1 /* SPDX-License-Identifier: LGPL-2.1+ */
6 #include "alloc-util.h"
8 #include "dbus-device.h"
10 #include "device-private.h"
11 #include "device-util.h"
14 #include "parse-util.h"
15 #include "path-util.h"
16 #include "serialize.h"
17 #include "stat-util.h"
18 #include "string-util.h"
20 #include "udev-util.h"
21 #include "unit-name.h"
24 static const UnitActiveState state_translation_table
[_DEVICE_STATE_MAX
] = {
25 [DEVICE_DEAD
] = UNIT_INACTIVE
,
26 [DEVICE_TENTATIVE
] = UNIT_ACTIVATING
,
27 [DEVICE_PLUGGED
] = UNIT_ACTIVE
,
30 static int device_dispatch_io(sd_device_monitor
*monitor
, sd_device
*dev
, void *userdata
);
31 static void device_update_found_one(Device
*d
, DeviceFound found
, DeviceFound mask
);
33 static void device_unset_sysfs(Device
*d
) {
42 /* Remove this unit from the chain of devices which share the
44 devices
= UNIT(d
)->manager
->devices_by_sysfs
;
45 first
= hashmap_get(devices
, d
->sysfs
);
46 LIST_REMOVE(same_sysfs
, first
, d
);
49 hashmap_remove_and_replace(devices
, d
->sysfs
, first
->sysfs
, first
);
51 hashmap_remove(devices
, d
->sysfs
);
53 d
->sysfs
= mfree(d
->sysfs
);
56 static int device_set_sysfs(Device
*d
, const char *sysfs
) {
57 _cleanup_free_
char *copy
= NULL
;
63 if (streq_ptr(d
->sysfs
, sysfs
))
66 r
= hashmap_ensure_allocated(&UNIT(d
)->manager
->devices_by_sysfs
, &path_hash_ops
);
74 device_unset_sysfs(d
);
76 first
= hashmap_get(UNIT(d
)->manager
->devices_by_sysfs
, sysfs
);
77 LIST_PREPEND(same_sysfs
, first
, d
);
79 r
= hashmap_replace(UNIT(d
)->manager
->devices_by_sysfs
, copy
, first
);
81 LIST_REMOVE(same_sysfs
, first
, d
);
85 d
->sysfs
= TAKE_PTR(copy
);
89 static void device_init(Unit
*u
) {
90 Device
*d
= DEVICE(u
);
93 assert(UNIT(d
)->load_state
== UNIT_STUB
);
95 /* In contrast to all other unit types we timeout jobs waiting
96 * for devices by default. This is because they otherwise wait
97 * indefinitely for plugged in devices, something which cannot
98 * happen for the other units since their operations time out
100 u
->job_running_timeout
= u
->manager
->default_timeout_start_usec
;
102 u
->ignore_on_isolate
= true;
104 d
->deserialized_state
= _DEVICE_STATE_INVALID
;
107 static void device_done(Unit
*u
) {
108 Device
*d
= DEVICE(u
);
112 device_unset_sysfs(d
);
113 d
->wants_property
= strv_free(d
->wants_property
);
116 static int device_load(Unit
*u
) {
119 r
= unit_load_fragment_and_dropin_optional(u
);
123 if (!u
->description
) {
124 /* Generate a description based on the path, to be used until the
125 device is initialized properly */
126 r
= unit_name_to_path(u
->id
, &u
->description
);
128 log_unit_debug_errno(u
, r
, "Failed to unescape name: %m");
134 static void device_set_state(Device
*d
, DeviceState state
) {
135 DeviceState old_state
;
138 if (d
->state
!= state
)
139 bus_unit_send_pending_change_signal(UNIT(d
), false);
141 old_state
= d
->state
;
144 if (state
== DEVICE_DEAD
)
145 device_unset_sysfs(d
);
147 if (state
!= old_state
)
148 log_unit_debug(UNIT(d
), "Changed %s -> %s", device_state_to_string(old_state
), device_state_to_string(state
));
150 unit_notify(UNIT(d
), state_translation_table
[old_state
], state_translation_table
[state
], 0);
153 static int device_coldplug(Unit
*u
) {
154 Device
*d
= DEVICE(u
);
157 assert(d
->state
== DEVICE_DEAD
);
159 /* First, let's put the deserialized state and found mask into effect, if we have it. */
161 if (d
->deserialized_state
< 0 ||
162 (d
->deserialized_state
== d
->state
&&
163 d
->deserialized_found
== d
->found
))
166 d
->found
= d
->deserialized_found
;
167 device_set_state(d
, d
->deserialized_state
);
171 static void device_catchup(Unit
*u
) {
172 Device
*d
= DEVICE(u
);
176 /* Second, let's update the state with the enumerated state if it's different */
177 if (d
->enumerated_found
== d
->found
)
180 device_update_found_one(d
, d
->enumerated_found
, DEVICE_FOUND_MASK
);
183 static const struct {
186 } device_found_map
[] = {
187 { DEVICE_FOUND_UDEV
, "found-udev" },
188 { DEVICE_FOUND_MOUNT
, "found-mount" },
189 { DEVICE_FOUND_SWAP
, "found-swap" },
192 static int device_found_to_string_many(DeviceFound flags
, char **ret
) {
193 _cleanup_free_
char *s
= NULL
;
198 for (i
= 0; i
< ELEMENTSOF(device_found_map
); i
++) {
199 if (!FLAGS_SET(flags
, device_found_map
[i
].flag
))
202 if (!strextend_with_separator(&s
, ",", device_found_map
[i
].name
, NULL
))
211 static int device_found_from_string_many(const char *name
, DeviceFound
*ret
) {
212 DeviceFound flags
= 0;
218 _cleanup_free_
char *word
= NULL
;
222 r
= extract_first_word(&name
, &word
, ",", 0);
228 for (i
= 0; i
< ELEMENTSOF(device_found_map
); i
++)
229 if (streq(word
, device_found_map
[i
].name
)) {
230 f
= device_found_map
[i
].flag
;
244 static int device_serialize(Unit
*u
, FILE *f
, FDSet
*fds
) {
245 _cleanup_free_
char *s
= NULL
;
246 Device
*d
= DEVICE(u
);
252 (void) serialize_item(f
, "state", device_state_to_string(d
->state
));
254 if (device_found_to_string_many(d
->found
, &s
) >= 0)
255 (void) serialize_item(f
, "found", s
);
260 static int device_deserialize_item(Unit
*u
, const char *key
, const char *value
, FDSet
*fds
) {
261 Device
*d
= DEVICE(u
);
269 if (streq(key
, "state")) {
272 state
= device_state_from_string(value
);
274 log_unit_debug(u
, "Failed to parse state value, ignoring: %s", value
);
276 d
->deserialized_state
= state
;
278 } else if (streq(key
, "found")) {
279 r
= device_found_from_string_many(value
, &d
->deserialized_found
);
281 log_unit_debug_errno(u
, r
, "Failed to parse found value '%s', ignoring: %m", value
);
284 log_unit_debug(u
, "Unknown serialization key: %s", key
);
289 static void device_dump(Unit
*u
, FILE *f
, const char *prefix
) {
290 Device
*d
= DEVICE(u
);
291 _cleanup_free_
char *s
= NULL
;
295 (void) device_found_to_string_many(d
->found
, &s
);
298 "%sDevice State: %s\n"
301 prefix
, device_state_to_string(d
->state
),
302 prefix
, strna(d
->sysfs
),
305 if (!strv_isempty(d
->wants_property
)) {
308 STRV_FOREACH(i
, d
->wants_property
)
309 fprintf(f
, "%sudev SYSTEMD_WANTS: %s\n",
314 _pure_
static UnitActiveState
device_active_state(Unit
*u
) {
317 return state_translation_table
[DEVICE(u
)->state
];
320 _pure_
static const char *device_sub_state_to_string(Unit
*u
) {
323 return device_state_to_string(DEVICE(u
)->state
);
326 static int device_update_description(Unit
*u
, sd_device
*dev
, const char *path
) {
327 _cleanup_free_
char *j
= NULL
;
328 const char *model
, *label
, *desc
;
337 (sd_device_get_property_value(dev
, "ID_MODEL_FROM_DATABASE", &model
) >= 0 ||
338 sd_device_get_property_value(dev
, "ID_MODEL", &model
) >= 0)) {
341 /* Try to concatenate the device model string with a label, if there is one */
342 if (sd_device_get_property_value(dev
, "ID_FS_LABEL", &label
) >= 0 ||
343 sd_device_get_property_value(dev
, "ID_PART_ENTRY_NAME", &label
) >= 0 ||
344 sd_device_get_property_value(dev
, "ID_PART_ENTRY_NUMBER", &label
) >= 0) {
346 desc
= j
= strjoin(model
, " ", label
);
352 r
= unit_set_description(u
, desc
);
354 return log_unit_error_errno(u
, r
, "Failed to set device description: %m");
359 static int device_add_udev_wants(Unit
*u
, sd_device
*dev
) {
360 _cleanup_strv_free_
char **added
= NULL
;
361 const char *wants
, *property
;
362 Device
*d
= DEVICE(u
);
368 property
= MANAGER_IS_USER(u
->manager
) ? "SYSTEMD_USER_WANTS" : "SYSTEMD_WANTS";
370 r
= sd_device_get_property_value(dev
, property
, &wants
);
375 _cleanup_free_
char *word
= NULL
, *k
= NULL
;
377 r
= extract_first_word(&wants
, &word
, NULL
, EXTRACT_QUOTES
);
383 return log_unit_error_errno(u
, r
, "Failed to parse property %s with value %s: %m", property
, wants
);
385 if (unit_name_is_valid(word
, UNIT_NAME_TEMPLATE
) && d
->sysfs
) {
386 _cleanup_free_
char *escaped
= NULL
;
388 /* If the unit name is specified as template, then automatically fill in the sysfs path of the
389 * device as instance name, properly escaped. */
391 r
= unit_name_path_escape(d
->sysfs
, &escaped
);
393 return log_unit_error_errno(u
, r
, "Failed to escape %s: %m", d
->sysfs
);
395 r
= unit_name_replace_instance(word
, escaped
, &k
);
397 return log_unit_error_errno(u
, r
, "Failed to build %s instance of template %s: %m", escaped
, word
);
399 /* If this is not a template, then let's mangle it so, that it becomes a valid unit name. */
401 r
= unit_name_mangle(word
, UNIT_NAME_MANGLE_WARN
, &k
);
403 return log_unit_error_errno(u
, r
, "Failed to mangle unit name \"%s\": %m", word
);
406 r
= unit_add_dependency_by_name(u
, UNIT_WANTS
, k
, true, UNIT_DEPENDENCY_UDEV
);
408 return log_unit_error_errno(u
, r
, "Failed to add Wants= dependency: %m");
410 r
= strv_push(&added
, k
);
417 if (d
->state
!= DEVICE_DEAD
) {
420 /* So here's a special hack, to compensate for the fact that the udev database's reload cycles are not
421 * synchronized with our own reload cycles: when we detect that the SYSTEMD_WANTS property of a device
422 * changes while the device unit is already up, let's manually trigger any new units listed in it not
423 * seen before. This typically happens during the boot-time switch root transition, as udev devices
424 * will generally already be up in the initrd, but SYSTEMD_WANTS properties get then added through udev
425 * rules only available on the host system, and thus only when the initial udev coldplug trigger runs.
427 * We do this only if the device has been up already when we parse this, as otherwise the usual
428 * dependency logic that is run from the dead → plugged transition will trigger these deps. */
430 STRV_FOREACH(i
, added
) {
431 _cleanup_(sd_bus_error_free
) sd_bus_error error
= SD_BUS_ERROR_NULL
;
433 if (strv_contains(d
->wants_property
, *i
)) /* Was this unit already listed before? */
436 r
= manager_add_job_by_name(u
->manager
, JOB_START
, *i
, JOB_FAIL
, NULL
, &error
, NULL
);
438 log_unit_warning_errno(u
, r
, "Failed to enqueue SYSTEMD_WANTS= job, ignoring: %s", bus_error_message(&error
, r
));
442 strv_free(d
->wants_property
);
443 d
->wants_property
= TAKE_PTR(added
);
448 static bool device_is_bound_by_mounts(Device
*d
, sd_device
*dev
) {
449 const char *bound_by
;
455 if (sd_device_get_property_value(dev
, "SYSTEMD_MOUNT_DEVICE_BOUND", &bound_by
) >= 0) {
456 r
= parse_boolean(bound_by
);
458 log_device_warning_errno(dev
, r
, "Failed to parse SYSTEMD_MOUNT_DEVICE_BOUND='%s' udev property, ignoring: %m", bound_by
);
460 d
->bind_mounts
= r
> 0;
462 d
->bind_mounts
= false;
464 return d
->bind_mounts
;
467 static void device_upgrade_mount_deps(Unit
*u
) {
473 /* Let's upgrade Requires= to BindsTo= on us. (Used when SYSTEMD_MOUNT_DEVICE_BOUND is set) */
475 HASHMAP_FOREACH_KEY(v
, other
, u
->dependencies
[UNIT_REQUIRED_BY
], i
) {
476 if (other
->type
!= UNIT_MOUNT
)
479 r
= unit_add_dependency(other
, UNIT_BINDS_TO
, u
, true, UNIT_DEPENDENCY_UDEV
);
481 log_unit_warning_errno(u
, r
, "Failed to add BindsTo= dependency between device and mount unit, ignoring: %m");
485 static int device_setup_unit(Manager
*m
, sd_device
*dev
, const char *path
, bool main
) {
486 _cleanup_free_
char *e
= NULL
;
487 const char *sysfs
= NULL
;
496 r
= sd_device_get_syspath(dev
, &sysfs
);
498 log_device_debug_errno(dev
, r
, "Couldn't get syspath from device, ignoring: %m");
503 r
= unit_name_from_path(path
, ".device", &e
);
505 return log_device_error_errno(dev
, r
, "Failed to generate unit name from device path: %m");
507 u
= manager_get_unit(m
, e
);
509 /* The device unit can still be present even if the device was unplugged: a mount unit can reference it
510 * hence preventing the GC to have garbaged it. That's desired since the device unit may have a
511 * dependency on the mount unit which was added during the loading of the later. When the device is
512 * plugged the sysfs might not be initialized yet, as we serialize the device's state but do not
513 * serialize the sysfs path across reloads/reexecs. Hence, when coming back from a reload/restart we
514 * might have the state valid, but not the sysfs path. Hence, let's filter out conflicting devices, but
515 * let's accept devices in any state with no sysfs path set. */
517 if (DEVICE(u
)->state
== DEVICE_PLUGGED
&&
520 !path_equal(DEVICE(u
)->sysfs
, sysfs
)) {
521 log_unit_debug(u
, "Device %s appeared twice with different sysfs paths %s and %s, ignoring the latter.",
522 e
, DEVICE(u
)->sysfs
, sysfs
);
528 /* Let's remove all dependencies generated due to udev properties. We'll re-add whatever is configured
530 unit_remove_dependencies(u
, UNIT_DEPENDENCY_UDEV
);
534 r
= unit_new_for_name(m
, sizeof(Device
), e
, &u
);
536 log_device_error_errno(dev
, r
, "Failed to allocate device unit %s: %m", e
);
540 unit_add_to_load_queue(u
);
543 /* If this was created via some dependency and has not actually been seen yet ->sysfs will not be
544 * initialized. Hence initialize it if necessary. */
546 r
= device_set_sysfs(DEVICE(u
), sysfs
);
548 log_unit_error_errno(u
, r
, "Failed to set sysfs path %s: %m", sysfs
);
552 /* The additional systemd udev properties we only interpret for the main object */
554 (void) device_add_udev_wants(u
, dev
);
557 (void) device_update_description(u
, dev
, path
);
559 /* So the user wants the mount units to be bound to the device but a mount unit might has been seen by systemd
560 * before the device appears on its radar. In this case the device unit is partially initialized and includes
561 * the deps on the mount unit but at that time the "bind mounts" flag wasn't not present. Fix this up now. */
562 if (dev
&& device_is_bound_by_mounts(DEVICE(u
), dev
))
563 device_upgrade_mount_deps(u
);
565 /* Note that this won't dispatch the load queue, the caller has to do that if needed and appropriate */
566 unit_add_to_dbus_queue(u
);
577 static int device_process_new(Manager
*m
, sd_device
*dev
) {
578 const char *sysfs
, *dn
, *alias
;
584 if (sd_device_get_syspath(dev
, &sysfs
) < 0)
587 /* Add the main unit named after the sysfs path */
588 r
= device_setup_unit(m
, dev
, sysfs
, true);
592 /* Add an additional unit for the device node */
593 if (sd_device_get_devname(dev
, &dn
) >= 0)
594 (void) device_setup_unit(m
, dev
, dn
, false);
596 /* Add additional units for all symlinks */
597 if (sd_device_get_devnum(dev
, &devnum
) >= 0) {
600 FOREACH_DEVICE_DEVLINK(dev
, p
) {
603 if (PATH_STARTSWITH_SET(p
, "/dev/block/", "/dev/char/"))
606 /* Verify that the symlink in the FS actually belongs
607 * to this device. This is useful to deal with
608 * conflicting devices, e.g. when two disks want the
609 * same /dev/disk/by-label/xxx link because they have
610 * the same label. We want to make sure that the same
611 * device that won the symlink wins in systemd, so we
612 * check the device node major/minor */
613 if (stat(p
, &st
) >= 0 &&
614 ((!S_ISBLK(st
.st_mode
) && !S_ISCHR(st
.st_mode
)) ||
615 st
.st_rdev
!= devnum
))
618 (void) device_setup_unit(m
, dev
, p
, false);
622 /* Add additional units for all explicitly configured aliases */
623 if (sd_device_get_property_value(dev
, "SYSTEMD_ALIAS", &alias
) < 0)
627 _cleanup_free_
char *word
= NULL
;
629 r
= extract_first_word(&alias
, &word
, NULL
, EXTRACT_QUOTES
);
635 return log_device_warning_errno(dev
, r
, "Failed to parse SYSTEMD_ALIAS property: %m");
637 if (!path_is_absolute(word
))
638 log_device_warning(dev
, "SYSTEMD_ALIAS is not an absolute path, ignoring: %s", word
);
639 else if (!path_is_normalized(word
))
640 log_device_warning(dev
, "SYSTEMD_ALIAS is not a normalized path, ignoring: %s", word
);
642 (void) device_setup_unit(m
, dev
, word
, false);
648 static void device_found_changed(Device
*d
, DeviceFound previous
, DeviceFound now
) {
651 /* Didn't exist before, but does now? if so, generate a new invocation ID for it */
652 if (previous
== DEVICE_NOT_FOUND
&& now
!= DEVICE_NOT_FOUND
)
653 (void) unit_acquire_invocation_id(UNIT(d
));
655 if (FLAGS_SET(now
, DEVICE_FOUND_UDEV
))
656 /* When the device is known to udev we consider it plugged. */
657 device_set_state(d
, DEVICE_PLUGGED
);
658 else if (now
!= DEVICE_NOT_FOUND
&& !FLAGS_SET(previous
, DEVICE_FOUND_UDEV
))
659 /* If the device has not been seen by udev yet, but is now referenced by the kernel, then we assume the
660 * kernel knows it now, and udev might soon too. */
661 device_set_state(d
, DEVICE_TENTATIVE
);
663 /* If nobody sees the device, or if the device was previously seen by udev and now is only referenced
664 * from the kernel, then we consider the device is gone, the kernel just hasn't noticed it yet. */
665 device_set_state(d
, DEVICE_DEAD
);
668 static void device_update_found_one(Device
*d
, DeviceFound found
, DeviceFound mask
) {
673 m
= UNIT(d
)->manager
;
675 if (MANAGER_IS_RUNNING(m
) && (m
->honor_device_enumeration
|| MANAGER_IS_USER(m
))) {
676 DeviceFound n
, previous
;
678 /* When we are already running, then apply the new mask right-away, and trigger state changes
681 n
= (d
->found
& ~mask
) | (found
& mask
);
688 device_found_changed(d
, previous
, n
);
690 /* We aren't running yet, let's apply the new mask to the shadow variable instead, which we'll apply as
691 * soon as we catch-up with the state. */
692 d
->enumerated_found
= (d
->enumerated_found
& ~mask
) | (found
& mask
);
695 static void device_update_found_by_sysfs(Manager
*m
, const char *sysfs
, DeviceFound found
, DeviceFound mask
) {
704 l
= hashmap_get(m
->devices_by_sysfs
, sysfs
);
705 LIST_FOREACH_SAFE(same_sysfs
, d
, n
, l
)
706 device_update_found_one(d
, found
, mask
);
709 static int device_update_found_by_name(Manager
*m
, const char *path
, DeviceFound found
, DeviceFound mask
) {
710 _cleanup_free_
char *e
= NULL
;
720 r
= unit_name_from_path(path
, ".device", &e
);
722 return log_error_errno(r
, "Failed to generate unit name from device path: %m");
724 u
= manager_get_unit(m
, e
);
728 device_update_found_one(DEVICE(u
), found
, mask
);
732 static bool device_is_ready(sd_device
*dev
) {
737 if (device_is_renaming(dev
) > 0)
740 if (sd_device_get_property_value(dev
, "SYSTEMD_READY", &ready
) < 0)
743 return parse_boolean(ready
) != 0;
746 static Unit
*device_following(Unit
*u
) {
747 Device
*d
= DEVICE(u
);
748 Device
*other
, *first
= NULL
;
752 if (startswith(u
->id
, "sys-"))
755 /* Make everybody follow the unit that's named after the sysfs path */
756 LIST_FOREACH_AFTER(same_sysfs
, other
, d
)
757 if (startswith(UNIT(other
)->id
, "sys-"))
760 LIST_FOREACH_BEFORE(same_sysfs
, other
, d
) {
761 if (startswith(UNIT(other
)->id
, "sys-"))
770 static int device_following_set(Unit
*u
, Set
**_set
) {
771 Device
*d
= DEVICE(u
), *other
;
772 _cleanup_set_free_ Set
*set
= NULL
;
778 if (LIST_JUST_US(same_sysfs
, d
)) {
787 LIST_FOREACH_AFTER(same_sysfs
, other
, d
) {
788 r
= set_put(set
, other
);
793 LIST_FOREACH_BEFORE(same_sysfs
, other
, d
) {
794 r
= set_put(set
, other
);
799 *_set
= TAKE_PTR(set
);
803 static void device_shutdown(Manager
*m
) {
806 m
->device_monitor
= sd_device_monitor_unref(m
->device_monitor
);
807 m
->devices_by_sysfs
= hashmap_free(m
->devices_by_sysfs
);
810 static void device_enumerate(Manager
*m
) {
811 _cleanup_(sd_device_enumerator_unrefp
) sd_device_enumerator
*e
= NULL
;
817 if (!m
->device_monitor
) {
818 r
= sd_device_monitor_new(&m
->device_monitor
);
820 log_error_errno(r
, "Failed to allocate device monitor: %m");
824 /* This will fail if we are unprivileged, but that
825 * should not matter much, as user instances won't run
827 (void) sd_device_monitor_set_receive_buffer_size(m
->device_monitor
, 128*1024*1024);
829 r
= sd_device_monitor_filter_add_match_tag(m
->device_monitor
, "systemd");
831 log_error_errno(r
, "Failed to add udev tag match: %m");
835 r
= sd_device_monitor_attach_event(m
->device_monitor
, m
->event
);
837 log_error_errno(r
, "Failed to attach event to device monitor: %m");
841 r
= sd_device_monitor_start(m
->device_monitor
, device_dispatch_io
, m
);
843 log_error_errno(r
, "Failed to start device monitor: %m");
848 r
= sd_device_enumerator_new(&e
);
850 log_error_errno(r
, "Failed to allocate device enumerator: %m");
854 r
= sd_device_enumerator_add_match_tag(e
, "systemd");
856 log_error_errno(r
, "Failed to set tag for device enumeration: %m");
860 FOREACH_DEVICE(e
, dev
) {
863 if (!device_is_ready(dev
))
866 (void) device_process_new(m
, dev
);
868 if (sd_device_get_syspath(dev
, &sysfs
) < 0)
871 device_update_found_by_sysfs(m
, sysfs
, DEVICE_FOUND_UDEV
, DEVICE_FOUND_UDEV
);
880 static void device_propagate_reload_by_sysfs(Manager
*m
, const char *sysfs
) {
887 l
= hashmap_get(m
->devices_by_sysfs
, sysfs
);
888 LIST_FOREACH_SAFE(same_sysfs
, d
, n
, l
) {
889 if (d
->state
== DEVICE_DEAD
)
892 r
= manager_propagate_reload(m
, UNIT(d
), JOB_REPLACE
, NULL
);
894 log_warning_errno(r
, "Failed to propagate reload, ignoring: %m");
898 static int device_dispatch_io(sd_device_monitor
*monitor
, sd_device
*dev
, void *userdata
) {
899 Manager
*m
= userdata
;
907 r
= sd_device_get_syspath(dev
, &sysfs
);
909 log_device_error_errno(dev
, r
, "Failed to get device sys path: %m");
913 r
= device_get_action(dev
, &action
);
915 log_device_error_errno(dev
, r
, "Failed to get udev action: %m");
919 if (action
== DEVICE_ACTION_CHANGE
)
920 device_propagate_reload_by_sysfs(m
, sysfs
);
922 /* A change event can signal that a device is becoming ready, in particular if
923 * the device is using the SYSTEMD_READY logic in udev
924 * so we need to reach the else block of the following if, even for change events */
925 if (action
== DEVICE_ACTION_REMOVE
) {
926 r
= swap_process_device_remove(m
, dev
);
928 log_device_warning_errno(dev
, r
, "Failed to process swap device remove event, ignoring: %m");
930 /* If we get notified that a device was removed by
931 * udev, then it's completely gone, hence unset all
933 device_update_found_by_sysfs(m
, sysfs
, 0, DEVICE_FOUND_UDEV
|DEVICE_FOUND_MOUNT
|DEVICE_FOUND_SWAP
);
935 } else if (device_is_ready(dev
)) {
937 (void) device_process_new(m
, dev
);
939 r
= swap_process_device_new(m
, dev
);
941 log_device_warning_errno(dev
, r
, "Failed to process swap device new event, ignoring: %m");
943 manager_dispatch_load_queue(m
);
945 /* The device is found now, set the udev found bit */
946 device_update_found_by_sysfs(m
, sysfs
, DEVICE_FOUND_UDEV
, DEVICE_FOUND_UDEV
);
949 /* The device is nominally around, but not ready for
950 * us. Hence unset the udev bit, but leave the rest
953 device_update_found_by_sysfs(m
, sysfs
, 0, DEVICE_FOUND_UDEV
);
959 static bool device_supported(void) {
960 static int read_only
= -1;
962 /* If /sys is read-only we don't support device units, and any
963 * attempts to start one should fail immediately. */
966 read_only
= path_is_read_only_fs("/sys");
968 return read_only
<= 0;
971 static int validate_node(Manager
*m
, const char *node
, sd_device
**ret
) {
979 /* Validates a device node that showed up in /proc/swaps or /proc/self/mountinfo if it makes sense for us to
980 * track. Note that this validator is fine within missing device nodes, but not with badly set up ones! */
982 if (!path_startswith(node
, "/dev")) {
987 if (stat(node
, &st
) < 0) {
989 return log_error_errno(errno
, "Failed to stat() device node file %s: %m", node
);
992 return 1; /* good! (though missing) */
995 _cleanup_(sd_device_unrefp
) sd_device
*dev
= NULL
;
997 r
= device_new_from_stat_rdev(&dev
, &st
);
1000 return 1; /* good! (though missing) */
1001 } else if (r
== -ENOTTY
) {
1003 return 0; /* bad! (not a device node but some other kind of file system node) */
1005 return log_error_errno(r
, "Failed to get udev device from devnum %u:%u: %m", major(st
.st_rdev
), minor(st
.st_rdev
));
1007 *ret
= TAKE_PTR(dev
);
1008 return 1; /* good! */
1012 void device_found_node(Manager
*m
, const char *node
, DeviceFound found
, DeviceFound mask
) {
1018 if (!device_supported())
1024 /* This is called whenever we find a device referenced in /proc/swaps or /proc/self/mounts. Such a device might
1025 * be mounted/enabled at a time where udev has not finished probing it yet, and we thus haven't learned about
1026 * it yet. In this case we will set the device unit to "tentative" state.
1028 * This takes a pair of DeviceFound flags parameters. The 'mask' parameter is a bit mask that indicates which
1029 * bits of 'found' to copy into the per-device DeviceFound flags field. Thus, this function may be used to set
1030 * and unset individual bits in a single call, while merging partially with previous state. */
1032 if ((found
& mask
) != 0) {
1033 _cleanup_(sd_device_unrefp
) sd_device
*dev
= NULL
;
1035 /* If the device is known in the kernel and newly appeared, then we'll create a device unit for it,
1036 * under the name referenced in /proc/swaps or /proc/self/mountinfo. But first, let's validate if
1037 * everything is alright with the device node. */
1039 r
= validate_node(m
, node
, &dev
);
1041 return; /* Don't create a device unit for this if the device node is borked. */
1043 (void) device_setup_unit(m
, dev
, node
, false);
1046 /* Update the device unit's state, should it exist */
1047 (void) device_update_found_by_name(m
, node
, found
, mask
);
1050 bool device_shall_be_bound_by(Unit
*device
, Unit
*u
) {
1054 if (u
->type
!= UNIT_MOUNT
)
1057 return DEVICE(device
)->bind_mounts
;
1060 const UnitVTable device_vtable
= {
1061 .object_size
= sizeof(Device
),
1069 .init
= device_init
,
1070 .done
= device_done
,
1071 .load
= device_load
,
1073 .coldplug
= device_coldplug
,
1074 .catchup
= device_catchup
,
1076 .serialize
= device_serialize
,
1077 .deserialize_item
= device_deserialize_item
,
1079 .dump
= device_dump
,
1081 .active_state
= device_active_state
,
1082 .sub_state_to_string
= device_sub_state_to_string
,
1084 .bus_vtable
= bus_device_vtable
,
1086 .following
= device_following
,
1087 .following_set
= device_following_set
,
1089 .enumerate
= device_enumerate
,
1090 .shutdown
= device_shutdown
,
1091 .supported
= device_supported
,
1093 .status_message_formats
= {
1094 .starting_stopping
= {
1095 [0] = "Expecting device %s...",
1097 .finished_start_job
= {
1098 [JOB_DONE
] = "Found device %s.",
1099 [JOB_TIMEOUT
] = "Timed out waiting for device %s.",