MFC TO 6.X (6.3?) to fix aio_return() ?

[David Xu]

Julian Elischer wrote:
> 
> This diff is a partial MFC (picking parts out of -current)
> that makes aio_return() return the error return of a completed AIO 
> request. (as it does on othe OS's and  in 7.x).
> 
> The man page for 6.x and other OS's indicate that aio_return shoud 
> return all the same results as a returning read() or write()
> including setting errno  on error.
> 
> in 6.x this does not happen. on 7.0 it does.
> 
> The included test program can show the result when using gnop()
> to simulate IO errors.
> 
> BTW the test program could be used as a start to sample code as to how 
> to use kqueue and aio together.
> 
> 
> If people agree this is worth fixing,  it would be nice to get it in 6.3
> 
> 
> 

Looks OK to me.

Regards,
David Xu