On 9/11/23 6:46 PM, Jens Axboe wrote:
>>> + ret = __io_read(req, issue_flags);
>>> +
>>> + /*
>>> + * If we get -EAGAIN, recycle our buffer and just let normal poll
>>> + * handling arm it.
>>> + */
>>> + if (ret == -EAGAIN) {
>>> + io_kbuf_recycle(req, issue_flags);
>>> + return -EAGAIN;
>>> + }
>>> +
>>> + /*
>>> + * Any error will terminate a multishot request
>>> + */
>>> + if (ret <= 0) {
>>> +finish:
>>> + io_req_set_res(req, ret, cflags);
>>> + if (issue_flags & IO_URING_F_MULTISHOT)
>>> + return IOU_STOP_MULTISHOT;
>>> + return IOU_OK;
>>
>> Just a style detail, but I'd prefer to unfold this on the end of the
>> function instead of jumping backwards here..
>
> Sure, that might look better. I'll make the edit.
Actually we can just indent the next case and get rid of the goto
completely:
int io_read_mshot(struct io_kiocb *req, unsigned int issue_flags)
{
unsigned int cflags = 0;
int ret;
/*
* Multishot MUST be used on a pollable file
*/
if (!file_can_poll(req->file))
return -EBADFD;
ret = __io_read(req, issue_flags);
/*
* If we get -EAGAIN, recycle our buffer and just let normal poll
* handling arm it.
*/
if (ret == -EAGAIN) {
io_kbuf_recycle(req, issue_flags);
return -EAGAIN;
}
/*
* Any successful return value will keep the multishot read armed.
*/
if (ret > 0) {
/*
* Put our buffer and post a CQE. If we fail to post a CQE, then
* jump to the termination path. This request is then done.
*/
cflags = io_put_kbuf(req, issue_flags);
if (io_fill_cqe_req_aux(req,
issue_flags & IO_URING_F_COMPLETE_DEFER,
ret, cflags | IORING_CQE_F_MORE)) {
if (issue_flags & IO_URING_F_MULTISHOT)
return IOU_ISSUE_SKIP_COMPLETE;
return -EAGAIN;
}
}
/*
* Either an error, or we've hit overflow posting the CQE. For any
* multishot request, hitting overflow will terminate it.
*/
io_req_set_res(req, ret, cflags);
if (issue_flags & IO_URING_F_MULTISHOT)
return IOU_STOP_MULTISHOT;
return IOU_OK;
}
--
Jens Axboe
