/* SPDX-License-Identifier: LGPL-2.1-or-later */ #include #include #include "sd-messages.h" #include "alloc-util.h" #include "bus-common-errors.h" #include "dbus-device.h" #include "dbus-unit.h" #include "device-private.h" #include "device-util.h" #include "device.h" #include "log.h" #include "parse-util.h" #include "path-util.h" #include "ratelimit.h" #include "serialize.h" #include "stat-util.h" #include "string-util.h" #include "swap.h" #include "udev-util.h" #include "unit-name.h" #include "unit.h" static const UnitActiveState state_translation_table[_DEVICE_STATE_MAX] = { [DEVICE_DEAD] = UNIT_INACTIVE, [DEVICE_TENTATIVE] = UNIT_ACTIVATING, [DEVICE_PLUGGED] = UNIT_ACTIVE, }; static int device_dispatch_io(sd_device_monitor *monitor, sd_device *dev, void *userdata); static int device_by_path(Manager *m, const char *path, Unit **ret) { _cleanup_free_ char *e = NULL; Unit *u; int r; assert(m); assert(path); r = unit_name_from_path(path, ".device", &e); if (r < 0) return r; u = manager_get_unit(m, e); if (!u) return -ENOENT; if (ret) *ret = u; return 0; } static void device_unset_sysfs(Device *d) { Hashmap *devices; assert(d); if (!d->sysfs) return; /* Remove this unit from the chain of devices which share the same sysfs path. */ devices = UNIT(d)->manager->devices_by_sysfs; if (d->same_sysfs_prev) /* If this is not the first unit, then simply remove this unit. */ d->same_sysfs_prev->same_sysfs_next = d->same_sysfs_next; else if (d->same_sysfs_next) /* If this is the first unit, replace with the next unit. */ assert_se(hashmap_replace(devices, d->same_sysfs_next->sysfs, d->same_sysfs_next) >= 0); else /* Otherwise, remove the entry. */ hashmap_remove(devices, d->sysfs); if (d->same_sysfs_next) d->same_sysfs_next->same_sysfs_prev = d->same_sysfs_prev; d->same_sysfs_prev = d->same_sysfs_next = NULL; d->sysfs = mfree(d->sysfs); } static int device_set_sysfs(Device *d, const char *sysfs) { _cleanup_free_ char *copy = NULL; Device *first; int r; assert(d); if (streq_ptr(d->sysfs, sysfs)) return 0; r = hashmap_ensure_allocated(&UNIT(d)->manager->devices_by_sysfs, &path_hash_ops); if (r < 0) return r; copy = strdup(sysfs); if (!copy) return -ENOMEM; device_unset_sysfs(d); first = hashmap_get(UNIT(d)->manager->devices_by_sysfs, sysfs); LIST_PREPEND(same_sysfs, first, d); r = hashmap_replace(UNIT(d)->manager->devices_by_sysfs, copy, first); if (r < 0) { LIST_REMOVE(same_sysfs, first, d); return r; } d->sysfs = TAKE_PTR(copy); unit_add_to_dbus_queue(UNIT(d)); return 0; } static void device_init(Unit *u) { Device *d = DEVICE(u); assert(d); assert(UNIT(d)->load_state == UNIT_STUB); /* In contrast to all other unit types we timeout jobs waiting * for devices by default. This is because they otherwise wait * indefinitely for plugged in devices, something which cannot * happen for the other units since their operations time out * anyway. */ u->job_running_timeout = u->manager->defaults.device_timeout_usec; u->ignore_on_isolate = true; d->deserialized_state = _DEVICE_STATE_INVALID; } static void device_done(Unit *u) { Device *d = DEVICE(u); assert(d); device_unset_sysfs(d); d->deserialized_sysfs = mfree(d->deserialized_sysfs); d->wants_property = strv_free(d->wants_property); d->path = mfree(d->path); } static int device_load(Unit *u) { int r; r = unit_load_fragment_and_dropin(u, false); if (r < 0) return r; if (!u->description) { /* Generate a description based on the path, to be used until the device is initialized properly */ r = unit_name_to_path(u->id, &u->description); if (r < 0) log_unit_debug_errno(u, r, "Failed to unescape name: %m"); } return 0; } static void device_set_state(Device *d, DeviceState state) { DeviceState old_state; assert(d); if (d->state != state) bus_unit_send_pending_change_signal(UNIT(d), false); old_state = d->state; d->state = state; if (state == DEVICE_DEAD) device_unset_sysfs(d); if (state != old_state) log_unit_debug(UNIT(d), "Changed %s -> %s", device_state_to_string(old_state), device_state_to_string(state)); unit_notify(UNIT(d), state_translation_table[old_state], state_translation_table[state], /* reload_success = */ true); } static void device_found_changed(Device *d, DeviceFound previous, DeviceFound now) { assert(d); /* Didn't exist before, but does now? if so, generate a new invocation ID for it */ if (previous == DEVICE_NOT_FOUND && now != DEVICE_NOT_FOUND) (void) unit_acquire_invocation_id(UNIT(d)); if (FLAGS_SET(now, DEVICE_FOUND_UDEV)) /* When the device is known to udev we consider it plugged. */ device_set_state(d, DEVICE_PLUGGED); else if (now != DEVICE_NOT_FOUND && !FLAGS_SET(previous, DEVICE_FOUND_UDEV)) /* If the device has not been seen by udev yet, but is now referenced by the kernel, then we assume the * kernel knows it now, and udev might soon too. */ device_set_state(d, DEVICE_TENTATIVE); else /* If nobody sees the device, or if the device was previously seen by udev and now is only referenced * from the kernel, then we consider the device is gone, the kernel just hasn't noticed it yet. */ device_set_state(d, DEVICE_DEAD); } static void device_update_found_one(Device *d, DeviceFound found, DeviceFound mask) { assert(d); if (MANAGER_IS_RUNNING(UNIT(d)->manager)) { DeviceFound n, previous; /* When we are already running, then apply the new mask right-away, and trigger state changes * right-away */ n = (d->found & ~mask) | (found & mask); if (n == d->found) return; previous = d->found; d->found = n; device_found_changed(d, previous, n); } else /* We aren't running yet, let's apply the new mask to the shadow variable instead, which we'll apply as * soon as we catch-up with the state. */ d->enumerated_found = (d->enumerated_found & ~mask) | (found & mask); } static void device_update_found_by_sysfs(Manager *m, const char *sysfs, DeviceFound found, DeviceFound mask) { Device *l; assert(m); assert(sysfs); if (mask == 0) return; l = hashmap_get(m->devices_by_sysfs, sysfs); LIST_FOREACH(same_sysfs, d, l) device_update_found_one(d, found, mask); } static void device_update_found_by_name(Manager *m, const char *path, DeviceFound found, DeviceFound mask) { Unit *u; assert(m); assert(path); if (mask == 0) return; if (device_by_path(m, path, &u) < 0) return; device_update_found_one(DEVICE(u), found, mask); } static int device_coldplug(Unit *u) { Device *d = DEVICE(u); assert(d); assert(d->state == DEVICE_DEAD); /* First, let's put the deserialized state and found mask into effect, if we have it. */ if (d->deserialized_state < 0) return 0; Manager *m = u->manager; DeviceFound found = d->deserialized_found; DeviceState state = d->deserialized_state; /* On initial boot, switch-root, reload, reexecute, the following happen: * 1. MANAGER_IS_RUNNING() == false * 2. enumerate devices: manager_enumerate() -> device_enumerate() * Device.enumerated_found is set. * 3. deserialize devices: manager_deserialize() -> device_deserialize_item() * Device.deserialize_state and Device.deserialized_found are set. * 4. coldplug devices: manager_coldplug() -> device_coldplug() * deserialized properties are copied to the main properties. * 5. MANAGER_IS_RUNNING() == true: manager_ready() * 6. catchup devices: manager_catchup() -> device_catchup() * Device.enumerated_found is applied to Device.found, and state is updated based on that. * * Notes: * - On initial boot, no udev database exists. Hence, no devices are enumerated in the step 2. * Also, there is no deserialized device. Device units are (a) generated based on dependencies of * other units, or (b) generated when uevents are received. * * - On switch-root, the udev database may be cleared, except for devices with sticky bit, i.e. * OPTIONS="db_persist". Hence, almost no devices are enumerated in the step 2. However, in * general, we have several serialized devices. So, DEVICE_FOUND_UDEV bit in the * Device.deserialized_found must be ignored, as udev rules in initrd and the main system are often * different. If the deserialized state is DEVICE_PLUGGED, we need to downgrade it to * DEVICE_TENTATIVE. Unlike the other starting mode, MANAGER_IS_SWITCHING_ROOT() is true when * device_coldplug() and device_catchup() are called. Hence, let's conditionalize the operations by * using the flag. After switch-root, systemd-udevd will (re-)process all devices, and the * Device.found and Device.state will be adjusted. * * - On reload or reexecute, we can trust Device.enumerated_found, Device.deserialized_found, and * Device.deserialized_state. Of course, deserialized parameters may be outdated, but the unit * state can be adjusted later by device_catchup() or uevents. */ if (MANAGER_IS_SWITCHING_ROOT(m) && !FLAGS_SET(d->enumerated_found, DEVICE_FOUND_UDEV)) { /* The device has not been enumerated. On switching-root, such situation is natural. See the * above comment. To prevent problematic state transition active → dead → active, let's * drop the DEVICE_FOUND_UDEV flag and downgrade state to DEVICE_TENTATIVE(activating). See * issue #12953 and #23208. */ found &= ~DEVICE_FOUND_UDEV; if (state == DEVICE_PLUGGED) state = DEVICE_TENTATIVE; /* Also check the validity of the device syspath. Without this check, if the device was * removed while switching root, it would never go to inactive state, as both Device.found * and Device.enumerated_found do not have the DEVICE_FOUND_UDEV flag, so device_catchup() in * device_update_found_one() does nothing in most cases. See issue #25106. Note that the * syspath field is only serialized when systemd is sufficiently new and the device has been * already processed by udevd. */ if (d->deserialized_sysfs) { _cleanup_(sd_device_unrefp) sd_device *dev = NULL; if (sd_device_new_from_syspath(&dev, d->deserialized_sysfs) < 0) state = DEVICE_DEAD; } } if (d->found == found && d->state == state) return 0; d->found = found; device_set_state(d, state); return 0; } static void device_catchup(Unit *u) { Device *d = DEVICE(u); assert(d); /* Second, let's update the state with the enumerated state */ device_update_found_one(d, d->enumerated_found, DEVICE_FOUND_MASK); } static const struct { DeviceFound flag; const char *name; } device_found_map[] = { { DEVICE_FOUND_UDEV, "found-udev" }, { DEVICE_FOUND_MOUNT, "found-mount" }, { DEVICE_FOUND_SWAP, "found-swap" }, }; static int device_found_to_string_many(DeviceFound flags, char **ret) { _cleanup_free_ char *s = NULL; assert(ret); for (size_t i = 0; i < ELEMENTSOF(device_found_map); i++) { if (!FLAGS_SET(flags, device_found_map[i].flag)) continue; if (!strextend_with_separator(&s, ",", device_found_map[i].name)) return -ENOMEM; } *ret = TAKE_PTR(s); return 0; } static int device_found_from_string_many(const char *name, DeviceFound *ret) { DeviceFound flags = 0; int r; assert(ret); for (;;) { _cleanup_free_ char *word = NULL; DeviceFound f = 0; unsigned i; r = extract_first_word(&name, &word, ",", 0); if (r < 0) return r; if (r == 0) break; for (i = 0; i < ELEMENTSOF(device_found_map); i++) if (streq(word, device_found_map[i].name)) { f = device_found_map[i].flag; break; } if (f == 0) return -EINVAL; flags |= f; } *ret = flags; return 0; } static int device_serialize(Unit *u, FILE *f, FDSet *fds) { _cleanup_free_ char *s = NULL; Device *d = DEVICE(u); assert(d); assert(u); assert(f); assert(fds); if (d->sysfs) (void) serialize_item(f, "sysfs", d->sysfs); if (d->path) (void) serialize_item(f, "path", d->path); (void) serialize_item(f, "state", device_state_to_string(d->state)); if (device_found_to_string_many(d->found, &s) >= 0) (void) serialize_item(f, "found", s); return 0; } static int device_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) { Device *d = DEVICE(u); int r; assert(d); assert(u); assert(key); assert(value); assert(fds); if (streq(key, "sysfs")) { if (!d->deserialized_sysfs) { d->deserialized_sysfs = strdup(value); if (!d->deserialized_sysfs) log_oom_debug(); } } else if (streq(key, "path")) { if (!d->path) { d->path = strdup(value); if (!d->path) log_oom_debug(); } } else if (streq(key, "state")) { DeviceState state; state = device_state_from_string(value); if (state < 0) log_unit_debug(u, "Failed to parse state value, ignoring: %s", value); else d->deserialized_state = state; } else if (streq(key, "found")) { r = device_found_from_string_many(value, &d->deserialized_found); if (r < 0) log_unit_debug_errno(u, r, "Failed to parse found value '%s', ignoring: %m", value); } else log_unit_debug(u, "Unknown serialization key: %s", key); return 0; } static void device_dump(Unit *u, FILE *f, const char *prefix) { Device *d = DEVICE(u); _cleanup_free_ char *s = NULL; assert(d); (void) device_found_to_string_many(d->found, &s); fprintf(f, "%sDevice State: %s\n" "%sDevice Path: %s\n" "%sSysfs Path: %s\n" "%sFound: %s\n", prefix, device_state_to_string(d->state), prefix, strna(d->path), prefix, strna(d->sysfs), prefix, strna(s)); STRV_FOREACH(i, d->wants_property) fprintf(f, "%sudev SYSTEMD_WANTS: %s\n", prefix, *i); } static UnitActiveState device_active_state(Unit *u) { assert(u); return state_translation_table[DEVICE(u)->state]; } static const char *device_sub_state_to_string(Unit *u) { assert(u); return device_state_to_string(DEVICE(u)->state); } static int device_update_description(Unit *u, sd_device *dev, const char *path) { _cleanup_free_ char *j = NULL; const char *model, *label, *desc; int r; assert(u); assert(path); desc = path; if (dev && device_get_model_string(dev, &model) >= 0) { desc = model; /* Try to concatenate the device model string with a label, if there is one */ if (sd_device_get_property_value(dev, "ID_FS_LABEL", &label) >= 0 || sd_device_get_property_value(dev, "ID_PART_ENTRY_NAME", &label) >= 0 || sd_device_get_property_value(dev, "ID_PART_ENTRY_NUMBER", &label) >= 0) { desc = j = strjoin(model, " ", label); if (!j) return log_oom(); } } r = unit_set_description(u, desc); if (r < 0) return log_unit_error_errno(u, r, "Failed to set device description: %m"); return 0; } static int device_add_udev_wants(Unit *u, sd_device *dev) { _cleanup_strv_free_ char **added = NULL; const char *wants, *property; Device *d = DEVICE(u); int r; assert(d); assert(dev); property = MANAGER_IS_USER(u->manager) ? "SYSTEMD_USER_WANTS" : "SYSTEMD_WANTS"; r = sd_device_get_property_value(dev, property, &wants); if (r < 0) return 0; for (;;) { _cleanup_free_ char *word = NULL, *k = NULL; r = extract_first_word(&wants, &word, NULL, EXTRACT_UNQUOTE); if (r == 0) break; if (r == -ENOMEM) return log_oom(); if (r < 0) return log_unit_error_errno(u, r, "Failed to parse property %s with value %s: %m", property, wants); if (unit_name_is_valid(word, UNIT_NAME_TEMPLATE) && d->sysfs) { _cleanup_free_ char *escaped = NULL; /* If the unit name is specified as template, then automatically fill in the sysfs path of the * device as instance name, properly escaped. */ r = unit_name_path_escape(d->sysfs, &escaped); if (r < 0) return log_unit_error_errno(u, r, "Failed to escape %s: %m", d->sysfs); r = unit_name_replace_instance(word, escaped, &k); if (r < 0) return log_unit_error_errno(u, r, "Failed to build %s instance of template %s: %m", escaped, word); } else { /* If this is not a template, then let's mangle it so, that it becomes a valid unit name. */ r = unit_name_mangle(word, UNIT_NAME_MANGLE_WARN, &k); if (r < 0) return log_unit_error_errno(u, r, "Failed to mangle unit name \"%s\": %m", word); } r = unit_add_dependency_by_name(u, UNIT_WANTS, k, true, UNIT_DEPENDENCY_UDEV); if (r < 0) return log_unit_error_errno(u, r, "Failed to add Wants= dependency: %m"); r = strv_consume(&added, TAKE_PTR(k)); if (r < 0) return log_oom(); } if (d->state != DEVICE_DEAD) /* So here's a special hack, to compensate for the fact that the udev database's reload cycles are not * synchronized with our own reload cycles: when we detect that the SYSTEMD_WANTS property of a device * changes while the device unit is already up, let's skip to trigger units that were already listed * and are active, and start units otherwise. This typically happens during the boot-time switch root * transition, as udev devices will generally already be up in the initrd, but SYSTEMD_WANTS properties * get then added through udev rules only available on the host system, and thus only when the initial * udev coldplug trigger runs. * * We do this only if the device has been up already when we parse this, as otherwise the usual * dependency logic that is run from the dead → plugged transition will trigger these deps. */ STRV_FOREACH(i, added) { _cleanup_(sd_bus_error_free) sd_bus_error error = SD_BUS_ERROR_NULL; if (strv_contains(d->wants_property, *i)) { Unit *v; v = manager_get_unit(u->manager, *i); if (v && UNIT_IS_ACTIVE_OR_RELOADING(unit_active_state(v))) continue; /* The unit was already listed and is running. */ } r = manager_add_job_by_name(u->manager, JOB_START, *i, JOB_FAIL, NULL, &error, NULL); if (r < 0) log_unit_full_errno(u, sd_bus_error_has_name(&error, BUS_ERROR_NO_SUCH_UNIT) ? LOG_DEBUG : LOG_WARNING, r, "Failed to enqueue %s job, ignoring: %s", property, bus_error_message(&error, r)); } return strv_free_and_replace(d->wants_property, added); } static bool device_is_bound_by_mounts(Device *d, sd_device *dev) { int r; assert(d); assert(dev); r = device_get_property_bool(dev, "SYSTEMD_MOUNT_DEVICE_BOUND"); if (r < 0 && r != -ENOENT) log_device_warning_errno(dev, r, "Failed to parse SYSTEMD_MOUNT_DEVICE_BOUND= udev property, ignoring: %m"); d->bind_mounts = r > 0; return d->bind_mounts; } static void device_upgrade_mount_deps(Unit *u) { Unit *other; void *v; int r; /* Let's upgrade Requires= to BindsTo= on us. (Used when SYSTEMD_MOUNT_DEVICE_BOUND is set) */ HASHMAP_FOREACH_KEY(v, other, unit_get_dependencies(u, UNIT_REQUIRED_BY)) { if (other->type != UNIT_MOUNT) continue; r = unit_add_dependency(other, UNIT_BINDS_TO, u, true, UNIT_DEPENDENCY_UDEV); if (r < 0) log_unit_warning_errno(u, r, "Failed to add BindsTo= dependency between device and mount unit, ignoring: %m"); } } static int device_setup_unit(Manager *m, sd_device *dev, const char *path, bool main, Set **units) { _cleanup_(unit_freep) Unit *new_unit = NULL; _cleanup_free_ char *e = NULL; const char *sysfs = NULL; Unit *u; int r; assert(m); assert(path); if (dev) { r = sd_device_get_syspath(dev, &sysfs); if (r < 0) return log_device_debug_errno(dev, r, "Couldn't get syspath from device, ignoring: %m"); } r = unit_name_from_path(path, ".device", &e); if (r < 0) return log_struct_errno( LOG_WARNING, r, "MESSAGE_ID=" SD_MESSAGE_DEVICE_PATH_NOT_SUITABLE_STR, "DEVICE=%s", path, LOG_MESSAGE("Failed to generate valid unit name from device path '%s', ignoring device: %m", path)); u = manager_get_unit(m, e); if (u) { /* The device unit can still be present even if the device was unplugged: a mount unit can reference it * hence preventing the GC to have garbaged it. That's desired since the device unit may have a * dependency on the mount unit which was added during the loading of the later. When the device is * plugged the sysfs might not be initialized yet, as we serialize the device's state but do not * serialize the sysfs path across reloads/reexecs. Hence, when coming back from a reload/restart we * might have the state valid, but not the sysfs path. Also, there is another possibility; when multiple * devices have the same devlink (e.g. /dev/disk/by-uuid/xxxx), adding/updating/removing one of the * device causes syspath change. Hence, let's always update sysfs path. */ /* Let's remove all dependencies generated due to udev properties. We'll re-add whatever is configured * now below. */ unit_remove_dependencies(u, UNIT_DEPENDENCY_UDEV); } else { r = unit_new_for_name(m, sizeof(Device), e, &new_unit); if (r < 0) return log_device_error_errno(dev, r, "Failed to allocate device unit %s: %m", e); u = new_unit; unit_add_to_load_queue(u); } if (!DEVICE(u)->path) { DEVICE(u)->path = strdup(path); if (!DEVICE(u)->path) return log_oom(); } /* If this was created via some dependency and has not actually been seen yet ->sysfs will not be * initialized. Hence initialize it if necessary. */ if (sysfs) { r = device_set_sysfs(DEVICE(u), sysfs); if (r < 0) return log_unit_error_errno(u, r, "Failed to set sysfs path %s: %m", sysfs); /* The additional systemd udev properties we only interpret for the main object */ if (main) (void) device_add_udev_wants(u, dev); } (void) device_update_description(u, dev, path); /* So the user wants the mount units to be bound to the device but a mount unit might has been seen * by systemd before the device appears on its radar. In this case the device unit is partially * initialized and includes the deps on the mount unit but at that time the "bind mounts" flag wasn't * present. Fix this up now. */ if (dev && device_is_bound_by_mounts(DEVICE(u), dev)) device_upgrade_mount_deps(u); if (units) { r = set_ensure_put(units, NULL, DEVICE(u)); if (r < 0) return log_unit_error_errno(u, r, "Failed to store unit: %m"); } TAKE_PTR(new_unit); return 0; } static bool device_is_ready(sd_device *dev) { int r; assert(dev); if (device_for_action(dev, SD_DEVICE_REMOVE)) return false; r = device_is_renaming(dev); if (r < 0) log_device_warning_errno(dev, r, "Failed to check if device is renaming, assuming device is not renaming: %m"); if (r > 0) { log_device_debug(dev, "Device busy: device is renaming"); return false; } /* Is it really tagged as 'systemd' right now? */ r = sd_device_has_current_tag(dev, "systemd"); if (r < 0) log_device_warning_errno(dev, r, "Failed to check if device has \"systemd\" tag, assuming device is not tagged with \"systemd\": %m"); if (r == 0) log_device_debug(dev, "Device busy: device is not tagged with \"systemd\""); if (r <= 0) return false; r = device_get_property_bool(dev, "SYSTEMD_READY"); if (r < 0 && r != -ENOENT) log_device_warning_errno(dev, r, "Failed to get device SYSTEMD_READY property, assuming device does not have \"SYSTEMD_READY\" property: %m"); if (r == 0) log_device_debug(dev, "Device busy: SYSTEMD_READY property from device is false"); return r != 0; } static int device_setup_devlink_unit_one(Manager *m, const char *devlink, Set **ready_units, Set **not_ready_units) { _cleanup_(sd_device_unrefp) sd_device *dev = NULL; Unit *u; assert(m); assert(devlink); assert(ready_units); assert(not_ready_units); if (sd_device_new_from_devname(&dev, devlink) >= 0 && device_is_ready(dev)) return device_setup_unit(m, dev, devlink, /* main = */ false, ready_units); /* the devlink is already removed or not ready */ if (device_by_path(m, devlink, &u) < 0) return 0; /* The corresponding .device unit not found. That's fine. */ return set_ensure_put(not_ready_units, NULL, DEVICE(u)); } static int device_setup_extra_units(Manager *m, sd_device *dev, Set **ready_units, Set **not_ready_units) { _cleanup_strv_free_ char **aliases = NULL; const char *syspath, *devname = NULL; Device *l; int r; assert(m); assert(dev); assert(ready_units); assert(not_ready_units); r = sd_device_get_syspath(dev, &syspath); if (r < 0) return r; (void) sd_device_get_devname(dev, &devname); /* devlink units */ FOREACH_DEVICE_DEVLINK(dev, devlink) { /* These are a kind of special devlink. They should be always unique, but neither persistent * nor predictable. Hence, let's refuse them. See also the comments for alias units below. */ if (PATH_STARTSWITH_SET(devlink, "/dev/block/", "/dev/char/")) continue; (void) device_setup_devlink_unit_one(m, devlink, ready_units, not_ready_units); } if (device_is_ready(dev)) { const char *s; r = sd_device_get_property_value(dev, "SYSTEMD_ALIAS", &s); if (r < 0 && r != -ENOENT) log_device_warning_errno(dev, r, "Failed to get SYSTEMD_ALIAS property, ignoring: %m"); if (r >= 0) { r = strv_split_full(&aliases, s, NULL, EXTRACT_UNQUOTE); if (r < 0) log_device_warning_errno(dev, r, "Failed to parse SYSTEMD_ALIAS property, ignoring: %m"); } } /* alias units */ STRV_FOREACH(alias, aliases) { if (!path_is_absolute(*alias)) { log_device_warning(dev, "The alias \"%s\" specified in SYSTEMD_ALIAS is not an absolute path, ignoring.", *alias); continue; } if (!path_is_safe(*alias)) { log_device_warning(dev, "The alias \"%s\" specified in SYSTEMD_ALIAS is not safe, ignoring.", *alias); continue; } /* Note, even if the devlink is not persistent, LVM expects /dev/block/ symlink units exist. * To achieve that, they set the path to SYSTEMD_ALIAS. Hence, we cannot refuse aliases start * with /dev/, unfortunately. */ (void) device_setup_unit(m, dev, *alias, /* main = */ false, ready_units); } l = hashmap_get(m->devices_by_sysfs, syspath); LIST_FOREACH(same_sysfs, d, l) { if (!d->path) continue; if (path_equal(d->path, syspath)) continue; /* This is the main unit. */ if (devname && path_equal(d->path, devname)) continue; /* This is the real device node. */ if (device_has_devlink(dev, d->path)) continue; /* The devlink was already processed in the above loop. */ if (strv_contains(aliases, d->path)) continue; /* This is already processed in the above, and ready. */ if (path_startswith(d->path, "/dev/")) /* This is a devlink unit. Check existence and update syspath. */ (void) device_setup_devlink_unit_one(m, d->path, ready_units, not_ready_units); else /* This is an alias unit of dropped or not ready device. */ (void) set_ensure_put(not_ready_units, NULL, d); } return 0; } static int device_setup_units(Manager *m, sd_device *dev, Set **ready_units, Set **not_ready_units) { const char *syspath, *devname = NULL; int r; assert(m); assert(dev); assert(ready_units); assert(not_ready_units); r = sd_device_get_syspath(dev, &syspath); if (r < 0) return log_device_debug_errno(dev, r, "Couldn't get syspath from device, ignoring: %m"); /* First, process the main (that is, points to the syspath) and (real, not symlink) devnode units. */ if (device_for_action(dev, SD_DEVICE_REMOVE)) /* If the device is removed, the main and devnode units will be removed by * device_update_found_by_sysfs() in device_dispatch_io(). Hence, it is not necessary to * store them to not_ready_units, and we have nothing to do here. * * Note, still we need to process devlink units below, as a devlink previously points to this * device may still exist and now point to another device node. That is, do not forget to * call device_setup_extra_units(). */ ; else if (device_is_ready(dev)) { /* Add the main unit named after the syspath. If this one fails, don't bother with the rest, * as this one shall be the main device unit the others just follow. (Compare with how * device_following() is implemented, see below, which looks for the sysfs device.) */ r = device_setup_unit(m, dev, syspath, /* main = */ true, ready_units); if (r < 0) return r; /* Add an additional unit for the device node */ if (sd_device_get_devname(dev, &devname) >= 0) (void) device_setup_unit(m, dev, devname, /* main = */ false, ready_units); } else { Unit *u; /* If the device exists but not ready, then save the units and unset udev bits later. */ if (device_by_path(m, syspath, &u) >= 0) { r = set_ensure_put(not_ready_units, NULL, DEVICE(u)); if (r < 0) log_unit_debug_errno(u, r, "Failed to store unit, ignoring: %m"); } if (sd_device_get_devname(dev, &devname) >= 0 && device_by_path(m, devname, &u) >= 0) { r = set_ensure_put(not_ready_units, NULL, DEVICE(u)); if (r < 0) log_unit_debug_errno(u, r, "Failed to store unit, ignoring: %m"); } } /* Next, add/update additional .device units point to aliases and symlinks. */ (void) device_setup_extra_units(m, dev, ready_units, not_ready_units); /* Safety check: no unit should be in ready_units and not_ready_units simultaneously. */ Unit *u; SET_FOREACH(u, *not_ready_units) if (set_remove(*ready_units, u)) log_unit_error(u, "Cannot activate and deactivate the unit simultaneously. Deactivating."); return 0; } static Unit *device_following(Unit *u) { Device *d = DEVICE(u); Device *first = NULL; assert(d); if (startswith(u->id, "sys-")) return NULL; /* Make everybody follow the unit that's named after the sysfs path */ LIST_FOREACH(same_sysfs, other, d->same_sysfs_next) if (startswith(UNIT(other)->id, "sys-")) return UNIT(other); LIST_FOREACH_BACKWARDS(same_sysfs, other, d->same_sysfs_prev) { if (startswith(UNIT(other)->id, "sys-")) return UNIT(other); first = other; } return UNIT(first); } static int device_following_set(Unit *u, Set **_set) { Device *d = DEVICE(u); _cleanup_set_free_ Set *set = NULL; int r; assert(d); assert(_set); if (LIST_JUST_US(same_sysfs, d)) { *_set = NULL; return 0; } set = set_new(NULL); if (!set) return -ENOMEM; LIST_FOREACH(same_sysfs, other, d->same_sysfs_next) { r = set_put(set, other); if (r < 0) return r; } LIST_FOREACH_BACKWARDS(same_sysfs, other, d->same_sysfs_prev) { r = set_put(set, other); if (r < 0) return r; } *_set = TAKE_PTR(set); return 1; } static void device_shutdown(Manager *m) { assert(m); m->device_monitor = sd_device_monitor_unref(m->device_monitor); m->devices_by_sysfs = hashmap_free(m->devices_by_sysfs); } static void device_enumerate(Manager *m) { _cleanup_(sd_device_enumerator_unrefp) sd_device_enumerator *e = NULL; int r; assert(m); if (!m->device_monitor) { r = sd_device_monitor_new(&m->device_monitor); if (r < 0) { log_error_errno(r, "Failed to allocate device monitor: %m"); goto fail; } r = sd_device_monitor_filter_add_match_tag(m->device_monitor, "systemd"); if (r < 0) { log_error_errno(r, "Failed to add udev tag match: %m"); goto fail; } r = sd_device_monitor_attach_event(m->device_monitor, m->event); if (r < 0) { log_error_errno(r, "Failed to attach event to device monitor: %m"); goto fail; } r = sd_device_monitor_start(m->device_monitor, device_dispatch_io, m); if (r < 0) { log_error_errno(r, "Failed to start device monitor: %m"); goto fail; } } r = sd_device_enumerator_new(&e); if (r < 0) { log_error_errno(r, "Failed to allocate device enumerator: %m"); goto fail; } r = sd_device_enumerator_add_match_tag(e, "systemd"); if (r < 0) { log_error_errno(r, "Failed to set tag for device enumeration: %m"); goto fail; } FOREACH_DEVICE(e, dev) { _cleanup_set_free_ Set *ready_units = NULL, *not_ready_units = NULL; Device *d; if (device_setup_units(m, dev, &ready_units, ¬_ready_units) < 0) continue; SET_FOREACH(d, ready_units) device_update_found_one(d, DEVICE_FOUND_UDEV, DEVICE_FOUND_UDEV); SET_FOREACH(d, not_ready_units) device_update_found_one(d, DEVICE_NOT_FOUND, DEVICE_FOUND_UDEV); } return; fail: device_shutdown(m); } static void device_propagate_reload(Manager *m, Device *d) { int r; assert(m); assert(d); if (d->state == DEVICE_DEAD) return; r = manager_propagate_reload(m, UNIT(d), JOB_REPLACE, NULL); if (r < 0) log_unit_warning_errno(UNIT(d), r, "Failed to propagate reload, ignoring: %m"); } static void device_remove_old_on_move(Manager *m, sd_device *dev) { _cleanup_free_ char *syspath_old = NULL; const char *devpath_old; int r; assert(m); assert(dev); r = sd_device_get_property_value(dev, "DEVPATH_OLD", &devpath_old); if (r < 0) return (void) log_device_debug_errno(dev, r, "Failed to get DEVPATH_OLD= property on 'move' uevent, ignoring: %m"); syspath_old = path_join("/sys", devpath_old); if (!syspath_old) return (void) log_oom(); device_update_found_by_sysfs(m, syspath_old, DEVICE_NOT_FOUND, DEVICE_FOUND_MASK); } static int device_dispatch_io(sd_device_monitor *monitor, sd_device *dev, void *userdata) { _cleanup_set_free_ Set *ready_units = NULL, *not_ready_units = NULL; Manager *m = ASSERT_PTR(userdata); sd_device_action_t action; const char *sysfs; bool ready; Device *d; int r; assert(dev); log_device_uevent(dev, "Processing udev action"); r = sd_device_get_syspath(dev, &sysfs); if (r < 0) { log_device_warning_errno(dev, r, "Failed to get device syspath, ignoring: %m"); return 0; } r = sd_device_get_action(dev, &action); if (r < 0) { log_device_warning_errno(dev, r, "Failed to get udev action, ignoring: %m"); return 0; } log_device_debug(dev, "Got '%s' action on syspath '%s'.", device_action_to_string(action), sysfs); if (action == SD_DEVICE_MOVE) device_remove_old_on_move(m, dev); /* When udevd failed to process the device, SYSTEMD_ALIAS or any other properties may contain invalid * values. Let's refuse to handle the uevent. */ if (sd_device_get_property_value(dev, "UDEV_WORKER_FAILED", NULL) >= 0) { int v; if (device_get_property_int(dev, "UDEV_WORKER_ERRNO", &v) >= 0) log_device_warning_errno(dev, v, "systemd-udevd failed to process the device, ignoring: %m"); else if (device_get_property_int(dev, "UDEV_WORKER_EXIT_STATUS", &v) >= 0) log_device_warning(dev, "systemd-udevd failed to process the device with exit status %i, ignoring.", v); else if (device_get_property_int(dev, "UDEV_WORKER_SIGNAL", &v) >= 0) { const char *s; (void) sd_device_get_property_value(dev, "UDEV_WORKER_SIGNAL_NAME", &s); log_device_warning(dev, "systemd-udevd failed to process the device with signal %i(%s), ignoring.", v, strna(s)); } else log_device_warning(dev, "systemd-udevd failed to process the device with unknown result, ignoring."); return 0; } /* A change event can signal that a device is becoming ready, in particular if the device is using * the SYSTEMD_READY logic in udev so we need to reach the else block of the following if, even for * change events */ ready = device_is_ready(dev); (void) device_setup_units(m, dev, &ready_units, ¬_ready_units); if (action == SD_DEVICE_REMOVE) { r = swap_process_device_remove(m, dev); if (r < 0) log_device_warning_errno(dev, r, "Failed to process swap device remove event, ignoring: %m"); } else if (ready) { r = swap_process_device_new(m, dev); if (r < 0) log_device_warning_errno(dev, r, "Failed to process swap device new event, ignoring: %m"); } if (!IN_SET(action, SD_DEVICE_ADD, SD_DEVICE_REMOVE, SD_DEVICE_MOVE)) SET_FOREACH(d, ready_units) device_propagate_reload(m, d); if (!set_isempty(ready_units)) manager_dispatch_load_queue(m); if (action == SD_DEVICE_REMOVE) /* If we get notified that a device was removed by udev, then it's completely gone, hence * unset all found bits. Note this affects all .device units still point to the removed * device. */ device_update_found_by_sysfs(m, sysfs, DEVICE_NOT_FOUND, DEVICE_FOUND_MASK); /* These devices are found and ready now, set the udev found bit. Note, this is also necessary to do * on remove uevent, as some devlinks may be updated and now point to other device nodes. */ SET_FOREACH(d, ready_units) device_update_found_one(d, DEVICE_FOUND_UDEV, DEVICE_FOUND_UDEV); /* These devices may be nominally around, but not ready for us. Hence unset the udev bit, but leave * the rest around. This may be redundant for remove uevent, but should be harmless. */ SET_FOREACH(d, not_ready_units) device_update_found_one(d, DEVICE_NOT_FOUND, DEVICE_FOUND_UDEV); return 0; } void device_found_node(Manager *m, const char *node, DeviceFound found, DeviceFound mask) { int r; assert(m); assert(node); assert(!FLAGS_SET(mask, DEVICE_FOUND_UDEV)); if (!udev_available()) return; if (mask == 0) return; /* This is called whenever we find a device referenced in /proc/swaps or /proc/self/mounts. Such a device might * be mounted/enabled at a time where udev has not finished probing it yet, and we thus haven't learned about * it yet. In this case we will set the device unit to "tentative" state. * * This takes a pair of DeviceFound flags parameters. The 'mask' parameter is a bit mask that indicates which * bits of 'found' to copy into the per-device DeviceFound flags field. Thus, this function may be used to set * and unset individual bits in a single call, while merging partially with previous state. */ if ((found & mask) != 0) { _cleanup_(sd_device_unrefp) sd_device *dev = NULL; /* If the device is known in the kernel and newly appeared, then we'll create a device unit for it, * under the name referenced in /proc/swaps or /proc/self/mountinfo. But first, let's validate if * everything is alright with the device node. Note that we're fine with missing device nodes, * but not with badly set up ones. */ r = sd_device_new_from_devname(&dev, node); if (r == -ENODEV) log_debug("Could not find device for %s, continuing without device node", node); else if (r < 0) { /* Reduce log noise from nodes which are not device nodes by skipping EINVAL. */ if (r != -EINVAL) log_error_errno(r, "Failed to open %s device, ignoring: %m", node); return; } (void) device_setup_unit(m, dev, node, /* main = */ false, NULL); /* 'dev' may be NULL. */ } /* Update the device unit's state, should it exist */ (void) device_update_found_by_name(m, node, found, mask); } bool device_shall_be_bound_by(Unit *device, Unit *u) { assert(device); assert(u); if (u->type != UNIT_MOUNT) return false; return DEVICE(device)->bind_mounts; } const UnitVTable device_vtable = { .object_size = sizeof(Device), .sections = "Unit\0" "Device\0" "Install\0", .gc_jobs = true, .init = device_init, .done = device_done, .load = device_load, .coldplug = device_coldplug, .catchup = device_catchup, .serialize = device_serialize, .deserialize_item = device_deserialize_item, .dump = device_dump, .active_state = device_active_state, .sub_state_to_string = device_sub_state_to_string, .following = device_following, .following_set = device_following_set, .enumerate = device_enumerate, .shutdown = device_shutdown, .supported = udev_available, .status_message_formats = { .starting_stopping = { [0] = "Expecting device %s...", [1] = "Waiting for device %s to disappear...", }, .finished_start_job = { [JOB_DONE] = "Found device %s.", [JOB_TIMEOUT] = "Timed out waiting for device %s.", }, }, };