Re: AIO operation and CMSG

From: Christoph Hellwig
Date: Wed Jan 17 2018 - 14:22:22 EST


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.

Also you really want to Cc the relevant lists, I've only accidentally
seen this on linux-kernel.

>
> Thank you very much.
>
> [1] http://www.chronox.de/libkcapi.html
>
> Ciao
> Stephan
>
>
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