journald: fix silent loss of messages

[kmarinushkin]

Currently, systemd-journald may lose messages silently in some cases of
the reached rate limit. The expected behavior is to always log
"Suppressed ... messages".

This commit fixes the misbehavior.

Steps to reproduce:

0. Configuration:

RateLimitInterval=4s
RateLimitBurst=16

1. Before this commit - messages may become lost silently:

$ echo 'line 0' > lines.txt
$ for i in $(seq 1 1023); do echo "line $i" >> lines.txt; done
$ for i in $(seq 0 1023); do logger -f lines.txt; done
$ journalctl | less
<...>
May 23 05:00:53 target root[3312]: line 1022
May 23 05:00:53 target root[3312]: line 1023
May 23 05:00:53 target root[3313]: line 766
May 23 05:00:53 target root[3313]: line 767
<...>

2. After this commit - log "Suppressed ... messages":

$ echo 'line 0' > lines.txt
$ for i in $(seq 1 1023); do echo "line $i" >> lines.txt; done
$ for i in $(seq 0 1023); do logger -f lines.txt; done
$ journalctl | less
<...>
May 23 04:59:54 target root[3306]: line 13
May 23 04:59:54 target root[3306]: line 14
May 23 04:59:54 target systemd-journald[1422]: Suppressed 755 messages from /system.slice/system-ssh
d.slice
May 23 04:59:54 target root[3306]: line 770
May 23 04:59:54 target root[3306]: line 771
<...>

[keszybz]

Please submit this against the normal repo (https://githbu.com/systemd/systemd). This one is only for backporting patches.

[kmarinushkin]

@keszybz

This patch does not apply to the master branch of the systemd repo, as this functionality was re-written.
However, the bug exists in stable v234, so systemd-stable looks to be a good place to fix it.

How can I proceed in this situation?

[kmarinushkin]

Hello maintainers,

What is the concept for fixing bugs in stable, which cannot be backported from main git?
This PR is such a case.

Best Regards,
Kirill

[davidstrauss]

I can't speak on behalf of all the maintainers, but would this be possible to fix by making a more substantial backport from main git?

[kmarinushkin]

@davidstrauss

would this be possible to fix by making a more substantial backport from main git?

Thank you for the feedback.

I got your idea, but I cannot check this possibility. To follow this way, I would rather create a bugreport, including my patch as a proposal + steps to reproduce. In this case, we could close this PR and let someone else fix the issue following your proposal.

However, I cannot create a bugreport. Bugzilla says: "Sorry, entering a bug into the product systemd has been disabled".

So, how do I continue?

Best Regards,
Kirill

[kmarinushkin]

As this PR doesn't fit the concept of backporting, I created a corresponding issue in GitHub and close this PR.