Re: [PATCH] io_uring: don't set REQ_F_NOWAIT for regular files opend O_NONBLOCK

[Jiufei Xue <jiufei.xue@linux.alibaba.com>]

Hi Jens,

Could you please spent some time to look at this? 

Thanks,
Jiufei

On 2020/6/1 上午11:26, Jiufei Xue wrote:
> Hi Jens,
> 
> On 2020/5/29 下午10:20, Jens Axboe wrote:
>> On 5/29/20 1:18 AM, Jiufei Xue wrote:
>>> When read from a regular file that was opened O_NONBLOCK, it will
>>> return EAGAIN if the page is not cached, which is not expected and
>>> fails the application.
>>>
>>> Applications written before expect that the open flag O_NONBLOCK has
>>> no effect on a regular file.
>>>
>>> Fix this by not setting REQ_F_NOWAIT for regular files.
>>
>> Agree, this also matches what we do for sockets. You need to update
>> the comment as well, though.
>>
> Reading from an O_NONBLOCK socket will return EAGAIN if there isn't any
> unread data in the buffer which is expected.So I don't know what is your
> meaning about that. Do you mean the recv() interface? 
> 
> Regards,
> Jiufei
>