Update to newer API

- Fixed buffers are now available through io_uring_register()
- Various thread/wq options are now dead and automatic instead
- sqe->index is now sqe->buf_index
- Fixed buffers require flag, not separate opcode

Signed-off-by: Jens Axboe <axboe@kernel.dk>

src/io_uring.c

@@ -189,12 +189,11 @@ err:
  * contains the necessary information to read/write to the rings.
  */
 int io_uring_queue_init(unsigned entries, struct io_uring_params *p,
-			struct iovec *iovecs, unsigned nr_iovecs,
 			struct io_uring *ring)
 {
 	int fd, ret;
 
-	fd = io_uring_setup(entries, iovecs, nr_iovecs, p);
+	fd = io_uring_setup(entries, p);
 	if (fd < 0)
 		return fd;
 

src/io_uring.h

@@ -29,25 +29,27 @@ struct io_uring_sqe {
 		__kernel_rwf_t	rw_flags;
 		__u32		__resv;
 	};
-	__u16	index;		/* index into fixed buffers, if used */
+	__u16	buf_index;	/* index into fixed buffers, if used */
 	__u16	__pad2[3];
 	__u64	data;		/* data to be passed back at completion time */
 };
 
+/*
+ * sqe->flags
+ */
+#define IOSQE_FIXED_BUFFER	(1 << 0)	/* use fixed buffer */
+
 /*
  * io_uring_setup() flags
  */
 #define IORING_SETUP_IOPOLL	(1 << 0)	/* io_context is polled */
-#define	IORING_SETUP_SQTHREAD	(1 << 1)	/* Use SQ thread */
-#define IORING_SETUP_SQWQ	(1 << 2)	/* Use SQ workqueue */
-#define IORING_SETUP_SQPOLL	(1 << 3)	/* SQ thread polls */
+#define IORING_SETUP_SQPOLL	(1 << 1)	/* SQ poll thread */
+#define IORING_SETUP_SQ_AFF	(1 << 2)	/* sq_thread_cpu is valid */
 
 #define IORING_OP_READV		1
 #define IORING_OP_WRITEV	2
 #define IORING_OP_FSYNC		3
 #define IORING_OP_FDSYNC	4
-#define IORING_OP_READ_FIXED	5
-#define IORING_OP_WRITE_FIXED	6
 
 /*
  * IO completion data structure (Completion Queue Entry)
@@ -114,4 +116,15 @@ struct io_uring_params {
 	struct io_cqring_offsets cq_off;
 };
 
+/*
+ * io_uring_register(2) opcodes and arguments
+ */
+#define IORING_REGISTER_BUFFERS		0
+#define IORING_UNREGISTER_BUFFERS	1
+
+struct io_uring_register_buffers {
+	struct iovec *iovecs;
+	unsigned nr_iovecs;
+};
+
 #endif

src/liburing.h

@@ -43,16 +43,16 @@ struct io_uring {
 /*
  * System calls
  */
-extern int io_uring_setup(unsigned entries, struct iovec *iovecs,
-	unsigned nr_iovecs, struct io_uring_params *p);
+extern int io_uring_setup(unsigned entries, struct io_uring_params *p);
 extern int io_uring_enter(unsigned fd, unsigned to_submit,
 	unsigned min_complete, unsigned flags);
+extern int io_uring_register(int fd, unsigned int opcode, void *arg);
 
 /*
  * Library interface
  */
 extern int io_uring_queue_init(unsigned entries, struct io_uring_params *p,
-	struct iovec *iovecs, unsigned nr_iovecs, struct io_uring *ring);
+	struct io_uring *ring);
 extern void io_uring_queue_exit(struct io_uring *ring);
 extern int io_uring_get_completion(struct io_uring *ring,
 	struct io_uring_cqe **cqe_ptr);

src/syscall.c

@@ -8,19 +8,26 @@
 
 #if defined(__x86_64)
 #ifndef __NR_sys_io_uring_setup
-#define __NR_sys_io_uring_setup	335
+#define __NR_sys_io_uring_setup		335
 #endif
 #ifndef __NR_sys_io_uring_enter
-#define __NR_sys_io_uring_enter	336
+#define __NR_sys_io_uring_enter		336
+#endif
+#ifndef __NR_sys_io_uring_register
+#define __NR_sys_io_uring_register	337
 #endif
 #else
 #error "Arch not supported yet"
 #endif
 
-int io_uring_setup(unsigned int entries, struct iovec *iovecs,
-		   unsigned nr_iovecs, struct io_uring_params *p)
+int io_uring_register(int fd, unsigned int opcode, void *arg)
 {
-	return syscall(__NR_sys_io_uring_setup, entries, iovecs, nr_iovecs, p);
+	return syscall(__NR_sys_io_uring_register, fd, opcode, arg);
+}
+
+int io_uring_setup(unsigned int entries, struct io_uring_params *p)
+{
+	return syscall(__NR_sys_io_uring_setup, entries, p);
 }
 
 int io_uring_enter(int fd, unsigned int to_submit, unsigned int min_complete,

test/io_uring-cp.c

@@ -23,16 +23,14 @@ struct io_data {
 	struct iovec *iov;
 };
 
-static int setup_context(unsigned entries, struct io_uring *ring, int offload)
+static int setup_context(unsigned entries, struct io_uring *ring)
 {
 	struct io_uring_params p;
 	int ret;
 
 	memset(&p, 0, sizeof(p));
-	if (offload)
-		p.flags = IORING_SETUP_SQWQ;
 
-	ret = io_uring_queue_init(entries, &p, NULL, 0, ring);
+	ret = io_uring_queue_init(entries, &p, ring);
 	if (ret < 0) {
 		fprintf(stderr, "queue_init: %s\n", strerror(-ret));
 		return -1;
@@ -79,6 +77,7 @@ static int queue_read(int fd, off_t size, off_t offset)
 	sqe->fd = fd;
 	sqe->off = offset;
 	sqe->addr = data->iov;
+	sqe->buf_index = 0;
 	sqe->data = (unsigned long) data;
 	iovecs[sqe_index(sqe)].iov_len = size;
 	sqe->len = 1;
@@ -128,6 +127,7 @@ static void queue_write(int fd, struct io_uring_cqe *cqe)
 	sqe->fd = fd;
 	sqe->off = data->offset;
 	sqe->addr = data->iov;
+	sqe->buf_index = 0;
 	sqe->data = 0;
 	data->iov->iov_len = cqe->res;
 	sqe->len = 1;
@@ -166,9 +166,9 @@ int main(int argc, char *argv[])
 		iovecs[i].iov_len = BS;
 	}
 
-	if (setup_context(QD, &in_ring, 1))
+	if (setup_context(QD, &in_ring))
 		return 1;
-	if (setup_context(QD, &out_ring, 0))
+	if (setup_context(QD, &out_ring))
 		return 1;
 	if (get_file_size(infd, &read_left))
 		return 1;

test/io_uring-test.c

@@ -32,7 +32,7 @@ int main(int argc, char *argv[])
 	memset(&p, 0, sizeof(p));
 	p.flags = IORING_SETUP_IOPOLL;
 
-	ret = io_uring_queue_init(QD, &p, NULL, 0, &ring);
+	ret = io_uring_queue_init(QD, &p, &ring);
 	if (ret < 0) {
 		fprintf(stderr, "queue_init: %s\n", strerror(-ret));
 		return 1;
@@ -65,6 +65,7 @@ int main(int argc, char *argv[])
 		sqe->off = offset;
 		sqe->addr = &iovecs[i];
 		sqe->len = 1;
+		sqe->buf_index = 0;
 		offset += iovecs[i].iov_len;
 	} while (1);