nspawn: introduce the new /machine/ tree in the cgroup tree and move containers there

Containers will now carry a label (normally derived from the root
directory name, but configurable by the user), and the container's root
cgroup is /machine/<label>. This label is called "machine name", and can
cover both containers and VMs (as soon as libvirt also makes use of
/machine/).

libsystemd-login can be used to query the machine name from a process.

This patch also includes numerous clean-ups for the cgroup code.

1 files changed, 30 insertions, 10 deletions

diff --git a/src/test/test-cgroup-util.c b/src/test/test-cgroup-util.c
index 8e24d1ceca..5eaa129418 100644
--- a/src/test/test-cgroup-util.c
+++ b/src/test/test-cgroup-util.c
@@ -24,20 +24,20 @@
 #include "util.h"
 #include "cgroup-util.h"
 
-static void check_c_t_u(const char *path, int code, const char *result) {
+static void check_p_d_u(const char *path, int code, const char *result) {
         _cleanup_free_ char *unit = NULL;
 
-        assert_se(cg_cgroup_to_unit(path, &unit) == code);
+        assert_se(cg_path_decode_unit(path, &unit) == code);
         assert_se(streq_ptr(unit, result));
 }
 
-static void test_cgroup_to_unit(void) {
-        check_c_t_u("getty@.service/tty2", 0, "getty@tty2.service");
-        check_c_t_u("getty@.service/tty2/xxx", 0, "getty@tty2.service");
-        check_c_t_u("getty@.service/", -EINVAL, NULL);
-        check_c_t_u("getty@.service", -EINVAL, NULL);
-        check_c_t_u("getty.service", 0, "getty.service");
-        check_c_t_u("getty", -EINVAL, NULL);
+static void test_path_decode_unit(void) {
+        check_p_d_u("getty@.service/tty2", 0, "getty@tty2.service");
+        check_p_d_u("getty@.service/tty2/xxx", 0, "getty@tty2.service");
+        check_p_d_u("getty@.service/", -EINVAL, NULL);
+        check_p_d_u("getty@.service", -EINVAL, NULL);
+        check_p_d_u("getty.service", 0, "getty.service");
+        check_p_d_u("getty", -EINVAL, NULL);
 }
 
 static void check_p_g_u(const char *path, int code, const char *result) {
@@ -62,7 +62,9 @@ static void test_path_get_unit(void) {
         check_p_g_u("/system/getty@tty6.service/tty5", 0, "getty@tty6.service");
         check_p_g_u("sadfdsafsda", -ENOENT, NULL);
         check_p_g_u("/system/getty####@tty6.service/tty5", -EINVAL, NULL);
+}
 
+static void test_path_get_user_unit(void) {
         check_p_g_u_u("/user/lennart/2/systemd-21548/foobar.service", 0, "foobar.service");
         check_p_g_u_u("/user/lennart/2/systemd-21548/foobar.service/waldo", 0, "foobar.service");
         check_p_g_u_u("/user/lennart/2/systemd-21548/foobar.service/waldo/uuuux", 0, "foobar.service");
@@ -71,9 +73,27 @@ static void test_path_get_unit(void) {
         check_p_g_u_u("/user/lennart/2/systemd-21548/foobar@.service/pie/pa/po", 0, "foobar@pie.service");
 }
 
+static void test_get_paths(void) {
+        _cleanup_free_ char *a = NULL, *b = NULL, *c = NULL, *d = NULL;
+
+        assert_se(cg_get_root_path(&a) >= 0);
+        log_info("Root = %s", a);
+
+        assert_se(cg_get_system_path(&b) >= 0);
+        log_info("System = %s", b);
+
+        assert_se(cg_get_user_path(&c) >= 0);
+        log_info("User = %s", c);
+
+        assert_se(cg_get_machine_path(&d) >= 0);
+        log_info("Machine = %s", d);
+}
+
 int main(void) {
-        test_cgroup_to_unit();
+        test_path_decode_unit();
         test_path_get_unit();
+        test_path_get_user_unit();
+        test_get_paths();
 
         return 0;
 }