systemd: Support OOMPolicy in scope units

Closes #25376.

(cherry picked from commit 5fa098357e)

man/org.freedesktop.systemd1.xml

@@ -10139,6 +10139,8 @@ node /org/freedesktop/systemd1/unit/session_2d1_2escope {
       readonly t RuntimeMaxUSec = ...;
       @org.freedesktop.DBus.Property.EmitsChangedSignal("const")
       readonly t RuntimeRandomizedExtraUSec = ...;
+      @org.freedesktop.DBus.Property.EmitsChangedSignal("const")
+      readonly s OOMPolicy = '...';
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
       readonly s Slice = '...';
       @org.freedesktop.DBus.Property.EmitsChangedSignal("false")
@@ -10313,6 +10315,8 @@ node /org/freedesktop/systemd1/unit/session_2d1_2escope {
 
     <!--property RuntimeRandomizedExtraUSec is not documented!-->
 
+    <!--property OOMPolicy is not documented!-->
+
     <!--property Slice is not documented!-->
 
     <!--property ControlGroupId is not documented!-->
@@ -10495,6 +10499,8 @@ node /org/freedesktop/systemd1/unit/session_2d1_2escope {
 
     <variablelist class="dbus-property" generated="True" extra-ref="RuntimeRandomizedExtraUSec"/>
 
+    <variablelist class="dbus-property" generated="True" extra-ref="OOMPolicy"/>
+
     <variablelist class="dbus-property" generated="True" extra-ref="Slice"/>
 
     <variablelist class="dbus-property" generated="True" extra-ref="ControlGroup"/>

src/core/dbus-scope.c

@@ -5,6 +5,7 @@
 #include "bus-get-properties.h"
 #include "dbus-cgroup.h"
 #include "dbus-kill.h"
+#include "dbus-manager.h"
 #include "dbus-scope.h"
 #include "dbus-unit.h"
 #include "dbus-util.h"
@@ -39,6 +40,7 @@ int bus_scope_method_abandon(sd_bus_message *message, void *userdata, sd_bus_err
 }
 
 static BUS_DEFINE_PROPERTY_GET_ENUM(property_get_result, scope_result, ScopeResult);
+static BUS_DEFINE_SET_TRANSIENT_PARSE(oom_policy, OOMPolicy, oom_policy_from_string);
 
 const sd_bus_vtable bus_scope_vtable[] = {
         SD_BUS_VTABLE_START(0),
@@ -47,6 +49,7 @@ const sd_bus_vtable bus_scope_vtable[] = {
         SD_BUS_PROPERTY("Result", "s", property_get_result, offsetof(Scope, result), SD_BUS_VTABLE_PROPERTY_EMITS_CHANGE),
         SD_BUS_PROPERTY("RuntimeMaxUSec", "t", bus_property_get_usec, offsetof(Scope, runtime_max_usec), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("RuntimeRandomizedExtraUSec", "t", bus_property_get_usec, offsetof(Scope, runtime_rand_extra_usec), SD_BUS_VTABLE_PROPERTY_CONST),
+        SD_BUS_PROPERTY("OOMPolicy", "s", bus_property_get_oom_policy, offsetof(Scope, oom_policy), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_SIGNAL("RequestStop", NULL, 0),
         SD_BUS_METHOD("Abandon", NULL, NULL, bus_scope_method_abandon, SD_BUS_VTABLE_UNPRIVILEGED),
         SD_BUS_VTABLE_END
@@ -77,6 +80,9 @@ static int bus_scope_set_transient_property(
         if (streq(name, "RuntimeRandomizedExtraUSec"))
                 return bus_set_transient_usec(u, name, &s->runtime_rand_extra_usec, message, flags, error);
 
+        if (streq(name, "OOMPolicy"))
+                return bus_set_transient_oom_policy(u, name, &s->oom_policy, message, flags, error);
+
         if (streq(name, "PIDs")) {
                 _cleanup_(sd_bus_creds_unrefp) sd_bus_creds *creds = NULL;
                 unsigned n = 0;

src/core/scope.c

@@ -43,6 +43,7 @@ static void scope_init(Unit *u) {
         s->timeout_stop_usec = u->manager->default_timeout_stop_usec;
         u->ignore_on_isolate = true;
         s->user = s->group = NULL;
+        s->oom_policy = _OOM_POLICY_INVALID;
 }
 
 static void scope_done(Unit *u) {
@@ -194,6 +195,11 @@ static int scope_add_extras(Scope *s) {
         if (r < 0)
                 return r;
 
+        if (s->oom_policy < 0)
+                s->oom_policy = s->cgroup_context.delegate ? OOM_CONTINUE : UNIT(s)->manager->default_oom_policy;
+
+        s->cgroup_context.memory_oom_group = s->oom_policy == OOM_KILL;
+
         return scope_add_default_dependencies(s);
 }
 
@@ -286,11 +292,13 @@ static void scope_dump(Unit *u, FILE *f, const char *prefix) {
                 "%sScope State: %s\n"
                 "%sResult: %s\n"
                 "%sRuntimeMaxSec: %s\n"
-                "%sRuntimeRandomizedExtraSec: %s\n",
+                "%sRuntimeRandomizedExtraSec: %s\n"
+                "%sOOMPolicy: %s\n",
                 prefix, scope_state_to_string(s->state),
                 prefix, scope_result_to_string(s->result),
                 prefix, FORMAT_TIMESPAN(s->runtime_max_usec, USEC_PER_SEC),
-                prefix, FORMAT_TIMESPAN(s->runtime_rand_extra_usec, USEC_PER_SEC));
+                prefix, FORMAT_TIMESPAN(s->runtime_rand_extra_usec, USEC_PER_SEC),
+                prefix, oom_policy_to_string(s->oom_policy));
 
         cgroup_context_dump(UNIT(s), f, prefix);
         kill_context_dump(&s->kill_context, f, prefix);
@@ -635,11 +643,16 @@ static void scope_notify_cgroup_oom_event(Unit *u, bool managed_oom) {
         else
                 log_unit_debug(u, "Process of control group was killed by the OOM killer.");
 
-        /* This will probably need to be modified when scope units get an oom-policy */
+        if (s->oom_policy == OOM_CONTINUE)
+                return;
+
         switch (s->state) {
 
         case SCOPE_START_CHOWN:
         case SCOPE_RUNNING:
+                scope_enter_signal(s, SCOPE_STOP_SIGTERM, SCOPE_FAILURE_OOM_KILL);
+                break;
+
         case SCOPE_STOP_SIGTERM:
                 scope_enter_signal(s, SCOPE_STOP_SIGKILL, SCOPE_FAILURE_OOM_KILL);
                 break;

src/core/scope.h

@@ -38,6 +38,8 @@ struct Scope {
 
         char *user;
         char *group;
+
+        OOMPolicy oom_policy;
 };
 
 extern const UnitVTable scope_vtable;

src/shared/bus-unit-util.c

@@ -2142,6 +2142,9 @@ static int bus_append_scope_property(sd_bus_message *m, const char *field, const
         if (STR_IN_SET(field, "User", "Group"))
                 return bus_append_string(m, field, eq);
 
+        if (streq(field, "OOMPolicy"))
+                return bus_append_string(m, field, eq);
+
         return 0;
 }