From 82063a88d1fbcceade7e0475ebef2fc69fa5fa87 Mon Sep 17 00:00:00 2001 From: Kay Sievers Date: Mon, 18 Apr 2011 02:14:24 +0200 Subject: [PATCH 1/1] udevd: ppoll() -> epoll + signalfd --- TODO | 2 - udev/udevd.c | 128 ++++++++++++++++++++++++++++++--------------------- 2 files changed, 76 insertions(+), 54 deletions(-) diff --git a/TODO b/TODO index c09613313..80d508601 100644 --- a/TODO +++ b/TODO @@ -1,5 +1,3 @@ - - get rid of select() - - use signalfd instead of ppoll() - remove deprecated trigger --type=failed logic diff --git a/udev/udevd.c b/udev/udevd.c index b30a27bf7..f730cab48 100644 --- a/udev/udevd.c +++ b/udev/udevd.c @@ -85,7 +85,6 @@ static sigset_t orig_sigmask; static UDEV_LIST(event_list); static UDEV_LIST(worker_list); static bool udev_exit; -static volatile sig_atomic_t worker_exit; enum event_state { EVENT_UNDEF, @@ -168,18 +167,6 @@ static void event_queue_delete(struct event *event, bool export) free(event); } -static void event_sig_handler(int signum) -{ - switch (signum) { - case SIGALRM: - _exit(1); - break; - case SIGTERM: - worker_exit = true; - break; - } -} - static struct worker *worker_ref(struct worker *worker) { worker->refcount++; @@ -220,7 +207,6 @@ static void worker_new(struct event *event) struct worker *worker; struct udev_monitor *worker_monitor; pid_t pid; - struct sigaction act; /* listen for new events */ worker_monitor = udev_monitor_new_from_netlink(udev, NULL); @@ -242,12 +228,11 @@ static void worker_new(struct event *event) pid = fork(); switch (pid) { case 0: { - sigset_t sigmask; - struct udev_device *dev; - struct pollfd pmon = { - .fd = udev_monitor_get_fd(worker_monitor), - .events = POLLIN, - }; + struct udev_device *dev = NULL; + int fd_monitor; + struct epoll_event ep_signal, ep_monitor; + sigset_t mask; + int rc = EXIT_SUCCESS; /* move initial device from queue */ dev = event->dev; @@ -265,25 +250,41 @@ static void worker_new(struct event *event) udev_log_close(); udev_log_init("udevd-work"); - /* set signal handlers */ - memset(&act, 0x00, sizeof(act)); - act.sa_handler = event_sig_handler; - sigemptyset (&act.sa_mask); - act.sa_flags = 0; - sigaction(SIGTERM, &act, NULL); - sigaction(SIGALRM, &act, NULL); - - /* unblock SIGALRM */ - sigfillset(&sigmask); - sigdelset(&sigmask, SIGALRM); - sigprocmask(SIG_SETMASK, &sigmask, NULL); - /* SIGTERM is unblocked in ppoll() */ - sigdelset(&sigmask, SIGTERM); + sigfillset(&mask); + fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC); + if (fd_signal < 0) { + err(udev, "error creating signalfd %m\n"); + rc = 2; + goto out; + } + + fd_ep = epoll_create1(EPOLL_CLOEXEC); + if (fd_ep < 0) { + err(udev, "error creating epoll fd: %m\n"); + rc = 3; + goto out; + } + + memset(&ep_signal, 0, sizeof(struct epoll_event)); + ep_signal.events = EPOLLIN; + ep_signal.data.fd = fd_signal; + + fd_monitor = udev_monitor_get_fd(worker_monitor); + memset(&ep_monitor, 0, sizeof(struct epoll_event)); + ep_monitor.events = EPOLLIN; + ep_monitor.data.fd = fd_monitor; + + if (epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_signal, &ep_signal) < 0 || + epoll_ctl(fd_ep, EPOLL_CTL_ADD, fd_monitor, &ep_monitor) < 0) { + err(udev, "fail to add fds to epoll: %m\n"); + rc = 4; + goto out; + } /* request TERM signal if parent exits */ prctl(PR_SET_PDEATHSIG, SIGTERM); - do { + for (;;) { struct udev_event *udev_event; struct worker_message msg = {}; int err; @@ -291,8 +292,10 @@ static void worker_new(struct event *event) info(udev, "seq %llu running\n", udev_device_get_seqnum(dev)); udev_event = udev_event_new(dev); - if (udev_event == NULL) - _exit(3); + if (udev_event == NULL) { + rc = 5; + goto out; + } /* set timeout to prevent hanging processes */ alarm(UDEV_EVENT_TIMEOUT); @@ -334,29 +337,50 @@ static void worker_new(struct event *event) udev_device_unref(dev); dev = NULL; - /* wait for more device messages or signal from udevd */ - while (!worker_exit) { + /* wait for more device messages from main udevd, or term signal */ + while (dev == NULL) { + struct epoll_event ev[4]; int fdcount; + int i; - fdcount = ppoll(&pmon, 1, NULL, &sigmask); + fdcount = epoll_wait(fd_ep, ev, ARRAY_SIZE(ev), -1); if (fdcount < 0) continue; - if (pmon.revents & POLLIN) { - dev = udev_monitor_receive_device(worker_monitor); - if (dev != NULL) - break; + for (i = 0; i < fdcount; i++) { + if (ev[i].data.fd == fd_monitor && ev[i].events & EPOLLIN) { + dev = udev_monitor_receive_device(worker_monitor); + } else if (ev[i].data.fd == fd_signal && ev[i].events & EPOLLIN) { + struct signalfd_siginfo fdsi; + ssize_t size; + + size = read(fd_signal, &fdsi, sizeof(struct signalfd_siginfo)); + if (size != sizeof(struct signalfd_siginfo)) + continue; + switch (fdsi.ssi_signo) { + case SIGTERM: + goto out; + case SIGALRM: + rc = EXIT_FAILURE; + goto out; + } + } } } - } while (dev != NULL); - + } +out: + udev_device_unref(dev); + if (fd_signal >= 0) + close(fd_signal); + if (fd_ep >= 0) + close(fd_ep); close(fd_inotify); close(worker_watch[WRITE_END]); udev_rules_unref(rules); udev_monitor_unref(worker_monitor); udev_unref(udev); udev_log_close(); - exit(EXIT_SUCCESS); + exit(rc); } case -1: udev_monitor_unref(worker_monitor); @@ -1455,18 +1479,18 @@ int main(int argc, char *argv[]) /* block and listen to all signals on signalfd */ sigfillset(&mask); sigprocmask(SIG_SETMASK, &mask, &orig_sigmask); - fd_signal = signalfd(-1, &mask, SFD_CLOEXEC); + fd_signal = signalfd(-1, &mask, SFD_NONBLOCK|SFD_CLOEXEC); if (fd_signal < 0) { - fprintf(stderr, "error getting signalfd\n"); - err(udev, "error getting signalfd\n"); + fprintf(stderr, "error creating signalfd\n"); + err(udev, "error creating signalfd\n"); rc = 5; goto exit; } /* unnamed socket from workers to the main daemon */ if (socketpair(AF_LOCAL, SOCK_DGRAM|SOCK_CLOEXEC, 0, worker_watch) < 0) { - fprintf(stderr, "error getting socketpair\n"); - err(udev, "error getting socketpair\n"); + fprintf(stderr, "error creating socketpair\n"); + err(udev, "error creating socketpair\n"); rc = 6; goto exit; } -- 2.30.2