6.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Konstantin Shkolnyy kshk@linux.ibm.com
[ Upstream commit 7fd7ad6f36af36f30a06d165eff3780cb139fa79 ]
These tests: "SOCK_STREAM ioctl(SIOCOUTQ) 0 unsent bytes" "SOCK_SEQPACKET ioctl(SIOCOUTQ) 0 unsent bytes" output: "Unexpected 'SIOCOUTQ' value, expected 0, got 64 (CLIENT)".
They test that the SIOCOUTQ ioctl reports 0 unsent bytes after the data have been received by the other side. However, sometimes there is a delay in updating this "unsent bytes" counter, and the test fails even though the counter properly goes to 0 several milliseconds later.
The delay occurs in the kernel because the used buffer notification callback virtio_vsock_tx_done(), called upon receipt of the data by the other side, doesn't update the counter itself. It delegates that to a kernel thread (via vsock->tx_work). Sometimes that thread is delayed more than the test expects.
Change the test to poll SIOCOUTQ until it returns 0 or a timeout occurs.
Signed-off-by: Konstantin Shkolnyy kshk@linux.ibm.com Reviewed-by: Stefano Garzarella sgarzare@redhat.com Fixes: 18ee44ce97c1 ("test/vsock: add ioctl unsent bytes test") Link: https://patch.msgid.link/20250507151456.2577061-1-kshk@linux.ibm.com Signed-off-by: Jakub Kicinski kuba@kernel.org Signed-off-by: Sasha Levin sashal@kernel.org --- tools/testing/vsock/vsock_test.c | 28 ++++++++++++++++------------ 1 file changed, 16 insertions(+), 12 deletions(-)
diff --git a/tools/testing/vsock/vsock_test.c b/tools/testing/vsock/vsock_test.c index d0f6d253ac72d..613551132a966 100644 --- a/tools/testing/vsock/vsock_test.c +++ b/tools/testing/vsock/vsock_test.c @@ -1264,21 +1264,25 @@ static void test_unsent_bytes_client(const struct test_opts *opts, int type) send_buf(fd, buf, sizeof(buf), 0, sizeof(buf)); control_expectln("RECEIVED");
- ret = ioctl(fd, SIOCOUTQ, &sock_bytes_unsent); - if (ret < 0) { - if (errno == EOPNOTSUPP) { - fprintf(stderr, "Test skipped, SIOCOUTQ not supported.\n"); - } else { + /* SIOCOUTQ isn't guaranteed to instantly track sent data. Even though + * the "RECEIVED" message means that the other side has received the + * data, there can be a delay in our kernel before updating the "unsent + * bytes" counter. Repeat SIOCOUTQ until it returns 0. + */ + timeout_begin(TIMEOUT); + do { + ret = ioctl(fd, SIOCOUTQ, &sock_bytes_unsent); + if (ret < 0) { + if (errno == EOPNOTSUPP) { + fprintf(stderr, "Test skipped, SIOCOUTQ not supported.\n"); + break; + } perror("ioctl"); exit(EXIT_FAILURE); } - } else if (ret == 0 && sock_bytes_unsent != 0) { - fprintf(stderr, - "Unexpected 'SIOCOUTQ' value, expected 0, got %i\n", - sock_bytes_unsent); - exit(EXIT_FAILURE); - } - + timeout_check("SIOCOUTQ"); + } while (sock_bytes_unsent != 0); + timeout_end(); close(fd); }