Re: [PATCH 5.13] io_uring: don't set IORING_SQ_NEED_WAKEUP when sqthread is dying

[Hao Xu <haoxu@linux.alibaba.com>]

在 2021/4/27 下午9:13, Pavel Begunkov 写道:
> On 4/27/21 1:45 PM, Hao Xu wrote:
>> we don't need to re-fork the sqthread over exec, so no need to set
>> IORING_SQ_NEED_WAKEUP when sqthread is dying.
> 
> It forces users to call io_uring_enter() for it to return
> -EOWNERDEAD. Consider that scenario with the ring given
> away to some other task not in current group, e.g. via socket.
> 
Ah, I see. Thank you Pavel.
> if (ctx->flags & IORING_SETUP_SQPOLL) {
> 	io_cqring_overflow_flush(ctx, false);
> 
> 	ret = -EOWNERDEAD;
> 	if (unlikely(ctx->sq_data->thread == NULL)) {
> 		goto out;
> 	}
> 	...
> }
> 
> btw, can use a comment
> 
>>
>> Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
>> ---
>>   fs/io_uring.c | 2 --
>>   1 file changed, 2 deletions(-)
>>
>> diff --git a/fs/io_uring.c b/fs/io_uring.c
>> index 6b578c380e73..92dcd1c21516 100644
>> --- a/fs/io_uring.c
>> +++ b/fs/io_uring.c
>> @@ -6897,8 +6897,6 @@ static int io_sq_thread(void *data)
>>   
>>   	io_uring_cancel_sqpoll(sqd);
>>   	sqd->thread = NULL;
>> -	list_for_each_entry(ctx, &sqd->ctx_list, sqd_list)
>> -		io_ring_set_wakeup_flag(ctx);
>>   	io_run_task_work();
>>   	io_run_task_work_head(&sqd->park_task_work);
>>   	mutex_unlock(&sqd->lock);
>>
>