Add test program for pseudofs's DeviceID

test/initramfs/src/apps/pseudofs/pseudo_dev_id.c

@@ -0,0 +1,118 @@
+// SPDX-License-Identifier: MPL-2.0
+
+#define _GNU_SOURCE
+#include <sys/stat.h>
+#include <sys/sysmacros.h>
+#include <sys/types.h>
+
+#include "../test.h"
+
+struct dev_id {
+	unsigned int major;
+	unsigned int minor;
+	dev_t st_dev;
+};
+
+static int get_dev_id(const char *path, struct dev_id *dev_id)
+{
+	struct stat st;
+
+	if (stat(path, &st) < 0) {
+		return -1;
+	}
+
+	dev_id->st_dev = st.st_dev;
+	dev_id->major = major(st.st_dev);
+	dev_id->minor = minor(st.st_dev);
+
+	return 0;
+}
+
+static int dev_id_equal(const struct dev_id *a, const struct dev_id *b)
+{
+	return a->st_dev == b->st_dev;
+}
+
+FN_TEST(pseudo_fs_dev_id_major_is_zero)
+{
+	struct dev_id dev_id;
+
+	TEST_SUCC(get_dev_id("/proc", &dev_id));
+	TEST_RES(dev_id.major, _ret == 0);
+
+	TEST_SUCC(get_dev_id("/sys", &dev_id));
+	TEST_RES(dev_id.major, _ret == 0);
+
+	TEST_SUCC(get_dev_id("/dev/pts", &dev_id));
+	TEST_RES(dev_id.major, _ret == 0);
+
+	TEST_SUCC(get_dev_id("/sys/fs/cgroup", &dev_id));
+	TEST_RES(dev_id.major, _ret == 0);
+
+	TEST_SUCC(get_dev_id("/sys/kernel/config", &dev_id));
+	TEST_RES(dev_id.major, _ret == 0);
+
+	TEST_SUCC(get_dev_id("/dev", &dev_id));
+	TEST_RES(dev_id.major, _ret == 0);
+}
+END_TEST()
+
+FN_TEST(pseudo_fs_dev_id_minor_is_positive)
+{
+	struct dev_id dev_id;
+
+	TEST_SUCC(get_dev_id("/proc", &dev_id));
+	TEST_RES(dev_id.minor, _ret > 0);
+
+	TEST_SUCC(get_dev_id("/sys", &dev_id));
+	TEST_RES(dev_id.minor, _ret > 0);
+
+	TEST_SUCC(get_dev_id("/dev/pts", &dev_id));
+	TEST_RES(dev_id.minor, _ret > 0);
+
+	TEST_SUCC(get_dev_id("/sys/fs/cgroup", &dev_id));
+	TEST_RES(dev_id.minor, _ret > 0);
+
+	TEST_SUCC(get_dev_id("/sys/kernel/config", &dev_id));
+	TEST_RES(dev_id.minor, _ret > 0);
+
+	TEST_SUCC(get_dev_id("/dev", &dev_id));
+	TEST_RES(dev_id.minor, _ret > 0);
+}
+END_TEST()
+
+FN_TEST(pseudo_fs_dev_id_unique_per_mount)
+{
+	struct dev_id dev_ids[6];
+
+	TEST_SUCC(get_dev_id("/proc", &dev_ids[0]));
+	TEST_SUCC(get_dev_id("/sys", &dev_ids[1]));
+	TEST_SUCC(get_dev_id("/dev/pts", &dev_ids[2]));
+	TEST_SUCC(get_dev_id("/sys/fs/cgroup", &dev_ids[3]));
+	TEST_SUCC(get_dev_id("/sys/kernel/config", &dev_ids[4]));
+	TEST_SUCC(get_dev_id("/dev", &dev_ids[5]));
+
+	// Test that each pseudo filesystem has a unique device ID
+	for (int i = 0; i < 6; i++) {
+		for (int j = i + 1; j < 6; j++) {
+			TEST_RES(0, !dev_id_equal(&dev_ids[i], &dev_ids[j]));
+		}
+	}
+}
+END_TEST()
+
+FN_TEST(pseudo_fs_files_share_same_container_dev_id)
+{
+	struct dev_id dev_id_proc_self, dev_id_proc_cpuinfo;
+	struct dev_id dev_id_sys_kernel, dev_id_sys_fs;
+
+	// Files in the same pseudo fs should share the same container dev_id
+	TEST_SUCC(get_dev_id("/proc/self", &dev_id_proc_self));
+	TEST_SUCC(get_dev_id("/proc/cpuinfo", &dev_id_proc_cpuinfo));
+	TEST_RES(0, dev_id_equal(&dev_id_proc_self, &dev_id_proc_cpuinfo));
+
+	TEST_SUCC(get_dev_id("/sys/kernel", &dev_id_sys_kernel));
+	TEST_SUCC(get_dev_id("/sys/fs", &dev_id_sys_fs));
+	TEST_RES(0, dev_id_equal(&dev_id_sys_kernel, &dev_id_sys_fs));
+}
+END_TEST()

test/initramfs/src/apps/scripts/fs.sh

@@ -111,3 +111,8 @@ devfs/full
 devfs/random
 devfs/framebuffer
 devfs/evdev
+pseudofs/memfd_access_err
+pseudofs/pseudo_dentry
+pseudofs/pseudo_dev_id
+pseudofs/pseudo_inode
+pseudofs/pseudo_mount