LU-6401 uapi: migrate remaining uapi headers to uapi directory

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

/*
 * 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.gnu.org/licenses/gpl-2.0.html
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2016, Intel Corporation.
 */
/*
 * 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
 */

#define DEBUG_SUBSYSTEM S_OSD

#include <linux/module.h>
#include <linux/user_namespace.h>
#ifdef HAVE_UIDGID_HEADER
# include <linux/uidgid.h>
#endif

/* 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>

#include <ldiskfs/ldiskfs.h>
#include <ldiskfs/xattr.h>
#include <ldiskfs/ldiskfs_extents.h>
#undef ENTRY
/*
 * struct OBD_{ALLOC,FREE}*()
 * OBD_FAIL_CHECK
 */
#include <obd_support.h>
/* struct ptlrpc_thread */
#include <lustre_net.h>
#include <lustre_fid.h>
/* process_config */
#include <uapi/linux/lustre/lustre_param.h>

#include "osd_internal.h"
#include "osd_dynlocks.h"

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

#include <lustre_linkea.h>

#define PFID_STRIPE_IDX_BITS    16
#define PFID_STRIPE_COUNT_MASK  ((1 << PFID_STRIPE_IDX_BITS) - 1)

int ldiskfs_pdo = 1;
module_param(ldiskfs_pdo, int, 0644);
MODULE_PARM_DESC(ldiskfs_pdo, "ldiskfs with parallel directory operations");

int ldiskfs_track_declares_assert;
module_param(ldiskfs_track_declares_assert, int, 0644);
MODULE_PARM_DESC(ldiskfs_track_declares_assert, "LBUG during tracking of declares");

/* Slab to allocate dynlocks */
struct kmem_cache *dynlock_cachep;

/* Slab to allocate osd_it_ea */
struct kmem_cache *osd_itea_cachep;

static struct lu_kmem_descr ldiskfs_caches[] = {
        {
                .ckd_cache = &dynlock_cachep,
                .ckd_name  = "dynlock_cache",
                .ckd_size  = sizeof(struct dynlock_handle)
        },
        {
                .ckd_cache = &osd_itea_cachep,
                .ckd_name  = "osd_itea_cache",
                .ckd_size  = sizeof(struct osd_it_ea)
        },
        {
                .ckd_cache = NULL
        }
};

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

static const struct lu_object_operations      osd_lu_obj_ops;
static const struct dt_object_operations      osd_obj_ops;
static const struct dt_object_operations      osd_obj_otable_it_ops;
static const struct dt_index_operations       osd_index_iam_ops;
static const struct dt_index_operations       osd_index_ea_ops;

static int osd_remote_fid(const struct lu_env *env, struct osd_device *osd,
                          const struct lu_fid *fid);
static int osd_process_scheduled_agent_removals(const struct lu_env *env,
                                                struct osd_device *osd);

int osd_trans_declare_op2rb[] = {
        [OSD_OT_ATTR_SET]       = OSD_OT_ATTR_SET,
        [OSD_OT_PUNCH]          = OSD_OT_MAX,
        [OSD_OT_XATTR_SET]      = OSD_OT_XATTR_SET,
        [OSD_OT_CREATE]         = OSD_OT_DESTROY,
        [OSD_OT_DESTROY]        = OSD_OT_CREATE,
        [OSD_OT_REF_ADD]        = OSD_OT_REF_DEL,
        [OSD_OT_REF_DEL]        = OSD_OT_REF_ADD,
        [OSD_OT_WRITE]          = OSD_OT_WRITE,
        [OSD_OT_INSERT]         = OSD_OT_DELETE,
        [OSD_OT_DELETE]         = OSD_OT_INSERT,
        [OSD_OT_QUOTA]          = OSD_OT_MAX,
};

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));
}

/*
 * Concurrency: doesn't matter
 */
static int osd_is_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)
{
        lu_local_obj_fid(f, OSD_FS_ROOT_OID);
        return 0;
}

/*
 * the following set of functions are used to maintain per-thread
 * cache of FID->ino mapping. this mechanism is needed to resolve
 * FID to inode at dt_insert() which in turn stores ino in the
 * directory entries to keep ldiskfs compatible with ext[34].
 * due to locking-originated restrictions we can't lookup ino
 * using LU cache (deadlock is possible). lookup using OI is quite
 * expensive. so instead we maintain this cache and methods like
 * dt_create() fill it. so in the majority of cases dt_insert() is
 * able to find needed mapping in lockless manner.
 */
static struct osd_idmap_cache *
osd_idc_find(const struct lu_env *env, struct osd_device *osd,
             const struct lu_fid *fid)
{
        struct osd_thread_info  *oti   = osd_oti_get(env);
        struct osd_idmap_cache  *idc    = oti->oti_ins_cache;
        int i;
        for (i = 0; i < oti->oti_ins_cache_used; i++) {
                if (!lu_fid_eq(&idc[i].oic_fid, fid))
                        continue;
                if (idc[i].oic_dev != osd)
                        continue;

                return idc + i;
        }

        return NULL;
}

static struct osd_idmap_cache *
osd_idc_add(const struct lu_env *env, struct osd_device *osd,
            const struct lu_fid *fid)
{
        struct osd_thread_info  *oti   = osd_oti_get(env);
        struct osd_idmap_cache  *idc;
        int i;

        if (unlikely(oti->oti_ins_cache_used >= oti->oti_ins_cache_size)) {
                i = oti->oti_ins_cache_size * 2;
                if (i == 0)
                        i = OSD_INS_CACHE_SIZE;
                OBD_ALLOC(idc, sizeof(*idc) * i);
                if (idc == NULL)
                        return ERR_PTR(-ENOMEM);
                if (oti->oti_ins_cache != NULL) {
                        memcpy(idc, oti->oti_ins_cache,
                               oti->oti_ins_cache_used * sizeof(*idc));
                        OBD_FREE(oti->oti_ins_cache,
                                 oti->oti_ins_cache_used * sizeof(*idc));
                }
                oti->oti_ins_cache = idc;
                oti->oti_ins_cache_size = i;
        }

        idc = oti->oti_ins_cache + oti->oti_ins_cache_used++;
        idc->oic_fid = *fid;
        idc->oic_dev = osd;
        idc->oic_lid.oii_ino = 0;
        idc->oic_lid.oii_gen = 0;
        idc->oic_remote = 0;

        return idc;
}

/*
 * lookup mapping for the given fid in the cache, initialize a
 * new one if not found. the initialization checks whether the
 * object is local or remote. for local objects, OI is used to
 * learn ino/generation. the function is used when the caller
 * has no information about the object, e.g. at dt_insert().
 */
static struct osd_idmap_cache *
osd_idc_find_or_init(const struct lu_env *env, struct osd_device *osd,
                     const struct lu_fid *fid)
{
        struct osd_idmap_cache *idc;
        int rc;

        idc = osd_idc_find(env, osd, fid);
        LASSERT(!IS_ERR(idc));
        if (idc != NULL)
                return idc;

        /* new mapping is needed */
        idc = osd_idc_add(env, osd, fid);
        if (IS_ERR(idc))
                return idc;

        /* initialize it */
        rc = osd_remote_fid(env, osd, fid);
        if (unlikely(rc < 0))
                return ERR_PTR(rc);

        if (rc == 0) {
                /* the object is local, lookup in OI */
                /* XXX: probably cheaper to lookup in LU first? */
                rc = osd_oi_lookup(osd_oti_get(env), osd, fid,
                                   &idc->oic_lid, 0);
                if (unlikely(rc < 0)) {
                        CERROR("can't lookup: rc = %d\n", rc);
                        return ERR_PTR(rc);
                }
        } else {
                /* the object is remote */
                idc->oic_remote = 1;
        }

        return idc;
}

/*
 * lookup mapping for given FID and fill it from the given object.
 * the object is lolcal by definition.
 */
static int osd_idc_find_and_init(const struct lu_env *env,
                                 struct osd_device *osd,
                                 struct osd_object *obj)
{
        const struct lu_fid     *fid = lu_object_fid(&obj->oo_dt.do_lu);
        struct osd_idmap_cache  *idc;

        idc = osd_idc_find(env, osd, fid);
        LASSERT(!IS_ERR(idc));
        if (idc != NULL) {
                if (obj->oo_inode == NULL)
                        return 0;
                if (idc->oic_lid.oii_ino != obj->oo_inode->i_ino) {
                        LASSERT(idc->oic_lid.oii_ino == 0);
                        idc->oic_lid.oii_ino = obj->oo_inode->i_ino;
                        idc->oic_lid.oii_gen = obj->oo_inode->i_generation;
                }
                return 0;
        }

        /* new mapping is needed */
        idc = osd_idc_add(env, osd, fid);
        if (IS_ERR(idc))
                return PTR_ERR(idc);

        if (obj->oo_inode != NULL) {
                idc->oic_lid.oii_ino = obj->oo_inode->i_ino;
                idc->oic_lid.oii_gen = obj->oo_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);
                mo->oo_dt.do_ops = &osd_obj_ops;
                l->lo_ops = &osd_lu_obj_ops;
                init_rwsem(&mo->oo_sem);
                init_rwsem(&mo->oo_ext_idx_sem);
                spin_lock_init(&mo->oo_guard);
                INIT_LIST_HEAD(&mo->oo_xattr_list);
                return l;
        } else {
                return NULL;
        }
}

int osd_get_lma(struct osd_thread_info *info, struct inode *inode,
                struct dentry *dentry, struct lustre_ost_attrs *loa)
{
        int rc;

        rc = __osd_xattr_get(inode, dentry, XATTR_NAME_LMA,
                             (void *)loa, sizeof(*loa));
        if (rc > 0) {
                struct lustre_mdt_attrs *lma = &loa->loa_lma;

                if (rc < sizeof(*lma))
                        return -EINVAL;

                rc = 0;
                lustre_loa_swab(loa, true);
                /* Check LMA compatibility */
                if (lma->lma_incompat & ~LMA_INCOMPAT_SUPP) {
                        CWARN("%s: unsupported incompat LMA feature(s) %#x "
                              "for fid = "DFID", ino = %lu\n",
                              osd_ino2name(inode),
                              lma->lma_incompat & ~LMA_INCOMPAT_SUPP,
                              PFID(&lma->lma_self_fid), inode->i_ino);
                        rc = -EOPNOTSUPP;
                }
        } else if (rc == 0) {
                rc = -ENODATA;
        }

        return rc;
}

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

        /* if we look for an inode withing a running
         * transaction, then we risk to deadlock */
        /* osd_dirent_check_repair() breaks this */
        /*LASSERT(current->journal_info == NULL);*/

        inode = ldiskfs_iget(osd_sb(dev), id->oii_ino);
        if (IS_ERR(inode)) {
                CDEBUG(D_INODE, "no inode: ino = %u, rc = %ld\n",
                       id->oii_ino, PTR_ERR(inode));
        } else if (id->oii_gen != OSD_OII_NOGEN &&
                   inode->i_generation != id->oii_gen) {
                CDEBUG(D_INODE, "unmatched inode: ino = %u, oii_gen = %u, "
                       "i_generation = %u\n",
                       id->oii_ino, id->oii_gen, inode->i_generation);
                iput(inode);
                inode = ERR_PTR(-ESTALE);
        } else if (inode->i_nlink == 0) {
                /* due to parallel readdir and unlink,
                * we can have dead inode here. */
                CDEBUG(D_INODE, "stale inode: ino = %u\n", id->oii_ino);
                iput(inode);
                inode = ERR_PTR(-ESTALE);
        } else if (is_bad_inode(inode)) {
                CWARN("%s: bad inode: ino = %u\n",
                osd_dev2name(dev), id->oii_ino);
                iput(inode);
                inode = ERR_PTR(-ENOENT);
        } else if ((rc = osd_attach_jinode(inode))) {
                iput(inode);
                inode = ERR_PTR(rc);
        } else {
                ldiskfs_clear_inode_state(inode, LDISKFS_STATE_LUSTRE_DESTROY);
                if (id->oii_gen == OSD_OII_NOGEN)
                        osd_id_gen(id, inode->i_ino, inode->i_generation);

                /* Do not update file c/mtime in ldiskfs.
                 * NB: we don't have any lock to protect this because we don't
                 * have reference on osd_object now, but contention with
                 * another lookup + attr_set can't happen in the tiny window
                 * between if (...) and set S_NOCMTIME. */
                if (!(inode->i_flags & S_NOCMTIME))
                        inode->i_flags |= S_NOCMTIME;
        }
        return inode;
}

int osd_ldiskfs_add_entry(struct osd_thread_info *info, struct osd_device *osd,
                          handle_t *handle, struct dentry *child,
                          struct inode *inode, struct htree_lock *hlock)
{
        int rc, rc2;

        rc = __ldiskfs_add_entry(handle, child, inode, hlock);
        if (rc == -ENOBUFS || rc == -ENOSPC) {
                struct lustre_ost_attrs *loa = &info->oti_ost_attrs;
                struct inode *parent = child->d_parent->d_inode;
                struct lu_fid *fid = NULL;

                rc2 = osd_get_lma(info, parent, child->d_parent, loa);
                if (!rc2) {
                        fid = &loa->loa_lma.lma_self_fid;
                } else if (rc2 == -ENODATA) {
                        if (unlikely(parent == inode->i_sb->s_root->d_inode)) {
                                fid = &info->oti_fid3;
                                lu_local_obj_fid(fid, OSD_FS_ROOT_OID);
                        } else if (!osd->od_is_ost && osd->od_index == 0) {
                                fid = &info->oti_fid3;
                                lu_igif_build(fid, parent->i_ino,
                                              parent->i_generation);
                        }
                }

                if (fid != NULL)
                        CWARN("%s: directory (inode: %lu, FID: "DFID") %s "
                              "maximum entry limit\n",
                              osd_name(osd), parent->i_ino, PFID(fid),
                              rc == -ENOSPC ? "has reached" : "is approaching");
                else
                        CWARN("%s: directory (inode: %lu, FID: unknown) %s "
                              "maximum entry limit\n",
                              osd_name(osd), parent->i_ino,
                              rc == -ENOSPC ? "has reached" : "is approaching");

                /* ignore such error now */
                if (rc == -ENOBUFS)
                        rc = 0;
        }

        return rc;
}


static struct inode *
osd_iget_fid(struct osd_thread_info *info, struct osd_device *dev,
             struct osd_inode_id *id, struct lu_fid *fid)
{
        struct lustre_ost_attrs *loa = &info->oti_ost_attrs;
        struct inode *inode;
        int rc;

        inode = osd_iget(info, dev, id);
        if (IS_ERR(inode))
                return inode;

        rc = osd_get_lma(info, inode, &info->oti_obj_dentry, loa);
        if (!rc) {
                *fid = loa->loa_lma.lma_self_fid;
        } else if (rc == -ENODATA) {
                if (unlikely(inode == osd_sb(dev)->s_root->d_inode))
                        lu_local_obj_fid(fid, OSD_FS_ROOT_OID);
                else
                        lu_igif_build(fid, inode->i_ino, inode->i_generation);
        } else {
                iput(inode);
                inode = ERR_PTR(rc);
        }
        return inode;
}

static struct inode *osd_iget_check(struct osd_thread_info *info,
                                    struct osd_device *dev,
                                    const struct lu_fid *fid,
                                    struct osd_inode_id *id,
                                    bool trusted)
{
        struct inode *inode;
        int rc = 0;
        ENTRY;

        /* The cached OI mapping is trustable. If we cannot locate the inode
         * via the cached OI mapping, then return the failure to the caller
         * directly without further OI checking. */

again:
        inode = ldiskfs_iget(osd_sb(dev), id->oii_ino);
        if (IS_ERR(inode)) {
                rc = PTR_ERR(inode);
                if (!trusted && (rc == -ENOENT || rc == -ESTALE))
                        goto check_oi;

                CDEBUG(D_INODE, "no inode for FID: "DFID", ino = %u, rc = %d\n",
                       PFID(fid), id->oii_ino, rc);
                GOTO(put, rc);
        }

        if (is_bad_inode(inode)) {
                rc = -ENOENT;
                if (!trusted)
                        goto check_oi;

                CDEBUG(D_INODE, "bad inode for FID: "DFID", ino = %u\n",
                       PFID(fid), id->oii_ino);
                GOTO(put, rc);
        }

        if (id->oii_gen != OSD_OII_NOGEN &&
            inode->i_generation != id->oii_gen) {
                rc = -ESTALE;
                if (!trusted)
                        goto check_oi;

                CDEBUG(D_INODE, "unmatched inode for FID: "DFID", ino = %u, "
                       "oii_gen = %u, i_generation = %u\n", PFID(fid),
                       id->oii_ino, id->oii_gen, inode->i_generation);
                GOTO(put, rc);
        }

        if (inode->i_nlink == 0) {
                rc = -ENOENT;
                if (!trusted)
                        goto check_oi;

                CDEBUG(D_INODE, "stale inode for FID: "DFID", ino = %u\n",
                       PFID(fid), id->oii_ino);
                GOTO(put, rc);
        }

        ldiskfs_clear_inode_state(inode, LDISKFS_STATE_LUSTRE_DESTROY);

check_oi:
        if (rc != 0) {
                __u32 saved_ino = id->oii_ino;
                __u32 saved_gen = id->oii_gen;

                LASSERT(!trusted);
                LASSERTF(rc == -ESTALE || rc == -ENOENT, "rc = %d\n", rc);

                rc = osd_oi_lookup(info, dev, fid, id, OI_CHECK_FLD);
                /* XXX: There are four possible cases:
                 *      1. rc = 0.
                 *         Backup/restore caused the OI invalid.
                 *      2. rc = 0.
                 *         Someone unlinked the object but NOT removed
                 *         the OI mapping, such as mount target device
                 *         as ldiskfs, and modify something directly.
                 *      3. rc = -ENOENT.
                 *         Someone just removed the object between the
                 *         former oi_lookup and the iget. It is normal.
                 *      4. Other failure cases.
                 *
                 *      Generally, when the device is mounted, it will
                 *      auto check whether the system is restored from
                 *      file-level backup or not. We trust such detect
                 *      to distinguish the 1st case from the 2nd case:
                 *      if the OI files are consistent but may contain
                 *      stale OI mappings because of case 2, if iget()
                 *      returns -ENOENT or -ESTALE, then it should be
                 *      the case 2. */
                if (rc != 0)
                        /* If the OI mapping was in OI file before the
                         * osd_iget_check(), but now, it is disappear,
                         * then it must be removed by race. That is a
                         * normal race case. */
                        GOTO(put, rc);

                /* It is the OI scrub updated the OI mapping by race.
                 * The new OI mapping must be valid. */
                if (saved_ino != id->oii_ino ||
                    (saved_gen != id->oii_gen && saved_gen != OSD_OII_NOGEN)) {
                        if (!IS_ERR(inode))
                                iput(inode);

                        trusted = true;
                        goto again;
                }

                if (IS_ERR(inode)) {
                        if (dev->od_scrub.os_file.sf_flags & SF_INCONSISTENT)
                                /* It still can be the case 2, but we cannot
                                 * distinguish it from the case 1. So return
                                 * -EREMCHG to block current operation until
                                 *  OI scrub rebuilt the OI mappings. */
                                rc = -EREMCHG;
                        else
                                rc = -ENOENT;

                        GOTO(put, rc);
                }

                if (inode->i_generation == id->oii_gen)
                        rc = -ENOENT;
                else
                        rc = -EREMCHG;
        } else {
                if (id->oii_gen == OSD_OII_NOGEN)
                        osd_id_gen(id, inode->i_ino, inode->i_generation);

                /* Do not update file c/mtime in ldiskfs.
                 * NB: we don't have any lock to protect this because we don't
                 * have reference on osd_object now, but contention with
                 * another lookup + attr_set can't happen in the tiny window
                 * between if (...) and set S_NOCMTIME. */
                if (!(inode->i_flags & S_NOCMTIME))
                        inode->i_flags |= S_NOCMTIME;
        }

        GOTO(put, rc);

put:
        if (rc != 0) {
                if (!IS_ERR(inode))
                        iput(inode);

                inode = ERR_PTR(rc);
        }

        return inode;
}

/**
 * \retval +v: new filter_fid, does not contain self-fid
 * \retval 0:  filter_fid_old, contains self-fid
 * \retval -v: other failure cases
 */
int osd_get_idif(struct osd_thread_info *info, struct inode *inode,
                 struct dentry *dentry, struct lu_fid *fid)
{
        struct filter_fid_old   *ff     = &info->oti_ff;
        struct ost_id           *ostid  = &info->oti_ostid;
        int                      rc;

        rc = __osd_xattr_get(inode, dentry, XATTR_NAME_FID, ff, sizeof(*ff));
        if (rc == sizeof(*ff)) {
                rc = 0;
                ostid_set_seq(ostid, le64_to_cpu(ff->ff_seq));
                rc = ostid_set_id(ostid, le64_to_cpu(ff->ff_objid));
                /*
                 * XXX: use 0 as the index for compatibility, the caller will
                 *      handle index related issues when necessary.
                 */
                if (!rc)
                        ostid_to_fid(fid, ostid, 0);
        } else if (rc == sizeof(struct filter_fid)) {
                rc = 1;
        } else if (rc >= 0) {
                rc = -EINVAL;
        }

        return rc;
}

static int osd_lma_self_repair(struct osd_thread_info *info,
                               struct osd_device *osd, struct inode *inode,
                               const struct lu_fid *fid, __u32 compat)
{
        handle_t *jh;
        int       rc;

        LASSERT(current->journal_info == NULL);

        jh = osd_journal_start_sb(osd_sb(osd), LDISKFS_HT_MISC,
                                  osd_dto_credits_noquota[DTO_XATTR_SET]);
        if (IS_ERR(jh)) {
                rc = PTR_ERR(jh);
                CWARN("%s: cannot start journal for lma_self_repair: rc = %d\n",
                      osd_name(osd), rc);
                return rc;
        }

        rc = osd_ea_fid_set(info, inode, fid, compat, 0);
        if (rc != 0)
                CWARN("%s: cannot self repair the LMA: rc = %d\n",
                      osd_name(osd), rc);
        ldiskfs_journal_stop(jh);
        return rc;
}

static int osd_check_lma(const struct lu_env *env, struct osd_object *obj)
{
        struct osd_thread_info  *info   = osd_oti_get(env);
        struct osd_device       *osd    = osd_obj2dev(obj);
        struct lustre_ost_attrs *loa    = &info->oti_ost_attrs;
        struct lustre_mdt_attrs *lma    = &loa->loa_lma;
        struct inode            *inode  = obj->oo_inode;
        struct dentry           *dentry = &info->oti_obj_dentry;
        struct lu_fid           *fid    = NULL;
        const struct lu_fid     *rfid   = lu_object_fid(&obj->oo_dt.do_lu);
        int                      rc;
        ENTRY;

        rc = __osd_xattr_get(inode, dentry, XATTR_NAME_LMA,
                             (void *)loa, sizeof(*loa));
        if (rc == -ENODATA && !fid_is_igif(rfid) && osd->od_check_ff) {
                fid = &lma->lma_self_fid;
                rc = osd_get_idif(info, inode, dentry, fid);
                if ((rc > 0) || (rc == -ENODATA && osd->od_index_in_idif)) {
                        /* For the given OST-object, if it has neither LMA nor
                         * FID in XATTR_NAME_FID, then the given FID (which is
                         * contained in the @obj, from client RPC for locating
                         * the OST-object) is trusted. We use it to generate
                         * the LMA. */
                        osd_lma_self_repair(info, osd, inode, rfid,
                                            LMAC_FID_ON_OST);
                        RETURN(0);
                }
        }

        if (rc < 0)
                RETURN(rc);

        if (rc > 0) {
                rc = 0;
                lustre_lma_swab(lma);
                if (unlikely((lma->lma_incompat & ~LMA_INCOMPAT_SUPP) ||
                             (CFS_FAIL_CHECK(OBD_FAIL_OSD_LMA_INCOMPAT) &&
                              S_ISREG(inode->i_mode)))) {
                        CWARN("%s: unsupported incompat LMA feature(s) %#x for "
                              "fid = "DFID", ino = %lu\n", osd_name(osd),
                              lma->lma_incompat & ~LMA_INCOMPAT_SUPP,
                              PFID(rfid), inode->i_ino);
                        rc = -EOPNOTSUPP;
                } else {
                        fid = &lma->lma_self_fid;
                }
        }

        if (fid != NULL && unlikely(!lu_fid_eq(rfid, fid))) {
                if (fid_is_idif(rfid) && fid_is_idif(fid)) {
                        struct ost_id   *oi   = &info->oti_ostid;
                        struct lu_fid   *fid1 = &info->oti_fid3;
                        __u32            idx  = fid_idif_ost_idx(rfid);

                        /* For old IDIF, the OST index is not part of the IDIF,
                         * Means that different OSTs may have the same IDIFs.
                         * Under such case, we need to make some compatible
                         * check to make sure to trigger OI scrub properly. */
                        if (idx != 0 && fid_idif_ost_idx(fid) == 0) {
                                /* Given @rfid is new, LMA is old. */
                                fid_to_ostid(fid, oi);
                                ostid_to_fid(fid1, oi, idx);
                                if (lu_fid_eq(fid1, rfid)) {
                                        if (osd->od_index_in_idif)
                                                osd_lma_self_repair(info, osd,
                                                        inode, rfid,
                                                        LMAC_FID_ON_OST);
                                        RETURN(0);
                                }
                        }
                }

                rc = -EREMCHG;
        }

        RETURN(rc);
}

struct osd_check_lmv_buf {
#ifdef HAVE_DIR_CONTEXT
        /* please keep it as first member */
        struct dir_context       ctx;
#endif
        struct osd_thread_info  *oclb_info;
        struct osd_device       *oclb_dev;
        struct osd_idmap_cache  *oclb_oic;
};

/**
 * It is called internally by ->readdir() to filter out the
 * local slave object's FID of the striped directory.
 *
 * \retval      1 found the local slave's FID
 * \retval      0 continue to check next item
 * \retval      -ve for failure
 */
#ifdef HAVE_FILLDIR_USE_CTX
static int osd_stripe_dir_filldir(struct dir_context *buf,
#else
static int osd_stripe_dir_filldir(void *buf,
#endif
                                  const char *name, int namelen,
                                  loff_t offset, __u64 ino, unsigned d_type)
{
        struct osd_check_lmv_buf *oclb = (struct osd_check_lmv_buf *)buf;
        struct osd_thread_info *oti = oclb->oclb_info;
        struct lu_fid *fid = &oti->oti_fid3;
        struct osd_inode_id *id = &oti->oti_id3;
        struct osd_device *dev = oclb->oclb_dev;
        struct osd_idmap_cache *oic = oclb->oclb_oic;
        struct inode *inode;
        int rc;

        if (name[0] == '.')
                return 0;

        fid_zero(fid);
        sscanf(name + 1, SFID, RFID(fid));
        if (!fid_is_sane(fid))
                return 0;

        if (osd_remote_fid(oti->oti_env, dev, fid))
                return 0;

        osd_id_gen(id, ino, OSD_OII_NOGEN);
        inode = osd_iget(oti, dev, id);
        if (IS_ERR(inode))
                return PTR_ERR(inode);

        iput(inode);
        osd_add_oi_cache(oti, dev, id, fid);
        oic->oic_fid = *fid;
        oic->oic_lid = *id;
        oic->oic_dev = dev;
        rc = osd_oii_insert(dev, oic, true);

        return rc == 0 ? 1 : rc;
}

/* When lookup item under striped directory, we need to locate the master
 * MDT-object of the striped directory firstly, then the client will send
 * lookup (getattr_by_name) RPC to the MDT with some slave MDT-object's FID
 * and the item's name. If the system is restored from MDT file level backup,
 * then before the OI scrub completely built the OI files, the OI mappings of
 * the master MDT-object and slave MDT-object may be invalid. Usually, it is
 * not a problem for the master MDT-object. Because when locate the master
 * MDT-object, we will do name based lookup (for the striped directory itself)
 * firstly, during such process we can setup the correct OI mapping for the
 * master MDT-object. But it will be trouble for the slave MDT-object. Because
 * the client will not trigger name based lookup on the MDT to locate the slave
 * MDT-object before locating item under the striped directory, then when
 * osd_fid_lookup(), it will find that the OI mapping for the slave MDT-object
 * is invalid and does not know what the right OI mapping is, then the MDT has
 * to return -EINPROGRESS to the client to notify that the OI scrub is rebuiding
 * the OI file, related OI mapping is unknown yet, please try again later. And
 * then client will re-try the RPC again and again until related OI mapping has
 * been updated. That is quite inefficient.
 *
 * To resolve above trouble, we will handle it as the following two cases:
 *
 * 1) The slave MDT-object and the master MDT-object are on different MDTs.
 *    It is relative easy. Be as one of remote MDT-objects, the slave MDT-object
 *    is linked under /REMOTE_PARENT_DIR with the name of its FID string.
 *    We can locate the slave MDT-object via lookup the /REMOTE_PARENT_DIR
 *    directly. Please check osd_fid_lookup().
 *
 * 2) The slave MDT-object and the master MDT-object reside on the same MDT.
 *    Under such case, during lookup the master MDT-object, we will lookup the
 *    slave MDT-object via readdir against the master MDT-object, because the
 *    slave MDT-objects information are stored as sub-directories with the name
 *    "${FID}:${index}". Then when find the local slave MDT-object, its OI
 *    mapping will be recorded. Then subsequent osd_fid_lookup() will know
 *    the correct OI mapping for the slave MDT-object. */
static int osd_check_lmv(struct osd_thread_info *oti, struct osd_device *dev,
                         struct inode *inode, struct osd_idmap_cache *oic)
{
        struct lu_buf *buf = &oti->oti_big_buf;
        struct dentry *dentry = &oti->oti_obj_dentry;
        struct file *filp = &oti->oti_file;
        const struct file_operations *fops;
        struct lmv_mds_md_v1 *lmv1;
        struct osd_check_lmv_buf oclb = {
#ifdef HAVE_DIR_CONTEXT
                .ctx.actor = osd_stripe_dir_filldir,
#endif
                .oclb_info = oti,
                .oclb_dev = dev,
                .oclb_oic = oic
        };
        int rc = 0;
        ENTRY;

again:
        rc = __osd_xattr_get(inode, dentry, XATTR_NAME_LMV, buf->lb_buf,
                             buf->lb_len);
        if (rc == -ERANGE) {
                rc = __osd_xattr_get(inode, dentry, XATTR_NAME_LMV, NULL, 0);
                if (rc > 0) {
                        lu_buf_realloc(buf, rc);
                        if (buf->lb_buf == NULL)
                                GOTO(out, rc = -ENOMEM);

                        goto again;
                }
        }

        if (unlikely(rc == 0 || rc == -ENODATA))
                GOTO(out, rc = 0);

        if (rc < 0)
                GOTO(out, rc);

        if (unlikely(buf->lb_buf == NULL)) {
                lu_buf_realloc(buf, rc);
                if (buf->lb_buf == NULL)
                        GOTO(out, rc = -ENOMEM);

                goto again;
        }

        lmv1 = buf->lb_buf;
        if (le32_to_cpu(lmv1->lmv_magic) != LMV_MAGIC_V1)
                GOTO(out, rc = 0);

        fops = inode->i_fop;
        dentry->d_inode = inode;
        dentry->d_sb = inode->i_sb;
        filp->f_pos = 0;
        filp->f_path.dentry = dentry;
        filp->f_mode = FMODE_64BITHASH;
        filp->f_mapping = inode->i_mapping;
        filp->f_op = fops;
        filp->private_data = NULL;
        set_file_inode(filp, inode);

#ifdef HAVE_DIR_CONTEXT
        oclb.ctx.pos = filp->f_pos;
        rc = fops->iterate(filp, &oclb.ctx);
        filp->f_pos = oclb.ctx.pos;
#else
        rc = fops->readdir(filp, &oclb, osd_stripe_dir_filldir);
#endif
        fops->release(inode, filp);

out:
        if (rc < 0)
                CDEBUG(D_LFSCK, "%s: fail to check LMV EA, inode = %lu/%u,"
                       DFID": rc = %d\n", osd_ino2name(inode),
                       inode->i_ino, inode->i_generation,
                       PFID(&oic->oic_fid), rc);
        else
                rc = 0;

        RETURN(rc);
}

static int osd_fid_lookup(const struct lu_env *env, struct osd_object *obj,
                          const struct lu_fid *fid,
                          const struct lu_object_conf *conf)
{
        struct osd_thread_info *info;
        struct lu_device *ldev = obj->oo_dt.do_lu.lo_dev;
        struct osd_device *dev;
        struct osd_idmap_cache *oic;
        struct osd_inode_id *id;
        struct inode *inode = NULL;
        struct osd_scrub *scrub;
        struct scrub_file *sf;
        __u32 flags = SS_CLEAR_DRYRUN | SS_CLEAR_FAILOUT | SS_AUTO_FULL;
        __u32 saved_ino;
        __u32 saved_gen;
        int result = 0;
        int rc1 = 0;
        bool remote = false;
        bool trusted = true;
        bool updated = false;
        ENTRY;

        LINVRNT(osd_invariant(obj));
        LASSERT(obj->oo_inode == NULL);
        LASSERTF(fid_is_sane(fid) || fid_is_idif(fid), DFID"\n", PFID(fid));

        dev = osd_dev(ldev);
        scrub = &dev->od_scrub;
        sf = &scrub->os_file;
        info = osd_oti_get(env);
        LASSERT(info);
        oic = &info->oti_cache;

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

        /* For the object is created as locking anchor, or for the object to
         * be created on disk. No need to osd_oi_lookup() at here because FID
         * shouldn't never be re-used, if it's really a duplicate FID from
         * unexpected reason, we should be able to detect it later by calling
         * do_create->osd_oi_insert(). */
        if (conf && conf->loc_flags & LOC_F_NEW)
                GOTO(out, result = 0);

        /* Search order: 1. per-thread cache. */
        if (lu_fid_eq(fid, &oic->oic_fid) && likely(oic->oic_dev == dev)) {
                id = &oic->oic_lid;
                goto iget;
        }

        id = &info->oti_id;
        if (!list_empty(&scrub->os_inconsistent_items)) {
                /* Search order: 2. OI scrub pending list. */
                result = osd_oii_lookup(dev, fid, id);
                if (!result)
                        goto iget;
        }

        /* The OI mapping in the OI file can be updated by the OI scrub
         * when we locate the inode via FID. So it may be not trustable. */
        trusted = false;

        /* Search order: 3. OI files. */
        result = osd_oi_lookup(info, dev, fid, id, OI_CHECK_FLD);
        if (result == -ENOENT) {
                if (!(fid_is_norm(fid) || fid_is_igif(fid)) ||
                    fid_is_on_ost(info, dev, fid, OI_CHECK_FLD) ||
                    !ldiskfs_test_bit(osd_oi_fid2idx(dev,fid),
                                      sf->sf_oi_bitmap))
                        GOTO(out, result = 0);

                goto trigger;
        }

        if (result)
                GOTO(out, result);

iget:
        obj->oo_inode = NULL;
        /* for later passes through checks, not true on first pass */
        if (!IS_ERR_OR_NULL(inode))
                iput(inode);

        inode = osd_iget_check(info, dev, fid, id, trusted);
        if (!IS_ERR(inode)) {
                obj->oo_inode = inode;
                result = 0;
                if (remote)
                        goto trigger;

                goto check_lma;
        }

        result = PTR_ERR(inode);
        if (result == -ENOENT || result == -ESTALE)
                GOTO(out, result = 0);

        if (result != -EREMCHG)
                GOTO(out, result);

trigger:
        /* We still have chance to get the valid inode: for the
         * object which is referenced by remote name entry, the
         * object on the local MDT will be linked under the dir
         * of "/REMOTE_PARENT_DIR" with its FID string as name.
         *
         * We do not know whether the object for the given FID
         * is referenced by some remote name entry or not, and
         * especially for DNE II, a multiple-linked object may
         * have many name entries reside on many MDTs.
         *
         * To simplify the operation, OSD will not distinguish
         * more, just lookup "/REMOTE_PARENT_DIR". Usually, it
         * only happened for the RPC from other MDT during the
         * OI scrub, or for the client side RPC with FID only,
         * such as FID to path, or from old connected client. */
        if (!remote && !fid_is_on_ost(info, dev, fid, OI_CHECK_FLD)) {
                rc1 = osd_lookup_in_remote_parent(info, dev, fid, id);
                if (!rc1) {
                        remote = true;
                        trusted = true;
                        flags |= SS_AUTO_PARTIAL;
                        flags &= ~SS_AUTO_FULL;
                        goto iget;
                }
        }

        if (thread_is_running(&scrub->os_thread)) {
                if (scrub->os_partial_scan && !scrub->os_in_join)
                        goto join;

                if (IS_ERR_OR_NULL(inode) || result)
                        GOTO(out, result = -EINPROGRESS);

                LASSERT(remote);
                LASSERT(obj->oo_inode == inode);

                osd_add_oi_cache(info, dev, id, fid);
                osd_oii_insert(dev, oic, true);
                goto found;
        }

        if (dev->od_noscrub) {
                if (!remote)
                        GOTO(out, result = -EREMCHG);

                LASSERT(!result);
                LASSERT(obj->oo_inode == inode);

                osd_add_oi_cache(info, dev, id, fid);
                goto found;
        }

join:
        rc1 = osd_scrub_start(dev, flags);
        LCONSOLE_WARN("%s: trigger OI scrub by RPC for the " DFID" with flags "
                      "0x%x, rc = %d\n", osd_name(dev), PFID(fid), flags, rc1);
        if (rc1 && rc1 != -EALREADY)
                GOTO(out, result = -EREMCHG);

        if (IS_ERR_OR_NULL(inode) || result)
                GOTO(out, result = -EINPROGRESS);

        LASSERT(remote);
        LASSERT(obj->oo_inode == inode);

        osd_add_oi_cache(info, dev, id, fid);
        osd_oii_insert(dev, oic, true);
        goto found;

check_lma:
        result = osd_check_lma(env, obj);
        if (!result)
                goto found;

        LASSERTF(id->oii_ino == inode->i_ino &&
                 id->oii_gen == inode->i_generation,
                 "locate wrong inode for FID: "DFID", %u/%u => %ld/%u\n",
                 PFID(fid), id->oii_ino, id->oii_gen,
                 inode->i_ino, inode->i_generation);

        saved_ino = inode->i_ino;
        saved_gen = inode->i_generation;

        if (unlikely(result == -ENODATA)) {
                /* If the OI scrub updated the OI mapping by race, it
                 * must be valid. Trust the inode that has no LMA EA. */
                if (updated)
                        goto found;

                result = osd_oi_lookup(info, dev, fid, id, OI_CHECK_FLD);
                if (!result) {
                        /* The OI mapping is still there, the inode is still
                         * valid. It is just becaues the inode has no LMA EA. */
                        if (saved_ino == id->oii_ino &&
                            saved_gen == id->oii_gen)
                                goto found;

                        /* It is the OI scrub updated the OI mapping by race.
                         * The new OI mapping must be valid. */
                        trusted = true;
                        updated = true;
                        goto iget;
                }

                /* "result == -ENOENT" means that the OI mappinghas been
                 * removed by race, so the inode belongs to other object.
                 *
                 * Others error can be returned  directly. */
                if (result == -ENOENT) {
                        LASSERT(trusted);

                        obj->oo_inode = NULL;
                        result = 0;
                }
        }

        if (result != -EREMCHG)
                GOTO(out, result);

        LASSERT(!updated);

        result = osd_oi_lookup(info, dev, fid, id, OI_CHECK_FLD);
        /* "result == -ENOENT" means the cached OI mapping has been removed
         * from the OI file by race, above inode belongs to other object. */
        if (result == -ENOENT) {
                LASSERT(trusted);

                obj->oo_inode = NULL;
                GOTO(out, result = 0);
        }

        if (result)
                GOTO(out, result);

        if (saved_ino == id->oii_ino && saved_gen == id->oii_gen) {
                result = -EREMCHG;
                goto trigger;
        }

        /* It is the OI scrub updated the OI mapping by race.
         * The new OI mapping must be valid. */
        trusted = true;
        updated = true;
        goto iget;

found:
        obj->oo_compat_dot_created = 1;
        obj->oo_compat_dotdot_created = 1;

        if (S_ISDIR(inode->i_mode) &&
            (flags & SS_AUTO_PARTIAL || sf->sf_status == SS_SCANNING))
                osd_check_lmv(info, dev, inode, oic);

        result = osd_attach_jinode(inode);
        if (result)
                GOTO(out, result);

        if (!ldiskfs_pdo)
                GOTO(out, result = 0);

        LASSERT(!obj->oo_hl_head);
        obj->oo_hl_head = ldiskfs_htree_lock_head_alloc(HTREE_HBITS_DEF);

        GOTO(out, result = (!obj->oo_hl_head ? -ENOMEM : 0));

out:
        if (result || !obj->oo_inode) {
                if (!IS_ERR_OR_NULL(inode))
                        iput(inode);

                obj->oo_inode = NULL;
                if (trusted)
                        fid_zero(&oic->oic_fid);
        }

        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 *conf)
{
        struct osd_object *obj = osd_obj(l);
        int result;

        LINVRNT(osd_invariant(obj));

        if (fid_is_otable_it(&l->lo_header->loh_fid)) {
                obj->oo_dt.do_ops = &osd_obj_otable_it_ops;
                l->lo_header->loh_attr |= LOHA_EXISTS;
                return 0;
        }

        result = osd_fid_lookup(env, obj, lu_object_fid(l), conf);
        obj->oo_dt.do_body_ops = &osd_body_ops_new;
        if (result == 0 && obj->oo_inode != NULL) {
                struct osd_thread_info *oti = osd_oti_get(env);
                struct lustre_ost_attrs *loa = &oti->oti_ost_attrs;

                osd_object_init0(obj);
                result = osd_get_lma(oti, obj->oo_inode,
                                     &oti->oti_obj_dentry, loa);
                if (!result) {
                        /* Convert LMAI flags to lustre LMA flags
                         * and cache it to oo_lma_flags */
                        obj->oo_lma_flags =
                                lma_to_lustre_flags(loa->loa_lma.lma_incompat);
                } else if (result == -ENODATA) {
                        result = 0;
                }
        }

        LINVRNT(osd_invariant(obj));
        return result;
}

/* The first part of oxe_buf is xattr name, and is '\0' terminated.
 * The left part is for value, binary mode. */
struct osd_xattr_entry {
        struct list_head        oxe_list;
        size_t                  oxe_len;
        size_t                  oxe_namelen;
        bool                    oxe_exist;
        struct rcu_head         oxe_rcu;
        char                    oxe_buf[0];
};

static int osd_oxc_get(struct osd_object *obj, const char *name,
                       struct lu_buf *buf)
{
        struct osd_xattr_entry *tmp;
        struct osd_xattr_entry *oxe = NULL;
        size_t namelen = strlen(name);
        int rc;
        ENTRY;

        rcu_read_lock();
        list_for_each_entry_rcu(tmp, &obj->oo_xattr_list, oxe_list) {
                if (namelen == tmp->oxe_namelen &&
                    strncmp(name, tmp->oxe_buf, namelen) == 0) {
                        oxe = tmp;
                        break;
                }
        }

        if (oxe == NULL)
                GOTO(out, rc = -ENOENT);

        if (!oxe->oxe_exist)
                GOTO(out, rc = -ENODATA);

        /* vallen */
        rc = oxe->oxe_len - sizeof(*oxe) - oxe->oxe_namelen - 1;
        LASSERT(rc > 0);

        if (buf->lb_buf == NULL)
                GOTO(out, rc);

        if (buf->lb_len < rc)
                GOTO(out, rc = -ERANGE);

        memcpy(buf->lb_buf, &oxe->oxe_buf[namelen + 1], rc);
        EXIT;
out:
        rcu_read_unlock();

        return rc;
}

static void osd_oxc_free(struct rcu_head *head)
{
        struct osd_xattr_entry *oxe;

        oxe = container_of(head, struct osd_xattr_entry, oxe_rcu);
        OBD_FREE(oxe, oxe->oxe_len);
}

static void osd_oxc_add(struct osd_object *obj, const char *name,
                        const char *buf, int buflen)
{
        struct osd_xattr_entry *oxe;
        struct osd_xattr_entry *old = NULL;
        struct osd_xattr_entry *tmp;
        size_t namelen = strlen(name);
        size_t len = sizeof(*oxe) + namelen + 1 + buflen;

        OBD_ALLOC(oxe, len);
        if (oxe == NULL)
                return;

        INIT_LIST_HEAD(&oxe->oxe_list);
        oxe->oxe_len = len;
        oxe->oxe_namelen = namelen;
        memcpy(oxe->oxe_buf, name, namelen);
        if (buflen > 0) {
                LASSERT(buf != NULL);
                memcpy(oxe->oxe_buf + namelen + 1, buf, buflen);
                oxe->oxe_exist = true;
        } else {
                oxe->oxe_exist = false;
        }

        /* this should be rarely called, just remove old and add new */
        spin_lock(&obj->oo_guard);
        list_for_each_entry(tmp, &obj->oo_xattr_list, oxe_list) {
                if (namelen == tmp->oxe_namelen &&
                    strncmp(name, tmp->oxe_buf, namelen) == 0) {
                        old = tmp;
                        break;
                }
        }
        if (old != NULL) {
                list_replace_rcu(&old->oxe_list, &oxe->oxe_list);
                call_rcu(&old->oxe_rcu, osd_oxc_free);
        } else {
                list_add_tail_rcu(&oxe->oxe_list, &obj->oo_xattr_list);
        }
        spin_unlock(&obj->oo_guard);
}

static void osd_oxc_del(struct osd_object *obj, const char *name)
{
        struct osd_xattr_entry *oxe;
        size_t namelen = strlen(name);

        spin_lock(&obj->oo_guard);
        list_for_each_entry(oxe, &obj->oo_xattr_list, oxe_list) {
                if (namelen == oxe->oxe_namelen &&
                    strncmp(name, oxe->oxe_buf, namelen) == 0) {
                        list_del_rcu(&oxe->oxe_list);
                        call_rcu(&oxe->oxe_rcu, osd_oxc_free);
                        break;
                }
        }
        spin_unlock(&obj->oo_guard);
}

static void osd_oxc_fini(struct osd_object *obj)
{
        struct osd_xattr_entry *oxe, *next;

        list_for_each_entry_safe(oxe, next, &obj->oo_xattr_list, oxe_list) {
                list_del(&oxe->oxe_list);
                OBD_FREE(oxe, oxe->oxe_len);
        }
}

/*
 * 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));

        osd_oxc_fini(obj);
        dt_object_fini(&obj->oo_dt);
        if (obj->oo_hl_head != NULL)
                ldiskfs_htree_lock_head_free(obj->oo_hl_head);
        OBD_FREE_PTR(obj);
}

/*
 * 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
 */

#if OSD_THANDLE_STATS
/**
 * Set time when the handle is allocated
 */
static void osd_th_alloced(struct osd_thandle *oth)
{
        oth->oth_alloced = ktime_get();
}

/**
 * Set time when the handle started
 */
static void osd_th_started(struct osd_thandle *oth)
{
        oth->oth_started = ktime_get();
}

/**
 * Check whether the we deal with this handle for too long.
 */
static void __osd_th_check_slow(void *oth, struct osd_device *dev,
                                ktime_t alloced, ktime_t started,
                                ktime_t closed)
{
        ktime_t now = ktime_get();

        LASSERT(dev != NULL);

        lprocfs_counter_add(dev->od_stats, LPROC_OSD_THANDLE_STARTING,
                            ktime_us_delta(started, alloced));
        lprocfs_counter_add(dev->od_stats, LPROC_OSD_THANDLE_OPEN,
                            ktime_us_delta(closed, started));
        lprocfs_counter_add(dev->od_stats, LPROC_OSD_THANDLE_CLOSING,
                            ktime_us_delta(now, closed));

        if (ktime_before(ktime_add_ns(alloced, 30 * NSEC_PER_SEC), now)) {
                CWARN("transaction handle %p was open for too long: now %lld, alloced %lld, started %lld, closed %lld\n",
                      oth, now, alloced, started, closed);
                libcfs_debug_dumpstack(NULL);
        }
}

#define OSD_CHECK_SLOW_TH(oth, dev, expr)                               \
{                                                                       \
        ktime_t __closed = ktime_get();                                 \
        ktime_t __alloced = oth->oth_alloced;                           \
        ktime_t __started = oth->oth_started;                           \
                                                                        \
        expr;                                                           \
        __osd_th_check_slow(oth, dev, __alloced, __started, __closed);  \
}

#else /* OSD_THANDLE_STATS */

#define osd_th_alloced(h)                  do {} while(0)
#define osd_th_started(h)                  do {} while(0)
#define OSD_CHECK_SLOW_TH(oth, dev, expr)  expr

#endif /* OSD_THANDLE_STATS */

/*
 * Concurrency: doesn't access mutable data.
 */
static int osd_param_is_not_sane(const struct osd_device *dev,
                                 const struct thandle *th)
{
        struct osd_thandle *oh = container_of(th, typeof(*oh), ot_super);

        return oh->ot_credits > osd_transaction_size(dev);
}

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

        LASSERT(oh->ot_handle == NULL);

        if (error)
                CERROR("transaction @0x%p commit error: %d\n", th, error);

        dt_txn_hook_commit(th);

        /* call per-transaction callbacks if any */
        list_for_each_entry_safe(dcb, tmp, &oh->ot_commit_dcb_list,
                                 dcb_linkage) {
                LASSERTF(dcb->dcb_magic == TRANS_COMMIT_CB_MAGIC,
                         "commit callback entry: magic=%x name='%s'\n",
                         dcb->dcb_magic, dcb->dcb_name);
                list_del_init(&dcb->dcb_linkage);
                dcb->dcb_func(NULL, th, dcb, error);
        }

        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);
}

#ifndef HAVE_SB_START_WRITE
# define sb_start_write(sb) do {} while (0)
# define sb_end_write(sb) do {} while (0)
#endif

static struct thandle *osd_trans_create(const struct lu_env *env,
                                        struct dt_device *d)
{
        struct osd_thread_info  *oti = osd_oti_get(env);
        struct osd_iobuf        *iobuf = &oti->oti_iobuf;
        struct osd_thandle      *oh;
        struct thandle          *th;
        ENTRY;

        if (d->dd_rdonly) {
                CERROR("%s: someone try to start transaction under "
                       "readonly mode, should be disabled.\n",
                       osd_name(osd_dt_dev(d)));
                dump_stack();
                RETURN(ERR_PTR(-EROFS));
        }

        /* on pending IO in this thread should left from prev. request */
        LASSERT(atomic_read(&iobuf->dr_numreqs) == 0);

        sb_start_write(osd_sb(osd_dt_dev(d)));

        OBD_ALLOC_GFP(oh, sizeof *oh, GFP_NOFS);
        if (oh != NULL) {
                oh->ot_quota_trans = &oti->oti_quota_trans;
                memset(oh->ot_quota_trans, 0, sizeof(*oh->ot_quota_trans));
                th = &oh->ot_super;
                th->th_dev = d;
                th->th_result = 0;
                th->th_tags = LCT_TX_HANDLE;
                oh->ot_credits = 0;
                INIT_LIST_HEAD(&oh->ot_commit_dcb_list);
                INIT_LIST_HEAD(&oh->ot_stop_dcb_list);
                osd_th_alloced(oh);

                memset(oti->oti_declare_ops, 0,
                       sizeof(oti->oti_declare_ops));
                memset(oti->oti_declare_ops_cred, 0,
                       sizeof(oti->oti_declare_ops_cred));
                memset(oti->oti_declare_ops_used, 0,
                       sizeof(oti->oti_declare_ops_used));
        } else {
                sb_end_write(osd_sb(osd_dt_dev(d)));
                th = ERR_PTR(-ENOMEM);
        }
        RETURN(th);
}

void osd_trans_dump_creds(const struct lu_env *env, struct thandle *th)
{
        struct osd_thread_info  *oti = osd_oti_get(env);
        struct osd_thandle      *oh;

        oh = container_of0(th, struct osd_thandle, ot_super);
        LASSERT(oh != NULL);

        CWARN("  create: %u/%u/%u, destroy: %u/%u/%u\n",
              oti->oti_declare_ops[OSD_OT_CREATE],
              oti->oti_declare_ops_cred[OSD_OT_CREATE],
              oti->oti_declare_ops_used[OSD_OT_CREATE],
              oti->oti_declare_ops[OSD_OT_DESTROY],
              oti->oti_declare_ops_cred[OSD_OT_DESTROY],
              oti->oti_declare_ops_used[OSD_OT_DESTROY]);
        CWARN("  attr_set: %u/%u/%u, xattr_set: %u/%u/%u\n",
              oti->oti_declare_ops[OSD_OT_ATTR_SET],
              oti->oti_declare_ops_cred[OSD_OT_ATTR_SET],
              oti->oti_declare_ops_used[OSD_OT_ATTR_SET],
              oti->oti_declare_ops[OSD_OT_XATTR_SET],
              oti->oti_declare_ops_cred[OSD_OT_XATTR_SET],
              oti->oti_declare_ops_used[OSD_OT_XATTR_SET]);
        CWARN("  write: %u/%u/%u, punch: %u/%u/%u, quota %u/%u/%u\n",
              oti->oti_declare_ops[OSD_OT_WRITE],
              oti->oti_declare_ops_cred[OSD_OT_WRITE],
              oti->oti_declare_ops_used[OSD_OT_WRITE],
              oti->oti_declare_ops[OSD_OT_PUNCH],
              oti->oti_declare_ops_cred[OSD_OT_PUNCH],
              oti->oti_declare_ops_used[OSD_OT_PUNCH],
              oti->oti_declare_ops[OSD_OT_QUOTA],
              oti->oti_declare_ops_cred[OSD_OT_QUOTA],
              oti->oti_declare_ops_used[OSD_OT_QUOTA]);
        CWARN("  insert: %u/%u/%u, delete: %u/%u/%u\n",
              oti->oti_declare_ops[OSD_OT_INSERT],
              oti->oti_declare_ops_cred[OSD_OT_INSERT],
              oti->oti_declare_ops_used[OSD_OT_INSERT],
              oti->oti_declare_ops[OSD_OT_DELETE],
              oti->oti_declare_ops_cred[OSD_OT_DELETE],
              oti->oti_declare_ops_used[OSD_OT_DELETE]);
        CWARN("  ref_add: %u/%u/%u, ref_del: %u/%u/%u\n",
              oti->oti_declare_ops[OSD_OT_REF_ADD],
              oti->oti_declare_ops_cred[OSD_OT_REF_ADD],
              oti->oti_declare_ops_used[OSD_OT_REF_ADD],
              oti->oti_declare_ops[OSD_OT_REF_DEL],
              oti->oti_declare_ops_cred[OSD_OT_REF_DEL],
              oti->oti_declare_ops_used[OSD_OT_REF_DEL]);
}

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

        ENTRY;

        LASSERT(current->journal_info == NULL);

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

        rc = dt_txn_hook_start(env, d, th);
        if (rc != 0)
                GOTO(out, rc);

        if (unlikely(osd_param_is_not_sane(dev, th))) {
                static unsigned long last_printed;
                static int last_credits;

                /* don't make noise on a tiny testing systems
                 * actual credits misuse will be caught anyway */
                if (last_credits != oh->ot_credits &&
                    time_after(jiffies, last_printed +
                               msecs_to_jiffies(60 * MSEC_PER_SEC)) &&
                    osd_transaction_size(dev) > 512) {
                        CWARN("%s: credits %u > trans_max %u\n", osd_name(dev),
                              oh->ot_credits, osd_transaction_size(dev));
                        osd_trans_dump_creds(env, th);
                        libcfs_debug_dumpstack(NULL);
                        last_credits = oh->ot_credits;
                        last_printed = jiffies;
                }
                /* XXX Limit the credits to 'max_transaction_buffers', and
                 *     let the underlying filesystem to catch the error if
                 *     we really need so many credits.
                 *
                 *     This should be removed when we can calculate the
                 *     credits precisely. */
                oh->ot_credits = osd_transaction_size(dev);
        } else if (ldiskfs_track_declares_assert != 0) {
                /* reserve few credits to prevent an assertion in JBD
                 * our debugging mechanism will be able to detected
                 * overuse. this can help to debug single-update
                 * transactions */
                oh->ot_credits += 10;
                if (unlikely(osd_param_is_not_sane(dev, th)))
                        oh->ot_credits = osd_transaction_size(dev);
        }

        /*
         * XXX temporary stuff. Some abstraction layer should
         * be used.
         */
        jh = osd_journal_start_sb(osd_sb(dev), LDISKFS_HT_MISC, oh->ot_credits);
        osd_th_started(oh);
        if (!IS_ERR(jh)) {
                oh->ot_handle = jh;
                LASSERT(oti->oti_txns == 0);
                lu_context_init(&th->th_ctx, th->th_tags);
                lu_context_enter(&th->th_ctx);

                lu_device_get(&d->dd_lu_dev);
                lu_ref_add_at(&d->dd_lu_dev.ld_reference, &oh->ot_dev_link,
                              "osd-tx", th);
                oti->oti_txns++;
                rc = 0;
        } else {
                rc = PTR_ERR(jh);
        }
out:
        RETURN(rc);
}

static int osd_seq_exists(const struct lu_env *env,
                          struct osd_device *osd, u64 seq)
{
        struct lu_seq_range     *range = &osd_oti_get(env)->oti_seq_range;
        struct seq_server_site  *ss = osd_seq_site(osd);
        int                     rc;
        ENTRY;

        LASSERT(ss != NULL);
        LASSERT(ss->ss_server_fld != NULL);

        rc = osd_fld_lookup(env, osd, seq, range);
        if (rc != 0) {
                if (rc != -ENOENT)
                        CERROR("%s: can't lookup FLD sequence %#llx: rc = %d\n",
                               osd_name(osd), seq, rc);
                RETURN(0);
        }

        RETURN(ss->ss_node_id == range->lsr_index);
}

static void osd_trans_stop_cb(struct osd_thandle *oth, int result)
{
        struct dt_txn_commit_cb *dcb;
        struct dt_txn_commit_cb *tmp;

        /* call per-transaction stop callbacks if any */
        list_for_each_entry_safe(dcb, tmp, &oth->ot_stop_dcb_list,
                                 dcb_linkage) {
                LASSERTF(dcb->dcb_magic == TRANS_COMMIT_CB_MAGIC,
                         "commit callback entry: magic=%x name='%s'\n",
                         dcb->dcb_magic, dcb->dcb_name);
                list_del_init(&dcb->dcb_linkage);
                dcb->dcb_func(NULL, &oth->ot_super, dcb, result);
        }
}

/*
 * Concurrency: shouldn't matter.
 */
static int osd_trans_stop(const struct lu_env *env, struct dt_device *dt,
                          struct thandle *th)
{
        int                     rc = 0, remove_agents = 0;
        struct osd_thandle     *oh;
        struct osd_thread_info *oti = osd_oti_get(env);
        struct osd_iobuf       *iobuf = &oti->oti_iobuf;
        struct osd_device      *osd = osd_dt_dev(th->th_dev);
        struct qsd_instance    *qsd = osd->od_quota_slave;
        struct lquota_trans    *qtrans;
        ENTRY;

        oh = container_of0(th, struct osd_thandle, ot_super);

        /* reset OI cache for safety */
        oti->oti_ins_cache_used = 0;

        remove_agents = oh->ot_remove_agents;

        qtrans = oh->ot_quota_trans;
        oh->ot_quota_trans = NULL;

        if (oh->ot_handle != NULL) {
                int rc2;
                handle_t *hdl = oh->ot_handle;

                /*
                 * add commit callback
                 * notice we don't do this in osd_trans_start()
                 * as underlying transaction can change during truncate
                 */
                ldiskfs_journal_callback_add(hdl, osd_trans_commit_cb,
                                         &oh->ot_jcb);

                LASSERT(oti->oti_txns == 1);
                oti->oti_txns--;

                rc = dt_txn_hook_stop(env, th);
                if (rc != 0)
                        CERROR("%s: failed in transaction hook: rc = %d\n",
                               osd_name(osd), rc);

                osd_trans_stop_cb(oh, rc);
                /* hook functions might modify th_sync */
                hdl->h_sync = th->th_sync;

                oh->ot_handle = NULL;
                OSD_CHECK_SLOW_TH(oh, osd, rc2 = ldiskfs_journal_stop(hdl));
                if (rc2 != 0)
                        CERROR("%s: failed to stop transaction: rc = %d\n",
                               osd_name(osd), rc2);
                if (!rc)
                        rc = rc2;
        } else {
                osd_trans_stop_cb(oh, th->th_result);
                OBD_FREE_PTR(oh);
        }

        /* inform the quota slave device that the transaction is stopping */
        qsd_op_end(env, qsd, qtrans);

        /* as we want IO to journal and data IO be concurrent, we don't block
         * awaiting data IO completion in osd_do_bio(), instead we wait here
         * once transaction is submitted to the journal. all reqular requests
         * don't do direct IO (except read/write), thus this wait_event becomes
         * no-op for them.
         *
         * IMPORTANT: we have to wait till any IO submited by the thread is
         * completed otherwise iobuf may be corrupted by different request
         */
        wait_event(iobuf->dr_wait,
                       atomic_read(&iobuf->dr_numreqs) == 0);
        osd_fini_iobuf(osd, iobuf);
        if (!rc)
                rc = iobuf->dr_error;

        if (unlikely(remove_agents != 0))
                osd_process_scheduled_agent_removals(env, osd);

        sb_end_write(osd_sb(osd));

        RETURN(rc);
}

static int osd_trans_cb_add(struct thandle *th, struct dt_txn_commit_cb *dcb)
{
        struct osd_thandle *oh = container_of0(th, struct osd_thandle,
                                               ot_super);

        LASSERT(dcb->dcb_magic == TRANS_COMMIT_CB_MAGIC);
        LASSERT(&dcb->dcb_func != NULL);
        if (dcb->dcb_flags & DCB_TRANS_STOP)
                list_add(&dcb->dcb_linkage, &oh->ot_stop_dcb_list);
        else
                list_add(&dcb->dcb_linkage, &oh->ot_commit_dcb_list);

        return 0;
}

/*
 * 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) {
                struct qsd_instance     *qsd = osd_obj2dev(obj)->od_quota_slave;
                qid_t                    uid = i_uid_read(inode);
                qid_t                    gid = i_gid_read(inode);

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

                if (qsd != NULL) {
                        struct osd_thread_info  *info = osd_oti_get(env);
                        struct lquota_id_info   *qi = &info->oti_qi;

                        /* Release granted quota to master if necessary */
                        qi->lqi_id.qid_uid = uid;
                        qsd_op_adjust(env, qsd, &qi->lqi_id, USRQUOTA);

                        qi->lqi_id.qid_uid = gid;
                        qsd_op_adjust(env, qsd, &qi->lqi_id, GRPQUOTA);

                        qi->lqi_id.qid_uid = i_projid_read(inode);
                        qsd_op_adjust(env, qsd, &qi->lqi_id, PRJQUOTA);
                }
        }
}

/*
 * 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);
        /* nobody should be releasing a non-destroyed object with nlink=0
         * the API allows this, but ldiskfs doesn't like and then report
         * this inode as deleted */
        if (unlikely(!o->oo_destroyed && o->oo_inode && o->oo_inode->i_nlink == 0))
                LBUG();
}

/*
 * 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_LDISKFS_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,
               struct obd_statfs *sfs)
{
        struct osd_device       *osd = osd_dt_dev(d);
        struct super_block      *sb = osd_sb(osd);
        struct kstatfs          *ksfs;
        __u64                    reserved;
        int                      result = 0;

        if (unlikely(osd->od_mnt == NULL))
                return -EINPROGRESS;

        /* osd_lproc.c call this without env, allocate ksfs for that case */
        if (unlikely(env == NULL)) {
                OBD_ALLOC_PTR(ksfs);
                if (ksfs == NULL)
                        return -ENOMEM;
        } else {
                ksfs = &osd_oti_get(env)->oti_ksfs;
        }

        result = sb->s_op->statfs(sb->s_root, ksfs);
        if (result)
                goto out;

        statfs_pack(sfs, ksfs);
        if (unlikely(sb->s_flags & MS_RDONLY))
                sfs->os_state |= OS_STATE_READONLY;
        if (LDISKFS_HAS_INCOMPAT_FEATURE(sb,
                                         LDISKFS_FEATURE_INCOMPAT_EXTENTS))
                sfs->os_maxbytes = sb->s_maxbytes;
        else
                sfs->os_maxbytes = LDISKFS_SB(sb)->s_bitmap_maxbytes;

        /*
         * Reserve some space so to avoid fragmenting the filesystem too much.
         * Fragmentation not only impacts performance, but can also increase
         * metadata overhead significantly, causing grant calculation to be
         * wrong.
         *
         * Reserve 0.78% of total space, at least 8MB for small filesystems.
         */
        CLASSERT(OSD_STATFS_RESERVED > LDISKFS_MAX_BLOCK_SIZE);
        reserved = OSD_STATFS_RESERVED >> sb->s_blocksize_bits;
        if (likely(sfs->os_blocks >= reserved << OSD_STATFS_RESERVED_SHIFT))
                reserved = sfs->os_blocks >> OSD_STATFS_RESERVED_SHIFT;

        sfs->os_blocks -= reserved;
        sfs->os_bfree  -= min(reserved, sfs->os_bfree);
        sfs->os_bavail -= min(reserved, sfs->os_bavail);

out:
        if (unlikely(env == NULL))
                OBD_FREE_PTR(ksfs);
        return result;
}

/**
 * Estimate space needed for file creations. We assume the largest filename
 * which is 2^64 - 1, hence a filename of 20 chars.
 * This is 28 bytes per object which is 28MB for 1M objects ... no so bad.
 */
#ifdef __LDISKFS_DIR_REC_LEN
#define PER_OBJ_USAGE __LDISKFS_DIR_REC_LEN(20)
#else
#define PER_OBJ_USAGE LDISKFS_DIR_REC_LEN(20)
#endif

/*
 * 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)
{
        struct super_block *sb = osd_sb(osd_dt_dev(dev));
        int                ea_overhead;

        /*
         * 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_symlink_max  = sb->s_blocksize;
        param->ddp_mount_type     = LDD_MT_LDISKFS;
        if (LDISKFS_HAS_INCOMPAT_FEATURE(sb, LDISKFS_FEATURE_INCOMPAT_EXTENTS))
                param->ddp_maxbytes = sb->s_maxbytes;
        else
                param->ddp_maxbytes = LDISKFS_SB(sb)->s_bitmap_maxbytes;
        /* inode are statically allocated, so per-inode space consumption
         * is the space consumed by the directory entry */
        param->ddp_inodespace     = PER_OBJ_USAGE;
        /* EXT_INIT_MAX_LEN is the theoretical maximum extent size  (32k blocks
         * = 128MB) which is unlikely to be hit in real life. Report a smaller
         * maximum length to not under count the actual number of extents
         * needed for writing a file. */
        param->ddp_max_extent_blks = EXT_INIT_MAX_LEN >> 2;
        /* worst-case extent insertion metadata overhead */
        param->ddp_extent_tax = 6 * LDISKFS_BLOCK_SIZE(sb);
        param->ddp_mntopts      = 0;
        if (test_opt(sb, XATTR_USER))
                param->ddp_mntopts |= MNTOPT_USERXATTR;
        if (test_opt(sb, POSIX_ACL))
                param->ddp_mntopts |= MNTOPT_ACL;

        /* LOD might calculate the max stripe count based on max_ea_size,
         * so we need take account in the overhead as well,
         * xattr_header + magic + xattr_entry_head */
        ea_overhead = sizeof(struct ldiskfs_xattr_header) + sizeof(__u32) +
                      LDISKFS_XATTR_LEN(XATTR_NAME_MAX_LEN);

#if defined(LDISKFS_FEATURE_INCOMPAT_EA_INODE)
        if (LDISKFS_HAS_INCOMPAT_FEATURE(sb, LDISKFS_FEATURE_INCOMPAT_EA_INODE))
                param->ddp_max_ea_size = LDISKFS_XATTR_MAX_LARGE_EA_SIZE -
                                                                ea_overhead;
        else
#endif
                param->ddp_max_ea_size = sb->s_blocksize - ea_overhead;
}

/*
 * Concurrency: shouldn't matter.
 */
static int osd_sync(const struct lu_env *env, struct dt_device *d)
{
        int rc;

        CDEBUG(D_CACHE, "%s: syncing OSD\n", osd_dt_dev(d)->od_svname);

        rc = ldiskfs_force_commit(osd_sb(osd_dt_dev(d)));

        CDEBUG(D_CACHE, "%s: synced OSD: rc = %d\n", osd_dt_dev(d)->od_svname,
               rc);

        return rc;
}

/**
 * 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, "%s: async commit OSD\n", osd_dt_dev(d)->od_svname);
        RETURN(s->s_op->sync_fs(s, 0));
}

/* Our own copy of the set readonly functions if present, or NU if not. */
static int (*priv_dev_set_rdonly)(struct block_device *bdev);
static int (*priv_dev_check_rdonly)(struct block_device *bdev);
/* static int (*priv_dev_clear_rdonly)(struct block_device *bdev); */

/*
 * Concurrency: shouldn't matter.
 */
static int osd_ro(const struct lu_env *env, struct dt_device *d)
{
        struct super_block *sb = osd_sb(osd_dt_dev(d));
        struct block_device *dev = sb->s_bdev;
        int rc = -EOPNOTSUPP;
        ENTRY;

        if (priv_dev_set_rdonly) {
                struct block_device *jdev = LDISKFS_SB(sb)->journal_bdev;

                rc = 0;
                CERROR("*** setting %s read-only ***\n",
                       osd_dt_dev(d)->od_svname);

                if (sb->s_op->freeze_fs) {
                        rc = sb->s_op->freeze_fs(sb);
                        if (rc)
                                goto out;
                }

                if (jdev && (jdev != dev)) {
                        CDEBUG(D_IOCTL | D_HA, "set journal dev %lx rdonly\n",
                               (long)jdev);
                        priv_dev_set_rdonly(jdev);
                }
                CDEBUG(D_IOCTL | D_HA, "set dev %lx rdonly\n", (long)dev);
                priv_dev_set_rdonly(dev);

                if (sb->s_op->unfreeze_fs)
                        sb->s_op->unfreeze_fs(sb);
        }

out:
        if (rc)
                CERROR("%s: %lx CANNOT BE SET READONLY: rc = %d\n",
                       osd_dt_dev(d)->od_svname, (long)dev, rc);

        RETURN(rc);
}

/**
 * Note: we do not count into QUOTA here.
 * If we mount with --data_journal we may need more.
 */
const int osd_dto_credits_noquota[DTO_NR] = {
        /**
         * Insert.
         * 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,
        /**
         * Delete
         * just modify a single entry, probably merge few within a block
         */
        [DTO_INDEX_DELETE]  = 1,
        /**
         * Used for OI scrub
         */
        [DTO_INDEX_UPDATE]  = 16,
        /**
         * 4(inode, inode bits, groups, GDT)
         *   notice: OI updates are counted separately with DTO_INDEX_INSERT
         */
        [DTO_OBJECT_CREATE] = 4,
        /**
         * 4(inode, inode bits, groups, GDT)
         *   notice: OI updates are counted separately with DTO_INDEX_DELETE
         */
        [DTO_OBJECT_DELETE] = 4,
        /**
         * Attr set credits (inode)
         */
        [DTO_ATTR_SET_BASE] = 1,
        /**
         * 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,
        /**
         * credits 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
};

static const struct dt_device_operations osd_dt_ops = {
        .dt_root_get       = osd_root_get,
        .dt_statfs         = osd_statfs,
        .dt_trans_create   = osd_trans_create,
        .dt_trans_start    = osd_trans_start,
        .dt_trans_stop     = osd_trans_stop,
        .dt_trans_cb_add   = osd_trans_cb_add,
        .dt_conf_get       = osd_conf_get,
        .dt_sync           = osd_sync,
        .dt_ro             = osd_ro,
        .dt_commit_async   = osd_commit_async,
};

static void osd_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);
        down_read_nested(&obj->oo_sem, role);

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

static void osd_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);
        down_write_nested(&obj->oo_sem, role);

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

static void osd_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--;
        up_read(&obj->oo_sem);
}

static void osd_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;
        up_write(&obj->oo_sem);
}

static int osd_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 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, inode->i_sb->s_time_gran);
        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_PROJID | LA_FLAGS | LA_NLINK | LA_RDEV |
                           LA_BLKSIZE | LA_TYPE;

        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     = i_uid_read(inode);
        attr->la_gid     = i_gid_read(inode);
        attr->la_projid  = i_projid_read(inode);
        attr->la_flags   = ll_inode_to_ext_flags(inode->i_flags);
        attr->la_nlink   = inode->i_nlink;
        attr->la_rdev    = inode->i_rdev;
        attr->la_blksize = 1 << inode->i_blkbits;
        attr->la_blkbits = inode->i_blkbits;
        /*
         * Ext4 did not transfer inherit flags from raw inode
         * to inode flags, and ext4 internally test raw inode
         * @i_flags directly. Instead of patching ext4, we do it here.
         */
        if (LDISKFS_I(inode)->i_flags & LUSTRE_PROJINHERIT_FL)
                attr->la_flags |= LUSTRE_PROJINHERIT_FL;
}

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

        if (unlikely(!dt_object_exists(dt)))
                return -ENOENT;
        if (unlikely(obj->oo_destroyed))
                return -ENOENT;

        LASSERT(!dt_object_remote(dt));
        LINVRNT(osd_invariant(obj));

        spin_lock(&obj->oo_guard);
        osd_inode_getattr(env, obj->oo_inode, attr);
        if (obj->oo_lma_flags & LUSTRE_ORPHAN_FL)
                attr->la_flags |= LUSTRE_ORPHAN_FL;
        spin_unlock(&obj->oo_guard);

        return 0;
}

static int osd_declare_attr_qid(const struct lu_env *env,
                                struct osd_object *obj,
                                struct osd_thandle *oh, long long bspace,
                                qid_t old_id, qid_t new_id, bool enforce,
                                unsigned type)
{
        int rc;
        struct osd_thread_info *info = osd_oti_get(env);
        struct lquota_id_info  *qi = &info->oti_qi;

        qi->lqi_type = type;
        /* inode accounting */
        qi->lqi_is_blk = false;

        /* one more inode for the new id ... */
        qi->lqi_id.qid_uid = new_id;
        qi->lqi_space      = 1;
        /* Reserve credits for the new id */
        rc = osd_declare_qid(env, oh, qi, NULL, enforce, NULL);
        if (rc == -EDQUOT || rc == -EINPROGRESS)
                rc = 0;
        if (rc)
                RETURN(rc);

        /* and one less inode for the current id */
        qi->lqi_id.qid_uid = old_id;
        qi->lqi_space      = -1;
        rc = osd_declare_qid(env, oh, qi, obj, enforce, NULL);
        if (rc == -EDQUOT || rc == -EINPROGRESS)
                rc = 0;
        if (rc)
                RETURN(rc);

        /* block accounting */
        qi->lqi_is_blk = true;

        /* more blocks for the new id ... */
        qi->lqi_id.qid_uid = new_id;
        qi->lqi_space      = bspace;
        /*
         * Credits for the new uid has been reserved, re-use "obj"
         * to save credit reservation.
         */
        rc = osd_declare_qid(env, oh, qi, obj, enforce, NULL);
        if (rc == -EDQUOT || rc == -EINPROGRESS)
                rc = 0;
        if (rc)
                RETURN(rc);

        /* and finally less blocks for the current uid */
        qi->lqi_id.qid_uid = old_id;
        qi->lqi_space      = -bspace;
        rc = osd_declare_qid(env, oh, qi, obj, enforce, NULL);
        if (rc == -EDQUOT || rc == -EINPROGRESS)
                rc = 0;

        RETURN(rc);
}

static int osd_declare_attr_set(const struct lu_env *env,
                                struct dt_object *dt,
                                const struct lu_attr *attr,
                                struct thandle *handle)
{
        struct osd_thandle     *oh;
        struct osd_object      *obj;
        qid_t                   uid;
        qid_t                   gid;
        long long               bspace;
        int                     rc = 0;
        bool                    enforce;
        ENTRY;

        LASSERT(dt != NULL);
        LASSERT(handle != NULL);

        obj = osd_dt_obj(dt);
        LASSERT(osd_invariant(obj));

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

        osd_trans_declare_op(env, oh, OSD_OT_ATTR_SET,
                             osd_dto_credits_noquota[DTO_ATTR_SET_BASE]);

        osd_trans_declare_op(env, oh, OSD_OT_XATTR_SET,
                             osd_dto_credits_noquota[DTO_XATTR_SET]);

        if (attr == NULL || obj->oo_inode == NULL)
                RETURN(rc);

        bspace   = obj->oo_inode->i_blocks;
        bspace <<= obj->oo_inode->i_sb->s_blocksize_bits;
        bspace   = toqb(bspace);

        /* Changing ownership is always preformed by super user, it should not
         * fail with EDQUOT.
         *
         * We still need to call the osd_declare_qid() to calculate the journal
         * credits for updating quota accounting files and to trigger quota
         * space adjustment once the operation is completed.*/
        if (attr->la_valid & LA_UID || attr->la_valid & LA_GID) {
                /* USERQUOTA */
                uid = i_uid_read(obj->oo_inode);
                enforce = (attr->la_valid & LA_UID) && (attr->la_uid != uid);
                rc = osd_declare_attr_qid(env, obj, oh, bspace, uid,
                                          attr->la_uid, enforce, USRQUOTA);
                if (rc)
                        RETURN(rc);

                gid = i_gid_read(obj->oo_inode);
                enforce = (attr->la_valid & LA_GID) && (attr->la_gid != gid);
                rc = osd_declare_attr_qid(env, obj, oh, bspace,
                                          i_gid_read(obj->oo_inode),
                                          attr->la_gid, enforce, GRPQUOTA);
                if (rc)
                        RETURN(rc);

        }
#ifdef HAVE_PROJECT_QUOTA
        if (attr->la_valid & LA_PROJID) {
                __u32 projid = i_projid_read(obj->oo_inode);
                enforce = (attr->la_valid & LA_PROJID) &&
                                        (attr->la_projid != projid);
                rc = osd_declare_attr_qid(env, obj, oh, bspace,
                                          (qid_t)projid, (qid_t)attr->la_projid,
                                          enforce, PRJQUOTA);
                if (rc)
                        RETURN(rc);
        }
#endif
        RETURN(rc);
}

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

        /* Only allow set size for regular file */
        if (!S_ISREG(inode->i_mode))
                bits &= ~(LA_SIZE | LA_BLOCKS);

        if (bits == 0)
                return 0;

        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) {
                spin_lock(&inode->i_lock);
                LDISKFS_I(inode)->i_disksize = attr->la_size;
                i_size_write(inode, attr->la_size);
                spin_unlock(&inode->i_lock);
        }

        /* OSD should not change "i_blocks" which is used by quota.
         * "i_blocks" should be changed by ldiskfs only. */
        if (bits & LA_MODE)
                inode->i_mode = (inode->i_mode & S_IFMT) |
                                (attr->la_mode & ~S_IFMT);
        if (bits & LA_UID)
                i_uid_write(inode, attr->la_uid);
        if (bits & LA_GID)
                i_gid_write(inode, attr->la_gid);
        if (bits & LA_PROJID)
                i_projid_write(inode, attr->la_projid);
        if (bits & LA_NLINK)
                set_nlink(inode, attr->la_nlink);
        if (bits & LA_RDEV)
                inode->i_rdev = attr->la_rdev;

        if (bits & LA_FLAGS) {
                /* always keep S_NOCMTIME */
                inode->i_flags = ll_ext_to_inode_flags(attr->la_flags) |
                                 S_NOCMTIME;
                /*
                 * Ext4 did not transfer inherit flags from
                 * @inode->i_flags to raw inode i_flags when writing
                 * flags, we do it explictly here.
                 */
                if (attr->la_flags & LUSTRE_PROJINHERIT_FL)
                        LDISKFS_I(inode)->i_flags |= LUSTRE_PROJINHERIT_FL;
        }
        return 0;
}

static int osd_quota_transfer(struct inode *inode, const struct lu_attr *attr)
{
        int rc;

        if ((attr->la_valid & LA_UID && attr->la_uid != i_uid_read(inode)) ||
            (attr->la_valid & LA_GID && attr->la_gid != i_gid_read(inode))) {
                struct iattr    iattr;

                ll_vfs_dq_init(inode);
                iattr.ia_valid = 0;
                if (attr->la_valid & LA_UID)
                        iattr.ia_valid |= ATTR_UID;
                if (attr->la_valid & LA_GID)
                        iattr.ia_valid |= ATTR_GID;
                iattr.ia_uid = make_kuid(&init_user_ns, attr->la_uid);
                iattr.ia_gid = make_kgid(&init_user_ns, attr->la_gid);

                rc = ll_vfs_dq_transfer(inode, &iattr);
                if (rc) {
                        CERROR("%s: quota transfer failed: rc = %d. Is quota "
                               "enforcement enabled on the ldiskfs "
                               "filesystem?\n", inode->i_sb->s_id, rc);
                        return rc;
                }
        }

#ifdef HAVE_PROJECT_QUOTA
        /* Handle project id transfer here properly */
        if (attr->la_valid & LA_PROJID &&
            attr->la_projid != i_projid_read(inode)) {
                rc = __ldiskfs_ioctl_setproject(inode, attr->la_projid);
                if (rc) {
                        CERROR("%s: quota transfer failed: rc = %d. Is quota "
                               "enforcement enabled on the ldiskfs "
                               "filesystem?\n", inode->i_sb->s_id, rc);
                        return rc;
                }
        }
#endif
        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 osd_object *obj = osd_dt_obj(dt);
        struct inode      *inode;
        int rc;

        if (!dt_object_exists(dt))
                return -ENOENT;

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

        osd_trans_exec_op(env, handle, OSD_OT_ATTR_SET);

        if (OBD_FAIL_CHECK(OBD_FAIL_OSD_FID_MAPPING)) {
                struct osd_thread_info  *oti  = osd_oti_get(env);
                const struct lu_fid     *fid0 = lu_object_fid(&dt->do_lu);
                struct lu_fid           *fid1 = &oti->oti_fid;
                struct osd_inode_id     *id   = &oti->oti_id;
                struct iam_path_descr   *ipd;
                struct iam_container    *bag;
                struct osd_thandle      *oh;
                int                      rc;

                fid_cpu_to_be(fid1, fid0);
                memset(id, 1, sizeof(*id));
                bag = &osd_fid2oi(osd_dev(dt->do_lu.lo_dev),
                                  fid0)->oi_dir.od_container;
                ipd = osd_idx_ipd_get(env, bag);
                if (unlikely(ipd == NULL))
                        RETURN(-ENOMEM);

                oh = container_of0(handle, struct osd_thandle, ot_super);
                rc = iam_update(oh->ot_handle, bag, (const struct iam_key *)fid1,
                                (const struct iam_rec *)id, ipd);
                osd_ipd_put(env, bag, ipd);
                return(rc > 0 ? 0 : rc);
        }

        inode = obj->oo_inode;

        rc = osd_quota_transfer(inode, attr);
        if (rc)
                return rc;

        spin_lock(&obj->oo_guard);
        rc = osd_inode_setattr(env, inode, attr);
        spin_unlock(&obj->oo_guard);
        if (rc != 0)
                GOTO(out, rc);

        ll_dirty_inode(inode, I_DIRTY_DATASYNC);

        if (!(attr->la_valid & LA_FLAGS))
                GOTO(out, rc);

        /* Let's check if there are extra flags need to be set into LMA */
        if (attr->la_flags & LUSTRE_LMA_FL_MASKS) {
                struct osd_thread_info *info = osd_oti_get(env);
                struct lustre_mdt_attrs *lma = &info->oti_ost_attrs.loa_lma;

                rc = osd_get_lma(info, inode, &info->oti_obj_dentry,
                                 &info->oti_ost_attrs);
                if (rc)
                        GOTO(out, rc);

                lma->lma_incompat |=
                        lustre_to_lma_flags(attr->la_flags);
                lustre_lma_swab(lma);
                rc = __osd_xattr_set(info, inode, XATTR_NAME_LMA,
                                     lma, sizeof(*lma), XATTR_REPLACE);
                if (rc != 0) {
                        struct osd_device *osd = osd_obj2dev(obj);

                        CWARN("%s: set "DFID" lma flags %u failed: rc = %d\n",
                              osd_name(osd), PFID(lu_object_fid(&dt->do_lu)),
                              lma->lma_incompat, rc);
                } else {
                        obj->oo_lma_flags =
                                attr->la_flags & LUSTRE_LMA_FL_MASKS;
                }
                osd_trans_exec_check(env, handle, OSD_OT_XATTR_SET);
        }
out:
        osd_trans_exec_check(env, handle, OSD_OT_ATTR_SET);

        return rc;
}

static struct dentry *osd_child_dentry_get(const struct lu_env *env,
                                           struct osd_object *obj,
                                           const char *name, const int namelen)
{
        return osd_child_dentry_by_inode(env, obj->oo_inode, name, namelen);
}

static int osd_mkfile(struct osd_thread_info *info, struct osd_object *obj,
                      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 = NULL;
        struct inode       *inode;

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

        if (S_ISDIR(mode) && ldiskfs_pdo) {
                obj->oo_hl_head =ldiskfs_htree_lock_head_alloc(HTREE_HBITS_DEF);
                if (obj->oo_hl_head == NULL)
                        return -ENOMEM;
        }

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

        if (hint != NULL && hint->dah_parent != NULL &&
            !dt_object_remote(hint->dah_parent))
                parent = hint->dah_parent;

        inode = ldiskfs_create_inode(oth->ot_handle,
                                     parent ? osd_dt_obj(parent)->oo_inode :
                                              osd_sb(osd)->s_root->d_inode,
                                     mode);
        if (!IS_ERR(inode)) {
                /* Do not update file c/mtime in ldiskfs. */
                inode->i_flags |= S_NOCMTIME;

                /* For new created object, it must be consistent,
                 * and it is unnecessary to scrub against it. */
                ldiskfs_set_inode_state(inode, LDISKFS_STATE_LUSTRE_NOSCRUB);

                obj->oo_inode = inode;
                result = 0;
        } else {
                if (obj->oo_hl_head != NULL) {
                        ldiskfs_htree_lock_head_free(obj->oo_hl_head);
                        obj->oo_hl_head = NULL;
                }
                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;
        __u32 mode = (attr->la_mode & (S_IFMT | S_IRWXUGO | S_ISVTX | S_ISGID));

        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);

        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_IALLUGO | 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_IALLUGO | 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_IALLUGO | 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)
{
        umode_t mode = attr->la_mode & (S_IFMT | S_IALLUGO | 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);
                /*
                 * This inode should be marked dirty for i_rdev.  Currently
                 * that is done in the osd_attr_init().
                 */
                init_special_inode(obj->oo_inode, obj->oo_inode->i_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, struct dt_object *child,
                        umode_t child_mode)
{
        LASSERT(ah);

        ah->dah_parent = parent;
        ah->dah_mode = child_mode;

        if (parent != NULL && !dt_object_remote(parent)) {
                /* will help to find FID->ino at dt_insert("..") */
                struct osd_object *pobj = osd_dt_obj(parent);
                osd_idc_find_and_init(env, osd_obj2dev(pobj), pobj);
        }
}

static void osd_attr_init(struct osd_thread_info *info, struct osd_object *obj,
                          struct lu_attr *attr, struct dt_object_format *dof)
{
        struct inode   *inode = obj->oo_inode;
        __u64           valid = attr->la_valid;
        int             result;

        attr->la_valid &= ~(LA_TYPE | LA_MODE);

        if (dof->dof_type != DFT_NODE)
                attr->la_valid &= ~LA_RDEV;
        if ((valid & LA_ATIME) && (attr->la_atime == LTIME_S(inode->i_atime)))
                attr->la_valid &= ~LA_ATIME;
        if ((valid & LA_CTIME) && (attr->la_ctime == LTIME_S(inode->i_ctime)))
                attr->la_valid &= ~LA_CTIME;
        if ((valid & LA_MTIME) && (attr->la_mtime == LTIME_S(inode->i_mtime)))
                attr->la_valid &= ~LA_MTIME;

        result = osd_quota_transfer(inode, attr);
        if (result)
                return;

        if (attr->la_valid != 0) {
                result = osd_inode_setattr(info->oti_env, inode, attr);
                /*
                 * The osd_inode_setattr() should always succeed here.  The
                 * only error that could be returned is EDQUOT when we are
                 * trying to change the UID or GID of the inode. However, this
                 * should not happen since quota enforcement is no longer
                 * enabled on ldiskfs (lquota takes care of it).
                 */
                LASSERTF(result == 0, "%d\n", result);
                ll_dirty_inode(inode, I_DIRTY_DATASYNC);
        }

        attr->la_valid = valid;
}

/**
 * Helper function for osd_create()
 *
 * \retval 0, on success
 */
static int __osd_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;
        __u32   umask;

        osd_trans_exec_op(info->oti_env, th, OSD_OT_CREATE);

        /* we drop umask so that permissions we pass are not affected */
        umask = current->fs->umask;
        current->fs->umask = 0;

        result = osd_create_type_f(dof->dof_type)(info, obj, attr, hint, dof,
                                                  th);
        if (likely(obj->oo_inode != NULL)) {
                LASSERT(obj->oo_inode->i_state & I_NEW);

                /* Unlock the inode before attr initialization to avoid
                 * unnecessary dqget operations. LU-6378 */
                unlock_new_inode(obj->oo_inode);
        }

        if (likely(result == 0)) {
                osd_attr_init(info, obj, attr, dof);
                osd_object_init0(obj);
        }

        /* restore previous umask value */
        current->fs->umask = umask;

        osd_trans_exec_check(info->oti_env, th, OSD_OT_CREATE);

        return result;
}

/**
 * Helper function for osd_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 osd_thandle     *oh;
        int                     rc;

        LASSERT(obj->oo_inode != NULL);

        oh = container_of0(th, struct osd_thandle, ot_super);
        LASSERT(oh->ot_handle);
        osd_trans_exec_op(env, th, OSD_OT_INSERT);

        osd_id_gen(id, obj->oo_inode->i_ino, obj->oo_inode->i_generation);
        rc = osd_oi_insert(info, osd, fid, id, oh->ot_handle,
                           OI_CHECK_FLD, NULL);
        osd_trans_exec_check(env, th, OSD_OT_INSERT);

        return rc;
}

int osd_fld_lookup(const struct lu_env *env, struct osd_device *osd,
                   u64 seq, struct lu_seq_range *range)
{
        struct seq_server_site  *ss = osd_seq_site(osd);

        if (fid_seq_is_idif(seq)) {
                fld_range_set_ost(range);
                range->lsr_index = idif_ost_idx(seq);
                return 0;
        }

        if (!fid_seq_in_fldb(seq)) {
                fld_range_set_mdt(range);
                if (ss != NULL)
                        /* FIXME: If ss is NULL, it suppose not get lsr_index
                         * at all */
                        range->lsr_index = ss->ss_node_id;
                return 0;
        }

        LASSERT(ss != NULL);
        fld_range_set_any(range);
        /* OSD will only do local fld lookup */
        return fld_local_lookup(env, ss->ss_server_fld, seq, range);
}

static int osd_declare_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 *handle)
{
        struct osd_thandle *oh;
        int rc;
        ENTRY;

        LASSERT(handle != NULL);

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

        /* EA object consumes more credits than regular object: osd_mk_index
         * vs. osd_mkreg: osd_mk_index will create 2 blocks for root_node and
         * leaf_node, could involves the block, block bitmap, groups, GDT
         * change for each block, so add 4 * 2 credits in that case. */
        osd_trans_declare_op(env, oh, OSD_OT_CREATE,
                             osd_dto_credits_noquota[DTO_OBJECT_CREATE] +
                             (dof->dof_type == DFT_INDEX) ? 4 * 2 : 0);
        /* Reuse idle OI block may cause additional one OI block
         * to be changed. */
        osd_trans_declare_op(env, oh, OSD_OT_INSERT,
                             osd_dto_credits_noquota[DTO_INDEX_INSERT] + 1);

        if (!attr)
                RETURN(0);

        rc = osd_declare_inode_qid(env, attr->la_uid, attr->la_gid,
                                   attr->la_projid, 1, oh, osd_dt_obj(dt),
                                   NULL, OSD_QID_INODE);
        if (rc != 0)
                RETURN(rc);

        /* will help to find FID->ino mapping at dt_insert() */
        rc = osd_idc_find_and_init(env, osd_obj2dev(osd_dt_obj(dt)),
                                   osd_dt_obj(dt));

        RETURN(rc);
}

/**
 * Called to destroy on-disk representation of the object
 *
 * Concurrency: must be locked
 */
static int osd_declare_destroy(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;
        struct osd_thandle *oh;
        int                 rc;
        ENTRY;

        if (inode == NULL)
                RETURN(-ENOENT);

        oh = container_of0(th, struct osd_thandle, ot_super);
        LASSERT(oh->ot_handle == NULL);

        osd_trans_declare_op(env, oh, OSD_OT_DESTROY,
                             osd_dto_credits_noquota[DTO_OBJECT_DELETE]);
        /* Recycle idle OI leaf may cause additional three OI blocks
         * to be changed. */
        if (!OBD_FAIL_CHECK(OBD_FAIL_LFSCK_LOST_MDTOBJ2))
                osd_trans_declare_op(env, oh, OSD_OT_DELETE,
                             osd_dto_credits_noquota[DTO_INDEX_DELETE] + 3);
        /* one less inode */
        rc = osd_declare_inode_qid(env, i_uid_read(inode), i_gid_read(inode),
                                   i_projid_read(inode), -1, oh, obj, NULL,
                                   OSD_QID_INODE);
        if (rc)
                RETURN(rc);
        /* data to be truncated */
        rc = osd_declare_inode_qid(env, i_uid_read(inode), i_gid_read(inode),
                                   i_projid_read(inode), 0, oh, obj, NULL,
                                   OSD_QID_BLK);
        if (rc)
                RETURN(rc);

        /* will help to find FID->ino when this object is being
         * added to PENDING/ */
        rc = osd_idc_find_and_init(env, osd_obj2dev(obj), obj);

        RETURN(rc);
}

static int osd_destroy(const struct lu_env *env, struct dt_object *dt,
                       struct thandle *th)
{
        const struct lu_fid *fid = lu_object_fid(&dt->do_lu);
        struct osd_object *obj = osd_dt_obj(dt);
        struct inode *inode = obj->oo_inode;
        struct osd_device *osd = osd_obj2dev(obj);
        struct osd_thandle *oh;
        int result;
        ENTRY;

        oh = container_of0(th, struct osd_thandle, ot_super);
        LASSERT(oh->ot_handle);
        LASSERT(inode);
        LASSERT(!lu_object_is_dying(dt->do_lu.lo_header));

        if (unlikely(fid_is_acct(fid)))
                RETURN(-EPERM);

        if (S_ISDIR(inode->i_mode)) {
                LASSERT(osd_inode_unlinked(inode) || inode->i_nlink == 1 ||
                        inode->i_nlink == 2);
                /* it will check/delete the inode from remote parent,
                 * how to optimize it? unlink performance impaction XXX */
                result = osd_delete_from_remote_parent(env, osd, obj, oh);
                if (result != 0)
                        CERROR("%s: delete inode "DFID": rc = %d\n",
                               osd_name(osd), PFID(fid), result);

                spin_lock(&obj->oo_guard);
                clear_nlink(inode);
                spin_unlock(&obj->oo_guard);
                ll_dirty_inode(inode, I_DIRTY_DATASYNC);
        }

        osd_trans_exec_op(env, th, OSD_OT_DESTROY);

        ldiskfs_set_inode_state(inode, LDISKFS_STATE_LUSTRE_DESTROY);

        if (!OBD_FAIL_CHECK(OBD_FAIL_LFSCK_LOST_MDTOBJ2))
                result = osd_oi_delete(osd_oti_get(env), osd, fid,
                                       oh->ot_handle, OI_CHECK_FLD);

        osd_trans_exec_check(env, th, OSD_OT_DESTROY);
        /* XXX: add to ext3 orphan list */
        /* rc = ext3_orphan_add(handle_t *handle, struct inode *inode) */

        /* not needed in the cache anymore */
        set_bit(LU_OBJECT_HEARD_BANSHEE, &dt->do_lu.lo_header->loh_flags);
        obj->oo_destroyed = 1;

        RETURN(0);
}

/**
 * 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
 */
int osd_ea_fid_set(struct osd_thread_info *info, struct inode *inode,
                   const struct lu_fid *fid, __u32 compat, __u32 incompat)
{
        struct lustre_ost_attrs *loa = &info->oti_ost_attrs;
        struct lustre_mdt_attrs *lma = &loa->loa_lma;
        int rc;
        ENTRY;

        if (OBD_FAIL_CHECK(OBD_FAIL_FID_INLMA))
                RETURN(0);

        if (OBD_FAIL_CHECK(OBD_FAIL_OSD_OST_EA_FID_SET))
                rc = -ENOMEM;

        lustre_loa_init(loa, fid, compat, incompat);
        lustre_loa_swab(loa, false);

        /* For the OST device with 256 bytes inode size by default,
         * the PFID EA will be stored together with LMA EA to avoid
         * performance trouble. Otherwise the PFID EA can be stored
         * independently. LU-8998 */
        if ((compat & LMAC_FID_ON_OST) &&
            LDISKFS_INODE_SIZE(inode->i_sb) <= 256)
                rc = __osd_xattr_set(info, inode, XATTR_NAME_LMA, loa,
                                     sizeof(*loa), XATTR_CREATE);
        else
                rc = __osd_xattr_set(info, inode, XATTR_NAME_LMA, lma,
                                     sizeof(*lma), XATTR_CREATE);
        /* LMA may already exist, but we need to check that all the
         * desired compat/incompat flags have been added. */
        if (unlikely(rc == -EEXIST)) {
                rc = __osd_xattr_get(inode, &info->oti_obj_dentry,
                                     XATTR_NAME_LMA, (void *)loa, sizeof(*loa));
                if (rc < 0)
                        RETURN(rc);

                if (rc < sizeof(*lma))
                        RETURN(-EINVAL);

                lustre_loa_swab(loa, true);
                if (lu_fid_eq(fid, &lma->lma_self_fid) &&
                    ((compat == 0 && incompat == 0) ||
                     (!(~lma->lma_compat & compat) &&
                      !(~lma->lma_incompat & incompat))))
                        RETURN(0);

                lma->lma_self_fid = *fid;
                lma->lma_compat |= compat;
                lma->lma_incompat |= incompat;
                if (rc == sizeof(*lma)) {
                        lustre_lma_swab(lma);
                        rc = __osd_xattr_set(info, inode, XATTR_NAME_LMA, lma,
                                             sizeof(*lma), XATTR_REPLACE);
                } else {
                        lustre_loa_swab(loa, false);
                        rc = __osd_xattr_set(info, inode, XATTR_NAME_LMA, loa,
                                             sizeof(*loa), XATTR_REPLACE);
                }
        }

        RETURN(rc);
}

/**
 * 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.
 */
static void osd_get_ldiskfs_dirent_param(struct ldiskfs_dentry_param *param,
                                         const struct lu_fid *fid)
{
        if (!fid_is_namespace_visible(fid) ||
            OBD_FAIL_CHECK(OBD_FAIL_FID_IGIF)) {
                param->edp_magic = 0;
                return;
        }

        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);
}

/**
 * Try to read the fid from inode ea into dt_rec.
 *
 * \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_inode_id *id)
{
        struct osd_thread_info *info  = osd_oti_get(env);
        struct inode           *inode;
        ENTRY;

        osd_id_gen(id, ino, OSD_OII_NOGEN);
        inode = osd_iget_fid(info, osd_obj2dev(obj), id, fid);
        if (IS_ERR(inode))
                RETURN(PTR_ERR(inode));

        iput(inode);
        RETURN(0);
}

static int osd_add_dot_dotdot_internal(struct osd_thread_info *info,
                                        struct inode *dir,
                                        struct inode *parent_dir,
                                        const struct lu_fid *dot_fid,
                                        const struct lu_fid *dot_dot_fid,
                                        struct osd_thandle *oth)
{
        struct ldiskfs_dentry_param *dot_ldp;
        struct ldiskfs_dentry_param *dot_dot_ldp;
        __u32 saved_nlink = dir->i_nlink;
        int rc;

        dot_dot_ldp = (struct ldiskfs_dentry_param *)info->oti_ldp2;
        osd_get_ldiskfs_dirent_param(dot_dot_ldp, dot_dot_fid);

        dot_ldp = (struct ldiskfs_dentry_param *)info->oti_ldp;
        dot_ldp->edp_magic = 0;

        rc = ldiskfs_add_dot_dotdot(oth->ot_handle, parent_dir,
                                    dir, dot_ldp, dot_dot_ldp);
        /* The ldiskfs_add_dot_dotdot() may dir->i_nlink as 2, then
         * the subseqent ref_add() will increase the dir->i_nlink
         * as 3. That is incorrect for new created directory.
         *
         * It looks like hack, because we want to make the OSD API
         * to be order-independent for new created directory object
         * between dt_insert(..) and ref_add() operations.
         *
         * Here, we only restore the in-RAM dir-inode's nlink attr,
         * becuase if the nlink attr is not 2, then there will be
         * ref_add() called following the dt_insert(..), such call
         * will make both the in-RAM and on-disk dir-inode's nlink
         * attr to be set as 2. LU-7447 */
        set_nlink(dir, saved_nlink);
        return rc;
}

/**
 * Create an local agent inode for remote entry
 */
static struct inode *osd_create_local_agent_inode(const struct lu_env *env,
                                                  struct osd_device *osd,
                                                  struct osd_object *pobj,
                                                  const struct lu_fid *fid,
                                                  __u32 type,
                                                  struct thandle *th)
{
        struct osd_thread_info  *info = osd_oti_get(env);
        struct inode            *local;
        struct osd_thandle      *oh;
        int                     rc;
        ENTRY;

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

        local = ldiskfs_create_inode(oh->ot_handle, pobj->oo_inode, type);
        if (IS_ERR(local)) {
                CERROR("%s: create local error %d\n", osd_name(osd),
                       (int)PTR_ERR(local));
                RETURN(local);
        }

        /* restore i_gid in case S_ISGID is set, we will inherit S_ISGID and set
         * correct gid on remote file, not agent here */
        local->i_gid = current_fsgid();
        ldiskfs_set_inode_state(local, LDISKFS_STATE_LUSTRE_NOSCRUB);
        unlock_new_inode(local);

        /* Agent inode should not have project ID */
#ifdef  HAVE_PROJECT_QUOTA
        if (LDISKFS_I(pobj->oo_inode)->i_flags & LUSTRE_PROJINHERIT_FL) {
                rc = __ldiskfs_ioctl_setproject(local, 0);
                if (rc) {
                        CERROR("%s: quota transfer failed: rc = %d. Is project "
                               "quota enforcement enabled on the ldiskfs "
                               "filesystem?\n", local->i_sb->s_id, rc);
                        RETURN(ERR_PTR(rc));
                }
        }
#endif
        /* Set special LMA flag for local agent inode */
        rc = osd_ea_fid_set(info, local, fid, 0, LMAI_AGENT);
        if (rc != 0) {
                CERROR("%s: set LMA for "DFID" remote inode failed: rc = %d\n",
                       osd_name(osd), PFID(fid), rc);
                RETURN(ERR_PTR(rc));
        }

        if (!S_ISDIR(type))
                RETURN(local);

        rc = osd_add_dot_dotdot_internal(info, local, pobj->oo_inode,
                                         lu_object_fid(&pobj->oo_dt.do_lu),
                                         fid, oh);
        if (rc != 0) {
                CERROR("%s: "DFID" add dot dotdot error: rc = %d\n",
                        osd_name(osd), PFID(fid), rc);
                RETURN(ERR_PTR(rc));
        }

        RETURN(local);
}

/**
 * when direntry is deleted, we have to take care of possible agent inode
 * referenced by that. unfortunately we can't do this at that point:
 * iget() within a running transaction leads to deadlock and we better do
 * not call that every delete declaration to save performance. so we put
 * a potention agent inode on a list and process that once the transaction
 * is over. Notice it's not any worse in terms of real orphans as regular
 * object destroy doesn't put inodes on the on-disk orphan list. this should
 * be addressed separately
 */
static int osd_schedule_agent_inode_removal(const struct lu_env *env,
                                            struct osd_thandle *oh,
                                            __u32 ino)
{
        struct osd_device      *osd = osd_dt_dev(oh->ot_super.th_dev);
        struct osd_obj_orphan *oor;

        OBD_ALLOC_PTR(oor);
        if (oor == NULL)
                return -ENOMEM;

        oor->oor_ino = ino;
        oor->oor_env = (struct lu_env *)env;
        spin_lock(&osd->od_osfs_lock);
        list_add(&oor->oor_list, &osd->od_orphan_list);
        spin_unlock(&osd->od_osfs_lock);

        oh->ot_remove_agents = 1;

        return 0;

}

static int osd_process_scheduled_agent_removals(const struct lu_env *env,
                                                struct osd_device *osd)
{
        struct osd_thread_info *info = osd_oti_get(env);
        struct osd_obj_orphan *oor, *tmp;
        struct osd_inode_id id;
        struct list_head list;
        struct inode *inode;
        struct lu_fid fid;
        handle_t *jh;
        __u32 ino;

        INIT_LIST_HEAD(&list);

        spin_lock(&osd->od_osfs_lock);
        list_for_each_entry_safe(oor, tmp, &osd->od_orphan_list, oor_list) {
                if (oor->oor_env == env) {
                        list_del(&oor->oor_list);
                        list_add(&oor->oor_list, &list);
                }
        }
        spin_unlock(&osd->od_osfs_lock);

        list_for_each_entry_safe(oor, tmp, &list, oor_list) {

                ino = oor->oor_ino;

                list_del(&oor->oor_list);
                OBD_FREE_PTR(oor);

                osd_id_gen(&id, ino, OSD_OII_NOGEN);
                inode = osd_iget_fid(info, osd, &id, &fid);
                if (IS_ERR(inode))
                        continue;

                if (!osd_remote_fid(env, osd, &fid)) {
                        iput(inode);
                        continue;
                }

                jh = osd_journal_start_sb(osd_sb(osd), LDISKFS_HT_MISC, 1);
                clear_nlink(inode);
                mark_inode_dirty(inode);
                ldiskfs_journal_stop(jh);
                iput(inode);
        }

        return 0;
}

/**
 * OSD layer object create function for OST objects (b=11826).
 *
 * The FID is inserted into inode xattr here.
 *
 * \retval   0, on success
 * \retval -ve, on error
 */
static int osd_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, on_ost = 0;

        ENTRY;

        if (dt_object_exists(dt))
                RETURN(-EEXIST);

        LINVRNT(osd_invariant(obj));
        LASSERT(!dt_object_remote(dt));
        LASSERT(osd_is_write_locked(env, obj));
        LASSERT(th != NULL);

        if (unlikely(fid_is_acct(fid)))
                /* Quota files can't be created from the kernel any more,
                 * 'tune2fs -O quota' will take care of creating them */
                RETURN(-EPERM);

        result = __osd_create(info, obj, attr, hint, dof, th);
        if (result == 0) {
                if (fid_is_idif(fid) &&
                    !osd_dev(dt->do_lu.lo_dev)->od_index_in_idif) {
                        struct lu_fid *tfid = &info->oti_fid;
                        struct ost_id *oi   = &info->oti_ostid;

                        fid_to_ostid(fid, oi);
                        ostid_to_fid(tfid, oi, 0);
                        on_ost = 1;
                        result = osd_ea_fid_set(info, obj->oo_inode, tfid,
                                                LMAC_FID_ON_OST, 0);
                } else {
                        on_ost = fid_is_on_ost(info, osd_obj2dev(obj),
                                               fid, OI_CHECK_FLD);
                        result = osd_ea_fid_set(info, obj->oo_inode, fid,
                                                on_ost ? LMAC_FID_ON_OST : 0,
                                                0);
                }
                if (obj->oo_dt.do_body_ops == &osd_body_ops_new)
                        obj->oo_dt.do_body_ops = &osd_body_ops;
        }

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

        /* a small optimization - dt_insert() isn't usually applied
         * to OST objects, so we don't need to cache OI mapping for
         * OST objects */
        if (result == 0 && on_ost == 0) {
                struct osd_device *osd = osd_dev(dt->do_lu.lo_dev);
                result = osd_idc_find_and_init(env, osd, obj);
                LASSERT(result == 0);
        }

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

static int osd_declare_ref_add(const struct lu_env *env, struct dt_object *dt,
                               struct thandle *handle)
{
        struct osd_thandle *oh;

        /* it's possible that object doesn't exist yet */
        LASSERT(handle != NULL);

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

        osd_trans_declare_op(env, oh, OSD_OT_REF_ADD,
                             osd_dto_credits_noquota[DTO_ATTR_SET_BASE]);

        return 0;
}

/*
 * Concurrency: @dt is write locked.
 */
static int osd_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;
        struct osd_thandle *oh;
        int                 rc = 0;

        if (!dt_object_exists(dt) || obj->oo_destroyed)
                return -ENOENT;

        LINVRNT(osd_invariant(obj));
        LASSERT(!dt_object_remote(dt));
        LASSERT(osd_is_write_locked(env, obj));
        LASSERT(th != NULL);

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

        osd_trans_exec_op(env, th, OSD_OT_REF_ADD);

        CDEBUG(D_INODE, DFID" increase nlink %d\n",
               PFID(lu_object_fid(&dt->do_lu)), inode->i_nlink);
        /*
         * The DIR_NLINK feature allows directories to exceed LDISKFS_LINK_MAX
         * (65000) subdirectories by storing "1" in i_nlink if the link count
         * would otherwise overflow. Directory tranversal tools understand
         * that (st_nlink == 1) indicates that the filesystem dose not track
         * hard links count on the directory, and will not abort subdirectory
         * scanning early once (st_nlink - 2) subdirs have been found.
         *
         * This also has to properly handle the case of inodes with nlink == 0
         * in case they are being linked into the PENDING directory
         */
        spin_lock(&obj->oo_guard);
        if (unlikely(inode->i_nlink == 0))
                /* inc_nlink from 0 may cause WARN_ON */
                set_nlink(inode, 1);
        else {
                ldiskfs_inc_count(oh->ot_handle, inode);
                if (!S_ISDIR(inode->i_mode))
                        LASSERT(inode->i_nlink <= LDISKFS_LINK_MAX);
        }
        spin_unlock(&obj->oo_guard);

        ll_dirty_inode(inode, I_DIRTY_DATASYNC);
        LINVRNT(osd_invariant(obj));

        osd_trans_exec_check(env, th, OSD_OT_REF_ADD);

        return rc;
}

static int osd_declare_ref_del(const struct lu_env *env, struct dt_object *dt,
                               struct thandle *handle)
{
        struct osd_thandle *oh;

        if (!dt_object_exists(dt))
                return -ENOENT;

        LASSERT(!dt_object_remote(dt));
        LASSERT(handle != NULL);

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

        osd_trans_declare_op(env, oh, OSD_OT_REF_DEL,
                             osd_dto_credits_noquota[DTO_ATTR_SET_BASE]);

        return 0;
}

/*
 * Concurrency: @dt is write locked.
 */
static int osd_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;
        struct osd_device       *osd = osd_dev(dt->do_lu.lo_dev);
        struct osd_thandle      *oh;

        if (!dt_object_exists(dt))
                return -ENOENT;

        LINVRNT(osd_invariant(obj));
        LASSERT(!dt_object_remote(dt));
        LASSERT(osd_is_write_locked(env, obj));
        LASSERT(th != NULL);

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

        osd_trans_exec_op(env, th, OSD_OT_REF_DEL);

        spin_lock(&obj->oo_guard);
        /* That can be result of upgrade from old Lustre version and
         * applied only to local files.  Just skip this ref_del call.
         * ext4_unlink() only treats this as a warning, don't LASSERT here.*/
        if (inode->i_nlink == 0) {
                CDEBUG_LIMIT(fid_is_norm(lu_object_fid(&dt->do_lu)) ?
                             D_ERROR : D_INODE, "%s: nlink == 0 on "DFID
                             ", maybe an upgraded file? (LU-3915)\n",
                             osd_name(osd), PFID(lu_object_fid(&dt->do_lu)));
                spin_unlock(&obj->oo_guard);
                return 0;
        }

        CDEBUG(D_INODE, DFID" decrease nlink %d\n",
               PFID(lu_object_fid(&dt->do_lu)), inode->i_nlink);

        ldiskfs_dec_count(oh->ot_handle, inode);
        spin_unlock(&obj->oo_guard);

        ll_dirty_inode(inode, I_DIRTY_DATASYNC);
        LINVRNT(osd_invariant(obj));

        osd_trans_exec_check(env, th, OSD_OT_REF_DEL);

        return 0;
}

/*
 * 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 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;
        bool                    cache_xattr = false;
        int                     rc;

        LASSERT(buf);

        /* version get is not real XATTR but uses xattr API */
        if (strcmp(name, XATTR_NAME_VERSION) == 0) {
                dt_obj_version_t *ver = buf->lb_buf;

                /* for version we are just using xattr API but change inode
                 * field instead */
                if (buf->lb_len == 0)
                        return sizeof(dt_obj_version_t);

                if (buf->lb_len < sizeof(dt_obj_version_t))
                        return -ERANGE;

                CDEBUG(D_INODE, "Get version %#llx for inode %lu\n",
                       LDISKFS_I(inode)->i_fs_version, inode->i_ino);

                *ver = LDISKFS_I(inode)->i_fs_version;

                return sizeof(dt_obj_version_t);
        }

        if (!dt_object_exists(dt))
                return -ENOENT;

        LASSERT(!dt_object_remote(dt));
        LASSERT(inode->i_op != NULL);
        LASSERT(inode->i_op->getxattr != NULL);

        if (strcmp(name, XATTR_NAME_LOV) == 0 ||
            strcmp(name, XATTR_NAME_DEFAULT_LMV) == 0)
                cache_xattr = true;

        if (cache_xattr) {
                rc = osd_oxc_get(obj, name, buf);
                if (rc != -ENOENT)
                        return rc;
        }

        rc = __osd_xattr_get(inode, dentry, name, buf->lb_buf, buf->lb_len);
        if (rc == -ENODATA && strcmp(name, XATTR_NAME_FID) == 0) {
                struct lustre_ost_attrs *loa = &info->oti_ost_attrs;
                struct lustre_mdt_attrs *lma = &loa->loa_lma;
                struct filter_fid *ff;
                struct ost_layout *ol;

                LASSERT(osd_dev(dt->do_lu.lo_dev)->od_is_ost);

                rc = osd_get_lma(info, inode, &info->oti_obj_dentry, loa);
                if (rc)
                        return rc;

                if (!(lma->lma_compat & LMAC_STRIPE_INFO)) {
                        rc = -ENODATA;
                        goto cache;
                }

                rc = sizeof(*ff);
                if (buf->lb_len == 0 || !buf->lb_buf)
                        return rc;

                if (buf->lb_len < rc)
                        return -ERANGE;

                ff = buf->lb_buf;
                ol = &ff->ff_layout;
                ol->ol_stripe_count = cpu_to_le32(loa->loa_parent_fid.f_ver >>
                                                  PFID_STRIPE_IDX_BITS);
                ol->ol_stripe_size = cpu_to_le32(loa->loa_stripe_size);
                loa->loa_parent_fid.f_ver &= PFID_STRIPE_COUNT_MASK;
                fid_cpu_to_le(&ff->ff_parent, &loa->loa_parent_fid);
                if (lma->lma_compat & LMAC_COMP_INFO) {
                        ol->ol_comp_start = cpu_to_le64(loa->loa_comp_start);
                        ol->ol_comp_end = cpu_to_le64(loa->loa_comp_end);
                        ol->ol_comp_id = cpu_to_le32(loa->loa_comp_id);
                } else {
                        ol->ol_comp_start = 0;
                        ol->ol_comp_end = 0;
                        ol->ol_comp_id = 0;
                }
        }

cache:
        if (cache_xattr) {
                if (rc == -ENOENT || rc == -ENODATA)
                        osd_oxc_add(obj, name, NULL, 0);
                else if (rc > 0 && buf->lb_buf != NULL)
                        osd_oxc_add(obj, name, buf->lb_buf, rc);
        }

        return rc;
}

static int osd_declare_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 osd_thandle *oh;
        int credits = 0;
        struct super_block *sb = osd_sb(osd_dev(dt->do_lu.lo_dev));

        LASSERT(handle != NULL);

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

        if (strcmp(name, XATTR_NAME_LMA) == 0) {
                /* For non-upgrading case, the LMA is set first and
                 * usually fit inode. But for upgrade case, the LMA
                 * may be in another separated EA block. */
                if (dt_object_exists(dt)) {
                        if (fl == LU_XATTR_REPLACE)
                                credits = 1;
                        else
                                goto upgrade;
                }
        } else if (strcmp(name, XATTR_NAME_VERSION) == 0) {
                credits = 1;
        } else if (strcmp(name, XATTR_NAME_FID) == 0) {
                /* We may need to delete the old PFID EA. */
                credits = LDISKFS_MAXQUOTAS_DEL_BLOCKS(sb);
                if (fl == LU_XATTR_REPLACE)
                        credits += 1;
                else
                        goto upgrade;
        } else {

upgrade:
                credits += osd_dto_credits_noquota[DTO_XATTR_SET];

                if (buf != NULL) {
                        ssize_t buflen;

                        if (buf->lb_buf == NULL && dt_object_exists(dt)) {
                                /* learn xattr size from osd_xattr_get if
                                   attribute has not been read yet */
                                buflen = __osd_xattr_get(
                                    osd_dt_obj(dt)->oo_inode,
                                    &osd_oti_get(env)->oti_obj_dentry,
                                    name, NULL, 0);
                                if (buflen < 0)
                                        buflen = 0;
                        } else {
                                buflen = buf->lb_len;
                        }

                        if (buflen > sb->s_blocksize) {
                                credits += osd_calc_bkmap_credits(
                                    sb, NULL, 0, -1,
                                    (buflen + sb->s_blocksize - 1) >>
                                    sb->s_blocksize_bits);
                        }
                }
                /*
                 * xattr set may involve inode quota change, reserve credits for
                 * dquot_initialize()
                 */
                credits += LDISKFS_MAXQUOTAS_INIT_BLOCKS(sb);
        }

        osd_trans_declare_op(env, oh, OSD_OT_XATTR_SET, credits);

        return 0;
}

/*
 * 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 osd_object *obj = osd_dt_obj(dt);
        struct inode *inode = obj->oo_inode;
        struct osd_thread_info *info = osd_oti_get(env);
        struct lustre_ost_attrs *loa = &info->oti_ost_attrs;
        struct lustre_mdt_attrs *lma = &loa->loa_lma;
        int fs_flags = 0;
        int len;
        int rc;
        ENTRY;

        LASSERT(handle);
        LASSERT(buf);

        /* version set is not real XATTR */
        if (strcmp(name, XATTR_NAME_VERSION) == 0) {
                dt_obj_version_t *version = buf->lb_buf;

                /* for version we are just using xattr API but change inode
                 * field instead */
                LASSERT(buf->lb_len == sizeof(dt_obj_version_t));

                CDEBUG(D_INODE, "Set version %#llx (old %#llx) for inode %lu\n",
                       *version, LDISKFS_I(inode)->i_fs_version, inode->i_ino);

                LDISKFS_I(inode)->i_fs_version = *version;
                /* Version is set after all inode operations are finished,
                 * so we should mark it dirty here */
                ll_dirty_inode(inode, I_DIRTY_DATASYNC);

                RETURN(0);
        }

        CDEBUG(D_INODE, DFID" set xattr '%s' with size %zu\n",
               PFID(lu_object_fid(&dt->do_lu)), name, buf->lb_len);

        len = buf->lb_len;
        osd_trans_exec_op(env, handle, OSD_OT_XATTR_SET);
        if (fl & LU_XATTR_REPLACE)
                fs_flags |= XATTR_REPLACE;

        if (fl & LU_XATTR_CREATE)
                fs_flags |= XATTR_CREATE;

        /* For the OST device with 256 bytes inode size by default,
         * the PFID EA will be stored together with LMA EA to avoid
         * performance trouble. Otherwise the PFID EA can be stored
         * independently. LU-8998 */
        if (strcmp(name, XATTR_NAME_FID) == 0 &&
            LDISKFS_INODE_SIZE(inode->i_sb) <= 256) {
                struct dentry *dentry = &info->oti_obj_dentry;
                struct filter_fid *ff;
                struct ost_layout *ol;
                int fl;

                LASSERT(osd_dev(dt->do_lu.lo_dev)->od_is_ost);

                ff = buf->lb_buf;
                ol = &ff->ff_layout;
                /* Old client does not send stripe information, store
                 * the PFID EA on disk directly. */
                if (buf->lb_len == sizeof(struct lu_fid) ||
                    ol->ol_stripe_size == 0) {
                        len = sizeof(struct lu_fid);
                        goto set;
                }

                if (buf->lb_len != sizeof(*ff))
                        RETURN(-EINVAL);

                rc = osd_get_lma(info, inode, dentry, loa);
                if (unlikely(rc == -ENODATA)) {
                        /* Usually for upgarding from old device */
                        lustre_loa_init(loa, lu_object_fid(&dt->do_lu),
                                        LMAC_FID_ON_OST, 0);
                        fl = XATTR_CREATE;
                } else if (rc) {
                        RETURN(rc);
                } else {
                        fl = XATTR_REPLACE;
                }

                fid_le_to_cpu(&loa->loa_parent_fid, &ff->ff_parent);
                loa->loa_parent_fid.f_ver |= le32_to_cpu(ol->ol_stripe_count) <<
                                             PFID_STRIPE_IDX_BITS;
                loa->loa_stripe_size = le32_to_cpu(ol->ol_stripe_size);
                lma->lma_compat |= LMAC_STRIPE_INFO;
                if (ol->ol_comp_id != 0) {
                        loa->loa_comp_id = le32_to_cpu(ol->ol_comp_id);
                        loa->loa_comp_start = le64_to_cpu(ol->ol_comp_start);
                        loa->loa_comp_end = le64_to_cpu(ol->ol_comp_end);
                        lma->lma_compat |= LMAC_COMP_INFO;
                }

                lustre_loa_swab(loa, false);

                /* Remove old PFID EA entry firstly. */
                ll_vfs_dq_init(inode);
                rc = inode->i_op->removexattr(dentry, name);
                if (rc && rc != -ENODATA)
                        RETURN(rc);

                /* Store the PFID EA inside the LMA EA. */
                rc = __osd_xattr_set(info, inode, XATTR_NAME_LMA, loa,
                                     sizeof(*loa), fl);

                RETURN(rc);
        } else if (strcmp(name, XATTR_NAME_LMV) == 0) {
                rc = osd_get_lma(info, inode, &info->oti_obj_dentry, loa);
                if (rc)
                        RETURN(rc);

                lma->lma_incompat |= LMAI_STRIPED;
                lustre_lma_swab(lma);
                rc = __osd_xattr_set(info, inode, XATTR_NAME_LMA, lma,
                                     sizeof(*lma), XATTR_REPLACE);
                if (rc != 0)
                        RETURN(rc);
        }

set:
        rc = __osd_xattr_set(info, inode, name, buf->lb_buf, len, fs_flags);
        osd_trans_exec_check(env, handle, OSD_OT_XATTR_SET);

        if (rc == 0 &&
            (strcmp(name, XATTR_NAME_LOV) == 0 ||
             strcmp(name, XATTR_NAME_DEFAULT_LMV) == 0))
                osd_oxc_add(obj, name, buf->lb_buf, buf->lb_len);

        return rc;
}

/*
 * Concurrency: @dt is read locked.
 */
static int osd_xattr_list(const struct lu_env *env, struct dt_object *dt,
                          const struct lu_buf *buf)
{
        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;

        if (!dt_object_exists(dt))
                return -ENOENT;

        LASSERT(!dt_object_remote(dt));
        LASSERT(inode->i_op != NULL);
        LASSERT(inode->i_op->listxattr != NULL);

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

static int osd_declare_xattr_del(const struct lu_env *env,
                                 struct dt_object *dt, const char *name,
                                 struct thandle *handle)
{
        struct osd_thandle *oh;
        struct super_block *sb = osd_sb(osd_dev(dt->do_lu.lo_dev));

        LASSERT(!dt_object_remote(dt));
        LASSERT(handle != NULL);

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

        osd_trans_declare_op(env, oh, OSD_OT_XATTR_SET,
                             osd_dto_credits_noquota[DTO_XATTR_SET]);
        /*
         * xattr del may involve inode quota change, reserve credits for
         * dquot_initialize()
         */
        oh->ot_credits += LDISKFS_MAXQUOTAS_INIT_BLOCKS(sb);

        return 0;
}

/*
 * 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 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;
        int                     rc;

        if (!dt_object_exists(dt))
                return -ENOENT;

        LASSERT(!dt_object_remote(dt));
        LASSERT(inode->i_op != NULL);
        LASSERT(inode->i_op->removexattr != NULL);
        LASSERT(handle != NULL);

        osd_trans_exec_op(env, handle, OSD_OT_XATTR_SET);

        ll_vfs_dq_init(inode);
        dentry->d_inode = inode;
        dentry->d_sb = inode->i_sb;
        rc = inode->i_op->removexattr(dentry, name);
        if (rc == -ENODATA && strcmp(name, XATTR_NAME_FID) == 0) {
                struct lustre_mdt_attrs *lma = &info->oti_ost_attrs.loa_lma;

                LASSERT(osd_dev(dt->do_lu.lo_dev)->od_is_ost);

                rc = osd_get_lma(info, inode, &info->oti_obj_dentry,
                                 &info->oti_ost_attrs);
                if (!rc) {
                        if (!(lma->lma_compat & LMAC_STRIPE_INFO)) {
                                rc = -ENODATA;
                                goto out;
                        }

                        lma->lma_compat &= ~(LMAC_STRIPE_INFO | LMAC_COMP_INFO);
                        lustre_lma_swab(lma);
                        rc = __osd_xattr_set(info, inode, XATTR_NAME_LMA, lma,
                                             sizeof(*lma), XATTR_REPLACE);
                }
        }

out:
        osd_trans_exec_check(env, handle, OSD_OT_XATTR_SET);

        if (rc == 0 &&
            (strcmp(name, XATTR_NAME_LOV) == 0 ||
             strcmp(name, XATTR_NAME_DEFAULT_LMV) == 0))
                osd_oxc_del(obj, name);

        return rc;
}

static int osd_object_sync(const struct lu_env *env, struct dt_object *dt,
                           __u64 start, __u64 end)
{
        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;
        int                     rc;

        ENTRY;

        dentry->d_inode = inode;
        dentry->d_sb = inode->i_sb;
        file->f_path.dentry = dentry;
        file->f_mapping = inode->i_mapping;
        file->f_op = inode->i_fop;
        set_file_inode(file, inode);

        rc = ll_vfs_fsync_range(file, start, end, 0);

        RETURN(rc);
}

static int osd_invalidate(const struct lu_env *env, struct dt_object *dt)
{
        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)
{
        struct iam_container *bag = &dir->od_container;
        int result;

        result = iam_container_init(bag, &dir->od_descr, obj->oo_inode);
        if (result != 0)
                return result;

        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                      skip_iam = 0;
        struct osd_object       *obj = osd_dt_obj(dt);

        LINVRNT(osd_invariant(obj));

        if (osd_object_is_root(obj)) {
                dt->do_index_ops = &osd_index_ea_ops;
                result = 0;
        } else if (feat == &dt_directory_features) {
                dt->do_index_ops = &osd_index_ea_ops;
                if (obj->oo_inode == NULL || S_ISDIR(obj->oo_inode->i_mode))
                        result = 0;
                else
                        result = -ENOTDIR;
                skip_iam = 1;
        } else if (unlikely(feat == &dt_otable_features)) {
                dt->do_index_ops = &osd_otable_ops;
                return 0;
        } else if (unlikely(feat == &dt_acct_features)) {
                dt->do_index_ops = &osd_acct_index_ops;
                result = 0;
                skip_iam = 1;
        } else if (!osd_has_index(obj)) {
                struct osd_directory *dir;

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

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

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

        return result;
}

static int osd_otable_it_attr_get(const struct lu_env *env,
                                 struct dt_object *dt,
                                 struct lu_attr *attr)
{
        attr->la_valid = 0;
        return 0;
}

static const struct dt_object_operations osd_obj_ops = {
        .do_read_lock           = osd_read_lock,
        .do_write_lock          = osd_write_lock,
        .do_read_unlock         = osd_read_unlock,
        .do_write_unlock        = osd_write_unlock,
        .do_write_locked        = osd_write_locked,
        .do_attr_get            = osd_attr_get,
        .do_declare_attr_set    = osd_declare_attr_set,
        .do_attr_set            = osd_attr_set,
        .do_ah_init             = osd_ah_init,
        .do_declare_create      = osd_declare_create,
        .do_create              = osd_create,
        .do_declare_destroy     = osd_declare_destroy,
        .do_destroy             = osd_destroy,
        .do_index_try           = osd_index_try,
        .do_declare_ref_add     = osd_declare_ref_add,
        .do_ref_add             = osd_ref_add,
        .do_declare_ref_del     = osd_declare_ref_del,
        .do_ref_del             = osd_ref_del,
        .do_xattr_get           = osd_xattr_get,
        .do_declare_xattr_set   = osd_declare_xattr_set,
        .do_xattr_set           = osd_xattr_set,
        .do_declare_xattr_del   = osd_declare_xattr_del,
        .do_xattr_del           = osd_xattr_del,
        .do_xattr_list          = osd_xattr_list,
        .do_object_sync         = osd_object_sync,
        .do_invalidate          = osd_invalidate,
};

static const struct dt_object_operations osd_obj_otable_it_ops = {
        .do_attr_get    = osd_otable_it_attr_get,
        .do_index_try   = osd_index_try,
};

static int osd_index_declare_iam_delete(const struct lu_env *env,
                                        struct dt_object *dt,
                                        const struct dt_key *key,
                                        struct thandle *handle)
{
        struct osd_thandle    *oh;

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

        /* Recycle  may cause additional three blocks to be changed. */
        osd_trans_declare_op(env, oh, OSD_OT_DELETE,
                             osd_dto_credits_noquota[DTO_INDEX_DELETE] + 3);

        return 0;
}

/**
 *      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 osd_thread_info *oti = osd_oti_get(env);
        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;

        if (!dt_object_exists(dt))
                RETURN(-ENOENT);

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

        osd_trans_exec_op(env, handle, OSD_OT_DELETE);

        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);

        if (fid_is_quota(lu_object_fid(&dt->do_lu))) {
                /* swab quota uid/gid provided by caller */
                oti->oti_quota_id = cpu_to_le64(*((__u64 *)key));
                key = (const struct dt_key *)&oti->oti_quota_id;
        }

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

static int osd_index_declare_ea_delete(const struct lu_env *env,
                                       struct dt_object *dt,
                                       const struct dt_key *key,
                                       struct thandle *handle)
{
        struct osd_thandle *oh;
        struct inode       *inode;
        int                 rc, credits;
        ENTRY;

        LASSERT(!dt_object_remote(dt));
        LASSERT(handle != NULL);

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

        credits = osd_dto_credits_noquota[DTO_INDEX_DELETE];
        if (key != NULL && unlikely(strcmp((char *)key, dotdot) == 0)) {
                /* '..' to a remote object has a local representative */
                credits += osd_dto_credits_noquota[DTO_INDEX_DELETE];
                /* to reset LMAI_REMOTE_PARENT */
                credits += 1;
        }
        osd_trans_declare_op(env, oh, OSD_OT_DELETE, credits);

        inode = osd_dt_obj(dt)->oo_inode;
        if (inode == NULL)
                RETURN(-ENOENT);

        rc = osd_declare_inode_qid(env, i_uid_read(inode), i_gid_read(inode),
                                   i_projid_read(inode), 0, oh, osd_dt_obj(dt),
                                   NULL, OSD_QID_BLK);
        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);
                if (rc == 0 && unlikely(!fid_is_sane((struct lu_fid *)fid)))
                        rc = -EINVAL;
        }
        return rc;
}

static int osd_remote_fid(const struct lu_env *env, struct osd_device *osd,
                          const struct lu_fid *fid)
{
        struct seq_server_site  *ss = osd_seq_site(osd);
        ENTRY;

        /* FID seqs not in FLDB, must be local seq */
        if (unlikely(!fid_seq_in_fldb(fid_seq(fid))))
                RETURN(0);

        /* If FLD is not being initialized yet, it only happens during the
         * initialization, likely during mgs initialization, and we assume
         * this is local FID. */
        if (ss == NULL || ss->ss_server_fld == NULL)
                RETURN(0);

        /* Only check the local FLDB here */
        if (osd_seq_exists(env, osd, fid_seq(fid)))
                RETURN(0);

        RETURN(1);
}

/**
 * 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 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 = NULL;
        struct buffer_head         *bh;
        struct htree_lock          *hlock = NULL;
        struct lu_fid              *fid = &osd_oti_get(env)->oti_fid;
        struct osd_device          *osd = osd_dev(dt->do_lu.lo_dev);
        int                        rc;
        ENTRY;

        if (!dt_object_exists(dt))
                RETURN(-ENOENT);

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

        osd_trans_exec_op(env, handle, OSD_OT_DELETE);

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

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

        if (obj->oo_hl_head != NULL) {
                hlock = osd_oti_get(env)->oti_hlock;
                ldiskfs_htree_lock(hlock, obj->oo_hl_head,
                                   dir, LDISKFS_HLOCK_DEL);
        } else {
                down_write(&obj->oo_ext_idx_sem);
        }

        bh = osd_ldiskfs_find_entry(dir, &dentry->d_name, &de, NULL, hlock);
        if (!IS_ERR(bh)) {
                /* If this is not the ".." entry, it might be a remote DNE
                 * entry and  we need to check if the FID is for a remote
                 * MDT.  If the FID is  not in the directory entry (e.g.
                 * upgraded 1.8 filesystem without dirdata enabled) then
                 * we need to get the FID from the LMA. For a remote directory
                 * there HAS to be an LMA, it cannot be an IGIF inode in this
                 * case.
                 *
                 * Delete the entry before the agent inode in order to
                 * simplify error handling.  At worst an error after deleting
                 * the entry first might leak the agent inode afterward. The
                 * reverse would need filesystem abort in case of error deleting
                 * the entry after the agent had been removed, or leave a
                 * dangling entry pointing at a random inode. */
                if (strcmp((char *)key, dotdot) != 0) {
                        LASSERT(de != NULL);
                        rc = osd_get_fid_from_dentry(de, (struct dt_rec *)fid);
                        if (rc == -ENODATA) {
                                /* can't get FID, postpone to the end of the
                                 * transaction when iget() is safe */
                                osd_schedule_agent_inode_removal(env, oh,
                                                le32_to_cpu(de->inode));
                        } else if (rc == 0 &&
                                   unlikely(osd_remote_fid(env, osd, fid))) {
                                osd_schedule_agent_inode_removal(env, oh,
                                                le32_to_cpu(de->inode));
                        }
                }
                rc = ldiskfs_delete_entry(oh->ot_handle, dir, de, bh);
                brelse(bh);
        } else {
                rc = PTR_ERR(bh);
        }
        if (hlock != NULL)
                ldiskfs_htree_unlock(hlock);
        else
                up_write(&obj->oo_ext_idx_sem);

        if (rc != 0)
                GOTO(out, rc);

        /* For inode on the remote MDT, .. will point to
         * /Agent directory, Check whether it needs to delete
         * from agent directory */
        if (unlikely(strcmp((char *)key, dotdot) == 0)) {
                int ret;

                ret = osd_delete_from_remote_parent(env, osd_obj2dev(obj),
                                                    obj, oh);
                if (ret != 0)
                        /* Sigh, the entry has been deleted, and
                         * it is not easy to revert it back, so
                         * let's keep this error private, and let
                         * LFSCK fix it. XXX */
                        CERROR("%s: delete remote parent "DFID": rc = %d\n",
                               osd_name(osd), PFID(fid), ret);
        }
out:
        LASSERT(osd_invariant(obj));
        osd_trans_exec_check(env, handle, OSD_OT_DELETE);
        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 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;

        if (!dt_object_exists(dt))
                RETURN(-ENOENT);

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

        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);

        if (fid_is_quota(lu_object_fid(&dt->do_lu))) {
                /* swab quota uid/gid provided by caller */
                oti->oti_quota_id = cpu_to_le64(*((__u64 *)key));
                key = (const struct dt_key *)&oti->oti_quota_id;
        }

        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);
                else if (fid_is_quota(lu_object_fid(&dt->do_lu)))
                        osd_quota_unpack(obj, rec);
        }

        iam_it_put(it);
        iam_it_fini(it);
        osd_ipd_put(env, bag, ipd);

        LINVRNT(osd_invariant(obj));

        RETURN(rc);
}

static int osd_index_declare_iam_insert(const struct lu_env *env,
                                        struct dt_object *dt,
                                        const struct dt_rec *rec,
                                        const struct dt_key *key,
                                        struct thandle *handle)
{
        struct osd_thandle *oh;

        LASSERT(handle != NULL);

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

        osd_trans_declare_op(env, oh, OSD_OT_INSERT,
                             osd_dto_credits_noquota[DTO_INDEX_INSERT]);

        return 0;
}

/**
 *      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,
                                int ignore_quota)
{
        struct osd_object     *obj = osd_dt_obj(dt);
        struct iam_path_descr *ipd;
        struct osd_thandle    *oh;
        struct iam_container  *bag;
        struct osd_thread_info *oti = osd_oti_get(env);
        struct iam_rec         *iam_rec;
        int                     rc;
        ENTRY;

        if (!dt_object_exists(dt))
                RETURN(-ENOENT);

        LINVRNT(osd_invariant(obj));
        LASSERT(!dt_object_remote(dt));

        bag = &obj->oo_dir->od_container;
        LASSERT(bag->ic_object == obj->oo_inode);
        LASSERT(th != NULL);

        osd_trans_exec_op(env, th, OSD_OT_INSERT);

        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);
        if (S_ISDIR(obj->oo_inode->i_mode)) {
                iam_rec = (struct iam_rec *)oti->oti_ldp;
                osd_fid_pack((struct osd_fid_pack *)iam_rec, rec, &oti->oti_fid);
        } else if (fid_is_quota(lu_object_fid(&dt->do_lu))) {
                /* pack quota uid/gid */
                oti->oti_quota_id = cpu_to_le64(*((__u64 *)key));
                key = (const struct dt_key *)&oti->oti_quota_id;
                /* pack quota record */
                rec = osd_quota_pack(obj, rec, &oti->oti_quota_rec);
                iam_rec = (struct iam_rec *)rec;
        } else {
                iam_rec = (struct iam_rec *)rec;
        }

        rc = iam_insert(oh->ot_handle, bag, (const struct iam_key *)key,
                        iam_rec, ipd);
        osd_ipd_put(env, bag, ipd);
        LINVRNT(osd_invariant(obj));
        osd_trans_exec_check(env, th, OSD_OT_INSERT);
        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 lu_fid *fid,
                            struct htree_lock *hlock, 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);
        LASSERT(pobj->oo_inode);

        ldp = (struct ldiskfs_dentry_param *)info->oti_ldp;
        if (unlikely(pobj->oo_inode ==
                     osd_sb(osd_obj2dev(pobj))->s_root->d_inode))
                ldp->edp_magic = 0;
        else
                osd_get_ldiskfs_dirent_param(ldp, fid);
        child = osd_child_dentry_get(info->oti_env, pobj, name, strlen(name));
        child->d_fsdata = (void *)ldp;
        ll_vfs_dq_init(pobj->oo_inode);
        rc = osd_ldiskfs_add_entry(info, osd_obj2dev(pobj), oth->ot_handle,
                                   child, cinode, hlock);
        if (rc == 0 && OBD_FAIL_CHECK(OBD_FAIL_LFSCK_BAD_TYPE)) {
                struct ldiskfs_dir_entry_2      *de;
                struct buffer_head              *bh;
                int                              rc1;

                bh = osd_ldiskfs_find_entry(pobj->oo_inode, &child->d_name, &de,
                                            NULL, hlock);
                if (!IS_ERR(bh)) {
                        rc1 = ldiskfs_journal_get_write_access(oth->ot_handle,
                                                               bh);
                        if (rc1 == 0) {
                                if (S_ISDIR(cinode->i_mode))
                                        de->file_type = LDISKFS_DIRENT_LUFID |
                                                        LDISKFS_FT_REG_FILE;
                                else
                                        de->file_type = LDISKFS_DIRENT_LUFID |
                                                        LDISKFS_FT_DIR;
                                ldiskfs_handle_dirty_metadata(oth->ot_handle,
                                                              NULL, bh);
                        }
                        brelse(bh);
                }
        }

        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 lu_fid *dot_fid,
                              const struct lu_fid *dot_dot_fid,
                              struct thandle *th)
{
        struct inode                *inode = dir->oo_inode;
        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->i_ino == parent_dir->i_ino);
                        dir->oo_compat_dot_created = 1;
                        result = 0;
                }
        } else if (strcmp(name, dotdot) == 0) {
                if (!dir->oo_compat_dot_created)
                        return -EINVAL;
                /* 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, NULL, th);
                }

                if (OBD_FAIL_CHECK(OBD_FAIL_LFSCK_BAD_PARENT)) {
                        struct lu_fid tfid = *dot_dot_fid;

                        tfid.f_oid--;
                        result = osd_add_dot_dotdot_internal(info,
                                        dir->oo_inode, parent_dir, dot_fid,
                                        &tfid, oth);
                } else {
                        result = osd_add_dot_dotdot_internal(info,
                                        dir->oo_inode, parent_dir, dot_fid,
                                        dot_dot_fid, oth);
                }

                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 lu_fid *fid, struct thandle *th)
{
        struct osd_thread_info *info   = osd_oti_get(env);
        struct htree_lock      *hlock;
        int                     rc;

        hlock = pobj->oo_hl_head != NULL ? info->oti_hlock : NULL;

        if (name[0] == '.' && (name[1] == '\0' || (name[1] == '.' &&
                                                   name[2] =='\0'))) {
                if (hlock != NULL) {
                        ldiskfs_htree_lock(hlock, pobj->oo_hl_head,
                                           pobj->oo_inode, 0);
                } else {
                        down_write(&pobj->oo_ext_idx_sem);
                }

                rc = osd_add_dot_dotdot(info, pobj, cinode, name,
                                        lu_object_fid(&pobj->oo_dt.do_lu),
                                        fid, th);
        } else {
                if (hlock != NULL) {
                        ldiskfs_htree_lock(hlock, pobj->oo_hl_head,
                                           pobj->oo_inode, LDISKFS_HLOCK_ADD);
                } else {
                        down_write(&pobj->oo_ext_idx_sem);
                }

                if (OBD_FAIL_CHECK(OBD_FAIL_FID_INDIR)) {
                        struct lu_fid *tfid = &info->oti_fid;

                        *tfid = *fid;
                        tfid->f_ver = ~0;
                        rc = __osd_ea_add_rec(info, pobj, cinode, name,
                                              tfid, hlock, th);
                } else {
                        rc = __osd_ea_add_rec(info, pobj, cinode, name, fid,
                                              hlock, th);
                }
        }
        if (hlock != NULL)
                ldiskfs_htree_unlock(hlock);
        else
                up_write(&pobj->oo_ext_idx_sem);

        return rc;
}

static int
osd_consistency_check(struct osd_thread_info *oti, struct osd_device *dev,
                      struct osd_idmap_cache *oic)
{
        struct osd_scrub *scrub = &dev->od_scrub;
        struct lu_fid *fid = &oic->oic_fid;
        struct osd_inode_id *id = &oic->oic_lid;
        struct inode *inode = NULL;
        int once  = 0;
        bool insert;
        int rc;
        ENTRY;

        if (!fid_is_norm(fid) && !fid_is_igif(fid))
                RETURN(0);

        if (scrub->os_pos_current > id->oii_ino)
                RETURN(0);

again:
        rc = osd_oi_lookup(oti, dev, fid, &oti->oti_id, 0);
        if (rc == -ENOENT) {
                __u32 gen = id->oii_gen;

                insert = true;
                if (inode != NULL)
                        goto trigger;

                inode = osd_iget(oti, dev, id);
                /* The inode has been removed (by race maybe). */
                if (IS_ERR(inode)) {
                        rc = PTR_ERR(inode);

                        RETURN(rc == -ESTALE ? -ENOENT : rc);
                }

                /* The OI mapping is lost. */
                if (gen != OSD_OII_NOGEN)
                        goto trigger;

                /* The inode may has been reused by others, we do not know,
                 * leave it to be handled by subsequent osd_fid_lookup(). */
                GOTO(out, rc = 0);
        } else if (rc || osd_id_eq(id, &oti->oti_id)) {
                GOTO(out, rc);
        }

        insert = false;

trigger:
        if (thread_is_running(&scrub->os_thread)) {
                if (inode == NULL) {
                        inode = osd_iget(oti, dev, id);
                        /* The inode has been removed (by race maybe). */
                        if (IS_ERR(inode)) {
                                rc = PTR_ERR(inode);

                                RETURN(rc == -ESTALE ? -ENOENT : rc);
                        }
                }

                rc = osd_oii_insert(dev, oic, insert);
                /* There is race condition between osd_oi_lookup and OI scrub.
                 * The OI scrub finished just after osd_oi_lookup() failure.
                 * Under such case, it is unnecessary to trigger OI scrub again,
                 * but try to call osd_oi_lookup() again. */
                if (unlikely(rc == -EAGAIN))
                        goto again;

                if (!S_ISDIR(inode->i_mode))
                        rc = 0;
                else
                        rc = osd_check_lmv(oti, dev, inode, oic);

                GOTO(out, rc);
        }

        if (!dev->od_noscrub && ++once == 1) {
                rc = osd_scrub_start(dev, SS_AUTO_PARTIAL | SS_CLEAR_DRYRUN |
                                     SS_CLEAR_FAILOUT);
                CDEBUG(D_LFSCK | D_CONSOLE | D_WARNING,
                       "%s: trigger partial OI scrub for RPC inconsistency "
                       "checking FID "DFID": rc = %d\n",
                       osd_dev2name(dev), PFID(fid), rc);
                if (rc == 0 || rc == -EALREADY)
                        goto again;
        }

        GOTO(out, rc);

out:
        if (inode)
                iput(inode);

        RETURN(rc);
}

static int osd_fail_fid_lookup(struct osd_thread_info *oti,
                               struct osd_device *dev,
                               struct osd_idmap_cache *oic,
                               struct lu_fid *fid, __u32 ino)
{
        struct lustre_ost_attrs *loa = &oti->oti_ost_attrs;
        struct inode *inode;
        int rc;

        osd_id_gen(&oic->oic_lid, ino, OSD_OII_NOGEN);
        inode = osd_iget(oti, dev, &oic->oic_lid);
        if (IS_ERR(inode)) {
                fid_zero(&oic->oic_fid);
                return PTR_ERR(inode);
        }

        rc = osd_get_lma(oti, inode, &oti->oti_obj_dentry, loa);
        iput(inode);
        if (rc != 0)
                fid_zero(&oic->oic_fid);
        else
                *fid = oic->oic_fid = loa->loa_lma.lma_self_fid;
        return rc;
}

void osd_add_oi_cache(struct osd_thread_info *info, struct osd_device *osd,
                      struct osd_inode_id *id, const struct lu_fid *fid)
{
        CDEBUG(D_INODE, "add "DFID" %u:%u to info %p\n", PFID(fid),
               id->oii_ino, id->oii_gen, info);
        info->oti_cache.oic_lid = *id;
        info->oti_cache.oic_fid = *fid;
        info->oti_cache.oic_dev = osd;
}

/**
 * Get parent FID from the linkEA.
 *
 * For a directory which parent resides on remote MDT, to satisfy the
 * local e2fsck, we insert it into the /REMOTE_PARENT_DIR locally. On
 * the other hand, to make the lookup(..) on the directory can return
 * the real parent FID, we append the real parent FID after its ".."
 * name entry in the /REMOTE_PARENT_DIR.
 *
 * Unfortunately, such PFID-in-dirent cannot be preserved via file-level
 * backup. So after the restore, we cannot get the right parent FID from
 * its ".." name entry in the /REMOTE_PARENT_DIR. Under such case, since
 * we have stored the real parent FID in the directory object's linkEA,
 * we can parse the linkEA for the real parent FID.
 *
 * \param[in] env       pointer to the thread context
 * \param[in] obj       pointer to the object to be handled
 * \param[out]fid       pointer to the buffer to hold the parent FID
 *
 * \retval              0 for getting the real parent FID successfully
 * \retval              negative error number on failure
 */
static int osd_get_pfid_from_linkea(const struct lu_env *env,
                                    struct osd_object *obj,
                                    struct lu_fid *fid)
{
        struct osd_thread_info  *oti    = osd_oti_get(env);
        struct lu_buf           *buf    = &oti->oti_big_buf;
        struct dentry           *dentry = &oti->oti_obj_dentry;
        struct inode            *inode  = obj->oo_inode;
        struct linkea_data       ldata  = { NULL };
        int                      rc;
        ENTRY;

        fid_zero(fid);
        if (!S_ISDIR(inode->i_mode))
                RETURN(-EIO);

again:
        rc = __osd_xattr_get(inode, dentry, XATTR_NAME_LINK,
                             buf->lb_buf, buf->lb_len);
        if (rc == -ERANGE) {
                rc = __osd_xattr_get(inode, dentry, XATTR_NAME_LINK,
                                     NULL, 0);
                if (rc > 0) {
                        lu_buf_realloc(buf, rc);
                        if (buf->lb_buf == NULL)
                                RETURN(-ENOMEM);

                        goto again;
                }
        }

        if (unlikely(rc == 0))
                RETURN(-ENODATA);

        if (rc < 0)
                RETURN(rc);

        if (unlikely(buf->lb_buf == NULL)) {
                lu_buf_realloc(buf, rc);
                if (buf->lb_buf == NULL)
                        RETURN(-ENOMEM);

                goto again;
        }

        ldata.ld_buf = buf;
        rc = linkea_init_with_rec(&ldata);
        if (!rc) {
                linkea_first_entry(&ldata);
                linkea_entry_unpack(ldata.ld_lee, &ldata.ld_reclen, NULL, fid);
        }

        RETURN(rc);
}

static int osd_verify_ent_by_linkea(const struct lu_env *env,
                                    struct inode *inode,
                                    const struct lu_fid *pfid,
                                    const char *name, const int namelen)
{
        struct osd_thread_info *oti = osd_oti_get(env);
        struct lu_buf *buf = &oti->oti_big_buf;
        struct dentry *dentry = &oti->oti_obj_dentry;
        struct linkea_data ldata = { NULL };
        struct lu_name cname = { .ln_name = name,
                                 .ln_namelen = namelen };
        int rc;
        ENTRY;

again:
        rc = __osd_xattr_get(inode, dentry, XATTR_NAME_LINK,
                             buf->lb_buf, buf->lb_len);
        if (rc == -ERANGE)
                rc = __osd_xattr_get(inode, dentry, XATTR_NAME_LINK, NULL, 0);

        if (rc < 0)
                RETURN(rc);

        if (unlikely(rc == 0))
                RETURN(-ENODATA);

        if (buf->lb_len < rc) {
                lu_buf_realloc(buf, rc);
                if (buf->lb_buf == NULL)
                        RETURN(-ENOMEM);

                goto again;
        }

        ldata.ld_buf = buf;
        rc = linkea_init_with_rec(&ldata);
        if (!rc)
                rc = linkea_links_find(&ldata, &cname, pfid);

        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;
        struct htree_lock               *hlock = NULL;
        int                             ino;
        int                             rc;
        ENTRY;

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

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

        if (obj->oo_hl_head != NULL) {
                hlock = osd_oti_get(env)->oti_hlock;
                ldiskfs_htree_lock(hlock, obj->oo_hl_head,
                                   dir, LDISKFS_HLOCK_LOOKUP);
        } else {
                down_read(&obj->oo_ext_idx_sem);
        }

        bh = osd_ldiskfs_find_entry(dir, &dentry->d_name, &de, NULL, hlock);
        if (!IS_ERR(bh)) {
                struct osd_thread_info *oti = osd_oti_get(env);
                struct osd_inode_id *id = &oti->oti_id;
                struct osd_idmap_cache *oic = &oti->oti_cache;
                struct osd_device *dev = osd_obj2dev(obj);

                ino = le32_to_cpu(de->inode);
                if (OBD_FAIL_CHECK(OBD_FAIL_FID_LOOKUP)) {
                        brelse(bh);
                        rc = osd_fail_fid_lookup(oti, dev, oic, fid, ino);
                        GOTO(out, rc);
                }

                rc = osd_get_fid_from_dentry(de, rec);

                /* done with de, release bh */
                brelse(bh);
                if (rc != 0) {
                        if (unlikely(ino == osd_remote_parent_ino(dev))) {
                                const char *name = (const char *)key;

                                /* If the parent is on remote MDT, and there
                                 * is no FID-in-dirent, then we have to get
                                 * the parent FID from the linkEA.  */
                                if (likely(strlen(name) == 2 &&
                                           name[0] == '.' && name[1] == '.'))
                                        rc = osd_get_pfid_from_linkea(env, obj,
                                                                      fid);
                        } else {
                                rc = osd_ea_fid_get(env, obj, ino, fid, id);
                        }
                } else {
                        osd_id_gen(id, ino, OSD_OII_NOGEN);
                }

                if (rc != 0 || osd_remote_fid(env, dev, fid)) {
                        fid_zero(&oic->oic_fid);

                        GOTO(out, rc);
                }

                osd_add_oi_cache(osd_oti_get(env), osd_obj2dev(obj), id, fid);
                rc = osd_consistency_check(oti, dev, oic);
                if (rc != 0)
                        fid_zero(&oic->oic_fid);
        } else {
                rc = PTR_ERR(bh);
        }

        GOTO(out, rc);

out:
        if (hlock != NULL)
                ldiskfs_htree_unlock(hlock);
        else
                up_read(&obj->oo_ext_idx_sem);
        return rc;
}

static int osd_index_declare_ea_insert(const struct lu_env *env,
                                       struct dt_object *dt,
                                       const struct dt_rec *rec,
                                       const struct dt_key *key,
                                       struct thandle *handle)
{
        struct osd_thandle      *oh;
        struct osd_device       *osd   = osd_dev(dt->do_lu.lo_dev);
        struct dt_insert_rec    *rec1   = (struct dt_insert_rec *)rec;
        const struct lu_fid     *fid    = rec1->rec_fid;
        int                      credits, rc = 0;
        struct osd_idmap_cache  *idc;
        ENTRY;

        LASSERT(!dt_object_remote(dt));
        LASSERT(handle != NULL);
        LASSERT(fid != NULL);
        LASSERT(rec1->rec_type != 0);

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

        credits = osd_dto_credits_noquota[DTO_INDEX_INSERT];

        /* we can't call iget() while a transactions is running
         * (this can lead to a deadlock), but we need to know
         * inum and object type. so we find this information at
         * declaration and cache in per-thread info */
        idc = osd_idc_find_or_init(env, osd, fid);
        if (IS_ERR(idc))
                RETURN(PTR_ERR(idc));
        if (idc->oic_remote) {
                /* a reference to remote inode is represented by an
                 * agent inode which we have to create */
                credits += osd_dto_credits_noquota[DTO_OBJECT_CREATE];
                credits += osd_dto_credits_noquota[DTO_INDEX_INSERT];
        }

        osd_trans_declare_op(env, oh, OSD_OT_INSERT, credits);

        if (osd_dt_obj(dt)->oo_inode != NULL) {
                struct inode *inode = osd_dt_obj(dt)->oo_inode;

                /* We ignore block quota on meta pool (MDTs), so needn't
                 * calculate how many blocks will be consumed by this index
                 * insert */
                rc = osd_declare_inode_qid(env, i_uid_read(inode),
                                           i_gid_read(inode),
                                           i_projid_read(inode), 0,
                                           oh, osd_dt_obj(dt), NULL,
                                           OSD_QID_BLK);
        }

        RETURN(rc);
}

/**
 * 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,
                               int ignore_quota)
{
        struct osd_object       *obj = osd_dt_obj(dt);
        struct osd_device       *osd = osd_dev(dt->do_lu.lo_dev);
        struct dt_insert_rec    *rec1   = (struct dt_insert_rec *)rec;
        const struct lu_fid     *fid    = rec1->rec_fid;
        const char              *name = (const char *)key;
        struct osd_thread_info  *oti   = osd_oti_get(env);
        struct inode            *child_inode = NULL;
        struct osd_idmap_cache  *idc;
        int                     rc;
        ENTRY;

        if (!dt_object_exists(dt))
                RETURN(-ENOENT);

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

        osd_trans_exec_op(env, th, OSD_OT_INSERT);

        LASSERTF(fid_is_sane(fid), "fid"DFID" is insane!\n", PFID(fid));

        idc = osd_idc_find(env, osd, fid);
        if (unlikely(idc == NULL)) {
                /* this dt_insert() wasn't declared properly, so
                 * FID is missing in OI cache. we better do not
                 * lookup FID in FLDB/OI and don't risk to deadlock,
                 * but in some special cases (lfsck testing, etc)
                 * it's much simpler than fixing a caller */
                CERROR("%s: "DFID" wasn't declared for insert\n",
                       osd_name(osd), PFID(fid));
                dump_stack();
                idc = osd_idc_find_or_init(env, osd, fid);
                if (IS_ERR(idc))
                        RETURN(PTR_ERR(idc));
        }

        if (idc->oic_remote) {
                /* Insert remote entry */
                if (strcmp(name, dotdot) == 0 && strlen(name) == 2) {
                        struct osd_mdobj_map    *omm = osd->od_mdt_map;
                        struct osd_thandle      *oh;

                        /* If parent on remote MDT, we need put this object
                         * under AGENT */
                        oh = container_of(th, typeof(*oh), ot_super);
                        rc = osd_add_to_remote_parent(env, osd, obj, oh);
                        if (rc != 0) {
                                CERROR("%s: add "DFID" error: rc = %d\n",
                                       osd_name(osd),
                                       PFID(lu_object_fid(&dt->do_lu)), rc);
                                RETURN(rc);
                        }

                        child_inode = igrab(omm->omm_remote_parent->d_inode);
                } else {
                        child_inode = osd_create_local_agent_inode(env, osd,
                                        obj, fid, rec1->rec_type & S_IFMT, th);
                        if (IS_ERR(child_inode))
                                RETURN(PTR_ERR(child_inode));
                }
        } else {
                /* Insert local entry */
                if (unlikely(idc->oic_lid.oii_ino == 0)) {
                        /* for a reason OI cache wasn't filled properly */
                        CERROR("%s: OIC for "DFID" isn't filled\n",
                               osd_name(osd), PFID(fid));
                        RETURN(-EINVAL);
                }
                child_inode = oti->oti_inode;
                if (unlikely(child_inode == NULL)) {
                        struct ldiskfs_inode_info *lii;
                        OBD_ALLOC_PTR(lii);
                        if (lii == NULL)
                                RETURN(-ENOMEM);
                        child_inode = oti->oti_inode = &lii->vfs_inode;
                }
                child_inode->i_sb = osd_sb(osd);
                child_inode->i_ino = idc->oic_lid.oii_ino;
                child_inode->i_mode = rec1->rec_type & S_IFMT;
        }

        rc = osd_ea_add_rec(env, obj, child_inode, name, fid, th);

        CDEBUG(D_INODE, "parent %lu insert %s:%lu rc = %d\n",
               obj->oo_inode->i_ino, name, child_inode->i_ino, rc);

        if (child_inode && child_inode != oti->oti_inode)
                iput(child_inode);
        LASSERT(osd_invariant(obj));
        osd_trans_exec_check(env, th, OSD_OT_INSERT);
        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,
                                     __u32 unused)
{
        struct osd_it_iam      *it;
        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;

        if (!dt_object_exists(dt))
                return ERR_PTR(-ENOENT);

        OBD_ALLOC_PTR(it);
        if (it == NULL)
                return ERR_PTR(-ENOMEM);

        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;
        } else {
                OBD_FREE_PTR(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);
        osd_object_put(env, obj);
        OBD_FREE_PTR(it);
}

/**
 *  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_thread_info  *oti = osd_oti_get(env);
        struct osd_it_iam       *it = (struct osd_it_iam *)di;

        if (fid_is_quota(lu_object_fid(&it->oi_obj->oo_dt.do_lu))) {
                /* swab quota uid/gid */
                oti->oti_quota_id = cpu_to_le64(*((__u64 *)key));
                key = (struct dt_key *)&oti->oti_quota_id;
        }

        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_thread_info *oti = osd_oti_get(env);
        struct osd_it_iam      *it = (struct osd_it_iam *)di;
        struct osd_object      *obj = it->oi_obj;
        struct dt_key          *key;

        key = (struct dt_key *)iam_it_key_get(&it->oi_it);

        if (!IS_ERR(key) && fid_is_quota(lu_object_fid(&obj->oo_dt.do_lu))) {
                /* swab quota uid/gid */
                oti->oti_quota_id = le64_to_cpu(*((__u64 *)key));
                key = (struct dt_key *)&oti->oti_quota_id;
        }

        return key;
}

/**
 * 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, int len, __u16 type)
{
        /* check if file type is required */
        if (ent->lde_attrs & LUDA_TYPE) {
                struct luda_type *lt;
                int align = sizeof(*lt) - 1;

                len = (len + align) & ~align;
                lt = (struct luda_type *)(ent->lde_name + len);
                lt->lt_type = cpu_to_le16(DTTOIF(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)
{
        ent->lde_attrs = attr | LUDA_FID;
        fid_cpu_to_le(&ent->lde_fid, 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_name[namelen] = '\0';
        ent->lde_namelen = cpu_to_le16(namelen);

        /* append lustre attributes */
        osd_it_append_attrs(ent, 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 dt_rec *dtrec, __u32 attr)
{
        struct osd_it_iam      *it   = (struct osd_it_iam *)di;
        struct osd_thread_info *info = osd_oti_get(env);
        ENTRY;

        if (S_ISDIR(it->oi_obj->oo_inode->i_mode)) {
                const struct osd_fid_pack *rec;
                struct lu_fid             *fid = &info->oti_fid;
                struct lu_dirent          *lde = (struct lu_dirent *)dtrec;
                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);
        } else if (fid_is_quota(lu_object_fid(&it->oi_obj->oo_dt.do_lu))) {
                iam_reccpy(&it->oi_it.ii_path.ip_leaf,
                           (struct iam_rec *)dtrec);
                osd_quota_unpack(it->oi_obj, dtrec);
        } else {
                iam_reccpy(&it->oi_it.ii_path.ip_leaf,
                           (struct iam_rec *)dtrec);
        }

        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_declare_insert = osd_index_declare_iam_insert,
        .dio_insert         = osd_index_iam_insert,
        .dio_declare_delete = osd_index_declare_iam_delete,
        .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,
                                    __u32 attr)
{
        struct osd_object       *obj  = osd_dt_obj(dt);
        struct osd_thread_info  *info = osd_oti_get(env);
        struct osd_it_ea        *oie;
        struct file             *file;
        struct lu_object        *lo   = &dt->do_lu;
        struct dentry           *obj_dentry;
        ENTRY;

        if (!dt_object_exists(dt) || obj->oo_destroyed)
                RETURN(ERR_PTR(-ENOENT));

        OBD_SLAB_ALLOC_PTR_GFP(oie, osd_itea_cachep, GFP_NOFS);
        if (oie == NULL)
                RETURN(ERR_PTR(-ENOMEM));
        obj_dentry = &oie->oie_dentry;

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

        oie->oie_rd_dirent       = 0;
        oie->oie_it_dirent       = 0;
        oie->oie_dirent          = NULL;
        if (unlikely(!info->oti_it_ea_buf_used)) {
                oie->oie_buf = info->oti_it_ea_buf;
                info->oti_it_ea_buf_used = 1;
        } else {
                OBD_ALLOC(oie->oie_buf, OSD_IT_EA_BUFSIZE);
                if (oie->oie_buf == NULL)
                        RETURN(ERR_PTR(-ENOMEM));
        }
        oie->oie_obj             = obj;

        file = &oie->oie_file;

        /* Only FMODE_64BITHASH or FMODE_32BITHASH should be set, NOT both. */
        if (attr & LUDA_64BITHASH)
                file->f_mode    = FMODE_64BITHASH;
        else
                file->f_mode    = FMODE_32BITHASH;
        file->f_path.dentry     = obj_dentry;
        file->f_mapping         = obj->oo_inode->i_mapping;
        file->f_op              = obj->oo_inode->i_fop;
        set_file_inode(file, obj->oo_inode);

        lu_object_get(lo);
        RETURN((struct dt_it *) oie);
}

/**
 * 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_thread_info  *info = osd_oti_get(env);
        struct osd_it_ea        *oie    = (struct osd_it_ea *)di;
        struct osd_object       *obj    = oie->oie_obj;
        struct inode            *inode  = obj->oo_inode;

        ENTRY;
        oie->oie_file.f_op->release(inode, &oie->oie_file);
        osd_object_put(env, obj);
        if (unlikely(oie->oie_buf != info->oti_it_ea_buf))
                OBD_FREE(oie->oie_buf, OSD_IT_EA_BUFSIZE);
        else
                info->oti_it_ea_buf_used = 0;
        OBD_SLAB_FREE_PTR(oie, osd_itea_cachep);
        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)
{
}

struct osd_filldir_cbs {
#ifdef HAVE_DIR_CONTEXT
        struct dir_context ctx;
#endif
        struct osd_it_ea  *it;
};
/**
 * 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
 */
#ifdef HAVE_FILLDIR_USE_CTX
static int osd_ldiskfs_filldir(struct dir_context *buf,
#else
static int osd_ldiskfs_filldir(void *buf,
#endif
                               const char *name, int namelen,
                               loff_t offset, __u64 ino, unsigned d_type)
{
        struct osd_it_ea        *it   =
                ((struct osd_filldir_cbs *)buf)->it;
        struct osd_object       *obj  = it->oie_obj;
        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);

        /* "." is just the object itself. */
        if (namelen == 1 && name[0] == '.') {
                *fid = obj->oo_dt.do_lu.lo_header->loh_fid;
        } else if (d_type & LDISKFS_DIRENT_LUFID) {
                rec = (struct osd_fid_pack*) (name + namelen + 1);
                if (osd_fid_unpack(fid, rec) != 0)
                        fid_zero(fid);
        } else {
                fid_zero(fid);
        }
        d_type &= ~LDISKFS_DIRENT_LUFID;

        /* NOT export local root. */
        if (unlikely(osd_sb(osd_obj2dev(obj))->s_root->d_inode->i_ino == ino)) {
                ino = obj->oo_inode->i_ino;
                *fid = obj->oo_dt.do_lu.lo_header->loh_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
 * \retval +1 reach the end of entry
 */
static int osd_ldiskfs_it_fill(const struct lu_env *env,
                               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;
        struct htree_lock  *hlock = NULL;
        struct file        *filp  = &it->oie_file;
        int                 rc = 0;
        struct osd_filldir_cbs buf = {
#ifdef HAVE_DIR_CONTEXT
                .ctx.actor = osd_ldiskfs_filldir,
#endif
                .it = it
        };

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

        if (obj->oo_hl_head != NULL) {
                hlock = osd_oti_get(env)->oti_hlock;
                ldiskfs_htree_lock(hlock, obj->oo_hl_head,
                                   inode, LDISKFS_HLOCK_READDIR);
        } else {
                down_read(&obj->oo_ext_idx_sem);
        }

#ifdef HAVE_DIR_CONTEXT
        buf.ctx.pos = filp->f_pos;
        rc = inode->i_fop->iterate(filp, &buf.ctx);
        filp->f_pos = buf.ctx.pos;
#else
        rc = inode->i_fop->readdir(filp, &buf, osd_ldiskfs_filldir);
#endif

        if (hlock != NULL)
                ldiskfs_htree_unlock(hlock);
        else
                up_read(&obj->oo_ext_idx_sem);

        if (it->oie_rd_dirent == 0) {
                /*If it does not get any dirent, it means it has been reached
                 *to the end of the dir */
                it->oie_file.f_pos = ldiskfs_get_htree_eof(&it->oie_file);
                if (rc == 0)
                        rc = 1;
        } else {
                it->oie_dirent = it->oie_buf;
                it->oie_it_dirent = 1;
        }

        RETURN(rc);
}

/**
 * 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_get_htree_eof(&it->oie_file))
                        rc = +1;
                else
                        rc = osd_ldiskfs_it_fill(env, 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;

        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;

        return it->oie_dirent->oied_namelen;
}

static inline bool osd_dotdot_has_space(struct ldiskfs_dir_entry_2 *de)
{
        if (LDISKFS_DIR_REC_LEN(de) >=
            __LDISKFS_DIR_REC_LEN(2 + 1 + sizeof(struct osd_fid_pack)))
                return true;

        return false;
}

static inline bool
osd_dirent_has_space(struct ldiskfs_dir_entry_2 *de, __u16 namelen,
                     unsigned blocksize, bool dotdot)
{
        if (dotdot)
                return osd_dotdot_has_space(de);

        if (ldiskfs_rec_len_from_disk(de->rec_len, blocksize) >=
            __LDISKFS_DIR_REC_LEN(namelen + 1 + sizeof(struct osd_fid_pack)))
                return true;

        return false;
}

static int
osd_dirent_reinsert(const struct lu_env *env, struct osd_device *dev,
                    handle_t *jh, struct dentry *dentry,
                    const struct lu_fid *fid, struct buffer_head *bh,
                    struct ldiskfs_dir_entry_2 *de, struct htree_lock *hlock,
                    bool dotdot)
{
        struct inode                *dir        = dentry->d_parent->d_inode;
        struct inode                *inode      = dentry->d_inode;
        struct osd_fid_pack         *rec;
        struct ldiskfs_dentry_param *ldp;
        int                          namelen    = dentry->d_name.len;
        int                          rc;
        struct osd_thread_info     *info        = osd_oti_get(env);
        ENTRY;

        if (!LDISKFS_HAS_INCOMPAT_FEATURE(inode->i_sb,
                                          LDISKFS_FEATURE_INCOMPAT_DIRDATA))
                RETURN(0);

        /* There is enough space to hold the FID-in-dirent. */
        if (osd_dirent_has_space(de, namelen, dir->i_sb->s_blocksize, dotdot)) {
                rc = ldiskfs_journal_get_write_access(jh, bh);
                if (rc != 0)
                        RETURN(rc);

                de->name[namelen] = 0;
                rec = (struct osd_fid_pack *)(de->name + namelen + 1);
                rec->fp_len = sizeof(struct lu_fid) + 1;
                fid_cpu_to_be((struct lu_fid *)rec->fp_area, fid);
                de->file_type |= LDISKFS_DIRENT_LUFID;
                rc = ldiskfs_handle_dirty_metadata(jh, NULL, bh);

                RETURN(rc);
        }

        LASSERT(!dotdot);

        rc = ldiskfs_delete_entry(jh, dir, de, bh);
        if (rc != 0)
                RETURN(rc);

        ldp = (struct ldiskfs_dentry_param *)osd_oti_get(env)->oti_ldp;
        osd_get_ldiskfs_dirent_param(ldp, fid);
        dentry->d_fsdata = (void *)ldp;
        ll_vfs_dq_init(dir);
        rc = osd_ldiskfs_add_entry(info, dev, jh, dentry, inode, hlock);
        /* It is too bad, we cannot reinsert the name entry back.
         * That means we lose it! */
        if (rc != 0)
                CDEBUG(D_LFSCK, "%s: fail to reinsert the dirent, "
                       "dir = %lu/%u, name = %.*s, "DFID": rc = %d\n",
                       osd_ino2name(inode),
                       dir->i_ino, dir->i_generation, namelen,
                       dentry->d_name.name, PFID(fid), rc);

        RETURN(rc);
}

static int
osd_dirent_check_repair(const struct lu_env *env, struct osd_object *obj,
                        struct osd_it_ea *it, struct lu_fid *fid,
                        struct osd_inode_id *id, __u32 *attr)
{
        struct osd_thread_info     *info        = osd_oti_get(env);
        struct lustre_mdt_attrs    *lma         = &info->oti_ost_attrs.loa_lma;
        struct osd_device          *dev         = osd_obj2dev(obj);
        struct super_block         *sb          = osd_sb(dev);
        const char                 *devname     = osd_name(dev);
        struct osd_it_ea_dirent    *ent         = it->oie_dirent;
        struct inode               *dir         = obj->oo_inode;
        struct htree_lock          *hlock       = NULL;
        struct buffer_head         *bh          = NULL;
        handle_t                   *jh          = NULL;
        struct ldiskfs_dir_entry_2 *de;
        struct dentry              *dentry;
        struct inode               *inode;
        const struct lu_fid *pfid = lu_object_fid(&obj->oo_dt.do_lu);
        int                         credits;
        int                         rc;
        bool                        dotdot      = false;
        bool                        dirty       = false;
        ENTRY;

        if (ent->oied_name[0] == '.') {
                if (ent->oied_namelen == 1)
                        RETURN(0);

                if (ent->oied_namelen == 2 && ent->oied_name[1] == '.')
                        dotdot = true;
        }

        osd_id_gen(id, ent->oied_ino, OSD_OII_NOGEN);
        inode = osd_iget(info, dev, id);
        if (IS_ERR(inode)) {
                rc = PTR_ERR(inode);
                if (rc == -ENOENT || rc == -ESTALE) {
                        /* Maybe dangling name entry, or
                         * corrupted directory entry. */
                        *attr |= LUDA_UNKNOWN;
                        rc = 0;
                } else {
                        CDEBUG(D_LFSCK, "%s: fail to iget() for dirent "
                               "check_repair, dir = %lu/%u, name = %.*s, "
                               "ino = %llu, rc = %d\n",
                               devname, dir->i_ino, dir->i_generation,
                               ent->oied_namelen, ent->oied_name,
                               ent->oied_ino, rc);
                }

                RETURN(rc);
        }

        dentry = osd_child_dentry_by_inode(env, dir, ent->oied_name,
                                           ent->oied_namelen);
        rc = osd_get_lma(info, inode, dentry, &info->oti_ost_attrs);
        if (rc == -ENODATA || !fid_is_sane(&lma->lma_self_fid))
                lma = NULL;
        else if (rc != 0)
                GOTO(out, rc);

        /* We need to ensure that the name entry is still valid.
         * Because it may be removed or renamed by other already.
         *
         * The unlink or rename operation will start journal before PDO lock,
         * so to avoid deadlock, here we need to start journal handle before
         * related PDO lock also. But because we do not know whether there
         * will be something to be repaired before PDO lock, we just start
         * journal without conditions.
         *
         * We may need to remove the name entry firstly, then insert back.
         * One credit is for user quota file update.
         * One credit is for group quota file update.
         * Two credits are for dirty inode. */
        credits = osd_dto_credits_noquota[DTO_INDEX_DELETE] +
                  osd_dto_credits_noquota[DTO_INDEX_INSERT] + 1 + 1 + 2;

        if (dev->od_dirent_journal != 0) {

again:
                jh = osd_journal_start_sb(sb, LDISKFS_HT_MISC, credits);
                if (IS_ERR(jh)) {
                        rc = PTR_ERR(jh);
                        CDEBUG(D_LFSCK, "%s: fail to start trans for dirent "
                               "check_repair, dir = %lu/%u, credits = %d, "
                               "name = %.*s, ino = %llu: rc = %d\n",
                               devname, dir->i_ino, dir->i_generation, credits,
                               ent->oied_namelen, ent->oied_name,
                               ent->oied_ino, rc);

                        GOTO(out_inode, rc);
                }

                if (obj->oo_hl_head != NULL) {
                        hlock = osd_oti_get(env)->oti_hlock;
                        /* "0" means exclusive lock for the whole directory.
                         * We need to prevent others access such name entry
                         * during the delete + insert. Neither HLOCK_ADD nor
                         * HLOCK_DEL cannot guarantee the atomicity. */
                        ldiskfs_htree_lock(hlock, obj->oo_hl_head, dir, 0);
                } else {
                        down_write(&obj->oo_ext_idx_sem);
                }
        } else {
                if (obj->oo_hl_head != NULL) {
                        hlock = osd_oti_get(env)->oti_hlock;
                        ldiskfs_htree_lock(hlock, obj->oo_hl_head, dir,
                                           LDISKFS_HLOCK_LOOKUP);
                } else {
                        down_read(&obj->oo_ext_idx_sem);
                }
        }

        bh = osd_ldiskfs_find_entry(dir, &dentry->d_name, &de, NULL, hlock);
        if (IS_ERR(bh) || le32_to_cpu(de->inode) != inode->i_ino) {
                *attr |= LUDA_IGNORE;

                GOTO(out, rc = 0);
        }

        /* For dotdot entry, if there is not enough space to hold the
         * FID-in-dirent, just keep them there. It only happens when the
         * device upgraded from 1.8 or restored from MDT file-level backup.
         * For the whole directory, only dotdot entry have no FID-in-dirent
         * and needs to get FID from LMA when readdir, it will not affect the
         * performance much. */
        if (dotdot && !osd_dotdot_has_space(de)) {
                *attr |= LUDA_UNKNOWN;

                GOTO(out, rc = 0);
        }

        if (lma != NULL) {
                if (lu_fid_eq(fid, &lma->lma_self_fid))
                        GOTO(out, rc = 0);

                if (unlikely(lma->lma_compat & LMAC_NOT_IN_OI)) {
                        struct lu_fid *tfid = &lma->lma_self_fid;

                        if (likely(dotdot &&
                                   fid_seq(tfid) == FID_SEQ_LOCAL_FILE &&
                                   fid_oid(tfid) == REMOTE_PARENT_DIR_OID)) {
                                /* It must be REMOTE_PARENT_DIR and as the
                                 * 'dotdot' entry of remote directory */
                                *attr |= LUDA_IGNORE;
                        } else {
                                CDEBUG(D_LFSCK, "%s: expect remote agent "
                                       "parent directory, but got %.*s under "
                                       "dir = %lu/%u with the FID "DFID"\n",
                                       devname, ent->oied_namelen,
                                       ent->oied_name, dir->i_ino,
                                       dir->i_generation, PFID(tfid));

                                *attr |= LUDA_UNKNOWN;
                        }

                        GOTO(out, rc = 0);
                }
        }

        if (!fid_is_zero(fid)) {
                rc = osd_verify_ent_by_linkea(env, inode, pfid, ent->oied_name,
                                              ent->oied_namelen);
                if (rc == -ENOENT ||
                    (rc == -ENODATA &&
                     !(dev->od_scrub.os_file.sf_flags & SF_UPGRADE))) {
                        /* linkEA does not recognize the dirent entry,
                         * it may because the dirent entry corruption
                         * and points to other's inode. */
                        CDEBUG(D_LFSCK, "%s: the target inode does not "
                               "recognize the dirent, dir = %lu/%u, "
                               " name = %.*s, ino = %llu, "
                               DFID": rc = %d\n", devname, dir->i_ino,
                               dir->i_generation, ent->oied_namelen,
                               ent->oied_name, ent->oied_ino, PFID(fid), rc);
                        *attr |= LUDA_UNKNOWN;

                        GOTO(out, rc = 0);
                }

                if (rc && rc != -ENODATA) {
                        CDEBUG(D_LFSCK, "%s: fail to verify FID in the dirent, "
                               "dir = %lu/%u, name = %.*s, ino = %llu, "
                               DFID": rc = %d\n", devname, dir->i_ino,
                               dir->i_generation, ent->oied_namelen,
                               ent->oied_name, ent->oied_ino, PFID(fid), rc);
                        *attr |= LUDA_UNKNOWN;

                        GOTO(out, rc = 0);
                }
        }

        if (lma != NULL) {
                /* linkEA recognizes the dirent entry, the FID-in-LMA is
                 * valid, trusted, in spite of fid_is_sane(fid) or not. */
                if (*attr & LUDA_VERIFY_DRYRUN) {
                        *fid = lma->lma_self_fid;
                        *attr |= LUDA_REPAIR;

                        GOTO(out, rc = 0);
                }

                if (jh == NULL) {
                        brelse(bh);
                        dev->od_dirent_journal = 1;
                        if (hlock != NULL) {
                                ldiskfs_htree_unlock(hlock);
                                hlock = NULL;
                        } else {
                                up_read(&obj->oo_ext_idx_sem);
                        }

                        goto again;
                }

                *fid = lma->lma_self_fid;
                dirty = true;
                /* Update or append the FID-in-dirent. */
                rc = osd_dirent_reinsert(env, dev, jh, dentry, fid,
                                         bh, de, hlock, dotdot);
                if (rc == 0)
                        *attr |= LUDA_REPAIR;
                else
                        CDEBUG(D_LFSCK, "%s: fail to re-insert FID after "
                               "the dirent, dir = %lu/%u, name = %.*s, "
                               "ino = %llu, "DFID": rc = %d\n",
                               devname, dir->i_ino, dir->i_generation,
                               ent->oied_namelen, ent->oied_name,
                               ent->oied_ino, PFID(fid), rc);
        } else {
                /* lma is NULL, trust the FID-in-dirent if it is valid. */
                if (*attr & LUDA_VERIFY_DRYRUN) {
                        if (fid_is_sane(fid)) {
                                *attr |= LUDA_REPAIR;
                        } else if (dev->od_index == 0) {
                                lu_igif_build(fid, inode->i_ino,
                                              inode->i_generation);
                                *attr |= LUDA_UPGRADE;
                        }

                        GOTO(out, rc = 0);
                }

                if (jh == NULL) {
                        brelse(bh);
                        dev->od_dirent_journal = 1;
                        if (hlock != NULL) {
                                ldiskfs_htree_unlock(hlock);
                                hlock = NULL;
                        } else {
                                up_read(&obj->oo_ext_idx_sem);
                        }

                        goto again;
                }

                dirty = true;
                if (unlikely(fid_is_sane(fid))) {
                        /* FID-in-dirent exists, but FID-in-LMA is lost.
                         * Trust the FID-in-dirent, and add FID-in-LMA. */
                        rc = osd_ea_fid_set(info, inode, fid, 0, 0);
                        if (rc == 0)
                                *attr |= LUDA_REPAIR;
                        else
                                CDEBUG(D_LFSCK, "%s: fail to set LMA for "
                                       "update dirent, dir = %lu/%u, "
                                       "name = %.*s, ino = %llu, "
                                       DFID": rc = %d\n",
                                       devname, dir->i_ino, dir->i_generation,
                                       ent->oied_namelen, ent->oied_name,
                                       ent->oied_ino, PFID(fid), rc);
                } else if (dev->od_index == 0) {
                        lu_igif_build(fid, inode->i_ino, inode->i_generation);
                        /* It is probably IGIF object. Only aappend the
                         * FID-in-dirent. OI scrub will process FID-in-LMA. */
                        rc = osd_dirent_reinsert(env, dev, jh, dentry, fid,
                                                 bh, de, hlock, dotdot);
                        if (rc == 0)
                                *attr |= LUDA_UPGRADE;
                        else
                                CDEBUG(D_LFSCK, "%s: fail to append IGIF "
                                       "after the dirent, dir = %lu/%u, "
                                       "name = %.*s, ino = %llu, "
                                       DFID": rc = %d\n",
                                       devname, dir->i_ino, dir->i_generation,
                                       ent->oied_namelen, ent->oied_name,
                                       ent->oied_ino, PFID(fid), rc);
                }
        }

        GOTO(out, rc);

out:
        if (!IS_ERR(bh))
                brelse(bh);
        if (hlock != NULL) {
                ldiskfs_htree_unlock(hlock);
        } else {
                if (dev->od_dirent_journal != 0)
                        up_write(&obj->oo_ext_idx_sem);
                else
                        up_read(&obj->oo_ext_idx_sem);
        }

        if (jh != NULL)
                ldiskfs_journal_stop(jh);

out_inode:
        iput(inode);
        if (rc >= 0 && !dirty)
                dev->od_dirent_journal = 0;

        return rc;
}

/**
 * Returns the value 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 dt_rec *dtrec, __u32 attr)
{
        struct osd_it_ea       *it    = (struct osd_it_ea *)di;
        struct osd_object      *obj   = it->oie_obj;
        struct osd_device      *dev   = osd_obj2dev(obj);
        struct osd_thread_info *oti   = osd_oti_get(env);
        struct osd_inode_id    *id    = &oti->oti_id;
        struct lu_fid          *fid   = &it->oie_dirent->oied_fid;
        struct lu_dirent       *lde   = (struct lu_dirent *)dtrec;
        __u32                   ino   = it->oie_dirent->oied_ino;
        int                     rc    = 0;
        ENTRY;

        LASSERT(obj->oo_inode != dev->od_mdt_map->omm_remote_parent->d_inode);

        if (attr & LUDA_VERIFY) {
                if (unlikely(ino == osd_remote_parent_ino(dev))) {
                        attr |= LUDA_IGNORE;
                        /* If the parent is on remote MDT, and there
                         * is no FID-in-dirent, then we have to get
                         * the parent FID from the linkEA.  */
                        if (!fid_is_sane(fid) &&
                            it->oie_dirent->oied_namelen == 2 &&
                            it->oie_dirent->oied_name[0] == '.' &&
                            it->oie_dirent->oied_name[1] == '.')
                                osd_get_pfid_from_linkea(env, obj, fid);
                } else {
                        rc = osd_dirent_check_repair(env, obj, it, fid, id,
                                                     &attr);
                }

                if (!fid_is_sane(fid))
                        attr |= LUDA_UNKNOWN;
        } else {
                attr &= ~LU_DIRENT_ATTRS_MASK;
                if (!fid_is_sane(fid)) {
                        bool is_dotdot = false;
                        if (it->oie_dirent->oied_namelen == 2 &&
                            it->oie_dirent->oied_name[0] == '.' &&
                            it->oie_dirent->oied_name[1] == '.')
                                is_dotdot = true;
                        /* If the parent is on remote MDT, and there
                         * is no FID-in-dirent, then we have to get
                         * the parent FID from the linkEA.  */
                        if (ino == osd_remote_parent_ino(dev) && is_dotdot) {
                                rc = osd_get_pfid_from_linkea(env, obj, fid);
                        } else {
                                if (is_dotdot == false &&
                                    OBD_FAIL_CHECK(OBD_FAIL_FID_LOOKUP))
                                        RETURN(-ENOENT);

                                rc = osd_ea_fid_get(env, obj, ino, fid, id);
                        }
                } else {
                        osd_id_gen(id, ino, OSD_OII_NOGEN);
                }
        }

        /* Pack the entry anyway, at least the offset is right. */
        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);

        if (rc < 0)
                RETURN(rc);

        if (osd_remote_fid(env, dev, fid))
                RETURN(0);

        if (likely(!(attr & (LUDA_IGNORE | LUDA_UNKNOWN)) && rc == 0))
                osd_add_oi_cache(oti, dev, id, fid);

        RETURN(rc > 0 ? 0 : rc);
}

/**
 * Returns the record size size at current position.
 *
 * This function will return record(lu_dirent) size in bytes.
 *
 * \param[in] env       execution environment
 * \param[in] di        iterator's in memory structure
 * \param[in] attr      attribute of the entry, only requires LUDA_TYPE to
 *                      calculate the lu_dirent size.
 *
 * \retval      record size(in bytes & in memory) of the current lu_dirent
 *              entry.
 */
static int osd_it_ea_rec_size(const struct lu_env *env, const struct dt_it *di,
                              __u32 attr)
{
        struct osd_it_ea *it = (struct osd_it_ea *)di;

        return lu_dirent_calc_size(it->oie_dirent->oied_namelen, attr);
}

/**
 * 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;

        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(env, di);
        if (rc > 0)
                rc = -ENODATA;

        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 osd_object *obj = osd_dt_obj(dt);
        int rc = 0;

        ENTRY;

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

        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_declare_insert = osd_index_declare_ea_insert,
        .dio_insert         = osd_index_ea_insert,
        .dio_declare_delete = osd_index_declare_ea_delete,
        .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,
                .rec_size = osd_it_ea_rec_size,
                .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)
                return ERR_PTR(-ENOMEM);

        OBD_ALLOC(info->oti_it_ea_buf, OSD_IT_EA_BUFSIZE);
        if (info->oti_it_ea_buf == NULL)
                goto out_free_info;

        info->oti_env = container_of(ctx, struct lu_env, le_ctx);

        info->oti_hlock = ldiskfs_htree_lock_alloc();
        if (info->oti_hlock == NULL)
                goto out_free_ea;

        return info;

 out_free_ea:
        OBD_FREE(info->oti_it_ea_buf, OSD_IT_EA_BUFSIZE);
 out_free_info:
        OBD_FREE_PTR(info);
        return ERR_PTR(-ENOMEM);
}

static void osd_key_fini(const struct lu_context *ctx,
                         struct lu_context_key *key, void* data)
{
        struct osd_thread_info *info = data;
        struct ldiskfs_inode_info *lli = LDISKFS_I(info->oti_inode);
        struct osd_idmap_cache  *idc = info->oti_ins_cache;

        if (info->oti_inode != NULL)
                OBD_FREE_PTR(lli);
        if (info->oti_hlock != NULL)
                ldiskfs_htree_lock_free(info->oti_hlock);
        OBD_FREE(info->oti_it_ea_buf, OSD_IT_EA_BUFSIZE);
        lu_buf_free(&info->oti_iobuf.dr_pg_buf);
        lu_buf_free(&info->oti_iobuf.dr_bl_buf);
        lu_buf_free(&info->oti_big_buf);
        if (idc != NULL) {
                LASSERT(info->oti_ins_cache_size > 0);
                OBD_FREE(idc, sizeof(*idc) * info->oti_ins_cache_size);
                info->oti_ins_cache = NULL;
                info->oti_ins_cache_size = 0;
        }
        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);

struct lu_context_key osd_key = {
        .lct_tags = LCT_DT_THREAD | LCT_MD_THREAD | LCT_MG_THREAD | LCT_LOCAL,
        .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)
{
        struct osd_device *osd = osd_dev(d);

        if (strlcpy(osd->od_svname, name, sizeof(osd->od_svname))
            >= sizeof(osd->od_svname))
                return -E2BIG;
        return osd_procfs_init(osd, name);
}

static int osd_fid_init(const struct lu_env *env, struct osd_device *osd)
{
        struct seq_server_site  *ss = osd_seq_site(osd);
        int                     rc;
        ENTRY;

        if (osd->od_is_ost || osd->od_cl_seq != NULL)
                RETURN(0);

        if (unlikely(ss == NULL))
                RETURN(-ENODEV);

        OBD_ALLOC_PTR(osd->od_cl_seq);
        if (osd->od_cl_seq == NULL)
                RETURN(-ENOMEM);

        rc = seq_client_init(osd->od_cl_seq, NULL, LUSTRE_SEQ_METADATA,
                             osd->od_svname, ss->ss_server_seq);
        if (rc != 0) {
                OBD_FREE_PTR(osd->od_cl_seq);
                osd->od_cl_seq = NULL;
                RETURN(rc);
        }

        if (ss->ss_node_id == 0) {
                /* If the OSD on the sequence controller(MDT0), then allocate
                 * sequence here, otherwise allocate sequence after connected
                 * to MDT0 (see mdt_register_lwp_callback()). */
                rc = seq_server_alloc_meta(osd->od_cl_seq->lcs_srv,
                                   &osd->od_cl_seq->lcs_space, env);
        }

        RETURN(rc);
}

static void osd_fid_fini(const struct lu_env *env, struct osd_device *osd)
{
        if (osd->od_cl_seq == NULL)
                return;

        seq_client_fini(osd->od_cl_seq);
        OBD_FREE_PTR(osd->od_cl_seq);
        osd->od_cl_seq = NULL;
}

static int osd_shutdown(const struct lu_env *env, struct osd_device *o)
{
        ENTRY;

        /* shutdown quota slave instance associated with the device */
        if (o->od_quota_slave != NULL) {
                qsd_fini(env, o->od_quota_slave);
                o->od_quota_slave = NULL;
        }

        osd_fid_fini(env, o);

        RETURN(0);
}

static void osd_umount(const struct lu_env *env, struct osd_device *o)
{
        ENTRY;

        if (o->od_mnt != NULL) {
                shrink_dcache_sb(osd_sb(o));
                osd_sync(env, &o->od_dt_dev);

                mntput(o->od_mnt);
                o->od_mnt = NULL;
        }

        EXIT;
}

static int osd_mount(const struct lu_env *env,
                     struct osd_device *o, struct lustre_cfg *cfg)
{
        const char              *name  = lustre_cfg_string(cfg, 0);
        const char              *dev  = lustre_cfg_string(cfg, 1);
        const char              *opts;
        unsigned long            page, s_flags, lmd_flags = 0;
        struct page             *__page;
        struct file_system_type *type;
        char                    *options = NULL;
        char                    *str;
        struct osd_thread_info  *info = osd_oti_get(env);
        struct lu_fid           *fid = &info->oti_fid;
        struct inode            *inode;
        int                      rc = 0, force_over_512tb = 0;
        ENTRY;

        if (o->od_mnt != NULL)
                RETURN(0);

        if (strlen(dev) >= sizeof(o->od_mntdev))
                RETURN(-E2BIG);
        strcpy(o->od_mntdev, dev);

        str = lustre_cfg_string(cfg, 2);
        s_flags = simple_strtoul(str, NULL, 0);
        str = strstr(str, ":");
        if (str)
                lmd_flags = simple_strtoul(str + 1, NULL, 0);
        opts = lustre_cfg_string(cfg, 3);
#ifdef __BIG_ENDIAN
        if (opts == NULL || strstr(opts, "bigendian_extents") == NULL) {
                CERROR("%s: device %s extents feature is not guaranteed to "
                       "work on big-endian systems. Use \"bigendian_extents\" "
                       "mount option to override.\n", name, dev);
                RETURN(-EINVAL);
        }
#endif
#if LUSTRE_VERSION_CODE < OBD_OCD_VERSION(3, 0, 53, 0)
        if (opts != NULL && strstr(opts, "force_over_128tb") != NULL) {
                CWARN("force_over_128tb option is deprecated. "
                      "Filesystems less than 512TB can be created without any "
                      "force options. Use force_over_512tb option for "
                      "filesystems greater than 512TB.\n");
        }
#endif
#if LUSTRE_VERSION_CODE < OBD_OCD_VERSION(3, 1, 53, 0)
        if (opts != NULL && strstr(opts, "force_over_256tb") != NULL) {
                CWARN("force_over_256tb option is deprecated. "
                      "Filesystems less than 512TB can be created without any "
                      "force options. Use force_over_512tb option for "
                      "filesystems greater than 512TB.\n");
        }
#endif

        if (opts != NULL && strstr(opts, "force_over_512tb") != NULL)
                force_over_512tb = 1;

        __page = alloc_page(GFP_KERNEL);
        if (__page == NULL)
                GOTO(out, rc = -ENOMEM);
        page = (unsigned long)page_address(__page);
        options = (char *)page;
        *options = '\0';
        if (opts != NULL) {
                /* strip out the options for back compatiblity */
                static char *sout[] = {
                        "mballoc",
                        "iopen",
                        "noiopen",
                        "iopen_nopriv",
                        "extents",
                        "noextents",
                        /* strip out option we processed in osd */
                        "bigendian_extents",
                        "force_over_128tb",
                        "force_over_256tb",
                        "force_over_512tb",
                        NULL
                };
                strcat(options, opts);
                for (rc = 0, str = options; sout[rc]; ) {
                        char *op = strstr(str, sout[rc]);
                        if (op == NULL) {
                                rc++;
                                str = options;
                                continue;
                        }
                        if (op == options || *(op - 1) == ',') {
                                str = op + strlen(sout[rc]);
                                if (*str == ',' || *str == '\0') {
                                        *str == ',' ? str++ : str;
                                        memmove(op, str, strlen(str) + 1);
                                }
                        }
                        for (str = op; *str != ',' && *str != '\0'; str++)
                                ;
                }
        } else {
                strncat(options, "user_xattr,acl", 14);
        }

        /* Glom up mount options */
        if (*options != '\0')
                strcat(options, ",");
        strlcat(options, "no_mbcache,nodelalloc", PAGE_SIZE);

        type = get_fs_type("ldiskfs");
        if (!type) {
                CERROR("%s: cannot find ldiskfs module\n", name);
                GOTO(out, rc = -ENODEV);
        }

        o->od_mnt = vfs_kern_mount(type, s_flags, dev, options);
        module_put(type->owner);

        if (IS_ERR(o->od_mnt)) {
                rc = PTR_ERR(o->od_mnt);
                o->od_mnt = NULL;
                CERROR("%s: can't mount %s: %d\n", name, dev, rc);
                GOTO(out, rc);
        }

        if (ldiskfs_blocks_count(LDISKFS_SB(osd_sb(o))->s_es) <<
                                 osd_sb(o)->s_blocksize_bits > 512ULL << 40 &&
                                 force_over_512tb == 0) {
                CERROR("%s: device %s LDISKFS does not support filesystems "
                       "greater than 512TB and can cause data corruption. "
                       "Use \"force_over_512tb\" mount option to override.\n",
                       name, dev);
                GOTO(out_mnt, rc = -EINVAL);
        }

        if (lmd_flags & LMD_FLG_DEV_RDONLY) {
                if (priv_dev_set_rdonly) {
                        priv_dev_set_rdonly(osd_sb(o)->s_bdev);
                        o->od_dt_dev.dd_rdonly = 1;
                        LCONSOLE_WARN("%s: set dev_rdonly on this device\n",
                                      name);
                } else {
                        LCONSOLE_WARN("%s: not support dev_rdonly on this device",
                                      name);

                        GOTO(out_mnt, rc = -EOPNOTSUPP);
                }
        } else if (priv_dev_check_rdonly &&
                   priv_dev_check_rdonly(osd_sb(o)->s_bdev)) {
                CERROR("%s: underlying device %s is marked as "
                       "read-only. Setup failed\n", name, dev);

                GOTO(out_mnt, rc = -EROFS);
        }

        if (!LDISKFS_HAS_COMPAT_FEATURE(o->od_mnt->mnt_sb,
                                        LDISKFS_FEATURE_COMPAT_HAS_JOURNAL)) {
                CERROR("%s: device %s is mounted w/o journal\n", name, dev);
                GOTO(out_mnt, rc = -EINVAL);
        }

#ifdef LDISKFS_MOUNT_DIRDATA
        if (LDISKFS_HAS_INCOMPAT_FEATURE(o->od_mnt->mnt_sb,
                                         LDISKFS_FEATURE_INCOMPAT_DIRDATA))
                LDISKFS_SB(osd_sb(o))->s_mount_opt |= LDISKFS_MOUNT_DIRDATA;
        else if (!o->od_is_ost)
                CWARN("%s: device %s was upgraded from Lustre-1.x without "
                      "enabling the dirdata feature. If you do not want to "
                      "downgrade to Lustre-1.x again, you can enable it via "
                      "'tune2fs -O dirdata device'\n", name, dev);
#endif
        inode = osd_sb(o)->s_root->d_inode;
        lu_local_obj_fid(fid, OSD_FS_ROOT_OID);
        rc = osd_ea_fid_set(info, inode, fid, LMAC_NOT_IN_OI, 0);
        if (rc != 0) {
                CERROR("%s: failed to set lma on %s root inode\n", name, dev);
                GOTO(out_mnt, rc);
        }

        if (lmd_flags & LMD_FLG_NOSCRUB)
                o->od_noscrub = 1;

        GOTO(out, rc = 0);

out_mnt:
        mntput(o->od_mnt);
        o->od_mnt = NULL;

out:
        if (__page)
                __free_page(__page);

        return rc;
}

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

        osd_shutdown(env, o);
        osd_procfs_fini(o);
        osd_scrub_cleanup(env, o);
        osd_obj_map_fini(o);
        osd_umount(env, o);

        RETURN(NULL);
}

static int osd_device_init0(const struct lu_env *env,
                            struct osd_device *o,
                            struct lustre_cfg *cfg)
{
        struct lu_device        *l = osd2lu_dev(o);
        struct osd_thread_info *info;
        int                     rc;
        int                     cplen = 0;

        /* if the module was re-loaded, env can loose its keys */
        rc = lu_env_refill((struct lu_env *) env);
        if (rc)
                GOTO(out, rc);
        info = osd_oti_get(env);
        LASSERT(info);

        l->ld_ops = &osd_lu_ops;
        o->od_dt_dev.dd_ops = &osd_dt_ops;

        spin_lock_init(&o->od_osfs_lock);
        mutex_init(&o->od_otable_mutex);
        INIT_LIST_HEAD(&o->od_orphan_list);

        o->od_read_cache = 1;
        o->od_writethrough_cache = 1;
        o->od_readcache_max_filesize = OSD_MAX_CACHE_SIZE;

        cplen = strlcpy(o->od_svname, lustre_cfg_string(cfg, 4),
                        sizeof(o->od_svname));
        if (cplen >= sizeof(o->od_svname)) {
                rc = -E2BIG;
                GOTO(out, rc);
        }

        o->od_index = -1; /* -1 means index is invalid */
        rc = server_name2index(o->od_svname, &o->od_index, NULL);
        if (rc == LDD_F_SV_TYPE_OST)
                o->od_is_ost = 1;

        o->od_full_scrub_ratio = OFSR_DEFAULT;
        o->od_full_scrub_threshold_rate = FULL_SCRUB_THRESHOLD_RATE_DEFAULT;
        rc = osd_mount(env, o, cfg);
        if (rc != 0)
                GOTO(out, rc);

        rc = osd_obj_map_init(env, o);
        if (rc != 0)
                GOTO(out_mnt, rc);

        rc = lu_site_init(&o->od_site, l);
        if (rc != 0)
                GOTO(out_compat, rc);
        o->od_site.ls_bottom_dev = l;

        rc = lu_site_init_finish(&o->od_site);
        if (rc != 0)
                GOTO(out_site, rc);

        INIT_LIST_HEAD(&o->od_ios_list);
        /* setup scrub, including OI files initialization */
        rc = osd_scrub_setup(env, o);
        if (rc < 0)
                GOTO(out_site, rc);

        rc = osd_procfs_init(o, o->od_svname);
        if (rc != 0) {
                CERROR("%s: can't initialize procfs: rc = %d\n",
                       o->od_svname, rc);
                GOTO(out_scrub, rc);
        }

        LASSERT(l->ld_site->ls_linkage.next != NULL);
        LASSERT(l->ld_site->ls_linkage.prev != NULL);

        /* initialize quota slave instance */
        o->od_quota_slave = qsd_init(env, o->od_svname, &o->od_dt_dev,
                                     o->od_proc_entry);
        if (IS_ERR(o->od_quota_slave)) {
                rc = PTR_ERR(o->od_quota_slave);
                o->od_quota_slave = NULL;
                GOTO(out_procfs, rc);
        }

        RETURN(0);

out_procfs:
        osd_procfs_fini(o);
out_scrub:
        osd_scrub_cleanup(env, o);
out_site:
        lu_site_fini(&o->od_site);
out_compat:
        osd_obj_map_fini(o);
out_mnt:
        osd_umount(env, o);
out:
        return rc;
}

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

        OBD_ALLOC_PTR(o);
        if (o == NULL)
                return ERR_PTR(-ENOMEM);

        rc = dt_device_init(&o->od_dt_dev, t);
        if (rc == 0) {
                /* Because the ctx might be revived in dt_device_init,
                 * refill the env here */
                lu_env_refill((struct lu_env *)env);
                rc = osd_device_init0(env, o, cfg);
                if (rc)
                        dt_device_fini(&o->od_dt_dev);
        }

        if (unlikely(rc != 0))
                OBD_FREE_PTR(o);

        return rc == 0 ? osd2lu_dev(o) : ERR_PTR(rc);
}

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

        /* XXX: make osd top device in order to release reference */
        d->ld_site->ls_top_dev = d;
        lu_site_purge(env, d->ld_site, -1);
        if (!cfs_hash_is_empty(d->ld_site->ls_obj_hash)) {
                LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, D_ERROR, NULL);
                lu_site_print(env, d->ld_site, &msgdata, lu_cdebug_printer);
        }
        lu_site_fini(&o->od_site);
        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                             rc;
        ENTRY;

        switch (cfg->lcfg_command) {
        case LCFG_SETUP:
                rc = osd_mount(env, o, cfg);
                break;
        case LCFG_CLEANUP:
                lu_dev_del_linkage(d->ld_site, d);
                rc = osd_shutdown(env, o);
                break;
        case LCFG_PARAM:
                LASSERT(&o->od_dt_dev);
                rc = class_process_proc_param(PARAM_OSD, lprocfs_osd_obd_vars,
                                              cfg, &o->od_dt_dev);
                if (rc > 0 || rc == -ENOSYS) {
                        rc = class_process_proc_param(PARAM_OST,
                                                      lprocfs_osd_obd_vars,
                                                      cfg, &o->od_dt_dev);
                        if (rc > 0)
                                rc = 0;
                }
                break;
        default:
                rc = -ENOSYS;
        }

        RETURN(rc);
}

static int osd_recovery_complete(const struct lu_env *env,
                                 struct lu_device *d)
{
        struct osd_device       *osd = osd_dev(d);
        int                      rc = 0;
        ENTRY;

        if (osd->od_quota_slave == NULL)
                RETURN(0);

        /* start qsd instance on recovery completion, this notifies the quota
         * slave code that we are about to process new requests now */
        rc = qsd_start(env, osd->od_quota_slave);
        RETURN(rc);
}

/*
 * we use exports to track all osd users
 */
static int osd_obd_connect(const struct lu_env *env, struct obd_export **exp,
                           struct obd_device *obd, struct obd_uuid *cluuid,
                           struct obd_connect_data *data, void *localdata)
{
        struct osd_device    *osd = osd_dev(obd->obd_lu_dev);
        struct lustre_handle  conn;
        int                   rc;
        ENTRY;

        CDEBUG(D_CONFIG, "connect #%d\n", osd->od_connects);

        rc = class_connect(&conn, obd, cluuid);
        if (rc)
                RETURN(rc);

        *exp = class_conn2export(&conn);

        spin_lock(&osd->od_osfs_lock);
        osd->od_connects++;
        spin_unlock(&osd->od_osfs_lock);

        RETURN(0);
}

/*
 * once last export (we don't count self-export) disappeared
 * osd can be released
 */
static int osd_obd_disconnect(struct obd_export *exp)
{
        struct obd_device *obd = exp->exp_obd;
        struct osd_device *osd = osd_dev(obd->obd_lu_dev);
        int                rc, release = 0;
        ENTRY;

        /* Only disconnect the underlying layers on the final disconnect. */
        spin_lock(&osd->od_osfs_lock);
        osd->od_connects--;
        if (osd->od_connects == 0)
                release = 1;
        spin_unlock(&osd->od_osfs_lock);

        rc = class_disconnect(exp); /* bz 9811 */

        if (rc == 0 && release)
                class_manual_cleanup(obd);
        RETURN(rc);
}

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 lr_server_data   *lsd    =
                        &osd->od_dt_dev.dd_lu_dev.ld_site->ls_tgt->lut_lsd;
        int                      result = 0;
        ENTRY;

        if (osd->od_quota_slave != NULL) {
                /* set up quota slave objects */
                result = qsd_prepare(env, osd->od_quota_slave);
                if (result != 0)
                        RETURN(result);
        }

        if (lsd->lsd_feature_incompat & OBD_COMPAT_OST) {
#if LUSTRE_VERSION_CODE < OBD_OCD_VERSION(3, 0, 52, 0)
                if (lsd->lsd_feature_rocompat & OBD_ROCOMPAT_IDX_IN_IDIF) {
                        osd->od_index_in_idif = 1;
                } else {
                        osd->od_index_in_idif = 0;
                        result = osd_register_proc_index_in_idif(osd);
                        if (result != 0)
                                RETURN(result);
                }
#else
                osd->od_index_in_idif = 1;
#endif
        }

        result = osd_fid_init(env, osd);

        RETURN(result);
}

static int osd_fid_alloc(const struct lu_env *env, struct obd_export *exp,
                         struct lu_fid *fid, struct md_op_data *op_data)
{
        struct osd_device *osd = osd_dev(exp->exp_obd->obd_lu_dev);

        return seq_client_alloc_fid(env, osd->od_cl_seq, fid);
}

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
};

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_LDISKFS_NAME,
        .ldt_ops      = &osd_device_type_ops,
        .ldt_ctx_tags = LCT_LOCAL,
};

static int osd_health_check(const struct lu_env *env, struct obd_device *obd)
{
        struct osd_device *osd = osd_dev(obd->obd_lu_dev);
        struct super_block *sb = osd_sb(osd);

        return (osd->od_mnt == NULL || sb->s_flags & MS_RDONLY);
}

/*
 * lprocfs legacy support.
 */
static struct obd_ops osd_obd_device_ops = {
        .o_owner = THIS_MODULE,
        .o_connect      = osd_obd_connect,
        .o_disconnect   = osd_obd_disconnect,
        .o_fid_alloc    = osd_fid_alloc,
        .o_health_check = osd_health_check,
};

static int __init osd_init(void)
{
        int rc;

        LASSERT(BH_DXLock < sizeof(((struct buffer_head *)0)->b_state) * 8);
#if !defined(CONFIG_DEBUG_MUTEXES) && !defined(CONFIG_DEBUG_SPINLOCK)
        /* please, try to keep osd_thread_info smaller than a page */
        CLASSERT(sizeof(struct osd_thread_info) <= PAGE_SIZE);
#endif

        osd_oi_mod_init();

        rc = lu_kmem_init(ldiskfs_caches);
        if (rc)
                return rc;

#ifdef CONFIG_KALLSYMS
        priv_dev_set_rdonly = (void *)kallsyms_lookup_name("dev_set_rdonly");
        priv_dev_check_rdonly = (void *)kallsyms_lookup_name("dev_check_rdonly");
        /* Clear readonly is unused at this time */
        /*priv_dev_clear_rdonly = (void *)kallsyms_lookup_name("dev_clear_rdonly");*/
#endif

        rc = class_register_type(&osd_obd_device_ops, NULL, true,
                                 lprocfs_osd_module_vars,
                                 LUSTRE_OSD_LDISKFS_NAME, &osd_device_type);
        if (rc)
                lu_kmem_fini(ldiskfs_caches);
        return rc;
}

static void __exit osd_exit(void)
{
        class_unregister_type(LUSTRE_OSD_LDISKFS_NAME);
        lu_kmem_fini(ldiskfs_caches);
}

MODULE_AUTHOR("OpenSFS, Inc. <http://www.lustre.org/>");
MODULE_DESCRIPTION("Lustre Object Storage Device ("LUSTRE_OSD_LDISKFS_NAME")");
MODULE_VERSION(LUSTRE_VERSION_STRING);
MODULE_LICENSE("GPL");

module_init(osd_init);
module_exit(osd_exit);