/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
 * vim:expandtab:shiftwidth=8:tabstop=8:
 *
 *  Copyright (C) 2001-2003 Cluster File Systems, Inc.
 *   Author: Andreas Dilger <adilger@clusterfs.com>
 *
 *   This file is part of Lustre, http://www.lustre.org.
 *
 *   Lustre is free software; you can redistribute it and/or
 *   modify it under the terms of version 2 of the GNU General Public
 *   License as published by the Free Software Foundation.
 *
 *   Lustre 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 Lustre; if not, write to the Free Software
 *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * OST<->MDS recovery logging infrastructure.
 *
 * Invariants in implementation:
 * - we do not share logs among different OST<->MDS connections, so that
 *   if an OST or MDS fails it need only look at log(s) relevant to itself
 */

#define DEBUG_SUBSYSTEM S_LOG

#ifndef EXPORT_SYMTAB
#define EXPORT_SYMTAB
#endif

#ifdef __KERNEL__
#include <linux/fs.h>
#else
#include <liblustre.h>
#endif

#include <linux/obd_class.h>
#include <linux/lustre_log.h>
#include <libcfs/list.h>
#include <linux/lvfs.h>

#ifdef __KERNEL__
int llog_origin_connect(struct llog_ctxt *ctxt, int count,
                        struct llog_logid *logid, struct llog_gen *gen,
                        struct obd_uuid *uuid)
{
        struct llog_gen_rec *lgr;
        struct obd_import *imp;
        struct ptlrpc_request *request;
        struct llogd_conn_body *req_body;
        int size = sizeof(struct llogd_conn_body);
        int rc;
        ENTRY;

        if (list_empty(&ctxt->loc_handle->u.chd.chd_head)) {
                CDEBUG(D_HA, "there is no record related to ctxt %p\n", ctxt);
                RETURN(0);
        }

        /* FIXME what value for gen->conn_cnt */
        LLOG_GEN_INC(ctxt->loc_gen);

        /* first add llog_gen_rec */
        OBD_ALLOC(lgr, sizeof(*lgr));
        if (!lgr)
                RETURN(-ENOMEM);
        lgr->lgr_hdr.lrh_len = lgr->lgr_tail.lrt_len = sizeof(*lgr);
        lgr->lgr_hdr.lrh_type = LLOG_GEN_REC;
        lgr->lgr_gen = ctxt->loc_gen;
        rc = llog_add(ctxt, &lgr->lgr_hdr, NULL, NULL, 1, NULL, NULL, NULL);
        OBD_FREE(lgr, sizeof(*lgr));
        if (rc != 1)
                RETURN(rc);

        LASSERT(ctxt->loc_imp);
        imp = ctxt->loc_imp;

        request = ptlrpc_prep_req(imp, LUSTRE_LOG_VERSION, LLOG_ORIGIN_CONNECT,
                                  1, &size, NULL);
        if (!request)
                RETURN(-ENOMEM);

        req_body = lustre_msg_buf(request->rq_reqmsg, 0, sizeof(*req_body));
        req_body->lgdc_gen = ctxt->loc_gen;
        req_body->lgdc_logid = ctxt->loc_handle->lgh_id;
        req_body->lgdc_ctxt_idx = ctxt->loc_idx + 1;
        request->rq_replen = lustre_msg_size(0, NULL);

        rc = ptlrpc_queue_wait(request);
        ptlrpc_req_finished(request);

        RETURN(rc);
}
EXPORT_SYMBOL(llog_origin_connect);

int llog_handle_connect(struct ptlrpc_request *req)
{
        struct obd_device *obd = req->rq_export->exp_obd;
        struct llogd_conn_body *req_body;
        struct llog_ctxt *ctxt;
        int rc;
        ENTRY;

        req_body = lustre_msg_buf(req->rq_reqmsg, 0, sizeof(*req_body));

#warning "FIXME: shouldn't llogs be passed directly?"
        ctxt = llog_get_context(&obd->obd_llogs, req_body->lgdc_ctxt_idx);
        rc = llog_connect(ctxt, 1, &req_body->lgdc_logid,
                          &req_body->lgdc_gen, NULL);
        if (rc != 0)
                CERROR("failed at llog_relp_connect\n");

        RETURN(rc);
}
EXPORT_SYMBOL(llog_handle_connect);

int llog_receptor_accept(struct llog_ctxt *ctxt, struct obd_import *imp)
{
        ENTRY;
        LASSERT(ctxt);
        ctxt->loc_imp = imp;
        RETURN(0);
}
EXPORT_SYMBOL(llog_receptor_accept);

int llog_initiator_connect(struct llog_ctxt *ctxt)
{
        ENTRY;
        LASSERT(ctxt);
        ctxt->loc_imp = ctxt->loc_obd->u.cli.cl_import;
        RETURN(0);
}
EXPORT_SYMBOL(llog_initiator_connect);

#else /* !__KERNEL__ */

int llog_origin_connect(struct llog_ctxt *ctxt, int count,
                        struct llog_logid *logid, struct llog_gen *gen,
                        struct obd_uuid *uuid)
{
        return 0;
}

int llog_initiator_connect(struct llog_ctxt *ctxt)
{
        return 0;
}
#endif