service.c

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/* -*- C -*- */
/*
 * Copyright (c) 2012-2020 Seagate Technology LLC and/or its Affiliates
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 * For any questions about this software or licensing,
 * please email opensource@seagate.com or cortx-questions@seagate.com.
 *
 */



#define M0_TRACE_SUBSYSTEM M0_TRACE_SUBSYS_RPC
#include "lib/errno.h"
#include "lib/trace.h"
#include "lib/tlist.h"
#include "lib/time.h"     /* m0_time_from_now */
#include "lib/bob.h"
#include "lib/memory.h"   /* m0_alloc() */
#include "rpc/link.h"
#include "rpc/service.h"
#include "rpc/rev_conn.h"
#include "rpc/rpc_internal.h"
#include "reqh/reqh.h"
#include "reqh/reqh_service.h"
#include "ha/note_fops.h"  /* m0_ha_state_fop_init */

M0_TL_DESCR_DEFINE(rev_conn, "Reverse Connections", static,
                   struct m0_reverse_connection, rcf_linkage, rcf_magic,
                   M0_RM_REV_CONN_LIST_MAGIC, M0_RM_REV_CONN_LIST_HEAD_MAGIC);
M0_TL_DEFINE(rev_conn, static, struct m0_reverse_connection);

static const struct m0_bob_type rpc_svc_bob = {
        .bt_name = "rpc service",
        .bt_magix_offset = offsetof(struct m0_rpc_service, rps_magix),
        .bt_magix = M0_RPC_SERVICE_MAGIC,
        .bt_check = NULL
};
M0_BOB_DEFINE(M0_INTERNAL, &rpc_svc_bob, m0_rpc_service);

static int rpc_service_start(struct m0_reqh_service *service)
{
        struct m0_rpc_service *svc;

        svc = bob_of(service, struct m0_rpc_service, rps_svc, &rpc_svc_bob);
        rev_conn_tlist_init(&svc->rps_rev_conns);

        return 0;
}

static void rpc_service_stop(struct m0_reqh_service *service)
{
        struct m0_rpc_service *svc;

        svc = bob_of(service, struct m0_rpc_service, rps_svc, &rpc_svc_bob);
        m0_rpc_service_reverse_sessions_cleanup(service);
        rev_conn_tlist_fini(&svc->rps_rev_conns);
}

static void rpc_service_fini(struct m0_reqh_service *service)
{
        struct m0_rpc_service *svc;

        svc = bob_of(service, struct m0_rpc_service, rps_svc, &rpc_svc_bob);
        m0_rpc_service_bob_fini(svc);
        m0_free(svc);
}

static int
rpc_service_fop_accept(struct m0_reqh_service *service, struct m0_fop *fop)
{
        return 0;
}

static const struct m0_reqh_service_ops rpc_ops = {
        .rso_start      = rpc_service_start,
        .rso_stop       = rpc_service_stop,
        .rso_fini       = rpc_service_fini,
        .rso_fop_accept = rpc_service_fop_accept
};

static int rpc_service_allocate(struct m0_reqh_service **service,
                                const struct m0_reqh_service_type *stype)
{
        struct m0_rpc_service *svc;

        M0_PRE(stype != NULL && service != NULL);

        M0_ALLOC_PTR(svc);
        if (svc == NULL)
                return M0_ERR(-ENOMEM);

        m0_rpc_service_bob_init(svc);
        svc->rps_svc.rs_ops = &rpc_ops;
        *service = &svc->rps_svc;
        return 0;
}

static const struct m0_reqh_service_type_ops rpc_service_type_ops = {
        .rsto_service_allocate = rpc_service_allocate
};

struct m0_reqh_service_type m0_rpc_service_type = {
        .rst_name       = "rpcservice",
        .rst_ops        = &rpc_service_type_ops,
        .rst_level      = M0_RPC_SVC_LEVEL,
        .rst_keep_alive = true,
};
M0_EXPORTED(m0_rpc_service_type);

M0_INTERNAL int m0_rpc_service_register(void)
{
        m0_ha_state_fop_init();
        return m0_reqh_service_type_register(&m0_rpc_service_type);
}

M0_INTERNAL void m0_rpc_service_unregister(void)
{
        m0_reqh_service_type_unregister(&m0_rpc_service_type);
        m0_ha_state_fop_fini();
}

M0_INTERNAL struct m0_rpc_session *
m0_rpc_service_reverse_session_lookup(struct m0_reqh_service   *service,
                                      const struct m0_rpc_item *item)
{

        struct m0_reverse_connection     *revc;
        struct m0_rpc_service            *svc;
        const struct m0_rpc_item_header2 *header;

        M0_PRE(item != NULL && service->rs_type == &m0_rpc_service_type);
        header = &item->ri_header;
        svc    = bob_of(service, struct m0_rpc_service, rps_svc, &rpc_svc_bob);
        if (header->osr_sender_id == SENDER_ID_INVALID)
                revc = m0_tl_find(rev_conn, revc, &svc->rps_rev_conns,
                                m0_uint128_cmp(&revc->rcf_rlink.rlk_conn.c_uuid,
                                               &header->osr_uuid) == 0);
        else
                revc = m0_tl_find(rev_conn, revc, &svc->rps_rev_conns,
                                  revc->rcf_rlink.rlk_conn.c_sender_id ==
                                  header->osr_sender_id);
        return revc == NULL ? NULL : &revc->rcf_rlink.rlk_sess;
}

M0_INTERNAL int
m0_rpc_service_reverse_session_get(struct m0_reqh_service   *service,
                                   const struct m0_rpc_item *item,
                                   struct m0_clink          *clink,
                                   struct m0_rpc_session   **session)
{
        int                           rc;
        const char                   *rem_ep;
        struct m0_reverse_connection *revc;
        struct m0_rpc_service        *svc;

        M0_ENTRY();
        M0_PRE(item != NULL && service->rs_type == &m0_rpc_service_type);

        svc    = bob_of(service, struct m0_rpc_service, rps_svc, &rpc_svc_bob);
        rem_ep = m0_rpc_item_remote_ep_addr(item);

        M0_ALLOC_PTR(revc);
        rc = revc == NULL ? -ENOMEM : 0;
        rc = rc ?: m0_rpc_link_init(&revc->rcf_rlink,
                                    item->ri_rmachine, NULL, rem_ep,
                                    M0_REV_CONN_MAX_RPCS_IN_FLIGHT);
        if (rc == 0) {
                m0_rpc_link_connect_async(&revc->rcf_rlink,
                                m0_time_from_now(M0_REV_CONN_TIMEOUT, 0),
                                clink);
                *session = &revc->rcf_rlink.rlk_sess;
                rev_conn_tlink_init_at_tail(revc, &svc->rps_rev_conns);
        }
        return M0_RC(rc);
}

static void rev_conn_free(struct m0_sm_group *grp, struct m0_sm_ast *ast)
{
        struct m0_reverse_connection *revc = ast->sa_datum;

        M0_ENTRY("revc=%p", revc);
        m0_rpc_link_fini(&revc->rcf_rlink);
        rev_conn_tlink_del_fini(revc);
        m0_free(revc);
        M0_LEAVE("revc=%p", revc);
}

static bool rev_conn_disconnected_cb(struct m0_clink *link)
{
        struct m0_reverse_connection *revc;

        revc = container_of(link, struct m0_reverse_connection, rcf_disc_wait);
        revc->rcf_free_ast = (struct m0_sm_ast){
                .sa_cb    = &rev_conn_free,
                .sa_datum = revc,
        };
        m0_sm_ast_post(m0_locality0_get()->lo_grp, &revc->rcf_free_ast);
        return true;
}

M0_INTERNAL void
m0_rpc_service_reverse_session_put(struct m0_rpc_session *sess)
{
        struct m0_rpc_link           *rlk;
        struct m0_reverse_connection *revc;

        M0_ENTRY();

        rlk  = container_of(sess, struct m0_rpc_link, rlk_sess);
        revc = container_of(rlk, struct m0_reverse_connection, rcf_rlink);

        M0_SET0(&revc->rcf_disc_wait);
        if (revc->rcf_rlink.rlk_connected) {
                m0_clink_init(&revc->rcf_disc_wait, rev_conn_disconnected_cb);
                revc->rcf_disc_wait.cl_is_oneshot = true;
                m0_rpc_link_disconnect_async(&revc->rcf_rlink,
                                m0_time_from_now(M0_REV_CONN_TIMEOUT, 0),
                                &revc->rcf_disc_wait);
        }

        M0_LEAVE();
}

M0_INTERNAL void
m0_rpc_service_reverse_sessions_cleanup(struct m0_reqh_service *service)
{
        struct m0_rpc_service        *svc;
        struct m0_reverse_connection *revc;

        M0_ENTRY();
        M0_PRE(service->rs_type == &m0_rpc_service_type);

        /*
         * We take the lock here on locality0 to avoid races with
         * rev_conn_free() AST which runs in locality0.
         */
        m0_sm_group_lock(m0_locality0_get()->lo_grp);
        svc = bob_of(service, struct m0_rpc_service, rps_svc, &rpc_svc_bob);
        m0_tl_for(rev_conn, &svc->rps_rev_conns, revc) {
                M0_SET0(&revc->rcf_disc_wait);
                if (revc->rcf_rlink.rlk_connected) {
                        m0_clink_init(&revc->rcf_disc_wait, NULL);
                        revc->rcf_disc_wait.cl_is_oneshot = true;
                        m0_rpc_link_disconnect_async(&revc->rcf_rlink,
                                m0_time_from_now(M0_REV_CONN_TIMEOUT, 0),
                                &revc->rcf_disc_wait);
                }
        } m0_tlist_endfor;
        m0_tl_teardown(rev_conn, &svc->rps_rev_conns, revc) {
                if (revc->rcf_disc_wait.cl_group != NULL) {
                        m0_chan_wait(&revc->rcf_disc_wait);
                        m0_clink_fini(&revc->rcf_disc_wait);
                }
                m0_rpc_link_fini(&revc->rcf_rlink);
                rev_conn_tlink_fini(revc);
                m0_free(revc);
        }
        m0_sm_group_unlock(m0_locality0_get()->lo_grp);

        M0_LEAVE();
}

M0_INTERNAL int m0_rpc_session_status(struct m0_rpc_session *session)
{
        return container_of(session, struct m0_rpc_link, rlk_sess)->rlk_rc;
}

M0_INTERNAL struct m0_reqh_service *
m0_reqh_rpc_service_find(struct m0_reqh *reqh)
{
        return m0_reqh_service_find(&m0_rpc_service_type, reqh);
}

M0_INTERNAL int m0_rpc_service_start(struct m0_reqh *reqh)
{
        return reqh->rh_rpc_service == NULL ?
                m0_reqh_service_setup(&reqh->rh_rpc_service,
                                      &m0_rpc_service_type, reqh, NULL, NULL) :
                0;
}

M0_INTERNAL void m0_rpc_service_stop(struct m0_reqh *reqh)
{
        if (m0_reqh_rpc_mach_tlist_is_empty(&reqh->rh_rpc_machines)) {
                m0_reqh_service_quit(reqh->rh_rpc_service);
                reqh->rh_rpc_service = NULL;
        }
}

#undef M0_TRACE_SUBSYSTEM

/*
 *  Local variables:
 *  c-indentation-style: "K&R"
 *  c-basic-offset: 8
 *  tab-width: 8
 *  fill-column: 80
 *  scroll-step: 1
 *  End:
 */