manager: merge serialization and desrialization counter into one, and increase it when reexecuting

Instead of having individual counters n_serializing and n_deserializing
have a single one n_reloading, which should be sufficient.

Set n_reloading when we are about to go down for reexecution to avoid
cgroup trimming when we free the units for reexecution.

7 files changed, 36 insertions, 32 deletions

diff --git a/src/fdset.c b/src/fdset.c
index 9bf3788849..e67fe6fabf 100644
--- a/src/fdset.c
+++ b/src/fdset.c
@@ -49,6 +49,12 @@ void fdset_free(FDSet *s) {
                  * here, so that the EBADFD that valgrind will return
                  * us on close() doesn't influence us */
 
+                /* When reloading duplicates of the private bus
+                 * connection fds and suchlike are closed here, which
+                 * has no effect at all, since they are only
+                 * duplicates. So don't be surprised about these log
+                 * messages. */
+
                 log_debug("Closing left-over fd %i", PTR_TO_FD(p));
                 close_nointr(PTR_TO_FD(p));
         }
diff --git a/src/main.c b/src/main.c
index 76a0943832..5a8ef529d2 100644
--- a/src/main.c
+++ b/src/main.c
@@ -898,6 +898,9 @@ static int prepare_reexecute(Manager *m, FILE **_f, FDSet **_fds) {
         assert(_f);
         assert(_fds);
 
+        /* Make sure nothing is really destructed when we shut down */
+        m->n_reloading ++;
+
         if ((r = manager_open_serialization(m, &f)) < 0) {
                 log_error("Failed to create serialization file: %s", strerror(-r));
                 goto fail;
diff --git a/src/manager.c b/src/manager.c
index 7b725e34d8..3291275d0a 100644
--- a/src/manager.c
+++ b/src/manager.c
@@ -595,7 +595,7 @@ int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
          * this is already known, so we increase the counter here
          * already */
         if (serialization)
-                m->n_deserializing ++;
+                m->n_reloading ++;
 
         /* First, enumerate what we can from all config files */
         r = manager_enumerate(m);
@@ -610,8 +610,8 @@ int manager_startup(Manager *m, FILE *serialization, FDSet *fds) {
                 r = q;
 
         if (serialization) {
-                assert(m->n_deserializing > 0);
-                m->n_deserializing --;
+                assert(m->n_reloading > 0);
+                m->n_reloading --;
         }
 
         return r;
@@ -2476,7 +2476,7 @@ void manager_send_unit_audit(Manager *m, Unit *u, int type, bool success) {
 
         /* Don't generate audit events if the service was already
          * started and we're just deserializing */
-        if (m->n_deserializing > 0)
+        if (m->n_reloading > 0)
                 return;
 
         if (m->running_as != MANAGER_SYSTEM)
@@ -2517,7 +2517,7 @@ void manager_send_unit_plymouth(Manager *m, Unit *u) {
 
         /* Don't generate plymouth events if the service was already
          * started and we're just deserializing */
-        if (m->n_deserializing > 0)
+        if (m->n_reloading > 0)
                 return;
 
         if (m->running_as != MANAGER_SYSTEM)
@@ -2659,7 +2659,7 @@ int manager_serialize(Manager *m, FILE *f, FDSet *fds) {
         assert(f);
         assert(fds);
 
-        m->n_serializing ++;
+        m->n_reloading ++;
 
         fprintf(f, "current-job-id=%i\n", m->current_job_id);
         fprintf(f, "taint-usr=%s\n", yes_no(m->taint_usr));
@@ -2682,13 +2682,13 @@ int manager_serialize(Manager *m, FILE *f, FDSet *fds) {
                 fputc('\n', f);
 
                 if ((r = unit_serialize(u, f, fds)) < 0) {
-                        m->n_serializing --;
+                        m->n_reloading --;
                         return r;
                 }
         }
 
-        assert(m->n_serializing > 0);
-        m->n_serializing --;
+        assert(m->n_reloading > 0);
+        m->n_reloading --;
 
         if (ferror(f))
                 return -EIO;
@@ -2708,7 +2708,7 @@ int manager_deserialize(Manager *m, FILE *f, FDSet *fds) {
 
         log_debug("Deserializing state...");
 
-        m->n_deserializing ++;
+        m->n_reloading ++;
 
         for (;;) {
                 char line[LINE_MAX], *l;
@@ -2781,8 +2781,8 @@ finish:
                 goto finish;
         }
 
-        assert(m->n_deserializing > 0);
-        m->n_deserializing --;
+        assert(m->n_reloading > 0);
+        m->n_reloading --;
 
         return r;
 }
@@ -2797,21 +2797,21 @@ int manager_reload(Manager *m) {
         if ((r = manager_open_serialization(m, &f)) < 0)
                 return r;
 
-        m->n_serializing ++;
+        m->n_reloading ++;
 
         if (!(fds = fdset_new())) {
-                m->n_serializing --;
+                m->n_reloading --;
                 r = -ENOMEM;
                 goto finish;
         }
 
         if ((r = manager_serialize(m, f, fds)) < 0) {
-                m->n_serializing --;
+                m->n_reloading --;
                 goto finish;
         }
 
         if (fseeko(f, 0, SEEK_SET) < 0) {
-                m->n_serializing --;
+                m->n_reloading --;
                 r = -errno;
                 goto finish;
         }
@@ -2820,9 +2820,6 @@ int manager_reload(Manager *m) {
         manager_clear_jobs_and_units(m);
         manager_undo_generators(m);
 
-        assert(m->n_serializing > 0);
-        m->n_serializing --;
-
         /* Find new unit paths */
         lookup_paths_free(&m->lookup_paths);
         if ((q = lookup_paths_init(&m->lookup_paths, m->running_as)) < 0)
@@ -2832,8 +2829,6 @@ int manager_reload(Manager *m) {
 
         manager_build_unit_path_cache(m);
 
-        m->n_deserializing ++;
-
         /* First, enumerate what we can from all config files */
         if ((q = manager_enumerate(m)) < 0)
                 r = q;
@@ -2849,8 +2844,8 @@ int manager_reload(Manager *m) {
         if ((q = manager_coldplug(m)) < 0)
                 r = q;
 
-        assert(m->n_deserializing > 0);
-        m->n_deserializing--;
+        assert(m->n_reloading > 0);
+        m->n_reloading--;
 
 finish:
         if (f)
diff --git a/src/manager.h b/src/manager.h
index 4557d5f0d5..22730d2176 100644
--- a/src/manager.h
+++ b/src/manager.h
@@ -223,8 +223,8 @@ struct Manager {
 
         ExecOutput default_std_output, default_std_error;
 
-        int n_serializing;
-        int n_deserializing;
+        /* non-zero if we are reloading or reexecuting, */
+        int n_reloading;
 
         unsigned n_installed_jobs;
         unsigned n_failed_jobs;
diff --git a/src/service.c b/src/service.c
index 5c7e62f3b0..b684a37cd7 100644
--- a/src/service.c
+++ b/src/service.c
@@ -1496,7 +1496,7 @@ static void service_set_state(Service *s, ServiceState state) {
 
         /* For the inactive states unit_notify() will trim the cgroup,
          * but for exit we have to do that ourselves... */
-        if (state == SERVICE_EXITED && s->meta.manager->n_deserializing <= 0)
+        if (state == SERVICE_EXITED && s->meta.manager->n_reloading <= 0)
                 cgroup_bonding_trim_list(s->meta.cgroup_bondings, true);
 
         if (old_state != state)
diff --git a/src/snapshot.c b/src/snapshot.c
index 9825f90521..270dc4f252 100644
--- a/src/snapshot.c
+++ b/src/snapshot.c
@@ -66,7 +66,7 @@ static int snapshot_load(Unit *u) {
 
         /* Make sure that only snapshots created via snapshot_create()
          * can be loaded */
-        if (!s->by_snapshot_create && s->meta.manager->n_deserializing <= 0)
+        if (!s->by_snapshot_create && s->meta.manager->n_reloading <= 0)
                 return -ENOENT;
 
         u->meta.load_state = UNIT_LOADED;
diff --git a/src/unit.c b/src/unit.c
index a2072621b0..d4142098d1 100644
--- a/src/unit.c
+++ b/src/unit.c
@@ -370,7 +370,7 @@ void unit_free(Unit *u) {
                 u->meta.manager->n_in_gc_queue--;
         }
 
-        cgroup_bonding_free_list(u->meta.cgroup_bondings, u->meta.manager->n_serializing <= 0);
+        cgroup_bonding_free_list(u->meta.cgroup_bondings, u->meta.manager->n_reloading <= 0);
 
         free(u->meta.description);
         free(u->meta.fragment_path);
@@ -1137,7 +1137,7 @@ void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, bool reload_su
          * behaviour here. For example: if a mount point is remounted
          * this function will be called too! */
 
-        if (u->meta.manager->n_deserializing <= 0) {
+        if (u->meta.manager->n_reloading <= 0) {
                 dual_timestamp ts;
 
                 dual_timestamp_get(&ts);
@@ -1225,7 +1225,7 @@ void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, bool reload_su
         } else
                 unexpected = true;
 
-        if (u->meta.manager->n_deserializing <= 0) {
+        if (u->meta.manager->n_reloading <= 0) {
 
                 /* If this state change happened without being
                  * requested by a job, then let's retroactively start
@@ -1258,7 +1258,7 @@ void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, bool reload_su
 
                 if (u->meta.type == UNIT_SERVICE &&
                     !UNIT_IS_ACTIVE_OR_RELOADING(os) &&
-                    u->meta.manager->n_deserializing <= 0) {
+                    u->meta.manager->n_reloading <= 0) {
                         /* Write audit record if we have just finished starting up */
                         manager_send_unit_audit(u->meta.manager, u, AUDIT_SERVICE_START, true);
                         u->meta.in_audit = true;
@@ -1275,7 +1275,7 @@ void unit_notify(Unit *u, UnitActiveState os, UnitActiveState ns, bool reload_su
                 if (u->meta.type == UNIT_SERVICE &&
                     UNIT_IS_INACTIVE_OR_FAILED(ns) &&
                     !UNIT_IS_INACTIVE_OR_FAILED(os) &&
-                    u->meta.manager->n_deserializing <= 0) {
+                    u->meta.manager->n_reloading <= 0) {
 
                         /* Hmm, if there was no start record written
                          * write it now, so that we always have a nice