diff options
Diffstat (limited to 'src/core/device.c')
| -rw-r--r-- | src/core/device.c | 1301 |
1 files changed, 1301 insertions, 0 deletions
diff --git a/src/core/device.c b/src/core/device.c new file mode 100644 index 0000000..6b2d7c3 --- /dev/null +++ b/src/core/device.c @@ -0,0 +1,1301 @@ +/* SPDX-License-Identifier: LGPL-2.1-or-later */ + +#include <errno.h> +#include <sys/epoll.h> + +#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.", + }, + }, +}; |