/*
 * 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) 2012, 2014, 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 LOV layer.
 *
 *   Author: Nikita Danilov <nikita.danilov@sun.com>
 */

#define DEBUG_SUBSYSTEM S_LOV

/* class_name2obd() */
#include <obd_class.h>

#include "lov_cl_internal.h"

struct kmem_cache *lov_lock_kmem;
struct kmem_cache *lov_object_kmem;
struct kmem_cache *lov_thread_kmem;
struct kmem_cache *lov_session_kmem;
struct kmem_cache *lov_req_kmem;

struct kmem_cache *lovsub_lock_kmem;
struct kmem_cache *lovsub_object_kmem;
struct kmem_cache *lovsub_req_kmem;

struct kmem_cache *lov_lock_link_kmem;

/** Lock class of lov_device::ld_mutex. */
static struct lock_class_key cl_lov_device_mutex_class;

struct lu_kmem_descr lov_caches[] = {
        {
                .ckd_cache = &lov_lock_kmem,
                .ckd_name  = "lov_lock_kmem",
                .ckd_size  = sizeof (struct lov_lock)
        },
        {
                .ckd_cache = &lov_object_kmem,
                .ckd_name  = "lov_object_kmem",
                .ckd_size  = sizeof (struct lov_object)
        },
        {
                .ckd_cache = &lov_thread_kmem,
                .ckd_name  = "lov_thread_kmem",
                .ckd_size  = sizeof (struct lov_thread_info)
        },
        {
                .ckd_cache = &lov_session_kmem,
                .ckd_name  = "lov_session_kmem",
                .ckd_size  = sizeof (struct lov_session)
        },
        {
                .ckd_cache = &lov_req_kmem,
                .ckd_name  = "lov_req_kmem",
                .ckd_size  = sizeof (struct lov_req)
        },
        {
                .ckd_cache = &lovsub_lock_kmem,
                .ckd_name  = "lovsub_lock_kmem",
                .ckd_size  = sizeof (struct lovsub_lock)
        },
        {
                .ckd_cache = &lovsub_object_kmem,
                .ckd_name  = "lovsub_object_kmem",
                .ckd_size  = sizeof (struct lovsub_object)
        },
        {
                .ckd_cache = &lovsub_req_kmem,
                .ckd_name  = "lovsub_req_kmem",
                .ckd_size  = sizeof (struct lovsub_req)
        },
        {
                .ckd_cache = &lov_lock_link_kmem,
                .ckd_name  = "lov_lock_link_kmem",
                .ckd_size  = sizeof (struct lov_lock_link)
        },
        {
                .ckd_cache = NULL
        }
};

/*****************************************************************************
 *
 * Lov transfer operations.
 *
 */

static void lov_req_completion(const struct lu_env *env,
                               const struct cl_req_slice *slice, int ioret)
{
        struct lov_req *lr;

        ENTRY;
        lr = cl2lov_req(slice);
        OBD_SLAB_FREE_PTR(lr, lov_req_kmem);
        EXIT;
}

static const struct cl_req_operations lov_req_ops = {
        .cro_completion = lov_req_completion
};

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

static void *lov_key_init(const struct lu_context *ctx,
			  struct lu_context_key *key)
{
	struct lov_thread_info *info;

	OBD_SLAB_ALLOC_PTR_GFP(info, lov_thread_kmem, GFP_NOFS);
	if (info == NULL)
		info = ERR_PTR(-ENOMEM);
	return info;
}

static void lov_key_fini(const struct lu_context *ctx,
			 struct lu_context_key *key, void *data)
{
	struct lov_thread_info *info = data;
	OBD_SLAB_FREE_PTR(info, lov_thread_kmem);
}

struct lu_context_key lov_key = {
        .lct_tags = LCT_CL_THREAD,
        .lct_init = lov_key_init,
        .lct_fini = lov_key_fini
};

static void *lov_session_key_init(const struct lu_context *ctx,
				  struct lu_context_key *key)
{
	struct lov_session *info;

	OBD_SLAB_ALLOC_PTR_GFP(info, lov_session_kmem, GFP_NOFS);
	if (info == NULL)
		info = ERR_PTR(-ENOMEM);
	return info;
}

static void lov_session_key_fini(const struct lu_context *ctx,
                                 struct lu_context_key *key, void *data)
{
        struct lov_session *info = data;
        OBD_SLAB_FREE_PTR(info, lov_session_kmem);
}

struct lu_context_key lov_session_key = {
        .lct_tags = LCT_SESSION,
        .lct_init = lov_session_key_init,
        .lct_fini = lov_session_key_fini
};

/* type constructor/destructor: lov_type_{init,fini,start,stop}() */
LU_TYPE_INIT_FINI(lov, &lov_key, &lov_session_key);

static struct lu_device *lov_device_fini(const struct lu_env *env,
                                         struct lu_device *d)
{
        int i;
        struct lov_device *ld = lu2lov_dev(d);

        LASSERT(ld->ld_lov != NULL);
        if (ld->ld_target == NULL)
                RETURN(NULL);

        lov_foreach_target(ld, i) {
                struct lovsub_device *lsd;

                lsd = ld->ld_target[i];
                if (lsd != NULL) {
                        cl_stack_fini(env, lovsub2cl_dev(lsd));
                        ld->ld_target[i] = NULL;
                }
        }
        RETURN(NULL);
}

static int lov_device_init(const struct lu_env *env, struct lu_device *d,
                           const char *name, struct lu_device *next)
{
        struct lov_device *ld = lu2lov_dev(d);
        int i;
        int rc = 0;

        LASSERT(d->ld_site != NULL);
        if (ld->ld_target == NULL)
                RETURN(rc);

        lov_foreach_target(ld, i) {
                struct lovsub_device *lsd;
                struct cl_device     *cl;
                struct lov_tgt_desc  *desc;

                desc = ld->ld_lov->lov_tgts[i];
                if (desc == NULL)
                        continue;

                cl = cl_type_setup(env, d->ld_site, &lovsub_device_type,
                                   desc->ltd_obd->obd_lu_dev);
                if (IS_ERR(cl)) {
                        rc = PTR_ERR(cl);
                        break;
                }
                lsd = cl2lovsub_dev(cl);
                lsd->acid_idx = i;
                lsd->acid_super = ld;
                ld->ld_target[i] = lsd;
        }

        if (rc)
                lov_device_fini(env, d);
        else
                ld->ld_flags |= LOV_DEV_INITIALIZED;

        RETURN(rc);
}

static int lov_req_init(const struct lu_env *env, struct cl_device *dev,
			struct cl_req *req)
{
	struct lov_req *lr;
	int result;

	ENTRY;
	OBD_SLAB_ALLOC_PTR_GFP(lr, lov_req_kmem, GFP_NOFS);
	if (lr != NULL) {
		cl_req_slice_add(req, &lr->lr_cl, dev, &lov_req_ops);
		result = 0;
	} else
		result = -ENOMEM;
	RETURN(result);
}

static const struct cl_device_operations lov_cl_ops = {
        .cdo_req_init = lov_req_init
};

static void lov_emerg_free(struct lov_device_emerg **emrg, int nr)
{
        int i;

        for (i = 0; i < nr; ++i) {
                struct lov_device_emerg *em;

                em = emrg[i];
                if (em != NULL) {
                        LASSERT(em->emrg_page_list.pl_nr == 0);
                        if (em->emrg_env != NULL)
                                cl_env_put(em->emrg_env, &em->emrg_refcheck);
                        OBD_FREE_PTR(em);
                }
        }
        OBD_FREE(emrg, nr * sizeof emrg[0]);
}

static struct lu_device *lov_device_free(const struct lu_env *env,
                                         struct lu_device *d)
{
        struct lov_device *ld = lu2lov_dev(d);
        const int          nr = ld->ld_target_nr;

        cl_device_fini(lu2cl_dev(d));
        if (ld->ld_target != NULL)
                OBD_FREE(ld->ld_target, nr * sizeof ld->ld_target[0]);
        if (ld->ld_emrg != NULL)
                lov_emerg_free(ld->ld_emrg, nr);
        OBD_FREE_PTR(ld);
        return NULL;
}

static void lov_cl_del_target(const struct lu_env *env, struct lu_device *dev,
                              __u32 index)
{
        struct lov_device *ld = lu2lov_dev(dev);
        ENTRY;

        if (ld->ld_target[index] != NULL) {
                cl_stack_fini(env, lovsub2cl_dev(ld->ld_target[index]));
                ld->ld_target[index] = NULL;
        }
        EXIT;
}

static struct lov_device_emerg **lov_emerg_alloc(int nr)
{
        struct lov_device_emerg **emerg;
        int i;
        int result;

        OBD_ALLOC(emerg, nr * sizeof emerg[0]);
        if (emerg == NULL)
                return ERR_PTR(-ENOMEM);
        for (result = i = 0; i < nr && result == 0; i++) {
                struct lov_device_emerg *em;

                OBD_ALLOC_PTR(em);
                if (em != NULL) {
                        emerg[i] = em;
                        cl_page_list_init(&em->emrg_page_list);
                        em->emrg_env = cl_env_alloc(&em->emrg_refcheck,
                                                    LCT_REMEMBER|LCT_NOREF);
                        if (!IS_ERR(em->emrg_env))
                                em->emrg_env->le_ctx.lc_cookie = 0x2;
                        else {
                                result = PTR_ERR(em->emrg_env);
                                em->emrg_env = NULL;
                        }
                } else
                        result = -ENOMEM;
        }
        if (result != 0) {
                lov_emerg_free(emerg, nr);
                emerg = ERR_PTR(result);
        }
        return emerg;
}

static int lov_expand_targets(const struct lu_env *env, struct lov_device *dev)
{
        int   result;
        __u32 tgt_size;
        __u32 sub_size;

        ENTRY;
        result = 0;
        tgt_size = dev->ld_lov->lov_tgt_size;
        sub_size = dev->ld_target_nr;
        if (sub_size < tgt_size) {
                struct lovsub_device    **newd;
                struct lov_device_emerg **emerg;
                const size_t              sz   = sizeof newd[0];

                emerg = lov_emerg_alloc(tgt_size);
                if (IS_ERR(emerg))
                        RETURN(PTR_ERR(emerg));

                OBD_ALLOC(newd, tgt_size * sz);
                if (newd != NULL) {
			mutex_lock(&dev->ld_mutex);
                        if (sub_size > 0) {
                                memcpy(newd, dev->ld_target, sub_size * sz);
                                OBD_FREE(dev->ld_target, sub_size * sz);
                        }
                        dev->ld_target    = newd;
                        dev->ld_target_nr = tgt_size;

                        if (dev->ld_emrg != NULL)
                                lov_emerg_free(dev->ld_emrg, sub_size);
                        dev->ld_emrg = emerg;
			mutex_unlock(&dev->ld_mutex);
                } else {
                        lov_emerg_free(emerg, tgt_size);
                        result = -ENOMEM;
                }
        }
        RETURN(result);
}

static int lov_cl_add_target(const struct lu_env *env, struct lu_device *dev,
                             __u32 index)
{
        struct obd_device    *obd = dev->ld_obd;
        struct lov_device    *ld  = lu2lov_dev(dev);
        struct lov_tgt_desc  *tgt;
        struct lovsub_device *lsd;
        struct cl_device     *cl;
        int rc;
        ENTRY;

        obd_getref(obd);

        tgt = obd->u.lov.lov_tgts[index];
        LASSERT(tgt != NULL);
        LASSERT(tgt->ltd_obd != NULL);

        if (!tgt->ltd_obd->obd_set_up) {
                CERROR("Target %s not set up\n", obd_uuid2str(&tgt->ltd_uuid));
                RETURN(-EINVAL);
        }

        rc = lov_expand_targets(env, ld);
        if (rc == 0 && ld->ld_flags & LOV_DEV_INITIALIZED) {
                LASSERT(dev->ld_site != NULL);

                cl = cl_type_setup(env, dev->ld_site, &lovsub_device_type,
                                   tgt->ltd_obd->obd_lu_dev);
                if (!IS_ERR(cl)) {
                        lsd = cl2lovsub_dev(cl);
                        lsd->acid_idx = index;
                        lsd->acid_super = ld;
                        ld->ld_target[index] = lsd;
                } else {
                        CERROR("add failed (%d), deleting %s\n", rc,
                               obd_uuid2str(&tgt->ltd_uuid));
                        lov_cl_del_target(env, dev, index);
                        rc = PTR_ERR(cl);
                }
        }
        obd_putref(obd);
        RETURN(rc);
}

static int lov_process_config(const struct lu_env *env,
                              struct lu_device *d, struct lustre_cfg *cfg)
{
        struct obd_device *obd = d->ld_obd;
        int cmd;
        int rc;
        int gen;
        __u32 index;

        obd_getref(obd);

        cmd = cfg->lcfg_command;
        rc = lov_process_config_base(d->ld_obd, cfg, &index, &gen);
        if (rc == 0) {
                switch(cmd) {
                case LCFG_LOV_ADD_OBD:
                case LCFG_LOV_ADD_INA:
                        rc = lov_cl_add_target(env, d, index);
                        if (rc != 0)
				lov_del_target(d->ld_obd, index, NULL, 0);
                        break;
                case LCFG_LOV_DEL_OBD:
                        lov_cl_del_target(env, d, index);
                        break;
                }
        }
        obd_putref(obd);
        RETURN(rc);
}

static const struct lu_device_operations lov_lu_ops = {
        .ldo_object_alloc      = lov_object_alloc,
        .ldo_process_config    = lov_process_config,
};

static struct lu_device *lov_device_alloc(const struct lu_env *env,
                                          struct lu_device_type *t,
                                          struct lustre_cfg *cfg)
{
        struct lu_device *d;
        struct lov_device *ld;
        struct obd_device *obd;
        int rc;

        OBD_ALLOC_PTR(ld);
        if (ld == NULL)
                RETURN(ERR_PTR(-ENOMEM));

        cl_device_init(&ld->ld_cl, t);
        d = lov2lu_dev(ld);
        d->ld_ops        = &lov_lu_ops;
        ld->ld_cl.cd_ops = &lov_cl_ops;

	mutex_init(&ld->ld_mutex);
	lockdep_set_class(&ld->ld_mutex, &cl_lov_device_mutex_class);

        /* setup the LOV OBD */
        obd = class_name2obd(lustre_cfg_string(cfg, 0));
        LASSERT(obd != NULL);
        rc = lov_setup(obd, cfg);
        if (rc) {
                lov_device_free(env, d);
                RETURN(ERR_PTR(rc));
        }

        ld->ld_lov = &obd->u.lov;
        RETURN(d);
}

static const struct lu_device_type_operations lov_device_type_ops = {
        .ldto_init = lov_type_init,
        .ldto_fini = lov_type_fini,

        .ldto_start = lov_type_start,
        .ldto_stop  = lov_type_stop,

        .ldto_device_alloc = lov_device_alloc,
        .ldto_device_free  = lov_device_free,

        .ldto_device_init    = lov_device_init,
        .ldto_device_fini    = lov_device_fini
};

struct lu_device_type lov_device_type = {
        .ldt_tags     = LU_DEVICE_CL,
        .ldt_name     = LUSTRE_LOV_NAME,
        .ldt_ops      = &lov_device_type_ops,
        .ldt_ctx_tags = LCT_CL_THREAD
};

/** @} lov */