From bbb015bed0b09ddd9e86583f15d8a9366a892c6d Mon Sep 17 00:00:00 2001
From: Michal Sekletar <msekleta@redhat.com>
Date: Fri, 20 Jul 2012 15:55:01 +0200
Subject: [PATCH] systemd: added new dependency PartOf

This should address TODO item "new dependency type to "group" services
in a target". Semantic of new dependency is as follows. Once configured
it creates dependency which will cause that all dependent units get
stopped if unit they all depend on is stopped or restarted.  Usual use
case would be configuring PartOf=some.target in template unit file
and WantedBy=some.target in [Install] section and enabling desired
number of instances. In this case starting one instance won't pull in
target but stopping or starting target(in case of WantedBy is properly
configured) will cause stop/start of all instances.
(cherry picked from commit 85e9a1010d16064ce435b84f02dc585bc645aade)
---
 man/systemd.unit.xml                  | 15 +++++++++++++++
 src/core/load-fragment-gperf.gperf.m4 |  1 +
 src/core/transaction.c                | 12 ++++++++++++
 src/core/unit.c                       |  3 ++-
 src/core/unit.h                       |  2 ++
 5 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/man/systemd.unit.xml b/man/systemd.unit.xml
index 698cbe3..5b708b3 100644
--- a/man/systemd.unit.xml
+++ b/man/systemd.unit.xml
@@ -427,6 +427,21 @@
                         </varlistentry>
 
                         <varlistentry>
+                                <term><varname>PartOf=</varname></term>
+
+                                 <listitem><para>Configures dependency
+                                 on other unit. When systemd stops or
+                                 restarts unit listed here, stop or
+                                 restart is propagated to dependent
+                                 units. Note that this is one way
+                                 dependency and changes to dependent
+                                 units does not affect listed unit. If
+                                 something else is desired, please
+                                 use some other type of dependency.
+                                 </para></listitem>
+                        </varlistentry>
+
+                        <varlistentry>
                                 <term><varname>Conflicts=</varname></term>
 
                                 <listitem><para>Configures negative
diff --git a/src/core/load-fragment-gperf.gperf.m4 b/src/core/load-fragment-gperf.gperf.m4
index e6d0db3..1489342 100644
--- a/src/core/load-fragment-gperf.gperf.m4
+++ b/src/core/load-fragment-gperf.gperf.m4
@@ -108,6 +108,7 @@ Unit.PropagatesReloadTo,         config_parse_unit_deps,             UNIT_PROPAG
 Unit.PropagateReloadTo,          config_parse_unit_deps,             UNIT_PROPAGATES_RELOAD_TO,     0
 Unit.ReloadPropagatedFrom,       config_parse_unit_deps,             UNIT_RELOAD_PROPAGATED_FROM,   0
 Unit.PropagateReloadFrom,        config_parse_unit_deps,             UNIT_RELOAD_PROPAGATED_FROM,   0
+Unit.PartOf,                     config_parse_unit_deps,             UNIT_PART_OF,                  0
 Unit.RequiresMountsFor,          config_parse_unit_requires_mounts_for, 0,                          offsetof(Unit, requires_mounts_for)
 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/transaction.c b/src/core/transaction.c
index a1cf706..1f8d803 100644
--- a/src/core/transaction.c
+++ b/src/core/transaction.c
@@ -994,6 +994,18 @@ int transaction_add_job_and_dependencies(
                                                 dbus_error_free(e);
                                 }
                         }
+
+                        SET_FOREACH(dep, ret->unit->dependencies[UNIT_CONSISTS_OF], i) {
+                                r = transaction_add_job_and_dependencies(tr, type, dep, ret, true, override, false, false, ignore_order, e);
+                                if (r < 0) {
+                                        if (r != -EBADR)
+                                                goto fail;
+
+                                        if (e)
+                                                dbus_error_free(e);
+                                }
+                        }
+
                 }
 
                 if (type == JOB_RELOAD) {
diff --git a/src/core/unit.c b/src/core/unit.c
index ca3892c..f0880a3 100644
--- a/src/core/unit.c
+++ b/src/core/unit.c
@@ -1606,7 +1606,8 @@ int unit_add_dependency(Unit *u, UnitDependency d, Unit *other, bool add_referen
                 [UNIT_TRIGGERS] = UNIT_TRIGGERED_BY,
                 [UNIT_TRIGGERED_BY] = UNIT_TRIGGERS,
                 [UNIT_PROPAGATES_RELOAD_TO] = UNIT_RELOAD_PROPAGATED_FROM,
-                [UNIT_RELOAD_PROPAGATED_FROM] = UNIT_PROPAGATES_RELOAD_TO
+                [UNIT_RELOAD_PROPAGATED_FROM] = UNIT_PROPAGATES_RELOAD_TO,
+                [UNIT_PART_OF] = UNIT_CONSISTS_OF
         };
         int r, q = 0, v = 0, w = 0;
 
diff --git a/src/core/unit.h b/src/core/unit.h
index ed31c62..992afa2 100644
--- a/src/core/unit.h
+++ b/src/core/unit.h
@@ -77,12 +77,14 @@ enum UnitDependency {
         UNIT_REQUISITE_OVERRIDABLE,
         UNIT_WANTS,
         UNIT_BINDS_TO,
+        UNIT_PART_OF,
 
         /* Inverse of the above */
         UNIT_REQUIRED_BY,             /* inverse of 'requires' and 'requisite' is 'required_by' */
         UNIT_REQUIRED_BY_OVERRIDABLE, /* inverse of 'requires_overridable' and 'requisite_overridable' is 'soft_required_by' */
         UNIT_WANTED_BY,               /* inverse of 'wants' */
         UNIT_BOUND_BY,                /* inverse of 'binds_to' */
+        UNIT_CONSISTS_OF,             /* inverse of 'part_of' */
 
         /* Negative dependencies */
         UNIT_CONFLICTS,               /* inverse of 'conflicts' is 'conflicted_by' */