Re: [PATCH] swap: Check nrexceptional of swap cache before being freed

[Matthew Wilcox]

On Wed, Jan 20, 2021 at 03:27:11PM +0800, Huang Ying wrote:
> To catch the error in updating the swap cache shadow entries or their count.

I just resent a patch that removes nrexceptional tracking.

Can you use !mapping_empty() instead?

>  void exit_swap_address_space(unsigned int type)
>  {
> -	kvfree(swapper_spaces[type]);
> +	int i;
> +	struct address_space *spaces = swapper_spaces[type];
> +
> +	for (i = 0; i < nr_swapper_spaces[type]; i++)
> +		VM_BUG_ON(spaces[i].nrexceptional);
> +	kvfree(spaces);
>  	nr_swapper_spaces[type] = 0;
>  	swapper_spaces[type] = NULL;
>  }
> -- 
> 2.29.2
> 
>