1 /*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/
4 This file is part of systemd.
6 Copyright 2010 Lennart Poettering
8 systemd is free software; you can redistribute it and/or modify it
9 under the terms of the GNU Lesser General Public License as published by
10 the Free Software Foundation; either version 2.1 of the License, or
11 (at your option) any later version.
13 systemd is distributed in the hope that it will be useful, but
14 WITHOUT ANY WARRANTY; without even the implied warranty of
15 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 Lesser General Public License for more details.
18 You should have received a copy of the GNU Lesser General Public License
19 along with systemd; If not, see <http://www.gnu.org/licenses/>.
22 #include <sys/inotify.h>
23 #include <sys/epoll.h>
24 #include <sys/ioctl.h>
29 #include "unit-name.h"
32 #include "dbus-path.h"
34 #include "path-util.h"
37 #include "bus-error.h"
39 static const UnitActiveState state_translation_table[_PATH_STATE_MAX] = {
40 [PATH_DEAD] = UNIT_INACTIVE,
41 [PATH_WAITING] = UNIT_ACTIVE,
42 [PATH_RUNNING] = UNIT_ACTIVE,
43 [PATH_FAILED] = UNIT_FAILED
46 static int path_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata);
48 int path_spec_watch(PathSpec *s, sd_event_io_handler_t handler) {
50 static const int flags_table[_PATH_TYPE_MAX] = {
51 [PATH_EXISTS] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB,
52 [PATH_EXISTS_GLOB] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB,
53 [PATH_CHANGED] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CLOSE_WRITE|IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO,
54 [PATH_MODIFIED] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CLOSE_WRITE|IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO|IN_MODIFY,
55 [PATH_DIRECTORY_NOT_EMPTY] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CREATE|IN_MOVED_TO
59 char *slash, *oldslash = NULL;
68 s->inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
69 if (s->inotify_fd < 0) {
74 r = sd_event_add_io(s->unit->manager->event, &s->event_source, s->inotify_fd, EPOLLIN, handler, s);
78 /* This assumes the path was passed through path_kill_slashes()! */
80 for (slash = strchr(s->path, '/'); ; slash = strchr(slash+1, '/')) {
86 cut = slash + (slash == s->path);
90 flags = IN_MOVE_SELF | IN_DELETE_SELF | IN_ATTRIB | IN_CREATE | IN_MOVED_TO;
92 flags = flags_table[s->type];
94 r = inotify_add_watch(s->inotify_fd, s->path, flags);
96 if (errno == EACCES || errno == ENOENT) {
102 log_warning("Failed to add watch on %s: %m", s->path);
110 /* Path exists, we don't need to watch parent
113 char *cut2 = oldslash + (oldslash == s->path);
117 inotify_add_watch(s->inotify_fd, s->path, IN_MOVE_SELF);
118 /* Error is ignored, the worst can happen is
119 we get spurious events. */
131 /* whole path has been iterated over */
138 log_error("Failed to add watch on any of the components of %s: %m",
140 r = -errno; /* either EACCESS or ENOENT */
147 path_spec_unwatch(s);
151 void path_spec_unwatch(PathSpec *s) {
154 s->event_source = sd_event_source_unref(s->event_source);
155 s->inotify_fd = safe_close(s->inotify_fd);
158 int path_spec_fd_event(PathSpec *s, uint32_t revents) {
159 _cleanup_free_ uint8_t *buf = NULL;
160 struct inotify_event *e;
165 if (revents != EPOLLIN) {
166 log_error("Got invalid poll event on inotify.");
170 if (ioctl(s->inotify_fd, FIONREAD, &l) < 0) {
171 log_error("FIONREAD failed: %m");
181 k = read(s->inotify_fd, buf, l);
183 log_error("Failed to read inotify event: %m");
187 e = (struct inotify_event*) buf;
192 if ((s->type == PATH_CHANGED || s->type == PATH_MODIFIED) &&
193 s->primary_wd == e->wd)
196 step = sizeof(struct inotify_event) + e->len;
197 assert(step <= (size_t) k);
199 e = (struct inotify_event*) ((uint8_t*) e + step);
206 static bool path_spec_check_good(PathSpec *s, bool initial) {
212 good = access(s->path, F_OK) >= 0;
215 case PATH_EXISTS_GLOB:
216 good = glob_exists(s->path) > 0;
219 case PATH_DIRECTORY_NOT_EMPTY: {
222 k = dir_is_empty(s->path);
223 good = !(k == -ENOENT || k > 0);
228 case PATH_MODIFIED: {
231 b = access(s->path, F_OK) >= 0;
232 good = !initial && b != s->previous_exists;
233 s->previous_exists = b;
244 static void path_spec_mkdir(PathSpec *s, mode_t mode) {
247 if (s->type == PATH_EXISTS || s->type == PATH_EXISTS_GLOB)
250 r = mkdir_p_label(s->path, mode);
252 log_warning("mkdir(%s) failed: %s", s->path, strerror(-r));
255 static void path_spec_dump(PathSpec *s, FILE *f, const char *prefix) {
259 path_type_to_string(s->type),
263 void path_spec_done(PathSpec *s) {
265 assert(s->inotify_fd == -1);
270 static void path_init(Unit *u) {
274 assert(u->load_state == UNIT_STUB);
276 p->directory_mode = 0755;
279 void path_free_specs(Path *p) {
284 while ((s = p->specs)) {
285 path_spec_unwatch(s);
286 LIST_REMOVE(spec, p->specs, s);
292 static void path_done(Unit *u) {
300 static int path_add_mount_links(Path *p) {
306 LIST_FOREACH(spec, s, p->specs) {
307 r = unit_require_mounts_for(UNIT(p), s->path);
315 static int path_verify(Path *p) {
318 if (UNIT(p)->load_state != UNIT_LOADED)
322 log_error_unit(UNIT(p)->id,
323 "%s lacks path setting. Refusing.", UNIT(p)->id);
330 static int path_add_default_dependencies(Path *p) {
335 r = unit_add_dependency_by_name(UNIT(p), UNIT_BEFORE,
336 SPECIAL_PATHS_TARGET, NULL, true);
340 if (UNIT(p)->manager->running_as == SYSTEMD_SYSTEM) {
341 r = unit_add_two_dependencies_by_name(UNIT(p), UNIT_AFTER, UNIT_REQUIRES,
342 SPECIAL_SYSINIT_TARGET, NULL, true);
347 return unit_add_two_dependencies_by_name(UNIT(p), UNIT_BEFORE, UNIT_CONFLICTS,
348 SPECIAL_SHUTDOWN_TARGET, NULL, true);
351 static int path_load(Unit *u) {
356 assert(u->load_state == UNIT_STUB);
358 r = unit_load_fragment_and_dropin(u);
362 if (u->load_state == UNIT_LOADED) {
364 if (set_isempty(u->dependencies[UNIT_TRIGGERS])) {
367 r = unit_load_related_unit(u, ".service", &x);
371 r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, x, true);
376 r = path_add_mount_links(p);
380 if (UNIT(p)->default_dependencies) {
381 r = path_add_default_dependencies(p);
387 return path_verify(p);
390 static void path_dump(Unit *u, FILE *f, const char *prefix) {
398 trigger = UNIT_TRIGGER(u);
404 "%sMakeDirectory: %s\n"
405 "%sDirectoryMode: %04o\n",
406 prefix, path_state_to_string(p->state),
407 prefix, path_result_to_string(p->result),
408 prefix, trigger ? trigger->id : "n/a",
409 prefix, yes_no(p->make_directory),
410 prefix, p->directory_mode);
412 LIST_FOREACH(spec, s, p->specs)
413 path_spec_dump(s, f, prefix);
416 static void path_unwatch(Path *p) {
421 LIST_FOREACH(spec, s, p->specs)
422 path_spec_unwatch(s);
425 static int path_watch(Path *p) {
431 LIST_FOREACH(spec, s, p->specs) {
432 r = path_spec_watch(s, path_dispatch_io);
440 static void path_set_state(Path *p, PathState state) {
444 old_state = p->state;
447 if (state != PATH_WAITING &&
448 (state != PATH_RUNNING || p->inotify_triggered))
451 if (state != old_state)
452 log_debug("%s changed %s -> %s",
454 path_state_to_string(old_state),
455 path_state_to_string(state));
457 unit_notify(UNIT(p), state_translation_table[old_state], state_translation_table[state], true);
460 static void path_enter_waiting(Path *p, bool initial, bool recheck);
462 static int path_coldplug(Unit *u) {
466 assert(p->state == PATH_DEAD);
468 if (p->deserialized_state != p->state) {
470 if (p->deserialized_state == PATH_WAITING ||
471 p->deserialized_state == PATH_RUNNING)
472 path_enter_waiting(p, true, true);
474 path_set_state(p, p->deserialized_state);
480 static void path_enter_dead(Path *p, PathResult f) {
483 if (f != PATH_SUCCESS)
486 path_set_state(p, p->result != PATH_SUCCESS ? PATH_FAILED : PATH_DEAD);
489 static void path_enter_running(Path *p) {
490 _cleanup_bus_error_free_ sd_bus_error error = SD_BUS_ERROR_NULL;
495 /* Don't start job if we are supposed to go down */
496 if (unit_stop_pending(UNIT(p)))
499 r = manager_add_job(UNIT(p)->manager, JOB_START, UNIT_TRIGGER(UNIT(p)),
500 JOB_REPLACE, true, &error, NULL);
504 p->inotify_triggered = false;
510 path_set_state(p, PATH_RUNNING);
514 log_warning("%s failed to queue unit startup job: %s",
515 UNIT(p)->id, bus_error_message(&error, r));
516 path_enter_dead(p, PATH_FAILURE_RESOURCES);
519 static bool path_check_good(Path *p, bool initial) {
525 LIST_FOREACH(spec, s, p->specs) {
526 good = path_spec_check_good(s, initial);
535 static void path_enter_waiting(Path *p, bool initial, bool recheck) {
539 if (path_check_good(p, initial)) {
540 log_debug("%s got triggered.", UNIT(p)->id);
541 path_enter_running(p);
549 /* Hmm, so now we have created inotify watches, but the file
550 * might have appeared/been removed by now, so we must
554 if (path_check_good(p, false)) {
555 log_debug("%s got triggered.", UNIT(p)->id);
556 path_enter_running(p);
560 path_set_state(p, PATH_WAITING);
564 log_warning("%s failed to enter waiting state: %s",
565 UNIT(p)->id, strerror(-r));
566 path_enter_dead(p, PATH_FAILURE_RESOURCES);
569 static void path_mkdir(Path *p) {
574 if (!p->make_directory)
577 LIST_FOREACH(spec, s, p->specs)
578 path_spec_mkdir(s, p->directory_mode);
581 static int path_start(Unit *u) {
585 assert(p->state == PATH_DEAD || p->state == PATH_FAILED);
587 if (UNIT_TRIGGER(u)->load_state != UNIT_LOADED)
592 p->result = PATH_SUCCESS;
593 path_enter_waiting(p, true, true);
598 static int path_stop(Unit *u) {
602 assert(p->state == PATH_WAITING || p->state == PATH_RUNNING);
604 path_enter_dead(p, PATH_SUCCESS);
608 static int path_serialize(Unit *u, FILE *f, FDSet *fds) {
615 unit_serialize_item(u, f, "state", path_state_to_string(p->state));
616 unit_serialize_item(u, f, "result", path_result_to_string(p->result));
621 static int path_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
629 if (streq(key, "state")) {
632 state = path_state_from_string(value);
634 log_debug("Failed to parse state value %s", value);
636 p->deserialized_state = state;
638 } else if (streq(key, "result")) {
641 f = path_result_from_string(value);
643 log_debug("Failed to parse result value %s", value);
644 else if (f != PATH_SUCCESS)
648 log_debug("Unknown serialization key '%s'", key);
653 _pure_ static UnitActiveState path_active_state(Unit *u) {
656 return state_translation_table[PATH(u)->state];
659 _pure_ static const char *path_sub_state_to_string(Unit *u) {
662 return path_state_to_string(PATH(u)->state);
665 static int path_dispatch_io(sd_event_source *source, int fd, uint32_t revents, void *userdata) {
666 PathSpec *s = userdata;
676 if (p->state != PATH_WAITING &&
677 p->state != PATH_RUNNING)
680 /* log_debug("inotify wakeup on %s.", u->id); */
682 LIST_FOREACH(spec, s, p->specs)
683 if (path_spec_owns_inotify_fd(s, fd))
687 log_error("Got event on unknown fd.");
691 changed = path_spec_fd_event(s, revents);
695 /* If we are already running, then remember that one event was
696 * dispatched so that we restart the service only if something
697 * actually changed on disk */
698 p->inotify_triggered = true;
701 path_enter_running(p);
703 path_enter_waiting(p, false, true);
708 path_enter_dead(p, PATH_FAILURE_RESOURCES);
712 static void path_trigger_notify(Unit *u, Unit *other) {
718 /* Invoked whenever the unit we trigger changes state or gains
721 if (other->load_state != UNIT_LOADED)
724 if (p->state == PATH_RUNNING &&
725 UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other))) {
726 log_debug_unit(UNIT(p)->id,
727 "%s got notified about unit deactivation.",
730 /* Hmm, so inotify was triggered since the
731 * last activation, so I guess we need to
732 * recheck what is going on. */
733 path_enter_waiting(p, false, p->inotify_triggered);
737 static void path_reset_failed(Unit *u) {
742 if (p->state == PATH_FAILED)
743 path_set_state(p, PATH_DEAD);
745 p->result = PATH_SUCCESS;
748 static const char* const path_state_table[_PATH_STATE_MAX] = {
749 [PATH_DEAD] = "dead",
750 [PATH_WAITING] = "waiting",
751 [PATH_RUNNING] = "running",
752 [PATH_FAILED] = "failed"
755 DEFINE_STRING_TABLE_LOOKUP(path_state, PathState);
757 static const char* const path_type_table[_PATH_TYPE_MAX] = {
758 [PATH_EXISTS] = "PathExists",
759 [PATH_EXISTS_GLOB] = "PathExistsGlob",
760 [PATH_DIRECTORY_NOT_EMPTY] = "DirectoryNotEmpty",
761 [PATH_CHANGED] = "PathChanged",
762 [PATH_MODIFIED] = "PathModified",
765 DEFINE_STRING_TABLE_LOOKUP(path_type, PathType);
767 static const char* const path_result_table[_PATH_RESULT_MAX] = {
768 [PATH_SUCCESS] = "success",
769 [PATH_FAILURE_RESOURCES] = "resources",
772 DEFINE_STRING_TABLE_LOOKUP(path_result, PathResult);
774 const UnitVTable path_vtable = {
775 .object_size = sizeof(Path),
786 .coldplug = path_coldplug,
793 .serialize = path_serialize,
794 .deserialize_item = path_deserialize_item,
796 .active_state = path_active_state,
797 .sub_state_to_string = path_sub_state_to_string,
799 .trigger_notify = path_trigger_notify,
801 .reset_failed = path_reset_failed,
803 .bus_interface = "org.freedesktop.systemd1.Path",
804 .bus_vtable = bus_path_vtable