diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c
index 77fb72ac6b81ed..a1d7609162468d 100644
--- a/drivers/md/bcache/writeback.c
+++ b/drivers/md/bcache/writeback.c
@@ -977,14 +977,22 @@ static int bch_btre_dirty_init_thread_nr(void)
 void bch_sectors_dirty_init(struct bcache_device *d)
 {
 	int i;
+	struct btree *b = NULL;
 	struct bkey *k = NULL;
 	struct btree_iter iter;
 	struct sectors_dirty_init op;
 	struct cache_set *c = d->c;
 	struct bch_dirty_init_state state;
 
+retry_lock:
+	b = c->root;
+	rw_lock(0, b, b->level);
+	if (b != c->root) {
+		rw_unlock(0, b);
+		goto retry_lock;
+	}
+
 	/* Just count root keys if no leaf node */
-	rw_lock(0, c->root, c->root->level);
 	if (c->root->level == 0) {
 		bch_btree_op_init(&op.op, -1);
 		op.inode = d->id;
@@ -997,7 +1005,7 @@ void bch_sectors_dirty_init(struct bcache_device *d)
 			sectors_dirty_init_fn(&op.op, c->root, k);
 		}
 
-		rw_unlock(0, c->root);
+		rw_unlock(0, b);
 		return;
 	}
 
@@ -1033,7 +1041,7 @@ void bch_sectors_dirty_init(struct bcache_device *d)
 out:
 	/* Must wait for all threads to stop. */
 	wait_event(state.wait, atomic_read(&state.started) == 0);
-	rw_unlock(0, c->root);
+	rw_unlock(0, b);
 }
 
 void bch_cached_dev_writeback_init(struct cached_dev *dc)