/*
 * 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) 2002, 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_OSC

#include "../../include/linux/libcfs/libcfs.h"


#include "../include/lustre_dlm.h"
#include "../include/lustre_net.h"
#include "../include/lustre/lustre_user.h"
#include "../include/obd_cksum.h"
#include "../include/obd_ost.h"

#include "../include/lustre_ha.h"
#include "../include/lprocfs_status.h"
#include "../include/lustre_log.h"
#include "../include/lustre_debug.h"
#include "../include/lustre_param.h"
#include "../include/lustre_fid.h"
#include "osc_internal.h"
#include "osc_cl_internal.h"

static void osc_release_ppga(struct brw_page **ppga, obd_count count);
static int brw_interpret(const struct lu_env *env,
                         struct ptlrpc_request *req, void *data, int rc);
int osc_cleanup(struct obd_device *obd);

/* Pack OSC object metadata for disk storage (LE byte order). */
static int osc_packmd(struct obd_export *exp, struct lov_mds_md **lmmp,
                      struct lov_stripe_md *lsm)
{
        int lmm_size;

        lmm_size = sizeof(**lmmp);
        if (lmmp == NULL)
                return lmm_size;

        if (*lmmp != NULL && lsm == NULL) {
                OBD_FREE(*lmmp, lmm_size);
                *lmmp = NULL;
                return 0;
        } else if (unlikely(lsm != NULL && ostid_id(&lsm->lsm_oi) == 0)) {
                return -EBADF;
        }

        if (*lmmp == NULL) {
                OBD_ALLOC(*lmmp, lmm_size);
                if (*lmmp == NULL)
                        return -ENOMEM;
        }

        if (lsm)
                ostid_cpu_to_le(&lsm->lsm_oi, &(*lmmp)->lmm_oi);

        return lmm_size;
}

/* Unpack OSC object metadata from disk storage (LE byte order). */
static int osc_unpackmd(struct obd_export *exp, struct lov_stripe_md **lsmp,
                        struct lov_mds_md *lmm, int lmm_bytes)
{
        int lsm_size;
        struct obd_import *imp = class_exp2cliimp(exp);

        if (lmm != NULL) {
                if (lmm_bytes < sizeof(*lmm)) {
                        CERROR("%s: lov_mds_md too small: %d, need %d\n",
                               exp->exp_obd->obd_name, lmm_bytes,
                               (int)sizeof(*lmm));
                        return -EINVAL;
                }
                /* XXX LOV_MAGIC etc check? */

                if (unlikely(ostid_id(&lmm->lmm_oi) == 0)) {
                        CERROR("%s: zero lmm_object_id: rc = %d\n",
                               exp->exp_obd->obd_name, -EINVAL);
                        return -EINVAL;
                }
        }

        lsm_size = lov_stripe_md_size(1);
        if (lsmp == NULL)
                return lsm_size;

        if (*lsmp != NULL && lmm == NULL) {
                OBD_FREE((*lsmp)->lsm_oinfo[0], sizeof(struct lov_oinfo));
                OBD_FREE(*lsmp, lsm_size);
                *lsmp = NULL;
                return 0;
        }

        if (*lsmp == NULL) {
                OBD_ALLOC(*lsmp, lsm_size);
                if (unlikely(*lsmp == NULL))
                        return -ENOMEM;
                OBD_ALLOC((*lsmp)->lsm_oinfo[0], sizeof(struct lov_oinfo));
                if (unlikely((*lsmp)->lsm_oinfo[0] == NULL)) {
                        OBD_FREE(*lsmp, lsm_size);
                        return -ENOMEM;
                }
                loi_init((*lsmp)->lsm_oinfo[0]);
        } else if (unlikely(ostid_id(&(*lsmp)->lsm_oi) == 0)) {
                return -EBADF;
        }

        if (lmm != NULL)
                /* XXX zero *lsmp? */
                ostid_le_to_cpu(&lmm->lmm_oi, &(*lsmp)->lsm_oi);

        if (imp != NULL &&
            (imp->imp_connect_data.ocd_connect_flags & OBD_CONNECT_MAXBYTES))
                (*lsmp)->lsm_maxbytes = imp->imp_connect_data.ocd_maxbytes;
        else
                (*lsmp)->lsm_maxbytes = LUSTRE_STRIPE_MAXBYTES;

        return lsm_size;
}

static inline void osc_pack_capa(struct ptlrpc_request *req,
                                 struct ost_body *body, void *capa)
{
        struct obd_capa *oc = (struct obd_capa *)capa;
        struct lustre_capa *c;

        if (!capa)
                return;

        c = req_capsule_client_get(&req->rq_pill, &RMF_CAPA1);
        LASSERT(c);
        capa_cpy(c, oc);
        body->oa.o_valid |= OBD_MD_FLOSSCAPA;
        DEBUG_CAPA(D_SEC, c, "pack");
}

static inline void osc_pack_req_body(struct ptlrpc_request *req,
                                     struct obd_info *oinfo)
{
        struct ost_body *body;

        body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
        LASSERT(body);

        lustre_set_wire_obdo(&req->rq_import->imp_connect_data, &body->oa,
                             oinfo->oi_oa);
        osc_pack_capa(req, body, oinfo->oi_capa);
}

static inline void osc_set_capa_size(struct ptlrpc_request *req,
                                     const struct req_msg_field *field,
                                     struct obd_capa *oc)
{
        if (oc == NULL)
                req_capsule_set_size(&req->rq_pill, field, RCL_CLIENT, 0);
        else
                /* it is already calculated as sizeof struct obd_capa */
                ;
}

static int osc_getattr_interpret(const struct lu_env *env,
                                 struct ptlrpc_request *req,
                                 struct osc_async_args *aa, int rc)
{
        struct ost_body *body;

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

        body = req_capsule_server_get(&req->rq_pill, &RMF_OST_BODY);
        if (body) {
                CDEBUG(D_INODE, "mode: %o\n", body->oa.o_mode);
                lustre_get_wire_obdo(&req->rq_import->imp_connect_data,
                                     aa->aa_oi->oi_oa, &body->oa);

                /* This should really be sent by the OST */
                aa->aa_oi->oi_oa->o_blksize = DT_MAX_BRW_SIZE;
                aa->aa_oi->oi_oa->o_valid |= OBD_MD_FLBLKSZ;
        } else {
                CDEBUG(D_INFO, "can't unpack ost_body\n");
                rc = -EPROTO;
                aa->aa_oi->oi_oa->o_valid = 0;
        }
out:
        rc = aa->aa_oi->oi_cb_up(aa->aa_oi, rc);
        return rc;
}

static int osc_getattr_async(struct obd_export *exp, struct obd_info *oinfo,
                             struct ptlrpc_request_set *set)
{
        struct ptlrpc_request *req;
        struct osc_async_args *aa;
        int                 rc;

        req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_OST_GETATTR);
        if (req == NULL)
                return -ENOMEM;

        osc_set_capa_size(req, &RMF_CAPA1, oinfo->oi_capa);
        rc = ptlrpc_request_pack(req, LUSTRE_OST_VERSION, OST_GETATTR);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        osc_pack_req_body(req, oinfo);

        ptlrpc_request_set_replen(req);
        req->rq_interpret_reply = (ptlrpc_interpterer_t)osc_getattr_interpret;

        CLASSERT(sizeof(*aa) <= sizeof(req->rq_async_args));
        aa = ptlrpc_req_async_args(req);
        aa->aa_oi = oinfo;

        ptlrpc_set_add_req(set, req);
        return 0;
}

static int osc_getattr(const struct lu_env *env, struct obd_export *exp,
                       struct obd_info *oinfo)
{
        struct ptlrpc_request *req;
        struct ost_body       *body;
        int                 rc;

        req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_OST_GETATTR);
        if (req == NULL)
                return -ENOMEM;

        osc_set_capa_size(req, &RMF_CAPA1, oinfo->oi_capa);
        rc = ptlrpc_request_pack(req, LUSTRE_OST_VERSION, OST_GETATTR);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        osc_pack_req_body(req, oinfo);

        ptlrpc_request_set_replen(req);

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

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

        CDEBUG(D_INODE, "mode: %o\n", body->oa.o_mode);
        lustre_get_wire_obdo(&req->rq_import->imp_connect_data, oinfo->oi_oa,
                             &body->oa);

        oinfo->oi_oa->o_blksize = cli_brw_size(exp->exp_obd);
        oinfo->oi_oa->o_valid |= OBD_MD_FLBLKSZ;

 out:
        ptlrpc_req_finished(req);
        return rc;
}

static int osc_setattr(const struct lu_env *env, struct obd_export *exp,
                       struct obd_info *oinfo, struct obd_trans_info *oti)
{
        struct ptlrpc_request *req;
        struct ost_body       *body;
        int                 rc;

        LASSERT(oinfo->oi_oa->o_valid & OBD_MD_FLGROUP);

        req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_OST_SETATTR);
        if (req == NULL)
                return -ENOMEM;

        osc_set_capa_size(req, &RMF_CAPA1, oinfo->oi_capa);
        rc = ptlrpc_request_pack(req, LUSTRE_OST_VERSION, OST_SETATTR);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        osc_pack_req_body(req, oinfo);

        ptlrpc_request_set_replen(req);

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

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

        lustre_get_wire_obdo(&req->rq_import->imp_connect_data, oinfo->oi_oa,
                             &body->oa);

out:
        ptlrpc_req_finished(req);
        return rc;
}

static int osc_setattr_interpret(const struct lu_env *env,
                                 struct ptlrpc_request *req,
                                 struct osc_setattr_args *sa, int rc)
{
        struct ost_body *body;

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

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

        lustre_get_wire_obdo(&req->rq_import->imp_connect_data, sa->sa_oa,
                             &body->oa);
out:
        rc = sa->sa_upcall(sa->sa_cookie, rc);
        return rc;
}

int osc_setattr_async_base(struct obd_export *exp, struct obd_info *oinfo,
                           struct obd_trans_info *oti,
                           obd_enqueue_update_f upcall, void *cookie,
                           struct ptlrpc_request_set *rqset)
{
        struct ptlrpc_request   *req;
        struct osc_setattr_args *sa;
        int                   rc;

        req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_OST_SETATTR);
        if (req == NULL)
                return -ENOMEM;

        osc_set_capa_size(req, &RMF_CAPA1, oinfo->oi_capa);
        rc = ptlrpc_request_pack(req, LUSTRE_OST_VERSION, OST_SETATTR);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        if (oti && oinfo->oi_oa->o_valid & OBD_MD_FLCOOKIE)
                oinfo->oi_oa->o_lcookie = *oti->oti_logcookies;

        osc_pack_req_body(req, oinfo);

        ptlrpc_request_set_replen(req);

        /* do mds to ost setattr asynchronously */
        if (!rqset) {
                /* Do not wait for response. */
                ptlrpcd_add_req(req, PDL_POLICY_ROUND, -1);
        } else {
                req->rq_interpret_reply =
                        (ptlrpc_interpterer_t)osc_setattr_interpret;

                CLASSERT (sizeof(*sa) <= sizeof(req->rq_async_args));
                sa = ptlrpc_req_async_args(req);
                sa->sa_oa = oinfo->oi_oa;
                sa->sa_upcall = upcall;
                sa->sa_cookie = cookie;

                if (rqset == PTLRPCD_SET)
                        ptlrpcd_add_req(req, PDL_POLICY_ROUND, -1);
                else
                        ptlrpc_set_add_req(rqset, req);
        }

        return 0;
}

static int osc_setattr_async(struct obd_export *exp, struct obd_info *oinfo,
                             struct obd_trans_info *oti,
                             struct ptlrpc_request_set *rqset)
{
        return osc_setattr_async_base(exp, oinfo, oti,
                                      oinfo->oi_cb_up, oinfo, rqset);
}

int osc_real_create(struct obd_export *exp, struct obdo *oa,
                    struct lov_stripe_md **ea, struct obd_trans_info *oti)
{
        struct ptlrpc_request *req;
        struct ost_body       *body;
        struct lov_stripe_md  *lsm;
        int                 rc;

        LASSERT(oa);
        LASSERT(ea);

        lsm = *ea;
        if (!lsm) {
                rc = obd_alloc_memmd(exp, &lsm);
                if (rc < 0)
                        return rc;
        }

        req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_OST_CREATE);
        if (req == NULL)
                GOTO(out, rc = -ENOMEM);

        rc = ptlrpc_request_pack(req, LUSTRE_OST_VERSION, OST_CREATE);
        if (rc) {
                ptlrpc_request_free(req);
                GOTO(out, rc);
        }

        body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
        LASSERT(body);

        lustre_set_wire_obdo(&req->rq_import->imp_connect_data, &body->oa, oa);

        ptlrpc_request_set_replen(req);

        if ((oa->o_valid & OBD_MD_FLFLAGS) &&
            oa->o_flags == OBD_FL_DELORPHAN) {
                DEBUG_REQ(D_HA, req,
                          "delorphan from OST integration");
                /* Don't resend the delorphan req */
                req->rq_no_resend = req->rq_no_delay = 1;
        }

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

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

        CDEBUG(D_INFO, "oa flags %x\n", oa->o_flags);
        lustre_get_wire_obdo(&req->rq_import->imp_connect_data, oa, &body->oa);

        oa->o_blksize = cli_brw_size(exp->exp_obd);
        oa->o_valid |= OBD_MD_FLBLKSZ;

        /* XXX LOV STACKING: the lsm that is passed to us from LOV does not
         * have valid lsm_oinfo data structs, so don't go touching that.
         * This needs to be fixed in a big way.
         */
        lsm->lsm_oi = oa->o_oi;
        *ea = lsm;

        if (oti != NULL) {
                oti->oti_transno = lustre_msg_get_transno(req->rq_repmsg);

                if (oa->o_valid & OBD_MD_FLCOOKIE) {
                        if (!oti->oti_logcookies)
                                oti_alloc_cookies(oti, 1);
                        *oti->oti_logcookies = oa->o_lcookie;
                }
        }

        CDEBUG(D_HA, "transno: %lld\n",
               lustre_msg_get_transno(req->rq_repmsg));
out_req:
        ptlrpc_req_finished(req);
out:
        if (rc && !*ea)
                obd_free_memmd(exp, &lsm);
        return rc;
}

int osc_punch_base(struct obd_export *exp, struct obd_info *oinfo,
                   obd_enqueue_update_f upcall, void *cookie,
                   struct ptlrpc_request_set *rqset)
{
        struct ptlrpc_request   *req;
        struct osc_setattr_args *sa;
        struct ost_body  *body;
        int                   rc;

        req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_OST_PUNCH);
        if (req == NULL)
                return -ENOMEM;

        osc_set_capa_size(req, &RMF_CAPA1, oinfo->oi_capa);
        rc = ptlrpc_request_pack(req, LUSTRE_OST_VERSION, OST_PUNCH);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }
        req->rq_request_portal = OST_IO_PORTAL; /* bug 7198 */
        ptlrpc_at_set_req_timeout(req);

        body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
        LASSERT(body);
        lustre_set_wire_obdo(&req->rq_import->imp_connect_data, &body->oa,
                             oinfo->oi_oa);
        osc_pack_capa(req, body, oinfo->oi_capa);

        ptlrpc_request_set_replen(req);

        req->rq_interpret_reply = (ptlrpc_interpterer_t)osc_setattr_interpret;
        CLASSERT (sizeof(*sa) <= sizeof(req->rq_async_args));
        sa = ptlrpc_req_async_args(req);
        sa->sa_oa     = oinfo->oi_oa;
        sa->sa_upcall = upcall;
        sa->sa_cookie = cookie;
        if (rqset == PTLRPCD_SET)
                ptlrpcd_add_req(req, PDL_POLICY_ROUND, -1);
        else
                ptlrpc_set_add_req(rqset, req);

        return 0;
}

static int osc_punch(const struct lu_env *env, struct obd_export *exp,
                     struct obd_info *oinfo, struct obd_trans_info *oti,
                     struct ptlrpc_request_set *rqset)
{
        oinfo->oi_oa->o_size   = oinfo->oi_policy.l_extent.start;
        oinfo->oi_oa->o_blocks = oinfo->oi_policy.l_extent.end;
        oinfo->oi_oa->o_valid |= OBD_MD_FLSIZE | OBD_MD_FLBLOCKS;
        return osc_punch_base(exp, oinfo,
                              oinfo->oi_cb_up, oinfo, rqset);
}

static int osc_sync_interpret(const struct lu_env *env,
                              struct ptlrpc_request *req,
                              void *arg, int rc)
{
        struct osc_fsync_args *fa = arg;
        struct ost_body *body;

        if (rc)
                GOTO(out, rc);

        body = req_capsule_server_get(&req->rq_pill, &RMF_OST_BODY);
        if (body == NULL) {
                CERROR ("can't unpack ost_body\n");
                GOTO(out, rc = -EPROTO);
        }

        *fa->fa_oi->oi_oa = body->oa;
out:
        rc = fa->fa_upcall(fa->fa_cookie, rc);
        return rc;
}

int osc_sync_base(struct obd_export *exp, struct obd_info *oinfo,
                  obd_enqueue_update_f upcall, void *cookie,
                  struct ptlrpc_request_set *rqset)
{
        struct ptlrpc_request *req;
        struct ost_body       *body;
        struct osc_fsync_args *fa;
        int                 rc;

        req = ptlrpc_request_alloc(class_exp2cliimp(exp), &RQF_OST_SYNC);
        if (req == NULL)
                return -ENOMEM;

        osc_set_capa_size(req, &RMF_CAPA1, oinfo->oi_capa);
        rc = ptlrpc_request_pack(req, LUSTRE_OST_VERSION, OST_SYNC);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        /* overload the size and blocks fields in the oa with start/end */
        body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
        LASSERT(body);
        lustre_set_wire_obdo(&req->rq_import->imp_connect_data, &body->oa,
                             oinfo->oi_oa);
        osc_pack_capa(req, body, oinfo->oi_capa);

        ptlrpc_request_set_replen(req);
        req->rq_interpret_reply = osc_sync_interpret;

        CLASSERT(sizeof(*fa) <= sizeof(req->rq_async_args));
        fa = ptlrpc_req_async_args(req);
        fa->fa_oi = oinfo;
        fa->fa_upcall = upcall;
        fa->fa_cookie = cookie;

        if (rqset == PTLRPCD_SET)
                ptlrpcd_add_req(req, PDL_POLICY_ROUND, -1);
        else
                ptlrpc_set_add_req(rqset, req);

        return 0;
}

static int osc_sync(const struct lu_env *env, struct obd_export *exp,
                    struct obd_info *oinfo, obd_size start, obd_size end,
                    struct ptlrpc_request_set *set)
{
        if (!oinfo->oi_oa) {
                CDEBUG(D_INFO, "oa NULL\n");
                return -EINVAL;
        }

        oinfo->oi_oa->o_size = start;
        oinfo->oi_oa->o_blocks = end;
        oinfo->oi_oa->o_valid |= (OBD_MD_FLSIZE | OBD_MD_FLBLOCKS);

        return osc_sync_base(exp, oinfo, oinfo->oi_cb_up, oinfo, set);
}

/* Find and cancel locally locks matched by @mode in the resource found by
 * @objid. Found locks are added into @cancel list. Returns the amount of
 * locks added to @cancels list. */
static int osc_resource_get_unused(struct obd_export *exp, struct obdo *oa,
                                   struct list_head *cancels,
                                   ldlm_mode_t mode, __u64 lock_flags)
{
        struct ldlm_namespace *ns = exp->exp_obd->obd_namespace;
        struct ldlm_res_id res_id;
        struct ldlm_resource *res;
        int count;

        /* Return, i.e. cancel nothing, only if ELC is supported (flag in
         * export) but disabled through procfs (flag in NS).
         *
         * This distinguishes from a case when ELC is not supported originally,
         * when we still want to cancel locks in advance and just cancel them
         * locally, without sending any RPC. */
        if (exp_connect_cancelset(exp) && !ns_connect_cancelset(ns))
                return 0;

        ostid_build_res_name(&oa->o_oi, &res_id);
        res = ldlm_resource_get(ns, NULL, &res_id, 0, 0);
        if (res == NULL)
                return 0;

        LDLM_RESOURCE_ADDREF(res);
        count = ldlm_cancel_resource_local(res, cancels, NULL, mode,
                                           lock_flags, 0, NULL);
        LDLM_RESOURCE_DELREF(res);
        ldlm_resource_putref(res);
        return count;
}

static int osc_destroy_interpret(const struct lu_env *env,
                                 struct ptlrpc_request *req, void *data,
                                 int rc)
{
        struct client_obd *cli = &req->rq_import->imp_obd->u.cli;

        atomic_dec(&cli->cl_destroy_in_flight);
        wake_up(&cli->cl_destroy_waitq);
        return 0;
}

static int osc_can_send_destroy(struct client_obd *cli)
{
        if (atomic_inc_return(&cli->cl_destroy_in_flight) <=
            cli->cl_max_rpcs_in_flight) {
                /* The destroy request can be sent */
                return 1;
        }
        if (atomic_dec_return(&cli->cl_destroy_in_flight) <
            cli->cl_max_rpcs_in_flight) {
                /*
                 * The counter has been modified between the two atomic
                 * operations.
                 */
                wake_up(&cli->cl_destroy_waitq);
        }
        return 0;
}

int osc_create(const struct lu_env *env, struct obd_export *exp,
               struct obdo *oa, struct lov_stripe_md **ea,
               struct obd_trans_info *oti)
{
        int rc = 0;

        LASSERT(oa);
        LASSERT(ea);
        LASSERT(oa->o_valid & OBD_MD_FLGROUP);

        if ((oa->o_valid & OBD_MD_FLFLAGS) &&
            oa->o_flags == OBD_FL_RECREATE_OBJS) {
                return osc_real_create(exp, oa, ea, oti);
        }

        if (!fid_seq_is_mdt(ostid_seq(&oa->o_oi)))
                return osc_real_create(exp, oa, ea, oti);

        /* we should not get here anymore */
        LBUG();

        return rc;
}

/* Destroy requests can be async always on the client, and we don't even really
 * care about the return code since the client cannot do anything at all about
 * a destroy failure.
 * When the MDS is unlinking a filename, it saves the file objects into a
 * recovery llog, and these object records are cancelled when the OST reports
 * they were destroyed and sync'd to disk (i.e. transaction committed).
 * If the client dies, or the OST is down when the object should be destroyed,
 * the records are not cancelled, and when the OST reconnects to the MDS next,
 * it will retrieve the llog unlink logs and then sends the log cancellation
 * cookies to the MDS after committing destroy transactions. */
static int osc_destroy(const struct lu_env *env, struct obd_export *exp,
                       struct obdo *oa, struct lov_stripe_md *ea,
                       struct obd_trans_info *oti, struct obd_export *md_export,
                       void *capa)
{
        struct client_obd     *cli = &exp->exp_obd->u.cli;
        struct ptlrpc_request *req;
        struct ost_body       *body;
        LIST_HEAD(cancels);
        int rc, count;

        if (!oa) {
                CDEBUG(D_INFO, "oa NULL\n");
                return -EINVAL;
        }

        count = osc_resource_get_unused(exp, oa, &cancels, LCK_PW,
                                        LDLM_FL_DISCARD_DATA);

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

        osc_set_capa_size(req, &RMF_CAPA1, (struct obd_capa *)capa);
        rc = ldlm_prep_elc_req(exp, req, LUSTRE_OST_VERSION, OST_DESTROY,
                               0, &cancels, count);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }

        req->rq_request_portal = OST_IO_PORTAL; /* bug 7198 */
        ptlrpc_at_set_req_timeout(req);

        if (oti != NULL && oa->o_valid & OBD_MD_FLCOOKIE)
                oa->o_lcookie = *oti->oti_logcookies;
        body = req_capsule_client_get(&req->rq_pill, &RMF_OST_BODY);
        LASSERT(body);
        lustre_set_wire_obdo(&req->rq_import->imp_connect_data, &body->oa, oa);

        osc_pack_capa(req, body, (struct obd_capa *)capa);
        ptlrpc_request_set_replen(req);

        /* If osc_destroy is for destroying the unlink orphan,
         * sent from MDT to OST, which should not be blocked here,
         * because the process might be triggered by ptlrpcd, and
         * it is not good to block ptlrpcd thread (b=16006)*/
        if (!(oa->o_flags & OBD_FL_DELORPHAN)) {
                req->rq_interpret_reply = osc_destroy_interpret;
                if (!osc_can_send_destroy(cli)) {
                        struct l_wait_info lwi = LWI_INTR(LWI_ON_SIGNAL_NOOP,
                                                          NULL);

                        /*
                         * Wait until the number of on-going destroy RPCs drops
                         * under max_rpc_in_flight
                         */
                        l_wait_event_exclusive(cli->cl_destroy_waitq,
                                               osc_can_send_destroy(cli), &lwi);
                }
        }

        /* Do not wait for response */
        ptlrpcd_add_req(req, PDL_POLICY_ROUND, -1);
        return 0;
}

static void osc_announce_cached(struct client_obd *cli, struct obdo *oa,
                                long writing_bytes)
{
        obd_flag bits = OBD_MD_FLBLOCKS|OBD_MD_FLGRANT;

        LASSERT(!(oa->o_valid & bits));

        oa->o_valid |= bits;
        client_obd_list_lock(&cli->cl_loi_list_lock);
        oa->o_dirty = cli->cl_dirty;
        if (unlikely(cli->cl_dirty - cli->cl_dirty_transit >
                     cli->cl_dirty_max)) {
                CERROR("dirty %lu - %lu > dirty_max %lu\n",
                       cli->cl_dirty, cli->cl_dirty_transit, cli->cl_dirty_max);
                oa->o_undirty = 0;
        } else if (unlikely(atomic_read(&obd_dirty_pages) -
                            atomic_read(&obd_dirty_transit_pages) >
                            (long)(obd_max_dirty_pages + 1))) {
                /* The atomic_read() allowing the atomic_inc() are
                 * not covered by a lock thus they may safely race and trip
                 * this CERROR() unless we add in a small fudge factor (+1). */
                CERROR("dirty %d - %d > system dirty_max %d\n",
                       atomic_read(&obd_dirty_pages),
                       atomic_read(&obd_dirty_transit_pages),
                       obd_max_dirty_pages);
                oa->o_undirty = 0;
        } else if (unlikely(cli->cl_dirty_max - cli->cl_dirty > 0x7fffffff)) {
                CERROR("dirty %lu - dirty_max %lu too big???\n",
                       cli->cl_dirty, cli->cl_dirty_max);
                oa->o_undirty = 0;
        } else {
                long max_in_flight = (cli->cl_max_pages_per_rpc <<
                                      PAGE_CACHE_SHIFT)*
                                     (cli->cl_max_rpcs_in_flight + 1);
                oa->o_undirty = max(cli->cl_dirty_max, max_in_flight);
        }
        oa->o_grant = cli->cl_avail_grant + cli->cl_reserved_grant;
        oa->o_dropped = cli->cl_lost_grant;
        cli->cl_lost_grant = 0;
        client_obd_list_unlock(&cli->cl_loi_list_lock);
        CDEBUG(D_CACHE,"dirty: %llu undirty: %u dropped %u grant: %llu\n",
               oa->o_dirty, oa->o_undirty, oa->o_dropped, oa->o_grant);

}

void osc_update_next_shrink(struct client_obd *cli)
{
        cli->cl_next_shrink_grant =
                cfs_time_shift(cli->cl_grant_shrink_interval);
        CDEBUG(D_CACHE, "next time %ld to shrink grant \n",
               cli->cl_next_shrink_grant);
}

static void __osc_update_grant(struct client_obd *cli, obd_size grant)
{
        client_obd_list_lock(&cli->cl_loi_list_lock);
        cli->cl_avail_grant += grant;
        client_obd_list_unlock(&cli->cl_loi_list_lock);
}

static void osc_update_grant(struct client_obd *cli, struct ost_body *body)
{
        if (body->oa.o_valid & OBD_MD_FLGRANT) {
                CDEBUG(D_CACHE, "got %llu extra grant\n", body->oa.o_grant);
                __osc_update_grant(cli, body->oa.o_grant);
        }
}

static int osc_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);

static int osc_shrink_grant_interpret(const struct lu_env *env,
                                      struct ptlrpc_request *req,
                                      void *aa, int rc)
{
        struct client_obd *cli = &req->rq_import->imp_obd->u.cli;
        struct obdo *oa = ((struct osc_grant_args *)aa)->aa_oa;
        struct ost_body *body;

        if (rc != 0) {
                __osc_update_grant(cli, oa->o_grant);
                GOTO(out, rc);
        }

        body = req_capsule_server_get(&req->rq_pill, &RMF_OST_BODY);
        LASSERT(body);
        osc_update_grant(cli, body);
out:
        OBDO_FREE(oa);
        return rc;
}

static void osc_shrink_grant_local(struct client_obd *cli, struct obdo *oa)
{
        client_obd_list_lock(&cli->cl_loi_list_lock);
        oa->o_grant = cli->cl_avail_grant / 4;
        cli->cl_avail_grant -= oa->o_grant;
        client_obd_list_unlock(&cli->cl_loi_list_lock);
        if (!(oa->o_valid & OBD_MD_FLFLAGS)) {
                oa->o_valid |= OBD_MD_FLFLAGS;
                oa->o_flags = 0;
        }
        oa->o_flags |= OBD_FL_SHRINK_GRANT;
        osc_update_next_shrink(cli);
}

/* Shrink the current grant, either from some large amount to enough for a
 * full set of in-flight RPCs, or if we have already shrunk to that limit
 * then to enough for a single RPC.  This avoids keeping more grant than
 * needed, and avoids shrinking the grant piecemeal. */
static int osc_shrink_grant(struct client_obd *cli)
{
        __u64 target_bytes = (cli->cl_max_rpcs_in_flight + 1) *
                             (cli->cl_max_pages_per_rpc << PAGE_CACHE_SHIFT);

        client_obd_list_lock(&cli->cl_loi_list_lock);
        if (cli->cl_avail_grant <= target_bytes)
                target_bytes = cli->cl_max_pages_per_rpc << PAGE_CACHE_SHIFT;
        client_obd_list_unlock(&cli->cl_loi_list_lock);

        return osc_shrink_grant_to_target(cli, target_bytes);
}

int osc_shrink_grant_to_target(struct client_obd *cli, __u64 target_bytes)
{
        int                     rc = 0;
        struct ost_body *body;

        client_obd_list_lock(&cli->cl_loi_list_lock);
        /* Don't shrink if we are already above or below the desired limit
         * We don't want to shrink below a single RPC, as that will negatively
         * impact block allocation and long-term performance. */
        if (target_bytes < cli->cl_max_pages_per_rpc << PAGE_CACHE_SHIFT)
                target_bytes = cli->cl_max_pages_per_rpc << PAGE_CACHE_SHIFT;

        if (target_bytes >= cli->cl_avail_grant) {
                client_obd_list_unlock(&cli->cl_loi_list_lock);
                return 0;
        }
        client_obd_list_unlock(&cli->cl_loi_list_lock);

        OBD_ALLOC_PTR(body);
        if (!body)
                return -ENOMEM;

        osc_announce_cached(cli, &body->oa, 0);

        client_obd_list_lock(&cli->cl_loi_list_lock);
        body->oa.o_grant = cli->cl_avail_grant - target_bytes;
        cli->cl_avail_grant = target_bytes;
        client_obd_list_unlock(&cli->cl_loi_list_lock);
        if (!(body->oa.o_valid & OBD_MD_FLFLAGS)) {
                body->oa.o_valid |= OBD_MD_FLFLAGS;
                body->oa.o_flags = 0;
        }
        body->oa.o_flags |= OBD_FL_SHRINK_GRANT;
        osc_update_next_shrink(cli);

        rc = osc_set_info_async(NULL, cli->cl_import->imp_obd->obd_self_export,
                                sizeof(KEY_GRANT_SHRINK), KEY_GRANT_SHRINK,
                                sizeof(*body), body, NULL);
        if (rc != 0)
                __osc_update_grant(cli, body->oa.o_grant);
        OBD_FREE_PTR(body);
        return rc;
}

static int osc_should_shrink_grant(struct client_obd *client)
{
        unsigned long time = cfs_time_current();
        unsigned long next_shrink = client->cl_next_shrink_grant;

        if ((client->cl_import->imp_connect_data.ocd_connect_flags &
             OBD_CONNECT_GRANT_SHRINK) == 0)
                return 0;

        if (cfs_time_aftereq(time, next_shrink - 5 * CFS_TICK)) {
                /* Get the current RPC size directly, instead of going via:
                 * cli_brw_size(obd->u.cli.cl_import->imp_obd->obd_self_export)
                 * Keep comment here so that it can be found by searching. */
                int brw_size = client->cl_max_pages_per_rpc << PAGE_CACHE_SHIFT;

                if (client->cl_import->imp_state == LUSTRE_IMP_FULL &&
                    client->cl_avail_grant > brw_size)
                        return 1;
                else
                        osc_update_next_shrink(client);
        }
        return 0;
}

static int osc_grant_shrink_grant_cb(struct timeout_item *item, void *data)
{
        struct client_obd *client;

        list_for_each_entry(client, &item->ti_obd_list,
                                cl_grant_shrink_list) {
                if (osc_should_shrink_grant(client))
                        osc_shrink_grant(client);
        }
        return 0;

}

static int osc_add_shrink_grant(struct client_obd *client)
{
        int rc;

        rc = ptlrpc_add_timeout_client(client->cl_grant_shrink_interval,
                                       TIMEOUT_GRANT,
                                       osc_grant_shrink_grant_cb, NULL,
                                       &client->cl_grant_shrink_list);
        if (rc) {
                CERROR("add grant client %s error %d\n",
                        client->cl_import->imp_obd->obd_name, rc);
                return rc;
        }
        CDEBUG(D_CACHE, "add grant client %s \n",
               client->cl_import->imp_obd->obd_name);
        osc_update_next_shrink(client);
        return 0;
}

static int osc_del_shrink_grant(struct client_obd *client)
{
        return ptlrpc_del_timeout_client(&client->cl_grant_shrink_list,
                                         TIMEOUT_GRANT);
}

static void osc_init_grant(struct client_obd *cli, struct obd_connect_data *ocd)
{
        /*
         * ocd_grant is the total grant amount we're expect to hold: if we've
         * been evicted, it's the new avail_grant amount, cl_dirty will drop
         * to 0 as inflight RPCs fail out; otherwise, it's avail_grant + dirty.
         *
         * race is tolerable here: if we're evicted, but imp_state already
         * left EVICTED state, then cl_dirty must be 0 already.
         */
        client_obd_list_lock(&cli->cl_loi_list_lock);
        if (cli->cl_import->imp_state == LUSTRE_IMP_EVICTED)
                cli->cl_avail_grant = ocd->ocd_grant;
        else
                cli->cl_avail_grant = ocd->ocd_grant - cli->cl_dirty;

        if (cli->cl_avail_grant < 0) {
                CWARN("%s: available grant < 0: avail/ocd/dirty %ld/%u/%ld\n",
                      cli->cl_import->imp_obd->obd_name, cli->cl_avail_grant,
                      ocd->ocd_grant, cli->cl_dirty);
                /* workaround for servers which do not have the patch from
                 * LU-2679 */
                cli->cl_avail_grant = ocd->ocd_grant;
        }

        /* determine the appropriate chunk size used by osc_extent. */
        cli->cl_chunkbits = max_t(int, PAGE_CACHE_SHIFT, ocd->ocd_blocksize);
        client_obd_list_unlock(&cli->cl_loi_list_lock);

        CDEBUG(D_CACHE, "%s, setting cl_avail_grant: %ld cl_lost_grant: %ld."
                "chunk bits: %d.\n", cli->cl_import->imp_obd->obd_name,
                cli->cl_avail_grant, cli->cl_lost_grant, cli->cl_chunkbits);

        if (ocd->ocd_connect_flags & OBD_CONNECT_GRANT_SHRINK &&
            list_empty(&cli->cl_grant_shrink_list))
                osc_add_shrink_grant(cli);
}

/* We assume that the reason this OSC got a short read is because it read
 * beyond the end of a stripe file; i.e. lustre is reading a sparse file
 * via the LOV, and it _knows_ it's reading inside the file, it's just that
 * this stripe never got written at or beyond this stripe offset yet. */
static void handle_short_read(int nob_read, obd_count page_count,
                              struct brw_page **pga)
{
        char *ptr;
        int i = 0;

        /* skip bytes read OK */
        while (nob_read > 0) {
                LASSERT (page_count > 0);

                if (pga[i]->count > nob_read) {
                        /* EOF inside this page */
                        ptr = kmap(pga[i]->pg) +
                                (pga[i]->off & ~CFS_PAGE_MASK);
                        memset(ptr + nob_read, 0, pga[i]->count - nob_read);
                        kunmap(pga[i]->pg);
                        page_count--;
                        i++;
                        break;
                }

                nob_read -= pga[i]->count;
                page_count--;
                i++;
        }

        /* zero remaining pages */
        while (page_count-- > 0) {
                ptr = kmap(pga[i]->pg) + (pga[i]->off & ~CFS_PAGE_MASK);
                memset(ptr, 0, pga[i]->count);
                kunmap(pga[i]->pg);
                i++;
        }
}

static int check_write_rcs(struct ptlrpc_request *req,
                           int requested_nob, int niocount,
                           obd_count page_count, struct brw_page **pga)
{
        int     i;
        __u32   *remote_rcs;

        remote_rcs = req_capsule_server_sized_get(&req->rq_pill, &RMF_RCS,
                                                  sizeof(*remote_rcs) *
                                                  niocount);
        if (remote_rcs == NULL) {
                CDEBUG(D_INFO, "Missing/short RC vector on BRW_WRITE reply\n");
                return(-EPROTO);
        }

        /* return error if any niobuf was in error */
        for (i = 0; i < niocount; i++) {
                if ((int)remote_rcs[i] < 0)
                        return(remote_rcs[i]);

                if (remote_rcs[i] != 0) {
                        CDEBUG(D_INFO, "rc[%d] invalid (%d) req %p\n",
                                i, remote_rcs[i], req);
                        return(-EPROTO);
                }
        }

        if (req->rq_bulk->bd_nob_transferred != requested_nob) {
                CERROR("Unexpected # bytes transferred: %d (requested %d)\n",
                       req->rq_bulk->bd_nob_transferred, requested_nob);
                return(-EPROTO);
        }

        return (0);
}

static inline int can_merge_pages(struct brw_page *p1, struct brw_page *p2)
{
        if (p1->flag != p2->flag) {
                unsigned mask = ~(OBD_BRW_FROM_GRANT| OBD_BRW_NOCACHE|
                                  OBD_BRW_SYNC|OBD_BRW_ASYNC|OBD_BRW_NOQUOTA);

                /* warn if we try to combine flags that we don't know to be
                 * safe to combine */
                if (unlikely((p1->flag & mask) != (p2->flag & mask))) {
                        CWARN("Saw flags 0x%x and 0x%x in the same brw, please "
                              "report this at http://bugs.whamcloud.com/\n",
                              p1->flag, p2->flag);
                }
                return 0;
        }

        return (p1->off + p1->count == p2->off);
}

static obd_count osc_checksum_bulk(int nob, obd_count pg_count,
                                   struct brw_page **pga, int opc,
                                   cksum_type_t cksum_type)
{
        __u32                           cksum;
        int                             i = 0;
        struct cfs_crypto_hash_desc     *hdesc;
        unsigned int                    bufsize;
        int                             err;
        unsigned char                   cfs_alg = cksum_obd2cfs(cksum_type);

        LASSERT(pg_count > 0);

        hdesc = cfs_crypto_hash_init(cfs_alg, NULL, 0);
        if (IS_ERR(hdesc)) {
                CERROR("Unable to initialize checksum hash %s\n",
                       cfs_crypto_hash_name(cfs_alg));
                return PTR_ERR(hdesc);
        }

        while (nob > 0 && pg_count > 0) {
                int count = pga[i]->count > nob ? nob : pga[i]->count;

                /* corrupt the data before we compute the checksum, to
                 * simulate an OST->client data error */
                if (i == 0 && opc == OST_READ &&
                    OBD_FAIL_CHECK(OBD_FAIL_OSC_CHECKSUM_RECEIVE)) {
                        unsigned char *ptr = kmap(pga[i]->pg);
                        int off = pga[i]->off & ~CFS_PAGE_MASK;
                        memcpy(ptr + off, "bad1", min(4, nob));
                        kunmap(pga[i]->pg);
                }
                cfs_crypto_hash_update_page(hdesc, pga[i]->pg,
                                  pga[i]->off & ~CFS_PAGE_MASK,
                                  count);
                CDEBUG(D_PAGE,
                       "page %p map %p index %lu flags %lx count %u priv %0lx: off %d\n",
                       pga[i]->pg, pga[i]->pg->mapping, pga[i]->pg->index,
                       (long)pga[i]->pg->flags, page_count(pga[i]->pg),
                       page_private(pga[i]->pg),
                       (int)(pga[i]->off & ~CFS_PAGE_MASK));

                nob -= pga[i]->count;
                pg_count--;
                i++;
        }

        bufsize = 4;
        err = cfs_crypto_hash_final(hdesc, (unsigned char *)&cksum, &bufsize);

        if (err)
                cfs_crypto_hash_final(hdesc, NULL, NULL);

        /* For sending we only compute the wrong checksum instead
         * of corrupting the data so it is still correct on a redo */
        if (opc == OST_WRITE && OBD_FAIL_CHECK(OBD_FAIL_OSC_CHECKSUM_SEND))
                cksum++;

        return cksum;
}

static int osc_brw_prep_request(int cmd, struct client_obd *cli,struct obdo *oa,
                                struct lov_stripe_md *lsm, obd_count page_count,
                                struct brw_page **pga,
                                struct ptlrpc_request **reqp,
                                struct obd_capa *ocapa, int reserve,
                                int resend)
{
        struct ptlrpc_request   *req;
        struct ptlrpc_bulk_desc *desc;
        struct ost_body  *body;
        struct obd_ioobj        *ioobj;
        struct niobuf_remote    *niobuf;
        int niocount, i, requested_nob, opc, rc;
        struct osc_brw_async_args *aa;
        struct req_capsule      *pill;
        struct brw_page *pg_prev;

        if (OBD_FAIL_CHECK(OBD_FAIL_OSC_BRW_PREP_REQ))
                return -ENOMEM; /* Recoverable */
        if (OBD_FAIL_CHECK(OBD_FAIL_OSC_BRW_PREP_REQ2))
                return -EINVAL; /* Fatal */

        if ((cmd & OBD_BRW_WRITE) != 0) {
                opc = OST_WRITE;
                req = ptlrpc_request_alloc_pool(cli->cl_import,
                                                cli->cl_import->imp_rq_pool,
                                                &RQF_OST_BRW_WRITE);
        } else {
                opc = OST_READ;
                req = ptlrpc_request_alloc(cli->cl_import, &RQF_OST_BRW_READ);
        }
        if (req == NULL)
                return -ENOMEM;

        for (niocount = i = 1; i < page_count; i++) {
                if (!can_merge_pages(pga[i - 1], pga[i]))
                        niocount++;
        }

        pill = &req->rq_pill;
        req_capsule_set_size(pill, &RMF_OBD_IOOBJ, RCL_CLIENT,
                             sizeof(*ioobj));
        req_capsule_set_size(pill, &RMF_NIOBUF_REMOTE, RCL_CLIENT,
                             niocount * sizeof(*niobuf));
        osc_set_capa_size(req, &RMF_CAPA1, ocapa);

        rc = ptlrpc_request_pack(req, LUSTRE_OST_VERSION, opc);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }
        req->rq_request_portal = OST_IO_PORTAL; /* bug 7198 */
        ptlrpc_at_set_req_timeout(req);
        /* ask ptlrpc not to resend on EINPROGRESS since BRWs have their own
         * retry logic */
        req->rq_no_retry_einprogress = 1;

        desc = ptlrpc_prep_bulk_imp(req, page_count,
                cli->cl_import->imp_connect_data.ocd_brw_size >> LNET_MTU_BITS,
                opc == OST_WRITE ? BULK_GET_SOURCE : BULK_PUT_SINK,
                OST_BULK_PORTAL);

        if (desc == NULL)
                GOTO(out, rc = -ENOMEM);
        /* NB request now owns desc and will free it when it gets freed */

        body = req_capsule_client_get(pill, &RMF_OST_BODY);
        ioobj = req_capsule_client_get(pill, &RMF_OBD_IOOBJ);
        niobuf = req_capsule_client_get(pill, &RMF_NIOBUF_REMOTE);
        LASSERT(body != NULL && ioobj != NULL && niobuf != NULL);

        lustre_set_wire_obdo(&req->rq_import->imp_connect_data, &body->oa, oa);

        obdo_to_ioobj(oa, ioobj);
        ioobj->ioo_bufcnt = niocount;
        /* The high bits of ioo_max_brw tells server _maximum_ number of bulks
         * that might be send for this request.  The actual number is decided
         * when the RPC is finally sent in ptlrpc_register_bulk(). It sends
         * "max - 1" for old client compatibility sending "0", and also so the
         * the actual maximum is a power-of-two number, not one less. LU-1431 */
        ioobj_max_brw_set(ioobj, desc->bd_md_max_brw);
        osc_pack_capa(req, body, ocapa);
        LASSERT(page_count > 0);
        pg_prev = pga[0];
        for (requested_nob = i = 0; i < page_count; i++, niobuf++) {
                struct brw_page *pg = pga[i];
                int poff = pg->off & ~CFS_PAGE_MASK;

                LASSERT(pg->count > 0);
                /* make sure there is no gap in the middle of page array */
                LASSERTF(page_count == 1 ||
                         (ergo(i == 0, poff + pg->count == PAGE_CACHE_SIZE) &&
                          ergo(i > 0 && i < page_count - 1,
                               poff == 0 && pg->count == PAGE_CACHE_SIZE)   &&
                          ergo(i == page_count - 1, poff == 0)),
                         "i: %d/%d pg: %p off: %llu, count: %u\n",
                         i, page_count, pg, pg->off, pg->count);
                LASSERTF(i == 0 || pg->off > pg_prev->off,
                         "i %d p_c %u pg %p [pri %lu ind %lu] off %llu"
                         " prev_pg %p [pri %lu ind %lu] off %llu\n",
                         i, page_count,
                         pg->pg, page_private(pg->pg), pg->pg->index, pg->off,
                         pg_prev->pg, page_private(pg_prev->pg),
                         pg_prev->pg->index, pg_prev->off);
                LASSERT((pga[0]->flag & OBD_BRW_SRVLOCK) ==
                        (pg->flag & OBD_BRW_SRVLOCK));

                ptlrpc_prep_bulk_page_pin(desc, pg->pg, poff, pg->count);
                requested_nob += pg->count;

                if (i > 0 && can_merge_pages(pg_prev, pg)) {
                        niobuf--;
                        niobuf->len += pg->count;
                } else {
                        niobuf->offset = pg->off;
                        niobuf->len    = pg->count;
                        niobuf->flags  = pg->flag;
                }
                pg_prev = pg;
        }

        LASSERTF((void *)(niobuf - niocount) ==
                req_capsule_client_get(&req->rq_pill, &RMF_NIOBUF_REMOTE),
                "want %p - real %p\n", req_capsule_client_get(&req->rq_pill,
                &RMF_NIOBUF_REMOTE), (void *)(niobuf - niocount));

        osc_announce_cached(cli, &body->oa, opc == OST_WRITE ? requested_nob:0);
        if (resend) {
                if ((body->oa.o_valid & OBD_MD_FLFLAGS) == 0) {
                        body->oa.o_valid |= OBD_MD_FLFLAGS;
                        body->oa.o_flags = 0;
                }
                body->oa.o_flags |= OBD_FL_RECOV_RESEND;
        }

        if (osc_should_shrink_grant(cli))
                osc_shrink_grant_local(cli, &body->oa);

        /* size[REQ_REC_OFF] still sizeof (*body) */
        if (opc == OST_WRITE) {
                if (cli->cl_checksum &&
                    !sptlrpc_flavor_has_bulk(&req->rq_flvr)) {
                        /* store cl_cksum_type in a local variable since
                         * it can be changed via lprocfs */
                        cksum_type_t cksum_type = cli->cl_cksum_type;

                        if ((body->oa.o_valid & OBD_MD_FLFLAGS) == 0) {
                                oa->o_flags &= OBD_FL_LOCAL_MASK;
                                body->oa.o_flags = 0;
                        }
                        body->oa.o_flags |= cksum_type_pack(cksum_type);
                        body->oa.o_valid |= OBD_MD_FLCKSUM | OBD_MD_FLFLAGS;
                        body->oa.o_cksum = osc_checksum_bulk(requested_nob,
                                                             page_count, pga,
                                                             OST_WRITE,
                                                             cksum_type);
                        CDEBUG(D_PAGE, "checksum at write origin: %x\n",
                               body->oa.o_cksum);
                        /* save this in 'oa', too, for later checking */
                        oa->o_valid |= OBD_MD_FLCKSUM | OBD_MD_FLFLAGS;
                        oa->o_flags |= cksum_type_pack(cksum_type);
                } else {
                        /* clear out the checksum flag, in case this is a
                         * resend but cl_checksum is no longer set. b=11238 */
                        oa->o_valid &= ~OBD_MD_FLCKSUM;
                }
                oa->o_cksum = body->oa.o_cksum;
                /* 1 RC per niobuf */
                req_capsule_set_size(pill, &RMF_RCS, RCL_SERVER,
                                     sizeof(__u32) * niocount);
        } else {
                if (cli->cl_checksum &&
                    !sptlrpc_flavor_has_bulk(&req->rq_flvr)) {
                        if ((body->oa.o_valid & OBD_MD_FLFLAGS) == 0)
                                body->oa.o_flags = 0;
                        body->oa.o_flags |= cksum_type_pack(cli->cl_cksum_type);
                        body->oa.o_valid |= OBD_MD_FLCKSUM | OBD_MD_FLFLAGS;
                }
        }
        ptlrpc_request_set_replen(req);

        CLASSERT(sizeof(*aa) <= sizeof(req->rq_async_args));
        aa = ptlrpc_req_async_args(req);
        aa->aa_oa = oa;
        aa->aa_requested_nob = requested_nob;
        aa->aa_nio_count = niocount;
        aa->aa_page_count = page_count;
        aa->aa_resends = 0;
        aa->aa_ppga = pga;
        aa->aa_cli = cli;
        INIT_LIST_HEAD(&aa->aa_oaps);
        if (ocapa && reserve)
                aa->aa_ocapa = capa_get(ocapa);

        *reqp = req;
        return 0;

 out:
        ptlrpc_req_finished(req);
        return rc;
}

static int check_write_checksum(struct obdo *oa, const lnet_process_id_t *peer,
                                __u32 client_cksum, __u32 server_cksum, int nob,
                                obd_count page_count, struct brw_page **pga,
                                cksum_type_t client_cksum_type)
{
        __u32 new_cksum;
        char *msg;
        cksum_type_t cksum_type;

        if (server_cksum == client_cksum) {
                CDEBUG(D_PAGE, "checksum %x confirmed\n", client_cksum);
                return 0;
        }

        cksum_type = cksum_type_unpack(oa->o_valid & OBD_MD_FLFLAGS ?
                                       oa->o_flags : 0);
        new_cksum = osc_checksum_bulk(nob, page_count, pga, OST_WRITE,
                                      cksum_type);

        if (cksum_type != client_cksum_type)
                msg = "the server did not use the checksum type specified in "
                      "the original request - likely a protocol problem";
        else if (new_cksum == server_cksum)
                msg = "changed on the client after we checksummed it - "
                      "likely false positive due to mmap IO (bug 11742)";
        else if (new_cksum == client_cksum)
                msg = "changed in transit before arrival at OST";
        else
                msg = "changed in transit AND doesn't match the original - "
                      "likely false positive due to mmap IO (bug 11742)";

        LCONSOLE_ERROR_MSG(0x132, "BAD WRITE CHECKSUM: %s: from %s inode "DFID
                           " object "DOSTID" extent [%llu-%llu]\n",
                           msg, libcfs_nid2str(peer->nid),
                           oa->o_valid & OBD_MD_FLFID ? oa->o_parent_seq : (__u64)0,
                           oa->o_valid & OBD_MD_FLFID ? oa->o_parent_oid : 0,
                           oa->o_valid & OBD_MD_FLFID ? oa->o_parent_ver : 0,
                           POSTID(&oa->o_oi), pga[0]->off,
                           pga[page_count-1]->off + pga[page_count-1]->count - 1);
        CERROR("original client csum %x (type %x), server csum %x (type %x), "
               "client csum now %x\n", client_cksum, client_cksum_type,
               server_cksum, cksum_type, new_cksum);
        return 1;
}

/* Note rc enters this function as number of bytes transferred */
static int osc_brw_fini_request(struct ptlrpc_request *req, int rc)
{
        struct osc_brw_async_args *aa = (void *)&req->rq_async_args;
        const lnet_process_id_t *peer =
                        &req->rq_import->imp_connection->c_peer;
        struct client_obd *cli = aa->aa_cli;
        struct ost_body *body;
        __u32 client_cksum = 0;

        if (rc < 0 && rc != -EDQUOT) {
                DEBUG_REQ(D_INFO, req, "Failed request with rc = %d\n", rc);
                return rc;
        }

        LASSERTF(req->rq_repmsg != NULL, "rc = %d\n", rc);
        body = req_capsule_server_get(&req->rq_pill, &RMF_OST_BODY);
        if (body == NULL) {
                DEBUG_REQ(D_INFO, req, "Can't unpack body\n");
                return -EPROTO;
        }

        /* set/clear over quota flag for a uid/gid */
        if (lustre_msg_get_opc(req->rq_reqmsg) == OST_WRITE &&
            body->oa.o_valid & (OBD_MD_FLUSRQUOTA | OBD_MD_FLGRPQUOTA)) {
                unsigned int qid[MAXQUOTAS] = { body->oa.o_uid, body->oa.o_gid };

                CDEBUG(D_QUOTA, "setdq for [%u %u] with valid %#llx, flags %x\n",
                       body->oa.o_uid, body->oa.o_gid, body->oa.o_valid,
                       body->oa.o_flags);
                osc_quota_setdq(cli, qid, body->oa.o_valid, body->oa.o_flags);
        }

        osc_update_grant(cli, body);

        if (rc < 0)
                return rc;

        if (aa->aa_oa->o_valid & OBD_MD_FLCKSUM)
                client_cksum = aa->aa_oa->o_cksum; /* save for later */

        if (lustre_msg_get_opc(req->rq_reqmsg) == OST_WRITE) {
                if (rc > 0) {
                        CERROR("Unexpected +ve rc %d\n", rc);
                        return -EPROTO;
                }
                LASSERT(req->rq_bulk->bd_nob == aa->aa_requested_nob);

                if (sptlrpc_cli_unwrap_bulk_write(req, req->rq_bulk))
                        return -EAGAIN;

                if ((aa->aa_oa->o_valid & OBD_MD_FLCKSUM) && client_cksum &&
                    check_write_checksum(&body->oa, peer, client_cksum,
                                         body->oa.o_cksum, aa->aa_requested_nob,
                                         aa->aa_page_count, aa->aa_ppga,
                                         cksum_type_unpack(aa->aa_oa->o_flags)))
                        return -EAGAIN;

                rc = check_write_rcs(req, aa->aa_requested_nob,aa->aa_nio_count,
                                     aa->aa_page_count, aa->aa_ppga);
                GOTO(out, rc);
        }

        /* The rest of this function executes only for OST_READs */

        /* if unwrap_bulk failed, return -EAGAIN to retry */
        rc = sptlrpc_cli_unwrap_bulk_read(req, req->rq_bulk, rc);
        if (rc < 0)
                GOTO(out, rc = -EAGAIN);

        if (rc > aa->aa_requested_nob) {
                CERROR("Unexpected rc %d (%d requested)\n", rc,
                       aa->aa_requested_nob);
                return -EPROTO;
        }

        if (rc != req->rq_bulk->bd_nob_transferred) {
                CERROR ("Unexpected rc %d (%d transferred)\n",
                        rc, req->rq_bulk->bd_nob_transferred);
                return (-EPROTO);
        }

        if (rc < aa->aa_requested_nob)
                handle_short_read(rc, aa->aa_page_count, aa->aa_ppga);

        if (body->oa.o_valid & OBD_MD_FLCKSUM) {
                static int cksum_counter;
                __u32      server_cksum = body->oa.o_cksum;
                char      *via;
                char      *router;
                cksum_type_t cksum_type;

                cksum_type = cksum_type_unpack(body->oa.o_valid &OBD_MD_FLFLAGS?
                                               body->oa.o_flags : 0);
                client_cksum = osc_checksum_bulk(rc, aa->aa_page_count,
                                                 aa->aa_ppga, OST_READ,
                                                 cksum_type);

                if (peer->nid == req->rq_bulk->bd_sender) {
                        via = router = "";
                } else {
                        via = " via ";
                        router = libcfs_nid2str(req->rq_bulk->bd_sender);
                }

                if (server_cksum != client_cksum) {
                        LCONSOLE_ERROR_MSG(0x133, "%s: BAD READ CHECKSUM: from "
                                           "%s%s%s inode "DFID" object "DOSTID
                                           " extent [%llu-%llu]\n",
                                           req->rq_import->imp_obd->obd_name,
                                           libcfs_nid2str(peer->nid),
                                           via, router,
                                           body->oa.o_valid & OBD_MD_FLFID ?
                                                body->oa.o_parent_seq : (__u64)0,
                                           body->oa.o_valid & OBD_MD_FLFID ?
                                                body->oa.o_parent_oid : 0,
                                           body->oa.o_valid & OBD_MD_FLFID ?
                                                body->oa.o_parent_ver : 0,
                                           POSTID(&body->oa.o_oi),
                                           aa->aa_ppga[0]->off,
                                           aa->aa_ppga[aa->aa_page_count-1]->off +
                                           aa->aa_ppga[aa->aa_page_count-1]->count -
                                                                        1);
                        CERROR("client %x, server %x, cksum_type %x\n",
                               client_cksum, server_cksum, cksum_type);
                        cksum_counter = 0;
                        aa->aa_oa->o_cksum = client_cksum;
                        rc = -EAGAIN;
                } else {
                        cksum_counter++;
                        CDEBUG(D_PAGE, "checksum %x confirmed\n", client_cksum);
                        rc = 0;
                }
        } else if (unlikely(client_cksum)) {
                static int cksum_missed;

                cksum_missed++;
                if ((cksum_missed & (-cksum_missed)) == cksum_missed)
                        CERROR("Checksum %u requested from %s but not sent\n",
                               cksum_missed, libcfs_nid2str(peer->nid));
        } else {
                rc = 0;
        }
out:
        if (rc >= 0)
                lustre_get_wire_obdo(&req->rq_import->imp_connect_data,
                                     aa->aa_oa, &body->oa);

        return rc;
}

static int osc_brw_internal(int cmd, struct obd_export *exp, struct obdo *oa,
                            struct lov_stripe_md *lsm,
                            obd_count page_count, struct brw_page **pga,
                            struct obd_capa *ocapa)
{
        struct ptlrpc_request *req;
        int                 rc;
        wait_queue_head_t           waitq;
        int                 generation, resends = 0;
        struct l_wait_info     lwi;

        init_waitqueue_head(&waitq);
        generation = exp->exp_obd->u.cli.cl_import->imp_generation;

restart_bulk:
        rc = osc_brw_prep_request(cmd, &exp->exp_obd->u.cli, oa, lsm,
                                  page_count, pga, &req, ocapa, 0, resends);
        if (rc != 0)
                return (rc);

        if (resends) {
                req->rq_generation_set = 1;
                req->rq_import_generation = generation;
                req->rq_sent = get_seconds() + resends;
        }

        rc = ptlrpc_queue_wait(req);

        if (rc == -ETIMEDOUT && req->rq_resend) {
                DEBUG_REQ(D_HA, req,  "BULK TIMEOUT");
                ptlrpc_req_finished(req);
                goto restart_bulk;
        }

        rc = osc_brw_fini_request(req, rc);

        ptlrpc_req_finished(req);
        /* When server return -EINPROGRESS, client should always retry
         * regardless of the number of times the bulk was resent already.*/
        if (osc_recoverable_error(rc)) {
                resends++;
                if (rc != -EINPROGRESS &&
                    !client_should_resend(resends, &exp->exp_obd->u.cli)) {
                        CERROR("%s: too many resend retries for object: "
                               ""DOSTID", rc = %d.\n", exp->exp_obd->obd_name,
                               POSTID(&oa->o_oi), rc);
                        goto out;
                }
                if (generation !=
                    exp->exp_obd->u.cli.cl_import->imp_generation) {
                        CDEBUG(D_HA, "%s: resend cross eviction for object: "
                               ""DOSTID", rc = %d.\n", exp->exp_obd->obd_name,
                               POSTID(&oa->o_oi), rc);
                        goto out;
                }

                lwi = LWI_TIMEOUT_INTR(cfs_time_seconds(resends), NULL, NULL,
                                       NULL);
                l_wait_event(waitq, 0, &lwi);

                goto restart_bulk;
        }
out:
        if (rc == -EAGAIN || rc == -EINPROGRESS)
                rc = -EIO;
        return rc;
}

static int osc_brw_redo_request(struct ptlrpc_request *request,
                                struct osc_brw_async_args *aa, int rc)
{
        struct ptlrpc_request *new_req;
        struct osc_brw_async_args *new_aa;
        struct osc_async_page *oap;

        DEBUG_REQ(rc == -EINPROGRESS ? D_RPCTRACE : D_ERROR, request,
                  "redo for recoverable error %d", rc);

        rc = osc_brw_prep_request(lustre_msg_get_opc(request->rq_reqmsg) ==
                                        OST_WRITE ? OBD_BRW_WRITE :OBD_BRW_READ,
                                  aa->aa_cli, aa->aa_oa,
                                  NULL /* lsm unused by osc currently */,
                                  aa->aa_page_count, aa->aa_ppga,
                                  &new_req, aa->aa_ocapa, 0, 1);
        if (rc)
                return rc;

        list_for_each_entry(oap, &aa->aa_oaps, oap_rpc_item) {
                if (oap->oap_request != NULL) {
                        LASSERTF(request == oap->oap_request,
                                 "request %p != oap_request %p\n",
                                 request, oap->oap_request);
                        if (oap->oap_interrupted) {
                                ptlrpc_req_finished(new_req);
                                return -EINTR;
                        }
                }
        }
        /* New request takes over pga and oaps from old request.
         * Note that copying a list_head doesn't work, need to move it... */
        aa->aa_resends++;
        new_req->rq_interpret_reply = request->rq_interpret_reply;
        new_req->rq_async_args = request->rq_async_args;
        /* cap resend delay to the current request timeout, this is similar to
         * what ptlrpc does (see after_reply()) */
        if (aa->aa_resends > new_req->rq_timeout)
                new_req->rq_sent = get_seconds() + new_req->rq_timeout;
        else
                new_req->rq_sent = get_seconds() + aa->aa_resends;
        new_req->rq_generation_set = 1;
        new_req->rq_import_generation = request->rq_import_generation;

        new_aa = ptlrpc_req_async_args(new_req);

        INIT_LIST_HEAD(&new_aa->aa_oaps);
        list_splice_init(&aa->aa_oaps, &new_aa->aa_oaps);
        INIT_LIST_HEAD(&new_aa->aa_exts);
        list_splice_init(&aa->aa_exts, &new_aa->aa_exts);
        new_aa->aa_resends = aa->aa_resends;

        list_for_each_entry(oap, &new_aa->aa_oaps, oap_rpc_item) {
                if (oap->oap_request) {
                        ptlrpc_req_finished(oap->oap_request);
                        oap->oap_request = ptlrpc_request_addref(new_req);
                }
        }

        new_aa->aa_ocapa = aa->aa_ocapa;
        aa->aa_ocapa = NULL;

        /* XXX: This code will run into problem if we're going to support
         * to add a series of BRW RPCs into a self-defined ptlrpc_request_set
         * and wait for all of them to be finished. We should inherit request
         * set from old request. */
        ptlrpcd_add_req(new_req, PDL_POLICY_SAME, -1);

        DEBUG_REQ(D_INFO, new_req, "new request");
        return 0;
}

/*
 * ugh, we want disk allocation on the target to happen in offset order.  we'll
 * follow sedgewicks advice and stick to the dead simple shellsort -- it'll do
 * fine for our small page arrays and doesn't require allocation.  its an
 * insertion sort that swaps elements that are strides apart, shrinking the
 * stride down until its '1' and the array is sorted.
 */
static void sort_brw_pages(struct brw_page **array, int num)
{
        int stride, i, j;
        struct brw_page *tmp;

        if (num == 1)
                return;
        for (stride = 1; stride < num ; stride = (stride * 3) + 1)
                ;

        do {
                stride /= 3;
                for (i = stride ; i < num ; i++) {
                        tmp = array[i];
                        j = i;
                        while (j >= stride && array[j - stride]->off > tmp->off) {
                                array[j] = array[j - stride];
                                j -= stride;
                        }
                        array[j] = tmp;
                }
        } while (stride > 1);
}

static obd_count max_unfragmented_pages(struct brw_page **pg, obd_count pages)
{
        int count = 1;
        int offset;
        int i = 0;

        LASSERT (pages > 0);
        offset = pg[i]->off & ~CFS_PAGE_MASK;

        for (;;) {
                pages--;
                if (pages == 0)  /* that's all */
                        return count;

                if (offset + pg[i]->count < PAGE_CACHE_SIZE)
                        return count;   /* doesn't end on page boundary */

                i++;
                offset = pg[i]->off & ~CFS_PAGE_MASK;
                if (offset != 0)        /* doesn't start on page boundary */
                        return count;

                count++;
        }
}

static struct brw_page **osc_build_ppga(struct brw_page *pga, obd_count count)
{
        struct brw_page **ppga;
        int i;

        OBD_ALLOC(ppga, sizeof(*ppga) * count);
        if (ppga == NULL)
                return NULL;

        for (i = 0; i < count; i++)
                ppga[i] = pga + i;
        return ppga;
}

static void osc_release_ppga(struct brw_page **ppga, obd_count count)
{
        LASSERT(ppga != NULL);
        OBD_FREE(ppga, sizeof(*ppga) * count);
}

static int osc_brw(int cmd, struct obd_export *exp, struct obd_info *oinfo,
                   obd_count page_count, struct brw_page *pga,
                   struct obd_trans_info *oti)
{
        struct obdo *saved_oa = NULL;
        struct brw_page **ppga, **orig;
        struct obd_import *imp = class_exp2cliimp(exp);
        struct client_obd *cli;
        int rc, page_count_orig;

        LASSERT((imp != NULL) && (imp->imp_obd != NULL));
        cli = &imp->imp_obd->u.cli;

        if (cmd & OBD_BRW_CHECK) {
                /* The caller just wants to know if there's a chance that this
                 * I/O can succeed */

                if (imp->imp_invalid)
                        return -EIO;
                return 0;
        }

        /* test_brw with a failed create can trip this, maybe others. */
        LASSERT(cli->cl_max_pages_per_rpc);

        rc = 0;

        orig = ppga = osc_build_ppga(pga, page_count);
        if (ppga == NULL)
                return -ENOMEM;
        page_count_orig = page_count;

        sort_brw_pages(ppga, page_count);
        while (page_count) {
                obd_count pages_per_brw;

                if (page_count > cli->cl_max_pages_per_rpc)
                        pages_per_brw = cli->cl_max_pages_per_rpc;
                else
                        pages_per_brw = page_count;

                pages_per_brw = max_unfragmented_pages(ppga, pages_per_brw);

                if (saved_oa != NULL) {
                        /* restore previously saved oa */
                        *oinfo->oi_oa = *saved_oa;
                } else if (page_count > pages_per_brw) {
                        /* save a copy of oa (brw will clobber it) */
                        OBDO_ALLOC(saved_oa);
                        if (saved_oa == NULL)
                                GOTO(out, rc = -ENOMEM);
                        *saved_oa = *oinfo->oi_oa;
                }

                rc = osc_brw_internal(cmd, exp, oinfo->oi_oa, oinfo->oi_md,
                                      pages_per_brw, ppga, oinfo->oi_capa);

                if (rc != 0)
                        break;

                page_count -= pages_per_brw;
                ppga += pages_per_brw;
        }

out:
        osc_release_ppga(orig, page_count_orig);

        if (saved_oa != NULL)
                OBDO_FREE(saved_oa);

        return rc;
}

static int brw_interpret(const struct lu_env *env,
                         struct ptlrpc_request *req, void *data, int rc)
{
        struct osc_brw_async_args *aa = data;
        struct osc_extent *ext;
        struct osc_extent *tmp;
        struct cl_object  *obj = NULL;
        struct client_obd *cli = aa->aa_cli;

        rc = osc_brw_fini_request(req, rc);
        CDEBUG(D_INODE, "request %p aa %p rc %d\n", req, aa, rc);
        /* When server return -EINPROGRESS, client should always retry
         * regardless of the number of times the bulk was resent already. */
        if (osc_recoverable_error(rc)) {
                if (req->rq_import_generation !=
                    req->rq_import->imp_generation) {
                        CDEBUG(D_HA, "%s: resend cross eviction for object: "
                               ""DOSTID", rc = %d.\n",
                               req->rq_import->imp_obd->obd_name,
                               POSTID(&aa->aa_oa->o_oi), rc);
                } else if (rc == -EINPROGRESS ||
                    client_should_resend(aa->aa_resends, aa->aa_cli)) {
                        rc = osc_brw_redo_request(req, aa, rc);
                } else {
                        CERROR("%s: too many resent retries for object: %llu:%llu, rc = %d.\n",
                               req->rq_import->imp_obd->obd_name,
                               POSTID(&aa->aa_oa->o_oi), rc);
                }

                if (rc == 0)
                        return 0;
                else if (rc == -EAGAIN || rc == -EINPROGRESS)
                        rc = -EIO;
        }

        if (aa->aa_ocapa) {
                capa_put(aa->aa_ocapa);
                aa->aa_ocapa = NULL;
        }

        list_for_each_entry_safe(ext, tmp, &aa->aa_exts, oe_link) {
                if (obj == NULL && rc == 0) {
                        obj = osc2cl(ext->oe_obj);
                        cl_object_get(obj);
                }

                list_del_init(&ext->oe_link);
                osc_extent_finish(env, ext, 1, rc);
        }
        LASSERT(list_empty(&aa->aa_exts));
        LASSERT(list_empty(&aa->aa_oaps));

        if (obj != NULL) {
                struct obdo *oa = aa->aa_oa;
                struct cl_attr *attr  = &osc_env_info(env)->oti_attr;
                unsigned long valid = 0;

                LASSERT(rc == 0);
                if (oa->o_valid & OBD_MD_FLBLOCKS) {
                        attr->cat_blocks = oa->o_blocks;
                        valid |= CAT_BLOCKS;
                }
                if (oa->o_valid & OBD_MD_FLMTIME) {
                        attr->cat_mtime = oa->o_mtime;
                        valid |= CAT_MTIME;
                }
                if (oa->o_valid & OBD_MD_FLATIME) {
                        attr->cat_atime = oa->o_atime;
                        valid |= CAT_ATIME;
                }
                if (oa->o_valid & OBD_MD_FLCTIME) {
                        attr->cat_ctime = oa->o_ctime;
                        valid |= CAT_CTIME;
                }
                if (valid != 0) {
                        cl_object_attr_lock(obj);
                        cl_object_attr_set(env, obj, attr, valid);
                        cl_object_attr_unlock(obj);
                }
                cl_object_put(env, obj);
        }
        OBDO_FREE(aa->aa_oa);

        cl_req_completion(env, aa->aa_clerq, rc < 0 ? rc :
                          req->rq_bulk->bd_nob_transferred);
        osc_release_ppga(aa->aa_ppga, aa->aa_page_count);
        ptlrpc_lprocfs_brw(req, req->rq_bulk->bd_nob_transferred);

        client_obd_list_lock(&cli->cl_loi_list_lock);
        /* We need to decrement before osc_ap_completion->osc_wake_cache_waiters
         * is called so we know whether to go to sync BRWs or wait for more
         * RPCs to complete */

        if (lustre_msg_get_opc(req->rq_reqmsg) == OST_WRITE)
                cli->cl_w_in_flight--;
        else
                cli->cl_r_in_flight--;
        osc_wake_cache_waiters(cli);
        client_obd_list_unlock(&cli->cl_loi_list_lock);

        osc_io_unplug(env, cli, NULL, PDL_POLICY_SAME);
        return rc;
}

/**
 * Build an RPC by the list of extent @ext_list. The caller must ensure
 * that the total pages in this list are NOT over max pages per RPC.
 * Extents in the list must be in OES_RPC state.
 */
int osc_build_rpc(const struct lu_env *env, struct client_obd *cli,
                  struct list_head *ext_list, int cmd, pdl_policy_t pol)
{
        struct ptlrpc_request           *req = NULL;
        struct osc_extent               *ext;
        struct brw_page                 **pga = NULL;
        struct osc_brw_async_args       *aa = NULL;
        struct obdo                     *oa = NULL;
        struct osc_async_page           *oap;
        struct osc_async_page           *tmp;
        struct cl_req                   *clerq = NULL;
        enum cl_req_type                crt = (cmd & OBD_BRW_WRITE) ? CRT_WRITE :
                                                                      CRT_READ;
        struct ldlm_lock                *lock = NULL;
        struct cl_req_attr              *crattr = NULL;
        obd_off                         starting_offset = OBD_OBJECT_EOF;
        obd_off                         ending_offset = 0;
        int                             mpflag = 0;
        int                             mem_tight = 0;
        int                             page_count = 0;
        int                             i;
        int                             rc;
        LIST_HEAD(rpc_list);

        LASSERT(!list_empty(ext_list));

        /* add pages into rpc_list to build BRW rpc */
        list_for_each_entry(ext, ext_list, oe_link) {
                LASSERT(ext->oe_state == OES_RPC);
                mem_tight |= ext->oe_memalloc;
                list_for_each_entry(oap, &ext->oe_pages, oap_pending_item) {
                        ++page_count;
                        list_add_tail(&oap->oap_rpc_item, &rpc_list);
                        if (starting_offset > oap->oap_obj_off)
                                starting_offset = oap->oap_obj_off;
                        else
                                LASSERT(oap->oap_page_off == 0);
                        if (ending_offset < oap->oap_obj_off + oap->oap_count)
                                ending_offset = oap->oap_obj_off +
                                                oap->oap_count;
                        else
                                LASSERT(oap->oap_page_off + oap->oap_count ==
                                        PAGE_CACHE_SIZE);
                }
        }

        if (mem_tight)
                mpflag = cfs_memory_pressure_get_and_set();

        OBD_ALLOC(crattr, sizeof(*crattr));
        if (crattr == NULL)
                GOTO(out, rc = -ENOMEM);

        OBD_ALLOC(pga, sizeof(*pga) * page_count);
        if (pga == NULL)
                GOTO(out, rc = -ENOMEM);

        OBDO_ALLOC(oa);
        if (oa == NULL)
                GOTO(out, rc = -ENOMEM);

        i = 0;
        list_for_each_entry(oap, &rpc_list, oap_rpc_item) {
                struct cl_page *page = oap2cl_page(oap);
                if (clerq == NULL) {
                        clerq = cl_req_alloc(env, page, crt,
                                             1 /* only 1-object rpcs for now */);
                        if (IS_ERR(clerq))
                                GOTO(out, rc = PTR_ERR(clerq));
                        lock = oap->oap_ldlm_lock;
                }
                if (mem_tight)
                        oap->oap_brw_flags |= OBD_BRW_MEMALLOC;
                pga[i] = &oap->oap_brw_page;
                pga[i]->off = oap->oap_obj_off + oap->oap_page_off;
                CDEBUG(0, "put page %p index %lu oap %p flg %x to pga\n",
                       pga[i]->pg, page_index(oap->oap_page), oap,
                       pga[i]->flag);
                i++;
                cl_req_page_add(env, clerq, page);
        }

        /* always get the data for the obdo for the rpc */
        LASSERT(clerq != NULL);
        crattr->cra_oa = oa;
        cl_req_attr_set(env, clerq, crattr, ~0ULL);
        if (lock) {
                oa->o_handle = lock->l_remote_handle;
                oa->o_valid |= OBD_MD_FLHANDLE;
        }

        rc = cl_req_prep(env, clerq);
        if (rc != 0) {
                CERROR("cl_req_prep failed: %d\n", rc);
                GOTO(out, rc);
        }

        sort_brw_pages(pga, page_count);
        rc = osc_brw_prep_request(cmd, cli, oa, NULL, page_count,
                        pga, &req, crattr->cra_capa, 1, 0);
        if (rc != 0) {
                CERROR("prep_req failed: %d\n", rc);
                GOTO(out, rc);
        }

        req->rq_interpret_reply = brw_interpret;

        if (mem_tight != 0)
                req->rq_memalloc = 1;

        /* Need to update the timestamps after the request is built in case
         * we race with setattr (locally or in queue at OST).  If OST gets
         * later setattr before earlier BRW (as determined by the request xid),
         * the OST will not use BRW timestamps.  Sadly, there is no obvious
         * way to do this in a single call.  bug 10150 */
        cl_req_attr_set(env, clerq, crattr,
                        OBD_MD_FLMTIME|OBD_MD_FLCTIME|OBD_MD_FLATIME);

        lustre_msg_set_jobid(req->rq_reqmsg, crattr->cra_jobid);

        CLASSERT(sizeof(*aa) <= sizeof(req->rq_async_args));
        aa = ptlrpc_req_async_args(req);
        INIT_LIST_HEAD(&aa->aa_oaps);
        list_splice_init(&rpc_list, &aa->aa_oaps);
        INIT_LIST_HEAD(&aa->aa_exts);
        list_splice_init(ext_list, &aa->aa_exts);
        aa->aa_clerq = clerq;

        /* queued sync pages can be torn down while the pages
         * were between the pending list and the rpc */
        tmp = NULL;
        list_for_each_entry(oap, &aa->aa_oaps, oap_rpc_item) {
                /* only one oap gets a request reference */
                if (tmp == NULL)
                        tmp = oap;
                if (oap->oap_interrupted && !req->rq_intr) {
                        CDEBUG(D_INODE, "oap %p in req %p interrupted\n",
                                        oap, req);
                        ptlrpc_mark_interrupted(req);
                }
        }
        if (tmp != NULL)
                tmp->oap_request = ptlrpc_request_addref(req);

        client_obd_list_lock(&cli->cl_loi_list_lock);
        starting_offset >>= PAGE_CACHE_SHIFT;
        if (cmd == OBD_BRW_READ) {
                cli->cl_r_in_flight++;
                lprocfs_oh_tally_log2(&cli->cl_read_page_hist, page_count);
                lprocfs_oh_tally(&cli->cl_read_rpc_hist, cli->cl_r_in_flight);
                lprocfs_oh_tally_log2(&cli->cl_read_offset_hist,
                                      starting_offset + 1);
        } else {
                cli->cl_w_in_flight++;
                lprocfs_oh_tally_log2(&cli->cl_write_page_hist, page_count);
                lprocfs_oh_tally(&cli->cl_write_rpc_hist, cli->cl_w_in_flight);
                lprocfs_oh_tally_log2(&cli->cl_write_offset_hist,
                                      starting_offset + 1);
        }
        client_obd_list_unlock(&cli->cl_loi_list_lock);

        DEBUG_REQ(D_INODE, req, "%d pages, aa %p. now %dr/%dw in flight",
                  page_count, aa, cli->cl_r_in_flight,
                  cli->cl_w_in_flight);

        /* XXX: Maybe the caller can check the RPC bulk descriptor to
         * see which CPU/NUMA node the majority of pages were allocated
         * on, and try to assign the async RPC to the CPU core
         * (PDL_POLICY_PREFERRED) to reduce cross-CPU memory traffic.
         *
         * But on the other hand, we expect that multiple ptlrpcd
         * threads and the initial write sponsor can run in parallel,
         * especially when data checksum is enabled, which is CPU-bound
         * operation and single ptlrpcd thread cannot process in time.
         * So more ptlrpcd threads sharing BRW load
         * (with PDL_POLICY_ROUND) seems better.
         */
        ptlrpcd_add_req(req, pol, -1);
        rc = 0;

out:
        if (mem_tight != 0)
                cfs_memory_pressure_restore(mpflag);

        if (crattr != NULL) {
                capa_put(crattr->cra_capa);
                OBD_FREE(crattr, sizeof(*crattr));
        }

        if (rc != 0) {
                LASSERT(req == NULL);

                if (oa)
                        OBDO_FREE(oa);
                if (pga)
                        OBD_FREE(pga, sizeof(*pga) * page_count);
                /* this should happen rarely and is pretty bad, it makes the
                 * pending list not follow the dirty order */
                while (!list_empty(ext_list)) {
                        ext = list_entry(ext_list->next, struct osc_extent,
                                             oe_link);
                        list_del_init(&ext->oe_link);
                        osc_extent_finish(env, ext, 0, rc);
                }
                if (clerq && !IS_ERR(clerq))
                        cl_req_completion(env, clerq, rc);
        }
        return rc;
}

static int osc_set_lock_data_with_check(struct ldlm_lock *lock,
                                        struct ldlm_enqueue_info *einfo)
{
        void *data = einfo->ei_cbdata;
        int set = 0;

        LASSERT(lock != NULL);
        LASSERT(lock->l_blocking_ast == einfo->ei_cb_bl);
        LASSERT(lock->l_resource->lr_type == einfo->ei_type);
        LASSERT(lock->l_completion_ast == einfo->ei_cb_cp);
        LASSERT(lock->l_glimpse_ast == einfo->ei_cb_gl);

        lock_res_and_lock(lock);
        spin_lock(&osc_ast_guard);

        if (lock->l_ast_data == NULL)
                lock->l_ast_data = data;
        if (lock->l_ast_data == data)
                set = 1;

        spin_unlock(&osc_ast_guard);
        unlock_res_and_lock(lock);

        return set;
}

static int osc_set_data_with_check(struct lustre_handle *lockh,
                                   struct ldlm_enqueue_info *einfo)
{
        struct ldlm_lock *lock = ldlm_handle2lock(lockh);
        int set = 0;

        if (lock != NULL) {
                set = osc_set_lock_data_with_check(lock, einfo);
                LDLM_LOCK_PUT(lock);
        } else
                CERROR("lockh %p, data %p - client evicted?\n",
                       lockh, einfo->ei_cbdata);
        return set;
}

static int osc_change_cbdata(struct obd_export *exp, struct lov_stripe_md *lsm,
                             ldlm_iterator_t replace, void *data)
{
        struct ldlm_res_id res_id;
        struct obd_device *obd = class_exp2obd(exp);

        ostid_build_res_name(&lsm->lsm_oi, &res_id);
        ldlm_resource_iterate(obd->obd_namespace, &res_id, replace, data);
        return 0;
}

/* find any ldlm lock of the inode in osc
 * return 0    not find
 *      1    find one
 *      < 0    error */
static int osc_find_cbdata(struct obd_export *exp, struct lov_stripe_md *lsm,
                           ldlm_iterator_t replace, void *data)
{
        struct ldlm_res_id res_id;
        struct obd_device *obd = class_exp2obd(exp);
        int rc = 0;

        ostid_build_res_name(&lsm->lsm_oi, &res_id);
        rc = ldlm_resource_iterate(obd->obd_namespace, &res_id, replace, data);
        if (rc == LDLM_ITER_STOP)
                return(1);
        if (rc == LDLM_ITER_CONTINUE)
                return(0);
        return(rc);
}

static int osc_enqueue_fini(struct ptlrpc_request *req, struct ost_lvb *lvb,
                            obd_enqueue_update_f upcall, void *cookie,
                            __u64 *flags, int agl, int rc)
{
        int intent = *flags & LDLM_FL_HAS_INTENT;

        if (intent) {
                /* The request was created before ldlm_cli_enqueue call. */
                if (rc == ELDLM_LOCK_ABORTED) {
                        struct ldlm_reply *rep;
                        rep = req_capsule_server_get(&req->rq_pill,
                                                     &RMF_DLM_REP);

                        LASSERT(rep != NULL);
                        rep->lock_policy_res1 =
                                ptlrpc_status_ntoh(rep->lock_policy_res1);
                        if (rep->lock_policy_res1)
                                rc = rep->lock_policy_res1;
                }
        }

        if ((intent != 0 && rc == ELDLM_LOCK_ABORTED && agl == 0) ||
            (rc == 0)) {
                *flags |= LDLM_FL_LVB_READY;
                CDEBUG(D_INODE,"got kms %llu blocks %llu mtime %llu\n",
                       lvb->lvb_size, lvb->lvb_blocks, lvb->lvb_mtime);
        }

        /* Call the update callback. */
        rc = (*upcall)(cookie, rc);
        return rc;
}

static int osc_enqueue_interpret(const struct lu_env *env,
                                 struct ptlrpc_request *req,
                                 struct osc_enqueue_args *aa, int rc)
{
        struct ldlm_lock *lock;
        struct lustre_handle handle;
        __u32 mode;
        struct ost_lvb *lvb;
        __u32 lvb_len;
        __u64 *flags = aa->oa_flags;

        /* Make a local copy of a lock handle and a mode, because aa->oa_*
         * might be freed anytime after lock upcall has been called. */
        lustre_handle_copy(&handle, aa->oa_lockh);
        mode = aa->oa_ei->ei_mode;

        /* ldlm_cli_enqueue is holding a reference on the lock, so it must
         * be valid. */
        lock = ldlm_handle2lock(&handle);

        /* Take an additional reference so that a blocking AST that
         * ldlm_cli_enqueue_fini() might post for a failed lock, is guaranteed
         * to arrive after an upcall has been executed by
         * osc_enqueue_fini(). */
        ldlm_lock_addref(&handle, mode);

        /* Let CP AST to grant the lock first. */
        OBD_FAIL_TIMEOUT(OBD_FAIL_OSC_CP_ENQ_RACE, 1);

        if (aa->oa_agl && rc == ELDLM_LOCK_ABORTED) {
                lvb = NULL;
                lvb_len = 0;
        } else {
                lvb = aa->oa_lvb;
                lvb_len = sizeof(*aa->oa_lvb);
        }

        /* Complete obtaining the lock procedure. */
        rc = ldlm_cli_enqueue_fini(aa->oa_exp, req, aa->oa_ei->ei_type, 1,
                                   mode, flags, lvb, lvb_len, &handle, rc);
        /* Complete osc stuff. */
        rc = osc_enqueue_fini(req, aa->oa_lvb, aa->oa_upcall, aa->oa_cookie,
                              flags, aa->oa_agl, rc);

        OBD_FAIL_TIMEOUT(OBD_FAIL_OSC_CP_CANCEL_RACE, 10);

        /* Release the lock for async request. */
        if (lustre_handle_is_used(&handle) && rc == ELDLM_OK)
                /*
                 * Releases a reference taken by ldlm_cli_enqueue(), if it is
                 * not already released by
                 * ldlm_cli_enqueue_fini()->failed_lock_cleanup()
                 */
                ldlm_lock_decref(&handle, mode);

        LASSERTF(lock != NULL, "lockh %p, req %p, aa %p - client evicted?\n",
                 aa->oa_lockh, req, aa);
        ldlm_lock_decref(&handle, mode);
        LDLM_LOCK_PUT(lock);
        return rc;
}

void osc_update_enqueue(struct lustre_handle *lov_lockhp,
                        struct lov_oinfo *loi, __u64 flags,
                        struct ost_lvb *lvb, __u32 mode, int rc)
{
        struct ldlm_lock *lock = ldlm_handle2lock(lov_lockhp);

        if (rc == ELDLM_OK) {
                __u64 tmp;

                LASSERT(lock != NULL);
                loi->loi_lvb = *lvb;
                tmp = loi->loi_lvb.lvb_size;
                /* Extend KMS up to the end of this lock and no further
                 * A lock on [x,y] means a KMS of up to y + 1 bytes! */
                if (tmp > lock->l_policy_data.l_extent.end)
                        tmp = lock->l_policy_data.l_extent.end + 1;
                if (tmp >= loi->loi_kms) {
                        LDLM_DEBUG(lock, "lock acquired, setting rss=%llu, kms=%llu",
                                   loi->loi_lvb.lvb_size, tmp);
                        loi_kms_set(loi, tmp);
                } else {
                        LDLM_DEBUG(lock, "lock acquired, setting rss=%llu; leaving kms=%llu, end=%llu",
                                   loi->loi_lvb.lvb_size, loi->loi_kms,
                                   lock->l_policy_data.l_extent.end);
                }
                ldlm_lock_allow_match(lock);
        } else if (rc == ELDLM_LOCK_ABORTED && (flags & LDLM_FL_HAS_INTENT)) {
                LASSERT(lock != NULL);
                loi->loi_lvb = *lvb;
                ldlm_lock_allow_match(lock);
                CDEBUG(D_INODE, "glimpsed, setting rss=%llu; leaving kms=%llu\n",
                       loi->loi_lvb.lvb_size, loi->loi_kms);
                rc = ELDLM_OK;
        }

        if (lock != NULL) {
                if (rc != ELDLM_OK)
                        ldlm_lock_fail_match(lock);

                LDLM_LOCK_PUT(lock);
        }
}
EXPORT_SYMBOL(osc_update_enqueue);

struct ptlrpc_request_set *PTLRPCD_SET = (void *)1;

/* When enqueuing asynchronously, locks are not ordered, we can obtain a lock
 * from the 2nd OSC before a lock from the 1st one. This does not deadlock with
 * other synchronous requests, however keeping some locks and trying to obtain
 * others may take a considerable amount of time in a case of ost failure; and
 * when other sync requests do not get released lock from a client, the client
 * is excluded from the cluster -- such scenarious make the life difficult, so
 * release locks just after they are obtained. */
int osc_enqueue_base(struct obd_export *exp, struct ldlm_res_id *res_id,
                     __u64 *flags, ldlm_policy_data_t *policy,
                     struct ost_lvb *lvb, int kms_valid,
                     obd_enqueue_update_f upcall, void *cookie,
                     struct ldlm_enqueue_info *einfo,
                     struct lustre_handle *lockh,
                     struct ptlrpc_request_set *rqset, int async, int agl)
{
        struct obd_device *obd = exp->exp_obd;
        struct ptlrpc_request *req = NULL;
        int intent = *flags & LDLM_FL_HAS_INTENT;
        __u64 match_lvb = (agl != 0 ? 0 : LDLM_FL_LVB_READY);
        ldlm_mode_t mode;
        int rc;

        /* Filesystem lock extents are extended to page boundaries so that
         * dealing with the page cache is a little smoother.  */
        policy->l_extent.start -= policy->l_extent.start & ~CFS_PAGE_MASK;
        policy->l_extent.end |= ~CFS_PAGE_MASK;

        /*
         * kms is not valid when either object is completely fresh (so that no
         * locks are cached), or object was evicted. In the latter case cached
         * lock cannot be used, because it would prime inode state with
         * potentially stale LVB.
         */
        if (!kms_valid)
                goto no_match;

        /* Next, search for already existing extent locks that will cover us */
        /* If we're trying to read, we also search for an existing PW lock.  The
         * VFS and page cache already protect us locally, so lots of readers/
         * writers can share a single PW lock.
         *
         * There are problems with conversion deadlocks, so instead of
         * converting a read lock to a write lock, we'll just enqueue a new
         * one.
         *
         * At some point we should cancel the read lock instead of making them
         * send us a blocking callback, but there are problems with canceling
         * locks out from other users right now, too. */
        mode = einfo->ei_mode;
        if (einfo->ei_mode == LCK_PR)
                mode |= LCK_PW;
        mode = ldlm_lock_match(obd->obd_namespace, *flags | match_lvb, res_id,
                               einfo->ei_type, policy, mode, lockh, 0);
        if (mode) {
                struct ldlm_lock *matched = ldlm_handle2lock(lockh);

                if ((agl != 0) && !(matched->l_flags & LDLM_FL_LVB_READY)) {
                        /* For AGL, if enqueue RPC is sent but the lock is not
                         * granted, then skip to process this strpe.
                         * Return -ECANCELED to tell the caller. */
                        ldlm_lock_decref(lockh, mode);
                        LDLM_LOCK_PUT(matched);
                        return -ECANCELED;
                } else if (osc_set_lock_data_with_check(matched, einfo)) {
                        *flags |= LDLM_FL_LVB_READY;
                        /* addref the lock only if not async requests and PW
                         * lock is matched whereas we asked for PR. */
                        if (!rqset && einfo->ei_mode != mode)
                                ldlm_lock_addref(lockh, LCK_PR);
                        if (intent) {
                                /* I would like to be able to ASSERT here that
                                 * rss <= kms, but I can't, for reasons which
                                 * are explained in lov_enqueue() */
                        }

                        /* We already have a lock, and it's referenced.
                         *
                         * At this point, the cl_lock::cll_state is CLS_QUEUING,
                         * AGL upcall may change it to CLS_HELD directly. */
                        (*upcall)(cookie, ELDLM_OK);

                        if (einfo->ei_mode != mode)
                                ldlm_lock_decref(lockh, LCK_PW);
                        else if (rqset)
                                /* For async requests, decref the lock. */
                                ldlm_lock_decref(lockh, einfo->ei_mode);
                        LDLM_LOCK_PUT(matched);
                        return ELDLM_OK;
                } else {
                        ldlm_lock_decref(lockh, mode);
                        LDLM_LOCK_PUT(matched);
                }
        }

 no_match:
        if (intent) {
                LIST_HEAD(cancels);
                req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                           &RQF_LDLM_ENQUEUE_LVB);
                if (req == NULL)
                        return -ENOMEM;

                rc = ldlm_prep_enqueue_req(exp, req, &cancels, 0);
                if (rc) {
                        ptlrpc_request_free(req);
                        return rc;
                }

                req_capsule_set_size(&req->rq_pill, &RMF_DLM_LVB, RCL_SERVER,
                                     sizeof(*lvb));
                ptlrpc_request_set_replen(req);
        }

        /* users of osc_enqueue() can pass this flag for ldlm_lock_match() */
        *flags &= ~LDLM_FL_BLOCK_GRANTED;

        rc = ldlm_cli_enqueue(exp, &req, einfo, res_id, policy, flags, lvb,
                              sizeof(*lvb), LVB_T_OST, lockh, async);
        if (rqset) {
                if (!rc) {
                        struct osc_enqueue_args *aa;
                        CLASSERT (sizeof(*aa) <= sizeof(req->rq_async_args));
                        aa = ptlrpc_req_async_args(req);
                        aa->oa_ei = einfo;
                        aa->oa_exp = exp;
                        aa->oa_flags  = flags;
                        aa->oa_upcall = upcall;
                        aa->oa_cookie = cookie;
                        aa->oa_lvb    = lvb;
                        aa->oa_lockh  = lockh;
                        aa->oa_agl    = !!agl;

                        req->rq_interpret_reply =
                                (ptlrpc_interpterer_t)osc_enqueue_interpret;
                        if (rqset == PTLRPCD_SET)
                                ptlrpcd_add_req(req, PDL_POLICY_ROUND, -1);
                        else
                                ptlrpc_set_add_req(rqset, req);
                } else if (intent) {
                        ptlrpc_req_finished(req);
                }
                return rc;
        }

        rc = osc_enqueue_fini(req, lvb, upcall, cookie, flags, agl, rc);
        if (intent)
                ptlrpc_req_finished(req);

        return rc;
}

static int osc_enqueue(struct obd_export *exp, struct obd_info *oinfo,
                       struct ldlm_enqueue_info *einfo,
                       struct ptlrpc_request_set *rqset)
{
        struct ldlm_res_id res_id;
        int rc;

        ostid_build_res_name(&oinfo->oi_md->lsm_oi, &res_id);
        rc = osc_enqueue_base(exp, &res_id, &oinfo->oi_flags, &oinfo->oi_policy,
                              &oinfo->oi_md->lsm_oinfo[0]->loi_lvb,
                              oinfo->oi_md->lsm_oinfo[0]->loi_kms_valid,
                              oinfo->oi_cb_up, oinfo, einfo, oinfo->oi_lockh,
                              rqset, rqset != NULL, 0);
        return rc;
}

int osc_match_base(struct obd_export *exp, struct ldlm_res_id *res_id,
                   __u32 type, ldlm_policy_data_t *policy, __u32 mode,
                   __u64 *flags, void *data, struct lustre_handle *lockh,
                   int unref)
{
        struct obd_device *obd = exp->exp_obd;
        __u64 lflags = *flags;
        ldlm_mode_t rc;

        if (OBD_FAIL_CHECK(OBD_FAIL_OSC_MATCH))
                return -EIO;

        /* Filesystem lock extents are extended to page boundaries so that
         * dealing with the page cache is a little smoother */
        policy->l_extent.start -= policy->l_extent.start & ~CFS_PAGE_MASK;
        policy->l_extent.end |= ~CFS_PAGE_MASK;

        /* Next, search for already existing extent locks that will cover us */
        /* If we're trying to read, we also search for an existing PW lock.  The
         * VFS and page cache already protect us locally, so lots of readers/
         * writers can share a single PW lock. */
        rc = mode;
        if (mode == LCK_PR)
                rc |= LCK_PW;
        rc = ldlm_lock_match(obd->obd_namespace, lflags,
                             res_id, type, policy, rc, lockh, unref);
        if (rc) {
                if (data != NULL) {
                        if (!osc_set_data_with_check(lockh, data)) {
                                if (!(lflags & LDLM_FL_TEST_LOCK))
                                        ldlm_lock_decref(lockh, rc);
                                return 0;
                        }
                }
                if (!(lflags & LDLM_FL_TEST_LOCK) && mode != rc) {
                        ldlm_lock_addref(lockh, LCK_PR);
                        ldlm_lock_decref(lockh, LCK_PW);
                }
                return rc;
        }
        return rc;
}

int osc_cancel_base(struct lustre_handle *lockh, __u32 mode)
{
        if (unlikely(mode == LCK_GROUP))
                ldlm_lock_decref_and_cancel(lockh, mode);
        else
                ldlm_lock_decref(lockh, mode);

        return 0;
}

static int osc_cancel(struct obd_export *exp, struct lov_stripe_md *md,
                      __u32 mode, struct lustre_handle *lockh)
{
        return osc_cancel_base(lockh, mode);
}

static int osc_cancel_unused(struct obd_export *exp,
                             struct lov_stripe_md *lsm,
                             ldlm_cancel_flags_t flags,
                             void *opaque)
{
        struct obd_device *obd = class_exp2obd(exp);
        struct ldlm_res_id res_id, *resp = NULL;

        if (lsm != NULL) {
                ostid_build_res_name(&lsm->lsm_oi, &res_id);
                resp = &res_id;
        }

        return ldlm_cli_cancel_unused(obd->obd_namespace, resp, flags, opaque);
}

static int osc_statfs_interpret(const struct lu_env *env,
                                struct ptlrpc_request *req,
                                struct osc_async_args *aa, int rc)
{
        struct obd_statfs *msfs;

        if (rc == -EBADR)
                /* The request has in fact never been sent
                 * due to issues at a higher level (LOV).
                 * Exit immediately since the caller is
                 * aware of the problem and takes care
                 * of the clean up */
                 return rc;

        if ((rc == -ENOTCONN || rc == -EAGAIN) &&
            (aa->aa_oi->oi_flags & OBD_STATFS_NODELAY))
                GOTO(out, rc = 0);

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

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

        *aa->aa_oi->oi_osfs = *msfs;
out:
        rc = aa->aa_oi->oi_cb_up(aa->aa_oi, rc);
        return rc;
}

static int osc_statfs_async(struct obd_export *exp,
                            struct obd_info *oinfo, __u64 max_age,
                            struct ptlrpc_request_set *rqset)
{
        struct obd_device     *obd = class_exp2obd(exp);
        struct ptlrpc_request *req;
        struct osc_async_args *aa;
        int                 rc;

        /* We could possibly pass max_age in the request (as an absolute
         * timestamp or a "seconds.usec ago") so the target can avoid doing
         * extra calls into the filesystem if that isn't necessary (e.g.
         * during mount that would help a bit).  Having relative timestamps
         * is not so great if request processing is slow, while absolute
         * timestamps are not ideal because they need time synchronization. */
        req = ptlrpc_request_alloc(obd->u.cli.cl_import, &RQF_OST_STATFS);
        if (req == NULL)
                return -ENOMEM;

        rc = ptlrpc_request_pack(req, LUSTRE_OST_VERSION, OST_STATFS);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }
        ptlrpc_request_set_replen(req);
        req->rq_request_portal = OST_CREATE_PORTAL;
        ptlrpc_at_set_req_timeout(req);

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

        req->rq_interpret_reply = (ptlrpc_interpterer_t)osc_statfs_interpret;
        CLASSERT (sizeof(*aa) <= sizeof(req->rq_async_args));
        aa = ptlrpc_req_async_args(req);
        aa->aa_oi = oinfo;

        ptlrpc_set_add_req(rqset, req);
        return 0;
}

static int osc_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 obd_statfs     *msfs;
        struct ptlrpc_request *req;
        struct obd_import     *imp = NULL;
        int rc;

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

        /* We could possibly pass max_age in the request (as an absolute
         * timestamp or a "seconds.usec ago") so the target can avoid doing
         * extra calls into the filesystem if that isn't necessary (e.g.
         * during mount that would help a bit).  Having relative timestamps
         * is not so great if request processing is slow, while absolute
         * timestamps are not ideal because they need time synchronization. */
        req = ptlrpc_request_alloc(imp, &RQF_OST_STATFS);

        class_import_put(imp);

        if (req == NULL)
                return -ENOMEM;

        rc = ptlrpc_request_pack(req, LUSTRE_OST_VERSION, OST_STATFS);
        if (rc) {
                ptlrpc_request_free(req);
                return rc;
        }
        ptlrpc_request_set_replen(req);
        req->rq_request_portal = OST_CREATE_PORTAL;
        ptlrpc_at_set_req_timeout(req);

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

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

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

        *osfs = *msfs;

 out:
        ptlrpc_req_finished(req);
        return rc;
}

/* Retrieve object striping information.
 *
 * @lmmu is a pointer to an in-core struct with lmm_ost_count indicating
 * the maximum number of OST indices which will fit in the user buffer.
 * lmm_magic must be LOV_MAGIC (we only use 1 slot here).
 */
static int osc_getstripe(struct lov_stripe_md *lsm, struct lov_user_md *lump)
{
        /* we use lov_user_md_v3 because it is larger than lov_user_md_v1 */
        struct lov_user_md_v3 lum, *lumk;
        struct lov_user_ost_data_v1 *lmm_objects;
        int rc = 0, lum_size;

        if (!lsm)
                return -ENODATA;

        /* we only need the header part from user space to get lmm_magic and
         * lmm_stripe_count, (the header part is common to v1 and v3) */
        lum_size = sizeof(struct lov_user_md_v1);
        if (copy_from_user(&lum, lump, lum_size))
                return -EFAULT;

        if ((lum.lmm_magic != LOV_USER_MAGIC_V1) &&
            (lum.lmm_magic != LOV_USER_MAGIC_V3))
                return -EINVAL;

        /* lov_user_md_vX and lov_mds_md_vX must have the same size */
        LASSERT(sizeof(struct lov_user_md_v1) == sizeof(struct lov_mds_md_v1));
        LASSERT(sizeof(struct lov_user_md_v3) == sizeof(struct lov_mds_md_v3));
        LASSERT(sizeof(lum.lmm_objects[0]) == sizeof(lumk->lmm_objects[0]));

        /* we can use lov_mds_md_size() to compute lum_size
         * because lov_user_md_vX and lov_mds_md_vX have the same size */
        if (lum.lmm_stripe_count > 0) {
                lum_size = lov_mds_md_size(lum.lmm_stripe_count, lum.lmm_magic);
                OBD_ALLOC(lumk, lum_size);
                if (!lumk)
                        return -ENOMEM;

                if (lum.lmm_magic == LOV_USER_MAGIC_V1)
                        lmm_objects =
                            &(((struct lov_user_md_v1 *)lumk)->lmm_objects[0]);
                else
                        lmm_objects = &(lumk->lmm_objects[0]);
                lmm_objects->l_ost_oi = lsm->lsm_oi;
        } else {
                lum_size = lov_mds_md_size(0, lum.lmm_magic);
                lumk = &lum;
        }

        lumk->lmm_oi = lsm->lsm_oi;
        lumk->lmm_stripe_count = 1;

        if (copy_to_user(lump, lumk, lum_size))
                rc = -EFAULT;

        if (lumk != &lum)
                OBD_FREE(lumk, lum_size);

        return rc;
}


static int osc_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;
        int err = 0;

        if (!try_module_get(THIS_MODULE)) {
                CERROR("Can't get module. Is it alive?");
                return -EINVAL;
        }
        switch (cmd) {
        case OBD_IOC_LOV_GET_CONFIG: {
                char *buf;
                struct lov_desc *desc;
                struct obd_uuid uuid;

                buf = NULL;
                len = 0;
                if (obd_ioctl_getdata(&buf, &len, (void *)uarg))
                        GOTO(out, err = -EINVAL);

                data = (struct obd_ioctl_data *)buf;

                if (sizeof(*desc) > data->ioc_inllen1) {
                        obd_ioctl_freedata(buf, len);
                        GOTO(out, err = -EINVAL);
                }

                if (data->ioc_inllen2 < sizeof(uuid)) {
                        obd_ioctl_freedata(buf, len);
                        GOTO(out, err = -EINVAL);
                }

                desc = (struct lov_desc *)data->ioc_inlbuf1;
                desc->ld_tgt_count = 1;
                desc->ld_active_tgt_count = 1;
                desc->ld_default_stripe_count = 1;
                desc->ld_default_stripe_size = 0;
                desc->ld_default_stripe_offset = 0;
                desc->ld_pattern = 0;
                memcpy(&desc->ld_uuid, &obd->obd_uuid, sizeof(uuid));

                memcpy(data->ioc_inlbuf2, &obd->obd_uuid, sizeof(uuid));

                err = copy_to_user((void *)uarg, buf, len);
                if (err)
                        err = -EFAULT;
                obd_ioctl_freedata(buf, len);
                GOTO(out, err);
        }
        case LL_IOC_LOV_SETSTRIPE:
                err = obd_alloc_memmd(exp, karg);
                if (err > 0)
                        err = 0;
                GOTO(out, err);
        case LL_IOC_LOV_GETSTRIPE:
                err = osc_getstripe(karg, uarg);
                GOTO(out, err);
        case OBD_IOC_CLIENT_RECOVER:
                err = ptlrpc_recover_import(obd->u.cli.cl_import,
                                            data->ioc_inlbuf1, 0);
                if (err > 0)
                        err = 0;
                GOTO(out, err);
        case IOC_OSC_SET_ACTIVE:
                err = ptlrpc_set_import_active(obd->u.cli.cl_import,
                                               data->ioc_offset);
                GOTO(out, err);
        case OBD_IOC_POLL_QUOTACHECK:
                err = osc_quota_poll_check(exp, (struct if_quotacheck *)karg);
                GOTO(out, err);
        case OBD_IOC_PING_TARGET:
                err = ptlrpc_obd_ping(obd);
                GOTO(out, err);
        default:
                CDEBUG(D_INODE, "unrecognised ioctl %#x by %s\n",
                       cmd, current_comm());
                GOTO(out, err = -ENOTTY);
        }
out:
        module_put(THIS_MODULE);
        return err;
}

static int osc_get_info(const struct lu_env *env, struct obd_export *exp,
                        obd_count keylen, void *key, __u32 *vallen, void *val,
                        struct lov_stripe_md *lsm)
{
        if (!vallen || !val)
                return -EFAULT;

        if (KEY_IS(KEY_LOCK_TO_STRIPE)) {
                __u32 *stripe = val;
                *vallen = sizeof(*stripe);
                *stripe = 0;
                return 0;
        } else if (KEY_IS(KEY_LAST_ID)) {
                struct ptlrpc_request *req;
                obd_id          *reply;
                char              *tmp;
                int                 rc;

                req = ptlrpc_request_alloc(class_exp2cliimp(exp),
                                           &RQF_OST_GET_INFO_LAST_ID);
                if (req == NULL)
                        return -ENOMEM;

                req_capsule_set_size(&req->rq_pill, &RMF_SETINFO_KEY,
                                     RCL_CLIENT, keylen);
                rc = ptlrpc_request_pack(req, LUSTRE_OST_VERSION, OST_GET_INFO);
                if (rc) {
                        ptlrpc_request_free(req);
                        return rc;
                }

                tmp = req_capsule_client_get(&req->rq_pill, &RMF_SETINFO_KEY);
                memcpy(tmp, key, keylen);