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 Lustre, http://www.lustre.org.
   9  *
  10  *   Lustre is free software; you can redistribute it and/or
  11  *   modify it under the terms of version 2 of the GNU General Public
  12  *   License as published by the Free Software Foundation.
  13  *
  14  *   Lustre is distributed in the hope that it will be useful,
  15  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  *   GNU General Public License for more details.
  18  *
  19  *   You should have received a copy of the GNU General Public License
  20  *   along with Lustre; if not, write to the Free Software
  21  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  22  */
  23
  24 #ifndef EXPORT_SYMTAB
  25 # define EXPORT_SYMTAB
  26 #endif
  27
  28 #include <linux/version.h>
  29 #include <linux/module.h>
  30 #include <linux/mm.h>
  31 #include <linux/highmem.h>
  32 #include <linux/fs.h>
  33 #include <linux/stat.h>
  34 #include <linux/sched.h>
  35 #include <linux/smp_lock.h>
  36 #include <linux/proc_fs.h>
  37 #include <linux/init.h>
  38 #include <asm/unistd.h>
  39
  40 #define DEBUG_SUBSYSTEM S_ECHO
  41
  42 #include <linux/obd_support.h>
  43 #include <linux/obd_class.h>
  44 #include <linux/obd_echo.h>
  45 #include <linux/lustre_debug.h>
  46 #include <linux/lustre_dlm.h>
  47 #include <linux/lprocfs_status.h>
  48
  49 #define ECHO_INIT_OBJID      0x1000000000000000ULL
  50 #define ECHO_HANDLE_MAGIC    0xabcd0123fedc9876ULL
  51
  52 #define ECHO_PERSISTENT_PAGES (ECHO_PERSISTENT_SIZE/PAGE_SIZE)
  53 static struct page *echo_persistent_pages[ECHO_PERSISTENT_PAGES];
  54
  55 enum {
  56         LPROC_ECHO_READ_BYTES = 1,
  57         LPROC_ECHO_WRITE_BYTES = 2,
  58         LPROC_ECHO_LAST
  59 };
  60
  61 static int echo_connect(struct lustre_handle *conn, struct obd_device *obd,
  62                         struct obd_uuid *cluuid, struct obd_connect_data *data,
  63                         unsigned long connect_flags)
  64 {
  65         return class_connect(conn, obd, cluuid);
  66 }
  67
  68 static int echo_disconnect(struct obd_export *exp, unsigned long flags)
  69 {
  70         unsigned long irqflags;
  71
  72         LASSERT (exp != NULL);
  73
  74         ldlm_cancel_locks_for_export(exp);
  75
  76         spin_lock_irqsave(&exp->exp_lock, irqflags);
  77         exp->exp_flags = flags;
  78         /* complete all outstanding replies */
  79         spin_lock_irqsave(&exp->exp_lock, irqflags);
  80         while (!list_empty(&exp->exp_outstanding_replies)) {
  81                 struct ptlrpc_reply_state *rs =
  82                         list_entry(exp->exp_outstanding_replies.next,
  83                                    struct ptlrpc_reply_state, rs_exp_list);
  84                 struct ptlrpc_service *svc = rs->rs_srv_ni->sni_service;
  85
  86                 spin_lock(&svc->srv_lock);
  87                 list_del_init(&rs->rs_exp_list);
  88                 ptlrpc_schedule_difficult_reply(rs);
  89                 spin_unlock(&svc->srv_lock);
  90         }
  91         spin_unlock_irqrestore(&exp->exp_lock, irqflags);
  92
  93         return class_disconnect(exp, flags);
  94 }
  95
  96 static int echo_destroy_export(struct obd_export *exp)
  97 {
  98         ENTRY;
  99
 100         target_destroy_export(exp);
 101
 102         RETURN(0);
 103 }
 104
 105  static __u64 echo_next_id(struct obd_device *obddev)
 106 {
 107         obd_id id;
 108
 109         spin_lock(&obddev->u.echo.eo_lock);
 110         id = ++obddev->u.echo.eo_lastino;
 111         spin_unlock(&obddev->u.echo.eo_lock);
 112
 113         return id;
 114 }
 115
 116 int echo_create(struct obd_export *exp, struct obdo *oa,
 117                 struct lov_stripe_md **ea, struct obd_trans_info *oti)
 118 {
 119         struct obd_device *obd = class_exp2obd(exp);
 120
 121         if (!obd) {
 122                 CERROR("invalid client cookie "LPX64"\n",
 123                        exp->exp_handle.h_cookie);
 124                 return -EINVAL;
 125         }
 126
 127         if (!(oa->o_mode && S_IFMT)) {
 128                 CERROR("echo obd: no type!\n");
 129                 return -ENOENT;
 130         }
 131
 132         if (!(oa->o_valid & OBD_MD_FLTYPE)) {
 133                 CERROR("invalid o_valid "LPX64"\n", oa->o_valid);
 134                 return -EINVAL;
 135         }
 136
 137         oa->o_id = echo_next_id(obd);
 138         oa->o_valid = OBD_MD_FLID;
 139
 140         return 0;
 141 }
 142
 143 int echo_destroy(struct obd_export *exp, struct obdo *oa,
 144                  struct lov_stripe_md *ea, struct obd_trans_info *oti)
 145 {
 146         struct obd_device *obd = class_exp2obd(exp);
 147
 148         if (!obd) {
 149                 CERROR("invalid client cookie "LPX64"\n",
 150                        exp->exp_handle.h_cookie);
 151                 RETURN(-EINVAL);
 152         }
 153
 154         if (!(oa->o_valid & OBD_MD_FLID)) {
 155                 CERROR("obdo missing FLID valid flag: "LPX64"\n", oa->o_valid);
 156                 RETURN(-EINVAL);
 157         }
 158
 159         if (oa->o_id > obd->u.echo.eo_lastino || oa->o_id < ECHO_INIT_OBJID) {
 160                 CERROR("bad destroy objid: "LPX64"\n", oa->o_id);
 161                 RETURN(-EINVAL);
 162         }
 163
 164
 165         return 0;
 166 }
 167
 168 static int echo_getattr(struct obd_export *exp, struct obdo *oa,
 169                         struct lov_stripe_md *md)
 170 {
 171         struct obd_device *obd = class_exp2obd(exp);
 172         obd_id id = oa->o_id;
 173
 174         if (!obd) {
 175                 CERROR("invalid client cookie "LPX64"\n",
 176                        exp->exp_handle.h_cookie);
 177                 RETURN(-EINVAL);
 178         }
 179
 180         if (!(oa->o_valid & OBD_MD_FLID)) {
 181                 CERROR("obdo missing FLID valid flag: "LPX64"\n", oa->o_valid);
 182                 RETURN(-EINVAL);
 183         }
 184
 185         obdo_cpy_md(oa, &obd->u.echo.eo_oa, oa->o_valid);
 186         oa->o_id = id;
 187
 188         return 0;
 189 }
 190
 191 static int echo_setattr(struct obd_export *exp, struct obdo *oa,
 192                         struct lov_stripe_md *md, struct obd_trans_info *oti)
 193 {
 194         struct obd_device *obd = class_exp2obd(exp);
 195
 196         if (!obd) {
 197                 CERROR("invalid client cookie "LPX64"\n",
 198                        exp->exp_handle.h_cookie);
 199                 RETURN(-EINVAL);
 200         }
 201
 202         if (!(oa->o_valid & OBD_MD_FLID)) {
 203                 CERROR("obdo missing FLID valid flag: "LPX64"\n", oa->o_valid);
 204                 RETURN(-EINVAL);
 205         }
 206
 207         memcpy(&obd->u.echo.eo_oa, oa, sizeof(*oa));
 208
 209         if (oa->o_id & 4) {
 210                 /* Save lock to force ACKed reply */
 211                 ldlm_lock_addref (&obd->u.echo.eo_nl_lock, LCK_NL);
 212                 oti->oti_ack_locks[0].mode = LCK_NL;
 213                 oti->oti_ack_locks[0].lock = obd->u.echo.eo_nl_lock;
 214         }
 215         return 0;
 216 }
 217
 218 static void
 219 echo_page_debug_setup(struct page *page, int rw, obd_id id,
 220                       __u64 offset, int len)
 221 {
 222         int   page_offset = offset & (PAGE_SIZE - 1);
 223         char *addr        = ((char *)kmap(page)) + page_offset;
 224
 225         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 226                 CERROR("Unexpected block size %d\n", len);
 227
 228         while (len > 0) {
 229                 if (rw & OBD_BRW_READ)
 230                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 231                                           offset, id);
 232                 else
 233                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 234                                           0xecc0ecc0ecc0ecc0ULL,
 235                                           0xecc0ecc0ecc0ecc0ULL);
 236
 237                 addr   += OBD_ECHO_BLOCK_SIZE;
 238                 offset += OBD_ECHO_BLOCK_SIZE;
 239                 len    -= OBD_ECHO_BLOCK_SIZE;
 240         }
 241
 242         kunmap(page);
 243 }
 244
 245 static int
 246 echo_page_debug_check(struct page *page, obd_id id,
 247                       __u64 offset, int len)
 248 {
 249         int   page_offset = offset & (PAGE_SIZE - 1);
 250         char *addr        = ((char *)kmap(page)) + page_offset;
 251         int   rc          = 0;
 252         int   rc2;
 253
 254         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 255                 CERROR("Unexpected block size %d\n", len);
 256
 257         while (len > 0) {
 258                 rc2 = block_debug_check("echo", addr, OBD_ECHO_BLOCK_SIZE,
 259                                         offset, id);
 260
 261                 if (rc2 != 0 && rc == 0)
 262                         rc = rc2;
 263
 264                 addr   += OBD_ECHO_BLOCK_SIZE;
 265                 offset += OBD_ECHO_BLOCK_SIZE;
 266                 len    -= OBD_ECHO_BLOCK_SIZE;
 267         }
 268
 269         kunmap(page);
 270
 271         return (rc);
 272 }
 273
 274 /* This allows us to verify that desc_private is passed unmolested */
 275 #define DESC_PRIV 0x10293847
 276
 277 int echo_preprw(int cmd, struct obd_export *export, struct obdo *oa,
 278                 int objcount, struct obd_ioobj *obj, int niocount,
 279                 struct niobuf_remote *nb, struct niobuf_local *res,
 280                 struct obd_trans_info *oti)
 281 {
 282         struct obd_device *obd;
 283         struct niobuf_local *r = res;
 284         int tot_bytes = 0;
 285         int rc = 0;
 286         int i;
 287         ENTRY;
 288
 289         obd = export->exp_obd;
 290         if (obd == NULL)
 291                 RETURN(-EINVAL);
 292
 293         /* Temp fix to stop falling foul of osc_announce_cached() */
 294         oa->o_valid &= ~(OBD_MD_FLBLOCKS | OBD_MD_FLGRANT);
 295
 296         memset(res, 0, sizeof(*res) * niocount);
 297
 298         CDEBUG(D_PAGE, "%s %d obdos with %d IOs\n",
 299                cmd == OBD_BRW_READ ? "reading" : "writing", objcount, niocount);
 300
 301         if (oti)
 302                 oti->oti_handle = (void *)DESC_PRIV;
 303
 304         for (i = 0; i < objcount; i++, obj++) {
 305                 int gfp_mask = (obj->ioo_id & 1) ? GFP_HIGHUSER : GFP_KERNEL;
 306                 int ispersistent = obj->ioo_id == ECHO_PERSISTENT_OBJID;
 307                 int debug_setup = (!ispersistent &&
 308                                    (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 309                                    (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 310                 int j;
 311
 312                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, nb++, r++) {
 313
 314                         if (ispersistent &&
 315                             (nb->offset >> PAGE_SHIFT) < ECHO_PERSISTENT_PAGES) {
 316                                 r->page = echo_persistent_pages[nb->offset >>
 317                                                                 PAGE_SHIFT];
 318                                 /* Take extra ref so __free_pages() can be called OK */
 319                                 get_page (r->page);
 320                         } else {
 321                                 r->page = alloc_pages(gfp_mask, 0);
 322                                 if (r->page == NULL) {
 323                                         CERROR("can't get page %u/%u for id "
 324                                                LPU64"\n",
 325                                                j, obj->ioo_bufcnt, obj->ioo_id);
 326                                         GOTO(preprw_cleanup, rc = -ENOMEM);
 327                                 }
 328                         }
 329
 330                         tot_bytes += nb->len;
 331
 332                         atomic_inc(&obd->u.echo.eo_prep);
 333
 334                         r->offset = nb->offset;
 335                         r->len = nb->len;
 336                         LASSERT((r->offset & ~PAGE_MASK) + r->len <= PAGE_SIZE);
 337
 338                         CDEBUG(D_PAGE, "$$$$ get page %p @ "LPU64" for %d\n",
 339                                r->page, r->offset, r->len);
 340
 341                         if (cmd & OBD_BRW_READ)
 342                                 r->rc = r->len;
 343
 344                         if (debug_setup)
 345                                 echo_page_debug_setup(r->page, cmd, obj->ioo_id,
 346                                                       r->offset, r->len);
 347                 }
 348         }
 349         if (cmd & OBD_BRW_READ)
 350                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 351                                     tot_bytes);
 352         else
 353                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 354                                     tot_bytes);
 355
 356         CDEBUG(D_PAGE, "%d pages allocated after prep\n",
 357                atomic_read(&obd->u.echo.eo_prep));
 358
 359         RETURN(0);
 360
 361 preprw_cleanup:
 362         /* It is possible that we would rather handle errors by  allow
 363          * any already-set-up pages to complete, rather than tearing them
 364          * all down again.  I believe that this is what the in-kernel
 365          * prep/commit operations do.
 366          */
 367         CERROR("cleaning up %ld pages (%d obdos)\n", (long)(r - res), objcount);
 368         while (r-- > res) {
 369                 kunmap(r->page);
 370                 /* NB if this is a persistent page, __free_pages will just
 371                  * lose the extra ref gained above */
 372                 __free_pages(r->page, 0);
 373                 atomic_dec(&obd->u.echo.eo_prep);
 374         }
 375         memset(res, 0, sizeof(*res) * niocount);
 376
 377         return rc;
 378 }
 379
 380 int echo_commitrw(int cmd, struct obd_export *export, struct obdo *oa,
 381                   int objcount, struct obd_ioobj *obj, int niocount,
 382                   struct niobuf_local *res, struct obd_trans_info *oti, int rc)
 383 {
 384         struct obd_device *obd;
 385         struct niobuf_local *r = res;
 386         int i, vrc = 0;
 387         ENTRY;
 388
 389         obd = export->exp_obd;
 390         if (obd == NULL)
 391                 RETURN(-EINVAL);
 392
 393         if (rc)
 394                 GOTO(commitrw_cleanup, rc);
 395
 396         if ((cmd & OBD_BRW_RWMASK) == OBD_BRW_READ) {
 397                 CDEBUG(D_PAGE, "reading %d obdos with %d IOs\n",
 398                        objcount, niocount);
 399         } else {
 400                 CDEBUG(D_PAGE, "writing %d obdos with %d IOs\n",
 401                        objcount, niocount);
 402         }
 403
 404         if (niocount && !r) {
 405                 CERROR("NULL res niobuf with niocount %d\n", niocount);
 406                 RETURN(-EINVAL);
 407         }
 408
 409         LASSERT(oti == NULL || oti->oti_handle == (void *)DESC_PRIV);
 410
 411         for (i = 0; i < objcount; i++, obj++) {
 412                 int verify = (rc == 0 &&
 413                               obj->ioo_id != ECHO_PERSISTENT_OBJID &&
 414                               (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 415                               (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 416
 417                 int j;
 418
 419                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, r++) {
 420                         struct page *page = r->page;
 421                         void *addr;
 422
 423                         if (page == NULL) {
 424                                 CERROR("null page objid "LPU64":%p, buf %d/%d\n",
 425                                        obj->ioo_id, page, j, obj->ioo_bufcnt);
 426                                 GOTO(commitrw_cleanup, rc = -EFAULT);
 427                         }
 428
 429                         addr = kmap(page);
 430
 431                         CDEBUG(D_PAGE, "$$$$ use page %p, addr %p@"LPU64"\n",
 432                                r->page, addr, r->offset);
 433
 434                         if (verify) {
 435                                 vrc = echo_page_debug_check(page, obj->ioo_id,
 436                                                             r->offset, r->len);
 437                                 /* check all the pages always */
 438                                 if (vrc != 0 && rc == 0)
 439                                         rc = vrc;
 440                         }
 441
 442                         kunmap(page);
 443                         /* NB see comment above regarding persistent pages */
 444                         __free_pages(page, 0);
 445                         atomic_dec(&obd->u.echo.eo_prep);
 446                 }
 447         }
 448         CDEBUG(D_PAGE, "%d pages remain after commit\n",
 449                atomic_read(&obd->u.echo.eo_prep));
 450         RETURN(rc);
 451
 452 commitrw_cleanup:
 453         CERROR("cleaning up %ld pages (%d obdos)\n",
 454                niocount - (long)(r - res) - 1, objcount);
 455         while (++r < res + niocount) {
 456                 struct page *page = r->page;
 457
 458                 /* NB see comment above regarding persistent pages */
 459                 __free_pages(page, 0);
 460                 atomic_dec(&obd->u.echo.eo_prep);
 461         }
 462         return rc;
 463 }
 464
 465 static int echo_setup(struct obd_device *obd, obd_count len, void *buf)
 466 {
 467         int                        rc;
 468         int                        lock_flags = 0;
 469         struct ldlm_res_id         res_id = {.name = {1}};
 470
 471         ENTRY;
 472
 473         spin_lock_init(&obd->u.echo.eo_lock);
 474         obd->u.echo.eo_lastino = ECHO_INIT_OBJID;
 475
 476         obd->obd_namespace = ldlm_namespace_new("echo-tgt",
 477                                                 LDLM_NAMESPACE_SERVER);
 478         if (obd->obd_namespace == NULL) {
 479                 LBUG();
 480                 RETURN(-ENOMEM);
 481         }
 482         rc = ldlm_cli_enqueue(NULL, NULL, obd->obd_namespace, res_id,
 483                               LDLM_PLAIN, NULL, LCK_NL, &lock_flags,
 484                               NULL, ldlm_completion_ast, NULL, NULL,
 485                               NULL, 0, NULL, &obd->u.echo.eo_nl_lock);
 486         LASSERT (rc == ELDLM_OK);
 487
 488
 489
 490         ptlrpc_init_client (LDLM_CB_REQUEST_PORTAL, LDLM_CB_REPLY_PORTAL,
 491                             "echo_ldlm_cb_client", &obd->obd_ldlm_client);
 492         RETURN(0);
 493 }
 494
 495 static int echo_cleanup(struct obd_device *obd, int flags)
 496 {
 497         int leaked;
 498         ENTRY;
 499
 500         ldlm_lock_decref (&obd->u.echo.eo_nl_lock, LCK_NL);
 501
 502         /* XXX Bug 3413; wait for a bit to ensure the BL callback has
 503          * happened before calling ldlm_namespace_free() */
 504         set_current_state (TASK_UNINTERRUPTIBLE);
 505         schedule_timeout (HZ);
 506
 507         ldlm_namespace_free(obd->obd_namespace, flags & OBD_OPT_FORCE);
 508
 509         leaked = atomic_read(&obd->u.echo.eo_prep);
 510         if (leaked != 0)
 511                 CERROR("%d prep/commitrw pages leaked\n", leaked);
 512
 513         RETURN(0);
 514 }
 515
 516 int echo_attach(struct obd_device *obd, obd_count len, void *data)
 517 {
 518         struct lprocfs_static_vars lvars;
 519         int rc;
 520
 521         lprocfs_init_vars(echo, &lvars);
 522         rc = lprocfs_obd_attach(obd, lvars.obd_vars);
 523         if (rc != 0)
 524                 return rc;
 525         rc = lprocfs_alloc_obd_stats(obd, LPROC_ECHO_LAST);
 526         if (rc != 0)
 527                 return rc;
 528
 529         lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 530                              LPROCFS_CNTR_AVGMINMAX, "read_bytes", "bytes");
 531         lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 532                              LPROCFS_CNTR_AVGMINMAX, "write_bytes", "bytes");
 533         return rc;
 534 }
 535
 536 int echo_detach(struct obd_device *dev)
 537 {
 538         lprocfs_free_obd_stats(dev);
 539         return lprocfs_obd_detach(dev);
 540 }
 541
 542 static struct obd_ops echo_obd_ops = {
 543         .o_owner           = THIS_MODULE,
 544         .o_attach          = echo_attach,
 545         .o_detach          = echo_detach,
 546         .o_connect         = echo_connect,
 547         .o_disconnect      = echo_disconnect,
 548         .o_destroy_export  = echo_destroy_export,
 549         .o_create          = echo_create,
 550         .o_destroy         = echo_destroy,
 551         .o_getattr         = echo_getattr,
 552         .o_setattr         = echo_setattr,
 553         .o_preprw          = echo_preprw,
 554         .o_commitrw        = echo_commitrw,
 555         .o_setup           = echo_setup,
 556         .o_cleanup         = echo_cleanup
 557 };
 558
 559 extern int echo_client_init(void);
 560 extern void echo_client_exit(void);
 561
 562 static void
 563 echo_persistent_pages_fini (void)
 564 {
 565         int     i;
 566
 567         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++)
 568                 if (echo_persistent_pages[i] != NULL) {
 569                         __free_pages (echo_persistent_pages[i], 0);
 570                         echo_persistent_pages[i] = NULL;
 571                 }
 572 }
 573
 574 static int
 575 echo_persistent_pages_init (void)
 576 {
 577         struct page *pg;
 578         int          i;
 579
 580         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++) {
 581                 int gfp_mask = (i < ECHO_PERSISTENT_PAGES/2) ?
 582                         GFP_KERNEL : GFP_HIGHUSER;
 583
 584                 pg = alloc_pages (gfp_mask, 0);
 585                 if (pg == NULL) {
 586                         echo_persistent_pages_fini ();
 587                         return (-ENOMEM);
 588                 }
 589
 590                 memset (kmap (pg), 0, PAGE_SIZE);
 591                 kunmap (pg);
 592
 593                 echo_persistent_pages[i] = pg;
 594         }
 595
 596         return (0);
 597 }
 598
 599 static int __init obdecho_init(void)
 600 {
 601         struct lprocfs_static_vars lvars;
 602         int rc;
 603
 604         printk(KERN_INFO "Lustre: Echo OBD driver; info@clusterfs.com\n");
 605
 606         LASSERT(PAGE_SIZE % OBD_ECHO_BLOCK_SIZE == 0);
 607
 608         lprocfs_init_vars(echo, &lvars);
 609
 610         rc = echo_persistent_pages_init ();
 611         if (rc != 0)
 612                 goto failed_0;
 613
 614         rc = class_register_type(&echo_obd_ops, NULL, lvars.module_vars,
 615                                  OBD_ECHO_DEVICENAME);
 616         if (rc != 0)
 617                 goto failed_1;
 618
 619         rc = echo_client_init();
 620         if (rc == 0)
 621                 RETURN (0);
 622
 623         class_unregister_type(OBD_ECHO_DEVICENAME);
 624  failed_1:
 625         echo_persistent_pages_fini ();
 626  failed_0:
 627         RETURN(rc);
 628 }
 629
 630 static void /*__exit*/ obdecho_exit(void)
 631 {
 632         echo_client_exit();
 633         class_unregister_type(OBD_ECHO_DEVICENAME);
 634         echo_persistent_pages_fini ();
 635 }
 636
 637 MODULE_AUTHOR("Cluster File Systems, Inc. <info@clusterfs.com>");
 638 MODULE_DESCRIPTION("Lustre Testing Echo OBD driver");
 639 MODULE_LICENSE("GPL");
 640
 641 module_init(obdecho_init);
 642 module_exit(obdecho_exit);