Re: bug with fastpoll accept and sqpoll + IOSQE_FIXED_FILE

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

On 02/02/2021 05:36, Victor Stewart wrote:
> started experimenting with sqpoll and my fastpoll accepts started
> failing. was banging my head against the wall for a few hours... wrote
> this test case below....
> 
> basically fastpoll accept only works without sqpoll, and without
> adding IOSQE_FIXED_FILE to the sqe. fails with both, fails with
> either. these must be bugs?
> 
> I'm running Clear Linux 5.10.10-1017.native.
> 
> i hope no one here is allergic to C++, haha. compilation command
> commented in the gist, just replace the two paths. and I can fold
> these checks if needed into a liburing PR later.
> 
> https://gist.github.com/victorstewart/98814b65ed702c33480487c05b40eb56

Please don't forget about checking error codes. At least fixed
files don't work for you because of

int fds[10];
memset(fds, -1, 10); // 10 bytes, not 10 ints

So io_uring_register_files() silently fails.


For me, all two "with SQPOLL" tests spit SUCCESS, then it hangs.
But need to test it with upstream to be sure.

-- 
Pavel Begunkov