summaryrefslogtreecommitdiffstats
path: root/src/udev/udev-manager.c
diff options
context:
space:
mode:
authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-10 20:49:52 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-10 20:49:52 +0000
commit55944e5e40b1be2afc4855d8d2baf4b73d1876b5 (patch)
tree33f869f55a1b149e9b7c2b7e201867ca5dd52992 /src/udev/udev-manager.c
parentInitial commit. (diff)
downloadsystemd-55944e5e40b1be2afc4855d8d2baf4b73d1876b5.tar.xz
systemd-55944e5e40b1be2afc4855d8d2baf4b73d1876b5.zip
Adding upstream version 255.4.upstream/255.4
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/udev/udev-manager.c')
-rw-r--r--src/udev/udev-manager.c1352
1 files changed, 1352 insertions, 0 deletions
diff --git a/src/udev/udev-manager.c b/src/udev/udev-manager.c
new file mode 100644
index 0000000..8077e51
--- /dev/null
+++ b/src/udev/udev-manager.c
@@ -0,0 +1,1352 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include "blockdev-util.h"
+#include "cgroup-util.h"
+#include "common-signal.h"
+#include "cpu-set-util.h"
+#include "daemon-util.h"
+#include "device-monitor-private.h"
+#include "device-private.h"
+#include "device-util.h"
+#include "errno-list.h"
+#include "event-util.h"
+#include "fd-util.h"
+#include "fs-util.h"
+#include "hashmap.h"
+#include "inotify-util.h"
+#include "iovec-util.h"
+#include "limits-util.h"
+#include "list.h"
+#include "mkdir.h"
+#include "process-util.h"
+#include "selinux-util.h"
+#include "signal-util.h"
+#include "socket-util.h"
+#include "string-util.h"
+#include "syslog-util.h"
+#include "udev-builtin.h"
+#include "udev-ctrl.h"
+#include "udev-event.h"
+#include "udev-manager.h"
+#include "udev-node.h"
+#include "udev-spawn.h"
+#include "udev-trace.h"
+#include "udev-util.h"
+#include "udev-watch.h"
+#include "udev-worker.h"
+
+#define WORKER_NUM_MAX UINT64_C(2048)
+
+#define EVENT_RETRY_INTERVAL_USEC (200 * USEC_PER_MSEC)
+#define EVENT_RETRY_TIMEOUT_USEC (3 * USEC_PER_MINUTE)
+
+typedef enum EventState {
+ EVENT_UNDEF,
+ EVENT_QUEUED,
+ EVENT_RUNNING,
+} EventState;
+
+typedef struct Event {
+ Manager *manager;
+ Worker *worker;
+ EventState state;
+
+ sd_device *dev;
+
+ sd_device_action_t action;
+ uint64_t seqnum;
+ uint64_t blocker_seqnum;
+ const char *id;
+ const char *devpath;
+ const char *devpath_old;
+ const char *devnode;
+
+ /* Used when the device is locked by another program. */
+ usec_t retry_again_next_usec;
+ usec_t retry_again_timeout_usec;
+ sd_event_source *retry_event_source;
+
+ sd_event_source *timeout_warning_event;
+ sd_event_source *timeout_event;
+
+ LIST_FIELDS(Event, event);
+} Event;
+
+typedef enum WorkerState {
+ WORKER_UNDEF,
+ WORKER_RUNNING,
+ WORKER_IDLE,
+ WORKER_KILLED,
+ WORKER_KILLING,
+} WorkerState;
+
+typedef struct Worker {
+ Manager *manager;
+ pid_t pid;
+ sd_event_source *child_event_source;
+ sd_device_monitor *monitor;
+ WorkerState state;
+ Event *event;
+} Worker;
+
+static Event *event_free(Event *event) {
+ if (!event)
+ return NULL;
+
+ assert(event->manager);
+
+ LIST_REMOVE(event, event->manager->events, event);
+ sd_device_unref(event->dev);
+
+ sd_event_source_unref(event->retry_event_source);
+ sd_event_source_unref(event->timeout_warning_event);
+ sd_event_source_unref(event->timeout_event);
+
+ if (event->worker)
+ event->worker->event = NULL;
+
+ return mfree(event);
+}
+
+static void event_queue_cleanup(Manager *manager, EventState match_state) {
+ LIST_FOREACH(event, event, manager->events) {
+ if (match_state != EVENT_UNDEF && match_state != event->state)
+ continue;
+
+ event_free(event);
+ }
+}
+
+static Worker *worker_free(Worker *worker) {
+ if (!worker)
+ return NULL;
+
+ if (worker->manager)
+ hashmap_remove(worker->manager->workers, PID_TO_PTR(worker->pid));
+
+ sd_event_source_unref(worker->child_event_source);
+ sd_device_monitor_unref(worker->monitor);
+ event_free(worker->event);
+
+ return mfree(worker);
+}
+
+DEFINE_TRIVIAL_CLEANUP_FUNC(Worker*, worker_free);
+DEFINE_PRIVATE_HASH_OPS_WITH_VALUE_DESTRUCTOR(worker_hash_op, void, trivial_hash_func, trivial_compare_func, Worker, worker_free);
+
+Manager* manager_free(Manager *manager) {
+ if (!manager)
+ return NULL;
+
+ udev_builtin_exit();
+
+ hashmap_free_free_free(manager->properties);
+ udev_rules_free(manager->rules);
+
+ hashmap_free(manager->workers);
+ event_queue_cleanup(manager, EVENT_UNDEF);
+
+ safe_close(manager->inotify_fd);
+ safe_close_pair(manager->worker_watch);
+
+ sd_device_monitor_unref(manager->monitor);
+ udev_ctrl_unref(manager->ctrl);
+
+ sd_event_source_unref(manager->inotify_event);
+ sd_event_source_unref(manager->kill_workers_event);
+ sd_event_source_unref(manager->memory_pressure_event_source);
+ sd_event_source_unref(manager->sigrtmin18_event_source);
+ sd_event_unref(manager->event);
+
+ free(manager->cgroup);
+ return mfree(manager);
+}
+
+static int on_sigchld(sd_event_source *s, const siginfo_t *si, void *userdata);
+
+static int worker_new(Worker **ret, Manager *manager, sd_device_monitor *worker_monitor, pid_t pid) {
+ _cleanup_(worker_freep) Worker *worker = NULL;
+ int r;
+
+ assert(ret);
+ assert(manager);
+ assert(worker_monitor);
+ assert(pid > 1);
+
+ /* close monitor, but keep address around */
+ device_monitor_disconnect(worker_monitor);
+
+ worker = new(Worker, 1);
+ if (!worker)
+ return -ENOMEM;
+
+ *worker = (Worker) {
+ .monitor = sd_device_monitor_ref(worker_monitor),
+ .pid = pid,
+ };
+
+ r = sd_event_add_child(manager->event, &worker->child_event_source, pid, WEXITED, on_sigchld, worker);
+ if (r < 0)
+ return r;
+
+ r = hashmap_ensure_put(&manager->workers, &worker_hash_op, PID_TO_PTR(pid), worker);
+ if (r < 0)
+ return r;
+
+ worker->manager = manager;
+
+ *ret = TAKE_PTR(worker);
+ return 0;
+}
+
+static void manager_kill_workers(Manager *manager, bool force) {
+ Worker *worker;
+
+ assert(manager);
+
+ HASHMAP_FOREACH(worker, manager->workers) {
+ if (worker->state == WORKER_KILLED)
+ continue;
+
+ if (worker->state == WORKER_RUNNING && !force) {
+ worker->state = WORKER_KILLING;
+ continue;
+ }
+
+ worker->state = WORKER_KILLED;
+ (void) kill(worker->pid, SIGTERM);
+ }
+}
+
+static void manager_exit(Manager *manager) {
+ assert(manager);
+
+ manager->exit = true;
+
+ (void) sd_notify(/* unset= */ false, NOTIFY_STOPPING);
+
+ /* close sources of new events and discard buffered events */
+ manager->ctrl = udev_ctrl_unref(manager->ctrl);
+
+ manager->inotify_event = sd_event_source_disable_unref(manager->inotify_event);
+ manager->inotify_fd = safe_close(manager->inotify_fd);
+
+ manager->monitor = sd_device_monitor_unref(manager->monitor);
+
+ /* discard queued events and kill workers */
+ event_queue_cleanup(manager, EVENT_QUEUED);
+ manager_kill_workers(manager, true);
+}
+
+static void notify_ready(Manager *manager) {
+ int r;
+
+ assert(manager);
+
+ r = sd_notifyf(/* unset= */ false,
+ "READY=1\n"
+ "STATUS=Processing with %u children at max", manager->children_max);
+ if (r < 0)
+ log_warning_errno(r, "Failed to send readiness notification, ignoring: %m");
+}
+
+/* reload requested, HUP signal received, rules changed, builtin changed */
+static void manager_reload(Manager *manager, bool force) {
+ _cleanup_(udev_rules_freep) UdevRules *rules = NULL;
+ usec_t now_usec;
+ int r;
+
+ assert(manager);
+
+ assert_se(sd_event_now(manager->event, CLOCK_MONOTONIC, &now_usec) >= 0);
+ if (!force && now_usec < usec_add(manager->last_usec, 3 * USEC_PER_SEC))
+ /* check for changed config, every 3 seconds at most */
+ return;
+ manager->last_usec = now_usec;
+
+ /* Reload SELinux label database, to make the child inherit the up-to-date database. */
+ mac_selinux_maybe_reload();
+
+ /* Nothing changed. It is not necessary to reload. */
+ if (!udev_rules_should_reload(manager->rules) && !udev_builtin_should_reload()) {
+
+ if (!force)
+ return;
+
+ /* If we eat this up, then tell our service manager to just continue */
+ (void) sd_notifyf(/* unset= */ false,
+ "RELOADING=1\n"
+ "STATUS=Skipping configuration reloading, nothing changed.\n"
+ "MONOTONIC_USEC=" USEC_FMT, now(CLOCK_MONOTONIC));
+ } else {
+ (void) sd_notifyf(/* unset= */ false,
+ "RELOADING=1\n"
+ "STATUS=Flushing configuration...\n"
+ "MONOTONIC_USEC=" USEC_FMT, now(CLOCK_MONOTONIC));
+
+ manager_kill_workers(manager, false);
+
+ udev_builtin_exit();
+ udev_builtin_init();
+
+ r = udev_rules_load(&rules, manager->resolve_name_timing);
+ if (r < 0)
+ log_warning_errno(r, "Failed to read udev rules, using the previously loaded rules, ignoring: %m");
+ else
+ udev_rules_free_and_replace(manager->rules, rules);
+ }
+
+ notify_ready(manager);
+}
+
+static int on_kill_workers_event(sd_event_source *s, uint64_t usec, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+
+ log_debug("Cleanup idle workers");
+ manager_kill_workers(manager, false);
+
+ return 1;
+}
+
+static int on_event_timeout(sd_event_source *s, uint64_t usec, void *userdata) {
+ Event *event = ASSERT_PTR(userdata);
+
+ assert(event->manager);
+ assert(event->worker);
+
+ kill_and_sigcont(event->worker->pid, event->manager->timeout_signal);
+ event->worker->state = WORKER_KILLED;
+
+ log_device_error(event->dev, "Worker ["PID_FMT"] processing SEQNUM=%"PRIu64" killed", event->worker->pid, event->seqnum);
+
+ return 1;
+}
+
+static int on_event_timeout_warning(sd_event_source *s, uint64_t usec, void *userdata) {
+ Event *event = ASSERT_PTR(userdata);
+
+ assert(event->worker);
+
+ log_device_warning(event->dev, "Worker ["PID_FMT"] processing SEQNUM=%"PRIu64" is taking a long time", event->worker->pid, event->seqnum);
+
+ return 1;
+}
+
+static void worker_attach_event(Worker *worker, Event *event) {
+ Manager *manager;
+ sd_event *e;
+
+ assert(worker);
+ assert(worker->manager);
+ assert(event);
+ assert(!event->worker);
+ assert(!worker->event);
+
+ worker->state = WORKER_RUNNING;
+ worker->event = event;
+ event->state = EVENT_RUNNING;
+ event->worker = worker;
+
+ manager = worker->manager;
+ e = manager->event;
+
+ (void) sd_event_add_time_relative(e, &event->timeout_warning_event, CLOCK_MONOTONIC,
+ udev_warn_timeout(manager->timeout_usec), USEC_PER_SEC,
+ on_event_timeout_warning, event);
+
+ (void) sd_event_add_time_relative(e, &event->timeout_event, CLOCK_MONOTONIC,
+ manager->timeout_usec, USEC_PER_SEC,
+ on_event_timeout, event);
+}
+
+static int worker_spawn(Manager *manager, Event *event) {
+ _cleanup_(sd_device_monitor_unrefp) sd_device_monitor *worker_monitor = NULL;
+ Worker *worker;
+ pid_t pid;
+ int r;
+
+ /* listen for new events */
+ r = device_monitor_new_full(&worker_monitor, MONITOR_GROUP_NONE, -1);
+ if (r < 0)
+ return r;
+
+ (void) sd_device_monitor_set_description(worker_monitor, "worker");
+
+ /* allow the main daemon netlink address to send devices to the worker */
+ r = device_monitor_allow_unicast_sender(worker_monitor, manager->monitor);
+ if (r < 0)
+ return log_error_errno(r, "Worker: Failed to set unicast sender: %m");
+
+ r = device_monitor_enable_receiving(worker_monitor);
+ if (r < 0)
+ return log_error_errno(r, "Worker: Failed to enable receiving of device: %m");
+
+ r = safe_fork("(udev-worker)", FORK_DEATHSIG_SIGTERM, &pid);
+ if (r < 0) {
+ event->state = EVENT_QUEUED;
+ return log_error_errno(r, "Failed to fork() worker: %m");
+ }
+ if (r == 0) {
+ _cleanup_(udev_worker_done) UdevWorker w = {
+ .monitor = TAKE_PTR(worker_monitor),
+ .properties = TAKE_PTR(manager->properties),
+ .rules = TAKE_PTR(manager->rules),
+ .pipe_fd = TAKE_FD(manager->worker_watch[WRITE_END]),
+ .inotify_fd = TAKE_FD(manager->inotify_fd),
+ .exec_delay_usec = manager->exec_delay_usec,
+ .timeout_usec = manager->timeout_usec,
+ .timeout_signal = manager->timeout_signal,
+ .log_level = manager->log_level,
+ .blockdev_read_only = manager->blockdev_read_only,
+ };
+
+ /* Worker process */
+ r = udev_worker_main(&w, event->dev);
+ log_close();
+ _exit(r < 0 ? EXIT_FAILURE : EXIT_SUCCESS);
+ }
+
+ r = worker_new(&worker, manager, worker_monitor, pid);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create worker object: %m");
+
+ worker_attach_event(worker, event);
+
+ log_device_debug(event->dev, "Worker ["PID_FMT"] is forked for processing SEQNUM=%"PRIu64".", pid, event->seqnum);
+ return 0;
+}
+
+static int event_run(Event *event) {
+ static bool log_children_max_reached = true;
+ Manager *manager;
+ Worker *worker;
+ int r;
+
+ assert(event);
+ assert(event->manager);
+
+ log_device_uevent(event->dev, "Device ready for processing");
+
+ (void) event_source_disable(event->retry_event_source);
+
+ manager = event->manager;
+ HASHMAP_FOREACH(worker, manager->workers) {
+ if (worker->state != WORKER_IDLE)
+ continue;
+
+ r = device_monitor_send_device(manager->monitor, worker->monitor, event->dev);
+ if (r < 0) {
+ log_device_error_errno(event->dev, r, "Worker ["PID_FMT"] did not accept message, killing the worker: %m",
+ worker->pid);
+ (void) kill(worker->pid, SIGKILL);
+ worker->state = WORKER_KILLED;
+ continue;
+ }
+ worker_attach_event(worker, event);
+ return 1; /* event is now processing. */
+ }
+
+ if (hashmap_size(manager->workers) >= manager->children_max) {
+ /* Avoid spamming the debug logs if the limit is already reached and
+ * many events still need to be processed */
+ if (log_children_max_reached && manager->children_max > 1) {
+ log_debug("Maximum number (%u) of children reached.", hashmap_size(manager->workers));
+ log_children_max_reached = false;
+ }
+ return 0; /* no free worker */
+ }
+
+ /* Re-enable the debug message for the next batch of events */
+ log_children_max_reached = true;
+
+ /* start new worker and pass initial device */
+ r = worker_spawn(manager, event);
+ if (r < 0)
+ return r;
+
+ return 1; /* event is now processing. */
+}
+
+bool devpath_conflict(const char *a, const char *b) {
+ /* This returns true when two paths are equivalent, or one is a child of another. */
+
+ if (!a || !b)
+ return false;
+
+ for (; *a != '\0' && *b != '\0'; a++, b++)
+ if (*a != *b)
+ return false;
+
+ return *a == '/' || *b == '/' || *a == *b;
+}
+
+static int event_is_blocked(Event *event) {
+ Event *loop_event = NULL;
+ int r;
+
+ /* lookup event for identical, parent, child device */
+
+ assert(event);
+ assert(event->manager);
+ assert(event->blocker_seqnum <= event->seqnum);
+
+ if (event->retry_again_next_usec > 0) {
+ usec_t now_usec;
+
+ r = sd_event_now(event->manager->event, CLOCK_BOOTTIME, &now_usec);
+ if (r < 0)
+ return r;
+
+ if (event->retry_again_next_usec > now_usec)
+ return true;
+ }
+
+ if (event->blocker_seqnum == event->seqnum)
+ /* we have checked previously and no blocker found */
+ return false;
+
+ LIST_FOREACH(event, e, event->manager->events) {
+ loop_event = e;
+
+ /* we already found a later event, earlier cannot block us, no need to check again */
+ if (loop_event->seqnum < event->blocker_seqnum)
+ continue;
+
+ /* event we checked earlier still exists, no need to check again */
+ if (loop_event->seqnum == event->blocker_seqnum)
+ return true;
+
+ /* found ourself, no later event can block us */
+ if (loop_event->seqnum >= event->seqnum)
+ goto no_blocker;
+
+ /* found event we have not checked */
+ break;
+ }
+
+ assert(loop_event);
+ assert(loop_event->seqnum > event->blocker_seqnum &&
+ loop_event->seqnum < event->seqnum);
+
+ /* check if queue contains events we depend on */
+ LIST_FOREACH(event, e, loop_event) {
+ loop_event = e;
+
+ /* found ourself, no later event can block us */
+ if (loop_event->seqnum >= event->seqnum)
+ goto no_blocker;
+
+ if (streq_ptr(loop_event->id, event->id))
+ break;
+
+ if (devpath_conflict(event->devpath, loop_event->devpath) ||
+ devpath_conflict(event->devpath, loop_event->devpath_old) ||
+ devpath_conflict(event->devpath_old, loop_event->devpath))
+ break;
+
+ if (event->devnode && streq_ptr(event->devnode, loop_event->devnode))
+ break;
+ }
+
+ assert(loop_event);
+
+ log_device_debug(event->dev, "SEQNUM=%" PRIu64 " blocked by SEQNUM=%" PRIu64,
+ event->seqnum, loop_event->seqnum);
+
+ event->blocker_seqnum = loop_event->seqnum;
+ return true;
+
+no_blocker:
+ event->blocker_seqnum = event->seqnum;
+ return false;
+}
+
+static int event_queue_start(Manager *manager) {
+ int r;
+
+ assert(manager);
+
+ if (!manager->events || manager->exit || manager->stop_exec_queue)
+ return 0;
+
+ /* To make the stack directory /run/udev/links cleaned up later. */
+ manager->udev_node_needs_cleanup = true;
+
+ r = event_source_disable(manager->kill_workers_event);
+ if (r < 0)
+ log_warning_errno(r, "Failed to disable event source for cleaning up idle workers, ignoring: %m");
+
+ manager_reload(manager, /* force = */ false);
+
+ LIST_FOREACH(event, event, manager->events) {
+ if (event->state != EVENT_QUEUED)
+ continue;
+
+ /* do not start event if parent or child event is still running or queued */
+ r = event_is_blocked(event);
+ if (r > 0)
+ continue;
+ if (r < 0)
+ log_device_warning_errno(event->dev, r,
+ "Failed to check dependencies for event (SEQNUM=%"PRIu64", ACTION=%s), "
+ "assuming there is no blocking event, ignoring: %m",
+ event->seqnum,
+ strna(device_action_to_string(event->action)));
+
+ r = event_run(event);
+ if (r <= 0) /* 0 means there are no idle workers. Let's escape from the loop. */
+ return r;
+ }
+
+ return 0;
+}
+
+static int on_event_retry(sd_event_source *s, uint64_t usec, void *userdata) {
+ /* This does nothing. The on_post() callback will start the event if there exists an idle worker. */
+ return 1;
+}
+
+static int event_requeue(Event *event) {
+ usec_t now_usec;
+ int r;
+
+ assert(event);
+ assert(event->manager);
+ assert(event->manager->event);
+
+ event->timeout_warning_event = sd_event_source_disable_unref(event->timeout_warning_event);
+ event->timeout_event = sd_event_source_disable_unref(event->timeout_event);
+
+ /* add a short delay to suppress busy loop */
+ r = sd_event_now(event->manager->event, CLOCK_BOOTTIME, &now_usec);
+ if (r < 0)
+ return log_device_warning_errno(event->dev, r,
+ "Failed to get current time, "
+ "skipping event (SEQNUM=%"PRIu64", ACTION=%s): %m",
+ event->seqnum, strna(device_action_to_string(event->action)));
+
+ if (event->retry_again_timeout_usec > 0 && event->retry_again_timeout_usec <= now_usec)
+ return log_device_warning_errno(event->dev, SYNTHETIC_ERRNO(ETIMEDOUT),
+ "The underlying block device is locked by a process more than %s, "
+ "skipping event (SEQNUM=%"PRIu64", ACTION=%s).",
+ FORMAT_TIMESPAN(EVENT_RETRY_TIMEOUT_USEC, USEC_PER_MINUTE),
+ event->seqnum, strna(device_action_to_string(event->action)));
+
+ event->retry_again_next_usec = usec_add(now_usec, EVENT_RETRY_INTERVAL_USEC);
+ if (event->retry_again_timeout_usec == 0)
+ event->retry_again_timeout_usec = usec_add(now_usec, EVENT_RETRY_TIMEOUT_USEC);
+
+ r = event_reset_time_relative(event->manager->event, &event->retry_event_source,
+ CLOCK_MONOTONIC, EVENT_RETRY_INTERVAL_USEC, 0,
+ on_event_retry, NULL,
+ 0, "retry-event", true);
+ if (r < 0)
+ return log_device_warning_errno(event->dev, r, "Failed to reset timer event source for retrying event, "
+ "skipping event (SEQNUM=%"PRIu64", ACTION=%s): %m",
+ event->seqnum, strna(device_action_to_string(event->action)));
+
+ if (event->worker && event->worker->event == event)
+ event->worker->event = NULL;
+ event->worker = NULL;
+
+ event->state = EVENT_QUEUED;
+ return 0;
+}
+
+static int event_queue_assume_block_device_unlocked(Manager *manager, sd_device *dev) {
+ const char *devname;
+ int r;
+
+ /* When a new event for a block device is queued or we get an inotify event, assume that the
+ * device is not locked anymore. The assumption may not be true, but that should not cause any
+ * issues, as in that case events will be requeued soon. */
+
+ r = udev_get_whole_disk(dev, NULL, &devname);
+ if (r <= 0)
+ return r;
+
+ LIST_FOREACH(event, event, manager->events) {
+ const char *event_devname;
+
+ if (event->state != EVENT_QUEUED)
+ continue;
+
+ if (event->retry_again_next_usec == 0)
+ continue;
+
+ if (udev_get_whole_disk(event->dev, NULL, &event_devname) <= 0)
+ continue;
+
+ if (!streq(devname, event_devname))
+ continue;
+
+ event->retry_again_next_usec = 0;
+ }
+
+ return 0;
+}
+
+static int event_queue_insert(Manager *manager, sd_device *dev) {
+ const char *devpath, *devpath_old = NULL, *id = NULL, *devnode = NULL;
+ sd_device_action_t action;
+ uint64_t seqnum;
+ Event *event;
+ int r;
+
+ assert(manager);
+ assert(dev);
+
+ /* We only accepts devices received by device monitor. */
+ r = sd_device_get_seqnum(dev, &seqnum);
+ if (r < 0)
+ return r;
+
+ r = sd_device_get_action(dev, &action);
+ if (r < 0)
+ return r;
+
+ r = sd_device_get_devpath(dev, &devpath);
+ if (r < 0)
+ return r;
+
+ r = sd_device_get_property_value(dev, "DEVPATH_OLD", &devpath_old);
+ if (r < 0 && r != -ENOENT)
+ return r;
+
+ r = device_get_device_id(dev, &id);
+ if (r < 0 && r != -ENOENT)
+ return r;
+
+ r = sd_device_get_devname(dev, &devnode);
+ if (r < 0 && r != -ENOENT)
+ return r;
+
+ event = new(Event, 1);
+ if (!event)
+ return -ENOMEM;
+
+ *event = (Event) {
+ .manager = manager,
+ .dev = sd_device_ref(dev),
+ .seqnum = seqnum,
+ .action = action,
+ .id = id,
+ .devpath = devpath,
+ .devpath_old = devpath_old,
+ .devnode = devnode,
+ .state = EVENT_QUEUED,
+ };
+
+ if (!manager->events) {
+ r = touch("/run/udev/queue");
+ if (r < 0)
+ log_warning_errno(r, "Failed to touch /run/udev/queue, ignoring: %m");
+ }
+
+ LIST_APPEND(event, manager->events, event);
+
+ log_device_uevent(dev, "Device is queued");
+
+ return 0;
+}
+
+static int on_uevent(sd_device_monitor *monitor, sd_device *dev, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+ int r;
+
+ DEVICE_TRACE_POINT(kernel_uevent_received, dev);
+
+ device_ensure_usec_initialized(dev, NULL);
+
+ r = event_queue_insert(manager, dev);
+ if (r < 0) {
+ log_device_error_errno(dev, r, "Failed to insert device into event queue: %m");
+ return 1;
+ }
+
+ (void) event_queue_assume_block_device_unlocked(manager, dev);
+
+ return 1;
+}
+
+static int on_worker(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+
+ for (;;) {
+ EventResult result;
+ struct iovec iovec = IOVEC_MAKE(&result, sizeof(result));
+ CMSG_BUFFER_TYPE(CMSG_SPACE(sizeof(struct ucred))) control;
+ struct msghdr msghdr = {
+ .msg_iov = &iovec,
+ .msg_iovlen = 1,
+ .msg_control = &control,
+ .msg_controllen = sizeof(control),
+ };
+ ssize_t size;
+ struct ucred *ucred;
+ Worker *worker;
+
+ size = recvmsg_safe(fd, &msghdr, MSG_DONTWAIT);
+ if (size == -EINTR)
+ continue;
+ if (size == -EAGAIN)
+ /* nothing more to read */
+ break;
+ if (size < 0)
+ return log_error_errno(size, "Failed to receive message: %m");
+
+ cmsg_close_all(&msghdr);
+
+ if (size != sizeof(result)) {
+ log_warning("Ignoring worker message with invalid size %zi bytes", size);
+ continue;
+ }
+
+ ucred = CMSG_FIND_DATA(&msghdr, SOL_SOCKET, SCM_CREDENTIALS, struct ucred);
+ if (!ucred || ucred->pid <= 0) {
+ log_warning("Ignoring worker message without valid PID");
+ continue;
+ }
+
+ /* lookup worker who sent the signal */
+ worker = hashmap_get(manager->workers, PID_TO_PTR(ucred->pid));
+ if (!worker) {
+ log_debug("Worker ["PID_FMT"] returned, but is no longer tracked", ucred->pid);
+ continue;
+ }
+
+ if (worker->state == WORKER_KILLING) {
+ worker->state = WORKER_KILLED;
+ (void) kill(worker->pid, SIGTERM);
+ } else if (worker->state != WORKER_KILLED)
+ worker->state = WORKER_IDLE;
+
+ /* worker returned */
+ if (result == EVENT_RESULT_TRY_AGAIN &&
+ event_requeue(worker->event) < 0)
+ udev_broadcast_result(manager->monitor, worker->event->dev, -ETIMEDOUT);
+
+ /* When event_requeue() succeeds, worker->event is NULL, and event_free() handles NULL gracefully. */
+ event_free(worker->event);
+ }
+
+ return 1;
+}
+
+static void manager_set_default_children_max(Manager *manager) {
+ uint64_t cpu_limit, mem_limit, cpu_count = 1;
+ int r;
+
+ assert(manager);
+
+ if (manager->children_max != 0)
+ return;
+
+ r = cpus_in_affinity_mask();
+ if (r < 0)
+ log_warning_errno(r, "Failed to determine number of local CPUs, ignoring: %m");
+ else
+ cpu_count = r;
+
+ cpu_limit = cpu_count * 2 + 16;
+ mem_limit = MAX(physical_memory() / (128*1024*1024), UINT64_C(10));
+
+ manager->children_max = MIN3(cpu_limit, mem_limit, WORKER_NUM_MAX);
+ log_debug("Set children_max to %u", manager->children_max);
+}
+
+/* receive the udevd message from userspace */
+static int on_ctrl_msg(UdevCtrl *uctrl, UdevCtrlMessageType type, const UdevCtrlMessageValue *value, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+ int r;
+
+ assert(value);
+
+ switch (type) {
+ case UDEV_CTRL_SET_LOG_LEVEL:
+ if ((value->intval & LOG_PRIMASK) != value->intval) {
+ log_debug("Received invalid udev control message (SET_LOG_LEVEL, %i), ignoring.", value->intval);
+ break;
+ }
+
+ log_debug("Received udev control message (SET_LOG_LEVEL), setting log_level=%i", value->intval);
+
+ r = log_get_max_level();
+ if (r == value->intval)
+ break;
+
+ log_set_max_level(value->intval);
+ manager->log_level = value->intval;
+ manager_kill_workers(manager, false);
+ break;
+ case UDEV_CTRL_STOP_EXEC_QUEUE:
+ log_debug("Received udev control message (STOP_EXEC_QUEUE)");
+ manager->stop_exec_queue = true;
+ break;
+ case UDEV_CTRL_START_EXEC_QUEUE:
+ log_debug("Received udev control message (START_EXEC_QUEUE)");
+ manager->stop_exec_queue = false;
+ /* It is not necessary to call event_queue_start() here, as it will be called in on_post() if necessary. */
+ break;
+ case UDEV_CTRL_RELOAD:
+ log_debug("Received udev control message (RELOAD)");
+ manager_reload(manager, /* force = */ true);
+ break;
+ case UDEV_CTRL_SET_ENV: {
+ _unused_ _cleanup_free_ char *old_val = NULL, *old_key = NULL;
+ _cleanup_free_ char *key = NULL, *val = NULL;
+ const char *eq;
+
+ eq = strchr(value->buf, '=');
+ if (!eq) {
+ log_error("Invalid key format '%s'", value->buf);
+ return 1;
+ }
+
+ key = strndup(value->buf, eq - value->buf);
+ if (!key) {
+ log_oom();
+ return 1;
+ }
+
+ old_val = hashmap_remove2(manager->properties, key, (void **) &old_key);
+
+ r = hashmap_ensure_allocated(&manager->properties, &string_hash_ops);
+ if (r < 0) {
+ log_oom();
+ return 1;
+ }
+
+ eq++;
+ if (isempty(eq))
+ log_debug("Received udev control message (ENV), unsetting '%s'", key);
+ else {
+ val = strdup(eq);
+ if (!val) {
+ log_oom();
+ return 1;
+ }
+
+ log_debug("Received udev control message (ENV), setting '%s=%s'", key, val);
+
+ r = hashmap_put(manager->properties, key, val);
+ if (r < 0) {
+ log_oom();
+ return 1;
+ }
+ }
+
+ key = val = NULL;
+ manager_kill_workers(manager, false);
+ break;
+ }
+ case UDEV_CTRL_SET_CHILDREN_MAX:
+ if (value->intval < 0) {
+ log_debug("Received invalid udev control message (SET_MAX_CHILDREN, %i), ignoring.", value->intval);
+ return 0;
+ }
+
+ log_debug("Received udev control message (SET_MAX_CHILDREN), setting children_max=%i", value->intval);
+ manager->children_max = value->intval;
+
+ /* When 0 is specified, determine the maximum based on the system resources. */
+ manager_set_default_children_max(manager);
+
+ notify_ready(manager);
+ break;
+ case UDEV_CTRL_PING:
+ log_debug("Received udev control message (PING)");
+ break;
+ case UDEV_CTRL_EXIT:
+ log_debug("Received udev control message (EXIT)");
+ manager_exit(manager);
+ break;
+ default:
+ log_debug("Received unknown udev control message, ignoring");
+ }
+
+ return 1;
+}
+
+static int synthesize_change_one(sd_device *dev, sd_device *target) {
+ int r;
+
+ if (DEBUG_LOGGING) {
+ const char *syspath = NULL;
+ (void) sd_device_get_syspath(target, &syspath);
+ log_device_debug(dev, "device is closed, synthesising 'change' on %s", strna(syspath));
+ }
+
+ r = sd_device_trigger(target, SD_DEVICE_CHANGE);
+ if (r < 0)
+ return log_device_debug_errno(target, r, "Failed to trigger 'change' uevent: %m");
+
+ DEVICE_TRACE_POINT(synthetic_change_event, dev);
+
+ return 0;
+}
+
+static int synthesize_change(sd_device *dev) {
+ _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL;
+ bool part_table_read;
+ const char *sysname;
+ int r, k;
+
+ r = sd_device_get_sysname(dev, &sysname);
+ if (r < 0)
+ return r;
+
+ if (startswith(sysname, "dm-") || block_device_is_whole_disk(dev) <= 0)
+ return synthesize_change_one(dev, dev);
+
+ r = blockdev_reread_partition_table(dev);
+ if (r < 0)
+ log_device_debug_errno(dev, r, "Failed to re-read partition table, ignoring: %m");
+ part_table_read = r >= 0;
+
+ /* search for partitions */
+ r = partition_enumerator_new(dev, &e);
+ if (r < 0)
+ return r;
+
+ /* We have partitions and re-read the table, the kernel already sent out a "change"
+ * event for the disk, and "remove/add" for all partitions. */
+ if (part_table_read && sd_device_enumerator_get_device_first(e))
+ return 0;
+
+ /* We have partitions but re-reading the partition table did not work, synthesize
+ * "change" for the disk and all partitions. */
+ r = synthesize_change_one(dev, dev);
+ FOREACH_DEVICE(e, d) {
+ k = synthesize_change_one(dev, d);
+ if (k < 0 && r >= 0)
+ r = k;
+ }
+
+ return r;
+}
+
+static int on_inotify(sd_event_source *s, int fd, uint32_t revents, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+ union inotify_event_buffer buffer;
+ ssize_t l;
+ int r;
+
+ l = read(fd, &buffer, sizeof(buffer));
+ if (l < 0) {
+ if (ERRNO_IS_TRANSIENT(errno))
+ return 0;
+
+ return log_error_errno(errno, "Failed to read inotify fd: %m");
+ }
+
+ FOREACH_INOTIFY_EVENT_WARN(e, buffer, l) {
+ _cleanup_(sd_device_unrefp) sd_device *dev = NULL;
+ const char *devnode;
+
+ /* Do not handle IN_IGNORED here. Especially, do not try to call udev_watch_end() from the
+ * main process. Otherwise, the pair of the symlinks may become inconsistent, and several
+ * garbage may remain. The old symlinks are removed by a worker that processes the
+ * corresponding 'remove' uevent;
+ * udev_event_execute_rules() -> event_execute_rules_on_remove() -> udev_watch_end(). */
+
+ if (!FLAGS_SET(e->mask, IN_CLOSE_WRITE))
+ continue;
+
+ r = device_new_from_watch_handle(&dev, e->wd);
+ if (r < 0) {
+ /* Device may be removed just after closed. */
+ log_debug_errno(r, "Failed to create sd_device object from watch handle, ignoring: %m");
+ continue;
+ }
+
+ r = sd_device_get_devname(dev, &devnode);
+ if (r < 0) {
+ /* Also here, device may be already removed. */
+ log_device_debug_errno(dev, r, "Failed to get device node, ignoring: %m");
+ continue;
+ }
+
+ log_device_debug(dev, "Received inotify event for %s.", devnode);
+
+ (void) event_queue_assume_block_device_unlocked(manager, dev);
+ (void) synthesize_change(dev);
+ }
+
+ return 0;
+}
+
+static int on_sigterm(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+
+ manager_exit(manager);
+
+ return 1;
+}
+
+static int on_sighup(sd_event_source *s, const struct signalfd_siginfo *si, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+
+ manager_reload(manager, /* force = */ true);
+
+ return 1;
+}
+
+static int on_sigchld(sd_event_source *s, const siginfo_t *si, void *userdata) {
+ Worker *worker = ASSERT_PTR(userdata);
+ Manager *manager = ASSERT_PTR(worker->manager);
+ sd_device *dev = worker->event ? ASSERT_PTR(worker->event->dev) : NULL;
+ EventResult result;
+
+ assert(si);
+
+ switch (si->si_code) {
+ case CLD_EXITED:
+ if (si->si_status == 0)
+ log_device_debug(dev, "Worker ["PID_FMT"] exited.", si->si_pid);
+ else
+ log_device_warning(dev, "Worker ["PID_FMT"] exited with return code %i.",
+ si->si_pid, si->si_status);
+ result = EVENT_RESULT_EXIT_STATUS_BASE + si->si_status;
+ break;
+
+ case CLD_KILLED:
+ case CLD_DUMPED:
+ log_device_warning(dev, "Worker ["PID_FMT"] terminated by signal %i (%s).",
+ si->si_pid, si->si_status, signal_to_string(si->si_status));
+ result = EVENT_RESULT_SIGNAL_BASE + si->si_status;
+ break;
+
+ default:
+ assert_not_reached();
+ }
+
+ if (result != EVENT_RESULT_SUCCESS && dev) {
+ /* delete state from disk */
+ device_delete_db(dev);
+ device_tag_index(dev, NULL, false);
+
+ /* Forward kernel event to libudev listeners */
+ udev_broadcast_result(manager->monitor, dev, result);
+ }
+
+ worker_free(worker);
+
+ return 1;
+}
+
+static int on_post(sd_event_source *s, void *userdata) {
+ Manager *manager = ASSERT_PTR(userdata);
+
+ if (manager->events) {
+ /* Try to process pending events if idle workers exist. Why is this necessary?
+ * When a worker finished an event and became idle, even if there was a pending event,
+ * the corresponding device might have been locked and the processing of the event
+ * delayed for a while, preventing the worker from processing the event immediately.
+ * Now, the device may be unlocked. Let's try again! */
+ event_queue_start(manager);
+ return 1;
+ }
+
+ /* There are no queued events. Let's remove /run/udev/queue and clean up the idle processes. */
+
+ if (unlink("/run/udev/queue") < 0) {
+ if (errno != ENOENT)
+ log_warning_errno(errno, "Failed to unlink /run/udev/queue, ignoring: %m");
+ } else
+ log_debug("No events are queued, removing /run/udev/queue.");
+
+ if (!hashmap_isempty(manager->workers)) {
+ /* There are idle workers */
+ (void) event_reset_time_relative(manager->event, &manager->kill_workers_event,
+ CLOCK_MONOTONIC, 3 * USEC_PER_SEC, USEC_PER_SEC,
+ on_kill_workers_event, manager,
+ 0, "kill-workers-event", false);
+ return 1;
+ }
+
+ /* There are no idle workers. */
+
+ if (manager->udev_node_needs_cleanup) {
+ (void) udev_node_cleanup();
+ manager->udev_node_needs_cleanup = false;
+ }
+
+ if (manager->exit)
+ return sd_event_exit(manager->event, 0);
+
+ if (manager->cgroup)
+ /* cleanup possible left-over processes in our cgroup */
+ (void) cg_kill(manager->cgroup, SIGKILL, CGROUP_IGNORE_SELF, /* set=*/ NULL, /* kill_log= */ NULL, /* userdata= */ NULL);
+
+ return 1;
+}
+
+Manager* manager_new(void) {
+ Manager *manager;
+
+ manager = new(Manager, 1);
+ if (!manager)
+ return NULL;
+
+ *manager = (Manager) {
+ .inotify_fd = -EBADF,
+ .worker_watch = EBADF_PAIR,
+ .log_level = LOG_INFO,
+ .resolve_name_timing = RESOLVE_NAME_EARLY,
+ .timeout_usec = 180 * USEC_PER_SEC,
+ .timeout_signal = SIGKILL,
+ };
+
+ return manager;
+}
+
+int manager_init(Manager *manager, int fd_ctrl, int fd_uevent) {
+ _cleanup_free_ char *cgroup = NULL;
+ int r;
+
+ assert(manager);
+
+ r = udev_ctrl_new_from_fd(&manager->ctrl, fd_ctrl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to initialize udev control socket: %m");
+
+ r = udev_ctrl_enable_receiving(manager->ctrl);
+ if (r < 0)
+ return log_error_errno(r, "Failed to bind udev control socket: %m");
+
+ r = device_monitor_new_full(&manager->monitor, MONITOR_GROUP_KERNEL, fd_uevent);
+ if (r < 0)
+ return log_error_errno(r, "Failed to initialize device monitor: %m");
+
+ (void) sd_device_monitor_set_description(manager->monitor, "manager");
+
+ r = device_monitor_enable_receiving(manager->monitor);
+ if (r < 0)
+ return log_error_errno(r, "Failed to bind netlink socket: %m");
+
+ manager->log_level = log_get_max_level();
+
+ r = cg_pid_get_path(SYSTEMD_CGROUP_CONTROLLER, 0, &cgroup);
+ if (r < 0)
+ log_debug_errno(r, "Failed to get cgroup, ignoring: %m");
+ else if (endswith(cgroup, "/udev")) { /* If we are in a subcgroup /udev/ we assume it was delegated to us */
+ log_debug("Running in delegated subcgroup '%s'.", cgroup);
+ manager->cgroup = TAKE_PTR(cgroup);
+ }
+
+ return 0;
+}
+
+int manager_main(Manager *manager) {
+ int fd_worker, r;
+
+ manager_set_default_children_max(manager);
+
+ /* unnamed socket from workers to the main daemon */
+ r = socketpair(AF_UNIX, SOCK_DGRAM|SOCK_CLOEXEC, 0, manager->worker_watch);
+ if (r < 0)
+ return log_error_errno(errno, "Failed to create socketpair for communicating with workers: %m");
+
+ fd_worker = manager->worker_watch[READ_END];
+
+ r = setsockopt_int(fd_worker, SOL_SOCKET, SO_PASSCRED, true);
+ if (r < 0)
+ return log_error_errno(r, "Failed to enable SO_PASSCRED: %m");
+
+ manager->inotify_fd = inotify_init1(IN_CLOEXEC);
+ if (manager->inotify_fd < 0)
+ return log_error_errno(errno, "Failed to create inotify descriptor: %m");
+
+ udev_watch_restore(manager->inotify_fd);
+
+ /* block and listen to all signals on signalfd */
+ assert_se(sigprocmask_many(SIG_BLOCK, NULL, SIGTERM, SIGINT, SIGHUP, SIGCHLD, SIGRTMIN+18, -1) >= 0);
+
+ r = sd_event_default(&manager->event);
+ if (r < 0)
+ return log_error_errno(r, "Failed to allocate event loop: %m");
+
+ r = sd_event_add_signal(manager->event, NULL, SIGINT, on_sigterm, manager);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create SIGINT event source: %m");
+
+ r = sd_event_add_signal(manager->event, NULL, SIGTERM, on_sigterm, manager);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create SIGTERM event source: %m");
+
+ r = sd_event_add_signal(manager->event, NULL, SIGHUP, on_sighup, manager);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create SIGHUP event source: %m");
+
+ r = sd_event_set_watchdog(manager->event, true);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create watchdog event source: %m");
+
+ r = udev_ctrl_attach_event(manager->ctrl, manager->event);
+ if (r < 0)
+ return log_error_errno(r, "Failed to attach event to udev control: %m");
+
+ r = udev_ctrl_start(manager->ctrl, on_ctrl_msg, manager);
+ if (r < 0)
+ return log_error_errno(r, "Failed to start udev control: %m");
+
+ /* This needs to be after the inotify and uevent handling, to make sure
+ * that the ping is send back after fully processing the pending uevents
+ * (including the synthetic ones we may create due to inotify events).
+ */
+ r = sd_event_source_set_priority(udev_ctrl_get_event_source(manager->ctrl), SD_EVENT_PRIORITY_IDLE);
+ if (r < 0)
+ return log_error_errno(r, "Failed to set IDLE event priority for udev control event source: %m");
+
+ r = sd_event_add_io(manager->event, &manager->inotify_event, manager->inotify_fd, EPOLLIN, on_inotify, manager);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create inotify event source: %m");
+
+ r = sd_device_monitor_attach_event(manager->monitor, manager->event);
+ if (r < 0)
+ return log_error_errno(r, "Failed to attach event to device monitor: %m");
+
+ r = sd_device_monitor_start(manager->monitor, on_uevent, manager);
+ if (r < 0)
+ return log_error_errno(r, "Failed to start device monitor: %m");
+
+ r = sd_event_add_io(manager->event, NULL, fd_worker, EPOLLIN, on_worker, manager);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create worker event source: %m");
+
+ r = sd_event_add_post(manager->event, NULL, on_post, manager);
+ if (r < 0)
+ return log_error_errno(r, "Failed to create post event source: %m");
+
+ /* Eventually, we probably want to do more here on memory pressure, for example, kill idle workers immediately */
+ r = sd_event_add_memory_pressure(manager->event, &manager->memory_pressure_event_source, NULL, NULL);
+ if (r < 0)
+ log_full_errno(ERRNO_IS_NOT_SUPPORTED(r) || ERRNO_IS_PRIVILEGE(r) || (r == -EHOSTDOWN) ? LOG_DEBUG : LOG_WARNING, r,
+ "Failed to allocate memory pressure watch, ignoring: %m");
+
+ r = sd_event_add_signal(manager->event, &manager->memory_pressure_event_source, SIGRTMIN+18, sigrtmin18_handler, NULL);
+ if (r < 0)
+ return log_error_errno(r, "Failed to allocate SIGRTMIN+18 event source, ignoring: %m");
+
+ manager->last_usec = now(CLOCK_MONOTONIC);
+
+ udev_builtin_init();
+
+ r = udev_rules_load(&manager->rules, manager->resolve_name_timing);
+ if (r < 0)
+ return log_error_errno(r, "Failed to read udev rules: %m");
+
+ r = udev_rules_apply_static_dev_perms(manager->rules);
+ if (r < 0)
+ log_warning_errno(r, "Failed to apply permissions on static device nodes, ignoring: %m");
+
+ notify_ready(manager);
+
+ r = sd_event_loop(manager->event);
+ if (r < 0)
+ log_error_errno(r, "Event loop failed: %m");
+
+ (void) sd_notify(/* unset= */ false, NOTIFY_STOPPING);
+ return r;
+}