BTRFS_COMPARE_TREE_CHANGED,
        BTRFS_COMPARE_TREE_SAME,
 };
-typedef int (*btrfs_changed_cb_t)(struct btrfs_path *left_path,
-                                 struct btrfs_path *right_path,
-                                 struct btrfs_key *key,
-                                 enum btrfs_compare_tree_result result,
-                                 void *ctx);
 
 __cold
 static void inconsistent_snapshot_error(struct send_ctx *sctx,
  * If it detects a change, it aborts immediately.
  */
 static int btrfs_compare_trees(struct btrfs_root *left_root,
-                       struct btrfs_root *right_root,
-                       btrfs_changed_cb_t changed_cb, void *ctx)
+                       struct btrfs_root *right_root, void *ctx)
 {
        struct btrfs_fs_info *fs_info = left_root->fs_info;
        int ret;
                goto out;
 
        if (sctx->parent_root) {
-               ret = btrfs_compare_trees(sctx->send_root, sctx->parent_root,
-                               changed_cb, sctx);
+               ret = btrfs_compare_trees(sctx->send_root, sctx->parent_root, sctx);
                if (ret < 0)
                        goto out;
                ret = finish_inode_if_needed(sctx, 1);