
 			int status = generic_disconnect((void*)trans_input);
 			if (status < 0) {
 				MARS_ERR("disconnect failed\n");