core,network: major per-object logging rework

This changes log_unit_info() (and friends) to take a real Unit* object
insted of just a unit name as parameter. The call will now prefix all
logged messages with the unit name, thus allowing the unit name to be
dropped from the various passed romat strings, simplifying invocations
drastically, and unifying log output across messages. Also, UNIT= vs.
USER_UNIT= is now derived from the Manager object attached to the Unit
object, instead of getpid(). This has the benefit of correcting the
field for --test runs.

Also contains a couple of other logging improvements:

- Drops a couple of strerror() invocations in favour of using %m.

- Not only .mount units now warn if a symlinks exist for the mount
  point already, .automount units do that too, now.

- A few invocations of log_struct() that didn't actually pass any
  additional structured data have been replaced by simpler invocations
  of log_unit_info() and friends.

- For structured data a new LOG_UNIT_MESSAGE() macro has been added,
  that works like LOG_MESSAGE() but prefixes the message with the unit
  name. Similar, there's now LOG_LINK_MESSAGE() and
  LOG_NETDEV_MESSAGE().

- For structured data new LOG_UNIT_ID(), LOG_LINK_INTERFACE(),
  LOG_NETDEV_INTERFACE() macros have been added that generate the
  necessary per object fields. The old log_unit_struct() call has been
  removed in favour of these new macros used in raw log_struct()
  invocations. In addition to removing one more function call this
  allows generated structured log messages that contain two object
  fields, as necessary for example for network interfaces that are
  joined into another network interface, and whose messages shall be
  indexed by both.

- The LOG_ERRNO() macro has been removed, in favour of
  log_struct_errno(). The latter has the benefit of ensuring that %m in
  format strings is properly resolved to the specified error number.

- A number of logging messages have been converted to use
  log_unit_info() instead of log_info()

- The client code in sysv-generator no longer #includes core code from
  src/core/.

- log_unit_full_errno() has been removed, log_unit_full() instead takes
  an errno now, too.

- log_unit_info(), log_link_info(), log_netdev_info() and friends, now
  avoid double evaluation of their parameters

1 files changed, 82 insertions, 94 deletions

diff --git a/src/core/socket.c b/src/core/socket.c
index 3fb3b362e1..33682073c9 100644
--- a/src/core/socket.c
+++ b/src/core/socket.c
@@ -398,33 +398,32 @@ static int socket_verify(Socket *s) {
                 return 0;
 
         if (!s->ports) {
-                log_unit_error(UNIT(s)->id, "%s lacks Listen setting. Refusing.", UNIT(s)->id);
+                log_unit_error(UNIT(s), "Unit lacks Listen setting. Refusing.");
                 return -EINVAL;
         }
 
         if (s->accept && have_non_accept_socket(s)) {
-                log_unit_error(UNIT(s)->id, "%s configured for accepting sockets, but sockets are non-accepting. Refusing.",
-                               UNIT(s)->id);
+                log_unit_error(UNIT(s), "Unit configured for accepting sockets, but sockets are non-accepting. Refusing.");
                 return -EINVAL;
         }
 
         if (s->accept && s->max_connections <= 0) {
-                log_unit_error(UNIT(s)->id, "%s's MaxConnection setting too small. Refusing.", UNIT(s)->id);
+                log_unit_error(UNIT(s), "MaxConnection= setting too small. Refusing.");
                 return -EINVAL;
         }
 
         if (s->accept && UNIT_DEREF(s->service)) {
-                log_unit_error(UNIT(s)->id, "Explicit service configuration for accepting sockets not supported on %s. Refusing.", UNIT(s)->id);
+                log_unit_error(UNIT(s), "Explicit service configuration for accepting socket units not supported. Refusing.");
                 return -EINVAL;
         }
 
         if (s->exec_context.pam_name && s->kill_context.kill_mode != KILL_CONTROL_GROUP) {
-                log_unit_error(UNIT(s)->id, "%s has PAM enabled. Kill mode must be set to 'control-group'. Refusing.", UNIT(s)->id);
+                log_unit_error(UNIT(s), "Unit has PAM enabled. Kill mode must be set to 'control-group'. Refusing.");
                 return -EINVAL;
         }
 
         if (!strv_isempty(s->symlinks) && !socket_find_symlink_target(s)) {
-                log_unit_error(UNIT(s)->id, "%s has symlinks set but none or more than one node in the file system. Refusing.", UNIT(s)->id);
+                log_unit_error(UNIT(s), "Unit has symlinks set but none or more than one node in the file system. Refusing.");
                 return -EINVAL;
         }
 
@@ -822,60 +821,60 @@ static void socket_apply_socket_options(Socket *s, int fd) {
         if (s->keep_alive) {
                 int b = s->keep_alive;
                 if (setsockopt(fd, SOL_SOCKET, SO_KEEPALIVE, &b, sizeof(b)) < 0)
-                        log_unit_warning(UNIT(s)->id, "SO_KEEPALIVE failed: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "SO_KEEPALIVE failed: %m");
         }
 
         if (s->keep_alive_time) {
                 int value = s->keep_alive_time / USEC_PER_SEC;
                 if (setsockopt(fd, SOL_TCP, TCP_KEEPIDLE, &value, sizeof(value)) < 0)
-                        log_unit_warning(UNIT(s)->id, "TCP_KEEPIDLE failed: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "TCP_KEEPIDLE failed: %m");
         }
 
         if (s->keep_alive_interval) {
                 int value =  s->keep_alive_interval / USEC_PER_SEC;
                 if (setsockopt(fd, SOL_TCP, TCP_KEEPINTVL, &value, sizeof(value)) < 0)
-                        log_unit_warning(UNIT(s)->id, "TCP_KEEPINTVL failed: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "TCP_KEEPINTVL failed: %m");
         }
 
         if (s->keep_alive_cnt) {
                 int value = s->keep_alive_cnt;
                 if (setsockopt(fd, SOL_SOCKET, TCP_KEEPCNT, &value, sizeof(value)) < 0)
-                        log_unit_warning(UNIT(s)->id, "TCP_KEEPCNT failed: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "TCP_KEEPCNT failed: %m");
         }
 
         if (s->defer_accept) {
                 int value = s->defer_accept / USEC_PER_SEC;
                 if (setsockopt(fd, SOL_TCP, TCP_DEFER_ACCEPT, &value, sizeof(value)) < 0)
-                        log_unit_warning(UNIT(s)->id, "TCP_DEFER_ACCEPT failed: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "TCP_DEFER_ACCEPT failed: %m");
         }
 
         if (s->no_delay) {
                 int b = s->no_delay;
                 if (setsockopt(fd, SOL_TCP, TCP_NODELAY, &b, sizeof(b)) < 0)
-                        log_unit_warning(UNIT(s)->id, "TCP_NODELAY failed: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "TCP_NODELAY failed: %m");
         }
 
         if (s->broadcast) {
                 int one = 1;
                 if (setsockopt(fd, SOL_SOCKET, SO_BROADCAST, &one, sizeof(one)) < 0)
-                        log_unit_warning(UNIT(s)->id, "SO_BROADCAST failed: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "SO_BROADCAST failed: %m");
         }
 
         if (s->pass_cred) {
                 int one = 1;
                 if (setsockopt(fd, SOL_SOCKET, SO_PASSCRED, &one, sizeof(one)) < 0)
-                        log_unit_warning(UNIT(s)->id, "SO_PASSCRED failed: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "SO_PASSCRED failed: %m");
         }
 
         if (s->pass_sec) {
                 int one = 1;
                 if (setsockopt(fd, SOL_SOCKET, SO_PASSSEC, &one, sizeof(one)) < 0)
-                        log_unit_warning(UNIT(s)->id, "SO_PASSSEC failed: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "SO_PASSSEC failed: %m");
         }
 
         if (s->priority >= 0)
                 if (setsockopt(fd, SOL_SOCKET, SO_PRIORITY, &s->priority, sizeof(s->priority)) < 0)
-                        log_unit_warning(UNIT(s)->id, "SO_PRIORITY failed: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "SO_PRIORITY failed: %m");
 
         if (s->receive_buffer > 0) {
                 int value = (int) s->receive_buffer;
@@ -884,23 +883,23 @@ static void socket_apply_socket_options(Socket *s, int fd) {
 
                 if (setsockopt(fd, SOL_SOCKET, SO_RCVBUFFORCE, &value, sizeof(value)) < 0)
                         if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &value, sizeof(value)) < 0)
-                                log_unit_warning(UNIT(s)->id, "SO_RCVBUF failed: %m");
+                                log_unit_warning_errno(UNIT(s), errno, "SO_RCVBUF failed: %m");
         }
 
         if (s->send_buffer > 0) {
                 int value = (int) s->send_buffer;
                 if (setsockopt(fd, SOL_SOCKET, SO_SNDBUFFORCE, &value, sizeof(value)) < 0)
                         if (setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &value, sizeof(value)) < 0)
-                                log_unit_warning(UNIT(s)->id, "SO_SNDBUF failed: %m");
+                                log_unit_warning_errno(UNIT(s), errno, "SO_SNDBUF failed: %m");
         }
 
         if (s->mark >= 0)
                 if (setsockopt(fd, SOL_SOCKET, SO_MARK, &s->mark, sizeof(s->mark)) < 0)
-                        log_unit_warning(UNIT(s)->id, "SO_MARK failed: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "SO_MARK failed: %m");
 
         if (s->ip_tos >= 0)
                 if (setsockopt(fd, IPPROTO_IP, IP_TOS, &s->ip_tos, sizeof(s->ip_tos)) < 0)
-                        log_unit_warning(UNIT(s)->id, "IP_TOS failed: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "IP_TOS failed: %m");
 
         if (s->ip_ttl >= 0) {
                 int x;
@@ -915,30 +914,29 @@ static void socket_apply_socket_options(Socket *s, int fd) {
                 }
 
                 if (r < 0 && x < 0)
-                        log_unit_warning(UNIT(s)->id,
-                                         "IP_TTL/IPV6_UNICAST_HOPS failed: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "IP_TTL/IPV6_UNICAST_HOPS failed: %m");
         }
 
         if (s->tcp_congestion)
                 if (setsockopt(fd, SOL_TCP, TCP_CONGESTION, s->tcp_congestion, strlen(s->tcp_congestion)+1) < 0)
-                        log_unit_warning(UNIT(s)->id, "TCP_CONGESTION failed: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "TCP_CONGESTION failed: %m");
 
         if (s->reuse_port) {
                 int b = s->reuse_port;
                 if (setsockopt(fd, SOL_SOCKET, SO_REUSEPORT, &b, sizeof(b)) < 0)
-                        log_unit_warning(UNIT(s)->id, "SO_REUSEPORT failed: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "SO_REUSEPORT failed: %m");
         }
 
         if (s->smack_ip_in) {
                 r = mac_smack_apply_ip_in_fd(fd, s->smack_ip_in);
                 if (r < 0)
-                        log_unit_error_errno(UNIT(s)->id, r, "mac_smack_apply_ip_in_fd: %m");
+                        log_unit_error_errno(UNIT(s), r, "mac_smack_apply_ip_in_fd: %m");
         }
 
         if (s->smack_ip_out) {
                 r = mac_smack_apply_ip_out_fd(fd, s->smack_ip_out);
                 if (r < 0)
-                        log_unit_error_errno(UNIT(s)->id, r, "mac_smack_apply_ip_out_fd: %m");
+                        log_unit_error_errno(UNIT(s), r, "mac_smack_apply_ip_out_fd: %m");
         }
 }
 
@@ -950,12 +948,12 @@ static void socket_apply_fifo_options(Socket *s, int fd) {
 
         if (s->pipe_size > 0)
                 if (fcntl(fd, F_SETPIPE_SZ, s->pipe_size) < 0)
-                        log_unit_warning(UNIT(s)->id, "F_SETPIPE_SZ: %m");
+                        log_unit_warning_errno(UNIT(s), errno, "F_SETPIPE_SZ: %m");
 
         if (s->smack) {
                 r = mac_smack_apply_fd(fd, s->smack);
                 if (r < 0)
-                        log_unit_error_errno(UNIT(s)->id, r, "mac_smack_apply_fd: %m");
+                        log_unit_error_errno(UNIT(s), r, "mac_smack_apply_fd: %m");
         }
 }
 
@@ -1256,7 +1254,7 @@ static void socket_unwatch_fds(Socket *s) {
 
                 r = sd_event_source_set_enabled(p->event_source, SD_EVENT_OFF);
                 if (r < 0)
-                        log_unit_debug(UNIT(s)->id, "Failed to disable event source.");
+                        log_unit_debug_errno(UNIT(s), r, "Failed to disable event source: %m");
         }
 }
 
@@ -1276,7 +1274,7 @@ static int socket_watch_fds(Socket *s) {
                         r = sd_event_add_io(UNIT(s)->manager->event, &p->event_source, p->fd, EPOLLIN, socket_dispatch_io, p);
 
                 if (r < 0) {
-                        log_unit_warning_errno(UNIT(s)->id, r, "Failed to watch listening fds: %m");
+                        log_unit_warning_errno(UNIT(s), r, "Failed to watch listening fds: %m");
                         goto fail;
                 }
 
@@ -1328,8 +1326,7 @@ static void socket_set_state(Socket *s, SocketState state) {
                 socket_close_fds(s);
 
         if (state != old_state)
-                log_unit_debug(UNIT(s)->id, "%s changed %s -> %s",
-                               UNIT(s)->id, socket_state_to_string(old_state), socket_state_to_string(state));
+                log_unit_debug(UNIT(s), "Changed %s -> %s", socket_state_to_string(old_state), socket_state_to_string(state));
 
         unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
 }
@@ -1430,9 +1427,9 @@ static int socket_spawn(Socket *s, ExecCommand *c, pid_t *_pid) {
         exec_params.cgroup_path = UNIT(s)->cgroup_path;
         exec_params.cgroup_delegate = s->cgroup_context.delegate;
         exec_params.runtime_prefix = manager_get_runtime_prefix(UNIT(s)->manager);
-        exec_params.unit_id = UNIT(s)->id;
 
-        r = exec_spawn(c,
+        r = exec_spawn(UNIT(s),
+                       c,
                        &s->exec_context,
                        &exec_params,
                        s->exec_runtime,
@@ -1576,9 +1573,7 @@ static void socket_enter_stop_post(Socket *s, SocketResult f) {
         return;
 
 fail:
-        log_unit_warning(UNIT(s)->id,
-                         "%s failed to run 'stop-post' task: %s",
-                         UNIT(s)->id, strerror(-r));
+        log_unit_warning_errno(UNIT(s), r, "Failed to run 'stop-post' task: %m");
         socket_enter_signal(s, SOCKET_FINAL_SIGTERM, SOCKET_FAILURE_RESOURCES);
 }
 
@@ -1619,7 +1614,7 @@ static void socket_enter_signal(Socket *s, SocketState state, SocketResult f) {
         return;
 
 fail:
-        log_unit_warning_errno(UNIT(s)->id, r, "%s failed to kill processes: %m", UNIT(s)->id);
+        log_unit_warning_errno(UNIT(s), r, "Failed to kill processes: %m");
 
         if (state == SOCKET_STOP_PRE_SIGTERM || state == SOCKET_STOP_PRE_SIGKILL)
                 socket_enter_stop_post(s, SOCKET_FAILURE_RESOURCES);
@@ -1650,7 +1645,7 @@ static void socket_enter_stop_pre(Socket *s, SocketResult f) {
         return;
 
 fail:
-        log_unit_warning_errno(UNIT(s)->id, r, "%s failed to run 'stop-pre' task: %m", UNIT(s)->id);
+        log_unit_warning_errno(UNIT(s), r, "Failed to run 'stop-pre' task: %m");
         socket_enter_stop_post(s, SOCKET_FAILURE_RESOURCES);
 }
 
@@ -1660,7 +1655,7 @@ static void socket_enter_listening(Socket *s) {
 
         r = socket_watch_fds(s);
         if (r < 0) {
-                log_unit_warning_errno(UNIT(s)->id, r, "%s failed to watch sockets: %m", UNIT(s)->id);
+                log_unit_warning_errno(UNIT(s), r, "Failed to watch sockets: %m");
                 goto fail;
         }
 
@@ -1682,7 +1677,7 @@ static void socket_enter_start_post(Socket *s) {
         if (s->control_command) {
                 r = socket_spawn(s, s->control_command, &s->control_pid);
                 if (r < 0) {
-                        log_unit_warning_errno(UNIT(s)->id, r, "%s failed to run 'start-post' task: %m", UNIT(s)->id);
+                        log_unit_warning_errno(UNIT(s), r, "Failed to run 'start-post' task: %m");
                         goto fail;
                 }
 
@@ -1703,7 +1698,7 @@ static void socket_enter_start_chown(Socket *s) {
 
         r = socket_open_fds(s);
         if (r < 0) {
-                log_unit_warning_errno(UNIT(s)->id, r, "%s failed to listen on sockets: %m", UNIT(s)->id);
+                log_unit_warning_errno(UNIT(s), r, "Failed to listen on sockets: %m");
                 goto fail;
         }
 
@@ -1715,7 +1710,7 @@ static void socket_enter_start_chown(Socket *s) {
 
                 r = socket_chown(s, &s->control_pid);
                 if (r < 0) {
-                        log_unit_warning_errno(UNIT(s)->id, r, "%s failed to fork 'start-chown' task: %m", UNIT(s)->id);
+                        log_unit_warning_errno(UNIT(s), r, "Failed to fork 'start-chown' task: %m");
                         goto fail;
                 }
 
@@ -1740,7 +1735,7 @@ static void socket_enter_start_pre(Socket *s) {
         if (s->control_command) {
                 r = socket_spawn(s, s->control_command, &s->control_pid);
                 if (r < 0) {
-                        log_unit_warning_errno(UNIT(s)->id, r, "%s failed to run 'start-pre' task: %m", UNIT(s)->id);
+                        log_unit_warning_errno(UNIT(s), r, "Failed to run 'start-pre' task: %m");
                         goto fail;
                 }
 
@@ -1764,7 +1759,7 @@ static void socket_enter_running(Socket *s, int cfd) {
          * shut down anyway */
         if (unit_stop_pending(UNIT(s))) {
 
-                log_unit_debug(UNIT(s)->id, "Suppressing connection request on %s since unit stop is scheduled.", UNIT(s)->id);
+                log_unit_debug(UNIT(s), "Suppressing connection request since unit stop is scheduled.");
 
                 if (cfd >= 0)
                         safe_close(cfd);
@@ -1774,14 +1769,14 @@ static void socket_enter_running(Socket *s, int cfd) {
 
                         r = socket_open_fds(s);
                         if (r < 0) {
-                                log_unit_warning_errno(UNIT(s)->id, r, "%s failed to listen on sockets: %m", UNIT(s)->id);
+                                log_unit_warning_errno(UNIT(s), r, "Failed to listen on sockets: %m");
                                 socket_enter_stop_pre(s, SOCKET_FAILURE_RESOURCES);
                                 return;
                         }
 
                         r = socket_watch_fds(s);
                         if (r < 0) {
-                                log_unit_warning_errno(UNIT(s)->id, r, "%s failed to watch sockets: %m", UNIT(s)->id);
+                                log_unit_warning_errno(UNIT(s), r, "Failed to watch sockets: %m");
                                 socket_enter_stop_pre(s, SOCKET_FAILURE_RESOURCES);
                         }
                 }
@@ -1804,7 +1799,7 @@ static void socket_enter_running(Socket *s, int cfd) {
 
                 if (!pending) {
                         if (!UNIT_ISSET(s->service)) {
-                                log_unit_error(UNIT(s)->id, "%s: service to activate vanished, refusing activation.", UNIT(s)->id);
+                                log_unit_error(UNIT(s), "Service to activate vanished, refusing activation.");
                                 r = -ENOENT;
                                 goto fail;
                         }
@@ -1820,7 +1815,7 @@ static void socket_enter_running(Socket *s, int cfd) {
                 Service *service;
 
                 if (s->n_connections >= s->max_connections) {
-                        log_unit_warning(UNIT(s)->id, "%s: Too many incoming connections (%u)", UNIT(s)->id, s->n_connections);
+                        log_unit_warning(UNIT(s), "Too many incoming connections (%u)", s->n_connections);
                         safe_close(cfd);
                         return;
                 }
@@ -1878,8 +1873,8 @@ static void socket_enter_running(Socket *s, int cfd) {
         return;
 
 fail:
-        log_unit_warning(UNIT(s)->id, "%s failed to queue service startup job (Maybe the service file is missing or not a %s unit?): %s",
-                         UNIT(s)->id, cfd >= 0 ? "template" : "non-template",
+        log_unit_warning(UNIT(s), "Failed to queue service startup job (Maybe the service file is missing or not a %s unit?): %s",
+                         cfd >= 0 ? "template" : "non-template",
                          bus_error_message(&error, r));
 
         socket_enter_stop_pre(s, SOCKET_FAILURE_RESOURCES);
@@ -1904,7 +1899,7 @@ static void socket_run_next(Socket *s) {
         return;
 
 fail:
-        log_unit_warning_errno(UNIT(s)->id, r, "%s failed to run next task: %m", UNIT(s)->id);
+        log_unit_warning_errno(UNIT(s), r, "Failed to run next task: %m");
 
         if (s->state == SOCKET_START_POST)
                 socket_enter_stop_pre(s, SOCKET_FAILURE_RESOURCES);
@@ -1944,7 +1939,7 @@ static int socket_start(Unit *u) {
                 service = SERVICE(UNIT_DEREF(s->service));
 
                 if (UNIT(service)->load_state != UNIT_LOADED) {
-                        log_unit_error(u->id, "Socket service %s not loaded, refusing.", UNIT(service)->id);
+                        log_unit_error(u, "Socket service %s not loaded, refusing.", UNIT(service)->id);
                         return -ENOENT;
                 }
 
@@ -1953,7 +1948,7 @@ static int socket_start(Unit *u) {
                 if (service->state != SERVICE_DEAD &&
                     service->state != SERVICE_FAILED &&
                     service->state != SERVICE_AUTO_RESTART) {
-                        log_unit_error(u->id, "Socket service %s already active, refusing.", UNIT(service)->id);
+                        log_unit_error(u, "Socket service %s already active, refusing.", UNIT(service)->id);
                         return -EBUSY;
                 }
         }
@@ -2065,7 +2060,7 @@ static int socket_deserialize_item(Unit *u, const char *key, const char *value,
 
                 state = socket_state_from_string(value);
                 if (state < 0)
-                        log_unit_debug(u->id, "Failed to parse state value %s", value);
+                        log_unit_debug(u, "Failed to parse state value: %s", value);
                 else
                         s->deserialized_state = state;
         } else if (streq(key, "result")) {
@@ -2073,7 +2068,7 @@ static int socket_deserialize_item(Unit *u, const char *key, const char *value,
 
                 f = socket_result_from_string(value);
                 if (f < 0)
-                        log_unit_debug(u->id, "Failed to parse result value %s", value);
+                        log_unit_debug(u, "Failed to parse result value: %s", value);
                 else if (f != SOCKET_SUCCESS)
                         s->result = f;
 
@@ -2081,14 +2076,14 @@ static int socket_deserialize_item(Unit *u, const char *key, const char *value,
                 unsigned k;
 
                 if (safe_atou(value, &k) < 0)
-                        log_unit_debug(u->id, "Failed to parse n-accepted value %s", value);
+                        log_unit_debug(u, "Failed to parse n-accepted value: %s", value);
                 else
                         s->n_accepted += k;
         } else if (streq(key, "control-pid")) {
                 pid_t pid;
 
                 if (parse_pid(value, &pid) < 0)
-                        log_unit_debug(u->id, "Failed to parse control-pid value %s", value);
+                        log_unit_debug(u, "Failed to parse control-pid value: %s", value);
                 else
                         s->control_pid = pid;
         } else if (streq(key, "control-command")) {
@@ -2096,7 +2091,7 @@ static int socket_deserialize_item(Unit *u, const char *key, const char *value,
 
                 id = socket_exec_command_from_string(value);
                 if (id < 0)
-                        log_unit_debug(u->id, "Failed to parse exec-command value %s", value);
+                        log_unit_debug(u, "Failed to parse exec-command value: %s", value);
                 else {
                         s->control_command_id = id;
                         s->control_command = s->exec_command[id];
@@ -2106,7 +2101,7 @@ static int socket_deserialize_item(Unit *u, const char *key, const char *value,
                 SocketPort *p;
 
                 if (sscanf(value, "%i %n", &fd, &skip) < 1 || fd < 0 || !fdset_contains(fds, fd))
-                        log_unit_debug(u->id, "Failed to parse fifo value %s", value);
+                        log_unit_debug(u, "Failed to parse fifo value: %s", value);
                 else {
 
                         LIST_FOREACH(port, p, s->ports)
@@ -2125,7 +2120,7 @@ static int socket_deserialize_item(Unit *u, const char *key, const char *value,
                 SocketPort *p;
 
                 if (sscanf(value, "%i %n", &fd, &skip) < 1 || fd < 0 || !fdset_contains(fds, fd))
-                        log_unit_debug(u->id, "Failed to parse special value %s", value);
+                        log_unit_debug(u, "Failed to parse special value: %s", value);
                 else {
 
                         LIST_FOREACH(port, p, s->ports)
@@ -2144,7 +2139,7 @@ static int socket_deserialize_item(Unit *u, const char *key, const char *value,
                 SocketPort *p;
 
                 if (sscanf(value, "%i %n", &fd, &skip) < 1 || fd < 0 || !fdset_contains(fds, fd))
-                        log_unit_debug(u->id, "Failed to parse mqueue value %s", value);
+                        log_unit_debug(u, "Failed to parse mqueue value: %s", value);
                 else {
 
                         LIST_FOREACH(port, p, s->ports)
@@ -2163,7 +2158,7 @@ static int socket_deserialize_item(Unit *u, const char *key, const char *value,
                 SocketPort *p;
 
                 if (sscanf(value, "%i %i %n", &fd, &type, &skip) < 2 || fd < 0 || type < 0 || !fdset_contains(fds, fd))
-                        log_unit_debug(u->id, "Failed to parse socket value %s", value);
+                        log_unit_debug(u, "Failed to parse socket value: %s", value);
                 else {
 
                         LIST_FOREACH(port, p, s->ports)
@@ -2181,7 +2176,7 @@ static int socket_deserialize_item(Unit *u, const char *key, const char *value,
                 SocketPort *p;
 
                 if (sscanf(value, "%i %n", &fd, &skip) < 1 || fd < 0 || !fdset_contains(fds, fd))
-                        log_unit_debug(u->id, "Failed to parse socket value %s", value);
+                        log_unit_debug(u, "Failed to parse socket value: %s", value);
                 else {
 
                         LIST_FOREACH(port, p, s->ports)
@@ -2194,7 +2189,7 @@ static int socket_deserialize_item(Unit *u, const char *key, const char *value,
                         }
                 }
         } else
-                log_unit_debug(UNIT(s)->id, "Unknown serialization key '%s'", key);
+                log_unit_debug(UNIT(s), "Unknown serialization key: %s", key);
 
         return 0;
 }
@@ -2298,16 +2293,14 @@ static int socket_dispatch_io(sd_event_source *source, int fd, uint32_t revents,
         if (p->socket->state != SOCKET_LISTENING)
                 return 0;
 
-        log_unit_debug(UNIT(p->socket)->id, "Incoming traffic on %s", UNIT(p->socket)->id);
+        log_unit_debug(UNIT(p->socket), "Incoming traffic");
 
         if (revents != EPOLLIN) {
 
                 if (revents & EPOLLHUP)
-                        log_unit_error(UNIT(p->socket)->id, "%s: Got POLLHUP on a listening socket. The service probably invoked shutdown() on it, and should better not do that.",
-                                       UNIT(p->socket)->id);
+                        log_unit_error(UNIT(p->socket), "Got POLLHUP on a listening socket. The service probably invoked shutdown() on it, and should better not do that.");
                 else
-                        log_unit_error(UNIT(p->socket)->id, "%s: Got unexpected poll event (0x%x) on socket.",
-                                       UNIT(p->socket)->id, revents);
+                        log_unit_error(UNIT(p->socket), "Got unexpected poll event (0x%x) on socket.", revents);
 
                 goto fail;
         }
@@ -2324,7 +2317,7 @@ static int socket_dispatch_io(sd_event_source *source, int fd, uint32_t revents,
                                 if (errno == EINTR)
                                         continue;
 
-                                log_unit_error(UNIT(p->socket)->id, "Failed to accept socket: %m");
+                                log_unit_error_errno(UNIT(p->socket), errno, "Failed to accept socket: %m");
                                 goto fail;
                         }
 
@@ -2372,10 +2365,9 @@ static void socket_sigchld_event(Unit *u, pid_t pid, int code, int status) {
                         f = SOCKET_SUCCESS;
         }
 
-        log_unit_full(u->id,
-                      f == SOCKET_SUCCESS ? LOG_DEBUG : LOG_NOTICE,
-                      "%s control process exited, code=%s status=%i",
-                      u->id, sigchld_code_to_string(code), status);
+        log_unit_full(u, f == SOCKET_SUCCESS ? LOG_DEBUG : LOG_NOTICE, 0,
+                      "Control process exited, code=%s status=%i",
+                      sigchld_code_to_string(code), status);
 
         if (f != SOCKET_SUCCESS)
                 s->result = f;
@@ -2384,9 +2376,7 @@ static void socket_sigchld_event(Unit *u, pid_t pid, int code, int status) {
             s->control_command->command_next &&
             f == SOCKET_SUCCESS) {
 
-                log_unit_debug(u->id,
-                               "%s running next command for state %s",
-                               u->id, socket_state_to_string(s->state));
+                log_unit_debug(u, "Running next command for state %s", socket_state_to_string(s->state));
                 socket_run_next(s);
         } else {
                 s->control_command = NULL;
@@ -2395,9 +2385,7 @@ static void socket_sigchld_event(Unit *u, pid_t pid, int code, int status) {
                 /* No further commands for this step, so let's figure
                  * out what to do next */
 
-                log_unit_debug(u->id,
-                               "%s got final SIGCHLD for state %s",
-                               u->id, socket_state_to_string(s->state));
+                log_unit_debug(u, "Got final SIGCHLD for state %s", socket_state_to_string(s->state));
 
                 switch (s->state) {
 
@@ -2452,53 +2440,53 @@ static int socket_dispatch_timer(sd_event_source *source, usec_t usec, void *use
         switch (s->state) {
 
         case SOCKET_START_PRE:
-                log_unit_warning(UNIT(s)->id, "%s starting timed out. Terminating.", UNIT(s)->id);
+                log_unit_warning(UNIT(s), "Starting timed out. Terminating.");
                 socket_enter_signal(s, SOCKET_FINAL_SIGTERM, SOCKET_FAILURE_TIMEOUT);
                 break;
 
         case SOCKET_START_CHOWN:
         case SOCKET_START_POST:
-                log_unit_warning(UNIT(s)->id, "%s starting timed out. Stopping.", UNIT(s)->id);
+                log_unit_warning(UNIT(s), "Starting timed out. Stopping.");
                 socket_enter_stop_pre(s, SOCKET_FAILURE_TIMEOUT);
                 break;
 
         case SOCKET_STOP_PRE:
-                log_unit_warning(UNIT(s)->id, "%s stopping timed out. Terminating.", UNIT(s)->id);
+                log_unit_warning(UNIT(s), "Stopping timed out. Terminating.");
                 socket_enter_signal(s, SOCKET_STOP_PRE_SIGTERM, SOCKET_FAILURE_TIMEOUT);
                 break;
 
         case SOCKET_STOP_PRE_SIGTERM:
                 if (s->kill_context.send_sigkill) {
-                        log_unit_warning(UNIT(s)->id, "%s stopping timed out. Killing.", UNIT(s)->id);
+                        log_unit_warning(UNIT(s), "Stopping timed out. Killing.");
                         socket_enter_signal(s, SOCKET_STOP_PRE_SIGKILL, SOCKET_FAILURE_TIMEOUT);
                 } else {
-                        log_unit_warning(UNIT(s)->id, "%s stopping timed out. Skipping SIGKILL. Ignoring.", UNIT(s)->id);
+                        log_unit_warning(UNIT(s), "Stopping timed out. Skipping SIGKILL. Ignoring.");
                         socket_enter_stop_post(s, SOCKET_FAILURE_TIMEOUT);
                 }
                 break;
 
         case SOCKET_STOP_PRE_SIGKILL:
-                log_unit_warning(UNIT(s)->id, "%s still around after SIGKILL. Ignoring.", UNIT(s)->id);
+                log_unit_warning(UNIT(s), "Processes still around after SIGKILL. Ignoring.");
                 socket_enter_stop_post(s, SOCKET_FAILURE_TIMEOUT);
                 break;
 
         case SOCKET_STOP_POST:
-                log_unit_warning(UNIT(s)->id, "%s stopping timed out (2). Terminating.", UNIT(s)->id);
+                log_unit_warning(UNIT(s), "Stopping timed out (2). Terminating.");
                 socket_enter_signal(s, SOCKET_FINAL_SIGTERM, SOCKET_FAILURE_TIMEOUT);
                 break;
 
         case SOCKET_FINAL_SIGTERM:
                 if (s->kill_context.send_sigkill) {
-                        log_unit_warning(UNIT(s)->id, "%s stopping timed out (2). Killing.", UNIT(s)->id);
+                        log_unit_warning(UNIT(s), "Stopping timed out (2). Killing.");
                         socket_enter_signal(s, SOCKET_FINAL_SIGKILL, SOCKET_FAILURE_TIMEOUT);
                 } else {
-                        log_unit_warning(UNIT(s)->id, "%s stopping timed out (2). Skipping SIGKILL. Ignoring.", UNIT(s)->id);
+                        log_unit_warning(UNIT(s), "Stopping timed out (2). Skipping SIGKILL. Ignoring.");
                         socket_enter_dead(s, SOCKET_FAILURE_TIMEOUT);
                 }
                 break;
 
         case SOCKET_FINAL_SIGKILL:
-                log_unit_warning(UNIT(s)->id, "%s still around after SIGKILL (2). Entering failed mode.", UNIT(s)->id);
+                log_unit_warning(UNIT(s), "Still around after SIGKILL (2). Entering failed mode.");
                 socket_enter_dead(s, SOCKET_FAILURE_TIMEOUT);
                 break;
 
@@ -2568,7 +2556,7 @@ static void socket_notify_service_dead(Socket *s, bool failed_permanent) {
          * services. */
 
         if (s->state == SOCKET_RUNNING) {
-                log_unit_debug(UNIT(s)->id, "%s got notified about service death (failed permanently: %s)", UNIT(s)->id, yes_no(failed_permanent));
+                log_unit_debug(UNIT(s), "Got notified about service death (failed permanently: %s)", yes_no(failed_permanent));
                 if (failed_permanent)
                         socket_enter_stop_pre(s, SOCKET_FAILURE_SERVICE_FAILED_PERMANENT);
                 else
@@ -2587,7 +2575,7 @@ void socket_connection_unref(Socket *s) {
         assert(s->n_connections > 0);
         s->n_connections--;
 
-        log_unit_debug(UNIT(s)->id, "%s: One connection closed, %u left.", UNIT(s)->id, s->n_connections);
+        log_unit_debug(UNIT(s), "One connection closed, %u left.", s->n_connections);
 }
 
 static void socket_trigger_notify(Unit *u, Unit *other) {