Re: [PATCH 30/32] aio: add delayed cancel support
From: Christoph Hellwig
Date: Thu Jan 11 2018 - 08:44:05 EST
On Wed, Jan 10, 2018 at 06:26:39PM -0500, Jeff Moyer wrote:
> >> The upcoming aio poll support would like to be able to complete the
> >> iocb inline from the cancellation context, but that would cause
> >> a lock order reversal. Add support for optionally moving the cancelation
> >> outside the context lock to avoid this reversal.
> >>
> >> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> >
> > Acked-by: Jeff Moyer <jmoyer@xxxxxxxxxx>
>
> Actually, let's move these two defines:
>
> #define AIO_IOCB_DELAYED_CANCEL (1 << 0)
> #define AIO_IOCB_CANCELLED (1 << 1)
>
> to include/linux/aio.h so that drivers outside of fs/aio.c can make use
> of them.
struct aio_kiocb is private to aio.c, so just exposing them won't
do anything useful. If we really need these elsewhere we'll need
to come up with a proper interface.