udevd: read debug settings from kernel commandline

[elogind.git] / udev / udevd.c

diff --git a/udev/udevd.c b/udev/udevd.c
index 5e74f6e01332cfb8808163dbb9162482d1e484c3..612f04d1b95012a512db8a5a18891ce22dbadfe7 100644 (file)
--- a/udev/udevd.c
+++ b/udev/udevd.c
@@ -69,7 +69,6 @@ static void log_fn(struct udev *udev, int priority,
        }
 }
 
-static bool debug_trace;
 static struct udev_rules *rules;
 static struct udev_queue_export *udev_queue_export;
 static struct udev_ctrl *udev_ctrl;
@@ -80,6 +79,7 @@ static bool stop_exec_queue;
 static bool reload_config;
 static int children;
 static int children_max;
+static int exec_delay;
 static sigset_t orig_sigmask;
 static struct udev_list_node event_list;
 static struct udev_list_node worker_list;
@@ -286,6 +286,9 @@ static void worker_new(struct event *event)
                        /* set timeout to prevent hanging processes */
                        alarm(UDEV_EVENT_TIMEOUT);
 
+                       if (exec_delay > 0)
+                               udev_event->exec_delay = exec_delay;
+
                        /* apply rules, create node, symlinks */
                        err = udev_event_execute_rules(udev_event, rules);
 
@@ -387,7 +390,8 @@ static void event_run(struct event *event, bool force)
        }
 
        if (!force && children >= children_max) {
-               info(event->udev, "maximum number (%i) of children reached\n", children);
+               if (children_max > 1)
+                       info(event->udev, "maximum number (%i) of children reached\n", children);
                return;
        }
 
@@ -952,16 +956,16 @@ int main(int argc, char *argv[])
        int fd;
        FILE *f;
        sigset_t mask;
-       const char *value;
        int daemonize = false;
        int resolve_names = 1;
        static const struct option options[] = {
                { "daemon", no_argument, NULL, 'd' },
-               { "debug-trace", no_argument, NULL, 't' },
                { "debug", no_argument, NULL, 'D' },
+               { "children-max", required_argument, NULL, 'c' },
+               { "exec-delay", required_argument, NULL, 'e' },
+               { "resolve-names", required_argument, NULL, 'N' },
                { "help", no_argument, NULL, 'h' },
                { "version", no_argument, NULL, 'V' },
-               { "resolve-names", required_argument, NULL, 'N' },
                {}
        };
        int rc = 1;
@@ -978,7 +982,7 @@ int main(int argc, char *argv[])
        for (;;) {
                int option;
 
-               option = getopt_long(argc, argv, "dDthV", options, NULL);
+               option = getopt_long(argc, argv, "cdeDthV", options, NULL);
                if (option == -1)
                        break;
 
@@ -986,8 +990,11 @@ int main(int argc, char *argv[])
                case 'd':
                        daemonize = true;
                        break;
-               case 't':
-                       debug_trace = true;
+               case 'c':
+                       children_max = strtoul(optarg, NULL, 0);
+                       break;
+               case 'e':
+                       exec_delay = strtoul(optarg, NULL, 0);
                        break;
                case 'D':
                        debug = true;
@@ -1008,8 +1015,15 @@ int main(int argc, char *argv[])
                        }
                        break;
                case 'h':
-                       printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] "
-                              "[--resolve-names=early|late|never] [--version]\n");
+                       printf("Usage: udevd OPTIONS\n"
+                              "  --daemon\n"
+                              "  --debug\n"
+                              "  --children-max=<maximum number of workers>\n"
+                              "  --exec-delay=<seconds to wait before executing RUN=>\n"
+                              "  --resolve-names=early|late|never\n" 
+                              "  --version\n"
+                              "  --help\n"
+                              "\n");
                        goto exit;
                case 'V':
                        printf("%s\n", VERSION);
@@ -1025,7 +1039,41 @@ int main(int argc, char *argv[])
                goto exit;
        }
 
-       /* make sure std{in,out,err} fd's are in a sane state */
+       /*
+        * read the kernel commandline, in case we need to get into debug mode
+        *   udev.log-priority=<level>              syslog priority
+        *   udev.children-max=<number of workers>  events are fully serialized if set to 1
+        *
+        */
+       f = fopen("/proc/cmdline", "r");
+       if (f != NULL) {
+               char cmdline[4096];
+
+               if (fgets(cmdline, sizeof(cmdline), f) != NULL) {
+                       char *pos;
+
+                       pos = strstr(cmdline, "udev.log-priority=");
+                       if (pos != NULL) {
+                               pos += strlen("udev.log-priority=");
+                               udev_set_log_priority(udev, util_log_priority(pos));
+                       }
+
+                       pos = strstr(cmdline, "udev.children-max=");
+                       if (pos != NULL) {
+                               pos += strlen("udev.children-max=");
+                               children_max = strtoul(pos, NULL, 0);
+                       }
+
+                       pos = strstr(cmdline, "udev.exec-delay=");
+                       if (pos != NULL) {
+                               pos += strlen("udev.exec-delay=");
+                               exec_delay = strtoul(pos, NULL, 0);
+                       }
+               }
+               fclose(f);
+       }
+
+       /* make sure std{in,out,err} fds are in a sane state */
        fd = open("/dev/null", O_RDWR);
        if (fd < 0) {
                fprintf(stderr, "cannot open /dev/null\n");
@@ -1036,7 +1084,6 @@ int main(int argc, char *argv[])
        if (write(STDERR_FILENO, 0, 0) < 0)
                dup2(fd, STDERR_FILENO);
 
-       /* init control socket, bind() ensures, that only one udevd instance is running */
        udev_ctrl = udev_ctrl_new_from_socket(udev, UDEV_CTRL_SOCK_PATH);
        if (udev_ctrl == NULL) {
                fprintf(stderr, "error initializing control socket");
@@ -1150,8 +1197,7 @@ int main(int argc, char *argv[])
                fclose(f);
        }
 
-       /* redirect std{out,err} */
-       if (!debug && !debug_trace) {
+       if (!debug) {
                dup2(fd, STDIN_FILENO);
                dup2(fd, STDOUT_FILENO);
                dup2(fd, STDERR_FILENO);
@@ -1159,7 +1205,7 @@ int main(int argc, char *argv[])
        if (fd > STDERR_FILENO)
                close(fd);
 
-       /* set scheduling priority for the daemon */
+       /* set scheduling priority for the main daemon process */
        setpriority(PRIO_PROCESS, 0, UDEVD_PRIORITY);
 
        chdir("/");
@@ -1175,23 +1221,16 @@ int main(int argc, char *argv[])
                close(fd);
        }
 
-       /* in trace mode run one event after the other */
-       if (debug_trace) {
-               children_max = 1;
-       } else {
+       if (children_max <= 0) {
                int memsize = mem_size_mb();
 
+               /* set value depending on the amount of RAM */
                if (memsize > 0)
                        children_max = 128 + (memsize / 8);
                else
                        children_max = 128;
        }
-
-       /* possibly overwrite maximum limit of executed events */
-       value = getenv("UDEVD_MAX_CHILDREN");
-       if (value)
-               children_max = strtoul(value, NULL, 10);
-       info(udev, "initialize children_max to %u\n", children_max);
+       info(udev, "set children_max to %u\n", children_max);
 
        static_dev_create(udev);
        static_dev_create_from_modules(udev);