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