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-rw-r--r--src/core/path.c771
1 files changed, 771 insertions, 0 deletions
diff --git a/src/core/path.c b/src/core/path.c
new file mode 100644
index 0000000000..1d50885ed4
--- /dev/null
+++ b/src/core/path.c
@@ -0,0 +1,771 @@
+/*-*- 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 "mkdir.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
+};
+
+int path_spec_watch(PathSpec *s, Unit *u) {
+
+ 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_MODIFIED] = IN_DELETE_SELF|IN_MOVE_SELF|IN_ATTRIB|IN_CLOSE_WRITE|IN_CREATE|IN_DELETE|IN_MOVED_FROM|IN_MOVED_TO|IN_MODIFY,
+ [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(u);
+ assert(s);
+
+ path_spec_unwatch(s, u);
+
+ 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(u, 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_spec_unwatch(s, u);
+ return r;
+}
+
+void path_spec_unwatch(PathSpec *s, Unit *u) {
+
+ if (s->inotify_fd < 0)
+ return;
+
+ unit_unwatch_fd(u, &s->watch);
+
+ close_nointr_nofail(s->inotify_fd);
+ s->inotify_fd = -1;
+}
+
+int path_spec_fd_event(PathSpec *s, uint32_t events) {
+ uint8_t *buf = NULL;
+ struct inotify_event *e;
+ ssize_t k;
+ int l;
+ int r = 0;
+
+ if (events != EPOLLIN) {
+ log_error("Got Invalid poll event on inotify.");
+ r = -EINVAL;
+ goto out;
+ }
+
+ if (ioctl(s->inotify_fd, FIONREAD, &l) < 0) {
+ log_error("FIONREAD failed: %m");
+ r = -errno;
+ goto out;
+ }
+
+ assert(l > 0);
+
+ if (!(buf = malloc(l))) {
+ log_error("Failed to allocate buffer: %m");
+ r = -errno;
+ goto out;
+ }
+
+ if ((k = read(s->inotify_fd, buf, l)) < 0) {
+ log_error("Failed to read inotify event: %m");
+ r = -errno;
+ goto out;
+ }
+
+ e = (struct inotify_event*) buf;
+
+ while (k > 0) {
+ size_t step;
+
+ if ((s->type == PATH_CHANGED || s->type == PATH_MODIFIED) &&
+ s->primary_wd == e->wd)
+ r = 1;
+
+ step = sizeof(struct inotify_event) + e->len;
+ assert(step <= (size_t) k);
+
+ e = (struct inotify_event*) ((uint8_t*) e + step);
+ k -= step;
+ }
+out:
+ free(buf);
+ return r;
+}
+
+static bool path_spec_check_good(PathSpec *s, bool initial) {
+ bool good = false;
+
+ 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:
+ case PATH_MODIFIED: {
+ bool b;
+
+ b = access(s->path, F_OK) >= 0;
+ good = !initial && b != s->previous_exists;
+ s->previous_exists = b;
+ break;
+ }
+
+ default:
+ ;
+ }
+
+ return good;
+}
+
+static bool path_spec_startswith(PathSpec *s, const char *what) {
+ return path_startswith(s->path, what);
+}
+
+static void path_spec_mkdir(PathSpec *s, mode_t mode) {
+ int r;
+
+ if (s->type == PATH_EXISTS || s->type == PATH_EXISTS_GLOB)
+ return;
+
+ if ((r = mkdir_p(s->path, mode)) < 0)
+ log_warning("mkdir(%s) failed: %s", s->path, strerror(-r));
+}
+
+static void path_spec_dump(PathSpec *s, FILE *f, const char *prefix) {
+ fprintf(f,
+ "%s%s: %s\n",
+ prefix,
+ path_type_to_string(s->type),
+ s->path);
+}
+
+void path_spec_done(PathSpec *s) {
+ assert(s);
+ assert(s->inotify_fd == -1);
+
+ free(s->path);
+}
+
+static void path_init(Unit *u) {
+ Path *p = PATH(u);
+
+ assert(u);
+ assert(u->load_state == UNIT_STUB);
+
+ p->directory_mode = 0755;
+}
+
+static void path_done(Unit *u) {
+ Path *p = PATH(u);
+ PathSpec *s;
+
+ assert(p);
+
+ unit_ref_unset(&p->unit);
+
+ while ((s = p->specs)) {
+ path_spec_unwatch(s, u);
+ LIST_REMOVE(PathSpec, spec, p->specs, s);
+ path_spec_done(s);
+ free(s);
+ }
+}
+
+int path_add_one_mount_link(Path *p, Mount *m) {
+ PathSpec *s;
+ int r;
+
+ assert(p);
+ assert(m);
+
+ if (UNIT(p)->load_state != UNIT_LOADED ||
+ UNIT(m)->load_state != UNIT_LOADED)
+ return 0;
+
+ LIST_FOREACH(spec, s, p->specs) {
+
+ if (!path_spec_startswith(s, 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) {
+ Unit *other;
+ int r;
+
+ assert(p);
+
+ LIST_FOREACH(units_by_type, other, UNIT(p)->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 (UNIT(p)->load_state != UNIT_LOADED)
+ return 0;
+
+ if (!p->specs) {
+ log_error("%s lacks path setting. Refusing.", UNIT(p)->id);
+ return -EINVAL;
+ }
+
+ return 0;
+}
+
+static int path_add_default_dependencies(Path *p) {
+ int r;
+
+ assert(p);
+
+ if (UNIT(p)->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->load_state == UNIT_STUB);
+
+ if ((r = unit_load_fragment_and_dropin(u)) < 0)
+ return r;
+
+ if (u->load_state == UNIT_LOADED) {
+
+ if (!UNIT_DEREF(p->unit)) {
+ Unit *x;
+
+ r = unit_load_related_unit(u, ".service", &x);
+ if (r < 0)
+ return r;
+
+ unit_ref_set(&p->unit, x);
+ }
+
+ r = unit_add_two_dependencies(u, UNIT_BEFORE, UNIT_TRIGGERS, UNIT_DEREF(p->unit), true);
+ if (r < 0)
+ return r;
+
+ if ((r = path_add_mount_links(p)) < 0)
+ return r;
+
+ if (UNIT(p)->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"
+ "%sResult: %s\n"
+ "%sUnit: %s\n"
+ "%sMakeDirectory: %s\n"
+ "%sDirectoryMode: %04o\n",
+ prefix, path_state_to_string(p->state),
+ prefix, path_result_to_string(p->result),
+ prefix, UNIT_DEREF(p->unit)->id,
+ prefix, yes_no(p->make_directory),
+ prefix, p->directory_mode);
+
+ LIST_FOREACH(spec, s, p->specs)
+ path_spec_dump(s, f, prefix);
+}
+
+static void path_unwatch(Path *p) {
+ PathSpec *s;
+
+ assert(p);
+
+ LIST_FOREACH(spec, s, p->specs)
+ path_spec_unwatch(s, UNIT(p));
+}
+
+static int path_watch(Path *p) {
+ int r;
+ PathSpec *s;
+
+ assert(p);
+
+ LIST_FOREACH(spec, s, p->specs)
+ if ((r = path_spec_watch(s, UNIT(p))) < 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",
+ UNIT(p)->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, PathResult f) {
+ assert(p);
+
+ if (f != PATH_SUCCESS)
+ p->result = f;
+
+ path_set_state(p, p->result != PATH_SUCCESS ? 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 (UNIT(p)->job && UNIT(p)->job->type == JOB_STOP)
+ return;
+
+ if ((r = manager_add_job(UNIT(p)->manager, JOB_START, UNIT_DEREF(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", UNIT(p)->id, bus_error(&error, r));
+ path_enter_dead(p, PATH_FAILURE_RESOURCES);
+
+ 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) {
+ good = path_spec_check_good(s, initial);
+
+ 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.", UNIT(p)->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.", UNIT(p)->id);
+ path_enter_running(p);
+ return;
+ }
+
+ path_set_state(p, PATH_WAITING);
+ return;
+
+fail:
+ log_warning("%s failed to enter waiting state: %s", UNIT(p)->id, strerror(-r));
+ path_enter_dead(p, PATH_FAILURE_RESOURCES);
+}
+
+static void path_mkdir(Path *p) {
+ PathSpec *s;
+
+ assert(p);
+
+ if (!p->make_directory)
+ return;
+
+ LIST_FOREACH(spec, s, p->specs)
+ path_spec_mkdir(s, p->directory_mode);
+}
+
+static int path_start(Unit *u) {
+ Path *p = PATH(u);
+
+ assert(p);
+ assert(p->state == PATH_DEAD || p->state == PATH_FAILED);
+
+ if (UNIT_DEREF(p->unit)->load_state != UNIT_LOADED)
+ return -ENOENT;
+
+ path_mkdir(p);
+
+ p->result = PATH_SUCCESS;
+ 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, PATH_SUCCESS);
+ 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));
+ unit_serialize_item(u, f, "result", path_result_to_string(p->result));
+
+ 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 if (streq(key, "result")) {
+ PathResult f;
+
+ f = path_result_from_string(value);
+ if (f < 0)
+ log_debug("Failed to parse result value %s", value);
+ else if (f != PATH_SUCCESS)
+ p->result = f;
+
+ } 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);
+ PathSpec *s;
+ int changed;
+
+ assert(p);
+ assert(fd >= 0);
+
+ if (p->state != PATH_WAITING &&
+ p->state != PATH_RUNNING)
+ return;
+
+ /* log_debug("inotify wakeup on %s.", u->id); */
+
+ LIST_FOREACH(spec, s, p->specs)
+ if (path_spec_owns_inotify_fd(s, fd))
+ break;
+
+ if (!s) {
+ log_error("Got event on unknown fd.");
+ goto fail;
+ }
+
+ changed = path_spec_fd_event(s, events);
+ if (changed < 0)
+ 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;
+
+ if (changed)
+ path_enter_running(p);
+ else
+ path_enter_waiting(p, false, true);
+
+ return;
+
+fail:
+ path_enter_dead(p, PATH_FAILURE_RESOURCES);
+}
+
+void path_unit_notify(Unit *u, UnitActiveState new_state) {
+ Iterator i;
+ Unit *k;
+
+ if (u->type == UNIT_PATH)
+ return;
+
+ SET_FOREACH(k, u->dependencies[UNIT_TRIGGERED_BY], i) {
+ Path *p;
+
+ if (k->type != UNIT_PATH)
+ continue;
+
+ if (k->load_state != UNIT_LOADED)
+ continue;
+
+ p = PATH(k);
+
+ if (p->state == PATH_RUNNING && new_state == UNIT_INACTIVE) {
+ log_debug("%s got notified about unit deactivation.", UNIT(p)->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);
+ }
+ }
+}
+
+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->result = PATH_SUCCESS;
+}
+
+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_MODIFIED] = "PathModified",
+ [PATH_DIRECTORY_NOT_EMPTY] = "DirectoryNotEmpty"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(path_type, PathType);
+
+static const char* const path_result_table[_PATH_RESULT_MAX] = {
+ [PATH_SUCCESS] = "success",
+ [PATH_FAILURE_RESOURCES] = "resources"
+};
+
+DEFINE_STRING_TABLE_LOOKUP(path_result, PathResult);
+
+const UnitVTable path_vtable = {
+ .suffix = ".path",
+ .object_size = sizeof(Path),
+ .sections =
+ "Unit\0"
+ "Path\0"
+ "Install\0",
+
+ .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,
+ .bus_invalidating_properties = bus_path_invalidating_properties
+};