chiark / gitweb /
manager: merge /etc/xdg/systemd/session and /etc/systemd/session
[elogind.git] / manager.c
index 9e4fbbbaeddd0d70973817bc0c76433de776dcf4..88dc64bb655771d56055fa8bf50d29d59b046c15 100644 (file)
--- a/manager.c
+++ b/manager.c
 #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 "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 (5*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)) < 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, 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, SIGTERM) == 0);
         assert_se(sigaddset(&mask, SIGHUP) == 0);
         assert_se(sigaddset(&mask, SIGUSR1) == 0);
         assert_se(sigaddset(&mask, SIGUSR2) == 0);
-        assert_se(sigaddset(&mask, SIGPIPE) == 0);
-        assert_se(sigaddset(&mask, SIGPWR) == 0);
-        assert_se(sigaddset(&mask, SIGTTIN) == 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;
@@ -73,15 +116,8 @@ static int manager_setup_signals(Manager *m) {
         if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_watch.fd, &ev) < 0)
                 return -errno;
 
-        if (m->running_as == MANAGER_INIT) {
-                /* Enable that we get SIGINT on control-alt-del */
-                if (reboot(RB_DISABLE_CAD) < 0)
-                        log_warning("Failed to enable ctrl-alt-del handling: %s", strerror(errno));
-
-                /* Enable that we get SIGWINCH on kbrequest */
-                if (ioctl(0, KDSIGACCEPT, SIGWINCH) < 0)
-                        log_warning("Failed to enable kbrequest handling: %s", strerror(errno));
-        }
+        if (m->running_as == MANAGER_INIT)
+                return enable_special_signals(m);
 
         return 0;
 }
@@ -113,12 +149,12 @@ static char** session_dirs(void) {
         }
 
         if ((e = getenv("XDG_CONFIG_DIRS")))
-                config_dirs = strv_split(e, ":");
-        else
-                config_dirs = strv_new("/etc/xdg", NULL);
+                if (!(config_dirs = strv_split(e, ":")))
+                        goto fail;
 
-        if (!config_dirs)
-                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)
@@ -218,7 +254,7 @@ static int manager_find_paths(Manager *m) {
         }
 
         if (m->running_as == MANAGER_INIT) {
-                /* /etc/init.d/ compativility does not matter to users */
+                /* /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)))
@@ -280,7 +316,7 @@ static int manager_find_paths(Manager *m) {
         return 0;
 }
 
-int manager_new(ManagerRunningAs running_as, Manager **_m) {
+int manager_new(ManagerRunningAs running_as, bool confirm_spawn, Manager **_m) {
         Manager *m;
         int r = -ENOMEM;
 
@@ -291,10 +327,19 @@ int manager_new(ManagerRunningAs running_as, Manager **_m) {
         if (!(m = new0(Manager, 1)))
                 return -ENOMEM;
 
+        m->boot_timestamp = now(CLOCK_REALTIME);
+
         m->running_as = running_as;
-        m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = -1;
+        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;
 
@@ -310,6 +355,9 @@ int manager_new(ManagerRunningAs running_as, Manager **_m) {
         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;
 
@@ -351,10 +399,113 @@ static unsigned manager_dispatch_cleanup_queue(Manager *m) {
         return n;
 }
 
-void manager_free(Manager *m) {
-        UnitType c;
-        Unit *u;
+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);
 
@@ -363,14 +514,23 @@ void manager_free(Manager *m) {
 
         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);
 
-        manager_shutdown_cgroup(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);
@@ -379,56 +539,88 @@ void manager_free(Manager *m) {
         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(m->epoll_fd);
+                close_nointr_nofail(m->epoll_fd);
         if (m->signal_watch.fd >= 0)
-                close_nointr(m->signal_watch.fd);
+                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);
 
-        assert(hashmap_isempty(m->cgroup_bondings));
         hashmap_free(m->cgroup_bondings);
 
         free(m);
 }
 
-int manager_coldplug(Manager *m) {
-        int r;
+int manager_enumerate(Manager *m) {
+        int r = 0, q;
         UnitType c;
-        Iterator i;
-        Unit *u;
-        char *k;
 
         assert(m);
 
-        /* First, let's ask every type to load all units from
-         * disk/kernel that it might know */
+        /* 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 ((r = unit_vtable[c]->enumerate(m)) < 0)
-                                return r;
+                        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 (unit_id(u) != k)
+                if (u->meta.id != k)
                         continue;
 
                 if (UNIT_VTABLE(u)->coldplug)
-                        if ((r = UNIT_VTABLE(u)->coldplug(u)) < 0)
-                                return r;
+                        if ((q = UNIT_VTABLE(u)->coldplug(u)) < 0)
+                                r = q;
         }
 
-        return 0;
+        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) {
@@ -531,7 +723,7 @@ static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, Job
 
         j->type = t;
         j->state = JOB_WAITING;
-        j->forced = j->forced || other->forced;
+        j->override = j->override || other->override;
 
         j->matters_to_anchor = j->matters_to_anchor || other->matters_to_anchor;
 
@@ -603,7 +795,7 @@ static int delete_one_unmergeable_job(Manager *m, Job *j) {
                                 return -ENOEXEC;
 
                         /* Ok, we can drop one, so let's do so. */
-                        log_debug("Trying to fix job merging by deleting job %s/%s", unit_id(d->unit), job_type_to_string(d->type));
+                        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;
                 }
@@ -703,7 +895,7 @@ static void transaction_drop_redundant(Manager *m) {
                         if (changes_something)
                                 continue;
 
-                        log_debug("Found redundant job %s/%s, dropping.", unit_id(j->unit), job_type_to_string(j->type));
+                        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;
@@ -749,17 +941,17 @@ static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned
                  * since smart how we are we stored our way back in
                  * there. */
 
-                log_debug("Found ordering cycle on %s/%s", unit_id(j->unit), job_type_to_string(j->type));
+                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", unit_id(k->unit), job_type_to_string(k->type));
+                        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", unit_id(k->unit), job_type_to_string(k->type));
+                                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;
                         }
@@ -840,7 +1032,7 @@ static void transaction_collect_garbage(Manager *m) {
                         if (j->object_list)
                                 continue;
 
-                        log_debug("Garbage collecting job %s/%s", unit_id(j->unit), job_type_to_string(j->type));
+                        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;
@@ -849,7 +1041,7 @@ static void transaction_collect_garbage(Manager *m) {
         } while (again);
 }
 
-static int transaction_is_destructive(Manager *m, JobMode mode) {
+static int transaction_is_destructive(Manager *m) {
         Iterator i;
         Job *j;
 
@@ -908,13 +1100,13 @@ static void transaction_minimize_impact(Manager *m) {
                                         continue;
 
                                 if (stops_running_service)
-                                        log_debug("%s/%s would stop a running service.", unit_id(j->unit), job_type_to_string(j->type));
+                                        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.", unit_id(j->unit), job_type_to_string(j->type));
+                                        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.", unit_id(j->unit), job_type_to_string(j->type));
+                                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;
@@ -928,7 +1120,7 @@ static void transaction_minimize_impact(Manager *m) {
         } while (again);
 }
 
-static int transaction_apply(Manager *m, JobMode mode) {
+static int transaction_apply(Manager *m) {
         Iterator i;
         Job *j;
         int r;
@@ -1048,13 +1240,13 @@ static int transaction_activate(Manager *m, JobMode mode) {
 
         /* Ninth step: check whether we can actually apply this */
         if (mode == JOB_FAIL)
-                if ((r = transaction_is_destructive(m, mode)) < 0) {
+                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, mode)) < 0) {
+        if ((r = transaction_apply(m)) < 0) {
                 log_debug("Failed to apply transaction: %s", strerror(-r));
                 goto rollback;
         }
@@ -1069,7 +1261,7 @@ rollback:
         return r;
 }
 
-static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool force, bool *is_new) {
+static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool override, bool *is_new) {
         Job *j, *f;
         int r;
 
@@ -1100,7 +1292,7 @@ static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool f
         j->generation = 0;
         j->marker = NULL;
         j->matters_to_anchor = false;
-        j->forced = force;
+        j->override = override;
 
         LIST_PREPEND(Job, transaction, f, j);
 
@@ -1112,7 +1304,7 @@ static Job* transaction_add_one_job(Manager *m, JobType type, Unit *unit, bool f
         if (is_new)
                 *is_new = true;
 
-        log_debug("Added job %s/%s to transaction.", unit_id(unit), job_type_to_string(type));
+        log_debug("Added job %s/%s to transaction.", unit->meta.id, job_type_to_string(type));
 
         return j;
 }
@@ -1143,14 +1335,21 @@ void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies
 
                 if (other && delete_dependencies) {
                         log_debug("Deleting job %s/%s as dependency of job %s/%s",
-                                  unit_id(other->unit), job_type_to_string(other->type),
-                                  unit_id(j->unit), job_type_to_string(j->type));
+                                  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 force, Job **_ret) {
+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;
@@ -1168,7 +1367,7 @@ static int transaction_add_job_and_dependencies(Manager *m, JobType type, Unit *
                 return -EBADR;
 
         /* First add the job. */
-        if (!(ret = transaction_add_one_job(m, type, unit, force, &is_new)))
+        if (!(ret = transaction_add_one_job(m, type, unit, override, &is_new)))
                 return -ENOMEM;
 
         /* Then, add a link to the job. */
@@ -1179,28 +1378,33 @@ static int transaction_add_job_and_dependencies(Manager *m, JobType type, Unit *
                 /* 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, force, NULL)) < 0 && r != -EBADR)
-                                        goto fail;
-                        SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUIRES], i)
-                                if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
+                                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, force, NULL)) < 0)
-                                        log_warning("Cannot add dependency job for unit %s, ignoring: %s", unit_id(dep), strerror(-r));
+                                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, force, NULL)) < 0 && r != -EBADR)
-                                        goto fail;
-                        SET_FOREACH(dep, ret->unit->meta.dependencies[UNIT_SOFT_REQUISITE], i)
-                                if ((r = transaction_add_job_and_dependencies(m, JOB_VERIFY_ACTIVE, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
+                                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, force, NULL)) < 0 && r != -EBADR)
+                                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, force, NULL)) < 0 && r != -EBADR)
+                                if ((r = transaction_add_job_and_dependencies(m, type, dep, ret, true, override, NULL)) < 0 && r != -EBADR)
                                         goto fail;
                 }
 
@@ -1216,7 +1420,39 @@ fail:
         return r;
 }
 
-int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool force, Job **_ret) {
+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;
 
@@ -1225,17 +1461,26 @@ int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool for
         assert(unit);
         assert(mode < _JOB_MODE_MAX);
 
-        log_debug("Trying to enqueue job %s/%s", unit_id(unit), job_type_to_string(type));
+        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, force, &ret)) < 0) {
+        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_id(unit), job_type_to_string(type), (unsigned) ret->id);
+        log_debug("Enqueued job %s/%s as %u", unit->meta.id, job_type_to_string(type), (unsigned) ret->id);
 
         if (_ret)
                 *_ret = ret;
@@ -1243,6 +1488,21 @@ int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool for
         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);
 
@@ -1282,19 +1542,24 @@ unsigned manager_dispatch_load_queue(Manager *m) {
         return n;
 }
 
-int manager_load_unit(Manager *m, const char *path, Unit **_ret) {
+int manager_load_unit_prepare(Manager *m, const char *name, const char *path, Unit **_ret) {
         Unit *ret;
         int r;
-        const char *name;
 
         assert(m);
-        assert(path);
-        assert(_ret);
+        assert(name || path);
 
-        /* This will load the service information files, but not actually
-         * start any services or anything. */
+        /* This will prepare the unit for loading, but not actually
+         * load anything from disk. */
+
+        if (path && !is_path(path))
+                return -EINVAL;
 
-        name = file_name_from_path(path);
+        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;
@@ -1304,12 +1569,11 @@ int manager_load_unit(Manager *m, const char *path, Unit **_ret) {
         if (!(ret = unit_new(m)))
                 return -ENOMEM;
 
-        if (is_path(path)) {
+        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);
@@ -1319,9 +1583,29 @@ int manager_load_unit(Manager *m, const char *path, Unit **_ret) {
         unit_add_to_load_queue(ret);
         unit_add_to_dbus_queue(ret);
 
+        if (_ret)
+                *_ret = ret;
+
+        return 0;
+}
+
+int manager_load_unit(Manager *m, const char *name, const char *path, Unit **_ret) {
+        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);
 
-        *_ret = unit_follow_merge(ret);
+        if (_ret)
+                *_ret = unit_follow_merge(ret);
+
         return 0;
 }
 
@@ -1345,7 +1629,7 @@ void manager_dump_units(Manager *s, FILE *f, const char *prefix) {
         assert(f);
 
         HASHMAP_FOREACH_KEY(u, t, s->units, i)
-                if (unit_id(u) == t)
+                if (u->meta.id == t)
                         unit_dump(u, f, prefix);
 }
 
@@ -1419,26 +1703,53 @@ static int manager_dispatch_sigchld(Manager *m) {
                 Unit *u;
 
                 zero(si);
-                if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG) < 0) {
+
+                /* 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)
+                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)", (long long unsigned) si.si_pid, sigchld_code_to_string(si.si_code), si.si_status);
+                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, unit_id(u));
+                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);
         }
@@ -1446,7 +1757,14 @@ static int manager_dispatch_sigchld(Manager *m) {
         return 0;
 }
 
-static int manager_process_signal_fd(Manager *m, bool *quit) {
+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;
@@ -1467,62 +1785,69 @@ static int manager_process_signal_fd(Manager *m, bool *quit) {
 
                 switch (sfsi.ssi_signo) {
 
-                case SIGCHLD: {
-                        char *name = NULL;
-
-                        get_process_name(sfsi.ssi_pid, &name);
-                        log_debug("Got SIGCHLD for process %llu (%s)", (unsigned long long) sfsi.ssi_pid, strna(name));
-                        free(name);
-
+                case SIGCHLD:
                         sigchld = true;
                         break;
-                }
 
-                case SIGINT:
                 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;
 
-                        if (m->running_as != MANAGER_INIT) {
-                                *quit = true;
-                                return 0;
-
-                        } else {
-                                Unit *target;
-                                int r;
-
-                                if ((r = manager_load_unit(m, SPECIAL_CTRL_ALT_DEL_TARGET, &target)) < 0)
-                                        log_error("Failed to load ctrl-alt-del target: %s", strerror(-r));
-                                else if ((r = manager_add_job(m, JOB_START, target, JOB_REPLACE, true, NULL)) < 0)
-                                        log_error("Failed to enqueue ctrl-alt-del job: %s", strerror(-r));
+                        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);
 
-                        if (m->running_as == MANAGER_INIT) {
-                                Unit *target;
-                                int r;
+                        /* This is a nop on non-init */
+                        break;
 
-                                if ((r = manager_load_unit(m, SPECIAL_KBREQUEST_TARGET, &target)) < 0)
-                                        log_error("Failed to load kbrequest target: %s", strerror(-r));
-                                else if ((r = manager_add_job(m, JOB_START, target, JOB_REPLACE, true, NULL)) < 0)
-                                        log_error("Failed to enqueue kbrequest job: %s", strerror(-r));
+                case SIGPWR:
+                        if (m->running_as == MANAGER_INIT)
+                                manager_start_target(m, SPECIAL_SIGPWR_TARGET);
 
-                                break;
+                        /* 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);
                         }
 
-                        /* This is a nop on non-init systemd's */
+                        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 SIGUSR1:
-
-                        printf("→ By units:\n");
+                case SIGUSR2:
                         manager_dump_units(m, stdout, "\t");
-
-                        printf("→ By jobs:\n");
                         manager_dump_jobs(m, stdout, "\t");
+                        break;
 
+                case SIGHUP:
+                        m->exit_code = MANAGER_RELOAD;
                         break;
 
                 default:
@@ -1536,7 +1861,7 @@ static int manager_process_signal_fd(Manager *m, bool *quit) {
         return 0;
 }
 
-static int process_event(Manager *m, struct epoll_event *ev, bool *quit) {
+static int process_event(Manager *m, struct epoll_event *ev) {
         int r;
         Watch *w;
 
@@ -1553,7 +1878,7 @@ static int process_event(Manager *m, struct epoll_event *ev, bool *quit) {
                 if (ev->events != EPOLLIN)
                         return -EINVAL;
 
-                if ((r = manager_process_signal_fd(m, quit)) < 0)
+                if ((r = manager_process_signal_fd(m)) < 0)
                         return r;
 
                 break;
@@ -1608,13 +1933,13 @@ static int process_event(Manager *m, struct epoll_event *ev, bool *quit) {
 
 int manager_loop(Manager *m) {
         int r;
-        bool quit = false;
 
         RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
 
         assert(m);
+        m->exit_code = MANAGER_RUNNING;
 
-        do {
+        while (m->exit_code == MANAGER_RUNNING) {
                 struct epoll_event event;
                 int n;
 
@@ -1627,6 +1952,9 @@ int manager_loop(Manager *m) {
                 if (manager_dispatch_cleanup_queue(m) > 0)
                         continue;
 
+                if (manager_dispatch_gc_queue(m) > 0)
+                        continue;
+
                 if (manager_dispatch_load_queue(m) > 0)
                         continue;
 
@@ -1641,7 +1969,7 @@ int manager_loop(Manager *m) {
 
                 if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
 
-                        if (errno == -EINTR)
+                        if (errno == EINTR)
                                 continue;
 
                         return -errno;
@@ -1649,11 +1977,11 @@ int manager_loop(Manager *m) {
 
                 assert(n == 1);
 
-                if ((r = process_event(m, &event, &quit)) < 0)
+                if ((r = process_event(m, &event)) < 0)
                         return r;
-        } while (!quit);
+        }
 
-        return 0;
+        return m->exit_code;
 }
 
 int manager_get_unit_from_dbus_path(Manager *m, const char *s, Unit **_u) {
@@ -1704,6 +2032,256 @@ int manager_get_job_from_dbus_path(Manager *m, const char *s, Job **_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",