Re: [PATCH] Btrfs: setup blank root and fs_info for mount time

[Li Zefan <lizf@cn.fujitsu.com>]

> +	/*
> +	 * Setup a dummy root and fs_info for test/set super.  This is because
> +	 * we don't actually fill this stuff out until open_ctree, but we need
> +	 * it for searching for existing supers, so this lets us do that and
> +	 * then open_ctree will properly initialize everything later.
> +	 */
> +	fs_info = kzalloc(sizeof(struct btrfs_fs_info), GFP_NOFS);
> +	tree_root = kzalloc(sizeof(struct btrfs_root), GFP_NOFS);
> +	if (!fs_info || !tree_root) {
> +		kfree(fs_info);
> +		kfree(tree_root);

The above 2 kfree() calls are redundant.

And error should be set to -ENOMEM.

> +		goto error_close_devices;
> +	}
> +	fs_info->tree_root = tree_root;
> +	fs_info->fs_devices = fs_devices;
> +	tree_root->fs_info = fs_info;
> +
>  	bdev = fs_devices->latest_bdev;
> -	s = sget(fs_type, btrfs_test_super, set_anon_super, fs_devices);
> +	s = sget(fs_type, btrfs_test_super, btrfs_set_super, tree_root);
>  	if (IS_ERR(s))
>  		goto error_s;
>  
> @@ -675,6 +702,8 @@ error_s:
>  	error = PTR_ERR(s);
>  error_close_devices:
>  	btrfs_close_devices(fs_devices);
> +	kfree(fs_info);
> +	kfree(tree_root);
>  error_free_subvol_name:
>  	kfree(subvol_name);
>  	return ERR_PTR(error);