From 4a1405998671caaaad5b24d4cef309c05175b1c1 Mon Sep 17 00:00:00 2001

From: ypf791 <ypf791@gmail.com>

Date: Fri, 19 Jul 2019 18:28:04 +0800

Subject: [PATCH] core: coldplug possible nop_job

When a unit in a state INACTIVE or DEACTIVATING, JobType JOB_TRY_RESTART or

JOB_TRY_RELOAD will be collapsed to JOB_NOP. And use u->nop_job instead

of u->job.

If a JOB_NOP job is going on with a waiting state, a parallel daemon-reload

just install it during deserialization. Without a coldplug, the job will

not be in m->run_queue, which results in a hung try-restart or

try-reload process.

Reproduce:

    run systemctl try-restart test.servcie (inactive) repeatly in a terminal.

    run systemctl daemon-reload repeatly in other terminals.

After successful reproduce, systemctl list-jobs will list the hang job.

Upsteam:

systemd/systemd#13124

(cherry picked from commit b49e14d5f3081dfcd363d8199a14c0924ae9152f)

Resolves: #1829798

---

 src/core/unit.c | 6 ++++--

 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/core/unit.c b/src/core/unit.c

index 61799bf9e3..f57260727f 100644

--- a/src/core/unit.c

+++ b/src/core/unit.c

@@ -3696,6 +3696,7 @@ int unit_add_node_dependency(Unit *u, const char *what, bool wants, UnitDependen

 int unit_coldplug(Unit *u) {

         int r = 0, q;

         char **i;

+        Job *uj;

         assert(u);

@@ -3718,8 +3719,9 @@ int unit_coldplug(Unit *u) {

                         r = q;

         }

-        if (u->job) {

-                q = job_coldplug(u->job);

+        uj = u->job ?: u->nop_job;

+        if (uj) {

+                q = job_coldplug(uj);

                 if (q < 0 && r >= 0)

                         r = q;

         }