core: add IgnoreOnSoftReboot= unit option

As it says on the tin, configures the unit to survive a soft reboot.
Currently all the following options have to be set by hand:

Conflicts=reboot.target kexec.target poweroff.target halt.target
Before=reboot.target kexec.target poweroff.target halt.target
After=sysinit.target basic.target
DefaultDependencies=no
IgnoreOnIsolate=yes

This is not very user friendly. If new default dependencies are added,
or new shutdown/reboot types, they also have to be added manually.

The new option is much simpler, easy to find, and does the right thing
by default.

1 files changed, 14 insertions, 2 deletions

diff --git a/src/core/timer.c b/src/core/timer.c
index f6e6605507..3aaebe72c6 100644
--- a/src/core/timer.c
+++ b/src/core/timer.c
@@ -94,7 +94,12 @@ static int timer_add_default_dependencies(Timer *t) {
                 return r;
 
         if (MANAGER_IS_SYSTEM(UNIT(t)->manager)) {
-                r = unit_add_two_dependencies_by_name(UNIT(t), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
+                r = unit_add_two_dependencies_by_name(UNIT(t),
+                                UNIT_AFTER,
+                                UNIT(t)->ignore_on_soft_reboot ? -EINVAL : UNIT_REQUIRES,
+                                SPECIAL_SYSINIT_TARGET,
+                                true,
+                                UNIT_DEPENDENCY_DEFAULT);
                 if (r < 0)
                         return r;
 
@@ -112,7 +117,14 @@ static int timer_add_default_dependencies(Timer *t) {
                 }
         }
 
-        return unit_add_two_dependencies_by_name(UNIT(t), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, true, UNIT_DEPENDENCY_DEFAULT);
+        if (!UNIT(t)->ignore_on_soft_reboot)
+                return unit_add_two_dependencies_by_name(
+                                UNIT(t),
+                                UNIT_BEFORE, UNIT_CONFLICTS,
+                                SPECIAL_SHUTDOWN_TARGET, true,
+                                UNIT_DEPENDENCY_DEFAULT);
+
+        return unit_add_dependencies_on_real_shutdown_targets(UNIT(t));
 }
 
 static int timer_add_trigger_dependencies(Timer *t) {