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-rw-r--r--src/core/slice.c462
1 files changed, 462 insertions, 0 deletions
diff --git a/src/core/slice.c b/src/core/slice.c
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--- /dev/null
+++ b/src/core/slice.c
@@ -0,0 +1,462 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <errno.h>
+
+#include "alloc-util.h"
+#include "dbus-slice.h"
+#include "dbus-unit.h"
+#include "fd-util.h"
+#include "log.h"
+#include "serialize.h"
+#include "slice.h"
+#include "special.h"
+#include "string-util.h"
+#include "strv.h"
+#include "unit-name.h"
+#include "unit.h"
+
+static const UnitActiveState state_translation_table[_SLICE_STATE_MAX] = {
+ [SLICE_DEAD] = UNIT_INACTIVE,
+ [SLICE_ACTIVE] = UNIT_ACTIVE
+};
+
+static void slice_init(Unit *u) {
+ assert(u);
+ assert(u->load_state == UNIT_STUB);
+
+ u->ignore_on_isolate = true;
+}
+
+static void slice_set_state(Slice *t, SliceState state) {
+ SliceState old_state;
+ assert(t);
+
+ if (t->state != state)
+ bus_unit_send_pending_change_signal(UNIT(t), false);
+
+ old_state = t->state;
+ t->state = state;
+
+ if (state != old_state)
+ log_debug("%s changed %s -> %s",
+ UNIT(t)->id,
+ slice_state_to_string(old_state),
+ slice_state_to_string(state));
+
+ unit_notify(UNIT(t), state_translation_table[old_state], state_translation_table[state], /* reload_success = */ true);
+}
+
+static int slice_add_parent_slice(Slice *s) {
+ Unit *u = UNIT(s);
+ _cleanup_free_ char *a = NULL;
+ int r;
+
+ assert(s);
+
+ if (UNIT_GET_SLICE(u))
+ return 0;
+
+ r = slice_build_parent_slice(u->id, &a);
+ if (r <= 0) /* 0 means root slice */
+ return r;
+
+ return unit_add_dependency_by_name(u, UNIT_IN_SLICE, a, true, UNIT_DEPENDENCY_IMPLICIT);
+}
+
+static int slice_add_default_dependencies(Slice *s) {
+ int r;
+
+ assert(s);
+
+ if (!UNIT(s)->default_dependencies)
+ return 0;
+
+ /* Make sure slices are unloaded on shutdown */
+ r = unit_add_two_dependencies_by_name(
+ UNIT(s),
+ UNIT_BEFORE, UNIT_CONFLICTS,
+ SPECIAL_SHUTDOWN_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
+ if (r < 0)
+ return r;
+
+ return 0;
+}
+
+static int slice_verify(Slice *s) {
+ _cleanup_free_ char *parent = NULL;
+ int r;
+
+ assert(s);
+ assert(UNIT(s)->load_state == UNIT_LOADED);
+
+ if (!slice_name_is_valid(UNIT(s)->id))
+ return log_unit_error_errno(UNIT(s), SYNTHETIC_ERRNO(ENOEXEC), "Slice name %s is not valid. Refusing.", UNIT(s)->id);
+
+ r = slice_build_parent_slice(UNIT(s)->id, &parent);
+ if (r < 0)
+ return log_unit_error_errno(UNIT(s), r, "Failed to determine parent slice: %m");
+
+ /* If recursive errors are to be ignored, the parent slice should not be verified */
+ if (UNIT(s)->manager && FLAGS_SET(UNIT(s)->manager->test_run_flags, MANAGER_TEST_RUN_IGNORE_DEPENDENCIES))
+ return 0;
+
+ if (parent ? !unit_has_name(UNIT_GET_SLICE(UNIT(s)), parent) : !!UNIT_GET_SLICE(UNIT(s)))
+ return log_unit_error_errno(UNIT(s), SYNTHETIC_ERRNO(ENOEXEC), "Located outside of parent slice. Refusing.");
+
+ return 0;
+}
+
+static int slice_load_root_slice(Unit *u) {
+ assert(u);
+
+ if (!unit_has_name(u, SPECIAL_ROOT_SLICE))
+ return 0;
+
+ u->perpetual = true;
+
+ /* The root slice is a bit special. For example it is always running and cannot be terminated. Because of its
+ * special semantics we synthesize it here, instead of relying on the unit file on disk. */
+
+ u->default_dependencies = false;
+
+ if (!u->description)
+ u->description = strdup("Root Slice");
+ if (!u->documentation)
+ u->documentation = strv_new("man:systemd.special(7)");
+
+ return 1;
+}
+
+static int slice_load_system_slice(Unit *u) {
+ assert(u);
+
+ if (!MANAGER_IS_SYSTEM(u->manager))
+ return 0;
+ if (!unit_has_name(u, SPECIAL_SYSTEM_SLICE))
+ return 0;
+
+ u->perpetual = true;
+
+ /* The system slice is a bit special. For example it is always running and cannot be terminated. Because of its
+ * special semantics we synthesize it here, instead of relying on the unit file on disk. */
+
+ u->default_dependencies = false;
+
+ if (!u->description)
+ u->description = strdup("System Slice");
+ if (!u->documentation)
+ u->documentation = strv_new("man:systemd.special(7)");
+
+ return 1;
+}
+
+static int slice_load(Unit *u) {
+ Slice *s = SLICE(u);
+ int r;
+
+ assert(s);
+ assert(u->load_state == UNIT_STUB);
+
+ r = slice_load_root_slice(u);
+ if (r < 0)
+ return r;
+ r = slice_load_system_slice(u);
+ if (r < 0)
+ return r;
+
+ r = unit_load_fragment_and_dropin(u, false);
+ if (r < 0)
+ return r;
+
+ if (u->load_state != UNIT_LOADED)
+ return 0;
+
+ /* This is a new unit? Then let's add in some extras */
+ r = unit_patch_contexts(u);
+ if (r < 0)
+ return r;
+
+ r = slice_add_parent_slice(s);
+ if (r < 0)
+ return r;
+
+ r = slice_add_default_dependencies(s);
+ if (r < 0)
+ return r;
+
+ if (!u->description) {
+ _cleanup_free_ char *tmp = NULL;
+
+ r = unit_name_to_path(u->id, &tmp);
+ if (r >= 0) /* Failure is ignored… */
+ u->description = strjoin("Slice ", tmp);
+ }
+
+ return slice_verify(s);
+}
+
+static int slice_coldplug(Unit *u) {
+ Slice *t = SLICE(u);
+
+ assert(t);
+ assert(t->state == SLICE_DEAD);
+
+ if (t->deserialized_state != t->state)
+ slice_set_state(t, t->deserialized_state);
+
+ return 0;
+}
+
+static void slice_dump(Unit *u, FILE *f, const char *prefix) {
+ Slice *t = SLICE(u);
+
+ assert(t);
+ assert(f);
+
+ fprintf(f,
+ "%sSlice State: %s\n",
+ prefix, slice_state_to_string(t->state));
+
+ cgroup_context_dump(UNIT(t), f, prefix);
+}
+
+static int slice_start(Unit *u) {
+ Slice *t = SLICE(u);
+ int r;
+
+ assert(t);
+ assert(t->state == SLICE_DEAD);
+
+ r = unit_acquire_invocation_id(u);
+ if (r < 0)
+ return r;
+
+ (void) unit_realize_cgroup(u);
+ (void) unit_reset_accounting(u);
+
+ slice_set_state(t, SLICE_ACTIVE);
+ return 1;
+}
+
+static int slice_stop(Unit *u) {
+ Slice *t = SLICE(u);
+
+ assert(t);
+ assert(t->state == SLICE_ACTIVE);
+
+ /* We do not need to destroy the cgroup explicitly,
+ * unit_notify() will do that for us anyway. */
+
+ slice_set_state(t, SLICE_DEAD);
+ return 1;
+}
+
+static int slice_serialize(Unit *u, FILE *f, FDSet *fds) {
+ Slice *s = SLICE(u);
+
+ assert(s);
+ assert(f);
+ assert(fds);
+
+ (void) serialize_item(f, "state", slice_state_to_string(s->state));
+
+ return 0;
+}
+
+static int slice_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
+ Slice *s = SLICE(u);
+
+ assert(u);
+ assert(key);
+ assert(value);
+ assert(fds);
+
+ if (streq(key, "state")) {
+ SliceState state;
+
+ state = slice_state_from_string(value);
+ if (state < 0)
+ log_debug("Failed to parse state value %s", value);
+ else
+ s->deserialized_state = state;
+
+ } else
+ log_debug("Unknown serialization key '%s'", key);
+
+ return 0;
+}
+
+static UnitActiveState slice_active_state(Unit *u) {
+ assert(u);
+
+ return state_translation_table[SLICE(u)->state];
+}
+
+static const char *slice_sub_state_to_string(Unit *u) {
+ assert(u);
+
+ return slice_state_to_string(SLICE(u)->state);
+}
+
+static int slice_make_perpetual(Manager *m, const char *name, Unit **ret) {
+ Unit *u;
+ int r;
+
+ assert(m);
+ assert(name);
+
+ u = manager_get_unit(m, name);
+ if (!u) {
+ r = unit_new_for_name(m, sizeof(Slice), name, &u);
+ if (r < 0)
+ return log_error_errno(r, "Failed to allocate the special %s unit: %m", name);
+ }
+
+ u->perpetual = true;
+ SLICE(u)->deserialized_state = SLICE_ACTIVE;
+
+ unit_add_to_load_queue(u);
+ unit_add_to_dbus_queue(u);
+
+ if (ret)
+ *ret = u;
+
+ return 0;
+}
+
+static void slice_enumerate_perpetual(Manager *m) {
+ Unit *u;
+ int r;
+
+ assert(m);
+
+ r = slice_make_perpetual(m, SPECIAL_ROOT_SLICE, &u);
+ if (r >= 0 && manager_owns_host_root_cgroup(m)) {
+ Slice *s = SLICE(u);
+
+ /* If we are managing the root cgroup then this means our root slice covers the whole system, which
+ * means the kernel will track CPU/tasks/memory for us anyway, and it is all available in /proc. Let's
+ * hence turn accounting on here, so that our APIs to query this data are available. */
+
+ s->cgroup_context.cpu_accounting = true;
+ s->cgroup_context.tasks_accounting = true;
+ s->cgroup_context.memory_accounting = true;
+ }
+
+ if (MANAGER_IS_SYSTEM(m))
+ (void) slice_make_perpetual(m, SPECIAL_SYSTEM_SLICE, NULL);
+}
+
+static bool slice_freezer_action_supported_by_children(Unit *s) {
+ Unit *member;
+
+ assert(s);
+
+ UNIT_FOREACH_DEPENDENCY(member, s, UNIT_ATOM_SLICE_OF) {
+
+ if (member->type == UNIT_SLICE &&
+ !slice_freezer_action_supported_by_children(member))
+ return false;
+
+ if (!UNIT_VTABLE(member)->freeze)
+ return false;
+ }
+
+ return true;
+}
+
+static int slice_freezer_action(Unit *s, FreezerAction action) {
+ Unit *member;
+ int r;
+
+ assert(s);
+ assert(IN_SET(action, FREEZER_FREEZE, FREEZER_THAW));
+
+ if (action == FREEZER_FREEZE && !slice_freezer_action_supported_by_children(s)) {
+ log_unit_warning(s, "Requested freezer operation is not supported by all children of the slice");
+ return 0;
+ }
+
+ UNIT_FOREACH_DEPENDENCY(member, s, UNIT_ATOM_SLICE_OF) {
+ if (!member->cgroup_realized)
+ continue;
+
+ if (action == FREEZER_FREEZE)
+ r = UNIT_VTABLE(member)->freeze(member);
+ else if (UNIT_VTABLE(member)->thaw)
+ r = UNIT_VTABLE(member)->thaw(member);
+ else
+ /* Thawing is requested but no corresponding method is available, ignore. */
+ r = 0;
+ if (r < 0)
+ return r;
+ }
+
+ return unit_cgroup_freezer_action(s, action);
+}
+
+static int slice_freeze(Unit *s) {
+ assert(s);
+
+ return slice_freezer_action(s, FREEZER_FREEZE);
+}
+
+static int slice_thaw(Unit *s) {
+ assert(s);
+
+ return slice_freezer_action(s, FREEZER_THAW);
+}
+
+static bool slice_can_freeze(Unit *s) {
+ assert(s);
+
+ return slice_freezer_action_supported_by_children(s);
+}
+
+const UnitVTable slice_vtable = {
+ .object_size = sizeof(Slice),
+ .cgroup_context_offset = offsetof(Slice, cgroup_context),
+
+ .sections =
+ "Unit\0"
+ "Slice\0"
+ "Install\0",
+ .private_section = "Slice",
+
+ .can_transient = true,
+ .can_set_managed_oom = true,
+
+ .init = slice_init,
+ .load = slice_load,
+
+ .coldplug = slice_coldplug,
+
+ .dump = slice_dump,
+
+ .start = slice_start,
+ .stop = slice_stop,
+
+ .freeze = slice_freeze,
+ .thaw = slice_thaw,
+ .can_freeze = slice_can_freeze,
+
+ .serialize = slice_serialize,
+ .deserialize_item = slice_deserialize_item,
+
+ .active_state = slice_active_state,
+ .sub_state_to_string = slice_sub_state_to_string,
+
+ .bus_set_property = bus_slice_set_property,
+ .bus_commit_properties = bus_slice_commit_properties,
+
+ .enumerate_perpetual = slice_enumerate_perpetual,
+
+ .status_message_formats = {
+ .finished_start_job = {
+ [JOB_DONE] = "Created slice %s.",
+ },
+ .finished_stop_job = {
+ [JOB_DONE] = "Removed slice %s.",
+ },
+ },
+};
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