"Huang, Ying" <ying.huang@xxxxxxxxx> writes:
>> On Wed, May 23, 2018 at 04:26:07PM +0800, Huang, Ying wrote:
>>> @@ -3516,11 +3512,39 @@ static int __swap_duplicate(swp_entry_t entry, unsigned char usage)
>>
>> Two comments about this part of __swap_duplicate as long as you're moving it to
>> another function:
>>
>> } else if (count || has_cache) {
>>
>> if ((count & ~COUNT_CONTINUED) < SWAP_MAP_MAX) /* #1 */
>> count += usage;
>> else if ((count & ~COUNT_CONTINUED) > SWAP_MAP_MAX) /* #2 */
>> err = -EINVAL;
>>
>> #1: __swap_duplicate_locked might use
>>
>> VM_BUG_ON(usage != SWAP_HAS_CACHE && usage != 1);
>>
>> to document the unstated assumption that usage is 1 (otherwise count could
>> overflow).
>
> Sounds good. Will do this.
Found usage parameter of __swap_duplicate() could be SWAP_MAP_SHMEM too.
We can improve the parameter checking. But that appears not belong to
this series.
Best Regards,
Huang, Ying
