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Diffstat (limited to 'src/core/snapshot.c')
| -rw-r--r-- | src/core/snapshot.c | 309 |
1 files changed, 309 insertions, 0 deletions
diff --git a/src/core/snapshot.c b/src/core/snapshot.c new file mode 100644 index 000000000..82ec5104d --- /dev/null +++ b/src/core/snapshot.c @@ -0,0 +1,309 @@ +/*-*- 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 <errno.h> + +#include "unit.h" +#include "snapshot.h" +#include "unit-name.h" +#include "dbus-snapshot.h" +#include "bus-errors.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; +} + +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)->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], 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 (!s->by_snapshot_create && 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 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->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; + + 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, "wants")) { + + if ((r = unit_add_two_dependencies_by_name(u, UNIT_AFTER, UNIT_WANTS, 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, DBusError *e, 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, false)) { + dbus_set_error(e, BUS_ERROR_INVALID_NAME, "Unit name %s is not valid.", name); + return -EINVAL; + } + + if (unit_name_to_type(name) != UNIT_SNAPSHOT) { + dbus_set_error(e, BUS_ERROR_UNIT_TYPE_MISMATCH, "Unit name %s lacks snapshot suffix.", name); + return -EINVAL; + } + + if (manager_get_unit(m, name)) { + dbus_set_error(e, BUS_ERROR_UNIT_EXISTS, "Snapshot %s exists already.", 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_prepare(m, name, NULL, e, &u); + free(n); + + if (r < 0) + goto fail; + + SNAPSHOT(u)->by_snapshot_create = 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) + 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; + + if ((r = unit_add_two_dependencies(u, UNIT_AFTER, UNIT_WANTS, 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", + .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_interface = "org.freedesktop.systemd1.Snapshot", + .bus_message_handler = bus_snapshot_message_handler +}; 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