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