udevd: merge exec and run queue to minimize devpath string compares

diff --git a/udev/udev-event.c b/udev/udev-event.c
index 02c5c99dc1b4b6cfc2b7b46497c3ac1bb2dbc435..79a4cde65142643f8812c3f8d87f49830b433c84 100644 (file)
--- a/udev/udev-event.c
+++ b/udev/udev-event.c
@@ -706,6 +706,11 @@ int udev_event_execute_run(struct udev_event *event)
 
                        util_strlcpy(program, cmd, sizeof(program));
                        udev_event_apply_format(event, program, sizeof(program));
+                       if (event->trace)
+                               printf("run  %s (%llu) '%s'\n",
+                                      udev_device_get_syspath(event->dev),
+                                      udev_device_get_seqnum(event->dev),
+                                      program);
                        envp = udev_device_get_properties_envp(event->dev);
                        if (util_run_program(event->udev, program, envp, NULL, 0, NULL) != 0) {
                                if (!udev_list_entry_get_flag(list_entry))

diff --git a/udev/udev.h b/udev/udev.h
index faa1bf68516cb6737c4f8069bcd8008101aba58c..732b1313900f70903cd5925b674eeb1e6db4126b 100644 (file)
--- a/udev/udev.h
+++ b/udev/udev.h
@@ -71,6 +71,7 @@ struct udev_event {
        pid_t pid;
        int exitstatus;
        time_t queue_time;
+       unsigned long long int delaying_seqnum;
        unsigned int group_final:1;
        unsigned int owner_final:1;
        unsigned int mode_final:1;
@@ -78,6 +79,7 @@ struct udev_event {
        unsigned int devlink_final:1;
        unsigned int run_final:1;
        unsigned int ignore_device:1;
+       unsigned int trace:1;
        unsigned int test:1;
 };
 

diff --git a/udev/udevd.c b/udev/udevd.c
index 0bacb3994b00a716fa2af15aaaa64af7391fa4c5..6f2e188ceaaa07a198f3a337a7a7cca126dfad72 100644 (file)
--- a/udev/udevd.c
+++ b/udev/udevd.c
@@ -62,7 +62,6 @@ 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;
@@ -70,9 +69,8 @@ static volatile int reload_config;
 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,
@@ -137,7 +135,7 @@ static void export_event_state(struct udev_event *event, enum event_state state)
                unlink(filename);
 
                /* clean up possibly empty queue directory */
-               if (udev_list_is_empty(&exec_list) && udev_list_is_empty(&running_list))
+               if (udev_list_is_empty(&event_list))
                        util_delete_path(event->udev, filename);
                break;
        case EVENT_FAILED:
@@ -146,7 +144,7 @@ static void export_event_state(struct udev_event *event, enum event_state state)
                rename(filename, filename_failed);
 
                /* clean up possibly empty queue directory */
-               if (udev_list_is_empty(&exec_list) && udev_list_is_empty(&running_list))
+               if (udev_list_is_empty(&event_list))
                        util_delete_path(event->udev, filename);
                break;
        }
@@ -180,6 +178,13 @@ static void event_fork(struct udev_event *event)
        struct sigaction act;
        int err;
 
+       if (debug_trace) {
+               event->trace = 1;
+               printf("fork %s (%llu)\n",
+                      udev_device_get_syspath(event->dev),
+                      udev_device_get_seqnum(event->dev));
+       }
+
        pid = fork();
        switch (pid) {
        case 0:
@@ -221,6 +226,7 @@ static void event_fork(struct udev_event *event)
                /* execute RUN= */
                if (err == 0 && !event->ignore_device && udev_get_run(event->udev))
                        udev_event_execute_run(event);
+
                info(event->udev, "seq %llu exit with %i\n", udev_device_get_seqnum(event->dev), err);
                logging_close();
                if (err != 0)
@@ -239,6 +245,7 @@ static void event_fork(struct udev_event *event)
                     udev_device_get_subsystem(event->dev),
                     time(NULL) - event->queue_time);
                event->pid = pid;
+               childs++;
        }
 }
 
@@ -265,24 +272,15 @@ 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)
@@ -312,7 +310,7 @@ static int compare_devpath(const char *running, const char *waiting)
 {
        int i = 0;
 
-       while (running[i] == waiting[i] && running[i] != '\0')
+       while (running[i] != '\0' && running[i] == waiting[i])
                i++;
 
        /* identical device event found */
@@ -332,23 +330,34 @@ static int compare_devpath(const char *running, const char *waiting)
 }
 
 /* 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) {
@@ -356,57 +365,10 @@ 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) &&
@@ -415,7 +377,8 @@ 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) */
@@ -427,7 +390,8 @@ 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;
@@ -439,23 +403,34 @@ 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))
+       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);
+               /* do dendencies, start event */
                event_fork(loop_event);
                dbg(udev, "moved seq %llu to running list\n", udev_device_get_seqnum(loop_event->dev));
        }
@@ -526,7 +501,6 @@ static void handle_ctrl_msg(struct udev_ctrl *uctrl)
                info(udev, "udevd message (SET_MAX_CHILDS) received, max_childs=%i\n", i);
                max_childs = i;
        }
-
        udev_ctrl_msg_unref(ctrl_msg);
 }
 
@@ -555,7 +529,7 @@ 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) {
@@ -563,9 +537,14 @@ 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)
+                               printf("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;
                }
@@ -690,8 +669,6 @@ 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)
@@ -755,8 +732,7 @@ int main(int argc, char *argv[])
                err(udev, "error reading rules\n");
                goto exit;
        }
-       udev_list_init(&running_list);
-       udev_list_init(&exec_list);
+       udev_list_init(&event_list);
        export_initial_seqnum(udev);
 
        if (daemonize) {
@@ -779,7 +755,8 @@ 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);
        }
@@ -840,7 +817,7 @@ int main(int argc, char *argv[])
                        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);
@@ -858,17 +835,20 @@ int main(int argc, char *argv[])
        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 {
+       /* 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);