Revert "core: do not spawn jobs or touch other units during coldplugging"

This reverts commit 6e392c9c45643d106673c6643ac8bf4e65da13c1.

We really shouldn't invent external state keeping hashmaps, if we can
keep this state in the units themselves.

16 files changed, 33 insertions, 89 deletions

diff --git a/src/core/automount.c b/src/core/automount.c
index b3e96fc2e1..6fc214b704 100644
--- a/src/core/automount.c
+++ b/src/core/automount.c
@@ -259,7 +259,7 @@ static void automount_set_state(Automount *a, AutomountState state) {
         unit_notify(UNIT(a), state_translation_table[old_state], state_translation_table[state], true);
 }
 
-static int automount_coldplug(Unit *u, Hashmap *deferred_work) {
+static int automount_coldplug(Unit *u) {
         Automount *a = AUTOMOUNT(u);
         int r;
 
diff --git a/src/core/busname.c b/src/core/busname.c
index b1b953aadf..aba2a96c1a 100644
--- a/src/core/busname.c
+++ b/src/core/busname.c
@@ -336,7 +336,7 @@ static void busname_set_state(BusName *n, BusNameState state) {
         unit_notify(UNIT(n), state_translation_table[old_state], state_translation_table[state], true);
 }
 
-static int busname_coldplug(Unit *u, Hashmap *deferred_work) {
+static int busname_coldplug(Unit *u) {
         BusName *n = BUSNAME(u);
         int r;
 
diff --git a/src/core/device.c b/src/core/device.c
index a7572306d7..63bae978a6 100644
--- a/src/core/device.c
+++ b/src/core/device.c
@@ -140,7 +140,7 @@ static void device_set_state(Device *d, DeviceState state) {
         unit_notify(UNIT(d), state_translation_table[old_state], state_translation_table[state], true);
 }
 
-static int device_coldplug(Unit *u, Hashmap *deferred_work) {
+static int device_coldplug(Unit *u) {
         Device *d = DEVICE(u);
 
         assert(d);
diff --git a/src/core/manager.c b/src/core/manager.c
index 2b04644dc1..39a868fed6 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -981,28 +981,7 @@ static int manager_coldplug(Manager *m) {
         Unit *u;
         char *k;
 
-        /*
-         * Some unit types tend to spawn jobs or check other units' state
-         * during coldplug. This is wrong because it is undefined whether the
-         * units in question have been already coldplugged (i. e. their state
-         * restored). This way, we can easily re-start an already started unit
-         * or otherwise make a wrong decision based on the unit's state.
-         *
-         * Solve this by providing a way for coldplug functions to defer
-         * such actions until after all units have been coldplugged.
-         *
-         * We store Unit* -> int(*)(Unit*).
-         *
-         * https://bugs.freedesktop.org/show_bug.cgi?id=88401
-         */
-        _cleanup_hashmap_free_ Hashmap *deferred_work = NULL;
-        int(*proc)(Unit*);
-
-        assert(m);
-
-        deferred_work = hashmap_new(&trivial_hash_ops);
-        if (!deferred_work)
-                return -ENOMEM;
+        assert(m);
 
         /* Then, let's set up their initial state. */
         HASHMAP_FOREACH_KEY(u, k, m->units, i) {
@@ -1012,17 +991,7 @@ static int manager_coldplug(Manager *m) {
                 if (u->id != k)
                         continue;
 
-                q = unit_coldplug(u, deferred_work);
-                if (q < 0)
-                        r = q;
-        }
-
-        /* After coldplugging and setting up initial state of the units,
-         * let's perform operations which spawn jobs or query units' state. */
-        HASHMAP_FOREACH_KEY(proc, u, deferred_work, i) {
-                int q;
-
-                q = proc(u);
+                q = unit_coldplug(u);
                 if (q < 0)
                         r = q;
         }
diff --git a/src/core/mount.c b/src/core/mount.c
index d3a4098f1a..eb25bcbdbe 100644
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -601,7 +601,7 @@ static void mount_set_state(Mount *m, MountState state) {
         m->reload_result = MOUNT_SUCCESS;
 }
 
-static int mount_coldplug(Unit *u, Hashmap *deferred_work) {
+static int mount_coldplug(Unit *u) {
         Mount *m = MOUNT(u);
         MountState new_state = MOUNT_DEAD;
         int r;
diff --git a/src/core/path.c b/src/core/path.c
index 6be9ac84be..fbb695d87f 100644
--- a/src/core/path.c
+++ b/src/core/path.c
@@ -438,12 +438,7 @@ static void path_set_state(Path *p, PathState state) {
 
 static void path_enter_waiting(Path *p, bool initial, bool recheck);
 
-static int path_enter_waiting_coldplug(Unit *u) {
-        path_enter_waiting(PATH(u), true, true);
-        return 0;
-}
-
-static int path_coldplug(Unit *u, Hashmap *deferred_work) {
+static int path_coldplug(Unit *u) {
         Path *p = PATH(u);
 
         assert(p);
@@ -452,10 +447,9 @@ static int path_coldplug(Unit *u, Hashmap *deferred_work) {
         if (p->deserialized_state != p->state) {
 
                 if (p->deserialized_state == PATH_WAITING ||
-                    p->deserialized_state == PATH_RUNNING) {
-                        hashmap_put(deferred_work, u, &path_enter_waiting_coldplug);
-                        path_set_state(p, PATH_WAITING);
-                } else
+                    p->deserialized_state == PATH_RUNNING)
+                        path_enter_waiting(p, true, true);
+                else
                         path_set_state(p, p->deserialized_state);
         }
 
diff --git a/src/core/scope.c b/src/core/scope.c
index 8b2bb29ed8..1c3c6bb540 100644
--- a/src/core/scope.c
+++ b/src/core/scope.c
@@ -171,7 +171,7 @@ static int scope_load(Unit *u) {
         return scope_verify(s);
 }
 
-static int scope_coldplug(Unit *u, Hashmap *deferred_work) {
+static int scope_coldplug(Unit *u) {
         Scope *s = SCOPE(u);
         int r;
 
diff --git a/src/core/service.c b/src/core/service.c
index 0e2f114135..9104347f27 100644
--- a/src/core/service.c
+++ b/src/core/service.c
@@ -879,7 +879,7 @@ static void service_set_state(Service *s, ServiceState state) {
         s->reload_result = SERVICE_SUCCESS;
 }
 
-static int service_coldplug(Unit *u, Hashmap *deferred_work) {
+static int service_coldplug(Unit *u) {
         Service *s = SERVICE(u);
         int r;
 
diff --git a/src/core/slice.c b/src/core/slice.c
index 0285c49aeb..0bebdbcbc6 100644
--- a/src/core/slice.c
+++ b/src/core/slice.c
@@ -150,7 +150,7 @@ static int slice_load(Unit *u) {
         return slice_verify(s);
 }
 
-static int slice_coldplug(Unit *u, Hashmap *deferred_work) {
+static int slice_coldplug(Unit *u) {
         Slice *t = SLICE(u);
 
         assert(t);
diff --git a/src/core/snapshot.c b/src/core/snapshot.c
index b1d8448771..b70c3beb60 100644
--- a/src/core/snapshot.c
+++ b/src/core/snapshot.c
@@ -75,7 +75,7 @@ static int snapshot_load(Unit *u) {
         return 0;
 }
 
-static int snapshot_coldplug(Unit *u, Hashmap *deferred_work) {
+static int snapshot_coldplug(Unit *u) {
         Snapshot *s = SNAPSHOT(u);
 
         assert(s);
diff --git a/src/core/socket.c b/src/core/socket.c
index dd805d51df..1f931eb986 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -1323,7 +1323,7 @@ static void socket_set_state(Socket *s, SocketState state) {
         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
 }
 
-static int socket_coldplug(Unit *u, Hashmap *deferred_work) {
+static int socket_coldplug(Unit *u) {
         Socket *s = SOCKET(u);
         int r;
 
diff --git a/src/core/swap.c b/src/core/swap.c
index 76660cc963..74f26b7a76 100644
--- a/src/core/swap.c
+++ b/src/core/swap.c
@@ -507,7 +507,7 @@ static void swap_set_state(Swap *s, SwapState state) {
                         job_add_to_run_queue(UNIT(other)->job);
 }
 
-static int swap_coldplug(Unit *u, Hashmap *deferred_work) {
+static int swap_coldplug(Unit *u) {
         Swap *s = SWAP(u);
         SwapState new_state = SWAP_DEAD;
         int r;
diff --git a/src/core/target.c b/src/core/target.c
index 5f64402475..8817ef21c4 100644
--- a/src/core/target.c
+++ b/src/core/target.c
@@ -103,7 +103,7 @@ static int target_load(Unit *u) {
         return 0;
 }
 
-static int target_coldplug(Unit *u, Hashmap *deferred_work) {
+static int target_coldplug(Unit *u) {
         Target *t = TARGET(u);
 
         assert(t);
diff --git a/src/core/timer.c b/src/core/timer.c
index 79a7540553..940550194b 100644
--- a/src/core/timer.c
+++ b/src/core/timer.c
@@ -267,12 +267,7 @@ static void timer_set_state(Timer *t, TimerState state) {
 
 static void timer_enter_waiting(Timer *t, bool initial);
 
-static int timer_enter_waiting_coldplug(Unit *u) {
-        timer_enter_waiting(TIMER(u), false);
-        return 0;
-}
-
-static int timer_coldplug(Unit *u, Hashmap *deferred_work) {
+static int timer_coldplug(Unit *u) {
         Timer *t = TIMER(u);
 
         assert(t);
@@ -280,10 +275,9 @@ static int timer_coldplug(Unit *u, Hashmap *deferred_work) {
 
         if (t->deserialized_state != t->state) {
 
-                if (t->deserialized_state == TIMER_WAITING) {
-                        hashmap_put(deferred_work, u, &timer_enter_waiting_coldplug);
-                        timer_set_state(t, TIMER_WAITING);
-                } else
+                if (t->deserialized_state == TIMER_WAITING)
+                        timer_enter_waiting(t, false);
+                else
                         timer_set_state(t, t->deserialized_state);
         }
 
diff --git a/src/core/unit.c b/src/core/unit.c
index e921b48fc4..70a2b57fa3 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -2875,34 +2875,27 @@ int unit_add_node_link(Unit *u, const char *what, bool wants) {
         return 0;
 }
 
-static int unit_add_deserialized_job_coldplug(Unit *u) {
-        int r;
-
-        r = manager_add_job(u->manager, u->deserialized_job, u, JOB_IGNORE_REQUIREMENTS, false, NULL, NULL);
-        if (r < 0)
-                return r;
-
-        u->deserialized_job = _JOB_TYPE_INVALID;
-
-        return 0;
-}
-
-int unit_coldplug(Unit *u, Hashmap *deferred_work) {
+int unit_coldplug(Unit *u) {
         int r;
 
         assert(u);
 
         if (UNIT_VTABLE(u)->coldplug)
-                if ((r = UNIT_VTABLE(u)->coldplug(u, deferred_work)) < 0)
+                if ((r = UNIT_VTABLE(u)->coldplug(u)) < 0)
                         return r;
 
         if (u->job) {
                 r = job_coldplug(u->job);
                 if (r < 0)
                         return r;
-        } else if (u->deserialized_job >= 0)
+        } else if (u->deserialized_job >= 0) {
                 /* legacy */
-                hashmap_put(deferred_work, u, &unit_add_deserialized_job_coldplug);
+                r = manager_add_job(u->manager, u->deserialized_job, u, JOB_IGNORE_REQUIREMENTS, false, NULL, NULL);
+                if (r < 0)
+                        return r;
+
+                u->deserialized_job = _JOB_TYPE_INVALID;
+        }
 
         return 0;
 }
diff --git a/src/core/unit.h b/src/core/unit.h
index 260dc451c7..be306a004b 100644
--- a/src/core/unit.h
+++ b/src/core/unit.h
@@ -303,14 +303,8 @@ struct UnitVTable {
         int (*load)(Unit *u);
 
         /* If a lot of units got created via enumerate(), this is
-         * where to actually set the state and call unit_notify().
-         *
-         * This must not reference other units (maybe implicitly through spawning
-         * jobs), because it is possible that they are not yet coldplugged.
-         * Such actions must be deferred until the end of coldplug bу adding
-         * a "Unit* -> int(*)(Unit*)" entry into the hashmap.
-         */
-        int (*coldplug)(Unit *u, Hashmap *deferred_work);
+         * where to actually set the state and call unit_notify(). */
+        int (*coldplug)(Unit *u);
 
         void (*dump)(Unit *u, FILE *f, const char *prefix);
 
@@ -546,7 +540,7 @@ int unit_deserialize(Unit *u, FILE *f, FDSet *fds);
 
 int unit_add_node_link(Unit *u, const char *what, bool wants);
 
-int unit_coldplug(Unit *u, Hashmap *deferred_work);
+int unit_coldplug(Unit *u);
 
 void unit_status_printf(Unit *u, const char *status, const char *unit_status_msg_format) _printf_(3, 0);