Goldwyn Rodrigues <rgoldwyn@xxxxxxx> writes:
> From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
>
> This flag informs kernel to bail out if an AIO request will block
> for reasons such as file allocations, or a writeback triggered
> by direct I/O.
>
> IOCB_FLAG_NONBLOCKING is translated to IOCB_NONBLOCKING for
> iocb->ki_flags.
This shouldn't be an option, it should be the default. This is what
users want when using this interface to begin with.
Cheers,
Jeff
>
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
> ---
> fs/aio.c | 3 +++
> include/linux/fs.h | 1 +
> include/uapi/linux/aio_abi.h | 3 +++
> 3 files changed, 7 insertions(+)
>
> diff --git a/fs/aio.c b/fs/aio.c
> index 428484f..0725756 100644
> --- a/fs/aio.c
> +++ b/fs/aio.c
> @@ -1551,6 +1551,9 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
> req->common.ki_flags |= IOCB_EVENTFD;
> }
>
> + if (iocb->aio_flags & IOCB_FLAG_NONBLOCKING)
> + req->common.ki_flags |= IOCB_NONBLOCKING;
> +
> ret = put_user(KIOCB_KEY, &user_iocb->aio_key);
> if (unlikely(ret)) {
> pr_debug("EFAULT: aio_key\n");
> diff --git a/include/linux/fs.h b/include/linux/fs.h
> index dc0478c..bfbaba6 100644
> --- a/include/linux/fs.h
> +++ b/include/linux/fs.h
> @@ -322,6 +322,7 @@ struct writeback_control;
> #define IOCB_DSYNC (1 << 4)
> #define IOCB_SYNC (1 << 5)
> #define IOCB_WRITE (1 << 6)
> +#define IOCB_NONBLOCKING (1 << 7)
>
> struct kiocb {
> struct file *ki_filp;
> diff --git a/include/uapi/linux/aio_abi.h b/include/uapi/linux/aio_abi.h
> index bb2554f..03ce4c2 100644
> --- a/include/uapi/linux/aio_abi.h
> +++ b/include/uapi/linux/aio_abi.h
> @@ -51,8 +51,11 @@ enum {
> *
> * IOCB_FLAG_RESFD - Set if the "aio_resfd" member of the "struct iocb"
> * is valid.
> + * IOCB_FLAG_NOBLOCK - Set if the user wants the iocb to fail if it would block
> + * for operations such as disk allocation.
> */
> #define IOCB_FLAG_RESFD (1 << 0)
> +#define IOCB_FLAG_NONBLOCKING (1 << 1)
>
> /* read() from /dev/aio returns these structures. */
> struct io_event {
