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 General Public License as published by
10 the Free Software Foundation; either version 2 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 General Public License for more details.
18 You should have received a copy of the GNU 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 "bus-errors.h"
36 static const UnitActiveState state_translation_table[_PATH_STATE_MAX] = {
37 [PATH_DEAD] = UNIT_INACTIVE,
38 [PATH_WAITING] = UNIT_ACTIVE,
39 [PATH_RUNNING] = UNIT_ACTIVE,
40 [PATH_FAILED] = UNIT_FAILED
43 int path_spec_watch(PathSpec *s, Unit *u) {
45 static const int flags_table[_PATH_TYPE_MAX] = {
46 [PATH_EXISTS] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB,
47 [PATH_EXISTS_GLOB] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB,
48 [PATH_CHANGED] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CLOSE_WRITE|IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO,
49 [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,
50 [PATH_DIRECTORY_NOT_EMPTY] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CREATE|IN_MOVED_TO
60 path_spec_unwatch(s, u);
62 if (!(k = strdup(s->path)))
65 if ((s->inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC)) < 0) {
70 if (unit_watch_fd(u, s->inotify_fd, EPOLLIN, &s->watch) < 0) {
75 if ((s->primary_wd = inotify_add_watch(s->inotify_fd, k, flags_table[s->type])) >= 0)
81 /* This assumes the path was passed through path_kill_slashes()! */
82 if (!(slash = strrchr(k, '/')))
85 /* Trim the path at the last slash. Keep the slash if it's the root dir. */
86 slash[slash == k] = 0;
90 flags |= IN_DELETE_SELF | IN_ATTRIB | IN_CREATE | IN_MOVED_TO;
92 if (inotify_add_watch(s->inotify_fd, k, flags) >= 0)
101 path_spec_unwatch(s, u);
105 void path_spec_unwatch(PathSpec *s, Unit *u) {
107 if (s->inotify_fd < 0)
110 unit_unwatch_fd(u, &s->watch);
112 close_nointr_nofail(s->inotify_fd);
116 int path_spec_fd_event(PathSpec *s, uint32_t events) {
118 struct inotify_event *e;
123 if (events != EPOLLIN) {
124 log_error("Got Invalid poll event on inotify.");
129 if (ioctl(s->inotify_fd, FIONREAD, &l) < 0) {
130 log_error("FIONREAD failed: %m");
137 if (!(buf = malloc(l))) {
138 log_error("Failed to allocate buffer: %m");
143 if ((k = read(s->inotify_fd, buf, l)) < 0) {
144 log_error("Failed to read inotify event: %m");
149 e = (struct inotify_event*) buf;
154 if ((s->type == PATH_CHANGED || s->type == PATH_MODIFIED) &&
155 s->primary_wd == e->wd)
158 step = sizeof(struct inotify_event) + e->len;
159 assert(step <= (size_t) k);
161 e = (struct inotify_event*) ((uint8_t*) e + step);
169 static bool path_spec_check_good(PathSpec *s, bool initial) {
175 good = access(s->path, F_OK) >= 0;
178 case PATH_EXISTS_GLOB:
179 good = glob_exists(s->path) > 0;
182 case PATH_DIRECTORY_NOT_EMPTY: {
185 k = dir_is_empty(s->path);
186 good = !(k == -ENOENT || k > 0);
191 case PATH_MODIFIED: {
194 b = access(s->path, F_OK) >= 0;
195 good = !initial && b != s->previous_exists;
196 s->previous_exists = b;
207 static bool path_spec_startswith(PathSpec *s, const char *what) {
208 return path_startswith(s->path, what);
211 static void path_spec_mkdir(PathSpec *s, mode_t mode) {
214 if (s->type == PATH_EXISTS || s->type == PATH_EXISTS_GLOB)
217 if ((r = mkdir_p(s->path, mode)) < 0)
218 log_warning("mkdir(%s) failed: %s", s->path, strerror(-r));
221 static void path_spec_dump(PathSpec *s, FILE *f, const char *prefix) {
225 path_type_to_string(s->type),
229 void path_spec_done(PathSpec *s) {
231 assert(s->inotify_fd == -1);
236 static void path_init(Unit *u) {
240 assert(u->load_state == UNIT_STUB);
242 p->directory_mode = 0755;
245 static void path_done(Unit *u) {
251 unit_ref_unset(&p->unit);
253 while ((s = p->specs)) {
254 path_spec_unwatch(s, u);
255 LIST_REMOVE(PathSpec, spec, p->specs, s);
261 int path_add_one_mount_link(Path *p, Mount *m) {
268 if (UNIT(p)->load_state != UNIT_LOADED ||
269 UNIT(m)->load_state != UNIT_LOADED)
272 LIST_FOREACH(spec, s, p->specs) {
274 if (!path_spec_startswith(s, m->where))
277 if ((r = unit_add_two_dependencies(UNIT(p), UNIT_AFTER, UNIT_REQUIRES, UNIT(m), true)) < 0)
284 static int path_add_mount_links(Path *p) {
290 LIST_FOREACH(units_by_type, other, UNIT(p)->manager->units_by_type[UNIT_MOUNT])
291 if ((r = path_add_one_mount_link(p, MOUNT(other))) < 0)
297 static int path_verify(Path *p) {
300 if (UNIT(p)->load_state != UNIT_LOADED)
304 log_error("%s lacks path setting. Refusing.", UNIT(p)->id);
311 static int path_add_default_dependencies(Path *p) {
316 if (UNIT(p)->manager->running_as == MANAGER_SYSTEM) {
317 if ((r = unit_add_dependency_by_name(UNIT(p), UNIT_BEFORE, SPECIAL_BASIC_TARGET, NULL, true)) < 0)
320 if ((r = unit_add_two_dependencies_by_name(UNIT(p), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true)) < 0)
324 return unit_add_two_dependencies_by_name(UNIT(p), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true);
327 static int path_load(Unit *u) {
332 assert(u->load_state == UNIT_STUB);
334 if ((r = unit_load_fragment_and_dropin(u)) < 0)
337 if (u->load_state == UNIT_LOADED) {
339 if (!UNIT_DEREF(p->unit)) {
342 r = unit_load_related_unit(u, ".service", &x);
346 unit_ref_set(&p->unit, x);
349 r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, UNIT_DEREF(p->unit), true);
353 if ((r = path_add_mount_links(p)) < 0)
356 if (UNIT(p)->default_dependencies)
357 if ((r = path_add_default_dependencies(p)) < 0)
361 return path_verify(p);
364 static void path_dump(Unit *u, FILE *f, const char *prefix) {
375 "%sMakeDirectory: %s\n"
376 "%sDirectoryMode: %04o\n",
377 prefix, path_state_to_string(p->state),
378 prefix, path_result_to_string(p->result),
379 prefix, UNIT_DEREF(p->unit)->id,
380 prefix, yes_no(p->make_directory),
381 prefix, p->directory_mode);
383 LIST_FOREACH(spec, s, p->specs)
384 path_spec_dump(s, f, prefix);
387 static void path_unwatch(Path *p) {
392 LIST_FOREACH(spec, s, p->specs)
393 path_spec_unwatch(s, UNIT(p));
396 static int path_watch(Path *p) {
402 LIST_FOREACH(spec, s, p->specs)
403 if ((r = path_spec_watch(s, UNIT(p))) < 0)
409 static void path_set_state(Path *p, PathState state) {
413 old_state = p->state;
416 if (state != PATH_WAITING &&
417 (state != PATH_RUNNING || p->inotify_triggered))
420 if (state != old_state)
421 log_debug("%s changed %s -> %s",
423 path_state_to_string(old_state),
424 path_state_to_string(state));
426 unit_notify(UNIT(p), state_translation_table[old_state], state_translation_table[state], true);
429 static void path_enter_waiting(Path *p, bool initial, bool recheck);
431 static int path_coldplug(Unit *u) {
435 assert(p->state == PATH_DEAD);
437 if (p->deserialized_state != p->state) {
439 if (p->deserialized_state == PATH_WAITING ||
440 p->deserialized_state == PATH_RUNNING)
441 path_enter_waiting(p, true, true);
443 path_set_state(p, p->deserialized_state);
449 static void path_enter_dead(Path *p, PathResult f) {
452 if (f != PATH_SUCCESS)
455 path_set_state(p, p->result != PATH_SUCCESS ? PATH_FAILED : PATH_DEAD);
458 static void path_enter_running(Path *p) {
463 dbus_error_init(&error);
465 /* Don't start job if we are supposed to go down */
466 if (UNIT(p)->job && UNIT(p)->job->type == JOB_STOP)
469 if ((r = manager_add_job(UNIT(p)->manager, JOB_START, UNIT_DEREF(p->unit), JOB_REPLACE, true, &error, NULL)) < 0)
472 p->inotify_triggered = false;
474 if ((r = path_watch(p)) < 0)
477 path_set_state(p, PATH_RUNNING);
481 log_warning("%s failed to queue unit startup job: %s", UNIT(p)->id, bus_error(&error, r));
482 path_enter_dead(p, PATH_FAILURE_RESOURCES);
484 dbus_error_free(&error);
487 static bool path_check_good(Path *p, bool initial) {
493 LIST_FOREACH(spec, s, p->specs) {
494 good = path_spec_check_good(s, initial);
503 static void path_enter_waiting(Path *p, bool initial, bool recheck) {
507 if (path_check_good(p, initial)) {
508 log_debug("%s got triggered.", UNIT(p)->id);
509 path_enter_running(p);
513 if ((r = path_watch(p)) < 0)
516 /* Hmm, so now we have created inotify watches, but the file
517 * might have appeared/been removed by now, so we must
521 if (path_check_good(p, false)) {
522 log_debug("%s got triggered.", UNIT(p)->id);
523 path_enter_running(p);
527 path_set_state(p, PATH_WAITING);
531 log_warning("%s failed to enter waiting state: %s", UNIT(p)->id, strerror(-r));
532 path_enter_dead(p, PATH_FAILURE_RESOURCES);
535 static void path_mkdir(Path *p) {
540 if (!p->make_directory)
543 LIST_FOREACH(spec, s, p->specs)
544 path_spec_mkdir(s, p->directory_mode);
547 static int path_start(Unit *u) {
551 assert(p->state == PATH_DEAD || p->state == PATH_FAILED);
553 if (UNIT_DEREF(p->unit)->load_state != UNIT_LOADED)
558 p->result = PATH_SUCCESS;
559 path_enter_waiting(p, true, true);
564 static int path_stop(Unit *u) {
568 assert(p->state == PATH_WAITING || p->state == PATH_RUNNING);
570 path_enter_dead(p, PATH_SUCCESS);
574 static int path_serialize(Unit *u, FILE *f, FDSet *fds) {
581 unit_serialize_item(u, f, "state", path_state_to_string(p->state));
582 unit_serialize_item(u, f, "result", path_result_to_string(p->result));
587 static int path_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
595 if (streq(key, "state")) {
598 if ((state = path_state_from_string(value)) < 0)
599 log_debug("Failed to parse state value %s", value);
601 p->deserialized_state = state;
603 } else if (streq(key, "result")) {
606 f = path_result_from_string(value);
608 log_debug("Failed to parse result value %s", value);
609 else if (f != PATH_SUCCESS)
613 log_debug("Unknown serialization key '%s'", key);
618 static UnitActiveState path_active_state(Unit *u) {
621 return state_translation_table[PATH(u)->state];
624 static const char *path_sub_state_to_string(Unit *u) {
627 return path_state_to_string(PATH(u)->state);
630 static void path_fd_event(Unit *u, int fd, uint32_t events, Watch *w) {
638 if (p->state != PATH_WAITING &&
639 p->state != PATH_RUNNING)
642 /* log_debug("inotify wakeup on %s.", u->id); */
644 LIST_FOREACH(spec, s, p->specs)
645 if (path_spec_owns_inotify_fd(s, fd))
649 log_error("Got event on unknown fd.");
653 changed = path_spec_fd_event(s, events);
657 /* If we are already running, then remember that one event was
658 * dispatched so that we restart the service only if something
659 * actually changed on disk */
660 p->inotify_triggered = true;
663 path_enter_running(p);
665 path_enter_waiting(p, false, true);
670 path_enter_dead(p, PATH_FAILURE_RESOURCES);
673 void path_unit_notify(Unit *u, UnitActiveState new_state) {
677 if (u->type == UNIT_PATH)
680 SET_FOREACH(k, u->dependencies[UNIT_TRIGGERED_BY], i) {
683 if (k->type != UNIT_PATH)
686 if (k->load_state != UNIT_LOADED)
691 if (p->state == PATH_RUNNING && new_state == UNIT_INACTIVE) {
692 log_debug("%s got notified about unit deactivation.", UNIT(p)->id);
694 /* Hmm, so inotify was triggered since the
695 * last activation, so I guess we need to
696 * recheck what is going on. */
697 path_enter_waiting(p, false, p->inotify_triggered);
702 static void path_reset_failed(Unit *u) {
707 if (p->state == PATH_FAILED)
708 path_set_state(p, PATH_DEAD);
710 p->result = PATH_SUCCESS;
713 static const char* const path_state_table[_PATH_STATE_MAX] = {
714 [PATH_DEAD] = "dead",
715 [PATH_WAITING] = "waiting",
716 [PATH_RUNNING] = "running",
717 [PATH_FAILED] = "failed"
720 DEFINE_STRING_TABLE_LOOKUP(path_state, PathState);
722 static const char* const path_type_table[_PATH_TYPE_MAX] = {
723 [PATH_EXISTS] = "PathExists",
724 [PATH_EXISTS_GLOB] = "PathExistsGlob",
725 [PATH_CHANGED] = "PathChanged",
726 [PATH_MODIFIED] = "PathModified",
727 [PATH_DIRECTORY_NOT_EMPTY] = "DirectoryNotEmpty"
730 DEFINE_STRING_TABLE_LOOKUP(path_type, PathType);
732 static const char* const path_result_table[_PATH_RESULT_MAX] = {
733 [PATH_SUCCESS] = "success",
734 [PATH_FAILURE_RESOURCES] = "resources"
737 DEFINE_STRING_TABLE_LOOKUP(path_result, PathResult);
739 const UnitVTable path_vtable = {
741 .object_size = sizeof(Path),
751 .coldplug = path_coldplug,
758 .serialize = path_serialize,
759 .deserialize_item = path_deserialize_item,
761 .active_state = path_active_state,
762 .sub_state_to_string = path_sub_state_to_string,
764 .fd_event = path_fd_event,
766 .reset_failed = path_reset_failed,
768 .bus_interface = "org.freedesktop.systemd1.Path",
769 .bus_message_handler = bus_path_message_handler,
770 .bus_invalidating_properties = bus_path_invalidating_properties