/*-*- Mode: C; c-basic-offset: 8; indent-tabs-mode: nil -*-*/ /*** This file is part of systemd. Copyright 2010 Lennart Poettering systemd is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. systemd is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with systemd; If not, see <http://www.gnu.org/licenses/>. ***/ #include <sys/inotify.h> #include <sys/epoll.h> #include <sys/ioctl.h> #include <errno.h> #include <unistd.h> #include "unit.h" #include "unit-name.h" #include "path.h" #include "dbus-path.h" #include "special.h" #include "bus-errors.h" static const UnitActiveState state_translation_table[_PATH_STATE_MAX] = { [PATH_DEAD] = UNIT_INACTIVE, [PATH_WAITING] = UNIT_ACTIVE, [PATH_RUNNING] = UNIT_ACTIVE, [PATH_FAILED] = UNIT_FAILED }; static void path_init(Unit *u) { Path *p = PATH(u); assert(u); assert(u->meta.load_state == UNIT_STUB); p->directory_mode = 0755; } static void path_unwatch_one(Path *p, PathSpec *s) { if (s->inotify_fd < 0) return; unit_unwatch_fd(UNIT(p), &s->watch); close_nointr_nofail(s->inotify_fd); s->inotify_fd = -1; } static void path_done(Unit *u) { Path *p = PATH(u); PathSpec *s; assert(p); while ((s = p->specs)) { path_unwatch_one(p, s); LIST_REMOVE(PathSpec, spec, p->specs, s); free(s->path); free(s); } } int path_add_one_mount_link(Path *p, Mount *m) { PathSpec *s; int r; assert(p); assert(m); if (p->meta.load_state != UNIT_LOADED || m->meta.load_state != UNIT_LOADED) return 0; LIST_FOREACH(spec, s, p->specs) { if (!path_startswith(s->path, m->where)) continue; if ((r = unit_add_two_dependencies(UNIT(p), UNIT_AFTER, UNIT_REQUIRES, UNIT(m), true)) < 0) return r; } return 0; } static int path_add_mount_links(Path *p) { Meta *other; int r; assert(p); LIST_FOREACH(units_by_type, other, p->meta.manager->units_by_type[UNIT_MOUNT]) if ((r = path_add_one_mount_link(p, (Mount*) other)) < 0) return r; return 0; } static int path_verify(Path *p) { assert(p); if (p->meta.load_state != UNIT_LOADED) return 0; if (!p->specs) { log_error("%s lacks path setting. Refusing.", p->meta.id); return -EINVAL; } return 0; } static int path_add_default_dependencies(Path *p) { int r; assert(p); if (p->meta.manager->running_as == MANAGER_SYSTEM) { if ((r = unit_add_dependency_by_name(UNIT(p), UNIT_BEFORE, SPECIAL_BASIC_TARGET, NULL, true)) < 0) return r; if ((r = unit_add_two_dependencies_by_name(UNIT(p), UNIT_AFTER, UNIT_REQUIRES, SPECIAL_SYSINIT_TARGET, NULL, true)) < 0) return r; } return unit_add_two_dependencies_by_name(UNIT(p), UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true); } static int path_load(Unit *u) { Path *p = PATH(u); int r; assert(u); assert(u->meta.load_state == UNIT_STUB); if ((r = unit_load_fragment_and_dropin(u)) < 0) return r; if (u->meta.load_state == UNIT_LOADED) { if (!p->unit) if ((r = unit_load_related_unit(u, ".service", &p->unit))) return r; if ((r = unit_add_dependency(u, UNIT_BEFORE, p->unit, true)) < 0) return r; if ((r = path_add_mount_links(p)) < 0) return r; if (p->meta.default_dependencies) if ((r = path_add_default_dependencies(p)) < 0) return r; } return path_verify(p); } static void path_dump(Unit *u, FILE *f, const char *prefix) { Path *p = PATH(u); PathSpec *s; assert(p); assert(f); fprintf(f, "%sPath State: %s\n" "%sUnit: %s\n" "%sMakeDirectory: %s\n" "%sDirectoryMode: %04o\n", prefix, path_state_to_string(p->state), prefix, p->unit->meta.id, prefix, yes_no(p->make_directory), prefix, p->directory_mode); LIST_FOREACH(spec, s, p->specs) fprintf(f, "%s%s: %s\n", prefix, path_type_to_string(s->type), s->path); } static int path_watch_one(Path *p, PathSpec *s) { static const int flags_table[_PATH_TYPE_MAX] = { [PATH_EXISTS] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB, [PATH_EXISTS_GLOB] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB, [PATH_CHANGED] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CLOSE_WRITE|IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO, [PATH_DIRECTORY_NOT_EMPTY] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CREATE|IN_MOVED_TO }; bool exists = false; char *k, *slash; int r; assert(p); assert(s); path_unwatch_one(p, s); if (!(k = strdup(s->path))) return -ENOMEM; if ((s->inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC)) < 0) { r = -errno; goto fail; } if (unit_watch_fd(UNIT(p), s->inotify_fd, EPOLLIN, &s->watch) < 0) { r = -errno; goto fail; } if ((s->primary_wd = inotify_add_watch(s->inotify_fd, k, flags_table[s->type])) >= 0) exists = true; do { int flags; /* This assumes the path was passed through path_kill_slashes()! */ if (!(slash = strrchr(k, '/'))) break; /* Trim the path at the last slash. Keep the slash if it's the root dir. */ slash[slash == k] = 0; flags = IN_MOVE_SELF; if (!exists) flags |= IN_DELETE_SELF | IN_ATTRIB | IN_CREATE | IN_MOVED_TO; if (inotify_add_watch(s->inotify_fd, k, flags) >= 0) exists = true; } while (slash != k); return 0; fail: free(k); path_unwatch_one(p, s); return r; } static void path_unwatch(Path *p) { PathSpec *s; assert(p); LIST_FOREACH(spec, s, p->specs) path_unwatch_one(p, s); } static int path_watch(Path *p) { int r; PathSpec *s; assert(p); LIST_FOREACH(spec, s, p->specs) if ((r = path_watch_one(p, s)) < 0) return r; return 0; } static void path_set_state(Path *p, PathState state) { PathState old_state; assert(p); old_state = p->state; p->state = state; if (state != PATH_WAITING && (state != PATH_RUNNING || p->inotify_triggered)) path_unwatch(p); if (state != old_state) log_debug("%s changed %s -> %s", p->meta.id, path_state_to_string(old_state), path_state_to_string(state)); unit_notify(UNIT(p), state_translation_table[old_state], state_translation_table[state], true); } static void path_enter_waiting(Path *p, bool initial, bool recheck); static int path_coldplug(Unit *u) { Path *p = PATH(u); assert(p); assert(p->state == PATH_DEAD); if (p->deserialized_state != p->state) { if (p->deserialized_state == PATH_WAITING || p->deserialized_state == PATH_RUNNING) path_enter_waiting(p, true, true); else path_set_state(p, p->deserialized_state); } return 0; } static void path_enter_dead(Path *p, bool success) { assert(p); if (!success) p->failure = true; path_set_state(p, p->failure ? PATH_FAILED : PATH_DEAD); } static void path_enter_running(Path *p) { int r; DBusError error; assert(p); dbus_error_init(&error); /* Don't start job if we are supposed to go down */ if (p->meta.job && p->meta.job->type == JOB_STOP) return; if ((r = manager_add_job(p->meta.manager, JOB_START, p->unit, JOB_REPLACE, true, &error, NULL)) < 0) goto fail; p->inotify_triggered = false; if ((r = path_watch(p)) < 0) goto fail; path_set_state(p, PATH_RUNNING); return; fail: log_warning("%s failed to queue unit startup job: %s", p->meta.id, bus_error(&error, r)); path_enter_dead(p, false); dbus_error_free(&error); } static bool path_check_good(Path *p, bool initial) { PathSpec *s; bool good = false; assert(p); LIST_FOREACH(spec, s, p->specs) { switch (s->type) { case PATH_EXISTS: good = access(s->path, F_OK) >= 0; break; case PATH_EXISTS_GLOB: good = glob_exists(s->path) > 0; break; case PATH_DIRECTORY_NOT_EMPTY: { int k; k = dir_is_empty(s->path); good = !(k == -ENOENT || k > 0); break; } case PATH_CHANGED: { bool b; b = access(s->path, F_OK) >= 0; good = !initial && b != s->previous_exists; s->previous_exists = b; break; } default: ; } if (good) break; } return good; } static void path_enter_waiting(Path *p, bool initial, bool recheck) { int r; if (recheck) if (path_check_good(p, initial)) { log_debug("%s got triggered.", p->meta.id); path_enter_running(p); return; } if ((r = path_watch(p)) < 0) goto fail; /* Hmm, so now we have created inotify watches, but the file * might have appeared/been removed by now, so we must * recheck */ if (recheck) if (path_check_good(p, false)) { log_debug("%s got triggered.", p->meta.id); path_enter_running(p); return; } path_set_state(p, PATH_WAITING); return; fail: log_warning("%s failed to enter waiting state: %s", p->meta.id, strerror(-r)); path_enter_dead(p, false); } static void path_mkdir(Path *p) { PathSpec *s; assert(p); if (!p->make_directory) return; LIST_FOREACH(spec, s, p->specs) { int r; if (s->type == PATH_EXISTS || s->type == PATH_EXISTS_GLOB) continue; if ((r = mkdir_p(s->path, p->directory_mode)) < 0) log_warning("mkdir(%s) failed: %s", s->path, strerror(-r)); } } static int path_start(Unit *u) { Path *p = PATH(u); assert(p); assert(p->state == PATH_DEAD || p->state == PATH_FAILED); if (p->unit->meta.load_state != UNIT_LOADED) return -ENOENT; path_mkdir(p); p->failure = false; path_enter_waiting(p, true, true); return 0; } static int path_stop(Unit *u) { Path *p = PATH(u); assert(p); assert(p->state == PATH_WAITING || p->state == PATH_RUNNING); path_enter_dead(p, true); return 0; } static int path_serialize(Unit *u, FILE *f, FDSet *fds) { Path *p = PATH(u); assert(u); assert(f); assert(fds); unit_serialize_item(u, f, "state", path_state_to_string(p->state)); return 0; } static int path_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) { Path *p = PATH(u); assert(u); assert(key); assert(value); assert(fds); if (streq(key, "state")) { PathState state; if ((state = path_state_from_string(value)) < 0) log_debug("Failed to parse state value %s", value); else p->deserialized_state = state; } else log_debug("Unknown serialization key '%s'", key); return 0; } static UnitActiveState path_active_state(Unit *u) { assert(u); return state_translation_table[PATH(u)->state]; } static const char *path_sub_state_to_string(Unit *u) { assert(u); return path_state_to_string(PATH(u)->state); } static void path_fd_event(Unit *u, int fd, uint32_t events, Watch *w) { Path *p = PATH(u); int l; ssize_t k; uint8_t *buf = NULL; struct inotify_event *e; PathSpec *s; bool changed; assert(p); assert(fd >= 0); if (p->state != PATH_WAITING && p->state != PATH_RUNNING) return; /* log_debug("inotify wakeup on %s.", u->meta.id); */ if (events != EPOLLIN) { log_error("Got Invalid poll event on inotify."); goto fail; } LIST_FOREACH(spec, s, p->specs) if (s->inotify_fd == fd) break; if (!s) { log_error("Got event on unknown fd."); goto fail; } if (ioctl(fd, FIONREAD, &l) < 0) { log_error("FIONREAD failed: %s", strerror(errno)); goto fail; } assert(l > 0); if (!(buf = malloc(l))) { log_error("Failed to allocate buffer: %s", strerror(-ENOMEM)); goto fail; } if ((k = read(fd, buf, l)) < 0) { log_error("Failed to read inotify event: %s", strerror(-errno)); goto fail; } /* If we are already running, then remember that one event was * dispatched so that we restart the service only if something * actually changed on disk */ p->inotify_triggered = true; e = (struct inotify_event*) buf; changed = false; while (k > 0) { size_t step; if (s->type == PATH_CHANGED && s->primary_wd == e->wd) changed = true; step = sizeof(struct inotify_event) + e->len; assert(step <= (size_t) k); e = (struct inotify_event*) ((uint8_t*) e + step); k -= step; } if (changed) path_enter_running(p); else path_enter_waiting(p, false, true); free(buf); return; fail: free(buf); path_enter_dead(p, false); } void path_unit_notify(Unit *u, UnitActiveState new_state) { char *n; int r; Iterator i; if (u->meta.type == UNIT_PATH) return; SET_FOREACH(n, u->meta.names, i) { char *k; Unit *t; Path *p; if (!(k = unit_name_change_suffix(n, ".path"))) { r = -ENOMEM; goto fail; } t = manager_get_unit(u->meta.manager, k); free(k); if (!t) continue; if (t->meta.load_state != UNIT_LOADED) continue; p = PATH(t); if (p->unit != u) continue; if (p->state == PATH_RUNNING && new_state == UNIT_INACTIVE) { log_debug("%s got notified about unit deactivation.", p->meta.id); /* Hmm, so inotify was triggered since the * last activation, so I guess we need to * recheck what is going on. */ path_enter_waiting(p, false, p->inotify_triggered); } } return; fail: log_error("Failed find path unit: %s", strerror(-r)); } static void path_reset_failed(Unit *u) { Path *p = PATH(u); assert(p); if (p->state == PATH_FAILED) path_set_state(p, PATH_DEAD); p->failure = false; } static const char* const path_state_table[_PATH_STATE_MAX] = { [PATH_DEAD] = "dead", [PATH_WAITING] = "waiting", [PATH_RUNNING] = "running", [PATH_FAILED] = "failed" }; DEFINE_STRING_TABLE_LOOKUP(path_state, PathState); static const char* const path_type_table[_PATH_TYPE_MAX] = { [PATH_EXISTS] = "PathExists", [PATH_EXISTS_GLOB] = "PathExistsGlob", [PATH_CHANGED] = "PathChanged", [PATH_DIRECTORY_NOT_EMPTY] = "DirectoryNotEmpty" }; DEFINE_STRING_TABLE_LOOKUP(path_type, PathType); const UnitVTable path_vtable = { .suffix = ".path", .init = path_init, .done = path_done, .load = path_load, .coldplug = path_coldplug, .dump = path_dump, .start = path_start, .stop = path_stop, .serialize = path_serialize, .deserialize_item = path_deserialize_item, .active_state = path_active_state, .sub_state_to_string = path_sub_state_to_string, .fd_event = path_fd_event, .reset_failed = path_reset_failed, .bus_interface = "org.freedesktop.systemd1.Path", .bus_message_handler = bus_path_message_handler };