build-sys: move source files to subdirectory

1 files changed, 2291 insertions, 0 deletions

diff --git a/src/manager.c b/src/manager.c
new file mode 100644
index 0000000000..688d9fa65b
--- /dev/null
+++ b/src/manager.c
@@ -0,0 +1,2291 @@
+/*-*- Mode: C; c-basic-offset: 8 -*-*/
+
+/***
+  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 General Public License as published by
+  the Free Software Foundation; either version 2 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
+  General Public License for more details.
+
+  You should have received a copy of the GNU General Public License
+  along with systemd; If not, see <http://www.gnu.org/licenses/>.
+***/
+
+#include <assert.h>
+#include <errno.h>
+#include <string.h>
+#include <sys/epoll.h>
+#include <signal.h>
+#include <sys/signalfd.h>
+#include <sys/wait.h>
+#include <unistd.h>
+#include <utmpx.h>
+#include <sys/poll.h>
+#include <sys/reboot.h>
+#include <sys/ioctl.h>
+#include <linux/kd.h>
+#include <libcgroup.h>
+#include <termios.h>
+#include <fcntl.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+
+#include "manager.h"
+#include "hashmap.h"
+#include "macro.h"
+#include "strv.h"
+#include "log.h"
+#include "util.h"
+#include "ratelimit.h"
+#include "cgroup.h"
+#include "mount-setup.h"
+#include "utmp-wtmp.h"
+#include "unit-name.h"
+#include "dbus-unit.h"
+#include "dbus-job.h"
+#include "missing.h"
+
+/* As soon as 16 units are in our GC queue, make sure to run a gc sweep */
+#define GC_QUEUE_ENTRIES_MAX 16
+
+/* As soon as 5s passed since a unit was added to our GC queue, make sure to run a gc sweep */
+#define GC_QUEUE_USEC_MAX (10*USEC_PER_SEC)
+
+static int enable_special_signals(Manager *m) {
+        char fd;
+
+        assert(m);
+
+        /* Enable that we get SIGINT on control-alt-del */
+        if (reboot(RB_DISABLE_CAD) < 0)
+                log_warning("Failed to enable ctrl-alt-del handling: %m");
+
+        if ((fd = open_terminal("/dev/tty0", O_RDWR|O_NOCTTY)) < 0)
+                log_warning("Failed to open /dev/tty0: %m");
+        else {
+                /* Enable that we get SIGWINCH on kbrequest */
+                if (ioctl(fd, KDSIGACCEPT, SIGWINCH) < 0)
+                        log_warning("Failed to enable kbrequest handling: %s", strerror(errno));
+
+                close_nointr_nofail(fd);
+        }
+
+        return 0;
+}
+
+static int manager_setup_signals(Manager *m) {
+        sigset_t mask;
+        struct epoll_event ev;
+        struct sigaction sa;
+
+        assert(m);
+
+        /* We are not interested in SIGSTOP and friends. */
+        zero(sa);
+        sa.sa_handler = SIG_DFL;
+        sa.sa_flags = SA_NOCLDSTOP|SA_RESTART;
+        assert_se(sigaction(SIGCHLD, &sa, NULL) == 0);
+
+        assert_se(sigemptyset(&mask) == 0);
+        assert_se(sigaddset(&mask, SIGCHLD) == 0);
+        assert_se(sigaddset(&mask, SIGTERM) == 0);
+        assert_se(sigaddset(&mask, SIGHUP) == 0);
+        assert_se(sigaddset(&mask, SIGUSR1) == 0);
+        assert_se(sigaddset(&mask, SIGUSR2) == 0);
+        assert_se(sigaddset(&mask, SIGINT) == 0);   /* Kernel sends us this on control-alt-del */
+        assert_se(sigaddset(&mask, SIGWINCH) == 0); /* Kernel sends us this on kbrequest (alt-arrowup) */
+        assert_se(sigaddset(&mask, SIGPWR) == 0);   /* Some kernel drivers and upsd send us this on power failure */
+        assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
+
+        m->signal_watch.type = WATCH_SIGNAL;
+        if ((m->signal_watch.fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
+                return -errno;
+
+        zero(ev);
+        ev.events = EPOLLIN;
+        ev.data.ptr = &m->signal_watch;
+
+        if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
+                return -errno;
+
+        if (m->running_as == MANAGER_INIT)
+                return enable_special_signals(m);
+
+        return 0;
+}
+
+static char** session_dirs(void) {
+        const char *home, *e;
+        char *config_home = NULL, *data_home = NULL;
+        char **config_dirs = NULL, **data_dirs = NULL;
+        char **r = NULL, **t;
+
+        /* Implement the mechanisms defined in
+         *
+         * http://standards.freedesktop.org/basedir-spec/basedir-spec-0.6.html
+         *
+         * We look in both the config and the data dirs because we
+         * want to encourage that distributors ship their unit files
+         * as data, and allow overriding as configuration.
+         */
+
+        home = getenv("HOME");
+
+        if ((e = getenv("XDG_CONFIG_HOME"))) {
+                if (asprintf(&config_home, "%s/systemd/session", e) < 0)
+                        goto fail;
+
+        } else if (home) {
+                if (asprintf(&config_home, "%s/.config/systemd/session", home) < 0)
+                        goto fail;
+        }
+
+        if ((e = getenv("XDG_CONFIG_DIRS")))
+                if (!(config_dirs = strv_split(e, ":")))
+                        goto fail;
+
+        /* We don't treat /etc/xdg/systemd here as the spec
+         * suggests because we assume that that is a link to
+         * /etc/systemd/ anyway. */
+
+        if ((e = getenv("XDG_DATA_HOME"))) {
+                if (asprintf(&data_home, "%s/systemd/session", e) < 0)
+                        goto fail;
+
+        } else if (home) {
+                if (asprintf(&data_home, "%s/.local/share/systemd/session", home) < 0)
+                        goto fail;
+        }
+
+        if ((e = getenv("XDG_DATA_DIRS")))
+                data_dirs = strv_split(e, ":");
+        else
+                data_dirs = strv_new("/usr/local/share", "/usr/share", NULL);
+
+        if (!data_dirs)
+                goto fail;
+
+        /* Now merge everything we found. */
+        if (config_home) {
+                if (!(t = strv_append(r, config_home)))
+                        goto fail;
+                strv_free(r);
+                r = t;
+        }
+
+        if (!(t = strv_merge_concat(r, config_dirs, "/systemd/session")))
+                goto finish;
+        strv_free(r);
+        r = t;
+
+        if (!(t = strv_append(r, SESSION_CONFIG_UNIT_PATH)))
+                goto fail;
+        strv_free(r);
+        r = t;
+
+        if (data_home) {
+                if (!(t = strv_append(r, data_home)))
+                        goto fail;
+                strv_free(r);
+                r = t;
+        }
+
+        if (!(t = strv_merge_concat(r, data_dirs, "/systemd/session")))
+                goto fail;
+        strv_free(r);
+        r = t;
+
+        if (!(t = strv_append(r, SESSION_DATA_UNIT_PATH)))
+                goto fail;
+        strv_free(r);
+        r = t;
+
+        if (!strv_path_make_absolute_cwd(r))
+            goto fail;
+
+finish:
+        free(config_home);
+        strv_free(config_dirs);
+        free(data_home);
+        strv_free(data_dirs);
+
+        return r;
+
+fail:
+        strv_free(r);
+        r = NULL;
+        goto finish;
+}
+
+static int manager_find_paths(Manager *m) {
+        const char *e;
+        char *t;
+
+        assert(m);
+
+        /* First priority is whatever has been passed to us via env
+         * vars */
+        if ((e = getenv("SYSTEMD_UNIT_PATH")))
+                if (!(m->unit_path = split_path_and_make_absolute(e)))
+                        return -ENOMEM;
+
+        if (strv_isempty(m->unit_path)) {
+
+                /* Nothing is set, so let's figure something out. */
+                strv_free(m->unit_path);
+
+                if (m->running_as == MANAGER_SESSION) {
+                        if (!(m->unit_path = session_dirs()))
+                                return -ENOMEM;
+                } else
+                        if (!(m->unit_path = strv_new(
+                                              SYSTEM_CONFIG_UNIT_PATH,  /* /etc/systemd/system/ */
+                                              SYSTEM_DATA_UNIT_PATH,    /* /lib/systemd/system/ */
+                                              NULL)))
+                                return -ENOMEM;
+        }
+
+        if (m->running_as == MANAGER_INIT) {
+                /* /etc/init.d/ compatibility does not matter to users */
+
+                if ((e = getenv("SYSTEMD_SYSVINIT_PATH")))
+                        if (!(m->sysvinit_path = split_path_and_make_absolute(e)))
+                                return -ENOMEM;
+
+                if (strv_isempty(m->sysvinit_path)) {
+                        strv_free(m->sysvinit_path);
+
+                        if (!(m->sysvinit_path = strv_new(
+                                              SYSTEM_SYSVINIT_PATH,     /* /etc/init.d/ */
+                                              NULL)))
+                                return -ENOMEM;
+                }
+
+                if ((e = getenv("SYSTEMD_SYSVRCND_PATH")))
+                        if (!(m->sysvrcnd_path = split_path_and_make_absolute(e)))
+                                return -ENOMEM;
+
+                if (strv_isempty(m->sysvrcnd_path)) {
+                        strv_free(m->sysvrcnd_path);
+
+                        if (!(m->sysvrcnd_path = strv_new(
+                                              SYSTEM_SYSVRCND_PATH,     /* /etc/rcN.d/ */
+                                              NULL)))
+                                return -ENOMEM;
+                }
+        }
+
+        strv_uniq(m->unit_path);
+        strv_uniq(m->sysvinit_path);
+        strv_uniq(m->sysvrcnd_path);
+
+        assert(!strv_isempty(m->unit_path));
+        if (!(t = strv_join(m->unit_path, "\n\t")))
+                return -ENOMEM;
+        log_debug("Looking for unit files in:\n\t%s", t);
+        free(t);
+
+        if (!strv_isempty(m->sysvinit_path)) {
+
+                if (!(t = strv_join(m->sysvinit_path, "\n\t")))
+                        return -ENOMEM;
+
+                log_debug("Looking for SysV init scripts in:\n\t%s", t);
+                free(t);
+        } else
+                log_debug("Ignoring SysV init scripts.");
+
+        if (!strv_isempty(m->sysvrcnd_path)) {
+
+                if (!(t = strv_join(m->sysvrcnd_path, "\n\t")))
+                        return -ENOMEM;
+
+                log_debug("Looking for SysV rcN.d links in:\n\t%s", t);
+                free(t);
+        } else
+                log_debug("Ignoring SysV rcN.d links.");
+
+        return 0;
+}
+
+int manager_new(ManagerRunningAs running_as, bool confirm_spawn, Manager **_m) {
+        Manager *m;
+        int r = -ENOMEM;
+
+        assert(_m);
+        assert(running_as >= 0);
+        assert(running_as < _MANAGER_RUNNING_AS_MAX);
+
+        if (!(m = new0(Manager, 1)))
+                return -ENOMEM;
+
+        m->boot_timestamp = now(CLOCK_REALTIME);
+
+        m->running_as = running_as;
+        m->confirm_spawn = confirm_spawn;
+        m->name_data_slot = -1;
+        m->exit_code = _MANAGER_EXIT_CODE_INVALID;
+
+        m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = m->dev_autofs_fd = -1;
+        m->current_job_id = 1; /* start as id #1, so that we can leave #0 around as "null-like" value */
+
+        if (!(m->environment = strv_copy(environ)))
+                goto fail;
+
+        if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
+                goto fail;
+
+        if (!(m->jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
+                goto fail;
+
+        if (!(m->transaction_jobs = hashmap_new(trivial_hash_func, trivial_compare_func)))
+                goto fail;
+
+        if (!(m->watch_pids = hashmap_new(trivial_hash_func, trivial_compare_func)))
+                goto fail;
+
+        if (!(m->cgroup_bondings = hashmap_new(string_hash_func, string_compare_func)))
+                goto fail;
+
+        if (!(m->watch_bus = hashmap_new(string_hash_func, string_compare_func)))
+                goto fail;
+
+        if ((m->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
+                goto fail;
+
+        if ((r = manager_find_paths(m)) < 0)
+                goto fail;
+
+        if ((r = manager_setup_signals(m)) < 0)
+                goto fail;
+
+        if ((r = manager_setup_cgroup(m)) < 0)
+                goto fail;
+
+        /* Try to connect to the busses, if possible. */
+        if ((r = bus_init_system(m)) < 0 ||
+            (r = bus_init_api(m)) < 0)
+                goto fail;
+
+        *_m = m;
+        return 0;
+
+fail:
+        manager_free(m);
+        return r;
+}
+
+static unsigned manager_dispatch_cleanup_queue(Manager *m) {
+        Meta *meta;
+        unsigned n = 0;
+
+        assert(m);
+
+        while ((meta = m->cleanup_queue)) {
+                assert(meta->in_cleanup_queue);
+
+                unit_free(UNIT(meta));
+                n++;
+        }
+
+        return n;
+}
+
+enum {
+        GC_OFFSET_IN_PATH,  /* This one is on the path we were travelling */
+        GC_OFFSET_UNSURE,   /* No clue */
+        GC_OFFSET_GOOD,     /* We still need this unit */
+        GC_OFFSET_BAD,      /* We don't need this unit anymore */
+        _GC_OFFSET_MAX
+};
+
+static void unit_gc_sweep(Unit *u, unsigned gc_marker) {
+        Iterator i;
+        Unit *other;
+        bool is_bad;
+
+        assert(u);
+
+        if (u->meta.gc_marker == gc_marker + GC_OFFSET_GOOD ||
+            u->meta.gc_marker == gc_marker + GC_OFFSET_BAD ||
+            u->meta.gc_marker == gc_marker + GC_OFFSET_IN_PATH)
+                return;
+
+        if (u->meta.in_cleanup_queue)
+                goto bad;
+
+        if (unit_check_gc(u))
+                goto good;
+
+        u->meta.gc_marker = gc_marker + GC_OFFSET_IN_PATH;
+
+        is_bad = true;
+
+        SET_FOREACH(other, u->meta.dependencies[UNIT_REFERENCED_BY], i) {
+                unit_gc_sweep(other, gc_marker);
+
+                if (other->meta.gc_marker == gc_marker + GC_OFFSET_GOOD)
+                        goto good;
+
+                if (other->meta.gc_marker != gc_marker + GC_OFFSET_BAD)
+                        is_bad = false;
+        }
+
+        if (is_bad)
+                goto bad;
+
+        /* We were unable to find anything out about this entry, so
+         * let's investigate it later */
+        u->meta.gc_marker = gc_marker + GC_OFFSET_UNSURE;
+        unit_add_to_gc_queue(u);
+        return;
+
+bad:
+        /* We definitely know that this one is not useful anymore, so
+         * let's mark it for deletion */
+        u->meta.gc_marker = gc_marker + GC_OFFSET_BAD;
+        unit_add_to_cleanup_queue(u);
+        return;
+
+good:
+        u->meta.gc_marker = gc_marker + GC_OFFSET_GOOD;
+}
+
+static unsigned manager_dispatch_gc_queue(Manager *m) {
+        Meta *meta;
+        unsigned n = 0;
+        unsigned gc_marker;
+
+        assert(m);
+
+        if ((m->n_in_gc_queue < GC_QUEUE_ENTRIES_MAX) &&
+            (m->gc_queue_timestamp <= 0 ||
+             (m->gc_queue_timestamp + GC_QUEUE_USEC_MAX) > now(CLOCK_MONOTONIC)))
+                return 0;
+
+        log_debug("Running GC...");
+
+        m->gc_marker += _GC_OFFSET_MAX;
+        if (m->gc_marker + _GC_OFFSET_MAX <= _GC_OFFSET_MAX)
+                m->gc_marker = 1;
+
+        gc_marker = m->gc_marker;
+
+        while ((meta = m->gc_queue)) {
+                assert(meta->in_gc_queue);
+
+                unit_gc_sweep(UNIT(meta), gc_marker);
+
+                LIST_REMOVE(Meta, gc_queue, m->gc_queue, meta);
+                meta->in_gc_queue = false;
+
+                n++;
+
+                if (meta->gc_marker == gc_marker + GC_OFFSET_BAD ||
+                    meta->gc_marker == gc_marker + GC_OFFSET_UNSURE) {
+                        log_debug("Collecting %s", meta->id);
+                        meta->gc_marker = gc_marker + GC_OFFSET_BAD;
+                        unit_add_to_cleanup_queue(UNIT(meta));
+                }
+        }
+
+        m->n_in_gc_queue = 0;
+        m->gc_queue_timestamp = 0;
+
+        return n;
+}
+
+static void manager_clear_jobs_and_units(Manager *m) {
+        Job *j;
+        Unit *u;
+
+        assert(m);
+
+        while ((j = hashmap_first(m->transaction_jobs)))
+                job_free(j);
+
+        while ((u = hashmap_first(m->units)))
+                unit_free(u);
+}
+
+void manager_free(Manager *m) {
+        UnitType c;
+
+        assert(m);
+
+        manager_dispatch_cleanup_queue(m);
+        manager_clear_jobs_and_units(m);
+
+        for (c = 0; c < _UNIT_TYPE_MAX; c++)
+                if (unit_vtable[c]->shutdown)
+                        unit_vtable[c]->shutdown(m);
+
+        /* If we reexecute ourselves, we keep the root cgroup
+         * around */
+        manager_shutdown_cgroup(m, m->exit_code != MANAGER_REEXECUTE);
+
+        bus_done_api(m);
+        bus_done_system(m);
+
+        hashmap_free(m->units);
+        hashmap_free(m->jobs);
+        hashmap_free(m->transaction_jobs);
+        hashmap_free(m->watch_pids);
+        hashmap_free(m->watch_bus);
+
+        if (m->epoll_fd >= 0)
+                close_nointr_nofail(m->epoll_fd);
+        if (m->signal_watch.fd >= 0)
+                close_nointr_nofail(m->signal_watch.fd);
+
+        strv_free(m->unit_path);
+        strv_free(m->sysvinit_path);
+        strv_free(m->sysvrcnd_path);
+        strv_free(m->environment);
+
+        free(m->cgroup_controller);
+        free(m->cgroup_hierarchy);
+
+        hashmap_free(m->cgroup_bondings);
+
+        free(m);
+}
+
+int manager_enumerate(Manager *m) {
+        int r = 0, q;
+        UnitType c;
+
+        assert(m);
+
+        /* Let's ask every type to load all units from disk/kernel
+         * that it might know */
+        for (c = 0; c < _UNIT_TYPE_MAX; c++)
+                if (unit_vtable[c]->enumerate)
+                        if ((q = unit_vtable[c]->enumerate(m)) < 0)
+                                r = q;
+
+        manager_dispatch_load_queue(m);
+        return r;
+}
+
+int manager_coldplug(Manager *m) {
+        int r = 0, q;
+        Iterator i;
+        Unit *u;
+        char *k;
+
+        assert(m);
+
+        /* Then, let's set up their initial state. */
+        HASHMAP_FOREACH_KEY(u, k, m->units, i) {
+
+                /* ignore aliases */
+                if (u->meta.id != k)
+                        continue;
+
+                if (UNIT_VTABLE(u)->coldplug)
+                        if ((q = UNIT_VTABLE(u)->coldplug(u)) < 0)
+                                r = q;
+        }
+
+        return r;
+}
+
+int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
+        int r, q;
+
+        assert(m);
+
+        /* First, enumerate what we can from all config files */
+        r = manager_enumerate(m);
+
+        /* Second, deserialize if there is something to deserialize */
+        if (serialization)
+                if ((q = manager_deserialize(m, serialization, fds)) < 0)
+                        r = q;
+
+        /* Third, fire things up! */
+        if ((q = manager_coldplug(m)) < 0)
+                r = q;
+
+        /* Now that the initial devices are available, let's see if we
+         * can write the utmp file */
+        manager_write_utmp_reboot(m);
+
+        return r;
+}
+
+static void transaction_delete_job(Manager *m, Job *j, bool delete_dependencies) {
+        assert(m);
+        assert(j);
+
+        /* Deletes one job from the transaction */
+
+        manager_transaction_unlink_job(m, j, delete_dependencies);
+
+        if (!j->installed)
+                job_free(j);
+}
+
+static void transaction_delete_unit(Manager *m, Unit *u) {
+        Job *j;
+
+        /* Deletes all jobs associated with a certain unit from the
+         * transaction */
+
+        while ((j = hashmap_get(m->transaction_jobs, u)))
+                transaction_delete_job(m, j, true);
+}
+
+static void transaction_clean_dependencies(Manager *m) {
+        Iterator i;
+        Job *j;
+
+        assert(m);
+
+        /* Drops all dependencies of all installed jobs */
+
+        HASHMAP_FOREACH(j, m->jobs, i) {
+                while (j->subject_list)
+                        job_dependency_free(j->subject_list);
+                while (j->object_list)
+                        job_dependency_free(j->object_list);
+        }
+
+        assert(!m->transaction_anchor);
+}
+
+static void transaction_abort(Manager *m) {
+        Job *j;
+
+        assert(m);
+
+        while ((j = hashmap_first(m->transaction_jobs)))
+                if (j->installed)
+                        transaction_delete_job(m, j, true);
+                else
+                        job_free(j);
+
+        assert(hashmap_isempty(m->transaction_jobs));
+
+        transaction_clean_dependencies(m);
+}
+
+static void transaction_find_jobs_that_matter_to_anchor(Manager *m, Job *j, unsigned generation) {
+        JobDependency *l;
+
+        assert(m);
+
+        /* A recursive sweep through the graph that marks all units
+         * that matter to the anchor job, i.e. are directly or
+         * indirectly a dependency of the anchor job via paths that
+         * are fully marked as mattering. */
+
+        if (j)
+                l = j->subject_list;
+        else
+                l = m->transaction_anchor;
+
+        LIST_FOREACH(subject, l, l) {
+
+                /* This link does not matter */
+                if (!l->matters)
+                        continue;
+
+                /* This unit has already been marked */
+                if (l->object->generation == generation)
+                        continue;
+
+                l->object->matters_to_anchor = true;
+                l->object->generation = generation;
+
+                transaction_find_jobs_that_matter_to_anchor(m, l->object, generation);
+        }
+}
+
+static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, JobType t) {
+        JobDependency *l, *last;
+
+        assert(j);
+        assert(other);
+        assert(j->unit == other->unit);
+        assert(!j->installed);
+
+        /* Merges 'other' into 'j' and then deletes j. */
+
+        j->type = t;
+        j->state = JOB_WAITING;
+        j->override = j->override || other->override;
+
+        j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
+
+        /* Patch us in as new owner of the JobDependency objects */
+        last = NULL;
+        LIST_FOREACH(subject, l, other->subject_list) {
+                assert(l->subject == other);
+                l->subject = j;
+                last = l;
+        }
+
+        /* Merge both lists */
+        if (last) {
+                last->subject_next = j->subject_list;
+                if (j->subject_list)
+                        j->subject_list->subject_prev = last;
+                j->subject_list = other->subject_list;
+        }
+
+        /* Patch us in as new owner of the JobDependency objects */
+        last = NULL;
+        LIST_FOREACH(object, l, other->object_list) {
+                assert(l->object == other);
+                l->object = j;
+                last = l;
+        }
+
+        /* Merge both lists */
+        if (last) {
+                last->object_next = j->object_list;
+                if (j->object_list)
+                        j->object_list->object_prev = last;
+                j->object_list = other->object_list;
+        }
+
+        /* Kill the other job */
+        other->subject_list = NULL;
+        other->object_list = NULL;
+        transaction_delete_job(m, other, true);
+}
+
+static int delete_one_unmergeable_job(Manager *m, Job *j) {
+        Job *k;
+
+        assert(j);
+
+        /* Tries to delete one item in the linked list
+         * j->transaction_next->transaction_next->... that conflicts
+         * whith another one, in an attempt to make an inconsistent
+         * transaction work. */
+
+        /* We rely here on the fact that if a merged with b does not
+         * merge with c, either a or b merge with c neither */
+        LIST_FOREACH(transaction, j, j)
+                LIST_FOREACH(transaction, k, j->transaction_next) {
+                        Job *d;
+
+                        /* Is this one mergeable? Then skip it */
+                        if (job_type_is_mergeable(j->type, k->type))
+                                continue;
+
+                        /* Ok, we found two that conflict, let's see if we can
+                         * drop one of them */
+                        if (!j->matters_to_anchor)
+                                d = j;
+                        else if (!k->matters_to_anchor)
+                                d = k;
+                        else
+                                return -ENOEXEC;
+
+                        /* Ok, we can drop one, so let's do so. */
+                        log_debug("Trying to fix job merging by deleting job %s/%s", d->unit->meta.id, job_type_to_string(d->type));
+                        transaction_delete_job(m, d, true);
+                        return 0;
+                }
+
+        return -EINVAL;
+}
+
+static int transaction_merge_jobs(Manager *m) {
+        Job *j;
+        Iterator i;
+        int r;
+
+        assert(m);
+
+        /* First step, check whether any of the jobs for one specific
+         * task conflict. If so, try to drop one of them. */
+        HASHMAP_FOREACH(j, m->transaction_jobs, i) {
+                JobType t;
+                Job *k;
+
+                t = j->type;
+                LIST_FOREACH(transaction, k, j->transaction_next) {
+                        if ((r = job_type_merge(&t, k->type)) >= 0)
+                                continue;
+
+                        /* OK, we could not merge all jobs for this
+                         * action. Let's see if we can get rid of one
+                         * of them */
+
+                        if ((r = delete_one_unmergeable_job(m, j)) >= 0)
+                                /* Ok, we managed to drop one, now
+                                 * let's ask our callers to call us
+                                 * again after garbage collecting */
+                                return -EAGAIN;
+
+                        /* We couldn't merge anything. Failure */
+                        return r;
+                }
+        }
+
+        /* Second step, merge the jobs. */
+        HASHMAP_FOREACH(j, m->transaction_jobs, i) {
+                JobType t = j->type;
+                Job *k;
+
+                /* Merge all transactions */
+                LIST_FOREACH(transaction, k, j->transaction_next)
+                        assert_se(job_type_merge(&t, k->type) == 0);
+
+                /* If an active job is mergeable, merge it too */
+                if (j->unit->meta.job)
+                        job_type_merge(&t, j->unit->meta.job->type); /* Might fail. Which is OK */
+
+                while ((k = j->transaction_next)) {
+                        if (j->installed) {
+                                transaction_merge_and_delete_job(m, k, j, t);
+                                j = k;
+                        } else
+                                transaction_merge_and_delete_job(m, j, k, t);
+                }
+
+                assert(!j->transaction_next);
+                assert(!j->transaction_prev);
+        }
+
+        return 0;
+}
+
+static void transaction_drop_redundant(Manager *m) {
+        bool again;
+
+        assert(m);
+
+        /* Goes through the transaction and removes all jobs that are
+         * a noop */
+
+        do {
+                Job *j;
+                Iterator i;
+
+                again = false;
+
+                HASHMAP_FOREACH(j, m->transaction_jobs, i) {
+                        bool changes_something = false;
+                        Job *k;
+
+                        LIST_FOREACH(transaction, k, j) {
+
+                                if (!job_is_anchor(k) &&
+                                    job_type_is_redundant(k->type, unit_active_state(k->unit)))
+                                        continue;
+
+                                changes_something = true;
+                                break;
+                        }
+
+                        if (changes_something)
+                                continue;
+
+                        log_debug("Found redundant job %s/%s, dropping.", j->unit->meta.id, job_type_to_string(j->type));
+                        transaction_delete_job(m, j, false);
+                        again = true;
+                        break;
+                }
+
+        } while (again);
+}
+
+static bool unit_matters_to_anchor(Unit *u, Job *j) {
+        assert(u);
+        assert(!j->transaction_prev);
+
+        /* Checks whether at least one of the jobs for this unit
+         * matters to the anchor. */
+
+        LIST_FOREACH(transaction, j, j)
+                if (j->matters_to_anchor)
+                        return true;
+
+        return false;
+}
+
+static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned generation) {
+        Iterator i;
+        Unit *u;
+        int r;
+
+        assert(m);
+        assert(j);
+        assert(!j->transaction_prev);
+
+        /* Does a recursive sweep through the ordering graph, looking
+         * for a cycle. If we find cycle we try to break it. */
+
+        /* Did we find a cycle? */
+        if (j->marker && j->generation == generation) {
+                Job *k;
+
+                /* So, we already have been here. We have a
+                 * cycle. Let's try to break it. We go backwards in
+                 * our path and try to find a suitable job to
+                 * remove. We use the marker to find our way back,
+                 * since smart how we are we stored our way back in
+                 * there. */
+
+                log_debug("Found ordering cycle on %s/%s", j->unit->meta.id, job_type_to_string(j->type));
+
+                for (k = from; k; k = (k->generation == generation ? k->marker : NULL)) {
+
+                        log_debug("Walked on cycle path to %s/%s", k->unit->meta.id, job_type_to_string(k->type));
+
+                        if (!k->installed &&
+                            !unit_matters_to_anchor(k->unit, k)) {
+                                /* Ok, we can drop this one, so let's
+                                 * do so. */
+                                log_debug("Breaking order cycle by deleting job %s/%s", k->unit->meta.id, job_type_to_string(k->type));
+                                transaction_delete_unit(m, k->unit);
+                                return -EAGAIN;
+                        }
+
+                        /* Check if this in fact was the beginning of
+                         * the cycle */
+                        if (k == j)
+                                break;
+                }
+
+                log_debug("Unable to break cycle");
+
+                return -ENOEXEC;
+        }
+
+        /* Make the marker point to where we come from, so that we can
+         * find our way backwards if we want to break a cycle */
+        j->marker = from;
+        j->generation = generation;
+
+        /* We assume that the the dependencies are bidirectional, and
+         * hence can ignore UNIT_AFTER */
+        SET_FOREACH(u, j->unit->meta.dependencies[UNIT_BEFORE], i) {
+                Job *o;
+
+                /* Is there a job for this unit? */
+                if (!(o = hashmap_get(m->transaction_jobs, u)))
+
+                        /* Ok, there is no job for this in the
+                         * transaction, but maybe there is already one
+                         * running? */
+                        if (!(o = u->meta.job))
+                                continue;
+
+                if ((r = transaction_verify_order_one(m, o, j, generation)) < 0)
+                        return r;
+        }
+
+        /* Ok, let's backtrack, and remember that this entry is not on
+         * our path anymore. */
+        j->marker = NULL;
+
+        return 0;
+}
+
+static int transaction_verify_order(Manager *m, unsigned *generation) {
+        Job *j;
+        int r;
+        Iterator i;
+
+        assert(m);
+        assert(generation);
+
+        /* Check if the ordering graph is cyclic. If it is, try to fix
+         * that up by dropping one of the jobs. */
+
+        HASHMAP_FOREACH(j, m->transaction_jobs, i)
+                if ((r = transaction_verify_order_one(m, j, NULL, (*generation)++)) < 0)
+                        return r;
+
+        return 0;
+}
+
+static void transaction_collect_garbage(Manager *m) {
+        bool again;
+
+        assert(m);
+
+        /* Drop jobs that are not required by any other job */
+
+        do {
+                Iterator i;
+                Job *j;
+
+                again = false;
+
+                HASHMAP_FOREACH(j, m->transaction_jobs, i) {
+                        if (j->object_list)
+                                continue;
+
+                        log_debug("Garbage collecting job %s/%s", j->unit->meta.id, job_type_to_string(j->type));
+                        transaction_delete_job(m, j, true);
+                        again = true;
+                        break;
+                }
+
+        } while (again);
+}
+
+static int transaction_is_destructive(Manager *m) {
+        Iterator i;
+        Job *j;
+
+        assert(m);
+
+        /* Checks whether applying this transaction means that
+         * existing jobs would be replaced */
+
+        HASHMAP_FOREACH(j, m->transaction_jobs, i) {
+
+                /* Assume merged */
+                assert(!j->transaction_prev);
+                assert(!j->transaction_next);
+
+                if (j->unit->meta.job &&
+                    j->unit->meta.job != j &&
+                    !job_type_is_superset(j->type, j->unit->meta.job->type))
+                        return -EEXIST;
+        }
+
+        return 0;
+}
+
+static void transaction_minimize_impact(Manager *m) {
+        bool again;
+        assert(m);
+
+        /* Drops all unnecessary jobs that reverse already active jobs
+         * or that stop a running service. */
+
+        do {
+                Job *j;
+                Iterator i;
+
+                again = false;
+
+                HASHMAP_FOREACH(j, m->transaction_jobs, i) {
+                        LIST_FOREACH(transaction, j, j) {
+                                bool stops_running_service, changes_existing_job;
+
+                                /* If it matters, we shouldn't drop it */
+                                if (j->matters_to_anchor)
+                                        continue;
+
+                                /* Would this stop a running service?
+                                 * Would this change an existing job?
+                                 * If so, let's drop this entry */
+
+                                stops_running_service =
+                                        j->type == JOB_STOP && UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(j->unit));
+
+                                changes_existing_job =
+                                        j->unit->meta.job && job_type_is_conflicting(j->type, j->unit->meta.job->state);
+
+                                if (!stops_running_service && !changes_existing_job)
+                                        continue;
+
+                                if (stops_running_service)
+                                        log_debug("%s/%s would stop a running service.", j->unit->meta.id, job_type_to_string(j->type));
+
+                                if (changes_existing_job)
+                                        log_debug("%s/%s would change existing job.", j->unit->meta.id, job_type_to_string(j->type));
+
+                                /* Ok, let's get rid of this */
+                                log_debug("Deleting %s/%s to minimize impact.", j->unit->meta.id, job_type_to_string(j->type));
+
+                                transaction_delete_job(m, j, true);
+                                again = true;
+                                break;
+                        }
+
+                        if (again)
+                                break;
+                }
+
+        } while (again);
+}
+
+static int transaction_apply(Manager *m) {
+        Iterator i;
+        Job *j;
+        int r;
+
+        /* Moves the transaction jobs to the set of active jobs */
+
+        HASHMAP_FOREACH(j, m->transaction_jobs, i) {
+                /* Assume merged */
+                assert(!j->transaction_prev);
+                assert(!j->transaction_next);
+
+                if (j->installed)
+                        continue;
+
+                if ((r = hashmap_put(m->jobs, UINT32_TO_PTR(j->id), j)) < 0)
+                        goto rollback;
+        }
+
+        while ((j = hashmap_steal_first(m->transaction_jobs))) {
+                if (j->installed)
+                        continue;
+
+                if (j->unit->meta.job)
+                        job_free(j->unit->meta.job);
+
+                j->unit->meta.job = j;
+                j->installed = true;
+
+                /* We're fully installed. Now let's free data we don't
+                 * need anymore. */
+
+                assert(!j->transaction_next);
+                assert(!j->transaction_prev);
+
+                job_add_to_run_queue(j);
+                job_add_to_dbus_queue(j);
+        }
+
+        /* As last step, kill all remaining job dependencies. */
+        transaction_clean_dependencies(m);
+
+        return 0;
+
+rollback:
+
+        HASHMAP_FOREACH(j, m->transaction_jobs, i) {
+                if (j->installed)
+                        continue;
+
+                hashmap_remove(m->jobs, UINT32_TO_PTR(j->id));
+        }
+
+        return r;
+}
+
+static int transaction_activate(Manager *m, JobMode mode) {
+        int r;
+        unsigned generation = 1;
+
+        assert(m);
+
+        /* This applies the changes recorded in transaction_jobs to
+         * the actual list of jobs, if possible. */
+
+        /* First step: figure out which jobs matter */
+        transaction_find_jobs_that_matter_to_anchor(m, NULL, generation++);
+
+        /* Second step: Try not to stop any running services if
+         * we don't have to. Don't try to reverse running
+         * jobs if we don't have to. */
+        transaction_minimize_impact(m);
+
+        /* Third step: Drop redundant jobs */
+        transaction_drop_redundant(m);
+
+        for (;;) {
+                /* Fourth step: Let's remove unneeded jobs that might
+                 * be lurking. */
+                transaction_collect_garbage(m);
+
+                /* Fifth step: verify order makes sense and correct
+                 * cycles if necessary and possible */
+                if ((r = transaction_verify_order(m, &generation)) >= 0)
+                        break;
+
+                if (r != -EAGAIN) {
+                        log_debug("Requested transaction contains an unfixable cyclic ordering dependency: %s", strerror(-r));
+                        goto rollback;
+                }
+
+                /* Let's see if the resulting transaction ordering
+                 * graph is still cyclic... */
+        }
+
+        for (;;) {
+                /* Sixth step: let's drop unmergeable entries if
+                 * necessary and possible, merge entries we can
+                 * merge */
+                if ((r = transaction_merge_jobs(m)) >= 0)
+                        break;
+
+                if (r != -EAGAIN) {
+                        log_debug("Requested transaction contains unmergable jobs: %s", strerror(-r));
+                        goto rollback;
+                }
+
+                /* Seventh step: an entry got dropped, let's garbage
+                 * collect its dependencies. */
+                transaction_collect_garbage(m);
+
+                /* Let's see if the resulting transaction still has
+                 * unmergeable entries ... */
+        }
+
+        /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
+        transaction_drop_redundant(m);
+
+        /* Ninth step: check whether we can actually apply this */
+        if (mode == JOB_FAIL)
+                if ((r = transaction_is_destructive(m)) < 0) {
+                        log_debug("Requested transaction contradicts existing jobs: %s", strerror(-r));
+                        goto rollback;
+                }
+
+        /* Tenth step: apply changes */
+        if ((r = transaction_apply(m)) < 0) {
+                log_debug("Failed to apply transaction: %s", strerror(-r));
+                goto rollback;
+        }
+
+        assert(hashmap_isempty(m->transaction_jobs));
+        assert(!m->transaction_anchor);
+
+        return 0;
+
+rollback:
+        transaction_abort(m);
+        return r;
+}
+
+static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool override, bool *is_new) {
+        Job *j, *f;
+        int r;
+
+        assert(m);
+        assert(unit);
+
+        /* Looks for an axisting prospective job and returns that. If
+         * it doesn't exist it is created and added to the prospective
+         * jobs list. */
+
+        f = hashmap_get(m->transaction_jobs, unit);
+
+        LIST_FOREACH(transaction, j, f) {
+                assert(j->unit == unit);
+
+                if (j->type == type) {
+                        if (is_new)
+                                *is_new = false;
+                        return j;
+                }
+        }
+
+        if (unit->meta.job && unit->meta.job->type == type)
+                j = unit->meta.job;
+        else if (!(j = job_new(m, type, unit)))
+                return NULL;
+
+        j->generation = 0;
+        j->marker = NULL;
+        j->matters_to_anchor = false;
+        j->override = override;
+
+        LIST_PREPEND(Job, transaction, f, j);
+
+        if ((r = hashmap_replace(m->transaction_jobs, unit, f)) < 0) {
+                job_free(j);
+                return NULL;
+        }
+
+        if (is_new)
+                *is_new = true;
+
+        log_debug("Added job %s/%s to transaction.", unit->meta.id, job_type_to_string(type));
+
+        return j;
+}
+
+void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
+        assert(m);
+        assert(j);
+
+        if (j->transaction_prev)
+                j->transaction_prev->transaction_next = j->transaction_next;
+        else if (j->transaction_next)
+                hashmap_replace(m->transaction_jobs, j->unit, j->transaction_next);
+        else
+                hashmap_remove_value(m->transaction_jobs, j->unit, j);
+
+        if (j->transaction_next)
+                j->transaction_next->transaction_prev = j->transaction_prev;
+
+        j->transaction_prev = j->transaction_next = NULL;
+
+        while (j->subject_list)
+                job_dependency_free(j->subject_list);
+
+        while (j->object_list) {
+                Job *other = j->object_list->matters ? j->object_list->subject : NULL;
+
+                job_dependency_free(j->object_list);
+
+                if (other && delete_dependencies) {
+                        log_debug("Deleting job %s/%s as dependency of job %s/%s",
+                                  other->unit->meta.id, job_type_to_string(other->type),
+                                  j->unit->meta.id, job_type_to_string(j->type));
+                        transaction_delete_job(m, other, delete_dependencies);
+                }
+        }
+}
+
+static int transaction_add_job_and_dependencies(
+                Manager *m,
+                JobType type,
+                Unit *unit,
+                Job *by,
+                bool matters,
+                bool override,
+                Job **_ret) {
+        Job *ret;
+        Iterator i;
+        Unit *dep;
+        int r;
+        bool is_new;
+
+        assert(m);
+        assert(type < _JOB_TYPE_MAX);
+        assert(unit);
+
+        if (unit->meta.load_state != UNIT_LOADED)
+                return -EINVAL;
+
+        if (!unit_job_is_applicable(unit, type))
+                return -EBADR;
+
+        /* First add the job. */
+        if (!(ret = transaction_add_one_job(m, type, unit, override, &is_new)))
+                return -ENOMEM;
+
+        /* Then, add a link to the job. */
+        if (!job_dependency_new(by, ret, matters))
+                return -ENOMEM;
+
+        if (is_new) {
+                /* Finally, recursively add in all dependencies. */
+                if (type == JOB_START || type == JOB_RELOAD_OR_START) {
+                        SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES], i)
+                                if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
+                                        goto fail;
+
+                        SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
+                                if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !override, override, NULL)) < 0 && r != -EBADR)
+                                        log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
+
+                        SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_WANTS], i)
+                                if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, false, false, NULL)) < 0)
+                                        log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
+
+                        SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE], i)
+                                if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
+                                        goto fail;
+
+                        SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
+                                if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !override, override, NULL)) < 0 && r != -EBADR)
+                                        log_warning("Cannot add dependency job for unit %s, ignoring: %s", dep->meta.id, strerror(-r));
+
+                        SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_CONFLICTS], i)
+                                if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
+                                        goto fail;
+
+                } else if (type == JOB_STOP || type == JOB_RESTART || type == JOB_TRY_RESTART) {
+
+                        SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_REQUIRED_BY], i)
+                                if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
+                                        goto fail;
+                }
+
+                /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
+        }
+
+        if (_ret)
+                *_ret = ret;
+
+        return 0;
+
+fail:
+        return r;
+}
+
+static int transaction_add_isolate_jobs(Manager *m) {
+        Iterator i;
+        Unit *u;
+        char *k;
+        int r;
+
+        assert(m);
+
+        HASHMAP_FOREACH_KEY(u, k, m->units, i) {
+
+                /* ignore aliases */
+                if (u->meta.id != k)
+                        continue;
+
+                if (UNIT_VTABLE(u)->no_isolate)
+                        continue;
+
+                /* No need to stop inactive jobs */
+                if (unit_active_state(u) == UNIT_INACTIVE)
+                        continue;
+
+                /* Is there already something listed for this? */
+                if (hashmap_get(m->transaction_jobs, u))
+                        continue;
+
+                if ((r = transaction_add_job_and_dependencies(m, JOB_STOP, u, NULL, true, false, NULL)) < 0)
+                        log_warning("Cannot add isolate job for unit %s, ignoring: %s", u->meta.id, strerror(-r));
+        }
+
+        return 0;
+}
+
+int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, Job **_ret) {
+        int r;
+        Job *ret;
+
+        assert(m);
+        assert(type < _JOB_TYPE_MAX);
+        assert(unit);
+        assert(mode < _JOB_MODE_MAX);
+
+        if (mode == JOB_ISOLATE && type != JOB_START)
+                return -EINVAL;
+
+        log_debug("Trying to enqueue job %s/%s", unit->meta.id, job_type_to_string(type));
+
+        if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, override, &ret)) < 0) {
+                transaction_abort(m);
+                return r;
+        }
+
+        if (mode == JOB_ISOLATE)
+                if ((r = transaction_add_isolate_jobs(m)) < 0) {
+                        transaction_abort(m);
+                        return r;
+                }
+
+        if ((r = transaction_activate(m, mode)) < 0)
+                return r;
+
+        log_debug("Enqueued job %s/%s as %u", unit->meta.id, job_type_to_string(type), (unsigned) ret->id);
+
+        if (_ret)
+                *_ret = ret;
+
+        return 0;
+}
+
+int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool override, Job **_ret) {
+        Unit *unit;
+        int r;
+
+        assert(m);
+        assert(type < _JOB_TYPE_MAX);
+        assert(name);
+        assert(mode < _JOB_MODE_MAX);
+
+        if ((r = manager_load_unit(m, name, NULL, &unit)) < 0)
+                return r;
+
+        return manager_add_job(m, type, unit, mode, override, _ret);
+}
+
+Job *manager_get_job(Manager *m, uint32_t id) {
+        assert(m);
+
+        return hashmap_get(m->jobs, UINT32_TO_PTR(id));
+}
+
+Unit *manager_get_unit(Manager *m, const char *name) {
+        assert(m);
+        assert(name);
+
+        return hashmap_get(m->units, name);
+}
+
+unsigned manager_dispatch_load_queue(Manager *m) {
+        Meta *meta;
+        unsigned n = 0;
+
+        assert(m);
+
+        /* Make sure we are not run recursively */
+        if (m->dispatching_load_queue)
+                return 0;
+
+        m->dispatching_load_queue = true;
+
+        /* Dispatches the load queue. Takes a unit from the queue and
+         * tries to load its data until the queue is empty */
+
+        while ((meta = m->load_queue)) {
+                assert(meta->in_load_queue);
+
+                unit_load(UNIT(meta));
+                n++;
+        }
+
+        m->dispatching_load_queue = false;
+        return n;
+}
+
+int manager_load_unit_prepare(Manager *m, const char *name, const char *path, Unit **_ret) {
+        Unit *ret;
+        int r;
+
+        assert(m);
+        assert(name || path);
+
+        /* This will prepare the unit for loading, but not actually
+         * load anything from disk. */
+
+        if (path && !is_path(path))
+                return -EINVAL;
+
+        if (!name)
+                name = file_name_from_path(path);
+
+        if (!unit_name_is_valid(name))
+                return -EINVAL;
+
+        if ((ret = manager_get_unit(m, name))) {
+                *_ret = ret;
+                return 1;
+        }
+
+        if (!(ret = unit_new(m)))
+                return -ENOMEM;
+
+        if (path)
+                if (!(ret->meta.fragment_path = strdup(path))) {
+                        unit_free(ret);
+                        return -ENOMEM;
+                }
+
+        if ((r = unit_add_name(ret, name)) < 0) {
+                unit_free(ret);
+                return r;
+        }
+
+        unit_add_to_load_queue(ret);
+        unit_add_to_dbus_queue(ret);
+        unit_add_to_gc_queue(ret);
+
+        if (_ret)
+                *_ret = ret;
+
+        return 0;
+}
+
+int manager_load_unit(Manager *m, const char *name, const char *path, Unit **_ret) {
+        int r;
+
+        assert(m);
+
+        /* This will load the service information files, but not actually
+         * start any services or anything. */
+
+        if ((r = manager_load_unit_prepare(m, name, path, _ret)) != 0)
+                return r;
+
+        manager_dispatch_load_queue(m);
+
+        if (_ret)
+                *_ret = unit_follow_merge(*_ret);
+
+        return 0;
+}
+
+void manager_dump_jobs(Manager *s, FILE *f, const char *prefix) {
+        Iterator i;
+        Job *j;
+
+        assert(s);
+        assert(f);
+
+        HASHMAP_FOREACH(j, s->jobs, i)
+                job_dump(j, f, prefix);
+}
+
+void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
+        Iterator i;
+        Unit *u;
+        const char *t;
+
+        assert(s);
+        assert(f);
+
+        HASHMAP_FOREACH_KEY(u, t, s->units, i)
+                if (u->meta.id == t)
+                        unit_dump(u, f, prefix);
+}
+
+void manager_clear_jobs(Manager *m) {
+        Job *j;
+
+        assert(m);
+
+        transaction_abort(m);
+
+        while ((j = hashmap_first(m->jobs)))
+                job_free(j);
+}
+
+unsigned manager_dispatch_run_queue(Manager *m) {
+        Job *j;
+        unsigned n = 0;
+
+        if (m->dispatching_run_queue)
+                return 0;
+
+        m->dispatching_run_queue = true;
+
+        while ((j = m->run_queue)) {
+                assert(j->installed);
+                assert(j->in_run_queue);
+
+                job_run_and_invalidate(j);
+                n++;
+        }
+
+        m->dispatching_run_queue = false;
+        return n;
+}
+
+unsigned manager_dispatch_dbus_queue(Manager *m) {
+        Job *j;
+        Meta *meta;
+        unsigned n = 0;
+
+        assert(m);
+
+        if (m->dispatching_dbus_queue)
+                return 0;
+
+        m->dispatching_dbus_queue = true;
+
+        while ((meta = m->dbus_unit_queue)) {
+                assert(meta->in_dbus_queue);
+
+                bus_unit_send_change_signal(UNIT(meta));
+                n++;
+        }
+
+        while ((j = m->dbus_job_queue)) {
+                assert(j->in_dbus_queue);
+
+                bus_job_send_change_signal(j);
+                n++;
+        }
+
+        m->dispatching_dbus_queue = false;
+        return n;
+}
+
+static int manager_dispatch_sigchld(Manager *m) {
+        assert(m);
+
+        for (;;) {
+                siginfo_t si;
+                Unit *u;
+
+                zero(si);
+
+                /* First we call waitd() for a PID and do not reap the
+                 * zombie. That way we can still access /proc/$PID for
+                 * it while it is a zombie. */
+                if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG|WNOWAIT) < 0) {
+
+                        if (errno == ECHILD)
+                                break;
+
+                        if (errno == EINTR)
+                                continue;
+
+                        return -errno;
+                }
+
+                if (si.si_pid <= 0)
+                        break;
+
+                if (si.si_code == CLD_EXITED || si.si_code == CLD_KILLED || si.si_code == CLD_DUMPED) {
+                        char *name = NULL;
+
+                        get_process_name(si.si_pid, &name);
+                        log_debug("Got SIGCHLD for process %llu (%s)", (unsigned long long) si.si_pid, strna(name));
+                        free(name);
+                }
+
+                /* And now, we actually reap the zombie. */
+                if (waitid(P_PID, si.si_pid, &si, WEXITED) < 0) {
+                        if (errno == EINTR)
+                                continue;
+
+                        return -errno;
+                }
+
+                if (si.si_code != CLD_EXITED && si.si_code != CLD_KILLED && si.si_code != CLD_DUMPED)
+                        continue;
+
+                log_debug("Child %llu died (code=%s, status=%i/%s)",
+                          (long long unsigned) si.si_pid,
+                          sigchld_code_to_string(si.si_code),
+                          si.si_status,
+                          strna(si.si_code == CLD_EXITED ? exit_status_to_string(si.si_status) : strsignal(si.si_status)));
+
+                if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
+                        continue;
+
+                log_debug("Child %llu belongs to %s", (long long unsigned) si.si_pid, u->meta.id);
+
+                UNIT_VTABLE(u)->sigchld_event(u, si.si_pid, si.si_code, si.si_status);
+        }
+
+        return 0;
+}
+
+static void manager_start_target(Manager *m, const char *name) {
+        int r;
+
+        if ((r = manager_add_job_by_name(m, JOB_START, name, JOB_REPLACE, true, NULL)) < 0)
+                log_error("Failed to enqueue %s job: %s", name, strerror(-r));
+}
+
+static int manager_process_signal_fd(Manager *m) {
+        ssize_t n;
+        struct signalfd_siginfo sfsi;
+        bool sigchld = false;
+
+        assert(m);
+
+        for (;;) {
+                if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
+
+                        if (n >= 0)
+                                return -EIO;
+
+                        if (errno == EAGAIN)
+                                break;
+
+                        return -errno;
+                }
+
+                switch (sfsi.ssi_signo) {
+
+                case SIGCHLD:
+                        sigchld = true;
+                        break;
+
+                case SIGTERM:
+                        if (m->running_as == MANAGER_INIT)
+                                /* This is for compatibility with the
+                                 * original sysvinit */
+                                m->exit_code = MANAGER_REEXECUTE;
+                        else
+                                m->exit_code = MANAGER_EXIT;
+
+                        return 0;
+
+                case SIGINT:
+                        if (m->running_as == MANAGER_INIT) {
+                                manager_start_target(m, SPECIAL_CTRL_ALT_DEL_TARGET);
+                                break;
+                        }
+
+                        m->exit_code = MANAGER_EXIT;
+                        return 0;
+
+                case SIGWINCH:
+                        if (m->running_as == MANAGER_INIT)
+                                manager_start_target(m, SPECIAL_KBREQUEST_TARGET);
+
+                        /* This is a nop on non-init */
+                        break;
+
+                case SIGPWR:
+                        if (m->running_as == MANAGER_INIT)
+                                manager_start_target(m, SPECIAL_SIGPWR_TARGET);
+
+                        /* This is a nop on non-init */
+                        break;
+
+                case SIGUSR1: {
+                        Unit *u;
+
+                        u = manager_get_unit(m, SPECIAL_DBUS_SERVICE);
+
+                        if (!u || UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(u))) {
+                                log_info("Trying to reconnect to bus...");
+                                bus_init_system(m);
+                                bus_init_api(m);
+                        }
+
+                        if (!u || !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(u))) {
+                                log_info("Loading D-Bus service...");
+                                manager_start_target(m, SPECIAL_DBUS_SERVICE);
+                        }
+
+                        break;
+                }
+
+                case SIGUSR2:
+                        manager_dump_units(m, stdout, "\t");
+                        manager_dump_jobs(m, stdout, "\t");
+                        break;
+
+                case SIGHUP:
+                        m->exit_code = MANAGER_RELOAD;
+                        break;
+
+                default:
+                        log_info("Got unhandled signal <%s>.", strsignal(sfsi.ssi_signo));
+                }
+        }
+
+        if (sigchld)
+                return manager_dispatch_sigchld(m);
+
+        return 0;
+}
+
+static int process_event(Manager *m, struct epoll_event *ev) {
+        int r;
+        Watch *w;
+
+        assert(m);
+        assert(ev);
+
+        assert(w = ev->data.ptr);
+
+        switch (w->type) {
+
+        case WATCH_SIGNAL:
+
+                /* An incoming signal? */
+                if (ev->events != EPOLLIN)
+                        return -EINVAL;
+
+                if ((r = manager_process_signal_fd(m)) < 0)
+                        return r;
+
+                break;
+
+        case WATCH_FD:
+
+                /* Some fd event, to be dispatched to the units */
+                UNIT_VTABLE(w->data.unit)->fd_event(w->data.unit, w->fd, ev->events, w);
+                break;
+
+        case WATCH_TIMER: {
+                uint64_t v;
+                ssize_t k;
+
+                /* Some timer event, to be dispatched to the units */
+                if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
+
+                        if (k < 0 && (errno == EINTR || errno == EAGAIN))
+                                break;
+
+                        return k < 0 ? -errno : -EIO;
+                }
+
+                UNIT_VTABLE(w->data.unit)->timer_event(w->data.unit, v, w);
+                break;
+        }
+
+        case WATCH_MOUNT:
+                /* Some mount table change, intended for the mount subsystem */
+                mount_fd_event(m, ev->events);
+                break;
+
+        case WATCH_UDEV:
+                /* Some notification from udev, intended for the device subsystem */
+                device_fd_event(m, ev->events);
+                break;
+
+        case WATCH_DBUS_WATCH:
+                bus_watch_event(m, w, ev->events);
+                break;
+
+        case WATCH_DBUS_TIMEOUT:
+                bus_timeout_event(m, w, ev->events);
+                break;
+
+        default:
+                assert_not_reached("Unknown epoll event type.");
+        }
+
+        return 0;
+}
+
+int manager_loop(Manager *m) {
+        int r;
+
+        RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
+
+        assert(m);
+        m->exit_code = MANAGER_RUNNING;
+
+        while (m->exit_code == MANAGER_RUNNING) {
+                struct epoll_event event;
+                int n;
+
+                if (!ratelimit_test(&rl)) {
+                        /* Yay, something is going seriously wrong, pause a little */
+                        log_warning("Looping too fast. Throttling execution a little.");
+                        sleep(1);
+                }
+
+                if (manager_dispatch_load_queue(m) > 0)
+                        continue;
+
+                if (manager_dispatch_run_queue(m) > 0)
+                        continue;
+
+                if (bus_dispatch(m) > 0)
+                        continue;
+
+                if (manager_dispatch_cleanup_queue(m) > 0)
+                        continue;
+
+                if (manager_dispatch_gc_queue(m) > 0)
+                        continue;
+
+                if (manager_dispatch_dbus_queue(m) > 0)
+                        continue;
+
+                if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
+
+                        if (errno == EINTR)
+                                continue;
+
+                        return -errno;
+                }
+
+                assert(n == 1);
+
+                if ((r = process_event(m, &event)) < 0)
+                        return r;
+        }
+
+        return m->exit_code;
+}
+
+int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
+        char *n;
+        Unit *u;
+
+        assert(m);
+        assert(s);
+        assert(_u);
+
+        if (!startswith(s, "/org/freedesktop/systemd1/unit/"))
+                return -EINVAL;
+
+        if (!(n = bus_path_unescape(s+31)))
+                return -ENOMEM;
+
+        u = manager_get_unit(m, n);
+        free(n);
+
+        if (!u)
+                return -ENOENT;
+
+        *_u = u;
+
+        return 0;
+}
+
+int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_j) {
+        Job *j;
+        unsigned id;
+        int r;
+
+        assert(m);
+        assert(s);
+        assert(_j);
+
+        if (!startswith(s, "/org/freedesktop/systemd1/job/"))
+                return -EINVAL;
+
+        if ((r = safe_atou(s + 30, &id)) < 0)
+                return r;
+
+        if (!(j = manager_get_job(m, id)))
+                return -ENOENT;
+
+        *_j = j;
+
+        return 0;
+}
+
+static bool manager_utmp_good(Manager *m) {
+        int r;
+
+        assert(m);
+
+        if ((r = mount_path_is_mounted(m, _PATH_UTMPX)) <= 0) {
+
+                if (r < 0)
+                        log_warning("Failed to determine whether " _PATH_UTMPX " is mounted: %s", strerror(-r));
+
+                return false;
+        }
+
+        return true;
+}
+
+void manager_write_utmp_reboot(Manager *m) {
+        int r;
+
+        assert(m);
+
+        if (m->utmp_reboot_written)
+                return;
+
+        if (m->running_as != MANAGER_INIT)
+                return;
+
+        if (!manager_utmp_good(m))
+                return;
+
+        if ((r = utmp_put_reboot(m->boot_timestamp)) < 0) {
+
+                if (r != -ENOENT && r != -EROFS)
+                        log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
+
+                return;
+        }
+
+        m->utmp_reboot_written = true;
+}
+
+void manager_write_utmp_runlevel(Manager *m, Unit *u) {
+        int runlevel, r;
+
+        assert(m);
+        assert(u);
+
+        if (u->meta.type != UNIT_TARGET)
+                return;
+
+        if (m->running_as != MANAGER_INIT)
+                return;
+
+        if (!manager_utmp_good(m))
+                return;
+
+        if ((runlevel = target_get_runlevel(TARGET(u))) <= 0)
+                return;
+
+        if ((r = utmp_put_runlevel(0, runlevel, 0)) < 0) {
+
+                if (r != -ENOENT && r != -EROFS)
+                        log_warning("Failed to write utmp/wtmp: %s", strerror(-r));
+        }
+}
+
+void manager_dispatch_bus_name_owner_changed(
+                Manager *m,
+                const char *name,
+                const char* old_owner,
+                const char *new_owner) {
+
+        Unit *u;
+
+        assert(m);
+        assert(name);
+
+        if (!(u = hashmap_get(m->watch_bus, name)))
+                return;
+
+        UNIT_VTABLE(u)->bus_name_owner_change(u, name, old_owner, new_owner);
+}
+
+void manager_dispatch_bus_query_pid_done(
+                Manager *m,
+                const char *name,
+                pid_t pid) {
+
+        Unit *u;
+
+        assert(m);
+        assert(name);
+        assert(pid >= 1);
+
+        if (!(u = hashmap_get(m->watch_bus, name)))
+                return;
+
+        UNIT_VTABLE(u)->bus_query_pid_done(u, name, pid);
+}
+
+int manager_open_serialization(FILE **_f) {
+        char *path;
+        mode_t saved_umask;
+        int fd;
+        FILE *f;
+
+        assert(_f);
+
+        if (asprintf(&path, "/dev/shm/systemd-%u.dump-XXXXXX", (unsigned) getpid()) < 0)
+                return -ENOMEM;
+
+        saved_umask = umask(0077);
+        fd = mkostemp(path, O_RDWR|O_CLOEXEC);
+        umask(saved_umask);
+
+        if (fd < 0) {
+                free(path);
+                return -errno;
+        }
+
+        unlink(path);
+
+        log_debug("Serializing state to %s", path);
+        free(path);
+
+        if (!(f = fdopen(fd, "w+")) < 0)
+                return -errno;
+
+        *_f = f;
+
+        return 0;
+}
+
+int manager_serialize(Manager *m, FILE *f, FDSet *fds) {
+        Iterator i;
+        Unit *u;
+        const char *t;
+        int r;
+
+        assert(m);
+        assert(f);
+        assert(fds);
+
+        HASHMAP_FOREACH_KEY(u, t, m->units, i) {
+                if (u->meta.id != t)
+                        continue;
+
+                if (!unit_can_serialize(u))
+                        continue;
+
+                /* Start marker */
+                fputs(u->meta.id, f);
+                fputc('\n', f);
+
+                if ((r = unit_serialize(u, f, fds)) < 0)
+                        return r;
+        }
+
+        if (ferror(f))
+                return -EIO;
+
+        return 0;
+}
+
+int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
+        int r = 0;
+
+        assert(m);
+        assert(f);
+
+        log_debug("Deserializing state...");
+
+        for (;;) {
+                Unit *u;
+                char name[UNIT_NAME_MAX+2];
+
+                /* Start marker */
+                if (!fgets(name, sizeof(name), f)) {
+                        if (feof(f))
+                                break;
+
+                        return -errno;
+                }
+
+                char_array_0(name);
+
+                if ((r = manager_load_unit(m, strstrip(name), NULL, &u)) < 0)
+                        return r;
+
+                if ((r = unit_deserialize(u, f, fds)) < 0)
+                        return r;
+        }
+
+        if (ferror(f))
+                return -EIO;
+
+        return 0;
+}
+
+int manager_reload(Manager *m) {
+        int r, q;
+        FILE *f;
+        FDSet *fds;
+
+        assert(m);
+
+        if ((r = manager_open_serialization(&f)) < 0)
+                return r;
+
+        if (!(fds = fdset_new())) {
+                r = -ENOMEM;
+                goto finish;
+        }
+
+        if ((r = manager_serialize(m, f, fds)) < 0)
+                goto finish;
+
+        if (fseeko(f, 0, SEEK_SET) < 0) {
+                r = -errno;
+                goto finish;
+        }
+
+        /* From here on there is no way back. */
+        manager_clear_jobs_and_units(m);
+
+        /* First, enumerate what we can from all config files */
+        if ((q = manager_enumerate(m)) < 0)
+                r = q;
+
+        /* Second, deserialize our stored data */
+        if ((q = manager_deserialize(m, f, fds)) < 0)
+                r = q;
+
+        fclose(f);
+        f = NULL;
+
+        /* Third, fire things up! */
+        if ((q = manager_coldplug(m)) < 0)
+                r = q;
+
+finish:
+        if (f)
+                fclose(f);
+
+        if (fds)
+                fdset_free(fds);
+
+        return r;
+}
+
+static const char* const manager_running_as_table[_MANAGER_RUNNING_AS_MAX] = {
+        [MANAGER_INIT] = "init",
+        [MANAGER_SYSTEM] = "system",
+        [MANAGER_SESSION] = "session"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(manager_running_as, ManagerRunningAs);