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 "dbus-common.h"
35 #include "path-util.h"
38 static const UnitActiveState state_translation_table[_PATH_STATE_MAX] = {
39 [PATH_DEAD] = UNIT_INACTIVE,
40 [PATH_WAITING] = UNIT_ACTIVE,
41 [PATH_RUNNING] = UNIT_ACTIVE,
42 [PATH_FAILED] = UNIT_FAILED
45 int path_spec_watch(PathSpec *s, Unit *u) {
47 static const int flags_table[_PATH_TYPE_MAX] = {
48 [PATH_EXISTS] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB,
49 [PATH_EXISTS_GLOB] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB,
50 [PATH_CHANGED] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CLOSE_WRITE|IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO,
51 [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,
52 [PATH_DIRECTORY_NOT_EMPTY] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CREATE|IN_MOVED_TO
56 char *slash, *oldslash = NULL;
62 path_spec_unwatch(s, u);
64 s->inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC);
65 if (s->inotify_fd < 0) {
70 r = unit_watch_fd(u, s->inotify_fd, EPOLLIN, &s->watch);
74 /* This assumes the path was passed through path_kill_slashes()! */
76 for (slash = strchr(s->path, '/'); ; slash = strchr(slash+1, '/')) {
82 cut = slash + (slash == s->path);
86 flags = IN_MOVE_SELF | IN_DELETE_SELF | IN_ATTRIB | IN_CREATE | IN_MOVED_TO;
88 flags = flags_table[s->type];
90 r = inotify_add_watch(s->inotify_fd, s->path, flags);
92 if (errno == EACCES || errno == ENOENT) {
98 log_warning("Failed to add watch on %s: %m", s->path);
106 /* Path exists, we don't need to watch parent
109 char *cut2 = oldslash + (oldslash == s->path);
113 inotify_add_watch(s->inotify_fd, s->path, IN_MOVE_SELF);
114 /* Error is ignored, the worst can happen is
115 we get spurious events. */
127 /* whole path has been iterated over */
134 log_error("Failed to add watch on any of the components of %s: %m",
136 r = -errno; /* either EACCESS or ENOENT */
143 path_spec_unwatch(s, u);
147 void path_spec_unwatch(PathSpec *s, Unit *u) {
149 if (s->inotify_fd < 0)
152 unit_unwatch_fd(u, &s->watch);
154 close_nointr_nofail(s->inotify_fd);
158 int path_spec_fd_event(PathSpec *s, uint32_t events) {
159 _cleanup_free_ uint8_t *buf = NULL;
160 struct inotify_event *e;
165 if (events != 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 bool path_spec_startswith(PathSpec *s, const char *what) {
245 return path_startswith(s->path, what);
248 static void path_spec_mkdir(PathSpec *s, mode_t mode) {
251 if (s->type == PATH_EXISTS || s->type == PATH_EXISTS_GLOB)
254 r = mkdir_p_label(s->path, mode);
256 log_warning("mkdir(%s) failed: %s", s->path, strerror(-r));
259 static void path_spec_dump(PathSpec *s, FILE *f, const char *prefix) {
263 path_type_to_string(s->type),
267 void path_spec_done(PathSpec *s) {
269 assert(s->inotify_fd == -1);
274 static void path_init(Unit *u) {
278 assert(u->load_state == UNIT_STUB);
280 p->directory_mode = 0755;
283 void path_free_specs(Path *p) {
288 while ((s = p->specs)) {
289 path_spec_unwatch(s, UNIT(p));
290 LIST_REMOVE(PathSpec, spec, p->specs, s);
296 static void path_done(Unit *u) {
304 int path_add_one_mount_link(Path *p, Mount *m) {
311 if (UNIT(p)->load_state != UNIT_LOADED ||
312 UNIT(m)->load_state != UNIT_LOADED)
315 LIST_FOREACH(spec, s, p->specs) {
316 if (!path_spec_startswith(s, m->where))
319 r = unit_add_two_dependencies(UNIT(p), UNIT_AFTER, UNIT_REQUIRES,
328 static int path_add_mount_links(Path *p) {
334 LIST_FOREACH(units_by_type, other, UNIT(p)->manager->units_by_type[UNIT_MOUNT]) {
335 r = path_add_one_mount_link(p, MOUNT(other));
343 static int path_verify(Path *p) {
346 if (UNIT(p)->load_state != UNIT_LOADED)
350 log_error_unit(UNIT(p)->id,
351 "%s lacks path setting. Refusing.", UNIT(p)->id);
358 static int path_add_default_dependencies(Path *p) {
363 r = unit_add_dependency_by_name(UNIT(p), UNIT_BEFORE,
364 SPECIAL_PATHS_TARGET, NULL, true);
368 if (UNIT(p)->manager->running_as == SYSTEMD_SYSTEM) {
369 r = unit_add_two_dependencies_by_name(UNIT(p), UNIT_AFTER, UNIT_REQUIRES,
370 SPECIAL_SYSINIT_TARGET, NULL, true);
375 return unit_add_two_dependencies_by_name(UNIT(p), UNIT_BEFORE, UNIT_CONFLICTS,
376 SPECIAL_SHUTDOWN_TARGET, NULL, true);
379 static int path_load(Unit *u) {
384 assert(u->load_state == UNIT_STUB);
386 r = unit_load_fragment_and_dropin(u);
390 if (u->load_state == UNIT_LOADED) {
392 if (set_isempty(u->dependencies[UNIT_TRIGGERS])) {
395 r = unit_load_related_unit(u, ".service", &x);
399 r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, x, true);
404 r = path_add_mount_links(p);
408 if (UNIT(p)->default_dependencies) {
409 r = path_add_default_dependencies(p);
415 return path_verify(p);
418 static void path_dump(Unit *u, FILE *f, const char *prefix) {
426 trigger = UNIT_TRIGGER(u);
432 "%sMakeDirectory: %s\n"
433 "%sDirectoryMode: %04o\n",
434 prefix, path_state_to_string(p->state),
435 prefix, path_result_to_string(p->result),
436 prefix, trigger ? trigger->id : "n/a",
437 prefix, yes_no(p->make_directory),
438 prefix, p->directory_mode);
440 LIST_FOREACH(spec, s, p->specs)
441 path_spec_dump(s, f, prefix);
444 static void path_unwatch(Path *p) {
449 LIST_FOREACH(spec, s, p->specs)
450 path_spec_unwatch(s, UNIT(p));
453 static int path_watch(Path *p) {
459 LIST_FOREACH(spec, s, p->specs) {
460 r = path_spec_watch(s, UNIT(p));
468 static void path_set_state(Path *p, PathState state) {
472 old_state = p->state;
475 if (state != PATH_WAITING &&
476 (state != PATH_RUNNING || p->inotify_triggered))
479 if (state != old_state)
480 log_debug("%s changed %s -> %s",
482 path_state_to_string(old_state),
483 path_state_to_string(state));
485 unit_notify(UNIT(p), state_translation_table[old_state], state_translation_table[state], true);
488 static void path_enter_waiting(Path *p, bool initial, bool recheck);
490 static int path_coldplug(Unit *u) {
494 assert(p->state == PATH_DEAD);
496 if (p->deserialized_state != p->state) {
498 if (p->deserialized_state == PATH_WAITING ||
499 p->deserialized_state == PATH_RUNNING)
500 path_enter_waiting(p, true, true);
502 path_set_state(p, p->deserialized_state);
508 static void path_enter_dead(Path *p, PathResult f) {
511 if (f != PATH_SUCCESS)
514 path_set_state(p, p->result != PATH_SUCCESS ? PATH_FAILED : PATH_DEAD);
517 static void path_enter_running(Path *p) {
518 _cleanup_dbus_error_free_ DBusError error;
523 dbus_error_init(&error);
525 /* Don't start job if we are supposed to go down */
526 if (unit_stop_pending(UNIT(p)))
529 r = manager_add_job(UNIT(p)->manager, JOB_START, UNIT_TRIGGER(UNIT(p)),
530 JOB_REPLACE, true, &error, NULL);
534 p->inotify_triggered = false;
540 path_set_state(p, PATH_RUNNING);
544 log_warning("%s failed to queue unit startup job: %s",
545 UNIT(p)->id, bus_error(&error, r));
546 path_enter_dead(p, PATH_FAILURE_RESOURCES);
549 static bool path_check_good(Path *p, bool initial) {
555 LIST_FOREACH(spec, s, p->specs) {
556 good = path_spec_check_good(s, initial);
565 static void path_enter_waiting(Path *p, bool initial, bool recheck) {
569 if (path_check_good(p, initial)) {
570 log_debug("%s got triggered.", UNIT(p)->id);
571 path_enter_running(p);
579 /* Hmm, so now we have created inotify watches, but the file
580 * might have appeared/been removed by now, so we must
584 if (path_check_good(p, false)) {
585 log_debug("%s got triggered.", UNIT(p)->id);
586 path_enter_running(p);
590 path_set_state(p, PATH_WAITING);
594 log_warning("%s failed to enter waiting state: %s",
595 UNIT(p)->id, strerror(-r));
596 path_enter_dead(p, PATH_FAILURE_RESOURCES);
599 static void path_mkdir(Path *p) {
604 if (!p->make_directory)
607 LIST_FOREACH(spec, s, p->specs)
608 path_spec_mkdir(s, p->directory_mode);
611 static int path_start(Unit *u) {
615 assert(p->state == PATH_DEAD || p->state == PATH_FAILED);
617 if (UNIT_TRIGGER(u)->load_state != UNIT_LOADED)
622 p->result = PATH_SUCCESS;
623 path_enter_waiting(p, true, true);
628 static int path_stop(Unit *u) {
632 assert(p->state == PATH_WAITING || p->state == PATH_RUNNING);
634 path_enter_dead(p, PATH_SUCCESS);
638 static int path_serialize(Unit *u, FILE *f, FDSet *fds) {
645 unit_serialize_item(u, f, "state", path_state_to_string(p->state));
646 unit_serialize_item(u, f, "result", path_result_to_string(p->result));
651 static int path_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
659 if (streq(key, "state")) {
662 state = path_state_from_string(value);
664 log_debug("Failed to parse state value %s", value);
666 p->deserialized_state = state;
668 } else if (streq(key, "result")) {
671 f = path_result_from_string(value);
673 log_debug("Failed to parse result value %s", value);
674 else if (f != PATH_SUCCESS)
678 log_debug("Unknown serialization key '%s'", key);
683 _pure_ static UnitActiveState path_active_state(Unit *u) {
686 return state_translation_table[PATH(u)->state];
689 _pure_ static const char *path_sub_state_to_string(Unit *u) {
692 return path_state_to_string(PATH(u)->state);
695 static void path_fd_event(Unit *u, int fd, uint32_t events, Watch *w) {
703 if (p->state != PATH_WAITING &&
704 p->state != PATH_RUNNING)
707 /* log_debug("inotify wakeup on %s.", u->id); */
709 LIST_FOREACH(spec, s, p->specs)
710 if (path_spec_owns_inotify_fd(s, fd))
714 log_error("Got event on unknown fd.");
718 changed = path_spec_fd_event(s, events);
722 /* If we are already running, then remember that one event was
723 * dispatched so that we restart the service only if something
724 * actually changed on disk */
725 p->inotify_triggered = true;
728 path_enter_running(p);
730 path_enter_waiting(p, false, true);
735 path_enter_dead(p, PATH_FAILURE_RESOURCES);
738 static void path_trigger_notify(Unit *u, Unit *other) {
744 /* Invoked whenever the unit we trigger changes state or gains
747 if (other->load_state != UNIT_LOADED)
750 if (p->state == PATH_RUNNING &&
751 UNIT_IS_INACTIVE_OR_FAILED(unit_active_state(other))) {
752 log_debug_unit(UNIT(p)->id,
753 "%s got notified about unit deactivation.",
756 /* Hmm, so inotify was triggered since the
757 * last activation, so I guess we need to
758 * recheck what is going on. */
759 path_enter_waiting(p, false, p->inotify_triggered);
763 static void path_reset_failed(Unit *u) {
768 if (p->state == PATH_FAILED)
769 path_set_state(p, PATH_DEAD);
771 p->result = PATH_SUCCESS;
774 static const char* const path_state_table[_PATH_STATE_MAX] = {
775 [PATH_DEAD] = "dead",
776 [PATH_WAITING] = "waiting",
777 [PATH_RUNNING] = "running",
778 [PATH_FAILED] = "failed"
781 DEFINE_STRING_TABLE_LOOKUP(path_state, PathState);
783 static const char* const path_type_table[_PATH_TYPE_MAX] = {
784 [PATH_EXISTS] = "PathExists",
785 [PATH_EXISTS_GLOB] = "PathExistsGlob",
786 [PATH_CHANGED] = "PathChanged",
787 [PATH_MODIFIED] = "PathModified",
788 [PATH_DIRECTORY_NOT_EMPTY] = "DirectoryNotEmpty"
791 DEFINE_STRING_TABLE_LOOKUP(path_type, PathType);
793 static const char* const path_result_table[_PATH_RESULT_MAX] = {
794 [PATH_SUCCESS] = "success",
795 [PATH_FAILURE_RESOURCES] = "resources"
798 DEFINE_STRING_TABLE_LOOKUP(path_result, PathResult);
800 const UnitVTable path_vtable = {
801 .object_size = sizeof(Path),
811 .coldplug = path_coldplug,
818 .serialize = path_serialize,
819 .deserialize_item = path_deserialize_item,
821 .active_state = path_active_state,
822 .sub_state_to_string = path_sub_state_to_string,
824 .fd_event = path_fd_event,
826 .trigger_notify = path_trigger_notify,
828 .reset_failed = path_reset_failed,
830 .bus_interface = "org.freedesktop.systemd1.Path",
831 .bus_message_handler = bus_path_message_handler,
832 .bus_invalidating_properties = bus_path_invalidating_properties