pinger.c

来自「lustre 1.6.5 source code」· C语言 代码 · 共 703 行 · 第 1/2 页

        struct obd_device *obd;
        struct obd_export *exp;
        struct l_wait_info lwi = { 0 };
        time_t expire_time;
        ENTRY;

        ptlrpc_daemonize("ll_evictor");

        CDEBUG(D_HA, "Starting Ping Evictor\n");
        pet_exp = NULL;
        pet_state = PET_READY;
        while (1) {
                l_wait_event(pet_waitq, pet_exp ||
                             (pet_state == PET_TERMINATE), &lwi);
                if (pet_state == PET_TERMINATE)
                        break;

                /* we only get here if pet_exp != NULL, and the end of this
                 * loop is the only place which sets it NULL again, so lock
                 * is not strictly necessary. */
                spin_lock(&pet_lock);
                obd = pet_exp->exp_obd;
                spin_unlock(&pet_lock);

                expire_time = cfs_time_current_sec() - PING_EVICT_TIMEOUT;

                CDEBUG(D_HA, "evicting all exports of obd %s older than %ld\n",
                       obd->obd_name, expire_time);

                /* Exports can't be deleted out of the list while we hold
                 * the obd lock (class_unlink_export), which means we can't
                 * lose the last ref on the export.  If they've already been
                 * removed from the list, we won't find them here. */
                spin_lock(&obd->obd_dev_lock);
                while (!list_empty(&obd->obd_exports_timed)) {
                        exp = list_entry(obd->obd_exports_timed.next,
                                         struct obd_export,exp_obd_chain_timed);
                        if (expire_time > exp->exp_last_request_time) {
                                class_export_get(exp);
                                spin_unlock(&obd->obd_dev_lock);
                                LCONSOLE_WARN("%s: haven't heard from client %s"
                                              " (at %s) in %ld seconds. I think"
                                              " it's dead, and I am evicting"
                                              " it.\n", obd->obd_name,
                                              obd_uuid2str(&exp->exp_client_uuid),
                                              obd_export_nid2str(exp),
                                              (long)(cfs_time_current_sec() -
                                                     exp->exp_last_request_time));
                                CDEBUG(D_HA, "Last request was at %ld\n",
                                       exp->exp_last_request_time);
                                class_fail_export(exp);
                                class_export_put(exp);
                                spin_lock(&obd->obd_dev_lock);
                        } else {
                                /* List is sorted, so everyone below is ok */
                                break;
                        }
                }
                spin_unlock(&obd->obd_dev_lock);

                class_export_put(pet_exp);

                spin_lock(&pet_lock);
                pet_exp = NULL;
                spin_unlock(&pet_lock);
        }
        CDEBUG(D_HA, "Exiting Ping Evictor\n");

        RETURN(0);
}

void ping_evictor_start(void)
{
        int rc;

        if (++pet_refcount > 1)
                return;

        init_waitqueue_head(&pet_waitq);

        rc = cfs_kernel_thread(ping_evictor_main, NULL, CLONE_VM | CLONE_FILES);
        if (rc < 0) {
                pet_refcount--;
                CERROR("Cannot start ping evictor thread: %d\n", rc);
        }
}
EXPORT_SYMBOL(ping_evictor_start);

void ping_evictor_stop(void)
{
        if (--pet_refcount > 0)
                return;

        pet_state = PET_TERMINATE;
        wake_up(&pet_waitq);
}
EXPORT_SYMBOL(ping_evictor_stop);
#else /* !__KERNEL__ */

/* XXX
 * the current implementation of pinger in liblustre is not optimized
 */

#ifdef ENABLE_PINGER
static struct pinger_data {
        int             pd_recursion;
        cfs_time_t      pd_this_ping;   /* jiffies */
        cfs_time_t      pd_next_ping;   /* jiffies */
        struct ptlrpc_request_set *pd_set;
} pinger_args;

static int pinger_check_rpcs(void *arg)
{
        cfs_time_t curtime = cfs_time_current();
        struct ptlrpc_request *req;
        struct ptlrpc_request_set *set;
        struct list_head *iter;
        struct pinger_data *pd = &pinger_args;
        int rc;

        /* prevent recursion */
        if (pd->pd_recursion++) {
                CDEBUG(D_HA, "pinger: recursion! quit\n");
                LASSERT(pd->pd_set);
                pd->pd_recursion--;
                return 0;
        }

        /* have we reached ping point? */
        if (!pd->pd_set && time_before(curtime, pd->pd_next_ping)) {
                pd->pd_recursion--;
                return 0;
        }

        /* if we have rpc_set already, continue processing it */
        if (pd->pd_set) {
                LASSERT(pd->pd_this_ping);
                set = pd->pd_set;
                goto do_check_set;
        }

        pd->pd_this_ping = curtime;
        pd->pd_set = ptlrpc_prep_set();
        if (pd->pd_set == NULL)
                goto out;
        set = pd->pd_set;

        /* add rpcs into set */
        mutex_down(&pinger_sem);
        list_for_each(iter, &pinger_imports) {
                struct obd_import *imp =
                        list_entry(iter, struct obd_import, imp_pinger_chain);
                int generation, level;

                if (cfs_time_aftereq(pd->pd_this_ping, 
                                     imp->imp_next_ping - 5 * CFS_TICK)) {
                        /* Add a ping. */
                        spin_lock(&imp->imp_lock);
                        generation = imp->imp_generation;
                        level = imp->imp_state;
                        spin_unlock(&imp->imp_lock);

                        if (level != LUSTRE_IMP_FULL) {
                                CDEBUG(D_HA,
                                       "not pinging %s (in recovery)\n",
                                       obd2cli_tgt(imp->imp_obd));
                                continue;
                        }

                        req = ptlrpc_prep_req(imp, LUSTRE_OBD_VERSION, OBD_PING,
                                              1, NULL, NULL);
                        if (!req) {
                                CERROR("out of memory\n");
                                break;
                        }
                        req->rq_no_resend = 1;
                        ptlrpc_req_set_repsize(req, 1, NULL);
                        req->rq_send_state = LUSTRE_IMP_FULL;
                        req->rq_phase = RQ_PHASE_RPC;
                        req->rq_import_generation = generation;
                        ptlrpc_set_add_req(set, req);
                } else {
                        CDEBUG(D_INFO, "don't need to ping %s ("CFS_TIME_T
                               " > "CFS_TIME_T")\n", obd2cli_tgt(imp->imp_obd),
                               imp->imp_next_ping, pd->pd_this_ping);
                }
        }
        pd->pd_this_ping = curtime;
        mutex_up(&pinger_sem);

        /* Might be empty, that's OK. */
        if (set->set_remaining == 0)
                CDEBUG(D_RPCTRACE, "nothing to ping\n");

        list_for_each(iter, &set->set_requests) {
                struct ptlrpc_request *req =
                        list_entry(iter, struct ptlrpc_request,
                                   rq_set_chain);
                DEBUG_REQ(D_RPCTRACE, req, "pinging %s->%s",
                          req->rq_import->imp_obd->obd_uuid.uuid,
                          obd2cli_tgt(req->rq_import->imp_obd));
                (void)ptl_send_rpc(req, 0);
        }

do_check_set:
        rc = ptlrpc_check_set(set);

        /* not finished, and we are not expired, simply return */
        if (!rc && cfs_time_before(curtime, cfs_time_add(pd->pd_this_ping,
                                            cfs_time_seconds(PING_INTERVAL)))) {
                CDEBUG(D_RPCTRACE, "not finished, but also not expired\n");
                pd->pd_recursion--;
                return 0;
        }

        /* Expire all the requests that didn't come back. */
        mutex_down(&pinger_sem);
        list_for_each(iter, &set->set_requests) {
                req = list_entry(iter, struct ptlrpc_request,
                                 rq_set_chain);

                if (req->rq_phase == RQ_PHASE_COMPLETE)
                        continue;

                req->rq_phase = RQ_PHASE_COMPLETE;
                atomic_dec(&req->rq_import->imp_inflight);
                set->set_remaining--;
                /* If it was disconnected, don't sweat it. */
                if (list_empty(&req->rq_import->imp_pinger_chain)) {
                        ptlrpc_unregister_reply(req);
                        continue;
                }

                CDEBUG(D_RPCTRACE, "pinger initiate expire_one_request\n");
                ptlrpc_expire_one_request(req);
        }
        mutex_up(&pinger_sem);

        ptlrpc_set_destroy(set);
        pd->pd_set = NULL;

out:
        pd->pd_next_ping = cfs_time_add(pd->pd_this_ping,
                                        cfs_time_seconds(PING_INTERVAL));
        pd->pd_this_ping = 0; /* XXX for debug */

        CDEBUG(D_INFO, "finished a round ping\n");
        pd->pd_recursion--;
        return 0;
}

static void *pinger_callback = NULL;
#endif /* ENABLE_PINGER */

int ptlrpc_start_pinger(void)
{
#ifdef ENABLE_PINGER
        memset(&pinger_args, 0, sizeof(pinger_args));
        pinger_callback = liblustre_register_wait_callback("pinger_check_rpcs",
                                                           &pinger_check_rpcs,
                                                           &pinger_args);
#endif
        return 0;
}

int ptlrpc_stop_pinger(void)
{
#ifdef ENABLE_PINGER
        if (pinger_callback)
                liblustre_deregister_wait_callback(pinger_callback);
#endif
        return 0;
}

void ptlrpc_pinger_sending_on_import(struct obd_import *imp)
{
#ifdef ENABLE_PINGER
        mutex_down(&pinger_sem);
        ptlrpc_update_next_ping(imp);
        if (pinger_args.pd_set == NULL &&
            time_before(imp->imp_next_ping, pinger_args.pd_next_ping)) {
                CDEBUG(D_HA, "set next ping to "CFS_TIME_T"(cur "CFS_TIME_T")\n",
                        imp->imp_next_ping, cfs_time_current());
                pinger_args.pd_next_ping = imp->imp_next_ping;
        }
        mutex_up(&pinger_sem);
#endif
}

int ptlrpc_pinger_add_import(struct obd_import *imp)
{
        ENTRY;
        if (!list_empty(&imp->imp_pinger_chain))
                RETURN(-EALREADY);

        CDEBUG(D_HA, "adding pingable import %s->%s\n",
               imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
        ptlrpc_pinger_sending_on_import(imp);

        mutex_down(&pinger_sem);
        list_add_tail(&imp->imp_pinger_chain, &pinger_imports);
        class_import_get(imp);
        mutex_up(&pinger_sem);

        RETURN(0);
}

int ptlrpc_pinger_del_import(struct obd_import *imp)
{
        ENTRY;
        if (list_empty(&imp->imp_pinger_chain))
                RETURN(-ENOENT);

        mutex_down(&pinger_sem);
        list_del_init(&imp->imp_pinger_chain);
        CDEBUG(D_HA, "removing pingable import %s->%s\n",
               imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
        class_import_put(imp);
        mutex_up(&pinger_sem);
        RETURN(0);
}

void ptlrpc_pinger_wake_up()
{
#ifdef ENABLE_PINGER
        ENTRY;
        /* XXX force pinger to run, if needed */
        struct obd_import *imp;
        list_for_each_entry(imp, &pinger_imports, imp_pinger_chain) {
                CDEBUG(D_RPCTRACE, "checking import %s->%s\n",
                       imp->imp_obd->obd_uuid.uuid, obd2cli_tgt(imp->imp_obd));
#ifdef ENABLE_LIBLUSTRE_RECOVERY
                if (imp->imp_state == LUSTRE_IMP_DISCON && !imp->imp_deactive)
#else
                /*XXX only recover for the initial connection */
                if (!lustre_handle_is_used(&imp->imp_remote_handle) &&
                    imp->imp_state == LUSTRE_IMP_DISCON && !imp->imp_deactive)
#endif
                        ptlrpc_initiate_recovery(imp);
                else if (imp->imp_state != LUSTRE_IMP_FULL)
                        CDEBUG(D_HA, "Refused to recover import %s->%s "
                                     "state %d, deactive %d\n",
                                     imp->imp_obd->obd_uuid.uuid,
                                     obd2cli_tgt(imp->imp_obd), imp->imp_state,
                                     imp->imp_deactive);
        }
#endif
        EXIT;
}
#endif /* !__KERNEL__ */