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device.c
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device.c
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/* 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-error.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 void device_unset_sysfs(Device *d) {
Hashmap *devices;
Device *first;
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;
first = hashmap_get(devices, d->sysfs);
LIST_REMOVE(same_sysfs, first, d);
if (first)
hashmap_remove_and_replace(devices, d->sysfs, first->sysfs, first);
else
hashmap_remove(devices, d->sysfs);
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->default_timeout_start_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->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], 0);
}
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) {
_cleanup_free_ char *e = NULL;
Unit *u;
int r;
assert(m);
assert(path);
if (mask == 0)
return;
r = unit_name_from_path(path, ".device", &e);
if (r < 0)
return (void) log_debug_errno(r, "Failed to generate unit name from device path, ignoring: %m");
u = manager_get_unit(m, e);
if (!u)
return;
device_update_found_one(DEVICE(u), found, mask);
}
static int device_coldplug(Unit *u) {
Device *d = DEVICE(u);
DeviceFound f;
DeviceState s;
Manager *m;
assert(d);
assert(d->state == DEVICE_DEAD);
/* For backward compatibility, set the path from the unit name. This fails when the unit name is hashed. */
if (!d->path)
(void) unit_name_to_path(u->id, &d->path);
/* First, let's put the deserialized state and found mask into effect, if we have it. */
if (d->deserialized_state < 0)
return 0;
m = u->manager;
f = d->deserialized_found;
s = 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()
* 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 exist. 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, no udev databse exist, 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. But, DEVICE_FOUND_UDEV bit in the deserialized_found and enumerated_found
* must be ignored, as udev rules in initramfs and the main system are often different. Hence, if the
* deserialized state is DEVICE_PLUGGED, we need to downgrade it to DEVICE_TENTATIVE (rather than
* DEVICE_DEAD, otherwise the corresponding mount units will be unmounted). Unlike the other starting
* mode, Manager::honor_device_enumeration == false (maybe, it is better to rename the flag) 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-)processes all devices. So, the
* Device::found and Device::state are adjusted after the device being processed by systemd-udevd.
* FIXME: there is a possibility that some devices are unplugged during switching root. Then, the
* devices are remaining in the tentative state and will never be freed until the PID1 is reloaded
* or reexecuted.
* - On reload or reexecute, we can trust enumerated_found, deserialized_found, and deserialized_state.
* Of course, deserialized parameters may be outdated, but the unit state can be adjusted later by
* device_catchup() or uevents. */
if (!m->honor_device_enumeration && !MANAGER_IS_USER(m)) {
f &= ~DEVICE_FOUND_UDEV;
if (s == DEVICE_PLUGGED)
s = DEVICE_TENTATIVE;
}
d->found = f;
device_set_state(d, s);
return 0;
}
static void device_catchup(Unit *u) {
Device *d = DEVICE(u);
DeviceFound mask;
Manager *m;
assert(d);
/* Second, let's update the state with the enumerated state. */
m = u->manager;
mask = DEVICE_FOUND_MASK;
if (!m->honor_device_enumeration && !MANAGER_IS_USER(m))
/* On switch-root, ignore DEVICE_FOUND_UDEV. See comments in device_coldplug(). */
mask &= ~DEVICE_FOUND_UDEV;
device_update_found_one(d, d->enumerated_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);
(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, "path")) {
d->path = strdup(value);
if (!d->path)
log_oom_debug();
} 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);
}
_pure_ static UnitActiveState device_active_state(Unit *u) {
assert(u);
return state_translation_table[DEVICE(u)->state];
}
_pure_ 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 &&
(sd_device_get_property_value(dev, "ID_MODEL_FROM_DATABASE", &model) >= 0 ||
sd_device_get_property_value(dev, "ID_MODEL", &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 manually trigger any new units listed in it not
* seen before. 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)) /* Was this unit already listed before? */
continue;
r = manager_add_job_by_name(u->manager, JOB_START, *i, JOB_FAIL, NULL, &error, NULL);
if (r < 0)
log_unit_warning_errno(u, r, "Failed to enqueue SYSTEMD_WANTS= job, ignoring: %s", 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) {
_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;
DEVICE(u)->path = strdup(path);
if (!DEVICE(u)->path)
return log_oom();
unit_add_to_load_queue(u);
}
/* 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);
TAKE_PTR(new_unit);
return 0;
}
static bool device_is_ready(sd_device *dev) {
assert(dev);
if (device_is_renaming(dev) > 0)
return false;
/* Is it really tagged as 'systemd' right now? */
if (sd_device_has_current_tag(dev, "systemd") <= 0)
return false;
return device_get_property_bool(dev, "SYSTEMD_READY") != 0;
}
static int device_setup_devlink_unit_one(Manager *m, const char *devlink, sd_device **ret) {
_cleanup_(sd_device_unrefp) sd_device *dev = NULL;
int r;
assert(m);
assert(devlink);
if (sd_device_new_from_devname(&dev, devlink) < 0 || !device_is_ready(dev)) {
/* the devlink is already removed or not ready */
device_update_found_by_name(m, devlink, 0, DEVICE_FOUND_UDEV);
*ret = NULL;
return 0; /* not ready */
}
r = device_setup_unit(m, dev, devlink, false);
if (r < 0)
return log_device_warning_errno(dev, r, "Failed to setup unit for '%s': %m", devlink);
*ret = TAKE_PTR(dev);
return 1; /* ready */
}
static int device_setup_devlink_units(Manager *m, sd_device *dev, char ***ret_ready_devlinks) {
_cleanup_strv_free_ char **ready_devlinks = NULL;
const char *devlink, *syspath;
int r;
assert(m);
assert(dev);
assert(ret_ready_devlinks);
r = sd_device_get_syspath(dev, &syspath);
if (r < 0)
return r;
FOREACH_DEVICE_DEVLINK(dev, devlink) {
_cleanup_(sd_device_unrefp) sd_device *assigned = NULL;
const char *s;
if (PATH_STARTSWITH_SET(devlink, "/dev/block/", "/dev/char/"))
continue;
if (device_setup_devlink_unit_one(m, devlink, &assigned) <= 0)
continue;
if (sd_device_get_syspath(assigned, &s) < 0)
continue;
if (path_equal(s, syspath))
continue;
r = strv_extend(&ready_devlinks, devlink);
if (r < 0)
return -ENOMEM;
}
*ret_ready_devlinks = TAKE_PTR(ready_devlinks);
return 0;
}
static int device_setup_devlink_units_on_remove(Manager *m, sd_device *dev, char ***ret_ready_devlinks) {
_cleanup_strv_free_ char **ready_devlinks = NULL;
const char *syspath;
Device *l;
int r;
assert(m);
assert(dev);
assert(ret_ready_devlinks);
r = sd_device_get_syspath(dev, &syspath);
if (r < 0)
return r;
l = hashmap_get(m->devices_by_sysfs, syspath);
LIST_FOREACH(same_sysfs, d, l) {
_cleanup_(sd_device_unrefp) sd_device *assigned = NULL;
const char *s;
if (!path_startswith(d->path, "/dev/"))
continue;
if (device_setup_devlink_unit_one(m, d->path, &assigned) <= 0)
continue;
if (sd_device_get_syspath(assigned, &s) < 0)
continue;
if (path_equal(s, syspath))
continue;
r = strv_extend(&ready_devlinks, d->path);
if (r < 0)
return -ENOMEM;
}
*ret_ready_devlinks = TAKE_PTR(ready_devlinks);
return 0;
}
static void device_process_new(Manager *m, sd_device *dev) {
const char *sysfs, *dn, *alias;
int r;
assert(m);
assert(dev);
if (sd_device_get_syspath(dev, &sysfs) < 0)
return;
/* Add the main unit named after the sysfs path. 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.) */
if (device_setup_unit(m, dev, sysfs, true) < 0)
return;
/* Add an additional unit for the device node */
if (sd_device_get_devname(dev, &dn) >= 0)
(void) device_setup_unit(m, dev, dn, false);
/* Add additional units for all explicitly configured aliases */
if (sd_device_get_property_value(dev, "SYSTEMD_ALIAS", &alias) < 0)
return;
for (;;) {
_cleanup_free_ char *word = NULL;
r = extract_first_word(&alias, &word, NULL, EXTRACT_UNQUOTE);
if (r == 0)
break;
if (r == -ENOMEM)
return (void) log_oom();
if (r < 0)
return (void) log_device_warning_errno(dev, r, "Failed to parse SYSTEMD_ALIAS property, ignoring: %m");
if (!path_is_absolute(word))
log_device_warning(dev, "SYSTEMD_ALIAS is not an absolute path, ignoring: %s", word);
else if (!path_is_normalized(word))
log_device_warning(dev, "SYSTEMD_ALIAS is not a normalized path, ignoring: %s", word);
else
(void) device_setup_unit(m, dev, word, false);
}
}
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;
sd_device *dev;
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;
}
/* This will fail if we are unprivileged, but that
* should not matter much, as user instances won't run
* during boot. */
(void) sd_device_monitor_set_receive_buffer_size(m->device_monitor, 128*1024*1024);
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_strv_free_ char **ready_devlinks = NULL;
const char *sysfs;
if (sd_device_get_syspath(dev, &sysfs) < 0)
continue;
if (device_is_ready(dev)) {
device_process_new(m, dev);
device_update_found_by_sysfs(m, sysfs, DEVICE_FOUND_UDEV, DEVICE_FOUND_UDEV);
}
/* Add additional units for all symlinks */
if (device_setup_devlink_units(m, dev, &ready_devlinks) < 0)
goto fail;
STRV_FOREACH(devlink, ready_devlinks)
device_update_found_by_name(m, *devlink, DEVICE_FOUND_UDEV, DEVICE_FOUND_UDEV);
}
return;
fail:
device_shutdown(m);
}
static void device_propagate_reload_by_sysfs(Manager *m, const char *sysfs) {
Device *l;
int r;
assert(m);
assert(sysfs);
l = hashmap_get(m->devices_by_sysfs, sysfs);
LIST_FOREACH(same_sysfs, d, l) {
if (d->state == DEVICE_DEAD)