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

Matthew Wilcox [off-list ref] writes:

On Wed, Jan 20, 2021 at 03:27:11PM +0800, Huang Ying wrote:

quoted

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?

Sure.  Will use that in the next version.

Best Regards,
Huang, Ying

quoted

 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