[PATCH v4 12/12] io_uring: support CQE32 for nop operation

[Stefan Roesch <shr@fb.com>]

This adds support for filling the extra1 and extra2 fields for large
CQE's.

Co-developed-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Stefan Roesch <shr@fb.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Reviewed-by: Kanchan Joshi <joshi.k@samsung.com>
---
 fs/io_uring.c | 28 ++++++++++++++++++++++++++--
 1 file changed, 26 insertions(+), 2 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index caeddcf8a61c..9e1fb8be9687 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -744,6 +744,12 @@ struct io_msg {
 	u32 len;
 };
 
+struct io_nop {
+	struct file			*file;
+	u64				extra1;
+	u64				extra2;
+};
+
 struct io_async_connect {
 	struct sockaddr_storage		address;
 };
@@ -937,6 +943,7 @@ struct io_kiocb {
 		struct io_msg		msg;
 		struct io_xattr		xattr;
 		struct io_socket	sock;
+		struct io_nop		nop;
 	};
 
 	u8				opcode;
@@ -4872,6 +4879,19 @@ static int io_splice(struct io_kiocb *req, unsigned int issue_flags)
 	return 0;
 }
 
+static int io_nop_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
+{
+	/*
+	 * If the ring is setup with CQE32, relay back addr/addr
+	 */
+	if (req->ctx->flags & IORING_SETUP_CQE32) {
+		req->nop.extra1 = READ_ONCE(sqe->addr);
+		req->nop.extra2 = READ_ONCE(sqe->addr2);
+	}
+
+	return 0;
+}
+
 /*
  * IORING_OP_NOP just posts a completion event, nothing else.
  */
@@ -4882,7 +4902,11 @@ static int io_nop(struct io_kiocb *req, unsigned int issue_flags)
 	if (unlikely(ctx->flags & IORING_SETUP_IOPOLL))
 		return -EINVAL;
 
-	__io_req_complete(req, issue_flags, 0, 0);
+	if (!(ctx->flags & IORING_SETUP_CQE32))
+		__io_req_complete(req, issue_flags, 0, 0);
+	else
+		__io_req_complete32(req, issue_flags, 0, 0, req->nop.extra1,
+					req->nop.extra2);
 	return 0;
 }
 
@@ -7354,7 +7378,7 @@ static int io_req_prep(struct io_kiocb *req, const struct io_uring_sqe *sqe)
 {
 	switch (req->opcode) {
 	case IORING_OP_NOP:
-		return 0;
+		return io_nop_prep(req, sqe);
 	case IORING_OP_READV:
 	case IORING_OP_READ_FIXED:
 	case IORING_OP_READ:
-- 
2.30.2