chiark / gitweb /
manager: if wanted dependencies are invalid, don't fail
[elogind.git] / manager.c
index 3430b97bc10e7851ed791e1f36f733cec801ea8d..87941e3f56f4dfab2d2ac65f38b1e81dc8f28dd0 100644 (file)
--- a/manager.c
+++ b/manager.c
@@ -1,5 +1,24 @@
 /*-*- 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/wait.h>
 #include <unistd.h>
 #include <sys/poll.h>
+#include <sys/reboot.h>
+#include <sys/ioctl.h>
+#include <linux/kd.h>
+#include <libcgroup.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"
 
-Manager* manager_new(void) {
-        Manager *m;
+static int manager_setup_signals(Manager *m) {
         sigset_t mask;
         struct epoll_event ev;
 
+        assert(m);
+
+        assert_se(reset_all_signal_handlers() == 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(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) {
+                /* 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));
+        }
+
+        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")))
+                config_dirs = strv_split(e, ":");
+        else
+                config_dirs = strv_new("/etc/xdg", NULL);
+
+        if (!config_dirs)
+                goto fail;
+
+        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/ compativility 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;
+                }
+        }
+
+        strv_uniq(m->unit_path);
+        strv_uniq(m->sysvinit_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.");
+
+        return 0;
+}
+
+int manager_new(Manager **_m) {
+        Manager *m;
+        int r = -ENOMEM;
+
+        assert(_m);
+
         if (!(m = new0(Manager, 1)))
-                return NULL;
+                return -ENOMEM;
 
-        m->signal_fd = m->epoll_fd = -1;
+        m->signal_watch.fd = m->mount_watch.fd = m->udev_watch.fd = m->epoll_fd = -1;
+        m->current_job_id = 1; /* start as id #1, so that we can leave #0 around as "null-like" value */
 
         if (!(m->units = hashmap_new(string_hash_func, string_compare_func)))
                 goto fail;
@@ -38,31 +282,69 @@ Manager* manager_new(void) {
         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->epoll_fd = epoll_create1(EPOLL_CLOEXEC)) < 0)
                 goto fail;
 
-        assert_se(sigemptyset(&mask) == 0);
-        assert_se(sigaddset(&mask, SIGCHLD) == 0);
-        assert_se(sigprocmask(SIG_SETMASK, &mask, NULL) == 0);
+        if (getpid() == 1)
+                m->running_as = MANAGER_INIT;
+        else if (getuid() == 0)
+                m->running_as = MANAGER_SYSTEM;
+        else
+                m->running_as = MANAGER_SESSION;
+
+        log_debug("systemd running in %s mode.", manager_running_as_to_string(m->running_as));
 
-        if ((m->signal_fd = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC)) < 0)
+        if ((r = manager_find_paths(m)) < 0)
                 goto fail;
 
-        zero(ev);
-        ev.events = EPOLLIN;
-        ev.data.fd = m->signal_fd;
+        if (chdir("/") < 0)
+                log_warning("Failed to chdir to /: %s", strerror(errno));
+
+        /* Become a session leader if we aren't one yet. */
+        setsid();
+
+        if ((r = manager_setup_signals(m)) < 0)
+                goto fail;
+
+        if ((r = mount_setup()) < 0)
+                goto fail;
+
+        if ((r = manager_setup_cgroup(m)) < 0)
+                goto fail;
 
-        if (epoll_ctl(m->epoll_fd, EPOLL_CTL_ADD, m->signal_fd, &ev) < 0)
+        /* FIXME: this should be called only when the D-Bus bus daemon is running */
+        if ((r = bus_init(m)) < 0)
                 goto fail;
 
-        return m;
+        *_m = m;
+        return 0;
 
 fail:
         manager_free(m);
-        return NULL;
+        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;
 }
 
 void manager_free(Manager *m) {
+        UnitType c;
         Unit *u;
         Job *j;
 
@@ -74,6 +356,16 @@ void manager_free(Manager *m) {
         while ((u = hashmap_first(m->units)))
                 unit_free(u);
 
+        manager_dispatch_cleanup_queue(m);
+
+        for (c = 0; c < _UNIT_TYPE_MAX; c++)
+                if (unit_vtable[c]->shutdown)
+                        unit_vtable[c]->shutdown(m);
+
+        manager_shutdown_cgroup(m);
+
+        bus_done(m);
+
         hashmap_free(m->units);
         hashmap_free(m->jobs);
         hashmap_free(m->transaction_jobs);
@@ -81,19 +373,61 @@ void manager_free(Manager *m) {
 
         if (m->epoll_fd >= 0)
                 close_nointr(m->epoll_fd);
-        if (m->signal_fd >= 0)
-                close_nointr(m->signal_fd);
+        if (m->signal_watch.fd >= 0)
+                close_nointr(m->signal_watch.fd);
+
+        strv_free(m->unit_path);
+        strv_free(m->sysvinit_path);
+
+        free(m->cgroup_controller);
+        free(m->cgroup_hierarchy);
+
+        assert(hashmap_isempty(m->cgroup_bondings));
+        hashmap_free(m->cgroup_bondings);
 
         free(m);
 }
 
-static void transaction_delete_job(Manager *m, Job *j) {
+int manager_coldplug(Manager *m) {
+        int r;
+        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 */
+        for (c = 0; c < _UNIT_TYPE_MAX; c++)
+                if (unit_vtable[c]->enumerate)
+                        if ((r = unit_vtable[c]->enumerate(m)) < 0)
+                                return r;
+
+        manager_dispatch_load_queue(m);
+
+        /* Then, let's set up their initial state. */
+        HASHMAP_FOREACH_KEY(u, k, m->units, i) {
+
+                /* ignore aliases */
+                if (unit_id(u) != k)
+                        continue;
+
+                if (UNIT_VTABLE(u)->coldplug)
+                        if ((r = UNIT_VTABLE(u)->coldplug(u)) < 0)
+                                return r;
+        }
+
+        return 0;
+}
+
+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);
+        manager_transaction_unlink_job(m, j, delete_dependencies);
 
         if (!j->installed)
                 job_free(j);
@@ -106,7 +440,7 @@ static void transaction_delete_unit(Manager *m, Unit *u) {
          * transaction */
 
         while ((j = hashmap_get(m->transaction_jobs, u)))
-                transaction_delete_job(m, j);
+                transaction_delete_job(m, j, true);
 }
 
 static void transaction_clean_dependencies(Manager *m) {
@@ -134,7 +468,7 @@ static void transaction_abort(Manager *m) {
 
         while ((j = hashmap_first(m->transaction_jobs)))
                 if (j->installed)
-                        transaction_delete_job(m, j);
+                        transaction_delete_job(m, j, true);
                 else
                         job_free(j);
 
@@ -226,7 +560,7 @@ static void transaction_merge_and_delete_job(Manager *m, Job *j, Job *other, Job
         /* Kill the other job */
         other->subject_list = NULL;
         other->object_list = NULL;
-        transaction_delete_job(m, other);
+        transaction_delete_job(m, other, true);
 }
 
 static int delete_one_unmergeable_job(Manager *m, Job *j) {
@@ -259,8 +593,8 @@ static int delete_one_unmergeable_job(Manager *m, Job *j) {
                                 return -ENOEXEC;
 
                         /* Ok, we can drop one, so let's do so. */
-                        log_debug("Try to fix job merging by deleting job %s/%s", unit_id(d->unit), job_type_to_string(d->type));
-                        transaction_delete_job(m, d);
+                        log_debug("Trying to fix job merging by deleting job %s/%s", unit_id(d->unit), job_type_to_string(d->type));
+                        transaction_delete_job(m, d, true);
                         return 0;
                 }
 
@@ -328,6 +662,46 @@ static int transaction_merge_jobs(Manager *m) {
         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.", unit_id(j->unit), 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);
@@ -365,8 +739,12 @@ 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));
+
                 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));
+
                         if (!k->installed &&
                             !unit_matters_to_anchor(k->unit, k)) {
                                 /* Ok, we can drop this one, so let's
@@ -382,6 +760,8 @@ static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned
                                 break;
                 }
 
+                log_debug("Unable to break cycle");
+
                 return -ENOEXEC;
         }
 
@@ -408,6 +788,10 @@ static int transaction_verify_order_one(Manager *m, Job *j, Job *from, unsigned
                         return r;
         }
 
+        /* Ok, let's backtrack, and remember that this entry is not on
+         * our path anymore. */
+        j->marker = NULL;
+
         return 0;
 }
 
@@ -447,7 +831,7 @@ static void transaction_collect_garbage(Manager *m) {
                                 continue;
 
                         log_debug("Garbage collecting job %s/%s", unit_id(j->unit), job_type_to_string(j->type));
-                        transaction_delete_job(m, j);
+                        transaction_delete_job(m, j, true);
                         again = true;
                         break;
                 }
@@ -494,6 +878,7 @@ static void transaction_minimize_impact(Manager *m) {
 
                 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)
@@ -502,13 +887,26 @@ static void transaction_minimize_impact(Manager *m) {
                                 /* Would this stop a running service?
                                  * Would this change an existing job?
                                  * If so, let's drop this entry */
-                                if ((j->type != JOB_STOP || UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(j->unit))) &&
-                                    (!j->unit->meta.job  || job_type_is_conflicting(j->type, j->unit->meta.job->state)))
+
+                                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.", unit_id(j->unit), 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));
+
                                 /* 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));
-                                transaction_delete_job(m, j);
+                                log_debug("Deleting %s/%s to minimize impact.", unit_id(j->unit), job_type_to_string(j->type));
+
+                                transaction_delete_job(m, j, true);
                                 again = true;
                                 break;
                         }
@@ -555,6 +953,8 @@ static int transaction_apply(Manager *m, JobMode mode) {
                 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. */
@@ -591,34 +991,41 @@ static int transaction_activate(Manager *m, JobMode mode) {
          * jobs if we don't have to. */
         transaction_minimize_impact(m);
 
+        /* Third step: Drop redundant jobs */
+        transaction_drop_redundant(m);
+
         for (;;) {
-                /* Third step: Let's remove unneeded jobs that might
+                /* Fourth step: Let's remove unneeded jobs that might
                  * be lurking. */
                 transaction_collect_garbage(m);
 
-                /* Fourth step: verify order makes sense and correct
+                /* 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)
+                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 (;;) {
-                /* Fifth step: let's drop unmergeable entries if
+                /* 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)
+                if (r != -EAGAIN) {
+                        log_debug("Requested transaction contains unmergable jobs: %s", strerror(-r));
                         goto rollback;
+                }
 
-                /* Sixth step: an entry got dropped, let's garbage
+                /* Seventh step: an entry got dropped, let's garbage
                  * collect its dependencies. */
                 transaction_collect_garbage(m);
 
@@ -626,14 +1033,21 @@ static int transaction_activate(Manager *m, JobMode mode) {
                  * unmergeable entries ... */
         }
 
-        /* Seventh step: check whether we can actually apply this */
+        /* 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, mode)) < 0)
+                if ((r = transaction_is_destructive(m, mode)) < 0) {
+                        log_debug("Requested transaction contradicts existing jobs: %s", strerror(-r));
                         goto rollback;
+                }
 
-        /* Eights step: apply changes */
-        if ((r = transaction_apply(m, mode)) < 0)
+        /* Tenth step: apply changes */
+        if ((r = transaction_apply(m, mode)) < 0) {
+                log_debug("Failed to apply transaction: %s", strerror(-r));
                 goto rollback;
+        }
 
         assert(hashmap_isempty(m->transaction_jobs));
         assert(!m->transaction_anchor);
@@ -688,10 +1102,12 @@ 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));
+
         return j;
 }
 
-void manager_transaction_unlink_job(Manager *m, Job *j) {
+void manager_transaction_unlink_job(Manager *m, Job *j, bool delete_dependencies) {
         assert(m);
         assert(j);
 
@@ -715,11 +1131,11 @@ void manager_transaction_unlink_job(Manager *m, Job *j) {
 
                 job_dependency_free(j->object_list);
 
-                if (other) {
+                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));
-                        transaction_delete_job(m, other);
+                        transaction_delete_job(m, other, delete_dependencies);
                 }
         }
 }
@@ -759,8 +1175,8 @@ static int transaction_add_job_and_dependencies(Manager *m, JobType type, Unit *
                                 if ((r = transaction_add_job_and_dependencies(m, JOB_START, dep, ret, !force, force, NULL)) < 0 && r != -EBADR)
                                         goto fail;
                         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 && r != -EBADR)
-                                        goto fail;
+                                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));
                         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;
@@ -781,6 +1197,9 @@ static int transaction_add_job_and_dependencies(Manager *m, JobType type, Unit *
                 /* JOB_VERIFY_STARTED, JOB_RELOAD require no dependency handling */
         }
 
+        if (_ret)
+                *_ret = ret;
+
         return 0;
 
 fail:
@@ -796,7 +1215,9 @@ int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool for
         assert(unit);
         assert(mode < _JOB_MODE_MAX);
 
-        if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, force, &ret))) {
+        log_debug("Trying to enqueue job %s/%s", unit_id(unit), job_type_to_string(type));
+
+        if ((r = transaction_add_job_and_dependencies(m, type, unit, NULL, true, force, &ret)) < 0) {
                 transaction_abort(m);
                 return r;
         }
@@ -804,6 +1225,8 @@ int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool for
         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);
+
         if (_ret)
                 *_ret = ret;
 
@@ -823,14 +1246,15 @@ Unit *manager_get_unit(Manager *m, const char *name) {
         return hashmap_get(m->units, name);
 }
 
-static void dispatch_load_queue(Manager *m) {
+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;
+                return 0;
 
         m->dispatching_load_queue = true;
 
@@ -841,9 +1265,11 @@ static void dispatch_load_queue(Manager *m) {
                 assert(meta->in_load_queue);
 
                 unit_load(UNIT(meta));
+                n++;
         }
 
         m->dispatching_load_queue = false;
+        return n;
 }
 
 int manager_load_unit(Manager *m, const char *path, Unit **_ret) {
@@ -869,7 +1295,7 @@ int manager_load_unit(Manager *m, const char *path, Unit **_ret) {
                 return -ENOMEM;
 
         if (is_path(path)) {
-                if (!(ret->meta.load_path = strdup(path))) {
+                if (!(ret->meta.fragment_path = strdup(path))) {
                         unit_free(ret);
                         return -ENOMEM;
                 }
@@ -881,9 +1307,11 @@ int manager_load_unit(Manager *m, const char *path, Unit **_ret) {
         }
 
         unit_add_to_load_queue(ret);
-        dispatch_load_queue(m);
+        unit_add_to_dbus_queue(ret);
+
+        manager_dispatch_load_queue(m);
 
-        *_ret = ret;
+        *_ret = unit_follow_merge(ret);
         return 0;
 }
 
@@ -922,11 +1350,12 @@ void manager_clear_jobs(Manager *m) {
                 job_free(j);
 }
 
-void manager_dispatch_run_queue(Manager *m) {
+unsigned manager_dispatch_run_queue(Manager *m) {
         Job *j;
+        unsigned n = 0;
 
         if (m->dispatching_run_queue)
-                return;
+                return 0;
 
         m->dispatching_run_queue = true;
 
@@ -935,21 +1364,60 @@ void manager_dispatch_run_queue(Manager *m) {
                 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);
 
+        log_debug("dispatching SIGCHLD");
+
         for (;;) {
                 siginfo_t si;
                 Unit *u;
 
                 zero(si);
-                if (waitid(P_ALL, 0, &si, WNOHANG) < 0)
+                if (waitid(P_ALL, 0, &si, WEXITED|WNOHANG) < 0) {
+
+                        if (errno == ECHILD)
+                                break;
+
                         return -errno;
+                }
 
                 if (si.si_pid == 0)
                         break;
@@ -957,6 +1425,8 @@ static int manager_dispatch_sigchld(Manager *m) {
                 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);
+
                 if (!(u = hashmap_remove(m->watch_pids, UINT32_TO_PTR(si.si_pid))))
                         continue;
 
@@ -966,7 +1436,7 @@ static int manager_dispatch_sigchld(Manager *m) {
         return 0;
 }
 
-static int manager_process_signal_fd(Manager *m) {
+static int manager_process_signal_fd(Manager *m, bool *quit) {
         ssize_t n;
         struct signalfd_siginfo sfsi;
         bool sigchld = false;
@@ -974,19 +1444,63 @@ static int manager_process_signal_fd(Manager *m) {
         assert(m);
 
         for (;;) {
-                if ((n = read(m->signal_fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
+                if ((n = read(m->signal_watch.fd, &sfsi, sizeof(sfsi))) != sizeof(sfsi)) {
 
                         if (n >= 0)
                                 return -EIO;
 
                         if (errno == EAGAIN)
-                                return 0;
+                                break;
 
                         return -errno;
                 }
 
-                if (sfsi.ssi_signo == SIGCHLD)
+                switch (sfsi.ssi_signo) {
+
+                case SIGCHLD:
                         sigchld = true;
+                        break;
+
+                case SIGINT:
+                case SIGTERM:
+
+                        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));
+
+                                break;
+                        }
+
+                case SIGWINCH:
+
+                        if (m->running_as == MANAGER_INIT) {
+                                Unit *target;
+                                int r;
+
+                                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));
+
+                                break;
+                        }
+
+                        /* This is a nop on non-init systemd's */
+
+                        break;
+
+                default:
+                        log_info("Got unhandled signal <%s>.", strsignal(sfsi.ssi_signo));
+                }
         }
 
         if (sigchld)
@@ -995,56 +1509,71 @@ static int manager_process_signal_fd(Manager *m) {
         return 0;
 }
 
-static int process_event(Manager *m, struct epoll_event *ev) {
+static int process_event(Manager *m, struct epoll_event *ev, bool *quit) {
         int r;
+        Watch *w;
 
         assert(m);
         assert(ev);
 
-        switch (ev->data.u32) {
+        assert(w = ev->data.ptr);
 
-                case MANAGER_SIGNAL:
-                        assert(ev->data.fd == m->signal_fd);
+        switch (w->type) {
 
-                        /* An incoming signal? */
-                        if (ev->events != POLLIN)
-                                return -EINVAL;
+        case WATCH_SIGNAL:
 
-                        if ((r = manager_process_signal_fd(m)) < 0)
-                                return -r;
+                /* An incoming signal? */
+                if (ev->events != EPOLLIN)
+                        return -EINVAL;
 
-                        break;
+                if ((r = manager_process_signal_fd(m, quit)) < 0)
+                        return r;
 
-                case MANAGER_FD: {
-                        Unit *u;
+                break;
 
-                        /* Some fd event, to be dispatched to the units */
-                        assert_se(u = ev->data.ptr);
-                        UNIT_VTABLE(u)->fd_event(u, ev->data.fd, ev->events);
-                        break;
-                }
+        case WATCH_FD:
 
-                case MANAGER_TIMER: {
-                        Unit *u;
-                        uint64_t v;
-                        ssize_t k;
+                /* 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;
 
-                        /* Some timer event, to be dispatched to the units */
-                        if ((k = read(ev->data.fd, &v, sizeof(v))) != sizeof(v)) {
+        case WATCH_TIMER: {
+                uint64_t v;
+                ssize_t k;
 
-                                if (k < 0 && (errno == EINTR || errno == EAGAIN))
-                                        break;
+                /* Some timer event, to be dispatched to the units */
+                if ((k = read(w->fd, &v, sizeof(v))) != sizeof(v)) {
 
-                                return k < 0 ? -errno : -EIO;
-                        }
+                        if (k < 0 && (errno == EINTR || errno == EAGAIN))
+                                break;
 
-                        assert_se(u = ev->data.ptr);
-                        UNIT_VTABLE(u)->timer_event(u, ev->data.fd, v);
-                        break;
+                        return k < 0 ? -errno : -EIO;
                 }
 
-                default:
-                        assert_not_reached("Unknown epoll event type.");
+                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;
@@ -1052,16 +1581,38 @@ static int process_event(Manager *m, struct epoll_event *ev) {
 
 int manager_loop(Manager *m) {
         int r;
+        bool quit = false;
+
+        RATELIMIT_DEFINE(rl, 1*USEC_PER_SEC, 1000);
 
         assert(m);
 
-        for (;;) {
-                struct epoll_event events[32];
-                int n, i;
+        do {
+                struct epoll_event event;
+                int n;
 
-                manager_dispatch_run_queue(m);
+                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 ((n = epoll_wait(m->epoll_fd, events, ELEMENTSOF(events), -1)) < 0) {
+                if (manager_dispatch_cleanup_queue(m) > 0)
+                        continue;
+
+                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_dbus_queue(m) > 0)
+                        continue;
+
+                if ((n = epoll_wait(m->epoll_fd, &event, 1, -1)) < 0) {
 
                         if (errno == -EINTR)
                                 continue;
@@ -1069,8 +1620,67 @@ int manager_loop(Manager *m) {
                         return -errno;
                 }
 
-                for (i = 0; i < n; i++)
-                        if ((r = process_event(m, events + i)) < 0)
-                                return r;
-        }
+                assert(n == 1);
+
+                if ((r = process_event(m, &event, &quit)) < 0)
+                        return r;
+        } while (!quit);
+
+        return 0;
 }
+
+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 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);