lustre/obdecho/echo.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright  2008 Sun Microsystems, Inc. All rights reserved
  30  * Use is subject to license terms.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/obdecho/echo.c
  37  *
  38  * Author: Peter Braam <braam@clusterfs.com>
  39  * Author: Andreas Dilger <adilger@clusterfs.com>
  40  */
  41
  42 #ifndef EXPORT_SYMTAB
  43 # define EXPORT_SYMTAB
  44 #endif
  45
  46 #define DEBUG_SUBSYSTEM S_ECHO
  47
  48 #include <obd_support.h>
  49 #include <obd_class.h>
  50 #include <obd_echo.h>
  51 #include <lustre_debug.h>
  52 #include <lustre_dlm.h>
  53 #include <lprocfs_status.h>
  54
  55 #define ECHO_INIT_OBJID      0x1000000000000000ULL
  56 #define ECHO_HANDLE_MAGIC    0xabcd0123fedc9876ULL
  57
  58 #define ECHO_PERSISTENT_PAGES (ECHO_PERSISTENT_SIZE >> CFS_PAGE_SHIFT)
  59 static cfs_page_t *echo_persistent_pages[ECHO_PERSISTENT_PAGES];
  60
  61 enum {
  62         LPROC_ECHO_READ_BYTES = 1,
  63         LPROC_ECHO_WRITE_BYTES = 2,
  64         LPROC_ECHO_LAST = LPROC_ECHO_WRITE_BYTES +1
  65 };
  66
  67 static int echo_connect(const struct lu_env *env,
  68                         struct lustre_handle *conn, struct obd_device *obd,
  69                         struct obd_uuid *cluuid, struct obd_connect_data *data,
  70                         void *localdata)
  71 {
  72         data->ocd_connect_flags &= ECHO_CONNECT_SUPPORTED;
  73         return class_connect(conn, obd, cluuid);
  74 }
  75
  76 static int echo_disconnect(struct obd_export *exp)
  77 {
  78         LASSERT (exp != NULL);
  79
  80         ldlm_cancel_locks_for_export(exp);
  81
  82         /* complete all outstanding replies */
  83         spin_lock(&exp->exp_lock);
  84         while (!list_empty(&exp->exp_outstanding_replies)) {
  85                 struct ptlrpc_reply_state *rs =
  86                         list_entry(exp->exp_outstanding_replies.next,
  87                                    struct ptlrpc_reply_state, rs_exp_list);
  88                 struct ptlrpc_service *svc = rs->rs_service;
  89
  90                 spin_lock(&svc->srv_lock);
  91                 list_del_init(&rs->rs_exp_list);
  92                 ptlrpc_schedule_difficult_reply(rs);
  93                 spin_unlock(&svc->srv_lock);
  94         }
  95         spin_unlock(&exp->exp_lock);
  96
  97         return class_disconnect(exp);
  98 }
  99
 100 static int echo_init_export(struct obd_export *exp)
 101 {
 102         return ldlm_init_export(exp);
 103 }
 104
 105 static int echo_destroy_export(struct obd_export *exp)
 106 {
 107         ENTRY;
 108
 109         target_destroy_export(exp);
 110         ldlm_destroy_export(exp);
 111
 112         RETURN(0);
 113 }
 114
 115  static __u64 echo_next_id(struct obd_device *obddev)
 116 {
 117         obd_id id;
 118
 119         spin_lock(&obddev->u.echo.eo_lock);
 120         id = ++obddev->u.echo.eo_lastino;
 121         spin_unlock(&obddev->u.echo.eo_lock);
 122
 123         return id;
 124 }
 125
 126 int echo_create(struct obd_export *exp, struct obdo *oa,
 127                 struct lov_stripe_md **ea, struct obd_trans_info *oti)
 128 {
 129         struct obd_device *obd = class_exp2obd(exp);
 130
 131         if (!obd) {
 132                 CERROR("invalid client cookie "LPX64"\n",
 133                        exp->exp_handle.h_cookie);
 134                 return -EINVAL;
 135         }
 136
 137         if (!(oa->o_mode && S_IFMT)) {
 138                 CERROR("echo obd: no type!\n");
 139                 return -ENOENT;
 140         }
 141
 142         if (!(oa->o_valid & OBD_MD_FLTYPE)) {
 143                 CERROR("invalid o_valid "LPX64"\n", oa->o_valid);
 144                 return -EINVAL;
 145         }
 146
 147         oa->o_id = echo_next_id(obd);
 148         oa->o_valid = OBD_MD_FLID;
 149
 150         return 0;
 151 }
 152
 153 int echo_destroy(struct obd_export *exp, struct obdo *oa,
 154                  struct lov_stripe_md *ea, struct obd_trans_info *oti,
 155                  struct obd_export *md_exp)
 156 {
 157         struct obd_device *obd = class_exp2obd(exp);
 158
 159         ENTRY;
 160         if (!obd) {
 161                 CERROR("invalid client cookie "LPX64"\n",
 162                        exp->exp_handle.h_cookie);
 163                 RETURN(-EINVAL);
 164         }
 165
 166         if (!(oa->o_valid & OBD_MD_FLID)) {
 167                 CERROR("obdo missing FLID valid flag: "LPX64"\n", oa->o_valid);
 168                 RETURN(-EINVAL);
 169         }
 170
 171         if (oa->o_id > obd->u.echo.eo_lastino || oa->o_id < ECHO_INIT_OBJID) {
 172                 CERROR("bad destroy objid: "LPX64"\n", oa->o_id);
 173                 RETURN(-EINVAL);
 174         }
 175
 176         RETURN(0);
 177 }
 178
 179 static int echo_getattr(struct obd_export *exp, struct obd_info *oinfo)
 180 {
 181         struct obd_device *obd = class_exp2obd(exp);
 182         obd_id id = oinfo->oi_oa->o_id;
 183
 184         ENTRY;
 185         if (!obd) {
 186                 CERROR("invalid client cookie "LPX64"\n",
 187                        exp->exp_handle.h_cookie);
 188                 RETURN(-EINVAL);
 189         }
 190
 191         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 192                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 193                        oinfo->oi_oa->o_valid);
 194                 RETURN(-EINVAL);
 195         }
 196
 197         obdo_cpy_md(oinfo->oi_oa, &obd->u.echo.eo_oa, oinfo->oi_oa->o_valid);
 198         oinfo->oi_oa->o_id = id;
 199
 200         RETURN(0);
 201 }
 202
 203 static int echo_setattr(struct obd_export *exp, struct obd_info *oinfo,
 204                         struct obd_trans_info *oti)
 205 {
 206         struct obd_device *obd = class_exp2obd(exp);
 207
 208         ENTRY;
 209         if (!obd) {
 210                 CERROR("invalid client cookie "LPX64"\n",
 211                        exp->exp_handle.h_cookie);
 212                 RETURN(-EINVAL);
 213         }
 214
 215         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 216                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 217                        oinfo->oi_oa->o_valid);
 218                 RETURN(-EINVAL);
 219         }
 220
 221         memcpy(&obd->u.echo.eo_oa, oinfo->oi_oa, sizeof(*oinfo->oi_oa));
 222
 223         if (oinfo->oi_oa->o_id & 4) {
 224                 /* Save lock to force ACKed reply */
 225                 ldlm_lock_addref (&obd->u.echo.eo_nl_lock, LCK_NL);
 226                 oti->oti_ack_locks[0].mode = LCK_NL;
 227                 oti->oti_ack_locks[0].lock = obd->u.echo.eo_nl_lock;
 228         }
 229
 230         RETURN(0);
 231 }
 232
 233 static void
 234 echo_page_debug_setup(cfs_page_t *page, int rw, obd_id id,
 235                       __u64 offset, int len)
 236 {
 237         int   page_offset = offset & ~CFS_PAGE_MASK;
 238         char *addr        = ((char *)cfs_kmap(page)) + page_offset;
 239
 240         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 241                 CERROR("Unexpected block size %d\n", len);
 242
 243         while (len > 0) {
 244                 if (rw & OBD_BRW_READ)
 245                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 246                                           offset, id);
 247                 else
 248                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 249                                           0xecc0ecc0ecc0ecc0ULL,
 250                                           0xecc0ecc0ecc0ecc0ULL);
 251
 252                 addr   += OBD_ECHO_BLOCK_SIZE;
 253                 offset += OBD_ECHO_BLOCK_SIZE;
 254                 len    -= OBD_ECHO_BLOCK_SIZE;
 255         }
 256
 257         cfs_kunmap(page);
 258 }
 259
 260 static int
 261 echo_page_debug_check(cfs_page_t *page, obd_id id,
 262                       __u64 offset, int len)
 263 {
 264         int   page_offset = offset & ~CFS_PAGE_MASK;
 265         char *addr        = ((char *)cfs_kmap(page)) + page_offset;
 266         int   rc          = 0;
 267         int   rc2;
 268
 269         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 270                 CERROR("Unexpected block size %d\n", len);
 271
 272         while (len > 0) {
 273                 rc2 = block_debug_check("echo", addr, OBD_ECHO_BLOCK_SIZE,
 274                                         offset, id);
 275
 276                 if (rc2 != 0 && rc == 0)
 277                         rc = rc2;
 278
 279                 addr   += OBD_ECHO_BLOCK_SIZE;
 280                 offset += OBD_ECHO_BLOCK_SIZE;
 281                 len    -= OBD_ECHO_BLOCK_SIZE;
 282         }
 283
 284         cfs_kunmap(page);
 285
 286         return (rc);
 287 }
 288
 289 /* This allows us to verify that desc_private is passed unmolested */
 290 #define DESC_PRIV 0x10293847
 291
 292 static int echo_map_nb_to_lb(struct obdo *oa, struct obd_ioobj *obj,
 293                              struct niobuf_remote *nb, int *pages,
 294                              struct niobuf_local *lb, int cmd, int *left)
 295 {
 296         int gfp_mask = (obj->ioo_id & 1) ? CFS_ALLOC_HIGHUSER : CFS_ALLOC_STD;
 297         int ispersistent = obj->ioo_id == ECHO_PERSISTENT_OBJID;
 298         int debug_setup = (!ispersistent &&
 299                            (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 300                            (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 301         struct niobuf_local *res = lb;
 302         obd_off offset = nb->offset;
 303         int len = nb->len;
 304
 305         while (len > 0) {
 306                 int plen = CFS_PAGE_SIZE - (offset & (CFS_PAGE_SIZE-1));
 307                 if (len < plen)
 308                         plen = len;
 309
 310                 /* check for local buf overflow */
 311                 if (*left == 0)
 312                         return -EINVAL;
 313
 314                 res->offset = offset;
 315                 res->len = plen;
 316                 LASSERT((res->offset & ~CFS_PAGE_MASK) + res->len <= CFS_PAGE_SIZE);
 317
 318
 319                 if (ispersistent &&
 320                     (res->offset >> CFS_PAGE_SHIFT) < ECHO_PERSISTENT_PAGES) {
 321                         res->page = echo_persistent_pages[res->offset >>
 322                                 CFS_PAGE_SHIFT];
 323                         /* Take extra ref so __free_pages() can be called OK */
 324                         cfs_get_page (res->page);
 325                 } else {
 326                         OBD_PAGE_ALLOC(res->page, gfp_mask);
 327                         if (res->page == NULL) {
 328                                 CERROR("can't get page for id " LPU64"\n",
 329                                        obj->ioo_id);
 330                                 return -ENOMEM;
 331                         }
 332                 }
 333
 334                 CDEBUG(D_PAGE, "$$$$ get page %p @ "LPU64" for %d\n",
 335                        res->page, res->offset, res->len);
 336
 337                 if (cmd & OBD_BRW_READ)
 338                         res->rc = res->len;
 339
 340                 if (debug_setup)
 341                         echo_page_debug_setup(res->page, cmd, obj->ioo_id,
 342                                               res->offset, res->len);
 343
 344                 offset += plen;
 345                 len -= plen;
 346                 res++;
 347
 348                 (*left)--;
 349                 (*pages)++;
 350         }
 351
 352         return 0;
 353 }
 354
 355 int echo_preprw(int cmd, struct obd_export *export, struct obdo *oa,
 356                 int objcount, struct obd_ioobj *obj, struct niobuf_remote *nb,
 357                 int *pages, struct niobuf_local *res,
 358                 struct obd_trans_info *oti, struct lustre_capa *unused)
 359 {
 360         struct obd_device *obd;
 361         struct niobuf_local *r = res;
 362         int tot_bytes = 0;
 363         int rc = 0;
 364         int i, left;
 365         ENTRY;
 366
 367         obd = export->exp_obd;
 368         if (obd == NULL)
 369                 RETURN(-EINVAL);
 370
 371         /* Temp fix to stop falling foul of osc_announce_cached() */
 372         oa->o_valid &= ~(OBD_MD_FLBLOCKS | OBD_MD_FLGRANT);
 373
 374         memset(res, 0, sizeof(*res) * *pages);
 375
 376         CDEBUG(D_PAGE, "%s %d obdos with %d IOs\n",
 377                cmd == OBD_BRW_READ ? "reading" : "writing", objcount, *pages);
 378
 379         if (oti)
 380                 oti->oti_handle = (void *)DESC_PRIV;
 381
 382         left = *pages;
 383         *pages = 0;
 384
 385         for (i = 0; i < objcount; i++, obj++) {
 386                 int j;
 387
 388                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, nb++, r++) {
 389
 390                         rc = echo_map_nb_to_lb(oa, obj, nb, pages,
 391                                                res + *pages, cmd, &left);
 392                         if (rc)
 393                                 GOTO(preprw_cleanup, rc);
 394
 395                         tot_bytes += nb->len;
 396                 }
 397         }
 398
 399         atomic_add(*pages, &obd->u.echo.eo_prep);
 400
 401         if (cmd & OBD_BRW_READ)
 402                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 403                                     tot_bytes);
 404         else
 405                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 406                                     tot_bytes);
 407
 408         CDEBUG(D_PAGE, "%d pages allocated after prep\n",
 409                atomic_read(&obd->u.echo.eo_prep));
 410
 411         RETURN(0);
 412
 413 preprw_cleanup:
 414         /* It is possible that we would rather handle errors by  allow
 415          * any already-set-up pages to complete, rather than tearing them
 416          * all down again.  I believe that this is what the in-kernel
 417          * prep/commit operations do.
 418          */
 419         CERROR("cleaning up %u pages (%d obdos)\n", *pages, objcount);
 420         for (i = 0; i < *pages; i++) {
 421                 cfs_kunmap(res[i].page);
 422                 /* NB if this is a persistent page, __free_pages will just
 423                  * lose the extra ref gained above */
 424                 OBD_PAGE_FREE(res[i].page);
 425                 res[i].page = NULL;
 426                 atomic_dec(&obd->u.echo.eo_prep);
 427         }
 428
 429         return rc;
 430 }
 431
 432 int echo_commitrw(int cmd, struct obd_export *export, struct obdo *oa,
 433                   int objcount, struct obd_ioobj *obj,
 434                   struct niobuf_remote *rb, int niocount,
 435                   struct niobuf_local *res, struct obd_trans_info *oti, int rc)
 436 {
 437         struct obd_device *obd;
 438         struct niobuf_local *r = res;
 439         int i, vrc = 0;
 440         ENTRY;
 441
 442         obd = export->exp_obd;
 443         if (obd == NULL)
 444                 RETURN(-EINVAL);
 445
 446         if (rc)
 447                 GOTO(commitrw_cleanup, rc);
 448
 449         if ((cmd & OBD_BRW_RWMASK) == OBD_BRW_READ) {
 450                 CDEBUG(D_PAGE, "reading %d obdos with %d IOs\n",
 451                        objcount, niocount);
 452         } else {
 453                 CDEBUG(D_PAGE, "writing %d obdos with %d IOs\n",
 454                        objcount, niocount);
 455         }
 456
 457         if (niocount && !r) {
 458                 CERROR("NULL res niobuf with niocount %d\n", niocount);
 459                 RETURN(-EINVAL);
 460         }
 461
 462         LASSERT(oti == NULL || oti->oti_handle == (void *)DESC_PRIV);
 463
 464         for (i = 0; i < objcount; i++, obj++) {
 465                 int verify = (rc == 0 &&
 466                               obj->ioo_id != ECHO_PERSISTENT_OBJID &&
 467                               (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 468                               (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 469                 int j;
 470
 471                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, r++) {
 472                         cfs_page_t *page = r->page;
 473                         void *addr;
 474
 475                         if (page == NULL) {
 476                                 CERROR("null page objid "LPU64":%p, buf %d/%d\n",
 477                                        obj->ioo_id, page, j, obj->ioo_bufcnt);
 478                                 GOTO(commitrw_cleanup, rc = -EFAULT);
 479                         }
 480
 481                         addr = cfs_kmap(page);
 482
 483                         CDEBUG(D_PAGE, "$$$$ use page %p, addr %p@"LPU64"\n",
 484                                r->page, addr, r->offset);
 485
 486                         if (verify) {
 487                                 vrc = echo_page_debug_check(page, obj->ioo_id,
 488                                                             r->offset, r->len);
 489                                 /* check all the pages always */
 490                                 if (vrc != 0 && rc == 0)
 491                                         rc = vrc;
 492                         }
 493
 494                         cfs_kunmap(page);
 495                         /* NB see comment above regarding persistent pages */
 496                         OBD_PAGE_FREE(page);
 497                         atomic_dec(&obd->u.echo.eo_prep);
 498                 }
 499         }
 500         CDEBUG(D_PAGE, "%d pages remain after commit\n",
 501                atomic_read(&obd->u.echo.eo_prep));
 502         RETURN(rc);
 503
 504 commitrw_cleanup:
 505         CERROR("cleaning up %ld pages (%d obdos)\n",
 506                niocount - (long)(r - res) - 1, objcount);
 507         while (++r < res + niocount) {
 508                 cfs_page_t *page = r->page;
 509
 510                 /* NB see comment above regarding persistent pages */
 511                 OBD_PAGE_FREE(page);
 512                 atomic_dec(&obd->u.echo.eo_prep);
 513         }
 514         return rc;
 515 }
 516
 517 static int echo_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
 518 {
 519         struct lprocfs_static_vars lvars;
 520         int                        rc;
 521         int                        lock_flags = 0;
 522         struct ldlm_res_id         res_id = {.name = {1}};
 523         ENTRY;
 524
 525         spin_lock_init(&obd->u.echo.eo_lock);
 526         obd->u.echo.eo_lastino = ECHO_INIT_OBJID;
 527
 528         obd->obd_namespace = ldlm_namespace_new(obd, "echo-tgt",
 529                                                 LDLM_NAMESPACE_SERVER,
 530                                                 LDLM_NAMESPACE_MODEST);
 531         if (obd->obd_namespace == NULL) {
 532                 LBUG();
 533                 RETURN(-ENOMEM);
 534         }
 535
 536         rc = ldlm_cli_enqueue_local(obd->obd_namespace, &res_id, LDLM_PLAIN,
 537                                     NULL, LCK_NL, &lock_flags, NULL,
 538                                     ldlm_completion_ast, NULL, NULL,
 539                                     0, NULL, NULL, &obd->u.echo.eo_nl_lock);
 540         LASSERT (rc == ELDLM_OK);
 541
 542         lprocfs_echo_init_vars(&lvars);
 543         if (lprocfs_obd_setup(obd, lvars.obd_vars) == 0 &&
 544             lprocfs_alloc_obd_stats(obd, LPROC_ECHO_LAST) == 0) {
 545                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 546                                      LPROCFS_CNTR_AVGMINMAX,
 547                                      "read_bytes", "bytes");
 548                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 549                                      LPROCFS_CNTR_AVGMINMAX,
 550                                      "write_bytes", "bytes");
 551         }
 552
 553         ptlrpc_init_client (LDLM_CB_REQUEST_PORTAL, LDLM_CB_REPLY_PORTAL,
 554                             "echo_ldlm_cb_client", &obd->obd_ldlm_client);
 555         RETURN(0);
 556 }
 557
 558 static int echo_cleanup(struct obd_device *obd)
 559 {
 560         int leaked;
 561         ENTRY;
 562
 563         lprocfs_obd_cleanup(obd);
 564         lprocfs_free_obd_stats(obd);
 565
 566         ldlm_lock_decref (&obd->u.echo.eo_nl_lock, LCK_NL);
 567
 568         /* XXX Bug 3413; wait for a bit to ensure the BL callback has
 569          * happened before calling ldlm_namespace_free() */
 570         cfs_schedule_timeout (CFS_TASK_UNINT, cfs_time_seconds(1));
 571
 572         ldlm_namespace_free(obd->obd_namespace, NULL, obd->obd_force);
 573         obd->obd_namespace = NULL;
 574
 575         leaked = atomic_read(&obd->u.echo.eo_prep);
 576         if (leaked != 0)
 577                 CERROR("%d prep/commitrw pages leaked\n", leaked);
 578
 579         RETURN(0);
 580 }
 581
 582 static struct obd_ops echo_obd_ops = {
 583         .o_owner           = THIS_MODULE,
 584         .o_connect         = echo_connect,
 585         .o_disconnect      = echo_disconnect,
 586         .o_init_export     = echo_init_export,
 587         .o_destroy_export  = echo_destroy_export,
 588         .o_create          = echo_create,
 589         .o_destroy         = echo_destroy,
 590         .o_getattr         = echo_getattr,
 591         .o_setattr         = echo_setattr,
 592         .o_preprw          = echo_preprw,
 593         .o_commitrw        = echo_commitrw,
 594         .o_setup           = echo_setup,
 595         .o_cleanup         = echo_cleanup
 596 };
 597
 598 extern int echo_client_init(void);
 599 extern void echo_client_exit(void);
 600
 601 static void
 602 echo_persistent_pages_fini (void)
 603 {
 604         int     i;
 605
 606         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++)
 607                 if (echo_persistent_pages[i] != NULL) {
 608                         OBD_PAGE_FREE(echo_persistent_pages[i]);
 609                         echo_persistent_pages[i] = NULL;
 610                 }
 611 }
 612
 613 static int
 614 echo_persistent_pages_init (void)
 615 {
 616         cfs_page_t *pg;
 617         int          i;
 618
 619         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++) {
 620                 int gfp_mask = (i < ECHO_PERSISTENT_PAGES/2) ?
 621                         CFS_ALLOC_STD : CFS_ALLOC_HIGHUSER;
 622
 623                 OBD_PAGE_ALLOC(pg, gfp_mask);
 624                 if (pg == NULL) {
 625                         echo_persistent_pages_fini ();
 626                         return (-ENOMEM);
 627                 }
 628
 629                 memset (cfs_kmap (pg), 0, CFS_PAGE_SIZE);
 630                 cfs_kunmap (pg);
 631
 632                 echo_persistent_pages[i] = pg;
 633         }
 634
 635         return (0);
 636 }
 637
 638 static int __init obdecho_init(void)
 639 {
 640         struct lprocfs_static_vars lvars;
 641         int rc;
 642
 643         ENTRY;
 644         LCONSOLE_INFO("Echo OBD driver; http://www.lustre.org/\n");
 645
 646         LASSERT(CFS_PAGE_SIZE % OBD_ECHO_BLOCK_SIZE == 0);
 647
 648         lprocfs_echo_init_vars(&lvars);
 649
 650         rc = echo_persistent_pages_init ();
 651         if (rc != 0)
 652                 goto failed_0;
 653
 654         rc = class_register_type(&echo_obd_ops, NULL, lvars.module_vars,
 655                                  LUSTRE_ECHO_NAME, NULL);
 656         if (rc != 0)
 657                 goto failed_1;
 658
 659         rc = echo_client_init();
 660         if (rc == 0)
 661                 RETURN (0);
 662
 663         class_unregister_type(LUSTRE_ECHO_NAME);
 664  failed_1:
 665         echo_persistent_pages_fini ();
 666  failed_0:
 667         RETURN(rc);
 668 }
 669
 670 static void /*__exit*/ obdecho_exit(void)
 671 {
 672         echo_client_exit();
 673         class_unregister_type(LUSTRE_ECHO_NAME);
 674         echo_persistent_pages_fini ();
 675 }
 676
 677 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 678 MODULE_DESCRIPTION("Lustre Testing Echo OBD driver");
 679 MODULE_LICENSE("GPL");
 680
 681 cfs_module(obdecho, "1.0.0", obdecho_init, obdecho_exit);