From a9906d1f4aeeaa39a2d57563d23cb7cdd9283bf8 Mon Sep 17 00:00:00 2001
From: Franck Bui <fbui@suse.com>
Date: Wed, 18 Mar 2020 16:18:46 +0100
Subject: [PATCH 1/1] Revert "job: Don't mark as redundant if deps are
 relevant"

This reverts commit 097537f07a2fab3cb73aef7bc59f2a66aa93f533, which involves a
significant behavior change which at least impacts plymouth [1] and some of the
services shipped by systemd (systemd-vconsole-setup.service).

Of course some other units shipped by other packages might rely on the old
behavior [2], which makes me wonder why this patch wasn't simply reverted until
the situation gets clarified, at least that what the author of the change
thinks too [3].

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1807771
[2] https://github.com/systemd/systemd/issues/15091#issuecomment-598238061
[3] https://github.com/systemd/systemd/pull/14086#issuecomment-598600479
---
 src/core/job.c         | 51 +++++++-------------------------------------------
 src/core/job.h         |  3 +--
 src/core/transaction.c |  8 ++++----
 3 files changed, 12 insertions(+), 50 deletions(-)

diff --git a/src/core/job.c b/src/core/job.c
index 9fe30359df..8610496109 100644
--- a/src/core/job.c
+++ b/src/core/job.c
@@ -383,62 +383,25 @@ JobType job_type_lookup_merge(JobType a, JobType b) {
         return job_merging_table[(a - 1) * a / 2 + b];
 }
 
-bool job_later_link_matters(Job *j, JobType type, unsigned generation) {
-        JobDependency *l;
-
-        assert(j);
-
-        j->generation = generation;
-
-        LIST_FOREACH(subject, l, j->subject_list) {
-                UnitActiveState state = _UNIT_ACTIVE_STATE_INVALID;
-
-                /* Have we seen this before? */
-                if (l->object->generation == generation)
-                        continue;
-
-                state = unit_active_state(l->object->unit);
-                switch (type) {
-
-                case JOB_START:
-                        return IN_SET(state, UNIT_INACTIVE, UNIT_FAILED) ||
-                               job_later_link_matters(l->object, type, generation);
-
-                case JOB_STOP:
-                        return IN_SET(state, UNIT_ACTIVE, UNIT_RELOADING) ||
-                               job_later_link_matters(l->object, type, generation);
-
-                default:
-                        assert_not_reached("Invalid job type");
-                }
-        }
-
-        return false;
-}
-
-bool job_is_redundant(Job *j, unsigned generation) {
-
-        assert(j);
-
-        UnitActiveState state = unit_active_state(j->unit);
-        switch (j->type) {
+bool job_type_is_redundant(JobType a, UnitActiveState b) {
+        switch (a) {
 
         case JOB_START:
-                return IN_SET(state, UNIT_ACTIVE, UNIT_RELOADING) && !job_later_link_matters(j, JOB_START, generation);
+                return IN_SET(b, UNIT_ACTIVE, UNIT_RELOADING);
 
         case JOB_STOP:
-                return IN_SET(state, UNIT_INACTIVE, UNIT_FAILED) && !job_later_link_matters(j, JOB_STOP, generation);
+                return IN_SET(b, UNIT_INACTIVE, UNIT_FAILED);
 
         case JOB_VERIFY_ACTIVE:
-                return IN_SET(state, UNIT_ACTIVE, UNIT_RELOADING);
+                return IN_SET(b, UNIT_ACTIVE, UNIT_RELOADING);
 
         case JOB_RELOAD:
                 return
-                        state == UNIT_RELOADING;
+                        b == UNIT_RELOADING;
 
         case JOB_RESTART:
                 return
-                        state == UNIT_ACTIVATING;
+                        b == UNIT_ACTIVATING;
 
         case JOB_NOP:
                 return true;
diff --git a/src/core/job.h b/src/core/job.h
index 02b057ee06..03ad640618 100644
--- a/src/core/job.h
+++ b/src/core/job.h
@@ -196,8 +196,7 @@ _pure_ static inline bool job_type_is_superset(JobType a, JobType b) {
         return a == job_type_lookup_merge(a, b);
 }
 
-bool job_later_link_matters(Job *j, JobType type, unsigned generation);
-bool job_is_redundant(Job *j, unsigned generation);
+bool job_type_is_redundant(JobType a, UnitActiveState b) _pure_;
 
 /* Collapses a state-dependent job type into a simpler type by observing
  * the state of the unit which it is going to be applied to. */
diff --git a/src/core/transaction.c b/src/core/transaction.c
index 49f43e0327..6dc4e95beb 100644
--- a/src/core/transaction.c
+++ b/src/core/transaction.c
@@ -279,7 +279,7 @@ static int transaction_merge_jobs(Transaction *tr, sd_bus_error *e) {
         return 0;
 }
 
-static void transaction_drop_redundant(Transaction *tr, unsigned generation) {
+static void transaction_drop_redundant(Transaction *tr) {
         bool again;
 
         /* Goes through the transaction and removes all jobs of the units whose jobs are all noops. If not
@@ -299,7 +299,7 @@ static void transaction_drop_redundant(Transaction *tr, unsigned generation) {
 
                         LIST_FOREACH(transaction, k, j)
                                 if (tr->anchor_job == k ||
-                                    !job_is_redundant(k, generation) ||
+                                    !job_type_is_redundant(k->type, unit_active_state(k->unit)) ||
                                     (k->unit->job && job_type_is_conflicting(k->type, k->unit->job->type))) {
                                         keep = true;
                                         break;
@@ -732,7 +732,7 @@ int transaction_activate(
                 transaction_minimize_impact(tr);
 
         /* Third step: Drop redundant jobs */
-        transaction_drop_redundant(tr, generation++);
+        transaction_drop_redundant(tr);
 
         for (;;) {
                 /* Fourth step: Let's remove unneeded jobs that might
@@ -774,7 +774,7 @@ int transaction_activate(
         }
 
         /* Eights step: Drop redundant jobs again, if the merging now allows us to drop more. */
-        transaction_drop_redundant(tr, generation++);
+        transaction_drop_redundant(tr);
 
         /* Ninth step: check whether we can actually apply this */
         r = transaction_is_destructive(tr, mode, e);
-- 
2.16.4