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 = LPROC_ECHO_WRITE_BYTES +1
  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, int flags)
  68 {
  69         unsigned long irqflags;
  70
  71         LASSERT (exp != NULL);
  72         ldlm_cancel_locks_for_export(exp);
  73
  74         spin_lock_irqsave(&exp->exp_lock, irqflags);
  75         exp->exp_flags = flags;
  76         /* complete all outstanding replies */
  77         spin_lock_irqsave(&exp->exp_lock, irqflags);
  78         while (!list_empty(&exp->exp_outstanding_replies)) {
  79                 struct ptlrpc_reply_state *rs =
  80                         list_entry(exp->exp_outstanding_replies.next,
  81                                    struct ptlrpc_reply_state, rs_exp_list);
  82                 struct ptlrpc_service *svc = rs->rs_srv_ni->sni_service;
  83
  84                 spin_lock(&svc->srv_lock);
  85                 list_del_init(&rs->rs_exp_list);
  86                 ptlrpc_schedule_difficult_reply(rs);
  87                 spin_unlock(&svc->srv_lock);
  88         }
  89         spin_unlock_irqrestore(&exp->exp_lock, irqflags);
  90
  91         return class_disconnect(exp, flags);
  92 }
  93
  94 static int echo_destroy_export(struct obd_export *exp)
  95 {
  96         ENTRY;
  97
  98         target_destroy_export(exp);
  99
 100         RETURN(0);
 101 }
 102
 103  static __u64 echo_next_id(struct obd_device *obddev)
 104 {
 105         obd_id id;
 106
 107         spin_lock(&obddev->u.echo.eo_lock);
 108         id = ++obddev->u.echo.eo_lastino;
 109         spin_unlock(&obddev->u.echo.eo_lock);
 110
 111         return id;
 112 }
 113
 114 int echo_create(struct obd_export *exp, struct obdo *oa,
 115                 struct lov_stripe_md **ea, struct obd_trans_info *oti)
 116 {
 117         struct obd_device *obd = class_exp2obd(exp);
 118
 119         if (!obd) {
 120                 CERROR("invalid client cookie "LPX64"\n",
 121                        exp->exp_handle.h_cookie);
 122                 return -EINVAL;
 123         }
 124
 125         if (!(oa->o_mode && S_IFMT)) {
 126                 CERROR("echo obd: no type!\n");
 127                 return -ENOENT;
 128         }
 129
 130         if (!(oa->o_valid & OBD_MD_FLTYPE)) {
 131                 CERROR("invalid o_valid %08x\n", oa->o_valid);
 132                 return -EINVAL;
 133         }
 134
 135         oa->o_id = echo_next_id(obd);
 136         oa->o_valid = OBD_MD_FLID;
 137
 138         return 0;
 139 }
 140
 141 int echo_destroy(struct obd_export *exp, struct obdo *oa,
 142                  struct lov_stripe_md *ea, struct obd_trans_info *oti)
 143 {
 144         struct obd_device *obd = class_exp2obd(exp);
 145
 146         if (!obd) {
 147                 CERROR("invalid client cookie "LPX64"\n",
 148                        exp->exp_handle.h_cookie);
 149                 RETURN(-EINVAL);
 150         }
 151
 152         if (!(oa->o_valid & OBD_MD_FLID)) {
 153                 CERROR("obdo missing FLID valid flag: %08x\n", oa->o_valid);
 154                 RETURN(-EINVAL);
 155         }
 156
 157         if (oa->o_id > obd->u.echo.eo_lastino || oa->o_id < ECHO_INIT_OBJID) {
 158                 CERROR("bad destroy objid: "LPX64"\n", oa->o_id);
 159                 RETURN(-EINVAL);
 160         }
 161
 162
 163         return 0;
 164 }
 165
 166 static int echo_getattr(struct obd_export *exp, struct obdo *oa,
 167                         struct lov_stripe_md *md)
 168 {
 169         struct obd_device *obd = class_exp2obd(exp);
 170         obd_id id = oa->o_id;
 171
 172         if (!obd) {
 173                 CERROR("invalid client cookie "LPX64"\n",
 174                        exp->exp_handle.h_cookie);
 175                 RETURN(-EINVAL);
 176         }
 177
 178         if (!(oa->o_valid & OBD_MD_FLID)) {
 179                 CERROR("obdo missing FLID valid flag: %08x\n", oa->o_valid);
 180                 RETURN(-EINVAL);
 181         }
 182
 183         obdo_cpy_md(oa, &obd->u.echo.eo_oa, oa->o_valid);
 184         oa->o_id = id;
 185
 186         return 0;
 187 }
 188
 189 static int echo_setattr(struct obd_export *exp, struct obdo *oa,
 190                         struct lov_stripe_md *md, struct obd_trans_info *oti)
 191 {
 192         struct obd_device *obd = class_exp2obd(exp);
 193
 194         if (!obd) {
 195                 CERROR("invalid client cookie "LPX64"\n",
 196                        exp->exp_handle.h_cookie);
 197                 RETURN(-EINVAL);
 198         }
 199
 200         if (!(oa->o_valid & OBD_MD_FLID)) {
 201                 CERROR("obdo missing FLID valid flag: %08x\n", oa->o_valid);
 202                 RETURN(-EINVAL);
 203         }
 204
 205         memcpy(&obd->u.echo.eo_oa, oa, sizeof(*oa));
 206
 207         if (oa->o_id & 4) {
 208                 /* Save lock to force ACKed reply */
 209                 ldlm_lock_addref (&obd->u.echo.eo_nl_lock, LCK_NL);
 210                 oti->oti_ack_locks[0].mode = LCK_NL;
 211                 oti->oti_ack_locks[0].lock = obd->u.echo.eo_nl_lock;
 212         }
 213         return 0;
 214 }
 215
 216 static void
 217 echo_page_debug_setup(struct page *page, int rw, obd_id id,
 218                       __u64 offset, int len)
 219 {
 220         int   page_offset = offset & (PAGE_SIZE - 1);
 221         char *addr        = ((char *)kmap(page)) + page_offset;
 222
 223         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 224                 CERROR("Unexpected block size %d\n", len);
 225
 226         while (len > 0) {
 227                 if (rw & OBD_BRW_READ)
 228                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 229                                           offset, id);
 230                 else
 231                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 232                                           0xecc0ecc0ecc0ecc0ULL,
 233                                           0xecc0ecc0ecc0ecc0ULL);
 234
 235                 addr   += OBD_ECHO_BLOCK_SIZE;
 236                 offset += OBD_ECHO_BLOCK_SIZE;
 237                 len    -= OBD_ECHO_BLOCK_SIZE;
 238         }
 239
 240         kunmap(page);
 241 }
 242
 243 static int
 244 echo_page_debug_check(struct page *page, obd_id id,
 245                       __u64 offset, int len)
 246 {
 247         int   page_offset = offset & (PAGE_SIZE - 1);
 248         char *addr        = ((char *)kmap(page)) + page_offset;
 249         int   rc          = 0;
 250         int   rc2;
 251
 252         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 253                 CERROR("Unexpected block size %d\n", len);
 254
 255         while (len > 0) {
 256                 rc2 = block_debug_check("echo", addr, OBD_ECHO_BLOCK_SIZE,
 257                                         offset, id);
 258
 259                 if (rc2 != 0 && rc == 0)
 260                         rc = rc2;
 261
 262                 addr   += OBD_ECHO_BLOCK_SIZE;
 263                 offset += OBD_ECHO_BLOCK_SIZE;
 264                 len    -= OBD_ECHO_BLOCK_SIZE;
 265         }
 266
 267         kunmap(page);
 268
 269         return (rc);
 270 }
 271
 272 /* This allows us to verify that desc_private is passed unmolested */
 273 #define DESC_PRIV 0x10293847
 274
 275 int echo_preprw(int cmd, struct obd_export *export, struct obdo *oa,
 276                 int objcount, struct obd_ioobj *obj, int niocount,
 277                 struct niobuf_remote *nb, struct niobuf_local *res,
 278                 struct obd_trans_info *oti)
 279 {
 280         struct obd_device *obd;
 281         struct niobuf_local *r = res;
 282         int tot_bytes = 0;
 283         int rc = 0;
 284         int i;
 285         ENTRY;
 286
 287         obd = export->exp_obd;
 288         if (obd == NULL)
 289                 RETURN(-EINVAL);
 290
 291         /* Temp fix to stop falling foul of osc_announce_cached() */
 292         oa->o_valid &= ~(OBD_MD_FLBLOCKS | OBD_MD_FLGRANT);
 293
 294         memset(res, 0, sizeof(*res) * niocount);
 295
 296         CDEBUG(D_PAGE, "%s %d obdos with %d IOs\n",
 297                cmd == OBD_BRW_READ ? "reading" : "writing", objcount, niocount);
 298
 299         if (oti)
 300                 oti->oti_handle = (void *)DESC_PRIV;
 301
 302         for (i = 0; i < objcount; i++, obj++) {
 303                 int gfp_mask = (obj->ioo_id & 1) ? GFP_HIGHUSER : GFP_KERNEL;
 304                 int ispersistent = obj->ioo_id == ECHO_PERSISTENT_OBJID;
 305                 int debug_setup = (!ispersistent &&
 306                                    (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 307                                    (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 308                 int j;
 309
 310                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, nb++, r++) {
 311
 312                         if (ispersistent &&
 313                             (nb->offset >> PAGE_SHIFT) < ECHO_PERSISTENT_PAGES) {
 314                                 r->page = echo_persistent_pages[nb->offset >>
 315                                                                 PAGE_SHIFT];
 316                                 /* Take extra ref so __free_pages() can be called OK */
 317                                 get_page (r->page);
 318                         } else {
 319                                 r->page = alloc_pages(gfp_mask, 0);
 320                                 if (r->page == NULL) {
 321                                         CERROR("can't get page %u/%u for id "
 322                                                LPU64"\n",
 323                                                j, obj->ioo_bufcnt, obj->ioo_id);
 324                                         GOTO(preprw_cleanup, rc = -ENOMEM);
 325                                 }
 326                         }
 327
 328                         tot_bytes += nb->len;
 329
 330                         atomic_inc(&obd->u.echo.eo_prep);
 331
 332                         r->offset = nb->offset;
 333                         r->len = nb->len;
 334                         LASSERT((r->offset & ~PAGE_MASK) + r->len <= PAGE_SIZE);
 335
 336                         CDEBUG(D_PAGE, "$$$$ get page %p @ "LPU64" for %d\n",
 337                                r->page, r->offset, r->len);
 338
 339                         if (cmd & OBD_BRW_READ)
 340                                 r->rc = r->len;
 341
 342                         if (debug_setup)
 343                                 echo_page_debug_setup(r->page, cmd, obj->ioo_id,
 344                                                       r->offset, r->len);
 345                 }
 346         }
 347         if (cmd & OBD_BRW_READ)
 348                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 349                                     tot_bytes);
 350         else
 351                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 352                                     tot_bytes);
 353
 354         CDEBUG(D_PAGE, "%d pages allocated after prep\n",
 355                atomic_read(&obd->u.echo.eo_prep));
 356
 357         RETURN(0);
 358
 359 preprw_cleanup:
 360         /* It is possible that we would rather handle errors by  allow
 361          * any already-set-up pages to complete, rather than tearing them
 362          * all down again.  I believe that this is what the in-kernel
 363          * prep/commit operations do.
 364          */
 365         CERROR("cleaning up %ld pages (%d obdos)\n", (long)(r - res), objcount);
 366         while (r-- > res) {
 367                 kunmap(r->page);
 368                 /* NB if this is a persistent page, __free_pages will just
 369                  * lose the extra ref gained above */
 370                 __free_pages(r->page, 0);
 371                 atomic_dec(&obd->u.echo.eo_prep);
 372         }
 373         memset(res, 0, sizeof(*res) * niocount);
 374
 375         return rc;
 376 }
 377
 378 int echo_commitrw(int cmd, struct obd_export *export, struct obdo *oa,
 379                   int objcount, struct obd_ioobj *obj, int niocount,
 380                   struct niobuf_local *res, struct obd_trans_info *oti, int rc)
 381 {
 382         struct obd_device *obd;
 383         struct niobuf_local *r = res;
 384         int i, vrc = 0;
 385         ENTRY;
 386
 387         obd = export->exp_obd;
 388         if (obd == NULL)
 389                 RETURN(-EINVAL);
 390
 391         if (rc)
 392                 GOTO(commitrw_cleanup, rc);
 393
 394         if ((cmd & OBD_BRW_RWMASK) == OBD_BRW_READ) {
 395                 CDEBUG(D_PAGE, "reading %d obdos with %d IOs\n",
 396                        objcount, niocount);
 397         } else {
 398                 CDEBUG(D_PAGE, "writing %d obdos with %d IOs\n",
 399                        objcount, niocount);
 400         }
 401
 402         if (niocount && !r) {
 403                 CERROR("NULL res niobuf with niocount %d\n", niocount);
 404                 RETURN(-EINVAL);
 405         }
 406
 407         LASSERT(oti == NULL || oti->oti_handle == (void *)DESC_PRIV);
 408
 409         for (i = 0; i < objcount; i++, obj++) {
 410                 int verify = (rc == 0 &&
 411                               obj->ioo_id != ECHO_PERSISTENT_OBJID &&
 412                               (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 413                               (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 414
 415                 int j;
 416
 417                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, r++) {
 418                         struct page *page = r->page;
 419                         void *addr;
 420
 421                         if (page == NULL) {
 422                                 CERROR("null page objid "LPU64":%p, buf %d/%d\n",
 423                                        obj->ioo_id, page, j, obj->ioo_bufcnt);
 424                                 GOTO(commitrw_cleanup, rc = -EFAULT);
 425                         }
 426
 427                         addr = kmap(page);
 428
 429                         CDEBUG(D_PAGE, "$$$$ use page %p, addr %p@"LPU64"\n",
 430                                r->page, addr, r->offset);
 431
 432                         if (verify) {
 433                                 vrc = echo_page_debug_check(page, obj->ioo_id,
 434                                                             r->offset, r->len);
 435                                 /* check all the pages always */
 436                                 if (vrc != 0 && rc == 0)
 437                                         rc = vrc;
 438                         }
 439
 440                         kunmap(page);
 441                         /* NB see comment above regarding persistent pages */
 442                         __free_pages(page, 0);
 443                         atomic_dec(&obd->u.echo.eo_prep);
 444                 }
 445         }
 446         CDEBUG(D_PAGE, "%d pages remain after commit\n",
 447                atomic_read(&obd->u.echo.eo_prep));
 448         RETURN(rc);
 449
 450 commitrw_cleanup:
 451         CERROR("cleaning up %ld pages (%d obdos)\n",
 452                niocount - (long)(r - res) - 1, objcount);
 453         while (++r < res + niocount) {
 454                 struct page *page = r->page;
 455
 456                 /* NB see comment above regarding persistent pages */
 457                 __free_pages(page, 0);
 458                 atomic_dec(&obd->u.echo.eo_prep);
 459         }
 460         return rc;
 461 }
 462
 463 static int echo_setup(struct obd_device *obd, obd_count len, void *buf)
 464 {
 465         int                        rc;
 466         int                        lock_flags = 0;
 467         struct ldlm_res_id         res_id = {.name = {1}};
 468
 469         ENTRY;
 470
 471         spin_lock_init(&obd->u.echo.eo_lock);
 472         obd->u.echo.eo_lastino = ECHO_INIT_OBJID;
 473
 474         obd->obd_namespace = ldlm_namespace_new("echo-tgt",
 475                                                 LDLM_NAMESPACE_SERVER);
 476         if (obd->obd_namespace == NULL) {
 477                 LBUG();
 478                 RETURN(-ENOMEM);
 479         }
 480         rc = ldlm_cli_enqueue(NULL, NULL, obd->obd_namespace, res_id,
 481                               LDLM_PLAIN, NULL, LCK_NL, &lock_flags,
 482                               NULL, ldlm_completion_ast, NULL, NULL,
 483                               NULL, 0, NULL, &obd->u.echo.eo_nl_lock);
 484         LASSERT (rc == ELDLM_OK);
 485
 486
 487
 488         ptlrpc_init_client (LDLM_CB_REQUEST_PORTAL, LDLM_CB_REPLY_PORTAL,
 489                             "echo_ldlm_cb_client", &obd->obd_ldlm_client);
 490         RETURN(0);
 491 }
 492
 493 static int echo_cleanup(struct obd_device *obd, int flags)
 494 {
 495         int leaked;
 496         ENTRY;
 497
 498         ldlm_lock_decref (&obd->u.echo.eo_nl_lock, LCK_NL);
 499
 500         /* XXX Bug 3413; wait for a bit to ensure the BL callback has
 501          * happened before calling ldlm_namespace_free() */
 502         set_current_state (TASK_UNINTERRUPTIBLE);
 503         schedule_timeout (HZ);
 504
 505         ldlm_namespace_free(obd->obd_namespace, flags & OBD_OPT_FORCE);
 506
 507         leaked = atomic_read(&obd->u.echo.eo_prep);
 508         if (leaked != 0)
 509                 CERROR("%d prep/commitrw pages leaked\n", leaked);
 510
 511         RETURN(0);
 512 }
 513
 514 int echo_attach(struct obd_device *obd, obd_count len, void *data)
 515 {
 516         struct lprocfs_static_vars lvars;
 517         int rc;
 518
 519         lprocfs_init_vars(echo, &lvars);
 520         rc = lprocfs_obd_attach(obd, lvars.obd_vars);
 521         if (rc != 0)
 522                 return rc;
 523         rc = lprocfs_alloc_obd_stats(obd, LPROC_ECHO_LAST);
 524         if (rc != 0)
 525                 return rc;
 526
 527         lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 528                              LPROCFS_CNTR_AVGMINMAX, "read_bytes", "bytes");
 529         lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 530                              LPROCFS_CNTR_AVGMINMAX, "write_bytes", "bytes");
 531         return rc;
 532 }
 533
 534 int echo_detach(struct obd_device *dev)
 535 {
 536         lprocfs_free_obd_stats(dev);
 537         return lprocfs_obd_detach(dev);
 538 }
 539
 540 static struct obd_ops echo_obd_ops = {
 541         .o_owner           = THIS_MODULE,
 542         .o_attach          = echo_attach,
 543         .o_detach          = echo_detach,
 544         .o_connect         = echo_connect,
 545         .o_disconnect      = echo_disconnect,
 546         .o_destroy_export  = echo_destroy_export,
 547         .o_create          = echo_create,
 548         .o_destroy         = echo_destroy,
 549         .o_getattr         = echo_getattr,
 550         .o_setattr         = echo_setattr,
 551         .o_preprw          = echo_preprw,
 552         .o_commitrw        = echo_commitrw,
 553         .o_setup           = echo_setup,
 554         .o_cleanup         = echo_cleanup
 555 };
 556
 557 extern int echo_client_init(void);
 558 extern void echo_client_exit(void);
 559
 560 static void
 561 echo_persistent_pages_fini (void)
 562 {
 563         int     i;
 564
 565         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++)
 566                 if (echo_persistent_pages[i] != NULL) {
 567                         __free_pages (echo_persistent_pages[i], 0);
 568                         echo_persistent_pages[i] = NULL;
 569                 }
 570 }
 571
 572 static int
 573 echo_persistent_pages_init (void)
 574 {
 575         struct page *pg;
 576         int          i;
 577
 578         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++) {
 579                 int gfp_mask = (i < ECHO_PERSISTENT_PAGES/2) ?
 580                         GFP_KERNEL : GFP_HIGHUSER;
 581
 582                 pg = alloc_pages (gfp_mask, 0);
 583                 if (pg == NULL) {
 584                         echo_persistent_pages_fini ();
 585                         return (-ENOMEM);
 586                 }
 587
 588                 memset (kmap (pg), 0, PAGE_SIZE);
 589                 kunmap (pg);
 590
 591                 echo_persistent_pages[i] = pg;
 592         }
 593
 594         return (0);
 595 }
 596
 597 static int __init obdecho_init(void)
 598 {
 599         struct lprocfs_static_vars lvars;
 600         int rc;
 601
 602         printk(KERN_INFO "Lustre: Echo OBD driver; info@clusterfs.com\n");
 603
 604         LASSERT(PAGE_SIZE % OBD_ECHO_BLOCK_SIZE == 0);
 605
 606         lprocfs_init_vars(echo, &lvars);
 607
 608         rc = echo_persistent_pages_init ();
 609         if (rc != 0)
 610                 goto failed_0;
 611
 612         rc = class_register_type(&echo_obd_ops, NULL, lvars.module_vars,
 613                                  OBD_ECHO_DEVICENAME);
 614         if (rc != 0)
 615                 goto failed_1;
 616
 617         rc = echo_client_init();
 618         if (rc == 0)
 619                 RETURN (0);
 620
 621         class_unregister_type(OBD_ECHO_DEVICENAME);
 622  failed_1:
 623         echo_persistent_pages_fini ();
 624  failed_0:
 625         RETURN(rc);
 626 }
 627
 628 static void /*__exit*/ obdecho_exit(void)
 629 {
 630         echo_client_exit();
 631         class_unregister_type(OBD_ECHO_DEVICENAME);
 632         echo_persistent_pages_fini ();
 633 }
 634
 635 MODULE_AUTHOR("Cluster File Systems, Inc. <info@clusterfs.com>");
 636 MODULE_DESCRIPTION("Lustre Testing Echo OBD driver");
 637 MODULE_LICENSE("GPL");
 638
 639 module_init(obdecho_init);
 640 module_exit(obdecho_exit);