From d70e1c2eb596b8144197192e2324abbb45f547a6 Mon Sep 17 00:00:00 2001

From: Jonathon Kowalski <bl0pbl33p@gmail.com>

Date: Thu, 17 Jan 2019 17:08:00 +0000

Subject: [PATCH] Change job mode of manager triggered restarts to JOB_REPLACE

Fixes: #11305

Fixes: #3260

Related: #11456

So, here's what happens in the described scenario in #11305. A unit goes

down, and that triggeres stop jobs for the other two units as they were

bound to it. Now, the timer for manager triggered restarts kicks in and

schedules a restart job with the JOB_FAIL job mode. This means there is

a stop job installed on those units, and now due to them being bound to

us they also get a restart job enqueued. This however is a conflicts, as

neither stop can merge into restart, nor restart into stop. However,

restart should be able to replace stop in any case. If the stop

procedure is ongoing, it can cancel the stop job, install itself, and

then after reaching dead finish and convert itself to a start job.

However, if we increase the timer, then it can always take those units

from inactive -> auto-restart.

We change the job mode to JOB_REPLACE so the restart job cancels the

stop job and installs itself.

Also, the original bug could be worked around by bumping RestartSec= to

avoid the conflicting.

This doesn't seem to be something that is going to break uses. That is

because for those who already had it working, there must have never been

conflicting jobs, as that would result in a desctructive transaction by

virtue of the job mode used.

After this change, the test case is able to work nicely without issues.

(cherry picked from commit 03ff2dc71ecb09272d728d458498b44f7f132f51)

Resolves: #1712524

---

 src/core/service.c | 2 +-

 1 file changed, 1 insertion(+), 1 deletion(-)

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

index 3eab749362..8342c131c8 100644

--- a/src/core/service.c

+++ b/src/core/service.c

@@ -2133,7 +2133,7 @@ static void service_enter_restart(Service *s) {

          * restarted. We use JOB_RESTART (instead of the more obvious

          * JOB_START) here so that those dependency jobs will be added

          * as well. */

-        r = manager_add_job(UNIT(s)->manager, JOB_RESTART, UNIT(s), JOB_FAIL, &error, NULL);

+        r = manager_add_job(UNIT(s)->manager, JOB_RESTART, UNIT(s), JOB_REPLACE, &error, NULL);

         if (r < 0)

                 goto fail;