lustre/obdecho/echo.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright  2008 Sun Microsystems, Inc. All rights reserved
  30  * Use is subject to license terms.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/obdecho/echo.c
  37  *
  38  * Author: Peter Braam <braam@clusterfs.com>
  39  * Author: Andreas Dilger <adilger@clusterfs.com>
  40  */
  41
  42 #ifndef EXPORT_SYMTAB
  43 # define EXPORT_SYMTAB
  44 #endif
  45
  46 #define DEBUG_SUBSYSTEM S_ECHO
  47
  48 #include <obd_support.h>
  49 #include <obd_class.h>
  50 #include <obd_echo.h>
  51 #include <lustre_debug.h>
  52 #include <lustre_dlm.h>
  53 #include <lprocfs_status.h>
  54
  55 #define ECHO_INIT_OBJID      0x1000000000000000ULL
  56 #define ECHO_HANDLE_MAGIC    0xabcd0123fedc9876ULL
  57
  58 #define ECHO_PERSISTENT_PAGES (ECHO_PERSISTENT_SIZE >> CFS_PAGE_SHIFT)
  59 static cfs_page_t *echo_persistent_pages[ECHO_PERSISTENT_PAGES];
  60
  61 enum {
  62         LPROC_ECHO_READ_BYTES = 1,
  63         LPROC_ECHO_WRITE_BYTES = 2,
  64         LPROC_ECHO_LAST = LPROC_ECHO_WRITE_BYTES +1
  65 };
  66
  67 static int echo_connect(const struct lu_env *env,
  68                         struct lustre_handle *conn, struct obd_device *obd,
  69                         struct obd_uuid *cluuid, struct obd_connect_data *data,
  70                         void *localdata)
  71 {
  72         data->ocd_connect_flags &= ECHO_CONNECT_SUPPORTED;
  73         return class_connect(conn, obd, cluuid);
  74 }
  75
  76 static int echo_disconnect(struct obd_export *exp)
  77 {
  78         LASSERT (exp != NULL);
  79
  80         ldlm_cancel_locks_for_export(exp);
  81
  82         /* complete all outstanding replies */
  83         spin_lock(&exp->exp_lock);
  84         while (!list_empty(&exp->exp_outstanding_replies)) {
  85                 struct ptlrpc_reply_state *rs =
  86                         list_entry(exp->exp_outstanding_replies.next,
  87                                    struct ptlrpc_reply_state, rs_exp_list);
  88                 struct ptlrpc_service *svc = rs->rs_service;
  89
  90                 spin_lock(&svc->srv_lock);
  91                 list_del_init(&rs->rs_exp_list);
  92                 ptlrpc_schedule_difficult_reply(rs);
  93                 spin_unlock(&svc->srv_lock);
  94         }
  95         spin_unlock(&exp->exp_lock);
  96
  97         return class_disconnect(exp);
  98 }
  99
 100 static int echo_destroy_export(struct obd_export *exp)
 101 {
 102         ENTRY;
 103
 104         target_destroy_export(exp);
 105
 106         RETURN(0);
 107 }
 108
 109  static __u64 echo_next_id(struct obd_device *obddev)
 110 {
 111         obd_id id;
 112
 113         spin_lock(&obddev->u.echo.eo_lock);
 114         id = ++obddev->u.echo.eo_lastino;
 115         spin_unlock(&obddev->u.echo.eo_lock);
 116
 117         return id;
 118 }
 119
 120 int echo_create(struct obd_export *exp, struct obdo *oa,
 121                 struct lov_stripe_md **ea, struct obd_trans_info *oti)
 122 {
 123         struct obd_device *obd = class_exp2obd(exp);
 124
 125         if (!obd) {
 126                 CERROR("invalid client cookie "LPX64"\n",
 127                        exp->exp_handle.h_cookie);
 128                 return -EINVAL;
 129         }
 130
 131         if (!(oa->o_mode && S_IFMT)) {
 132                 CERROR("echo obd: no type!\n");
 133                 return -ENOENT;
 134         }
 135
 136         if (!(oa->o_valid & OBD_MD_FLTYPE)) {
 137                 CERROR("invalid o_valid "LPX64"\n", oa->o_valid);
 138                 return -EINVAL;
 139         }
 140
 141         oa->o_id = echo_next_id(obd);
 142         oa->o_valid = OBD_MD_FLID;
 143
 144         return 0;
 145 }
 146
 147 int echo_destroy(struct obd_export *exp, struct obdo *oa,
 148                  struct lov_stripe_md *ea, struct obd_trans_info *oti,
 149                  struct obd_export *md_exp)
 150 {
 151         struct obd_device *obd = class_exp2obd(exp);
 152
 153         ENTRY;
 154         if (!obd) {
 155                 CERROR("invalid client cookie "LPX64"\n",
 156                        exp->exp_handle.h_cookie);
 157                 RETURN(-EINVAL);
 158         }
 159
 160         if (!(oa->o_valid & OBD_MD_FLID)) {
 161                 CERROR("obdo missing FLID valid flag: "LPX64"\n", oa->o_valid);
 162                 RETURN(-EINVAL);
 163         }
 164
 165         if (oa->o_id > obd->u.echo.eo_lastino || oa->o_id < ECHO_INIT_OBJID) {
 166                 CERROR("bad destroy objid: "LPX64"\n", oa->o_id);
 167                 RETURN(-EINVAL);
 168         }
 169
 170         RETURN(0);
 171 }
 172
 173 static int echo_getattr(struct obd_export *exp, struct obd_info *oinfo)
 174 {
 175         struct obd_device *obd = class_exp2obd(exp);
 176         obd_id id = oinfo->oi_oa->o_id;
 177
 178         ENTRY;
 179         if (!obd) {
 180                 CERROR("invalid client cookie "LPX64"\n",
 181                        exp->exp_handle.h_cookie);
 182                 RETURN(-EINVAL);
 183         }
 184
 185         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 186                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 187                        oinfo->oi_oa->o_valid);
 188                 RETURN(-EINVAL);
 189         }
 190
 191         obdo_cpy_md(oinfo->oi_oa, &obd->u.echo.eo_oa, oinfo->oi_oa->o_valid);
 192         oinfo->oi_oa->o_id = id;
 193
 194         RETURN(0);
 195 }
 196
 197 static int echo_setattr(struct obd_export *exp, struct obd_info *oinfo,
 198                         struct obd_trans_info *oti)
 199 {
 200         struct obd_device *obd = class_exp2obd(exp);
 201
 202         ENTRY;
 203         if (!obd) {
 204                 CERROR("invalid client cookie "LPX64"\n",
 205                        exp->exp_handle.h_cookie);
 206                 RETURN(-EINVAL);
 207         }
 208
 209         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 210                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 211                        oinfo->oi_oa->o_valid);
 212                 RETURN(-EINVAL);
 213         }
 214
 215         memcpy(&obd->u.echo.eo_oa, oinfo->oi_oa, sizeof(*oinfo->oi_oa));
 216
 217         if (oinfo->oi_oa->o_id & 4) {
 218                 /* Save lock to force ACKed reply */
 219                 ldlm_lock_addref (&obd->u.echo.eo_nl_lock, LCK_NL);
 220                 oti->oti_ack_locks[0].mode = LCK_NL;
 221                 oti->oti_ack_locks[0].lock = obd->u.echo.eo_nl_lock;
 222         }
 223
 224         RETURN(0);
 225 }
 226
 227 static void
 228 echo_page_debug_setup(cfs_page_t *page, int rw, obd_id id,
 229                       __u64 offset, int len)
 230 {
 231         int   page_offset = offset & ~CFS_PAGE_MASK;
 232         char *addr        = ((char *)cfs_kmap(page)) + page_offset;
 233
 234         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 235                 CERROR("Unexpected block size %d\n", len);
 236
 237         while (len > 0) {
 238                 if (rw & OBD_BRW_READ)
 239                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 240                                           offset, id);
 241                 else
 242                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 243                                           0xecc0ecc0ecc0ecc0ULL,
 244                                           0xecc0ecc0ecc0ecc0ULL);
 245
 246                 addr   += OBD_ECHO_BLOCK_SIZE;
 247                 offset += OBD_ECHO_BLOCK_SIZE;
 248                 len    -= OBD_ECHO_BLOCK_SIZE;
 249         }
 250
 251         cfs_kunmap(page);
 252 }
 253
 254 static int
 255 echo_page_debug_check(cfs_page_t *page, obd_id id,
 256                       __u64 offset, int len)
 257 {
 258         int   page_offset = offset & ~CFS_PAGE_MASK;
 259         char *addr        = ((char *)cfs_kmap(page)) + page_offset;
 260         int   rc          = 0;
 261         int   rc2;
 262
 263         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 264                 CERROR("Unexpected block size %d\n", len);
 265
 266         while (len > 0) {
 267                 rc2 = block_debug_check("echo", addr, OBD_ECHO_BLOCK_SIZE,
 268                                         offset, id);
 269
 270                 if (rc2 != 0 && rc == 0)
 271                         rc = rc2;
 272
 273                 addr   += OBD_ECHO_BLOCK_SIZE;
 274                 offset += OBD_ECHO_BLOCK_SIZE;
 275                 len    -= OBD_ECHO_BLOCK_SIZE;
 276         }
 277
 278         cfs_kunmap(page);
 279
 280         return (rc);
 281 }
 282
 283 /* This allows us to verify that desc_private is passed unmolested */
 284 #define DESC_PRIV 0x10293847
 285
 286 int echo_preprw(int cmd, struct obd_export *export, struct obdo *oa,
 287                 int objcount, struct obd_ioobj *obj, int niocount,
 288                 struct niobuf_remote *nb, struct niobuf_local *res,
 289                 struct obd_trans_info *oti, struct lustre_capa *unused)
 290 {
 291         struct obd_device *obd;
 292         struct niobuf_local *r = res;
 293         int tot_bytes = 0;
 294         int rc = 0;
 295         int i;
 296         ENTRY;
 297
 298         obd = export->exp_obd;
 299         if (obd == NULL)
 300                 RETURN(-EINVAL);
 301
 302         /* Temp fix to stop falling foul of osc_announce_cached() */
 303         oa->o_valid &= ~(OBD_MD_FLBLOCKS | OBD_MD_FLGRANT);
 304
 305         memset(res, 0, sizeof(*res) * niocount);
 306
 307         CDEBUG(D_PAGE, "%s %d obdos with %d IOs\n",
 308                cmd == OBD_BRW_READ ? "reading" : "writing", objcount, niocount);
 309
 310         if (oti)
 311                 oti->oti_handle = (void *)DESC_PRIV;
 312
 313         for (i = 0; i < objcount; i++, obj++) {
 314                 int gfp_mask = (obj->ioo_id & 1) ? CFS_ALLOC_HIGHUSER : CFS_ALLOC_STD;
 315                 int ispersistent = obj->ioo_id == ECHO_PERSISTENT_OBJID;
 316                 int debug_setup = (!ispersistent &&
 317                                    (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 318                                    (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 319                 int j;
 320
 321                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, nb++, r++) {
 322
 323                         if (ispersistent &&
 324                             (nb->offset >> CFS_PAGE_SHIFT) < ECHO_PERSISTENT_PAGES) {
 325                                 r->page = echo_persistent_pages[nb->offset >>
 326                                                                 CFS_PAGE_SHIFT];
 327                                 /* Take extra ref so __free_pages() can be called OK */
 328                                 cfs_get_page (r->page);
 329                         } else {
 330                                 OBD_PAGE_ALLOC(r->page, gfp_mask);
 331                                 if (r->page == NULL) {
 332                                         CERROR("can't get page %u/%u for id "
 333                                                LPU64"\n",
 334                                                j, obj->ioo_bufcnt, obj->ioo_id);
 335                                         GOTO(preprw_cleanup, rc = -ENOMEM);
 336                                 }
 337                         }
 338
 339                         tot_bytes += nb->len;
 340
 341                         atomic_inc(&obd->u.echo.eo_prep);
 342
 343                         r->offset = nb->offset;
 344                         r->len = nb->len;
 345                         LASSERT((r->offset & ~CFS_PAGE_MASK) + r->len <= CFS_PAGE_SIZE);
 346
 347                         CDEBUG(D_PAGE, "$$$$ get page %p @ "LPU64" for %d\n",
 348                                r->page, r->offset, r->len);
 349
 350                         if (cmd & OBD_BRW_READ)
 351                                 r->rc = r->len;
 352
 353                         if (debug_setup)
 354                                 echo_page_debug_setup(r->page, cmd, obj->ioo_id,
 355                                                       r->offset, r->len);
 356                 }
 357         }
 358         if (cmd & OBD_BRW_READ)
 359                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 360                                     tot_bytes);
 361         else
 362                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 363                                     tot_bytes);
 364
 365         CDEBUG(D_PAGE, "%d pages allocated after prep\n",
 366                atomic_read(&obd->u.echo.eo_prep));
 367
 368         RETURN(0);
 369
 370 preprw_cleanup:
 371         /* It is possible that we would rather handle errors by  allow
 372          * any already-set-up pages to complete, rather than tearing them
 373          * all down again.  I believe that this is what the in-kernel
 374          * prep/commit operations do.
 375          */
 376         CERROR("cleaning up %ld pages (%d obdos)\n", (long)(r - res), objcount);
 377         while (r-- > res) {
 378                 cfs_kunmap(r->page);
 379                 /* NB if this is a persistent page, __free_pages will just
 380                  * lose the extra ref gained above */
 381                 OBD_PAGE_FREE(r->page);
 382                 atomic_dec(&obd->u.echo.eo_prep);
 383         }
 384         memset(res, 0, sizeof(*res) * niocount);
 385
 386         return rc;
 387 }
 388
 389 int echo_commitrw(int cmd, struct obd_export *export, struct obdo *oa,
 390                   int objcount, struct obd_ioobj *obj, int niocount,
 391                   struct niobuf_local *res, struct obd_trans_info *oti, int rc)
 392 {
 393         struct obd_device *obd;
 394         struct niobuf_local *r = res;
 395         int i, vrc = 0;
 396         ENTRY;
 397
 398         obd = export->exp_obd;
 399         if (obd == NULL)
 400                 RETURN(-EINVAL);
 401
 402         if (rc)
 403                 GOTO(commitrw_cleanup, rc);
 404
 405         if ((cmd & OBD_BRW_RWMASK) == OBD_BRW_READ) {
 406                 CDEBUG(D_PAGE, "reading %d obdos with %d IOs\n",
 407                        objcount, niocount);
 408         } else {
 409                 CDEBUG(D_PAGE, "writing %d obdos with %d IOs\n",
 410                        objcount, niocount);
 411         }
 412
 413         if (niocount && !r) {
 414                 CERROR("NULL res niobuf with niocount %d\n", niocount);
 415                 RETURN(-EINVAL);
 416         }
 417
 418         LASSERT(oti == NULL || oti->oti_handle == (void *)DESC_PRIV);
 419
 420         for (i = 0; i < objcount; i++, obj++) {
 421                 int verify = (rc == 0 &&
 422                               obj->ioo_id != ECHO_PERSISTENT_OBJID &&
 423                               (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 424                               (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 425                 int j;
 426
 427                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, r++) {
 428                         cfs_page_t *page = r->page;
 429                         void *addr;
 430
 431                         if (page == NULL) {
 432                                 CERROR("null page objid "LPU64":%p, buf %d/%d\n",
 433                                        obj->ioo_id, page, j, obj->ioo_bufcnt);
 434                                 GOTO(commitrw_cleanup, rc = -EFAULT);
 435                         }
 436
 437                         addr = cfs_kmap(page);
 438
 439                         CDEBUG(D_PAGE, "$$$$ use page %p, addr %p@"LPU64"\n",
 440                                r->page, addr, r->offset);
 441
 442                         if (verify) {
 443                                 vrc = echo_page_debug_check(page, obj->ioo_id,
 444                                                             r->offset, r->len);
 445                                 /* check all the pages always */
 446                                 if (vrc != 0 && rc == 0)
 447                                         rc = vrc;
 448                         }
 449
 450                         cfs_kunmap(page);
 451                         /* NB see comment above regarding persistent pages */
 452                         OBD_PAGE_FREE(page);
 453                         atomic_dec(&obd->u.echo.eo_prep);
 454                 }
 455         }
 456         CDEBUG(D_PAGE, "%d pages remain after commit\n",
 457                atomic_read(&obd->u.echo.eo_prep));
 458         RETURN(rc);
 459
 460 commitrw_cleanup:
 461         CERROR("cleaning up %ld pages (%d obdos)\n",
 462                niocount - (long)(r - res) - 1, objcount);
 463         while (++r < res + niocount) {
 464                 cfs_page_t *page = r->page;
 465
 466                 /* NB see comment above regarding persistent pages */
 467                 OBD_PAGE_FREE(page);
 468                 atomic_dec(&obd->u.echo.eo_prep);
 469         }
 470         return rc;
 471 }
 472
 473 static int echo_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
 474 {
 475         struct lprocfs_static_vars lvars;
 476         int                        rc;
 477         int                        lock_flags = 0;
 478         struct ldlm_res_id         res_id = {.name = {1}};
 479         ENTRY;
 480
 481         spin_lock_init(&obd->u.echo.eo_lock);
 482         obd->u.echo.eo_lastino = ECHO_INIT_OBJID;
 483
 484         obd->obd_namespace = ldlm_namespace_new(obd, "echo-tgt",
 485                                                 LDLM_NAMESPACE_SERVER,
 486                                                 LDLM_NAMESPACE_MODEST);
 487         if (obd->obd_namespace == NULL) {
 488                 LBUG();
 489                 RETURN(-ENOMEM);
 490         }
 491
 492         rc = ldlm_cli_enqueue_local(obd->obd_namespace, &res_id, LDLM_PLAIN,
 493                                     NULL, LCK_NL, &lock_flags, NULL,
 494                                     ldlm_completion_ast, NULL, NULL,
 495                                     0, NULL, &obd->u.echo.eo_nl_lock);
 496         LASSERT (rc == ELDLM_OK);
 497
 498         lprocfs_echo_init_vars(&lvars);
 499         if (lprocfs_obd_setup(obd, lvars.obd_vars) == 0 &&
 500             lprocfs_alloc_obd_stats(obd, LPROC_ECHO_LAST) == 0) {
 501                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 502                                      LPROCFS_CNTR_AVGMINMAX,
 503                                      "read_bytes", "bytes");
 504                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 505                                      LPROCFS_CNTR_AVGMINMAX,
 506                                      "write_bytes", "bytes");
 507         }
 508
 509         ptlrpc_init_client (LDLM_CB_REQUEST_PORTAL, LDLM_CB_REPLY_PORTAL,
 510                             "echo_ldlm_cb_client", &obd->obd_ldlm_client);
 511         RETURN(0);
 512 }
 513
 514 static int echo_cleanup(struct obd_device *obd)
 515 {
 516         int leaked;
 517         ENTRY;
 518
 519         lprocfs_obd_cleanup(obd);
 520         lprocfs_free_obd_stats(obd);
 521
 522         ldlm_lock_decref (&obd->u.echo.eo_nl_lock, LCK_NL);
 523
 524         /* XXX Bug 3413; wait for a bit to ensure the BL callback has
 525          * happened before calling ldlm_namespace_free() */
 526         cfs_schedule_timeout (CFS_TASK_UNINT, cfs_time_seconds(1));
 527
 528         ldlm_namespace_free(obd->obd_namespace, NULL, obd->obd_force);
 529         obd->obd_namespace = NULL;
 530
 531         leaked = atomic_read(&obd->u.echo.eo_prep);
 532         if (leaked != 0)
 533                 CERROR("%d prep/commitrw pages leaked\n", leaked);
 534
 535         RETURN(0);
 536 }
 537
 538 static struct obd_ops echo_obd_ops = {
 539         .o_owner           = THIS_MODULE,
 540         .o_connect         = echo_connect,
 541         .o_disconnect      = echo_disconnect,
 542         .o_destroy_export  = echo_destroy_export,
 543         .o_create          = echo_create,
 544         .o_destroy         = echo_destroy,
 545         .o_getattr         = echo_getattr,
 546         .o_setattr         = echo_setattr,
 547         .o_preprw          = echo_preprw,
 548         .o_commitrw        = echo_commitrw,
 549         .o_setup           = echo_setup,
 550         .o_cleanup         = echo_cleanup
 551 };
 552
 553 extern int echo_client_init(void);
 554 extern void echo_client_exit(void);
 555
 556 static void
 557 echo_persistent_pages_fini (void)
 558 {
 559         int     i;
 560
 561         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++)
 562                 if (echo_persistent_pages[i] != NULL) {
 563                         OBD_PAGE_FREE(echo_persistent_pages[i]);
 564                         echo_persistent_pages[i] = NULL;
 565                 }
 566 }
 567
 568 static int
 569 echo_persistent_pages_init (void)
 570 {
 571         cfs_page_t *pg;
 572         int          i;
 573
 574         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++) {
 575                 int gfp_mask = (i < ECHO_PERSISTENT_PAGES/2) ?
 576                         CFS_ALLOC_STD : CFS_ALLOC_HIGHUSER;
 577
 578                 OBD_PAGE_ALLOC(pg, gfp_mask);
 579                 if (pg == NULL) {
 580                         echo_persistent_pages_fini ();
 581                         return (-ENOMEM);
 582                 }
 583
 584                 memset (cfs_kmap (pg), 0, CFS_PAGE_SIZE);
 585                 cfs_kunmap (pg);
 586
 587                 echo_persistent_pages[i] = pg;
 588         }
 589
 590         return (0);
 591 }
 592
 593 static int __init obdecho_init(void)
 594 {
 595         struct lprocfs_static_vars lvars;
 596         int rc;
 597
 598         ENTRY;
 599         LCONSOLE_INFO("Lustre: Echo OBD driver; http://www.lustre.org/\n");
 600
 601         LASSERT(CFS_PAGE_SIZE % OBD_ECHO_BLOCK_SIZE == 0);
 602
 603         lprocfs_echo_init_vars(&lvars);
 604
 605         rc = echo_persistent_pages_init ();
 606         if (rc != 0)
 607                 goto failed_0;
 608
 609         rc = class_register_type(&echo_obd_ops, NULL, lvars.module_vars,
 610                                  LUSTRE_ECHO_NAME, NULL);
 611         if (rc != 0)
 612                 goto failed_1;
 613
 614         rc = echo_client_init();
 615         if (rc == 0)
 616                 RETURN (0);
 617
 618         class_unregister_type(LUSTRE_ECHO_NAME);
 619  failed_1:
 620         echo_persistent_pages_fini ();
 621  failed_0:
 622         RETURN(rc);
 623 }
 624
 625 static void /*__exit*/ obdecho_exit(void)
 626 {
 627         echo_client_exit();
 628         class_unregister_type(LUSTRE_ECHO_NAME);
 629         echo_persistent_pages_fini ();
 630 }
 631
 632 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 633 MODULE_DESCRIPTION("Lustre Testing Echo OBD driver");
 634 MODULE_LICENSE("GPL");
 635
 636 cfs_module(obdecho, "1.0.0", obdecho_init, obdecho_exit);