On Wed, Mar 21, 2018 at 08:32:30AM +0100, Christoph Hellwig 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>
> ---
> fs/aio.c | 49 ++++++++++++++++++++++++++++++++++++++-----------
> 1 file changed, 38 insertions(+), 11 deletions(-)
>
> diff --git a/fs/aio.c b/fs/aio.c
> index 0b6394b4e528..9d7d6e4cde87 100644
> --- a/fs/aio.c
> +++ b/fs/aio.c
> @@ -170,6 +170,10 @@ struct aio_kiocb {
> struct list_head ki_list; /* the aio core uses this
> * for cancellation */
>
> + unsigned int flags; /* protected by ctx->ctx_lock */
> +#define AIO_IOCB_DELAYED_CANCEL (1 << 0)
> +#define AIO_IOCB_CANCELLED (1 << 1)
BIT(0) and BIT(1)?
Anyway, not a big deal...
Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
