a40eb73224
In order to simplify writing of unit files introduce default dependencies that are added to all units unless explictly disabled in a unit. This option can be switched off for select units that are involved in early boot-up ot late system shutdown, This should simplify service files for most normal daemons, but breaks existing service files for software involved in early boot (notably udev), which need to be updated for a DefaultDependencies=no setting)
582 lines
15 KiB
C
582 lines
15 KiB
C
/*-*- Mode: C; c-basic-offset: 8 -*-*/
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/***
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This file is part of systemd.
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Copyright 2010 Lennart Poettering
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systemd is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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systemd is distributed in the hope that it will be useful, but
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WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with systemd; If not, see <http://www.gnu.org/licenses/>.
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***/
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#include <sys/inotify.h>
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#include <sys/epoll.h>
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#include <sys/ioctl.h>
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#include <errno.h>
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#include <unistd.h>
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#include "unit.h"
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#include "unit-name.h"
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#include "path.h"
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#include "dbus-path.h"
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#include "special.h"
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static const UnitActiveState state_translation_table[_PATH_STATE_MAX] = {
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[PATH_DEAD] = UNIT_INACTIVE,
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[PATH_WAITING] = UNIT_ACTIVE,
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[PATH_RUNNING] = UNIT_ACTIVE,
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[PATH_MAINTENANCE] = UNIT_MAINTENANCE
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};
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static void path_done(Unit *u) {
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Path *p = PATH(u);
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PathSpec *s;
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assert(p);
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while ((s = p->specs)) {
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LIST_REMOVE(PathSpec, spec, p->specs, s);
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free(s);
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}
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}
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int path_add_one_mount_link(Path *p, Mount *m) {
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PathSpec *s;
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int r;
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assert(p);
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assert(m);
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if (p->meta.load_state != UNIT_LOADED ||
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m->meta.load_state != UNIT_LOADED)
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return 0;
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LIST_FOREACH(spec, s, p->specs) {
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if (!path_startswith(s->path, m->where))
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continue;
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if ((r = unit_add_two_dependencies(UNIT(p), UNIT_AFTER, UNIT_REQUIRES, UNIT(m), true)) < 0)
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return r;
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}
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return 0;
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}
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static int path_add_mount_links(Path *p) {
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Meta *other;
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int r;
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assert(p);
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LIST_FOREACH(units_per_type, other, p->meta.manager->units_per_type[UNIT_MOUNT])
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if ((r = path_add_one_mount_link(p, (Mount*) other)) < 0)
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return r;
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return 0;
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}
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static int path_verify(Path *p) {
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assert(p);
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if (p->meta.load_state != UNIT_LOADED)
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return 0;
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if (!p->specs) {
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log_error("%s lacks path setting. Refusing.", p->meta.id);
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return -EINVAL;
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}
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return 0;
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}
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static int path_load(Unit *u) {
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Path *p = PATH(u);
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int r;
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assert(u);
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assert(u->meta.load_state == UNIT_STUB);
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if ((r = unit_load_fragment_and_dropin(u)) < 0)
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return r;
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if (u->meta.load_state == UNIT_LOADED) {
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if (!p->unit)
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if ((r = unit_load_related_unit(u, ".service", &p->unit)))
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return r;
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if ((r = unit_add_dependency(u, UNIT_BEFORE, p->unit, true)) < 0)
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return r;
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if ((r = path_add_mount_links(p)) < 0)
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return r;
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/* Path units shouldn't stay around on shutdown */
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if (p->meta.default_dependencies)
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if ((r = unit_add_two_dependencies_by_name(u, UNIT_BEFORE, UNIT_CONFLICTS, SPECIAL_SHUTDOWN_TARGET, NULL, true)) < 0)
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return r;
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}
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return path_verify(p);
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}
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static void path_dump(Unit *u, FILE *f, const char *prefix) {
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Path *p = PATH(u);
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const char *prefix2;
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char *p2;
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PathSpec *s;
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p2 = strappend(prefix, "\t");
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prefix2 = p2 ? p2 : prefix;
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fprintf(f,
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"%sPath State: %s\n"
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"%sUnit: %s\n",
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prefix, path_state_to_string(p->state),
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prefix, p->unit->meta.id);
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LIST_FOREACH(spec, s, p->specs)
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fprintf(f,
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"%s%s: %s\n",
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prefix,
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path_type_to_string(s->type),
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s->path);
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free(p2);
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}
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static void path_unwatch_one(Path *p, PathSpec *s) {
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if (s->inotify_fd < 0)
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return;
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unit_unwatch_fd(UNIT(p), &s->watch);
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close_nointr_nofail(s->inotify_fd);
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s->inotify_fd = -1;
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}
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static int path_watch_one(Path *p, PathSpec *s) {
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static const int flags_table[_PATH_TYPE_MAX] = {
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[PATH_EXISTS] = IN_DELETE_SELF|IN_MOVE_SELF,
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[PATH_CHANGED] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CLOSE_WRITE|IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO,
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[PATH_DIRECTORY_NOT_EMPTY] = IN_DELETE_SELF|IN_MOVE_SELF|IN_CREATE|IN_MOVED_TO
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};
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bool exists = false;
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char *k;
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int r;
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assert(p);
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assert(s);
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path_unwatch_one(p, s);
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if (!(k = strdup(s->path)))
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return -ENOMEM;
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if ((s->inotify_fd = inotify_init1(IN_NONBLOCK|IN_CLOEXEC)) < 0) {
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r = -errno;
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goto fail;
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}
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if (unit_watch_fd(UNIT(p), s->inotify_fd, EPOLLIN, &s->watch) < 0) {
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r = -errno;
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goto fail;
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}
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if ((s->primary_wd = inotify_add_watch(s->inotify_fd, k, flags_table[s->type])) >= 0)
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exists = true;
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for (;;) {
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int flags;
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char *slash;
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/* This assumes the path was passed through path_kill_slashes()! */
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if (!(slash = strrchr(k, '/')))
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break;
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*slash = 0;
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flags = IN_DELETE_SELF|IN_MOVE_SELF;
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if (!exists)
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flags |= IN_CREATE | IN_MOVED_TO | IN_ATTRIB;
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if (inotify_add_watch(s->inotify_fd, k, flags) >= 0)
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exists = true;
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}
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return 0;
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fail:
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free(k);
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path_unwatch_one(p, s);
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return r;
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}
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static void path_unwatch(Path *p) {
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PathSpec *s;
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assert(p);
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LIST_FOREACH(spec, s, p->specs)
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path_unwatch_one(p, s);
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}
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static int path_watch(Path *p) {
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int r;
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PathSpec *s;
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assert(p);
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LIST_FOREACH(spec, s, p->specs)
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if ((r = path_watch_one(p, s)) < 0)
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return r;
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return 0;
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}
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static void path_set_state(Path *p, PathState state) {
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PathState old_state;
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assert(p);
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old_state = p->state;
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p->state = state;
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if (state != PATH_WAITING)
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path_unwatch(p);
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if (state != old_state)
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log_debug("%s changed %s -> %s",
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p->meta.id,
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path_state_to_string(old_state),
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path_state_to_string(state));
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unit_notify(UNIT(p), state_translation_table[old_state], state_translation_table[state]);
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}
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static void path_enter_waiting(Path *p, bool initial);
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static int path_coldplug(Unit *u) {
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Path *p = PATH(u);
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assert(p);
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assert(p->state == PATH_DEAD);
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if (p->deserialized_state != p->state) {
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if (p->deserialized_state == PATH_WAITING ||
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p->deserialized_state == PATH_RUNNING)
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path_enter_waiting(p, true);
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else
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path_set_state(p, p->deserialized_state);
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}
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return 0;
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}
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static void path_enter_dead(Path *p, bool success) {
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assert(p);
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if (!success)
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p->failure = true;
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path_set_state(p, p->failure ? PATH_MAINTENANCE : PATH_DEAD);
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}
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static void path_enter_running(Path *p) {
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int r;
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assert(p);
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if ((r = manager_add_job(p->meta.manager, JOB_START, p->unit, JOB_REPLACE, true, NULL)) < 0)
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goto fail;
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path_set_state(p, PATH_RUNNING);
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return;
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fail:
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log_warning("%s failed to queue unit startup job: %s", p->meta.id, strerror(-r));
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path_enter_dead(p, false);
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}
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static void path_enter_waiting(Path *p, bool initial) {
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PathSpec *s;
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int r;
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bool good = false;
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LIST_FOREACH(spec, s, p->specs) {
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|
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switch (s->type) {
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|
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case PATH_EXISTS:
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good = access(s->path, F_OK) >= 0;
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break;
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|
|
case PATH_DIRECTORY_NOT_EMPTY:
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good = dir_is_empty(s->path) == 0;
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break;
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|
|
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case PATH_CHANGED: {
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bool b;
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b = access(s->path, F_OK) >= 0;
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good = !initial && b != s->previous_exists;
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s->previous_exists = b;
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break;
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|
}
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|
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default:
|
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;
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}
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|
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if (good)
|
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break;
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}
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|
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if (good) {
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path_enter_running(p);
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return;
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}
|
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|
|
if ((r = path_watch(p)) < 0)
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goto fail;
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|
|
|
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);
|
|
}
|
|
|
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static int path_start(Unit *u) {
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Path *p = PATH(u);
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|
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assert(p);
|
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assert(p->state == PATH_DEAD || p->state == PATH_MAINTENANCE);
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|
|
if (p->unit->meta.load_state != UNIT_LOADED)
|
|
return -ENOENT;
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|
|
p->failure = false;
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path_enter_waiting(p, true);
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return 0;
|
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}
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|
|
static int path_stop(Unit *u) {
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Path *p = PATH(u);
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|
|
assert(p);
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assert(p->state == PATH_WAITING || p->state == PATH_RUNNING);
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|
|
path_enter_dead(p, true);
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|
return 0;
|
|
}
|
|
|
|
static int path_serialize(Unit *u, FILE *f, FDSet *fds) {
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|
Path *p = PATH(u);
|
|
|
|
assert(u);
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|
assert(f);
|
|
assert(fds);
|
|
|
|
unit_serialize_item(u, f, "state", path_state_to_string(p->state));
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|
|
|
return 0;
|
|
}
|
|
|
|
static int path_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
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|
Path *p = PATH(u);
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|
|
|
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);
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|
|
|
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;
|
|
struct inotify_event *buf = NULL;
|
|
PathSpec *s;
|
|
|
|
assert(p);
|
|
assert(fd >= 0);
|
|
|
|
if (p->state != PATH_WAITING)
|
|
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;
|
|
}
|
|
|
|
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 ((size_t) k < sizeof(struct inotify_event) ||
|
|
(size_t) k < sizeof(struct inotify_event) + buf->len) {
|
|
log_error("inotify event too small.");
|
|
goto fail;
|
|
}
|
|
|
|
if (s->type == PATH_CHANGED && s->primary_wd == buf->wd)
|
|
path_enter_running(p);
|
|
else
|
|
path_enter_waiting(p, false);
|
|
|
|
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);
|
|
path_enter_waiting(p, false);
|
|
}
|
|
}
|
|
|
|
return;
|
|
|
|
fail:
|
|
log_error("Failed find path unit: %s", strerror(-r));
|
|
}
|
|
|
|
static const char* const path_state_table[_PATH_STATE_MAX] = {
|
|
[PATH_DEAD] = "dead",
|
|
[PATH_WAITING] = "waiting",
|
|
[PATH_RUNNING] = "running",
|
|
[PATH_MAINTENANCE] = "maintenance"
|
|
};
|
|
|
|
DEFINE_STRING_TABLE_LOOKUP(path_state, PathState);
|
|
|
|
static const char* const path_type_table[_PATH_TYPE_MAX] = {
|
|
[PATH_EXISTS] = "PathExists",
|
|
[PATH_CHANGED] = "PathChanged",
|
|
[PATH_DIRECTORY_NOT_EMPTY] = "DirectoryNotEmpty"
|
|
};
|
|
|
|
DEFINE_STRING_TABLE_LOOKUP(path_type, PathType);
|
|
|
|
const UnitVTable path_vtable = {
|
|
.suffix = ".path",
|
|
|
|
.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,
|
|
|
|
.bus_message_handler = bus_path_message_handler
|
|
};
|