/*
 * 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) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2015, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 */

#define DEBUG_SUBSYSTEM S_MDC

# include <linux/module.h>
# include <linux/pagemap.h>
# include <linux/miscdevice.h>
# include <linux/init.h>
# include <linux/utsname.h>

#include "../include/lustre_acl.h"
#include "../include/lustre/lustre_ioctl.h"
#include "../include/obd_class.h"
#include "../include/lustre_lmv.h"
#include "../include/lustre_fid.h"
#include "../include/lprocfs_status.h"
#include "../include/lustre_param.h"
#include "../include/lustre_log.h"
#include "../include/lustre_kernelcomm.h"

#include "mdc_internal.h"

#define REQUEST_MINOR 244

static int mdc_cleanup(struct obd_device *obd);

static inline int mdc_queue_wait(struct ptlrpc_request *req)
{
        struct client_obd *cli = &req->rq_import->imp_obd->u.cli;
        int rc;

        /* obd_get_request_slot() ensures that this client has no more
         * than cl_max_rpcs_in_flight RPCs simultaneously inf light
         * against an MDT.
         */
        rc = obd_get_request_slot(cli);
        if (rc != 0)
                return rc;

        rc = ptlrpc_queue_wait(req);
        obd_put_request_slot(cli);

        return rc;
}

static int mdc_getstatus(struct obd_export *exp, struct lu_fid *rootfid)
{
        struct ptlrpc_request *req;
        struct mdt_body       *body;
        int                 rc;

        req = ptlrpc_request_alloc_pack(class_exp2cliimp(exp),
                                        &RQF_MDS_GETSTATUS,
                                        LUSTRE_MDS_VERSION, MDS_GETSTATUS);
        if (!req)
                return -ENOMEM;

        mdc_pack_body(req, NULL, 0, 0, -1, 0);
        req->rq_send_state = LUSTRE_IMP_FULL;

        ptlrpc_request_set_replen(req);

        rc = ptlrpc_queue_wait(req);
        if (rc)
                goto out;

        body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY);
        if (!body) {
                rc = -EPROTO;
                goto out;
        }

        *rootfid = body->mbo_fid1;
        CDEBUG(D_NET,
               "root fid="DFID", last_committed=%llu\n",
               PFID(rootfid),
               lustre_msg_get_last_committed(req->rq_repmsg));
out:
        ptlrpc_req_finished(req);
        return rc;
}

/*
 * This function now is known to always saying that it will receive 4 buffers
 * from server. Even for cases when acl_size and md_size is zero, RPC header
 * will contain 4 fields and RPC itself will contain zero size fields. This is
 * because mdt_getattr*() _always_ returns 4 fields, but if acl is not needed
 * and thus zero, it shrinks it, making zero size. The same story about
 * md_size. And this is course of problem when client waits for smaller number
 * of fields. This issue will be fixed later when client gets aware of RPC
 * layouts.  --umka
 */
static int mdc_getattr_common(struct obd_export *exp,
                              struct ptlrpc_request *req)
{
        struct req_capsule *pill = &req->rq_pill;
        struct mdt_body    *body;
        void           *eadata;
        int              rc;

        /* Request message already built. */
        rc = ptlrpc_queue_wait(req);
        if (rc != 0)
                return rc;

        /* sanity check for the reply */
        body = req_capsule_server_get(pill, &RMF_MDT_BODY);
        if (!body)
                return -EPROTO;

        CDEBUG(D_NET, "mode: %o\n", body->mbo_mode);

        mdc_update_max_ea_from_body(exp, body);
        if (body->mbo_eadatasize != 0) {
                eadata = req_capsule_server_sized_get(pill, &RMF_MDT_MD,
                                                      body->mbo_eadatasize);
                if (!eadata)
                        return -EPROTO;
        }

        return 0;
}

static int mdc_getattr(struct obd_export *exp, struct md_op_data *op_data,
                       struct ptlrpc_request **request)
{
        struct ptlrpc_request *req;
        int                 rc;

        /* Single MDS without an LMV case */
        if (op_data->op_flags & MF_GET_MDT_IDX) {
                op_data->op_mds = 0;
                return 0;
        }
        *request = NULL;
        req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_MDS_GETATTR);
        if (!req)
                return -ENOMEM;

        rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, MDS_GETATTR);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        mdc_pack_body(req, &op_data->op_fid1, op_data->op_valid,
                      op_data->op_mode, -1, 0);

        req_capsule_set_size(&req->rq_pill, &RMF_MDT_MD, RCL_SERVER,
                             op_data->op_mode);
        ptlrpc_request_set_replen(req);

        rc = mdc_getattr_common(exp, req);
        if (rc)
                ptlrpc_req_finished(req);
        else
                *request = req;
        return rc;
}

static int mdc_getattr_name(struct obd_export *exp, struct md_op_data *op_data,
                            struct ptlrpc_request **request)
{
        struct ptlrpc_request *req;
        int                 rc;

        *request = NULL;
        req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                   &RQF_MDS_GETATTR_NAME);
        if (!req)
                return -ENOMEM;

        req_capsule_set_size(&req->rq_pill, &RMF_NAME, RCL_CLIENT,
                             op_data->op_namelen + 1);

        rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, MDS_GETATTR_NAME);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        mdc_pack_body(req, &op_data->op_fid1, op_data->op_valid,
                      op_data->op_mode, op_data->op_suppgids[0], 0);

        if (op_data->op_name) {
                char *name = req_capsule_client_get(&req->rq_pill, &RMF_NAME);

                LASSERT(strnlen(op_data->op_name, op_data->op_namelen) ==
                                op_data->op_namelen);
                memcpy(name, op_data->op_name, op_data->op_namelen);
        }

        req_capsule_set_size(&req->rq_pill, &RMF_MDT_MD, RCL_SERVER,
                             op_data->op_mode);
        ptlrpc_request_set_replen(req);

        rc = mdc_getattr_common(exp, req);
        if (rc)
                ptlrpc_req_finished(req);
        else
                *request = req;
        return rc;
}

static int mdc_xattr_common(struct obd_export *exp,
                            const struct req_format *fmt,
                            const struct lu_fid *fid,
                            int opcode, u64 valid,
                            const char *xattr_name, const char *input,
                            int input_size, int output_size, int flags,
                            __u32 suppgid, struct ptlrpc_request **request)
{
        struct ptlrpc_request *req;
        int   xattr_namelen = 0;
        char *tmp;
        int   rc;

        *request = NULL;
        req = ptlrpc_request_alloc(class_exp2cliimp(exp), fmt);
        if (!req)
                return -ENOMEM;

        if (xattr_name) {
                xattr_namelen = strlen(xattr_name) + 1;
                req_capsule_set_size(&req->rq_pill, &RMF_NAME, RCL_CLIENT,
                                     xattr_namelen);
        }
        if (input_size) {
                LASSERT(input);
                req_capsule_set_size(&req->rq_pill, &RMF_EADATA, RCL_CLIENT,
                                     input_size);
        }

        /* Flush local XATTR locks to get rid of a possible cancel RPC */
        if (opcode == MDS_REINT && fid_is_sane(fid) &&
            exp->exp_connect_data.ocd_ibits_known & MDS_INODELOCK_XATTR) {
                LIST_HEAD(cancels);
                int count;

                /* Without that packing would fail */
                if (input_size == 0)
                        req_capsule_set_size(&req->rq_pill, &RMF_EADATA,
                                             RCL_CLIENT, 0);

                count = mdc_resource_get_unused(exp, fid,
                                                &cancels, LCK_EX,
                                                MDS_INODELOCK_XATTR);

                rc = mdc_prep_elc_req(exp, req, MDS_REINT, &cancels, count);
                if (rc) {
                        ptlrpc_request_free(req);
                        return rc;
                }
        } else {
                rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, opcode);
                if (rc) {
                        ptlrpc_request_free(req);
                        return rc;
                }
        }

        if (opcode == MDS_REINT) {
                struct mdt_rec_setxattr *rec;

                CLASSERT(sizeof(struct mdt_rec_setxattr) ==
                         sizeof(struct mdt_rec_reint));
                rec = req_capsule_client_get(&req->rq_pill, &RMF_REC_REINT);
                rec->sx_opcode = REINT_SETXATTR;
                rec->sx_fsuid  = from_kuid(&init_user_ns, current_fsuid());
                rec->sx_fsgid  = from_kgid(&init_user_ns, current_fsgid());
                rec->sx_cap    = cfs_curproc_cap_pack();
                rec->sx_suppgid1 = suppgid;
                rec->sx_suppgid2 = -1;
                rec->sx_fid    = *fid;
                rec->sx_valid  = valid | OBD_MD_FLCTIME;
                rec->sx_time   = ktime_get_real_seconds();
                rec->sx_size   = output_size;
                rec->sx_flags  = flags;

        } else {
                mdc_pack_body(req, fid, valid, output_size, suppgid, flags);
        }

        if (xattr_name) {
                tmp = req_capsule_client_get(&req->rq_pill, &RMF_NAME);
                memcpy(tmp, xattr_name, xattr_namelen);
        }
        if (input_size) {
                tmp = req_capsule_client_get(&req->rq_pill, &RMF_EADATA);
                memcpy(tmp, input, input_size);
        }

        if (req_capsule_has_field(&req->rq_pill, &RMF_EADATA, RCL_SERVER))
                req_capsule_set_size(&req->rq_pill, &RMF_EADATA,
                                     RCL_SERVER, output_size);
        ptlrpc_request_set_replen(req);

        /* make rpc */
        if (opcode == MDS_REINT)
                mdc_get_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);

        rc = ptlrpc_queue_wait(req);

        if (opcode == MDS_REINT)
                mdc_put_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);

        if (rc)
                ptlrpc_req_finished(req);
        else
                *request = req;
        return rc;
}

static int mdc_setxattr(struct obd_export *exp, const struct lu_fid *fid,
                        u64 valid, const char *xattr_name,
                        const char *input, int input_size, int output_size,
                        int flags, __u32 suppgid,
                        struct ptlrpc_request **request)
{
        return mdc_xattr_common(exp, &RQF_MDS_REINT_SETXATTR,
                                fid, MDS_REINT, valid, xattr_name,
                                input, input_size, output_size, flags,
                                suppgid, request);
}

static int mdc_getxattr(struct obd_export *exp, const struct lu_fid *fid,
                        u64 valid, const char *xattr_name,
                        const char *input, int input_size, int output_size,
                        int flags, struct ptlrpc_request **request)
{
        return mdc_xattr_common(exp, &RQF_MDS_GETXATTR,
                                fid, MDS_GETXATTR, valid, xattr_name,
                                input, input_size, output_size, flags,
                                -1, request);
}

#ifdef CONFIG_FS_POSIX_ACL
static int mdc_unpack_acl(struct ptlrpc_request *req, struct lustre_md *md)
{
        struct req_capsule     *pill = &req->rq_pill;
        struct mdt_body *body = md->body;
        struct posix_acl       *acl;
        void               *buf;
        int                  rc;

        if (!body->mbo_aclsize)
                return 0;

        buf = req_capsule_server_sized_get(pill, &RMF_ACL, body->mbo_aclsize);

        if (!buf)
                return -EPROTO;

        acl = posix_acl_from_xattr(&init_user_ns, buf, body->mbo_aclsize);
        if (!acl)
                return 0;

        if (IS_ERR(acl)) {
                rc = PTR_ERR(acl);
                CERROR("convert xattr to acl: %d\n", rc);
                return rc;
        }

        rc = posix_acl_valid(&init_user_ns, acl);
        if (rc) {
                CERROR("validate acl: %d\n", rc);
                posix_acl_release(acl);
                return rc;
        }

        md->posix_acl = acl;
        return 0;
}
#else
#define mdc_unpack_acl(req, md) 0
#endif

static int mdc_get_lustre_md(struct obd_export *exp,
                             struct ptlrpc_request *req,
                             struct obd_export *dt_exp,
                             struct obd_export *md_exp,
                             struct lustre_md *md)
{
        struct req_capsule *pill = &req->rq_pill;
        int rc;

        LASSERT(md);
        memset(md, 0, sizeof(*md));

        md->body = req_capsule_server_get(pill, &RMF_MDT_BODY);

        if (md->body->mbo_valid & OBD_MD_FLEASIZE) {
                int lmmsize;
                struct lov_mds_md *lmm;

                if (!S_ISREG(md->body->mbo_mode)) {
                        CDEBUG(D_INFO,
                               "OBD_MD_FLEASIZE set, should be a regular file, but is not\n");
                        rc = -EPROTO;
                        goto out;
                }

                if (md->body->mbo_eadatasize == 0) {
                        CDEBUG(D_INFO,
                               "OBD_MD_FLEASIZE set, but eadatasize 0\n");
                        rc = -EPROTO;
                        goto out;
                }
                lmmsize = md->body->mbo_eadatasize;
                lmm = req_capsule_server_sized_get(pill, &RMF_MDT_MD, lmmsize);
                if (!lmm) {
                        rc = -EPROTO;
                        goto out;
                }

                rc = obd_unpackmd(dt_exp, &md->lsm, lmm, lmmsize);
                if (rc < 0)
                        goto out;

                if (rc < (typeof(rc))sizeof(*md->lsm)) {
                        CDEBUG(D_INFO,
                               "lsm size too small: rc < sizeof (*md->lsm) (%d < %d)\n",
                               rc, (int)sizeof(*md->lsm));
                        rc = -EPROTO;
                        goto out;
                }

        } else if (md->body->mbo_valid & OBD_MD_FLDIREA) {
                int lmvsize;
                struct lov_mds_md *lmv;

                if (!S_ISDIR(md->body->mbo_mode)) {
                        CDEBUG(D_INFO,
                               "OBD_MD_FLDIREA set, should be a directory, but is not\n");
                        rc = -EPROTO;
                        goto out;
                }

                if (md->body->mbo_eadatasize == 0) {
                        CDEBUG(D_INFO,
                               "OBD_MD_FLDIREA is set, but eadatasize 0\n");
                        return -EPROTO;
                }
                if (md->body->mbo_valid & OBD_MD_MEA) {
                        lmvsize = md->body->mbo_eadatasize;
                        lmv = req_capsule_server_sized_get(pill, &RMF_MDT_MD,
                                                           lmvsize);
                        if (!lmv) {
                                rc = -EPROTO;
                                goto out;
                        }

                        rc = obd_unpackmd(md_exp, (void *)&md->lmv, lmv,
                                          lmvsize);
                        if (rc < 0)
                                goto out;

                        if (rc < (typeof(rc))sizeof(*md->lmv)) {
                                CDEBUG(D_INFO,
                                       "size too small: rc < sizeof(*md->lmv) (%d < %d)\n",
                                        rc, (int)sizeof(*md->lmv));
                                rc = -EPROTO;
                                goto out;
                        }
                }
        }
        rc = 0;

        if (md->body->mbo_valid & OBD_MD_FLACL) {
                /* for ACL, it's possible that FLACL is set but aclsize is zero.
                 * only when aclsize != 0 there's an actual segment for ACL
                 * in reply buffer.
                 */
                if (md->body->mbo_aclsize) {
                        rc = mdc_unpack_acl(req, md);
                        if (rc)
                                goto out;
#ifdef CONFIG_FS_POSIX_ACL
                } else {
                        md->posix_acl = NULL;
#endif
                }
        }

out:
        if (rc) {
#ifdef CONFIG_FS_POSIX_ACL
                posix_acl_release(md->posix_acl);
#endif
                if (md->lsm)
                        obd_free_memmd(dt_exp, &md->lsm);
        }
        return rc;
}

static int mdc_free_lustre_md(struct obd_export *exp, struct lustre_md *md)
{
        return 0;
}

/**
 * Handles both OPEN and SETATTR RPCs for OPEN-CLOSE and SETATTR-DONE_WRITING
 * RPC chains.
 */
void mdc_replay_open(struct ptlrpc_request *req)
{
        struct md_open_data *mod = req->rq_cb_data;
        struct ptlrpc_request *close_req;
        struct obd_client_handle *och;
        struct lustre_handle old;
        struct mdt_body *body;

        if (!mod) {
                DEBUG_REQ(D_ERROR, req,
                          "Can't properly replay without open data.");
                return;
        }

        body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY);

        och = mod->mod_och;
        if (och) {
                struct lustre_handle *file_fh;

                LASSERT(och->och_magic == OBD_CLIENT_HANDLE_MAGIC);

                file_fh = &och->och_fh;
                CDEBUG(D_HA, "updating handle from %#llx to %#llx\n",
                       file_fh->cookie, body->mbo_handle.cookie);
                old = *file_fh;
                *file_fh = body->mbo_handle;
        }
        close_req = mod->mod_close_req;
        if (close_req) {
                __u32 opc = lustre_msg_get_opc(close_req->rq_reqmsg);
                struct mdt_ioepoch *epoch;

                LASSERT(opc == MDS_CLOSE || opc == MDS_DONE_WRITING);
                epoch = req_capsule_client_get(&close_req->rq_pill,
                                               &RMF_MDT_EPOCH);
                LASSERT(epoch);

                if (och)
                        LASSERT(!memcmp(&old, &epoch->handle, sizeof(old)));
                DEBUG_REQ(D_HA, close_req, "updating close body with new fh");
                epoch->handle = body->mbo_handle;
        }
}

void mdc_commit_open(struct ptlrpc_request *req)
{
        struct md_open_data *mod = req->rq_cb_data;

        if (!mod)
                return;

        /**
         * No need to touch md_open_data::mod_och, it holds a reference on
         * \var mod and will zero references to each other, \var mod will be
         * freed after that when md_open_data::mod_och will put the reference.
         */

        /**
         * Do not let open request to disappear as it still may be needed
         * for close rpc to happen (it may happen on evict only, otherwise
         * ptlrpc_request::rq_replay does not let mdc_commit_open() to be
         * called), just mark this rpc as committed to distinguish these 2
         * cases, see mdc_close() for details. The open request reference will
         * be put along with freeing \var mod.
         */
        ptlrpc_request_addref(req);
        spin_lock(&req->rq_lock);
        req->rq_committed = 1;
        spin_unlock(&req->rq_lock);
        req->rq_cb_data = NULL;
        obd_mod_put(mod);
}

int mdc_set_open_replay_data(struct obd_export *exp,
                             struct obd_client_handle *och,
                             struct lookup_intent *it)
{
        struct md_open_data   *mod;
        struct mdt_rec_create *rec;
        struct mdt_body       *body;
        struct ptlrpc_request *open_req = it->it_request;
        struct obd_import     *imp = open_req->rq_import;

        if (!open_req->rq_replay)
                return 0;

        rec = req_capsule_client_get(&open_req->rq_pill, &RMF_REC_REINT);
        body = req_capsule_server_get(&open_req->rq_pill, &RMF_MDT_BODY);
        LASSERT(rec);
        /* Incoming message in my byte order (it's been swabbed). */
        /* Outgoing messages always in my byte order. */
        LASSERT(body);

        /* Only if the import is replayable, we set replay_open data */
        if (och && imp->imp_replayable) {
                mod = obd_mod_alloc();
                if (!mod) {
                        DEBUG_REQ(D_ERROR, open_req,
                                  "Can't allocate md_open_data");
                        return 0;
                }

                /**
                 * Take a reference on \var mod, to be freed on mdc_close().
                 * It protects \var mod from being freed on eviction (commit
                 * callback is called despite rq_replay flag).
                 * Another reference for \var och.
                 */
                obd_mod_get(mod);
                obd_mod_get(mod);

                spin_lock(&open_req->rq_lock);
                och->och_mod = mod;
                mod->mod_och = och;
                mod->mod_is_create = it_disposition(it, DISP_OPEN_CREATE) ||
                                     it_disposition(it, DISP_OPEN_STRIPE);
                mod->mod_open_req = open_req;
                open_req->rq_cb_data = mod;
                open_req->rq_commit_cb = mdc_commit_open;
                spin_unlock(&open_req->rq_lock);
        }

        rec->cr_fid2 = body->mbo_fid1;
        rec->cr_ioepoch = body->mbo_ioepoch;
        rec->cr_old_handle.cookie = body->mbo_handle.cookie;
        open_req->rq_replay_cb = mdc_replay_open;
        if (!fid_is_sane(&body->mbo_fid1)) {
                DEBUG_REQ(D_ERROR, open_req,
                          "Saving replay request with insane fid");
                LBUG();
        }

        DEBUG_REQ(D_RPCTRACE, open_req, "Set up open replay data");
        return 0;
}

static void mdc_free_open(struct md_open_data *mod)
{
        int committed = 0;

        if (mod->mod_is_create == 0 &&
            imp_connect_disp_stripe(mod->mod_open_req->rq_import))
                committed = 1;

        /*
         * No reason to asssert here if the open request has
         * rq_replay == 1. It means that mdc_close failed, and
         * close request wasn`t sent. It is not fatal to client.
         * The worst thing is eviction if the client gets open lock
         */
        DEBUG_REQ(D_RPCTRACE, mod->mod_open_req,
                  "free open request rq_replay = %d\n",
                   mod->mod_open_req->rq_replay);

        ptlrpc_request_committed(mod->mod_open_req, committed);
        if (mod->mod_close_req)
                ptlrpc_request_committed(mod->mod_close_req, committed);
}

static int mdc_clear_open_replay_data(struct obd_export *exp,
                                      struct obd_client_handle *och)
{
        struct md_open_data *mod = och->och_mod;

        /**
         * It is possible to not have \var mod in a case of eviction between
         * lookup and ll_file_open().
         **/
        if (!mod)
                return 0;

        LASSERT(mod != LP_POISON);
        LASSERT(mod->mod_open_req);
        mdc_free_open(mod);

        mod->mod_och = NULL;
        och->och_mod = NULL;
        obd_mod_put(mod);

        return 0;
}

/* Prepares the request for the replay by the given reply */
static void mdc_close_handle_reply(struct ptlrpc_request *req,
                                   struct md_op_data *op_data, int rc) {
        struct mdt_body  *repbody;
        struct mdt_ioepoch *epoch;

        if (req && rc == -EAGAIN) {
                repbody = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY);
                epoch = req_capsule_client_get(&req->rq_pill, &RMF_MDT_EPOCH);

                epoch->flags |= MF_SOM_AU;
                if (repbody->mbo_valid & OBD_MD_FLGETATTRLOCK)
                        op_data->op_flags |= MF_GETATTR_LOCK;
        }
}

static int mdc_close(struct obd_export *exp, struct md_op_data *op_data,
                     struct md_open_data *mod, struct ptlrpc_request **request)
{
        struct obd_device     *obd = class_exp2obd(exp);
        struct ptlrpc_request *req;
        struct req_format     *req_fmt;
        int                    rc;
        int                    saved_rc = 0;

        req_fmt = &RQF_MDS_CLOSE;
        if (op_data->op_bias & MDS_HSM_RELEASE) {
                req_fmt = &RQF_MDS_RELEASE_CLOSE;

                /* allocate a FID for volatile file */
                rc = mdc_fid_alloc(NULL, exp, &op_data->op_fid2, op_data);
                if (rc < 0) {
                        CERROR("%s: "DFID" failed to allocate FID: %d\n",
                               obd->obd_name, PFID(&op_data->op_fid1), rc);
                        /* save the errcode and proceed to close */
                        saved_rc = rc;
                }
        }

        *request = NULL;
        if (OBD_FAIL_CHECK(OBD_FAIL_MDC_CLOSE))
                req = NULL;
        else
                req = ptlrpc_request_alloc(class_exp2cliimp(exp), req_fmt);

        /* Ensure that this close's handle is fixed up during replay. */
        if (likely(mod)) {
                LASSERTF(mod->mod_open_req &&
                         mod->mod_open_req->rq_type != LI_POISON,
                         "POISONED open %p!\n", mod->mod_open_req);

                mod->mod_close_req = req;

                DEBUG_REQ(D_HA, mod->mod_open_req, "matched open");
                /* We no longer want to preserve this open for replay even
                 * though the open was committed. b=3632, b=3633
                 */
                spin_lock(&mod->mod_open_req->rq_lock);
                mod->mod_open_req->rq_replay = 0;
                spin_unlock(&mod->mod_open_req->rq_lock);
        } else {
                 CDEBUG(D_HA,
                        "couldn't find open req; expecting close error\n");
        }
        if (!req) {
                /*
                 * TODO: repeat close after errors
                 */
                CWARN("%s: close of FID "DFID" failed, file reference will be dropped when this client unmounts or is evicted\n",
                      obd->obd_name, PFID(&op_data->op_fid1));
                rc = -ENOMEM;
                goto out;
        }

        rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, MDS_CLOSE);
        if (rc) {
                ptlrpc_request_free(req);
                goto out;
        }

        /*
         * To avoid a livelock (bug 7034), we need to send CLOSE RPCs to a
         * portal whose threads are not taking any DLM locks and are therefore
         * always progressing
         */
        req->rq_request_portal = MDS_READPAGE_PORTAL;
        ptlrpc_at_set_req_timeout(req);

        mdc_close_pack(req, op_data);

        req_capsule_set_size(&req->rq_pill, &RMF_MDT_MD, RCL_SERVER,
                             obd->u.cli.cl_default_mds_easize);
        req_capsule_set_size(&req->rq_pill, &RMF_LOGCOOKIES, RCL_SERVER,
                             obd->u.cli.cl_default_mds_cookiesize);

        ptlrpc_request_set_replen(req);

        mdc_get_rpc_lock(obd->u.cli.cl_close_lock, NULL);
        rc = ptlrpc_queue_wait(req);
        mdc_put_rpc_lock(obd->u.cli.cl_close_lock, NULL);

        if (!req->rq_repmsg) {
                CDEBUG(D_RPCTRACE, "request failed to send: %p, %d\n", req,
                       req->rq_status);
                if (rc == 0)
                        rc = req->rq_status ?: -EIO;
        } else if (rc == 0 || rc == -EAGAIN) {
                struct mdt_body *body;

                rc = lustre_msg_get_status(req->rq_repmsg);
                if (lustre_msg_get_type(req->rq_repmsg) == PTL_RPC_MSG_ERR) {
                        DEBUG_REQ(D_ERROR, req,
                                  "type == PTL_RPC_MSG_ERR, err = %d", rc);
                        if (rc > 0)
                                rc = -rc;
                }
                body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY);
                if (!body)
                        rc = -EPROTO;
        } else if (rc == -ESTALE) {
                /**
                 * it can be allowed error after 3633 if open was committed and
                 * server failed before close was sent. Let's check if mod
                 * exists and return no error in that case
                 */
                if (mod) {
                        DEBUG_REQ(D_HA, req, "Reset ESTALE = %d", rc);
                        if (mod->mod_open_req->rq_committed)
                                rc = 0;
                }
        }

out:
        if (mod) {
                if (rc != 0)
                        mod->mod_close_req = NULL;
                /* Since now, mod is accessed through open_req only,
                 * thus close req does not keep a reference on mod anymore.
                 */
                obd_mod_put(mod);
        }
        *request = req;
        mdc_close_handle_reply(req, op_data, rc);
        return rc < 0 ? rc : saved_rc;
}

static int mdc_done_writing(struct obd_export *exp, struct md_op_data *op_data,
                            struct md_open_data *mod)
{
        struct obd_device     *obd = class_exp2obd(exp);
        struct ptlrpc_request *req;
        int                 rc;

        req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                   &RQF_MDS_DONE_WRITING);
        if (!req)
                return -ENOMEM;

        rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, MDS_DONE_WRITING);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        if (mod) {
                LASSERTF(mod->mod_open_req &&
                         mod->mod_open_req->rq_type != LI_POISON,
                         "POISONED setattr %p!\n", mod->mod_open_req);

                mod->mod_close_req = req;
                DEBUG_REQ(D_HA, mod->mod_open_req, "matched setattr");
                /* We no longer want to preserve this setattr for replay even
                 * though the open was committed. b=3632, b=3633
                 */
                spin_lock(&mod->mod_open_req->rq_lock);
                mod->mod_open_req->rq_replay = 0;
                spin_unlock(&mod->mod_open_req->rq_lock);
        }

        mdc_close_pack(req, op_data);
        ptlrpc_request_set_replen(req);

        mdc_get_rpc_lock(obd->u.cli.cl_close_lock, NULL);
        rc = ptlrpc_queue_wait(req);
        mdc_put_rpc_lock(obd->u.cli.cl_close_lock, NULL);

        if (rc == -ESTALE) {
                /**
                 * it can be allowed error after 3633 if open or setattr were
                 * committed and server failed before close was sent.
                 * Let's check if mod exists and return no error in that case
                 */
                if (mod) {
                        if (mod->mod_open_req->rq_committed)
                                rc = 0;
                }
        }

        if (mod) {
                if (rc != 0)
                        mod->mod_close_req = NULL;
                LASSERT(mod->mod_open_req);
                mdc_free_open(mod);

                /* Since now, mod is accessed through setattr req only,
                 * thus DW req does not keep a reference on mod anymore.
                 */
                obd_mod_put(mod);
        }

        mdc_close_handle_reply(req, op_data, rc);
        ptlrpc_req_finished(req);
        return rc;
}

static int mdc_getpage(struct obd_export *exp, const struct lu_fid *fid,
                       u64 offset, struct page **pages, int npages,
                       struct ptlrpc_request **request)
{
        struct ptlrpc_bulk_desc *desc;
        struct ptlrpc_request *req;
        wait_queue_head_t waitq;
        struct l_wait_info lwi;
        int resends = 0;
        int rc;
        int i;

        *request = NULL;
        init_waitqueue_head(&waitq);

restart_bulk:
        req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_MDS_READPAGE);
        if (!req)
                return -ENOMEM;

        rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, MDS_READPAGE);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        req->rq_request_portal = MDS_READPAGE_PORTAL;
        ptlrpc_at_set_req_timeout(req);

        desc = ptlrpc_prep_bulk_imp(req, npages, 1, BULK_PUT_SINK,
                                    MDS_BULK_PORTAL);
        if (!desc) {
                ptlrpc_request_free(req);
                return -ENOMEM;
        }

        /* NB req now owns desc and will free it when it gets freed */
        for (i = 0; i < npages; i++)
                ptlrpc_prep_bulk_page_pin(desc, pages[i], 0, PAGE_SIZE);

        mdc_readdir_pack(req, offset, PAGE_SIZE * npages, fid);

        ptlrpc_request_set_replen(req);
        rc = ptlrpc_queue_wait(req);
        if (rc) {
                ptlrpc_req_finished(req);
                if (rc != -ETIMEDOUT)
                        return rc;

                resends++;
                if (!client_should_resend(resends, &exp->exp_obd->u.cli)) {
                        CERROR("%s: too many resend retries: rc = %d\n",
                               exp->exp_obd->obd_name, -EIO);
                        return -EIO;
                }
                lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(resends), NULL, NULL,
                                       NULL);
                l_wait_event(waitq, 0, &lwi);

                goto restart_bulk;
        }

        rc = sptlrpc_cli_unwrap_bulk_read(req, req->rq_bulk,
                                          req->rq_bulk->bd_nob_transferred);
        if (rc < 0) {
                ptlrpc_req_finished(req);
                return rc;
        }

        if (req->rq_bulk->bd_nob_transferred & ~LU_PAGE_MASK) {
                CERROR("%s: unexpected bytes transferred: %d (%ld expected)\n",
                       exp->exp_obd->obd_name, req->rq_bulk->bd_nob_transferred,
                       PAGE_SIZE * npages);
                ptlrpc_req_finished(req);
                return -EPROTO;
        }

        *request = req;
        return 0;
}

static void mdc_release_page(struct page *page, int remove)
{
        if (remove) {
                lock_page(page);
                if (likely(page->mapping))
                        truncate_complete_page(page->mapping, page);
                unlock_page(page);
        }
        put_page(page);
}

static struct page *mdc_page_locate(struct address_space *mapping, __u64 *hash,
                                    __u64 *start, __u64 *end, int hash64)
{
        /*
         * Complement of hash is used as an index so that
         * radix_tree_gang_lookup() can be used to find a page with starting
         * hash _smaller_ than one we are looking for.
         */
        unsigned long offset = hash_x_index(*hash, hash64);
        struct page *page;
        int found;

        spin_lock_irq(&mapping->tree_lock);
        found = radix_tree_gang_lookup(&mapping->page_tree,
                                       (void **)&page, offset, 1);
        if (found > 0 && !radix_tree_exceptional_entry(page)) {
                struct lu_dirpage *dp;

                get_page(page);
                spin_unlock_irq(&mapping->tree_lock);
                /*
                 * In contrast to find_lock_page() we are sure that directory
                 * page cannot be truncated (while DLM lock is held) and,
                 * hence, can avoid restart.
                 *
                 * In fact, page cannot be locked here at all, because
                 * mdc_read_page_remote does synchronous io.
                 */
                wait_on_page_locked(page);
                if (PageUptodate(page)) {
                        dp = kmap(page);
                        if (BITS_PER_LONG == 32 && hash64) {
                                *start = le64_to_cpu(dp->ldp_hash_start) >> 32;
                                *end   = le64_to_cpu(dp->ldp_hash_end) >> 32;
                                *hash  = *hash >> 32;
                        } else {
                                *start = le64_to_cpu(dp->ldp_hash_start);
                                *end   = le64_to_cpu(dp->ldp_hash_end);
                        }
                        if (unlikely(*start == 1 && *hash == 0))
                                *hash = *start;
                        else
                                LASSERTF(*start <= *hash, "start = %#llx,end = %#llx,hash = %#llx\n",
                                         *start, *end, *hash);
                        CDEBUG(D_VFSTRACE, "offset %lx [%#llx %#llx], hash %#llx\n",
                               offset, *start, *end, *hash);
                        if (*hash > *end) {
                                kunmap(page);
                                mdc_release_page(page, 0);
                                page = NULL;
                        } else if (*end != *start && *hash == *end) {
                                /*
                                 * upon hash collision, remove this page,
                                 * otherwise put page reference, and
                                 * mdc_read_page_remote() will issue RPC to
                                 * fetch the page we want.
                                 */
                                kunmap(page);
                                mdc_release_page(page,
                                                 le32_to_cpu(dp->ldp_flags) & LDF_COLLIDE);
                                page = NULL;
                        }
                } else {
                        put_page(page);
                        page = ERR_PTR(-EIO);
                }
        } else {
                spin_unlock_irq(&mapping->tree_lock);
                page = NULL;
        }
        return page;
}

/*
 * Adjust a set of pages, each page containing an array of lu_dirpages,
 * so that each page can be used as a single logical lu_dirpage.
 *
 * A lu_dirpage is laid out as follows, where s = ldp_hash_start,
 * e = ldp_hash_end, f = ldp_flags, p = padding, and each "ent" is a
 * struct lu_dirent.  It has size up to LU_PAGE_SIZE. The ldp_hash_end
 * value is used as a cookie to request the next lu_dirpage in a
 * directory listing that spans multiple pages (two in this example):
 *   ________
 *  |        |
 * .|--------v-------   -----.
 * |s|e|f|p|ent|ent| ... |ent|
 * '--|--------------   -----'   Each PAGE contains a single
 *    '------.                   lu_dirpage.
 * .---------v-------   -----.
 * |s|e|f|p|ent| 0 | ... | 0 |
 * '-----------------   -----'
 *
 * However, on hosts where the native VM page size (PAGE_SIZE) is
 * larger than LU_PAGE_SIZE, a single host page may contain multiple
 * lu_dirpages. After reading the lu_dirpages from the MDS, the
 * ldp_hash_end of the first lu_dirpage refers to the one immediately
 * after it in the same PAGE (arrows simplified for brevity, but
 * in general e0==s1, e1==s2, etc.):
 *
 * .--------------------   -----.
 * |s0|e0|f0|p|ent|ent| ... |ent|
 * |---v----------------   -----|
 * |s1|e1|f1|p|ent|ent| ... |ent|
 * |---v----------------   -----|  Here, each PAGE contains
 *             ...                 multiple lu_dirpages.
 * |---v----------------   -----|
 * |s'|e'|f'|p|ent|ent| ... |ent|
 * '---|----------------   -----'
 *     v
 * .----------------------------.
 * |        next PAGE           |
 *
 * This structure is transformed into a single logical lu_dirpage as follows:
 *
 * - Replace e0 with e' so the request for the next lu_dirpage gets the page
 *   labeled 'next PAGE'.
 *
 * - Copy the LDF_COLLIDE flag from f' to f0 to correctly reflect whether
 *   a hash collision with the next page exists.
 *
 * - Adjust the lde_reclen of the ending entry of each lu_dirpage to span
 *   to the first entry of the next lu_dirpage.
 */
#if PAGE_SIZE > LU_PAGE_SIZE
static void mdc_adjust_dirpages(struct page **pages, int cfs_pgs, int lu_pgs)
{
        int i;

        for (i = 0; i < cfs_pgs; i++) {
                struct lu_dirpage *dp = kmap(pages[i]);
                __u64 hash_end = le64_to_cpu(dp->ldp_hash_end);
                __u32 flags = le32_to_cpu(dp->ldp_flags);
                struct lu_dirpage *first = dp;
                struct lu_dirent *end_dirent = NULL;
                struct lu_dirent *ent;

                while (--lu_pgs > 0) {
                        ent = lu_dirent_start(dp);
                        for (end_dirent = ent; ent;
                             end_dirent = ent, ent = lu_dirent_next(ent));

                        /* Advance dp to next lu_dirpage. */
                        dp = (struct lu_dirpage *)((char *)dp + LU_PAGE_SIZE);

                        /* Check if we've reached the end of the CFS_PAGE. */
                        if (!((unsigned long)dp & ~PAGE_MASK))
                                break;

                        /* Save the hash and flags of this lu_dirpage. */
                        hash_end = le64_to_cpu(dp->ldp_hash_end);
                        flags = le32_to_cpu(dp->ldp_flags);

                        /* Check if lu_dirpage contains no entries. */
                        if (!end_dirent)
                                break;

                        /*
                         * Enlarge the end entry lde_reclen from 0 to
                         * first entry of next lu_dirpage.
                         */
                        LASSERT(!le16_to_cpu(end_dirent->lde_reclen));
                        end_dirent->lde_reclen =
                                cpu_to_le16((char *)(dp->ldp_entries) -
                                            (char *)end_dirent);
                }

                first->ldp_hash_end = hash_end;
                first->ldp_flags &= ~cpu_to_le32(LDF_COLLIDE);
                first->ldp_flags |= flags & cpu_to_le32(LDF_COLLIDE);

                kunmap(pages[i]);
        }
        LASSERTF(lu_pgs == 0, "left = %d", lu_pgs);
}
#else
#define mdc_adjust_dirpages(pages, cfs_pgs, lu_pgs) do {} while (0)
#endif  /* PAGE_SIZE > LU_PAGE_SIZE */

/* parameters for readdir page */
struct readpage_param {
        struct md_op_data       *rp_mod;
        __u64                   rp_off;
        int                     rp_hash64;
        struct obd_export       *rp_exp;
        struct md_callback      *rp_cb;
};

/**
 * Read pages from server.
 *
 * Page in MDS_READPAGE RPC is packed in LU_PAGE_SIZE, and each page contains
 * a header lu_dirpage which describes the start/end hash, and whether this
 * page is empty (contains no dir entry) or hash collide with next page.
 * After client receives reply, several pages will be integrated into dir page
 * in PAGE_SIZE (if PAGE_SIZE greater than LU_PAGE_SIZE), and the
 * lu_dirpage for this integrated page will be adjusted.
 **/
static int mdc_read_page_remote(void *data, struct page *page0)
{
        struct readpage_param *rp = data;
        struct page **page_pool;
        struct page *page;
        struct lu_dirpage *dp;
        int rd_pgs = 0; /* number of pages read actually */
        int npages;
        struct md_op_data *op_data = rp->rp_mod;
        struct ptlrpc_request *req;
        int max_pages = op_data->op_max_pages;
        struct inode *inode;
        struct lu_fid *fid;
        int i;
        int rc;

        LASSERT(max_pages > 0 && max_pages <= PTLRPC_MAX_BRW_PAGES);
        inode = op_data->op_data;
        fid = &op_data->op_fid1;
        LASSERT(inode);

        page_pool = kcalloc(max_pages, sizeof(page), GFP_NOFS);
        if (page_pool) {
                page_pool[0] = page0;
        } else {
                page_pool = &page0;
                max_pages = 1;
        }

        for (npages = 1; npages < max_pages; npages++) {
                page = page_cache_alloc_cold(inode->i_mapping);
                if (!page)
                        break;
                page_pool[npages] = page;
        }

        rc = mdc_getpage(rp->rp_exp, fid, rp->rp_off, page_pool, npages, &req);
        if (!rc) {
                int lu_pgs = req->rq_bulk->bd_nob_transferred;

                rd_pgs = (req->rq_bulk->bd_nob_transferred +
                          PAGE_SIZE - 1) >> PAGE_SHIFT;
                lu_pgs >>= LU_PAGE_SHIFT;
                LASSERT(!(req->rq_bulk->bd_nob_transferred & ~LU_PAGE_MASK));

                CDEBUG(D_INODE, "read %d(%d) pages\n", rd_pgs, lu_pgs);

                mdc_adjust_dirpages(page_pool, rd_pgs, lu_pgs);

                SetPageUptodate(page0);
        }

        unlock_page(page0);
        ptlrpc_req_finished(req);
        CDEBUG(D_CACHE, "read %d/%d pages\n", rd_pgs, npages);
        for (i = 1; i < npages; i++) {
                unsigned long offset;
                __u64 hash;
                int ret;

                page = page_pool[i];

                if (rc < 0 || i >= rd_pgs) {
                        put_page(page);
                        continue;
                }

                SetPageUptodate(page);

                dp = kmap(page);
                hash = le64_to_cpu(dp->ldp_hash_start);
                kunmap(page);

                offset = hash_x_index(hash, rp->rp_hash64);

                prefetchw(&page->flags);
                ret = add_to_page_cache_lru(page, inode->i_mapping, offset,
                                            GFP_KERNEL);
                if (!ret)
                        unlock_page(page);
                else
                        CDEBUG(D_VFSTRACE, "page %lu add to page cache failed: rc = %d\n",
                               offset, ret);
                put_page(page);
        }

        if (page_pool != &page0)
                kfree(page_pool);

        return rc;
}

/**
 * Read dir page from cache first, if it can not find it, read it from
 * server and add into the cache.
 *
 * \param[in] exp       MDC export
 * \param[in] op_data   client MD stack parameters, transferring parameters
 *                      between different layers on client MD stack.
 * \param[in] cb_op     callback required for ldlm lock enqueue during
 *                      read page
 * \param[in] hash_offset the hash offset of the page to be read
 * \param[in] ppage     the page to be read
 *
 * retval               = 0 get the page successfully
 *                      errno(<0) get the page failed
 */
static int mdc_read_page(struct obd_export *exp, struct md_op_data *op_data,
                         struct md_callback *cb_op, __u64 hash_offset,
                         struct page **ppage)
{
        struct lookup_intent it = { .it_op = IT_READDIR };
        struct page *page;
        struct inode *dir = op_data->op_data;
        struct address_space *mapping;
        struct lu_dirpage *dp;
        __u64 start = 0;
        __u64 end = 0;
        struct lustre_handle lockh;
        struct ptlrpc_request *enq_req = NULL;
        struct readpage_param rp_param;
        int rc;

        *ppage = NULL;

        LASSERT(dir);
        mapping = dir->i_mapping;

        rc = mdc_intent_lock(exp, op_data, &it, &enq_req,
                             cb_op->md_blocking_ast, 0);
        if (enq_req)
                ptlrpc_req_finished(enq_req);

        if (rc < 0) {
                CERROR("%s: "DFID" lock enqueue fails: rc = %d\n",
                       exp->exp_obd->obd_name, PFID(&op_data->op_fid1), rc);
                return rc;
        }

        rc = 0;
        lockh.cookie = it.it_lock_handle;
        mdc_set_lock_data(exp, &lockh, dir, NULL);

        rp_param.rp_off = hash_offset;
        rp_param.rp_hash64 = op_data->op_cli_flags & CLI_HASH64;
        page = mdc_page_locate(mapping, &rp_param.rp_off, &start, &end,
                               rp_param.rp_hash64);
        if (IS_ERR(page)) {
                CDEBUG(D_INFO, "%s: dir page locate: " DFID " at %llu: rc %ld\n",
                       exp->exp_obd->obd_name, PFID(&op_data->op_fid1),
                       rp_param.rp_off, PTR_ERR(page));
                rc = PTR_ERR(page);
                goto out_unlock;
        } else if (page) {
                /*
                 * XXX nikita: not entirely correct handling of a corner case:
                 * suppose hash chain of entries with hash value HASH crosses
                 * border between pages P0 and P1. First both P0 and P1 are
                 * cached, seekdir() is called for some entry from the P0 part
                 * of the chain. Later P0 goes out of cache. telldir(HASH)
                 * happens and finds P1, as it starts with matching hash
                 * value. Remaining entries from P0 part of the chain are
                 * skipped. (Is that really a bug?)
                 *
                 * Possible solutions: 0. don't cache P1 is such case, handle
                 * it as an "overflow" page. 1. invalidate all pages at
                 * once. 2. use HASH|1 as an index for P1.
                 */
                goto hash_collision;
        }

        rp_param.rp_exp = exp;
        rp_param.rp_mod = op_data;
        page = read_cache_page(mapping,
                               hash_x_index(rp_param.rp_off,
                                            rp_param.rp_hash64),
                               mdc_read_page_remote, &rp_param);
        if (IS_ERR(page)) {
                CERROR("%s: read cache page: "DFID" at %llu: rc %ld\n",
                       exp->exp_obd->obd_name, PFID(&op_data->op_fid1),
                       rp_param.rp_off, PTR_ERR(page));
                rc = PTR_ERR(page);
                goto out_unlock;
        }

        wait_on_page_locked(page);
        (void)kmap(page);
        if (!PageUptodate(page)) {
                CERROR("%s: page not updated: "DFID" at %llu: rc %d\n",
                       exp->exp_obd->obd_name, PFID(&op_data->op_fid1),
                       rp_param.rp_off, -5);
                goto fail;
        }
        if (!PageChecked(page))
                SetPageChecked(page);
        if (PageError(page)) {
                CERROR("%s: page error: "DFID" at %llu: rc %d\n",
                       exp->exp_obd->obd_name, PFID(&op_data->op_fid1),
                       rp_param.rp_off, -5);
                goto fail;
        }

hash_collision:
        dp = page_address(page);
        if (BITS_PER_LONG == 32 && rp_param.rp_hash64) {
                start = le64_to_cpu(dp->ldp_hash_start) >> 32;
                end = le64_to_cpu(dp->ldp_hash_end) >> 32;
                rp_param.rp_off = hash_offset >> 32;
        } else {
                start = le64_to_cpu(dp->ldp_hash_start);
                end = le64_to_cpu(dp->ldp_hash_end);
                rp_param.rp_off = hash_offset;
        }
        if (end == start) {
                LASSERT(start == rp_param.rp_off);
                CWARN("Page-wide hash collision: %#lx\n", (unsigned long)end);
#if BITS_PER_LONG == 32
                CWARN("Real page-wide hash collision at [%llu %llu] with hash %llu\n",
                      le64_to_cpu(dp->ldp_hash_start),
                      le64_to_cpu(dp->ldp_hash_end), hash_offset);
#endif
                /*
                 * Fetch whole overflow chain...
                 *
                 * XXX not yet.
                 */
                goto fail;
        }
        *ppage = page;
out_unlock:
        ldlm_lock_decref(&lockh, it.it_lock_mode);
        return rc;
fail:
        kunmap(page);
        mdc_release_page(page, 1);
        rc = -EIO;
        goto out_unlock;
}

static int mdc_statfs(const struct lu_env *env,
                      struct obd_export *exp, struct obd_statfs *osfs,
                      __u64 max_age, __u32 flags)
{
        struct obd_device     *obd = class_exp2obd(exp);
        struct ptlrpc_request *req;
        struct obd_statfs     *msfs;
        struct obd_import     *imp = NULL;
        int                 rc;

        /*
         * Since the request might also come from lprocfs, so we need
         * sync this with client_disconnect_export Bug15684
         */
        down_read(&obd->u.cli.cl_sem);
        if (obd->u.cli.cl_import)
                imp = class_import_get(obd->u.cli.cl_import);
        up_read(&obd->u.cli.cl_sem);
        if (!imp)
                return -ENODEV;

        req = ptlrpc_request_alloc_pack(imp, &RQF_MDS_STATFS,
                                        LUSTRE_MDS_VERSION, MDS_STATFS);
        if (!req) {
                rc = -ENOMEM;
                goto output;
        }

        ptlrpc_request_set_replen(req);

        if (flags & OBD_STATFS_NODELAY) {
                /* procfs requests not want stay in wait for avoid deadlock */
                req->rq_no_resend = 1;
                req->rq_no_delay = 1;
        }

        rc = ptlrpc_queue_wait(req);
        if (rc) {
                /* check connection error first */
                if (imp->imp_connect_error)
                        rc = imp->imp_connect_error;
                goto out;
        }

        msfs = req_capsule_server_get(&req->rq_pill, &RMF_OBD_STATFS);
        if (!msfs) {
                rc = -EPROTO;
                goto out;
        }

        *osfs = *msfs;
out:
        ptlrpc_req_finished(req);
output:
        class_import_put(imp);
        return rc;
}

static int mdc_ioc_fid2path(struct obd_export *exp, struct getinfo_fid2path *gf)
{
        __u32 keylen, vallen;
        void *key;
        int rc;

        if (gf->gf_pathlen > PATH_MAX)
                return -ENAMETOOLONG;
        if (gf->gf_pathlen < 2)
                return -EOVERFLOW;

        /* Key is KEY_FID2PATH + getinfo_fid2path description */
        keylen = cfs_size_round(sizeof(KEY_FID2PATH)) + sizeof(*gf);
        key = kzalloc(keylen, GFP_NOFS);
        if (!key)
                return -ENOMEM;
        memcpy(key, KEY_FID2PATH, sizeof(KEY_FID2PATH));
        memcpy(key + cfs_size_round(sizeof(KEY_FID2PATH)), gf, sizeof(*gf));

        CDEBUG(D_IOCTL, "path get "DFID" from %llu #%d\n",
               PFID(&gf->gf_fid), gf->gf_recno, gf->gf_linkno);

        if (!fid_is_sane(&gf->gf_fid)) {
                rc = -EINVAL;
                goto out;
        }

        /* Val is struct getinfo_fid2path result plus path */
        vallen = sizeof(*gf) + gf->gf_pathlen;

        rc = obd_get_info(NULL, exp, keylen, key, &vallen, gf, NULL);
        if (rc != 0 && rc != -EREMOTE)
                goto out;

        if (vallen <= sizeof(*gf)) {
                rc = -EPROTO;
                goto out;
        } else if (vallen > sizeof(*gf) + gf->gf_pathlen) {
                rc = -EOVERFLOW;
                goto out;
        }

        CDEBUG(D_IOCTL, "path get "DFID" from %llu #%d\n%s\n",
               PFID(&gf->gf_fid), gf->gf_recno, gf->gf_linkno, gf->gf_path);

out:
        kfree(key);
        return rc;
}

static int mdc_ioc_hsm_progress(struct obd_export *exp,
                                struct hsm_progress_kernel *hpk)
{
        struct obd_import               *imp = class_exp2cliimp(exp);
        struct hsm_progress_kernel      *req_hpk;
        struct ptlrpc_request           *req;
        int                              rc;

        req = ptlrpc_request_alloc_pack(imp, &RQF_MDS_HSM_PROGRESS,
                                        LUSTRE_MDS_VERSION, MDS_HSM_PROGRESS);
        if (!req) {
                rc = -ENOMEM;
                goto out;
        }

        mdc_pack_body(req, NULL, 0, 0, -1, 0);

        /* Copy hsm_progress struct */
        req_hpk = req_capsule_client_get(&req->rq_pill, &RMF_MDS_HSM_PROGRESS);
        if (!req_hpk) {
                rc = -EPROTO;
                goto out;
        }

        *req_hpk = *hpk;
        req_hpk->hpk_errval = lustre_errno_hton(hpk->hpk_errval);

        ptlrpc_request_set_replen(req);

        rc = mdc_queue_wait(req);
out:
        ptlrpc_req_finished(req);
        return rc;
}

static int mdc_ioc_hsm_ct_register(struct obd_import *imp, __u32 archives)
{
        __u32                   *archive_mask;
        struct ptlrpc_request   *req;
        int                      rc;

        req = ptlrpc_request_alloc_pack(imp, &RQF_MDS_HSM_CT_REGISTER,
                                        LUSTRE_MDS_VERSION,
                                        MDS_HSM_CT_REGISTER);
        if (!req) {
                rc = -ENOMEM;
                goto out;
        }

        mdc_pack_body(req, NULL, 0, 0, -1, 0);

        /* Copy hsm_progress struct */
        archive_mask = req_capsule_client_get(&req->rq_pill,
                                              &RMF_MDS_HSM_ARCHIVE);
        if (!archive_mask) {
                rc = -EPROTO;
                goto out;
        }

        *archive_mask = archives;

        ptlrpc_request_set_replen(req);

        rc = mdc_queue_wait(req);
out:
        ptlrpc_req_finished(req);
        return rc;
}

static int mdc_ioc_hsm_current_action(struct obd_export *exp,
                                      struct md_op_data *op_data)
{
        struct hsm_current_action       *hca = op_data->op_data;
        struct hsm_current_action       *req_hca;
        struct ptlrpc_request           *req;
        int                              rc;

        req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                   &RQF_MDS_HSM_ACTION);
        if (!req)
                return -ENOMEM;

        rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, MDS_HSM_ACTION);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        mdc_pack_body(req, &op_data->op_fid1, 0, 0,
                      op_data->op_suppgids[0], 0);

        ptlrpc_request_set_replen(req);

        rc = mdc_queue_wait(req);
        if (rc)
                goto out;

        req_hca = req_capsule_server_get(&req->rq_pill,
                                         &RMF_MDS_HSM_CURRENT_ACTION);
        if (!req_hca) {
                rc = -EPROTO;
                goto out;
        }

        *hca = *req_hca;

out:
        ptlrpc_req_finished(req);
        return rc;
}

static int mdc_ioc_hsm_ct_unregister(struct obd_import *imp)
{
        struct ptlrpc_request   *req;
        int                      rc;

        req = ptlrpc_request_alloc_pack(imp, &RQF_MDS_HSM_CT_UNREGISTER,
                                        LUSTRE_MDS_VERSION,
                                        MDS_HSM_CT_UNREGISTER);
        if (!req) {
                rc = -ENOMEM;
                goto out;
        }

        mdc_pack_body(req, NULL, 0, 0, -1, 0);

        ptlrpc_request_set_replen(req);

        rc = mdc_queue_wait(req);
out:
        ptlrpc_req_finished(req);
        return rc;
}

static int mdc_ioc_hsm_state_get(struct obd_export *exp,
                                 struct md_op_data *op_data)
{
        struct hsm_user_state   *hus = op_data->op_data;
        struct hsm_user_state   *req_hus;
        struct ptlrpc_request   *req;
        int                      rc;

        req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                   &RQF_MDS_HSM_STATE_GET);
        if (!req)
                return -ENOMEM;

        rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, MDS_HSM_STATE_GET);
        if (rc != 0) {
                ptlrpc_request_free(req);
                return rc;
        }

        mdc_pack_body(req, &op_data->op_fid1, 0, 0,
                      op_data->op_suppgids[0], 0);

        ptlrpc_request_set_replen(req);

        rc = mdc_queue_wait(req);
        if (rc)
                goto out;

        req_hus = req_capsule_server_get(&req->rq_pill, &RMF_HSM_USER_STATE);
        if (!req_hus) {
                rc = -EPROTO;
                goto out;
        }

        *hus = *req_hus;

out:
        ptlrpc_req_finished(req);
        return rc;
}

static int mdc_ioc_hsm_state_set(struct obd_export *exp,
                                 struct md_op_data *op_data)
{
        struct hsm_state_set    *hss = op_data->op_data;
        struct hsm_state_set    *req_hss;
        struct ptlrpc_request   *req;
        int                      rc;

        req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                   &RQF_MDS_HSM_STATE_SET);
        if (!req)
                return -ENOMEM;

        rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, MDS_HSM_STATE_SET);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        mdc_pack_body(req, &op_data->op_fid1, 0, 0,
                      op_data->op_suppgids[0], 0);

        /* Copy states */
        req_hss = req_capsule_client_get(&req->rq_pill, &RMF_HSM_STATE_SET);
        if (!req_hss) {
                rc = -EPROTO;
                goto out;
        }
        *req_hss = *hss;

        ptlrpc_request_set_replen(req);

        rc = mdc_queue_wait(req);
out:
        ptlrpc_req_finished(req);
        return rc;
}

static int mdc_ioc_hsm_request(struct obd_export *exp,
                               struct hsm_user_request *hur)
{
        struct obd_import       *imp = class_exp2cliimp(exp);
        struct ptlrpc_request   *req;
        struct hsm_request      *req_hr;
        struct hsm_user_item    *req_hui;
        char                    *req_opaque;
        int                      rc;

        req = ptlrpc_request_alloc(imp, &RQF_MDS_HSM_REQUEST);
        if (!req) {
                rc = -ENOMEM;
                goto out;
        }

        req_capsule_set_size(&req->rq_pill, &RMF_MDS_HSM_USER_ITEM, RCL_CLIENT,
                             hur->hur_request.hr_itemcount
                             * sizeof(struct hsm_user_item));
        req_capsule_set_size(&req->rq_pill, &RMF_GENERIC_DATA, RCL_CLIENT,
                             hur->hur_request.hr_data_len);

        rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, MDS_HSM_REQUEST);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        mdc_pack_body(req, NULL, 0, 0, -1, 0);

        /* Copy hsm_request struct */
        req_hr = req_capsule_client_get(&req->rq_pill, &RMF_MDS_HSM_REQUEST);
        if (!req_hr) {
                rc = -EPROTO;
                goto out;
        }
        *req_hr = hur->hur_request;

        /* Copy hsm_user_item structs */
        req_hui = req_capsule_client_get(&req->rq_pill, &RMF_MDS_HSM_USER_ITEM);
        if (!req_hui) {
                rc = -EPROTO;
                goto out;
        }
        memcpy(req_hui, hur->hur_user_item,
               hur->hur_request.hr_itemcount * sizeof(struct hsm_user_item));

        /* Copy opaque field */
        req_opaque = req_capsule_client_get(&req->rq_pill, &RMF_GENERIC_DATA);
        if (!req_opaque) {
                rc = -EPROTO;
                goto out;
        }
        memcpy(req_opaque, hur_data(hur), hur->hur_request.hr_data_len);

        ptlrpc_request_set_replen(req);

        rc = mdc_queue_wait(req);
out:
        ptlrpc_req_finished(req);
        return rc;
}

static struct kuc_hdr *changelog_kuc_hdr(char *buf, size_t len, u32 flags)
{
        struct kuc_hdr *lh = (struct kuc_hdr *)buf;

        LASSERT(len <= KUC_CHANGELOG_MSG_MAXSIZE);

        lh->kuc_magic = KUC_MAGIC;
        lh->kuc_transport = KUC_TRANSPORT_CHANGELOG;
        lh->kuc_flags = flags;
        lh->kuc_msgtype = CL_RECORD;
        lh->kuc_msglen = len;
        return lh;
}

struct changelog_show {
        __u64           cs_startrec;
        enum changelog_send_flag        cs_flags;
        struct file     *cs_fp;
        char            *cs_buf;
        struct obd_device *cs_obd;
};

static inline char *cs_obd_name(struct changelog_show *cs)
{
        return cs->cs_obd->obd_name;
}

static int changelog_kkuc_cb(const struct lu_env *env, struct llog_handle *llh,
                             struct llog_rec_hdr *hdr, void *data)
{
        struct changelog_show *cs = data;
        struct llog_changelog_rec *rec = (struct llog_changelog_rec *)hdr;
        struct kuc_hdr *lh;
        size_t len;
        int rc;

        if (rec->cr_hdr.lrh_type != CHANGELOG_REC) {
                rc = -EINVAL;
                CERROR("%s: not a changelog rec %x/%d: rc = %d\n",
                       cs_obd_name(cs), rec->cr_hdr.lrh_type,
                       rec->cr.cr_type, rc);
                return rc;
        }

        if (rec->cr.cr_index < cs->cs_startrec) {
                /* Skip entries earlier than what we are interested in */
                CDEBUG(D_HSM, "rec=%llu start=%llu\n",
                       rec->cr.cr_index, cs->cs_startrec);
                return 0;
        }

        CDEBUG(D_HSM, "%llu %02d%-5s %llu 0x%x t=" DFID " p=" DFID
                " %.*s\n", rec->cr.cr_index, rec->cr.cr_type,
                changelog_type2str(rec->cr.cr_type), rec->cr.cr_time,
                rec->cr.cr_flags & CLF_FLAGMASK,
                PFID(&rec->cr.cr_tfid), PFID(&rec->cr.cr_pfid),
                rec->cr.cr_namelen, changelog_rec_name(&rec->cr));

        len = sizeof(*lh) + changelog_rec_size(&rec->cr) + rec->cr.cr_namelen;

        /* Set up the message */
        lh = changelog_kuc_hdr(cs->cs_buf, len, cs->cs_flags);
        memcpy(lh + 1, &rec->cr, len - sizeof(*lh));

        rc = libcfs_kkuc_msg_put(cs->cs_fp, lh);
        CDEBUG(D_HSM, "kucmsg fp %p len %zu rc %d\n", cs->cs_fp, len, rc);

        return rc;
}

static int mdc_changelog_send_thread(void *csdata)
{
        enum llog_flag flags = LLOG_F_IS_CAT;
        struct changelog_show *cs = csdata;
        struct llog_ctxt *ctxt = NULL;
        struct llog_handle *llh = NULL;
        struct kuc_hdr *kuch;
        int rc;

        CDEBUG(D_HSM, "changelog to fp=%p start %llu\n",
               cs->cs_fp, cs->cs_startrec);

        cs->cs_buf = kzalloc(KUC_CHANGELOG_MSG_MAXSIZE, GFP_NOFS);
        if (!cs->cs_buf) {
                rc = -ENOMEM;
                goto out;
        }

        /* Set up the remote catalog handle */
        ctxt = llog_get_context(cs->cs_obd, LLOG_CHANGELOG_REPL_CTXT);
        if (!ctxt) {
                rc = -ENOENT;
                goto out;
        }
        rc = llog_open(NULL, ctxt, &llh, NULL, CHANGELOG_CATALOG,
                       LLOG_OPEN_EXISTS);
        if (rc) {
                CERROR("%s: fail to open changelog catalog: rc = %d\n",
                       cs_obd_name(cs), rc);
                goto out;
        }

        if (cs->cs_flags & CHANGELOG_FLAG_JOBID)
                flags |= LLOG_F_EXT_JOBID;

        rc = llog_init_handle(NULL, llh, flags, NULL);
        if (rc) {
                CERROR("llog_init_handle failed %d\n", rc);
                goto out;
        }

        rc = llog_cat_process(NULL, llh, changelog_kkuc_cb, cs, 0, 0);

        /* Send EOF no matter what our result */
        kuch = changelog_kuc_hdr(cs->cs_buf, sizeof(*kuch), cs->cs_flags);
        if (kuch) {
                kuch->kuc_msgtype = CL_EOF;
                libcfs_kkuc_msg_put(cs->cs_fp, kuch);
        }

out:
        fput(cs->cs_fp);
        if (llh)
                llog_cat_close(NULL, llh);
        if (ctxt)
                llog_ctxt_put(ctxt);
        kfree(cs->cs_buf);
        kfree(cs);
        return rc;
}

static int mdc_ioc_changelog_send(struct obd_device *obd,
                                  struct ioc_changelog *icc)
{
        struct changelog_show *cs;
        struct task_struct *task;
        int rc;

        /* Freed in mdc_changelog_send_thread */
        cs = kzalloc(sizeof(*cs), GFP_NOFS);
        if (!cs)
                return -ENOMEM;

        cs->cs_obd = obd;
        cs->cs_startrec = icc->icc_recno;
        /* matching fput in mdc_changelog_send_thread */
        cs->cs_fp = fget(icc->icc_id);
        cs->cs_flags = icc->icc_flags;

        /*
         * New thread because we should return to user app before
         * writing into our pipe
         */
        task = kthread_run(mdc_changelog_send_thread, cs,
                           "mdc_clg_send_thread");
        if (IS_ERR(task)) {

                rc = PTR_ERR(task);
                CERROR("%s: can't start changelog thread: rc = %d\n",
                       cs_obd_name(cs), rc);
                kfree(cs);
        } else {
                rc = 0;
                CDEBUG(D_HSM, "%s: started changelog thread\n",
                       cs_obd_name(cs));
        }

        CERROR("Failed to start changelog thread: %d\n", rc);
        return rc;
}

static int mdc_ioc_hsm_ct_start(struct obd_export *exp,
                                struct lustre_kernelcomm *lk);

static int mdc_quotacheck(struct obd_device *unused, struct obd_export *exp,
                          struct obd_quotactl *oqctl)
{
        struct client_obd       *cli = &exp->exp_obd->u.cli;
        struct ptlrpc_request   *req;
        struct obd_quotactl     *body;
        int                   rc;

        req = ptlrpc_request_alloc_pack(class_exp2cliimp(exp),
                                        &RQF_MDS_QUOTACHECK, LUSTRE_MDS_VERSION,
                                        MDS_QUOTACHECK);
        if (!req)
                return -ENOMEM;

        body = req_capsule_client_get(&req->rq_pill, &RMF_OBD_QUOTACTL);
        *body = *oqctl;

        ptlrpc_request_set_replen(req);

        /* the next poll will find -ENODATA, that means quotacheck is
         * going on
         */
        cli->cl_qchk_stat = -ENODATA;
        rc = ptlrpc_queue_wait(req);
        if (rc)
                cli->cl_qchk_stat = rc;
        ptlrpc_req_finished(req);
        return rc;
}

static int mdc_quota_poll_check(struct obd_export *exp,
                                struct if_quotacheck *qchk)
{
        struct client_obd *cli = &exp->exp_obd->u.cli;
        int rc;

        qchk->obd_uuid = cli->cl_target_uuid;
        memcpy(qchk->obd_type, LUSTRE_MDS_NAME, strlen(LUSTRE_MDS_NAME));

        rc = cli->cl_qchk_stat;
        /* the client is not the previous one */
        if (rc == CL_NOT_QUOTACHECKED)
                rc = -EINTR;
        return rc;
}

static int mdc_quotactl(struct obd_device *unused, struct obd_export *exp,
                        struct obd_quotactl *oqctl)
{
        struct ptlrpc_request   *req;
        struct obd_quotactl     *oqc;
        int                   rc;

        req = ptlrpc_request_alloc_pack(class_exp2cliimp(exp),
                                        &RQF_MDS_QUOTACTL, LUSTRE_MDS_VERSION,
                                        MDS_QUOTACTL);
        if (!req)
                return -ENOMEM;

        oqc = req_capsule_client_get(&req->rq_pill, &RMF_OBD_QUOTACTL);
        *oqc = *oqctl;

        ptlrpc_request_set_replen(req);
        ptlrpc_at_set_req_timeout(req);
        req->rq_no_resend = 1;

        rc = ptlrpc_queue_wait(req);
        if (rc)
                CERROR("ptlrpc_queue_wait failed, rc: %d\n", rc);

        if (req->rq_repmsg) {
                oqc = req_capsule_server_get(&req->rq_pill, &RMF_OBD_QUOTACTL);
                if (oqc) {
                        *oqctl = *oqc;
                } else if (!rc) {
                        CERROR("Can't unpack obd_quotactl\n");
                        rc = -EPROTO;
                }
        } else if (!rc) {
                CERROR("Can't unpack obd_quotactl\n");
                rc = -EPROTO;
        }
        ptlrpc_req_finished(req);

        return rc;
}

static int mdc_ioc_swap_layouts(struct obd_export *exp,
                                struct md_op_data *op_data)
{
        LIST_HEAD(cancels);
        struct ptlrpc_request   *req;
        int                      rc, count;
        struct mdc_swap_layouts *msl, *payload;

        msl = op_data->op_data;

        /* When the MDT will get the MDS_SWAP_LAYOUTS RPC the
         * first thing it will do is to cancel the 2 layout
         * locks hold by this client.
         * So the client must cancel its layout locks on the 2 fids
         * with the request RPC to avoid extra RPC round trips
         */
        count = mdc_resource_get_unused(exp, &op_data->op_fid1, &cancels,
                                        LCK_CR, MDS_INODELOCK_LAYOUT |
                                        MDS_INODELOCK_XATTR);
        count += mdc_resource_get_unused(exp, &op_data->op_fid2, &cancels,
                                         LCK_CR, MDS_INODELOCK_LAYOUT |
                                         MDS_INODELOCK_XATTR);

        req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                   &RQF_MDS_SWAP_LAYOUTS);
        if (!req) {
                ldlm_lock_list_put(&cancels, l_bl_ast, count);
                return -ENOMEM;
        }

        rc = mdc_prep_elc_req(exp, req, MDS_SWAP_LAYOUTS, &cancels, count);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        mdc_swap_layouts_pack(req, op_data);

        payload = req_capsule_client_get(&req->rq_pill, &RMF_SWAP_LAYOUTS);
        LASSERT(payload);

        *payload = *msl;

        ptlrpc_request_set_replen(req);

        rc = ptlrpc_queue_wait(req);

        ptlrpc_req_finished(req);
        return rc;
}

static int mdc_iocontrol(unsigned int cmd, struct obd_export *exp, int len,
                         void *karg, void __user *uarg)
{
        struct obd_device *obd = exp->exp_obd;
        struct obd_ioctl_data *data = karg;
        struct obd_import *imp = obd->u.cli.cl_import;
        int rc;

        if (!try_module_get(THIS_MODULE)) {
                CERROR("%s: cannot get module '%s'\n", obd->obd_name,
                       module_name(THIS_MODULE));
                return -EINVAL;
        }
        switch (cmd) {
        case OBD_IOC_CHANGELOG_SEND:
                rc = mdc_ioc_changelog_send(obd, karg);
                goto out;
        case OBD_IOC_CHANGELOG_CLEAR: {
                struct ioc_changelog *icc = karg;
                struct changelog_setinfo cs = {
                        .cs_recno = icc->icc_recno,
                        .cs_id = icc->icc_id
                };

                rc = obd_set_info_async(NULL, exp, strlen(KEY_CHANGELOG_CLEAR),
                                        KEY_CHANGELOG_CLEAR, sizeof(cs), &cs,
                                        NULL);
                goto out;
        }
        case OBD_IOC_FID2PATH:
                rc = mdc_ioc_fid2path(exp, karg);
                goto out;
        case LL_IOC_HSM_CT_START:
                rc = mdc_ioc_hsm_ct_start(exp, karg);
                /* ignore if it was already registered on this MDS. */
                if (rc == -EEXIST)
                        rc = 0;
                goto out;
        case LL_IOC_HSM_PROGRESS:
                rc = mdc_ioc_hsm_progress(exp, karg);
                goto out;
        case LL_IOC_HSM_STATE_GET:
                rc = mdc_ioc_hsm_state_get(exp, karg);
                goto out;
        case LL_IOC_HSM_STATE_SET:
                rc = mdc_ioc_hsm_state_set(exp, karg);
                goto out;
        case LL_IOC_HSM_ACTION:
                rc = mdc_ioc_hsm_current_action(exp, karg);
                goto out;
        case LL_IOC_HSM_REQUEST:
                rc = mdc_ioc_hsm_request(exp, karg);
                goto out;
        case OBD_IOC_CLIENT_RECOVER:
                rc = ptlrpc_recover_import(imp, data->ioc_inlbuf1, 0);
                if (rc < 0)
                        goto out;
                rc = 0;
                goto out;
        case IOC_OSC_SET_ACTIVE:
                rc = ptlrpc_set_import_active(imp, data->ioc_offset);
                goto out;
        case OBD_IOC_POLL_QUOTACHECK:
                rc = mdc_quota_poll_check(exp, (struct if_quotacheck *)karg);
                goto out;
        case OBD_IOC_PING_TARGET:
                rc = ptlrpc_obd_ping(obd);
                goto out;
        /*
         * Normally IOC_OBD_STATFS, OBD_IOC_QUOTACTL iocontrol are handled by
         * LMV instead of MDC. But when the cluster is upgraded from 1.8,
         * there'd be no LMV layer thus we might be called here. Eventually
         * this code should be removed.
         * bz20731, LU-592.
         */
        case IOC_OBD_STATFS: {
                struct obd_statfs stat_buf = {0};

                if (*((__u32 *)data->ioc_inlbuf2) != 0) {
                        rc = -ENODEV;
                        goto out;
                }

                /* copy UUID */
                if (copy_to_user(data->ioc_pbuf2, obd2cli_tgt(obd),
                                 min_t(size_t, data->ioc_plen2,
                                       sizeof(struct obd_uuid)))) {
                        rc = -EFAULT;
                        goto out;
                }

                rc = mdc_statfs(NULL, obd->obd_self_export, &stat_buf,
                                cfs_time_shift_64(-OBD_STATFS_CACHE_SECONDS),
                                0);
                if (rc != 0)
                        goto out;

                if (copy_to_user(data->ioc_pbuf1, &stat_buf,
                                 min_t(size_t, data->ioc_plen1,
                                       sizeof(stat_buf)))) {
                        rc = -EFAULT;
                        goto out;
                }

                rc = 0;
                goto out;
        }
        case OBD_IOC_QUOTACTL: {
                struct if_quotactl *qctl = karg;
                struct obd_quotactl *oqctl;

                oqctl = kzalloc(sizeof(*oqctl), GFP_NOFS);
                if (!oqctl) {
                        rc = -ENOMEM;
                        goto out;
                }

                QCTL_COPY(oqctl, qctl);
                rc = obd_quotactl(exp, oqctl);
                if (rc == 0) {
                        QCTL_COPY(qctl, oqctl);
                        qctl->qc_valid = QC_MDTIDX;
                        qctl->obd_uuid = obd->u.cli.cl_target_uuid;
                }

                kfree(oqctl);
                goto out;
        }
        case LL_IOC_GET_CONNECT_FLAGS:
                if (copy_to_user(uarg, exp_connect_flags_ptr(exp),
                                 sizeof(*exp_connect_flags_ptr(exp)))) {
                        rc = -EFAULT;
                        goto out;
                }

                rc = 0;
                goto out;
        case LL_IOC_LOV_SWAP_LAYOUTS:
                rc = mdc_ioc_swap_layouts(exp, karg);
                goto out;
        default:
                CERROR("unrecognised ioctl: cmd = %#x\n", cmd);
                rc = -ENOTTY;
                goto out;
        }
out:
        module_put(THIS_MODULE);

        return rc;
}

static int mdc_get_info_rpc(struct obd_export *exp,
                            u32 keylen, void *key,
                            int vallen, void *val)
{
        struct obd_import      *imp = class_exp2cliimp(exp);
        struct ptlrpc_request  *req;
        char               *tmp;
        int                  rc = -EINVAL;

        req = ptlrpc_request_alloc(imp, &RQF_MDS_GET_INFO);
        if (!req)
                return -ENOMEM;

        req_capsule_set_size(&req->rq_pill, &RMF_GETINFO_KEY,
                             RCL_CLIENT, keylen);
        req_capsule_set_size(&req->rq_pill, &RMF_GETINFO_VALLEN,
                             RCL_CLIENT, sizeof(__u32));

        rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, MDS_GET_INFO);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        tmp = req_capsule_client_get(&req->rq_pill, &RMF_GETINFO_KEY);
        memcpy(tmp, key, keylen);
        tmp = req_capsule_client_get(&req->rq_pill, &RMF_GETINFO_VALLEN);
        memcpy(tmp, &vallen, sizeof(__u32));

        req_capsule_set_size(&req->rq_pill, &RMF_GETINFO_VAL,
                             RCL_SERVER, vallen);
        ptlrpc_request_set_replen(req);

        rc = ptlrpc_queue_wait(req);
        /* -EREMOTE means the get_info result is partial, and it needs to
         * continue on another MDT, see fid2path part in lmv_iocontrol
         */
        if (rc == 0 || rc == -EREMOTE) {
                tmp = req_capsule_server_get(&req->rq_pill, &RMF_GETINFO_VAL);
                memcpy(val, tmp, vallen);
                if (ptlrpc_rep_need_swab(req)) {
                        if (KEY_IS(KEY_FID2PATH))
                                lustre_swab_fid2path(val);
                }
        }
        ptlrpc_req_finished(req);

        return rc;
}

static void lustre_swab_hai(struct hsm_action_item *h)
{
        __swab32s(&h->hai_len);
        __swab32s(&h->hai_action);
        lustre_swab_lu_fid(&h->hai_fid);
        lustre_swab_lu_fid(&h->hai_dfid);
        __swab64s(&h->hai_cookie);
        __swab64s(&h->hai_extent.offset);
        __swab64s(&h->hai_extent.length);
        __swab64s(&h->hai_gid);
}

static void lustre_swab_hal(struct hsm_action_list *h)
{
        struct hsm_action_item  *hai;
        u32 i;

        __swab32s(&h->hal_version);
        __swab32s(&h->hal_count);
        __swab32s(&h->hal_archive_id);
        __swab64s(&h->hal_flags);
        hai = hai_first(h);
        for (i = 0; i < h->hal_count; i++, hai = hai_next(hai))
                lustre_swab_hai(hai);
}

static void lustre_swab_kuch(struct kuc_hdr *l)
{
        __swab16s(&l->kuc_magic);
        /* __u8 l->kuc_transport */
        __swab16s(&l->kuc_msgtype);
        __swab16s(&l->kuc_msglen);
}

static int mdc_ioc_hsm_ct_start(struct obd_export *exp,
                                struct lustre_kernelcomm *lk)
{
        struct obd_import  *imp = class_exp2cliimp(exp);
        __u32               archive = lk->lk_data;
        int                 rc = 0;

        if (lk->lk_group != KUC_GRP_HSM) {
                CERROR("Bad copytool group %d\n", lk->lk_group);
                return -EINVAL;
        }

        CDEBUG(D_HSM, "CT start r%d w%d u%d g%d f%#x\n", lk->lk_rfd, lk->lk_wfd,
               lk->lk_uid, lk->lk_group, lk->lk_flags);

        if (lk->lk_flags & LK_FLG_STOP) {
                /* Unregister with the coordinator */
                rc = mdc_ioc_hsm_ct_unregister(imp);
        } else {
                rc = mdc_ioc_hsm_ct_register(imp, archive);
        }

        return rc;
}

/**
 * Send a message to any listening copytools
 * @param val KUC message (kuc_hdr + hsm_action_list)
 * @param len total length of message
 */
static int mdc_hsm_copytool_send(size_t len, void *val)
{
        struct kuc_hdr          *lh = (struct kuc_hdr *)val;
        struct hsm_action_list  *hal = (struct hsm_action_list *)(lh + 1);

        if (len < sizeof(*lh) + sizeof(*hal)) {
                CERROR("Short HSM message %zu < %zu\n", len,
                       sizeof(*lh) + sizeof(*hal));
                return -EPROTO;
        }
        if (lh->kuc_magic == __swab16(KUC_MAGIC)) {
                lustre_swab_kuch(lh);
                lustre_swab_hal(hal);
        } else if (lh->kuc_magic != KUC_MAGIC) {
                CERROR("Bad magic %x!=%x\n", lh->kuc_magic, KUC_MAGIC);
                return -EPROTO;
        }

        CDEBUG(D_HSM,
               "Received message mg=%x t=%d m=%d l=%d actions=%d on %s\n",
               lh->kuc_magic, lh->kuc_transport, lh->kuc_msgtype,
               lh->kuc_msglen, hal->hal_count, hal->hal_fsname);

        /* Broadcast to HSM listeners */
        return libcfs_kkuc_group_put(KUC_GRP_HSM, lh);
}

/**
 * callback function passed to kuc for re-registering each HSM copytool
 * running on MDC, after MDT shutdown/recovery.
 * @param data copytool registration data
 * @param cb_arg callback argument (obd_import)
 */
static int mdc_hsm_ct_reregister(void *data, void *cb_arg)
{
        struct kkuc_ct_data     *kcd = data;
        struct obd_import       *imp = (struct obd_import *)cb_arg;
        int                      rc;

        if (!kcd || kcd->kcd_magic != KKUC_CT_DATA_MAGIC)
                return -EPROTO;

        if (!obd_uuid_equals(&kcd->kcd_uuid, &imp->imp_obd->obd_uuid))
                return 0;

        CDEBUG(D_HA, "%s: recover copytool registration to MDT (archive=%#x)\n",
               imp->imp_obd->obd_name, kcd->kcd_archive);
        rc = mdc_ioc_hsm_ct_register(imp, kcd->kcd_archive);

        /* ignore error if the copytool is already registered */
        return (rc == -EEXIST) ? 0 : rc;
}

static int mdc_set_info_async(const struct lu_env *env,
                              struct obd_export *exp,
                              u32 keylen, void *key,
                              u32 vallen, void *val,
                              struct ptlrpc_request_set *set)
{
        struct obd_import       *imp = class_exp2cliimp(exp);
        int                      rc;

        if (KEY_IS(KEY_READ_ONLY)) {
                if (vallen != sizeof(int))
                        return -EINVAL;

                spin_lock(&imp->imp_lock);
                if (*((int *)val)) {
                        imp->imp_connect_flags_orig |= OBD_CONNECT_RDONLY;
                        imp->imp_connect_data.ocd_connect_flags |=
                                                        OBD_CONNECT_RDONLY;
                } else {
                        imp->imp_connect_flags_orig &= ~OBD_CONNECT_RDONLY;
                        imp->imp_connect_data.ocd_connect_flags &=
                                                        ~OBD_CONNECT_RDONLY;
                }
                spin_unlock(&imp->imp_lock);

                return do_set_info_async(imp, MDS_SET_INFO, LUSTRE_MDS_VERSION,
                                         keylen, key, vallen, val, set);
        }
        if (KEY_IS(KEY_SPTLRPC_CONF)) {
                sptlrpc_conf_client_adapt(exp->exp_obd);
                return 0;
        }
        if (KEY_IS(KEY_FLUSH_CTX)) {
                sptlrpc_import_flush_my_ctx(imp);
                return 0;
        }
        if (KEY_IS(KEY_CHANGELOG_CLEAR)) {
                rc = do_set_info_async(imp, MDS_SET_INFO, LUSTRE_MDS_VERSION,
                                       keylen, key, vallen, val, set);
                return rc;
        }
        if (KEY_IS(KEY_HSM_COPYTOOL_SEND)) {
                rc = mdc_hsm_copytool_send(vallen, val);
                return rc;
        }
        if (KEY_IS(KEY_DEFAULT_EASIZE)) {
                u32 *default_easize = val;

                exp->exp_obd->u.cli.cl_default_mds_easize = *default_easize;
                return 0;
        }

        CERROR("Unknown key %s\n", (char *)key);
        return -EINVAL;
}

static int mdc_get_info(const struct lu_env *env, struct obd_export *exp,
                        __u32 keylen, void *key, __u32 *vallen, void *val,
                        struct lov_stripe_md *lsm)
{
        int rc = -EINVAL;

        if (KEY_IS(KEY_MAX_EASIZE)) {
                u32 mdsize, *max_easize;

                if (*vallen != sizeof(int))
                        return -EINVAL;
                mdsize = *(u32 *)val;
                if (mdsize > exp->exp_obd->u.cli.cl_max_mds_easize)
                        exp->exp_obd->u.cli.cl_max_mds_easize = mdsize;
                max_easize = val;
                *max_easize = exp->exp_obd->u.cli.cl_max_mds_easize;
                return 0;
        } else if (KEY_IS(KEY_DEFAULT_EASIZE)) {
                u32 *default_easize;

                if (*vallen != sizeof(int))
                        return -EINVAL;
                default_easize = val;
                *default_easize = exp->exp_obd->u.cli.cl_default_mds_easize;
                return 0;
        } else if (KEY_IS(KEY_CONN_DATA)) {
                struct obd_import *imp = class_exp2cliimp(exp);
                struct obd_connect_data *data = val;

                if (*vallen != sizeof(*data))
                        return -EINVAL;

                *data = imp->imp_connect_data;
                return 0;
        } else if (KEY_IS(KEY_TGT_COUNT)) {
                *((u32 *)val) = 1;
                return 0;
        }

        rc = mdc_get_info_rpc(exp, keylen, key, *vallen, val);

        return rc;
}

static int mdc_sync(struct obd_export *exp, const struct lu_fid *fid,
                    struct ptlrpc_request **request)
{
        struct ptlrpc_request *req;
        int                 rc;

        *request = NULL;
        req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_MDS_SYNC);
        if (!req)
                return -ENOMEM;

        rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, MDS_SYNC);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        mdc_pack_body(req, fid, 0, 0, -1, 0);

        ptlrpc_request_set_replen(req);

        rc = ptlrpc_queue_wait(req);
        if (rc)
                ptlrpc_req_finished(req);
        else
                *request = req;
        return rc;
}

static int mdc_import_event(struct obd_device *obd, struct obd_import *imp,
                            enum obd_import_event event)
{
        int rc = 0;

        LASSERT(imp->imp_obd == obd);

        switch (event) {
        case IMP_EVENT_DISCON: {
#if 0
                /* XXX Pass event up to OBDs stack. used only for FLD now */
                rc = obd_notify_observer(obd, obd, OBD_NOTIFY_DISCON, NULL);
#endif
                break;
        }
        case IMP_EVENT_INACTIVE: {
                struct client_obd *cli = &obd->u.cli;
                /*
                 * Flush current sequence to make client obtain new one
                 * from server in case of disconnect/reconnect.
                 */
                if (cli->cl_seq)
                        seq_client_flush(cli->cl_seq);

                rc = obd_notify_observer(obd, obd, OBD_NOTIFY_INACTIVE, NULL);
                break;
        }
        case IMP_EVENT_INVALIDATE: {
                struct ldlm_namespace *ns = obd->obd_namespace;

                ldlm_namespace_cleanup(ns, LDLM_FL_LOCAL_ONLY);

                break;
        }
        case IMP_EVENT_ACTIVE:
                rc = obd_notify_observer(obd, obd, OBD_NOTIFY_ACTIVE, NULL);
                /* redo the kuc registration after reconnecting */
                if (rc == 0)
                        /* re-register HSM agents */
                        rc = libcfs_kkuc_group_foreach(KUC_GRP_HSM,
                                                       mdc_hsm_ct_reregister,
                                                       (void *)imp);
                break;
        case IMP_EVENT_OCD:
                rc = obd_notify_observer(obd, obd, OBD_NOTIFY_OCD, NULL);
                break;
        case IMP_EVENT_DEACTIVATE:
        case IMP_EVENT_ACTIVATE:
                break;
        default:
                CERROR("Unknown import event %x\n", event);
                LBUG();
        }
        return rc;
}

int mdc_fid_alloc(const struct lu_env *env, struct obd_export *exp,
                  struct lu_fid *fid, struct md_op_data *op_data)
{
        struct client_obd *cli = &exp->exp_obd->u.cli;
        struct lu_client_seq *seq = cli->cl_seq;

        return seq_client_alloc_fid(env, seq, fid);
}

static struct obd_uuid *mdc_get_uuid(struct obd_export *exp)
{
        struct client_obd *cli = &exp->exp_obd->u.cli;

        return &cli->cl_target_uuid;
}

/**
 * Determine whether the lock can be canceled before replaying it during
 * recovery, non zero value will be return if the lock can be canceled,
 * or zero returned for not
 */
static int mdc_cancel_weight(struct ldlm_lock *lock)
{
        if (lock->l_resource->lr_type != LDLM_IBITS)
                return 0;

        /* FIXME: if we ever get into a situation where there are too many
         * opened files with open locks on a single node, then we really
         * should replay these open locks to reget it
         */
        if (lock->l_policy_data.l_inodebits.bits & MDS_INODELOCK_OPEN)
                return 0;

        return 1;
}

static int mdc_resource_inode_free(struct ldlm_resource *res)
{
        if (res->lr_lvb_inode)
                res->lr_lvb_inode = NULL;

        return 0;
}

static struct ldlm_valblock_ops inode_lvbo = {
        .lvbo_free = mdc_resource_inode_free,
};

static int mdc_llog_init(struct obd_device *obd)
{
        struct obd_llog_group   *olg = &obd->obd_olg;
        struct llog_ctxt        *ctxt;
        int                      rc;

        rc = llog_setup(NULL, obd, olg, LLOG_CHANGELOG_REPL_CTXT, obd,
                        &llog_client_ops);
        if (rc)
                return rc;

        ctxt = llog_group_get_ctxt(olg, LLOG_CHANGELOG_REPL_CTXT);
        llog_initiator_connect(ctxt);
        llog_ctxt_put(ctxt);

        return 0;
}

static void mdc_llog_finish(struct obd_device *obd)
{
        struct llog_ctxt *ctxt;

        ctxt = llog_get_context(obd, LLOG_CHANGELOG_REPL_CTXT);
        if (ctxt)
                llog_cleanup(NULL, ctxt);
}

static int mdc_setup(struct obd_device *obd, struct lustre_cfg *cfg)
{
        struct client_obd *cli = &obd->u.cli;
        struct lprocfs_static_vars lvars = { NULL };
        int rc;

        cli->cl_rpc_lock = kzalloc(sizeof(*cli->cl_rpc_lock), GFP_NOFS);
        if (!cli->cl_rpc_lock)
                return -ENOMEM;
        mdc_init_rpc_lock(cli->cl_rpc_lock);

        rc = ptlrpcd_addref();
        if (rc < 0)
                goto err_rpc_lock;

        cli->cl_close_lock = kzalloc(sizeof(*cli->cl_close_lock), GFP_NOFS);
        if (!cli->cl_close_lock) {
                rc = -ENOMEM;
                goto err_ptlrpcd_decref;
        }
        mdc_init_rpc_lock(cli->cl_close_lock);

        rc = client_obd_setup(obd, cfg);
        if (rc)
                goto err_close_lock;
        lprocfs_mdc_init_vars(&lvars);
        lprocfs_obd_setup(obd, lvars.obd_vars, lvars.sysfs_vars);
        sptlrpc_lprocfs_cliobd_attach(obd);
        ptlrpc_lprocfs_register_obd(obd);

        ns_register_cancel(obd->obd_namespace, mdc_cancel_weight);

        obd->obd_namespace->ns_lvbo = &inode_lvbo;

        rc = mdc_llog_init(obd);
        if (rc) {
                mdc_cleanup(obd);
                CERROR("failed to setup llogging subsystems\n");
        }

        return rc;

err_close_lock:
        kfree(cli->cl_close_lock);
err_ptlrpcd_decref:
        ptlrpcd_decref();
err_rpc_lock:
        kfree(cli->cl_rpc_lock);
        return rc;
}

/* Initialize the default and maximum LOV EA and cookie sizes.  This allows
 * us to make MDS RPCs with large enough reply buffers to hold a default
 * sized EA and cookie without having to calculate this (via a call into the
 * LOV + OSCs) each time we make an RPC.  The maximum size is also tracked
 * but not used to avoid wastefully vmalloc()'ing large reply buffers when
 * a large number of stripes is possible.  If a larger reply buffer is
 * required it will be reallocated in the ptlrpc layer due to overflow.
 */
static int mdc_init_ea_size(struct obd_export *exp, u32 easize, u32 def_easize,
                            u32 cookiesize, u32 def_cookiesize)
{
        struct obd_device *obd = exp->exp_obd;
        struct client_obd *cli = &obd->u.cli;

        if (cli->cl_max_mds_easize < easize)
                cli->cl_max_mds_easize = easize;

        if (cli->cl_default_mds_easize < def_easize)
                cli->cl_default_mds_easize = def_easize;

        if (cli->cl_max_mds_cookiesize < cookiesize)
                cli->cl_max_mds_cookiesize = cookiesize;

        if (cli->cl_default_mds_cookiesize < def_cookiesize)
                cli->cl_default_mds_cookiesize = def_cookiesize;

        return 0;
}

static int mdc_precleanup(struct obd_device *obd, enum obd_cleanup_stage stage)
{
        switch (stage) {
        case OBD_CLEANUP_EARLY:
                break;
        case OBD_CLEANUP_EXPORTS:
                /* Failsafe, ok if racy */
                if (obd->obd_type->typ_refcnt <= 1)
                        libcfs_kkuc_group_rem(0, KUC_GRP_HSM);

                obd_cleanup_client_import(obd);
                ptlrpc_lprocfs_unregister_obd(obd);
                lprocfs_obd_cleanup(obd);

                mdc_llog_finish(obd);
                break;
        }
        return 0;
}

static int mdc_cleanup(struct obd_device *obd)
{
        struct client_obd *cli = &obd->u.cli;

        kfree(cli->cl_rpc_lock);
        kfree(cli->cl_close_lock);

        ptlrpcd_decref();

        return client_obd_cleanup(obd);
}

static int mdc_process_config(struct obd_device *obd, u32 len, void *buf)
{
        struct lustre_cfg *lcfg = buf;
        struct lprocfs_static_vars lvars = { NULL };
        int rc = 0;

        lprocfs_mdc_init_vars(&lvars);
        switch (lcfg->lcfg_command) {
        default:
                rc = class_process_proc_param(PARAM_MDC, lvars.obd_vars,
                                              lcfg, obd);
                if (rc > 0)
                        rc = 0;
                break;
        }
        return rc;
}

static struct obd_ops mdc_obd_ops = {
        .owner          = THIS_MODULE,
        .setup          = mdc_setup,
        .precleanup     = mdc_precleanup,
        .cleanup        = mdc_cleanup,
        .add_conn       = client_import_add_conn,
        .del_conn       = client_import_del_conn,
        .connect        = client_connect_import,
        .disconnect     = client_disconnect_export,
        .iocontrol      = mdc_iocontrol,
        .set_info_async = mdc_set_info_async,
        .statfs         = mdc_statfs,
        .fid_init       = client_fid_init,
        .fid_fini       = client_fid_fini,
        .fid_alloc      = mdc_fid_alloc,
        .import_event   = mdc_import_event,
        .get_info       = mdc_get_info,
        .process_config = mdc_process_config,
        .get_uuid       = mdc_get_uuid,
        .quotactl       = mdc_quotactl,
        .quotacheck     = mdc_quotacheck
};

static struct md_ops mdc_md_ops = {
        .getstatus              = mdc_getstatus,
        .null_inode             = mdc_null_inode,
        .close                  = mdc_close,
        .create                 = mdc_create,
        .done_writing           = mdc_done_writing,
        .enqueue                = mdc_enqueue,
        .getattr                = mdc_getattr,
        .getattr_name           = mdc_getattr_name,
        .intent_lock            = mdc_intent_lock,
        .link                   = mdc_link,
        .rename                 = mdc_rename,
        .setattr                = mdc_setattr,
        .setxattr               = mdc_setxattr,
        .getxattr               = mdc_getxattr,
        .sync                   = mdc_sync,
        .read_page              = mdc_read_page,
        .unlink                 = mdc_unlink,
        .cancel_unused          = mdc_cancel_unused,
        .init_ea_size           = mdc_init_ea_size,
        .set_lock_data          = mdc_set_lock_data,
        .lock_match             = mdc_lock_match,
        .get_lustre_md          = mdc_get_lustre_md,
        .free_lustre_md         = mdc_free_lustre_md,
        .set_open_replay_data   = mdc_set_open_replay_data,
        .clear_open_replay_data = mdc_clear_open_replay_data,
        .intent_getattr_async   = mdc_intent_getattr_async,
        .revalidate_lock        = mdc_revalidate_lock
};

static int __init mdc_init(void)
{
        struct lprocfs_static_vars lvars = { NULL };

        lprocfs_mdc_init_vars(&lvars);

        return class_register_type(&mdc_obd_ops, &mdc_md_ops,
                                 LUSTRE_MDC_NAME, NULL);
}

static void /*__exit*/ mdc_exit(void)
{
        class_unregister_type(LUSTRE_MDC_NAME);
}

MODULE_AUTHOR("OpenSFS, Inc. <http://www.lustre.org/>");
MODULE_DESCRIPTION("Lustre Metadata Client");
MODULE_VERSION(LUSTRE_VERSION_STRING);
MODULE_LICENSE("GPL");

module_init(mdc_init);
module_exit(mdc_exit);