int create_subcgroup(pid_t pid, bool keep_unit, CGroupUnified unified_requested) {
_cleanup_free_ char *cgroup = NULL;
CGroupMask supported;
const char *payload;
int r;
assert(pid > 1);
/* In the unified hierarchy inner nodes may only contain subgroups, but not processes. Hence, if we running in
* the unified hierarchy and the container does the same, and we did not create a scope unit for the container
* move us and the container into two separate subcgroups.
*
* Moreover, container payloads such as systemd try to manage the cgroup they run in in full (i.e. including
* its attributes), while the host systemd will only delegate cgroups for children of the cgroup created for a
* delegation unit, instead of the cgroup itself. This means, if we'd pass on the cgroup allocated from the
* host systemd directly to the payload, the host and payload systemd might fight for the cgroup
* attributes. Hence, let's insert an intermediary cgroup to cover that case too.
*
* Note that we only bother with the main hierarchy here, not with any secondary ones. On the unified setup
* that's fine because there's only one hiearchy anyway and controllers are enabled directly on it. On the
* legacy setup, this is fine too, since delegation of controllers is generally not safe there, hence we won't
* do it. */
r = cg_mask_supported(&supported);
if (r < 0)
return log_error_errno(r, "Failed to determine supported controllers: %m");
if (keep_unit)
r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &cgroup);
else
r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, pid, &cgroup);
if (r < 0)
return log_error_errno(r, "Failed to get our control group: %m");
payload = strjoina(cgroup, "/payload");
r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, payload, pid);
if (r < 0)
return log_error_errno(r, "Failed to create %s subcgroup: %m", payload);
if (keep_unit) {
const char *supervisor;
supervisor = strjoina(cgroup, "/supervisor");
r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, supervisor, 0);
if (r < 0)
return log_error_errno(r, "Failed to create %s subcgroup: %m", supervisor);
}
/* Try to enable as many controllers as possible for the new payload. */
(void) cg_enable_everywhere(supported, supported, cgroup);
return 0;
}
int cgroup_bonding_install(CGroupBonding *b, pid_t pid, const char *cgroup_suffix) {
char *p = NULL;
const char *path;
int r;
assert(b);
assert(pid >= 0);
if (cgroup_suffix) {
p = strjoin(b->path, "/", cgroup_suffix, NULL);
if (!p)
return -ENOMEM;
path = p;
} else
path = b->path;
r = cg_create_and_attach(b->controller, path, pid);
free(p);
if (r < 0)
return r;
b->realized = true;
return 0;
}
int create_subcgroup(pid_t pid, CGroupUnified unified_requested) {
_cleanup_free_ char *cgroup = NULL;
const char *child;
int unified, r;
CGroupMask supported;
/* In the unified hierarchy inner nodes may only contain
* subgroups, but not processes. Hence, if we running in the
* unified hierarchy and the container does the same, and we
* did not create a scope unit for the container move us and
* the container into two separate subcgroups. */
if (unified_requested == CGROUP_UNIFIED_NONE)
return 0;
unified = cg_unified(SYSTEMD_CGROUP_CONTROLLER);
if (unified < 0)
return log_error_errno(unified, "Failed to determine whether the unified hierarchy is used: %m");
if (unified == 0)
return 0;
r = cg_mask_supported(&supported);
if (r < 0)
return log_error_errno(r, "Failed to determine supported controllers: %m");
r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &cgroup);
if (r < 0)
return log_error_errno(r, "Failed to get our control group: %m");
child = strjoina(cgroup, "/payload");
r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, child, pid);
if (r < 0)
return log_error_errno(r, "Failed to create %s subcgroup: %m", child);
child = strjoina(cgroup, "/supervisor");
r = cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, child, 0);
if (r < 0)
return log_error_errno(r, "Failed to create %s subcgroup: %m", child);
/* Try to enable as many controllers as possible for the new payload. */
(void) cg_enable_everywhere(supported, supported, cgroup);
return 0;
}
int main(int argc, char*argv[]) {
char *path;
char *c, *p;
assert_se(cg_create(SYSTEMD_CGROUP_CONTROLLER, "/test-a") == 0);
assert_se(cg_create(SYSTEMD_CGROUP_CONTROLLER, "/test-a") == 0);
assert_se(cg_create(SYSTEMD_CGROUP_CONTROLLER, "/test-b") == 0);
assert_se(cg_create(SYSTEMD_CGROUP_CONTROLLER, "/test-b/test-c") == 0);
assert_se(cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, "/test-b", 0) == 0);
assert_se(cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, getpid(), &path) == 0);
assert_se(streq(path, "/test-b"));
free(path);
assert_se(cg_attach(SYSTEMD_CGROUP_CONTROLLER, "/test-a", 0) == 0);
assert_se(cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, getpid(), &path) == 0);
assert_se(path_equal(path, "/test-a"));
free(path);
assert_se(cg_create_and_attach(SYSTEMD_CGROUP_CONTROLLER, "/test-b/test-d", 0) == 0);
assert_se(cg_get_by_pid(SYSTEMD_CGROUP_CONTROLLER, getpid(), &path) == 0);
assert_se(path_equal(path, "/test-b/test-d"));
free(path);
assert_se(cg_get_path(SYSTEMD_CGROUP_CONTROLLER, "/test-b/test-d", NULL, &path) == 0);
assert_se(path_equal(path, "/sys/fs/cgroup/systemd/test-b/test-d"));
free(path);
assert_se(cg_is_empty(SYSTEMD_CGROUP_CONTROLLER, "/test-a", false) > 0);
assert_se(cg_is_empty(SYSTEMD_CGROUP_CONTROLLER, "/test-b", false) > 0);
assert_se(cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, "/test-a", false) > 0);
assert_se(cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, "/test-b", false) == 0);
assert_se(cg_kill_recursive(SYSTEMD_CGROUP_CONTROLLER, "/test-a", 0, false, false, false, NULL) == 0);
assert_se(cg_kill_recursive(SYSTEMD_CGROUP_CONTROLLER, "/test-b", 0, false, false, false, NULL) > 0);
assert_se(cg_migrate_recursive(SYSTEMD_CGROUP_CONTROLLER, "/test-b", SYSTEMD_CGROUP_CONTROLLER, "/test-a", false, false) > 0);
assert_se(cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, "/test-a", false) == 0);
assert_se(cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, "/test-b", false) > 0);
assert_se(cg_kill_recursive(SYSTEMD_CGROUP_CONTROLLER, "/test-a", 0, false, false, false, NULL) > 0);
assert_se(cg_kill_recursive(SYSTEMD_CGROUP_CONTROLLER, "/test-b", 0, false, false, false, NULL) == 0);
cg_trim(SYSTEMD_CGROUP_CONTROLLER, "/", false);
assert_se(cg_delete(SYSTEMD_CGROUP_CONTROLLER, "/test-b") < 0);
assert_se(cg_delete(SYSTEMD_CGROUP_CONTROLLER, "/test-a") >= 0);
assert_se(cg_split_spec("foobar:/", &c, &p) == 0);
assert(streq(c, "foobar"));
assert(streq(p, "/"));
free(c);
free(p);
assert_se(cg_split_spec("foobar:", &c, &p) < 0);
assert_se(cg_split_spec("foobar:asdfd", &c, &p) < 0);
assert_se(cg_split_spec(":///", &c, &p) < 0);
assert_se(cg_split_spec(":", &c, &p) < 0);
assert_se(cg_split_spec("", &c, &p) < 0);
assert_se(cg_split_spec("fo/obar:/", &c, &p) < 0);
assert_se(cg_split_spec("/", &c, &p) >= 0);
assert(c == NULL);
assert(streq(p, "/"));
free(p);
assert_se(cg_split_spec("foo", &c, &p) >= 0);
assert(streq(c, "foo"));
assert(p == NULL);
free(c);
return 0;
}
