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