/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program 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 version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2013, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * Implementation of cl_device and cl_device_type for LOVSUB layer.
 *
 *   Author: Nikita Danilov <nikita.danilov@sun.com>
 */

#define DEBUG_SUBSYSTEM S_LOV

#include "lov_cl_internal.h"

/** \addtogroup lov
 *  @{
 */

/*****************************************************************************
 *
 * Lovsub transfer operations.
 *
 */

static void lovsub_req_completion(const struct lu_env *env,
                                  const struct cl_req_slice *slice, int ioret)
{
        struct lovsub_req *lsr;

        ENTRY;
        lsr = cl2lovsub_req(slice);
        OBD_SLAB_FREE_PTR(lsr, lovsub_req_kmem);
        EXIT;
}

/**
 * Implementation of struct cl_req_operations::cro_attr_set() for lovsub
 * layer. Lov and lovsub are responsible only for struct obdo::o_stripe_idx
 * field, which is filled there.
 */
static void lovsub_req_attr_set(const struct lu_env *env,
				const struct cl_req_slice *slice,
				const struct cl_object *obj,
				struct cl_req_attr *attr, u64 flags)
{
        struct lovsub_object *subobj;

        ENTRY;
        subobj = cl2lovsub(obj);
        /*
         * There is no OBD_MD_* flag for obdo::o_stripe_idx, so set it
         * unconditionally. It never changes anyway.
         */
        attr->cra_oa->o_stripe_idx = subobj->lso_index;
        EXIT;
}

static const struct cl_req_operations lovsub_req_ops = {
        .cro_attr_set   = lovsub_req_attr_set,
        .cro_completion = lovsub_req_completion
};

/*****************************************************************************
 *
 * Lov-sub device and device type functions.
 *
 */

static int lovsub_device_init(const struct lu_env *env, struct lu_device *d,
                              const char *name, struct lu_device *next)
{
        struct lovsub_device  *lsd = lu2lovsub_dev(d);
        struct lu_device_type *ldt;
        int rc;

        ENTRY;
        next->ld_site = d->ld_site;
        ldt = next->ld_type;
        LASSERT(ldt != NULL);
        rc = ldt->ldt_ops->ldto_device_init(env, next, ldt->ldt_name, NULL);
        if (rc) {
                next->ld_site = NULL;
                RETURN(rc);
        }

        lu_device_get(next);
        lu_ref_add(&next->ld_reference, "lu-stack", &lu_site_init);
        lsd->acid_next = lu2cl_dev(next);
        RETURN(rc);
}

static struct lu_device *lovsub_device_fini(const struct lu_env *env,
                                            struct lu_device *d)
{
        struct lu_device *next;
        struct lovsub_device *lsd;

        ENTRY;
        lsd = lu2lovsub_dev(d);
        next = cl2lu_dev(lsd->acid_next);
        lsd->acid_super = NULL;
        lsd->acid_next = NULL;
        RETURN(next);
}

static struct lu_device *lovsub_device_free(const struct lu_env *env,
					    struct lu_device *d)
{
	struct lovsub_device *lsd  = lu2lovsub_dev(d);
	struct lu_device     *next = cl2lu_dev(lsd->acid_next);

	if (atomic_read(&d->ld_ref) && d->ld_site) {
		LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, D_ERROR, NULL);
		lu_site_print(env, d->ld_site, &msgdata, lu_cdebug_printer);
	}
	cl_device_fini(lu2cl_dev(d));
	OBD_FREE_PTR(lsd);
	return next;
}

static int lovsub_req_init(const struct lu_env *env, struct cl_device *dev,
			   struct cl_req *req)
{
	struct lovsub_req *lsr;
	int result;

	OBD_SLAB_ALLOC_PTR_GFP(lsr, lovsub_req_kmem, GFP_NOFS);
	if (lsr != NULL) {
		cl_req_slice_add(req, &lsr->lsrq_cl, dev, &lovsub_req_ops);
		result = 0;
	} else
		result = -ENOMEM;
	return result;
}

static const struct lu_device_operations lovsub_lu_ops = {
        .ldo_object_alloc      = lovsub_object_alloc,
        .ldo_process_config    = NULL,
        .ldo_recovery_complete = NULL
};

static const struct cl_device_operations lovsub_cl_ops = {
        .cdo_req_init = lovsub_req_init
};

static struct lu_device *lovsub_device_alloc(const struct lu_env *env,
                                             struct lu_device_type *t,
                                             struct lustre_cfg *cfg)
{
        struct lu_device     *d;
        struct lovsub_device *lsd;

        OBD_ALLOC_PTR(lsd);
        if (lsd != NULL) {
                int result;

                result = cl_device_init(&lsd->acid_cl, t);
                if (result == 0) {
                        d = lovsub2lu_dev(lsd);
                        d->ld_ops         = &lovsub_lu_ops;
                        lsd->acid_cl.cd_ops = &lovsub_cl_ops;
                } else
                        d = ERR_PTR(result);
        } else
                d = ERR_PTR(-ENOMEM);
        return d;
}

static const struct lu_device_type_operations lovsub_device_type_ops = {
        .ldto_device_alloc = lovsub_device_alloc,
        .ldto_device_free  = lovsub_device_free,

        .ldto_device_init    = lovsub_device_init,
        .ldto_device_fini    = lovsub_device_fini
};

#define LUSTRE_LOVSUB_NAME         "lovsub"

struct lu_device_type lovsub_device_type = {
        .ldt_tags     = LU_DEVICE_CL,
        .ldt_name     = LUSTRE_LOVSUB_NAME,
        .ldt_ops      = &lovsub_device_type_ops,
        .ldt_ctx_tags = LCT_CL_THREAD
};


/** @} lov */