Re: [PATCH 2/7] io_uring/net: don't overflow multishot recv

[Pavel Begunkov <asml.silence@gmail.com>]

On 9/14/23 09:34, Jiri Slaby wrote:
> On 11. 08. 23, 14:53, Pavel Begunkov wrote:
>> Don't allow overflowing multishot recv CQEs, it might get out of
>> hand, hurt performanece, and in the worst case scenario OOM the task.
>>
>> Cc: stable@vger.kernel.org
>> Fixes: b3fdea6ecb55c ("io_uring: multishot recv")
>> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
>> ---
>>   io_uring/net.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/io_uring/net.c b/io_uring/net.c
>> index 1599493544a5..8c419c01a5db 100644
>> --- a/io_uring/net.c
>> +++ b/io_uring/net.c
>> @@ -642,7 +642,7 @@ static inline bool io_recv_finish(struct io_kiocb *req, int *ret,
>>       if (!mshot_finished) {
>>           if (io_aux_cqe(req, issue_flags & IO_URING_F_COMPLETE_DEFER,
>> -                   *ret, cflags | IORING_CQE_F_MORE, true)) {
>> +                   *ret, cflags | IORING_CQE_F_MORE, false)) {
> 
> This one breaks iouring's recv-multishot.t test:
> Running test recv-multishot.t                                       MORE flag not set
> test stream=0 wait_each=0 recvmsg=0 early_error=4  defer=0 failed
> Test recv-multishot.t failed with ret 1
> 
> Is the commit or the test broken ;)?

The test is not right. I fixed it up while sending the kernel patch,
but a new liburing version hasn't been cut yet and I assume you're
not using upstream version?

> 
>>               io_recv_prep_retry(req);
>>               /* Known not-empty or unknown state, retry */
>>               if (cflags & IORING_CQE_F_SOCK_NONEMPTY ||
> 
> thanks,

-- 
Pavel Begunkov