/*
 * GPL HEADER START
 *
 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 only,
 * as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful, but
 * WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License version 2 for more details (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * You should have received a copy of the GNU General Public License
 * version 2 along with this program; If not, see
 * http://www.gnu.org/licenses/gpl-2.0.html
 *
 * GPL HEADER END
 */
/*
 * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2011, 2015, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 */

#define DEBUG_SUBSYSTEM S_RPC
#include "../include/obd_support.h"
#include "../include/lustre_net.h"
#include "../include/lustre_lib.h"
#include "../include/obd.h"
#include "../include/obd_class.h"
#include "ptlrpc_internal.h"

/**
 * Helper function. Sends \a len bytes from \a base at offset \a offset
 * over \a conn connection to portal \a portal.
 * Returns 0 on success or error code.
 */
static int ptl_send_buf(struct lnet_handle_md *mdh, void *base, int len,
                        enum lnet_ack_req ack, struct ptlrpc_cb_id *cbid,
                        struct ptlrpc_connection *conn, int portal, __u64 xid,
                        unsigned int offset)
{
        int rc;
        struct lnet_md md;

        LASSERT(portal != 0);
        CDEBUG(D_INFO, "conn=%p id %s\n", conn, libcfs_id2str(conn->c_peer));
        md.start = base;
        md.length = len;
        md.threshold = (ack == LNET_ACK_REQ) ? 2 : 1;
        md.options = PTLRPC_MD_OPTIONS;
        md.user_ptr = cbid;
        md.eq_handle = ptlrpc_eq_h;

        if (unlikely(ack == LNET_ACK_REQ &&
                     OBD_FAIL_CHECK_ORSET(OBD_FAIL_PTLRPC_ACK,
                                          OBD_FAIL_ONCE))) {
                /* don't ask for the ack to simulate failing client */
                ack = LNET_NOACK_REQ;
        }

        rc = LNetMDBind(md, LNET_UNLINK, mdh);
        if (unlikely(rc != 0)) {
                CERROR("LNetMDBind failed: %d\n", rc);
                LASSERT(rc == -ENOMEM);
                return -ENOMEM;
        }

        CDEBUG(D_NET, "Sending %d bytes to portal %d, xid %lld, offset %u\n",
               len, portal, xid, offset);

        rc = LNetPut(conn->c_self, *mdh, ack,
                     conn->c_peer, portal, xid, offset, 0);
        if (unlikely(rc != 0)) {
                int rc2;
                /* We're going to get an UNLINK event when I unlink below,
                 * which will complete just like any other failed send, so
                 * I fall through and return success here!
                 */
                CERROR("LNetPut(%s, %d, %lld) failed: %d\n",
                       libcfs_id2str(conn->c_peer), portal, xid, rc);
                rc2 = LNetMDUnlink(*mdh);
                LASSERTF(rc2 == 0, "rc2 = %d\n", rc2);
        }

        return 0;
}

static void mdunlink_iterate_helper(struct lnet_handle_md *bd_mds, int count)
{
        int i;

        for (i = 0; i < count; i++)
                LNetMDUnlink(bd_mds[i]);
}

/**
 * Register bulk at the sender for later transfer.
 * Returns 0 on success or error code.
 */
static int ptlrpc_register_bulk(struct ptlrpc_request *req)
{
        struct ptlrpc_bulk_desc *desc = req->rq_bulk;
        struct lnet_process_id peer;
        int rc = 0;
        int rc2;
        int posted_md;
        int total_md;
        u64 mbits;
        struct lnet_handle_me me_h;
        struct lnet_md md;

        if (OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_BULK_GET_NET))
                return 0;

        /* NB no locking required until desc is on the network */
        LASSERT(desc->bd_nob > 0);
        LASSERT(desc->bd_md_count == 0);
        LASSERT(desc->bd_md_max_brw <= PTLRPC_BULK_OPS_COUNT);
        LASSERT(desc->bd_iov_count <= PTLRPC_MAX_BRW_PAGES);
        LASSERT(desc->bd_req);
        LASSERT(ptlrpc_is_bulk_op_passive(desc->bd_type));

        /* cleanup the state of the bulk for it will be reused */
        if (req->rq_resend || req->rq_send_state == LUSTRE_IMP_REPLAY)
                desc->bd_nob_transferred = 0;
        else
                LASSERT(desc->bd_nob_transferred == 0);

        desc->bd_failure = 0;

        peer = desc->bd_import->imp_connection->c_peer;

        LASSERT(desc->bd_cbid.cbid_fn == client_bulk_callback);
        LASSERT(desc->bd_cbid.cbid_arg == desc);

        total_md = DIV_ROUND_UP(desc->bd_iov_count, LNET_MAX_IOV);
        /* rq_mbits is matchbits of the final bulk */
        mbits = req->rq_mbits - total_md + 1;

        LASSERTF(mbits == (req->rq_mbits & PTLRPC_BULK_OPS_MASK),
                 "first mbits = x%llu, last mbits = x%llu\n",
                 mbits, req->rq_mbits);
        LASSERTF(!(desc->bd_registered &&
                   req->rq_send_state != LUSTRE_IMP_REPLAY) ||
                 mbits != desc->bd_last_mbits,
                 "registered: %d  rq_mbits: %llu bd_last_mbits: %llu\n",
                 desc->bd_registered, mbits, desc->bd_last_mbits);

        desc->bd_registered = 1;
        desc->bd_last_mbits = mbits;
        desc->bd_md_count = total_md;
        md.user_ptr = &desc->bd_cbid;
        md.eq_handle = ptlrpc_eq_h;
        md.threshold = 1;                      /* PUT or GET */

        for (posted_md = 0; posted_md < total_md; posted_md++, mbits++) {
                md.options = PTLRPC_MD_OPTIONS |
                             (ptlrpc_is_bulk_op_get(desc->bd_type) ?
                              LNET_MD_OP_GET : LNET_MD_OP_PUT);
                ptlrpc_fill_bulk_md(&md, desc, posted_md);

                rc = LNetMEAttach(desc->bd_portal, peer, mbits, 0,
                                  LNET_UNLINK, LNET_INS_AFTER, &me_h);
                if (rc != 0) {
                        CERROR("%s: LNetMEAttach failed x%llu/%d: rc = %d\n",
                               desc->bd_import->imp_obd->obd_name, mbits,
                               posted_md, rc);
                        break;
                }

                /* About to let the network at it... */
                rc = LNetMDAttach(me_h, md, LNET_UNLINK,
                                  &desc->bd_mds[posted_md]);
                if (rc != 0) {
                        CERROR("%s: LNetMDAttach failed x%llu/%d: rc = %d\n",
                               desc->bd_import->imp_obd->obd_name, mbits,
                               posted_md, rc);
                        rc2 = LNetMEUnlink(me_h);
                        LASSERT(rc2 == 0);
                        break;
                }
        }

        if (rc != 0) {
                LASSERT(rc == -ENOMEM);
                spin_lock(&desc->bd_lock);
                desc->bd_md_count -= total_md - posted_md;
                spin_unlock(&desc->bd_lock);
                LASSERT(desc->bd_md_count >= 0);
                mdunlink_iterate_helper(desc->bd_mds, desc->bd_md_max_brw);
                req->rq_status = -ENOMEM;
                return -ENOMEM;
        }

        spin_lock(&desc->bd_lock);
        /* Holler if peer manages to touch buffers before he knows the mbits */
        if (desc->bd_md_count != total_md)
                CWARN("%s: Peer %s touched %d buffers while I registered\n",
                      desc->bd_import->imp_obd->obd_name, libcfs_id2str(peer),
                      total_md - desc->bd_md_count);
        spin_unlock(&desc->bd_lock);

        CDEBUG(D_NET, "Setup %u bulk %s buffers: %u pages %u bytes, mbits x%#llx-%#llx, portal %u\n",
               desc->bd_md_count,
               ptlrpc_is_bulk_op_get(desc->bd_type) ? "get-source" : "put-sink",
               desc->bd_iov_count, desc->bd_nob,
               desc->bd_last_mbits, req->rq_mbits, desc->bd_portal);

        return 0;
}

/**
 * Disconnect a bulk desc from the network. Idempotent. Not
 * thread-safe (i.e. only interlocks with completion callback).
 * Returns 1 on success or 0 if network unregistration failed for whatever
 * reason.
 */
int ptlrpc_unregister_bulk(struct ptlrpc_request *req, int async)
{
        struct ptlrpc_bulk_desc *desc = req->rq_bulk;
        wait_queue_head_t *wq;
        struct l_wait_info lwi;
        int rc;

        LASSERT(!in_interrupt());     /* might sleep */

        /* Let's setup deadline for reply unlink. */
        if (OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_LONG_BULK_UNLINK) &&
            async && req->rq_bulk_deadline == 0 && cfs_fail_val == 0)
                req->rq_bulk_deadline = ktime_get_real_seconds() + LONG_UNLINK;

        if (ptlrpc_client_bulk_active(req) == 0)        /* completed or */
                return 1;                               /* never registered */

        LASSERT(desc->bd_req == req);  /* bd_req NULL until registered */

        /* the unlink ensures the callback happens ASAP and is the last
         * one.  If it fails, it must be because completion just happened,
         * but we must still l_wait_event() in this case to give liblustre
         * a chance to run client_bulk_callback()
         */
        mdunlink_iterate_helper(desc->bd_mds, desc->bd_md_max_brw);

        if (ptlrpc_client_bulk_active(req) == 0)        /* completed or */
                return 1;                               /* never registered */

        /* Move to "Unregistering" phase as bulk was not unlinked yet. */
        ptlrpc_rqphase_move(req, RQ_PHASE_UNREG_BULK);

        /* Do not wait for unlink to finish. */
        if (async)
                return 0;

        if (req->rq_set)
                wq = &req->rq_set->set_waitq;
        else
                wq = &req->rq_reply_waitq;

        for (;;) {
                /* Network access will complete in finite time but the HUGE
                 * timeout lets us CWARN for visibility of sluggish LNDs
                 */
                lwi = LWI_TIMEOUT_INTERVAL(cfs_time_seconds(LONG_UNLINK),
                                           cfs_time_seconds(1), NULL, NULL);
                rc = l_wait_event(*wq, !ptlrpc_client_bulk_active(req), &lwi);
                if (rc == 0) {
                        ptlrpc_rqphase_move(req, req->rq_next_phase);
                        return 1;
                }

                LASSERT(rc == -ETIMEDOUT);
                DEBUG_REQ(D_WARNING, req, "Unexpectedly long timeout: desc %p",
                          desc);
        }
        return 0;
}

static void ptlrpc_at_set_reply(struct ptlrpc_request *req, int flags)
{
        struct ptlrpc_service_part *svcpt = req->rq_rqbd->rqbd_svcpt;
        struct ptlrpc_service *svc = svcpt->scp_service;
        int service_time = max_t(int, ktime_get_real_seconds() -
                                 req->rq_arrival_time.tv_sec, 1);

        if (!(flags & PTLRPC_REPLY_EARLY) &&
            (req->rq_type != PTL_RPC_MSG_ERR) && req->rq_reqmsg &&
            !(lustre_msg_get_flags(req->rq_reqmsg) &
              (MSG_RESENT | MSG_REPLAY |
               MSG_REQ_REPLAY_DONE | MSG_LOCK_REPLAY_DONE))) {
                /* early replies, errors and recovery requests don't count
                 * toward our service time estimate
                 */
                int oldse = at_measured(&svcpt->scp_at_estimate, service_time);

                if (oldse != 0) {
                        DEBUG_REQ(D_ADAPTTO, req,
                                  "svc %s changed estimate from %d to %d",
                                  svc->srv_name, oldse,
                                  at_get(&svcpt->scp_at_estimate));
                }
        }
        /* Report actual service time for client latency calc */
        lustre_msg_set_service_time(req->rq_repmsg, service_time);
        /* Report service time estimate for future client reqs, but report 0
         * (to be ignored by client) if it's a error reply during recovery.
         * (bz15815)
         */
        if (req->rq_type == PTL_RPC_MSG_ERR && !req->rq_export)
                lustre_msg_set_timeout(req->rq_repmsg, 0);
        else
                lustre_msg_set_timeout(req->rq_repmsg,
                                       at_get(&svcpt->scp_at_estimate));

        if (req->rq_reqmsg &&
            !(lustre_msghdr_get_flags(req->rq_reqmsg) & MSGHDR_AT_SUPPORT)) {
                CDEBUG(D_ADAPTTO, "No early reply support: flags=%#x req_flags=%#x magic=%x/%x len=%d\n",
                       flags, lustre_msg_get_flags(req->rq_reqmsg),
                       lustre_msg_get_magic(req->rq_reqmsg),
                       lustre_msg_get_magic(req->rq_repmsg), req->rq_replen);
        }
}

/**
 * Send request reply from request \a req reply buffer.
 * \a flags defines reply types
 * Returns 0 on success or error code
 */
int ptlrpc_send_reply(struct ptlrpc_request *req, int flags)
{
        struct ptlrpc_reply_state *rs = req->rq_reply_state;
        struct ptlrpc_connection *conn;
        int rc;

        /* We must already have a reply buffer (only ptlrpc_error() may be
         * called without one). The reply generated by sptlrpc layer (e.g.
         * error notify, etc.) might have NULL rq->reqmsg; Otherwise we must
         * have a request buffer which is either the actual (swabbed) incoming
         * request, or a saved copy if this is a req saved in
         * target_queue_final_reply().
         */
        LASSERT(req->rq_no_reply == 0);
        LASSERT(req->rq_reqbuf);
        LASSERT(rs);
        LASSERT((flags & PTLRPC_REPLY_MAYBE_DIFFICULT) || !rs->rs_difficult);
        LASSERT(req->rq_repmsg);
        LASSERT(req->rq_repmsg == rs->rs_msg);
        LASSERT(rs->rs_cb_id.cbid_fn == reply_out_callback);
        LASSERT(rs->rs_cb_id.cbid_arg == rs);

        /* There may be no rq_export during failover */

        if (unlikely(req->rq_export && req->rq_export->exp_obd &&
                     req->rq_export->exp_obd->obd_fail)) {
                /* Failed obd's only send ENODEV */
                req->rq_type = PTL_RPC_MSG_ERR;
                req->rq_status = -ENODEV;
                CDEBUG(D_HA, "sending ENODEV from failed obd %d\n",
                       req->rq_export->exp_obd->obd_minor);
        }

        /* In order to keep interoperability with the client (< 2.3) which
         * doesn't have pb_jobid in ptlrpc_body, We have to shrink the
         * ptlrpc_body in reply buffer to ptlrpc_body_v2, otherwise, the
         * reply buffer on client will be overflow.
         *
         * XXX Remove this whenever we drop the interoperability with
         * such client.
         */
        req->rq_replen = lustre_shrink_msg(req->rq_repmsg, 0,
                                           sizeof(struct ptlrpc_body_v2), 1);

        if (req->rq_type != PTL_RPC_MSG_ERR)
                req->rq_type = PTL_RPC_MSG_REPLY;

        lustre_msg_set_type(req->rq_repmsg, req->rq_type);
        lustre_msg_set_status(req->rq_repmsg,
                              ptlrpc_status_hton(req->rq_status));
        lustre_msg_set_opc(req->rq_repmsg,
                           req->rq_reqmsg ?
                           lustre_msg_get_opc(req->rq_reqmsg) : 0);

        target_pack_pool_reply(req);

        ptlrpc_at_set_reply(req, flags);

        if (!req->rq_export || !req->rq_export->exp_connection)
                conn = ptlrpc_connection_get(req->rq_peer, req->rq_self, NULL);
        else
                conn = ptlrpc_connection_addref(req->rq_export->exp_connection);

        if (unlikely(!conn)) {
                CERROR("not replying on NULL connection\n"); /* bug 9635 */
                return -ENOTCONN;
        }
        ptlrpc_rs_addref(rs);              /* +1 ref for the network */

        rc = sptlrpc_svc_wrap_reply(req);
        if (unlikely(rc))
                goto out;

        req->rq_sent = ktime_get_real_seconds();

        rc = ptl_send_buf(&rs->rs_md_h, rs->rs_repbuf, rs->rs_repdata_len,
                          (rs->rs_difficult && !rs->rs_no_ack) ?
                          LNET_ACK_REQ : LNET_NOACK_REQ,
                          &rs->rs_cb_id, conn,
                          ptlrpc_req2svc(req)->srv_rep_portal,
                          req->rq_xid, req->rq_reply_off);
out:
        if (unlikely(rc != 0))
                ptlrpc_req_drop_rs(req);
        ptlrpc_connection_put(conn);
        return rc;
}

int ptlrpc_reply(struct ptlrpc_request *req)
{
        if (req->rq_no_reply)
                return 0;
        return ptlrpc_send_reply(req, 0);
}

/**
 * For request \a req send an error reply back. Create empty
 * reply buffers if necessary.
 */
int ptlrpc_send_error(struct ptlrpc_request *req, int may_be_difficult)
{
        int rc;

        if (req->rq_no_reply)
                return 0;

        if (!req->rq_repmsg) {
                rc = lustre_pack_reply(req, 1, NULL, NULL);
                if (rc)
                        return rc;
        }

        if (req->rq_status != -ENOSPC && req->rq_status != -EACCES &&
            req->rq_status != -EPERM && req->rq_status != -ENOENT &&
            req->rq_status != -EINPROGRESS && req->rq_status != -EDQUOT)
                req->rq_type = PTL_RPC_MSG_ERR;

        rc = ptlrpc_send_reply(req, may_be_difficult);
        return rc;
}

int ptlrpc_error(struct ptlrpc_request *req)
{
        return ptlrpc_send_error(req, 0);
}

/**
 * Send request \a request.
 * if \a noreply is set, don't expect any reply back and don't set up
 * reply buffers.
 * Returns 0 on success or error code.
 */
int ptl_send_rpc(struct ptlrpc_request *request, int noreply)
{
        int rc;
        int rc2;
        int mpflag = 0;
        struct ptlrpc_connection *connection;
        struct lnet_handle_me reply_me_h;
        struct lnet_md reply_md;
        struct obd_import *imp = request->rq_import;
        struct obd_device *obd = imp->imp_obd;

        if (OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_DROP_RPC))
                return 0;

        LASSERT(request->rq_type == PTL_RPC_MSG_REQUEST);
        LASSERT(request->rq_wait_ctx == 0);

        /* If this is a re-transmit, we're required to have disengaged
         * cleanly from the previous attempt
         */
        LASSERT(!request->rq_receiving_reply);
        LASSERT(!((lustre_msg_get_flags(request->rq_reqmsg) & MSG_REPLAY) &&
                  (imp->imp_state == LUSTRE_IMP_FULL)));

        if (unlikely(obd && obd->obd_fail)) {
                CDEBUG(D_HA, "muting rpc for failed imp obd %s\n",
                       obd->obd_name);
                /* this prevents us from waiting in ptlrpc_queue_wait */
                spin_lock(&request->rq_lock);
                request->rq_err = 1;
                spin_unlock(&request->rq_lock);
                request->rq_status = -ENODEV;
                return -ENODEV;
        }

        connection = imp->imp_connection;

        lustre_msg_set_handle(request->rq_reqmsg,
                              &imp->imp_remote_handle);
        lustre_msg_set_type(request->rq_reqmsg, PTL_RPC_MSG_REQUEST);
        lustre_msg_set_conn_cnt(request->rq_reqmsg, imp->imp_conn_cnt);
        lustre_msghdr_set_flags(request->rq_reqmsg, imp->imp_msghdr_flags);

        /*
         * If it's the first time to resend the request for EINPROGRESS,
         * we need to allocate a new XID (see after_reply()), it's different
         * from the resend for reply timeout.
         */
        if (request->rq_nr_resend && list_empty(&request->rq_unreplied_list)) {
                __u64 min_xid = 0;
                /*
                 * resend for EINPROGRESS, allocate new xid to avoid reply
                 * reconstruction
                 */
                spin_lock(&imp->imp_lock);
                ptlrpc_assign_next_xid_nolock(request);
                min_xid = ptlrpc_known_replied_xid(imp);
                spin_unlock(&imp->imp_lock);

                lustre_msg_set_last_xid(request->rq_reqmsg, min_xid);
                DEBUG_REQ(D_RPCTRACE, request, "Allocating new xid for resend on EINPROGRESS");
        }

        if (request->rq_bulk) {
                ptlrpc_set_bulk_mbits(request);
                lustre_msg_set_mbits(request->rq_reqmsg, request->rq_mbits);
        }

        if (list_empty(&request->rq_unreplied_list) ||
            request->rq_xid <= imp->imp_known_replied_xid) {
                DEBUG_REQ(D_ERROR, request,
                          "xid: %llu, replied: %llu, list_empty:%d\n",
                          request->rq_xid, imp->imp_known_replied_xid,
                          list_empty(&request->rq_unreplied_list));
                LBUG();
        }

        /**
         * For enabled AT all request should have AT_SUPPORT in the
         * FULL import state when OBD_CONNECT_AT is set
         */
        LASSERT(AT_OFF || imp->imp_state != LUSTRE_IMP_FULL ||
                (imp->imp_msghdr_flags & MSGHDR_AT_SUPPORT) ||
                !(imp->imp_connect_data.ocd_connect_flags &
                OBD_CONNECT_AT));

        if (request->rq_resend)
                lustre_msg_add_flags(request->rq_reqmsg, MSG_RESENT);

        if (request->rq_memalloc)
                mpflag = cfs_memory_pressure_get_and_set();

        rc = sptlrpc_cli_wrap_request(request);
        if (rc) {
                /*
                 * set rq_sent so that this request is treated
                 * as a delayed send in the upper layers
                 */
                if (rc == -ENOMEM)
                        request->rq_sent = ktime_get_seconds();
                goto out;
        }

        /* bulk register should be done after wrap_request() */
        if (request->rq_bulk) {
                rc = ptlrpc_register_bulk(request);
                if (rc != 0)
                        goto out;
        }

        if (!noreply) {
                LASSERT(request->rq_replen != 0);
                if (!request->rq_repbuf) {
                        LASSERT(!request->rq_repdata);
                        LASSERT(!request->rq_repmsg);
                        rc = sptlrpc_cli_alloc_repbuf(request,
                                                      request->rq_replen);
                        if (rc) {
                                /* this prevents us from looping in
                                 * ptlrpc_queue_wait
                                 */
                                spin_lock(&request->rq_lock);
                                request->rq_err = 1;
                                spin_unlock(&request->rq_lock);
                                request->rq_status = rc;
                                goto cleanup_bulk;
                        }
                } else {
                        request->rq_repdata = NULL;
                        request->rq_repmsg = NULL;
                }

                rc = LNetMEAttach(request->rq_reply_portal,/*XXX FIXME bug 249*/
                                  connection->c_peer, request->rq_xid, 0,
                                  LNET_UNLINK, LNET_INS_AFTER, &reply_me_h);
                if (rc != 0) {
                        CERROR("LNetMEAttach failed: %d\n", rc);
                        LASSERT(rc == -ENOMEM);
                        rc = -ENOMEM;
                        goto cleanup_bulk;
                }
        }

        spin_lock(&request->rq_lock);
        /* We are responsible for unlinking the reply buffer */
        request->rq_reply_unlinked = noreply;
        request->rq_receiving_reply = !noreply;
        /* Clear any flags that may be present from previous sends. */
        request->rq_req_unlinked = 0;
        request->rq_replied = 0;
        request->rq_err = 0;
        request->rq_timedout = 0;
        request->rq_net_err = 0;
        request->rq_resend = 0;
        request->rq_restart = 0;
        request->rq_reply_truncated = 0;
        spin_unlock(&request->rq_lock);

        if (!noreply) {
                reply_md.start = request->rq_repbuf;
                reply_md.length = request->rq_repbuf_len;
                /* Allow multiple early replies */
                reply_md.threshold = LNET_MD_THRESH_INF;
                /* Manage remote for early replies */
                reply_md.options = PTLRPC_MD_OPTIONS | LNET_MD_OP_PUT |
                        LNET_MD_MANAGE_REMOTE |
                        LNET_MD_TRUNCATE; /* allow to make EOVERFLOW error */
                reply_md.user_ptr = &request->rq_reply_cbid;
                reply_md.eq_handle = ptlrpc_eq_h;

                /* We must see the unlink callback to set rq_reply_unlinked,
                 * so we can't auto-unlink
                 */
                rc = LNetMDAttach(reply_me_h, reply_md, LNET_RETAIN,
                                  &request->rq_reply_md_h);
                if (rc != 0) {
                        CERROR("LNetMDAttach failed: %d\n", rc);
                        LASSERT(rc == -ENOMEM);
                        spin_lock(&request->rq_lock);
                        /* ...but the MD attach didn't succeed... */
                        request->rq_receiving_reply = 0;
                        spin_unlock(&request->rq_lock);
                        rc = -ENOMEM;
                        goto cleanup_me;
                }

                CDEBUG(D_NET, "Setup reply buffer: %u bytes, xid %llu, portal %u\n",
                       request->rq_repbuf_len, request->rq_xid,
                       request->rq_reply_portal);
        }

        /* add references on request for request_out_callback */
        ptlrpc_request_addref(request);
        if (obd && obd->obd_svc_stats)
                lprocfs_counter_add(obd->obd_svc_stats, PTLRPC_REQACTIVE_CNTR,
                        atomic_read(&imp->imp_inflight));

        OBD_FAIL_TIMEOUT(OBD_FAIL_PTLRPC_DELAY_SEND, request->rq_timeout + 5);

        ktime_get_real_ts64(&request->rq_sent_tv);
        request->rq_sent = ktime_get_real_seconds();
        /* We give the server rq_timeout secs to process the req, and
         * add the network latency for our local timeout.
         */
        request->rq_deadline = request->rq_sent + request->rq_timeout +
                ptlrpc_at_get_net_latency(request);

        ptlrpc_pinger_sending_on_import(imp);

        DEBUG_REQ(D_INFO, request, "send flg=%x",
                  lustre_msg_get_flags(request->rq_reqmsg));
        rc = ptl_send_buf(&request->rq_req_md_h,
                          request->rq_reqbuf, request->rq_reqdata_len,
                          LNET_NOACK_REQ, &request->rq_req_cbid,
                          connection,
                          request->rq_request_portal,
                          request->rq_xid, 0);
        if (likely(rc == 0))
                goto out;

        request->rq_req_unlinked = 1;
        ptlrpc_req_finished(request);
        if (noreply)
                goto out;

 cleanup_me:
        /* MEUnlink is safe; the PUT didn't even get off the ground, and
         * nobody apart from the PUT's target has the right nid+XID to
         * access the reply buffer.
         */
        rc2 = LNetMEUnlink(reply_me_h);
        LASSERT(rc2 == 0);
        /* UNLINKED callback called synchronously */
        LASSERT(!request->rq_receiving_reply);

 cleanup_bulk:
        /* We do sync unlink here as there was no real transfer here so
         * the chance to have long unlink to sluggish net is smaller here.
         */
        ptlrpc_unregister_bulk(request, 0);
 out:
        if (request->rq_memalloc)
                cfs_memory_pressure_restore(mpflag);
        return rc;
}
EXPORT_SYMBOL(ptl_send_rpc);

/**
 * Register request buffer descriptor for request receiving.
 */
int ptlrpc_register_rqbd(struct ptlrpc_request_buffer_desc *rqbd)
{
        struct ptlrpc_service *service = rqbd->rqbd_svcpt->scp_service;
        static struct lnet_process_id match_id = {LNET_NID_ANY, LNET_PID_ANY};
        int rc;
        struct lnet_md md;
        struct lnet_handle_me me_h;

        CDEBUG(D_NET, "LNetMEAttach: portal %d\n",
               service->srv_req_portal);

        if (OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_RQBD))
                return -ENOMEM;

        /* NB: CPT affinity service should use new LNet flag LNET_INS_LOCAL,
         * which means buffer can only be attached on local CPT, and LND
         * threads can find it by grabbing a local lock
         */
        rc = LNetMEAttach(service->srv_req_portal,
                          match_id, 0, ~0, LNET_UNLINK,
                          rqbd->rqbd_svcpt->scp_cpt >= 0 ?
                          LNET_INS_LOCAL : LNET_INS_AFTER, &me_h);
        if (rc != 0) {
                CERROR("LNetMEAttach failed: %d\n", rc);
                return -ENOMEM;
        }

        LASSERT(rqbd->rqbd_refcount == 0);
        rqbd->rqbd_refcount = 1;

        md.start = rqbd->rqbd_buffer;
        md.length = service->srv_buf_size;
        md.max_size = service->srv_max_req_size;
        md.threshold = LNET_MD_THRESH_INF;
        md.options = PTLRPC_MD_OPTIONS | LNET_MD_OP_PUT | LNET_MD_MAX_SIZE;
        md.user_ptr = &rqbd->rqbd_cbid;
        md.eq_handle = ptlrpc_eq_h;

        rc = LNetMDAttach(me_h, md, LNET_UNLINK, &rqbd->rqbd_md_h);
        if (rc == 0)
                return 0;

        CERROR("LNetMDAttach failed: %d;\n", rc);
        LASSERT(rc == -ENOMEM);
        rc = LNetMEUnlink(me_h);
        LASSERT(rc == 0);
        rqbd->rqbd_refcount = 0;

        return -ENOMEM;
}