/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
 *
 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
 * CA 95054 USA or visit www.sun.com if you need additional information or
 * have any questions.
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2012, 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 <lustre_acl.h>
#include <obd_class.h>
#include <lustre_fid.h>
#include <lprocfs_status.h>
#include <lustre_param.h>
#include <lustre_log.h>

#include "mdc_internal.h"

#define REQUEST_MINOR 244

struct mdc_renew_capa_args {
        struct obd_capa *ra_oc;
        renew_capa_cb_t  ra_cb;
};

static int mdc_cleanup(struct obd_device *obd);

int mdc_unpack_capa(struct obd_export *exp, struct ptlrpc_request *req,
                    const struct req_msg_field *field, struct obd_capa **oc)
{
        struct lustre_capa *capa;
        struct obd_capa *c;
        ENTRY;

        /* swabbed already in mdc_enqueue */
        capa = req_capsule_server_get(&req->rq_pill, field);
        if (capa == NULL)
                RETURN(-EPROTO);

        c = alloc_capa(CAPA_SITE_CLIENT);
        if (IS_ERR(c)) {
                CDEBUG(D_INFO, "alloc capa failed!\n");
                RETURN(PTR_ERR(c));
        } else {
                c->c_capa = *capa;
                *oc = c;
                RETURN(0);
        }
}

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

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

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

        return rc;
}

/* Helper that implements most of mdc_getstatus and signal_completed_replay. */
/* XXX this should become mdc_get_info("key"), sending MDS_GET_INFO RPC */
static int send_getstatus(struct obd_import *imp, struct lu_fid *rootfid,
                          struct obd_capa **pc, int level, int msg_flags)
{
        struct ptlrpc_request *req;
        struct mdt_body       *body;
        int                 rc;
        ENTRY;

        req = ptlrpc_request_alloc_pack(imp, &RQF_MDS_GETSTATUS,
                                        LUSTRE_MDS_VERSION, MDS_GETSTATUS);
        if (req == NULL)
                RETURN(-ENOMEM);

        mdc_pack_body(req, NULL, NULL, 0, 0, -1, 0);
        lustre_msg_add_flags(req->rq_reqmsg, msg_flags);
        req->rq_send_state = level;

        ptlrpc_request_set_replen(req);

        rc = ptlrpc_queue_wait(req);
        if (rc)
                GOTO(out, rc);

        body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY);
        if (body == NULL)
                GOTO(out, rc = -EPROTO);

        if (body->valid & OBD_MD_FLMDSCAPA) {
                rc = mdc_unpack_capa(NULL, req, &RMF_CAPA1, pc);
                if (rc)
                        GOTO(out, rc);
        }

        *rootfid = body->fid1;
        CDEBUG(D_NET,
               "root fid="DFID", last_committed="LPU64"\n",
               PFID(rootfid),
               lustre_msg_get_last_committed(req->rq_repmsg));
        EXIT;
out:
        ptlrpc_req_finished(req);
        return rc;
}

/* This should be mdc_get_info("rootfid") */
int mdc_getstatus(struct obd_export *exp, struct lu_fid *rootfid,
                  struct obd_capa **pc)
{
        return send_getstatus(class_exp2cliimp(exp), rootfid, pc,
                              LUSTRE_IMP_FULL, 0);
}

/*
 * 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;
        ENTRY;

        /* 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 == NULL)
                RETURN(-EPROTO);

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

        if (body->eadatasize != 0) {
                mdc_update_max_ea_from_body(exp, body);

                eadata = req_capsule_server_sized_get(pill, &RMF_MDT_MD,
                                                      body->eadatasize);
                if (eadata == NULL)
                        RETURN(-EPROTO);
        }

        if (body->valid & OBD_MD_FLRMTPERM) {
                struct mdt_remote_perm *perm;

                LASSERT(client_is_remote(exp));
                perm = req_capsule_server_swab_get(pill, &RMF_ACL,
                                                lustre_swab_mdt_remote_perm);
                if (perm == NULL)
                        RETURN(-EPROTO);
        }

        if (body->valid & OBD_MD_FLMDSCAPA) {
                struct lustre_capa *capa;
                capa = req_capsule_server_get(pill, &RMF_CAPA1);
                if (capa == NULL)
                        RETURN(-EPROTO);
        }

        RETURN(0);
}

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

        /* 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 == NULL)
                RETURN(-ENOMEM);

        mdc_set_capa_size(req, &RMF_CAPA1, op_data->op_capa1);

        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_capa1,
                      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);
        if (op_data->op_valid & OBD_MD_FLRMTPERM) {
                LASSERT(client_is_remote(exp));
                req_capsule_set_size(&req->rq_pill, &RMF_ACL, RCL_SERVER,
                                     sizeof(struct mdt_remote_perm));
        }
        ptlrpc_request_set_replen(req);

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

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

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

        mdc_set_capa_size(req, &RMF_CAPA1, op_data->op_capa1);
        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_capa1,
                      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_is_subdir(struct obd_export *exp,
                         const struct lu_fid *pfid,
                         const struct lu_fid *cfid,
                         struct ptlrpc_request **request)
{
        struct ptlrpc_request  *req;
        int                  rc;

        ENTRY;

        *request = NULL;
        req = ptlrpc_request_alloc_pack(class_exp2cliimp(exp),
                                        &RQF_MDS_IS_SUBDIR, LUSTRE_MDS_VERSION,
                                        MDS_IS_SUBDIR);
        if (req == NULL)
                RETURN(-ENOMEM);

        mdc_is_subdir_pack(req, pfid, cfid, 0);
        ptlrpc_request_set_replen(req);

        rc = ptlrpc_queue_wait(req);
        if (rc && rc != -EREMOTE)
                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,
                            struct obd_capa *oc, int opcode, obd_valid 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;
        ENTRY;

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

        mdc_set_capa_size(req, &RMF_CAPA1, oc);
        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);
        }

        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;
                /* TODO:
                 *  cfs_curproc_fs{u,g}id() should replace
                 *  current->fs{u,g}id for portability.
                 */
                rec->sx_fsuid  = current_fsuid();
                rec->sx_fsgid  = 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   = cfs_time_current_sec();
                rec->sx_size   = output_size;
                rec->sx_flags  = flags;

                mdc_pack_capa(req, &RMF_CAPA1, oc);
        } else {
                mdc_pack_body(req, fid, oc, 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);
}

int mdc_setxattr(struct obd_export *exp, const struct lu_fid *fid,
                 struct obd_capa *oc, obd_valid 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, oc, MDS_REINT, valid, xattr_name,
                                input, input_size, output_size, flags,
                                suppgid, request);
}

int mdc_getxattr(struct obd_export *exp, const struct lu_fid *fid,
                 struct obd_capa *oc, obd_valid 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, oc, 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;
        ENTRY;

        if (!body->aclsize)
                RETURN(0);

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

        if (!buf)
                RETURN(-EPROTO);

        acl = posix_acl_from_xattr(&init_user_ns, buf, body->aclsize);
        if (IS_ERR(acl)) {
                rc = PTR_ERR(acl);
                CERROR("convert xattr to acl: %d\n", rc);
                RETURN(rc);
        }

        rc = posix_acl_valid(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

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;
        ENTRY;

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

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

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

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

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

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

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

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

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

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

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

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

        if (md->body->valid & OBD_MD_FLRMTPERM) {
                /* remote permission */
                LASSERT(client_is_remote(exp));
                md->remote_perm = req_capsule_server_swab_get(pill, &RMF_ACL,
                                                lustre_swab_mdt_remote_perm);
                if (!md->remote_perm)
                        GOTO(out, rc = -EPROTO);
        }
        else if (md->body->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->aclsize) {
                        rc = mdc_unpack_acl(req, md);
                        if (rc)
                                GOTO(out, rc);
#ifdef CONFIG_FS_POSIX_ACL
                } else {
                        md->posix_acl = NULL;
#endif
                }
        }
        if (md->body->valid & OBD_MD_FLMDSCAPA) {
                struct obd_capa *oc = NULL;

                rc = mdc_unpack_capa(NULL, req, &RMF_CAPA1, &oc);
                if (rc)
                        GOTO(out, rc);
                md->mds_capa = oc;
        }

        if (md->body->valid & OBD_MD_FLOSSCAPA) {
                struct obd_capa *oc = NULL;

                rc = mdc_unpack_capa(NULL, req, &RMF_CAPA2, &oc);
                if (rc)
                        GOTO(out, rc);
                md->oss_capa = oc;
        }

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

int mdc_free_lustre_md(struct obd_export *exp, struct lustre_md *md)
{
        ENTRY;
        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;
        ENTRY;

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

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

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

                LASSERT(och->och_magic == OBD_CLIENT_HANDLE_MAGIC);

                file_fh = &och->och_fh;
                CDEBUG(D_HA, "updating handle from "LPX64" to "LPX64"\n",
                       file_fh->cookie, body->handle.cookie);
                old = *file_fh;
                *file_fh = body->handle;
        }
        close_req = mod->mod_close_req;
        if (close_req != NULL) {
                __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 != NULL)
                        LASSERT(!memcmp(&old, &epoch->handle, sizeof(old)));
                DEBUG_REQ(D_HA, close_req, "updating close body with new fh");
                epoch->handle = body->handle;
        }
        EXIT;
}

void mdc_commit_open(struct ptlrpc_request *req)
{
        struct md_open_data *mod = req->rq_cb_data;
        if (mod == NULL)
                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 ptlrpc_request *open_req)
{
        struct md_open_data   *mod;
        struct mdt_rec_create *rec;
        struct mdt_body       *body;
        struct obd_import     *imp = open_req->rq_import;
        ENTRY;

        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 != NULL);
        /* Incoming message in my byte order (it's been swabbed). */
        /* Outgoing messages always in my byte order. */
        LASSERT(body != NULL);

        /* Only if the import is replayable, we set replay_open data */
        if (och && imp->imp_replayable) {
                mod = obd_mod_alloc();
                if (mod == NULL) {
                        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_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->fid1;
        rec->cr_ioepoch = body->ioepoch;
        rec->cr_old_handle.cookie = body->handle.cookie;
        open_req->rq_replay_cb = mdc_replay_open;
        if (!fid_is_sane(&body->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);
}

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

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

        LASSERT(mod != LP_POISON);

        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->valid & OBD_MD_FLGETATTRLOCK)
                        op_data->op_flags |= MF_GETATTR_LOCK;
        }
}

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;
        int                 rc;
        ENTRY;

        *request = NULL;
        req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_MDS_CLOSE);
        if (req == NULL)
                RETURN(-ENOMEM);

        mdc_set_capa_size(req, &RMF_CAPA1, op_data->op_capa1);

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

        /* 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);

        /* Ensure that this close's handle is fixed up during replay. */
        if (likely(mod != NULL)) {
                LASSERTF(mod->mod_open_req != NULL &&
                         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");
        }

        mdc_close_pack(req, op_data);

        req_capsule_set_size(&req->rq_pill, &RMF_MDT_MD, RCL_SERVER,
                             obd->u.cli.cl_max_mds_easize);
        req_capsule_set_size(&req->rq_pill, &RMF_LOGCOOKIES, RCL_SERVER,
                             obd->u.cli.cl_max_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 == NULL) {
                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 == NULL)
                        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);
                        LASSERT(mod->mod_open_req != NULL);
                        if (mod->mod_open_req->rq_committed)
                                rc = 0;
                }
        }

        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);
}

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;
        ENTRY;

        req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                   &RQF_MDS_DONE_WRITING);
        if (req == NULL)
                RETURN(-ENOMEM);

        mdc_set_capa_size(req, &RMF_CAPA1, op_data->op_capa1);
        rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, MDS_DONE_WRITING);
        if (rc) {
                ptlrpc_request_free(req);
                RETURN(rc);
        }

        if (mod != NULL) {
                LASSERTF(mod->mod_open_req != NULL &&
                         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) {
                        LASSERT(mod->mod_open_req != NULL);
                        if (mod->mod_open_req->rq_committed)
                                rc = 0;
                }
        }

        if (mod) {
                if (rc != 0)
                        mod->mod_close_req = NULL;
                /* 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);
}


int mdc_readpage(struct obd_export *exp, struct md_op_data *op_data,
                 struct page **pages, struct ptlrpc_request **request)
{
        struct ptlrpc_request   *req;
        struct ptlrpc_bulk_desc *desc;
        int                   i;
        wait_queue_head_t             waitq;
        int                   resends = 0;
        struct l_wait_info       lwi;
        int                   rc;
        ENTRY;

        *request = NULL;
        init_waitqueue_head(&waitq);

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

        mdc_set_capa_size(req, &RMF_CAPA1, op_data->op_capa1);

        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, op_data->op_npages, 1, BULK_PUT_SINK,
                                    MDS_BULK_PORTAL);
        if (desc == NULL) {
                ptlrpc_request_free(req);
                RETURN(-ENOMEM);
        }

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

        mdc_readdir_pack(req, op_data->op_offset,
                         PAGE_CACHE_SIZE * op_data->op_npages,
                         &op_data->op_fid1, op_data->op_capa1);

        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("too many resend retries, returning error\n");
                        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("Unexpected # bytes transferred: %d (%ld expected)\n",
                        req->rq_bulk->bd_nob_transferred,
                        PAGE_CACHE_SIZE * op_data->op_npages);
                ptlrpc_req_finished(req);
                RETURN(-EPROTO);
        }

        *request = req;
        RETURN(0);
}

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;
        ENTRY;

        /*
         * 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 == NULL)
                GOTO(output, rc = -ENOMEM);

        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, rc);
        }

        msfs = req_capsule_server_get(&req->rq_pill, &RMF_OBD_STATFS);
        if (msfs == NULL)
                GOTO(out, rc = -EPROTO);

        *osfs = *msfs;
        EXIT;
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);
        OBD_ALLOC(key, keylen);
        if (key == NULL)
                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 "LPU64" #%d\n",
               PFID(&gf->gf_fid), gf->gf_recno, gf->gf_linkno);

        if (!fid_is_sane(&gf->gf_fid))
                GOTO(out, rc = -EINVAL);

        /* 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, rc);

        if (vallen <= sizeof(*gf))
                GOTO(out, rc = -EPROTO);
        else if (vallen > sizeof(*gf) + gf->gf_pathlen)
                GOTO(out, rc = -EOVERFLOW);

        CDEBUG(D_IOCTL, "path get "DFID" from "LPU64" #%d\n%s\n",
               PFID(&gf->gf_fid), gf->gf_recno, gf->gf_linkno, gf->gf_path);

out:
        OBD_FREE(key, keylen);
        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;
        ENTRY;

        req = ptlrpc_request_alloc_pack(imp, &RQF_MDS_HSM_PROGRESS,
                                        LUSTRE_MDS_VERSION, MDS_HSM_PROGRESS);
        if (req == NULL)
                GOTO(out, rc = -ENOMEM);

        mdc_pack_body(req, NULL, NULL, OBD_MD_FLRMTPERM, 0, 0, 0);

        /* Copy hsm_progress struct */
        req_hpk = req_capsule_client_get(&req->rq_pill, &RMF_MDS_HSM_PROGRESS);
        if (req_hpk == NULL)
                GOTO(out, rc = -EPROTO);

        *req_hpk = *hpk;

        ptlrpc_request_set_replen(req);

        rc = mdc_queue_wait(req);
        GOTO(out, rc);
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;
        ENTRY;

        req = ptlrpc_request_alloc_pack(imp, &RQF_MDS_HSM_CT_REGISTER,
                                        LUSTRE_MDS_VERSION,
                                        MDS_HSM_CT_REGISTER);
        if (req == NULL)
                GOTO(out, rc = -ENOMEM);

        mdc_pack_body(req, NULL, NULL, OBD_MD_FLRMTPERM, 0, 0, 0);

        /* Copy hsm_progress struct */
        archive_mask = req_capsule_client_get(&req->rq_pill,
                                              &RMF_MDS_HSM_ARCHIVE);
        if (archive_mask == NULL)
                GOTO(out, rc = -EPROTO);

        *archive_mask = archives;

        ptlrpc_request_set_replen(req);

        rc = mdc_queue_wait(req);
        GOTO(out, rc);
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;
        ENTRY;

        req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                   &RQF_MDS_HSM_ACTION);
        if (req == NULL)
                RETURN(-ENOMEM);

        mdc_set_capa_size(req, &RMF_CAPA1, op_data->op_capa1);

        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, op_data->op_capa1,
                      OBD_MD_FLRMTPERM, 0, op_data->op_suppgids[0], 0);

        ptlrpc_request_set_replen(req);

        rc = mdc_queue_wait(req);
        if (rc)
                GOTO(out, rc);

        req_hca = req_capsule_server_get(&req->rq_pill,
                                         &RMF_MDS_HSM_CURRENT_ACTION);
        if (req_hca == NULL)
                GOTO(out, rc = -EPROTO);

        *hca = *req_hca;

        EXIT;
out:
        ptlrpc_req_finished(req);
        return rc;
}

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

        req = ptlrpc_request_alloc_pack(imp, &RQF_MDS_HSM_CT_UNREGISTER,
                                        LUSTRE_MDS_VERSION,
                                        MDS_HSM_CT_UNREGISTER);
        if (req == NULL)
                GOTO(out, rc = -ENOMEM);

        mdc_pack_body(req, NULL, NULL, OBD_MD_FLRMTPERM, 0, 0, 0);

        ptlrpc_request_set_replen(req);

        rc = mdc_queue_wait(req);
        GOTO(out, rc);
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;
        ENTRY;

        req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                   &RQF_MDS_HSM_STATE_GET);
        if (req == NULL)
                RETURN(-ENOMEM);

        mdc_set_capa_size(req, &RMF_CAPA1, op_data->op_capa1);

        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, op_data->op_capa1,
                      OBD_MD_FLRMTPERM, 0, op_data->op_suppgids[0], 0);

        ptlrpc_request_set_replen(req);

        rc = mdc_queue_wait(req);
        if (rc)
                GOTO(out, rc);

        req_hus = req_capsule_server_get(&req->rq_pill, &RMF_HSM_USER_STATE);
        if (req_hus == NULL)
                GOTO(out, rc = -EPROTO);

        *hus = *req_hus;

        EXIT;
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;
        ENTRY;

        req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                   &RQF_MDS_HSM_STATE_SET);
        if (req == NULL)
                RETURN(-ENOMEM);

        mdc_set_capa_size(req, &RMF_CAPA1, op_data->op_capa1);

        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, op_data->op_capa1,
                      OBD_MD_FLRMTPERM, 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 == NULL)
                GOTO(out, rc = -EPROTO);
        *req_hss = *hss;

        ptlrpc_request_set_replen(req);

        rc = mdc_queue_wait(req);
        GOTO(out, rc);

        EXIT;
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;
        ENTRY;

        req = ptlrpc_request_alloc(imp, &RQF_MDS_HSM_REQUEST);
        if (req == NULL)
                GOTO(out, rc = -ENOMEM);

        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, NULL, OBD_MD_FLRMTPERM, 0, 0, 0);

        /* Copy hsm_request struct */
        req_hr = req_capsule_client_get(&req->rq_pill, &RMF_MDS_HSM_REQUEST);
        if (req_hr == NULL)
                GOTO(out, rc = -EPROTO);
        *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 == NULL)
                GOTO(out, rc = -EPROTO);
        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 == NULL)
                GOTO(out, rc = -EPROTO);
        memcpy(req_opaque, hur_data(hur), hur->hur_request.hr_data_len);

        ptlrpc_request_set_replen(req);

        rc = mdc_queue_wait(req);
        GOTO(out, rc);

out:
        ptlrpc_req_finished(req);
        return rc;
}

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

        LASSERT(len <= CR_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;
}

#define D_CHANGELOG 0

struct changelog_show {
        __u64           cs_startrec;
        __u32           cs_flags;
        struct file     *cs_fp;
        char            *cs_buf;
        struct obd_device *cs_obd;
};

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;
        int len, rc;
        ENTRY;

        if (rec->cr_hdr.lrh_type != CHANGELOG_REC) {
                rc = -EINVAL;
                CERROR("%s: not a changelog rec %x/%d: rc = %d\n",
                       cs->cs_obd->obd_name, 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_CHANGELOG, "rec="LPU64" start="LPU64"\n",
                       rec->cr.cr_index, cs->cs_startrec);
                RETURN(0);
        }

        CDEBUG(D_CHANGELOG, LPU64" %02d%-5s "LPU64" 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_CHANGELOG, "kucmsg fp %p len %d rc %d\n", cs->cs_fp, len,rc);

        RETURN(rc);
}

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

        CDEBUG(D_CHANGELOG, "changelog to fp=%p start "LPU64"\n",
               cs->cs_fp, cs->cs_startrec);

        OBD_ALLOC(cs->cs_buf, CR_MAXSIZE);
        if (cs->cs_buf == NULL)
                GOTO(out, rc = -ENOMEM);

        /* Set up the remote catalog handle */
        ctxt = llog_get_context(cs->cs_obd, LLOG_CHANGELOG_REPL_CTXT);
        if (ctxt == NULL)
                GOTO(out, rc = -ENOENT);
        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->cs_obd->obd_name, rc);
                GOTO(out, rc);
        }
        rc = llog_init_handle(NULL, llh, LLOG_F_IS_CAT, NULL);
        if (rc) {
                CERROR("llog_init_handle failed %d\n", rc);
                GOTO(out, rc);
        }

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

        /* Send EOF no matter what our result */
        if ((kuch = changelog_kuc_hdr(cs->cs_buf, sizeof(*kuch),
                                      cs->cs_flags))) {
                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);
        if (cs->cs_buf)
                OBD_FREE(cs->cs_buf, CR_MAXSIZE);
        OBD_FREE_PTR(cs);
        return rc;
}

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

        /* Freed in mdc_changelog_send_thread */
        OBD_ALLOC_PTR(cs);
        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
         */
        rc = PTR_ERR(kthread_run(mdc_changelog_send_thread, cs,
                                 "mdc_clg_send_thread"));
        if (!IS_ERR_VALUE(rc)) {
                CDEBUG(D_CHANGELOG, "start changelog thread\n");
                return 0;
        }

        CERROR("Failed to start changelog thread: %d\n", rc);
        OBD_FREE_PTR(cs);
        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;
        ENTRY;

        req = ptlrpc_request_alloc_pack(class_exp2cliimp(exp),
                                        &RQF_MDS_QUOTACHECK, LUSTRE_MDS_VERSION,
                                        MDS_QUOTACHECK);
        if (req == NULL)
                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;
        ENTRY;

        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;
        ENTRY;

        req = ptlrpc_request_alloc_pack(class_exp2cliimp(exp),
                                        &RQF_MDS_QUOTACTL, LUSTRE_MDS_VERSION,
                                        MDS_QUOTACTL);
        if (req == NULL)
                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))) {
                *oqctl = *oqc;
        } 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;
        ENTRY;

        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);
        count += mdc_resource_get_unused(exp, &op_data->op_fid2, &cancels,
                                         LCK_CR, MDS_INODELOCK_LAYOUT);

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

        mdc_set_capa_size(req, &RMF_CAPA1, op_data->op_capa1);
        mdc_set_capa_size(req, &RMF_CAPA2, op_data->op_capa2);

        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);
        if (rc)
                GOTO(out, rc);
        EXIT;

out:
        ptlrpc_req_finished(req);
        return rc;
}

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

        if (!try_module_get(THIS_MODULE)) {
                CERROR("Can't get module. Is it alive?");
                return -EINVAL;
        }
        switch (cmd) {
        case OBD_IOC_CHANGELOG_SEND:
                rc = mdc_ioc_changelog_send(obd, karg);
                GOTO(out, rc);
        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, rc);
        }
        case OBD_IOC_FID2PATH:
                rc = mdc_ioc_fid2path(exp, karg);
                GOTO(out, rc);
        case LL_IOC_HSM_CT_START:
                rc = mdc_ioc_hsm_ct_start(exp, karg);
                GOTO(out, rc);
        case LL_IOC_HSM_PROGRESS:
                rc = mdc_ioc_hsm_progress(exp, karg);
                GOTO(out, rc);
        case LL_IOC_HSM_STATE_GET:
                rc = mdc_ioc_hsm_state_get(exp, karg);
                GOTO(out, rc);
        case LL_IOC_HSM_STATE_SET:
                rc = mdc_ioc_hsm_state_set(exp, karg);
        case LL_IOC_HSM_ACTION:
                rc = mdc_ioc_hsm_current_action(exp, karg);
                GOTO(out, rc);
        case LL_IOC_HSM_REQUEST:
                rc = mdc_ioc_hsm_request(exp, karg);
                GOTO(out, rc);
        case OBD_IOC_CLIENT_RECOVER:
                rc = ptlrpc_recover_import(imp, data->ioc_inlbuf1, 0);
                if (rc < 0)
                        GOTO(out, rc);
                GOTO(out, rc = 0);
        case IOC_OSC_SET_ACTIVE:
                rc = ptlrpc_set_import_active(imp, data->ioc_offset);
                GOTO(out, rc);
        case OBD_IOC_PARSE: {
                ctxt = llog_get_context(exp->exp_obd, LLOG_CONFIG_REPL_CTXT);
                rc = class_config_parse_llog(NULL, ctxt, data->ioc_inlbuf1,
                                             NULL);
                llog_ctxt_put(ctxt);
                GOTO(out, rc);
        }
        case OBD_IOC_LLOG_INFO:
        case OBD_IOC_LLOG_PRINT: {
                ctxt = llog_get_context(obd, LLOG_CONFIG_REPL_CTXT);
                rc = llog_ioctl(NULL, ctxt, cmd, data);
                llog_ctxt_put(ctxt);
                GOTO(out, rc);
        }
        case OBD_IOC_POLL_QUOTACHECK:
                rc = mdc_quota_poll_check(exp, (struct if_quotacheck *)karg);
                GOTO(out, rc);
        case OBD_IOC_PING_TARGET:
                rc = ptlrpc_obd_ping(obd);
                GOTO(out, rc);
        /*
         * 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)
                        GOTO(out, rc = -ENODEV);

                /* copy UUID */
                if (copy_to_user(data->ioc_pbuf2, obd2cli_tgt(obd),
                                     min((int) data->ioc_plen2,
                                         (int) sizeof(struct obd_uuid))))
                        GOTO(out, rc = -EFAULT);

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

                if (copy_to_user(data->ioc_pbuf1, &stat_buf,
                                     min((int) data->ioc_plen1,
                                         (int) sizeof(stat_buf))))
                        GOTO(out, rc = -EFAULT);

                GOTO(out, rc = 0);
        }
        case OBD_IOC_QUOTACTL: {
                struct if_quotactl *qctl = karg;
                struct obd_quotactl *oqctl;

                OBD_ALLOC_PTR(oqctl);
                if (!oqctl)
                        RETURN(-ENOMEM);

                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;
                }
                OBD_FREE_PTR(oqctl);
                break;
        }
        case LL_IOC_GET_CONNECT_FLAGS: {
                if (copy_to_user(uarg,
                                     exp_connect_flags_ptr(exp),
                                     sizeof(__u64)))
                        GOTO(out, rc = -EFAULT);
                else
                        GOTO(out, rc = 0);
        }
        case LL_IOC_LOV_SWAP_LAYOUTS: {
                rc = mdc_ioc_swap_layouts(exp, karg);
                break;
        }
        default:
                CERROR("mdc_ioctl(): unrecognised ioctl %#x\n", cmd);
                GOTO(out, rc = -ENOTTY);
        }
out:
        module_put(THIS_MODULE);

        return rc;
}

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

        req = ptlrpc_request_alloc(imp, &RQF_MDS_GET_INFO);
        if (req == NULL)
                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;
        int                      i;

        __swab32s(&h->hal_version);
        __swab32s(&h->hal_count);
        __swab32s(&h->hal_archive_id);
        __swab64s(&h->hal_flags);
        hai = hai_zero(h);
        for (i = 0; i < h->hal_count; i++) {
                lustre_swab_hai(hai);
                hai = hai_next(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) {
                rc = libcfs_kkuc_group_rem(lk->lk_uid, lk->lk_group);
                /* Unregister with the coordinator */
                if (rc == 0)
                        rc = mdc_ioc_hsm_ct_unregister(imp);
        } else {
                struct file *fp = fget(lk->lk_wfd);

                rc = libcfs_kkuc_group_add(fp, lk->lk_uid, lk->lk_group,
                                           lk->lk_data);
                if (rc && fp)
                        fput(fp);
                if (rc == 0)
                        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(int len, void *val)
{
        struct kuc_hdr          *lh = (struct kuc_hdr *)val;
        struct hsm_action_list  *hal = (struct hsm_action_list *)(lh + 1);
        int                      rc;
        ENTRY;

        if (len < sizeof(*lh) + sizeof(*hal)) {
                CERROR("Short HSM message %d < %d\n", len,
                       (int) (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 */
        rc = libcfs_kkuc_group_put(KUC_GRP_HSM, lh);

        RETURN(rc);
}

/**
 * callback function passed to kuc for re-registering each HSM copytool
 * running on MDC, after MDT shutdown/recovery.
 * @param data archive id served by the copytool
 * @param cb_arg callback argument (obd_import)
 */
static int mdc_hsm_ct_reregister(__u32 data, void *cb_arg)
{
        struct obd_import       *imp = (struct obd_import *)cb_arg;
        __u32                    archive = data;
        int                      rc;

        CDEBUG(D_HA, "recover copytool registration to MDT (archive=%#x)\n",
               archive);
        rc = mdc_ioc_hsm_ct_register(imp, archive);

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

/**
 * Re-establish all kuc contexts with MDT
 * after MDT shutdown/recovery.
 */
static int mdc_kuc_reregister(struct obd_import *imp)
{
        /* re-register HSM agents */
        return libcfs_kkuc_group_foreach(KUC_GRP_HSM, mdc_hsm_ct_reregister,
                                         (void *)imp);
}

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

        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);

                rc = do_set_info_async(imp, MDS_SET_INFO, LUSTRE_MDS_VERSION,
                                       keylen, key, vallen, val, set);
                RETURN(rc);
        }
        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_MDS_CONN)) {
                /* mds-mds import */
                spin_lock(&imp->imp_lock);
                imp->imp_server_timeout = 1;
                spin_unlock(&imp->imp_lock);
                imp->imp_client->cli_request_portal = MDS_MDS_PORTAL;
                CDEBUG(D_OTHER, "%s: timeout / 2\n", exp->exp_obd->obd_name);
                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);
        }

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

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)) {
                int mdsize, *max_easize;

                if (*vallen != sizeof(int))
                        RETURN(-EINVAL);
                mdsize = *(int*)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_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)) {
                *((int *)val) = 1;
                RETURN(0);
        }

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

        RETURN(rc);
}

static int mdc_pin(struct obd_export *exp, const struct lu_fid *fid,
                   struct obd_capa *oc, struct obd_client_handle *handle,
                   int flags)
{
        struct ptlrpc_request *req;
        struct mdt_body       *body;
        int                 rc;
        ENTRY;

        req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_MDS_PIN);
        if (req == NULL)
                RETURN(-ENOMEM);

        mdc_set_capa_size(req, &RMF_CAPA1, oc);

        rc = ptlrpc_request_pack(req, LUSTRE_MDS_VERSION, MDS_PIN);
        if (rc) {
                ptlrpc_request_free(req);
                RETURN(rc);
        }

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

        ptlrpc_request_set_replen(req);

        mdc_get_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);
        rc = ptlrpc_queue_wait(req);
        mdc_put_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);
        if (rc) {
                CERROR("Pin failed: %d\n", rc);
                GOTO(err_out, rc);
        }

        body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY);
        if (body == NULL)
                GOTO(err_out, rc = -EPROTO);

        handle->och_fh = body->handle;
        handle->och_magic = OBD_CLIENT_HANDLE_MAGIC;

        handle->och_mod = obd_mod_alloc();
        if (handle->och_mod == NULL) {
                DEBUG_REQ(D_ERROR, req, "can't allocate md_open_data");
                GOTO(err_out, rc = -ENOMEM);
        }
        handle->och_mod->mod_open_req = req; /* will be dropped by unpin */

        RETURN(0);

err_out:
        ptlrpc_req_finished(req);
        RETURN(rc);
}

static int mdc_unpin(struct obd_export *exp, struct obd_client_handle *handle,
                     int flag)
{
        struct ptlrpc_request *req;
        struct mdt_body       *body;
        int                 rc;
        ENTRY;

        req = ptlrpc_request_alloc_pack(class_exp2cliimp(exp), &RQF_MDS_UNPIN,
                                        LUSTRE_MDS_VERSION, MDS_UNPIN);
        if (req == NULL)
                RETURN(-ENOMEM);

        body = req_capsule_client_get(&req->rq_pill, &RMF_MDT_BODY);
        body->handle = handle->och_fh;
        body->flags = flag;

        ptlrpc_request_set_replen(req);

        mdc_get_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);
        rc = ptlrpc_queue_wait(req);
        mdc_put_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);

        if (rc != 0)
                CERROR("Unpin failed: %d\n", rc);

        ptlrpc_req_finished(req);
        ptlrpc_req_finished(handle->och_mod->mod_open_req);

        obd_mod_put(handle->och_mod);
        RETURN(rc);
}

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

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

        mdc_set_capa_size(req, &RMF_CAPA1, oc);

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

        mdc_pack_body(req, fid, oc, 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 != NULL)
                        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);
                /* restore re-establish kuc registration after reconnecting */
                if (rc == 0)
                        rc = mdc_kuc_reregister(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(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;
        ENTRY;
        RETURN(seq_client_alloc_fid(NULL, seq, fid));
}

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_for_recovery(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;
}

struct ldlm_valblock_ops inode_lvbo = {
        lvbo_free: mdc_resource_inode_free
};

static int mdc_setup(struct obd_device *obd, struct lustre_cfg *cfg)
{
        struct client_obd *cli = &obd->u.cli;
        struct lprocfs_static_vars lvars = { 0 };
        int rc;
        ENTRY;

        OBD_ALLOC(cli->cl_rpc_lock, sizeof (*cli->cl_rpc_lock));
        if (!cli->cl_rpc_lock)
                RETURN(-ENOMEM);
        mdc_init_rpc_lock(cli->cl_rpc_lock);

        ptlrpcd_addref();

        OBD_ALLOC(cli->cl_close_lock, sizeof (*cli->cl_close_lock));
        if (!cli->cl_close_lock)
                GOTO(err_rpc_lock, rc = -ENOMEM);
        mdc_init_rpc_lock(cli->cl_close_lock);

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

        ns_register_cancel(obd->obd_namespace, mdc_cancel_for_recovery);

        obd->obd_namespace->ns_lvbo = &inode_lvbo;

        rc = obd_llog_init(obd, &obd->obd_olg, obd, NULL);
        if (rc) {
                mdc_cleanup(obd);
                CERROR("failed to setup llogging subsystems\n");
        }

        RETURN(rc);

err_close_lock:
        OBD_FREE(cli->cl_close_lock, sizeof (*cli->cl_close_lock));
err_rpc_lock:
        OBD_FREE(cli->cl_rpc_lock, sizeof (*cli->cl_rpc_lock));
        ptlrpcd_decref();
        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 the
 * maximum-sized (= maximum striped) EA and cookie without having to
 * calculate this (via a call into the LOV + OSCs) each time we make an RPC. */
static int mdc_init_ea_size(struct obd_export *exp, int easize,
                     int def_easize, int cookiesize)
{
        struct obd_device *obd = exp->exp_obd;
        struct client_obd *cli = &obd->u.cli;
        ENTRY;

        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;

        RETURN(0);
}

static int mdc_precleanup(struct obd_device *obd, enum obd_cleanup_stage stage)
{
        int rc = 0;
        ENTRY;

        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);

                rc = obd_llog_finish(obd, 0);
                if (rc != 0)
                        CERROR("failed to cleanup llogging subsystems\n");
                break;
        }
        RETURN(rc);
}

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

        OBD_FREE(cli->cl_rpc_lock, sizeof (*cli->cl_rpc_lock));
        OBD_FREE(cli->cl_close_lock, sizeof (*cli->cl_close_lock));

        ptlrpcd_decref();

        return client_obd_cleanup(obd);
}


static int mdc_llog_init(struct obd_device *obd, struct obd_llog_group *olg,
                         struct obd_device *tgt, int *index)
{
        struct llog_ctxt        *ctxt;
        int                      rc;

        ENTRY;

        LASSERT(olg == &obd->obd_olg);

        rc = llog_setup(NULL, obd, olg, LLOG_CHANGELOG_REPL_CTXT, tgt,
                        &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 int mdc_llog_finish(struct obd_device *obd, int count)
{
        struct llog_ctxt *ctxt;

        ENTRY;

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

        RETURN(0);
}

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


/* get remote permission for current user on fid */
int mdc_get_remote_perm(struct obd_export *exp, const struct lu_fid *fid,
                        struct obd_capa *oc, __u32 suppgid,
                        struct ptlrpc_request **request)
{
        struct ptlrpc_request  *req;
        int                 rc;
        ENTRY;

        LASSERT(client_is_remote(exp));

        *request = NULL;
        req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_MDS_GETATTR);
        if (req == NULL)
                RETURN(-ENOMEM);

        mdc_set_capa_size(req, &RMF_CAPA1, oc);

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

        mdc_pack_body(req, fid, oc, OBD_MD_FLRMTPERM, 0, suppgid, 0);

        req_capsule_set_size(&req->rq_pill, &RMF_ACL, RCL_SERVER,
                             sizeof(struct mdt_remote_perm));

        ptlrpc_request_set_replen(req);

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

static int mdc_interpret_renew_capa(const struct lu_env *env,
                                    struct ptlrpc_request *req, void *args,
                                    int status)
{
        struct mdc_renew_capa_args *ra = args;
        struct mdt_body *body = NULL;
        struct lustre_capa *capa;
        ENTRY;

        if (status)
                GOTO(out, capa = ERR_PTR(status));

        body = req_capsule_server_get(&req->rq_pill, &RMF_MDT_BODY);
        if (body == NULL)
                GOTO(out, capa = ERR_PTR(-EFAULT));

        if ((body->valid & OBD_MD_FLOSSCAPA) == 0)
                GOTO(out, capa = ERR_PTR(-ENOENT));

        capa = req_capsule_server_get(&req->rq_pill, &RMF_CAPA2);
        if (!capa)
                GOTO(out, capa = ERR_PTR(-EFAULT));
        EXIT;
out:
        ra->ra_cb(ra->ra_oc, capa);
        return 0;
}

static int mdc_renew_capa(struct obd_export *exp, struct obd_capa *oc,
                          renew_capa_cb_t cb)
{
        struct ptlrpc_request *req;
        struct mdc_renew_capa_args *ra;
        ENTRY;

        req = ptlrpc_request_alloc_pack(class_exp2cliimp(exp), &RQF_MDS_GETATTR,
                                        LUSTRE_MDS_VERSION, MDS_GETATTR);
        if (req == NULL)
                RETURN(-ENOMEM);

        /* NB, OBD_MD_FLOSSCAPA is set here, but it doesn't necessarily mean the
         * capa to renew is oss capa.
         */
        mdc_pack_body(req, &oc->c_capa.lc_fid, oc, OBD_MD_FLOSSCAPA, 0, -1, 0);
        ptlrpc_request_set_replen(req);

        CLASSERT(sizeof(*ra) <= sizeof(req->rq_async_args));
        ra = ptlrpc_req_async_args(req);
        ra->ra_oc = oc;
        ra->ra_cb = cb;
        req->rq_interpret_reply = mdc_interpret_renew_capa;
        ptlrpcd_add_req(req, PDL_POLICY_LOCAL, -1);
        RETURN(0);
}

static int mdc_connect(const struct lu_env *env,
                       struct obd_export **exp,
                       struct obd_device *obd, struct obd_uuid *cluuid,
                       struct obd_connect_data *data,
                       void *localdata)
{
        struct obd_import *imp = obd->u.cli.cl_import;

        /* mds-mds import features */
        if (data && (data->ocd_connect_flags & OBD_CONNECT_MDS_MDS)) {
                spin_lock(&imp->imp_lock);
                imp->imp_server_timeout = 1;
                spin_unlock(&imp->imp_lock);
                imp->imp_client->cli_request_portal = MDS_MDS_PORTAL;
                CDEBUG(D_OTHER, "%s: Set 'mds' portal and timeout\n",
                       obd->obd_name);
        }

        return client_connect_import(env, exp, obd, cluuid, data, NULL);
}

struct obd_ops mdc_obd_ops = {
        .o_owner            = THIS_MODULE,
        .o_setup            = mdc_setup,
        .o_precleanup       = mdc_precleanup,
        .o_cleanup        = mdc_cleanup,
        .o_add_conn      = client_import_add_conn,
        .o_del_conn      = client_import_del_conn,
        .o_connect        = mdc_connect,
        .o_disconnect       = client_disconnect_export,
        .o_iocontrol    = mdc_iocontrol,
        .o_set_info_async   = mdc_set_info_async,
        .o_statfs          = mdc_statfs,
        .o_pin        = mdc_pin,
        .o_unpin            = mdc_unpin,
        .o_fid_init         = client_fid_init,
        .o_fid_fini         = client_fid_fini,
        .o_fid_alloc    = mdc_fid_alloc,
        .o_import_event     = mdc_import_event,
        .o_llog_init    = mdc_llog_init,
        .o_llog_finish      = mdc_llog_finish,
        .o_get_info      = mdc_get_info,
        .o_process_config   = mdc_process_config,
        .o_get_uuid      = mdc_get_uuid,
        .o_quotactl      = mdc_quotactl,
        .o_quotacheck       = mdc_quotacheck
};

struct md_ops mdc_md_ops = {
        .m_getstatus    = mdc_getstatus,
        .m_null_inode       = mdc_null_inode,
        .m_find_cbdata      = mdc_find_cbdata,
        .m_close            = mdc_close,
        .m_create          = mdc_create,
        .m_done_writing     = mdc_done_writing,
        .m_enqueue        = mdc_enqueue,
        .m_getattr        = mdc_getattr,
        .m_getattr_name     = mdc_getattr_name,
        .m_intent_lock      = mdc_intent_lock,
        .m_link      = mdc_link,
        .m_is_subdir    = mdc_is_subdir,
        .m_rename          = mdc_rename,
        .m_setattr        = mdc_setattr,
        .m_setxattr      = mdc_setxattr,
        .m_getxattr      = mdc_getxattr,
        .m_sync      = mdc_sync,
        .m_readpage      = mdc_readpage,
        .m_unlink          = mdc_unlink,
        .m_cancel_unused    = mdc_cancel_unused,
        .m_init_ea_size     = mdc_init_ea_size,
        .m_set_lock_data    = mdc_set_lock_data,
        .m_lock_match       = mdc_lock_match,
        .m_get_lustre_md    = mdc_get_lustre_md,
        .m_free_lustre_md   = mdc_free_lustre_md,
        .m_set_open_replay_data = mdc_set_open_replay_data,
        .m_clear_open_replay_data = mdc_clear_open_replay_data,
        .m_renew_capa       = mdc_renew_capa,
        .m_unpack_capa      = mdc_unpack_capa,
        .m_get_remote_perm  = mdc_get_remote_perm,
        .m_intent_getattr_async = mdc_intent_getattr_async,
        .m_revalidate_lock      = mdc_revalidate_lock
};

int __init mdc_init(void)
{
        int rc;
        struct lprocfs_static_vars lvars = { 0 };
        lprocfs_mdc_init_vars(&lvars);

        rc = class_register_type(&mdc_obd_ops, &mdc_md_ops, lvars.module_vars,
                                 LUSTRE_MDC_NAME, NULL);
        RETURN(rc);
}

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

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

module_init(mdc_init);
module_exit(mdc_exit);