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Diffstat (limited to 'src/grp-system/libcore/scope.c')
| -rw-r--r-- | src/grp-system/libcore/scope.c | 608 |
1 files changed, 608 insertions, 0 deletions
diff --git a/src/grp-system/libcore/scope.c b/src/grp-system/libcore/scope.c new file mode 100644 index 0000000000..238f63a729 --- /dev/null +++ b/src/grp-system/libcore/scope.c @@ -0,0 +1,608 @@ +/*** + This file is part of systemd. + + Copyright 2013 Lennart Poettering + + systemd is free software; you can redistribute it and/or modify it + under the terms of the GNU Lesser General Public License as published by + the Free Software Foundation; either version 2.1 of the License, or + (at your option) any later version. + + systemd is distributed in the hope that it will be useful, but + WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + Lesser General Public License for more details. + + You should have received a copy of the GNU Lesser General Public License + along with systemd; If not, see <http://www.gnu.org/licenses/>. +***/ + +#include <errno.h> +#include <unistd.h> + +#include "alloc-util.h" +#include "dbus-scope.h" +#include "load-dropin.h" +#include "log.h" +#include "scope.h" +#include "special.h" +#include "string-table.h" +#include "string-util.h" +#include "strv.h" +#include "unit-name.h" +#include "unit.h" + +static const UnitActiveState state_translation_table[_SCOPE_STATE_MAX] = { + [SCOPE_DEAD] = UNIT_INACTIVE, + [SCOPE_RUNNING] = UNIT_ACTIVE, + [SCOPE_ABANDONED] = UNIT_ACTIVE, + [SCOPE_STOP_SIGTERM] = UNIT_DEACTIVATING, + [SCOPE_STOP_SIGKILL] = UNIT_DEACTIVATING, + [SCOPE_FAILED] = UNIT_FAILED +}; + +static int scope_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata); + +static void scope_init(Unit *u) { + Scope *s = SCOPE(u); + + assert(u); + assert(u->load_state == UNIT_STUB); + + s->timeout_stop_usec = u->manager->default_timeout_stop_usec; + u->ignore_on_isolate = true; +} + +static void scope_done(Unit *u) { + Scope *s = SCOPE(u); + + assert(u); + + free(s->controller); + + s->timer_event_source = sd_event_source_unref(s->timer_event_source); +} + +static int scope_arm_timer(Scope *s, usec_t usec) { + int r; + + assert(s); + + if (s->timer_event_source) { + r = sd_event_source_set_time(s->timer_event_source, usec); + if (r < 0) + return r; + + return sd_event_source_set_enabled(s->timer_event_source, SD_EVENT_ONESHOT); + } + + if (usec == USEC_INFINITY) + return 0; + + r = sd_event_add_time( + UNIT(s)->manager->event, + &s->timer_event_source, + CLOCK_MONOTONIC, + usec, 0, + scope_dispatch_timer, s); + if (r < 0) + return r; + + (void) sd_event_source_set_description(s->timer_event_source, "scope-timer"); + + return 0; +} + +static void scope_set_state(Scope *s, ScopeState state) { + ScopeState old_state; + assert(s); + + old_state = s->state; + s->state = state; + + if (!IN_SET(state, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL)) + s->timer_event_source = sd_event_source_unref(s->timer_event_source); + + if (IN_SET(state, SCOPE_DEAD, SCOPE_FAILED)) + unit_unwatch_all_pids(UNIT(s)); + + if (state != old_state) + log_debug("%s changed %s -> %s", UNIT(s)->id, scope_state_to_string(old_state), scope_state_to_string(state)); + + unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true); +} + +static int scope_add_default_dependencies(Scope *s) { + int r; + + assert(s); + + if (!UNIT(s)->default_dependencies) + return 0; + + /* Make sure scopes are unloaded on shutdown */ + r = unit_add_two_dependencies_by_name( + UNIT(s), + UNIT_BEFORE, UNIT_CONFLICTS, + SPECIAL_SHUTDOWN_TARGET, NULL, true); + if (r < 0) + return r; + + return 0; +} + +static int scope_verify(Scope *s) { + assert(s); + + if (UNIT(s)->load_state != UNIT_LOADED) + return 0; + + if (set_isempty(UNIT(s)->pids) && + !MANAGER_IS_RELOADING(UNIT(s)->manager) && + !unit_has_name(UNIT(s), SPECIAL_INIT_SCOPE)) { + log_unit_error(UNIT(s), "Scope has no PIDs. Refusing."); + return -EINVAL; + } + + return 0; +} + +static int scope_load(Unit *u) { + Scope *s = SCOPE(u); + int r; + + assert(s); + assert(u->load_state == UNIT_STUB); + + if (!u->transient && !MANAGER_IS_RELOADING(u->manager)) + /* Refuse to load non-transient scope units, but allow them while reloading. */ + return -ENOENT; + + r = unit_load_fragment_and_dropin_optional(u); + if (r < 0) + return r; + + if (u->load_state == UNIT_LOADED) { + r = unit_patch_contexts(u); + if (r < 0) + return r; + + r = unit_set_default_slice(u); + if (r < 0) + return r; + + r = scope_add_default_dependencies(s); + if (r < 0) + return r; + } + + return scope_verify(s); +} + +static int scope_coldplug(Unit *u) { + Scope *s = SCOPE(u); + int r; + + assert(s); + assert(s->state == SCOPE_DEAD); + + if (s->deserialized_state == s->state) + return 0; + + if (IN_SET(s->deserialized_state, SCOPE_STOP_SIGKILL, SCOPE_STOP_SIGTERM)) { + r = scope_arm_timer(s, usec_add(u->state_change_timestamp.monotonic, s->timeout_stop_usec)); + if (r < 0) + return r; + } + + if (!IN_SET(s->deserialized_state, SCOPE_DEAD, SCOPE_FAILED)) + unit_watch_all_pids(UNIT(s)); + + scope_set_state(s, s->deserialized_state); + return 0; +} + +static void scope_dump(Unit *u, FILE *f, const char *prefix) { + Scope *s = SCOPE(u); + + assert(s); + assert(f); + + fprintf(f, + "%sScope State: %s\n" + "%sResult: %s\n", + prefix, scope_state_to_string(s->state), + prefix, scope_result_to_string(s->result)); + + cgroup_context_dump(&s->cgroup_context, f, prefix); + kill_context_dump(&s->kill_context, f, prefix); +} + +static void scope_enter_dead(Scope *s, ScopeResult f) { + assert(s); + + if (f != SCOPE_SUCCESS) + s->result = f; + + scope_set_state(s, s->result != SCOPE_SUCCESS ? SCOPE_FAILED : SCOPE_DEAD); +} + +static void scope_enter_signal(Scope *s, ScopeState state, ScopeResult f) { + bool skip_signal = false; + int r; + + assert(s); + + if (f != SCOPE_SUCCESS) + s->result = f; + + unit_watch_all_pids(UNIT(s)); + + /* If we have a controller set let's ask the controller nicely + * to terminate the scope, instead of us going directly into + * SIGTERM beserk mode */ + if (state == SCOPE_STOP_SIGTERM) + skip_signal = bus_scope_send_request_stop(s) > 0; + + if (!skip_signal) { + r = unit_kill_context( + UNIT(s), + &s->kill_context, + state != SCOPE_STOP_SIGTERM ? KILL_KILL : KILL_TERMINATE, + -1, -1, false); + if (r < 0) + goto fail; + } else + r = 1; + + if (r > 0) { + r = scope_arm_timer(s, usec_add(now(CLOCK_MONOTONIC), s->timeout_stop_usec)); + if (r < 0) + goto fail; + + scope_set_state(s, state); + } else if (state == SCOPE_STOP_SIGTERM) + scope_enter_signal(s, SCOPE_STOP_SIGKILL, SCOPE_SUCCESS); + else + scope_enter_dead(s, SCOPE_SUCCESS); + + return; + +fail: + log_unit_warning_errno(UNIT(s), r, "Failed to kill processes: %m"); + + scope_enter_dead(s, SCOPE_FAILURE_RESOURCES); +} + +static int scope_start(Unit *u) { + Scope *s = SCOPE(u); + int r; + + assert(s); + + if (unit_has_name(u, SPECIAL_INIT_SCOPE)) + return -EPERM; + + if (s->state == SCOPE_FAILED) + return -EPERM; + + /* We can't fulfill this right now, please try again later */ + if (s->state == SCOPE_STOP_SIGTERM || + s->state == SCOPE_STOP_SIGKILL) + return -EAGAIN; + + assert(s->state == SCOPE_DEAD); + + if (!u->transient && !MANAGER_IS_RELOADING(u->manager)) + return -ENOENT; + + (void) unit_realize_cgroup(u); + (void) unit_reset_cpu_usage(u); + + r = unit_attach_pids_to_cgroup(u); + if (r < 0) { + log_unit_warning_errno(UNIT(s), r, "Failed to add PIDs to scope's control group: %m"); + scope_enter_dead(s, SCOPE_FAILURE_RESOURCES); + return r; + } + + s->result = SCOPE_SUCCESS; + + scope_set_state(s, SCOPE_RUNNING); + return 1; +} + +static int scope_stop(Unit *u) { + Scope *s = SCOPE(u); + + assert(s); + + if (s->state == SCOPE_STOP_SIGTERM || + s->state == SCOPE_STOP_SIGKILL) + return 0; + + assert(s->state == SCOPE_RUNNING || + s->state == SCOPE_ABANDONED); + + scope_enter_signal(s, SCOPE_STOP_SIGTERM, SCOPE_SUCCESS); + return 1; +} + +static void scope_reset_failed(Unit *u) { + Scope *s = SCOPE(u); + + assert(s); + + if (s->state == SCOPE_FAILED) + scope_set_state(s, SCOPE_DEAD); + + s->result = SCOPE_SUCCESS; +} + +static int scope_kill(Unit *u, KillWho who, int signo, sd_bus_error *error) { + return unit_kill_common(u, who, signo, -1, -1, error); +} + +static int scope_get_timeout(Unit *u, usec_t *timeout) { + Scope *s = SCOPE(u); + usec_t t; + int r; + + if (!s->timer_event_source) + return 0; + + r = sd_event_source_get_time(s->timer_event_source, &t); + if (r < 0) + return r; + if (t == USEC_INFINITY) + return 0; + + *timeout = t; + return 1; +} + +static int scope_serialize(Unit *u, FILE *f, FDSet *fds) { + Scope *s = SCOPE(u); + + assert(s); + assert(f); + assert(fds); + + unit_serialize_item(u, f, "state", scope_state_to_string(s->state)); + return 0; +} + +static int scope_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) { + Scope *s = SCOPE(u); + + assert(u); + assert(key); + assert(value); + assert(fds); + + if (streq(key, "state")) { + ScopeState state; + + state = scope_state_from_string(value); + if (state < 0) + log_unit_debug(u, "Failed to parse state value: %s", value); + else + s->deserialized_state = state; + + } else + log_unit_debug(u, "Unknown serialization key: %s", key); + + return 0; +} + +static bool scope_check_gc(Unit *u) { + assert(u); + + /* Never clean up scopes that still have a process around, + * even if the scope is formally dead. */ + + if (!u->cgroup_path) + return false; + + return cg_is_empty_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path) <= 0; +} + +static void scope_notify_cgroup_empty_event(Unit *u) { + Scope *s = SCOPE(u); + assert(u); + + log_unit_debug(u, "cgroup is empty"); + + if (IN_SET(s->state, SCOPE_RUNNING, SCOPE_ABANDONED, SCOPE_STOP_SIGTERM, SCOPE_STOP_SIGKILL)) + scope_enter_dead(s, SCOPE_SUCCESS); +} + +static void scope_sigchld_event(Unit *u, pid_t pid, int code, int status) { + + /* If we get a SIGCHLD event for one of the processes we were + interested in, then we look for others to watch, under the + assumption that we'll sooner or later get a SIGCHLD for + them, as the original process we watched was probably the + parent of them, and they are hence now our children. */ + + unit_tidy_watch_pids(u, 0, 0); + unit_watch_all_pids(u); + + /* If the PID set is empty now, then let's finish this off */ + if (set_isempty(u->pids)) + scope_notify_cgroup_empty_event(u); +} + +static int scope_dispatch_timer(sd_event_source *source, usec_t usec, void *userdata) { + Scope *s = SCOPE(userdata); + + assert(s); + assert(s->timer_event_source == source); + + switch (s->state) { + + case SCOPE_STOP_SIGTERM: + if (s->kill_context.send_sigkill) { + log_unit_warning(UNIT(s), "Stopping timed out. Killing."); + scope_enter_signal(s, SCOPE_STOP_SIGKILL, SCOPE_FAILURE_TIMEOUT); + } else { + log_unit_warning(UNIT(s), "Stopping timed out. Skipping SIGKILL."); + scope_enter_dead(s, SCOPE_FAILURE_TIMEOUT); + } + + break; + + case SCOPE_STOP_SIGKILL: + log_unit_warning(UNIT(s), "Still around after SIGKILL. Ignoring."); + scope_enter_dead(s, SCOPE_FAILURE_TIMEOUT); + break; + + default: + assert_not_reached("Timeout at wrong time."); + } + + return 0; +} + +int scope_abandon(Scope *s) { + assert(s); + + if (unit_has_name(UNIT(s), SPECIAL_INIT_SCOPE)) + return -EPERM; + + if (!IN_SET(s->state, SCOPE_RUNNING, SCOPE_ABANDONED)) + return -ESTALE; + + s->controller = mfree(s->controller); + + /* The client is no longer watching the remaining processes, + * so let's step in here, under the assumption that the + * remaining processes will be sooner or later reassigned to + * us as parent. */ + + unit_tidy_watch_pids(UNIT(s), 0, 0); + unit_watch_all_pids(UNIT(s)); + + /* If the PID set is empty now, then let's finish this off */ + if (set_isempty(UNIT(s)->pids)) + scope_notify_cgroup_empty_event(UNIT(s)); + else + scope_set_state(s, SCOPE_ABANDONED); + + return 0; +} + +_pure_ static UnitActiveState scope_active_state(Unit *u) { + assert(u); + + return state_translation_table[SCOPE(u)->state]; +} + +_pure_ static const char *scope_sub_state_to_string(Unit *u) { + assert(u); + + return scope_state_to_string(SCOPE(u)->state); +} + +static void scope_enumerate(Manager *m) { + Unit *u; + int r; + + assert(m); + + /* Let's unconditionally add the "init.scope" special unit + * that encapsulates PID 1. Note that PID 1 already is in the + * cgroup for this, we hence just need to allocate the object + * for it and that's it. */ + + u = manager_get_unit(m, SPECIAL_INIT_SCOPE); + if (!u) { + u = unit_new(m, sizeof(Scope)); + if (!u) { + log_oom(); + return; + } + + r = unit_add_name(u, SPECIAL_INIT_SCOPE); + if (r < 0) { + unit_free(u); + log_error_errno(r, "Failed to add init.scope name"); + return; + } + } + + u->transient = true; + u->default_dependencies = false; + u->no_gc = true; + u->ignore_on_isolate = true; + u->refuse_manual_start = true; + u->refuse_manual_stop = true; + SCOPE(u)->deserialized_state = SCOPE_RUNNING; + SCOPE(u)->kill_context.kill_signal = SIGRTMIN+14; + + /* Prettify things, if we can. */ + if (!u->description) + u->description = strdup("System and Service Manager"); + if (!u->documentation) + (void) strv_extend(&u->documentation, "man:systemd(1)"); + + unit_add_to_load_queue(u); + unit_add_to_dbus_queue(u); +} + +static const char* const scope_result_table[_SCOPE_RESULT_MAX] = { + [SCOPE_SUCCESS] = "success", + [SCOPE_FAILURE_RESOURCES] = "resources", + [SCOPE_FAILURE_TIMEOUT] = "timeout", +}; + +DEFINE_STRING_TABLE_LOOKUP(scope_result, ScopeResult); + +const UnitVTable scope_vtable = { + .object_size = sizeof(Scope), + .cgroup_context_offset = offsetof(Scope, cgroup_context), + .kill_context_offset = offsetof(Scope, kill_context), + + .sections = + "Unit\0" + "Scope\0" + "Install\0", + .private_section = "Scope", + + .can_transient = true, + + .init = scope_init, + .load = scope_load, + .done = scope_done, + + .coldplug = scope_coldplug, + + .dump = scope_dump, + + .start = scope_start, + .stop = scope_stop, + + .kill = scope_kill, + + .get_timeout = scope_get_timeout, + + .serialize = scope_serialize, + .deserialize_item = scope_deserialize_item, + + .active_state = scope_active_state, + .sub_state_to_string = scope_sub_state_to_string, + + .check_gc = scope_check_gc, + + .sigchld_event = scope_sigchld_event, + + .reset_failed = scope_reset_failed, + + .notify_cgroup_empty = scope_notify_cgroup_empty_event, + + .bus_vtable = bus_scope_vtable, + .bus_set_property = bus_scope_set_property, + .bus_commit_properties = bus_scope_commit_properties, + + .enumerate = scope_enumerate, +}; |