if (trans->aborted)
                return 0;
 again:
-       inode = lookup_free_space_inode(root, block_group, path);
+       inode = lookup_free_space_inode(fs_info, block_group, path);
        if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) {
                ret = PTR_ERR(inode);
                btrfs_release_path(path);
                if (block_group->ro)
                        goto out_free;
 
-               ret = create_free_space_inode(root, trans, block_group, path);
+               ret = create_free_space_inode(fs_info, trans, block_group,
+                                             path);
                if (ret)
                        goto out_free;
                goto again;
                if (ret)
                        goto out_put;
 
-               ret = btrfs_truncate_free_space_cache(root, trans, NULL, inode);
+               ret = btrfs_truncate_free_space_cache(trans, NULL, inode);
                if (ret)
                        goto out_put;
        }
         * get the inode first so any iput calls done for the io_list
         * aren't the final iput (no unlinks allowed now)
         */
-       inode = lookup_free_space_inode(tree_root, block_group, path);
+       inode = lookup_free_space_inode(fs_info, block_group, path);
 
        mutex_lock(&trans->transaction->cache_write_mutex);
        /*
 
        return inode;
 }
 
-struct inode *lookup_free_space_inode(struct btrfs_root *root,
+struct inode *lookup_free_space_inode(struct btrfs_fs_info *fs_info,
                                      struct btrfs_block_group_cache
                                      *block_group, struct btrfs_path *path)
 {
        struct inode *inode = NULL;
-       struct btrfs_fs_info *fs_info = root->fs_info;
        u32 flags = BTRFS_INODE_NODATASUM | BTRFS_INODE_NODATACOW;
 
        spin_lock(&block_group->lock);
        if (inode)
                return inode;
 
-       inode = __lookup_free_space_inode(root, path,
+       inode = __lookup_free_space_inode(fs_info->tree_root, path,
                                          block_group->key.objectid);
        if (IS_ERR(inode))
                return inode;
        return 0;
 }
 
-int create_free_space_inode(struct btrfs_root *root,
+int create_free_space_inode(struct btrfs_fs_info *fs_info,
                            struct btrfs_trans_handle *trans,
                            struct btrfs_block_group_cache *block_group,
                            struct btrfs_path *path)
        int ret;
        u64 ino;
 
-       ret = btrfs_find_free_objectid(root, &ino);
+       ret = btrfs_find_free_objectid(fs_info->tree_root, &ino);
        if (ret < 0)
                return ret;
 
-       return __create_free_space_inode(root, trans, path, ino,
+       return __create_free_space_inode(fs_info->tree_root, trans, path, ino,
                                         block_group->key.objectid);
 }
 
        return ret;
 }
 
-int btrfs_truncate_free_space_cache(struct btrfs_root *root,
-                                   struct btrfs_trans_handle *trans,
+int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
                                    struct btrfs_block_group_cache *block_group,
                                    struct inode *inode)
 {
+       struct btrfs_root *root = BTRFS_I(inode)->root;
        int ret = 0;
        struct btrfs_path *path = btrfs_alloc_path();
        bool locked = false;
                          struct btrfs_block_group_cache *block_group)
 {
        struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
-       struct btrfs_root *root = fs_info->tree_root;
        struct inode *inode;
        struct btrfs_path *path;
        int ret = 0;
        path->search_commit_root = 1;
        path->skip_locking = 1;
 
-       inode = lookup_free_space_inode(root, block_group, path);
+       inode = lookup_free_space_inode(fs_info, block_group, path);
        if (IS_ERR(inode)) {
                btrfs_free_path(path);
                return 0;
                          struct btrfs_block_group_cache *block_group,
                          struct btrfs_path *path)
 {
-       struct btrfs_root *root = fs_info->tree_root;
        struct btrfs_free_space_ctl *ctl = block_group->free_space_ctl;
        struct inode *inode;
        int ret = 0;
        }
        spin_unlock(&block_group->lock);
 
-       inode = lookup_free_space_inode(root, block_group, path);
+       inode = lookup_free_space_inode(fs_info, block_group, path);
        if (IS_ERR(inode))
                return 0;
 
-       ret = __btrfs_write_out_cache(root, inode, ctl, block_group,
-                                     &block_group->io_ctl, trans);
+       ret = __btrfs_write_out_cache(fs_info->tree_root, inode, ctl,
+                               block_group, &block_group->io_ctl, trans);
        if (ret) {
 #ifdef DEBUG
                btrfs_err(fs_info,
 
 
 struct btrfs_io_ctl;
 
-struct inode *lookup_free_space_inode(struct btrfs_root *root,
+struct inode *lookup_free_space_inode(struct btrfs_fs_info *fs_info,
                                      struct btrfs_block_group_cache
                                      *block_group, struct btrfs_path *path);
-int create_free_space_inode(struct btrfs_root *root,
+int create_free_space_inode(struct btrfs_fs_info *fs_info,
                            struct btrfs_trans_handle *trans,
                            struct btrfs_block_group_cache *block_group,
                            struct btrfs_path *path);
 
 int btrfs_check_trunc_cache_free_space(struct btrfs_fs_info *fs_info,
                                       struct btrfs_block_rsv *rsv);
-int btrfs_truncate_free_space_cache(struct btrfs_root *root,
-                                   struct btrfs_trans_handle *trans,
+int btrfs_truncate_free_space_cache(struct btrfs_trans_handle *trans,
                                    struct btrfs_block_group_cache *block_group,
                                    struct inode *inode);
 int load_free_space_cache(struct btrfs_fs_info *fs_info,