Re: [PATCH net-next v6 3/4] test/vsock: Add retry mechanism to ioctl wrapper

[Stefano Garzarella]

On Tue, Jul 08, 2025 at 02:36:13PM +0800, Xuewei Niu wrote:

Wrap the ioctl in `ioctl_int()`, which takes a pointer to the actual
int value and an expected int value. The function will not return until
either the ioctl returns the expected value or a timeout occurs, thus
avoiding immediate failure.

Signed-off-by: Xuewei Niu <niuxuewei....@antgroup.com>
---
tools/testing/vsock/util.c | 30 +++++++++++++++++++++---------
tools/testing/vsock/util.h |  1 +
2 files changed, 22 insertions(+), 9 deletions(-)

Reviewed-by: Stefano Garzarella <sgarz...@redhat.com>

diff --git a/tools/testing/vsock/util.c b/tools/testing/vsock/util.c
index 
803f1e075b62228c25f9dffa1eff131b8072a06a..1e65c5abd85b8bcf5886272de15437d7be13eb89
 100644
--- a/tools/testing/vsock/util.c
+++ b/tools/testing/vsock/util.c
@@ -17,6 +17,7 @@
#include <unistd.h>
#include <assert.h>
#include <sys/epoll.h>
+#include <sys/ioctl.h>
#include <sys/mman.h>
#include <linux/sockios.h>

@@ -101,28 +102,39 @@ void vsock_wait_remote_close(int fd)
        close(epollfd);
}

-/* Wait until transport reports no data left to be sent.
- * Return false if transport does not implement the unsent_bytes() callback.
+/* Wait until ioctl gives an expected int value.
+ * Return false if the op is not supported.
 */
-bool vsock_wait_sent(int fd)
+bool vsock_ioctl_int(int fd, unsigned long op, int expected)
{
-       int ret, sock_bytes_unsent;
+       int actual, ret;
+       char name[32];
+
+       snprintf(name, sizeof(name), "ioctl(%lu)", op);

        timeout_begin(TIMEOUT);
        do {
-               ret = ioctl(fd, SIOCOUTQ, &sock_bytes_unsent);
+               ret = ioctl(fd, op, &actual);
                if (ret < 0) {
                        if (errno == EOPNOTSUPP)
                                break;

-                       perror("ioctl(SIOCOUTQ)");
+                       perror(name);
                        exit(EXIT_FAILURE);
                }
-               timeout_check("SIOCOUTQ");
-       } while (sock_bytes_unsent != 0);
+               timeout_check(name);
+       } while (actual != expected);
        timeout_end();

-       return !ret;
+       return ret >= 0;
+}
+
+/* Wait until transport reports no data left to be sent.
+ * Return false if transport does not implement the unsent_bytes() callback.
+ */
+bool vsock_wait_sent(int fd)
+{
+       return vsock_ioctl_int(fd, SIOCOUTQ, 0);
}

/* Create socket <type>, bind to <cid, port>.
diff --git a/tools/testing/vsock/util.h b/tools/testing/vsock/util.h
index 
fdd4649fe2d49f57c93c4aa5dfbb37b710c65918..142c02a6834acb7117aca485b661332b73754b63
 100644
--- a/tools/testing/vsock/util.h
+++ b/tools/testing/vsock/util.h
@@ -87,6 +87,7 @@ int vsock_stream_listen(unsigned int cid, unsigned int port);
int vsock_seqpacket_accept(unsigned int cid, unsigned int port,
                           struct sockaddr_vm *clientaddrp);
void vsock_wait_remote_close(int fd);
+bool vsock_ioctl_int(int fd, unsigned long op, int expected);
bool vsock_wait_sent(int fd);
void send_buf(int fd, const void *buf, size_t len, int flags,
              ssize_t expected_ret);

--
2.34.1