eudev/snapshot.c

277 lines
7.3 KiB
C

/*-*- Mode: C; c-basic-offset: 8 -*-*/
/***
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 <errno.h>
#include "unit.h"
#include "snapshot.h"
#include "unit-name.h"
#include "dbus-snapshot.h"
static const UnitActiveState state_translation_table[_SNAPSHOT_STATE_MAX] = {
[SNAPSHOT_DEAD] = UNIT_INACTIVE,
[SNAPSHOT_ACTIVE] = UNIT_ACTIVE
};
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_debug("%s changed %s -> %s",
UNIT(s)->meta.id,
snapshot_state_to_string(old_state),
snapshot_state_to_string(state));
unit_notify(UNIT(s), state_translation_table[old_state], state_translation_table[state]);
}
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 0;
}
static int snapshot_stop(Unit *u) {
Snapshot *s = SNAPSHOT(u);
assert(s);
assert(s->state == SNAPSHOT_ACTIVE);
snapshot_set_state(s, SNAPSHOT_DEAD);
return 0;
}
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->meta.dependencies[UNIT_REQUIRES], i)
unit_serialize_item(u, f, "requires", other->meta.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;
if ((state = snapshot_state_from_string(value)) < 0)
log_debug("Failed to parse state value %s", value);
else
s->deserialized_state = state;
} else if (streq(key, "cleanup")) {
if ((r = parse_boolean(value)) < 0)
log_debug("Failed to parse cleanup value %s", value);
else
s->cleanup = r;
} else if (streq(key, "requires")) {
if ((r = unit_add_dependency_by_name(u, UNIT_AFTER, value, NULL, true)) < 0)
return r;
if ((r = unit_add_dependency_by_name(u, UNIT_REQUIRES, value, NULL, true)) < 0)
return r;
} else
log_debug("Unknown serialization key '%s'", key);
return 0;
}
static UnitActiveState snapshot_active_state(Unit *u) {
assert(u);
return state_translation_table[SNAPSHOT(u)->state];
}
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, Snapshot **_s) {
Iterator i;
Unit *other, *u = NULL;
char *n = NULL;
int r;
const char *k;
assert(m);
assert(_s);
if (name) {
if (!unit_name_is_valid(name))
return -EINVAL;
if (unit_name_to_type(name) != UNIT_SNAPSHOT)
return -EINVAL;
if (manager_get_unit(m, name))
return -EEXIST;
} else {
for (;;) {
if (asprintf(&n, "snapshot-%u.snapshot", ++ m->n_snapshots) < 0)
return -ENOMEM;
if (!manager_get_unit(m, n))
break;
free(n);
}
name = n;
}
r = manager_load_unit(m, name, NULL, &u);
free(n);
if (r < 0)
goto fail;
HASHMAP_FOREACH_KEY(other, k, m->units, i) {
if (UNIT_VTABLE(other)->no_snapshots)
continue;
if (k != other->meta.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;
if ((r = unit_add_dependency(u, UNIT_REQUIRES, other, true)) < 0)
goto fail;
if ((r = unit_add_dependency(u, UNIT_AFTER, other, true)) < 0)
goto fail;
}
SNAPSHOT(u)->cleanup = cleanup;
*_s = SNAPSHOT(u);
return 0;
fail:
if (u)
unit_add_to_cleanup_queue(u);
return r;
}
void snapshot_remove(Snapshot *s) {
assert(s);
unit_add_to_cleanup_queue(UNIT(s));
}
static const char* const snapshot_state_table[_SNAPSHOT_STATE_MAX] = {
[SNAPSHOT_DEAD] = "dead",
[SNAPSHOT_ACTIVE] = "active"
};
DEFINE_STRING_TABLE_LOOKUP(snapshot_state, SnapshotState);
const UnitVTable snapshot_vtable = {
.suffix = ".snapshot",
.no_alias = true,
.no_instances = true,
.no_snapshots = true,
.no_gc = true,
.load = unit_load_nop,
.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_message_handler = bus_snapshot_message_handler
};