snapshot.c revision b5efdb8af40ea759a1ea584c1bc44ecc81dd00ce
/*-*- 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 Lesser General Public License as published by
the Free Software Foundation; either version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public License
along with systemd; If not, see <http://www.gnu.org/licenses/>.
***/
#include <errno.h>
#include "alloc-util.h"
#include "bus-common-errors.h"
#include "dbus-snapshot.h"
#include "parse-util.h"
#include "parse-util.h"
#include "snapshot.h"
#include "string-util.h"
#include "unit-name.h"
#include "unit.h"
static const UnitActiveState state_translation_table[_SNAPSHOT_STATE_MAX] = {
[SNAPSHOT_DEAD] = UNIT_INACTIVE,
[SNAPSHOT_ACTIVE] = UNIT_ACTIVE
};
static void snapshot_init(Unit *u) {
Snapshot *s = SNAPSHOT(u);
assert(s);
assert(UNIT(s)->load_state == UNIT_STUB);
UNIT(s)->ignore_on_isolate = true;
UNIT(s)->ignore_on_snapshot = true;
UNIT(s)->allow_isolate = true;
}
static void snapshot_set_state(Snapshot *s, SnapshotState state) {
SnapshotState old_state;
assert(s);
old_state = s->state;
s->state = state;
if (state != old_state)
log_unit_debug(UNIT(s), "Changed %s -> %s", snapshot_state_to_string(old_state), snapshot_state_to_string(state));
unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state], true);
}
static int snapshot_load(Unit *u) {
Snapshot *s = SNAPSHOT(u);
assert(u);
assert(u->load_state == UNIT_STUB);
/* Make sure that only snapshots created via snapshot_create()
* can be loaded */
if (!u->transient && UNIT(s)->manager->n_reloading <= 0)
return -ENOENT;
u->load_state = UNIT_LOADED;
return 0;
}
static int snapshot_coldplug(Unit *u) {
Snapshot *s = SNAPSHOT(u);
assert(s);
assert(s->state == SNAPSHOT_DEAD);
if (s->deserialized_state != s->state)
snapshot_set_state(s, s->deserialized_state);
return 0;
}
static void snapshot_dump(Unit *u, FILE *f, const char *prefix) {
Snapshot *s = SNAPSHOT(u);
assert(s);
assert(f);
fprintf(f,
"%sSnapshot State: %s\n"
"%sClean Up: %s\n",
prefix, snapshot_state_to_string(s->state),
prefix, yes_no(s->cleanup));
}
static int snapshot_start(Unit *u) {
Snapshot *s = SNAPSHOT(u);
assert(s);
assert(s->state == SNAPSHOT_DEAD);
snapshot_set_state(s, SNAPSHOT_ACTIVE);
if (s->cleanup)
unit_add_to_cleanup_queue(u);
return 1;
}
static int snapshot_stop(Unit *u) {
Snapshot *s = SNAPSHOT(u);
assert(s);
assert(s->state == SNAPSHOT_ACTIVE);
snapshot_set_state(s, SNAPSHOT_DEAD);
return 1;
}
static int snapshot_serialize(Unit *u, FILE *f, FDSet *fds) {
Snapshot *s = SNAPSHOT(u);
Unit *other;
Iterator i;
assert(s);
assert(f);
assert(fds);
unit_serialize_item(u, f, "state", snapshot_state_to_string(s->state));
unit_serialize_item(u, f, "cleanup", yes_no(s->cleanup));
SET_FOREACH(other, u->dependencies[UNIT_WANTS], i)
unit_serialize_item(u, f, "wants", other->id);
return 0;
}
static int snapshot_deserialize_item(Unit *u, const char *key, const char *value, FDSet *fds) {
Snapshot *s = SNAPSHOT(u);
int r;
assert(u);
assert(key);
assert(value);
assert(fds);
if (streq(key, "state")) {
SnapshotState state;
state = snapshot_state_from_string(value);
if (state < 0)
log_unit_debug(u, "Failed to parse state value: %s", value);
else
s->deserialized_state = state;
} else if (streq(key, "cleanup")) {
r = parse_boolean(value);
if (r < 0)
log_unit_debug(u, "Failed to parse cleanup value: %s", value);
else
s->cleanup = r;
} else if (streq(key, "wants")) {
r = unit_add_two_dependencies_by_name(u, UNIT_AFTER, UNIT_WANTS, value, NULL, true);
if (r < 0)
return r;
} else
log_unit_debug(u, "Unknown serialization key: %s", key);
return 0;
}
_pure_ static UnitActiveState snapshot_active_state(Unit *u) {
assert(u);
return state_translation_table[SNAPSHOT(u)->state];
}
_pure_ static const char *snapshot_sub_state_to_string(Unit *u) {
assert(u);
return snapshot_state_to_string(SNAPSHOT(u)->state);
}
int snapshot_create(Manager *m, const char *name, bool cleanup, sd_bus_error *e, Snapshot **_s) {
_cleanup_free_ char *n = NULL;
Unit *other, *u = NULL;
Iterator i;
int r;
const char *k;
assert(m);
assert(_s);
if (name) {
if (!unit_name_is_valid(name, UNIT_NAME_PLAIN))
return sd_bus_error_setf(e, SD_BUS_ERROR_INVALID_ARGS, "Unit name %s is not valid.", name);
if (!endswith(name, ".snapshot"))
return sd_bus_error_setf(e, SD_BUS_ERROR_INVALID_ARGS, "Unit name %s lacks snapshot suffix.", name);
if (manager_get_unit(m, name))
return sd_bus_error_setf(e, BUS_ERROR_UNIT_EXISTS, "Snapshot %s exists already.", name);
} else {
for (;;) {
if (asprintf(&n, "snapshot-%u.snapshot", ++ m->n_snapshots) < 0)
return -ENOMEM;
if (!manager_get_unit(m, n)) {
name = n;
break;
}
n = mfree(n);
}
}
r = manager_load_unit_prepare(m, name, NULL, e, &u);
if (r < 0)
goto fail;
u->transient = true;
manager_dispatch_load_queue(m);
assert(u->load_state == UNIT_LOADED);
HASHMAP_FOREACH_KEY(other, k, m->units, i) {
if (other->ignore_on_snapshot ||
other->transient)
continue;
if (k != other->id)
continue;
if (UNIT_VTABLE(other)->check_snapshot)
if (!UNIT_VTABLE(other)->check_snapshot(other))
continue;
if (!UNIT_IS_ACTIVE_OR_ACTIVATING(unit_active_state(other)))
continue;
r = unit_add_two_dependencies(u, UNIT_AFTER, UNIT_WANTS, other, true);
if (r < 0)
goto fail;
}
SNAPSHOT(u)->cleanup = cleanup;
*_s = SNAPSHOT(u);
log_unit_info(u, "Created snapshot.");
return 0;
fail:
if (u)
unit_add_to_cleanup_queue(u);
return r;
}
void snapshot_remove(Snapshot *s) {
assert(s);
log_unit_info(UNIT(s), "Removing snapshot.");
unit_add_to_cleanup_queue(UNIT(s));
}
const UnitVTable snapshot_vtable = {
.object_size = sizeof(Snapshot),
.no_alias = true,
.no_instances = true,
.no_gc = true,
.init = snapshot_init,
.load = snapshot_load,
.coldplug = snapshot_coldplug,
.dump = snapshot_dump,
.start = snapshot_start,
.stop = snapshot_stop,
.serialize = snapshot_serialize,
.deserialize_item = snapshot_deserialize_item,
.active_state = snapshot_active_state,
.sub_state_to_string = snapshot_sub_state_to_string,
.bus_vtable = bus_snapshot_vtable
};