20321298054

Committed 17 Dec 2025 11:19PM UTC coverage: 72.709% (-0.03%) from 72.736%

Build # 20321298054

Build Type

push

github

Committed by

YHNdnzj

Commit Message

core: set Result=start-limit-hit when a unit is rate limited

There is currently no way to figure out a rate limit was hit on a unit,
as the last result is stripped in order to keep reporting the first
result, which is useful in case of a watchdog failure, which is the
reason why it was changed as such.

But rate limiting is also an important information to provide to
users, so allow the Result property to reflect it when it
happens.

Run Details

6 of 7 new or added lines in 7 files covered. (85.71%)

1358 existing lines in 49 files now uncovered.

309654 of 425883 relevant lines covered (72.71%)

1138050.05 hits per line

Source File
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83.21

/src/core/path.c

/* SPDX-License-Identifier: LGPL-2.1-or-later */

#include <sys/inotify.h>
#include <unistd.h>

#include "sd-bus.h"

#include "async.h"
#include "bus-error.h"
#include "dbus-path.h"
#include "dbus-unit.h"
#include "errno-util.h"
#include "escape.h"
#include "event-util.h"
#include "glob-util.h"
#include "inotify-util.h"
#include "manager.h"
#include "mkdir-label.h"
#include "path.h"
#include "path-util.h"
#include "serialize.h"
#include "special.h"
#include "stat-util.h"
#include "string-table.h"
#include "string-util.h"
#include "strv.h"
#include "unit.h"

static const UnitActiveState state_translation_table[_PATH_STATE_MAX] = {
        [PATH_DEAD]    = UNIT_INACTIVE,
        [PATH_WAITING] = UNIT_ACTIVE,
        [PATH_RUNNING] = UNIT_ACTIVE,
        [PATH_FAILED]  = UNIT_FAILED,
};

static int path_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata);

int path_spec_watch(PathSpec *s, sd_event_io_handler_t handler) {
        static const int flags_table[_PATH_TYPE_MAX] = {
                [PATH_EXISTS]              = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB,
                [PATH_EXISTS_GLOB]         = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB,
                [PATH_CHANGED]             = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CLOSE_WRITE|IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO,
                [PATH_MODIFIED]            = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CLOSE_WRITE|IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO|IN_MODIFY,
                [PATH_DIRECTORY_NOT_EMPTY] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CREATE|IN_MOVED_TO,
        };

        bool exists = false;
        char *slash, *oldslash = NULL;
        int r;

        assert(s);
        assert(s->unit);
        assert(handler);

        path_spec_unwatch(s);

        s->inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
        if (s->inotify_fd < 0) {
                r = log_error_errno(errno, "Failed to allocate inotify fd: %m");
                goto fail;
        }

        r = sd_event_add_io(s->unit->manager->event, &s->event_source, s->inotify_fd, EPOLLIN, handler, s);
        if (r < 0) {
                log_error_errno(r, "Failed to add inotify fd to event loop: %m");
                goto fail;
        }

        (void) sd_event_source_set_description(s->event_source, "path");

        /* This function assumes the path was passed through path_simplify()! */
        assert(!strstr(s->path, "//"));

        for (slash = strchr(s->path, '/'); ; slash = strchr(slash+1, '/')) {
                bool incomplete = false;
                int flags, wd = -1;
                char tmp, *cut;

                if (slash) {
                        cut = slash + (slash == s->path);
                        tmp = *cut;
                        *cut = '\0';

                        flags = IN_MOVE_SELF | IN_DELETE_SELF | IN_CREATE | IN_MOVED_TO;
                } else {
                        cut = NULL;
                        flags = flags_table[s->type];
                }

                /* If this is a symlink watch both the symlink inode and where it points to. If the inode is
                 * not a symlink both calls will install the same watch, which is redundant and doesn't
                 * hurt. */
                for (int follow_symlink = 0; follow_symlink < 2; follow_symlink++) {
                        uint32_t f = flags;

                        SET_FLAG(f, IN_DONT_FOLLOW, !follow_symlink);

                        wd = inotify_add_watch(s->inotify_fd, s->path, f);
                        if (wd < 0) {
                                if (IN_SET(errno, EACCES, ENOENT)) {
                                        incomplete = true; /* This is an expected error, let's accept this
                                                            * quietly: we have an incomplete watch for
                                                            * now. */
                                        break;
                                }

                                /* This second call to inotify_add_watch() should fail like the previous one
                                 * and is done for logging the error in a comprehensive way. */
                                wd = inotify_add_watch_and_warn(s->inotify_fd, s->path, f);
                                if (wd < 0) {
                                        if (cut)
                                                *cut = tmp;

                                        r = wd;
                                        goto fail;
                                }

                                /* Hmm, we succeeded in adding the watch this time... let's continue. */
                        }
                }

                if (incomplete) {
                        if (cut)
                                *cut = tmp;

                        break;
                }

                exists = true;

                /* Path exists, we don't need to watch parent too closely. */
                if (oldslash) {
                        char *cut2 = oldslash + (oldslash == s->path);
                        char tmp2 = *cut2;
                        *cut2 = '\0';

                        (void) inotify_add_watch(s->inotify_fd, s->path, IN_MOVE_SELF);
                        /* Error is ignored, the worst can happen is we get spurious events. */

                        *cut2 = tmp2;
                }

                if (cut)
                        *cut = tmp;

                if (slash)
                        oldslash = slash;
                else {
                        /* whole path has been iterated over */
                        s->primary_wd = wd;
                        break;
                }
        }

        if (!exists) {
                r = log_error_errno(errno, "Failed to add watch on any of the components of %s: %m", s->path);
                /* either EACCESS or ENOENT */
                goto fail;
        }

        return 0;

fail:
        path_spec_unwatch(s);
        return r;
}

void path_spec_unwatch(PathSpec *s) {
        assert(s);

        s->event_source = sd_event_source_disable_unref(s->event_source);
        s->inotify_fd = asynchronous_close(s->inotify_fd);
}

int path_spec_fd_event(PathSpec *s, uint32_t revents) {
        union inotify_event_buffer buffer;
        ssize_t l;

        assert(s);

        if (revents != EPOLLIN)
                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                       "Got invalid poll event on inotify.");

        l = read(s->inotify_fd, &buffer, sizeof(buffer));
        if (l < 0) {
                if (ERRNO_IS_TRANSIENT(errno))
                        return 0;

                return log_error_errno(errno, "Failed to read inotify event: %m");
        }

        if (IN_SET(s->type, PATH_CHANGED, PATH_MODIFIED))
                FOREACH_INOTIFY_EVENT_WARN(e, buffer, l)
                        if (s->primary_wd == e->wd)
                                return 1;

        return 0;
}

static bool path_spec_check_good(PathSpec *s, bool initial, bool from_trigger_notify, char **ret_trigger_path) {
        _cleanup_free_ char *trigger = NULL;
        bool b, good = false;

        assert(s);
        assert(ret_trigger_path);

        switch (s->type) {

        case PATH_EXISTS:
                good = access(s->path, F_OK) >= 0;
                break;

        case PATH_EXISTS_GLOB:
                good = glob_first(s->path, &trigger) > 0;
                break;

        case PATH_DIRECTORY_NOT_EMPTY: {
                int k;

                k = dir_is_empty(s->path, /* ignore_hidden_or_backup= */ true);
                good = !(IN_SET(k, -ENOENT, -ENOTDIR) || k > 0);
                break;
        }

        case PATH_CHANGED:
        case PATH_MODIFIED:
                b = access(s->path, F_OK) >= 0;
                good = !initial && !from_trigger_notify && b != s->previous_exists;
                s->previous_exists = b;
                break;

        default:
                ;
        }

        if (good) {
                if (!trigger) {
                        trigger = strdup(s->path);
                        if (!trigger)
                                (void) log_oom_debug();
                }
                *ret_trigger_path = TAKE_PTR(trigger);
        }

        return good;
}

static void path_spec_mkdir(PathSpec *s, mode_t mode) {
        int r;

        assert(s);

        if (IN_SET(s->type, PATH_EXISTS, PATH_EXISTS_GLOB))
                return;

        r = mkdir_p_label(s->path, mode);
        if (r < 0)
                log_warning_errno(r, "mkdir(%s) failed: %m", s->path);
}

static void path_spec_dump(PathSpec *s, FILE *f, const char *prefix) {
        const char *type;

        assert(s);
        assert(f);
        assert(prefix);

        assert_se(type = path_type_to_string(s->type));
        fprintf(f, "%s%s: %s\n", prefix, type, s->path);
}

void path_spec_done(PathSpec *s) {
        assert(s);
        assert(s->inotify_fd == -EBADF);

        free(s->path);
}

static void path_init(Unit *u) {
        Path *p = ASSERT_PTR(PATH(u));

        assert(u->load_state == UNIT_STUB);

        p->directory_mode = 0755;

        p->trigger_limit = RATELIMIT_OFF;
}

void path_free_specs(Path *p) {
        PathSpec *s;

        assert(p);

        while ((s = LIST_POP(spec, p->specs))) {
                path_spec_unwatch(s);
                path_spec_done(s);
                free(s);
        }
}

static void path_done(Unit *u) {
        Path *p = ASSERT_PTR(PATH(u));

        p->trigger_notify_event_source = sd_event_source_disable_unref(p->trigger_notify_event_source);
        path_free_specs(p);
}

static int path_add_mount_dependencies(Path *p) {
        int r;

        assert(p);

        LIST_FOREACH(spec, s, p->specs) {
                r = unit_add_mounts_for(UNIT(p), s->path, UNIT_DEPENDENCY_FILE, UNIT_MOUNT_REQUIRES);
                if (r < 0)
                        return r;
        }

        return 0;
}

static int path_verify(Path *p) {
        assert(p);
        assert(UNIT(p)->load_state == UNIT_LOADED);

        if (!p->specs)
                return log_unit_error_errno(UNIT(p), SYNTHETIC_ERRNO(ENOEXEC), "Path unit lacks path setting. Refusing.");

        return 0;
}

static int path_add_default_dependencies(Path *p) {
        int r;

        assert(p);

        if (!UNIT(p)->default_dependencies)
                return 0;

        r = unit_add_dependency_by_name(UNIT(p), UNIT_BEFORE, SPECIAL_PATHS_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
        if (r < 0)
                return r;

        if (MANAGER_IS_SYSTEM(UNIT(p)->manager)) {
                r = unit_add_two_dependencies_by_name(UNIT(p), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
                if (r < 0)
                        return r;
        }

        return unit_add_two_dependencies_by_name(UNIT(p), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
}

static int path_add_trigger_dependencies(Path *p) {
        Unit *x;
        int r;

        assert(p);

        if (UNIT_TRIGGER(UNIT(p)))
                return 0;

        r = unit_load_related_unit(UNIT(p), ".service", &x);
        if (r < 0)
                return r;

        return unit_add_two_dependencies(UNIT(p), UNIT_BEFORE, UNIT_TRIGGERS, x, true, UNIT_DEPENDENCY_IMPLICIT);
}

static int path_add_extras(Path *p) {
        int r;

        assert(p);

        /* To avoid getting pid1 in a busy-loop state (eg: unmet condition on associated service),
         * set a default trigger limit if the user didn't specify any. */
        if (p->trigger_limit.interval == USEC_INFINITY)
                p->trigger_limit.interval = 2 * USEC_PER_SEC;

        if (p->trigger_limit.burst == UINT_MAX)
                p->trigger_limit.burst = 200;

        r = path_add_trigger_dependencies(p);
        if (r < 0)
                return r;

        r = path_add_mount_dependencies(p);
        if (r < 0)
                return r;

        return path_add_default_dependencies(p);
}

static int path_load(Unit *u) {
        Path *p = ASSERT_PTR(PATH(u));
        int r;

        assert(u->load_state == UNIT_STUB);

        r = unit_load_fragment_and_dropin(u, true);
        if (r < 0)
                return r;

        if (u->load_state != UNIT_LOADED)
                return 0;

        r = path_add_extras(p);
        if (r < 0)
                return r;

        return path_verify(p);
}

static void path_dump(Unit *u, FILE *f, const char *prefix) {
        Path *p = ASSERT_PTR(PATH(u));
        Unit *trigger;

        assert(f);
        assert(prefix);

        trigger = UNIT_TRIGGER(u);

        fprintf(f,
                "%sPath State: %s\n"
                "%sResult: %s\n"
                "%sUnit: %s\n"
                "%sMakeDirectory: %s\n"
                "%sDirectoryMode: %04o\n"
                "%sTriggerLimitIntervalSec: %s\n"
                "%sTriggerLimitBurst: %u\n",
                prefix, path_state_to_string(p->state),
                prefix, path_result_to_string(p->result),
                prefix, trigger ? trigger->id : "n/a",
                prefix, yes_no(p->make_directory),
                prefix, p->directory_mode,
                prefix, FORMAT_TIMESPAN(p->trigger_limit.interval, USEC_PER_SEC),
                prefix, p->trigger_limit.burst);

        LIST_FOREACH(spec, s, p->specs)
                path_spec_dump(s, f, prefix);
}

static void path_unwatch(Path *p) {
        assert(p);

        LIST_FOREACH(spec, s, p->specs)
                path_spec_unwatch(s);
}

static int path_watch(Path *p) {
        int r;

        assert(p);

        LIST_FOREACH(spec, s, p->specs) {
                r = path_spec_watch(s, path_dispatch_io);
                if (r < 0)
                        return r;
        }

        return 0;
}

static void path_set_state(Path *p, PathState state) {
        PathState old_state;

        assert(p);

        if (p->state != state)
                bus_unit_send_pending_change_signal(UNIT(p), false);

        old_state = p->state;
        p->state = state;

        if (!IN_SET(state, PATH_WAITING, PATH_RUNNING))
                path_unwatch(p);

        if (state != old_state)
                log_unit_debug(UNIT(p), "Changed %s -> %s", path_state_to_string(old_state), path_state_to_string(state));

        unit_notify(UNIT(p), state_translation_table[old_state], state_translation_table[state], /* reload_success= */ true);
}

static void path_enter_waiting(Path *p, bool initial, bool from_trigger_notify);

static int path_coldplug(Unit *u) {
        Path *p = ASSERT_PTR(PATH(u));

        assert(p->state == PATH_DEAD);

        if (p->deserialized_state != p->state) {

                if (IN_SET(p->deserialized_state, PATH_WAITING, PATH_RUNNING))
                        path_enter_waiting(p, true, false);
                else
                        path_set_state(p, p->deserialized_state);
        }

        return 0;
}

static void path_enter_dead(Path *p, PathResult f) {
        assert(p);

        if (p->result == PATH_SUCCESS || IN_SET(f, PATH_FAILURE_START_LIMIT_HIT, PATH_FAILURE_UNIT_START_LIMIT_HIT))
                p->result = f;

        unit_log_result(UNIT(p), p->result == PATH_SUCCESS, path_result_to_string(p->result));
        path_set_state(p, p->result != PATH_SUCCESS ? PATH_FAILED : PATH_DEAD);
}

static void path_enter_running(Path *p, char *trigger_path) {
        _cleanup_(activation_details_unrefp) ActivationDetails *details = NULL;
        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
        Unit *trigger;
        Job *job;
        int r;

        assert(p);

        /* Don't start job if we are supposed to go down */
        if (unit_stop_pending(UNIT(p)))
                return;

        if (!ratelimit_below(&p->trigger_limit)) {
                log_unit_warning(UNIT(p), "Trigger limit hit, refusing further activation.");
                path_enter_dead(p, PATH_FAILURE_TRIGGER_LIMIT_HIT);
                return;
        }

        trigger = UNIT_TRIGGER(UNIT(p));
        if (!trigger) {
                log_unit_error(UNIT(p), "Unit to trigger vanished.");
                goto fail;
        }

        details = activation_details_new(UNIT(p));
        if (!details) {
                log_oom();
                goto fail;
        }

        r = free_and_strdup(&(ACTIVATION_DETAILS_PATH(details))->trigger_path_filename, trigger_path);
        if (r < 0) {
                log_oom();
                goto fail;
        }

        r = manager_add_job(UNIT(p)->manager, JOB_START, trigger, JOB_REPLACE, &error, &job);
        if (r < 0) {
                log_unit_warning(UNIT(p), "Failed to queue unit startup job: %s", bus_error_message(&error, r));
                goto fail;
        }

        job_set_activation_details(job, details);

        path_set_state(p, PATH_RUNNING);
        path_unwatch(p);

        return;

fail:
        path_enter_dead(p, PATH_FAILURE_RESOURCES);
}

static bool path_check_good(Path *p, bool initial, bool from_trigger_notify, char **ret_trigger_path) {
        assert(p);
        assert(ret_trigger_path);

        LIST_FOREACH(spec, s, p->specs)
                if (path_spec_check_good(s, initial, from_trigger_notify, ret_trigger_path))
                        return true;

        return false;
}

static void path_enter_waiting(Path *p, bool initial, bool from_trigger_notify) {
        _cleanup_free_ char *trigger_path = NULL;
        Unit *trigger;
        int r;

        if (p->trigger_notify_event_source)
                (void) event_source_disable(p->trigger_notify_event_source);

        /* If the triggered unit is already running, so are we */
        trigger = UNIT_TRIGGER(UNIT(p));
        if (trigger && !UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(trigger))) {
                path_set_state(p, PATH_RUNNING);
                path_unwatch(p);
                return;
        }

        if (path_check_good(p, initial, from_trigger_notify, &trigger_path)) {
                log_unit_debug(UNIT(p), "Got triggered by '%s'.", trigger_path);
                path_enter_running(p, trigger_path);
                return;
        }

        r = path_watch(p);
        if (r < 0) {
                log_unit_warning_errno(UNIT(p), r, "Failed to enter waiting state: %m");
                path_enter_dead(p, PATH_FAILURE_RESOURCES);
                return;
        }

        /* Hmm, so now we have created inotify watches, but the file
         * might have appeared/been removed by now, so we must
         * recheck */

        if (path_check_good(p, false, from_trigger_notify, &trigger_path)) {
                log_unit_debug(UNIT(p), "Got triggered by '%s'.", trigger_path);
                path_enter_running(p, trigger_path);
                return;
        }

        path_set_state(p, PATH_WAITING);
}

static void path_mkdir(Path *p) {
        assert(p);

        if (!p->make_directory)
                return;

        LIST_FOREACH(spec, s, p->specs)
                path_spec_mkdir(s, p->directory_mode);
}

static int path_start(Unit *u) {
        Path *p = ASSERT_PTR(PATH(u));
        int r;

        assert(IN_SET(p->state, PATH_DEAD, PATH_FAILED));

        r = unit_test_trigger_loaded(u);
        if (r < 0)
                return r;

        r = unit_acquire_invocation_id(u);
        if (r < 0)
                return r;

        path_mkdir(p);

        p->result = PATH_SUCCESS;
        path_enter_waiting(p, true, false);

        return 1;
}

static int path_stop(Unit *u) {
        Path *p = ASSERT_PTR(PATH(u));

        assert(IN_SET(p->state, PATH_WAITING, PATH_RUNNING));

        path_enter_dead(p, PATH_SUCCESS);
        return 1;
}

static int path_serialize(Unit *u, FILE *f, FDSet *fds) {
        Path *p = ASSERT_PTR(PATH(u));

        assert(f);
        assert(fds);

        (void) serialize_item(f, "state", path_state_to_string(p->state));
        (void) serialize_item(f, "result", path_result_to_string(p->result));

        LIST_FOREACH(spec, s, p->specs) {
                const char *type;
                _cleanup_free_ char *escaped = NULL;

                escaped = cescape(s->path);
                if (!escaped)
                        return log_oom();

                assert_se(type = path_type_to_string(s->type));
                (void) serialize_item_format(f, "path-spec", "%s %i %s",
                                             type,
                                             s->previous_exists,
                                             escaped);
        }

        (void) serialize_ratelimit(f, "trigger-ratelimit", &p->trigger_limit);

        return 0;
}

static int path_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
        Path *p = ASSERT_PTR(PATH(u));

        assert(key);
        assert(value);
        assert(fds);

        if (streq(key, "state")) {
                PathState state;

                state = path_state_from_string(value);
                if (state < 0)
                        log_unit_debug(u, "Failed to parse state value: %s", value);
                else
                        p->deserialized_state = state;

        } else if (streq(key, "result")) {
                PathResult f;

                f = path_result_from_string(value);
                if (f < 0)
                        log_unit_debug(u, "Failed to parse result value: %s", value);
                else if (f != PATH_SUCCESS)
                        p->result = f;

        } else if (streq(key, "path-spec")) {
                int previous_exists, skip = 0;
                _cleanup_free_ char *type_str = NULL;

                if (sscanf(value, "%ms %i %n", &type_str, &previous_exists, &skip) < 2)
                        log_unit_debug(u, "Failed to parse path-spec value: %s", value);
                else {
                        _cleanup_free_ char *unescaped = NULL;
                        ssize_t l;
                        PathType type;

                        type = path_type_from_string(type_str);
                        if (type < 0) {
                                log_unit_warning(u, "Unknown path type \"%s\", ignoring.", type_str);
                                return 0;
                        }

                        l = cunescape(value+skip, 0, &unescaped);
                        if (l < 0) {
                                log_unit_warning_errno(u, l, "Failed to unescape serialize path: %m");
                                return 0;
                        }

                        LIST_FOREACH(spec, s, p->specs)
                                if (s->type == type &&
                                    path_equal(s->path, unescaped)) {

                                        s->previous_exists = previous_exists;
                                        break;
                                }
                }

        } else if (streq(key, "trigger-ratelimit"))
                deserialize_ratelimit(&p->trigger_limit, key, value);

        else
                log_unit_debug(u, "Unknown serialization key: %s", key);

        return 0;
}

static UnitActiveState path_active_state(Unit *u) {
        Path *p = ASSERT_PTR(PATH(u));

        return state_translation_table[p->state];
}

static const char *path_sub_state_to_string(Unit *u) {
        Path *p = ASSERT_PTR(PATH(u));

        return path_state_to_string(p->state);
}

static int path_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
        PathSpec *s = ASSERT_PTR(userdata), *found = NULL;
        Path *p = ASSERT_PTR(PATH(s->unit));
        int changed;

        assert(fd >= 0);

        if (!IN_SET(p->state, PATH_WAITING, PATH_RUNNING))
                return 0;

        LIST_FOREACH(spec, i, p->specs)
                if (path_spec_owns_inotify_fd(i, fd)) {
                        found = i;
                        break;
                }

        if (!found) {
                log_error("Got event on unknown fd.");
                goto fail;
        }

        changed = path_spec_fd_event(found, revents);
        if (changed < 0)
                goto fail;

        if (changed)
                path_enter_running(p, found->path);
        else
                path_enter_waiting(p, false, false);

        return 0;

fail:
        path_enter_dead(p, PATH_FAILURE_RESOURCES);
        return 0;
}

static void path_trigger_notify_impl(Unit *u, Unit *other, bool on_defer);

static int path_trigger_notify_on_defer(sd_event_source *s, void *userdata) {
        Path *p = ASSERT_PTR(userdata);
        Unit *trigger;

        assert(s);

        trigger = UNIT_TRIGGER(UNIT(p));
        if (!trigger) {
                log_unit_error(UNIT(p), "Unit to trigger vanished.");
                path_enter_dead(p, PATH_FAILURE_RESOURCES);
                return 0;
        }

        path_trigger_notify_impl(UNIT(p), trigger, /* on_defer= */ true);
        return 0;
}

static void path_trigger_notify_impl(Unit *u, Unit *other, bool on_defer) {
        Path *p = ASSERT_PTR(PATH(u));
        int r;

        assert(other);

        /* Invoked whenever the unit we trigger changes state or gains or loses a job */

        /* Filter out invocations with bogus state */
        assert(UNIT_IS_LOAD_COMPLETE(other->load_state));

        /* Don't propagate state changes from the triggered unit if we are already down */
        if (!IN_SET(p->state, PATH_WAITING, PATH_RUNNING))
                return;

        /* Propagate start limit hit state */
        if (other->start_limit_hit) {
                path_enter_dead(p, PATH_FAILURE_UNIT_START_LIMIT_HIT);
                return;
        }

        /* Don't propagate anything if there's still a job queued */
        if (other->job)
                return;

        if (p->state == PATH_RUNNING &&
            UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other))) {
                if (!on_defer)
                        log_unit_debug(u, "Got notified about unit deactivation.");
        } else if (p->state == PATH_WAITING &&
                   !UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other))) {
                if (!on_defer)
                        log_unit_debug(u, "Got notified about unit activation.");
        } else
                return;

        if (on_defer) {
                path_enter_waiting(p, /* initial= */ false, /* from_trigger_notify= */ true);
                return;
        }

        /* Do not call path_enter_waiting() directly from path_trigger_notify(), as this may be called by
         * job_install() -> job_finish_and_invalidate() -> unit_trigger_notify(), and path_enter_waiting()
         * may install another job and will trigger assertion in job_install().
         * https://github.com/systemd/systemd/issues/24577#issuecomment-1522628906
         * Hence, first setup defer event source here, and call path_enter_waiting() slightly later. */
        if (p->trigger_notify_event_source) {
                r = sd_event_source_set_enabled(p->trigger_notify_event_source, SD_EVENT_ONESHOT);
                if (r < 0) {
                        log_unit_warning_errno(u, r, "Failed to enable event source for triggering notify: %m");
                        path_enter_dead(p, PATH_FAILURE_RESOURCES);
                        return;
                }
        } else {
                r = sd_event_add_defer(u->manager->event, &p->trigger_notify_event_source, path_trigger_notify_on_defer, p);
                if (r < 0) {
                        log_unit_warning_errno(u, r, "Failed to allocate event source for triggering notify: %m");
                        path_enter_dead(p, PATH_FAILURE_RESOURCES);
                        return;
                }

                (void) sd_event_source_set_description(p->trigger_notify_event_source, "path-trigger-notify");
        }
}

static void path_trigger_notify(Unit *u, Unit *other) {
        path_trigger_notify_impl(u, other, /* on_defer= */ false);
}

static void path_reset_failed(Unit *u) {
        Path *p = ASSERT_PTR(PATH(u));

        if (p->state == PATH_FAILED)
                path_set_state(p, PATH_DEAD);

        p->result = PATH_SUCCESS;
}

static int path_test_startable(Unit *u) {
        Path *p = ASSERT_PTR(PATH(u));
        int r;

        r = unit_test_start_limit(u);
        if (r < 0) {
                path_enter_dead(p, PATH_FAILURE_START_LIMIT_HIT);
                return r;
        }

        return true;
}

static void activation_details_path_done(ActivationDetails *details) {
        ActivationDetailsPath *p = ASSERT_PTR(ACTIVATION_DETAILS_PATH(details));

        p->trigger_path_filename = mfree(p->trigger_path_filename);
}

static void activation_details_path_serialize(const ActivationDetails *details, FILE *f) {
        const ActivationDetailsPath *p = ASSERT_PTR(ACTIVATION_DETAILS_PATH(details));

        assert(f);

        if (p->trigger_path_filename)
                (void) serialize_item(f, "activation-details-path-filename", p->trigger_path_filename);
}

static int activation_details_path_deserialize(const char *key, const char *value, ActivationDetails **details) {
        int r;

        assert(key);
        assert(value);

        if (!details || !*details)
                return -EINVAL;

        ActivationDetailsPath *p = ACTIVATION_DETAILS_PATH(*details);
        if (!p)
                return -EINVAL;

        if (!streq(key, "activation-details-path-filename"))
                return -EINVAL;

        r = free_and_strdup(&p->trigger_path_filename, value);
        if (r < 0)
                return r;

        return 0;
}

static int activation_details_path_append_env(const ActivationDetails *details, char ***strv) {
        const ActivationDetailsPath *p = ASSERT_PTR(ACTIVATION_DETAILS_PATH(details));
        char *s;
        int r;

        assert(strv);

        if (isempty(p->trigger_path_filename))
                return 0;

        s = strjoin("TRIGGER_PATH=", p->trigger_path_filename);
        if (!s)
                return -ENOMEM;

        r = strv_consume(strv, TAKE_PTR(s));
        if (r < 0)
                return r;

        return 1; /* Return the number of variables added to the env block */
}

static int activation_details_path_append_pair(const ActivationDetails *details, char ***strv) {
        const ActivationDetailsPath *p = ASSERT_PTR(ACTIVATION_DETAILS_PATH(details));
        int r;

        assert(strv);

        if (isempty(p->trigger_path_filename))
                return 0;

        r = strv_extend_many(strv, "trigger_path", p->trigger_path_filename);
        if (r < 0)
                return r;

        return 1; /* Return the number of pairs added to the env block */
}

static const char* const path_type_table[_PATH_TYPE_MAX] = {
        [PATH_EXISTS]              = "PathExists",
        [PATH_EXISTS_GLOB]         = "PathExistsGlob",
        [PATH_DIRECTORY_NOT_EMPTY] = "DirectoryNotEmpty",
        [PATH_CHANGED]             = "PathChanged",
        [PATH_MODIFIED]            = "PathModified",
};

DEFINE_STRING_TABLE_LOOKUP(path_type, PathType);

static const char* const path_result_table[_PATH_RESULT_MAX] = {
        [PATH_SUCCESS]                      = "success",
        [PATH_FAILURE_RESOURCES]            = "resources",
        [PATH_FAILURE_START_LIMIT_HIT]      = "start-limit-hit",
        [PATH_FAILURE_UNIT_START_LIMIT_HIT] = "unit-start-limit-hit",
        [PATH_FAILURE_TRIGGER_LIMIT_HIT]    = "trigger-limit-hit",
};

DEFINE_STRING_TABLE_LOOKUP(path_result, PathResult);

const UnitVTable path_vtable = {
        .object_size = sizeof(Path),

        .sections =
                "Unit\0"
                "Path\0"
                "Install\0",
        .private_section = "Path",

        .can_transient = true,
        .can_fail = true,
        .can_trigger = true,

        .init = path_init,
        .done = path_done,
        .load = path_load,

        .coldplug = path_coldplug,

        .dump = path_dump,

        .start = path_start,
        .stop = path_stop,

        .serialize = path_serialize,
        .deserialize_item = path_deserialize_item,

        .active_state = path_active_state,
        .sub_state_to_string = path_sub_state_to_string,

        .trigger_notify = path_trigger_notify,

        .reset_failed = path_reset_failed,

        .bus_set_property = bus_path_set_property,

        .test_startable = path_test_startable,
};

const ActivationDetailsVTable activation_details_path_vtable = {
        .object_size = sizeof(ActivationDetailsPath),

        .done = activation_details_path_done,
        .serialize = activation_details_path_serialize,
        .deserialize = activation_details_path_deserialize,
        .append_env = activation_details_path_append_env,
        .append_pair = activation_details_path_append_pair,
};

systemd / systemd / 20321298054

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