Test multiple children sharing same parent. Parent should stay active as long as ANY child is active. Signed-off-by: Christian Brauner --- .../selftests/namespaces/ns_active_ref_test.c | 177 +++++++++++++++++++++ 1 file changed, 177 insertions(+) diff --git a/tools/testing/selftests/namespaces/ns_active_ref_test.c b/tools/testing/selftests/namespaces/ns_active_ref_test.c index 87b435b64b45..15d001df981c 100644 --- a/tools/testing/selftests/namespaces/ns_active_ref_test.c +++ b/tools/testing/selftests/namespaces/ns_active_ref_test.c @@ -1176,4 +1176,181 @@ TEST(ns_multilevel_hierarchy) close(gp_fd); } +/* + * Test multiple children sharing same parent. + * Parent should stay active as long as ANY child is active. + */ +TEST(ns_multiple_children_same_parent) +{ + struct file_handle *p_handle, *c1_handle, *c2_handle; + int ret, pipefd[2]; + pid_t pid; + int status; + __u64 p_id, c1_id, c2_id; + char p_buf[sizeof(*p_handle) + MAX_HANDLE_SZ]; + char c1_buf[sizeof(*c1_handle) + MAX_HANDLE_SZ]; + char c2_buf[sizeof(*c2_handle) + MAX_HANDLE_SZ]; + + ASSERT_EQ(pipe(pipefd), 0); + pid = fork(); + ASSERT_GE(pid, 0); + + if (pid == 0) { + close(pipefd[0]); + + /* Create parent user namespace */ + if (setup_userns() < 0) { + close(pipefd[1]); + exit(1); + } + + int p_fd = open("/proc/self/ns/user", O_RDONLY); + if (p_fd < 0) { + close(pipefd[1]); + exit(1); + } + if (ioctl(p_fd, NS_GET_ID, &p_id) < 0) { + close(p_fd); + close(pipefd[1]); + exit(1); + } + close(p_fd); + + /* Create first child user namespace */ + if (setup_userns() < 0) { + close(pipefd[1]); + exit(1); + } + + int c1_fd = open("/proc/self/ns/user", O_RDONLY); + if (c1_fd < 0) { + close(pipefd[1]); + exit(1); + } + if (ioctl(c1_fd, NS_GET_ID, &c1_id) < 0) { + close(c1_fd); + close(pipefd[1]); + exit(1); + } + close(c1_fd); + + /* Return to parent user namespace and create second child */ + /* We can't actually do this easily, so let's create a sibling namespace + * by creating a network namespace instead */ + if (unshare(CLONE_NEWNET) < 0) { + close(pipefd[1]); + exit(1); + } + + int c2_fd = open("/proc/self/ns/net", O_RDONLY); + if (c2_fd < 0) { + close(pipefd[1]); + exit(1); + } + if (ioctl(c2_fd, NS_GET_ID, &c2_id) < 0) { + close(c2_fd); + close(pipefd[1]); + exit(1); + } + close(c2_fd); + + /* Send all namespace IDs */ + write(pipefd[1], &p_id, sizeof(p_id)); + write(pipefd[1], &c1_id, sizeof(c1_id)); + write(pipefd[1], &c2_id, sizeof(c2_id)); + close(pipefd[1]); + exit(0); + } + + close(pipefd[1]); + + /* Read all three namespace IDs - fixed size, no parsing needed */ + ret = read(pipefd[0], &p_id, sizeof(p_id)); + if (ret != sizeof(p_id)) { + close(pipefd[0]); + waitpid(pid, NULL, 0); + SKIP(return, "Failed to read parent namespace ID"); + } + + ret = read(pipefd[0], &c1_id, sizeof(c1_id)); + if (ret != sizeof(c1_id)) { + close(pipefd[0]); + waitpid(pid, NULL, 0); + SKIP(return, "Failed to read first child namespace ID"); + } + + ret = read(pipefd[0], &c2_id, sizeof(c2_id)); + close(pipefd[0]); + if (ret != sizeof(c2_id)) { + waitpid(pid, NULL, 0); + SKIP(return, "Failed to read second child namespace ID"); + } + + /* Construct file handles from namespace IDs */ + p_handle = (struct file_handle *)p_buf; + p_handle->handle_bytes = sizeof(struct nsfs_file_handle); + p_handle->handle_type = FILEID_NSFS; + struct nsfs_file_handle *p_fh = (struct nsfs_file_handle *)p_handle->f_handle; + p_fh->ns_id = p_id; + p_fh->ns_type = 0; + p_fh->ns_inum = 0; + + c1_handle = (struct file_handle *)c1_buf; + c1_handle->handle_bytes = sizeof(struct nsfs_file_handle); + c1_handle->handle_type = FILEID_NSFS; + struct nsfs_file_handle *c1_fh = (struct nsfs_file_handle *)c1_handle->f_handle; + c1_fh->ns_id = c1_id; + c1_fh->ns_type = 0; + c1_fh->ns_inum = 0; + + c2_handle = (struct file_handle *)c2_buf; + c2_handle->handle_bytes = sizeof(struct nsfs_file_handle); + c2_handle->handle_type = FILEID_NSFS; + struct nsfs_file_handle *c2_fh = (struct nsfs_file_handle *)c2_handle->f_handle; + c2_fh->ns_id = c2_id; + c2_fh->ns_type = 0; + c2_fh->ns_inum = 0; + + /* Open both children before process exits */ + int c1_fd = open_by_handle_at(FD_NSFS_ROOT, c1_handle, O_RDONLY); + int c2_fd = open_by_handle_at(FD_NSFS_ROOT, c2_handle, O_RDONLY); + + if (c1_fd < 0 || c2_fd < 0) { + if (c1_fd >= 0) close(c1_fd); + if (c2_fd >= 0) close(c2_fd); + waitpid(pid, NULL, 0); + SKIP(return, "Failed to open child namespaces"); + } + + waitpid(pid, &status, 0); + ASSERT_TRUE(WIFEXITED(status)); + if (WEXITSTATUS(status) != 0) { + close(c1_fd); + close(c2_fd); + SKIP(return, "Child failed"); + } + + /* Parent should be active (both children active) */ + TH_LOG("Both children active - parent should be active"); + int p_fd = open_by_handle_at(FD_NSFS_ROOT, p_handle, O_RDONLY); + ASSERT_GE(p_fd, 0); + close(p_fd); + + /* Close first child - parent should STILL be active */ + TH_LOG("Closing first child - parent should still be active"); + close(c1_fd); + p_fd = open_by_handle_at(FD_NSFS_ROOT, p_handle, O_RDONLY); + ASSERT_GE(p_fd, 0); + close(p_fd); + + /* Close second child - NOW parent should become inactive */ + TH_LOG("Closing second child - parent should become inactive"); + close(c2_fd); + p_fd = open_by_handle_at(FD_NSFS_ROOT, p_handle, O_RDONLY); + if (p_fd >= 0) { + close(p_fd); + TH_LOG("Warning: Parent still active after all children inactive"); + } +} + TEST_HARNESS_MAIN -- 2.47.3