core: remove support for RequiresOverridable= and RequisiteOverridable=

As discussed at systemd.conf 2015 and on also raised on the ML:

http://lists.freedesktop.org/archives/systemd-devel/2015-November/034880.html

This removes the two XyzOverridable= unit dependencies, that were
basically never used, and do not enhance user experience in any way.
Most folks looking for the functionality this provides probably opt for
the "ignore-dependencies" job mode, and that's probably a good idea.

Hence, let's simplify systemd's dependency engine and remove these two
dependency types (and their inverses).

The unit file parser and the dbus property parser will now redirect
the settings/properties to result in an equivalent non-overridable
dependency. In the case of the unit file parser we generate a warning,
to inform the user.

The dbus properties for this unit type stay available on the unit
objects, but they are now hidden from usual introspection and will
always return the empty list when queried.

This should provide enough compatibility for the few unit files that
actually ever made use of this.

9 files changed, 63 insertions, 66 deletions

diff --git a/src/core/dbus-unit.c b/src/core/dbus-unit.c
index 827e13497a..1fed39babb 100644
--- a/src/core/dbus-unit.c
+++ b/src/core/dbus-unit.c
@@ -118,6 +118,22 @@ static int property_get_dependencies(
         return sd_bus_message_close_container(reply);
 }
 
+static int property_get_obsolete_dependencies(
+                sd_bus *bus,
+                const char *path,
+                const char *interface,
+                const char *property,
+                sd_bus_message *reply,
+                void *userdata,
+                sd_bus_error *error) {
+
+        assert(bus);
+        assert(reply);
+
+        /* For dependency types we don't support anymore always return an empty array */
+        return sd_bus_message_append(reply, "as", 0);
+}
+
 static int property_get_description(
                 sd_bus *bus,
                 const char *path,
@@ -621,16 +637,12 @@ const sd_bus_vtable bus_unit_vtable[] = {
         SD_BUS_PROPERTY("Names", "as", property_get_names, 0, SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("Following", "s", property_get_following, 0, 0),
         SD_BUS_PROPERTY("Requires", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_REQUIRES]), SD_BUS_VTABLE_PROPERTY_CONST),
-        SD_BUS_PROPERTY("RequiresOverridable", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_REQUIRES_OVERRIDABLE]), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("Requisite", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_REQUISITE]), SD_BUS_VTABLE_PROPERTY_CONST),
-        SD_BUS_PROPERTY("RequisiteOverridable", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_REQUISITE_OVERRIDABLE]), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("Wants", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_WANTS]), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("BindsTo", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_BINDS_TO]), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("PartOf", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_PART_OF]), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("RequiredBy", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_REQUIRED_BY]), SD_BUS_VTABLE_PROPERTY_CONST),
-        SD_BUS_PROPERTY("RequiredByOverridable", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_REQUIRED_BY_OVERRIDABLE]), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("RequisiteOf", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_REQUISITE_OF]), SD_BUS_VTABLE_PROPERTY_CONST),
-        SD_BUS_PROPERTY("RequisiteOfOverridable", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_REQUISITE_OF_OVERRIDABLE]), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("WantedBy", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_WANTED_BY]), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("BoundBy", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_BOUND_BY]), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("ConsistsOf", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_CONSISTS_OF]), SD_BUS_VTABLE_PROPERTY_CONST),
@@ -644,6 +656,10 @@ const sd_bus_vtable bus_unit_vtable[] = {
         SD_BUS_PROPERTY("PropagatesReloadTo", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_PROPAGATES_RELOAD_TO]), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("ReloadPropagatedFrom", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_RELOAD_PROPAGATED_FROM]), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("JoinsNamespaceOf", "as", property_get_dependencies, offsetof(Unit, dependencies[UNIT_JOINS_NAMESPACE_OF]), SD_BUS_VTABLE_PROPERTY_CONST),
+        SD_BUS_PROPERTY("RequiresOverridable", "as", property_get_obsolete_dependencies, 0, SD_BUS_VTABLE_HIDDEN),
+        SD_BUS_PROPERTY("RequisiteOverridable", "as", property_get_obsolete_dependencies, 0, SD_BUS_VTABLE_HIDDEN),
+        SD_BUS_PROPERTY("RequiredByOverridable", "as", property_get_obsolete_dependencies, 0, SD_BUS_VTABLE_HIDDEN),
+        SD_BUS_PROPERTY("RequisiteOfOverridable", "as", property_get_obsolete_dependencies, 0, SD_BUS_VTABLE_HIDDEN),
         SD_BUS_PROPERTY("RequiresMountsFor", "as", NULL, offsetof(Unit, requires_mounts_for), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("Documentation", "as", NULL, offsetof(Unit, documentation), SD_BUS_VTABLE_PROPERTY_CONST),
         SD_BUS_PROPERTY("Description", "s", property_get_description, 0, SD_BUS_VTABLE_PROPERTY_CONST),
@@ -1108,9 +1124,15 @@ static int bus_unit_set_transient_property(
                 UnitDependency d;
                 const char *other;
 
-                d = unit_dependency_from_string(name);
-                if (d < 0)
-                        return -EINVAL;
+                if (streq(name, "RequiresOverridable"))
+                        d = UNIT_REQUIRES; /* redirect for obsolete unit dependency type */
+                else if (streq(name, "RequisiteOverridable"))
+                        d = UNIT_REQUISITE; /* same here */
+                else {
+                        d = unit_dependency_from_string(name);
+                        if (d < 0)
+                                return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "Invalid unit dependency: %s", name);
+                }
 
                 r = sd_bus_message_enter_container(message, 'a', "s");
                 if (r < 0)
diff --git a/src/core/job.c b/src/core/job.c
index 120381fc3b..6ca3e061c8 100644
--- a/src/core/job.c
+++ b/src/core/job.c
@@ -841,8 +841,6 @@ int job_finish_and_invalidate(Job *j, JobResult result, bool recursive) {
                         job_fail_dependencies(u, UNIT_REQUIRED_BY);
                         job_fail_dependencies(u, UNIT_REQUISITE_OF);
                         job_fail_dependencies(u, UNIT_BOUND_BY);
-                        job_fail_dependencies(u, UNIT_REQUIRED_BY_OVERRIDABLE);
-                        job_fail_dependencies(u, UNIT_REQUISITE_OF_OVERRIDABLE);
                 } else if (t == JOB_STOP)
                         job_fail_dependencies(u, UNIT_CONFLICTED_BY);
         }
diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index c7ec027954..4c5376d601 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -134,9 +134,7 @@ Unit.Description,                config_parse_unit_string_printf,    0,
 Unit.Documentation,              config_parse_documentation,         0,                             offsetof(Unit, documentation)
 Unit.SourcePath,                 config_parse_path,                  0,                             offsetof(Unit, source_path)
 Unit.Requires,                   config_parse_unit_deps,             UNIT_REQUIRES,                 0
-Unit.RequiresOverridable,        config_parse_unit_deps,             UNIT_REQUIRES_OVERRIDABLE,     0
 Unit.Requisite,                  config_parse_unit_deps,             UNIT_REQUISITE,                0
-Unit.RequisiteOverridable,       config_parse_unit_deps,             UNIT_REQUISITE_OVERRIDABLE,    0
 Unit.Wants,                      config_parse_unit_deps,             UNIT_WANTS,                    0
 Unit.BindsTo,                    config_parse_unit_deps,             UNIT_BINDS_TO,                 0
 Unit.BindTo,                     config_parse_unit_deps,             UNIT_BINDS_TO,                 0
@@ -150,6 +148,8 @@ Unit.ReloadPropagatedFrom,       config_parse_unit_deps,             UNIT_RELOAD
 Unit.PropagateReloadFrom,        config_parse_unit_deps,             UNIT_RELOAD_PROPAGATED_FROM,   0
 Unit.PartOf,                     config_parse_unit_deps,             UNIT_PART_OF,                  0
 Unit.JoinsNamespaceOf,           config_parse_unit_deps,             UNIT_JOINS_NAMESPACE_OF,       0
+Unit.RequiresOverridable,        config_parse_obsolete_unit_deps,    UNIT_REQUIRES,                 0
+Unit.RequisiteOverridable,       config_parse_obsolete_unit_deps,    UNIT_REQUISITE,    0
 Unit.RequiresMountsFor,          config_parse_unit_requires_mounts_for, 0,                          0
 Unit.StopWhenUnneeded,           config_parse_bool,                  0,                             offsetof(Unit, stop_when_unneeded)
 Unit.RefuseManualStart,          config_parse_bool,                  0,                             offsetof(Unit, refuse_manual_start)
diff --git a/src/core/load-fragment.c b/src/core/load-fragment.c
index 18cbbf0dcc..62cad0a0c0 100644
--- a/src/core/load-fragment.c
+++ b/src/core/load-fragment.c
@@ -98,16 +98,17 @@ int config_parse_warn_compat(
         return 0;
 }
 
-int config_parse_unit_deps(const char *unit,
-                           const char *filename,
-                           unsigned line,
-                           const char *section,
-                           unsigned section_line,
-                           const char *lvalue,
-                           int ltype,
-                           const char *rvalue,
-                           void *data,
-                           void *userdata) {
+int config_parse_unit_deps(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
 
         UnitDependency d = ltype;
         Unit *u = userdata;
@@ -146,6 +147,24 @@ int config_parse_unit_deps(const char *unit,
         return 0;
 }
 
+int config_parse_obsolete_unit_deps(
+                const char *unit,
+                const char *filename,
+                unsigned line,
+                const char *section,
+                unsigned section_line,
+                const char *lvalue,
+                int ltype,
+                const char *rvalue,
+                void *data,
+                void *userdata) {
+
+        log_syntax(unit, LOG_WARNING, filename, line, 0,
+                   "Unit dependency type %s= is obsolete, replacing by %s=, please update your unit file", lvalue, unit_dependency_to_string(ltype));
+
+        return config_parse_unit_deps(unit, filename, line, section, section_line, lvalue, ltype, rvalue, data, userdata);
+}
+
 int config_parse_unit_string_printf(
                 const char *unit,
                 const char *filename,
diff --git a/src/core/load-fragment.h b/src/core/load-fragment.h
index eb4de1582f..62300c10f9 100644
--- a/src/core/load-fragment.h
+++ b/src/core/load-fragment.h
@@ -31,6 +31,7 @@ void unit_dump_config_items(FILE *f);
 
 int config_parse_warn_compat(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_unit_deps(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
+int config_parse_obsolete_unit_deps(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_unit_string_printf(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_unit_strv_printf(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
 int config_parse_unit_path_printf(const char *unit, const char *filename, unsigned line, const char *section, unsigned section_line, const char *lvalue, int ltype, const char *rvalue, void *data, void *userdata);
diff --git a/src/core/manager.h b/src/core/manager.h
index b1f8576761..e3022488f4 100644
--- a/src/core/manager.h
+++ b/src/core/manager.h
@@ -326,8 +326,8 @@ int manager_load_unit_prepare(Manager *m, const char *name, const char *path, sd
 int manager_load_unit(Manager *m, const char *name, const char *path, sd_bus_error *e, Unit **_ret);
 int manager_load_unit_from_dbus_path(Manager *m, const char *s, sd_bus_error *e, Unit **_u);
 
-int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool force, sd_bus_error *e, Job **_ret);
-int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool force, sd_bus_error *e, Job **_ret);
+int manager_add_job(Manager *m, JobType type, Unit *unit, JobMode mode, bool override, sd_bus_error *e, Job **_ret);
+int manager_add_job_by_name(Manager *m, JobType type, const char *name, JobMode mode, bool override, sd_bus_error *e, Job **_ret);
 
 void manager_dump_units(Manager *s, FILE *f, const char *prefix);
 void manager_dump_jobs(Manager *s, FILE *f, const char *prefix);
diff --git a/src/core/target.c b/src/core/target.c
index c3e79fffc8..14f9b2e26a 100644
--- a/src/core/target.c
+++ b/src/core/target.c
@@ -52,9 +52,7 @@ static int target_add_default_dependencies(Target *t) {
 
         static const UnitDependency deps[] = {
                 UNIT_REQUIRES,
-                UNIT_REQUIRES_OVERRIDABLE,
                 UNIT_REQUISITE,
-                UNIT_REQUISITE_OVERRIDABLE,
                 UNIT_WANTS,
                 UNIT_BINDS_TO,
                 UNIT_PART_OF
diff --git a/src/core/transaction.c b/src/core/transaction.c
index 69f28c902f..31a1e1f1d3 100644
--- a/src/core/transaction.c
+++ b/src/core/transaction.c
@@ -950,17 +950,6 @@ int transaction_add_job_and_dependencies(
                                 }
                         }
 
-                        SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUIRES_OVERRIDABLE], i) {
-                                r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, !override, override, false, false, ignore_order, e);
-                                if (r < 0) {
-                                        log_unit_full(dep,
-                                                      r == -EADDRNOTAVAIL ? LOG_DEBUG : LOG_WARNING, r,
-                                                      "Cannot add dependency job, ignoring: %s",
-                                                      bus_error_message(e, r));
-                                        sd_bus_error_free(e);
-                                }
-                        }
-
                         SET_FOREACH(dep, ret->unit->dependencies[UNIT_WANTS], i) {
                                 r = transaction_add_job_and_dependencies(tr, JOB_START, dep, ret, false, false, false, false, ignore_order, e);
                                 if (r < 0) {
@@ -982,17 +971,6 @@ int transaction_add_job_and_dependencies(
                                 }
                         }
 
-                        SET_FOREACH(dep, ret->unit->dependencies[UNIT_REQUISITE_OVERRIDABLE], i) {
-                                r = transaction_add_job_and_dependencies(tr, JOB_VERIFY_ACTIVE, dep, ret, !override, override, false, false, ignore_order, e);
-                                if (r < 0) {
-                                        log_unit_full(dep,
-                                                      r == -EADDRNOTAVAIL ? LOG_DEBUG : LOG_WARNING, r,
-                                                      "Cannot add dependency job, ignoring: %s",
-                                                      bus_error_message(e, r));
-                                        sd_bus_error_free(e);
-                                }
-                        }
-
                         SET_FOREACH(dep, ret->unit->dependencies[UNIT_CONFLICTS], i) {
                                 r = transaction_add_job_and_dependencies(tr, JOB_STOP, dep, ret, true, override, true, false, ignore_order, e);
                                 if (r < 0) {
diff --git a/src/core/unit.c b/src/core/unit.c
index ccdc5191e8..2e4c720152 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -1101,9 +1101,7 @@ static int unit_add_target_dependencies(Unit *u) {
 
         static const UnitDependency deps[] = {
                 UNIT_REQUIRED_BY,
-                UNIT_REQUIRED_BY_OVERRIDABLE,
                 UNIT_REQUISITE_OF,
-                UNIT_REQUISITE_OF_OVERRIDABLE,
                 UNIT_WANTED_BY,
                 UNIT_BOUND_BY
         };
@@ -1607,9 +1605,7 @@ static void unit_check_unneeded(Unit *u) {
 
         static const UnitDependency needed_dependencies[] = {
                 UNIT_REQUIRED_BY,
-                UNIT_REQUIRED_BY_OVERRIDABLE,
                 UNIT_REQUISITE_OF,
-                UNIT_REQUISITE_OF_OVERRIDABLE,
                 UNIT_WANTED_BY,
                 UNIT_BOUND_BY,
         };
@@ -1713,11 +1709,6 @@ static void retroactively_start_dependencies(Unit *u) {
                     !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
                         manager_add_job(u->manager, JOB_START, other, JOB_REPLACE, true, NULL, NULL);
 
-        SET_FOREACH(other, u->dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
-                if (!set_get(u->dependencies[UNIT_AFTER], other) &&
-                    !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
-                        manager_add_job(u->manager, JOB_START, other, JOB_FAIL, false, NULL, NULL);
-
         SET_FOREACH(other, u->dependencies[UNIT_WANTS], i)
                 if (!set_get(u->dependencies[UNIT_AFTER], other) &&
                     !UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
@@ -1756,18 +1747,12 @@ static void check_unneeded_dependencies(Unit *u) {
         SET_FOREACH(other, u->dependencies[UNIT_REQUIRES], i)
                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
                         unit_check_unneeded(other);
-        SET_FOREACH(other, u->dependencies[UNIT_REQUIRES_OVERRIDABLE], i)
-                if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
-                        unit_check_unneeded(other);
         SET_FOREACH(other, u->dependencies[UNIT_WANTS], i)
                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
                         unit_check_unneeded(other);
         SET_FOREACH(other, u->dependencies[UNIT_REQUISITE], i)
                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
                         unit_check_unneeded(other);
-        SET_FOREACH(other, u->dependencies[UNIT_REQUISITE_OVERRIDABLE], i)
-                if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
-                        unit_check_unneeded(other);
         SET_FOREACH(other, u->dependencies[UNIT_BINDS_TO], i)
                 if (!UNIT_IS_INACTIVE_OR_DEACTIVATING(unit_active_state(other)))
                         unit_check_unneeded(other);
@@ -2135,16 +2120,12 @@ int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_referen
 
         static const UnitDependency inverse_table[_UNIT_DEPENDENCY_MAX] = {
                 [UNIT_REQUIRES] = UNIT_REQUIRED_BY,
-                [UNIT_REQUIRES_OVERRIDABLE] = UNIT_REQUIRED_BY_OVERRIDABLE,
                 [UNIT_WANTS] = UNIT_WANTED_BY,
                 [UNIT_REQUISITE] = UNIT_REQUISITE_OF,
-                [UNIT_REQUISITE_OVERRIDABLE] = UNIT_REQUISITE_OF_OVERRIDABLE,
                 [UNIT_BINDS_TO] = UNIT_BOUND_BY,
                 [UNIT_PART_OF] = UNIT_CONSISTS_OF,
                 [UNIT_REQUIRED_BY] = UNIT_REQUIRES,
-                [UNIT_REQUIRED_BY_OVERRIDABLE] = UNIT_REQUIRES_OVERRIDABLE,
                 [UNIT_REQUISITE_OF] = UNIT_REQUISITE,
-                [UNIT_REQUISITE_OF_OVERRIDABLE] = UNIT_REQUISITE_OVERRIDABLE,
                 [UNIT_WANTED_BY] = UNIT_WANTS,
                 [UNIT_BOUND_BY] = UNIT_BINDS_TO,
                 [UNIT_CONSISTS_OF] = UNIT_PART_OF,