5 files changed, 118 insertions, 61 deletions

diff --git a/tools/io_uring/io_uring-cp.c b/tools/io_uring/io_uring-cp.c
index 633f65bb43a7..81461813ec62 100644
--- a/tools/io_uring/io_uring-cp.c
+++ b/tools/io_uring/io_uring-cp.c
@@ -13,6 +13,7 @@
 #include <assert.h>
 #include <errno.h>
 #include <inttypes.h>
+#include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/ioctl.h>
 
@@ -85,11 +86,16 @@ static int queue_read(struct io_uring *ring, off_t size, off_t offset)
         struct io_uring_sqe *sqe;
         struct io_data *data;
 
+        data = malloc(size + sizeof(*data));
+        if (!data)
+                return 1;
+
         sqe = io_uring_get_sqe(ring);
-        if (!sqe)
+        if (!sqe) {
+                free(data);
                 return 1;
+        }
 
-        data = malloc(size + sizeof(*data));
         data->read = 1;
         data->offset = data->first_offset = offset;
 
@@ -166,22 +172,23 @@ static int copy_file(struct io_uring *ring, off_t insize)
                         struct io_data *data;
 
                         if (!got_comp) {
-                                ret = io_uring_wait_completion(ring, &cqe);
+                                ret = io_uring_wait_cqe(ring, &cqe);
                                 got_comp = 1;
                         } else
-                                ret = io_uring_get_completion(ring, &cqe);
+                                ret = io_uring_peek_cqe(ring, &cqe);
                         if (ret < 0) {
-                                fprintf(stderr, "io_uring_get_completion: %s\n",
+                                fprintf(stderr, "io_uring_peek_cqe: %s\n",
                                                         strerror(-ret));
                                 return 1;
                         }
                         if (!cqe)
                                 break;
 
-                        data = (struct io_data *) (uintptr_t) cqe->user_data;
+                        data = io_uring_cqe_get_data(cqe);
                         if (cqe->res < 0) {
                                 if (cqe->res == -EAGAIN) {
                                         queue_prepped(ring, data);
+                                        io_uring_cqe_seen(ring, cqe);
                                         continue;
                                 }
                                 fprintf(stderr, "cqe failed: %s\n",
@@ -193,6 +200,7 @@ static int copy_file(struct io_uring *ring, off_t insize)
                                 data->iov.iov_len -= cqe->res;
                                 data->offset += cqe->res;
                                 queue_prepped(ring, data);
+                                io_uring_cqe_seen(ring, cqe);
                                 continue;
                         }
 
@@ -209,6 +217,7 @@ static int copy_file(struct io_uring *ring, off_t insize)
                                 free(data);
                                 writes--;
                         }
+                        io_uring_cqe_seen(ring, cqe);
                 }
         }
 
diff --git a/tools/io_uring/liburing.h b/tools/io_uring/liburing.h
index cab0f50257ba..5f305c86b892 100644
--- a/tools/io_uring/liburing.h
+++ b/tools/io_uring/liburing.h
@@ -1,10 +1,16 @@
 #ifndef LIB_URING_H
 #define LIB_URING_H
 
+#ifdef __cplusplus
+extern "C" {
+#endif
+
 #include <sys/uio.h>
 #include <signal.h>
 #include <string.h>
 #include "../../include/uapi/linux/io_uring.h"
+#include <inttypes.h>
+#include "barrier.h"
 
 /*
  * Library interface to io_uring
@@ -46,7 +52,7 @@ struct io_uring {
  * System calls
  */
 extern int io_uring_setup(unsigned entries, struct io_uring_params *p);
-extern int io_uring_enter(unsigned fd, unsigned to_submit,
+extern int io_uring_enter(int fd, unsigned to_submit,
         unsigned min_complete, unsigned flags, sigset_t *sig);
 extern int io_uring_register(int fd, unsigned int opcode, void *arg,
         unsigned int nr_args);
@@ -59,14 +65,33 @@ extern int io_uring_queue_init(unsigned entries, struct io_uring *ring,
 extern int io_uring_queue_mmap(int fd, struct io_uring_params *p,
         struct io_uring *ring);
 extern void io_uring_queue_exit(struct io_uring *ring);
-extern int io_uring_get_completion(struct io_uring *ring,
+extern int io_uring_peek_cqe(struct io_uring *ring,
         struct io_uring_cqe **cqe_ptr);
-extern int io_uring_wait_completion(struct io_uring *ring,
+extern int io_uring_wait_cqe(struct io_uring *ring,
         struct io_uring_cqe **cqe_ptr);
 extern int io_uring_submit(struct io_uring *ring);
 extern struct io_uring_sqe *io_uring_get_sqe(struct io_uring *ring);
 
 /*
+ * Must be called after io_uring_{peek,wait}_cqe() after the cqe has
+ * been processed by the application.
+ */
+static inline void io_uring_cqe_seen(struct io_uring *ring,
+                                     struct io_uring_cqe *cqe)
+{
+        if (cqe) {
+                struct io_uring_cq *cq = &ring->cq;
+
+                (*cq->khead)++;
+                /*
+                 * Ensure that the kernel sees our new head, the kernel has
+                 * the matching read barrier.
+                 */
+                write_barrier();
+        }
+}
+
+/*
  * Command prep helpers
  */
 static inline void io_uring_sqe_set_data(struct io_uring_sqe *sqe, void *data)
@@ -74,8 +99,14 @@ static inline void io_uring_sqe_set_data(struct io_uring_sqe *sqe, void *data)
         sqe->user_data = (unsigned long) data;
 }
 
+static inline void *io_uring_cqe_get_data(struct io_uring_cqe *cqe)
+{
+        return (void *) (uintptr_t) cqe->user_data;
+}
+
 static inline void io_uring_prep_rw(int op, struct io_uring_sqe *sqe, int fd,
-                                    void *addr, unsigned len, off_t offset)
+                                    const void *addr, unsigned len,
+                                    off_t offset)
 {
         memset(sqe, 0, sizeof(*sqe));
         sqe->opcode = op;
@@ -86,8 +117,8 @@ static inline void io_uring_prep_rw(int op, struct io_uring_sqe *sqe, int fd,
 }
 
 static inline void io_uring_prep_readv(struct io_uring_sqe *sqe, int fd,
-                                       struct iovec *iovecs, unsigned nr_vecs,
-                                       off_t offset)
+                                       const struct iovec *iovecs,
+                                       unsigned nr_vecs, off_t offset)
 {
         io_uring_prep_rw(IORING_OP_READV, sqe, fd, iovecs, nr_vecs, offset);
 }
@@ -100,14 +131,14 @@ static inline void io_uring_prep_read_fixed(struct io_uring_sqe *sqe, int fd,
 }
 
 static inline void io_uring_prep_writev(struct io_uring_sqe *sqe, int fd,
-                                        struct iovec *iovecs, unsigned nr_vecs,
-                                        off_t offset)
+                                        const struct iovec *iovecs,
+                                        unsigned nr_vecs, off_t offset)
 {
         io_uring_prep_rw(IORING_OP_WRITEV, sqe, fd, iovecs, nr_vecs, offset);
 }
 
 static inline void io_uring_prep_write_fixed(struct io_uring_sqe *sqe, int fd,
-                                             void *buf, unsigned nbytes,
+                                             const void *buf, unsigned nbytes,
                                              off_t offset)
 {
         io_uring_prep_rw(IORING_OP_WRITE_FIXED, sqe, fd, buf, nbytes, offset);
@@ -131,13 +162,22 @@ static inline void io_uring_prep_poll_remove(struct io_uring_sqe *sqe,
 }
 
 static inline void io_uring_prep_fsync(struct io_uring_sqe *sqe, int fd,
-                                       int datasync)
+                                       unsigned fsync_flags)
 {
         memset(sqe, 0, sizeof(*sqe));
         sqe->opcode = IORING_OP_FSYNC;
         sqe->fd = fd;
-        if (datasync)
-                sqe->fsync_flags = IORING_FSYNC_DATASYNC;
+        sqe->fsync_flags = fsync_flags;
+}
+
+static inline void io_uring_prep_nop(struct io_uring_sqe *sqe)
+{
+        memset(sqe, 0, sizeof(*sqe));
+        sqe->opcode = IORING_OP_NOP;
+}
+
+#ifdef __cplusplus
 }
+#endif
 
 #endif
diff --git a/tools/io_uring/queue.c b/tools/io_uring/queue.c
index 88505e873ad9..321819c132c7 100644
--- a/tools/io_uring/queue.c
+++ b/tools/io_uring/queue.c
@@ -8,8 +8,8 @@
 #include "liburing.h"
 #include "barrier.h"
 
-static int __io_uring_get_completion(struct io_uring *ring,
-                                     struct io_uring_cqe **cqe_ptr, int wait)
+static int __io_uring_get_cqe(struct io_uring *ring,
+                              struct io_uring_cqe **cqe_ptr, int wait)
 {
         struct io_uring_cq *cq = &ring->cq;
         const unsigned mask = *cq->kring_mask;
@@ -39,34 +39,25 @@ static int __io_uring_get_completion(struct io_uring *ring,
                         return -errno;
         } while (1);
 
-        if (*cqe_ptr) {
-                *cq->khead = head + 1;
-                /*
-                 * Ensure that the kernel sees our new head, the kernel has
-                 * the matching read barrier.
-                 */
-                write_barrier();
-        }
-
         return 0;
 }
 
 /*
- * Return an IO completion, if one is readily available
+ * Return an IO completion, if one is readily available. Returns 0 with
+ * cqe_ptr filled in on success, -errno on failure.
  */
-int io_uring_get_completion(struct io_uring *ring,
-                            struct io_uring_cqe **cqe_ptr)
+int io_uring_peek_cqe(struct io_uring *ring, struct io_uring_cqe **cqe_ptr)
 {
-        return __io_uring_get_completion(ring, cqe_ptr, 0);
+        return __io_uring_get_cqe(ring, cqe_ptr, 0);
 }
 
 /*
- * Return an IO completion, waiting for it if necessary
+ * Return an IO completion, waiting for it if necessary. Returns 0 with
+ * cqe_ptr filled in on success, -errno on failure.
  */
-int io_uring_wait_completion(struct io_uring *ring,
-                             struct io_uring_cqe **cqe_ptr)
+int io_uring_wait_cqe(struct io_uring *ring, struct io_uring_cqe **cqe_ptr)
 {
-        return __io_uring_get_completion(ring, cqe_ptr, 1);
+        return __io_uring_get_cqe(ring, cqe_ptr, 1);
 }
 
 /*
@@ -78,7 +69,7 @@ int io_uring_submit(struct io_uring *ring)
 {
         struct io_uring_sq *sq = &ring->sq;
         const unsigned mask = *sq->kring_mask;
-        unsigned ktail, ktail_next, submitted;
+        unsigned ktail, ktail_next, submitted, to_submit;
         int ret;
 
         /*
@@ -100,7 +91,8 @@ int io_uring_submit(struct io_uring *ring)
          */
         submitted = 0;
         ktail = ktail_next = *sq->ktail;
-        while (sq->sqe_head < sq->sqe_tail) {
+        to_submit = sq->sqe_tail - sq->sqe_head;
+        while (to_submit--) {
                 ktail_next++;
                 read_barrier();
 
@@ -136,7 +128,7 @@ submit:
         if (ret < 0)
                 return -errno;
 
-        return 0;
+        return ret;
 }
 
 /*
diff --git a/tools/io_uring/setup.c b/tools/io_uring/setup.c
index 4da19a77132c..0b50fcd78520 100644
--- a/tools/io_uring/setup.c
+++ b/tools/io_uring/setup.c
@@ -27,7 +27,7 @@ static int io_uring_mmap(int fd, struct io_uring_params *p,
         sq->kdropped = ptr + p->sq_off.dropped;
         sq->array = ptr + p->sq_off.array;
 
-        size = p->sq_entries * sizeof(struct io_uring_sqe),
+        size = p->sq_entries * sizeof(struct io_uring_sqe);
         sq->sqes = mmap(0, size, PROT_READ | PROT_WRITE,
                                 MAP_SHARED | MAP_POPULATE, fd,
                                 IORING_OFF_SQES);
@@ -79,7 +79,7 @@ int io_uring_queue_mmap(int fd, struct io_uring_params *p, struct io_uring *ring
 int io_uring_queue_init(unsigned entries, struct io_uring *ring, unsigned flags)
 {
         struct io_uring_params p;
-        int fd;
+        int fd, ret;
 
         memset(&p, 0, sizeof(p));
         p.flags = flags;
@@ -88,7 +88,11 @@ int io_uring_queue_init(unsigned entries, struct io_uring *ring, unsigned flags)
         if (fd < 0)
                 return fd;
 
-        return io_uring_queue_mmap(fd, &p, ring);
+        ret = io_uring_queue_mmap(fd, &p, ring);
+        if (ret)
+                close(fd);
+
+        return ret;
 }
 
 void io_uring_queue_exit(struct io_uring *ring)
diff --git a/tools/io_uring/syscall.c b/tools/io_uring/syscall.c
index 6b835e5c6a5b..b22e0aa54e9d 100644
--- a/tools/io_uring/syscall.c
+++ b/tools/io_uring/syscall.c
@@ -7,34 +7,46 @@
 #include <signal.h>
 #include "liburing.h"
 
-#if defined(__x86_64) || defined(__i386__)
-#ifndef __NR_sys_io_uring_setup
-#define __NR_sys_io_uring_setup         425
-#endif
-#ifndef __NR_sys_io_uring_enter
-#define __NR_sys_io_uring_enter         426
-#endif
-#ifndef __NR_sys_io_uring_register
-#define __NR_sys_io_uring_register      427
-#endif
-#else
-#error "Arch not supported yet"
+#ifdef __alpha__
+/*
+ * alpha is the only exception, all other architectures
+ * have common numbers for new system calls.
+ */
+# ifndef __NR_io_uring_setup
+#  define __NR_io_uring_setup           535
+# endif
+# ifndef __NR_io_uring_enter
+#  define __NR_io_uring_enter           536
+# endif
+# ifndef __NR_io_uring_register
+#  define __NR_io_uring_register        537
+# endif
+#else /* !__alpha__ */
+# ifndef __NR_io_uring_setup
+#  define __NR_io_uring_setup           425
+# endif
+# ifndef __NR_io_uring_enter
+#  define __NR_io_uring_enter           426
+# endif
+# ifndef __NR_io_uring_register
+#  define __NR_io_uring_register        427
+# endif
 #endif
 
 int io_uring_register(int fd, unsigned int opcode, void *arg,
                       unsigned int nr_args)
 {
-        return syscall(__NR_sys_io_uring_register, fd, opcode, arg, nr_args);
+        return syscall(__NR_io_uring_register, fd, opcode, arg, nr_args);
 }
 
-int io_uring_setup(unsigned entries, struct io_uring_params *p)
+int io_uring_setup(unsigned int entries, struct io_uring_params *p)
 {
-        return syscall(__NR_sys_io_uring_setup, entries, p);
+        return syscall(__NR_io_uring_setup, entries, p);
 }
 
-int io_uring_enter(unsigned fd, unsigned to_submit, unsigned min_complete,
-                   unsigned flags, sigset_t *sig)
+int io_uring_enter(int fd, unsigned int to_submit, unsigned int min_complete,
+                   unsigned int flags, sigset_t *sig)
 {
-        return syscall(__NR_sys_io_uring_enter, fd, to_submit, min_complete,
+        return syscall(__NR_io_uring_enter, fd, to_submit, min_complete,
                         flags, sig, _NSIG / 8);
 }