[RFC PATCH liburing v1 0/4] Export io_uring syscall functions

[RFC PATCH liburing v1 0/4] Export io_uring syscall functions

[Ammar Faizi]

From: Ammar Faizi <ammarfaizi2@gnuweeb.org>

Hi Jens,

The background story of this series comes from the recent conversation with
Caleb Sander at:

   https://github.com/axboe/liburing/pull/646#issuecomment-1229639532

What do you think of this series?

There are 4 patches in this series.

1) syscall: Add io_uring syscall functions

We have:

  man 2 io_uring_setup;
  man 2 io_uring_enter;
  man 2 io_uring_register;

Those entries say that io_uring syscall functions are declared in
`<linux/io_uring.h>`. But they don't actually exist and never existed.
This is causing confusion for people who read the manpage. Let's just
implement them in liburing so they exist.

This also allows the user to invoke io_uring syscalls directly instead
of using the full liburing provided setup.

2) Clarify "man 2" entry for io_uring.

io_uring_enter(), io_uring_register(), io_uring_setup() are not
declared in `<linux/io_uring.h>` and never were. Plus, these
functions don't intentionally set the `errno` variable. Reflect this
fact in the manpage.

Side note: On architectures other than x86, x86-64, and aarch64, those
functions _do_ set the `errno`, this is because the syscall is done via
libc as we don't yet have nolibc support for the mentioned archs. Users
should not rely on this behavior.

3) man: Alias `io_uring_enter2()` to `io_uring_enter()`.

We have a new function io_uring_enter2(), add the man page entry for it
by aliasing it to io_uring_enter(). This aliased man entry has already
explained it.

4) test/io_uring_{enter,setup,register}: Use the exported syscall functions.

These tests use the internal definition of __sys_io_uring* functions.
A previous commit exported new functions that do the same thing with
those __sys_io_uring* functions. Test the exported functions instead of
the internal functions.

No functional change is intended.

Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
---

Ammar Faizi (4):
  syscall: Add io_uring syscall functions
  man: Clarify "man 2" entry for io_uring syscalls
  man: Alias `io_uring_enter2()` to `io_uring_enter()`
  test/io_uring_{enter,setup,register}: Use the exported syscall functions

 man/io_uring_enter.2     |  9 ++++-----
 man/io_uring_enter2.2    |  1 +
 man/io_uring_register.2  |  9 ++++-----
 man/io_uring_setup.2     |  8 +++-----
 src/Makefile             |  2 +-
 src/include/liburing.h   |  8 ++++++++
 src/liburing.map         |  4 ++++
 src/syscall.c            | 30 ++++++++++++++++++++++++++++++
 test/io_uring_enter.c    | 10 +++++-----
 test/io_uring_register.c | 34 ++++++++++++++++------------------
 test/io_uring_setup.c    |  4 ++--
 11 files changed, 78 insertions(+), 41 deletions(-)
 create mode 120000 man/io_uring_enter2.2
 create mode 100644 src/syscall.c


base-commit: bf248850dc2ae45d29d4fdde688e90d24f3dd6d2
-- 
Ammar Faizi

[RFC PATCH liburing v1 1/4] syscall: Add io_uring syscall functions

[Ammar Faizi]

From: Ammar Faizi <ammarfaizi2@gnuweeb.org>

We have:

  man 2 io_uring_setup;
  man 2 io_uring_enter;
  man 2 io_uring_register;

Those entries say that io_uring syscall functions are declared in
`<linux/io_uring.h>`. But they don't actually exist and never existed.
This is causing confusion for people who read the manpage. Let's just
implement them in liburing so they exist.

This also allows the user to invoke io_uring syscalls directly instead
of using the full liburing provided setup.

Link: https://github.com/axboe/liburing/pull/646#issuecomment-1229639532
Cc: Caleb Sander <csander@purestorage.com>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
---
 src/Makefile           |  2 +-
 src/include/liburing.h |  8 ++++++++
 src/liburing.map       |  4 ++++
 src/syscall.c          | 30 ++++++++++++++++++++++++++++++
 4 files changed, 43 insertions(+), 1 deletion(-)
 create mode 100644 src/syscall.c

diff --git a/src/Makefile b/src/Makefile
index dad379d..73a98ba 100644
--- a/src/Makefile
+++ b/src/Makefile
@@ -32,7 +32,7 @@ endif
 
 all: $(all_targets)
 
-liburing_srcs := setup.c queue.c register.c
+liburing_srcs := setup.c queue.c register.c syscall.c
 
 ifeq ($(CONFIG_NOLIBC),y)
 	liburing_srcs += nolibc.c
diff --git a/src/include/liburing.h b/src/include/liburing.h
index 66c5095..7db1ea9 100644
--- a/src/include/liburing.h
+++ b/src/include/liburing.h
@@ -202,6 +202,14 @@ int io_uring_register_file_alloc_range(struct io_uring *ring,
 int io_uring_register_notifications(struct io_uring *ring, unsigned nr,
 				    struct io_uring_notification_slot *slots);
 int io_uring_unregister_notifications(struct io_uring *ring);
+int io_uring_enter(unsigned int fd, unsigned int to_submit,
+		   unsigned int min_complete, unsigned int flags,
+		   sigset_t *sig);
+int io_uring_enter2(int fd, unsigned to_submit, unsigned min_complete,
+		    unsigned flags, sigset_t *sig, int sz);
+int io_uring_setup(unsigned entries, struct io_uring_params *p);
+int io_uring_register(int fd, unsigned opcode, const void *arg,
+		      unsigned nr_args);
 
 /*
  * Helper for the peek/wait single cqe functions. Exported because of that,
diff --git a/src/liburing.map b/src/liburing.map
index 7d8f143..8573dfc 100644
--- a/src/liburing.map
+++ b/src/liburing.map
@@ -62,4 +62,8 @@ LIBURING_2.3 {
 		io_uring_register_file_alloc_range;
 		io_uring_register_notifications;
 		io_uring_unregister_notifications;
+		io_uring_enter;
+		io_uring_enter2;
+		io_uring_setup;
+		io_uring_register;
 } LIBURING_2.2;
diff --git a/src/syscall.c b/src/syscall.c
new file mode 100644
index 0000000..fcc6808
--- /dev/null
+++ b/src/syscall.c
@@ -0,0 +1,30 @@
+/* SPDX-License-Identifier: MIT */
+
+#include "lib.h"
+#include "syscall.h"
+#include <liburing.h>
+
+int io_uring_enter(unsigned int fd, unsigned int to_submit,
+		   unsigned int min_complete, unsigned int flags,
+		   sigset_t *sig)
+{
+	return __sys_io_uring_enter(fd, to_submit, min_complete, flags, sig);
+}
+
+int io_uring_enter2(int fd, unsigned to_submit, unsigned min_complete,
+		    unsigned flags, sigset_t *sig, int sz)
+{
+	return __sys_io_uring_enter2(fd, to_submit, min_complete, flags, sig,
+				     sz);
+}
+
+int io_uring_setup(unsigned entries, struct io_uring_params *p)
+{
+	return __sys_io_uring_setup(entries, p);
+}
+
+int io_uring_register(int fd, unsigned opcode, const void *arg,
+		      unsigned nr_args)
+{
+	return __sys_io_uring_register(fd, opcode, arg, nr_args);
+}
-- 
Ammar Faizi

Re: [RFC PATCH liburing v1 1/4] syscall: Add io_uring syscall functions

[Caleb Sander]

On Sun, Aug 28, 2022 at 8:07 PM Ammar Faizi <ammarfaizi2@gnuweeb.org> wrote:
>
> --- a/src/include/liburing.h
> +++ b/src/include/liburing.h
> @@ -202,6 +202,14 @@ int io_uring_register_file_alloc_range(struct io_uring *ring,
>  int io_uring_register_notifications(struct io_uring *ring, unsigned nr,
>                                     struct io_uring_notification_slot *slots);
>  int io_uring_unregister_notifications(struct io_uring *ring);
> +int io_uring_enter(unsigned int fd, unsigned int to_submit,
> +                  unsigned int min_complete, unsigned int flags,
> +                  sigset_t *sig);
> +int io_uring_enter2(int fd, unsigned to_submit, unsigned min_complete,
> +                   unsigned flags, sigset_t *sig, int sz);
> +int io_uring_setup(unsigned entries, struct io_uring_params *p);
> +int io_uring_register(int fd, unsigned opcode, const void *arg,
> +                     unsigned nr_args);

Can we be consistent about using "int fd"? And either standardize on
"unsigned" or "unsigned int"? Looks like syscalls should maybe be
separated by an empty line from the register/unregister functions in
the header file.

> --- /dev/null
> +++ b/src/syscall.c
> @@ -0,0 +1,30 @@
> +/* SPDX-License-Identifier: MIT */
> +
> +#include "lib.h"

Looks like this include is unused?

Other than that,
Reviewed-by: Caleb Sander <csander@purestorage.com>

Re: [RFC PATCH liburing v1 1/4] syscall: Add io_uring syscall functions

[Caleb Sander]

On Sun, Aug 28, 2022 at 8:07 PM Ammar Faizi <ammarfaizi2@gnuweeb.org> wrote:
>
> --- a/src/include/liburing.h
> +++ b/src/include/liburing.h
> @@ -202,6 +202,14 @@ int io_uring_register_file_alloc_range(struct io_uring *ring,
>  int io_uring_register_notifications(struct io_uring *ring, unsigned nr,
>                                     struct io_uring_notification_slot *slots);
>  int io_uring_unregister_notifications(struct io_uring *ring);
> +int io_uring_enter(unsigned int fd, unsigned int to_submit,
> +                  unsigned int min_complete, unsigned int flags,
> +                  sigset_t *sig);
> +int io_uring_enter2(int fd, unsigned to_submit, unsigned min_complete,
> +                   unsigned flags, sigset_t *sig, int sz);

Also, from the io_uring_enter() man page, it appears that "void *"
would be a more appropriate type for the pointer argument in
io_uring_enter2(). And "size_t" for sz.

--Caleb

[RFC PATCH liburing v1 2/4] man: Clarify "man 2" entry for io_uring syscalls

[Ammar Faizi]

From: Ammar Faizi <ammarfaizi2@gnuweeb.org>

io_uring_enter(), io_uring_register(), io_uring_setup() are not
declared in `<linux/io_uring.h>` and never were. Plus, these
functions don't intentionally set the `errno` variable. Reflect this
fact in the manpage.

Side note: On architectures other than x86, x86-64, and aarch64, those
functions _do_ set the `errno`, this is because the syscall is done via
libc as we don't yet have nolibc support for the mentioned archs. Users
should not rely on this behavior.

Cc: Caleb Sander <csander@purestorage.com>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
---
 man/io_uring_enter.2    | 9 ++++-----
 man/io_uring_register.2 | 9 ++++-----
 man/io_uring_setup.2    | 8 +++-----
 3 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/man/io_uring_enter.2 b/man/io_uring_enter.2
index 6bfe9c9..05f9f72 100644
--- a/man/io_uring_enter.2
+++ b/man/io_uring_enter.2
@@ -8,7 +8,7 @@
 io_uring_enter \- initiate and/or complete asynchronous I/O
 .SH SYNOPSIS
 .nf
-.BR "#include <linux/io_uring.h>"
+.BR "#include <liburing.h>"
 .PP
 .BI "int io_uring_enter(unsigned int " fd ", unsigned int " to_submit ,
 .BI "                   unsigned int " min_complete ", unsigned int " flags ,
@@ -1299,11 +1299,10 @@ completion queue entry (see section
 rather than through the system call itself.
 
 Errors that occur not on behalf of a submission queue entry are returned via the
-system call directly. On such an error,
-.B -1
-is returned and
+system call directly. On such an error, a negative error code is returned. The
+caller should not rely on
 .I errno
-is set appropriately.
+variable.
 .PP
 .SH ERRORS
 These are the errors returned by
diff --git a/man/io_uring_register.2 b/man/io_uring_register.2
index 6c440b9..6791375 100644
--- a/man/io_uring_register.2
+++ b/man/io_uring_register.2
@@ -8,7 +8,7 @@
 io_uring_register \- register files or user buffers for asynchronous I/O 
 .SH SYNOPSIS
 .nf
-.BR "#include <linux/io_uring.h>"
+.BR "#include <liburing.h>"
 .PP
 .BI "int io_uring_register(unsigned int " fd ", unsigned int " opcode ,
 .BI "                      void *" arg ", unsigned int " nr_args );
@@ -583,11 +583,10 @@ Available since 5.18.
 
 On success,
 .BR io_uring_register ()
-returns 0.  On error,
-.B -1
-is returned, and
+returns 0.  On error, a negative error code is returned. The caller should not
+rely on
 .I errno
-is set accordingly.
+variable.
 
 .SH ERRORS
 .TP
diff --git a/man/io_uring_setup.2 b/man/io_uring_setup.2
index 0a5fa92..32a9e2e 100644
--- a/man/io_uring_setup.2
+++ b/man/io_uring_setup.2
@@ -9,7 +9,7 @@
 io_uring_setup \- setup a context for performing asynchronous I/O
 .SH SYNOPSIS
 .nf
-.BR "#include <linux/io_uring.h>"
+.BR "#include <liburing.h>"
 .PP
 .BI "int io_uring_setup(u32 " entries ", struct io_uring_params *" p );
 .fi
@@ -566,11 +566,9 @@ or
 .BR io_uring_enter (2)
 system calls.
 
-On error,
-.B -1
-is returned and
+On error, a negative error code is returned. The caller should not rely on
 .I errno
-is set appropriately.
+variable.
 .PP
 .SH ERRORS
 .TP
-- 
Ammar Faizi

[RFC PATCH liburing v1 3/4] man: Alias `io_uring_enter2()` to `io_uring_enter()`

[Ammar Faizi]

From: Ammar Faizi <ammarfaizi2@gnuweeb.org>

We have a new function io_uring_enter2(), add the man page entry for it
by aliasing it to io_uring_enter(). This aliased man entry has already
explained it.

Cc: Caleb Sander <csander@purestorage.com>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
---
 man/io_uring_enter2.2 | 1 +
 1 file changed, 1 insertion(+)
 create mode 120000 man/io_uring_enter2.2

diff --git a/man/io_uring_enter2.2 b/man/io_uring_enter2.2
new file mode 120000
index 0000000..5566c09
--- /dev/null
+++ b/man/io_uring_enter2.2
@@ -0,0 +1 @@
+io_uring_enter.2
\ No newline at end of file
-- 
Ammar Faizi

Re: [RFC PATCH liburing v1 3/4] man: Alias `io_uring_enter2()` to `io_uring_enter()`

[Caleb Sander]

There is no reference to "io_uring_enter2()" in this man page, only to
the updated signature of "io_uring_enter()". Can we make it clearer
that this is "io_uring_enter2()"? I would suggest adding the signature
for io_uring_enter2() to the top of the man page and renaming
"io_uring_enter()" to "io_uring_enter2()" in the "Since kernel 5.11"
section.

On Sun, Aug 28, 2022 at 8:08 PM Ammar Faizi <ammarfaizi2@gnuweeb.org> wrote:
>
> From: Ammar Faizi <ammarfaizi2@gnuweeb.org>
>
> We have a new function io_uring_enter2(), add the man page entry for it
> by aliasing it to io_uring_enter(). This aliased man entry has already
> explained it.
>
> Cc: Caleb Sander <csander@purestorage.com>
> Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
> ---
>  man/io_uring_enter2.2 | 1 +
>  1 file changed, 1 insertion(+)
>  create mode 120000 man/io_uring_enter2.2
>
> diff --git a/man/io_uring_enter2.2 b/man/io_uring_enter2.2
> new file mode 120000
> index 0000000..5566c09
> --- /dev/null
> +++ b/man/io_uring_enter2.2
> @@ -0,0 +1 @@
> +io_uring_enter.2
> \ No newline at end of file
> --
> Ammar Faizi
>

[RFC PATCH liburing v1 4/4] test/io_uring_{enter,setup,register}: Use the exported syscall functions

[Ammar Faizi]

From: Ammar Faizi <ammarfaizi2@gnuweeb.org>

These tests use the internal definition of __sys_io_uring* functions.
A previous commit exported new functions that do the same thing with
those __sys_io_uring* functions. Test the exported functions instead of
the internal functions.

No functional change is intended.

Cc: Caleb Sander <csander@purestorage.com>
Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
---
 test/io_uring_enter.c    | 10 +++++-----
 test/io_uring_register.c | 34 ++++++++++++++++------------------
 test/io_uring_setup.c    |  4 ++--
 3 files changed, 23 insertions(+), 25 deletions(-)

diff --git a/test/io_uring_enter.c b/test/io_uring_enter.c
index 67cc8c5..ecd54ff 100644
--- a/test/io_uring_enter.c
+++ b/test/io_uring_enter.c
@@ -38,7 +38,7 @@ static int expect_fail(int fd, unsigned int to_submit,
 {
 	int ret;
 
-	ret = __sys_io_uring_enter(fd, to_submit, min_complete, flags, sig);
+	ret = io_uring_enter(fd, to_submit, min_complete, flags, sig);
 	if (ret >= 0) {
 		fprintf(stderr, "expected %s, but call succeeded\n", strerror(-error));
 		return 1;
@@ -62,7 +62,7 @@ static int try_io_uring_enter(int fd, unsigned int to_submit,
 		return expect_fail(fd, to_submit, min_complete, flags, sig,
 				   expect);
 
-	ret = __sys_io_uring_enter(fd, to_submit, min_complete, flags, sig);
+	ret = io_uring_enter(fd, to_submit, min_complete, flags, sig);
 	if (ret != expect) {
 		fprintf(stderr, "Expected %d, got %d\n", expect, ret);
 		return 1;
@@ -211,8 +211,8 @@ int main(int argc, char **argv)
 	/* fill the sq ring */
 	sq_entries = ring.sq.ring_entries;
 	submit_io(&ring, sq_entries);
-	ret = __sys_io_uring_enter(ring.ring_fd, 0, sq_entries,
-					IORING_ENTER_GETEVENTS, NULL);
+	ret = io_uring_enter(ring.ring_fd, 0, sq_entries,
+			     IORING_ENTER_GETEVENTS, NULL);
 	if (ret < 0) {
 		fprintf(stderr, "io_uring_enter: %s\n", strerror(-ret));
 		status = 1;
@@ -246,7 +246,7 @@ int main(int argc, char **argv)
 	 */
 	io_uring_smp_store_release(sq->ktail, ktail);
 
-	ret = __sys_io_uring_enter(ring.ring_fd, 1, 0, 0, NULL);
+	ret = io_uring_enter(ring.ring_fd, 1, 0, 0, NULL);
 	/* now check to see if our sqe was dropped */
 	if (*sq->kdropped == dropped) {
 		fprintf(stderr, "dropped counter did not increase\n");
diff --git a/test/io_uring_register.c b/test/io_uring_register.c
index 4609354..dd4af7c 100644
--- a/test/io_uring_register.c
+++ b/test/io_uring_register.c
@@ -36,17 +36,17 @@ static int expect_fail(int fd, unsigned int opcode, void *arg,
 {
 	int ret;
 
-	ret = __sys_io_uring_register(fd, opcode, arg, nr_args);
+	ret = io_uring_register(fd, opcode, arg, nr_args);
 	if (ret >= 0) {
 		int ret2 = 0;
 
 		fprintf(stderr, "expected %s, but call succeeded\n", strerror(error));
 		if (opcode == IORING_REGISTER_BUFFERS) {
-			ret2 = __sys_io_uring_register(fd,
-					IORING_UNREGISTER_BUFFERS, 0, 0);
+			ret2 = io_uring_register(fd, IORING_UNREGISTER_BUFFERS,
+						 0, 0);
 		} else if (opcode == IORING_REGISTER_FILES) {
-			ret2 = __sys_io_uring_register(fd,
-					IORING_UNREGISTER_FILES, 0, 0);
+			ret2 = io_uring_register(fd, IORING_UNREGISTER_FILES, 0,
+						 0);
 		}
 		if (ret2) {
 			fprintf(stderr, "internal error: failed to unregister\n");
@@ -66,7 +66,7 @@ static int new_io_uring(int entries, struct io_uring_params *p)
 {
 	int fd;
 
-	fd = __sys_io_uring_setup(entries, p);
+	fd = io_uring_setup(entries, p);
 	if (fd < 0) {
 		perror("io_uring_setup");
 		exit(1);
@@ -186,15 +186,14 @@ static int test_max_fds(int uring_fd)
 	 */
 	nr_fds = UINT_MAX;
 	while (nr_fds) {
-		ret = __sys_io_uring_register(uring_fd, IORING_REGISTER_FILES,
-						fd_as, nr_fds);
+		ret = io_uring_register(uring_fd, IORING_REGISTER_FILES, fd_as,
+					nr_fds);
 		if (ret != 0) {
 			nr_fds /= 2;
 			continue;
 		}
 		status = 0;
-		ret = __sys_io_uring_register(uring_fd, IORING_UNREGISTER_FILES,
-						0, 0);
+		ret = io_uring_register(uring_fd, IORING_UNREGISTER_FILES, 0, 0);
 		if (ret < 0) {
 			ret = errno;
 			errno = ret;
@@ -230,7 +229,7 @@ static int test_memlock_exceeded(int fd)
 	iov.iov_base = buf;
 
 	while (iov.iov_len) {
-		ret = __sys_io_uring_register(fd, IORING_REGISTER_BUFFERS, &iov, 1);
+		ret = io_uring_register(fd, IORING_REGISTER_BUFFERS, &iov, 1);
 		if (ret < 0) {
 			if (errno == ENOMEM) {
 				iov.iov_len /= 2;
@@ -244,8 +243,7 @@ static int test_memlock_exceeded(int fd)
 			free(buf);
 			return 1;
 		}
-		ret = __sys_io_uring_register(fd, IORING_UNREGISTER_BUFFERS,
-						NULL, 0);
+		ret = io_uring_register(fd, IORING_UNREGISTER_BUFFERS, NULL, 0);
 		if (ret != 0) {
 			fprintf(stderr, "error: unregister failed with %d\n", errno);
 			free(buf);
@@ -283,14 +281,14 @@ static int test_iovec_nr(int fd)
 
 	/* reduce to UIO_MAXIOV */
 	nr = UIO_MAXIOV;
-	ret = __sys_io_uring_register(fd, IORING_REGISTER_BUFFERS, iovs, nr);
+	ret = io_uring_register(fd, IORING_REGISTER_BUFFERS, iovs, nr);
 	if (ret && (errno == ENOMEM || errno == EPERM) && geteuid()) {
 		fprintf(stderr, "can't register large iovec for regular users, skip\n");
 	} else if (ret != 0) {
 		fprintf(stderr, "expected success, got %d\n", errno);
 		status = 1;
 	} else {
-		__sys_io_uring_register(fd, IORING_UNREGISTER_BUFFERS, 0, 0);
+		io_uring_register(fd, IORING_UNREGISTER_BUFFERS, 0, 0);
 	}
 	free(buf);
 	free(iovs);
@@ -344,7 +342,7 @@ static int test_iovec_size(int fd)
 		 */
 		iov.iov_base = buf;
 		iov.iov_len = 2*1024*1024;
-		ret = __sys_io_uring_register(fd, IORING_REGISTER_BUFFERS, &iov, 1);
+		ret = io_uring_register(fd, IORING_REGISTER_BUFFERS, &iov, 1);
 		if (ret < 0) {
 			if (ret == -ENOMEM)
 				printf("Unable to test registering of a huge "
@@ -356,8 +354,8 @@ static int test_iovec_size(int fd)
 				status = 1;
 			}
 		} else {
-			ret = __sys_io_uring_register(fd,
-					IORING_UNREGISTER_BUFFERS, 0, 0);
+			ret = io_uring_register(fd, IORING_UNREGISTER_BUFFERS,
+						0, 0);
 			if (ret < 0) {
 				fprintf(stderr, "io_uring_unregister: %s\n",
 					strerror(-ret));
diff --git a/test/io_uring_setup.c b/test/io_uring_setup.c
index 67d5f4f..d945421 100644
--- a/test/io_uring_setup.c
+++ b/test/io_uring_setup.c
@@ -102,7 +102,7 @@ try_io_uring_setup(unsigned entries, struct io_uring_params *p, int expect)
 {
 	int ret;
 
-	ret = __sys_io_uring_setup(entries, p);
+	ret = io_uring_setup(entries, p);
 	if (ret != expect) {
 		fprintf(stderr, "expected %d, got %d\n", expect, ret);
 		/* if we got a valid uring, close it */
@@ -164,7 +164,7 @@ main(int argc, char **argv)
 
 	/* read/write on io_uring_fd */
 	memset(&p, 0, sizeof(p));
-	fd = __sys_io_uring_setup(1, &p);
+	fd = io_uring_setup(1, &p);
 	if (fd < 0) {
 		fprintf(stderr, "io_uring_setup failed with %d, expected success\n",
 		       -fd);
-- 
Ammar Faizi

Re: [RFC PATCH liburing v1 4/4] test/io_uring_{enter,setup,register}: Use the exported syscall functions

[Caleb Sander]

Reviewed-by: Caleb Sander <csander@purestorage.com>

On Sun, Aug 28, 2022 at 8:08 PM Ammar Faizi <ammarfaizi2@gnuweeb.org> wrote:
>
> From: Ammar Faizi <ammarfaizi2@gnuweeb.org>
>
> These tests use the internal definition of __sys_io_uring* functions.
> A previous commit exported new functions that do the same thing with
> those __sys_io_uring* functions. Test the exported functions instead of
> the internal functions.
>
> No functional change is intended.
>
> Cc: Caleb Sander <csander@purestorage.com>
> Signed-off-by: Ammar Faizi <ammarfaizi2@gnuweeb.org>
> ---
>  test/io_uring_enter.c    | 10 +++++-----
>  test/io_uring_register.c | 34 ++++++++++++++++------------------
>  test/io_uring_setup.c    |  4 ++--
>  3 files changed, 23 insertions(+), 25 deletions(-)
>
> diff --git a/test/io_uring_enter.c b/test/io_uring_enter.c
> index 67cc8c5..ecd54ff 100644
> --- a/test/io_uring_enter.c
> +++ b/test/io_uring_enter.c
> @@ -38,7 +38,7 @@ static int expect_fail(int fd, unsigned int to_submit,
>  {
>         int ret;
>
> -       ret = __sys_io_uring_enter(fd, to_submit, min_complete, flags, sig);
> +       ret = io_uring_enter(fd, to_submit, min_complete, flags, sig);
>         if (ret >= 0) {
>                 fprintf(stderr, "expected %s, but call succeeded\n", strerror(-error));
>                 return 1;
> @@ -62,7 +62,7 @@ static int try_io_uring_enter(int fd, unsigned int to_submit,
>                 return expect_fail(fd, to_submit, min_complete, flags, sig,
>                                    expect);
>
> -       ret = __sys_io_uring_enter(fd, to_submit, min_complete, flags, sig);
> +       ret = io_uring_enter(fd, to_submit, min_complete, flags, sig);
>         if (ret != expect) {
>                 fprintf(stderr, "Expected %d, got %d\n", expect, ret);
>                 return 1;
> @@ -211,8 +211,8 @@ int main(int argc, char **argv)
>         /* fill the sq ring */
>         sq_entries = ring.sq.ring_entries;
>         submit_io(&ring, sq_entries);
> -       ret = __sys_io_uring_enter(ring.ring_fd, 0, sq_entries,
> -                                       IORING_ENTER_GETEVENTS, NULL);
> +       ret = io_uring_enter(ring.ring_fd, 0, sq_entries,
> +                            IORING_ENTER_GETEVENTS, NULL);
>         if (ret < 0) {
>                 fprintf(stderr, "io_uring_enter: %s\n", strerror(-ret));
>                 status = 1;
> @@ -246,7 +246,7 @@ int main(int argc, char **argv)
>          */
>         io_uring_smp_store_release(sq->ktail, ktail);
>
> -       ret = __sys_io_uring_enter(ring.ring_fd, 1, 0, 0, NULL);
> +       ret = io_uring_enter(ring.ring_fd, 1, 0, 0, NULL);
>         /* now check to see if our sqe was dropped */
>         if (*sq->kdropped == dropped) {
>                 fprintf(stderr, "dropped counter did not increase\n");
> diff --git a/test/io_uring_register.c b/test/io_uring_register.c
> index 4609354..dd4af7c 100644
> --- a/test/io_uring_register.c
> +++ b/test/io_uring_register.c
> @@ -36,17 +36,17 @@ static int expect_fail(int fd, unsigned int opcode, void *arg,
>  {
>         int ret;
>
> -       ret = __sys_io_uring_register(fd, opcode, arg, nr_args);
> +       ret = io_uring_register(fd, opcode, arg, nr_args);
>         if (ret >= 0) {
>                 int ret2 = 0;
>
>                 fprintf(stderr, "expected %s, but call succeeded\n", strerror(error));
>                 if (opcode == IORING_REGISTER_BUFFERS) {
> -                       ret2 = __sys_io_uring_register(fd,
> -                                       IORING_UNREGISTER_BUFFERS, 0, 0);
> +                       ret2 = io_uring_register(fd, IORING_UNREGISTER_BUFFERS,
> +                                                0, 0);
>                 } else if (opcode == IORING_REGISTER_FILES) {
> -                       ret2 = __sys_io_uring_register(fd,
> -                                       IORING_UNREGISTER_FILES, 0, 0);
> +                       ret2 = io_uring_register(fd, IORING_UNREGISTER_FILES, 0,
> +                                                0);
>                 }
>                 if (ret2) {
>                         fprintf(stderr, "internal error: failed to unregister\n");
> @@ -66,7 +66,7 @@ static int new_io_uring(int entries, struct io_uring_params *p)
>  {
>         int fd;
>
> -       fd = __sys_io_uring_setup(entries, p);
> +       fd = io_uring_setup(entries, p);
>         if (fd < 0) {
>                 perror("io_uring_setup");
>                 exit(1);
> @@ -186,15 +186,14 @@ static int test_max_fds(int uring_fd)
>          */
>         nr_fds = UINT_MAX;
>         while (nr_fds) {
> -               ret = __sys_io_uring_register(uring_fd, IORING_REGISTER_FILES,
> -                                               fd_as, nr_fds);
> +               ret = io_uring_register(uring_fd, IORING_REGISTER_FILES, fd_as,
> +                                       nr_fds);
>                 if (ret != 0) {
>                         nr_fds /= 2;
>                         continue;
>                 }
>                 status = 0;
> -               ret = __sys_io_uring_register(uring_fd, IORING_UNREGISTER_FILES,
> -                                               0, 0);
> +               ret = io_uring_register(uring_fd, IORING_UNREGISTER_FILES, 0, 0);
>                 if (ret < 0) {
>                         ret = errno;
>                         errno = ret;
> @@ -230,7 +229,7 @@ static int test_memlock_exceeded(int fd)
>         iov.iov_base = buf;
>
>         while (iov.iov_len) {
> -               ret = __sys_io_uring_register(fd, IORING_REGISTER_BUFFERS, &iov, 1);
> +               ret = io_uring_register(fd, IORING_REGISTER_BUFFERS, &iov, 1);
>                 if (ret < 0) {
>                         if (errno == ENOMEM) {
>                                 iov.iov_len /= 2;
> @@ -244,8 +243,7 @@ static int test_memlock_exceeded(int fd)
>                         free(buf);
>                         return 1;
>                 }
> -               ret = __sys_io_uring_register(fd, IORING_UNREGISTER_BUFFERS,
> -                                               NULL, 0);
> +               ret = io_uring_register(fd, IORING_UNREGISTER_BUFFERS, NULL, 0);
>                 if (ret != 0) {
>                         fprintf(stderr, "error: unregister failed with %d\n", errno);
>                         free(buf);
> @@ -283,14 +281,14 @@ static int test_iovec_nr(int fd)
>
>         /* reduce to UIO_MAXIOV */
>         nr = UIO_MAXIOV;
> -       ret = __sys_io_uring_register(fd, IORING_REGISTER_BUFFERS, iovs, nr);
> +       ret = io_uring_register(fd, IORING_REGISTER_BUFFERS, iovs, nr);
>         if (ret && (errno == ENOMEM || errno == EPERM) && geteuid()) {
>                 fprintf(stderr, "can't register large iovec for regular users, skip\n");
>         } else if (ret != 0) {
>                 fprintf(stderr, "expected success, got %d\n", errno);
>                 status = 1;
>         } else {
> -               __sys_io_uring_register(fd, IORING_UNREGISTER_BUFFERS, 0, 0);
> +               io_uring_register(fd, IORING_UNREGISTER_BUFFERS, 0, 0);
>         }
>         free(buf);
>         free(iovs);
> @@ -344,7 +342,7 @@ static int test_iovec_size(int fd)
>                  */
>                 iov.iov_base = buf;
>                 iov.iov_len = 2*1024*1024;
> -               ret = __sys_io_uring_register(fd, IORING_REGISTER_BUFFERS, &iov, 1);
> +               ret = io_uring_register(fd, IORING_REGISTER_BUFFERS, &iov, 1);
>                 if (ret < 0) {
>                         if (ret == -ENOMEM)
>                                 printf("Unable to test registering of a huge "
> @@ -356,8 +354,8 @@ static int test_iovec_size(int fd)
>                                 status = 1;
>                         }
>                 } else {
> -                       ret = __sys_io_uring_register(fd,
> -                                       IORING_UNREGISTER_BUFFERS, 0, 0);
> +                       ret = io_uring_register(fd, IORING_UNREGISTER_BUFFERS,
> +                                               0, 0);
>                         if (ret < 0) {
>                                 fprintf(stderr, "io_uring_unregister: %s\n",
>                                         strerror(-ret));
> diff --git a/test/io_uring_setup.c b/test/io_uring_setup.c
> index 67d5f4f..d945421 100644
> --- a/test/io_uring_setup.c
> +++ b/test/io_uring_setup.c
> @@ -102,7 +102,7 @@ try_io_uring_setup(unsigned entries, struct io_uring_params *p, int expect)
>  {
>         int ret;
>
> -       ret = __sys_io_uring_setup(entries, p);
> +       ret = io_uring_setup(entries, p);
>         if (ret != expect) {
>                 fprintf(stderr, "expected %d, got %d\n", expect, ret);
>                 /* if we got a valid uring, close it */
> @@ -164,7 +164,7 @@ main(int argc, char **argv)
>
>         /* read/write on io_uring_fd */
>         memset(&p, 0, sizeof(p));
> -       fd = __sys_io_uring_setup(1, &p);
> +       fd = io_uring_setup(1, &p);
>         if (fd < 0) {
>                 fprintf(stderr, "io_uring_setup failed with %d, expected success\n",
>                        -fd);
> --
> Ammar Faizi
>