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udevd: make sure a worker finishes event handling before exiting

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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.
This commit is contained in:
Kay Sievers 2009-07-11 18:21:26 +02:00
parent 405c307a72
commit adda4c682a
2 changed files with 43 additions and 37 deletions
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4
libudev/libudev-util-private.c
View file

@ -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;
}
}

76
udev/udevd.c
View file

@ -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);