[pulseaudio-discuss] [PATCH 3/6] log: journal: Don't eat original message on logging failure

[Ahmed S. Darwish]

We fall back to syslog or stderr on journal logging failure. Do
not forget printing the original log message in that case.

Also print root cause of the systemd journal's failure.

Signed-off-by: Ahmed S. Darwish <darwish.07 at gmail.com>
---
 src/pulsecore/log.c | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/src/pulsecore/log.c b/src/pulsecore/log.c
index 0c561e8..ecbd2a8 100644
--- a/src/pulsecore/log.c
+++ b/src/pulsecore/log.c
@@ -363,7 +363,7 @@ static void log_syslog(pa_log_level_t level, char *t, char *timestamp, char *loc
     if ((local_t = pa_utf8_to_locale(t)))
         t = local_t;
 
-    syslog(level_to_syslog[level], "%s%s%s%s", timestamp, location, t, pa_strempty(bt));
+    syslog(level_to_syslog[level], "%s%s%s%s", timestamp, pa_strempty(location), t, pa_strempty(bt));
     pa_xfree(local_t);
 }
 #endif
@@ -377,7 +377,7 @@ void pa_log_levelv_meta(
         va_list ap) {
 
     char *t, *n;
-    int saved_errno = errno;
+    int saved_errno = errno, ret;
     char *bt = NULL;
     pa_log_target_type_t _target;
     pa_log_level_t _maximum_level;
@@ -386,7 +386,7 @@ void pa_log_levelv_meta(
 
     /* We don't use dynamic memory allocation here to minimize the hit
      * in RT threads */
-    char text[16*1024], location[128], timestamp[32];
+    char text[16*1024], location[128], timestamp[32], logging_error[120];
 
     pa_assert(level < PA_LOG_LEVEL_MAX);
     pa_assert(format);
@@ -507,24 +507,29 @@ void pa_log_levelv_meta(
 
 #ifdef HAVE_SYSTEMD_JOURNAL
             case PA_LOG_JOURNAL:
-                if (sd_journal_send("MESSAGE=%s", t,
+                if ((ret = sd_journal_send("MESSAGE=%s", t,
                                 "PRIORITY=%i", level_to_journal[level],
                                 "CODE_FILE=%s", file,
                                 "CODE_FUNC=%s", func,
                                 "CODE_LINE=%d", line,
                                 "PULSE_BACKTRACE=%s", pa_strempty(bt),
-                                NULL) < 0) {
+                                NULL)) < 0) {
+                    pa_log_target new_target = { .file = NULL, };
+                    pa_snprintf(logging_error, sizeof(logging_error), "Error writing logs to journal. Reason: %s",
+                                pa_cstrerror(ret));
 #ifdef HAVE_SYSLOG_H
-                    pa_log_target new_target = { .type = PA_LOG_SYSLOG, .file = NULL };
+                    new_target.type = PA_LOG_SYSLOG;
 
-                    syslog(level_to_syslog[PA_LOG_ERROR], "%s%s%s", timestamp, __FILE__,
-                           "Error writing logs to the journal. Redirect log messages to syslog.");
                     log_syslog(level, t, timestamp, location, bt);
+                    log_syslog(PA_LOG_ERROR, logging_error, timestamp, NULL, NULL);
+                    log_syslog(PA_LOG_ERROR, (char *)"Redirecting log messages to syslog.", timestamp, NULL, NULL);
 #else
-                    pa_log_target new_target = { .type = PA_LOG_STDERR, .file = NULL };
+                    new_target.type = PA_LOG_STDERR;
 
                     saved_errno = errno;
-                    fprintf(stderr, "%s\n", "Error writing logs to the journal. Redirect log messages to console.");
+                    fprintf(stderr, "%s%s%s%s\n", timestamp, location, t, bt);
+                    fprintf(stderr, "%s\n", logging_error);
+                    fprintf(stderr, "%s\n", "Redirecting log messages to console.");
 #endif
                     pa_log_set_target(&new_target);
                 }

Regards,

--
Darwish
http://darwish.chasingpointers.com