Re: AIO operation and CMSG

From: Stephan Mueller
Date: Thu Jan 18 2018 - 02:32:23 EST


Am Mittwoch, 17. Januar 2018, 20:22:13 CET schrieb Christoph Hellwig:

Hi Christoph,

> On Sun, Jan 14, 2018 at 09:01:00AM +0100, Stephan Müller wrote:
> > The syscall io_submit sends data to the kernel and invokes the respective
> > handler function in the kernel such as the recvmsg handler. What I am
> > wondering is whether there is a way to send CMSG data along with the
> > io_submit syscall? If not, is CMSG handling with the AIO syscalls
> > possible at all?
> Not as-is, but it could be easily added by repurposing unused fields
> in the iocb. The big question is if it should be done to the existing
> IOCB_CMD_PREADV/IOCB_CMD_PWRITEV types, or if new SENDMSG/RECVMSG ones
> should be added instead.

Thank you for the clarification. I think for the moment we have found another
solution that we are discussing at linux-crypto. Therefore, I would currently
not see the need for an additional support of CMSG in AIO.

Ciao
Stephan