/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
 * vim:expandtab:shiftwidth=8:tabstop=8:
 *
 *  Copyright (c) 2002 Cluster File Systems, Inc. <info@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.
 */

#define DEBUG_SUBSYSTEM S_CMOBD

#include <linux/version.h>
#include <linux/init.h>
#include <linux/obd_support.h>
#include <linux/lustre_lib.h>
#include <linux/lustre_net.h>
#include <linux/lustre_idl.h>
#include <linux/obd_class.h>
#include <linux/lustre_mds.h>
#include <linux/lustre_cmobd.h>
#include <linux/lprocfs_status.h>
#include <linux/obd_lov.h>
#include <linux/obd_lmv.h>

#include "cm_internal.h"

static int cmobd_attach(struct obd_device *obd,
                        obd_count len, void *data)
{
        struct lprocfs_static_vars lvars;

        lprocfs_init_vars(cmobd, &lvars);
        return lprocfs_obd_attach(obd, lvars.obd_vars);
}

static int cmobd_detach(struct obd_device *obd)
{
        return lprocfs_obd_detach(obd);
}

static inline int cmobd_lmv_obd(struct obd_device *obd)
{
        if (!strcmp(obd->obd_type->typ_name, LUSTRE_MDC_NAME) ||
            !strcmp(obd->obd_type->typ_name, OBD_LMV_DEVICENAME))
                return 1;

        return 0;
}

static inline int cmobd_lov_obd(struct obd_device *obd)
{
        if (!strcmp(obd->obd_type->typ_name, OBD_LOV_DEVICENAME))
                return 1;

        return 0;
}

static void cmobd_init_ea_size(struct obd_device *obd)
{
        int ost_count = 1, easize, cookiesize;
        struct cm_obd *cmobd = &obd->u.cm;
        ENTRY;

        /*
         * here we should also take into account that there is possible to have
         * few OSTs. --umka
         */
        easize = lov_mds_md_size(ost_count);
        cookiesize = ost_count * sizeof(struct llog_cookie);

        obd_init_ea_size(cmobd->master_exp, easize, cookiesize);

        cmobd->master_exp->exp_obd->u.cli.cl_max_mds_easize = easize;
        cmobd->master_exp->exp_obd->u.cli.cl_max_mds_cookiesize = cookiesize;
        
        EXIT;
}

static struct obd_device *
find_master_obd(struct obd_device *obd, struct obd_uuid *uuid)
{
        struct obd_device *master;

        CWARN("%s: looking for client obd %s\n",
              obd->obd_uuid.uuid, uuid->uuid);

        master = class_find_client_obd(NULL, OBD_LOV_DEVICENAME,
                                       uuid);
        if (master)
                return master;

        master = class_find_client_obd(NULL, OBD_LMV_DEVICENAME,
                                       uuid);
        if (master)
                return master;

        return class_find_client_obd(NULL, LUSTRE_MDC_NAME,
                                     uuid);
}

static int cmobd_setup(struct obd_device *obd, obd_count len, void *buf)
{
        struct obd_uuid master_uuid, cache_uuid;
        struct lustre_handle conn = { 0 };
        struct cm_obd *cmobd = &obd->u.cm;
        struct lustre_cfg* lcfg = buf;
        struct lustre_id mid, lid;
        int valsize, rc;
        ENTRY;

        if (lcfg->lcfg_inllen1 == 0 || lcfg->lcfg_inlbuf1 == NULL) {
                CERROR("%s: setup requires master device uuid\n", 
                       obd->obd_name);
                RETURN(-EINVAL);
        }

        if (lcfg->lcfg_inllen2 == 0 || lcfg->lcfg_inlbuf2 == NULL) {
                CERROR("%s: setup requires cache device uuid\n",
                       obd->obd_name);
                RETURN(-EINVAL);
        }

        obd_str2uuid(&master_uuid, lcfg->lcfg_inlbuf1);
        obd_str2uuid(&cache_uuid, lcfg->lcfg_inlbuf2);

        /* getting master obd */
        cmobd->master_obd = find_master_obd(obd, &master_uuid);
        if (!cmobd->master_obd) {
                CERROR("can't find master obd by uuid %s\n",
                       master_uuid.uuid);
                RETURN(-EINVAL);
        }

        /* getting cache obd */
        cmobd->cache_obd = class_uuid2obd(&cache_uuid);
        if (cmobd->cache_obd == NULL) {
                CERROR("CMOBD: unable to find obd by uuid: %s\n",
                       cache_uuid.uuid);
                RETURN(-EINVAL);
        }

        /* connecting master */
        memset(&conn, 0, sizeof(conn));
        rc = obd_connect(&conn, cmobd->master_obd, &obd->obd_uuid, NULL, 0);
        if (rc)
                RETURN(rc);
        cmobd->master_exp = class_conn2export(&conn);

        /* connecting cache */
        memset(&conn, 0, sizeof(conn));
        rc = class_connect(&conn, cmobd->cache_obd, &obd->obd_uuid);
        if (rc)
                GOTO(put_master, rc);
        cmobd->cache_exp = class_conn2export(&conn);
        
        if (cmobd_lov_obd(cmobd->master_exp->exp_obd)) {
                /* for master osc remove the recovery flag. */
                rc = obd_set_info(cmobd->master_exp, strlen("unrecovery"),
                                  "unrecovery", 0, NULL); 
                if (rc)
                        GOTO(put_cache, rc);
                
                rc = cmobd_init_write_srv(obd);
                if (rc)
                        GOTO(put_cache, rc);
        } else {
                cmobd_init_ea_size(obd);
                cmobd->write_srv = NULL;
        }

        if (cmobd_lmv_obd(cmobd->master_exp->exp_obd)) {
                /*
                 * making sure, that both obds are ready. This is especially
                 * important in the case of using LMV as master.
                 */
                rc = obd_getready(cmobd->master_exp);
                if (rc) {
                        CERROR("can't get %s obd ready.\n",
                               master_uuid.uuid);
                        GOTO(put_cache, rc);
                }
        
                rc = obd_getready(cmobd->cache_exp);
                if (rc) {
                        CERROR("can't get %s obd ready.\n",
                               cache_uuid.uuid);
                        GOTO(put_cache, rc);
                }
        
                /*
                 * requesting master obd to have its root inode store cookie to
                 * be able to save it to local root inode EA.
                 */
                valsize = sizeof(struct lustre_id);
        
                rc = obd_get_info(cmobd->master_exp, strlen("rootid"),
                                  "rootid", &valsize, &mid);
                if (rc) {
                        CERROR("can't get rootid from master MDS %s, "
                               "err= %d.\n", master_uuid.uuid, rc);
                        GOTO(put_cache, rc);
                }

                /*
                 * getting rootid from cache MDS. It is needed to update local
                 * (cache) root inode by rootid value from master obd.
                 */
                rc = obd_get_info(cmobd->cache_exp, strlen("rootid"),
                                  "rootid", &valsize, &lid);
                if (rc) {
                        CERROR("can't get rootid from local MDS %s, "
                               "err= %d.\n", cache_uuid.uuid, rc);
                        GOTO(put_cache, rc);
                }

                /* storing master MDS rootid to local root inode EA. */
                CWARN("storing "DLID4" to local inode "DLID4".\n",
                      OLID4(&mid), OLID4(&lid));

                rc = mds_update_mid(cmobd->cache_exp->exp_obd, &lid,
                                    &mid, sizeof(mid));
                if (rc) {
                        CERROR("can't update local root inode by ID "
                               "from master MDS %s, err = %d.\n",
                               master_uuid.uuid, rc);
                        GOTO(put_cache, rc);
                }
        }

        RETURN(rc);
put_cache:
        class_disconnect(cmobd->cache_exp, 0);
put_master:
        obd_disconnect(cmobd->master_exp, 0);
        return rc;
}

static int cmobd_cleanup(struct obd_device *obd, int flags)
{
        struct cm_obd *cmobd = &obd->u.cm;
        int rc;
        ENTRY;

        if (cmobd->write_srv)
                cmobd_cleanup_write_srv(obd);

        rc = obd_disconnect(cmobd->master_exp, flags);
        if (rc) {
                CERROR("error disconnecting master, err %d\n",
                       rc);
        }
        
        rc = class_disconnect(cmobd->cache_exp, flags);
        if (rc) {
                CERROR("error disconnecting cache, err %d\n",
                       rc);
        }
        
        RETURN(0);
}

static int cmobd_iocontrol(unsigned int cmd, struct obd_export *exp,
                           int len, void *karg, void *uarg)
{
        struct obd_device *obd = exp->exp_obd;
        int rc = 0;
        ENTRY;
        
        switch (cmd) {
        case OBD_IOC_CMOBD_SYNC: /* trigger reintegration */
                rc = cmobd_reintegrate(obd);
                break;
        default:
                CERROR("unrecognized ioctl %#x\n", cmd);
                rc = -EINVAL;
                break;
        }
                
        RETURN(rc);
}

static struct obd_ops cmobd_ops = {
        o_owner:                THIS_MODULE,
        o_attach:               cmobd_attach,
        o_detach:               cmobd_detach,
        o_setup:                cmobd_setup,
        o_cleanup:              cmobd_cleanup,
        o_iocontrol:            cmobd_iocontrol,
};

kmem_cache_t *cmobd_extent_slab;

static int __init cmobd_init(void)
{
        struct lprocfs_static_vars lvars;
        int rc;
        ENTRY;

        printk(KERN_INFO "Lustre: Cache Manager OBD driver; info@clusterfs.com\n");

        lprocfs_init_vars(cmobd, &lvars);
        rc = class_register_type(&cmobd_ops, NULL, lvars.module_vars,
                                 LUSTRE_CMOBD_NAME);
        if (rc)
                RETURN(rc);
        cmobd_extent_slab = kmem_cache_create("cmobd_extents",
                                               sizeof(struct cmobd_extent_info), 0,
                                               SLAB_HWCACHE_ALIGN, NULL, NULL);
        if (cmobd_extent_slab == NULL) {
                class_unregister_type(LUSTRE_CMOBD_NAME);
                RETURN(-ENOMEM);
        }
        RETURN(0);
}

static void __exit cmobd_exit(void)
{
        class_unregister_type(LUSTRE_CMOBD_NAME);
        if (kmem_cache_destroy(cmobd_extent_slab) != 0)
                CERROR("couldn't free cmobd extent slab\n");
}

MODULE_AUTHOR("Cluster File Systems, Inc. <info@clusterfs.com>");
MODULE_DESCRIPTION("Lustre Cache Manager OBD driver");
MODULE_LICENSE("GPL");

module_init(cmobd_init);
module_exit(cmobd_exit);