[fs/lustre-release.git] / lustre / osd / osd_handler.c

/* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
 * vim:expandtab:shiftwidth=8:tabstop=8:
 *
 * 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  2008 Sun Microsystems, Inc. All rights reserved
 * Use is subject to license terms.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 *
 * lustre/osd/osd_handler.c
 *
 * Top-level entry points into osd module
 *
 * Author: Nikita Danilov <nikita@clusterfs.com>
 *         Pravin Shelar <pravin.shelar@sun.com> : Added fid in dirent
 */

#ifndef EXPORT_SYMTAB
# define EXPORT_SYMTAB
#endif
#define DEBUG_SUBSYSTEM S_MDS

#include <linux/module.h>

/* LUSTRE_VERSION_CODE */
#include <lustre_ver.h>
/* prerequisite for linux/xattr.h */
#include <linux/types.h>
/* prerequisite for linux/xattr.h */
#include <linux/fs.h>
/* XATTR_{REPLACE,CREATE} */
#include <linux/xattr.h>
/* simple_mkdir() */
#include <lvfs.h>

/*
 * struct OBD_{ALLOC,FREE}*()
 * OBD_FAIL_CHECK
 */
#include <obd_support.h>
/* struct ptlrpc_thread */
#include <lustre_net.h>

/* fid_is_local() */
#include <lustre_fid.h>

#include "osd_internal.h"
#include "osd_igif.h"

/* llo_* api support */
#include <md_object.h>

static const char dot[] = ".";
static const char dotdot[] = "..";
static const char remote_obj_dir[] = "REM_OBJ_DIR";

struct osd_directory {
        struct iam_container od_container;
        struct iam_descr     od_descr;
};

struct osd_object {
        struct dt_object       oo_dt;
        /**
         * Inode for file system object represented by this osd_object. This
         * inode is pinned for the whole duration of lu_object life.
         *
         * Not modified concurrently (either setup early during object
         * creation, or assigned by osd_object_create() under write lock).
         */
        struct inode          *oo_inode;
        /**
         * to protect index ops.
         */
        cfs_rw_semaphore_t     oo_ext_idx_sem;
        cfs_rw_semaphore_t     oo_sem;
        struct osd_directory  *oo_dir;
        /** protects inode attributes. */
        cfs_spinlock_t         oo_guard;
        /**
         * Following two members are used to indicate the presence of dot and
         * dotdot in the given directory. This is required for interop mode
         * (b11826).
         */
        int                    oo_compat_dot_created;
        int                    oo_compat_dotdot_created;

        const struct lu_env   *oo_owner;
#ifdef CONFIG_LOCKDEP
        struct lockdep_map     oo_dep_map;
#endif
};

static const struct lu_object_operations      osd_lu_obj_ops;
static const struct lu_device_operations      osd_lu_ops;
static       struct lu_context_key            osd_key;
static const struct dt_object_operations      osd_obj_ops;
static const struct dt_object_operations      osd_obj_ea_ops;
static const struct dt_body_operations        osd_body_ops;
static const struct dt_index_operations       osd_index_iam_ops;
static const struct dt_index_operations       osd_index_ea_ops;

struct osd_thandle {
        struct thandle          ot_super;
        handle_t               *ot_handle;
        struct journal_callback ot_jcb;
        /* Link to the device, for debugging. */
        struct lu_ref_link     *ot_dev_link;

};

/*
 * Helpers.
 */
static int lu_device_is_osd(const struct lu_device *d)
{
        return ergo(d != NULL && d->ld_ops != NULL, d->ld_ops == &osd_lu_ops);
}

static struct osd_device *osd_dt_dev(const struct dt_device *d)
{
        LASSERT(lu_device_is_osd(&d->dd_lu_dev));
        return container_of0(d, struct osd_device, od_dt_dev);
}

static struct osd_device *osd_dev(const struct lu_device *d)
{
        LASSERT(lu_device_is_osd(d));
        return osd_dt_dev(container_of0(d, struct dt_device, dd_lu_dev));
}

static struct osd_device *osd_obj2dev(const struct osd_object *o)
{
        return osd_dev(o->oo_dt.do_lu.lo_dev);
}

static struct super_block *osd_sb(const struct osd_device *dev)
{
        return dev->od_mount->lmi_mnt->mnt_sb;
}

static int osd_object_is_root(const struct osd_object *obj)
{
        return osd_sb(osd_obj2dev(obj))->s_root->d_inode == obj->oo_inode;
}

static struct osd_object *osd_obj(const struct lu_object *o)
{
        LASSERT(lu_device_is_osd(o->lo_dev));
        return container_of0(o, struct osd_object, oo_dt.do_lu);
}

static struct osd_object *osd_dt_obj(const struct dt_object *d)
{
        return osd_obj(&d->do_lu);
}

static struct lu_device *osd2lu_dev(struct osd_device *osd)
{
        return &osd->od_dt_dev.dd_lu_dev;
}

static journal_t *osd_journal(const struct osd_device *dev)
{
        return LDISKFS_SB(osd_sb(dev))->s_journal;
}

static int osd_has_index(const struct osd_object *obj)
{
        return obj->oo_dt.do_index_ops != NULL;
}

static int osd_object_invariant(const struct lu_object *l)
{
        return osd_invariant(osd_obj(l));
}

#ifdef HAVE_QUOTA_SUPPORT
static inline void
osd_push_ctxt(const struct lu_env *env, struct osd_ctxt *save)
{
        struct md_ucred    *uc = md_ucred(env);

        LASSERT(uc != NULL);

        save->oc_uid = current->fsuid;
        save->oc_gid = current->fsgid;
        save->oc_cap = current->cap_effective;
        current->fsuid         = uc->mu_fsuid;
        current->fsgid         = uc->mu_fsgid;
        current->cap_effective = uc->mu_cap;
}

static inline void
osd_pop_ctxt(struct osd_ctxt *save)
{
        current->fsuid         = save->oc_uid;
        current->fsgid         = save->oc_gid;
        current->cap_effective = save->oc_cap;
}
#endif

static inline struct osd_thread_info *osd_oti_get(const struct lu_env *env)
{
        return lu_context_key_get(&env->le_ctx, &osd_key);
}

/*
 * Concurrency: doesn't matter
 */
static int osd_read_locked(const struct lu_env *env, struct osd_object *o)
{
        return osd_oti_get(env)->oti_r_locks > 0;
}

/*
 * Concurrency: doesn't matter
 */
static int osd_write_locked(const struct lu_env *env, struct osd_object *o)
{
        struct osd_thread_info *oti = osd_oti_get(env);
        return oti->oti_w_locks > 0 && o->oo_owner == env;
}

/*
 * Concurrency: doesn't access mutable data
 */
static int osd_root_get(const struct lu_env *env,
                        struct dt_device *dev, struct lu_fid *f)
{
        struct inode *inode;

        inode = osd_sb(osd_dt_dev(dev))->s_root->d_inode;
        lu_igif_build(f, inode->i_ino, inode->i_generation);
        return 0;
}

/*
 * OSD object methods.
 */

/*
 * Concurrency: no concurrent access is possible that early in object
 * life-cycle.
 */
static struct lu_object *osd_object_alloc(const struct lu_env *env,
                                          const struct lu_object_header *hdr,
                                          struct lu_device *d)
{
        struct osd_object *mo;

        OBD_ALLOC_PTR(mo);
        if (mo != NULL) {
                struct lu_object *l;

                l = &mo->oo_dt.do_lu;
                dt_object_init(&mo->oo_dt, NULL, d);
                if (osd_dev(d)->od_iop_mode)
                        mo->oo_dt.do_ops = &osd_obj_ea_ops;
                else
                        mo->oo_dt.do_ops = &osd_obj_ops;

                l->lo_ops = &osd_lu_obj_ops;
                cfs_init_rwsem(&mo->oo_sem);
                cfs_init_rwsem(&mo->oo_ext_idx_sem);
                cfs_spin_lock_init(&mo->oo_guard);
                return l;
        } else
                return NULL;
}

/*
 * retrieve object from backend ext fs.
 **/
static struct inode *osd_iget(struct osd_thread_info *info,
                              struct osd_device *dev,
                              const struct osd_inode_id *id)
{
        struct inode *inode = NULL;

#ifdef HAVE_EXT4_LDISKFS
        inode = ldiskfs_iget(osd_sb(dev), id->oii_ino);
        if (IS_ERR(inode))
        /* Newer kernels return an error instead of a NULL pointer */
                inode = NULL;
#else
        inode = iget(osd_sb(dev), id->oii_ino);
#endif
        if (inode == NULL) {
                CERROR("no inode\n");
                inode = ERR_PTR(-EACCES);
        } else if (id->oii_gen != OSD_OII_NOGEN &&
                   inode->i_generation != id->oii_gen) {
                iput(inode);
                inode = ERR_PTR(-ESTALE);
        } else if (inode->i_nlink == 0) {
                /* due to parallel readdir and unlink,
                * we can have dead inode here. */
                CWARN("stale inode\n");
                make_bad_inode(inode);
                iput(inode);
                inode = ERR_PTR(-ESTALE);
        } else if (is_bad_inode(inode)) {
                CERROR("bad inode %lx\n",inode->i_ino);
                iput(inode);
                inode = ERR_PTR(-ENOENT);
        }
        return inode;
}

static int osd_fid_lookup(const struct lu_env *env,
                          struct osd_object *obj, const struct lu_fid *fid)
{
        struct osd_thread_info *info;
        struct lu_device       *ldev = obj->oo_dt.do_lu.lo_dev;
        struct osd_device      *dev;
        struct osd_inode_id    *id;
        struct osd_oi          *oi;
        struct inode           *inode;
        int                     result;

        LINVRNT(osd_invariant(obj));
        LASSERT(obj->oo_inode == NULL);
        LASSERT(fid_is_sane(fid));
        /*
         * This assertion checks that osd layer sees only local
         * fids. Unfortunately it is somewhat expensive (does a
         * cache-lookup). Disabling it for production/acceptance-testing.
         */
        LASSERT(1 || fid_is_local(env, ldev->ld_site, fid));

        ENTRY;

        info = osd_oti_get(env);
        dev  = osd_dev(ldev);
        id   = &info->oti_id;
        oi   = &dev->od_oi;

        if (OBD_FAIL_CHECK(OBD_FAIL_OST_ENOENT))
                RETURN(-ENOENT);

        result = osd_oi_lookup(info, oi, fid, id);
        if (result == 0) {
                inode = osd_iget(info, dev, id);
                if (!IS_ERR(inode)) {
                        obj->oo_inode = inode;
                        LASSERT(obj->oo_inode->i_sb == osd_sb(dev));
                        if (dev->od_iop_mode) {
                                obj->oo_compat_dot_created = 1;
                                obj->oo_compat_dotdot_created = 1;
                        }
                        result = 0;
                } else
                        /*
                         * If fid wasn't found in oi, inode-less object is
                         * created, for which lu_object_exists() returns
                         * false. This is used in a (frequent) case when
                         * objects are created as locking anchors or
                         * place holders for objects yet to be created.
                         */
                        result = PTR_ERR(inode);
        } else if (result == -ENOENT)
                result = 0;
        LINVRNT(osd_invariant(obj));

        RETURN(result);
}

/*
 * Concurrency: shouldn't matter.
 */
static void osd_object_init0(struct osd_object *obj)
{
        LASSERT(obj->oo_inode != NULL);
        obj->oo_dt.do_body_ops = &osd_body_ops;
        obj->oo_dt.do_lu.lo_header->loh_attr |=
                (LOHA_EXISTS | (obj->oo_inode->i_mode & S_IFMT));
}

/*
 * Concurrency: no concurrent access is possible that early in object
 * life-cycle.
 */
static int osd_object_init(const struct lu_env *env, struct lu_object *l,
                           const struct lu_object_conf *unused)
{
        struct osd_object *obj = osd_obj(l);
        int result;

        LINVRNT(osd_invariant(obj));

        result = osd_fid_lookup(env, obj, lu_object_fid(l));
        if (result == 0) {
                if (obj->oo_inode != NULL)
                        osd_object_init0(obj);
        }
        LINVRNT(osd_invariant(obj));
        return result;
}

/*
 * Concurrency: no concurrent access is possible that late in object
 * life-cycle.
 */
static void osd_object_free(const struct lu_env *env, struct lu_object *l)
{
        struct osd_object *obj = osd_obj(l);

        LINVRNT(osd_invariant(obj));

        dt_object_fini(&obj->oo_dt);
        OBD_FREE_PTR(obj);
}

/**
 * IAM Iterator
 */
static struct iam_path_descr *osd_it_ipd_get(const struct lu_env *env,
                                             const struct iam_container *bag)
{
        return bag->ic_descr->id_ops->id_ipd_alloc(bag,
                                           osd_oti_get(env)->oti_it_ipd);
}

static struct iam_path_descr *osd_idx_ipd_get(const struct lu_env *env,
                                              const struct iam_container *bag)
{
        return bag->ic_descr->id_ops->id_ipd_alloc(bag,
                                           osd_oti_get(env)->oti_idx_ipd);
}

static void osd_ipd_put(const struct lu_env *env,
                        const struct iam_container *bag,
                        struct iam_path_descr *ipd)
{
        bag->ic_descr->id_ops->id_ipd_free(ipd);
}

/*
 * Concurrency: no concurrent access is possible that late in object
 * life-cycle.
 */
static void osd_index_fini(struct osd_object *o)
{
        struct iam_container *bag;

        if (o->oo_dir != NULL) {
                bag = &o->oo_dir->od_container;
                if (o->oo_inode != NULL) {
                        if (bag->ic_object == o->oo_inode)
                                iam_container_fini(bag);
                }
                OBD_FREE_PTR(o->oo_dir);
                o->oo_dir = NULL;
        }
}

/*
 * Concurrency: no concurrent access is possible that late in object
 * life-cycle (for all existing callers, that is. New callers have to provide
 * their own locking.)
 */
static int osd_inode_unlinked(const struct inode *inode)
{
        return inode->i_nlink == 0;
}

enum {
        OSD_TXN_OI_DELETE_CREDITS    = 20,
        OSD_TXN_INODE_DELETE_CREDITS = 20
};

/*
 * Journal
 */

/*
 * Concurrency: doesn't access mutable data.
 */
static int osd_param_is_sane(const struct osd_device *dev,
                             const struct txn_param *param)
{
        return param->tp_credits <= osd_journal(dev)->j_max_transaction_buffers;
}

/*
 * Concurrency: shouldn't matter.
 */
static void osd_trans_commit_cb(struct journal_callback *jcb, int error)
{
        struct osd_thandle *oh = container_of0(jcb, struct osd_thandle, ot_jcb);
        struct thandle     *th  = &oh->ot_super;
        struct dt_device   *dev = th->th_dev;
        struct lu_device   *lud = &dev->dd_lu_dev;

        LASSERT(dev != NULL);
        LASSERT(oh->ot_handle == NULL);

        if (error) {
                CERROR("transaction @0x%p commit error: %d\n", th, error);
        } else {
                struct lu_env *env = &osd_dt_dev(dev)->od_env_for_commit;
                /*
                 * This od_env_for_commit is only for commit usage.  see
                 * "struct dt_device"
                 */
                lu_context_enter(&env->le_ctx);
                dt_txn_hook_commit(env, th);
                lu_context_exit(&env->le_ctx);
        }

        lu_ref_del_at(&lud->ld_reference, oh->ot_dev_link, "osd-tx", th);
        lu_device_put(lud);
        th->th_dev = NULL;

        lu_context_exit(&th->th_ctx);
        lu_context_fini(&th->th_ctx);
        OBD_FREE_PTR(oh);
}

/*
 * Concurrency: shouldn't matter.
 */
static struct thandle *osd_trans_start(const struct lu_env *env,
                                       struct dt_device *d,
                                       struct txn_param *p)
{
        struct osd_device  *dev = osd_dt_dev(d);
        handle_t           *jh;
        struct osd_thandle *oh;
        struct thandle     *th;
        int hook_res;

        ENTRY;

        hook_res = dt_txn_hook_start(env, d, p);
        if (hook_res != 0)
                RETURN(ERR_PTR(hook_res));

        if (osd_param_is_sane(dev, p)) {
                OBD_ALLOC_GFP(oh, sizeof *oh, CFS_ALLOC_IO);
                if (oh != NULL) {
                        struct osd_thread_info *oti = osd_oti_get(env);

                        /*
                         * XXX temporary stuff. Some abstraction layer should
                         * be used.
                         */

                        jh = ldiskfs_journal_start_sb(osd_sb(dev), p->tp_credits);
                        if (!IS_ERR(jh)) {
                                oh->ot_handle = jh;
                                th = &oh->ot_super;
                                th->th_dev = d;
                                th->th_result = 0;
                                jh->h_sync = p->tp_sync;
                                lu_device_get(&d->dd_lu_dev);
                                oh->ot_dev_link = lu_ref_add
                                        (&d->dd_lu_dev.ld_reference,
                                         "osd-tx", th);
                                /* add commit callback */
                                lu_context_init(&th->th_ctx, LCT_TX_HANDLE);
                                lu_context_enter(&th->th_ctx);
                                osd_journal_callback_set(jh, osd_trans_commit_cb,
                                                         (struct journal_callback *)&oh->ot_jcb);
                                        LASSERT(oti->oti_txns == 0);
                                        LASSERT(oti->oti_r_locks == 0);
                                        LASSERT(oti->oti_w_locks == 0);
                                        oti->oti_txns++;
                        } else {
                                OBD_FREE_PTR(oh);
                                th = (void *)jh;
                        }
                } else
                        th = ERR_PTR(-ENOMEM);
        } else {
                CERROR("Invalid transaction parameters\n");
                th = ERR_PTR(-EINVAL);
        }

        RETURN(th);
}

/*
 * Concurrency: shouldn't matter.
 */
static void osd_trans_stop(const struct lu_env *env, struct thandle *th)
{
        int result;
        struct osd_thandle *oh;
        struct osd_thread_info *oti = osd_oti_get(env);

        ENTRY;

        oh = container_of0(th, struct osd_thandle, ot_super);
        if (oh->ot_handle != NULL) {
                handle_t *hdl = oh->ot_handle;

                LASSERT(oti->oti_txns == 1);
                oti->oti_txns--;
                LASSERT(oti->oti_r_locks == 0);
                LASSERT(oti->oti_w_locks == 0);
                result = dt_txn_hook_stop(env, th);
                if (result != 0)
                        CERROR("Failure in transaction hook: %d\n", result);
                oh->ot_handle = NULL;
                result = ldiskfs_journal_stop(hdl);
                if (result != 0)
                        CERROR("Failure to stop transaction: %d\n", result);
        }
        EXIT;
}

/*
 * Concurrency: no concurrent access is possible that late in object
 * life-cycle.
 */
static int osd_inode_remove(const struct lu_env *env, struct osd_object *obj)
{
        const struct lu_fid    *fid = lu_object_fid(&obj->oo_dt.do_lu);
        struct osd_device      *osd = osd_obj2dev(obj);
        struct osd_thread_info *oti = osd_oti_get(env);
        struct txn_param       *prm = &oti->oti_txn;
        struct lu_env          *env_del_obj = &oti->oti_obj_delete_tx_env;
        struct thandle         *th;
        int result;

        lu_env_init(env_del_obj, LCT_DT_THREAD);
        txn_param_init(prm, OSD_TXN_OI_DELETE_CREDITS +
                            OSD_TXN_INODE_DELETE_CREDITS);
        th = osd_trans_start(env_del_obj, &osd->od_dt_dev, prm);
        if (!IS_ERR(th)) {
                result = osd_oi_delete(osd_oti_get(env_del_obj),
                                       &osd->od_oi, fid, th);
                osd_trans_stop(env_del_obj, th);
        } else
                result = PTR_ERR(th);

        lu_env_fini(env_del_obj);
        return result;
}

/*
 * Called just before object is freed. Releases all resources except for
 * object itself (that is released by osd_object_free()).
 *
 * Concurrency: no concurrent access is possible that late in object
 * life-cycle.
 */
static void osd_object_delete(const struct lu_env *env, struct lu_object *l)
{
        struct osd_object *obj   = osd_obj(l);
        struct inode      *inode = obj->oo_inode;

        LINVRNT(osd_invariant(obj));

        /*
         * If object is unlinked remove fid->ino mapping from object index.
         */

        osd_index_fini(obj);
        if (inode != NULL) {
                int result;

                if (osd_inode_unlinked(inode)) {
                        result = osd_inode_remove(env, obj);
                        if (result != 0)
                                LU_OBJECT_DEBUG(D_ERROR, env, l,
                                                "Failed to cleanup: %d\n",
                                                result);
                }

                iput(inode);
                obj->oo_inode = NULL;
        }
}

/*
 * Concurrency: ->loo_object_release() is called under site spin-lock.
 */
static void osd_object_release(const struct lu_env *env,
                               struct lu_object *l)
{
        struct osd_object *o = osd_obj(l);

        LASSERT(!lu_object_is_dying(l->lo_header));
        if (o->oo_inode != NULL && osd_inode_unlinked(o->oo_inode))
                cfs_set_bit(LU_OBJECT_HEARD_BANSHEE, &l->lo_header->loh_flags);
}

/*
 * Concurrency: shouldn't matter.
 */
static int osd_object_print(const struct lu_env *env, void *cookie,
                            lu_printer_t p, const struct lu_object *l)
{
        struct osd_object *o = osd_obj(l);
        struct iam_descr  *d;

        if (o->oo_dir != NULL)
                d = o->oo_dir->od_container.ic_descr;
        else
                d = NULL;
        return (*p)(env, cookie, LUSTRE_OSD_NAME"-object@%p(i:%p:%lu/%u)[%s]",
                    o, o->oo_inode,
                    o->oo_inode ? o->oo_inode->i_ino : 0UL,
                    o->oo_inode ? o->oo_inode->i_generation : 0,
                    d ? d->id_ops->id_name : "plain");
}

/*
 * Concurrency: shouldn't matter.
 */
int osd_statfs(const struct lu_env *env, struct dt_device *d,
               cfs_kstatfs_t *sfs)
{
        struct osd_device *osd = osd_dt_dev(d);
        struct super_block *sb = osd_sb(osd);
        int result = 0;

        cfs_spin_lock(&osd->od_osfs_lock);
        /* cache 1 second */
        if (cfs_time_before_64(osd->od_osfs_age, cfs_time_shift_64(-1))) {
                result = ll_do_statfs(sb, &osd->od_kstatfs);
                if (likely(result == 0)) /* N.B. statfs can't really fail */
                        osd->od_osfs_age = cfs_time_current_64();
        }

        if (likely(result == 0))
                *sfs = osd->od_kstatfs;
        cfs_spin_unlock(&osd->od_osfs_lock);

        return result;
}

/*
 * Concurrency: doesn't access mutable data.
 */
static void osd_conf_get(const struct lu_env *env,
                         const struct dt_device *dev,
                         struct dt_device_param *param)
{
        /*
         * XXX should be taken from not-yet-existing fs abstraction layer.
         */
        param->ddp_max_name_len  = LDISKFS_NAME_LEN;
        param->ddp_max_nlink     = LDISKFS_LINK_MAX;
        param->ddp_block_shift   = osd_sb(osd_dt_dev(dev))->s_blocksize_bits;
}

/**
 * Helper function to get and fill the buffer with input values.
 */
static struct lu_buf *osd_buf_get(const struct lu_env *env, void *area, ssize_t len)
{
        struct lu_buf *buf;

        buf = &osd_oti_get(env)->oti_buf;
        buf->lb_buf = area;
        buf->lb_len = len;
        return buf;
}

/*
 * Concurrency: shouldn't matter.
 */
static int osd_sync(const struct lu_env *env, struct dt_device *d)
{
        CDEBUG(D_HA, "syncing OSD %s\n", LUSTRE_OSD_NAME);
        return ldiskfs_force_commit(osd_sb(osd_dt_dev(d)));
}

/**
 * Start commit for OSD device.
 *
 * An implementation of dt_commit_async method for OSD device.
 * Asychronously starts underlayng fs sync and thereby a transaction
 * commit.
 *
 * \param env environment
 * \param d dt device
 *
 * \see dt_device_operations
 */
static int osd_commit_async(const struct lu_env *env,
                            struct dt_device *d)
{
        struct super_block *s = osd_sb(osd_dt_dev(d));
        ENTRY;

        CDEBUG(D_HA, "async commit OSD %s\n", LUSTRE_OSD_NAME);
        RETURN(s->s_op->sync_fs(s, 0));
}

/*
 * Concurrency: shouldn't matter.
 */
lvfs_sbdev_type fsfilt_ldiskfs_journal_sbdev(struct super_block *);

static void osd_ro(const struct lu_env *env, struct dt_device *d)
{
        ENTRY;

        CERROR("*** setting device %s read-only ***\n", LUSTRE_OSD_NAME);

        __lvfs_set_rdonly(lvfs_sbdev(osd_sb(osd_dt_dev(d))),
                          fsfilt_ldiskfs_journal_sbdev(osd_sb(osd_dt_dev(d))));
        EXIT;
}


/*
 * Concurrency: serialization provided by callers.
 */
static int osd_init_capa_ctxt(const struct lu_env *env, struct dt_device *d,
                              int mode, unsigned long timeout, __u32 alg,
                              struct lustre_capa_key *keys)
{
        struct osd_device *dev = osd_dt_dev(d);
        ENTRY;

        dev->od_fl_capa = mode;
        dev->od_capa_timeout = timeout;
        dev->od_capa_alg = alg;
        dev->od_capa_keys = keys;
        RETURN(0);
}

/**
 * Concurrency: serialization provided by callers.
 */
static void osd_init_quota_ctxt(const struct lu_env *env, struct dt_device *d,
                               struct dt_quota_ctxt *ctxt, void *data)
{
        struct obd_device *obd = (void *)ctxt;
        struct vfsmount *mnt = (struct vfsmount *)data;
        ENTRY;

        obd->u.obt.obt_sb = mnt->mnt_root->d_inode->i_sb;
        OBD_SET_CTXT_MAGIC(&obd->obd_lvfs_ctxt);
        obd->obd_lvfs_ctxt.pwdmnt = mnt;
        obd->obd_lvfs_ctxt.pwd = mnt->mnt_root;
        obd->obd_lvfs_ctxt.fs = get_ds();

        EXIT;
}

/**
 * Note: we do not count into QUOTA here.
 * If we mount with --data_journal we may need more.
 */
static const int osd_dto_credits_noquota[DTO_NR] = {
        /**
         * Insert/Delete.
         * INDEX_EXTRA_TRANS_BLOCKS(8) +
         * SINGLEDATA_TRANS_BLOCKS(8)
         * XXX Note: maybe iam need more, since iam have more level than
         *           EXT3 htree.
         */
        [DTO_INDEX_INSERT]  = 16,
        [DTO_INDEX_DELETE]  = 16,
        /**
         * Unused now
         */
        [DTO_IDNEX_UPDATE]  = 16,
        /**
         * Create a object. The same as create object in EXT3.
         * DATA_TRANS_BLOCKS(14) +
         * INDEX_EXTRA_BLOCKS(8) +
         * 3(inode bits, groups, GDT)
         */
        [DTO_OBJECT_CREATE] = 25,
        /**
         * Unused now
         */
        [DTO_OBJECT_DELETE] = 25,
        /**
         * Attr set credits.
         * 3(inode bits, group, GDT)
         */
        [DTO_ATTR_SET_BASE] = 3,
        /**
         * Xattr set. The same as xattr of EXT3.
         * DATA_TRANS_BLOCKS(14)
         * XXX Note: in original MDS implmentation INDEX_EXTRA_TRANS_BLOCKS
         * are also counted in. Do not know why?
         */
        [DTO_XATTR_SET]     = 14,
        [DTO_LOG_REC]       = 14,
        /**
         * creadits for inode change during write.
         */
        [DTO_WRITE_BASE]    = 3,
        /**
         * credits for single block write.
         */
        [DTO_WRITE_BLOCK]   = 14,
        /**
         * Attr set credits for chown.
         * This is extra credits for setattr, and it is null without quota
         */
        [DTO_ATTR_SET_CHOWN]= 0
};

/**
 * Note: we count into QUOTA here.
 * If we mount with --data_journal we may need more.
 */
static const int osd_dto_credits_quota[DTO_NR] = {
        /**
         * INDEX_EXTRA_TRANS_BLOCKS(8) +
         * SINGLEDATA_TRANS_BLOCKS(8) +
         * 2 * QUOTA_TRANS_BLOCKS(2)
         */
        [DTO_INDEX_INSERT]  = 20,
        /**
         * INDEX_EXTRA_TRANS_BLOCKS(8) +
         * SINGLEDATA_TRANS_BLOCKS(8) +
         * 2 * QUOTA_TRANS_BLOCKS(2)
         */
        [DTO_INDEX_DELETE]  = 20,
        /**
         * Unused now.
         */
        [DTO_IDNEX_UPDATE]  = 16,
        /*
         * Create a object. Same as create object in EXT3 filesystem.
         * DATA_TRANS_BLOCKS(16) +
         * INDEX_EXTRA_BLOCKS(8) +
         * 3(inode bits, groups, GDT) +
         * 2 * QUOTA_INIT_BLOCKS(25)
         */
        [DTO_OBJECT_CREATE] = 77,
        /*
         * Unused now.
         * DATA_TRANS_BLOCKS(16) +
         * INDEX_EXTRA_BLOCKS(8) +
         * 3(inode bits, groups, GDT) +
         * QUOTA(?)
         */
        [DTO_OBJECT_DELETE] = 27,
        /**
         * Attr set credits.
         * 3 (inode bit, group, GDT) +
         */
        [DTO_ATTR_SET_BASE] = 3,
        /**
         * Xattr set. The same as xattr of EXT3.
         * DATA_TRANS_BLOCKS(16)
         * XXX Note: in original MDS implmentation INDEX_EXTRA_TRANS_BLOCKS are
         *           also counted in. Do not know why?
         */
        [DTO_XATTR_SET]     = 16,
        [DTO_LOG_REC]       = 16,
        /**
         * creadits for inode change during write.
         */
        [DTO_WRITE_BASE]    = 3,
        /**
         * credits for single block write.
         */
        [DTO_WRITE_BLOCK]   = 16,
        /**
         * Attr set credits for chown.
         * It is added to already set setattr credits
         * 2 * QUOTA_INIT_BLOCKS(25) +
         * 2 * QUOTA_DEL_BLOCKS(9)
         */
        [DTO_ATTR_SET_CHOWN]= 68,
};

static int osd_credit_get(const struct lu_env *env, struct dt_device *d,
                          enum dt_txn_op op)
{
        LASSERT(ARRAY_SIZE(osd_dto_credits_noquota) ==
                ARRAY_SIZE(osd_dto_credits_quota));
        LASSERT(0 <= op && op < ARRAY_SIZE(osd_dto_credits_noquota));
#ifdef HAVE_QUOTA_SUPPORT
        if (test_opt(osd_sb(osd_dt_dev(d)), QUOTA))
                return osd_dto_credits_quota[op];
        else
#endif
                return osd_dto_credits_noquota[op];
}

static const struct dt_device_operations osd_dt_ops = {
        .dt_root_get       = osd_root_get,
        .dt_statfs         = osd_statfs,
        .dt_trans_start    = osd_trans_start,
        .dt_trans_stop     = osd_trans_stop,
        .dt_conf_get       = osd_conf_get,
        .dt_sync           = osd_sync,
        .dt_ro             = osd_ro,
        .dt_commit_async   = osd_commit_async,
        .dt_credit_get     = osd_credit_get,
        .dt_init_capa_ctxt = osd_init_capa_ctxt,
        .dt_init_quota_ctxt= osd_init_quota_ctxt,
};

static void osd_object_read_lock(const struct lu_env *env,
                                 struct dt_object *dt, unsigned role)
{
        struct osd_object *obj = osd_dt_obj(dt);
        struct osd_thread_info *oti = osd_oti_get(env);

        LINVRNT(osd_invariant(obj));

        LASSERT(obj->oo_owner != env);
        cfs_down_read_nested(&obj->oo_sem, role);

        LASSERT(obj->oo_owner == NULL);
        oti->oti_r_locks++;
}

static void osd_object_write_lock(const struct lu_env *env,
                                  struct dt_object *dt, unsigned role)
{
        struct osd_object *obj = osd_dt_obj(dt);
        struct osd_thread_info *oti = osd_oti_get(env);

        LINVRNT(osd_invariant(obj));

        LASSERT(obj->oo_owner != env);
        cfs_down_write_nested(&obj->oo_sem, role);

        LASSERT(obj->oo_owner == NULL);
        obj->oo_owner = env;
        oti->oti_w_locks++;
}

static void osd_object_read_unlock(const struct lu_env *env,
                                   struct dt_object *dt)
{
        struct osd_object *obj = osd_dt_obj(dt);
        struct osd_thread_info *oti = osd_oti_get(env);

        LINVRNT(osd_invariant(obj));

        LASSERT(oti->oti_r_locks > 0);
        oti->oti_r_locks--;
        cfs_up_read(&obj->oo_sem);
}

static void osd_object_write_unlock(const struct lu_env *env,
                                    struct dt_object *dt)
{
        struct osd_object *obj = osd_dt_obj(dt);
        struct osd_thread_info *oti = osd_oti_get(env);

        LINVRNT(osd_invariant(obj));

        LASSERT(obj->oo_owner == env);
        LASSERT(oti->oti_w_locks > 0);
        oti->oti_w_locks--;
        obj->oo_owner = NULL;
        cfs_up_write(&obj->oo_sem);
}

static int osd_object_write_locked(const struct lu_env *env,
                                   struct dt_object *dt)
{
        struct osd_object *obj = osd_dt_obj(dt);

        LINVRNT(osd_invariant(obj));

        return obj->oo_owner == env;
}

static int capa_is_sane(const struct lu_env *env,
                        struct osd_device *dev,
                        struct lustre_capa *capa,
                        struct lustre_capa_key *keys)
{
        struct osd_thread_info *oti = osd_oti_get(env);
        struct lustre_capa *tcapa = &oti->oti_capa;
        struct obd_capa *oc;
        int i, rc = 0;
        ENTRY;

        oc = capa_lookup(dev->od_capa_hash, capa, 0);
        if (oc) {
                if (capa_is_expired(oc)) {
                        DEBUG_CAPA(D_ERROR, capa, "expired");
                        rc = -ESTALE;
                }
                capa_put(oc);
                RETURN(rc);
        }

        if (capa_is_expired_sec(capa)) {
                DEBUG_CAPA(D_ERROR, capa, "expired");
                RETURN(-ESTALE);
        }

        cfs_spin_lock(&capa_lock);
        for (i = 0; i < 2; i++) {
                if (keys[i].lk_keyid == capa->lc_keyid) {
                        oti->oti_capa_key = keys[i];
                        break;
                }
        }
        cfs_spin_unlock(&capa_lock);

        if (i == 2) {
                DEBUG_CAPA(D_ERROR, capa, "no matched capa key");
                RETURN(-ESTALE);
        }

        rc = capa_hmac(tcapa->lc_hmac, capa, oti->oti_capa_key.lk_key);
        if (rc)
                RETURN(rc);

        if (memcmp(tcapa->lc_hmac, capa->lc_hmac, sizeof(capa->lc_hmac))) {
                DEBUG_CAPA(D_ERROR, capa, "HMAC mismatch");
                RETURN(-EACCES);
        }

        oc = capa_add(dev->od_capa_hash, capa);
        capa_put(oc);

        RETURN(0);
}

static int osd_object_auth(const struct lu_env *env, struct dt_object *dt,
                           struct lustre_capa *capa, __u64 opc)
{
        const struct lu_fid *fid = lu_object_fid(&dt->do_lu);
        struct osd_device *dev = osd_dev(dt->do_lu.lo_dev);
        struct md_capainfo *ci;
        int rc;

        if (!dev->od_fl_capa)
                return 0;

        if (capa == BYPASS_CAPA)
                return 0;

        ci = md_capainfo(env);
        if (unlikely(!ci))
                return 0;

        if (ci->mc_auth == LC_ID_NONE)
                return 0;

        if (!capa) {
                CERROR("no capability is provided for fid "DFID"\n", PFID(fid));
                return -EACCES;
        }

        if (!lu_fid_eq(fid, &capa->lc_fid)) {
                DEBUG_CAPA(D_ERROR, capa, "fid "DFID" mismatch with",
                           PFID(fid));
                return -EACCES;
        }

        if (!capa_opc_supported(capa, opc)) {
                DEBUG_CAPA(D_ERROR, capa, "opc "LPX64" not supported by", opc);
                return -EACCES;
        }

        if ((rc = capa_is_sane(env, dev, capa, dev->od_capa_keys))) {
                DEBUG_CAPA(D_ERROR, capa, "insane (rc %d)", rc);
                return -EACCES;
        }

        return 0;
}

static struct timespec *osd_inode_time(const struct lu_env *env,
                                       struct inode *inode, __u64 seconds)
{
        struct osd_thread_info *oti = osd_oti_get(env);
        struct timespec        *t   = &oti->oti_time;

        t->tv_sec  = seconds;
        t->tv_nsec = 0;
        *t = timespec_trunc(*t, get_sb_time_gran(inode->i_sb));
        return t;
}


static void osd_inode_getattr(const struct lu_env *env,
                              struct inode *inode, struct lu_attr *attr)
{
        attr->la_valid      |= LA_ATIME | LA_MTIME | LA_CTIME | LA_MODE |
                               LA_SIZE | LA_BLOCKS | LA_UID | LA_GID |
                               LA_FLAGS | LA_NLINK | LA_RDEV | LA_BLKSIZE;

        attr->la_atime      = LTIME_S(inode->i_atime);
        attr->la_mtime      = LTIME_S(inode->i_mtime);
        attr->la_ctime      = LTIME_S(inode->i_ctime);
        attr->la_mode       = inode->i_mode;
        attr->la_size       = i_size_read(inode);
        attr->la_blocks     = inode->i_blocks;
        attr->la_uid        = inode->i_uid;
        attr->la_gid        = inode->i_gid;
        attr->la_flags      = LDISKFS_I(inode)->i_flags;
        attr->la_nlink      = inode->i_nlink;
        attr->la_rdev       = inode->i_rdev;
        attr->la_blksize    = ll_inode_blksize(inode);
        attr->la_blkbits    = inode->i_blkbits;
}

static int osd_attr_get(const struct lu_env *env,
                        struct dt_object *dt,
                        struct lu_attr *attr,
                        struct lustre_capa *capa)
{
        struct osd_object *obj = osd_dt_obj(dt);

        LASSERT(dt_object_exists(dt));
        LINVRNT(osd_invariant(obj));

        if (osd_object_auth(env, dt, capa, CAPA_OPC_META_READ))
                return -EACCES;

        cfs_spin_lock(&obj->oo_guard);
        osd_inode_getattr(env, obj->oo_inode, attr);
        cfs_spin_unlock(&obj->oo_guard);
        return 0;
}

static int osd_inode_setattr(const struct lu_env *env,
                             struct inode *inode, const struct lu_attr *attr)
{
        __u64 bits;

        bits = attr->la_valid;

        LASSERT(!(bits & LA_TYPE)); /* Huh? You want too much. */

#ifdef HAVE_QUOTA_SUPPORT
        if ((bits & LA_UID && attr->la_uid != inode->i_uid) ||
            (bits & LA_GID && attr->la_gid != inode->i_gid)) {
                struct osd_ctxt *save = &osd_oti_get(env)->oti_ctxt;
                struct iattr iattr;
                int rc;

                iattr.ia_valid = 0;
                if (bits & LA_UID)
                        iattr.ia_valid |= ATTR_UID;
                if (bits & LA_GID)
                        iattr.ia_valid |= ATTR_GID;
                iattr.ia_uid = attr->la_uid;
                iattr.ia_gid = attr->la_gid;
                osd_push_ctxt(env, save);
                rc = DQUOT_TRANSFER(inode, &iattr) ? -EDQUOT : 0;
                osd_pop_ctxt(save);
                if (rc != 0)
                        return rc;
        }
#endif

        if (bits & LA_ATIME)
                inode->i_atime  = *osd_inode_time(env, inode, attr->la_atime);
        if (bits & LA_CTIME)
                inode->i_ctime  = *osd_inode_time(env, inode, attr->la_ctime);
        if (bits & LA_MTIME)
                inode->i_mtime  = *osd_inode_time(env, inode, attr->la_mtime);
        if (bits & LA_SIZE) {
                LDISKFS_I(inode)->i_disksize = attr->la_size;
                i_size_write(inode, attr->la_size);
        }

#if 0
        /* OSD should not change "i_blocks" which is used by quota.
         * "i_blocks" should be changed by ldiskfs only. */
        if (bits & LA_BLOCKS)
                inode->i_blocks = attr->la_blocks;
#endif
        if (bits & LA_MODE)
                inode->i_mode   = (inode->i_mode & S_IFMT) |
                        (attr->la_mode & ~S_IFMT);
        if (bits & LA_UID)
                inode->i_uid    = attr->la_uid;
        if (bits & LA_GID)
                inode->i_gid    = attr->la_gid;
        if (bits & LA_NLINK)
                inode->i_nlink  = attr->la_nlink;
        if (bits & LA_RDEV)
                inode->i_rdev   = attr->la_rdev;

        if (bits & LA_FLAGS)
                inode->i_flags = ll_ext_to_inode_flags(attr->la_flags);
        return 0;
}

static int osd_attr_set(const struct lu_env *env,
                        struct dt_object *dt,
                        const struct lu_attr *attr,
                        struct thandle *handle,
                        struct lustre_capa *capa)
{
        struct osd_object *obj = osd_dt_obj(dt);
        int rc;

        LASSERT(handle != NULL);
        LASSERT(dt_object_exists(dt));
        LASSERT(osd_invariant(obj));

        if (osd_object_auth(env, dt, capa, CAPA_OPC_META_WRITE))
                return -EACCES;

        cfs_spin_lock(&obj->oo_guard);
        rc = osd_inode_setattr(env, obj->oo_inode, attr);
        cfs_spin_unlock(&obj->oo_guard);

        if (!rc)
                mark_inode_dirty(obj->oo_inode);
        return rc;
}

/*
 * Object creation.
 *
 * XXX temporary solution.
 */
static int osd_create_pre(struct osd_thread_info *info, struct osd_object *obj,
                          struct lu_attr *attr, struct thandle *th)
{
        return 0;
}

static int osd_create_post(struct osd_thread_info *info, struct osd_object *obj,
                           struct lu_attr *attr, struct thandle *th)
{
        osd_object_init0(obj);
        return 0;
}

static struct dentry * osd_child_dentry_get(const struct lu_env *env,
                                            struct osd_object *obj,
                                            const char *name,
                                            const int namelen)
{
        struct osd_thread_info *info   = osd_oti_get(env);
        struct dentry *child_dentry = &info->oti_child_dentry;
        struct dentry *obj_dentry = &info->oti_obj_dentry;

        obj_dentry->d_inode = obj->oo_inode;
        obj_dentry->d_sb = osd_sb(osd_obj2dev(obj));
        obj_dentry->d_name.hash = 0;

        child_dentry->d_name.hash = 0;
        child_dentry->d_parent = obj_dentry;
        child_dentry->d_name.name = name;
        child_dentry->d_name.len = namelen;
        return child_dentry;
}


static int osd_mkfile(struct osd_thread_info *info, struct osd_object *obj,
                      cfs_umode_t mode,
                      struct dt_allocation_hint *hint,
                      struct thandle *th)
{
        int result;
        struct osd_device  *osd = osd_obj2dev(obj);
        struct osd_thandle *oth;
        struct dt_object   *parent;
        struct inode       *inode;
#ifdef HAVE_QUOTA_SUPPORT
        struct osd_ctxt    *save = &info->oti_ctxt;
#endif

        LINVRNT(osd_invariant(obj));
        LASSERT(obj->oo_inode == NULL);

        oth = container_of(th, struct osd_thandle, ot_super);
        LASSERT(oth->ot_handle->h_transaction != NULL);

        if (hint && hint->dah_parent)
                parent = hint->dah_parent;
        else
                parent = osd->od_obj_area;

        LASSERT(parent != NULL);
        LASSERT(osd_dt_obj(parent)->oo_inode->i_op != NULL);

#ifdef HAVE_QUOTA_SUPPORT
        osd_push_ctxt(info->oti_env, save);
#endif
        inode = ldiskfs_create_inode(oth->ot_handle,
                                     osd_dt_obj(parent)->oo_inode, mode);
#ifdef HAVE_QUOTA_SUPPORT
        osd_pop_ctxt(save);
#endif
        if (!IS_ERR(inode)) {
                obj->oo_inode = inode;
                result = 0;
        } else
                result = PTR_ERR(inode);
        LINVRNT(osd_invariant(obj));
        return result;
}

enum {
        OSD_NAME_LEN = 255
};

static int osd_mkdir(struct osd_thread_info *info, struct osd_object *obj,
                     struct lu_attr *attr,
                     struct dt_allocation_hint *hint,
                     struct dt_object_format *dof,
                     struct thandle *th)
{
        int result;
        struct osd_thandle *oth;
        struct osd_device *osd = osd_obj2dev(obj);
        __u32 mode = (attr->la_mode & (S_IFMT | S_IRWXUGO | S_ISVTX));

        LASSERT(S_ISDIR(attr->la_mode));

        oth = container_of(th, struct osd_thandle, ot_super);
        LASSERT(oth->ot_handle->h_transaction != NULL);
        result = osd_mkfile(info, obj, mode, hint, th);
        if (result == 0 && osd->od_iop_mode == 0) {
                LASSERT(obj->oo_inode != NULL);
                /*
                 * XXX uh-oh... call low-level iam function directly.
                 */

                result = iam_lvar_create(obj->oo_inode, OSD_NAME_LEN, 4,
                                         sizeof (struct osd_fid_pack),
                                         oth->ot_handle);
        }
        return result;
}

static int osd_mk_index(struct osd_thread_info *info, struct osd_object *obj,
                        struct lu_attr *attr,
                        struct dt_allocation_hint *hint,
                        struct dt_object_format *dof,
                        struct thandle *th)
{
        int result;
        struct osd_thandle *oth;
        const struct dt_index_features *feat = dof->u.dof_idx.di_feat;

        __u32 mode = (attr->la_mode & (S_IFMT | S_IRWXUGO | S_ISVTX));

        LASSERT(S_ISREG(attr->la_mode));

        oth = container_of(th, struct osd_thandle, ot_super);
        LASSERT(oth->ot_handle->h_transaction != NULL);

        result = osd_mkfile(info, obj, mode, hint, th);
        if (result == 0) {
                LASSERT(obj->oo_inode != NULL);
                if (feat->dif_flags & DT_IND_VARKEY)
                        result = iam_lvar_create(obj->oo_inode,
                                                 feat->dif_keysize_max,
                                                 feat->dif_ptrsize,
                                                 feat->dif_recsize_max,
                                                 oth->ot_handle);
                else
                        result = iam_lfix_create(obj->oo_inode,
                                                 feat->dif_keysize_max,
                                                 feat->dif_ptrsize,
                                                 feat->dif_recsize_max,
                                                 oth->ot_handle);

        }
        return result;
}

static int osd_mkreg(struct osd_thread_info *info, struct osd_object *obj,
                     struct lu_attr *attr,
                     struct dt_allocation_hint *hint,
                     struct dt_object_format *dof,
                     struct thandle *th)
{
        LASSERT(S_ISREG(attr->la_mode));
        return osd_mkfile(info, obj, (attr->la_mode &
                               (S_IFMT | S_IRWXUGO | S_ISVTX)), hint, th);
}

static int osd_mksym(struct osd_thread_info *info, struct osd_object *obj,
                     struct lu_attr *attr,
                     struct dt_allocation_hint *hint,
                     struct dt_object_format *dof,
                     struct thandle *th)
{
        LASSERT(S_ISLNK(attr->la_mode));
        return osd_mkfile(info, obj, (attr->la_mode &
                              (S_IFMT | S_IRWXUGO | S_ISVTX)), hint, th);
}

static int osd_mknod(struct osd_thread_info *info, struct osd_object *obj,
                     struct lu_attr *attr,
                     struct dt_allocation_hint *hint,
                     struct dt_object_format *dof,
                     struct thandle *th)
{
        cfs_umode_t mode = attr->la_mode & (S_IFMT | S_IRWXUGO | S_ISVTX);
        int result;

        LINVRNT(osd_invariant(obj));
        LASSERT(obj->oo_inode == NULL);
        LASSERT(S_ISCHR(mode) || S_ISBLK(mode) ||
                S_ISFIFO(mode) || S_ISSOCK(mode));

        result = osd_mkfile(info, obj, mode, hint, th);
        if (result == 0) {
                LASSERT(obj->oo_inode != NULL);
                init_special_inode(obj->oo_inode, mode, attr->la_rdev);
        }
        LINVRNT(osd_invariant(obj));
        return result;
}

typedef int (*osd_obj_type_f)(struct osd_thread_info *, struct osd_object *,
                              struct lu_attr *,
                              struct dt_allocation_hint *hint,
                              struct dt_object_format *dof,
                              struct thandle *);

static osd_obj_type_f osd_create_type_f(enum dt_format_type type)
{
        osd_obj_type_f result;

        switch (type) {
        case DFT_DIR:
                result = osd_mkdir;
                break;
        case DFT_REGULAR:
                result = osd_mkreg;
                break;
        case DFT_SYM:
                result = osd_mksym;
                break;
        case DFT_NODE:
                result = osd_mknod;
                break;
        case DFT_INDEX:
                result = osd_mk_index;
                break;

        default:
                LBUG();
                break;
        }
        return result;
}


static void osd_ah_init(const struct lu_env *env, struct dt_allocation_hint *ah,
                        struct dt_object *parent, cfs_umode_t child_mode)
{
        LASSERT(ah);

        memset(ah, 0, sizeof(*ah));
        ah->dah_parent = parent;
        ah->dah_mode = child_mode;
}

/**
 * Helper function for osd_object_create()
 *
 * \retval 0, on success
 */
static int __osd_object_create(struct osd_thread_info *info,
                               struct osd_object *obj, struct lu_attr *attr,
                               struct dt_allocation_hint *hint,
                               struct dt_object_format *dof,
                               struct thandle *th)
{

        int result;

        result = osd_create_pre(info, obj, attr, th);
        if (result == 0) {
                result = osd_create_type_f(dof->dof_type)(info, obj,
                                           attr, hint, dof, th);
                if (result == 0)
                        result = osd_create_post(info, obj, attr, th);
        }
        return result;
}

/**
 * Helper function for osd_object_create()
 *
 * \retval 0, on success
 */
static int __osd_oi_insert(const struct lu_env *env, struct osd_object *obj,
                           const struct lu_fid *fid, struct thandle *th)
{
        struct osd_thread_info *info = osd_oti_get(env);
        struct osd_inode_id    *id   = &info->oti_id;
        struct osd_device      *osd  = osd_obj2dev(obj);
        struct md_ucred        *uc   = md_ucred(env);

        LASSERT(obj->oo_inode != NULL);
        LASSERT(uc != NULL);

        id->oii_ino = obj->oo_inode->i_ino;
        id->oii_gen = obj->oo_inode->i_generation;

        return osd_oi_insert(info, &osd->od_oi, fid, id, th,
                             uc->mu_cap & CFS_CAP_SYS_RESOURCE_MASK);
}

static int osd_object_create(const struct lu_env *env, struct dt_object *dt,
                             struct lu_attr *attr,
                             struct dt_allocation_hint *hint,
                             struct dt_object_format *dof,
                             struct thandle *th)
{
        const struct lu_fid    *fid    = lu_object_fid(&dt->do_lu);
        struct osd_object      *obj    = osd_dt_obj(dt);
        struct osd_thread_info *info   = osd_oti_get(env);
        int result;

        ENTRY;

        LINVRNT(osd_invariant(obj));
        LASSERT(!dt_object_exists(dt));
        LASSERT(osd_write_locked(env, obj));
        LASSERT(th != NULL);

        result = __osd_object_create(info, obj, attr, hint, dof, th);
        if (result == 0)
                result = __osd_oi_insert(env, obj, fid, th);

        LASSERT(ergo(result == 0, dt_object_exists(dt)));
        LASSERT(osd_invariant(obj));
        RETURN(result);
}

/**
 * Helper function for osd_xattr_set()
 */
static int __osd_xattr_set(const struct lu_env *env, struct dt_object *dt,
                           const struct lu_buf *buf, const char *name, int fl)
{
        struct osd_object      *obj      = osd_dt_obj(dt);
        struct inode           *inode    = obj->oo_inode;
        struct osd_thread_info *info     = osd_oti_get(env);
        struct dentry          *dentry   = &info->oti_child_dentry;
        struct timespec        *t        = &info->oti_time;
        int                     fs_flags = 0;
        int  rc;

        LASSERT(dt_object_exists(dt));
        LASSERT(inode->i_op != NULL && inode->i_op->setxattr != NULL);
        LASSERT(osd_write_locked(env, obj));

        if (fl & LU_XATTR_REPLACE)
                fs_flags |= XATTR_REPLACE;

        if (fl & LU_XATTR_CREATE)
                fs_flags |= XATTR_CREATE;

        dentry->d_inode = inode;
        *t = inode->i_ctime;
        rc = inode->i_op->setxattr(dentry, name, buf->lb_buf,
                                   buf->lb_len, fs_flags);
        /* ctime should not be updated with server-side time. */
        cfs_spin_lock(&obj->oo_guard);
        inode->i_ctime = *t;
        cfs_spin_unlock(&obj->oo_guard);
        mark_inode_dirty(inode);
        return rc;
}

/**
 * Put the fid into lustre_mdt_attrs, and then place the structure
 * inode's ea. This fid should not be altered during the life time
 * of the inode.
 *
 * \retval +ve, on success
 * \retval -ve, on error
 *
 * FIXME: It is good to have/use ldiskfs_xattr_set_handle() here
 */
static int osd_ea_fid_set(const struct lu_env *env, struct dt_object *dt,
                          const struct lu_fid *fid)
{
        struct osd_thread_info  *info      = osd_oti_get(env);
        struct lustre_mdt_attrs *mdt_attrs = &info->oti_mdt_attrs;

        lustre_lma_init(mdt_attrs, fid);
        lustre_lma_swab(mdt_attrs);
        return __osd_xattr_set(env, dt,
                               osd_buf_get(env, mdt_attrs, sizeof *mdt_attrs),
                               XATTR_NAME_LMA, LU_XATTR_CREATE);

}

/**
 * Helper function to form igif
 */
static inline void osd_igif_get(const struct lu_env *env, struct inode  *inode,
                                struct lu_fid *fid)
{
        lu_igif_build(fid, inode->i_ino, inode->i_generation);
}

/**
 * Helper function to pack the fid, ldiskfs stores fid in packed format.
 */
void osd_fid_pack(struct osd_fid_pack *pack, const struct dt_rec *fid,
                  struct lu_fid *befider)
{
        fid_cpu_to_be(befider, (struct lu_fid *)fid);
        memcpy(pack->fp_area, befider, sizeof(*befider));
        pack->fp_len =  sizeof(*befider) + 1;
}

/**
 * ldiskfs supports fid in dirent, it is passed in dentry->d_fsdata.
 * lustre 1.8 also uses d_fsdata for passing other info to ldiskfs.
 * To have compatilibility with 1.8 ldiskfs driver we need to have
 * magic number at start of fid data.
 * \ldiskfs_dentry_param is used only to pass fid from osd to ldiskfs.
 * its inmemory API.
 */
void osd_get_ldiskfs_dirent_param(struct ldiskfs_dentry_param *param,
                                  const struct dt_rec *fid)
{
        param->edp_magic = LDISKFS_LUFID_MAGIC;
        param->edp_len =  sizeof(struct lu_fid) + 1;

        fid_cpu_to_be((struct lu_fid *)param->edp_data,
                      (struct lu_fid *)fid);
}

int osd_fid_unpack(struct lu_fid *fid, const struct osd_fid_pack *pack)
{
        int result;

        result = 0;
        switch (pack->fp_len) {
        case sizeof *fid + 1:
                memcpy(fid, pack->fp_area, sizeof *fid);
                fid_be_to_cpu(fid, fid);
                break;
        default:
                CERROR("Unexpected packed fid size: %d\n", pack->fp_len);
                result = -EIO;
        }
        return result;
}

/**
 * Try to read the fid from inode ea into dt_rec, if return value
 * i.e. rc is +ve, then we got fid, otherwise we will have to form igif
 *
 * \param fid object fid.
 *
 * \retval 0 on success
 */
static int osd_ea_fid_get(const struct lu_env *env, struct osd_object *obj,
                          __u32 ino, struct lu_fid *fid)
{
        struct osd_thread_info  *info      = osd_oti_get(env);
        struct lustre_mdt_attrs *mdt_attrs = &info->oti_mdt_attrs;
        struct lu_device        *ldev   = obj->oo_dt.do_lu.lo_dev;
        struct dentry           *dentry = &info->oti_child_dentry;
        struct osd_inode_id     *id     = &info->oti_id;
        struct osd_device       *dev;
        struct inode            *inode;
        int                      rc;

        ENTRY;
        dev  = osd_dev(ldev);

        id->oii_ino = ino;
        id->oii_gen = OSD_OII_NOGEN;

        inode = osd_iget(info, dev, id);
        if (IS_ERR(inode)) {
                rc = PTR_ERR(inode);
                GOTO(out,rc);
        }
        dentry->d_inode = inode;

        LASSERT(inode->i_op != NULL && inode->i_op->getxattr != NULL);
        rc = inode->i_op->getxattr(dentry, XATTR_NAME_LMA, (void *)mdt_attrs,
                                   sizeof *mdt_attrs);

        /* Check LMA compatibility */
        if (rc > 0 &&
            (mdt_attrs->lma_incompat & ~cpu_to_le32(LMA_INCOMPAT_SUPP))) {
                CWARN("Inode %lx: Unsupported incompat LMA feature(s) %#x\n",
                      inode->i_ino, le32_to_cpu(mdt_attrs->lma_incompat) &
                      ~LMA_INCOMPAT_SUPP);
                return -ENOSYS;
        }

        if (rc > 0) {
                lustre_lma_swab(mdt_attrs);
                memcpy(fid, &mdt_attrs->lma_self_fid, sizeof(*fid));
                rc = 0;
        } else if (rc == -ENODATA) {
                osd_igif_get(env, inode, fid);
                rc = 0;
        }
        iput(inode);
out:
        RETURN(rc);
}

/**
 * OSD layer object create function for interoperability mode (b11826).
 * This is mostly similar to osd_object_create(). Only difference being, fid is
 * inserted into inode ea here.
 *
 * \retval   0, on success
 * \retval -ve, on error
 */
static int osd_object_ea_create(const struct lu_env *env, struct dt_object *dt,
                             struct lu_attr *attr,
                             struct dt_allocation_hint *hint,
                             struct dt_object_format *dof,
                             struct thandle *th)
{
        const struct lu_fid    *fid    = lu_object_fid(&dt->do_lu);
        struct osd_object      *obj    = osd_dt_obj(dt);
        struct osd_thread_info *info   = osd_oti_get(env);
        int result;

        ENTRY;

        LASSERT(osd_invariant(obj));
        LASSERT(!dt_object_exists(dt));
        LASSERT(osd_write_locked(env, obj));
        LASSERT(th != NULL);

        result = __osd_object_create(info, obj, attr, hint, dof, th);

        /* objects under osd root shld have igif fid, so dont add fid EA */
        if (result == 0 && fid_seq(fid) >= FID_SEQ_DISTRIBUTED_START)
                result = osd_ea_fid_set(env, dt, fid);

        if (result == 0)
                result = __osd_oi_insert(env, obj, fid, th);

        LASSERT(ergo(result == 0, dt_object_exists(dt)));
        LINVRNT(osd_invariant(obj));
        RETURN(result);
}

/*
 * Concurrency: @dt is write locked.
 */
static void osd_object_ref_add(const struct lu_env *env,
                               struct dt_object *dt,
                               struct thandle *th)
{
        struct osd_object *obj = osd_dt_obj(dt);
        struct inode *inode = obj->oo_inode;

        LINVRNT(osd_invariant(obj));
        LASSERT(dt_object_exists(dt));
        LASSERT(osd_write_locked(env, obj));
        LASSERT(th != NULL);

        cfs_spin_lock(&obj->oo_guard);
        LASSERT(inode->i_nlink < LDISKFS_LINK_MAX);
        inode->i_nlink++;
        cfs_spin_unlock(&obj->oo_guard);
        mark_inode_dirty(inode);
        LINVRNT(osd_invariant(obj));
}

/*
 * Concurrency: @dt is write locked.
 */
static void osd_object_ref_del(const struct lu_env *env,
                               struct dt_object *dt,
                               struct thandle *th)
{
        struct osd_object *obj = osd_dt_obj(dt);
        struct inode *inode = obj->oo_inode;

        LINVRNT(osd_invariant(obj));
        LASSERT(dt_object_exists(dt));
        LASSERT(osd_write_locked(env, obj));
        LASSERT(th != NULL);

        cfs_spin_lock(&obj->oo_guard);
        LASSERT(inode->i_nlink > 0);
        inode->i_nlink--;
        cfs_spin_unlock(&obj->oo_guard);
        mark_inode_dirty(inode);
        LINVRNT(osd_invariant(obj));
}

/*
 * Concurrency: @dt is read locked.
 */
static int osd_xattr_get(const struct lu_env *env,
                         struct dt_object *dt,
                         struct lu_buf *buf,
                         const char *name,
                         struct lustre_capa *capa)
{
        struct osd_object      *obj    = osd_dt_obj(dt);
        struct inode           *inode  = obj->oo_inode;
        struct osd_thread_info *info   = osd_oti_get(env);
        struct dentry          *dentry = &info->oti_obj_dentry;

        LASSERT(dt_object_exists(dt));
        LASSERT(inode->i_op != NULL && inode->i_op->getxattr != NULL);
        LASSERT(osd_read_locked(env, obj) || osd_write_locked(env, obj));

        if (osd_object_auth(env, dt, capa, CAPA_OPC_META_READ))
                return -EACCES;

        dentry->d_inode = inode;
        return inode->i_op->getxattr(dentry, name, buf->lb_buf, buf->lb_len);
}

/*
 * Concurrency: @dt is write locked.
 */
static int osd_xattr_set(const struct lu_env *env, struct dt_object *dt,
                         const struct lu_buf *buf, const char *name, int fl,
                         struct thandle *handle, struct lustre_capa *capa)
{
        LASSERT(handle != NULL);

        if (osd_object_auth(env, dt, capa, CAPA_OPC_META_WRITE))
                return -EACCES;

        return __osd_xattr_set(env, dt, buf, name, fl);
}

/*
 * Concurrency: @dt is read locked.
 */
static int osd_xattr_list(const struct lu_env *env,
                          struct dt_object *dt,
                          struct lu_buf *buf,
                          struct lustre_capa *capa)
{
        struct osd_object      *obj    = osd_dt_obj(dt);
        struct inode           *inode  = obj->oo_inode;
        struct osd_thread_info *info   = osd_oti_get(env);
        struct dentry          *dentry = &info->oti_obj_dentry;

        LASSERT(dt_object_exists(dt));
        LASSERT(inode->i_op != NULL && inode->i_op->listxattr != NULL);
        LASSERT(osd_read_locked(env, obj) || osd_write_locked(env, obj));

        if (osd_object_auth(env, dt, capa, CAPA_OPC_META_READ))
                return -EACCES;

        dentry->d_inode = inode;
        return inode->i_op->listxattr(dentry, buf->lb_buf, buf->lb_len);
}

/*
 * Concurrency: @dt is write locked.
 */
static int osd_xattr_del(const struct lu_env *env,
                         struct dt_object *dt,
                         const char *name,
                         struct thandle *handle,
                         struct lustre_capa *capa)
{
        struct osd_object      *obj    = osd_dt_obj(dt);
        struct inode           *inode  = obj->oo_inode;
        struct osd_thread_info *info   = osd_oti_get(env);
        struct dentry          *dentry = &info->oti_obj_dentry;
        struct timespec        *t      = &info->oti_time;
        int                     rc;

        LASSERT(dt_object_exists(dt));
        LASSERT(inode->i_op != NULL && inode->i_op->removexattr != NULL);
        LASSERT(osd_write_locked(env, obj));
        LASSERT(handle != NULL);

        if (osd_object_auth(env, dt, capa, CAPA_OPC_META_WRITE))
                return -EACCES;

        dentry->d_inode = inode;
        *t = inode->i_ctime;
        rc = inode->i_op->removexattr(dentry, name);
        /* ctime should not be updated with server-side time. */
        cfs_spin_lock(&obj->oo_guard);
        inode->i_ctime = *t;
        cfs_spin_unlock(&obj->oo_guard);
        mark_inode_dirty(inode);
        return rc;
}

static struct obd_capa *osd_capa_get(const struct lu_env *env,
                                     struct dt_object *dt,
                                     struct lustre_capa *old,
                                     __u64 opc)
{
        struct osd_thread_info *info = osd_oti_get(env);
        const struct lu_fid *fid = lu_object_fid(&dt->do_lu);
        struct osd_object *obj = osd_dt_obj(dt);
        struct osd_device *dev = osd_obj2dev(obj);
        struct lustre_capa_key *key = &info->oti_capa_key;
        struct lustre_capa *capa = &info->oti_capa;
        struct obd_capa *oc;
        struct md_capainfo *ci;
        int rc;
        ENTRY;

        if (!dev->od_fl_capa)
                RETURN(ERR_PTR(-ENOENT));

        LASSERT(dt_object_exists(dt));
        LINVRNT(osd_invariant(obj));

        /* renewal sanity check */
        if (old && osd_object_auth(env, dt, old, opc))
                RETURN(ERR_PTR(-EACCES));

        ci = md_capainfo(env);
        if (unlikely(!ci))
                RETURN(ERR_PTR(-ENOENT));

        switch (ci->mc_auth) {
        case LC_ID_NONE:
                RETURN(NULL);
        case LC_ID_PLAIN:
                capa->lc_uid = obj->oo_inode->i_uid;
                capa->lc_gid = obj->oo_inode->i_gid;
                capa->lc_flags = LC_ID_PLAIN;
                break;
        case LC_ID_CONVERT: {
                __u32 d[4], s[4];

                s[0] = obj->oo_inode->i_uid;
                ll_get_random_bytes(&(s[1]), sizeof(__u32));
                s[2] = obj->oo_inode->i_gid;
                ll_get_random_bytes(&(s[3]), sizeof(__u32));
                rc = capa_encrypt_id(d, s, key->lk_key, CAPA_HMAC_KEY_MAX_LEN);
                if (unlikely(rc))
                        RETURN(ERR_PTR(rc));

                capa->lc_uid   = ((__u64)d[1] << 32) | d[0];
                capa->lc_gid   = ((__u64)d[3] << 32) | d[2];
                capa->lc_flags = LC_ID_CONVERT;
                break;
        }
        default:
                RETURN(ERR_PTR(-EINVAL));
        }

        capa->lc_fid = *fid;
        capa->lc_opc = opc;
        capa->lc_flags |= dev->od_capa_alg << 24;
        capa->lc_timeout = dev->od_capa_timeout;
        capa->lc_expiry = 0;

        oc = capa_lookup(dev->od_capa_hash, capa, 1);
        if (oc) {
                LASSERT(!capa_is_expired(oc));
                RETURN(oc);
        }

        cfs_spin_lock(&capa_lock);
        *key = dev->od_capa_keys[1];
        cfs_spin_unlock(&capa_lock);

        capa->lc_keyid = key->lk_keyid;
        capa->lc_expiry = cfs_time_current_sec() + dev->od_capa_timeout;

        rc = capa_hmac(capa->lc_hmac, capa, key->lk_key);
        if (rc) {
                DEBUG_CAPA(D_ERROR, capa, "HMAC failed: %d for", rc);
                RETURN(ERR_PTR(rc));
        }

        oc = capa_add(dev->od_capa_hash, capa);
        RETURN(oc);
}

static int osd_object_sync(const struct lu_env *env, struct dt_object *dt)
{
        int rc;
        struct osd_object      *obj    = osd_dt_obj(dt);
        struct inode           *inode  = obj->oo_inode;
        struct osd_thread_info *info   = osd_oti_get(env);
        struct dentry          *dentry = &info->oti_obj_dentry;
        struct file            *file   = &info->oti_file;
        ENTRY;

        dentry->d_inode = inode;
        file->f_dentry = dentry;
        file->f_mapping = inode->i_mapping;
        file->f_op = inode->i_fop;
        LOCK_INODE_MUTEX(inode);
        rc = file->f_op->fsync(file, dentry, 0);
        UNLOCK_INODE_MUTEX(inode);
        RETURN(rc);
}

/*
 * Get the 64-bit version for an inode.
 */
static dt_obj_version_t osd_object_version_get(const struct lu_env *env,
                                               struct dt_object *dt)
{
        struct inode *inode = osd_dt_obj(dt)->oo_inode;

        CDEBUG(D_INFO, "Get version "LPX64" for inode %lu\n",
               LDISKFS_I(inode)->i_fs_version, inode->i_ino);
        return LDISKFS_I(inode)->i_fs_version;
}

/*
 * Set the 64-bit version and return the old version.
 */
static void osd_object_version_set(const struct lu_env *env, struct dt_object *dt,
                                   dt_obj_version_t new_version)
{
        struct inode *inode = osd_dt_obj(dt)->oo_inode;

        CDEBUG(D_INFO, "Set version "LPX64" (old "LPX64") for inode %lu\n",
               new_version, LDISKFS_I(inode)->i_fs_version, inode->i_ino);
        LDISKFS_I(inode)->i_fs_version = new_version;
        /** Version is set after all inode operations are finished,
         *  so we should mark it dirty here */
        inode->i_sb->s_op->dirty_inode(inode);
}

static int osd_data_get(const struct lu_env *env, struct dt_object *dt,
                        void **data)
{
        struct osd_object *obj = osd_dt_obj(dt);
        ENTRY;

        *data = (void *)obj->oo_inode;
        RETURN(0);
}

/*
 * Index operations.
 */

static int osd_iam_index_probe(const struct lu_env *env, struct osd_object *o,
                           const struct dt_index_features *feat)
{
        struct iam_descr *descr;

        if (osd_object_is_root(o))
                return feat == &dt_directory_features;

        LASSERT(o->oo_dir != NULL);

        descr = o->oo_dir->od_container.ic_descr;
        if (feat == &dt_directory_features) {
                if (descr->id_rec_size == sizeof(struct osd_fid_pack))
                        return 1;
                else
                        return 0;
        } else {
                return
                        feat->dif_keysize_min <= descr->id_key_size &&
                        descr->id_key_size <= feat->dif_keysize_max &&
                        feat->dif_recsize_min <= descr->id_rec_size &&
                        descr->id_rec_size <= feat->dif_recsize_max &&
                        !(feat->dif_flags & (DT_IND_VARKEY |
                                             DT_IND_VARREC | DT_IND_NONUNQ)) &&
                        ergo(feat->dif_flags & DT_IND_UPDATE,
                             1 /* XXX check that object (and file system) is
                                * writable */);
        }
}

static int osd_iam_container_init(const struct lu_env *env,
                                  struct osd_object *obj,
                                  struct osd_directory *dir)
{
        int result;
        struct iam_container *bag;

        bag    = &dir->od_container;
        result = iam_container_init(bag, &dir->od_descr, obj->oo_inode);
        if (result == 0) {
                result = iam_container_setup(bag);
                if (result == 0)
                        obj->oo_dt.do_index_ops = &osd_index_iam_ops;
                else
                        iam_container_fini(bag);
        }
        return result;
}


/*
 * Concurrency: no external locking is necessary.
 */
static int osd_index_try(const struct lu_env *env, struct dt_object *dt,
                         const struct dt_index_features *feat)
{
        int result;
        int ea_dir = 0;
        struct osd_object *obj = osd_dt_obj(dt);
        struct osd_device *osd = osd_obj2dev(obj);

        LINVRNT(osd_invariant(obj));
        LASSERT(dt_object_exists(dt));

        if (osd_object_is_root(obj)) {
                dt->do_index_ops = &osd_index_ea_ops;
                result = 0;
        } else if (feat == &dt_directory_features && osd->od_iop_mode) {
                dt->do_index_ops = &osd_index_ea_ops;
                if (S_ISDIR(obj->oo_inode->i_mode))
                        result = 0;
                else
                        result = -ENOTDIR;
                ea_dir = 1;
        } else if (!osd_has_index(obj)) {
                struct osd_directory *dir;

                OBD_ALLOC_PTR(dir);
                if (dir != NULL) {

                        cfs_spin_lock(&obj->oo_guard);
                        if (obj->oo_dir == NULL)
                                obj->oo_dir = dir;
                        else
                                /*
                                 * Concurrent thread allocated container data.
                                 */
                                OBD_FREE_PTR(dir);
                        cfs_spin_unlock(&obj->oo_guard);
                        /*
                         * Now, that we have container data, serialize its
                         * initialization.
                         */
                        cfs_down_write(&obj->oo_ext_idx_sem);
                        /*
                         * recheck under lock.
                         */
                        if (!osd_has_index(obj))
                                result = osd_iam_container_init(env, obj, dir);
                        else
                                result = 0;
                        cfs_up_write(&obj->oo_ext_idx_sem);
                } else
                        result = -ENOMEM;
        } else
                result = 0;

        if (result == 0 && ea_dir == 0) {
                if (!osd_iam_index_probe(env, obj, feat))
                        result = -ENOTDIR;
        }
        LINVRNT(osd_invariant(obj));

        return result;
}

static const struct dt_object_operations osd_obj_ops = {
        .do_read_lock    = osd_object_read_lock,
        .do_write_lock   = osd_object_write_lock,
        .do_read_unlock  = osd_object_read_unlock,
        .do_write_unlock = osd_object_write_unlock,
        .do_write_locked = osd_object_write_locked,
        .do_attr_get     = osd_attr_get,
        .do_attr_set     = osd_attr_set,
        .do_ah_init      = osd_ah_init,
        .do_create       = osd_object_create,
        .do_index_try    = osd_index_try,
        .do_ref_add      = osd_object_ref_add,
        .do_ref_del      = osd_object_ref_del,
        .do_xattr_get    = osd_xattr_get,
        .do_xattr_set    = osd_xattr_set,
        .do_xattr_del    = osd_xattr_del,
        .do_xattr_list   = osd_xattr_list,
        .do_capa_get     = osd_capa_get,
        .do_object_sync  = osd_object_sync,
        .do_version_get  = osd_object_version_get,
        .do_version_set  = osd_object_version_set,
        .do_data_get     = osd_data_get,
};

/**
 * dt_object_operations for interoperability mode
 * (i.e. to run 2.0 mds on 1.8 disk) (b11826)
 */
static const struct dt_object_operations osd_obj_ea_ops = {
        .do_read_lock    = osd_object_read_lock,
        .do_write_lock   = osd_object_write_lock,
        .do_read_unlock  = osd_object_read_unlock,
        .do_write_unlock = osd_object_write_unlock,
        .do_write_locked = osd_object_write_locked,
        .do_attr_get     = osd_attr_get,
        .do_attr_set     = osd_attr_set,
        .do_ah_init      = osd_ah_init,
        .do_create       = osd_object_ea_create,
        .do_index_try    = osd_index_try,
        .do_ref_add      = osd_object_ref_add,
        .do_ref_del      = osd_object_ref_del,
        .do_xattr_get    = osd_xattr_get,
        .do_xattr_set    = osd_xattr_set,
        .do_xattr_del    = osd_xattr_del,
        .do_xattr_list   = osd_xattr_list,
        .do_capa_get     = osd_capa_get,
        .do_object_sync  = osd_object_sync,
        .do_version_get  = osd_object_version_get,
        .do_version_set  = osd_object_version_set,
        .do_data_get     = osd_data_get,
};

/*
 * Body operations.
 */

/*
 * XXX: Another layering violation for now.
 *
 * We don't want to use ->f_op->read methods, because generic file write
 *
 *         - serializes on ->i_sem, and
 *
 *         - does a lot of extra work like balance_dirty_pages(),
 *
 * which doesn't work for globally shared files like /last-received.
 */
static int osd_ldiskfs_readlink(struct inode *inode, char *buffer, int buflen)
{
        struct ldiskfs_inode_info *ei = LDISKFS_I(inode);

        memcpy(buffer, (char*)ei->i_data, buflen);

        return  buflen;
}

static int osd_ldiskfs_read(struct inode *inode, void *buf, int size,
                            loff_t *offs)
{
        struct buffer_head *bh;
        unsigned long block;
        int osize = size;
        int blocksize;
        int csize;
        int boffs;
        int err;

        /* prevent reading after eof */
        spin_lock(&inode->i_lock);
        if (i_size_read(inode) < *offs + size) {
                size = i_size_read(inode) - *offs;
                spin_unlock(&inode->i_lock);
                if (size < 0) {
                        CDEBUG(D_EXT2, "size %llu is too short to read @%llu\n",
                               i_size_read(inode), *offs);
                        return -EBADR;
                } else if (size == 0) {
                        return 0;
                }
        } else {
                spin_unlock(&inode->i_lock);
        }

        blocksize = 1 << inode->i_blkbits;

        while (size > 0) {
                block = *offs >> inode->i_blkbits;
                boffs = *offs & (blocksize - 1);
                csize = min(blocksize - boffs, size);
                bh = ldiskfs_bread(NULL, inode, block, 0, &err);
                if (!bh) {
                        CERROR("can't read block: %d\n", err);
                        return err;
                }

                memcpy(buf, bh->b_data + boffs, csize);
                brelse(bh);

                *offs += csize;
                buf += csize;
                size -= csize;
        }
        return osize;
}

static ssize_t osd_read(const struct lu_env *env, struct dt_object *dt,
                        struct lu_buf *buf, loff_t *pos,
                        struct lustre_capa *capa)
{
        struct osd_object      *obj    = osd_dt_obj(dt);
        struct inode           *inode  = obj->oo_inode;
        int rc;

        if (osd_object_auth(env, dt, capa, CAPA_OPC_BODY_READ))
                RETURN(-EACCES);

        /* Read small symlink from inode body as we need to maintain correct
         * on-disk symlinks for ldiskfs.
         */
        if (S_ISLNK(obj->oo_dt.do_lu.lo_header->loh_attr) &&
            (buf->lb_len <= sizeof (LDISKFS_I(inode)->i_data)))
                rc = osd_ldiskfs_readlink(inode, buf->lb_buf, buf->lb_len);
        else
                rc = osd_ldiskfs_read(inode, buf->lb_buf, buf->lb_len, pos);

        return rc;
}

static int osd_ldiskfs_writelink(struct inode *inode, char *buffer, int buflen)
{

        memcpy((char*)&LDISKFS_I(inode)->i_data, (char *)buffer,
               buflen);
        LDISKFS_I(inode)->i_disksize = buflen;
        i_size_write(inode, buflen);
        inode->i_sb->s_op->dirty_inode(inode);

        return 0;
}

static int osd_ldiskfs_write_record(struct inode *inode, void *buf, int bufsize,
                                    loff_t *offs, handle_t *handle)
{
        struct buffer_head *bh = NULL;
        loff_t offset = *offs;
        loff_t new_size = i_size_read(inode);
        unsigned long block;
        int blocksize = 1 << inode->i_blkbits;
        int err = 0;
        int size;
        int boffs;

        while (bufsize > 0) {
                if (bh != NULL)
                        brelse(bh);

                block = offset >> inode->i_blkbits;
                boffs = offset & (blocksize - 1);
                size = min(blocksize - boffs, bufsize);
                bh = ldiskfs_bread(handle, inode, block, 1, &err);
                if (!bh) {
                        CERROR("can't read/create block: %d\n", err);
                        break;
                }

                err = ldiskfs_journal_get_write_access(handle, bh);
                if (err) {
                        CERROR("journal_get_write_access() returned error %d\n",
                               err);
                        break;
                }
                LASSERTF(boffs + size <= bh->b_size,
                         "boffs %d size %d bh->b_size %lu",
                         boffs, size, (unsigned long)bh->b_size);
                memcpy(bh->b_data + boffs, buf, size);
                err = ldiskfs_journal_dirty_metadata(handle, bh);
                if (err)
                        break;

                if (offset + size > new_size)
                        new_size = offset + size;
                offset += size;
                bufsize -= size;
                buf += size;
        }
        if (bh)
                brelse(bh);

        /* correct in-core and on-disk sizes */
        if (new_size > i_size_read(inode)) {
                spin_lock(&inode->i_lock);
                if (new_size > i_size_read(inode))
                        i_size_write(inode, new_size);
                if (i_size_read(inode) > LDISKFS_I(inode)->i_disksize) {
                        LDISKFS_I(inode)->i_disksize = i_size_read(inode);
                        inode->i_sb->s_op->dirty_inode(inode);
                }
                spin_unlock(&inode->i_lock);
        }

        if (err == 0)
                *offs = offset;
        return err;
}

static ssize_t osd_write(const struct lu_env *env, struct dt_object *dt,
                         const struct lu_buf *buf, loff_t *pos,
                         struct thandle *handle, struct lustre_capa *capa,
                         int ignore_quota)
{
        struct osd_object  *obj   = osd_dt_obj(dt);
        struct inode       *inode = obj->oo_inode;
        struct osd_thandle *oh;
        ssize_t            result = 0;
#ifdef HAVE_QUOTA_SUPPORT
        cfs_cap_t           save = current->cap_effective;
#endif

        LASSERT(handle != NULL);

        if (osd_object_auth(env, dt, capa, CAPA_OPC_BODY_WRITE))
                RETURN(-EACCES);

        oh = container_of(handle, struct osd_thandle, ot_super);
        LASSERT(oh->ot_handle->h_transaction != NULL);
#ifdef HAVE_QUOTA_SUPPORT
        if (ignore_quota)
                current->cap_effective |= CFS_CAP_SYS_RESOURCE_MASK;
        else
                current->cap_effective &= ~CFS_CAP_SYS_RESOURCE_MASK;
#endif
        /* Write small symlink to inode body as we need to maintain correct
         * on-disk symlinks for ldiskfs.
         */
        if(S_ISLNK(obj->oo_dt.do_lu.lo_header->loh_attr) &&
           (buf->lb_len < sizeof (LDISKFS_I(inode)->i_data)))
                result = osd_ldiskfs_writelink(inode, buf->lb_buf, buf->lb_len);
        else
                result = osd_ldiskfs_write_record(inode, buf->lb_buf,
                                                  buf->lb_len, pos,
                                                  oh->ot_handle);
#ifdef HAVE_QUOTA_SUPPORT
        current->cap_effective = save;
#endif
        if (result == 0)
                result = buf->lb_len;
        return result;
}

static const struct dt_body_operations osd_body_ops = {
        .dbo_read  = osd_read,
        .dbo_write = osd_write
};


/**
 *      delete a (key, value) pair from index \a dt specified by \a key
 *
 *      \param  dt      osd index object
 *      \param  key     key for index
 *      \param  rec     record reference
 *      \param  handle  transaction handler
 *
 *      \retval  0  success
 *      \retval -ve   failure
 */

static int osd_index_iam_delete(const struct lu_env *env, struct dt_object *dt,
                                const struct dt_key *key, struct thandle *handle,
                                struct lustre_capa *capa)
{
        struct osd_object     *obj = osd_dt_obj(dt);
        struct osd_thandle    *oh;
        struct iam_path_descr *ipd;
        struct iam_container  *bag = &obj->oo_dir->od_container;
        int rc;

        ENTRY;

        LINVRNT(osd_invariant(obj));
        LASSERT(dt_object_exists(dt));
        LASSERT(bag->ic_object == obj->oo_inode);
        LASSERT(handle != NULL);

        if (osd_object_auth(env, dt, capa, CAPA_OPC_INDEX_DELETE))
                RETURN(-EACCES);

        ipd = osd_idx_ipd_get(env, bag);
        if (unlikely(ipd == NULL))
                RETURN(-ENOMEM);

        oh = container_of0(handle, struct osd_thandle, ot_super);
        LASSERT(oh->ot_handle != NULL);
        LASSERT(oh->ot_handle->h_transaction != NULL);

        rc = iam_delete(oh->ot_handle, bag, (const struct iam_key *)key, ipd);
        osd_ipd_put(env, bag, ipd);
        LINVRNT(osd_invariant(obj));
        RETURN(rc);
}

static inline int osd_get_fid_from_dentry(struct ldiskfs_dir_entry_2 *de,
                                          struct dt_rec *fid)
{
        struct osd_fid_pack *rec;
        int rc = -ENODATA;

        if (de->file_type & LDISKFS_DIRENT_LUFID) {
                rec = (struct osd_fid_pack *) (de->name + de->name_len + 1);
                rc = osd_fid_unpack((struct lu_fid *)fid, rec);
        }
        RETURN(rc);
}

/**
 * Index delete function for interoperability mode (b11826).
 * It will remove the directory entry added by osd_index_ea_insert().
 * This entry is needed to maintain name->fid mapping.
 *
 * \param key,  key i.e. file entry to be deleted
 *
 * \retval   0, on success
 * \retval -ve, on error
 */
static int osd_index_ea_delete(const struct lu_env *env, struct dt_object *dt,
                               const struct dt_key *key, struct thandle *handle,
                               struct lustre_capa *capa)
{
        struct osd_object          *obj    = osd_dt_obj(dt);
        struct inode               *dir    = obj->oo_inode;
        struct dentry              *dentry;
        struct osd_thandle         *oh;
        struct ldiskfs_dir_entry_2 *de;
        struct buffer_head         *bh;

        int rc;

        ENTRY;

        LINVRNT(osd_invariant(obj));
        LASSERT(dt_object_exists(dt));
        LASSERT(handle != NULL);

        oh = container_of(handle, struct osd_thandle, ot_super);
        LASSERT(oh->ot_handle != NULL);
        LASSERT(oh->ot_handle->h_transaction != NULL);

        if (osd_object_auth(env, dt, capa, CAPA_OPC_INDEX_DELETE))
                RETURN(-EACCES);

        dentry = osd_child_dentry_get(env, obj,
                                      (char *)key, strlen((char *)key));

        cfs_down_write(&obj->oo_ext_idx_sem);
        bh = ll_ldiskfs_find_entry(dir, dentry, &de);
        if (bh) {
                struct osd_thread_info *oti = osd_oti_get(env);
                struct timespec *ctime = &oti->oti_time;
                struct timespec *mtime = &oti->oti_time2;

                *ctime = dir->i_ctime;
                *mtime = dir->i_mtime;
                rc = ldiskfs_delete_entry(oh->ot_handle,
                                dir, de, bh);
                /* xtime should not be updated with server-side time. */
                cfs_spin_lock(&obj->oo_guard);
                dir->i_ctime = *ctime;
                dir->i_mtime = *mtime;
                cfs_spin_unlock(&obj->oo_guard);
                mark_inode_dirty(dir);
                brelse(bh);
        } else
                rc = -ENOENT;

        cfs_up_write(&obj->oo_ext_idx_sem);
        LASSERT(osd_invariant(obj));
        RETURN(rc);
}

/**
 *      Lookup index for \a key and copy record to \a rec.
 *
 *      \param  dt      osd index object
 *      \param  key     key for index
 *      \param  rec     record reference
 *
 *      \retval  +ve  success : exact mach
 *      \retval  0    return record with key not greater than \a key
 *      \retval -ve   failure
 */
static int osd_index_iam_lookup(const struct lu_env *env, struct dt_object *dt,
                                struct dt_rec *rec, const struct dt_key *key,
                                struct lustre_capa *capa)
{
        struct osd_object     *obj = osd_dt_obj(dt);
        struct iam_path_descr *ipd;
        struct iam_container  *bag = &obj->oo_dir->od_container;
        struct osd_thread_info *oti = osd_oti_get(env);
        struct iam_iterator    *it = &oti->oti_idx_it;
        struct iam_rec *iam_rec;
        int rc;
        ENTRY;

        LASSERT(osd_invariant(obj));
        LASSERT(dt_object_exists(dt));
        LASSERT(bag->ic_object == obj->oo_inode);

        if (osd_object_auth(env, dt, capa, CAPA_OPC_INDEX_LOOKUP))
                RETURN(-EACCES);

        ipd = osd_idx_ipd_get(env, bag);
        if (IS_ERR(ipd))
                RETURN(-ENOMEM);

        /* got ipd now we can start iterator. */
        iam_it_init(it, bag, 0, ipd);

        rc = iam_it_get(it, (struct iam_key *)key);
        if (rc >= 0) {
                if (S_ISDIR(obj->oo_inode->i_mode))
                        iam_rec = (struct iam_rec *)oti->oti_ldp;
                else
                        iam_rec = (struct iam_rec *) rec;

                iam_reccpy(&it->ii_path.ip_leaf, (struct iam_rec *)iam_rec);
                if (S_ISDIR(obj->oo_inode->i_mode))
                        osd_fid_unpack((struct lu_fid *) rec,
                                       (struct osd_fid_pack *)iam_rec);
        }
        iam_it_put(it);
        iam_it_fini(it);
        osd_ipd_put(env, bag, ipd);

        LINVRNT(osd_invariant(obj));

        RETURN(rc);
}

/**
 *      Inserts (key, value) pair in \a dt index object.
 *
 *      \param  dt      osd index object
 *      \param  key     key for index
 *      \param  rec     record reference
 *      \param  th      transaction handler
 *
 *      \retval  0  success
 *      \retval -ve failure
 */
static int osd_index_iam_insert(const struct lu_env *env, struct dt_object *dt,
                                const struct dt_rec *rec, const struct dt_key *key,
                                struct thandle *th, struct lustre_capa *capa,
                                int ignore_quota)
{
        struct osd_object     *obj = osd_dt_obj(dt);
        struct iam_path_descr *ipd;
        struct osd_thandle    *oh;
        struct iam_container  *bag = &obj->oo_dir->od_container;
#ifdef HAVE_QUOTA_SUPPORT
        cfs_cap_t              save = current->cap_effective;
#endif
        struct osd_thread_info *oti = osd_oti_get(env);
        struct iam_rec *iam_rec = (struct iam_rec *)oti->oti_ldp;
        int rc;

        ENTRY;

        LINVRNT(osd_invariant(obj));
        LASSERT(dt_object_exists(dt));
        LASSERT(bag->ic_object == obj->oo_inode);
        LASSERT(th != NULL);

        if (osd_object_auth(env, dt, capa, CAPA_OPC_INDEX_INSERT))
                return -EACCES;

        ipd = osd_idx_ipd_get(env, bag);
        if (unlikely(ipd == NULL))
                RETURN(-ENOMEM);

        oh = container_of0(th, struct osd_thandle, ot_super);
        LASSERT(oh->ot_handle != NULL);
        LASSERT(oh->ot_handle->h_transaction != NULL);
#ifdef HAVE_QUOTA_SUPPORT
        if (ignore_quota)
                current->cap_effective |= CFS_CAP_SYS_RESOURCE_MASK;
        else
                current->cap_effective &= ~CFS_CAP_SYS_RESOURCE_MASK;
#endif
        if (S_ISDIR(obj->oo_inode->i_mode))
                osd_fid_pack((struct osd_fid_pack *)iam_rec, rec, &oti->oti_fid);
        else
                iam_rec = (struct iam_rec *) rec;
        rc = iam_insert(oh->ot_handle, bag, (const struct iam_key *)key,
                        iam_rec, ipd);
#ifdef HAVE_QUOTA_SUPPORT
        current->cap_effective = save;
#endif
        osd_ipd_put(env, bag, ipd);
        LINVRNT(osd_invariant(obj));
        RETURN(rc);
}

/**
 * Calls ldiskfs_add_entry() to add directory entry
 * into the directory. This is required for
 * interoperability mode (b11826)
 *
 * \retval   0, on success
 * \retval -ve, on error
 */
static int __osd_ea_add_rec(struct osd_thread_info *info,
                            struct osd_object *pobj,
                            struct inode  *cinode,
                            const char *name,
                            const struct dt_rec *fid,
                            struct thandle *th)
{
        struct ldiskfs_dentry_param *ldp;
        struct dentry      *child;
        struct osd_thandle *oth;
        int rc;

        oth = container_of(th, struct osd_thandle, ot_super);
        LASSERT(oth->ot_handle != NULL);
        LASSERT(oth->ot_handle->h_transaction != NULL);

        child = osd_child_dentry_get(info->oti_env, pobj, name, strlen(name));

        if (fid_is_igif((struct lu_fid *)fid) ||
            fid_seq((struct lu_fid *)fid) >= FID_SEQ_DISTRIBUTED_START) {
                ldp = (struct ldiskfs_dentry_param *)info->oti_ldp;
                osd_get_ldiskfs_dirent_param(ldp, fid);
                child->d_fsdata = (void*) ldp;
        } else
                child->d_fsdata = NULL;
        rc = ldiskfs_add_entry(oth->ot_handle, child, cinode);

        RETURN(rc);
}

/**
 * Calls ldiskfs_add_dot_dotdot() to add dot and dotdot entries
 * into the directory.Also sets flags into osd object to
 * indicate dot and dotdot are created. This is required for
 * interoperability mode (b11826)
 *
 * \param dir   directory for dot and dotdot fixup.
 * \param obj   child object for linking
 *
 * \retval   0, on success
 * \retval -ve, on error
 */
static int osd_add_dot_dotdot(struct osd_thread_info *info,
                              struct osd_object *dir,
                              struct inode  *parent_dir, const char *name,
                              const struct dt_rec *dot_fid,
                              const struct dt_rec *dot_dot_fid,
                              struct thandle *th)
{
        struct inode            *inode  = dir->oo_inode;
        struct ldiskfs_dentry_param *dot_ldp;
        struct ldiskfs_dentry_param *dot_dot_ldp;
        struct osd_thandle      *oth;
        int result = 0;

        oth = container_of(th, struct osd_thandle, ot_super);
        LASSERT(oth->ot_handle->h_transaction != NULL);
        LASSERT(S_ISDIR(dir->oo_inode->i_mode));

        if (strcmp(name, dot) == 0) {
                if (dir->oo_compat_dot_created) {
                        result = -EEXIST;
                } else {
                        LASSERT(inode == parent_dir);
                        dir->oo_compat_dot_created = 1;
                        result = 0;
                }
        } else if(strcmp(name, dotdot) == 0) {
                dot_ldp = (struct ldiskfs_dentry_param *)info->oti_ldp;
                dot_dot_ldp = (struct ldiskfs_dentry_param *)info->oti_ldp2;

                if (!dir->oo_compat_dot_created)
                        return -EINVAL;
                if (fid_seq((struct lu_fid *) dot_fid) >= FID_SEQ_DISTRIBUTED_START) {
                        osd_get_ldiskfs_dirent_param(dot_ldp, dot_fid);
                        osd_get_ldiskfs_dirent_param(dot_dot_ldp, dot_dot_fid);
                } else {
                        dot_ldp = NULL;
                        dot_dot_ldp = NULL;
                }
                /* in case of rename, dotdot is already created */
                if (dir->oo_compat_dotdot_created) {
                        return __osd_ea_add_rec(info, dir, parent_dir, name,
                                                dot_dot_fid, th);
                }

                result = ldiskfs_add_dot_dotdot(oth->ot_handle, parent_dir, inode,
                                                dot_ldp, dot_dot_ldp);
                if (result == 0)
                       dir->oo_compat_dotdot_created = 1;
        }

        return result;
}


/**
 * It will call the appropriate osd_add* function and return the
 * value, return by respective functions.
 */
static int osd_ea_add_rec(const struct lu_env *env,
                          struct osd_object *pobj,
                          struct inode *cinode,
                          const char *name,
                          const struct dt_rec *fid,
                          struct thandle *th)
{
        struct osd_thread_info    *info   = osd_oti_get(env);
        int rc;

        if (name[0] == '.' && (name[1] == '\0' || (name[1] == '.' &&
                                                   name[2] =='\0')))
                rc = osd_add_dot_dotdot(info, pobj, cinode, name,
                     (struct dt_rec *)lu_object_fid(&pobj->oo_dt.do_lu),
                                        fid, th);
        else
                rc = __osd_ea_add_rec(info, pobj, cinode, name, fid, th);

        return rc;
}

/**
 * Calls ->lookup() to find dentry. From dentry get inode and
 * read inode's ea to get fid. This is required for  interoperability
 * mode (b11826)
 *
 * \retval   0, on success
 * \retval -ve, on error
 */
static int osd_ea_lookup_rec(const struct lu_env *env, struct osd_object *obj,
                             struct dt_rec *rec, const struct dt_key *key)
{
        struct inode               *dir    = obj->oo_inode;
        struct dentry              *dentry;
        struct ldiskfs_dir_entry_2 *de;
        struct buffer_head         *bh;
        struct lu_fid              *fid = (struct lu_fid *) rec;
        int ino;
        int rc;

        LASSERT(dir->i_op != NULL && dir->i_op->lookup != NULL);

        dentry = osd_child_dentry_get(env, obj,
                                      (char *)key, strlen((char *)key));

        cfs_down_read(&obj->oo_ext_idx_sem);
        bh = ll_ldiskfs_find_entry(dir, dentry, &de);
        if (bh) {
                ino = le32_to_cpu(de->inode);
                rc = osd_get_fid_from_dentry(de, rec);

                /* done with de, release bh */
                brelse(bh);
                if (rc != 0)
                        rc = osd_ea_fid_get(env, obj, ino, fid);
        } else
                rc = -ENOENT;

        cfs_up_read(&obj->oo_ext_idx_sem);
        RETURN (rc);
}

/**
 * Find the osd object for given fid.
 *
 * \param fid need to find the osd object having this fid
 *
 * \retval osd_object on success
 * \retval        -ve on error
 */
struct osd_object *osd_object_find(const struct lu_env *env,
                                   struct dt_object *dt,
                                   const struct lu_fid *fid)
{
        struct lu_device         *ludev = dt->do_lu.lo_dev;
        struct osd_object        *child = NULL;
        struct lu_object         *luch;
        struct lu_object         *lo;

        luch = lu_object_find(env, ludev, fid, NULL);
        if (!IS_ERR(luch)) {
                if (lu_object_exists(luch)) {
                        lo = lu_object_locate(luch->lo_header, ludev->ld_type);
                        if (lo != NULL)
                                child = osd_obj(lo);
                        else
                                LU_OBJECT_DEBUG(D_ERROR, env, luch,
                                                "lu_object can't be located"
                                                ""DFID"\n", PFID(fid));

                        if (child == NULL) {
                                lu_object_put(env, luch);
                                CERROR("Unable to get osd_object\n");
                                child = ERR_PTR(-ENOENT);
                        }
                } else {
                        LU_OBJECT_DEBUG(D_ERROR, env, luch,
                                        "lu_object does not exists "DFID"\n",
                                        PFID(fid));
                        child = ERR_PTR(-ENOENT);
                }
        } else
                child = (void *)luch;

        return child;
}

/**
 * Put the osd object once done with it.
 *
 * \param obj osd object that needs to be put
 */
static inline void osd_object_put(const struct lu_env *env,
                                  struct osd_object *obj)
{
        lu_object_put(env, &obj->oo_dt.do_lu);
}

/**
 * Index add function for interoperability mode (b11826).
 * It will add the directory entry.This entry is needed to
 * maintain name->fid mapping.
 *
 * \param key it is key i.e. file entry to be inserted
 * \param rec it is value of given key i.e. fid
 *
 * \retval   0, on success
 * \retval -ve, on error
 */
static int osd_index_ea_insert(const struct lu_env *env, struct dt_object *dt,
                               const struct dt_rec *rec,
                               const struct dt_key *key, struct thandle *th,
                               struct lustre_capa *capa, int ignore_quota)
{
        struct osd_object        *obj   = osd_dt_obj(dt);
        struct lu_fid            *fid   = (struct lu_fid *) rec;
        const char               *name  = (const char *)key;
        struct osd_object        *child;
#ifdef HAVE_QUOTA_SUPPORT
        cfs_cap_t                 save  = current->cap_effective;
#endif
        int rc;

        ENTRY;

        LASSERT(osd_invariant(obj));
        LASSERT(dt_object_exists(dt));
        LASSERT(th != NULL);

        if (osd_object_auth(env, dt, capa, CAPA_OPC_INDEX_INSERT))
                RETURN(-EACCES);

        child = osd_object_find(env, dt, fid);
        if (!IS_ERR(child)) {
                struct inode *inode = obj->oo_inode;
                struct osd_thread_info *oti = osd_oti_get(env);
                struct timespec *ctime = &oti->oti_time;
                struct timespec *mtime = &oti->oti_time2;

                *ctime = inode->i_ctime;
                *mtime = inode->i_mtime;
#ifdef HAVE_QUOTA_SUPPORT
                if (ignore_quota)
                        current->cap_effective |= CFS_CAP_SYS_RESOURCE_MASK;
                else
                        current->cap_effective &= ~CFS_CAP_SYS_RESOURCE_MASK;
#endif
                cfs_down_write(&obj->oo_ext_idx_sem);
                rc = osd_ea_add_rec(env, obj, child->oo_inode, name, rec, th);
                cfs_up_write(&obj->oo_ext_idx_sem);
#ifdef HAVE_QUOTA_SUPPORT
                current->cap_effective = save;
#endif
                osd_object_put(env, child);
                /* xtime should not be updated with server-side time. */
                cfs_spin_lock(&obj->oo_guard);
                inode->i_ctime = *ctime;
                inode->i_mtime = *mtime;
                cfs_spin_unlock(&obj->oo_guard);
                mark_inode_dirty(inode);
        } else {
                rc = PTR_ERR(child);
        }

        LASSERT(osd_invariant(obj));
        RETURN(rc);
}

/**
 *  Initialize osd Iterator for given osd index object.
 *
 *  \param  dt      osd index object
 */

static struct dt_it *osd_it_iam_init(const struct lu_env *env,
                                 struct dt_object *dt,
                                 struct lustre_capa *capa)
{
        struct osd_it_iam         *it;
        struct osd_thread_info *oti = osd_oti_get(env);
        struct osd_object     *obj = osd_dt_obj(dt);
        struct lu_object      *lo  = &dt->do_lu;
        struct iam_path_descr *ipd;
        struct iam_container  *bag = &obj->oo_dir->od_container;

        LASSERT(lu_object_exists(lo));

        if (osd_object_auth(env, dt, capa, CAPA_OPC_BODY_READ))
                return ERR_PTR(-EACCES);

        it = &oti->oti_it;
        ipd = osd_it_ipd_get(env, bag);
        if (likely(ipd != NULL)) {
                it->oi_obj = obj;
                it->oi_ipd = ipd;
                lu_object_get(lo);
                iam_it_init(&it->oi_it, bag, IAM_IT_MOVE, ipd);
                return (struct dt_it *)it;
        }
        return ERR_PTR(-ENOMEM);
}

/**
 * free given Iterator.
 */

static void osd_it_iam_fini(const struct lu_env *env, struct dt_it *di)
{
        struct osd_it_iam     *it = (struct osd_it_iam *)di;
        struct osd_object *obj = it->oi_obj;

        iam_it_fini(&it->oi_it);
        osd_ipd_put(env, &obj->oo_dir->od_container, it->oi_ipd);
        lu_object_put(env, &obj->oo_dt.do_lu);
}

/**
 *  Move Iterator to record specified by \a key
 *
 *  \param  di      osd iterator
 *  \param  key     key for index
 *
 *  \retval +ve  di points to record with least key not larger than key
 *  \retval  0   di points to exact matched key
 *  \retval -ve  failure
 */

static int osd_it_iam_get(const struct lu_env *env,
                      struct dt_it *di, const struct dt_key *key)
{
        struct osd_it_iam *it = (struct osd_it_iam *)di;

        return iam_it_get(&it->oi_it, (const struct iam_key *)key);
}

/**
 *  Release Iterator
 *
 *  \param  di      osd iterator
 */

static void osd_it_iam_put(const struct lu_env *env, struct dt_it *di)
{
        struct osd_it_iam *it = (struct osd_it_iam *)di;

        iam_it_put(&it->oi_it);
}

/**
 *  Move iterator by one record
 *
 *  \param  di      osd iterator
 *
 *  \retval +1   end of container reached
 *  \retval  0   success
 *  \retval -ve  failure
 */

static int osd_it_iam_next(const struct lu_env *env, struct dt_it *di)
{
        struct osd_it_iam *it = (struct osd_it_iam *)di;

        return iam_it_next(&it->oi_it);
}

/**
 * Return pointer to the key under iterator.
 */

static struct dt_key *osd_it_iam_key(const struct lu_env *env,
                                 const struct dt_it *di)
{
        struct osd_it_iam *it = (struct osd_it_iam *)di;

        return (struct dt_key *)iam_it_key_get(&it->oi_it);
}

/**
 * Return size of key under iterator (in bytes)
 */

static int osd_it_iam_key_size(const struct lu_env *env, const struct dt_it *di)
{
        struct osd_it_iam *it = (struct osd_it_iam *)di;

        return iam_it_key_size(&it->oi_it);
}

static inline void osd_it_append_attrs(struct lu_dirent*ent,
                                       __u32 attr,
                                       int len,
                                       __u16 type)
{
        struct luda_type        *lt;
        const unsigned           align = sizeof(struct luda_type) - 1;

        /* check if file type is required */
        if (attr & LUDA_TYPE) {
                        len = (len + align) & ~align;

                        lt = (void *) ent->lde_name + len;
                        lt->lt_type = cpu_to_le16(CFS_DTTOIF(type));
                        ent->lde_attrs |= LUDA_TYPE;
        }

        ent->lde_attrs = cpu_to_le32(ent->lde_attrs);
}

/**
 * build lu direct from backend fs dirent.
 */

static inline void osd_it_pack_dirent(struct lu_dirent *ent,
                                      struct lu_fid *fid,
                                      __u64 offset,
                                      char *name,
                                      __u16 namelen,
                                      __u16 type,
                                      __u32 attr)
{
        fid_cpu_to_le(&ent->lde_fid, fid);
        ent->lde_attrs = LUDA_FID;

        ent->lde_hash = cpu_to_le64(offset);
        ent->lde_reclen = cpu_to_le16(lu_dirent_calc_size(namelen, attr));

        strncpy(ent->lde_name, name, namelen);
        ent->lde_namelen = cpu_to_le16(namelen);

        /* append lustre attributes */
        osd_it_append_attrs(ent, attr, namelen, type);
}

/**
 * Return pointer to the record under iterator.
 */
static int osd_it_iam_rec(const struct lu_env *env,
                          const struct dt_it *di,
                          struct lu_dirent *lde,
                          __u32 attr)
{
        struct osd_it_iam *it        = (struct osd_it_iam *)di;
        struct osd_thread_info *info = osd_oti_get(env);
        struct lu_fid     *fid       = &info->oti_fid;
        const struct osd_fid_pack *rec;
        char *name;
        int namelen;
        __u64 hash;
        int rc;

        name = (char *)iam_it_key_get(&it->oi_it);
        if (IS_ERR(name))
                RETURN(PTR_ERR(name));

        namelen = iam_it_key_size(&it->oi_it);

        rec = (const struct osd_fid_pack *) iam_it_rec_get(&it->oi_it);
        if (IS_ERR(rec))
                RETURN(PTR_ERR(rec));

        rc = osd_fid_unpack(fid, rec);
        if (rc)
                RETURN(rc);

        hash = iam_it_store(&it->oi_it);

        /* IAM does not store object type in IAM index (dir) */
        osd_it_pack_dirent(lde, fid, hash, name, namelen,
                           0, LUDA_FID);

        return 0;
}

/**
 * Returns cookie for current Iterator position.
 */
static __u64 osd_it_iam_store(const struct lu_env *env, const struct dt_it *di)
{
        struct osd_it_iam *it = (struct osd_it_iam *)di;

        return iam_it_store(&it->oi_it);
}

/**
 * Restore iterator from cookie.
 *
 * \param  di      osd iterator
 * \param  hash    Iterator location cookie
 *
 * \retval +ve  di points to record with least key not larger than key.
 * \retval  0   di points to exact matched key
 * \retval -ve  failure
 */

static int osd_it_iam_load(const struct lu_env *env,
                       const struct dt_it *di, __u64 hash)
{
        struct osd_it_iam *it = (struct osd_it_iam *)di;

        return iam_it_load(&it->oi_it, hash);
}

static const struct dt_index_operations osd_index_iam_ops = {
        .dio_lookup = osd_index_iam_lookup,
        .dio_insert = osd_index_iam_insert,
        .dio_delete = osd_index_iam_delete,
        .dio_it     = {
                .init     = osd_it_iam_init,
                .fini     = osd_it_iam_fini,
                .get      = osd_it_iam_get,
                .put      = osd_it_iam_put,
                .next     = osd_it_iam_next,
                .key      = osd_it_iam_key,
                .key_size = osd_it_iam_key_size,
                .rec      = osd_it_iam_rec,
                .store    = osd_it_iam_store,
                .load     = osd_it_iam_load
        }
};

/**
 * Creates or initializes iterator context.
 *
 * \retval struct osd_it_ea, iterator structure on success
 *
 */
static struct dt_it *osd_it_ea_init(const struct lu_env *env,
                                    struct dt_object *dt,
                                    struct lustre_capa *capa)
{
        struct osd_object       *obj  = osd_dt_obj(dt);
        struct osd_thread_info  *info = osd_oti_get(env);
        struct osd_it_ea        *it   = &info->oti_it_ea;
        struct lu_object        *lo   = &dt->do_lu;
        struct dentry           *obj_dentry = &info->oti_it_dentry;
        ENTRY;
        LASSERT(lu_object_exists(lo));

        obj_dentry->d_inode = obj->oo_inode;
        obj_dentry->d_sb = osd_sb(osd_obj2dev(obj));
        obj_dentry->d_name.hash = 0;

        it->oie_rd_dirent       = 0;
        it->oie_it_dirent       = 0;
        it->oie_dirent          = NULL;
        it->oie_buf             = info->oti_it_ea_buf;
        it->oie_obj             = obj;
        it->oie_file.f_pos      = 0;
        it->oie_file.f_dentry   = obj_dentry;
        it->oie_file.f_mapping    = obj->oo_inode->i_mapping;
        it->oie_file.f_op         = obj->oo_inode->i_fop;
        it->oie_file.private_data = NULL;
        lu_object_get(lo);
        RETURN((struct dt_it *) it);
}

/**
 * Destroy or finishes iterator context.
 *
 * \param di iterator structure to be destroyed
 */
static void osd_it_ea_fini(const struct lu_env *env, struct dt_it *di)
{
        struct osd_it_ea     *it   = (struct osd_it_ea *)di;
        struct osd_object    *obj  = it->oie_obj;
        struct inode       *inode  = obj->oo_inode;

        ENTRY;
        it->oie_file.f_op->release(inode, &it->oie_file);
        lu_object_put(env, &obj->oo_dt.do_lu);
        EXIT;
}

/**
 * It position the iterator at given key, so that next lookup continues from
 * that key Or it is similar to dio_it->load() but based on a key,
 * rather than file position.
 *
 * As a special convention, osd_it_ea_get(env, di, "") has to rewind iterator
 * to the beginning.
 *
 * TODO: Presently return +1 considering it is only used by mdd_dir_is_empty().
 */
static int osd_it_ea_get(const struct lu_env *env,
                         struct dt_it *di, const struct dt_key *key)
{
        struct osd_it_ea     *it   = (struct osd_it_ea *)di;

        ENTRY;
        LASSERT(((const char *)key)[0] == '\0');
        it->oie_file.f_pos      = 0;
        it->oie_rd_dirent       = 0;
        it->oie_it_dirent       = 0;
        it->oie_dirent          = NULL;

        RETURN(+1);
}

/**
 * Does nothing
 */
static void osd_it_ea_put(const struct lu_env *env, struct dt_it *di)
{
}

/**
 * It is called internally by ->readdir(). It fills the
 * iterator's in-memory data structure with required
 * information i.e. name, namelen, rec_size etc.
 *
 * \param buf in which information to be filled in.
 * \param name name of the file in given dir
 *
 * \retval 0 on success
 * \retval 1 on buffer full
 */
static int osd_ldiskfs_filldir(char *buf, const char *name, int namelen,
                               loff_t offset, __u64 ino,
                               unsigned d_type)
{
        struct osd_it_ea        *it   = (struct osd_it_ea *)buf;
        struct osd_it_ea_dirent *ent  = it->oie_dirent;
        struct lu_fid           *fid  = &ent->oied_fid;
        struct osd_fid_pack     *rec;
        ENTRY;

        /* this should never happen */
        if (unlikely(namelen == 0 || namelen > LDISKFS_NAME_LEN)) {
                CERROR("ldiskfs return invalid namelen %d\n", namelen);
                RETURN(-EIO);
        }

        if ((void *) ent - it->oie_buf + sizeof(*ent) + namelen >
            OSD_IT_EA_BUFSIZE)
                RETURN(1);

        if (d_type & LDISKFS_DIRENT_LUFID) {
                rec = (struct osd_fid_pack*) (name + namelen + 1);

                if (osd_fid_unpack(fid, rec) != 0)
                        fid_zero(fid);

                d_type &= ~LDISKFS_DIRENT_LUFID;
        } else {
                fid_zero(fid);
        }

        ent->oied_ino     = ino;
        ent->oied_off     = offset;
        ent->oied_namelen = namelen;
        ent->oied_type    = d_type;

        memcpy(ent->oied_name, name, namelen);

        it->oie_rd_dirent++;
        it->oie_dirent = (void *) ent + cfs_size_round(sizeof(*ent) + namelen);
        RETURN(0);
}

/**
 * Calls ->readdir() to load a directory entry at a time
 * and stored it in iterator's in-memory data structure.
 *
 * \param di iterator's in memory structure
 *
 * \retval   0 on success
 * \retval -ve on error
 */
static int osd_ldiskfs_it_fill(const struct dt_it *di)
{
        struct osd_it_ea   *it    = (struct osd_it_ea *)di;
        struct osd_object  *obj   = it->oie_obj;
        struct inode       *inode = obj->oo_inode;
        int                result = 0;

        ENTRY;
        it->oie_dirent = it->oie_buf;
        it->oie_rd_dirent = 0;

        cfs_down_read(&obj->oo_ext_idx_sem);
        result = inode->i_fop->readdir(&it->oie_file, it,
                                       (filldir_t) osd_ldiskfs_filldir);

        cfs_up_read(&obj->oo_ext_idx_sem);

        if (it->oie_rd_dirent == 0) {
                result = -EIO;
        } else {
                it->oie_dirent = it->oie_buf;
                it->oie_it_dirent = 1;
        }

        RETURN(result);
}

/**
 * It calls osd_ldiskfs_it_fill() which will use ->readdir()
 * to load a directory entry at a time and stored it in
 * iterator's in-memory data structure.
 *
 * \param di iterator's in memory structure
 *
 * \retval +ve iterator reached to end
 * \retval   0 iterator not reached to end
 * \retval -ve on error
 */
static int osd_it_ea_next(const struct lu_env *env, struct dt_it *di)
{
        struct osd_it_ea *it = (struct osd_it_ea *)di;
        int rc;

        ENTRY;

        if (it->oie_it_dirent < it->oie_rd_dirent) {
                it->oie_dirent =
                        (void *) it->oie_dirent +
                        cfs_size_round(sizeof(struct osd_it_ea_dirent) +
                                       it->oie_dirent->oied_namelen);
                it->oie_it_dirent++;
                RETURN(0);
        } else {
                if (it->oie_file.f_pos == LDISKFS_HTREE_EOF)
                        rc = +1;
                else
                        rc = osd_ldiskfs_it_fill(di);
        }

        RETURN(rc);
}

/**
 * Returns the key at current position from iterator's in memory structure.
 *
 * \param di iterator's in memory structure
 *
 * \retval key i.e. struct dt_key on success
 */
static struct dt_key *osd_it_ea_key(const struct lu_env *env,
                                    const struct dt_it *di)
{
        struct osd_it_ea *it = (struct osd_it_ea *)di;
        ENTRY;
        RETURN((struct dt_key *)it->oie_dirent->oied_name);
}

/**
 * Returns the key's size at current position from iterator's in memory structure.
 *
 * \param di iterator's in memory structure
 *
 * \retval key_size i.e. struct dt_key on success
 */
static int osd_it_ea_key_size(const struct lu_env *env, const struct dt_it *di)
{
        struct osd_it_ea *it = (struct osd_it_ea *)di;
        ENTRY;
        RETURN(it->oie_dirent->oied_namelen);
}


/**
 * Returns the value (i.e. fid/igif) at current position from iterator's
 * in memory structure.
 *
 * \param di struct osd_it_ea, iterator's in memory structure
 * \param attr attr requested for dirent.
 * \param lde lustre dirent
 *
 * \retval   0 no error and \param lde has correct lustre dirent.
 * \retval -ve on error
 */
static inline int osd_it_ea_rec(const struct lu_env *env,
                                const struct dt_it *di,
                                struct lu_dirent *lde,
                                __u32 attr)
{
        struct osd_it_ea        *it     = (struct osd_it_ea *)di;
        struct osd_object       *obj    = it->oie_obj;
        struct lu_fid           *fid    = &it->oie_dirent->oied_fid;
        int    rc = 0;

        ENTRY;

        if (!fid_is_sane(fid))
                rc = osd_ea_fid_get(env, obj, it->oie_dirent->oied_ino, fid);

        if (rc == 0)
                osd_it_pack_dirent(lde, fid, it->oie_dirent->oied_off,
                                   it->oie_dirent->oied_name,
                                   it->oie_dirent->oied_namelen,
                                   it->oie_dirent->oied_type,
                                   attr);
        RETURN(rc);
}

/**
 * Returns a cookie for current position of the iterator head, so that
 * user can use this cookie to load/start the iterator next time.
 *
 * \param di iterator's in memory structure
 *
 * \retval cookie for current position, on success
 */
static __u64 osd_it_ea_store(const struct lu_env *env, const struct dt_it *di)
{
        struct osd_it_ea *it = (struct osd_it_ea *)di;
        ENTRY;
        RETURN(it->oie_dirent->oied_off);
}

/**
 * It calls osd_ldiskfs_it_fill() which will use ->readdir()
 * to load a directory entry at a time and stored it i inn,
 * in iterator's in-memory data structure.
 *
 * \param di struct osd_it_ea, iterator's in memory structure
 *
 * \retval +ve on success
 * \retval -ve on error
 */
static int osd_it_ea_load(const struct lu_env *env,
                          const struct dt_it *di, __u64 hash)
{
        struct osd_it_ea *it = (struct osd_it_ea *)di;
        int rc;

        ENTRY;
        it->oie_file.f_pos = hash;

        rc =  osd_ldiskfs_it_fill(di);
        if (rc == 0)
                rc = +1;

        RETURN(rc);
}

/**
 * Index lookup function for interoperability mode (b11826).
 *
 * \param key,  key i.e. file name to be searched
 *
 * \retval +ve, on success
 * \retval -ve, on error
 */
static int osd_index_ea_lookup(const struct lu_env *env, struct dt_object *dt,
                               struct dt_rec *rec, const struct dt_key *key,
                               struct lustre_capa *capa)
{
        struct osd_object *obj = osd_dt_obj(dt);
        int rc = 0;

        ENTRY;

        LASSERT(S_ISDIR(obj->oo_inode->i_mode));
        LINVRNT(osd_invariant(obj));

        if (osd_object_auth(env, dt, capa, CAPA_OPC_INDEX_LOOKUP))
                return -EACCES;

        rc = osd_ea_lookup_rec(env, obj, rec, key);

        if (rc == 0)
                rc = +1;
        RETURN(rc);
}

/**
 * Index and Iterator operations for interoperability
 * mode (i.e. to run 2.0 mds on 1.8 disk) (b11826)
 */
static const struct dt_index_operations osd_index_ea_ops = {
        .dio_lookup = osd_index_ea_lookup,
        .dio_insert = osd_index_ea_insert,
        .dio_delete = osd_index_ea_delete,
        .dio_it     = {
                .init     = osd_it_ea_init,
                .fini     = osd_it_ea_fini,
                .get      = osd_it_ea_get,
                .put      = osd_it_ea_put,
                .next     = osd_it_ea_next,
                .key      = osd_it_ea_key,
                .key_size = osd_it_ea_key_size,
                .rec      = osd_it_ea_rec,
                .store    = osd_it_ea_store,
                .load     = osd_it_ea_load
        }
};

static void *osd_key_init(const struct lu_context *ctx,
                          struct lu_context_key *key)
{
        struct osd_thread_info *info;

        OBD_ALLOC_PTR(info);
        if (info != NULL) {
                OBD_ALLOC(info->oti_it_ea_buf, OSD_IT_EA_BUFSIZE);
                if (info->oti_it_ea_buf != NULL) {
                        info->oti_env = container_of(ctx, struct lu_env,
                                                     le_ctx);
                } else {
                        OBD_FREE_PTR(info);
                        info = ERR_PTR(-ENOMEM);
                }
        } else {
                info = ERR_PTR(-ENOMEM);
        }
        return info;
}

static void osd_key_fini(const struct lu_context *ctx,
                         struct lu_context_key *key, void* data)
{
        struct osd_thread_info *info = data;

        OBD_FREE(info->oti_it_ea_buf, OSD_IT_EA_BUFSIZE);
        OBD_FREE_PTR(info);
}

static void osd_key_exit(const struct lu_context *ctx,
                         struct lu_context_key *key, void *data)
{
        struct osd_thread_info *info = data;

        LASSERT(info->oti_r_locks == 0);
        LASSERT(info->oti_w_locks == 0);
        LASSERT(info->oti_txns    == 0);
}

/* type constructor/destructor: osd_type_init, osd_type_fini */
LU_TYPE_INIT_FINI(osd, &osd_key);

static struct lu_context_key osd_key = {
        .lct_tags = LCT_DT_THREAD | LCT_MD_THREAD,
        .lct_init = osd_key_init,
        .lct_fini = osd_key_fini,
        .lct_exit = osd_key_exit
};


static int osd_device_init(const struct lu_env *env, struct lu_device *d,
                           const char *name, struct lu_device *next)
{
        int rc;
        struct lu_context *ctx;

        /* context for commit hooks */
        ctx = &osd_dev(d)->od_env_for_commit.le_ctx;
        rc = lu_context_init(ctx, LCT_MD_THREAD|LCT_REMEMBER|LCT_NOREF);
        if (rc == 0) {
                rc = osd_procfs_init(osd_dev(d), name);
                ctx->lc_cookie = 0x3;
        }
        return rc;
}

static int osd_shutdown(const struct lu_env *env, struct osd_device *o)
{
        struct osd_thread_info *info = osd_oti_get(env);
        ENTRY;
        if (o->od_obj_area != NULL) {
                lu_object_put(env, &o->od_obj_area->do_lu);
                o->od_obj_area = NULL;
        }
        osd_oi_fini(info, &o->od_oi);

        RETURN(0);
}

static int osd_mount(const struct lu_env *env,
                     struct osd_device *o, struct lustre_cfg *cfg)
{
        struct lustre_mount_info *lmi;
        const char               *dev  = lustre_cfg_string(cfg, 0);
        struct lustre_disk_data  *ldd;
        struct lustre_sb_info    *lsi;

        ENTRY;
        if (o->od_mount != NULL) {
                CERROR("Already mounted (%s)\n", dev);
                RETURN(-EEXIST);
        }

        /* get mount */
        lmi = server_get_mount(dev);
        if (lmi == NULL) {
                CERROR("Cannot get mount info for %s!\n", dev);
                RETURN(-EFAULT);
        }

        LASSERT(lmi != NULL);
        /* save lustre_mount_info in dt_device */
        o->od_mount = lmi;

        lsi = s2lsi(lmi->lmi_sb);
        ldd = lsi->lsi_ldd;

        if (ldd->ldd_flags & LDD_F_IAM_DIR) {
                o->od_iop_mode = 0;
                LCONSOLE_WARN("OSD: IAM mode enabled\n");
        } else
                o->od_iop_mode = 1;

        o->od_obj_area = NULL;
        RETURN(0);
}

static struct lu_device *osd_device_fini(const struct lu_env *env,
                                         struct lu_device *d)
{
        int rc;
        ENTRY;

        shrink_dcache_sb(osd_sb(osd_dev(d)));
        osd_sync(env, lu2dt_dev(d));

        rc = osd_procfs_fini(osd_dev(d));
        if (rc) {
                CERROR("proc fini error %d \n", rc);
                RETURN (ERR_PTR(rc));
        }

        if (osd_dev(d)->od_mount)
                server_put_mount(osd_dev(d)->od_mount->lmi_name,
                                 osd_dev(d)->od_mount->lmi_mnt);
        osd_dev(d)->od_mount = NULL;

        lu_context_fini(&osd_dev(d)->od_env_for_commit.le_ctx);
        RETURN(NULL);
}

static struct lu_device *osd_device_alloc(const struct lu_env *env,
                                          struct lu_device_type *t,
                                          struct lustre_cfg *cfg)
{
        struct lu_device  *l;
        struct osd_device *o;

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

                result = dt_device_init(&o->od_dt_dev, t);
                if (result == 0) {
                        l = osd2lu_dev(o);
                        l->ld_ops = &osd_lu_ops;
                        o->od_dt_dev.dd_ops = &osd_dt_ops;
                        cfs_spin_lock_init(&o->od_osfs_lock);
                        o->od_osfs_age = cfs_time_shift_64(-1000);
                        o->od_capa_hash = init_capa_hash();
                        if (o->od_capa_hash == NULL) {
                                dt_device_fini(&o->od_dt_dev);
                                l = ERR_PTR(-ENOMEM);
                        }
                } else
                        l = ERR_PTR(result);

                if (IS_ERR(l))
                        OBD_FREE_PTR(o);
        } else
                l = ERR_PTR(-ENOMEM);
        return l;
}

static struct lu_device *osd_device_free(const struct lu_env *env,
                                         struct lu_device *d)
{
        struct osd_device *o = osd_dev(d);
        ENTRY;

        cleanup_capa_hash(o->od_capa_hash);
        dt_device_fini(&o->od_dt_dev);
        OBD_FREE_PTR(o);
        RETURN(NULL);
}

static int osd_process_config(const struct lu_env *env,
                              struct lu_device *d, struct lustre_cfg *cfg)
{
        struct osd_device *o = osd_dev(d);
        int err;
        ENTRY;

        switch(cfg->lcfg_command) {
        case LCFG_SETUP:
                err = osd_mount(env, o, cfg);
                break;
        case LCFG_CLEANUP:
                err = osd_shutdown(env, o);
                break;
        default:
                err = -ENOSYS;
        }

        RETURN(err);
}

static int osd_recovery_complete(const struct lu_env *env,
                                 struct lu_device *d)
{
        RETURN(0);
}

static int osd_prepare(const struct lu_env *env,
                       struct lu_device *pdev,
                       struct lu_device *dev)
{
        struct osd_device *osd = osd_dev(dev);
        struct lustre_sb_info *lsi;
        struct lustre_disk_data *ldd;
        struct lustre_mount_info  *lmi;
        struct osd_thread_info *oti = osd_oti_get(env);
        struct dt_object *d;
        int result;

        ENTRY;
        /* 1. initialize oi before any file create or file open */
        result = osd_oi_init(oti, &osd->od_oi,
                             &osd->od_dt_dev, lu2md_dev(pdev));
        if (result != 0)
                RETURN(result);

        lmi = osd->od_mount;
        lsi = s2lsi(lmi->lmi_sb);
        ldd = lsi->lsi_ldd;

        /* 2. setup local objects */
        result = llo_local_objects_setup(env, lu2md_dev(pdev), lu2dt_dev(dev));
        if (result)
                goto out;

        /* 3. open remote object dir */
        d = dt_store_open(env, lu2dt_dev(dev), "",
                          remote_obj_dir, &oti->oti_fid);
        if (!IS_ERR(d)) {
                osd->od_obj_area = d;
                result = 0;
        } else {
                result = PTR_ERR(d);
                osd->od_obj_area = NULL;
        }

out:
        RETURN(result);
}

static const struct lu_object_operations osd_lu_obj_ops = {
        .loo_object_init      = osd_object_init,
        .loo_object_delete    = osd_object_delete,
        .loo_object_release   = osd_object_release,
        .loo_object_free      = osd_object_free,
        .loo_object_print     = osd_object_print,
        .loo_object_invariant = osd_object_invariant
};

static const struct lu_device_operations osd_lu_ops = {
        .ldo_object_alloc      = osd_object_alloc,
        .ldo_process_config    = osd_process_config,
        .ldo_recovery_complete = osd_recovery_complete,
        .ldo_prepare           = osd_prepare,
};

static const struct lu_device_type_operations osd_device_type_ops = {
        .ldto_init = osd_type_init,
        .ldto_fini = osd_type_fini,

        .ldto_start = osd_type_start,
        .ldto_stop  = osd_type_stop,

        .ldto_device_alloc = osd_device_alloc,
        .ldto_device_free  = osd_device_free,

        .ldto_device_init    = osd_device_init,
        .ldto_device_fini    = osd_device_fini
};

static struct lu_device_type osd_device_type = {
        .ldt_tags     = LU_DEVICE_DT,
        .ldt_name     = LUSTRE_OSD_NAME,
        .ldt_ops      = &osd_device_type_ops,
        .ldt_ctx_tags = LCT_MD_THREAD|LCT_DT_THREAD
};

/*
 * lprocfs legacy support.
 */
static struct obd_ops osd_obd_device_ops = {
        .o_owner = THIS_MODULE
};

static struct lu_local_obj_desc llod_osd_rem_obj_dir = {
        .llod_name      = remote_obj_dir,
        .llod_oid       = OSD_REM_OBJ_DIR_OID,
        .llod_is_index  = 1,
        .llod_feat      = &dt_directory_features,
};

static int __init osd_mod_init(void)
{
        struct lprocfs_static_vars lvars;

        osd_oi_mod_init();
        llo_local_obj_register(&llod_osd_rem_obj_dir);
        lprocfs_osd_init_vars(&lvars);
        return class_register_type(&osd_obd_device_ops, NULL, lvars.module_vars,
                                   LUSTRE_OSD_NAME, &osd_device_type);
}

static void __exit osd_mod_exit(void)
{
        llo_local_obj_unregister(&llod_osd_rem_obj_dir);
        class_unregister_type(LUSTRE_OSD_NAME);
}

MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
MODULE_DESCRIPTION("Lustre Object Storage Device ("LUSTRE_OSD_NAME")");
MODULE_LICENSE("GPL");

cfs_module(osd, "0.0.2", osd_mod_init, osd_mod_exit);