lustre/ptlrpc/niobuf.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  Copyright (c) 2002, 2003 Cluster File Systems, Inc.
   5  *
   6  *   This file is part of Lustre, http://www.lustre.org.
   7  *
   8  *   Lustre is free software; you can redistribute it and/or
   9  *   modify it under the terms of version 2 of the GNU General Public
  10  *   License as published by the Free Software Foundation.
  11  *
  12  *   Lustre is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with Lustre; if not, write to the Free Software
  19  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  *
  21  */
  22
  23 #define DEBUG_SUBSYSTEM S_RPC
  24 #ifndef __KERNEL__
  25 #include <liblustre.h>
  26 #include <portals/lib-types.h>
  27 #endif
  28 #include <linux/obd_support.h>
  29 #include <linux/lustre_net.h>
  30 #include <linux/lustre_lib.h>
  31 #include <linux/obd.h>
  32 #include "ptlrpc_internal.h"
  33
  34 static int ptl_send_buf (ptl_handle_md_t *mdh, void *base, int len,
  35                          ptl_ack_req_t ack, struct ptlrpc_cb_id *cbid,
  36                          struct ptlrpc_connection *conn, int portal, __u64 xid)
  37 {
  38         ptl_process_id_t remote_id;
  39         int              rc;
  40         int              rc2;
  41         ptl_md_t         md;
  42         char str[PTL_NALFMT_SIZE];
  43         ENTRY;
  44
  45         LASSERT (portal != 0);
  46         LASSERT (conn != NULL);
  47         CDEBUG (D_INFO, "conn=%p ni %s nid "LPX64" (%s) on %s\n",
  48                 conn, conn->c_peer.peer_ni->pni_name,
  49                 conn->c_peer.peer_nid,
  50                 portals_nid2str(conn->c_peer.peer_ni->pni_number,
  51                                 conn->c_peer.peer_nid, str),
  52                 conn->c_peer.peer_ni->pni_name);
  53
  54         remote_id.nid = conn->c_peer.peer_nid,
  55         remote_id.pid = 0;
  56
  57         md.start     = base;
  58         md.length    = len;
  59         md.threshold = (ack == PTL_ACK_REQ) ? 2 : 1;
  60         md.options   = 0;
  61         md.user_ptr  = cbid;
  62         md.eventq    = conn->c_peer.peer_ni->pni_eq_h;
  63
  64         if (ack == PTL_ACK_REQ &&
  65             OBD_FAIL_CHECK(OBD_FAIL_PTLRPC_ACK | OBD_FAIL_ONCE)) {
  66                 /* don't ask for the ack to simulate failing client */
  67                 ack = PTL_NOACK_REQ;
  68                 obd_fail_loc |= OBD_FAIL_ONCE | OBD_FAILED;
  69         }
  70
  71         rc = PtlMDBind (conn->c_peer.peer_ni->pni_ni_h, md, mdh);
  72         if (rc != PTL_OK) {
  73                 CERROR ("PtlMDBind failed: %d\n", rc);
  74                 LASSERT (rc == PTL_NOSPACE);
  75                 RETURN (-ENOMEM);
  76         }
  77
  78         CDEBUG(D_NET, "Sending %d bytes to portal %d, xid "LPD64"\n",
  79                len, portal, xid);
  80
  81         rc2 = PtlPut (*mdh, ack, remote_id, portal, 0, xid, 0, 0);
  82         if (rc != PTL_OK) {
  83                 /* We're going to get an UNLINK event when I unlink below,
  84                  * which will complete just like any other failed send, so
  85                  * I fall through and return success here! */
  86                 CERROR("PtlPut("LPU64", %d, "LPD64") failed: %d\n",
  87                        remote_id.nid, portal, xid, rc);
  88                 rc2 = PtlMDUnlink(*mdh);
  89                 LASSERT (rc2 == PTL_OK);
  90         }
  91
  92         RETURN (0);
  93 }
  94
  95 int ptlrpc_start_bulk_transfer (struct ptlrpc_bulk_desc *desc)
  96 {
  97         int                 rc;
  98         int                 rc2;
  99         struct ptlrpc_peer *peer;
 100         ptl_process_id_t    remote_id;
 101         ptl_md_t            md;
 102         __u64               xid;
 103         ENTRY;
 104
 105         /* NB no locking required until desc is on the network */
 106         LASSERT (!desc->bd_network_rw);
 107         LASSERT (desc->bd_type == BULK_PUT_SOURCE ||
 108                  desc->bd_type == BULK_GET_SINK);
 109         desc->bd_success = 0;
 110         peer = &desc->bd_export->exp_connection->c_peer;
 111
 112         md.start = &desc->bd_iov[0];
 113         md.niov = desc->bd_page_count;
 114         md.length = desc->bd_nob;
 115         md.eventq = peer->peer_ni->pni_eq_h;
 116         md.threshold = 2; /* SENT and ACK/REPLY */
 117 #ifdef __KERNEL__
 118         md.options = PTL_MD_KIOV;
 119 #else
 120         md.options = PTL_MD_IOV;
 121 #endif
 122         md.user_ptr = &desc->bd_cbid;
 123         LASSERT (desc->bd_cbid.cbid_fn == server_bulk_callback);
 124         LASSERT (desc->bd_cbid.cbid_arg == desc);
 125
 126         /* NB total length may be 0 for a read past EOF, so we send a 0
 127          * length bulk, since the client expects a bulk event. */
 128
 129         rc = PtlMDBind(peer->peer_ni->pni_ni_h, md, &desc->bd_md_h);
 130         if (rc != PTL_OK) {
 131                 CERROR("PtlMDBind failed: %d\n", rc);
 132                 LASSERT (rc == PTL_NOSPACE);
 133                 RETURN(-ENOMEM);
 134         }
 135
 136         /* Client's bulk and reply matchbits are the same */
 137         xid = desc->bd_req->rq_xid;
 138         remote_id.nid = peer->peer_nid;
 139         remote_id.pid = 0;
 140
 141         CDEBUG(D_NET, "Transferring %u pages %u bytes via portal %d on %s "
 142                "nid "LPX64" pid %d xid "LPX64"\n",
 143                md.niov, md.length, desc->bd_portal, peer->peer_ni->pni_name,
 144                remote_id.nid, remote_id.pid, xid);
 145
 146         /* Network is about to get at the memory */
 147         desc->bd_network_rw = 1;
 148
 149         if (desc->bd_type == BULK_PUT_SOURCE)
 150                 rc = PtlPut (desc->bd_md_h, PTL_ACK_REQ, remote_id,
 151                              desc->bd_portal, 0, xid, 0, 0);
 152         else
 153                 rc = PtlGet (desc->bd_md_h, remote_id,
 154                              desc->bd_portal, 0, xid, 0);
 155
 156         if (rc != PTL_OK) {
 157                 /* Can't send, so we unlink the MD bound above.  The UNLINK
 158                  * event this creates will signal completion with failure,
 159                  * so we return SUCCESS here! */
 160                 CERROR("Transfer("LPU64", %d, "LPX64") failed: %d\n",
 161                        remote_id.nid, desc->bd_portal, xid, rc);
 162                 rc2 = PtlMDUnlink(desc->bd_md_h);
 163                 LASSERT (rc2 == PTL_OK);
 164         }
 165
 166         RETURN(0);
 167 }
 168
 169 void ptlrpc_abort_bulk (struct ptlrpc_bulk_desc *desc)
 170 {
 171         /* Server side bulk abort. Idempotent. Not thread-safe (i.e. only
 172          * serialises with completion callback) */
 173         struct l_wait_info lwi;
 174         int                rc;
 175
 176         LASSERT (!in_interrupt ());             /* might sleep */
 177
 178         if (!ptlrpc_bulk_active(desc))          /* completed or */
 179                 return;                         /* never started */
 180
 181         /* The unlink ensures the callback happens ASAP and is the last
 182          * one.  If it fails, it must be because completion just
 183          * happened. */
 184
 185         rc = PtlMDUnlink (desc->bd_md_h);
 186         if (rc == PTL_INV_MD) {
 187                 LASSERT(!ptlrpc_bulk_active(desc));
 188                 return;
 189         }
 190
 191         LASSERT (rc == PTL_OK);
 192
 193         for (;;) {
 194                 /* Network access will complete in finite time but the HUGE
 195                  * timeout lets us CWARN for visibility of sluggish NALs */
 196                 lwi = LWI_TIMEOUT (300 * HZ, NULL, NULL);
 197                 rc = l_wait_event(desc->bd_waitq,
 198                                   !ptlrpc_bulk_active(desc), &lwi);
 199                 if (rc == 0)
 200                         return;
 201
 202                 LASSERT(rc == -ETIMEDOUT);
 203                 CWARN("Unexpectedly long timeout: desc %p\n", desc);
 204         }
 205 }
 206
 207 int ptlrpc_register_bulk (struct ptlrpc_request *req)
 208 {
 209         struct ptlrpc_bulk_desc *desc = req->rq_bulk;
 210         struct ptlrpc_peer *peer;
 211         int rc;
 212         int rc2;
 213         ptl_process_id_t source_id;
 214         ptl_handle_me_t  me_h;
 215         ptl_md_t         md;
 216         ENTRY;
 217
 218         /* NB no locking required until desc is on the network */
 219         LASSERT (desc->bd_nob > 0);
 220         LASSERT (!desc->bd_network_rw);
 221         LASSERT (desc->bd_page_count <= PTL_MD_MAX_PAGES);
 222         LASSERT (desc->bd_req != NULL);
 223         LASSERT (desc->bd_type == BULK_PUT_SINK ||
 224                  desc->bd_type == BULK_GET_SOURCE);
 225
 226         desc->bd_success = 0;
 227
 228         peer = &desc->bd_import->imp_connection->c_peer;
 229
 230         md.start = &desc->bd_iov[0];
 231         md.niov = desc->bd_page_count;
 232         md.length = desc->bd_nob;
 233         md.eventq = peer->peer_ni->pni_eq_h;
 234         md.threshold = 1;                       /* PUT or GET */
 235         md.options = (desc->bd_type == BULK_GET_SOURCE) ?
 236                      PTL_MD_OP_GET : PTL_MD_OP_PUT;
 237 #ifdef __KERNEL__
 238         md.options |= PTL_MD_KIOV;
 239 #else
 240         md.options |= PTL_MD_IOV;
 241 #endif
 242         md.user_ptr = &desc->bd_cbid;
 243         LASSERT (desc->bd_cbid.cbid_fn == client_bulk_callback);
 244         LASSERT (desc->bd_cbid.cbid_arg == desc);
 245
 246         /* XXX Registering the same xid on retried bulk makes my head
 247          * explode trying to understand how the original request's bulk
 248          * might interfere with the retried request -eeb */
 249         LASSERT (!desc->bd_registered || req->rq_xid != desc->bd_last_xid);
 250         desc->bd_registered = 1;
 251         desc->bd_last_xid = req->rq_xid;
 252
 253         source_id.nid = desc->bd_import->imp_connection->c_peer.peer_nid;
 254         source_id.pid = PTL_PID_ANY;
 255
 256         rc = PtlMEAttach(peer->peer_ni->pni_ni_h,
 257                          desc->bd_portal, source_id, req->rq_xid, 0,
 258                          PTL_UNLINK, PTL_INS_AFTER, &me_h);
 259         if (rc != PTL_OK) {
 260                 CERROR("PtlMEAttach failed: %d\n", rc);
 261                 LASSERT (rc == PTL_NOSPACE);
 262                 RETURN (-ENOMEM);
 263         }
 264
 265         /* About to let the network at it... */
 266         desc->bd_network_rw = 1;
 267         rc = PtlMDAttach(me_h, md, PTL_UNLINK, &desc->bd_md_h);
 268         if (rc != PTL_OK) {
 269                 CERROR("PtlMDAttach failed: %d\n", rc);
 270                 LASSERT (rc == PTL_NOSPACE);
 271                 desc->bd_network_rw = 0;
 272                 rc2 = PtlMEUnlink (me_h);
 273                 LASSERT (rc2 == PTL_OK);
 274                 RETURN (-ENOMEM);
 275         }
 276
 277         CDEBUG(D_NET, "Setup bulk %s buffers: %u pages %u bytes, xid "LPX64", "
 278                "portal %u on %s\n",
 279                desc->bd_type == BULK_GET_SOURCE ? "get-source" : "put-sink",
 280                md.niov, md.length,
 281                req->rq_xid, desc->bd_portal, peer->peer_ni->pni_name);
 282         RETURN(0);
 283 }
 284
 285 void ptlrpc_unregister_bulk (struct ptlrpc_request *req)
 286 {
 287         /* Disconnect a bulk desc from the network. Idempotent. Not
 288          * thread-safe (i.e. only interlocks with completion callback). */
 289         struct ptlrpc_bulk_desc *desc = req->rq_bulk;
 290         wait_queue_head_t       *wq;
 291         struct l_wait_info       lwi;
 292         int                      rc;
 293
 294         LASSERT (!in_interrupt ());             /* might sleep */
 295
 296         if (!ptlrpc_bulk_active(desc))          /* completed or */
 297                 return;                         /* never registered */
 298
 299         LASSERT (desc->bd_req == req);          /* bd_req NULL until registered */
 300
 301         /* the unlink ensures the callback happens ASAP and is the last
 302          * one.  If it fails, it must be because completion just
 303          * happened. */
 304
 305         rc = PtlMDUnlink (desc->bd_md_h);
 306         if (rc == PTL_INV_MD) {
 307                 LASSERT(!ptlrpc_bulk_active(desc));
 308                 return;
 309         }
 310
 311         LASSERT (rc == PTL_OK);
 312
 313         if (desc->bd_req->rq_set != NULL)
 314                 wq = &req->rq_set->set_waitq;
 315         else
 316                 wq = &req->rq_reply_waitq;
 317
 318         for (;;) {
 319                 /* Network access will complete in finite time but the HUGE
 320                  * timeout lets us CWARN for visibility of sluggish NALs */
 321                 lwi = LWI_TIMEOUT (300 * HZ, NULL, NULL);
 322                 rc = l_wait_event(*wq, !ptlrpc_bulk_active(desc), &lwi);
 323                 if (rc == 0)
 324                         return;
 325
 326                 LASSERT (rc == -ETIMEDOUT);
 327                 CWARN("Unexpectedly long timeout: desc %p\n", desc);
 328         }
 329 }
 330
 331 int ptlrpc_send_reply (struct ptlrpc_request *req, int may_be_difficult)
 332 {
 333         struct ptlrpc_service     *svc = req->rq_rqbd->rqbd_srv_ni->sni_service;
 334         struct ptlrpc_reply_state *rs = req->rq_reply_state;
 335         struct ptlrpc_connection  *conn;
 336         int                        rc;
 337
 338         /* We must already have a reply buffer (only ptlrpc_error() may be
 339          * called without one).  We must also have a request buffer which
 340          * is either the actual (swabbed) incoming request, or a saved copy
 341          * if this is a req saved in target_queue_final_reply(). */
 342         LASSERT (req->rq_reqmsg != NULL);
 343         LASSERT (rs != NULL);
 344         LASSERT (req->rq_repmsg != NULL);
 345         LASSERT (may_be_difficult || !rs->rs_difficult);
 346         LASSERT (req->rq_repmsg == &rs->rs_msg);
 347         LASSERT (rs->rs_cb_id.cbid_fn == reply_out_callback);
 348         LASSERT (rs->rs_cb_id.cbid_arg == rs);
 349
 350         LASSERT (req->rq_repmsg != NULL);
 351         if (req->rq_type != PTL_RPC_MSG_ERR)
 352                 req->rq_type = PTL_RPC_MSG_REPLY;
 353
 354         req->rq_repmsg->type   = req->rq_type;
 355         req->rq_repmsg->status = req->rq_status;
 356         req->rq_repmsg->opc    = req->rq_reqmsg->opc;
 357
 358         if (req->rq_export == NULL)
 359                 conn = ptlrpc_get_connection(&req->rq_peer, NULL);
 360         else
 361                 conn = ptlrpc_connection_addref(req->rq_export->exp_connection);
 362
 363         atomic_inc (&svc->srv_outstanding_replies);
 364
 365         rc = ptl_send_buf (&rs->rs_md_h, req->rq_repmsg, req->rq_replen,
 366                            rs->rs_difficult ? PTL_ACK_REQ : PTL_NOACK_REQ,
 367                            &rs->rs_cb_id, conn,
 368                            svc->srv_rep_portal, req->rq_xid);
 369         if (rc != 0) {
 370                 atomic_dec (&svc->srv_outstanding_replies);
 371
 372                 if (!rs->rs_difficult) {
 373                         /* Callers other than target_send_reply() expect me
 374                          * to clean up on a comms error */
 375                         lustre_free_reply_state (rs);
 376                         req->rq_reply_state = NULL;
 377                         req->rq_repmsg = NULL;
 378                 }
 379         }
 380         ptlrpc_put_connection(conn);
 381         return rc;
 382 }
 383
 384 int ptlrpc_reply (struct ptlrpc_request *req)
 385 {
 386         return (ptlrpc_send_reply (req, 0));
 387 }
 388
 389 int ptlrpc_error(struct ptlrpc_request *req)
 390 {
 391         int rc;
 392         ENTRY;
 393
 394         if (!req->rq_repmsg) {
 395                 rc = lustre_pack_reply(req, 0, NULL, NULL);
 396                 if (rc)
 397                         RETURN(rc);
 398         }
 399
 400         req->rq_type = PTL_RPC_MSG_ERR;
 401
 402         rc = ptlrpc_send_reply (req, 0);
 403         RETURN(rc);
 404 }
 405
 406 int ptl_send_rpc(struct ptlrpc_request *request)
 407 {
 408         int rc;
 409         int rc2;
 410         struct ptlrpc_connection *connection;
 411         unsigned long flags;
 412         ptl_process_id_t source_id;
 413         ptl_handle_me_t  reply_me_h;
 414         ptl_md_t         reply_md;
 415         ENTRY;
 416
 417         LASSERT (request->rq_type == PTL_RPC_MSG_REQUEST);
 418
 419         /* If this is a re-transmit, we're required to have disengaged
 420          * cleanly from the previous attempt */
 421         LASSERT (!request->rq_receiving_reply);
 422
 423         connection = request->rq_import->imp_connection;
 424
 425         if (request->rq_bulk != NULL) {
 426                 rc = ptlrpc_register_bulk (request);
 427                 if (rc != 0)
 428                         RETURN(rc);
 429         }
 430
 431         request->rq_reqmsg->handle = request->rq_import->imp_remote_handle;
 432         request->rq_reqmsg->type = PTL_RPC_MSG_REQUEST;
 433         request->rq_reqmsg->conn_cnt = request->rq_import->imp_conn_cnt;
 434
 435         source_id.nid = connection->c_peer.peer_nid;
 436         source_id.pid = PTL_PID_ANY;
 437
 438         LASSERT (request->rq_replen != 0);
 439         if (request->rq_repmsg == NULL)
 440                 OBD_ALLOC(request->rq_repmsg, request->rq_replen);
 441         if (request->rq_repmsg == NULL)
 442                 GOTO(cleanup_bulk, rc = -ENOMEM);
 443
 444         rc = PtlMEAttach(connection->c_peer.peer_ni->pni_ni_h,
 445                          request->rq_reply_portal, /* XXX FIXME bug 249 */
 446                          source_id, request->rq_xid, 0, PTL_UNLINK,
 447                          PTL_INS_AFTER, &reply_me_h);
 448         if (rc != PTL_OK) {
 449                 CERROR("PtlMEAttach failed: %d\n", rc);
 450                 LASSERT (rc == PTL_NOSPACE);
 451                 GOTO(cleanup_repmsg, rc = -ENOMEM);
 452         }
 453
 454         spin_lock_irqsave (&request->rq_lock, flags);
 455         /* If the MD attach succeeds, there _will_ be a reply_in callback */
 456         request->rq_receiving_reply = 1;
 457         /* Clear any flags that may be present from previous sends. */
 458         request->rq_replied = 0;
 459         request->rq_err = 0;
 460         request->rq_timedout = 0;
 461         request->rq_resend = 0;
 462         request->rq_restart = 0;
 463         spin_unlock_irqrestore (&request->rq_lock, flags);
 464
 465         reply_md.start     = request->rq_repmsg;
 466         reply_md.length    = request->rq_replen;
 467         reply_md.threshold = 1;
 468         reply_md.options   = PTL_MD_OP_PUT;
 469         reply_md.user_ptr  = &request->rq_reply_cbid;
 470         reply_md.eventq    = connection->c_peer.peer_ni->pni_eq_h;
 471
 472         rc = PtlMDAttach(reply_me_h, reply_md, PTL_UNLINK,
 473                          &request->rq_reply_md_h);
 474         if (rc != PTL_OK) {
 475                 CERROR("PtlMDAttach failed: %d\n", rc);
 476                 LASSERT (rc == PTL_NOSPACE);
 477                 GOTO(cleanup_me, rc -ENOMEM);
 478         }
 479
 480         CDEBUG(D_NET, "Setup reply buffer: %u bytes, xid "LPU64
 481                ", portal %u on %s\n",
 482                request->rq_replen, request->rq_xid,
 483                request->rq_reply_portal,
 484                connection->c_peer.peer_ni->pni_name);
 485
 486         ptlrpc_request_addref(request);        /* +1 ref for the SENT callback */
 487
 488         request->rq_sent = LTIME_S(CURRENT_TIME);
 489         ptlrpc_pinger_sending_on_import(request->rq_import);
 490         rc = ptl_send_buf(&request->rq_req_md_h,
 491                           request->rq_reqmsg, request->rq_reqlen,
 492                           PTL_NOACK_REQ, &request->rq_req_cbid,
 493                           connection,
 494                           request->rq_request_portal,
 495                           request->rq_xid);
 496         if (rc == 0) {
 497                 ptlrpc_lprocfs_rpc_sent(request);
 498                 RETURN(rc);
 499         }
 500
 501         ptlrpc_req_finished (request);          /* drop callback ref */
 502
 503  cleanup_me:
 504         /* MEUnlink is safe; the PUT didn't even get off the ground, and
 505          * nobody apart from the PUT's target has the right nid+XID to
 506          * access the reply buffer. */
 507         rc2 = PtlMEUnlink(reply_me_h);
 508         LASSERT (rc2 == PTL_OK);
 509         /* UNLINKED callback called synchronously */
 510         LASSERT (!request->rq_receiving_reply);
 511
 512  cleanup_repmsg:
 513         OBD_FREE(request->rq_repmsg, request->rq_replen);
 514         request->rq_repmsg = NULL;
 515
 516  cleanup_bulk:
 517         if (request->rq_bulk != NULL)
 518                 ptlrpc_unregister_bulk(request);
 519
 520         return rc;
 521 }
 522
 523 int ptlrpc_register_rqbd (struct ptlrpc_request_buffer_desc *rqbd)
 524 {
 525         struct ptlrpc_srv_ni    *srv_ni = rqbd->rqbd_srv_ni;
 526         struct ptlrpc_service   *service = srv_ni->sni_service;
 527         static ptl_process_id_t  match_id = {PTL_NID_ANY, PTL_PID_ANY};
 528         int                      rc;
 529         ptl_md_t                 md;
 530         ptl_handle_me_t          me_h;
 531
 532         CDEBUG(D_NET, "PtlMEAttach: portal %d on %s h %lx."LPX64"\n",
 533                service->srv_req_portal, srv_ni->sni_ni->pni_name,
 534                srv_ni->sni_ni->pni_ni_h.nal_idx,
 535                srv_ni->sni_ni->pni_ni_h.cookie);
 536
 537         if (OBD_FAIL_CHECK_ONCE(OBD_FAIL_PTLRPC_RQBD))
 538                 return (-ENOMEM);
 539
 540         rc = PtlMEAttach(srv_ni->sni_ni->pni_ni_h, service->srv_req_portal,
 541                          match_id, 0, ~0, PTL_UNLINK, PTL_INS_AFTER, &me_h);
 542         if (rc != PTL_OK) {
 543                 CERROR("PtlMEAttach failed: %d\n", rc);
 544                 return (-ENOMEM);
 545         }
 546
 547         LASSERT(rqbd->rqbd_refcount == 0);
 548         rqbd->rqbd_refcount = 1;
 549
 550         md.start      = rqbd->rqbd_buffer;
 551         md.length     = service->srv_buf_size;
 552         md.max_size   = service->srv_max_req_size;
 553         md.threshold  = PTL_MD_THRESH_INF;
 554         md.options    = PTL_MD_OP_PUT | PTL_MD_MAX_SIZE | PTL_MD_AUTO_UNLINK;
 555         md.user_ptr   = &rqbd->rqbd_cbid;
 556         md.eventq     = srv_ni->sni_ni->pni_eq_h;
 557
 558         rc = PtlMDAttach(me_h, md, PTL_UNLINK, &rqbd->rqbd_md_h);
 559         if (rc == PTL_OK)
 560                 return (0);
 561
 562         CERROR("PtlMDAttach failed: %d; \n", rc);
 563         LASSERT (rc == PTL_NOSPACE);
 564         rc = PtlMEUnlink (me_h);
 565         LASSERT (rc == PTL_OK);
 566         rqbd->rqbd_refcount = 0;
 567
 568         return (-ENOMEM);
 569 }