Re: libaio asynchronous syscall io_getevents blocks on error

[Zubin Dittia <zubin@tintri.com>]

Thanks, Jeff, this makes sense.  In order to get error codes for all
I/Os that are being submitted, I'll have to loop calling io_submit on
successively smaller portions of the initial array of requests, each
time trimming off the ones that have been successfully submitted.
-Zubin

On Tue, Oct 20, 2009 at 4:59 PM, Jeff Moyer <jmoyer@redhat.com> wrote:
> Zubin Dittia <zubin@tintri.com> writes:
>
>> But this does bring up the interesting question of how to know which
>> of the I/Os I submitted had an error, and what the error was.  Does it
>
> If io_submit returned N, then the N+1 iocb had an error.
>
>> PS: It does seem a little strange that io_submit returns an error if
>> the first IOCB is invalid but not when any of the other IOCBs are
>> invalid (this appears to be the case, at least according to the man
>> page).
>
> It makes sense that it tells you how many it could successfully submit.
> If it can't submit any, you get the error from the first I/O.
>
> Cheers,
> Jeff
>