diff options
Diffstat (limited to 'src/core/slice.c')
| -rw-r--r-- | src/core/slice.c | 397 |
1 files changed, 397 insertions, 0 deletions
diff --git a/src/core/slice.c b/src/core/slice.c new file mode 100644 index 0000000..15b18bc --- /dev/null +++ b/src/core/slice.c @@ -0,0 +1,397 @@ +/* SPDX-License-Identifier: LGPL-2.1+ */ + +#include <errno.h> + +#include "alloc-util.h" +#include "dbus-slice.h" +#include "dbus-unit.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], 0); +} + +static int slice_add_parent_slice(Slice *s) { + Unit *u = UNIT(s), *parent; + _cleanup_free_ char *a = NULL; + int r; + + assert(s); + + if (UNIT_ISSET(u->slice)) + return 0; + + r = slice_build_parent_slice(u->id, &a); + if (r <= 0) /* 0 means root slice */ + return r; + + r = manager_load_unit(u->manager, a, NULL, NULL, &parent); + if (r < 0) + return r; + + unit_ref_set(&u->slice, u, parent); + return 0; +} + +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); + + if (UNIT(s)->load_state != UNIT_LOADED) + return 0; + + if (!slice_name_is_valid(UNIT(s)->id)) { + log_unit_error(UNIT(s), "Slice name %s is not valid. Refusing.", UNIT(s)->id); + return -ENOEXEC; + } + + 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 (parent ? !unit_has_name(UNIT_DEREF(UNIT(s)->slice), parent) : UNIT_ISSET(UNIT(s)->slice)) { + log_unit_error(UNIT(s), "Located outside of parent slice. Refusing."); + return -ENOEXEC; + } + + 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_optional(u); + if (r < 0) + return r; + + /* This is a new unit? Then let's add in some extras */ + if (u->load_state == UNIT_LOADED) { + + 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; + } + + 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(&t->cgroup_context, 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_cpu_accounting(u); + (void) unit_reset_ip_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_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) { + return unit_kill_common(u, who, signo, -1, -1, error); +} + +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; +} + +_pure_ static UnitActiveState slice_active_state(Unit *u) { + assert(u); + + return state_translation_table[SLICE(u)->state]; +} + +_pure_ 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); +} + +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, + + .init = slice_init, + .load = slice_load, + + .coldplug = slice_coldplug, + + .dump = slice_dump, + + .start = slice_start, + .stop = slice_stop, + + .kill = slice_kill, + + .serialize = slice_serialize, + .deserialize_item = slice_deserialize_item, + + .active_state = slice_active_state, + .sub_state_to_string = slice_sub_state_to_string, + + .bus_vtable = bus_slice_vtable, + .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.", + }, + }, +}; |