On 05/12/24 05:53PM, Keith Busch wrote:
>From: Keith Busch <kbusch@kernel.org>
>
>Adds a new attribute type to specify a write stream per-IO.
>
>Signed-off-by: Keith Busch <kbusch@kernel.org>
>---
> include/uapi/linux/io_uring.h |  9 ++++++++-
> io_uring/rw.c                 | 28 +++++++++++++++++++++++++++-
> 2 files changed, 35 insertions(+), 2 deletions(-)
>
>diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
>index 5fa38467d6070..263cd57aae72d 100644
>--- a/include/uapi/linux/io_uring.h
>+++ b/include/uapi/linux/io_uring.h
>@@ -123,7 +123,14 @@ struct io_uring_attr_pi {
> 	__u64	rsvd;
> };
>
>-#define IORING_RW_ATTR_FLAGS_SUPPORTED (IORING_RW_ATTR_FLAG_PI)
>+#define IORING_RW_ATTR_FLAG_WRITE_STREAM (1U << 1)
>+struct io_uring_write_stream {
Nit:
You can consider keeping a io_uring_attr_* prefix here, so that it aligns
with current attribute naming style.
s/io_uring_write_stream/io_uring_attr_write_stream

>+	__u16	write_stream;
>+	__u8	rsvd[6];
>+};
>+
>+#define IORING_RW_ATTR_FLAGS_SUPPORTED (IORING_RW_ATTR_FLAG_PI | 	\
>+					IORING_RW_ATTR_FLAG_WRITE_STREAM)
>
> /*
>  * If sqe->file_index is set to this for opcodes that instantiate a new
>diff --git a/io_uring/rw.c b/io_uring/rw.c
>index a2987aefb2cec..69b566e296f6d 100644
>--- a/io_uring/rw.c
>+++ b/io_uring/rw.c
>@@ -299,6 +299,22 @@ static int io_prep_rw_pi(struct io_kiocb *req, struct io_rw *rw, int ddir,
> 	return ret;
> }
>
>+static int io_prep_rw_write_stream(struct io_rw *rw, u64 *attr_ptr)
>+{
>+	struct io_uring_write_stream write_stream;
>+
>+	if (copy_from_user(&write_stream, u64_to_user_ptr(*attr_ptr),
>+			   sizeof(write_stream)))
>+		return -EFAULT;
>+
>+	if (!memchr_inv(write_stream.rsvd, 0, sizeof(write_stream.rsvd)))
This should be:
	if (memchr_inv(write_stream.rsvd, 0, sizeof(write_stream.rsvd)))