else
                btrfs_node_key(buf, &disk_key, 0);
 
-       cow = btrfs_alloc_free_block(trans, root, buf->len, 0,
-                                    new_root_objectid, &disk_key, level,
-                                    buf->start, 0);
+       cow = btrfs_alloc_tree_block(trans, root, 0, new_root_objectid,
+                       &disk_key, level, buf->start, 0);
        if (IS_ERR(cow))
                return PTR_ERR(cow);
 
        } else
                parent_start = 0;
 
-       cow = btrfs_alloc_free_block(trans, root, buf->len, parent_start,
-                                    root->root_key.objectid, &disk_key,
-                                    level, search_start, empty_size);
+       cow = btrfs_alloc_tree_block(trans, root, parent_start,
+                       root->root_key.objectid, &disk_key, level,
+                       search_start, empty_size);
        if (IS_ERR(cow))
                return PTR_ERR(cow);
 
        else
                btrfs_node_key(lower, &lower_key, 0);
 
-       c = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
-                                  root->root_key.objectid, &lower_key,
-                                  level, root->node->start, 0);
+       c = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid,
+                                  &lower_key, level, root->node->start, 0);
        if (IS_ERR(c))
                return PTR_ERR(c);
 
        mid = (c_nritems + 1) / 2;
        btrfs_node_key(c, &disk_key, mid);
 
-       split = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
-                                       root->root_key.objectid,
-                                       &disk_key, level, c->start, 0);
+       split = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid,
+                       &disk_key, level, c->start, 0);
        if (IS_ERR(split))
                return PTR_ERR(split);
 
        else
                btrfs_item_key(l, &disk_key, mid);
 
-       right = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
-                                       root->root_key.objectid,
-                                       &disk_key, 0, l->start, 0);
+       right = btrfs_alloc_tree_block(trans, root, 0, root->root_key.objectid,
+                       &disk_key, 0, l->start, 0);
        if (IS_ERR(right))
                return PTR_ERR(right);
 
 
                                                 u64 bytenr);
 void btrfs_put_block_group(struct btrfs_block_group_cache *cache);
 int get_block_group_index(struct btrfs_block_group_cache *cache);
-struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
-                                       struct btrfs_root *root, u32 blocksize,
-                                       u64 parent, u64 root_objectid,
+struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
+                                       struct btrfs_root *root, u64 parent,
+                                       u64 root_objectid,
                                        struct btrfs_disk_key *key, int level,
                                        u64 hint, u64 empty_size);
 void btrfs_free_tree_block(struct btrfs_trans_handle *trans,
 
        root->root_key.type = BTRFS_ROOT_ITEM_KEY;
        root->root_key.offset = 0;
 
-       leaf = btrfs_alloc_free_block(trans, root, root->nodesize,
-                                     0, objectid, NULL, 0, 0, 0);
+       leaf = btrfs_alloc_tree_block(trans, root, 0, objectid, NULL, 0, 0, 0);
        if (IS_ERR(leaf)) {
                ret = PTR_ERR(leaf);
                leaf = NULL;
         * updated (along with back refs to the log tree).
         */
 
-       leaf = btrfs_alloc_free_block(trans, root, root->nodesize, 0,
-                                     BTRFS_TREE_LOG_OBJECTID, NULL,
-                                     0, 0, 0);
+       leaf = btrfs_alloc_tree_block(trans, root, 0, BTRFS_TREE_LOG_OBJECTID,
+                       NULL, 0, 0, 0);
        if (IS_ERR(leaf)) {
                kfree(root);
                return ERR_CAST(leaf);
 
  *
  * returns the tree buffer or NULL.
  */
-struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans,
-                                       struct btrfs_root *root, u32 blocksize,
+struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans,
+                                       struct btrfs_root *root,
                                        u64 parent, u64 root_objectid,
                                        struct btrfs_disk_key *key, int level,
                                        u64 hint, u64 empty_size)
        struct extent_buffer *buf;
        u64 flags = 0;
        int ret;
+       u32 blocksize = root->nodesize;
        bool skinny_metadata = btrfs_fs_incompat(root->fs_info,
                                                 SKINNY_METADATA);