On Wed, Feb 26, 2020 at 07:24:06AM -0700, Jens Axboe wrote:

On 2/26/20 1:37 AM, Bob Liu wrote:

quoted

diff --git a/include/uapi/linux/io_uring.h b/include/uapi/linux/io_uring.h
index a3300e1..98fa3f1 100644
--- a/include/uapi/linux/io_uring.h
+++ b/include/uapi/linux/io_uring.h

@@ -62,6 +62,8 @@ enum {
 	IORING_OP_NOP,
 	IORING_OP_READV,
 	IORING_OP_WRITEV,
+	IORING_OP_READV_PI,
+	IORING_OP_WRITEV_PI,
 	IORING_OP_FSYNC,
 	IORING_OP_READ_FIXED,
 	IORING_OP_WRITE_FIXED,

So this one renumbers everything past IORING_OP_WRITEV, breaking the
ABI in a very bad way. I'm guessing that was entirely unintentional?
Any new command must go at the end of the list.

You're also not updating io_op_defs[] with the two new commands,
which means it won't compile at all. I'm guessing you tested this on
an older version of the kernel which didn't have io_op_defs[]?

And the real question is why we need ops insted of just a flag and
using previously reserved fields for the PI pointer.