From 8f7f7a1bd3a26f501b2d6546cce1c669b59dcc87 Mon Sep 17 00:00:00 2001 From: Michal Schmidt Date: Sun, 18 Dec 2011 14:57:54 +0100 Subject: log: never block on syslog in PID 1 Use a non-blocking syslog socket if logging from PID 1. If sendmsg fails with EAGAIN, fall back to kmsg or console only for the current message. Next message will try syslog again. --- src/log.c | 23 ++++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/src/log.c b/src/log.c index 5c5b734f2f..4f57821da3 100644 --- a/src/log.c +++ b/src/log.c @@ -118,6 +118,9 @@ static int create_log_socket(int type) { struct timeval tv; int fd; + if (getpid() == 1) + /* systemd should not block on syslog */ + type |= SOCK_NONBLOCK; if ((fd = socket(AF_UNIX, type|SOCK_CLOEXEC, 0)) < 0) return -errno; @@ -330,7 +333,8 @@ static int write_to_syslog( for (;;) { ssize_t n; - if ((n = sendmsg(syslog_fd, &msghdr, MSG_NOSIGNAL)) < 0) + n = sendmsg(syslog_fd, &msghdr, MSG_NOSIGNAL); + if (n < 0) return -errno; if (!syslog_is_stream || @@ -407,8 +411,10 @@ static int log_dispatch( log_target == LOG_TARGET_SYSLOG_OR_KMSG || log_target == LOG_TARGET_SYSLOG) { - if ((k = write_to_syslog(level, file, line, func, buffer)) < 0) { - log_close_syslog(); + k = write_to_syslog(level, file, line, func, buffer); + if (k < 0) { + if (k != -EAGAIN) + log_close_syslog(); log_open_kmsg(); } else if (k > 0) r++; @@ -419,16 +425,19 @@ static int log_dispatch( log_target == LOG_TARGET_SYSLOG_OR_KMSG || log_target == LOG_TARGET_KMSG)) { - if ((k = write_to_kmsg(level, file, line, func, buffer)) < 0) { + k = write_to_kmsg(level, file, line, func, buffer); + if (k < 0) { log_close_kmsg(); log_open_console(); } else if (k > 0) r++; } - if (k <= 0 && - (k = write_to_console(level, file, line, func, buffer)) < 0) - return k; + if (k <= 0) { + k = write_to_console(level, file, line, func, buffer); + if (k < 0) + return k; + } buffer = e; } while (buffer); -- cgit v1.2.3-54-g00ecf