Re: [PATCH v2] eventfd: convert to ->write_iter()

From: Jens Axboe
Date: Thu Nov 19 2020 - 13:48:11 EST


On 11/19/20 11:03 AM, Christoph Hellwig wrote:
> On Thu, Nov 19, 2020 at 07:00:19PM +0100, Michal Kubecek wrote:
>> While eventfd ->read() callback was replaced by ->read_iter() recently by
>> commit 12aceb89b0bc ("eventfd: convert to f_op->read_iter()"), ->write()
>> was not replaced.
>>
>> Convert also ->write() to ->write_iter() to make the interface more
>> consistent and allow non-blocking writes from e.g. io_uring. Also
>> reorganize the code and return value handling in a similar way as it was
>> done in eventfd_read().
>
> But this patch does not allow non-blocking writes.

What am I missing here? He checks the file and IOCB non-block flags,
and returns -EAGAIN if there's no space. If not, it waits and schedules.

--
Jens Axboe