log: never delay logging if the log server is stuck, always drop messages quickly

2 files changed, 9 insertions, 30 deletions

diff --git a/src/journal/journald.c b/src/journal/journald.c
index f63a12fae8..73f8ed6ae8 100644
--- a/src/journal/journald.c
+++ b/src/journal/journald.c
@@ -66,8 +66,6 @@
 
 #define RECHECK_VAR_AVAILABLE_USEC (30*USEC_PER_SEC)
 
-#define SYSLOG_TIMEOUT_USEC (250*USEC_PER_MSEC)
-
 #define N_IOVEC_META_FIELDS 17
 
 #define ENTRY_SIZE_MAX (1024*1024*32)
@@ -2220,7 +2218,6 @@ static int open_syslog_socket(Server *s) {
         union sockaddr_union sa;
         int one, r;
         struct epoll_event ev;
-        struct timeval tv;
 
         assert(s);
 
@@ -2245,7 +2242,8 @@ static int open_syslog_socket(Server *s) {
                 }
 
                 chmod(sa.un.sun_path, 0666);
-        }
+        } else
+                fd_nonblock(s->syslog_fd, 1);
 
         one = 1;
         r = setsockopt(s->syslog_fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
@@ -2261,15 +2259,6 @@ static int open_syslog_socket(Server *s) {
                 return -errno;
         }
 
-        /* Since we use the same socket for forwarding this to some
-         * other syslog implementation, make sure we don't hang
-         * forever */
-        timeval_store(&tv, SYSLOG_TIMEOUT_USEC);
-        if (setsockopt(s->syslog_fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)) < 0) {
-                log_error("SO_SNDTIMEO failed: %m");
-                return -errno;
-        }
-
         zero(ev);
         ev.events = EPOLLIN;
         ev.data.fd = s->syslog_fd;
@@ -2309,7 +2298,8 @@ static int open_native_socket(Server*s) {
                 }
 
                 chmod(sa.un.sun_path, 0666);
-        }
+        } else
+                fd_nonblock(s->native_fd, 1);
 
         one = 1;
         r = setsockopt(s->native_fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one));
@@ -2369,7 +2359,8 @@ static int open_stdout_socket(Server *s) {
                         log_error("liste() failed: %m");
                         return -errno;
                 }
-        }
+        } else
+                fd_nonblock(s->stdout_fd, 1);
 
         zero(ev);
         ev.events = EPOLLIN;
diff --git a/src/log.c b/src/log.c
index 1a6ea7e5a8..0594f7fde5 100644
--- a/src/log.c
+++ b/src/log.c
@@ -33,8 +33,6 @@
 #include "macro.h"
 #include "socket-util.h"
 
-#define SOCKET_TIMEOUT_USEC (5*USEC_PER_SEC)
-
 static LogTarget log_target = LOG_TARGET_CONSOLE;
 static int log_max_level = LOG_INFO;
 
@@ -120,25 +118,15 @@ void log_close_syslog(void) {
 }
 
 static int create_log_socket(int type) {
-        struct timeval tv;
         int fd;
 
-        if (getpid() == 1)
-                /* systemd should not block on syslog */
-                type |= SOCK_NONBLOCK;
+        /* All output to the syslog/journal fds we do asynchronously,
+         * and if the buffers are full we just drop the messages */
 
-        fd = socket(AF_UNIX, type|SOCK_CLOEXEC, 0);
+        fd = socket(AF_UNIX, type|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
         if (fd < 0)
                 return -errno;
 
-        /* Make sure we don't block for more than 5s when talking to
-         * syslog */
-        timeval_store(&tv, SOCKET_TIMEOUT_USEC);
-        if (setsockopt(fd, SOL_SOCKET, SO_SNDTIMEO, &tv, sizeof(tv)) < 0) {
-                close_nointr_nofail(fd);
-                return -errno;
-        }
-
         return fd;
 }