daandemeyer / rpms / systemd

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661545
From fe81f6f734ee46a4877df6dda6e31cdc24c00a3c Mon Sep 17 00:00:00 2001
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From: =?UTF-8?q?Michal=20Koutn=C3=BD?= <mkoutny@suse.com>
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Date: Tue, 16 Jan 2018 19:22:46 +0100
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Subject: [PATCH] core/timer: Prevent timer looping when unit cannot start
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When a unit job finishes early (e.g. when fork(2) fails) triggered unit goes
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through states
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        stopped->failed (or failed->failed),
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in case a ExecStart= command fails unit passes through
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        stopped->starting->failed.
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The former transition doesn't result in unit active/inactive timestamp being
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updated and timer (OnUnitActiveSec= or OnUnitInactiveSec=) would use an expired
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timestamp triggering immediately again (repeatedly).
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This patch exploits timer's last trigger timestamp to ensure the timer isn't
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triggered more frequently than OnUnitActiveSec=/OnUnitInactiveSec= period.
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Steps to reproduce:
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0) Create sample units:
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cat >~/.config/systemd/user/looper.service <
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[Service]
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ExecStart=/usr/bin/sleep 2
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EOD
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cat >~/.config/systemd/user/looper.timer <
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[Timer]
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AccuracySec=5
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OnUnitActiveSec=5
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EOD
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1) systemctl --user daemon-reload
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2) systemctl --user start looper.timer
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   # to have first activation timestamp/sentinel
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   systemctl --user start looper.service
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o  Observe the service is being regularly triggered.
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3) systemctl set-property user@$UID.service TasksMax=2
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o  Observe the tight looping as long as the looper.service cannot be started.
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Ref: #5969
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(cherry picked from commit 204d140c4def364c47d36226e4514a7e077fa196)
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661545
Resolves: #1710302
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---
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 src/core/timer.c | 2 ++
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 1 file changed, 2 insertions(+)
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diff --git a/src/core/timer.c b/src/core/timer.c
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index d32b007c7c..1d4868643a 100644
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--- a/src/core/timer.c
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+++ b/src/core/timer.c
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@@ -416,6 +416,7 @@ static void timer_enter_waiting(Timer *t, bool initial) {
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                                 if (base <= 0)
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                                         continue;
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+                                base = MAX(base, t->last_trigger.monotonic);
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                                 break;
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@@ -428,6 +429,7 @@ static void timer_enter_waiting(Timer *t, bool initial) {
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                                 if (base <= 0)
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                                         continue;
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+                                base = MAX(base, t->last_trigger.monotonic);
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                                 break;
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