./move.sh

1 files changed, 3756 insertions, 0 deletions

diff --git a/src/libcore/unit.c b/src/libcore/unit.c
new file mode 100644
index 0000000000..4f7c0e2449
--- /dev/null
+++ b/src/libcore/unit.c
@@ -0,0 +1,3756 @@
+/***
+  This file is part of systemd.
+
+  Copyright 2010 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 <stdlib.h>
+#include <string.h>
+#include <sys/stat.h>
+#include <unistd.h>
+
+#include <systemd/sd-id128.h>
+#include <systemd/sd-messages.h>
+
+#include "alloc-util.h"
+#include "bus-common-errors.h"
+#include "bus-util.h"
+#include "cgroup-util.h"
+#include "dbus-unit.h"
+#include "dbus.h"
+#include "dropin.h"
+#include "escape.h"
+#include "execute.h"
+#include "fileio-label.h"
+#include "formats-util.h"
+#include "load-dropin.h"
+#include "load-fragment.h"
+#include "log.h"
+#include "macro.h"
+#include "missing.h"
+#include "mkdir.h"
+#include "parse-util.h"
+#include "path-util.h"
+#include "process-util.h"
+#include "set.h"
+#include "special.h"
+#include "stat-util.h"
+#include "stdio-util.h"
+#include "string-util.h"
+#include "strv.h"
+#include "unit-name.h"
+#include "unit.h"
+#include "user-util.h"
+#include "virt.h"
+
+const UnitVTable * const unit_vtable[_UNIT_TYPE_MAX] = {
+        [UNIT_SERVICE] = &service_vtable,
+        [UNIT_SOCKET] = &socket_vtable,
+        [UNIT_BUSNAME] = &busname_vtable,
+        [UNIT_TARGET] = &target_vtable,
+        [UNIT_DEVICE] = &device_vtable,
+        [UNIT_MOUNT] = &mount_vtable,
+        [UNIT_AUTOMOUNT] = &automount_vtable,
+        [UNIT_SWAP] = &swap_vtable,
+        [UNIT_TIMER] = &timer_vtable,
+        [UNIT_PATH] = &path_vtable,
+        [UNIT_SLICE] = &slice_vtable,
+        [UNIT_SCOPE] = &scope_vtable
+};
+
+static void maybe_warn_about_dependency(Unit *u, const char *other, UnitDependency dependency);
+
+Unit *unit_new(Manager *m, size_t size) {
+        Unit *u;
+
+        assert(m);
+        assert(size >= sizeof(Unit));
+
+        u = malloc0(size);
+        if (!u)
+                return NULL;
+
+        u->names = set_new(&string_hash_ops);
+        if (!u->names) {
+                free(u);
+                return NULL;
+        }
+
+        u->manager = m;
+        u->type = _UNIT_TYPE_INVALID;
+        u->default_dependencies = true;
+        u->unit_file_state = _UNIT_FILE_STATE_INVALID;
+        u->unit_file_preset = -1;
+        u->on_failure_job_mode = JOB_REPLACE;
+        u->cgroup_inotify_wd = -1;
+        u->job_timeout = USEC_INFINITY;
+
+        RATELIMIT_INIT(u->start_limit, m->default_start_limit_interval, m->default_start_limit_burst);
+        RATELIMIT_INIT(u->auto_stop_ratelimit, 10 * USEC_PER_SEC, 16);
+
+        return u;
+}
+
+bool unit_has_name(Unit *u, const char *name) {
+        assert(u);
+        assert(name);
+
+        return !!set_get(u->names, (char*) name);
+}
+
+static void unit_init(Unit *u) {
+        CGroupContext *cc;
+        ExecContext *ec;
+        KillContext *kc;
+
+        assert(u);
+        assert(u->manager);
+        assert(u->type >= 0);
+
+        cc = unit_get_cgroup_context(u);
+        if (cc) {
+                cgroup_context_init(cc);
+
+                /* Copy in the manager defaults into the cgroup
+                 * context, _before_ the rest of the settings have
+                 * been initialized */
+
+                cc->cpu_accounting = u->manager->default_cpu_accounting;
+                cc->blockio_accounting = u->manager->default_blockio_accounting;
+                cc->memory_accounting = u->manager->default_memory_accounting;
+                cc->tasks_accounting = u->manager->default_tasks_accounting;
+
+                if (u->type != UNIT_SLICE)
+                        cc->tasks_max = u->manager->default_tasks_max;
+        }
+
+        ec = unit_get_exec_context(u);
+        if (ec)
+                exec_context_init(ec);
+
+        kc = unit_get_kill_context(u);
+        if (kc)
+                kill_context_init(kc);
+
+        if (UNIT_VTABLE(u)->init)
+                UNIT_VTABLE(u)->init(u);
+}
+
+int unit_add_name(Unit *u, const char *text) {
+        _cleanup_free_ char *s = NULL, *i = NULL;
+        UnitType t;
+        int r;
+
+        assert(u);
+        assert(text);
+
+        if (unit_name_is_valid(text, UNIT_NAME_TEMPLATE)) {
+
+                if (!u->instance)
+                        return -EINVAL;
+
+                r = unit_name_replace_instance(text, u->instance, &s);
+                if (r < 0)
+                        return r;
+        } else {
+                s = strdup(text);
+                if (!s)
+                        return -ENOMEM;
+        }
+
+        if (set_contains(u->names, s))
+                return 0;
+        if (hashmap_contains(u->manager->units, s))
+                return -EEXIST;
+
+        if (!unit_name_is_valid(s, UNIT_NAME_PLAIN|UNIT_NAME_INSTANCE))
+                return -EINVAL;
+
+        t = unit_name_to_type(s);
+        if (t < 0)
+                return -EINVAL;
+
+        if (u->type != _UNIT_TYPE_INVALID && t != u->type)
+                return -EINVAL;
+
+        r = unit_name_to_instance(s, &i);
+        if (r < 0)
+                return r;
+
+        if (i && unit_vtable[t]->no_instances)
+                return -EINVAL;
+
+        /* Ensure that this unit is either instanced or not instanced,
+         * but not both. Note that we do allow names with different
+         * instance names however! */
+        if (u->type != _UNIT_TYPE_INVALID && !u->instance != !i)
+                return -EINVAL;
+
+        if (unit_vtable[t]->no_alias && !set_isempty(u->names))
+                return -EEXIST;
+
+        if (hashmap_size(u->manager->units) >= MANAGER_MAX_NAMES)
+                return -E2BIG;
+
+        r = set_put(u->names, s);
+        if (r < 0)
+                return r;
+        assert(r > 0);
+
+        r = hashmap_put(u->manager->units, s, u);
+        if (r < 0) {
+                (void) set_remove(u->names, s);
+                return r;
+        }
+
+        if (u->type == _UNIT_TYPE_INVALID) {
+                u->type = t;
+                u->id = s;
+                u->instance = i;
+
+                LIST_PREPEND(units_by_type, u->manager->units_by_type[t], u);
+
+                unit_init(u);
+
+                i = NULL;
+        }
+
+        s = NULL;
+
+        unit_add_to_dbus_queue(u);
+        return 0;
+}
+
+int unit_choose_id(Unit *u, const char *name) {
+        _cleanup_free_ char *t = NULL;
+        char *s, *i;
+        int r;
+
+        assert(u);
+        assert(name);
+
+        if (unit_name_is_valid(name, UNIT_NAME_TEMPLATE)) {
+
+                if (!u->instance)
+                        return -EINVAL;
+
+                r = unit_name_replace_instance(name, u->instance, &t);
+                if (r < 0)
+                        return r;
+
+                name = t;
+        }
+
+        /* Selects one of the names of this unit as the id */
+        s = set_get(u->names, (char*) name);
+        if (!s)
+                return -ENOENT;
+
+        /* Determine the new instance from the new id */
+        r = unit_name_to_instance(s, &i);
+        if (r < 0)
+                return r;
+
+        u->id = s;
+
+        free(u->instance);
+        u->instance = i;
+
+        unit_add_to_dbus_queue(u);
+
+        return 0;
+}
+
+int unit_set_description(Unit *u, const char *description) {
+        char *s;
+
+        assert(u);
+
+        if (isempty(description))
+                s = NULL;
+        else {
+                s = strdup(description);
+                if (!s)
+                        return -ENOMEM;
+        }
+
+        free(u->description);
+        u->description = s;
+
+        unit_add_to_dbus_queue(u);
+        return 0;
+}
+
+bool unit_check_gc(Unit *u) {
+        UnitActiveState state;
+        assert(u);
+
+        if (u->job)
+                return true;
+
+        if (u->nop_job)
+                return true;
+
+        state = unit_active_state(u);
+
+        /* If the unit is inactive and failed and no job is queued for
+         * it, then release its runtime resources */
+        if (UNIT_IS_INACTIVE_OR_FAILED(state) &&
+            UNIT_VTABLE(u)->release_resources)
+                UNIT_VTABLE(u)->release_resources(u);
+
+        /* But we keep the unit object around for longer when it is
+         * referenced or configured to not be gc'ed */
+        if (state != UNIT_INACTIVE)
+                return true;
+
+        if (u->no_gc)
+                return true;
+
+        if (u->refs)
+                return true;
+
+        if (UNIT_VTABLE(u)->check_gc)
+                if (UNIT_VTABLE(u)->check_gc(u))
+                        return true;
+
+        return false;
+}
+
+void unit_add_to_load_queue(Unit *u) {
+        assert(u);
+        assert(u->type != _UNIT_TYPE_INVALID);
+
+        if (u->load_state != UNIT_STUB || u->in_load_queue)
+                return;
+
+        LIST_PREPEND(load_queue, u->manager->load_queue, u);
+        u->in_load_queue = true;
+}
+
+void unit_add_to_cleanup_queue(Unit *u) {
+        assert(u);
+
+        if (u->in_cleanup_queue)
+                return;
+
+        LIST_PREPEND(cleanup_queue, u->manager->cleanup_queue, u);
+        u->in_cleanup_queue = true;
+}
+
+void unit_add_to_gc_queue(Unit *u) {
+        assert(u);
+
+        if (u->in_gc_queue || u->in_cleanup_queue)
+                return;
+
+        if (unit_check_gc(u))
+                return;
+
+        LIST_PREPEND(gc_queue, u->manager->gc_queue, u);
+        u->in_gc_queue = true;
+
+        u->manager->n_in_gc_queue ++;
+}
+
+void unit_add_to_dbus_queue(Unit *u) {
+        assert(u);
+        assert(u->type != _UNIT_TYPE_INVALID);
+
+        if (u->load_state == UNIT_STUB || u->in_dbus_queue)
+                return;
+
+        /* Shortcut things if nobody cares */
+        if (sd_bus_track_count(u->manager->subscribed) <= 0 &&
+            set_isempty(u->manager->private_buses)) {
+                u->sent_dbus_new_signal = true;
+                return;
+        }
+
+        LIST_PREPEND(dbus_queue, u->manager->dbus_unit_queue, u);
+        u->in_dbus_queue = true;
+}
+
+static void bidi_set_free(Unit *u, Set *s) {
+        Iterator i;
+        Unit *other;
+
+        assert(u);
+
+        /* Frees the set and makes sure we are dropped from the
+         * inverse pointers */
+
+        SET_FOREACH(other, s, i) {
+                UnitDependency d;
+
+                for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
+                        set_remove(other->dependencies[d], u);
+
+                unit_add_to_gc_queue(other);
+        }
+
+        set_free(s);
+}
+
+static void unit_remove_transient(Unit *u) {
+        char **i;
+
+        assert(u);
+
+        if (!u->transient)
+                return;
+
+        if (u->fragment_path)
+                (void) unlink(u->fragment_path);
+
+        STRV_FOREACH(i, u->dropin_paths) {
+                _cleanup_free_ char *p = NULL;
+
+                (void) unlink(*i);
+
+                p = dirname_malloc(*i);
+                if (p)
+                        (void) rmdir(p);
+        }
+}
+
+static void unit_free_requires_mounts_for(Unit *u) {
+        char **j;
+
+        STRV_FOREACH(j, u->requires_mounts_for) {
+                char s[strlen(*j) + 1];
+
+                PATH_FOREACH_PREFIX_MORE(s, *j) {
+                        char *y;
+                        Set *x;
+
+                        x = hashmap_get2(u->manager->units_requiring_mounts_for, s, (void**) &y);
+                        if (!x)
+                                continue;
+
+                        set_remove(x, u);
+
+                        if (set_isempty(x)) {
+                                hashmap_remove(u->manager->units_requiring_mounts_for, y);
+                                free(y);
+                                set_free(x);
+                        }
+                }
+        }
+
+        u->requires_mounts_for = strv_free(u->requires_mounts_for);
+}
+
+static void unit_done(Unit *u) {
+        ExecContext *ec;
+        CGroupContext *cc;
+
+        assert(u);
+
+        if (u->type < 0)
+                return;
+
+        if (UNIT_VTABLE(u)->done)
+                UNIT_VTABLE(u)->done(u);
+
+        ec = unit_get_exec_context(u);
+        if (ec)
+                exec_context_done(ec);
+
+        cc = unit_get_cgroup_context(u);
+        if (cc)
+                cgroup_context_done(cc);
+}
+
+void unit_free(Unit *u) {
+        UnitDependency d;
+        Iterator i;
+        char *t;
+
+        assert(u);
+
+        if (u->manager->n_reloading <= 0)
+                unit_remove_transient(u);
+
+        bus_unit_send_removed_signal(u);
+
+        unit_done(u);
+
+        sd_bus_slot_unref(u->match_bus_slot);
+
+        unit_free_requires_mounts_for(u);
+
+        SET_FOREACH(t, u->names, i)
+                hashmap_remove_value(u->manager->units, t, u);
+
+        if (u->job) {
+                Job *j = u->job;
+                job_uninstall(j);
+                job_free(j);
+        }
+
+        if (u->nop_job) {
+                Job *j = u->nop_job;
+                job_uninstall(j);
+                job_free(j);
+        }
+
+        for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
+                bidi_set_free(u, u->dependencies[d]);
+
+        if (u->type != _UNIT_TYPE_INVALID)
+                LIST_REMOVE(units_by_type, u->manager->units_by_type[u->type], u);
+
+        if (u->in_load_queue)
+                LIST_REMOVE(load_queue, u->manager->load_queue, u);
+
+        if (u->in_dbus_queue)
+                LIST_REMOVE(dbus_queue, u->manager->dbus_unit_queue, u);
+
+        if (u->in_cleanup_queue)
+                LIST_REMOVE(cleanup_queue, u->manager->cleanup_queue, u);
+
+        if (u->in_gc_queue) {
+                LIST_REMOVE(gc_queue, u->manager->gc_queue, u);
+                u->manager->n_in_gc_queue--;
+        }
+
+        if (u->in_cgroup_queue)
+                LIST_REMOVE(cgroup_queue, u->manager->cgroup_queue, u);
+
+        unit_release_cgroup(u);
+
+        (void) manager_update_failed_units(u->manager, u, false);
+        set_remove(u->manager->startup_units, u);
+
+        free(u->description);
+        strv_free(u->documentation);
+        free(u->fragment_path);
+        free(u->source_path);
+        strv_free(u->dropin_paths);
+        free(u->instance);
+
+        free(u->job_timeout_reboot_arg);
+
+        set_free_free(u->names);
+
+        unit_unwatch_all_pids(u);
+
+        condition_free_list(u->conditions);
+        condition_free_list(u->asserts);
+
+        free(u->reboot_arg);
+
+        unit_ref_unset(&u->slice);
+
+        while (u->refs)
+                unit_ref_unset(u->refs);
+
+        free(u);
+}
+
+UnitActiveState unit_active_state(Unit *u) {
+        assert(u);
+
+        if (u->load_state == UNIT_MERGED)
+                return unit_active_state(unit_follow_merge(u));
+
+        /* After a reload it might happen that a unit is not correctly
+         * loaded but still has a process around. That's why we won't
+         * shortcut failed loading to UNIT_INACTIVE_FAILED. */
+
+        return UNIT_VTABLE(u)->active_state(u);
+}
+
+const char* unit_sub_state_to_string(Unit *u) {
+        assert(u);
+
+        return UNIT_VTABLE(u)->sub_state_to_string(u);
+}
+
+static int complete_move(Set **s, Set **other) {
+        int r;
+
+        assert(s);
+        assert(other);
+
+        if (!*other)
+                return 0;
+
+        if (*s) {
+                r = set_move(*s, *other);
+                if (r < 0)
+                        return r;
+        } else {
+                *s = *other;
+                *other = NULL;
+        }
+
+        return 0;
+}
+
+static int merge_names(Unit *u, Unit *other) {
+        char *t;
+        Iterator i;
+        int r;
+
+        assert(u);
+        assert(other);
+
+        r = complete_move(&u->names, &other->names);
+        if (r < 0)
+                return r;
+
+        set_free_free(other->names);
+        other->names = NULL;
+        other->id = NULL;
+
+        SET_FOREACH(t, u->names, i)
+                assert_se(hashmap_replace(u->manager->units, t, u) == 0);
+
+        return 0;
+}
+
+static int reserve_dependencies(Unit *u, Unit *other, UnitDependency d) {
+        unsigned n_reserve;
+
+        assert(u);
+        assert(other);
+        assert(d < _UNIT_DEPENDENCY_MAX);
+
+        /*
+         * If u does not have this dependency set allocated, there is no need
+         * to reserve anything. In that case other's set will be transferred
+         * as a whole to u by complete_move().
+         */
+        if (!u->dependencies[d])
+                return 0;
+
+        /* merge_dependencies() will skip a u-on-u dependency */
+        n_reserve = set_size(other->dependencies[d]) - !!set_get(other->dependencies[d], u);
+
+        return set_reserve(u->dependencies[d], n_reserve);
+}
+
+static void merge_dependencies(Unit *u, Unit *other, const char *other_id, UnitDependency d) {
+        Iterator i;
+        Unit *back;
+        int r;
+
+        assert(u);
+        assert(other);
+        assert(d < _UNIT_DEPENDENCY_MAX);
+
+        /* Fix backwards pointers */
+        SET_FOREACH(back, other->dependencies[d], i) {
+                UnitDependency k;
+
+                for (k = 0; k < _UNIT_DEPENDENCY_MAX; k++) {
+                        /* Do not add dependencies between u and itself */
+                        if (back == u) {
+                                if (set_remove(back->dependencies[k], other))
+                                        maybe_warn_about_dependency(u, other_id, k);
+                        } else {
+                                r = set_remove_and_put(back->dependencies[k], other, u);
+                                if (r == -EEXIST)
+                                        set_remove(back->dependencies[k], other);
+                                else
+                                        assert(r >= 0 || r == -ENOENT);
+                        }
+                }
+        }
+
+        /* Also do not move dependencies on u to itself */
+        back = set_remove(other->dependencies[d], u);
+        if (back)
+                maybe_warn_about_dependency(u, other_id, d);
+
+        /* The move cannot fail. The caller must have performed a reservation. */
+        assert_se(complete_move(&u->dependencies[d], &other->dependencies[d]) == 0);
+
+        other->dependencies[d] = set_free(other->dependencies[d]);
+}
+
+int unit_merge(Unit *u, Unit *other) {
+        UnitDependency d;
+        const char *other_id = NULL;
+        int r;
+
+        assert(u);
+        assert(other);
+        assert(u->manager == other->manager);
+        assert(u->type != _UNIT_TYPE_INVALID);
+
+        other = unit_follow_merge(other);
+
+        if (other == u)
+                return 0;
+
+        if (u->type != other->type)
+                return -EINVAL;
+
+        if (!u->instance != !other->instance)
+                return -EINVAL;
+
+        if (other->load_state != UNIT_STUB &&
+            other->load_state != UNIT_NOT_FOUND)
+                return -EEXIST;
+
+        if (other->job)
+                return -EEXIST;
+
+        if (other->nop_job)
+                return -EEXIST;
+
+        if (!UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other)))
+                return -EEXIST;
+
+        if (other->id)
+                other_id = strdupa(other->id);
+
+        /* Make reservations to ensure merge_dependencies() won't fail */
+        for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) {
+                r = reserve_dependencies(u, other, d);
+                /*
+                 * We don't rollback reservations if we fail. We don't have
+                 * a way to undo reservations. A reservation is not a leak.
+                 */
+                if (r < 0)
+                        return r;
+        }
+
+        /* Merge names */
+        r = merge_names(u, other);
+        if (r < 0)
+                return r;
+
+        /* Redirect all references */
+        while (other->refs)
+                unit_ref_set(other->refs, u);
+
+        /* Merge dependencies */
+        for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++)
+                merge_dependencies(u, other, other_id, d);
+
+        other->load_state = UNIT_MERGED;
+        other->merged_into = u;
+
+        /* If there is still some data attached to the other node, we
+         * don't need it anymore, and can free it. */
+        if (other->load_state != UNIT_STUB)
+                if (UNIT_VTABLE(other)->done)
+                        UNIT_VTABLE(other)->done(other);
+
+        unit_add_to_dbus_queue(u);
+        unit_add_to_cleanup_queue(other);
+
+        return 0;
+}
+
+int unit_merge_by_name(Unit *u, const char *name) {
+        Unit *other;
+        int r;
+        _cleanup_free_ char *s = NULL;
+
+        assert(u);
+        assert(name);
+
+        if (unit_name_is_valid(name, UNIT_NAME_TEMPLATE)) {
+                if (!u->instance)
+                        return -EINVAL;
+
+                r = unit_name_replace_instance(name, u->instance, &s);
+                if (r < 0)
+                        return r;
+
+                name = s;
+        }
+
+        other = manager_get_unit(u->manager, name);
+        if (other)
+                return unit_merge(u, other);
+
+        return unit_add_name(u, name);
+}
+
+Unit* unit_follow_merge(Unit *u) {
+        assert(u);
+
+        while (u->load_state == UNIT_MERGED)
+                assert_se(u = u->merged_into);
+
+        return u;
+}
+
+int unit_add_exec_dependencies(Unit *u, ExecContext *c) {
+        int r;
+
+        assert(u);
+        assert(c);
+
+        if (c->working_directory) {
+                r = unit_require_mounts_for(u, c->working_directory);
+                if (r < 0)
+                        return r;
+        }
+
+        if (c->root_directory) {
+                r = unit_require_mounts_for(u, c->root_directory);
+                if (r < 0)
+                        return r;
+        }
+
+        if (u->manager->running_as != MANAGER_SYSTEM)
+                return 0;
+
+        if (c->private_tmp) {
+                r = unit_require_mounts_for(u, "/tmp");
+                if (r < 0)
+                        return r;
+
+                r = unit_require_mounts_for(u, "/var/tmp");
+                if (r < 0)
+                        return r;
+        }
+
+        if (c->std_output != EXEC_OUTPUT_KMSG &&
+            c->std_output != EXEC_OUTPUT_SYSLOG &&
+            c->std_output != EXEC_OUTPUT_JOURNAL &&
+            c->std_output != EXEC_OUTPUT_KMSG_AND_CONSOLE &&
+            c->std_output != EXEC_OUTPUT_SYSLOG_AND_CONSOLE &&
+            c->std_output != EXEC_OUTPUT_JOURNAL_AND_CONSOLE &&
+            c->std_error != EXEC_OUTPUT_KMSG &&
+            c->std_error != EXEC_OUTPUT_SYSLOG &&
+            c->std_error != EXEC_OUTPUT_JOURNAL &&
+            c->std_error != EXEC_OUTPUT_KMSG_AND_CONSOLE &&
+            c->std_error != EXEC_OUTPUT_JOURNAL_AND_CONSOLE &&
+            c->std_error != EXEC_OUTPUT_SYSLOG_AND_CONSOLE)
+                return 0;
+
+        /* If syslog or kernel logging is requested, make sure our own
+         * logging daemon is run first. */
+
+        r = unit_add_dependency_by_name(u, UNIT_AFTER, SPECIAL_JOURNALD_SOCKET, NULL, true);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+const char *unit_description(Unit *u) {
+        assert(u);
+
+        if (u->description)
+                return u->description;
+
+        return strna(u->id);
+}
+
+void unit_dump(Unit *u, FILE *f, const char *prefix) {
+        char *t, **j;
+        UnitDependency d;
+        Iterator i;
+        const char *prefix2;
+        char
+                timestamp0[FORMAT_TIMESTAMP_MAX],
+                timestamp1[FORMAT_TIMESTAMP_MAX],
+                timestamp2[FORMAT_TIMESTAMP_MAX],
+                timestamp3[FORMAT_TIMESTAMP_MAX],
+                timestamp4[FORMAT_TIMESTAMP_MAX],
+                timespan[FORMAT_TIMESPAN_MAX];
+        Unit *following;
+        _cleanup_set_free_ Set *following_set = NULL;
+        int r;
+
+        assert(u);
+        assert(u->type >= 0);
+
+        prefix = strempty(prefix);
+        prefix2 = strjoina(prefix, "\t");
+
+        fprintf(f,
+                "%s-> Unit %s:\n"
+                "%s\tDescription: %s\n"
+                "%s\tInstance: %s\n"
+                "%s\tUnit Load State: %s\n"
+                "%s\tUnit Active State: %s\n"
+                "%s\nState Change Timestamp: %s\n"
+                "%s\tInactive Exit Timestamp: %s\n"
+                "%s\tActive Enter Timestamp: %s\n"
+                "%s\tActive Exit Timestamp: %s\n"
+                "%s\tInactive Enter Timestamp: %s\n"
+                "%s\tGC Check Good: %s\n"
+                "%s\tNeed Daemon Reload: %s\n"
+                "%s\tTransient: %s\n"
+                "%s\tSlice: %s\n"
+                "%s\tCGroup: %s\n"
+                "%s\tCGroup realized: %s\n"
+                "%s\tCGroup mask: 0x%x\n"
+                "%s\tCGroup members mask: 0x%x\n",
+                prefix, u->id,
+                prefix, unit_description(u),
+                prefix, strna(u->instance),
+                prefix, unit_load_state_to_string(u->load_state),
+                prefix, unit_active_state_to_string(unit_active_state(u)),
+                prefix, strna(format_timestamp(timestamp0, sizeof(timestamp0), u->state_change_timestamp.realtime)),
+                prefix, strna(format_timestamp(timestamp1, sizeof(timestamp1), u->inactive_exit_timestamp.realtime)),
+                prefix, strna(format_timestamp(timestamp2, sizeof(timestamp2), u->active_enter_timestamp.realtime)),
+                prefix, strna(format_timestamp(timestamp3, sizeof(timestamp3), u->active_exit_timestamp.realtime)),
+                prefix, strna(format_timestamp(timestamp4, sizeof(timestamp4), u->inactive_enter_timestamp.realtime)),
+                prefix, yes_no(unit_check_gc(u)),
+                prefix, yes_no(unit_need_daemon_reload(u)),
+                prefix, yes_no(u->transient),
+                prefix, strna(unit_slice_name(u)),
+                prefix, strna(u->cgroup_path),
+                prefix, yes_no(u->cgroup_realized),
+                prefix, u->cgroup_realized_mask,
+                prefix, u->cgroup_members_mask);
+
+        SET_FOREACH(t, u->names, i)
+                fprintf(f, "%s\tName: %s\n", prefix, t);
+
+        STRV_FOREACH(j, u->documentation)
+                fprintf(f, "%s\tDocumentation: %s\n", prefix, *j);
+
+        following = unit_following(u);
+        if (following)
+                fprintf(f, "%s\tFollowing: %s\n", prefix, following->id);
+
+        r = unit_following_set(u, &following_set);
+        if (r >= 0) {
+                Unit *other;
+
+                SET_FOREACH(other, following_set, i)
+                        fprintf(f, "%s\tFollowing Set Member: %s\n", prefix, other->id);
+        }
+
+        if (u->fragment_path)
+                fprintf(f, "%s\tFragment Path: %s\n", prefix, u->fragment_path);
+
+        if (u->source_path)
+                fprintf(f, "%s\tSource Path: %s\n", prefix, u->source_path);
+
+        STRV_FOREACH(j, u->dropin_paths)
+                fprintf(f, "%s\tDropIn Path: %s\n", prefix, *j);
+
+        if (u->job_timeout != USEC_INFINITY)
+                fprintf(f, "%s\tJob Timeout: %s\n", prefix, format_timespan(timespan, sizeof(timespan), u->job_timeout, 0));
+
+        if (u->job_timeout_action != FAILURE_ACTION_NONE)
+                fprintf(f, "%s\tJob Timeout Action: %s\n", prefix, failure_action_to_string(u->job_timeout_action));
+
+        if (u->job_timeout_reboot_arg)
+                fprintf(f, "%s\tJob Timeout Reboot Argument: %s\n", prefix, u->job_timeout_reboot_arg);
+
+        condition_dump_list(u->conditions, f, prefix, condition_type_to_string);
+        condition_dump_list(u->asserts, f, prefix, assert_type_to_string);
+
+        if (dual_timestamp_is_set(&u->condition_timestamp))
+                fprintf(f,
+                        "%s\tCondition Timestamp: %s\n"
+                        "%s\tCondition Result: %s\n",
+                        prefix, strna(format_timestamp(timestamp1, sizeof(timestamp1), u->condition_timestamp.realtime)),
+                        prefix, yes_no(u->condition_result));
+
+        if (dual_timestamp_is_set(&u->assert_timestamp))
+                fprintf(f,
+                        "%s\tAssert Timestamp: %s\n"
+                        "%s\tAssert Result: %s\n",
+                        prefix, strna(format_timestamp(timestamp1, sizeof(timestamp1), u->assert_timestamp.realtime)),
+                        prefix, yes_no(u->assert_result));
+
+        for (d = 0; d < _UNIT_DEPENDENCY_MAX; d++) {
+                Unit *other;
+
+                SET_FOREACH(other, u->dependencies[d], i)
+                        fprintf(f, "%s\t%s: %s\n", prefix, unit_dependency_to_string(d), other->id);
+        }
+
+        if (!strv_isempty(u->requires_mounts_for)) {
+                fprintf(f,
+                        "%s\tRequiresMountsFor:", prefix);
+
+                STRV_FOREACH(j, u->requires_mounts_for)
+                        fprintf(f, " %s", *j);
+
+                fputs("\n", f);
+        }
+
+        if (u->load_state == UNIT_LOADED) {
+
+                fprintf(f,
+                        "%s\tStopWhenUnneeded: %s\n"
+                        "%s\tRefuseManualStart: %s\n"
+                        "%s\tRefuseManualStop: %s\n"
+                        "%s\tDefaultDependencies: %s\n"
+                        "%s\tOnFailureJobMode: %s\n"
+                        "%s\tIgnoreOnIsolate: %s\n",
+                        prefix, yes_no(u->stop_when_unneeded),
+                        prefix, yes_no(u->refuse_manual_start),
+                        prefix, yes_no(u->refuse_manual_stop),
+                        prefix, yes_no(u->default_dependencies),
+                        prefix, job_mode_to_string(u->on_failure_job_mode),
+                        prefix, yes_no(u->ignore_on_isolate));
+
+                if (UNIT_VTABLE(u)->dump)
+                        UNIT_VTABLE(u)->dump(u, f, prefix2);
+
+        } else if (u->load_state == UNIT_MERGED)
+                fprintf(f,
+                        "%s\tMerged into: %s\n",
+                        prefix, u->merged_into->id);
+        else if (u->load_state == UNIT_ERROR)
+                fprintf(f, "%s\tLoad Error Code: %s\n", prefix, strerror(-u->load_error));
+
+
+        if (u->job)
+                job_dump(u->job, f, prefix2);
+
+        if (u->nop_job)
+                job_dump(u->nop_job, f, prefix2);
+
+}
+
+/* Common implementation for multiple backends */
+int unit_load_fragment_and_dropin(Unit *u) {
+        int r;
+
+        assert(u);
+
+        /* Load a .{service,socket,...} file */
+        r = unit_load_fragment(u);
+        if (r < 0)
+                return r;
+
+        if (u->load_state == UNIT_STUB)
+                return -ENOENT;
+
+        /* Load drop-in directory data */
+        r = unit_load_dropin(unit_follow_merge(u));
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+/* Common implementation for multiple backends */
+int unit_load_fragment_and_dropin_optional(Unit *u) {
+        int r;
+
+        assert(u);
+
+        /* Same as unit_load_fragment_and_dropin(), but whether
+         * something can be loaded or not doesn't matter. */
+
+        /* Load a .service file */
+        r = unit_load_fragment(u);
+        if (r < 0)
+                return r;
+
+        if (u->load_state == UNIT_STUB)
+                u->load_state = UNIT_LOADED;
+
+        /* Load drop-in directory data */
+        r = unit_load_dropin(unit_follow_merge(u));
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+int unit_add_default_target_dependency(Unit *u, Unit *target) {
+        assert(u);
+        assert(target);
+
+        if (target->type != UNIT_TARGET)
+                return 0;
+
+        /* Only add the dependency if both units are loaded, so that
+         * that loop check below is reliable */
+        if (u->load_state != UNIT_LOADED ||
+            target->load_state != UNIT_LOADED)
+                return 0;
+
+        /* If either side wants no automatic dependencies, then let's
+         * skip this */
+        if (!u->default_dependencies ||
+            !target->default_dependencies)
+                return 0;
+
+        /* Don't create loops */
+        if (set_get(target->dependencies[UNIT_BEFORE], u))
+                return 0;
+
+        return unit_add_dependency(target, UNIT_AFTER, u, true);
+}
+
+static int unit_add_target_dependencies(Unit *u) {
+
+        static const UnitDependency deps[] = {
+                UNIT_REQUIRED_BY,
+                UNIT_REQUISITE_OF,
+                UNIT_WANTED_BY,
+                UNIT_BOUND_BY
+        };
+
+        Unit *target;
+        Iterator i;
+        unsigned k;
+        int r = 0;
+
+        assert(u);
+
+        for (k = 0; k < ELEMENTSOF(deps); k++)
+                SET_FOREACH(target, u->dependencies[deps[k]], i) {
+                        r = unit_add_default_target_dependency(u, target);
+                        if (r < 0)
+                                return r;
+                }
+
+        return r;
+}
+
+static int unit_add_slice_dependencies(Unit *u) {
+        assert(u);
+
+        if (!UNIT_HAS_CGROUP_CONTEXT(u))
+                return 0;
+
+        if (UNIT_ISSET(u->slice))
+                return unit_add_two_dependencies(u, UNIT_AFTER, UNIT_REQUIRES, UNIT_DEREF(u->slice), true);
+
+        if (unit_has_name(u, SPECIAL_ROOT_SLICE))
+                return 0;
+
+        return unit_add_two_dependencies_by_name(u, UNIT_AFTER, UNIT_REQUIRES, SPECIAL_ROOT_SLICE, NULL, true);
+}
+
+static int unit_add_mount_dependencies(Unit *u) {
+        char **i;
+        int r;
+
+        assert(u);
+
+        STRV_FOREACH(i, u->requires_mounts_for) {
+                char prefix[strlen(*i) + 1];
+
+                PATH_FOREACH_PREFIX_MORE(prefix, *i) {
+                        _cleanup_free_ char *p = NULL;
+                        Unit *m;
+
+                        r = unit_name_from_path(prefix, ".mount", &p);
+                        if (r < 0)
+                                return r;
+
+                        m = manager_get_unit(u->manager, p);
+                        if (!m) {
+                                /* Make sure to load the mount unit if
+                                 * it exists. If so the dependencies
+                                 * on this unit will be added later
+                                 * during the loading of the mount
+                                 * unit. */
+                                (void) manager_load_unit_prepare(u->manager, p, NULL, NULL, &m);
+                                continue;
+                        }
+                        if (m == u)
+                                continue;
+
+                        if (m->load_state != UNIT_LOADED)
+                                continue;
+
+                        r = unit_add_dependency(u, UNIT_AFTER, m, true);
+                        if (r < 0)
+                                return r;
+
+                        if (m->fragment_path) {
+                                r = unit_add_dependency(u, UNIT_REQUIRES, m, true);
+                                if (r < 0)
+                                        return r;
+                        }
+                }
+        }
+
+        return 0;
+}
+
+static int unit_add_startup_units(Unit *u) {
+        CGroupContext *c;
+        int r;
+
+        c = unit_get_cgroup_context(u);
+        if (!c)
+                return 0;
+
+        if (c->startup_cpu_shares == CGROUP_CPU_SHARES_INVALID &&
+            c->startup_blockio_weight == CGROUP_BLKIO_WEIGHT_INVALID)
+                return 0;
+
+        r = set_ensure_allocated(&u->manager->startup_units, NULL);
+        if (r < 0)
+                return r;
+
+        return set_put(u->manager->startup_units, u);
+}
+
+int unit_load(Unit *u) {
+        int r;
+
+        assert(u);
+
+        if (u->in_load_queue) {
+                LIST_REMOVE(load_queue, u->manager->load_queue, u);
+                u->in_load_queue = false;
+        }
+
+        if (u->type == _UNIT_TYPE_INVALID)
+                return -EINVAL;
+
+        if (u->load_state != UNIT_STUB)
+                return 0;
+
+        if (UNIT_VTABLE(u)->load) {
+                r = UNIT_VTABLE(u)->load(u);
+                if (r < 0)
+                        goto fail;
+        }
+
+        if (u->load_state == UNIT_STUB) {
+                r = -ENOENT;
+                goto fail;
+        }
+
+        if (u->load_state == UNIT_LOADED) {
+
+                r = unit_add_target_dependencies(u);
+                if (r < 0)
+                        goto fail;
+
+                r = unit_add_slice_dependencies(u);
+                if (r < 0)
+                        goto fail;
+
+                r = unit_add_mount_dependencies(u);
+                if (r < 0)
+                        goto fail;
+
+                r = unit_add_startup_units(u);
+                if (r < 0)
+                        goto fail;
+
+                if (u->on_failure_job_mode == JOB_ISOLATE && set_size(u->dependencies[UNIT_ON_FAILURE]) > 1) {
+                        log_unit_error(u, "More than one OnFailure= dependencies specified but OnFailureJobMode=isolate set. Refusing.");
+                        r = -EINVAL;
+                        goto fail;
+                }
+
+                unit_update_cgroup_members_masks(u);
+        }
+
+        assert((u->load_state != UNIT_MERGED) == !u->merged_into);
+
+        unit_add_to_dbus_queue(unit_follow_merge(u));
+        unit_add_to_gc_queue(u);
+
+        return 0;
+
+fail:
+        u->load_state = u->load_state == UNIT_STUB ? UNIT_NOT_FOUND : UNIT_ERROR;
+        u->load_error = r;
+        unit_add_to_dbus_queue(u);
+        unit_add_to_gc_queue(u);
+
+        log_unit_debug_errno(u, r, "Failed to load configuration: %m");
+
+        return r;
+}
+
+static bool unit_condition_test_list(Unit *u, Condition *first, const char *(*to_string)(ConditionType t)) {
+        Condition *c;
+        int triggered = -1;
+
+        assert(u);
+        assert(to_string);
+
+        /* If the condition list is empty, then it is true */
+        if (!first)
+                return true;
+
+        /* Otherwise, if all of the non-trigger conditions apply and
+         * if any of the trigger conditions apply (unless there are
+         * none) we return true */
+        LIST_FOREACH(conditions, c, first) {
+                int r;
+
+                r = condition_test(c);
+                if (r < 0)
+                        log_unit_warning(u,
+                                         "Couldn't determine result for %s=%s%s%s, assuming failed: %m",
+                                         to_string(c->type),
+                                         c->trigger ? "|" : "",
+                                         c->negate ? "!" : "",
+                                         c->parameter);
+                else
+                        log_unit_debug(u,
+                                       "%s=%s%s%s %s.",
+                                       to_string(c->type),
+                                       c->trigger ? "|" : "",
+                                       c->negate ? "!" : "",
+                                       c->parameter,
+                                       condition_result_to_string(c->result));
+
+                if (!c->trigger && r <= 0)
+                        return false;
+
+                if (c->trigger && triggered <= 0)
+                        triggered = r > 0;
+        }
+
+        return triggered != 0;
+}
+
+static bool unit_condition_test(Unit *u) {
+        assert(u);
+
+        dual_timestamp_get(&u->condition_timestamp);
+        u->condition_result = unit_condition_test_list(u, u->conditions, condition_type_to_string);
+
+        return u->condition_result;
+}
+
+static bool unit_assert_test(Unit *u) {
+        assert(u);
+
+        dual_timestamp_get(&u->assert_timestamp);
+        u->assert_result = unit_condition_test_list(u, u->asserts, assert_type_to_string);
+
+        return u->assert_result;
+}
+
+void unit_status_printf(Unit *u, const char *status, const char *unit_status_msg_format) {
+        DISABLE_WARNING_FORMAT_NONLITERAL;
+        manager_status_printf(u->manager, STATUS_TYPE_NORMAL, status, unit_status_msg_format, unit_description(u));
+        REENABLE_WARNING;
+}
+
+_pure_ static const char* unit_get_status_message_format(Unit *u, JobType t) {
+        const char *format;
+        const UnitStatusMessageFormats *format_table;
+
+        assert(u);
+        assert(IN_SET(t, JOB_START, JOB_STOP, JOB_RELOAD));
+
+        if (t != JOB_RELOAD) {
+                format_table = &UNIT_VTABLE(u)->status_message_formats;
+                if (format_table) {
+                        format = format_table->starting_stopping[t == JOB_STOP];
+                        if (format)
+                                return format;
+                }
+        }
+
+        /* Return generic strings */
+        if (t == JOB_START)
+                return "Starting %s.";
+        else if (t == JOB_STOP)
+                return "Stopping %s.";
+        else
+                return "Reloading %s.";
+}
+
+static void unit_status_print_starting_stopping(Unit *u, JobType t) {
+        const char *format;
+
+        assert(u);
+
+        /* Reload status messages have traditionally not been printed to console. */
+        if (!IN_SET(t, JOB_START, JOB_STOP))
+                return;
+
+        format = unit_get_status_message_format(u, t);
+
+        DISABLE_WARNING_FORMAT_NONLITERAL;
+        unit_status_printf(u, "", format);
+        REENABLE_WARNING;
+}
+
+static void unit_status_log_starting_stopping_reloading(Unit *u, JobType t) {
+        const char *format;
+        char buf[LINE_MAX];
+        sd_id128_t mid;
+
+        assert(u);
+
+        if (!IN_SET(t, JOB_START, JOB_STOP, JOB_RELOAD))
+                return;
+
+        if (log_on_console())
+                return;
+
+        /* We log status messages for all units and all operations. */
+
+        format = unit_get_status_message_format(u, t);
+
+        DISABLE_WARNING_FORMAT_NONLITERAL;
+        xsprintf(buf, format, unit_description(u));
+        REENABLE_WARNING;
+
+        mid = t == JOB_START ? SD_MESSAGE_UNIT_STARTING :
+              t == JOB_STOP  ? SD_MESSAGE_UNIT_STOPPING :
+                               SD_MESSAGE_UNIT_RELOADING;
+
+        /* Note that we deliberately use LOG_MESSAGE() instead of
+         * LOG_UNIT_MESSAGE() here, since this is supposed to mimic
+         * closely what is written to screen using the status output,
+         * which is supposed the highest level, friendliest output
+         * possible, which means we should avoid the low-level unit
+         * name. */
+        log_struct(LOG_INFO,
+                   LOG_MESSAGE_ID(mid),
+                   LOG_UNIT_ID(u),
+                   LOG_MESSAGE("%s", buf),
+                   NULL);
+}
+
+void unit_status_emit_starting_stopping_reloading(Unit *u, JobType t) {
+        assert(u);
+        assert(t >= 0);
+        assert(t < _JOB_TYPE_MAX);
+
+        unit_status_log_starting_stopping_reloading(u, t);
+        unit_status_print_starting_stopping(u, t);
+}
+
+static int unit_start_limit_test(Unit *u) {
+        assert(u);
+
+        if (ratelimit_test(&u->start_limit)) {
+                u->start_limit_hit = false;
+                return 0;
+        }
+
+        log_unit_warning(u, "Start request repeated too quickly.");
+        u->start_limit_hit = true;
+
+        return failure_action(u->manager, u->start_limit_action, u->reboot_arg);
+}
+
+/* Errors:
+ *         -EBADR:      This unit type does not support starting.
+ *         -EALREADY:   Unit is already started.
+ *         -EAGAIN:     An operation is already in progress. Retry later.
+ *         -ECANCELED:  Too many requests for now.
+ *         -EPROTO:     Assert failed
+ *         -EINVAL:     Unit not loaded
+ *         -EOPNOTSUPP: Unit type not supported
+ */
+int unit_start(Unit *u) {
+        UnitActiveState state;
+        Unit *following;
+        int r;
+
+        assert(u);
+
+        /* If this is already started, then this will succeed. Note
+         * that this will even succeed if this unit is not startable
+         * by the user. This is relied on to detect when we need to
+         * wait for units and when waiting is finished. */
+        state = unit_active_state(u);
+        if (UNIT_IS_ACTIVE_OR_RELOADING(state))
+                return -EALREADY;
+
+        /* Make sure we don't enter a busy loop of some kind. */
+        r = unit_start_limit_test(u);
+        if (r < 0)
+                return r;
+
+        /* Units that aren't loaded cannot be started */
+        if (u->load_state != UNIT_LOADED)
+                return -EINVAL;
+
+        /* If the conditions failed, don't do anything at all. If we
+         * already are activating this call might still be useful to
+         * speed up activation in case there is some hold-off time,
+         * but we don't want to recheck the condition in that case. */
+        if (state != UNIT_ACTIVATING &&
+            !unit_condition_test(u)) {
+                log_unit_debug(u, "Starting requested but condition failed. Not starting unit.");
+                return -EALREADY;
+        }
+
+        /* If the asserts failed, fail the entire job */
+        if (state != UNIT_ACTIVATING &&
+            !unit_assert_test(u)) {
+                log_unit_notice(u, "Starting requested but asserts failed.");
+                return -EPROTO;
+        }
+
+        /* Units of types that aren't supported cannot be
+         * started. Note that we do this test only after the condition
+         * checks, so that we rather return condition check errors
+         * (which are usually not considered a true failure) than "not
+         * supported" errors (which are considered a failure).
+         */
+        if (!unit_supported(u))
+                return -EOPNOTSUPP;
+
+        /* Forward to the main object, if we aren't it. */
+        following = unit_following(u);
+        if (following) {
+                log_unit_debug(u, "Redirecting start request from %s to %s.", u->id, following->id);
+                return unit_start(following);
+        }
+
+        /* If it is stopped, but we cannot start it, then fail */
+        if (!UNIT_VTABLE(u)->start)
+                return -EBADR;
+
+        /* We don't suppress calls to ->start() here when we are
+         * already starting, to allow this request to be used as a
+         * "hurry up" call, for example when the unit is in some "auto
+         * restart" state where it waits for a holdoff timer to elapse
+         * before it will start again. */
+
+        unit_add_to_dbus_queue(u);
+
+        return UNIT_VTABLE(u)->start(u);
+}
+
+bool unit_can_start(Unit *u) {
+        assert(u);
+
+        if (u->load_state != UNIT_LOADED)
+                return false;
+
+        if (!unit_supported(u))
+                return false;
+
+        return !!UNIT_VTABLE(u)->start;
+}
+
+bool unit_can_isolate(Unit *u) {
+        assert(u);
+
+        return unit_can_start(u) &&
+                u->allow_isolate;
+}
+
+/* Errors:
+ *         -EBADR:    This unit type does not support stopping.
+ *         -EALREADY: Unit is already stopped.
+ *         -EAGAIN:   An operation is already in progress. Retry later.
+ */
+int unit_stop(Unit *u) {
+        UnitActiveState state;
+        Unit *following;
+
+        assert(u);
+
+        state = unit_active_state(u);
+        if (UNIT_IS_INACTIVE_OR_FAILED(state))
+                return -EALREADY;
+
+        following = unit_following(u);
+        if (following) {
+                log_unit_debug(u, "Redirecting stop request from %s to %s.", u->id, following->id);
+                return unit_stop(following);
+        }
+
+        if (!UNIT_VTABLE(u)->stop)
+                return -EBADR;
+
+        unit_add_to_dbus_queue(u);
+
+        return UNIT_VTABLE(u)->stop(u);
+}
+
+/* Errors:
+ *         -EBADR:    This unit type does not support reloading.
+ *         -ENOEXEC:  Unit is not started.
+ *         -EAGAIN:   An operation is already in progress. Retry later.
+ */
+int unit_reload(Unit *u) {
+        UnitActiveState state;
+        Unit *following;
+
+        assert(u);
+
+        if (u->load_state != UNIT_LOADED)
+                return -EINVAL;
+
+        if (!unit_can_reload(u))
+                return -EBADR;
+
+        state = unit_active_state(u);
+        if (state == UNIT_RELOADING)
+                return -EALREADY;
+
+        if (state != UNIT_ACTIVE) {
+                log_unit_warning(u, "Unit cannot be reloaded because it is inactive.");
+                return -ENOEXEC;
+        }
+
+        following = unit_following(u);
+        if (following) {
+                log_unit_debug(u, "Redirecting reload request from %s to %s.", u->id, following->id);
+                return unit_reload(following);
+        }
+
+        unit_add_to_dbus_queue(u);
+
+        return UNIT_VTABLE(u)->reload(u);
+}
+
+bool unit_can_reload(Unit *u) {
+        assert(u);
+
+        if (!UNIT_VTABLE(u)->reload)
+                return false;
+
+        if (!UNIT_VTABLE(u)->can_reload)
+                return true;
+
+        return UNIT_VTABLE(u)->can_reload(u);
+}
+
+static void unit_check_unneeded(Unit *u) {
+
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+
+        static const UnitDependency needed_dependencies[] = {
+                UNIT_REQUIRED_BY,
+                UNIT_REQUISITE_OF,
+                UNIT_WANTED_BY,
+                UNIT_BOUND_BY,
+        };
+
+        Unit *other;
+        Iterator i;
+        unsigned j;
+        int r;
+
+        assert(u);
+
+        /* If this service shall be shut down when unneeded then do
+         * so. */
+
+        if (!u->stop_when_unneeded)
+                return;
+
+        if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)))
+                return;
+
+        for (j = 0; j < ELEMENTSOF(needed_dependencies); j++)
+                SET_FOREACH(other, u->dependencies[needed_dependencies[j]], i)
+                        if (unit_active_or_pending(other))
+                                return;
+
+        /* If stopping a unit fails continously we might enter a stop
+         * loop here, hence stop acting on the service being
+         * unnecessary after a while. */
+        if (!ratelimit_test(&u->auto_stop_ratelimit)) {
+                log_unit_warning(u, "Unit not needed anymore, but not stopping since we tried this too often recently.");
+                return;
+        }
+
+        log_unit_info(u, "Unit not needed anymore. Stopping.");
+
+        /* Ok, nobody needs us anymore. Sniff. Then let's commit suicide */
+        r = manager_add_job(u->manager, JOB_STOP, u, JOB_FAIL, &error, NULL);
+        if (r < 0)
+                log_unit_warning_errno(u, r, "Failed to enqueue stop job, ignoring: %s", bus_error_message(&error, r));
+}
+
+static void unit_check_binds_to(Unit *u) {
+        _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL;
+        bool stop = false;
+        Unit *other;
+        Iterator i;
+        int r;
+
+        assert(u);
+
+        if (u->job)
+                return;
+
+        if (unit_active_state(u) != UNIT_ACTIVE)
+                return;
+
+        SET_FOREACH(other, u->dependencies[UNIT_BINDS_TO], i) {
+                if (other->job)
+                        continue;
+
+                if (!UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other)))
+                        continue;
+
+                stop = true;
+                break;
+        }
+
+        if (!stop)
+                return;
+
+        /* If stopping a unit fails continously we might enter a stop
+         * loop here, hence stop acting on the service being
+         * unnecessary after a while. */
+        if (!ratelimit_test(&u->auto_stop_ratelimit)) {
+                log_unit_warning(u, "Unit is bound to inactive unit %s, but not stopping since we tried this too often recently.", other->id);
+                return;
+        }
+
+        assert(other);
+        log_unit_info(u, "Unit is bound to inactive unit %s. Stopping, too.", other->id);
+
+        /* A unit we need to run is gone. Sniff. Let's stop this. */
+        r = manager_add_job(u->manager, JOB_STOP, u, JOB_FAIL, &error, NULL);
+        if (r < 0)
+                log_unit_warning_errno(u, r, "Failed to enqueue stop job, ignoring: %s", bus_error_message(&error, r));
+}
+
+static void retroactively_start_dependencies(Unit *u) {
+        Iterator i;
+        Unit *other;
+
+        assert(u);
+        assert(UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)));
+
+        SET_FOREACH(other, u->dependencies[UNIT_REQUIRES], i)
+                if (!set_get(u->dependencies[UNIT_AFTER], other) &&
+                    !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
+                        manager_add_job(u->manager, JOB_START, other, JOB_REPLACE, NULL, NULL);
+
+        SET_FOREACH(other, u->dependencies[UNIT_BINDS_TO], i)
+                if (!set_get(u->dependencies[UNIT_AFTER], other) &&
+                    !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
+                        manager_add_job(u->manager, JOB_START, other, JOB_REPLACE, NULL, NULL);
+
+        SET_FOREACH(other, u->dependencies[UNIT_WANTS], i)
+                if (!set_get(u->dependencies[UNIT_AFTER], other) &&
+                    !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
+                        manager_add_job(u->manager, JOB_START, other, JOB_FAIL, NULL, NULL);
+
+        SET_FOREACH(other, u->dependencies[UNIT_CONFLICTS], i)
+                if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
+                        manager_add_job(u->manager, JOB_STOP, other, JOB_REPLACE, NULL, NULL);
+
+        SET_FOREACH(other, u->dependencies[UNIT_CONFLICTED_BY], i)
+                if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
+                        manager_add_job(u->manager, JOB_STOP, other, JOB_REPLACE, NULL, NULL);
+}
+
+static void retroactively_stop_dependencies(Unit *u) {
+        Iterator i;
+        Unit *other;
+
+        assert(u);
+        assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
+
+        /* Pull down units which are bound to us recursively if enabled */
+        SET_FOREACH(other, u->dependencies[UNIT_BOUND_BY], i)
+                if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
+                        manager_add_job(u->manager, JOB_STOP, other, JOB_REPLACE, NULL, NULL);
+}
+
+static void check_unneeded_dependencies(Unit *u) {
+        Iterator i;
+        Unit *other;
+
+        assert(u);
+        assert(UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)));
+
+        /* Garbage collect services that might not be needed anymore, if enabled */
+        SET_FOREACH(other, u->dependencies[UNIT_REQUIRES], i)
+                if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
+                        unit_check_unneeded(other);
+        SET_FOREACH(other, u->dependencies[UNIT_WANTS], i)
+                if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
+                        unit_check_unneeded(other);
+        SET_FOREACH(other, u->dependencies[UNIT_REQUISITE], i)
+                if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
+                        unit_check_unneeded(other);
+        SET_FOREACH(other, u->dependencies[UNIT_BINDS_TO], i)
+                if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
+                        unit_check_unneeded(other);
+}
+
+void unit_start_on_failure(Unit *u) {
+        Unit *other;
+        Iterator i;
+
+        assert(u);
+
+        if (set_size(u->dependencies[UNIT_ON_FAILURE]) <= 0)
+                return;
+
+        log_unit_info(u, "Triggering OnFailure= dependencies.");
+
+        SET_FOREACH(other, u->dependencies[UNIT_ON_FAILURE], i) {
+                int r;
+
+                r = manager_add_job(u->manager, JOB_START, other, u->on_failure_job_mode, NULL, NULL);
+                if (r < 0)
+                        log_unit_error_errno(u, r, "Failed to enqueue OnFailure= job: %m");
+        }
+}
+
+void unit_trigger_notify(Unit *u) {
+        Unit *other;
+        Iterator i;
+
+        assert(u);
+
+        SET_FOREACH(other, u->dependencies[UNIT_TRIGGERED_BY], i)
+                if (UNIT_VTABLE(other)->trigger_notify)
+                        UNIT_VTABLE(other)->trigger_notify(other, u);
+}
+
+void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, bool reload_success) {
+        Manager *m;
+        bool unexpected;
+
+        assert(u);
+        assert(os < _UNIT_ACTIVE_STATE_MAX);
+        assert(ns < _UNIT_ACTIVE_STATE_MAX);
+
+        /* Note that this is called for all low-level state changes,
+         * even if they might map to the same high-level
+         * UnitActiveState! That means that ns == os is an expected
+         * behavior here. For example: if a mount point is remounted
+         * this function will be called too! */
+
+        m = u->manager;
+
+        /* Update timestamps for state changes */
+        if (m->n_reloading <= 0) {
+                dual_timestamp_get(&u->state_change_timestamp);
+
+                if (UNIT_IS_INACTIVE_OR_FAILED(os) && !UNIT_IS_INACTIVE_OR_FAILED(ns))
+                        u->inactive_exit_timestamp = u->state_change_timestamp;
+                else if (!UNIT_IS_INACTIVE_OR_FAILED(os) && UNIT_IS_INACTIVE_OR_FAILED(ns))
+                        u->inactive_enter_timestamp = u->state_change_timestamp;
+
+                if (!UNIT_IS_ACTIVE_OR_RELOADING(os) && UNIT_IS_ACTIVE_OR_RELOADING(ns))
+                        u->active_enter_timestamp = u->state_change_timestamp;
+                else if (UNIT_IS_ACTIVE_OR_RELOADING(os) && !UNIT_IS_ACTIVE_OR_RELOADING(ns))
+                        u->active_exit_timestamp = u->state_change_timestamp;
+        }
+
+        /* Keep track of failed units */
+        (void) manager_update_failed_units(u->manager, u, ns == UNIT_FAILED);
+
+        /* Make sure the cgroup is always removed when we become inactive */
+        if (UNIT_IS_INACTIVE_OR_FAILED(ns))
+                unit_prune_cgroup(u);
+
+        /* Note that this doesn't apply to RemainAfterExit services exiting
+         * successfully, since there's no change of state in that case. Which is
+         * why it is handled in service_set_state() */
+        if (UNIT_IS_INACTIVE_OR_FAILED(os) != UNIT_IS_INACTIVE_OR_FAILED(ns)) {
+                ExecContext *ec;
+
+                ec = unit_get_exec_context(u);
+                if (ec && exec_context_may_touch_console(ec)) {
+                        if (UNIT_IS_INACTIVE_OR_FAILED(ns)) {
+                                m->n_on_console --;
+
+                                if (m->n_on_console == 0)
+                                        /* unset no_console_output flag, since the console is free */
+                                        m->no_console_output = false;
+                        } else
+                                m->n_on_console ++;
+                }
+        }
+
+        if (u->job) {
+                unexpected = false;
+
+                if (u->job->state == JOB_WAITING)
+
+                        /* So we reached a different state for this
+                         * job. Let's see if we can run it now if it
+                         * failed previously due to EAGAIN. */
+                        job_add_to_run_queue(u->job);
+
+                /* Let's check whether this state change constitutes a
+                 * finished job, or maybe contradicts a running job and
+                 * hence needs to invalidate jobs. */
+
+                switch (u->job->type) {
+
+                case JOB_START:
+                case JOB_VERIFY_ACTIVE:
+
+                        if (UNIT_IS_ACTIVE_OR_RELOADING(ns))
+                                job_finish_and_invalidate(u->job, JOB_DONE, true);
+                        else if (u->job->state == JOB_RUNNING && ns != UNIT_ACTIVATING) {
+                                unexpected = true;
+
+                                if (UNIT_IS_INACTIVE_OR_FAILED(ns))
+                                        job_finish_and_invalidate(u->job, ns == UNIT_FAILED ? JOB_FAILED : JOB_DONE, true);
+                        }
+
+                        break;
+
+                case JOB_RELOAD:
+                case JOB_RELOAD_OR_START:
+                case JOB_TRY_RELOAD:
+
+                        if (u->job->state == JOB_RUNNING) {
+                                if (ns == UNIT_ACTIVE)
+                                        job_finish_and_invalidate(u->job, reload_success ? JOB_DONE : JOB_FAILED, true);
+                                else if (ns != UNIT_ACTIVATING && ns != UNIT_RELOADING) {
+                                        unexpected = true;
+
+                                        if (UNIT_IS_INACTIVE_OR_FAILED(ns))
+                                                job_finish_and_invalidate(u->job, ns == UNIT_FAILED ? JOB_FAILED : JOB_DONE, true);
+                                }
+                        }
+
+                        break;
+
+                case JOB_STOP:
+                case JOB_RESTART:
+                case JOB_TRY_RESTART:
+
+                        if (UNIT_IS_INACTIVE_OR_FAILED(ns))
+                                job_finish_and_invalidate(u->job, JOB_DONE, true);
+                        else if (u->job->state == JOB_RUNNING && ns != UNIT_DEACTIVATING) {
+                                unexpected = true;
+                                job_finish_and_invalidate(u->job, JOB_FAILED, true);
+                        }
+
+                        break;
+
+                default:
+                        assert_not_reached("Job type unknown");
+                }
+
+        } else
+                unexpected = true;
+
+        if (m->n_reloading <= 0) {
+
+                /* If this state change happened without being
+                 * requested by a job, then let's retroactively start
+                 * or stop dependencies. We skip that step when
+                 * deserializing, since we don't want to create any
+                 * additional jobs just because something is already
+                 * activated. */
+
+                if (unexpected) {
+                        if (UNIT_IS_INACTIVE_OR_FAILED(os) && UNIT_IS_ACTIVE_OR_ACTIVATING(ns))
+                                retroactively_start_dependencies(u);
+                        else if (UNIT_IS_ACTIVE_OR_ACTIVATING(os) && UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
+                                retroactively_stop_dependencies(u);
+                }
+
+                /* stop unneeded units regardless if going down was expected or not */
+                if (UNIT_IS_INACTIVE_OR_DEACTIVATING(ns))
+                        check_unneeded_dependencies(u);
+
+                if (ns != os && ns == UNIT_FAILED) {
+                        log_unit_notice(u, "Unit entered failed state.");
+                        unit_start_on_failure(u);
+                }
+        }
+
+        /* Some names are special */
+        if (UNIT_IS_ACTIVE_OR_RELOADING(ns)) {
+
+                if (unit_has_name(u, SPECIAL_DBUS_SERVICE))
+                        /* The bus might have just become available,
+                         * hence try to connect to it, if we aren't
+                         * yet connected. */
+                        bus_init(m, true);
+
+                if (u->type == UNIT_SERVICE &&
+                    !UNIT_IS_ACTIVE_OR_RELOADING(os) &&
+                    m->n_reloading <= 0) {
+                        /* Write audit record if we have just finished starting up */
+                        manager_send_unit_audit(m, u, AUDIT_SERVICE_START, true);
+                        u->in_audit = true;
+                }
+
+                if (!UNIT_IS_ACTIVE_OR_RELOADING(os))
+                        manager_send_unit_plymouth(m, u);
+
+        } else {
+
+                /* We don't care about D-Bus here, since we'll get an
+                 * asynchronous notification for it anyway. */
+
+                if (u->type == UNIT_SERVICE &&
+                    UNIT_IS_INACTIVE_OR_FAILED(ns) &&
+                    !UNIT_IS_INACTIVE_OR_FAILED(os) &&
+                    m->n_reloading <= 0) {
+
+                        /* Hmm, if there was no start record written
+                         * write it now, so that we always have a nice
+                         * pair */
+                        if (!u->in_audit) {
+                                manager_send_unit_audit(m, u, AUDIT_SERVICE_START, ns == UNIT_INACTIVE);
+
+                                if (ns == UNIT_INACTIVE)
+                                        manager_send_unit_audit(m, u, AUDIT_SERVICE_STOP, true);
+                        } else
+                                /* Write audit record if we have just finished shutting down */
+                                manager_send_unit_audit(m, u, AUDIT_SERVICE_STOP, ns == UNIT_INACTIVE);
+
+                        u->in_audit = false;
+                }
+        }
+
+        manager_recheck_journal(m);
+        unit_trigger_notify(u);
+
+        if (u->manager->n_reloading <= 0) {
+                /* Maybe we finished startup and are now ready for
+                 * being stopped because unneeded? */
+                unit_check_unneeded(u);
+
+                /* Maybe we finished startup, but something we needed
+                 * has vanished? Let's die then. (This happens when
+                 * something BindsTo= to a Type=oneshot unit, as these
+                 * units go directly from starting to inactive,
+                 * without ever entering started.) */
+                unit_check_binds_to(u);
+        }
+
+        unit_add_to_dbus_queue(u);
+        unit_add_to_gc_queue(u);
+}
+
+int unit_watch_pid(Unit *u, pid_t pid) {
+        int q, r;
+
+        assert(u);
+        assert(pid >= 1);
+
+        /* Watch a specific PID. We only support one or two units
+         * watching each PID for now, not more. */
+
+        r = set_ensure_allocated(&u->pids, NULL);
+        if (r < 0)
+                return r;
+
+        r = hashmap_ensure_allocated(&u->manager->watch_pids1, NULL);
+        if (r < 0)
+                return r;
+
+        r = hashmap_put(u->manager->watch_pids1, PID_TO_PTR(pid), u);
+        if (r == -EEXIST) {
+                r = hashmap_ensure_allocated(&u->manager->watch_pids2, NULL);
+                if (r < 0)
+                        return r;
+
+                r = hashmap_put(u->manager->watch_pids2, PID_TO_PTR(pid), u);
+        }
+
+        q = set_put(u->pids, PID_TO_PTR(pid));
+        if (q < 0)
+                return q;
+
+        return r;
+}
+
+void unit_unwatch_pid(Unit *u, pid_t pid) {
+        assert(u);
+        assert(pid >= 1);
+
+        (void) hashmap_remove_value(u->manager->watch_pids1, PID_TO_PTR(pid), u);
+        (void) hashmap_remove_value(u->manager->watch_pids2, PID_TO_PTR(pid), u);
+        (void) set_remove(u->pids, PID_TO_PTR(pid));
+}
+
+void unit_unwatch_all_pids(Unit *u) {
+        assert(u);
+
+        while (!set_isempty(u->pids))
+                unit_unwatch_pid(u, PTR_TO_PID(set_first(u->pids)));
+
+        u->pids = set_free(u->pids);
+}
+
+void unit_tidy_watch_pids(Unit *u, pid_t except1, pid_t except2) {
+        Iterator i;
+        void *e;
+
+        assert(u);
+
+        /* Cleans dead PIDs from our list */
+
+        SET_FOREACH(e, u->pids, i) {
+                pid_t pid = PTR_TO_PID(e);
+
+                if (pid == except1 || pid == except2)
+                        continue;
+
+                if (!pid_is_unwaited(pid))
+                        unit_unwatch_pid(u, pid);
+        }
+}
+
+bool unit_job_is_applicable(Unit *u, JobType j) {
+        assert(u);
+        assert(j >= 0 && j < _JOB_TYPE_MAX);
+
+        switch (j) {
+
+        case JOB_VERIFY_ACTIVE:
+        case JOB_START:
+        case JOB_STOP:
+        case JOB_NOP:
+                return true;
+
+        case JOB_RESTART:
+        case JOB_TRY_RESTART:
+                return unit_can_start(u);
+
+        case JOB_RELOAD:
+        case JOB_TRY_RELOAD:
+                return unit_can_reload(u);
+
+        case JOB_RELOAD_OR_START:
+                return unit_can_reload(u) && unit_can_start(u);
+
+        default:
+                assert_not_reached("Invalid job type");
+        }
+}
+
+static void maybe_warn_about_dependency(Unit *u, const char *other, UnitDependency dependency) {
+        assert(u);
+
+        /* Only warn about some unit types */
+        if (!IN_SET(dependency, UNIT_CONFLICTS, UNIT_CONFLICTED_BY, UNIT_BEFORE, UNIT_AFTER, UNIT_ON_FAILURE, UNIT_TRIGGERS, UNIT_TRIGGERED_BY))
+                return;
+
+        if (streq_ptr(u->id, other))
+                log_unit_warning(u, "Dependency %s=%s dropped", unit_dependency_to_string(dependency), u->id);
+        else
+                log_unit_warning(u, "Dependency %s=%s dropped, merged into %s", unit_dependency_to_string(dependency), strna(other), u->id);
+}
+
+int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_reference) {
+
+        static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
+                [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
+                [UNIT_WANTS] = UNIT_WANTED_BY,
+                [UNIT_REQUISITE] = UNIT_REQUISITE_OF,
+                [UNIT_BINDS_TO] = UNIT_BOUND_BY,
+                [UNIT_PART_OF] = UNIT_CONSISTS_OF,
+                [UNIT_REQUIRED_BY] = UNIT_REQUIRES,
+                [UNIT_REQUISITE_OF] = UNIT_REQUISITE,
+                [UNIT_WANTED_BY] = UNIT_WANTS,
+                [UNIT_BOUND_BY] = UNIT_BINDS_TO,
+                [UNIT_CONSISTS_OF] = UNIT_PART_OF,
+                [UNIT_CONFLICTS] = UNIT_CONFLICTED_BY,
+                [UNIT_CONFLICTED_BY] = UNIT_CONFLICTS,
+                [UNIT_BEFORE] = UNIT_AFTER,
+                [UNIT_AFTER] = UNIT_BEFORE,
+                [UNIT_ON_FAILURE] = _UNIT_DEPENDENCY_INVALID,
+                [UNIT_REFERENCES] = UNIT_REFERENCED_BY,
+                [UNIT_REFERENCED_BY] = UNIT_REFERENCES,
+                [UNIT_TRIGGERS] = UNIT_TRIGGERED_BY,
+                [UNIT_TRIGGERED_BY] = UNIT_TRIGGERS,
+                [UNIT_PROPAGATES_RELOAD_TO] = UNIT_RELOAD_PROPAGATED_FROM,
+                [UNIT_RELOAD_PROPAGATED_FROM] = UNIT_PROPAGATES_RELOAD_TO,
+                [UNIT_JOINS_NAMESPACE_OF] = UNIT_JOINS_NAMESPACE_OF,
+        };
+        int r, q = 0, v = 0, w = 0;
+        Unit *orig_u = u, *orig_other = other;
+
+        assert(u);
+        assert(d >= 0 && d < _UNIT_DEPENDENCY_MAX);
+        assert(other);
+
+        u = unit_follow_merge(u);
+        other = unit_follow_merge(other);
+
+        /* We won't allow dependencies on ourselves. We will not
+         * consider them an error however. */
+        if (u == other) {
+                maybe_warn_about_dependency(orig_u, orig_other->id, d);
+                return 0;
+        }
+
+        r = set_ensure_allocated(&u->dependencies[d], NULL);
+        if (r < 0)
+                return r;
+
+        if (inverse_table[d] != _UNIT_DEPENDENCY_INVALID) {
+                r = set_ensure_allocated(&other->dependencies[inverse_table[d]], NULL);
+                if (r < 0)
+                        return r;
+        }
+
+        if (add_reference) {
+                r = set_ensure_allocated(&u->dependencies[UNIT_REFERENCES], NULL);
+                if (r < 0)
+                        return r;
+
+                r = set_ensure_allocated(&other->dependencies[UNIT_REFERENCED_BY], NULL);
+                if (r < 0)
+                        return r;
+        }
+
+        q = set_put(u->dependencies[d], other);
+        if (q < 0)
+                return q;
+
+        if (inverse_table[d] != _UNIT_DEPENDENCY_INVALID && inverse_table[d] != d) {
+                v = set_put(other->dependencies[inverse_table[d]], u);
+                if (v < 0) {
+                        r = v;
+                        goto fail;
+                }
+        }
+
+        if (add_reference) {
+                w = set_put(u->dependencies[UNIT_REFERENCES], other);
+                if (w < 0) {
+                        r = w;
+                        goto fail;
+                }
+
+                r = set_put(other->dependencies[UNIT_REFERENCED_BY], u);
+                if (r < 0)
+                        goto fail;
+        }
+
+        unit_add_to_dbus_queue(u);
+        return 0;
+
+fail:
+        if (q > 0)
+                set_remove(u->dependencies[d], other);
+
+        if (v > 0)
+                set_remove(other->dependencies[inverse_table[d]], u);
+
+        if (w > 0)
+                set_remove(u->dependencies[UNIT_REFERENCES], other);
+
+        return r;
+}
+
+int unit_add_two_dependencies(Unit *u, UnitDependency d, UnitDependency e, Unit *other, bool add_reference) {
+        int r;
+
+        assert(u);
+
+        r = unit_add_dependency(u, d, other, add_reference);
+        if (r < 0)
+                return r;
+
+        return unit_add_dependency(u, e, other, add_reference);
+}
+
+static int resolve_template(Unit *u, const char *name, const char*path, char **buf, const char **ret) {
+        int r;
+
+        assert(u);
+        assert(name || path);
+        assert(buf);
+        assert(ret);
+
+        if (!name)
+                name = basename(path);
+
+        if (!unit_name_is_valid(name, UNIT_NAME_TEMPLATE)) {
+                *buf = NULL;
+                *ret = name;
+                return 0;
+        }
+
+        if (u->instance)
+                r = unit_name_replace_instance(name, u->instance, buf);
+        else {
+                _cleanup_free_ char *i = NULL;
+
+                r = unit_name_to_prefix(u->id, &i);
+                if (r < 0)
+                        return r;
+
+                r = unit_name_replace_instance(name, i, buf);
+        }
+        if (r < 0)
+                return r;
+
+        *ret = *buf;
+        return 0;
+}
+
+int unit_add_dependency_by_name(Unit *u, UnitDependency d, const char *name, const char *path, bool add_reference) {
+        _cleanup_free_ char *buf = NULL;
+        Unit *other;
+        int r;
+
+        assert(u);
+        assert(name || path);
+
+        r = resolve_template(u, name, path, &buf, &name);
+        if (r < 0)
+                return r;
+
+        r = manager_load_unit(u->manager, name, path, NULL, &other);
+        if (r < 0)
+                return r;
+
+        return unit_add_dependency(u, d, other, add_reference);
+}
+
+int unit_add_two_dependencies_by_name(Unit *u, UnitDependency d, UnitDependency e, const char *name, const char *path, bool add_reference) {
+        _cleanup_free_ char *buf = NULL;
+        Unit *other;
+        int r;
+
+        assert(u);
+        assert(name || path);
+
+        r = resolve_template(u, name, path, &buf, &name);
+        if (r < 0)
+                return r;
+
+        r = manager_load_unit(u->manager, name, path, NULL, &other);
+        if (r < 0)
+                return r;
+
+        return unit_add_two_dependencies(u, d, e, other, add_reference);
+}
+
+int set_unit_path(const char *p) {
+        /* This is mostly for debug purposes */
+        if (setenv("SYSTEMD_UNIT_PATH", p, 1) < 0)
+                return -errno;
+
+        return 0;
+}
+
+char *unit_dbus_path(Unit *u) {
+        assert(u);
+
+        if (!u->id)
+                return NULL;
+
+        return unit_dbus_path_from_name(u->id);
+}
+
+int unit_set_slice(Unit *u, Unit *slice) {
+        assert(u);
+        assert(slice);
+
+        /* Sets the unit slice if it has not been set before. Is extra
+         * careful, to only allow this for units that actually have a
+         * cgroup context. Also, we don't allow to set this for slices
+         * (since the parent slice is derived from the name). Make
+         * sure the unit we set is actually a slice. */
+
+        if (!UNIT_HAS_CGROUP_CONTEXT(u))
+                return -EOPNOTSUPP;
+
+        if (u->type == UNIT_SLICE)
+                return -EINVAL;
+
+        if (unit_active_state(u) != UNIT_INACTIVE)
+                return -EBUSY;
+
+        if (slice->type != UNIT_SLICE)
+                return -EINVAL;
+
+        if (unit_has_name(u, SPECIAL_INIT_SCOPE) &&
+            !unit_has_name(slice, SPECIAL_ROOT_SLICE))
+                return -EPERM;
+
+        if (UNIT_DEREF(u->slice) == slice)
+                return 0;
+
+        if (UNIT_ISSET(u->slice))
+                return -EBUSY;
+
+        unit_ref_set(&u->slice, slice);
+        return 1;
+}
+
+int unit_set_default_slice(Unit *u) {
+        _cleanup_free_ char *b = NULL;
+        const char *slice_name;
+        Unit *slice;
+        int r;
+
+        assert(u);
+
+        if (UNIT_ISSET(u->slice))
+                return 0;
+
+        if (u->instance) {
+                _cleanup_free_ char *prefix = NULL, *escaped = NULL;
+
+                /* Implicitly place all instantiated units in their
+                 * own per-template slice */
+
+                r = unit_name_to_prefix(u->id, &prefix);
+                if (r < 0)
+                        return r;
+
+                /* The prefix is already escaped, but it might include
+                 * "-" which has a special meaning for slice units,
+                 * hence escape it here extra. */
+                escaped = unit_name_escape(prefix);
+                if (!escaped)
+                        return -ENOMEM;
+
+                if (u->manager->running_as == MANAGER_SYSTEM)
+                        b = strjoin("system-", escaped, ".slice", NULL);
+                else
+                        b = strappend(escaped, ".slice");
+                if (!b)
+                        return -ENOMEM;
+
+                slice_name = b;
+        } else
+                slice_name =
+                        u->manager->running_as == MANAGER_SYSTEM && !unit_has_name(u, SPECIAL_INIT_SCOPE)
+                        ? SPECIAL_SYSTEM_SLICE
+                        : SPECIAL_ROOT_SLICE;
+
+        r = manager_load_unit(u->manager, slice_name, NULL, NULL, &slice);
+        if (r < 0)
+                return r;
+
+        return unit_set_slice(u, slice);
+}
+
+const char *unit_slice_name(Unit *u) {
+        assert(u);
+
+        if (!UNIT_ISSET(u->slice))
+                return NULL;
+
+        return UNIT_DEREF(u->slice)->id;
+}
+
+int unit_load_related_unit(Unit *u, const char *type, Unit **_found) {
+        _cleanup_free_ char *t = NULL;
+        int r;
+
+        assert(u);
+        assert(type);
+        assert(_found);
+
+        r = unit_name_change_suffix(u->id, type, &t);
+        if (r < 0)
+                return r;
+        if (unit_has_name(u, t))
+                return -EINVAL;
+
+        r = manager_load_unit(u->manager, t, NULL, NULL, _found);
+        assert(r < 0 || *_found != u);
+        return r;
+}
+
+static int signal_name_owner_changed(sd_bus_message *message, void *userdata, sd_bus_error *error) {
+        const char *name, *old_owner, *new_owner;
+        Unit *u = userdata;
+        int r;
+
+        assert(message);
+        assert(u);
+
+        r = sd_bus_message_read(message, "sss", &name, &old_owner, &new_owner);
+        if (r < 0) {
+                bus_log_parse_error(r);
+                return 0;
+        }
+
+        if (UNIT_VTABLE(u)->bus_name_owner_change)
+                UNIT_VTABLE(u)->bus_name_owner_change(u, name, old_owner, new_owner);
+
+        return 0;
+}
+
+int unit_install_bus_match(Unit *u, sd_bus *bus, const char *name) {
+        const char *match;
+
+        assert(u);
+        assert(bus);
+        assert(name);
+
+        if (u->match_bus_slot)
+                return -EBUSY;
+
+        match = strjoina("type='signal',"
+                        "sender='org.freedesktop.DBus',"
+                        "path='/org/freedesktop/DBus',"
+                        "interface='org.freedesktop.DBus',"
+                        "member='NameOwnerChanged',"
+                        "arg0='", name, "'",
+                        NULL);
+
+        return sd_bus_add_match(bus, &u->match_bus_slot, match, signal_name_owner_changed, u);
+}
+
+int unit_watch_bus_name(Unit *u, const char *name) {
+        int r;
+
+        assert(u);
+        assert(name);
+
+        /* Watch a specific name on the bus. We only support one unit
+         * watching each name for now. */
+
+        if (u->manager->api_bus) {
+                /* If the bus is already available, install the match directly.
+                 * Otherwise, just put the name in the list. bus_setup_api() will take care later. */
+                r = unit_install_bus_match(u, u->manager->api_bus, name);
+                if (r < 0)
+                        return log_warning_errno(r, "Failed to subscribe to NameOwnerChanged signal for '%s': %m", name);
+        }
+
+        r = hashmap_put(u->manager->watch_bus, name, u);
+        if (r < 0) {
+                u->match_bus_slot = sd_bus_slot_unref(u->match_bus_slot);
+                return log_warning_errno(r, "Failed to put bus name to hashmap: %m");
+        }
+
+        return 0;
+}
+
+void unit_unwatch_bus_name(Unit *u, const char *name) {
+        assert(u);
+        assert(name);
+
+        hashmap_remove_value(u->manager->watch_bus, name, u);
+        u->match_bus_slot = sd_bus_slot_unref(u->match_bus_slot);
+}
+
+bool unit_can_serialize(Unit *u) {
+        assert(u);
+
+        return UNIT_VTABLE(u)->serialize && UNIT_VTABLE(u)->deserialize_item;
+}
+
+int unit_serialize(Unit *u, FILE *f, FDSet *fds, bool serialize_jobs) {
+        int r;
+
+        assert(u);
+        assert(f);
+        assert(fds);
+
+        if (unit_can_serialize(u)) {
+                ExecRuntime *rt;
+
+                r = UNIT_VTABLE(u)->serialize(u, f, fds);
+                if (r < 0)
+                        return r;
+
+                rt = unit_get_exec_runtime(u);
+                if (rt) {
+                        r = exec_runtime_serialize(u, rt, f, fds);
+                        if (r < 0)
+                                return r;
+                }
+        }
+
+        dual_timestamp_serialize(f, "state-change-timestamp", &u->state_change_timestamp);
+
+        dual_timestamp_serialize(f, "inactive-exit-timestamp", &u->inactive_exit_timestamp);
+        dual_timestamp_serialize(f, "active-enter-timestamp", &u->active_enter_timestamp);
+        dual_timestamp_serialize(f, "active-exit-timestamp", &u->active_exit_timestamp);
+        dual_timestamp_serialize(f, "inactive-enter-timestamp", &u->inactive_enter_timestamp);
+
+        dual_timestamp_serialize(f, "condition-timestamp", &u->condition_timestamp);
+        dual_timestamp_serialize(f, "assert-timestamp", &u->assert_timestamp);
+
+        if (dual_timestamp_is_set(&u->condition_timestamp))
+                unit_serialize_item(u, f, "condition-result", yes_no(u->condition_result));
+
+        if (dual_timestamp_is_set(&u->assert_timestamp))
+                unit_serialize_item(u, f, "assert-result", yes_no(u->assert_result));
+
+        unit_serialize_item(u, f, "transient", yes_no(u->transient));
+        unit_serialize_item_format(u, f, "cpuacct-usage-base", "%" PRIu64, u->cpuacct_usage_base);
+
+        if (u->cgroup_path)
+                unit_serialize_item(u, f, "cgroup", u->cgroup_path);
+        unit_serialize_item(u, f, "cgroup-realized", yes_no(u->cgroup_realized));
+
+        if (serialize_jobs) {
+                if (u->job) {
+                        fprintf(f, "job\n");
+                        job_serialize(u->job, f, fds);
+                }
+
+                if (u->nop_job) {
+                        fprintf(f, "job\n");
+                        job_serialize(u->nop_job, f, fds);
+                }
+        }
+
+        /* End marker */
+        fputc('\n', f);
+        return 0;
+}
+
+int unit_serialize_item(Unit *u, FILE *f, const char *key, const char *value) {
+        assert(u);
+        assert(f);
+        assert(key);
+
+        if (!value)
+                return 0;
+
+        fputs(key, f);
+        fputc('=', f);
+        fputs(value, f);
+        fputc('\n', f);
+
+        return 1;
+}
+
+int unit_serialize_item_escaped(Unit *u, FILE *f, const char *key, const char *value) {
+        _cleanup_free_ char *c = NULL;
+
+        assert(u);
+        assert(f);
+        assert(key);
+
+        if (!value)
+                return 0;
+
+        c = cescape(value);
+        if (!c)
+                return -ENOMEM;
+
+        fputs(key, f);
+        fputc('=', f);
+        fputs(c, f);
+        fputc('\n', f);
+
+        return 1;
+}
+
+int unit_serialize_item_fd(Unit *u, FILE *f, FDSet *fds, const char *key, int fd) {
+        int copy;
+
+        assert(u);
+        assert(f);
+        assert(key);
+
+        if (fd < 0)
+                return 0;
+
+        copy = fdset_put_dup(fds, fd);
+        if (copy < 0)
+                return copy;
+
+        fprintf(f, "%s=%i\n", key, copy);
+        return 1;
+}
+
+void unit_serialize_item_format(Unit *u, FILE *f, const char *key, const char *format, ...) {
+        va_list ap;
+
+        assert(u);
+        assert(f);
+        assert(key);
+        assert(format);
+
+        fputs(key, f);
+        fputc('=', f);
+
+        va_start(ap, format);
+        vfprintf(f, format, ap);
+        va_end(ap);
+
+        fputc('\n', f);
+}
+
+int unit_deserialize(Unit *u, FILE *f, FDSet *fds) {
+        ExecRuntime **rt = NULL;
+        size_t offset;
+        int r;
+
+        assert(u);
+        assert(f);
+        assert(fds);
+
+        offset = UNIT_VTABLE(u)->exec_runtime_offset;
+        if (offset > 0)
+                rt = (ExecRuntime**) ((uint8_t*) u + offset);
+
+        for (;;) {
+                char line[LINE_MAX], *l, *v;
+                size_t k;
+
+                if (!fgets(line, sizeof(line), f)) {
+                        if (feof(f))
+                                return 0;
+                        return -errno;
+                }
+
+                char_array_0(line);
+                l = strstrip(line);
+
+                /* End marker */
+                if (isempty(l))
+                        break;
+
+                k = strcspn(l, "=");
+
+                if (l[k] == '=') {
+                        l[k] = 0;
+                        v = l+k+1;
+                } else
+                        v = l+k;
+
+                if (streq(l, "job")) {
+                        if (v[0] == '\0') {
+                                /* new-style serialized job */
+                                Job *j;
+
+                                j = job_new_raw(u);
+                                if (!j)
+                                        return log_oom();
+
+                                r = job_deserialize(j, f, fds);
+                                if (r < 0) {
+                                        job_free(j);
+                                        return r;
+                                }
+
+                                r = hashmap_put(u->manager->jobs, UINT32_TO_PTR(j->id), j);
+                                if (r < 0) {
+                                        job_free(j);
+                                        return r;
+                                }
+
+                                r = job_install_deserialized(j);
+                                if (r < 0) {
+                                        hashmap_remove(u->manager->jobs, UINT32_TO_PTR(j->id));
+                                        job_free(j);
+                                        return r;
+                                }
+                        } else  /* legacy for pre-44 */
+                                log_unit_warning(u, "Update from too old systemd versions are unsupported, cannot deserialize job: %s", v);
+                        continue;
+                } else if (streq(l, "state-change-timestamp")) {
+                        dual_timestamp_deserialize(v, &u->state_change_timestamp);
+                        continue;
+                } else if (streq(l, "inactive-exit-timestamp")) {
+                        dual_timestamp_deserialize(v, &u->inactive_exit_timestamp);
+                        continue;
+                } else if (streq(l, "active-enter-timestamp")) {
+                        dual_timestamp_deserialize(v, &u->active_enter_timestamp);
+                        continue;
+                } else if (streq(l, "active-exit-timestamp")) {
+                        dual_timestamp_deserialize(v, &u->active_exit_timestamp);
+                        continue;
+                } else if (streq(l, "inactive-enter-timestamp")) {
+                        dual_timestamp_deserialize(v, &u->inactive_enter_timestamp);
+                        continue;
+                } else if (streq(l, "condition-timestamp")) {
+                        dual_timestamp_deserialize(v, &u->condition_timestamp);
+                        continue;
+                } else if (streq(l, "assert-timestamp")) {
+                        dual_timestamp_deserialize(v, &u->assert_timestamp);
+                        continue;
+                } else if (streq(l, "condition-result")) {
+
+                        r = parse_boolean(v);
+                        if (r < 0)
+                                log_unit_debug(u, "Failed to parse condition result value %s, ignoring.", v);
+                        else
+                                u->condition_result = r;
+
+                        continue;
+
+                } else if (streq(l, "assert-result")) {
+
+                        r = parse_boolean(v);
+                        if (r < 0)
+                                log_unit_debug(u, "Failed to parse assert result value %s, ignoring.", v);
+                        else
+                                u->assert_result = r;
+
+                        continue;
+
+                } else if (streq(l, "transient")) {
+
+                        r = parse_boolean(v);
+                        if (r < 0)
+                                log_unit_debug(u, "Failed to parse transient bool %s, ignoring.", v);
+                        else
+                                u->transient = r;
+
+                        continue;
+
+                } else if (streq(l, "cpuacct-usage-base")) {
+
+                        r = safe_atou64(v, &u->cpuacct_usage_base);
+                        if (r < 0)
+                                log_unit_debug(u, "Failed to parse CPU usage %s, ignoring.", v);
+
+                        continue;
+
+                } else if (streq(l, "cgroup")) {
+
+                        r = unit_set_cgroup_path(u, v);
+                        if (r < 0)
+                                log_unit_debug_errno(u, r, "Failed to set cgroup path %s, ignoring: %m", v);
+
+                        (void) unit_watch_cgroup(u);
+
+                        continue;
+                } else if (streq(l, "cgroup-realized")) {
+                        int b;
+
+                        b = parse_boolean(v);
+                        if (b < 0)
+                                log_unit_debug(u, "Failed to parse cgroup-realized bool %s, ignoring.", v);
+                        else
+                                u->cgroup_realized = b;
+
+                        continue;
+                }
+
+                if (unit_can_serialize(u)) {
+                        if (rt) {
+                                r = exec_runtime_deserialize_item(u, rt, l, v, fds);
+                                if (r < 0) {
+                                        log_unit_warning(u, "Failed to deserialize runtime parameter '%s', ignoring.", l);
+                                        continue;
+                                }
+
+                                /* Returns positive if key was handled by the call */
+                                if (r > 0)
+                                        continue;
+                        }
+
+                        r = UNIT_VTABLE(u)->deserialize_item(u, l, v, fds);
+                        if (r < 0)
+                                log_unit_warning(u, "Failed to deserialize unit parameter '%s', ignoring.", l);
+                }
+        }
+
+        /* Versions before 228 did not carry a state change timestamp. In this case, take the current time. This is
+         * useful, so that timeouts based on this timestamp don't trigger too early, and is in-line with the logic from
+         * before 228 where the base for timeouts was not persistent across reboots. */
+
+        if (!dual_timestamp_is_set(&u->state_change_timestamp))
+                dual_timestamp_get(&u->state_change_timestamp);
+
+        return 0;
+}
+
+int unit_add_node_link(Unit *u, const char *what, bool wants, UnitDependency dep) {
+        Unit *device;
+        _cleanup_free_ char *e = NULL;
+        int r;
+
+        assert(u);
+
+        /* Adds in links to the device node that this unit is based on */
+        if (isempty(what))
+                return 0;
+
+        if (!is_device_path(what))
+                return 0;
+
+        /* When device units aren't supported (such as in a
+         * container), don't create dependencies on them. */
+        if (!unit_type_supported(UNIT_DEVICE))
+                return 0;
+
+        r = unit_name_from_path(what, ".device", &e);
+        if (r < 0)
+                return r;
+
+        r = manager_load_unit(u->manager, e, NULL, NULL, &device);
+        if (r < 0)
+                return r;
+
+        r = unit_add_two_dependencies(u, UNIT_AFTER,
+                                      u->manager->running_as == MANAGER_SYSTEM ? dep : UNIT_WANTS,
+                                      device, true);
+        if (r < 0)
+                return r;
+
+        if (wants) {
+                r = unit_add_dependency(device, UNIT_WANTS, u, false);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+int unit_coldplug(Unit *u) {
+        int r = 0, q = 0;
+
+        assert(u);
+
+        /* Make sure we don't enter a loop, when coldplugging
+         * recursively. */
+        if (u->coldplugged)
+                return 0;
+
+        u->coldplugged = true;
+
+        if (UNIT_VTABLE(u)->coldplug)
+                r = UNIT_VTABLE(u)->coldplug(u);
+
+        if (u->job)
+                q = job_coldplug(u->job);
+
+        if (r < 0)
+                return r;
+        if (q < 0)
+                return q;
+
+        return 0;
+}
+
+bool unit_need_daemon_reload(Unit *u) {
+        _cleanup_strv_free_ char **t = NULL;
+        char **path;
+        struct stat st;
+        unsigned loaded_cnt, current_cnt;
+
+        assert(u);
+
+        if (u->fragment_path) {
+                zero(st);
+                if (stat(u->fragment_path, &st) < 0)
+                        /* What, cannot access this anymore? */
+                        return true;
+
+                if (u->fragment_mtime > 0 &&
+                    timespec_load(&st.st_mtim) != u->fragment_mtime)
+                        return true;
+        }
+
+        if (u->source_path) {
+                zero(st);
+                if (stat(u->source_path, &st) < 0)
+                        return true;
+
+                if (u->source_mtime > 0 &&
+                    timespec_load(&st.st_mtim) != u->source_mtime)
+                        return true;
+        }
+
+        (void) unit_find_dropin_paths(u, &t);
+        loaded_cnt = strv_length(t);
+        current_cnt = strv_length(u->dropin_paths);
+
+        if (loaded_cnt == current_cnt) {
+                if (loaded_cnt == 0)
+                        return false;
+
+                if (strv_overlap(u->dropin_paths, t)) {
+                        STRV_FOREACH(path, u->dropin_paths) {
+                                zero(st);
+                                if (stat(*path, &st) < 0)
+                                        return true;
+
+                                if (u->dropin_mtime > 0 &&
+                                    timespec_load(&st.st_mtim) > u->dropin_mtime)
+                                        return true;
+                        }
+
+                        return false;
+                } else
+                        return true;
+        } else
+                return true;
+}
+
+void unit_reset_failed(Unit *u) {
+        assert(u);
+
+        if (UNIT_VTABLE(u)->reset_failed)
+                UNIT_VTABLE(u)->reset_failed(u);
+
+        RATELIMIT_RESET(u->start_limit);
+        u->start_limit_hit = false;
+}
+
+Unit *unit_following(Unit *u) {
+        assert(u);
+
+        if (UNIT_VTABLE(u)->following)
+                return UNIT_VTABLE(u)->following(u);
+
+        return NULL;
+}
+
+bool unit_stop_pending(Unit *u) {
+        assert(u);
+
+        /* This call does check the current state of the unit. It's
+         * hence useful to be called from state change calls of the
+         * unit itself, where the state isn't updated yet. This is
+         * different from unit_inactive_or_pending() which checks both
+         * the current state and for a queued job. */
+
+        return u->job && u->job->type == JOB_STOP;
+}
+
+bool unit_inactive_or_pending(Unit *u) {
+        assert(u);
+
+        /* Returns true if the unit is inactive or going down */
+
+        if (UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(u)))
+                return true;
+
+        if (unit_stop_pending(u))
+                return true;
+
+        return false;
+}
+
+bool unit_active_or_pending(Unit *u) {
+        assert(u);
+
+        /* Returns true if the unit is active or going up */
+
+        if (UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u)))
+                return true;
+
+        if (u->job &&
+            (u->job->type == JOB_START ||
+             u->job->type == JOB_RELOAD_OR_START ||
+             u->job->type == JOB_RESTART))
+                return true;
+
+        return false;
+}
+
+int unit_kill(Unit *u, KillWho w, int signo, sd_bus_error *error) {
+        assert(u);
+        assert(w >= 0 && w < _KILL_WHO_MAX);
+        assert(signo > 0);
+        assert(signo < _NSIG);
+
+        if (!UNIT_VTABLE(u)->kill)
+                return -EOPNOTSUPP;
+
+        return UNIT_VTABLE(u)->kill(u, w, signo, error);
+}
+
+static Set *unit_pid_set(pid_t main_pid, pid_t control_pid) {
+        Set *pid_set;
+        int r;
+
+        pid_set = set_new(NULL);
+        if (!pid_set)
+                return NULL;
+
+        /* Exclude the main/control pids from being killed via the cgroup */
+        if (main_pid > 0) {
+                r = set_put(pid_set, PID_TO_PTR(main_pid));
+                if (r < 0)
+                        goto fail;
+        }
+
+        if (control_pid > 0) {
+                r = set_put(pid_set, PID_TO_PTR(control_pid));
+                if (r < 0)
+                        goto fail;
+        }
+
+        return pid_set;
+
+fail:
+        set_free(pid_set);
+        return NULL;
+}
+
+int unit_kill_common(
+                Unit *u,
+                KillWho who,
+                int signo,
+                pid_t main_pid,
+                pid_t control_pid,
+                sd_bus_error *error) {
+
+        int r = 0;
+        bool killed = false;
+
+        if (IN_SET(who, KILL_MAIN, KILL_MAIN_FAIL)) {
+                if (main_pid < 0)
+                        return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_PROCESS, "%s units have no main processes", unit_type_to_string(u->type));
+                else if (main_pid == 0)
+                        return sd_bus_error_set_const(error, BUS_ERROR_NO_SUCH_PROCESS, "No main process to kill");
+        }
+
+        if (IN_SET(who, KILL_CONTROL, KILL_CONTROL_FAIL)) {
+                if (control_pid < 0)
+                        return sd_bus_error_setf(error, BUS_ERROR_NO_SUCH_PROCESS, "%s units have no control processes", unit_type_to_string(u->type));
+                else if (control_pid == 0)
+                        return sd_bus_error_set_const(error, BUS_ERROR_NO_SUCH_PROCESS, "No control process to kill");
+        }
+
+        if (IN_SET(who, KILL_CONTROL, KILL_CONTROL_FAIL, KILL_ALL, KILL_ALL_FAIL))
+                if (control_pid > 0) {
+                        if (kill(control_pid, signo) < 0)
+                                r = -errno;
+                        else
+                                killed = true;
+                }
+
+        if (IN_SET(who, KILL_MAIN, KILL_MAIN_FAIL, KILL_ALL, KILL_ALL_FAIL))
+                if (main_pid > 0) {
+                        if (kill(main_pid, signo) < 0)
+                                r = -errno;
+                        else
+                                killed = true;
+                }
+
+        if (IN_SET(who, KILL_ALL, KILL_ALL_FAIL) && u->cgroup_path) {
+                _cleanup_set_free_ Set *pid_set = NULL;
+                int q;
+
+                /* Exclude the main/control pids from being killed via the cgroup */
+                pid_set = unit_pid_set(main_pid, control_pid);
+                if (!pid_set)
+                        return -ENOMEM;
+
+                q = cg_kill_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, signo, false, false, false, pid_set);
+                if (q < 0 && q != -EAGAIN && q != -ESRCH && q != -ENOENT)
+                        r = q;
+                else
+                        killed = true;
+        }
+
+        if (r == 0 && !killed && IN_SET(who, KILL_ALL_FAIL, KILL_CONTROL_FAIL))
+                return -ESRCH;
+
+        return r;
+}
+
+int unit_following_set(Unit *u, Set **s) {
+        assert(u);
+        assert(s);
+
+        if (UNIT_VTABLE(u)->following_set)
+                return UNIT_VTABLE(u)->following_set(u, s);
+
+        *s = NULL;
+        return 0;
+}
+
+UnitFileState unit_get_unit_file_state(Unit *u) {
+        int r;
+
+        assert(u);
+
+        if (u->unit_file_state < 0 && u->fragment_path) {
+                r = unit_file_get_state(
+                                u->manager->running_as == MANAGER_SYSTEM ? UNIT_FILE_SYSTEM : UNIT_FILE_USER,
+                                NULL,
+                                basename(u->fragment_path),
+                                &u->unit_file_state);
+                if (r < 0)
+                        u->unit_file_state = UNIT_FILE_BAD;
+        }
+
+        return u->unit_file_state;
+}
+
+int unit_get_unit_file_preset(Unit *u) {
+        assert(u);
+
+        if (u->unit_file_preset < 0 && u->fragment_path)
+                u->unit_file_preset = unit_file_query_preset(
+                                u->manager->running_as == MANAGER_SYSTEM ? UNIT_FILE_SYSTEM : UNIT_FILE_USER,
+                                NULL,
+                                basename(u->fragment_path));
+
+        return u->unit_file_preset;
+}
+
+Unit* unit_ref_set(UnitRef *ref, Unit *u) {
+        assert(ref);
+        assert(u);
+
+        if (ref->unit)
+                unit_ref_unset(ref);
+
+        ref->unit = u;
+        LIST_PREPEND(refs, u->refs, ref);
+        return u;
+}
+
+void unit_ref_unset(UnitRef *ref) {
+        assert(ref);
+
+        if (!ref->unit)
+                return;
+
+        LIST_REMOVE(refs, ref->unit->refs, ref);
+        ref->unit = NULL;
+}
+
+int unit_patch_contexts(Unit *u) {
+        CGroupContext *cc;
+        ExecContext *ec;
+        unsigned i;
+        int r;
+
+        assert(u);
+
+        /* Patch in the manager defaults into the exec and cgroup
+         * contexts, _after_ the rest of the settings have been
+         * initialized */
+
+        ec = unit_get_exec_context(u);
+        if (ec) {
+                /* This only copies in the ones that need memory */
+                for (i = 0; i < _RLIMIT_MAX; i++)
+                        if (u->manager->rlimit[i] && !ec->rlimit[i]) {
+                                ec->rlimit[i] = newdup(struct rlimit, u->manager->rlimit[i], 1);
+                                if (!ec->rlimit[i])
+                                        return -ENOMEM;
+                        }
+
+                if (u->manager->running_as == MANAGER_USER &&
+                    !ec->working_directory) {
+
+                        r = get_home_dir(&ec->working_directory);
+                        if (r < 0)
+                                return r;
+
+                        /* Allow user services to run, even if the
+                         * home directory is missing */
+                        ec->working_directory_missing_ok = true;
+                }
+
+                if (u->manager->running_as == MANAGER_USER &&
+                    (ec->syscall_whitelist ||
+                     !set_isempty(ec->syscall_filter) ||
+                     !set_isempty(ec->syscall_archs) ||
+                     ec->address_families_whitelist ||
+                     !set_isempty(ec->address_families)))
+                        ec->no_new_privileges = true;
+
+                if (ec->private_devices)
+                        ec->capability_bounding_set &= ~(UINT64_C(1) << CAP_MKNOD);
+        }
+
+        cc = unit_get_cgroup_context(u);
+        if (cc) {
+
+                if (ec &&
+                    ec->private_devices &&
+                    cc->device_policy == CGROUP_AUTO)
+                        cc->device_policy = CGROUP_CLOSED;
+        }
+
+        return 0;
+}
+
+ExecContext *unit_get_exec_context(Unit *u) {
+        size_t offset;
+        assert(u);
+
+        if (u->type < 0)
+                return NULL;
+
+        offset = UNIT_VTABLE(u)->exec_context_offset;
+        if (offset <= 0)
+                return NULL;
+
+        return (ExecContext*) ((uint8_t*) u + offset);
+}
+
+KillContext *unit_get_kill_context(Unit *u) {
+        size_t offset;
+        assert(u);
+
+        if (u->type < 0)
+                return NULL;
+
+        offset = UNIT_VTABLE(u)->kill_context_offset;
+        if (offset <= 0)
+                return NULL;
+
+        return (KillContext*) ((uint8_t*) u + offset);
+}
+
+CGroupContext *unit_get_cgroup_context(Unit *u) {
+        size_t offset;
+
+        if (u->type < 0)
+                return NULL;
+
+        offset = UNIT_VTABLE(u)->cgroup_context_offset;
+        if (offset <= 0)
+                return NULL;
+
+        return (CGroupContext*) ((uint8_t*) u + offset);
+}
+
+ExecRuntime *unit_get_exec_runtime(Unit *u) {
+        size_t offset;
+
+        if (u->type < 0)
+                return NULL;
+
+        offset = UNIT_VTABLE(u)->exec_runtime_offset;
+        if (offset <= 0)
+                return NULL;
+
+        return *(ExecRuntime**) ((uint8_t*) u + offset);
+}
+
+static int unit_drop_in_dir(Unit *u, UnitSetPropertiesMode mode, bool transient, char **dir) {
+        assert(u);
+
+        if (u->manager->running_as == MANAGER_USER) {
+                int r;
+
+                if (mode == UNIT_PERSISTENT && !transient)
+                        r = user_config_home(dir);
+                else
+                        r = user_runtime_dir(dir);
+                if (r == 0)
+                        return -ENOENT;
+
+                return r;
+        }
+
+        if (mode == UNIT_PERSISTENT && !transient)
+                *dir = strdup("/etc/systemd/system");
+        else
+                *dir = strdup("/run/systemd/system");
+        if (!*dir)
+                return -ENOMEM;
+
+        return 0;
+}
+
+int unit_write_drop_in(Unit *u, UnitSetPropertiesMode mode, const char *name, const char *data) {
+
+        _cleanup_free_ char *dir = NULL, *p = NULL, *q = NULL;
+        int r;
+
+        assert(u);
+
+        if (!IN_SET(mode, UNIT_PERSISTENT, UNIT_RUNTIME))
+                return 0;
+
+        r = unit_drop_in_dir(u, mode, u->transient, &dir);
+        if (r < 0)
+                return r;
+
+        r = write_drop_in(dir, u->id, 50, name, data);
+        if (r < 0)
+                return r;
+
+        r = drop_in_file(dir, u->id, 50, name, &p, &q);
+        if (r < 0)
+                return r;
+
+        r = strv_extend(&u->dropin_paths, q);
+        if (r < 0)
+                return r;
+
+        strv_sort(u->dropin_paths);
+        strv_uniq(u->dropin_paths);
+
+        u->dropin_mtime = now(CLOCK_REALTIME);
+
+        return 0;
+}
+
+int unit_write_drop_in_format(Unit *u, UnitSetPropertiesMode mode, const char *name, const char *format, ...) {
+        _cleanup_free_ char *p = NULL;
+        va_list ap;
+        int r;
+
+        assert(u);
+        assert(name);
+        assert(format);
+
+        if (!IN_SET(mode, UNIT_PERSISTENT, UNIT_RUNTIME))
+                return 0;
+
+        va_start(ap, format);
+        r = vasprintf(&p, format, ap);
+        va_end(ap);
+
+        if (r < 0)
+                return -ENOMEM;
+
+        return unit_write_drop_in(u, mode, name, p);
+}
+
+int unit_write_drop_in_private(Unit *u, UnitSetPropertiesMode mode, const char *name, const char *data) {
+        _cleanup_free_ char *ndata = NULL;
+
+        assert(u);
+        assert(name);
+        assert(data);
+
+        if (!UNIT_VTABLE(u)->private_section)
+                return -EINVAL;
+
+        if (!IN_SET(mode, UNIT_PERSISTENT, UNIT_RUNTIME))
+                return 0;
+
+        ndata = strjoin("[", UNIT_VTABLE(u)->private_section, "]\n", data, NULL);
+        if (!ndata)
+                return -ENOMEM;
+
+        return unit_write_drop_in(u, mode, name, ndata);
+}
+
+int unit_write_drop_in_private_format(Unit *u, UnitSetPropertiesMode mode, const char *name, const char *format, ...) {
+        _cleanup_free_ char *p = NULL;
+        va_list ap;
+        int r;
+
+        assert(u);
+        assert(name);
+        assert(format);
+
+        if (!IN_SET(mode, UNIT_PERSISTENT, UNIT_RUNTIME))
+                return 0;
+
+        va_start(ap, format);
+        r = vasprintf(&p, format, ap);
+        va_end(ap);
+
+        if (r < 0)
+                return -ENOMEM;
+
+        return unit_write_drop_in_private(u, mode, name, p);
+}
+
+int unit_make_transient(Unit *u) {
+        assert(u);
+
+        if (!UNIT_VTABLE(u)->can_transient)
+                return -EOPNOTSUPP;
+
+        u->load_state = UNIT_STUB;
+        u->load_error = 0;
+        u->transient = true;
+
+        u->fragment_path = mfree(u->fragment_path);
+        u->source_path = mfree(u->source_path);
+        u->dropin_paths = strv_free(u->dropin_paths);
+        u->fragment_mtime = u->source_mtime = u->dropin_mtime = 0;
+
+        unit_add_to_dbus_queue(u);
+        unit_add_to_gc_queue(u);
+        unit_add_to_load_queue(u);
+
+        return 0;
+}
+
+int unit_kill_context(
+                Unit *u,
+                KillContext *c,
+                KillOperation k,
+                pid_t main_pid,
+                pid_t control_pid,
+                bool main_pid_alien) {
+
+        bool wait_for_exit = false;
+        int sig, r;
+
+        assert(u);
+        assert(c);
+
+        if (c->kill_mode == KILL_NONE)
+                return 0;
+
+        switch (k) {
+        case KILL_KILL:
+                sig = SIGKILL;
+                break;
+        case KILL_ABORT:
+                sig = SIGABRT;
+                break;
+        case KILL_TERMINATE:
+                sig = c->kill_signal;
+                break;
+        default:
+                assert_not_reached("KillOperation unknown");
+        }
+
+        if (main_pid > 0) {
+                r = kill_and_sigcont(main_pid, sig);
+
+                if (r < 0 && r != -ESRCH) {
+                        _cleanup_free_ char *comm = NULL;
+                        get_process_comm(main_pid, &comm);
+
+                        log_unit_warning_errno(u, r, "Failed to kill main process " PID_FMT " (%s), ignoring: %m", main_pid, strna(comm));
+                } else {
+                        if (!main_pid_alien)
+                                wait_for_exit = true;
+
+                        if (c->send_sighup && k == KILL_TERMINATE)
+                                (void) kill(main_pid, SIGHUP);
+                }
+        }
+
+        if (control_pid > 0) {
+                r = kill_and_sigcont(control_pid, sig);
+
+                if (r < 0 && r != -ESRCH) {
+                        _cleanup_free_ char *comm = NULL;
+                        get_process_comm(control_pid, &comm);
+
+                        log_unit_warning_errno(u, r, "Failed to kill control process " PID_FMT " (%s), ignoring: %m", control_pid, strna(comm));
+                } else {
+                        wait_for_exit = true;
+
+                        if (c->send_sighup && k == KILL_TERMINATE)
+                                (void) kill(control_pid, SIGHUP);
+                }
+        }
+
+        if (u->cgroup_path &&
+            (c->kill_mode == KILL_CONTROL_GROUP || (c->kill_mode == KILL_MIXED && k == KILL_KILL))) {
+                _cleanup_set_free_ Set *pid_set = NULL;
+
+                /* Exclude the main/control pids from being killed via the cgroup */
+                pid_set = unit_pid_set(main_pid, control_pid);
+                if (!pid_set)
+                        return -ENOMEM;
+
+                r = cg_kill_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, sig, true, k != KILL_TERMINATE, false, pid_set);
+                if (r < 0) {
+                        if (r != -EAGAIN && r != -ESRCH && r != -ENOENT)
+                                log_unit_warning_errno(u, r, "Failed to kill control group %s, ignoring: %m", u->cgroup_path);
+
+                } else if (r > 0) {
+
+                        /* FIXME: For now, on the legacy hierarchy, we
+                         * will not wait for the cgroup members to die
+                         * if we are running in a container or if this
+                         * is a delegation unit, simply because cgroup
+                         * notification is unreliable in these
+                         * cases. It doesn't work at all in
+                         * containers, and outside of containers it
+                         * can be confused easily by left-over
+                         * directories in the cgroup -- which however
+                         * should not exist in non-delegated units. On
+                         * the unified hierarchy that's different,
+                         * there we get proper events. Hence rely on
+                         * them.*/
+
+                        if  (cg_unified() > 0 ||
+                             (detect_container() == 0 && !unit_cgroup_delegate(u)))
+                                wait_for_exit = true;
+
+                        if (c->send_sighup && k != KILL_KILL) {
+                                set_free(pid_set);
+
+                                pid_set = unit_pid_set(main_pid, control_pid);
+                                if (!pid_set)
+                                        return -ENOMEM;
+
+                                cg_kill_recursive(SYSTEMD_CGROUP_CONTROLLER, u->cgroup_path, SIGHUP, false, true, false, pid_set);
+                        }
+                }
+        }
+
+        return wait_for_exit;
+}
+
+int unit_require_mounts_for(Unit *u, const char *path) {
+        char prefix[strlen(path) + 1], *p;
+        int r;
+
+        assert(u);
+        assert(path);
+
+        /* Registers a unit for requiring a certain path and all its
+         * prefixes. We keep a simple array of these paths in the
+         * unit, since its usually short. However, we build a prefix
+         * table for all possible prefixes so that new appearing mount
+         * units can easily determine which units to make themselves a
+         * dependency of. */
+
+        if (!path_is_absolute(path))
+                return -EINVAL;
+
+        p = strdup(path);
+        if (!p)
+                return -ENOMEM;
+
+        path_kill_slashes(p);
+
+        if (!path_is_safe(p)) {
+                free(p);
+                return -EPERM;
+        }
+
+        if (strv_contains(u->requires_mounts_for, p)) {
+                free(p);
+                return 0;
+        }
+
+        r = strv_consume(&u->requires_mounts_for, p);
+        if (r < 0)
+                return r;
+
+        PATH_FOREACH_PREFIX_MORE(prefix, p) {
+                Set *x;
+
+                x = hashmap_get(u->manager->units_requiring_mounts_for, prefix);
+                if (!x) {
+                        char *q;
+
+                        r = hashmap_ensure_allocated(&u->manager->units_requiring_mounts_for, &string_hash_ops);
+                        if (r < 0)
+                                return r;
+
+                        q = strdup(prefix);
+                        if (!q)
+                                return -ENOMEM;
+
+                        x = set_new(NULL);
+                        if (!x) {
+                                free(q);
+                                return -ENOMEM;
+                        }
+
+                        r = hashmap_put(u->manager->units_requiring_mounts_for, q, x);
+                        if (r < 0) {
+                                free(q);
+                                set_free(x);
+                                return r;
+                        }
+                }
+
+                r = set_put(x, u);
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+int unit_setup_exec_runtime(Unit *u) {
+        ExecRuntime **rt;
+        size_t offset;
+        Iterator i;
+        Unit *other;
+
+        offset = UNIT_VTABLE(u)->exec_runtime_offset;
+        assert(offset > 0);
+
+        /* Check if there already is an ExecRuntime for this unit? */
+        rt = (ExecRuntime**) ((uint8_t*) u + offset);
+        if (*rt)
+                return 0;
+
+        /* Try to get it from somebody else */
+        SET_FOREACH(other, u->dependencies[UNIT_JOINS_NAMESPACE_OF], i) {
+
+                *rt = unit_get_exec_runtime(other);
+                if (*rt) {
+                        exec_runtime_ref(*rt);
+                        return 0;
+                }
+        }
+
+        return exec_runtime_make(rt, unit_get_exec_context(u), u->id);
+}
+
+bool unit_type_supported(UnitType t) {
+        if (_unlikely_(t < 0))
+                return false;
+        if (_unlikely_(t >= _UNIT_TYPE_MAX))
+                return false;
+
+        if (!unit_vtable[t]->supported)
+                return true;
+
+        return unit_vtable[t]->supported();
+}
+
+void unit_warn_if_dir_nonempty(Unit *u, const char* where) {
+        int r;
+
+        assert(u);
+        assert(where);
+
+        r = dir_is_empty(where);
+        if (r > 0)
+                return;
+        if (r < 0) {
+                log_unit_warning_errno(u, r, "Failed to check directory %s: %m", where);
+                return;
+        }
+
+        log_struct(LOG_NOTICE,
+                   LOG_MESSAGE_ID(SD_MESSAGE_OVERMOUNTING),
+                   LOG_UNIT_ID(u),
+                   LOG_UNIT_MESSAGE(u, "Directory %s to mount over is not empty, mounting anyway.", where),
+                   "WHERE=%s", where,
+                   NULL);
+}
+
+int unit_fail_if_symlink(Unit *u, const char* where) {
+        int r;
+
+        assert(u);
+        assert(where);
+
+        r = is_symlink(where);
+        if (r < 0) {
+                log_unit_debug_errno(u, r, "Failed to check symlink %s, ignoring: %m", where);
+                return 0;
+        }
+        if (r == 0)
+                return 0;
+
+        log_struct(LOG_ERR,
+                   LOG_MESSAGE_ID(SD_MESSAGE_OVERMOUNTING),
+                   LOG_UNIT_ID(u),
+                   LOG_UNIT_MESSAGE(u, "Mount on symlink %s not allowed.", where),
+                   "WHERE=%s", where,
+                   NULL);
+
+        return -ELOOP;
+}
+
+bool unit_is_pristine(Unit *u) {
+        assert(u);
+
+        /* Check if the unit already exists or is already around,
+         * in a number of different ways. Note that to cater for unit
+         * types such as slice, we are generally fine with units that
+         * are marked UNIT_LOADED even even though nothing was
+         * actually loaded, as those unit types don't require a file
+         * on disk to validly load. */
+
+        return !(!IN_SET(u->load_state, UNIT_NOT_FOUND, UNIT_LOADED) ||
+                 u->fragment_path ||
+                 u->source_path ||
+                 !strv_isempty(u->dropin_paths) ||
+                 u->job ||
+                 u->merged_into);
+}