return result;
}
+static int lxcFreezeContainer(lxc_driver_t *driver, virDomainObjPtr vm)
+{
+ int timeout = 1000; /* In milliseconds */
+ int check_interval = 1; /* In milliseconds */
+ int exp = 10;
+ int waited_time = 0;
+ int ret = -1;
+ char *state = NULL;
+ virCgroupPtr cgroup = NULL;
+
+ if (!(driver->cgroup &&
+ virCgroupForDomain(driver->cgroup, vm->def->name, &cgroup, 0) == 0))
+ return -1;
+
+ while (waited_time < timeout) {
+ int r;
+ /*
+ * Writing "FROZEN" to the "freezer.state" freezes the group,
+ * i.e., the container, temporarily transiting "FREEZING" state.
+ * Once the freezing is completed, the state of the group transits
+ * to "FROZEN".
+ * (see linux-2.6/Documentation/cgroups/freezer-subsystem.txt)
+ */
+ r = virCgroupSetFreezerState(cgroup, "FROZEN");
+
+ /*
+ * Returning EBUSY explicitly indicates that the group is
+ * being freezed but incomplete and other errors are true
+ * errors.
+ */
+ if (r < 0 && r != -EBUSY) {
+ VIR_DEBUG("Writing freezer.state failed with errno: %d", r);
+ goto error;
+ }
+ if (r == -EBUSY)
+ VIR_DEBUG0("Writing freezer.state gets EBUSY");
+
+ /*
+ * Unfortunately, returning 0 (success) is likely to happen
+ * even when the freezing has not been completed. Sometimes
+ * the state of the group remains "FREEZING" like when
+ * returning -EBUSY and even worse may never transit to
+ * "FROZEN" even if writing "FROZEN" again.
+ *
+ * So we don't trust the return value anyway and always
+ * decide that the freezing has been complete only with
+ * the state actually transit to "FROZEN".
+ */
+ usleep(check_interval * 1000);
+
+ r = virCgroupGetFreezerState(cgroup, &state);
+
+ if (r < 0) {
+ VIR_DEBUG("Reading freezer.state failed with errno: %d", r);
+ goto error;
+ }
+ VIR_DEBUG("Read freezer.state: %s", state);
+
+ if (STREQ(state, "FROZEN")) {
+ ret = 0;
+ goto cleanup;
+ }
+
+ waited_time += check_interval;
+ /*
+ * Increasing check_interval exponentially starting with
+ * small initial value treats nicely two cases; One is
+ * a container is under no load and waiting for long period
+ * makes no sense. The other is under heavy load. The container
+ * may stay longer time in FREEZING or never transit to FROZEN.
+ * In that case, eager polling will just waste CPU time.
+ */
+ check_interval *= exp;
+ VIR_FREE(state);
+ }
+ VIR_DEBUG0("lxcFreezeContainer timeout");
+error:
+ /*
+ * If timeout or an error on reading the state occurs,
+ * activate the group again and return an error.
+ * This is likely to fall the group back again gracefully.
+ */
+ virCgroupSetFreezerState(cgroup, "THAWED");
+ ret = -1;
+
+cleanup:
+ if (cgroup)
+ virCgroupFree(&cgroup);
+ VIR_FREE(state);
+ return ret;
+}
+
+static int lxcDomainSuspend(virDomainPtr dom)
+{
+ lxc_driver_t *driver = dom->conn->privateData;
+ virDomainObjPtr vm;
+ virDomainEventPtr event = NULL;
+ int ret = -1;
+
+ lxcDriverLock(driver);
+ vm = virDomainFindByUUID(&driver->domains, dom->uuid);
+
+ if (!vm) {
+ char uuidstr[VIR_UUID_STRING_BUFLEN];
+ virUUIDFormat(dom->uuid, uuidstr);
+ lxcError(dom->conn, dom, VIR_ERR_NO_DOMAIN,
+ _("no domain with matching uuid '%s'"), uuidstr);
+ goto cleanup;
+ }
+
+ if (!virDomainIsActive(vm)) {
+ lxcError(dom->conn, dom, VIR_ERR_OPERATION_INVALID,
+ "%s", _("domain is not running"));
+ goto cleanup;
+ }
+
+ if (vm->state != VIR_DOMAIN_PAUSED) {
+ if (lxcFreezeContainer(driver, vm) < 0) {
+ lxcError(dom->conn, dom, VIR_ERR_OPERATION_FAILED,
+ "%s", _("suspend operation failed"));
+ goto cleanup;
+ }
+ vm->state = VIR_DOMAIN_PAUSED;
+
+ event = virDomainEventNewFromObj(vm,
+ VIR_DOMAIN_EVENT_SUSPENDED,
+ VIR_DOMAIN_EVENT_SUSPENDED_PAUSED);
+ }
+
+ if (virDomainSaveStatus(dom->conn, driver->stateDir, vm) < 0)
+ goto cleanup;
+ ret = 0;
+
+cleanup:
+ if (event)
+ lxcDomainEventQueue(driver, event);
+ if (vm)
+ virDomainObjUnlock(vm);
+ lxcDriverUnlock(driver);
+ return ret;
+}
+
+static int lxcUnfreezeContainer(lxc_driver_t *driver, virDomainObjPtr vm)
+{
+ int ret;
+ virCgroupPtr cgroup = NULL;
+
+ if (!(driver->cgroup &&
+ virCgroupForDomain(driver->cgroup, vm->def->name, &cgroup, 0) == 0))
+ return -1;
+
+ ret = virCgroupSetFreezerState(cgroup, "THAWED");
+
+ virCgroupFree(&cgroup);
+ return ret;
+}
+
+static int lxcDomainResume(virDomainPtr dom)
+{
+ lxc_driver_t *driver = dom->conn->privateData;
+ virDomainObjPtr vm;
+ virDomainEventPtr event = NULL;
+ int ret = -1;
+
+ lxcDriverLock(driver);
+ vm = virDomainFindByUUID(&driver->domains, dom->uuid);
+
+ if (!vm) {
+ char uuidstr[VIR_UUID_STRING_BUFLEN];
+ virUUIDFormat(dom->uuid, uuidstr);
+ lxcError(dom->conn, dom, VIR_ERR_NO_DOMAIN,
+ _("no domain with matching uuid '%s'"), uuidstr);
+ goto cleanup;
+ }
+
+ if (!virDomainIsActive(vm)) {
+ lxcError(dom->conn, dom, VIR_ERR_OPERATION_INVALID,
+ "%s", _("domain is not running"));
+ goto cleanup;
+ }
+
+ if (vm->state == VIR_DOMAIN_PAUSED) {
+ if (lxcUnfreezeContainer(driver, vm) < 0) {
+ lxcError(dom->conn, dom, VIR_ERR_OPERATION_FAILED,
+ "%s", _("resume operation failed"));
+ goto cleanup;
+ }
+ vm->state = VIR_DOMAIN_RUNNING;
+
+ event = virDomainEventNewFromObj(vm,
+ VIR_DOMAIN_EVENT_RESUMED,
+ VIR_DOMAIN_EVENT_RESUMED_UNPAUSED);
+ }
+
+ if (virDomainSaveStatus(dom->conn, driver->stateDir, vm) < 0)
+ goto cleanup;
+ ret = 0;
+
+cleanup:
+ if (event)
+ lxcDomainEventQueue(driver, event);
+ if (vm)
+ virDomainObjUnlock(vm);
+ lxcDriverUnlock(driver);
+ return ret;
+}
+
+
/* Function Tables */
static virDriver lxcDriver = {
VIR_DRV_LXC, /* the number virDrvNo */
lxcDomainLookupByID, /* domainLookupByID */
lxcDomainLookupByUUID, /* domainLookupByUUID */
lxcDomainLookupByName, /* domainLookupByName */
- NULL, /* domainSuspend */
- NULL, /* domainResume */
+ lxcDomainSuspend, /* domainSuspend */
+ lxcDomainResume, /* domainResume */
lxcDomainShutdown, /* domainShutdown */
NULL, /* domainReboot */
lxcDomainDestroy, /* domainDestroy */
projects / thirdparty / libvirt.git / commitdiff
