lustre/obdecho/echo.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  Copyright (c) 2001-2003 Cluster File Systems, Inc.
   5  *   Author: Peter Braam <braam@clusterfs.com>
   6  *   Author: Andreas Dilger <adilger@clusterfs.com>
   7  *
   8  *   This file is part of the Lustre file system, http://www.lustre.org
   9  *   Lustre is a trademark of Cluster File Systems, Inc.
  10  *
  11  *   You may have signed or agreed to another license before downloading
  12  *   this software.  If so, you are bound by the terms and conditions
  13  *   of that agreement, and the following does not apply to you.  See the
  14  *   LICENSE file included with this distribution for more information.
  15  *
  16  *   If you did not agree to a different license, then this copy of Lustre
  17  *   is open source software; you can redistribute it and/or modify it
  18  *   under the terms of version 2 of the GNU General Public License as
  19  *   published by the Free Software Foundation.
  20  *
  21  *   In either case, Lustre is distributed in the hope that it will be
  22  *   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  23  *   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  24  *   license text for more details.
  25  */
  26
  27 #ifndef EXPORT_SYMTAB
  28 # define EXPORT_SYMTAB
  29 #endif
  30
  31 #define DEBUG_SUBSYSTEM S_ECHO
  32
  33 #include <obd_support.h>
  34 #include <obd_class.h>
  35 #include <obd_echo.h>
  36 #include <lustre_debug.h>
  37 #include <lustre_dlm.h>
  38 #include <lprocfs_status.h>
  39
  40 #define ECHO_INIT_OBJID      0x1000000000000000ULL
  41 #define ECHO_HANDLE_MAGIC    0xabcd0123fedc9876ULL
  42
  43 #define ECHO_PERSISTENT_PAGES (ECHO_PERSISTENT_SIZE >> CFS_PAGE_SHIFT)
  44 static cfs_page_t *echo_persistent_pages[ECHO_PERSISTENT_PAGES];
  45
  46 enum {
  47         LPROC_ECHO_READ_BYTES = 1,
  48         LPROC_ECHO_WRITE_BYTES = 2,
  49         LPROC_ECHO_LAST = LPROC_ECHO_WRITE_BYTES +1
  50 };
  51
  52 static int echo_connect(const struct lu_env *env,
  53                         struct lustre_handle *conn, struct obd_device *obd,
  54                         struct obd_uuid *cluuid, struct obd_connect_data *data)
  55 {
  56         data->ocd_connect_flags &= ECHO_CONNECT_SUPPORTED;
  57         return class_connect(conn, obd, cluuid);
  58 }
  59
  60 static int echo_disconnect(struct obd_export *exp)
  61 {
  62         LASSERT (exp != NULL);
  63
  64         ldlm_cancel_locks_for_export(exp);
  65
  66         /* complete all outstanding replies */
  67         spin_lock(&exp->exp_lock);
  68         while (!list_empty(&exp->exp_outstanding_replies)) {
  69                 struct ptlrpc_reply_state *rs =
  70                         list_entry(exp->exp_outstanding_replies.next,
  71                                    struct ptlrpc_reply_state, rs_exp_list);
  72                 struct ptlrpc_service *svc = rs->rs_service;
  73
  74                 spin_lock(&svc->srv_lock);
  75                 list_del_init(&rs->rs_exp_list);
  76                 ptlrpc_schedule_difficult_reply(rs);
  77                 spin_unlock(&svc->srv_lock);
  78         }
  79         spin_unlock(&exp->exp_lock);
  80
  81         return class_disconnect(exp);
  82 }
  83
  84 static int echo_destroy_export(struct obd_export *exp)
  85 {
  86         ENTRY;
  87
  88         target_destroy_export(exp);
  89
  90         RETURN(0);
  91 }
  92
  93  static __u64 echo_next_id(struct obd_device *obddev)
  94 {
  95         obd_id id;
  96
  97         spin_lock(&obddev->u.echo.eo_lock);
  98         id = ++obddev->u.echo.eo_lastino;
  99         spin_unlock(&obddev->u.echo.eo_lock);
 100
 101         return id;
 102 }
 103
 104 int echo_create(struct obd_export *exp, struct obdo *oa,
 105                 struct lov_stripe_md **ea, struct obd_trans_info *oti)
 106 {
 107         struct obd_device *obd = class_exp2obd(exp);
 108
 109         if (!obd) {
 110                 CERROR("invalid client cookie "LPX64"\n",
 111                        exp->exp_handle.h_cookie);
 112                 return -EINVAL;
 113         }
 114
 115         if (!(oa->o_mode && S_IFMT)) {
 116                 CERROR("echo obd: no type!\n");
 117                 return -ENOENT;
 118         }
 119
 120         if (!(oa->o_valid & OBD_MD_FLTYPE)) {
 121                 CERROR("invalid o_valid "LPX64"\n", oa->o_valid);
 122                 return -EINVAL;
 123         }
 124
 125         oa->o_id = echo_next_id(obd);
 126         oa->o_valid = OBD_MD_FLID;
 127
 128         return 0;
 129 }
 130
 131 int echo_destroy(struct obd_export *exp, struct obdo *oa,
 132                  struct lov_stripe_md *ea, struct obd_trans_info *oti,
 133                  struct obd_export *md_exp)
 134 {
 135         struct obd_device *obd = class_exp2obd(exp);
 136
 137         ENTRY;
 138         if (!obd) {
 139                 CERROR("invalid client cookie "LPX64"\n",
 140                        exp->exp_handle.h_cookie);
 141                 RETURN(-EINVAL);
 142         }
 143
 144         if (!(oa->o_valid & OBD_MD_FLID)) {
 145                 CERROR("obdo missing FLID valid flag: "LPX64"\n", oa->o_valid);
 146                 RETURN(-EINVAL);
 147         }
 148
 149         if (oa->o_id > obd->u.echo.eo_lastino || oa->o_id < ECHO_INIT_OBJID) {
 150                 CERROR("bad destroy objid: "LPX64"\n", oa->o_id);
 151                 RETURN(-EINVAL);
 152         }
 153
 154         RETURN(0);
 155 }
 156
 157 static int echo_getattr(struct obd_export *exp, struct obd_info *oinfo)
 158 {
 159         struct obd_device *obd = class_exp2obd(exp);
 160         obd_id id = oinfo->oi_oa->o_id;
 161
 162         ENTRY;
 163         if (!obd) {
 164                 CERROR("invalid client cookie "LPX64"\n",
 165                        exp->exp_handle.h_cookie);
 166                 RETURN(-EINVAL);
 167         }
 168
 169         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 170                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 171                        oinfo->oi_oa->o_valid);
 172                 RETURN(-EINVAL);
 173         }
 174
 175         obdo_cpy_md(oinfo->oi_oa, &obd->u.echo.eo_oa, oinfo->oi_oa->o_valid);
 176         oinfo->oi_oa->o_id = id;
 177
 178         RETURN(0);
 179 }
 180
 181 static int echo_setattr(struct obd_export *exp, struct obd_info *oinfo,
 182                         struct obd_trans_info *oti)
 183 {
 184         struct obd_device *obd = class_exp2obd(exp);
 185
 186         ENTRY;
 187         if (!obd) {
 188                 CERROR("invalid client cookie "LPX64"\n",
 189                        exp->exp_handle.h_cookie);
 190                 RETURN(-EINVAL);
 191         }
 192
 193         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 194                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 195                        oinfo->oi_oa->o_valid);
 196                 RETURN(-EINVAL);
 197         }
 198
 199         memcpy(&obd->u.echo.eo_oa, oinfo->oi_oa, sizeof(*oinfo->oi_oa));
 200
 201         if (oinfo->oi_oa->o_id & 4) {
 202                 /* Save lock to force ACKed reply */
 203                 ldlm_lock_addref (&obd->u.echo.eo_nl_lock, LCK_NL);
 204                 oti->oti_ack_locks[0].mode = LCK_NL;
 205                 oti->oti_ack_locks[0].lock = obd->u.echo.eo_nl_lock;
 206         }
 207
 208         RETURN(0);
 209 }
 210
 211 static void
 212 echo_page_debug_setup(cfs_page_t *page, int rw, obd_id id,
 213                       __u64 offset, int len)
 214 {
 215         int   page_offset = offset & ~CFS_PAGE_MASK;
 216         char *addr        = ((char *)cfs_kmap(page)) + page_offset;
 217
 218         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 219                 CERROR("Unexpected block size %d\n", len);
 220
 221         while (len > 0) {
 222                 if (rw & OBD_BRW_READ)
 223                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 224                                           offset, id);
 225                 else
 226                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 227                                           0xecc0ecc0ecc0ecc0ULL,
 228                                           0xecc0ecc0ecc0ecc0ULL);
 229
 230                 addr   += OBD_ECHO_BLOCK_SIZE;
 231                 offset += OBD_ECHO_BLOCK_SIZE;
 232                 len    -= OBD_ECHO_BLOCK_SIZE;
 233         }
 234
 235         cfs_kunmap(page);
 236 }
 237
 238 static int
 239 echo_page_debug_check(cfs_page_t *page, obd_id id,
 240                       __u64 offset, int len)
 241 {
 242         int   page_offset = offset & ~CFS_PAGE_MASK;
 243         char *addr        = ((char *)cfs_kmap(page)) + page_offset;
 244         int   rc          = 0;
 245         int   rc2;
 246
 247         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 248                 CERROR("Unexpected block size %d\n", len);
 249
 250         while (len > 0) {
 251                 rc2 = block_debug_check("echo", addr, OBD_ECHO_BLOCK_SIZE,
 252                                         offset, id);
 253
 254                 if (rc2 != 0 && rc == 0)
 255                         rc = rc2;
 256
 257                 addr   += OBD_ECHO_BLOCK_SIZE;
 258                 offset += OBD_ECHO_BLOCK_SIZE;
 259                 len    -= OBD_ECHO_BLOCK_SIZE;
 260         }
 261
 262         cfs_kunmap(page);
 263
 264         return (rc);
 265 }
 266
 267 /* This allows us to verify that desc_private is passed unmolested */
 268 #define DESC_PRIV 0x10293847
 269
 270 int echo_preprw(int cmd, struct obd_export *export, struct obdo *oa,
 271                 int objcount, struct obd_ioobj *obj, int niocount,
 272                 struct niobuf_remote *nb, struct niobuf_local *res,
 273                 struct obd_trans_info *oti, struct lustre_capa *unused)
 274 {
 275         struct obd_device *obd;
 276         struct niobuf_local *r = res;
 277         int tot_bytes = 0;
 278         int rc = 0;
 279         int i;
 280         ENTRY;
 281
 282         obd = export->exp_obd;
 283         if (obd == NULL)
 284                 RETURN(-EINVAL);
 285
 286         /* Temp fix to stop falling foul of osc_announce_cached() */
 287         oa->o_valid &= ~(OBD_MD_FLBLOCKS | OBD_MD_FLGRANT);
 288
 289         memset(res, 0, sizeof(*res) * niocount);
 290
 291         CDEBUG(D_PAGE, "%s %d obdos with %d IOs\n",
 292                cmd == OBD_BRW_READ ? "reading" : "writing", objcount, niocount);
 293
 294         if (oti)
 295                 oti->oti_handle = (void *)DESC_PRIV;
 296
 297         for (i = 0; i < objcount; i++, obj++) {
 298                 int gfp_mask = (obj->ioo_id & 1) ? CFS_ALLOC_HIGHUSER : CFS_ALLOC_STD;
 299                 int ispersistent = obj->ioo_id == ECHO_PERSISTENT_OBJID;
 300                 int debug_setup = (!ispersistent &&
 301                                    (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 302                                    (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 303                 int j;
 304
 305                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, nb++, r++) {
 306
 307                         if (ispersistent &&
 308                             (nb->offset >> CFS_PAGE_SHIFT) < ECHO_PERSISTENT_PAGES) {
 309                                 r->page = echo_persistent_pages[nb->offset >>
 310                                                                 CFS_PAGE_SHIFT];
 311                                 /* Take extra ref so __free_pages() can be called OK */
 312                                 cfs_get_page (r->page);
 313                         } else {
 314                                 OBD_PAGE_ALLOC(r->page, gfp_mask);
 315                                 if (r->page == NULL) {
 316                                         CERROR("can't get page %u/%u for id "
 317                                                LPU64"\n",
 318                                                j, obj->ioo_bufcnt, obj->ioo_id);
 319                                         GOTO(preprw_cleanup, rc = -ENOMEM);
 320                                 }
 321                         }
 322
 323                         tot_bytes += nb->len;
 324
 325                         atomic_inc(&obd->u.echo.eo_prep);
 326
 327                         r->offset = nb->offset;
 328                         r->len = nb->len;
 329                         LASSERT((r->offset & ~CFS_PAGE_MASK) + r->len <= CFS_PAGE_SIZE);
 330
 331                         CDEBUG(D_PAGE, "$$$$ get page %p @ "LPU64" for %d\n",
 332                                r->page, r->offset, r->len);
 333
 334                         if (cmd & OBD_BRW_READ)
 335                                 r->rc = r->len;
 336
 337                         if (debug_setup)
 338                                 echo_page_debug_setup(r->page, cmd, obj->ioo_id,
 339                                                       r->offset, r->len);
 340                 }
 341         }
 342         if (cmd & OBD_BRW_READ)
 343                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 344                                     tot_bytes);
 345         else
 346                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 347                                     tot_bytes);
 348
 349         CDEBUG(D_PAGE, "%d pages allocated after prep\n",
 350                atomic_read(&obd->u.echo.eo_prep));
 351
 352         RETURN(0);
 353
 354 preprw_cleanup:
 355         /* It is possible that we would rather handle errors by  allow
 356          * any already-set-up pages to complete, rather than tearing them
 357          * all down again.  I believe that this is what the in-kernel
 358          * prep/commit operations do.
 359          */
 360         CERROR("cleaning up %ld pages (%d obdos)\n", (long)(r - res), objcount);
 361         while (r-- > res) {
 362                 cfs_kunmap(r->page);
 363                 /* NB if this is a persistent page, __free_pages will just
 364                  * lose the extra ref gained above */
 365                 OBD_PAGE_FREE(r->page);
 366                 atomic_dec(&obd->u.echo.eo_prep);
 367         }
 368         memset(res, 0, sizeof(*res) * niocount);
 369
 370         return rc;
 371 }
 372
 373 int echo_commitrw(int cmd, struct obd_export *export, struct obdo *oa,
 374                   int objcount, struct obd_ioobj *obj, int niocount,
 375                   struct niobuf_local *res, struct obd_trans_info *oti, int rc)
 376 {
 377         struct obd_device *obd;
 378         struct niobuf_local *r = res;
 379         int i, vrc = 0;
 380         ENTRY;
 381
 382         obd = export->exp_obd;
 383         if (obd == NULL)
 384                 RETURN(-EINVAL);
 385
 386         if (rc)
 387                 GOTO(commitrw_cleanup, rc);
 388
 389         if ((cmd & OBD_BRW_RWMASK) == OBD_BRW_READ) {
 390                 CDEBUG(D_PAGE, "reading %d obdos with %d IOs\n",
 391                        objcount, niocount);
 392         } else {
 393                 CDEBUG(D_PAGE, "writing %d obdos with %d IOs\n",
 394                        objcount, niocount);
 395         }
 396
 397         if (niocount && !r) {
 398                 CERROR("NULL res niobuf with niocount %d\n", niocount);
 399                 RETURN(-EINVAL);
 400         }
 401
 402         LASSERT(oti == NULL || oti->oti_handle == (void *)DESC_PRIV);
 403
 404         for (i = 0; i < objcount; i++, obj++) {
 405                 int verify = (rc == 0 &&
 406                               obj->ioo_id != ECHO_PERSISTENT_OBJID &&
 407                               (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 408                               (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 409                 int j;
 410
 411                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, r++) {
 412                         cfs_page_t *page = r->page;
 413                         void *addr;
 414
 415                         if (page == NULL) {
 416                                 CERROR("null page objid "LPU64":%p, buf %d/%d\n",
 417                                        obj->ioo_id, page, j, obj->ioo_bufcnt);
 418                                 GOTO(commitrw_cleanup, rc = -EFAULT);
 419                         }
 420
 421                         addr = cfs_kmap(page);
 422
 423                         CDEBUG(D_PAGE, "$$$$ use page %p, addr %p@"LPU64"\n",
 424                                r->page, addr, r->offset);
 425
 426                         if (verify) {
 427                                 vrc = echo_page_debug_check(page, obj->ioo_id,
 428                                                             r->offset, r->len);
 429                                 /* check all the pages always */
 430                                 if (vrc != 0 && rc == 0)
 431                                         rc = vrc;
 432                         }
 433
 434                         cfs_kunmap(page);
 435                         /* NB see comment above regarding persistent pages */
 436                         OBD_PAGE_FREE(page);
 437                         atomic_dec(&obd->u.echo.eo_prep);
 438                 }
 439         }
 440         CDEBUG(D_PAGE, "%d pages remain after commit\n",
 441                atomic_read(&obd->u.echo.eo_prep));
 442         RETURN(rc);
 443
 444 commitrw_cleanup:
 445         CERROR("cleaning up %ld pages (%d obdos)\n",
 446                niocount - (long)(r - res) - 1, objcount);
 447         while (++r < res + niocount) {
 448                 cfs_page_t *page = r->page;
 449
 450                 /* NB see comment above regarding persistent pages */
 451                 OBD_PAGE_FREE(page);
 452                 atomic_dec(&obd->u.echo.eo_prep);
 453         }
 454         return rc;
 455 }
 456
 457 static int echo_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
 458 {
 459         struct lprocfs_static_vars lvars;
 460         int                        rc;
 461         int                        lock_flags = 0;
 462         struct ldlm_res_id         res_id = {.name = {1}};
 463         ENTRY;
 464
 465         spin_lock_init(&obd->u.echo.eo_lock);
 466         obd->u.echo.eo_lastino = ECHO_INIT_OBJID;
 467
 468         obd->obd_namespace = ldlm_namespace_new("echo-tgt",
 469                                                 LDLM_NAMESPACE_SERVER,
 470                                                 LDLM_NAMESPACE_MODEST);
 471         if (obd->obd_namespace == NULL) {
 472                 LBUG();
 473                 RETURN(-ENOMEM);
 474         }
 475
 476         rc = ldlm_cli_enqueue_local(obd->obd_namespace, &res_id, LDLM_PLAIN,
 477                                     NULL, LCK_NL, &lock_flags, NULL,
 478                                     ldlm_completion_ast, NULL, NULL,
 479                                     0, NULL, &obd->u.echo.eo_nl_lock);
 480         LASSERT (rc == ELDLM_OK);
 481
 482         lprocfs_init_vars(echo, &lvars);
 483         if (lprocfs_obd_setup(obd, lvars.obd_vars) == 0 &&
 484             lprocfs_alloc_obd_stats(obd, LPROC_ECHO_LAST) == 0) {
 485                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 486                                      LPROCFS_CNTR_AVGMINMAX,
 487                                      "read_bytes", "bytes");
 488                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 489                                      LPROCFS_CNTR_AVGMINMAX,
 490                                      "write_bytes", "bytes");
 491         }
 492
 493         ptlrpc_init_client (LDLM_CB_REQUEST_PORTAL, LDLM_CB_REPLY_PORTAL,
 494                             "echo_ldlm_cb_client", &obd->obd_ldlm_client);
 495         RETURN(0);
 496 }
 497
 498 static int echo_cleanup(struct obd_device *obd)
 499 {
 500         int leaked;
 501         ENTRY;
 502
 503         lprocfs_obd_cleanup(obd);
 504         lprocfs_free_obd_stats(obd);
 505
 506         ldlm_lock_decref (&obd->u.echo.eo_nl_lock, LCK_NL);
 507
 508         /* XXX Bug 3413; wait for a bit to ensure the BL callback has
 509          * happened before calling ldlm_namespace_free() */
 510         set_current_state (TASK_UNINTERRUPTIBLE);
 511         cfs_schedule_timeout (CFS_TASK_UNINT, cfs_time_seconds(1));
 512
 513         ldlm_namespace_free(obd->obd_namespace, obd->obd_force);
 514
 515         leaked = atomic_read(&obd->u.echo.eo_prep);
 516         if (leaked != 0)
 517                 CERROR("%d prep/commitrw pages leaked\n", leaked);
 518
 519         RETURN(0);
 520 }
 521
 522 static struct obd_ops echo_obd_ops = {
 523         .o_owner           = THIS_MODULE,
 524         .o_connect         = echo_connect,
 525         .o_disconnect      = echo_disconnect,
 526         .o_destroy_export  = echo_destroy_export,
 527         .o_create          = echo_create,
 528         .o_destroy         = echo_destroy,
 529         .o_getattr         = echo_getattr,
 530         .o_setattr         = echo_setattr,
 531         .o_preprw          = echo_preprw,
 532         .o_commitrw        = echo_commitrw,
 533         .o_setup           = echo_setup,
 534         .o_cleanup         = echo_cleanup
 535 };
 536
 537 extern int echo_client_init(void);
 538 extern void echo_client_exit(void);
 539
 540 static void
 541 echo_persistent_pages_fini (void)
 542 {
 543         int     i;
 544
 545         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++)
 546                 if (echo_persistent_pages[i] != NULL) {
 547                         OBD_PAGE_FREE(echo_persistent_pages[i]);
 548                         echo_persistent_pages[i] = NULL;
 549                 }
 550 }
 551
 552 static int
 553 echo_persistent_pages_init (void)
 554 {
 555         cfs_page_t *pg;
 556         int          i;
 557
 558         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++) {
 559                 int gfp_mask = (i < ECHO_PERSISTENT_PAGES/2) ?
 560                         CFS_ALLOC_STD : CFS_ALLOC_HIGHUSER;
 561
 562                 OBD_PAGE_ALLOC(pg, gfp_mask);
 563                 if (pg == NULL) {
 564                         echo_persistent_pages_fini ();
 565                         return (-ENOMEM);
 566                 }
 567
 568                 memset (cfs_kmap (pg), 0, CFS_PAGE_SIZE);
 569                 cfs_kunmap (pg);
 570
 571                 echo_persistent_pages[i] = pg;
 572         }
 573
 574         return (0);
 575 }
 576
 577 static int __init obdecho_init(void)
 578 {
 579         struct lprocfs_static_vars lvars;
 580         int rc;
 581
 582         ENTRY;
 583         printk(KERN_INFO "Lustre: Echo OBD driver; info@clusterfs.com\n");
 584
 585         LASSERT(CFS_PAGE_SIZE % OBD_ECHO_BLOCK_SIZE == 0);
 586
 587         lprocfs_init_vars(echo, &lvars);
 588
 589         rc = echo_persistent_pages_init ();
 590         if (rc != 0)
 591                 goto failed_0;
 592
 593         rc = class_register_type(&echo_obd_ops, NULL, lvars.module_vars,
 594                                  LUSTRE_ECHO_NAME, NULL);
 595         if (rc != 0)
 596                 goto failed_1;
 597
 598         rc = echo_client_init();
 599         if (rc == 0)
 600                 RETURN (0);
 601
 602         class_unregister_type(LUSTRE_ECHO_NAME);
 603  failed_1:
 604         echo_persistent_pages_fini ();
 605  failed_0:
 606         RETURN(rc);
 607 }
 608
 609 static void /*__exit*/ obdecho_exit(void)
 610 {
 611         echo_client_exit();
 612         class_unregister_type(LUSTRE_ECHO_NAME);
 613         echo_persistent_pages_fini ();
 614 }
 615
 616 MODULE_AUTHOR("Cluster File Systems, Inc. <info@clusterfs.com>");
 617 MODULE_DESCRIPTION("Lustre Testing Echo OBD driver");
 618 MODULE_LICENSE("GPL");
 619
 620 cfs_module(obdecho, "1.0.0", obdecho_init, obdecho_exit);