Re: [PATCH v2] md/raid1: Fix stack memory use after return in raid1_reshape

[Wang Jinchao <wangjinchao600@gmail.com>]

On 2025/6/12 19:23, Yu Kuai wrote:
> Hi,
> 
> 在 2025/06/12 17:55, Wang Jinchao 写道:
>> Now that we have the same information, I prefer patch-v1 before 
>> refactoring raid1_reshape,
>> because it’s really simple (only one line) and clearer to show the 
>> backup and restore logic.
>> Another reason is that v2 freezes the RAID longer than v1.
>> Would you like me to provide a v3 patch combining the v2 explanation 
>> with the v1 diff?
>> Thanks for your reviewing.
> 
> I don't have preference here, feel free to do this.
> 
> BTW, I feel raid1_reshape can be better coding with following：
> 
> - covert r1bio_pool to use mempool_create_kmalloc_pool(use create
> instead of init to get rid of the werid assigment);
mempool_create_kmalloc_pool also calls init_waitqueue_head(&pool->wait) 
internally, just like mempool_init.
So the issue only exists if newpool is allocated on the stack.
> - no need to reallocate pool_info;
> - convert raid1_info to use krealloc;
I think reallocating pool_info is only for backup and restore, similar 
to newpool.
> 
> Welcome if you are willing to, otherwise I'll find myself sometime.
I'm a newcomer to RAID and can't quite catch up with it right now.
Maybe I can refactor it later, and I look forward to your guidance.
> 
> Thanks,
> Kuai
>