From: Daan De Meyer <daan.j.demeyer@gmail.com>
Date: Thu, 20 Apr 2023 08:43:21 +0000 (+0200)
Subject: log: Log when kmsg is being ratelimited
X-Git-Tag: v254-rc1~673^2~5
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=3fe07e952515448fb04fd421376ca965947196ce;p=thirdparty%2Fsystemd.git

log: Log when kmsg is being ratelimited

Let's avoid confusing developers and users when log messages suddenly
stop getting logged to kmsg because of ratelimiting by logging an
additional message if we start ratelimiting log messages to kmsg.
---

diff --git a/src/basic/log.c b/src/basic/log.c
index d0fef3554f5..4cd2d5a4ab6 100644
--- a/src/basic/log.c
+++ b/src/basic/log.c
@@ -553,8 +553,12 @@ static int write_to_kmsg(
         if (kmsg_fd < 0)
                 return 0;
 
-        if (ratelimit_kmsg && !ratelimit_below(&ratelimit))
-                return 0;
+        if (ratelimit_kmsg && !ratelimit_below(&ratelimit)) {
+                if (ratelimit_num_dropped(&ratelimit) > 1)
+                        return 0;
+
+                buffer = "Too many messages being logged to kmsg, ignoring";
+        }
 
         xsprintf(header_priority, "<%i>", level);
         xsprintf(header_pid, "["PID_FMT"]: ", getpid_cached());