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| author | Michael Chapman <mike@very.puzzling.org> | 2020-05-05 13:50:04 +1000 |
|---|---|---|
| committer | Michael Chapman <mike@very.puzzling.org> | 2020-05-05 13:56:02 +1000 |
| commit | 708961c7011b7578d3e6e10ca463d15edb62b5c1 (patch) | |
| tree | 04718bb896d254af53be3755eac1d5daf49d1b8e /test/test-path/path-modified.service | |
| parent | f285f07752d784e5fa1b84ac8cbc263c488eccd1 (diff) | |
| download | systemd-708961c7011b7578d3e6e10ca463d15edb62b5c1.tar.gz | |
core/path: recheck path specs when triggered unit changes state
As documented in systemd.path(5):
When a service unit triggered by a path unit terminates (regardless
whether it exited successfully or failed), monitored paths are
checked immediately again, and the service accordingly restarted
instantly.
This commit implements this behaviour for PathExists=, PathExistsGlob=,
and DirectoryNotEmpty=. These predicates are essentially
"level-triggered": the service should be activated whenever the
predicate is true. PathChanged= and PathModified=, on the other hand,
are "edge-triggered": the service should only be activated when the
predicate *becomes* true.
The behaviour has been broken since at least as far back as commit
8fca6944c2 ("path: stop watching path specs once we triggered the target
unit"). This commit had systemd stop monitoring inotify whenever the
triggered unit was activated. Unfortunately this meant it never updated
the ->inotify_triggered flag, so it never rechecked the path specs when
the triggered unit deactivated.
With this commit, systemd rechecks all paths specs whenever the
triggered unit deactivates. If any PathExists=, PathExistsGlob= or
DirectoryNotEmpty= predicate passes, the triggered unit is reactivated.
If the target unit is activated by something outside of the path unit,
the path unit immediately transitions to a running state. This ensures
the path unit stops monitoring inotify in this situation.
With this change in place, commit d7cf8c24d4 ("core/path: fix spurious
triggering of PathExists= on restart/reload") is no longer necessary.
The path unit (and its triggered unit) is now always active whenever
the PathExists= predicate passes, so there is no spurious restart when
systemd is reloaded or restarted.
Diffstat (limited to 'test/test-path/path-modified.service')
| -rw-r--r-- | test/test-path/path-modified.service | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/test/test-path/path-modified.service b/test/test-path/path-modified.service index f8499ec619..fb465d76bb 100644 --- a/test/test-path/path-modified.service +++ b/test/test-path/path-modified.service @@ -3,4 +3,5 @@ Description=Service Test for Path units [Service] ExecStart=/bin/true -Type=oneshot +Type=simple +RemainAfterExit=true |