[1.20] utils/RunUnderSystemdScope: fix wrt channel deadlock #6126
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As seen in [1], sometimes coreos/go-systemd/dbus package deadlocks: the jobCompete is stuck trying to send job result string to the channel while holding the jobListener lock, while startJob (called by StartTransientUnit) waits for the same lock. Alas, it is not clear why the channel is not being read, nor was I able to reproduce it locally. Make the job result channel buffered, so jobJistener won't block on channel send and thus StartTransientUnit won't be stuck either. While at it, - move the error wrapping out of mgr.RetryOnDisconnect function, and use fmt.Errorf with %w instead of obsoleted errors.Wrap; - improve error messages, printing the systemd unit name (so we can check it in systemd log); - do check the job result string -- in case it is not "done", return an error back to the caller, which should help avoid other issues down the line. [1] https://bugzilla.redhat.com/show_bug.cgi?id=2082344 Signed-off-by: Kir Kolyshkin <[email protected]> (cherry picked from commit 343bcdd) Signed-off-by: Kir Kolyshkin <[email protected]>
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As seen in [1], sometimes coreos/go-systemd/dbus package deadlocks: the
jobCompete is stuck trying to send job result string to the channel
while holding the jobListener lock, while startJob (called by
StartTransientUnit) waits for the same lock.
Alas, it is not clear why the channel is not being read, nor was I able
to reproduce it locally.
Make the job result channel buffered, so jobJistener won't block on
channel send and thus StartTransientUnit won't be stuck either.
While at it,
move the error wrapping out of mgr.RetryOnDisconnect function,
and use fmt.Errorf with %w instead of obsoleted errors.Wrap;
improve error messages, printing the systemd unit name (so we can
check it in systemd log);
do check the job result string -- in case it is not "done",
return an error back to the caller, which should help avoid other
issues down the line.
[1] https://bugzilla.redhat.com/show_bug.cgi?id=2082344
Cherry picked from commit 343bcdd / #5914
What type of PR is this?
/kind bug
What this PR does / why we need it:
See above.
Which issue(s) this PR fixes:
Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=2095389
Special notes for your reviewer:
None
Does this PR introduce a user-facing change?