X-Git-Url: http://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=src%2Fudev%2Fudevd.c;h=aecd208d40cd99f46a07a5d10d4faa52645d313d;hb=deb2e5230b4dcbc0e2e02cc47a0b2d0d7179a044;hp=0dfad762f1aea49e19e87e3c0d5832ba4bb0a2bb;hpb=ed14edc04f9355b0d3fc769638b167decf27dc23;p=elogind.git diff --git a/src/udev/udevd.c b/src/udev/udevd.c index 0dfad762f..aecd208d4 100644 --- a/src/udev/udevd.c +++ b/src/udev/udevd.c @@ -31,6 +31,7 @@ #include #include #include +#include #include #include #include @@ -60,7 +61,6 @@ void udev_main_log(struct udev *udev, int priority, } static struct udev_rules *rules; -static struct udev_queue_export *udev_queue_export; static struct udev_ctrl *udev_ctrl; static struct udev_monitor *monitor; static int worker_watch[2] = { -1, -1 }; @@ -139,14 +139,9 @@ static inline struct worker *node_to_worker(struct udev_list_node *node) return container_of(node, struct worker, node); } -static void event_queue_delete(struct event *event, bool export) +static void event_queue_delete(struct event *event) { udev_list_node_remove(&event->node); - - if (export) { - udev_queue_export_device_finished(udev_queue_export, event->dev); - log_debug("seq %llu done with %i", udev_device_get_seqnum(event->dev), event->exitcode); - } udev_device_unref(event->dev); free(event); } @@ -200,7 +195,7 @@ static void worker_new(struct event *event) udev_monitor_allow_unicast_sender(worker_monitor, monitor); udev_monitor_enable_receiving(worker_monitor); - worker = calloc(1, sizeof(struct worker)); + worker = new0(struct worker, 1); if (worker == NULL) { udev_monitor_unref(worker_monitor); return; @@ -225,7 +220,6 @@ static void worker_new(struct event *event) free(worker); worker_list_cleanup(udev); event_queue_cleanup(udev, EVENT_UNDEF); - udev_queue_export_unref(udev_queue_export); udev_monitor_unref(monitor); udev_ctrl_unref(udev_ctrl); close(fd_signal); @@ -247,12 +241,12 @@ static void worker_new(struct event *event) goto out; } - memset(&ep_signal, 0, sizeof(struct epoll_event)); + memzero(&ep_signal, 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)); + memzero(&ep_monitor, sizeof(struct epoll_event)); ep_monitor.events = EPOLLIN; ep_monitor.data.fd = fd_monitor; @@ -272,6 +266,7 @@ static void worker_new(struct event *event) for (;;) { struct udev_event *udev_event; struct worker_message msg; + int fd_lock = -1; int err; log_debug("seq %llu running", udev_device_get_seqnum(dev)); @@ -287,6 +282,30 @@ static void worker_new(struct event *event) if (exec_delay > 0) udev_event->exec_delay = exec_delay; + /* + * Take a "read lock" on the device node; this establishes + * a concept of device "ownership" to serialize device + * access. External processes holding a "write lock" will + * cause udev to skip the event handling; in the case udev + * acquired the lock, the external process will block until + * udev has finished its event handling. + */ + if (streq_ptr("block", udev_device_get_subsystem(dev))) { + struct udev_device *d = dev; + + if (streq_ptr("partition", udev_device_get_devtype(d))) + d = udev_device_get_parent(d); + + if (d) { + fd_lock = open(udev_device_get_devnode(d), O_RDONLY|O_CLOEXEC|O_NOFOLLOW|O_NONBLOCK); + if (fd_lock >= 0 && flock(fd_lock, LOCK_SH|LOCK_NB) < 0) { + log_debug("Unable to flock(%s), skipping event handling: %m", udev_device_get_devnode(d)); + err = -EWOULDBLOCK; + goto skip; + } + } + } + /* apply rules, create node, symlinks */ err = udev_event_execute_rules(udev_event, rules, &sigmask_orig); @@ -299,13 +318,16 @@ static void worker_new(struct event *event) udev_device_update_db(dev); } + if (fd_lock >= 0) + close(fd_lock); + /* send processed event back to libudev listeners */ udev_monitor_send_device(worker_monitor, NULL, dev); +skip: /* send udevd the result of the event execution */ - memset(&msg, 0, sizeof(struct worker_message)); - if (err != 0) - msg.exitcode = err; + memzero(&msg, sizeof(struct worker_message)); + msg.exitcode = err; msg.pid = getpid(); send(worker_watch[WRITE_END], &msg, sizeof(struct worker_message), 0); @@ -431,7 +453,7 @@ static int event_queue_insert(struct udev_device *dev) { struct event *event; - event = calloc(1, sizeof(struct event)); + event = new0(struct event, 1); if (event == NULL) return -1; @@ -449,7 +471,6 @@ static int event_queue_insert(struct udev_device *dev) event->nodelay = true; #endif - udev_queue_export_device_queued(udev_queue_export, dev); log_debug("seq %llu queued, '%s' '%s'", udev_device_get_seqnum(dev), udev_device_get_action(dev), udev_device_get_subsystem(dev)); @@ -580,7 +601,7 @@ static void event_queue_cleanup(struct udev *udev, enum event_state match_type) if (match_type != EVENT_UNDEF && match_type != event->state) continue; - event_queue_delete(event, false); + event_queue_delete(event); } } @@ -605,7 +626,7 @@ static void worker_returned(int fd_worker) /* worker returned */ if (worker->event) { worker->event->exitcode = msg.exitcode; - event_queue_delete(worker->event, true); + event_queue_delete(worker->event); worker->event = NULL; } if (worker->state != WORKER_KILLED) @@ -734,7 +755,7 @@ static int handle_inotify(struct udev *udev) log_debug("device %s closed, synthesising 'change'", udev_device_get_devnode(dev)); strscpyl(filename, sizeof(filename), udev_device_get_syspath(dev), "/uevent", NULL); - fd = open(filename, O_WRONLY); + fd = open(filename, O_WRONLY|O_CLOEXEC); if (fd >= 0) { if (write(fd, "change", 6) < 0) log_debug("error writing uevent: %m"); @@ -797,7 +818,8 @@ static void handle_signal(struct udev *udev, int signo) log_error("worker [%u] failed while handling '%s'", pid, worker->event->devpath); worker->event->exitcode = -32; - event_queue_delete(worker->event, true); + event_queue_delete(worker->event); + /* drop reference taken for state 'running' */ worker_unref(worker); } @@ -1076,14 +1098,7 @@ int main(int argc, char *argv[]) goto exit; } - udev_monitor_set_receive_buffer_size(monitor, 128*1024*1024); - - /* create queue file before signalling 'ready', to make sure we block 'settle' */ - udev_queue_export = udev_queue_export_new(udev); - if (udev_queue_export == NULL) { - log_error("error creating queue file"); - goto exit; - } + udev_monitor_set_receive_buffer_size(monitor, 128 * 1024 * 1024); if (daemonize) { pid_t pid; @@ -1159,23 +1174,23 @@ int main(int argc, char *argv[]) goto exit; } - memset(&ep_ctrl, 0, sizeof(struct epoll_event)); + memzero(&ep_ctrl, sizeof(struct epoll_event)); ep_ctrl.events = EPOLLIN; ep_ctrl.data.fd = fd_ctrl; - memset(&ep_inotify, 0, sizeof(struct epoll_event)); + memzero(&ep_inotify, sizeof(struct epoll_event)); ep_inotify.events = EPOLLIN; ep_inotify.data.fd = fd_inotify; - memset(&ep_signal, 0, sizeof(struct epoll_event)); + memzero(&ep_signal, sizeof(struct epoll_event)); ep_signal.events = EPOLLIN; ep_signal.data.fd = fd_signal; - memset(&ep_netlink, 0, sizeof(struct epoll_event)); + memzero(&ep_netlink, sizeof(struct epoll_event)); ep_netlink.events = EPOLLIN; ep_netlink.data.fd = fd_netlink; - memset(&ep_worker, 0, sizeof(struct epoll_event)); + memzero(&ep_worker, sizeof(struct epoll_event)); ep_worker.events = EPOLLIN; ep_worker.data.fd = fd_worker; @@ -1241,12 +1256,12 @@ int main(int argc, char *argv[]) worker_kill(udev); /* exit after all has cleaned up */ - if (udev_list_node_is_empty(&event_list) && udev_list_node_is_empty(&worker_list)) + if (udev_list_node_is_empty(&event_list) && children == 0) break; /* timeout at exit for workers to finish */ - timeout = 30 * 1000; - } else if (udev_list_node_is_empty(&event_list) && !children) { + timeout = 30 * MSEC_PER_SEC; + } else if (udev_list_node_is_empty(&event_list) && children == 0) { /* we are idle */ timeout = -1; @@ -1255,8 +1270,20 @@ int main(int argc, char *argv[]) cg_kill(SYSTEMD_CGROUP_CONTROLLER, udev_cgroup, SIGKILL, false, true, NULL); } else { /* kill idle or hanging workers */ - timeout = 3 * 1000; + timeout = 3 * MSEC_PER_SEC; } + + /* tell settle that we are busy or idle */ + if (!udev_list_node_is_empty(&event_list)) { + int fd; + + fd = open("/run/udev/queue", O_WRONLY|O_CREAT|O_CLOEXEC|O_TRUNC|O_NOFOLLOW, 0444); + if (fd >= 0) + close(fd); + } else { + unlink("/run/udev/queue"); + } + fdcount = epoll_wait(fd_ep, ev, ELEMENTSOF(ev), timeout); if (fdcount < 0) continue; @@ -1283,18 +1310,18 @@ int main(int argc, char *argv[]) if (worker->state != WORKER_RUNNING) continue; - if ((now(CLOCK_MONOTONIC) - worker->event_start_usec) > 30 * 1000 * 1000) { + if ((now(CLOCK_MONOTONIC) - worker->event_start_usec) > 30 * USEC_PER_SEC) { log_error("worker [%u] %s timeout; kill it", worker->pid, worker->event ? worker->event->devpath : ""); kill(worker->pid, SIGKILL); worker->state = WORKER_KILLED; + /* drop reference taken for state 'running' */ worker_unref(worker); if (worker->event) { - log_error("seq %llu '%s' killed", - udev_device_get_seqnum(worker->event->dev), worker->event->devpath); + log_error("seq %llu '%s' killed", udev_device_get_seqnum(worker->event->dev), worker->event->devpath); worker->event->exitcode = -64; - event_queue_delete(worker->event, true); + event_queue_delete(worker->event); worker->event = NULL; } } @@ -1317,7 +1344,7 @@ int main(int argc, char *argv[]) } /* check for changed config, every 3 seconds at most */ - if ((now(CLOCK_MONOTONIC) - last_usec) > 3 * 1000 * 1000) { + if ((now(CLOCK_MONOTONIC) - last_usec) > 3 * USEC_PER_SEC) { if (udev_rules_check_timestamp(rules)) reload = true; if (udev_builtin_validate(udev)) @@ -1390,8 +1417,8 @@ int main(int argc, char *argv[]) rc = EXIT_SUCCESS; exit: - udev_queue_export_cleanup(udev_queue_export); udev_ctrl_cleanup(udev_ctrl); + unlink("/run/udev/queue"); exit_daemonize: if (fd_ep >= 0) close(fd_ep); @@ -1406,7 +1433,6 @@ exit_daemonize: if (worker_watch[WRITE_END] >= 0) close(worker_watch[WRITE_END]); udev_monitor_unref(monitor); - udev_queue_export_unref(udev_queue_export); udev_ctrl_connection_unref(ctrl_conn); udev_ctrl_unref(udev_ctrl); label_finish();