From 1f0f9f21c1b19e1e450c3c2696955fd6f442ca2b Mon Sep 17 00:00:00 2001
From: Kevin Kuehler <keur@xcf.berkeley.edu>
Date: Fri, 1 Nov 2019 00:54:03 -0700
Subject: [PATCH] core: Add triggering job mode

When used with systemctl stop, follows TRIGGERED_BY dependencies and
adds them to the same transaction.

Fixes: #3043
---
 TODO                   |  2 --
 src/core/job.c         |  1 +
 src/core/job.h         |  1 +
 src/core/manager.c     |  9 +++++++++
 src/core/transaction.c | 25 +++++++++++++++++++++++++
 src/core/transaction.h |  1 +
 6 files changed, 37 insertions(+), 2 deletions(-)

diff --git a/TODO b/TODO
index 03d38da9a0..b86784bb28 100644
--- a/TODO
+++ b/TODO
@@ -483,8 +483,6 @@ Features:
 
 * cache sd_event_now() result from before the first iteration...
 
-* add systemctl stop --job-mode=triggering that follows TRIGGERED_BY deps and adds them to the same transaction
-
 * PID1: find a way how we can reload unit file configuration for
   specific units only, without reloading the whole of systemd
 
diff --git a/src/core/job.c b/src/core/job.c
index 9537366eb9..86185296dd 100644
--- a/src/core/job.c
+++ b/src/core/job.c
@@ -1610,6 +1610,7 @@ static const char* const job_mode_table[_JOB_MODE_MAX] = {
         [JOB_FLUSH] = "flush",
         [JOB_IGNORE_DEPENDENCIES] = "ignore-dependencies",
         [JOB_IGNORE_REQUIREMENTS] = "ignore-requirements",
+        [JOB_TRIGGERING] = "triggering",
 };
 
 DEFINE_STRING_TABLE_LOOKUP(job_mode, JobMode);
diff --git a/src/core/job.h b/src/core/job.h
index 0781328a56..03ad640618 100644
--- a/src/core/job.h
+++ b/src/core/job.h
@@ -75,6 +75,7 @@ enum JobMode {
         JOB_FLUSH,               /* Flush out all other queued jobs when queueing this one */
         JOB_IGNORE_DEPENDENCIES, /* Ignore both requirement and ordering dependencies */
         JOB_IGNORE_REQUIREMENTS, /* Ignore requirement dependencies */
+        JOB_TRIGGERING,          /* Adds TRIGGERED_BY dependencies to the same transaction */
         _JOB_MODE_MAX,
         _JOB_MODE_INVALID = -1
 };
diff --git a/src/core/manager.c b/src/core/manager.c
index c9032fced8..8f523e1151 100644
--- a/src/core/manager.c
+++ b/src/core/manager.c
@@ -1740,6 +1740,9 @@ int manager_add_job(
         if (mode == JOB_ISOLATE && !unit->allow_isolate)
                 return sd_bus_error_setf(error, BUS_ERROR_NO_ISOLATION, "Operation refused, unit may not be isolated.");
 
+        if (mode == JOB_TRIGGERING && type != JOB_STOP)
+                return sd_bus_error_setf(error, SD_BUS_ERROR_INVALID_ARGS, "--job-mode=triggering is only valid for stop.");
+
         log_unit_debug(unit, "Trying to enqueue job %s/%s/%s", unit->id, job_type_to_string(type), job_mode_to_string(mode));
 
         type = job_type_collapse(type, unit);
@@ -1760,6 +1763,12 @@ int manager_add_job(
                         goto tr_abort;
         }
 
+        if (mode == JOB_TRIGGERING) {
+                r = transaction_add_triggering_jobs(tr, unit);
+                if (r < 0)
+                        goto tr_abort;
+        }
+
         r = transaction_activate(tr, m, mode, affected_jobs, error);
         if (r < 0)
                 goto tr_abort;
diff --git a/src/core/transaction.c b/src/core/transaction.c
index a0825c595c..34647281a4 100644
--- a/src/core/transaction.c
+++ b/src/core/transaction.c
@@ -1141,6 +1141,31 @@ int transaction_add_isolate_jobs(Transaction *tr, Manager *m) {
         return 0;
 }
 
+int transaction_add_triggering_jobs(Transaction *tr, Unit *u) {
+        Iterator i;
+        void *v;
+        Unit *trigger;
+        int r;
+
+        assert(tr);
+
+        HASHMAP_FOREACH_KEY(v, trigger, u->dependencies[UNIT_TRIGGERED_BY], i) {
+                /* No need to stop inactive jobs */
+                if (UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(trigger)) && !trigger->job)
+                        continue;
+
+                /* Is there already something listed for this? */
+                if (hashmap_get(tr->jobs, trigger))
+                        continue;
+
+                r = transaction_add_job_and_dependencies(tr, JOB_STOP, trigger, tr->anchor_job, true, false, false, false, NULL);
+                if (r < 0)
+                        log_unit_warning_errno(u, r, "Cannot add triggered by job, ignoring: %m");
+        }
+
+        return 0;
+}
+
 Transaction *transaction_new(bool irreversible) {
         Transaction *tr;
 
diff --git a/src/core/transaction.h b/src/core/transaction.h
index 4b5620f5c8..ba42f58e07 100644
--- a/src/core/transaction.h
+++ b/src/core/transaction.h
@@ -31,4 +31,5 @@ int transaction_add_job_and_dependencies(
                 sd_bus_error *e);
 int transaction_activate(Transaction *tr, Manager *m, JobMode mode, Set *affected, sd_bus_error *e);
 int transaction_add_isolate_jobs(Transaction *tr, Manager *m);
+int transaction_add_triggering_jobs(Transaction *tr, Unit *u);
 void transaction_abort(Transaction *tr);