From: Kay Sievers Date: Sat, 11 Jul 2009 16:21:26 +0000 (+0200) Subject: udevd: make sure a worker finishes event handling before exiting X-Git-Tag: 174~901 X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?p=elogind.git;a=commitdiff_plain;h=adda4c682ad2c56fc091222be3bd94fa817013b9 udevd: make sure a worker finishes event handling before exiting Persistent network rules write out new rules files. When rules change, we need to kill all workers to update the in-memory copy of the rules. We need to make sure, that a worker finshes its work for all device messages it has accepted, before it exits after a SIGTERM from the main process. --- diff --git a/libudev/libudev-util-private.c b/libudev/libudev-util-private.c index 1a37490a9..5f5f4c1d8 100644 --- a/libudev/libudev-util-private.c +++ b/libudev/libudev-util-private.c @@ -435,11 +435,11 @@ int util_run_program(struct udev *udev, const char *command, char **envp, } waitpid(pid, &status, 0); if (WIFEXITED(status)) { - info(udev, "'%s' returned with status %i\n", argv[0], WEXITSTATUS(status)); + info(udev, "'%s' returned with exitcode %i\n", command, WEXITSTATUS(status)); if (WEXITSTATUS(status) != 0) err = -1; } else { - err(udev, "'%s' abnormal exit\n", command); + err(udev, "'%s' unexpected exit with status 0x%04x\n", command, status); err = -1; } } diff --git a/udev/udevd.c b/udev/udevd.c index cfb8823f4..876d2ec1d 100644 --- a/udev/udevd.c +++ b/udev/udevd.c @@ -205,8 +205,12 @@ static void worker_new(struct event *event) pid = fork(); switch (pid) { case 0: { - sigset_t mask; + sigset_t sigmask; struct udev_device *dev; + struct pollfd pmon = { + .fd = udev_monitor_get_fd(worker_monitor), + .events = POLLIN, + }; udev_queue_export_unref(udev_queue_export); udev_monitor_unref(monitor); @@ -225,11 +229,12 @@ static void worker_new(struct event *event) sigaction(SIGTERM, &act, NULL); sigaction(SIGALRM, &act, NULL); - /* unblock signals */ - sigfillset(&mask); - sigdelset(&mask, SIGTERM); - sigdelset(&mask, SIGALRM); - sigprocmask(SIG_SETMASK, &mask, NULL); + /* unblock SIGALRM */ + sigfillset(&sigmask); + sigdelset(&sigmask, SIGALRM); + sigprocmask(SIG_SETMASK, &sigmask, NULL); + /* SIGTERM is unblocked in ppoll() */ + sigdelset(&sigmask, SIGTERM); /* request TERM signal if parent exits */ prctl(PR_SET_PDEATHSIG, SIGTERM); @@ -237,7 +242,7 @@ static void worker_new(struct event *event) /* initial device */ dev = event->dev; - while (!worker_exit) { + do { struct udev_event *udev_event; struct worker_message msg; int err; @@ -272,20 +277,31 @@ static void worker_new(struct event *event) /* send processed event back to libudev listeners */ udev_monitor_send_device(worker_monitor, NULL, dev); - info(event->udev, "seq %llu processed with %i\n", udev_device_get_seqnum(dev), err); - udev_device_unref(dev); - udev_event_unref(udev_event); - /* send back the result of the event execution */ msg.exitcode = err; msg.pid = getpid(); send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0); - /* wait for more device messages from udevd */ - do - dev = udev_monitor_receive_device(worker_monitor); - while (!worker_exit && dev == NULL); - } + info(event->udev, "seq %llu processed with %i\n", udev_device_get_seqnum(dev), err); + udev_event_unref(udev_event); + udev_device_unref(dev); + dev = NULL; + + /* wait for more device messages or signal from udevd */ + while (!worker_exit) { + int fdcount; + + fdcount = ppoll(&pmon, 1, NULL, &sigmask); + if (fdcount < 0) + continue; + + if (pmon.revents & POLLIN) { + dev = udev_monitor_receive_device(worker_monitor); + if (dev != NULL) + break; + } + } + } while (dev != NULL); udev_monitor_unref(worker_monitor); udev_log_close(); @@ -376,7 +392,7 @@ static void event_queue_insert(struct udev_device *dev) } } -static void worker_kill(int retain) +static void worker_kill(struct udev *udev, int retain) { struct udev_list_node *loop; int max; @@ -522,14 +538,12 @@ static void worker_returned(void) if (worker->pid != msg.pid) continue; - if (worker->state != WORKER_RUNNING) - break; - /* worker returned */ worker->event->exitcode = msg.exitcode; event_queue_delete(worker->event); worker->event = NULL; - worker->state = WORKER_IDLE; + if (worker->state != WORKER_KILLED) + worker->state = WORKER_IDLE; break; } } @@ -551,7 +565,7 @@ static void handle_ctrl_msg(struct udev_ctrl *uctrl) if (i >= 0) { info(udev, "udevd message (SET_LOG_PRIORITY) received, log_priority=%i\n", i); udev_set_log_priority(udev, i); - worker_kill(0); + worker_kill(udev, 0); } if (udev_ctrl_get_stop_exec_queue(ctrl_msg) > 0) { @@ -593,7 +607,7 @@ static void handle_ctrl_msg(struct udev_ctrl *uctrl) } free(key); } - worker_kill(0); + worker_kill(udev, 0); } i = udev_ctrl_get_set_max_childs(ctrl_msg); @@ -690,16 +704,8 @@ static void handle_signal(struct udev *udev, int signo) /* fail event, if worker died unexpectedly */ if (worker->event != NULL) { - int exitcode; - - if (WIFEXITED(status)) - exitcode = WEXITSTATUS(status); - else if (WIFSIGNALED(status)) - exitcode = WTERMSIG(status) + 128; - else - exitcode = 0; - worker->event->exitcode = exitcode; - err(udev, "worker [%u] unexpectedly returned with %i\n", pid, exitcode); + worker->event->exitcode = status; + err(udev, "worker [%u] unexpectedly returned with status 0x%04x\n", pid, status); event_queue_delete(worker->event); } @@ -999,7 +1005,7 @@ int main(int argc, char *argv[]) /* timeout - kill idle workers */ if (fdcount == 0) - worker_kill(2); + worker_kill(udev, 2); /* event has finished */ if (pfd[FD_WORKER].revents & POLLIN) @@ -1048,7 +1054,7 @@ int main(int argc, char *argv[]) if (reload_config) { struct udev_rules *rules_new; - worker_kill(0); + worker_kill(udev, 0); rules_new = udev_rules_new(udev, resolve_names); if (rules_new != NULL) { udev_rules_unref(rules);