chiark / gitweb /
udevd: log error for too old kernels or CONFIG_SYSFS_DEPRECATED
[elogind.git] / udev / udevd.c
index 111f1200062de5d05f3a191323654edd5b2025d7..1aa50eb74cfbcdd00031aaf0c6d234c1416f91d7 100644 (file)
@@ -1,6 +1,8 @@
 /*
  * Copyright (C) 2004-2008 Kay Sievers <kay.sievers@vrfy.org>
  * Copyright (C) 2004 Chris Friesen <chris_friesen@sympatico.ca>
+ * Copyright (C) 2009 Canonical Ltd.
+ * Copyright (C) 2009 Scott James Remnant <scott@netsplit.com>
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by
@@ -27,7 +29,9 @@
 #include <fcntl.h>
 #include <time.h>
 #include <getopt.h>
+#include <dirent.h>
 #include <sys/select.h>
+#include <sys/poll.h>
 #include <sys/wait.h>
 #include <sys/stat.h>
 #include <sys/ioctl.h>
@@ -57,22 +61,22 @@ static void log_fn(struct udev *udev, int priority,
        }
 }
 
+static void reap_sigchilds(void);
+
 static int debug_trace;
 static struct udev_rules *rules;
 static struct udev_ctrl *udev_ctrl;
 static struct udev_monitor *kernel_monitor;
-static int inotify_fd = -1;
-
-static int signal_pipe[2] = {-1, -1};
 static volatile int sigchilds_waiting;
 static volatile int udev_exit;
 static volatile int reload_config;
+static volatile int signal_received;
+static volatile pid_t settle_pid;
 static int run_exec_q;
 static int stop_exec_q;
 static int max_childs;
-
-static struct udev_list_node exec_list;
-static struct udev_list_node running_list;
+static int childs;
+static struct udev_list_node event_list;
 
 enum event_state {
        EVENT_QUEUED,
@@ -109,8 +113,8 @@ static void export_event_state(struct udev_event *event, enum event_state state)
        switch (state) {
        case EVENT_QUEUED:
                if(unlink(filename_failed) == 0)
-                       delete_path(event->udev, filename_failed);
-               create_path(event->udev, filename);
+                       util_delete_path(event->udev, filename_failed);
+               util_create_path(event->udev, filename);
                udev_selinux_setfscreatecon(event->udev, filename, S_IFLNK);
                symlink(udev_device_get_devpath(event->dev), filename);
                udev_selinux_resetfscreatecon(event->udev);
@@ -131,23 +135,23 @@ static void export_event_state(struct udev_event *event, enum event_state state)
                                     udev_device_get_devpath_old(event->dev), udev_device_get_devpath(event->dev));
                } else {
                        if (unlink(filename_failed) == 0)
-                               delete_path(event->udev, filename_failed);
+                               util_delete_path(event->udev, filename_failed);
                }
 
                unlink(filename);
 
                /* clean up possibly empty queue directory */
-               if (udev_list_is_empty(&exec_list) && udev_list_is_empty(&running_list))
-                       delete_path(event->udev, filename);
+               if (udev_list_is_empty(&event_list))
+                       util_delete_path(event->udev, filename);
                break;
        case EVENT_FAILED:
                /* move failed event to the failed directory */
-               create_path(event->udev, filename_failed);
+               util_create_path(event->udev, filename_failed);
                rename(filename, filename_failed);
 
                /* clean up possibly empty queue directory */
-               if (udev_list_is_empty(&exec_list) && udev_list_is_empty(&running_list))
-                       delete_path(event->udev, filename);
+               if (udev_list_is_empty(&event_list))
+                       util_delete_path(event->udev, filename);
                break;
        }
 
@@ -180,16 +184,18 @@ static void event_fork(struct udev_event *event)
        struct sigaction act;
        int err;
 
+       if (debug_trace) {
+               event->trace = 1;
+               fprintf(stderr, "fork %s (%llu)\n",
+                      udev_device_get_syspath(event->dev),
+                      udev_device_get_seqnum(event->dev));
+       }
+
        pid = fork();
        switch (pid) {
        case 0:
                /* child */
-               udev_monitor_unref(kernel_monitor);
                udev_ctrl_unref(udev_ctrl);
-               if (inotify_fd >= 0)
-                       close(inotify_fd);
-               close(signal_pipe[READ_END]);
-               close(signal_pipe[WRITE_END]);
                logging_close();
                logging_init("udevd-event");
                setpriority(PRIO_PROCESS, 0, UDEV_PRIORITY);
@@ -220,7 +226,17 @@ static void event_fork(struct udev_event *event)
 
                /* execute RUN= */
                if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
-                       udev_rules_run(event);
+                       udev_event_execute_run(event);
+
+               /* apply/restore inotify watch */
+               if (err == 0 && event->inotify_watch) {
+                       udev_watch_begin(event->udev, event->dev);
+                       udev_device_update_db(event->dev);
+               }
+
+               /* send processed event back to the kernel netlink socket */
+               udev_monitor_send_device(kernel_monitor, event->dev);
+
                info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
                logging_close();
                if (err != 0)
@@ -239,6 +255,7 @@ static void event_fork(struct udev_event *event)
                     udev_device_get_subsystem(event->dev),
                     time(NULL) - event->queue_time);
                event->pid = pid;
+               childs++;
        }
 }
 
@@ -265,29 +282,20 @@ static void event_queue_insert(struct udev_event *event)
                close(fd);
        }
 
-       /* run one event after the other in debug mode */
-       if (debug_trace) {
-               udev_list_node_append(&event->node, &running_list);
-               event_fork(event);
-               waitpid(event->pid, NULL, 0);
-               event_queue_delete(event);
-               return;
-       }
+
+       udev_list_node_append(&event->node, &event_list);
+       run_exec_q = 1;
 
        /* run all events with a timeout set immediately */
        if (udev_device_get_timeout(event->dev) > 0) {
-               udev_list_node_append(&event->node, &running_list);
                event_fork(event);
                return;
        }
-
-       udev_list_node_append(&event->node, &exec_list);
-       run_exec_q = 1;
 }
 
 static int mem_size_mb(void)
 {
-       FILEf;
+       FILE *f;
        char buf[4096];
        long int memsize = -1;
 
@@ -310,47 +318,56 @@ static int mem_size_mb(void)
 
 static int compare_devpath(const char *running, const char *waiting)
 {
-       int i;
+       int i = 0;
 
-       for (i = 0; i < UTIL_PATH_SIZE; i++) {
-               /* identical device event found */
-               if (running[i] == '\0' && waiting[i] == '\0')
-                       return 1;
+       while (running[i] != '\0' && running[i] == waiting[i])
+               i++;
 
-               /* parent device event found */
-               if (running[i] == '\0' && waiting[i] == '/')
-                       return 2;
+       /* identical device event found */
+       if (running[i] == '\0' && waiting[i] == '\0')
+               return 1;
 
-               /* child device event found */
-               if (running[i] == '/' && waiting[i] == '\0')
-                       return 3;
+       /* parent device event found */
+       if (running[i] == '\0' && waiting[i] == '/')
+               return 2;
 
-               /* no matching event */
-               if (running[i] != waiting[i])
-                       break;
-       }
+       /* child device event found */
+       if (running[i] == '/' && waiting[i] == '\0')
+               return 3;
 
+       /* no matching event */
        return 0;
 }
 
 /* lookup event for identical, parent, child, or physical device */
-static int devpath_busy(struct udev_event *event, int limit)
+static int devpath_busy(struct udev_event *event)
 {
        struct udev_list_node *loop;
-       int childs_count = 0;
 
-       /* check exec-queue which may still contain delayed events we depend on */
-       udev_list_node_foreach(loop, &exec_list) {
+       if (event->delaying_seqnum > 0) {
+       }
+       /* check if queue contains events we depend on */
+       udev_list_node_foreach(loop, &event_list) {
                struct udev_event *loop_event = node_to_event(loop);
 
-               /* skip ourself and all later events */
+               /* we already found a later event, earlier can not block us, no need to check again */
+               if (udev_device_get_seqnum(loop_event->dev) < event->delaying_seqnum)
+                       continue;
+
+               /* event we checked earlier still exists, no need to check again */
+               if (udev_device_get_seqnum(loop_event->dev) == event->delaying_seqnum)
+                       return 2;
+
+               /* found ourself, no later event can block us */
                if (udev_device_get_seqnum(loop_event->dev) >= udev_device_get_seqnum(event->dev))
                        break;
 
                /* check our old name */
                if (udev_device_get_devpath_old(event->dev) != NULL)
-                       if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0)
-                               return 2;
+                       if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0) {
+                               event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
+                               return 3;
+                       }
 
                /* check identical, parent, or child device event */
                if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
@@ -358,57 +375,10 @@ static int devpath_busy(struct udev_event *event, int limit)
                            udev_device_get_seqnum(event->dev),
                            udev_device_get_seqnum(loop_event->dev),
                            udev_device_get_devpath(loop_event->dev));
-                       return 3;
-               }
-
-               /* check for our major:minor number */
-               if (major(udev_device_get_devnum(event->dev)) > 0 &&
-                   udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
-                   strcmp(udev_device_get_subsystem(event->dev), udev_device_get_subsystem(loop_event->dev)) == 0) {
-                       dbg(event->udev, "%llu, device event still pending %llu (%d:%d)\n",
-                           udev_device_get_seqnum(event->dev),
-                           udev_device_get_seqnum(loop_event->dev),
-                           major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
+                       event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
                        return 4;
                }
 
-               /* check physical device event (special case of parent) */
-               if (udev_device_get_physdevpath(event->dev) != NULL &&
-                   strcmp(udev_device_get_action(event->dev), "add") == 0)
-                       if (compare_devpath(udev_device_get_devpath(loop_event->dev),
-                                           udev_device_get_physdevpath(event->dev)) != 0) {
-                               dbg(event->udev, "%llu, physical device event still pending %llu (%s)\n",
-                                   udev_device_get_seqnum(event->dev),
-                                   udev_device_get_seqnum(loop_event->dev),
-                                   udev_device_get_devpath(loop_event->dev));
-                               return 5;
-                       }
-       }
-
-       /* check run queue for still running events */
-       udev_list_node_foreach(loop, &running_list) {
-               struct udev_event *loop_event = node_to_event(loop);
-
-               if (childs_count++ >= limit) {
-                       info(event->udev, "%llu, maximum number (%i) of childs reached\n",
-                            udev_device_get_seqnum(event->dev), childs_count);
-                       return 1;
-               }
-
-               /* check our old name */
-               if (udev_device_get_devpath_old(event->dev) != NULL)
-                       if (strcmp(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath_old(event->dev)) == 0)
-                               return 2;
-
-               /* check identical, parent, or child device event */
-               if (compare_devpath(udev_device_get_devpath(loop_event->dev), udev_device_get_devpath(event->dev)) != 0) {
-                       dbg(event->udev, "%llu, device event still running %llu (%s)\n",
-                           udev_device_get_seqnum(event->dev),
-                           udev_device_get_seqnum(loop_event->dev),
-                           udev_device_get_devpath(loop_event->dev));
-                       return 3;
-               }
-
                /* check for our major:minor number */
                if (major(udev_device_get_devnum(event->dev)) > 0 &&
                    udev_device_get_devnum(loop_event->dev) == udev_device_get_devnum(event->dev) &&
@@ -417,7 +387,8 @@ static int devpath_busy(struct udev_event *event, int limit)
                            udev_device_get_seqnum(event->dev),
                            udev_device_get_seqnum(loop_event->dev),
                            major(udev_device_get_devnum(loop_event->dev)), minor(udev_device_get_devnum(loop_event->dev)));
-                       return 4;
+                       event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
+                       return 5;
                }
 
                /* check physical device event (special case of parent) */
@@ -429,7 +400,8 @@ static int devpath_busy(struct udev_event *event, int limit)
                                    udev_device_get_seqnum(event->dev),
                                    udev_device_get_seqnum(loop_event->dev),
                                    udev_device_get_devpath(loop_event->dev));
-                               return 5;
+                               event->delaying_seqnum = udev_device_get_seqnum(loop_event->dev);
+                               return 6;
                        }
        }
        return 0;
@@ -441,25 +413,43 @@ static void event_queue_manager(struct udev *udev)
        struct udev_list_node *loop;
        struct udev_list_node *tmp;
 
-       if (udev_list_is_empty(&exec_list))
+start_over:
+       if (udev_list_is_empty(&event_list)) {
+               if (childs > 0) {
+                       err(udev, "event list empty, but childs count is %i", childs);
+                       childs = 0;
+               }
                return;
+       }
 
-       udev_list_node_foreach_safe(loop, tmp, &exec_list) {
+       udev_list_node_foreach_safe(loop, tmp, &event_list) {
                struct udev_event *loop_event = node_to_event(loop);
 
-               /* serialize and wait for parent or child events */
-               if (devpath_busy(loop_event, max_childs) != 0) {
+               if (childs >= max_childs) {
+                       info(udev, "maximum number (%i) of childs reached\n", childs);
+                       break;
+               }
+
+               if (loop_event->pid != 0)
+                       continue;
+
+               /* do not start event if parent or child event is still running */
+               if (devpath_busy(loop_event) != 0) {
                        dbg(udev, "delay seq %llu (%s)\n",
                            udev_device_get_seqnum(loop_event->dev),
                            udev_device_get_devpath(loop_event->dev));
                        continue;
                }
 
-               /* move event to run list */
-               udev_list_node_remove(&loop_event->node);
-               udev_list_node_append(&loop_event->node, &running_list);
                event_fork(loop_event);
                dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
+
+               /* retry if events finished in the meantime */
+               if (sigchilds_waiting) {
+                       sigchilds_waiting = 0;
+                       reap_sigchilds();
+                       goto start_over;
+               }
        }
 }
 
@@ -529,9 +519,70 @@ static void handle_ctrl_msg(struct udev_ctrl *uctrl)
                max_childs = i;
        }
 
+       settle_pid = udev_ctrl_get_settle(ctrl_msg);
+       if (settle_pid > 0) {
+               info(udev, "udevd message (SETTLE) received\n");
+       }
        udev_ctrl_msg_unref(ctrl_msg);
 }
 
+/* read inotify messages */
+static int handle_inotify(struct udev *udev)
+{
+       int nbytes, pos;
+       char *buf;
+       struct inotify_event *ev;
+
+       if ((ioctl(inotify_fd, FIONREAD, &nbytes) < 0) || (nbytes <= 0))
+               return 0;
+
+       buf = malloc(nbytes);
+       if (buf == NULL) {
+               err(udev, "error getting buffer for inotify, disable watching\n");
+               close(inotify_fd);
+               inotify_fd = -1;
+               return 0;
+       }
+
+       read(inotify_fd, buf, nbytes);
+
+       for (pos = 0; pos < nbytes; pos += sizeof(struct inotify_event) + ev->len) {
+               struct udev_device *dev;
+
+               ev = (struct inotify_event *)(buf + pos);
+               if (ev->len) {
+                       dbg(udev, "inotify event: %x for %s\n", ev->mask, ev->name);
+                       reload_config = 1;
+                       continue;
+               }
+
+               dev = udev_watch_lookup(udev, ev->wd);
+               if (dev != NULL) {
+                       dbg(udev, "inotify event: %x for %s\n", ev->mask, udev_device_get_devnode(dev));
+                       if (ev->mask & IN_CLOSE_WRITE) {
+                               char filename[UTIL_PATH_SIZE];
+                               int fd;
+
+                               info(udev, "device %s closed, synthesising 'change'\n", udev_device_get_devnode(dev));
+                               util_strlcpy(filename, udev_device_get_syspath(dev), sizeof(filename));
+                               util_strlcat(filename, "/uevent", sizeof(filename));
+                               fd = open(filename, O_WRONLY);
+                               if (fd < 0 || write(fd, "change", 6) < 0)
+                                       info(udev, "error writing uevent: %m\n");
+                               close(fd);
+                       }
+                       if (ev->mask & IN_IGNORED)
+                               udev_watch_end(udev, dev);
+
+                       udev_device_unref(dev);
+               }
+
+       }
+
+       free (buf);
+       return 0;
+}
+
 static void asmlinkage sig_handler(int signum)
 {
        switch (signum) {
@@ -548,8 +599,7 @@ static void asmlinkage sig_handler(int signum)
                        break;
        }
 
-       /* write to pipe, which will wakeup select() in our mainloop */
-       write(signal_pipe[WRITE_END], "", 1);
+       signal_received = 1;
 }
 
 static void udev_done(int pid, int exitstatus)
@@ -557,7 +607,7 @@ static void udev_done(int pid, int exitstatus)
        struct udev_list_node *loop;
 
        /* find event associated with pid and delete it */
-       udev_list_node_foreach(loop, &running_list) {
+       udev_list_node_foreach(loop, &event_list) {
                struct udev_event *loop_event = node_to_event(loop);
 
                if (loop_event->pid == pid) {
@@ -565,9 +615,14 @@ static void udev_done(int pid, int exitstatus)
                             udev_device_get_seqnum(loop_event->dev), loop_event->pid,
                             exitstatus, time(NULL) - loop_event->queue_time);
                        loop_event->exitstatus = exitstatus;
+                       if (debug_trace)
+                               fprintf(stderr, "exit %s (%llu)\n",
+                                      udev_device_get_syspath(loop_event->dev),
+                                      udev_device_get_seqnum(loop_event->dev));
                        event_queue_delete(loop_event);
+                       childs--;
 
-                       /* there may be events waiting with the same devpath */
+                       /* there may be dependent events waiting */
                        run_exec_q = 1;
                        return;
                }
@@ -593,6 +648,38 @@ static void reap_sigchilds(void)
        }
 }
 
+static void cleanup_queue_dir(struct udev *udev)
+{
+       char dirname[UTIL_PATH_SIZE];
+       char filename[UTIL_PATH_SIZE];
+       DIR *dir;
+
+       util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
+       util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
+       unlink(filename);
+
+       util_strlcpy(dirname, udev_get_dev_path(udev), sizeof(dirname));
+       util_strlcat(dirname, "/.udev/queue", sizeof(dirname));
+       dir = opendir(dirname);
+       if (dir != NULL) {
+               while (1) {
+                       struct dirent *dent;
+
+                       dent = readdir(dir);
+                       if (dent == NULL || dent->d_name[0] == '\0')
+                               break;
+                       if (dent->d_name[0] == '.')
+                               continue;
+                       util_strlcpy(filename, dirname, sizeof(filename));
+                       util_strlcat(filename, "/", sizeof(filename));
+                       util_strlcat(filename, dent->d_name, sizeof(filename));
+                       unlink(filename);
+               }
+               closedir(dir);
+               rmdir(dirname);
+       }
+}
+
 static void export_initial_seqnum(struct udev *udev)
 {
        char filename[UTIL_PATH_SIZE];
@@ -613,7 +700,7 @@ static void export_initial_seqnum(struct udev *udev)
        }
        util_strlcpy(filename, udev_get_dev_path(udev), sizeof(filename));
        util_strlcat(filename, "/.udev/uevent_seqnum", sizeof(filename));
-       create_path(udev, filename);
+       util_create_path(udev, filename);
        fd = open(filename, O_WRONLY|O_TRUNC|O_CREAT, 0644);
        if (fd >= 0) {
                write(fd, seqnum, len);
@@ -621,25 +708,52 @@ static void export_initial_seqnum(struct udev *udev)
        }
 }
 
+static void startup_log(struct udev *udev)
+{
+       FILE *f;
+       char path[UTIL_PATH_SIZE];
+       struct stat statbuf;
+
+       f = fopen("/dev/kmsg", "w");
+       if (f != NULL)
+               fprintf(f, "<6>udev: starting version " VERSION "\n");
+
+       util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
+       util_strlcat(path, "/class/mem/null", sizeof(path));
+       if (lstat(path, &statbuf) == 0 && S_ISDIR(statbuf.st_mode)) {
+               const char *depr_str =
+                       "udev: missing sysfs features; please update the kernel "
+                       "or disable the kernel's CONFIG_SYSFS_DEPRECATED option; "
+                       "udev may fail to work correctly";
+
+               if (f != NULL)
+                       fprintf(f, "<3>%s\n", depr_str);
+               err(udev, "%s\n", depr_str);
+               sleep(3);
+       }
+
+       if (f != NULL)
+               fclose(f);
+}
+
 int main(int argc, char *argv[])
 {
        struct udev *udev;
-       int err;
        int fd;
        struct sigaction act;
-       fd_set readfds;
        const char *value;
        int daemonize = 0;
+       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' },
                { "help", no_argument, NULL, 'h' },
                { "version", no_argument, NULL, 'V' },
+               { "resolve-names", required_argument, NULL, 'N' },
                {}
        };
        int rc = 1;
-       int maxfd;
 
        udev = udev_new();
        if (udev == NULL)
@@ -648,7 +762,7 @@ int main(int argc, char *argv[])
        logging_init("udevd");
        udev_set_log_fn(udev, log_fn);
        info(udev, "version %s\n", VERSION);
-       selinux_init(udev);
+       udev_selinux_init(udev);
 
        while (1) {
                int option;
@@ -669,8 +783,22 @@ int main(int argc, char *argv[])
                        if (udev_get_log_priority(udev) < LOG_INFO)
                                udev_set_log_priority(udev, LOG_INFO);
                        break;
+               case 'N':
+                       if (strcmp (optarg, "early") == 0) {
+                               resolve_names = 1;
+                       } else if (strcmp (optarg, "late") == 0) {
+                               resolve_names = 0;
+                       } else if (strcmp (optarg, "never") == 0) {
+                               resolve_names = -1;
+                       } else {
+                               fprintf(stderr, "resolve-names must be early, late or never\n");
+                               err(udev, "resolve-names must be early, late or never\n");
+                               goto exit;
+                       }
+                       break;
                case 'h':
-                       printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] [--version]\n");
+                       printf("Usage: udevd [--help] [--daemon] [--debug-trace] [--debug] "
+                              "[--resolve-names=early|late|never] [--version]\n");
                        goto exit;
                case 'V':
                        printf("%s\n", VERSION);
@@ -692,8 +820,6 @@ int main(int argc, char *argv[])
                fprintf(stderr, "cannot open /dev/null\n");
                err(udev, "cannot open /dev/null\n");
        }
-       if (fd > STDIN_FILENO)
-               dup2(fd, STDIN_FILENO);
        if (write(STDOUT_FILENO, 0, 0) < 0)
                dup2(fd, STDOUT_FILENO);
        if (write(STDERR_FILENO, 0, 0) < 0)
@@ -715,7 +841,7 @@ int main(int argc, char *argv[])
                goto exit;
        }
 
-       kernel_monitor = udev_monitor_new_from_netlink(udev);
+       kernel_monitor = udev_monitor_new_from_netlink(udev, "kernel");
        if (kernel_monitor == NULL || udev_monitor_enable_receiving(kernel_monitor) < 0) {
                fprintf(stderr, "error initializing netlink socket\n");
                err(udev, "error initializing netlink socket\n");
@@ -724,41 +850,13 @@ int main(int argc, char *argv[])
        }
        udev_monitor_set_receive_buffer_size(kernel_monitor, 128*1024*1024);
 
-       err = pipe(signal_pipe);
-       if (err < 0) {
-               err(udev, "error getting pipes: %m\n");
-               goto exit;
-       }
-
-       err = fcntl(signal_pipe[READ_END], F_GETFL, 0);
-       if (err < 0) {
-               err(udev, "error fcntl on read pipe: %m\n");
-               goto exit;
-       }
-       err = fcntl(signal_pipe[READ_END], F_SETFL, err | O_NONBLOCK);
-       if (err < 0) {
-               err(udev, "error fcntl on read pipe: %m\n");
-               goto exit;
-       }
-
-       err = fcntl(signal_pipe[WRITE_END], F_GETFL, 0);
-       if (err < 0) {
-               err(udev, "error fcntl on write pipe: %m\n");
-               goto exit;
-       }
-       err = fcntl(signal_pipe[WRITE_END], F_SETFL, err | O_NONBLOCK);
-       if (err < 0) {
-               err(udev, "error fcntl on write pipe: %m\n");
-               goto exit;
-       }
-
-       rules = udev_rules_new(udev, 1);
+       rules = udev_rules_new(udev, resolve_names);
        if (rules == NULL) {
                err(udev, "error reading rules\n");
                goto exit;
        }
-       udev_list_init(&running_list);
-       udev_list_init(&exec_list);
+       udev_list_init(&event_list);
+       cleanup_queue_dir(udev);
        export_initial_seqnum(udev);
 
        if (daemonize) {
@@ -781,7 +879,8 @@ int main(int argc, char *argv[])
        }
 
        /* redirect std{out,err} */
-       if (!debug) {
+       if (!debug && !debug_trace) {
+               dup2(fd, STDIN_FILENO);
                dup2(fd, STDOUT_FILENO);
                dup2(fd, STDERR_FILENO);
        }
@@ -804,26 +903,7 @@ int main(int argc, char *argv[])
                close(fd);
        }
 
-       fd = open("/dev/kmsg", O_WRONLY);
-       if (fd > 0) {
-               const char *ver_str = "<6>udev: starting version " VERSION "\n";
-               char path[UTIL_PATH_SIZE];
-               struct stat statbuf;
-
-               write(fd, ver_str, strlen(ver_str));
-               util_strlcpy(path, udev_get_sys_path(udev), sizeof(path));
-               util_strlcat(path, "/class/mem/null", sizeof(path));
-               if (lstat(path, &statbuf) == 0) {
-                       if (S_ISDIR(statbuf.st_mode)) {
-                               const char *depr_str = "<6>udev: deprecated sysfs layout (kernel too old, "
-                                                       "or CONFIG_SYSFS_DEPRECATED) is unsupported, some "
-                                                       "udev features may fail\n";
-
-                               write(fd, depr_str, strlen(depr_str));
-                       }
-               }
-               close(fd);
-       }
+       startup_log(udev);
 
        /* set signal handlers */
        memset(&act, 0x00, sizeof(struct sigaction));
@@ -836,13 +916,13 @@ int main(int argc, char *argv[])
        sigaction(SIGHUP, &act, NULL);
 
        /* watch rules directory */
-       inotify_fd = inotify_init();
+       udev_watch_init(udev);
        if (inotify_fd >= 0) {
                if (udev_get_rules_path(udev) != NULL) {
                        inotify_add_watch(inotify_fd, udev_get_rules_path(udev),
                                          IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
                } else {
-                       char filename[PATH_MAX];
+                       char filename[UTIL_PATH_SIZE];
 
                        inotify_add_watch(inotify_fd, UDEV_PREFIX "/lib/udev/rules.d",
                                          IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
@@ -855,50 +935,69 @@ int main(int argc, char *argv[])
                        inotify_add_watch(inotify_fd, filename,
                                          IN_CREATE | IN_DELETE | IN_MOVE | IN_CLOSE_WRITE);
                }
-       } else if (errno == ENOSYS)
-               err(udev, "the kernel does not support inotify, udevd can't monitor rules file changes\n");
-       else
-               err(udev, "inotify_init failed: %m\n");
 
-       /* maximum limit of forked childs */
-       value = getenv("UDEVD_MAX_CHILDS");
-       if (value)
-               max_childs = strtoul(value, NULL, 10);
-       else {
+               udev_watch_restore(udev);
+       }
+
+       /* in trace mode run one event after the other */
+       if (debug_trace) {
+               max_childs = 1;
+       } else {
                int memsize = mem_size_mb();
                if (memsize > 0)
                        max_childs = 128 + (memsize / 4);
                else
                        max_childs = UDEVD_MAX_CHILDS;
        }
+       /* possibly overwrite maximum limit of executed events */
+       value = getenv("UDEVD_MAX_CHILDS");
+       if (value)
+               max_childs = strtoul(value, NULL, 10);
        info(udev, "initialize max_childs to %u\n", max_childs);
 
-       maxfd = udev_ctrl_get_fd(udev_ctrl);
-       maxfd = UDEV_MAX(maxfd, udev_monitor_get_fd(kernel_monitor));
-       maxfd = UDEV_MAX(maxfd, signal_pipe[READ_END]);
-       maxfd = UDEV_MAX(maxfd, inotify_fd);
        while (!udev_exit) {
+               sigset_t blocked_mask, orig_mask;
+               struct pollfd pfd[4];
+               struct pollfd *ctrl_poll, *monitor_poll, *inotify_poll = NULL;
+               int nfds = 0;
                int fdcount;
 
-               FD_ZERO(&readfds);
-               FD_SET(signal_pipe[READ_END], &readfds);
-               FD_SET(udev_ctrl_get_fd(udev_ctrl), &readfds);
-               FD_SET(udev_monitor_get_fd(kernel_monitor), &readfds);
-               if (inotify_fd >= 0)
-                       FD_SET(inotify_fd, &readfds);
-               fdcount = select(maxfd+1, &readfds, NULL, NULL, NULL);
+               sigfillset(&blocked_mask);
+               sigprocmask(SIG_SETMASK, &blocked_mask, &orig_mask);
+               if (signal_received) {
+                       sigprocmask(SIG_SETMASK, &orig_mask, NULL);
+                       goto handle_signals;
+               }
+
+               ctrl_poll = &pfd[nfds++];
+               ctrl_poll->fd = udev_ctrl_get_fd(udev_ctrl);
+               ctrl_poll->events = POLLIN;
+
+               monitor_poll = &pfd[nfds++];
+               monitor_poll->fd = udev_monitor_get_fd(kernel_monitor);
+               monitor_poll->events = POLLIN;
+
+               if (inotify_fd >= 0) {
+                       inotify_poll = &pfd[nfds++];
+                       inotify_poll->fd = inotify_fd;
+                       inotify_poll->events = POLLIN;
+               }
+
+               fdcount = ppoll(pfd, nfds, NULL, &orig_mask);
+               sigprocmask(SIG_SETMASK, &orig_mask, NULL);
                if (fdcount < 0) {
-                       if (errno != EINTR)
-                               err(udev, "error in select: %m\n");
+                       if (errno == EINTR)
+                               goto handle_signals;
+                       err(udev, "error in select: %m\n");
                        continue;
                }
 
                /* get control message */
-               if (FD_ISSET(udev_ctrl_get_fd(udev_ctrl), &readfds))
+               if (ctrl_poll->revents & POLLIN)
                        handle_ctrl_msg(udev_ctrl);
 
                /* get kernel uevent */
-               if (FD_ISSET(udev_monitor_get_fd(kernel_monitor), &readfds)) {
+               if (monitor_poll->revents & POLLIN) {
                        struct udev_device *dev;
 
                        dev = udev_monitor_receive_device(kernel_monitor);
@@ -913,39 +1012,19 @@ int main(int argc, char *argv[])
                        }
                }
 
-               /* received a signal, clear our notification pipe */
-               if (FD_ISSET(signal_pipe[READ_END], &readfds)) {
-                       char buf[256];
-
-                       read(signal_pipe[READ_END], &buf, sizeof(buf));
-               }
-
                /* rules directory inotify watch */
-               if ((inotify_fd >= 0) && FD_ISSET(inotify_fd, &readfds)) {
-                       int nbytes;
-
-                       /* discard all possible events, we can just reload the config */
-                       if ((ioctl(inotify_fd, FIONREAD, &nbytes) == 0) && nbytes > 0) {
-                               char *buf;
-
-                               reload_config = 1;
-                               buf = malloc(nbytes);
-                               if (buf == NULL) {
-                                       err(udev, "error getting buffer for inotify, disable watching\n");
-                                       close(inotify_fd);
-                                       inotify_fd = -1;
-                               }
-                               read(inotify_fd, buf, nbytes);
-                               free(buf);
-                       }
-               }
+               if (inotify_poll && (inotify_poll->revents & POLLIN))
+                       handle_inotify(udev);
+
+handle_signals:
+               signal_received = 0;
 
                /* rules changed, set by inotify or a HUP signal */
                if (reload_config) {
                        struct udev_rules *rules_new;
 
                        reload_config = 0;
-                       rules_new = udev_rules_new(udev, 1);
+                       rules_new = udev_rules_new(udev, resolve_names);
                        if (rules_new != NULL) {
                                udev_rules_unref(rules);
                                rules = rules_new;
@@ -962,23 +1041,21 @@ int main(int argc, char *argv[])
                        if (!stop_exec_q)
                                event_queue_manager(udev);
                }
+
+               if (settle_pid > 0) {
+                       kill(settle_pid, SIGUSR1);
+                       settle_pid = 0;
+               }
        }
+       cleanup_queue_dir(udev);
        rc = 0;
-
 exit:
        udev_rules_unref(rules);
-
-       if (signal_pipe[READ_END] >= 0)
-               close(signal_pipe[READ_END]);
-       if (signal_pipe[WRITE_END] >= 0)
-               close(signal_pipe[WRITE_END]);
-
        udev_ctrl_unref(udev_ctrl);
        if (inotify_fd >= 0)
                close(inotify_fd);
        udev_monitor_unref(kernel_monitor);
-
-       selinux_exit(udev);
+       udev_selinux_exit(udev);
        udev_unref(udev);
        logging_close();
        return rc;