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core: introduce support for cgroup freezer 

With cgroup v2 the cgroup freezer is implemented as a cgroup
attribute called cgroup.freeze. cgroup can be frozen by writing "1"
to the file and kernel will send us a notification through
"cgroup.events" after the operation is finished and processes in the
cgroup entered quiescent state, i.e. they are not scheduled to
run. Writing "0" to the attribute file does the inverse and process
execution is resumed.

This commit exposes above low-level functionality through systemd's DBus
API. Each unit type must provide specialized implementation for these
methods, otherwise, we return an error. So far only service, scope, and
slice unit types provide the support. It is possible to check if a
given unit has the support using CanFreeze() DBus property.

Note that DBus API has a synchronous behavior and we dispatch the reply
to freeze/thaw requests only after the kernel has notified us that
requested operation was completed.
This commit is contained in:
Michal Sekletár 2020-04-29 17:53:43 +02:00
parent 25a1f04c68
commit d9e45bc3ab
19 changed files with 566 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
NEWS
View File

@ -10,6 +10,10 @@ CHANGES WITH 246 in spe:
their first output column with --no-legend. To hide the first column,
use --plain.
* The service manager gained basic support for cgroup v2 freezer. Units
can now be suspended or resumed either using new systemctl verbs,
freeze and thaw respectively, or via D-Bus.
CHANGES WITH 245:
* A new tool "systemd-repart" has been added, that operates as an

24
man/systemctl.xml
View File

@ -303,6 +303,30 @@ Sun 2017-02-26 20:57:49 EST 2h 3min left Sun 2017-02-26 11:56:36 EST 6h ago
generally redundant and reproducible on the next invocation of the unit).</para>
</listitem>
</varlistentry>
<varlistentry>
<term><command>freeze <replaceable>PATTERN</replaceable>…</command></term>
<listitem>
<para>Freeze one or more units specified on the
command line using cgroup freezer</para>
<para>Freezing the unit will cause all processes contained within the cgroup corresponding to the unit
to be suspended. Being suspended means that unit's processes won't be scheduled to run on CPU until thawed.
Note that this command is supported only on systems that use unified cgroup hierarchy. Unit is automatically
thawed just before we execute a job against the unit, e.g. before the unit is stopped.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><command>thaw <replaceable>PATTERN</replaceable>…</command></term>
<listitem>
<para>Thaw (unfreeze) one or more units specified on the
command line.</para>
<para>This is the inverse operation to the <command>freeze</command> command and resumes the execution of
processes in the unit's cgroup.</para>
</listitem>
</varlistentry>
<varlistentry>
<term><command>is-active <replaceable>PATTERN</replaceable>…</command></term>

18
src/basic/cgroup-util.c
View File

@ -149,6 +149,17 @@ bool cg_ns_supported(void) {
return enabled;
}
bool cg_freezer_supported(void) {
static thread_local int supported = -1;
if (supported >= 0)
return supported;
supported = cg_all_unified() > 0 && access("/sys/fs/cgroup/init.scope/cgroup.freeze", F_OK) == 0;
return supported;
}
int cg_enumerate_subgroups(const char *controller, const char *path, DIR **_d) {
_cleanup_free_ char *fs = NULL;
int r;
@ -1702,7 +1713,8 @@ int cg_get_keyed_attribute_full(
* all keys to retrieve. The 'ret_values' parameter should be passed as string size with the same number of
* entries as 'keys'. On success each entry will be set to the value of the matching key.
*
* If the attribute file doesn't exist at all returns ENOENT, if any key is not found returns ENXIO. */
* If the attribute file doesn't exist at all returns ENOENT, if any key is not found returns ENXIO. If mode
* is set to GG_KEY_MODE_GRACEFUL we ignore missing keys and return those that were parsed successfully. */
r = cg_get_path(controller, path, attribute, &filename);
if (r < 0)
@ -1752,8 +1764,8 @@ int cg_get_keyed_attribute_full(
if (mode & CG_KEY_MODE_GRACEFUL)
goto done;
else
r = -ENXIO;
r = -ENXIO;
fail:
for (i = 0; i < n; i++)

1
src/basic/cgroup-util.h
View File

@ -260,6 +260,7 @@ int cg_mask_to_string(CGroupMask mask, char **ret);
int cg_kernel_controllers(Set **controllers);
bool cg_ns_supported(void);
bool cg_freezer_supported(void);
int cg_all_unified(void);
int cg_hybrid_unified(void);

9
src/basic/unit-def.c
View File

@ -108,6 +108,15 @@ static const char* const unit_active_state_table[_UNIT_ACTIVE_STATE_MAX] = {
DEFINE_STRING_TABLE_LOOKUP(unit_active_state, UnitActiveState);
static const char* const freezer_state_table[_FREEZER_STATE_MAX] = {
[FREEZER_RUNNING] = "running",
[FREEZER_FREEZING] = "freezing",
[FREEZER_FROZEN] = "frozen",
[FREEZER_THAWING] = "thawing",
};
DEFINE_STRING_TABLE_LOOKUP(freezer_state, FreezerState);
static const char* const automount_state_table[_AUTOMOUNT_STATE_MAX] = {
[AUTOMOUNT_DEAD] = "dead",
[AUTOMOUNT_WAITING] = "waiting",

12
src/basic/unit-def.h
View File

@ -48,6 +48,15 @@ typedef enum UnitActiveState {
_UNIT_ACTIVE_STATE_INVALID = -1
} UnitActiveState;
typedef enum FreezerState {
FREEZER_RUNNING,
FREEZER_FREEZING,
FREEZER_FROZEN,
FREEZER_THAWING,
_FREEZER_STATE_MAX,
_FREEZER_STATE_INVALID = -1
} FreezerState;
typedef enum AutomountState {
AUTOMOUNT_DEAD,
AUTOMOUNT_WAITING,
@ -253,6 +262,9 @@ UnitLoadState unit_load_state_from_string(const char *s) _pure_;
const char *unit_active_state_to_string(UnitActiveState i) _const_;
UnitActiveState unit_active_state_from_string(const char *s) _pure_;
const char *freezer_state_to_string(FreezerState i) _const_;
FreezerState freezer_state_from_string(const char *s) _pure_;
const char* automount_state_to_string(AutomountState i) _const_;
AutomountState automount_state_from_string(const char *s) _pure_;

96
src/core/cgroup.c
View File

@ -16,7 +16,9 @@
#include "fd-util.h"
#include "fileio.h"
#include "fs-util.h"
#include "io-util.h"
#include "limits-util.h"
#include "nulstr-util.h"
#include "parse-util.h"
#include "path-util.h"
#include "process-util.h"
@ -2661,6 +2663,16 @@ void unit_add_to_cgroup_empty_queue(Unit *u) {
log_debug_errno(r, "Failed to enable cgroup empty event source: %m");
}
static void unit_remove_from_cgroup_empty_queue(Unit *u) {
assert(u);
if (!u->in_cgroup_empty_queue)
return;
LIST_REMOVE(cgroup_empty_queue, u->manager->cgroup_empty_queue, u);
u->in_cgroup_empty_queue = false;
}
int unit_check_oom(Unit *u) {
_cleanup_free_ char *oom_kill = NULL;
bool increased;
@ -2761,6 +2773,41 @@ static void unit_add_to_cgroup_oom_queue(Unit *u) {
log_error_errno(r, "Failed to enable cgroup oom event source: %m");
}
static int unit_check_cgroup_events(Unit *u) {
char *values[2] = {};
int r;
assert(u);
r = cg_get_keyed_attribute_graceful(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, "cgroup.events",
STRV_MAKE("populated", "frozen"), values);
if (r < 0)
return r;
/* The cgroup.events notifications can be merged together so act as we saw the given state for the
* first time. The functions we call to handle given state are idempotent, which makes them
* effectively remember the previous state. */
if (values[0]) {
if (streq(values[0], "1"))
unit_remove_from_cgroup_empty_queue(u);
else
unit_add_to_cgroup_empty_queue(u);
}
/* Disregard freezer state changes due to operations not initiated by us */
if (values[1] && IN_SET(u->freezer_state, FREEZER_FREEZING, FREEZER_THAWING)) {
if (streq(values[1], "0"))
unit_thawed(u);
else
unit_frozen(u);
}
free(values[0]);
free(values[1]);
return 0;
}
static int on_cgroup_inotify_event(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
Manager *m = userdata;
@ -2797,7 +2844,7 @@ static int on_cgroup_inotify_event(sd_event_source *s, int fd, uint32_t revents,
u = hashmap_get(m->cgroup_control_inotify_wd_unit, INT_TO_PTR(e->wd));
if (u)
unit_add_to_cgroup_empty_queue(u);
unit_check_cgroup_events(u);
u = hashmap_get(m->cgroup_memory_inotify_wd_unit, INT_TO_PTR(e->wd));
if (u)
@ -3550,6 +3597,46 @@ int compare_job_priority(const void *a, const void *b) {
return strcmp(x->unit->id, y->unit->id);
}
int unit_cgroup_freezer_action(Unit *u, FreezerAction action) {
_cleanup_free_ char *path = NULL;
FreezerState target, kernel = _FREEZER_STATE_INVALID;
int r;
assert(u);
assert(IN_SET(action, FREEZER_FREEZE, FREEZER_THAW));
if (!u->cgroup_realized)
return -EBUSY;
target = action == FREEZER_FREEZE ? FREEZER_FROZEN : FREEZER_RUNNING;
r = unit_freezer_state_kernel(u, &kernel);
if (r < 0)
log_unit_debug_errno(u, r, "Failed to obtain cgroup freezer state: %m");
if (target == kernel) {
u->freezer_state = target;
return 0;
}
r = cg_get_path(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, "cgroup.freeze", &path);
if (r < 0)
return r;
log_unit_debug(u, "%s unit.", action == FREEZER_FREEZE ? "Freezing" : "Thawing");
if (action == FREEZER_FREEZE)
u->freezer_state = FREEZER_FREEZING;
else
u->freezer_state = FREEZER_THAWING;
r = write_string_file(path, one_zero(action == FREEZER_FREEZE), WRITE_STRING_FILE_DISABLE_BUFFER);
if (r < 0)
return r;
return 0;
}
static const char* const cgroup_device_policy_table[_CGROUP_DEVICE_POLICY_MAX] = {
[CGROUP_DEVICE_POLICY_AUTO] = "auto",
[CGROUP_DEVICE_POLICY_CLOSED] = "closed",
@ -3585,3 +3672,10 @@ int unit_get_cpuset(Unit *u, CPUSet *cpus, const char *name) {
}
DEFINE_STRING_TABLE_LOOKUP(cgroup_device_policy, CGroupDevicePolicy);
static const char* const freezer_action_table[_FREEZER_ACTION_MAX] = {
[FREEZER_FREEZE] = "freeze",
[FREEZER_THAW] = "thaw",
};
DEFINE_STRING_TABLE_LOOKUP(freezer_action, FreezerAction);

12
src/core/cgroup.h
View File

@ -47,6 +47,14 @@ typedef enum CGroupDevicePolicy {
_CGROUP_DEVICE_POLICY_INVALID = -1
} CGroupDevicePolicy;
typedef enum FreezerAction {
FREEZER_FREEZE,
FREEZER_THAW,
_FREEZER_ACTION_MAX,
_FREEZER_ACTION_INVALID = -1,
} FreezerAction;
struct CGroupDeviceAllow {
LIST_FIELDS(CGroupDeviceAllow, device_allow);
char *path;
@ -274,3 +282,7 @@ bool unit_cgroup_delegate(Unit *u);
int compare_job_priority(const void *a, const void *b);
int unit_get_cpuset(Unit *u, CPUSet *cpus, const char *name);
int unit_cgroup_freezer_action(Unit *u, FreezerAction action);
const char* freezer_action_to_string(FreezerAction a) _const_;
FreezerAction freezer_action_from_string(const char *s) _pure_;

20
src/core/dbus-manager.c
View File

@ -620,6 +620,14 @@ static int method_clean_unit(sd_bus_message *message, void *userdata, sd_bus_err
return method_generic_unit_operation(message, userdata, error, bus_unit_method_clean, GENERIC_UNIT_LOAD|GENERIC_UNIT_VALIDATE_LOADED);
}
static int method_freeze_unit(sd_bus_message *message, void *userdata, sd_bus_error *error) {
return method_generic_unit_operation(message, userdata, error, bus_unit_method_freeze, 0);
}
static int method_thaw_unit(sd_bus_message *message, void *userdata, sd_bus_error *error) {
return method_generic_unit_operation(message, userdata, error, bus_unit_method_thaw, 0);
}
static int method_reset_failed_unit(sd_bus_message *message, void *userdata, sd_bus_error *error) {
/* Don't load the unit (because unloaded units can't be in failed state), and don't insist on the
* unit to be loaded properly (since a failed unit might have its unit file disappeared) */
@ -2584,6 +2592,18 @@ const sd_bus_vtable bus_manager_vtable[] = {
NULL,,
method_clean_unit,
SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD_WITH_NAMES("FreezeUnit",
"s",
SD_BUS_PARAM(name),
NULL,,
method_freeze_unit,
SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD_WITH_NAMES("ThawUnit",
"s",
SD_BUS_PARAM(name),
NULL,,
method_thaw_unit,
SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD_WITH_NAMES("ResetFailedUnit",
"s",
SD_BUS_PARAM(name),

104
src/core/dbus-unit.c
View File

@ -46,12 +46,14 @@ static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_job_mode, job_mode, JobMode);
static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_emergency_action, emergency_action, EmergencyAction);
static BUS_DEFINE_PROPERTY_GET(property_get_description, "s", Unit, unit_description);
static BUS_DEFINE_PROPERTY_GET2(property_get_active_state, "s", Unit, unit_active_state, unit_active_state_to_string);
static BUS_DEFINE_PROPERTY_GET2(property_get_freezer_state, "s", Unit, unit_freezer_state, freezer_state_to_string);
static BUS_DEFINE_PROPERTY_GET(property_get_sub_state, "s", Unit, unit_sub_state_to_string);
static BUS_DEFINE_PROPERTY_GET2(property_get_unit_file_state, "s", Unit, unit_get_unit_file_state, unit_file_state_to_string);
static BUS_DEFINE_PROPERTY_GET(property_get_can_reload, "b", Unit, unit_can_reload);
static BUS_DEFINE_PROPERTY_GET(property_get_can_start, "b", Unit, unit_can_start_refuse_manual);
static BUS_DEFINE_PROPERTY_GET(property_get_can_stop, "b", Unit, unit_can_stop_refuse_manual);
static BUS_DEFINE_PROPERTY_GET(property_get_can_isolate, "b", Unit, unit_can_isolate_refuse_manual);
static BUS_DEFINE_PROPERTY_GET(property_get_can_freeze, "b", Unit, unit_can_freeze);
static BUS_DEFINE_PROPERTY_GET(property_get_need_daemon_reload, "b", Unit, unit_need_daemon_reload);
static BUS_DEFINE_PROPERTY_GET_GLOBAL(property_get_empty_strv, "as", 0);
@ -724,6 +726,79 @@ int bus_unit_method_clean(sd_bus_message *message, void *userdata, sd_bus_error
return sd_bus_reply_method_return(message, NULL);
}
static int bus_unit_method_freezer_generic(sd_bus_message *message, void *userdata, sd_bus_error *error, FreezerAction action) {
const char* perm;
int (*method)(Unit*);
Unit *u = userdata;
bool reply_no_delay = false;
int r;
assert(message);
assert(u);
assert(IN_SET(action, FREEZER_FREEZE, FREEZER_THAW));
if (action == FREEZER_FREEZE) {
perm = "stop";
method = unit_freeze;
} else {
perm = "start";
method = unit_thaw;
}
r = mac_selinux_unit_access_check(u, message, perm, error);
if (r < 0)
return r;
r = bus_verify_manage_units_async_full(
u,
perm,
CAP_SYS_ADMIN,
N_("Authentication is required to freeze or thaw the processes of '$(unit)' unit."),
true,
message,
error);
if (r < 0)
return r;
if (r == 0)
return 1; /* No authorization for now, but the async polkit stuff will call us again when it has it */
r = method(u);
if (r == -EOPNOTSUPP)
return sd_bus_error_setf(error, SD_BUS_ERROR_NOT_SUPPORTED, "Unit '%s' does not support freezing.", u->id);
if (r == -EBUSY)
return sd_bus_error_setf(error, BUS_ERROR_UNIT_BUSY, "Unit has a pending job.");
if (r == -EHOSTDOWN)
return sd_bus_error_setf(error, BUS_ERROR_UNIT_INACTIVE, "Unit is inactive.");
if (r == -EALREADY)
return sd_bus_error_setf(error, SD_BUS_ERROR_FAILED, "Previously requested freezer operation for unit '%s' is still in progress.", u->id);
if (r < 0)
return r;
if (r == 0)
reply_no_delay = true;
assert(!u->pending_freezer_message);
r = sd_bus_message_new_method_return(message, &u->pending_freezer_message);
if (r < 0)
return r;
if (reply_no_delay) {
r = bus_unit_send_pending_freezer_message(u);
if (r < 0)
return r;
}
return 1;
}
int bus_unit_method_thaw(sd_bus_message *message, void *userdata, sd_bus_error *error) {
return bus_unit_method_freezer_generic(message, userdata, error, FREEZER_THAW);
}
int bus_unit_method_freeze(sd_bus_message *message, void *userdata, sd_bus_error *error) {
return bus_unit_method_freezer_generic(message, userdata, error, FREEZER_FREEZE);
}
static int property_get_refs(
sd_bus *bus,
const char *path,
@ -793,6 +868,7 @@ const sd_bus_vtable bus_unit_vtable[] = {
SD_BUS_PROPERTY("Description", "s", property_get_description, 0, SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("LoadState", "s", property_get_load_state, offsetof(Unit, load_state), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("ActiveState", "s", property_get_active_state, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
SD_BUS_PROPERTY("FreezerState", "s", property_get_freezer_state, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
SD_BUS_PROPERTY("SubState", "s", property_get_sub_state, 0, SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
SD_BUS_PROPERTY("FragmentPath", "s", NULL, offsetof(Unit, fragment_path), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("SourcePath", "s", NULL, offsetof(Unit, source_path), SD_BUS_VTABLE_PROPERTY_CONST),
@ -809,6 +885,7 @@ const sd_bus_vtable bus_unit_vtable[] = {
SD_BUS_PROPERTY("CanReload", "b", property_get_can_reload, 0, SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("CanIsolate", "b", property_get_can_isolate, 0, SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("CanClean", "as", property_get_can_clean, 0, SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("CanFreeze", "b", property_get_can_freeze, 0, SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("Job", "(uo)", property_get_job, offsetof(Unit, job), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
SD_BUS_PROPERTY("StopWhenUnneeded", "b", bus_property_get_bool, offsetof(Unit, stop_when_unneeded), SD_BUS_VTABLE_PROPERTY_CONST),
SD_BUS_PROPERTY("RefuseManualStart", "b", bus_property_get_bool, offsetof(Unit, refuse_manual_start), SD_BUS_VTABLE_PROPERTY_CONST),
@ -940,6 +1017,16 @@ const sd_bus_vtable bus_unit_vtable[] = {
NULL,,
bus_unit_method_clean,
SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("Freeze",
NULL,
NULL,
bus_unit_method_freeze,
SD_BUS_VTABLE_UNPRIVILEGED),
SD_BUS_METHOD("Thaw",
NULL,
NULL,
bus_unit_method_thaw,
SD_BUS_VTABLE_UNPRIVILEGED),
/* For dependency types we don't support anymore always return an empty array */
SD_BUS_PROPERTY("RequiresOverridable", "as", property_get_empty_strv, 0, SD_BUS_VTABLE_HIDDEN),
@ -1566,6 +1653,23 @@ void bus_unit_send_pending_change_signal(Unit *u, bool including_new) {
bus_unit_send_change_signal(u);
}
int bus_unit_send_pending_freezer_message(Unit *u) {
int r;
assert(u);
if (!u->pending_freezer_message)
return 0;
r = sd_bus_send(NULL, u->pending_freezer_message, NULL);
if (r < 0)
log_warning_errno(r, "Failed to send queued message, ignoring: %m");
u->pending_freezer_message = sd_bus_message_unref(u->pending_freezer_message);
return 0;
}
static int send_removed_signal(sd_bus *bus, void *userdata) {
_cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
_cleanup_free_ char *p = NULL;

3
src/core/dbus-unit.h
View File

@ -11,6 +11,7 @@ extern const sd_bus_vtable bus_unit_cgroup_vtable[];
void bus_unit_send_change_signal(Unit *u);
void bus_unit_send_pending_change_signal(Unit *u, bool including_new);
int bus_unit_send_pending_freezer_message(Unit *u);
void bus_unit_send_removed_signal(Unit *u);
int bus_unit_method_start_generic(sd_bus_message *message, Unit *u, JobType job_type, bool reload_if_possible, sd_bus_error *error);
@ -25,6 +26,8 @@ int bus_unit_method_attach_processes(sd_bus_message *message, void *userdata, sd
int bus_unit_method_ref(sd_bus_message *message, void *userdata, sd_bus_error *error);
int bus_unit_method_unref(sd_bus_message *message, void *userdata, sd_bus_error *error);
int bus_unit_method_clean(sd_bus_message *message, void *userdata, sd_bus_error *error);
int bus_unit_method_freeze(sd_bus_message *message, void *userdata, sd_bus_error *error);
int bus_unit_method_thaw(sd_bus_message *message, void *userdata, sd_bus_error *error);
typedef enum BusUnitQueueFlags {
BUS_UNIT_QUEUE_RELOAD_IF_POSSIBLE = 1 << 0,

7
src/core/dbus.c
View File

@ -960,10 +960,15 @@ static void destroy_bus(Manager *m, sd_bus **bus) {
if (j->bus_track && sd_bus_track_get_bus(j->bus_track) == *bus)
j->bus_track = sd_bus_track_unref(j->bus_track);
HASHMAP_FOREACH(u, m->units, i)
HASHMAP_FOREACH(u, m->units, i) {
if (u->bus_track && sd_bus_track_get_bus(u->bus_track) == *bus)
u->bus_track = sd_bus_track_unref(u->bus_track);
/* Get rid of pending freezer messages on this bus */
if (u->pending_freezer_message && sd_bus_message_get_bus(u->pending_freezer_message) == *bus)
u->pending_freezer_message = sd_bus_message_unref(u->pending_freezer_message);
}
/* Get rid of queued message on this bus */
if (m->pending_reload_message && sd_bus_message_get_bus(m->pending_reload_message) == *bus)
m->pending_reload_message = sd_bus_message_unref(m->pending_reload_message);

3
src/core/scope.c
View File

@ -635,6 +635,9 @@ const UnitVTable scope_vtable = {
.kill = scope_kill,
.freeze = unit_freeze_vtable_common,
.thaw = unit_thaw_vtable_common,
.get_timeout = scope_get_timeout,
.serialize = scope_serialize,

3
src/core/service.c
View File

@ -4449,6 +4449,9 @@ const UnitVTable service_vtable = {
.clean = service_clean,
.can_clean = service_can_clean,
.freeze = unit_freeze_vtable_common,
.thaw = unit_thaw_vtable_common,
.serialize = service_serialize,
.deserialize_item = service_deserialize_item,

81
src/core/slice.c
View File

@ -5,6 +5,7 @@
#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"
@ -347,6 +348,82 @@ static void slice_enumerate_perpetual(Manager *m) {
(void) slice_make_perpetual(m, SPECIAL_SYSTEM_SLICE, NULL);
}
static bool slice_freezer_action_supported_by_children(Unit *s) {
Unit *member;
void *v;
Iterator i;
assert(s);
HASHMAP_FOREACH_KEY(v, member, s->dependencies[UNIT_BEFORE], i) {
int r;
if (UNIT_DEREF(member->slice) != s)
continue;
if (member->type == UNIT_SLICE) {
r = slice_freezer_action_supported_by_children(member);
if (!r)
return r;
}
if (!UNIT_VTABLE(member)->freeze)
return false;
}
return true;
}
static int slice_freezer_action(Unit *s, FreezerAction action) {
Unit *member;
void *v;
Iterator i;
int r;
assert(s);
assert(IN_SET(action, FREEZER_FREEZE, FREEZER_THAW));
if (!slice_freezer_action_supported_by_children(s))
return log_unit_warning(s, "Requested freezer operation is not supported by all children of the slice");
HASHMAP_FOREACH_KEY(v, member, s->dependencies[UNIT_BEFORE], i) {
if (UNIT_DEREF(member->slice) != s)
continue;
if (action == FREEZER_FREEZE)
r = UNIT_VTABLE(member)->freeze(member);
else
r = UNIT_VTABLE(member)->thaw(member);
if (r < 0)
return r;
}
r = unit_cgroup_freezer_action(s, action);
if (r < 0)
return r;
return 0;
}
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),
@ -371,6 +448,10 @@ const UnitVTable slice_vtable = {
.kill = slice_kill,
.freeze = slice_freeze,
.thaw = slice_thaw,
.can_freeze = slice_can_freeze,
.serialize = slice_serialize,
.deserialize_item = slice_deserialize_item,

123
src/core/unit.c
View File

@ -628,6 +628,7 @@ void unit_free(Unit *u) {
sd_bus_slot_unref(u->match_bus_slot);
sd_bus_track_unref(u->bus_track);
u->deserialized_refs = strv_free(u->deserialized_refs);
u->pending_freezer_message = sd_bus_message_unref(u->pending_freezer_message);
unit_free_requires_mounts_for(u);
@ -737,6 +738,38 @@ void unit_free(Unit *u) {
free(u);
}
FreezerState unit_freezer_state(Unit *u) {
assert(u);
return u->freezer_state;
}
int unit_freezer_state_kernel(Unit *u, FreezerState *ret) {
char *values[1] = {};
int r;
assert(u);
r = cg_get_keyed_attribute(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, "cgroup.events",
STRV_MAKE("frozen"), values);
if (r < 0)
return r;
r = _FREEZER_STATE_INVALID;
if (values[0]) {
if (streq(values[0], "0"))
r = FREEZER_RUNNING;
else if (streq(values[0], "1"))
r = FREEZER_FROZEN;
}
free(values[0]);
*ret = r;
return 0;
}
UnitActiveState unit_active_state(Unit *u) {
assert(u);
@ -1846,6 +1879,7 @@ int unit_start(Unit *u) {
* waits for a holdoff timer to elapse before it will start again. */
unit_add_to_dbus_queue(u);
unit_cgroup_freezer_action(u, FREEZER_THAW);
return UNIT_VTABLE(u)->start(u);
}
@ -1898,6 +1932,7 @@ int unit_stop(Unit *u) {
return -EBADR;
unit_add_to_dbus_queue(u);
unit_cgroup_freezer_action(u, FREEZER_THAW);
return UNIT_VTABLE(u)->stop(u);
}
@ -1954,6 +1989,8 @@ int unit_reload(Unit *u) {
return 0;
}
unit_cgroup_freezer_action(u, FREEZER_THAW);
return UNIT_VTABLE(u)->reload(u);
}
@ -3497,6 +3534,8 @@ int unit_serialize(Unit *u, FILE *f, FDSet *fds, bool serialize_jobs) {
if (!sd_id128_is_null(u->invocation_id))
(void) serialize_item_format(f, "invocation-id", SD_ID128_FORMAT_STR, SD_ID128_FORMAT_VAL(u->invocation_id));
(void) serialize_item_format(f, "freezer-state", "%s", freezer_state_to_string(unit_freezer_state(u)));
bus_track_serialize(u->bus_track, f, "ref");
for (m = 0; m < _CGROUP_IP_ACCOUNTING_METRIC_MAX; m++) {
@ -3805,6 +3844,16 @@ int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
log_unit_warning_errno(u, r, "Failed to set invocation ID for unit: %m");
}
continue;
} else if (streq(l, "freezer-state")) {
FreezerState s;
s = freezer_state_from_string(v);
if (s < 0)
log_unit_debug(u, "Failed to deserialize freezer-state '%s', ignoring.", v);
else
u->freezer_state = s;
continue;
}
@ -6076,6 +6125,80 @@ int unit_can_clean(Unit *u, ExecCleanMask *ret) {
return UNIT_VTABLE(u)->can_clean(u, ret);
}
bool unit_can_freeze(Unit *u) {
assert(u);
if (UNIT_VTABLE(u)->can_freeze)
return UNIT_VTABLE(u)->can_freeze(u);
return UNIT_VTABLE(u)->freeze;
}
void unit_frozen(Unit *u) {
assert(u);
u->freezer_state = FREEZER_FROZEN;
bus_unit_send_pending_freezer_message(u);
}
void unit_thawed(Unit *u) {
assert(u);
u->freezer_state = FREEZER_RUNNING;
bus_unit_send_pending_freezer_message(u);
}
static int unit_freezer_action(Unit *u, FreezerAction action) {
UnitActiveState s;
int (*method)(Unit*);
int r;
assert(u);
assert(IN_SET(action, FREEZER_FREEZE, FREEZER_THAW));
method = action == FREEZER_FREEZE ? UNIT_VTABLE(u)->freeze : UNIT_VTABLE(u)->thaw;
if (!method || !cg_freezer_supported())
return -EOPNOTSUPP;
if (u->job)
return -EBUSY;
if (u->load_state != UNIT_LOADED)
return -EHOSTDOWN;
s = unit_active_state(u);
if (s != UNIT_ACTIVE)
return -EHOSTDOWN;
if (IN_SET(u->freezer_state, FREEZER_FREEZING, FREEZER_THAWING))
return -EALREADY;
r = method(u);
if (r <= 0)
return r;
return 1;
}
int unit_freeze(Unit *u) {
return unit_freezer_action(u, FREEZER_FREEZE);
}
int unit_thaw(Unit *u) {
return unit_freezer_action(u, FREEZER_THAW);
}
/* Wrappers around low-level cgroup freezer operations common for service and scope units */
int unit_freeze_vtable_common(Unit *u) {
return unit_cgroup_freezer_action(u, FREEZER_FREEZE);
}
int unit_thaw_vtable_common(Unit *u) {
return unit_cgroup_freezer_action(u, FREEZER_THAW);
}
static const char* const collect_mode_table[_COLLECT_MODE_MAX] = {
[COLLECT_INACTIVE] = "inactive",
[COLLECT_INACTIVE_OR_FAILED] = "inactive-or-failed",

20
src/core/unit.h
View File

@ -114,6 +114,9 @@ typedef struct Unit {
UnitLoadState load_state;
Unit *merged_into;
FreezerState freezer_state;
sd_bus_message *pending_freezer_message;
char *id; /* One name is special because we use it for identification. Points to an entry in the names set */
char *instance;
@ -483,6 +486,11 @@ typedef struct UnitVTable {
/* Clear out the various runtime/state/cache/logs/configuration data */
int (*clean)(Unit *u, ExecCleanMask m);
/* Freeze the unit */
int (*freeze)(Unit *u);
int (*thaw)(Unit *u);
bool (*can_freeze)(Unit *u);
/* Return which kind of data can be cleaned */
int (*can_clean)(Unit *u, ExecCleanMask *ret);
@ -695,6 +703,8 @@ const char *unit_status_string(Unit *u) _pure_;
bool unit_has_name(const Unit *u, const char *name);
UnitActiveState unit_active_state(Unit *u);
FreezerState unit_freezer_state(Unit *u);
int unit_freezer_state_kernel(Unit *u, FreezerState *ret);
const char* unit_sub_state_to_string(Unit *u);
@ -878,6 +888,16 @@ void unit_destroy_runtime_directory(Unit *u, const ExecContext *context);
int unit_clean(Unit *u, ExecCleanMask mask);
int unit_can_clean(Unit *u, ExecCleanMask *ret_mask);
bool unit_can_freeze(Unit *u);
int unit_freeze(Unit *u);
void unit_frozen(Unit *u);
int unit_thaw(Unit *u);
void unit_thawed(Unit *u);
int unit_freeze_vtable_common(Unit *u);
int unit_thaw_vtable_common(Unit *u);
/* Macros which append UNIT= or USER_UNIT= to the message */
#define log_unit_full(unit, level, error, ...) \

1
src/libsystemd/sd-bus/bus-common-errors.h
View File

@ -29,6 +29,7 @@
#define BUS_ERROR_DISK_FULL "org.freedesktop.systemd1.DiskFull"
#define BUS_ERROR_NOTHING_TO_CLEAN "org.freedesktop.systemd1.NothingToClean"
#define BUS_ERROR_UNIT_BUSY "org.freedesktop.systemd1.UnitBusy"
#define BUS_ERROR_UNIT_INACTIVE "org.freedesktop.systemd1.UnitInactive"
#define BUS_ERROR_NO_SUCH_MACHINE "org.freedesktop.machine1.NoSuchMachine"
#define BUS_ERROR_NO_SUCH_IMAGE "org.freedesktop.machine1.NoSuchImage"

39
src/systemctl/systemctl.c
View File

@ -3834,11 +3834,12 @@ static int kill_unit(int argc, char *argv[], void *userdata) {
return r;
}
static int clean_unit(int argc, char *argv[], void *userdata) {
static int clean_or_freeze_unit(int argc, char *argv[], void *userdata) {
_cleanup_(bus_wait_for_units_freep) BusWaitForUnits *w = NULL;
_cleanup_strv_free_ char **names = NULL;
int r, ret = EXIT_SUCCESS;
char **name;
const char *method;
sd_bus *bus;
r = acquire_bus(BUS_FULL, &bus);
@ -3863,6 +3864,13 @@ static int clean_unit(int argc, char *argv[], void *userdata) {
return log_error_errno(r, "Failed to allocate unit waiter: %m");
}
if (streq(argv[0], "clean"))
method = "CleanUnit";
else if (streq(argv[0], "freeze"))
method = "FreezeUnit";
else if (streq(argv[0], "thaw"))
method = "ThawUnit";
STRV_FOREACH(name, names) {
_cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
_cleanup_(sd_bus_message_unrefp) sd_bus_message *m = NULL;
@ -3892,7 +3900,7 @@ static int clean_unit(int argc, char *argv[], void *userdata) {
"org.freedesktop.systemd1",
"/org/freedesktop/systemd1",
"org.freedesktop.systemd1.Manager",
"CleanUnit");
method);
if (r < 0)
return bus_log_create_error(r);
@ -3900,13 +3908,15 @@ static int clean_unit(int argc, char *argv[], void *userdata) {
if (r < 0)
return bus_log_create_error(r);
r = sd_bus_message_append_strv(m, arg_clean_what);
if (r < 0)
return bus_log_create_error(r);
if (streq(method, "CleanUnit")) {
r = sd_bus_message_append_strv(m, arg_clean_what);
if (r < 0)
return bus_log_create_error(r);
}
r = sd_bus_call(bus, m, 0, &error, NULL);
if (r < 0) {
log_error_errno(r, "Failed to clean unit %s: %s", *name, bus_error_message(&error, r));
log_error_errno(r, "Failed to %s unit %s: %s", argv[0], *name, bus_error_message(&error, r));
if (ret == EXIT_SUCCESS) {
ret = r;
continue;
@ -4046,6 +4056,7 @@ typedef struct UnitStatusInfo {
const char *id;
const char *load_state;
const char *active_state;
const char *freezer_state;
const char *sub_state;
const char *unit_file_state;
const char *unit_file_preset;
@ -4182,7 +4193,7 @@ static void print_status_info(
bool *ellipsized) {
char since1[FORMAT_TIMESTAMP_RELATIVE_MAX], since2[FORMAT_TIMESTAMP_MAX];
const char *s1, *s2, *active_on, *active_off, *on, *off, *ss;
const char *s1, *s2, *active_on, *active_off, *on, *off, *ss, *fs;
_cleanup_free_ char *formatted_path = NULL;
ExecStatusInfo *p;
usec_t timestamp;
@ -4276,12 +4287,16 @@ static void print_status_info(
ss = streq_ptr(i->active_state, i->sub_state) ? NULL : i->sub_state;
if (ss)
printf(" Active: %s%s (%s)%s",
printf(" Active: %s%s (%s)%s",
active_on, strna(i->active_state), ss, active_off);
else
printf(" Active: %s%s%s",
active_on, strna(i->active_state), active_off);
fs = !isempty(i->freezer_state) && !streq(i->freezer_state, "running") ? i->freezer_state : NULL;
if (fs)
printf(" %s(%s)%s", ansi_highlight_yellow(), fs, active_off);
if (!isempty(i->result) && !streq(i->result, "success"))
printf(" (Result: %s)", i->result);
@ -5539,12 +5554,14 @@ static int show_one(
static const struct bus_properties_map property_map[] = {
{ "LoadState", "s", NULL, offsetof(UnitStatusInfo, load_state) },
{ "ActiveState", "s", NULL, offsetof(UnitStatusInfo, active_state) },
{ "FreezerState", "s", NULL, offsetof(UnitStatusInfo, freezer_state) },
{ "Documentation", "as", NULL, offsetof(UnitStatusInfo, documentation) },
{}
}, status_map[] = {
{ "Id", "s", NULL, offsetof(UnitStatusInfo, id) },
{ "LoadState", "s", NULL, offsetof(UnitStatusInfo, load_state) },
{ "ActiveState", "s", NULL, offsetof(UnitStatusInfo, active_state) },
{ "FreezerState", "s", NULL, offsetof(UnitStatusInfo, freezer_state) },
{ "SubState", "s", NULL, offsetof(UnitStatusInfo, sub_state) },
{ "UnitFileState", "s", NULL, offsetof(UnitStatusInfo, unit_file_state) },
{ "UnitFilePreset", "s", NULL, offsetof(UnitStatusInfo, unit_file_preset) },
@ -7887,6 +7904,8 @@ static int systemctl_help(void) {
" kill UNIT... Send signal to processes of a unit\n"
" clean UNIT... Clean runtime, cache, state, logs or\n"
" configuration of unit\n"
" freeze PATTERN... Freeze execution of unit processes\n"
" thaw PATTERN... Resume execution of a frozen unit\n"
" is-active PATTERN... Check whether units are active\n"
" is-failed PATTERN... Check whether units are failed\n"
" status [PATTERN...|PID...] Show runtime status of one or more units\n"
@ -9160,7 +9179,9 @@ static int systemctl_main(int argc, char *argv[]) {
{ "condrestart", 2, VERB_ANY, VERB_ONLINE_ONLY, start_unit }, /* For compatibility with RH */
{ "isolate", 2, 2, VERB_ONLINE_ONLY, start_unit },
{ "kill", 2, VERB_ANY, VERB_ONLINE_ONLY, kill_unit },
{ "clean", 2, VERB_ANY, VERB_ONLINE_ONLY, clean_unit },
{ "clean", 2, VERB_ANY, VERB_ONLINE_ONLY, clean_or_freeze_unit },
{ "freeze", 2, VERB_ANY, VERB_ONLINE_ONLY, clean_or_freeze_unit },
{ "thaw", 2, VERB_ANY, VERB_ONLINE_ONLY, clean_or_freeze_unit },
{ "is-active", 2, VERB_ANY, VERB_ONLINE_ONLY, check_unit_active },
{ "check", 2, VERB_ANY, VERB_ONLINE_ONLY, check_unit_active }, /* deprecated alias of is-active */
{ "is-failed", 2, VERB_ANY, VERB_ONLINE_ONLY, check_unit_failed },