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                 spin_lock(&rs->rs_lock);
  94                 ptlrpc_schedule_difficult_reply(rs);
  95                 spin_unlock(&rs->rs_lock);
  96                 spin_unlock(&svc->srv_lock);
  97         }
  98         spin_unlock(&exp->exp_lock);
  99
 100         return class_disconnect(exp);
 101 }
 102
 103 static int echo_init_export(struct obd_export *exp)
 104 {
 105         return ldlm_init_export(exp);
 106 }
 107
 108 static int echo_destroy_export(struct obd_export *exp)
 109 {
 110         ENTRY;
 111
 112         target_destroy_export(exp);
 113         ldlm_destroy_export(exp);
 114
 115         RETURN(0);
 116 }
 117
 118  static __u64 echo_next_id(struct obd_device *obddev)
 119 {
 120         obd_id id;
 121
 122         spin_lock(&obddev->u.echo.eo_lock);
 123         id = ++obddev->u.echo.eo_lastino;
 124         spin_unlock(&obddev->u.echo.eo_lock);
 125
 126         return id;
 127 }
 128
 129 int echo_create(struct obd_export *exp, struct obdo *oa,
 130                 struct lov_stripe_md **ea, struct obd_trans_info *oti)
 131 {
 132         struct obd_device *obd = class_exp2obd(exp);
 133
 134         if (!obd) {
 135                 CERROR("invalid client cookie "LPX64"\n",
 136                        exp->exp_handle.h_cookie);
 137                 return -EINVAL;
 138         }
 139
 140         if (!(oa->o_mode && S_IFMT)) {
 141                 CERROR("echo obd: no type!\n");
 142                 return -ENOENT;
 143         }
 144
 145         if (!(oa->o_valid & OBD_MD_FLTYPE)) {
 146                 CERROR("invalid o_valid "LPX64"\n", oa->o_valid);
 147                 return -EINVAL;
 148         }
 149
 150         oa->o_id = echo_next_id(obd);
 151         oa->o_valid = OBD_MD_FLID;
 152
 153         return 0;
 154 }
 155
 156 int echo_destroy(struct obd_export *exp, struct obdo *oa,
 157                  struct lov_stripe_md *ea, struct obd_trans_info *oti,
 158                  struct obd_export *md_exp, void *capa)
 159 {
 160         struct obd_device *obd = class_exp2obd(exp);
 161
 162         ENTRY;
 163         if (!obd) {
 164                 CERROR("invalid client cookie "LPX64"\n",
 165                        exp->exp_handle.h_cookie);
 166                 RETURN(-EINVAL);
 167         }
 168
 169         if (!(oa->o_valid & OBD_MD_FLID)) {
 170                 CERROR("obdo missing FLID valid flag: "LPX64"\n", oa->o_valid);
 171                 RETURN(-EINVAL);
 172         }
 173
 174         if (oa->o_id > obd->u.echo.eo_lastino || oa->o_id < ECHO_INIT_OBJID) {
 175                 CERROR("bad destroy objid: "LPX64"\n", oa->o_id);
 176                 RETURN(-EINVAL);
 177         }
 178
 179         RETURN(0);
 180 }
 181
 182 static int echo_getattr(struct obd_export *exp, struct obd_info *oinfo)
 183 {
 184         struct obd_device *obd = class_exp2obd(exp);
 185         obd_id id = oinfo->oi_oa->o_id;
 186
 187         ENTRY;
 188         if (!obd) {
 189                 CERROR("invalid client cookie "LPX64"\n",
 190                        exp->exp_handle.h_cookie);
 191                 RETURN(-EINVAL);
 192         }
 193
 194         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 195                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 196                        oinfo->oi_oa->o_valid);
 197                 RETURN(-EINVAL);
 198         }
 199
 200         obdo_cpy_md(oinfo->oi_oa, &obd->u.echo.eo_oa, oinfo->oi_oa->o_valid);
 201         oinfo->oi_oa->o_id = id;
 202
 203         RETURN(0);
 204 }
 205
 206 static int echo_setattr(struct obd_export *exp, struct obd_info *oinfo,
 207                         struct obd_trans_info *oti)
 208 {
 209         struct obd_device *obd = class_exp2obd(exp);
 210
 211         ENTRY;
 212         if (!obd) {
 213                 CERROR("invalid client cookie "LPX64"\n",
 214                        exp->exp_handle.h_cookie);
 215                 RETURN(-EINVAL);
 216         }
 217
 218         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 219                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 220                        oinfo->oi_oa->o_valid);
 221                 RETURN(-EINVAL);
 222         }
 223
 224         memcpy(&obd->u.echo.eo_oa, oinfo->oi_oa, sizeof(*oinfo->oi_oa));
 225
 226         if (oinfo->oi_oa->o_id & 4) {
 227                 /* Save lock to force ACKed reply */
 228                 ldlm_lock_addref (&obd->u.echo.eo_nl_lock, LCK_NL);
 229                 oti->oti_ack_locks[0].mode = LCK_NL;
 230                 oti->oti_ack_locks[0].lock = obd->u.echo.eo_nl_lock;
 231         }
 232
 233         RETURN(0);
 234 }
 235
 236 static void
 237 echo_page_debug_setup(cfs_page_t *page, int rw, obd_id id,
 238                       __u64 offset, int len)
 239 {
 240         int   page_offset = offset & ~CFS_PAGE_MASK;
 241         char *addr        = ((char *)cfs_kmap(page)) + page_offset;
 242
 243         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 244                 CERROR("Unexpected block size %d\n", len);
 245
 246         while (len > 0) {
 247                 if (rw & OBD_BRW_READ)
 248                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 249                                           offset, id);
 250                 else
 251                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 252                                           0xecc0ecc0ecc0ecc0ULL,
 253                                           0xecc0ecc0ecc0ecc0ULL);
 254
 255                 addr   += OBD_ECHO_BLOCK_SIZE;
 256                 offset += OBD_ECHO_BLOCK_SIZE;
 257                 len    -= OBD_ECHO_BLOCK_SIZE;
 258         }
 259
 260         cfs_kunmap(page);
 261 }
 262
 263 static int
 264 echo_page_debug_check(cfs_page_t *page, obd_id id,
 265                       __u64 offset, int len)
 266 {
 267         int   page_offset = offset & ~CFS_PAGE_MASK;
 268         char *addr        = ((char *)cfs_kmap(page)) + page_offset;
 269         int   rc          = 0;
 270         int   rc2;
 271
 272         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 273                 CERROR("Unexpected block size %d\n", len);
 274
 275         while (len > 0) {
 276                 rc2 = block_debug_check("echo", addr, OBD_ECHO_BLOCK_SIZE,
 277                                         offset, id);
 278
 279                 if (rc2 != 0 && rc == 0)
 280                         rc = rc2;
 281
 282                 addr   += OBD_ECHO_BLOCK_SIZE;
 283                 offset += OBD_ECHO_BLOCK_SIZE;
 284                 len    -= OBD_ECHO_BLOCK_SIZE;
 285         }
 286
 287         cfs_kunmap(page);
 288
 289         return (rc);
 290 }
 291
 292 /* This allows us to verify that desc_private is passed unmolested */
 293 #define DESC_PRIV 0x10293847
 294
 295 static int echo_map_nb_to_lb(struct obdo *oa, struct obd_ioobj *obj,
 296                              struct niobuf_remote *nb, int *pages,
 297                              struct niobuf_local *lb, int cmd, int *left)
 298 {
 299         int gfp_mask = (obj->ioo_id & 1) ? CFS_ALLOC_HIGHUSER : CFS_ALLOC_STD;
 300         int ispersistent = obj->ioo_id == ECHO_PERSISTENT_OBJID;
 301         int debug_setup = (!ispersistent &&
 302                            (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 303                            (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 304         struct niobuf_local *res = lb;
 305         obd_off offset = nb->offset;
 306         int len = nb->len;
 307
 308         while (len > 0) {
 309                 int plen = CFS_PAGE_SIZE - (offset & (CFS_PAGE_SIZE-1));
 310                 if (len < plen)
 311                         plen = len;
 312
 313                 /* check for local buf overflow */
 314                 if (*left == 0)
 315                         return -EINVAL;
 316
 317                 res->offset = offset;
 318                 res->len = plen;
 319                 LASSERT((res->offset & ~CFS_PAGE_MASK) + res->len <= CFS_PAGE_SIZE);
 320
 321
 322                 if (ispersistent &&
 323                     (res->offset >> CFS_PAGE_SHIFT) < ECHO_PERSISTENT_PAGES) {
 324                         res->page = echo_persistent_pages[res->offset >>
 325                                 CFS_PAGE_SHIFT];
 326                         /* Take extra ref so __free_pages() can be called OK */
 327                         cfs_get_page (res->page);
 328                 } else {
 329                         OBD_PAGE_ALLOC(res->page, gfp_mask);
 330                         if (res->page == NULL) {
 331                                 CERROR("can't get page for id " LPU64"\n",
 332                                        obj->ioo_id);
 333                                 return -ENOMEM;
 334                         }
 335                 }
 336
 337                 CDEBUG(D_PAGE, "$$$$ get page %p @ "LPU64" for %d\n",
 338                        res->page, res->offset, res->len);
 339
 340                 if (cmd & OBD_BRW_READ)
 341                         res->rc = res->len;
 342
 343                 if (debug_setup)
 344                         echo_page_debug_setup(res->page, cmd, obj->ioo_id,
 345                                               res->offset, res->len);
 346
 347                 offset += plen;
 348                 len -= plen;
 349                 res++;
 350
 351                 (*left)--;
 352                 (*pages)++;
 353         }
 354
 355         return 0;
 356 }
 357
 358 int echo_preprw(int cmd, struct obd_export *export, struct obdo *oa,
 359                 int objcount, struct obd_ioobj *obj, struct niobuf_remote *nb,
 360                 int *pages, struct niobuf_local *res,
 361                 struct obd_trans_info *oti, struct lustre_capa *unused)
 362 {
 363         struct obd_device *obd;
 364         struct niobuf_local *r = res;
 365         int tot_bytes = 0;
 366         int rc = 0;
 367         int i, left;
 368         ENTRY;
 369
 370         obd = export->exp_obd;
 371         if (obd == NULL)
 372                 RETURN(-EINVAL);
 373
 374         /* Temp fix to stop falling foul of osc_announce_cached() */
 375         oa->o_valid &= ~(OBD_MD_FLBLOCKS | OBD_MD_FLGRANT);
 376
 377         memset(res, 0, sizeof(*res) * *pages);
 378
 379         CDEBUG(D_PAGE, "%s %d obdos with %d IOs\n",
 380                cmd == OBD_BRW_READ ? "reading" : "writing", objcount, *pages);
 381
 382         if (oti)
 383                 oti->oti_handle = (void *)DESC_PRIV;
 384
 385         left = *pages;
 386         *pages = 0;
 387
 388         for (i = 0; i < objcount; i++, obj++) {
 389                 int j;
 390
 391                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, nb++, r++) {
 392
 393                         rc = echo_map_nb_to_lb(oa, obj, nb, pages,
 394                                                res + *pages, cmd, &left);
 395                         if (rc)
 396                                 GOTO(preprw_cleanup, rc);
 397
 398                         tot_bytes += nb->len;
 399                 }
 400         }
 401
 402         atomic_add(*pages, &obd->u.echo.eo_prep);
 403
 404         if (cmd & OBD_BRW_READ)
 405                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 406                                     tot_bytes);
 407         else
 408                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 409                                     tot_bytes);
 410
 411         CDEBUG(D_PAGE, "%d pages allocated after prep\n",
 412                atomic_read(&obd->u.echo.eo_prep));
 413
 414         RETURN(0);
 415
 416 preprw_cleanup:
 417         /* It is possible that we would rather handle errors by  allow
 418          * any already-set-up pages to complete, rather than tearing them
 419          * all down again.  I believe that this is what the in-kernel
 420          * prep/commit operations do.
 421          */
 422         CERROR("cleaning up %u pages (%d obdos)\n", *pages, objcount);
 423         for (i = 0; i < *pages; i++) {
 424                 cfs_kunmap(res[i].page);
 425                 /* NB if this is a persistent page, __free_pages will just
 426                  * lose the extra ref gained above */
 427                 OBD_PAGE_FREE(res[i].page);
 428                 res[i].page = NULL;
 429                 atomic_dec(&obd->u.echo.eo_prep);
 430         }
 431
 432         return rc;
 433 }
 434
 435 int echo_commitrw(int cmd, struct obd_export *export, struct obdo *oa,
 436                   int objcount, struct obd_ioobj *obj,
 437                   struct niobuf_remote *rb, int niocount,
 438                   struct niobuf_local *res, struct obd_trans_info *oti, int rc)
 439 {
 440         struct obd_device *obd;
 441         struct niobuf_local *r = res;
 442         int i, vrc = 0;
 443         ENTRY;
 444
 445         obd = export->exp_obd;
 446         if (obd == NULL)
 447                 RETURN(-EINVAL);
 448
 449         if (rc)
 450                 GOTO(commitrw_cleanup, rc);
 451
 452         if ((cmd & OBD_BRW_RWMASK) == OBD_BRW_READ) {
 453                 CDEBUG(D_PAGE, "reading %d obdos with %d IOs\n",
 454                        objcount, niocount);
 455         } else {
 456                 CDEBUG(D_PAGE, "writing %d obdos with %d IOs\n",
 457                        objcount, niocount);
 458         }
 459
 460         if (niocount && !r) {
 461                 CERROR("NULL res niobuf with niocount %d\n", niocount);
 462                 RETURN(-EINVAL);
 463         }
 464
 465         LASSERT(oti == NULL || oti->oti_handle == (void *)DESC_PRIV);
 466
 467         for (i = 0; i < objcount; i++, obj++) {
 468                 int verify = (rc == 0 &&
 469                               obj->ioo_id != ECHO_PERSISTENT_OBJID &&
 470                               (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 471                               (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 472                 int j;
 473
 474                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, r++) {
 475                         cfs_page_t *page = r->page;
 476                         void *addr;
 477
 478                         if (page == NULL) {
 479                                 CERROR("null page objid "LPU64":%p, buf %d/%d\n",
 480                                        obj->ioo_id, page, j, obj->ioo_bufcnt);
 481                                 GOTO(commitrw_cleanup, rc = -EFAULT);
 482                         }
 483
 484                         addr = cfs_kmap(page);
 485
 486                         CDEBUG(D_PAGE, "$$$$ use page %p, addr %p@"LPU64"\n",
 487                                r->page, addr, r->offset);
 488
 489                         if (verify) {
 490                                 vrc = echo_page_debug_check(page, obj->ioo_id,
 491                                                             r->offset, r->len);
 492                                 /* check all the pages always */
 493                                 if (vrc != 0 && rc == 0)
 494                                         rc = vrc;
 495                         }
 496
 497                         cfs_kunmap(page);
 498                         /* NB see comment above regarding persistent pages */
 499                         OBD_PAGE_FREE(page);
 500                         atomic_dec(&obd->u.echo.eo_prep);
 501                 }
 502         }
 503         CDEBUG(D_PAGE, "%d pages remain after commit\n",
 504                atomic_read(&obd->u.echo.eo_prep));
 505         RETURN(rc);
 506
 507 commitrw_cleanup:
 508         CERROR("cleaning up %ld pages (%d obdos)\n",
 509                niocount - (long)(r - res) - 1, objcount);
 510         while (++r < res + niocount) {
 511                 cfs_page_t *page = r->page;
 512
 513                 /* NB see comment above regarding persistent pages */
 514                 OBD_PAGE_FREE(page);
 515                 atomic_dec(&obd->u.echo.eo_prep);
 516         }
 517         return rc;
 518 }
 519
 520 static int echo_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
 521 {
 522         struct lprocfs_static_vars lvars;
 523         int                        rc;
 524         int                        lock_flags = 0;
 525         struct ldlm_res_id         res_id = {.name = {1}};
 526         ENTRY;
 527
 528         spin_lock_init(&obd->u.echo.eo_lock);
 529         obd->u.echo.eo_lastino = ECHO_INIT_OBJID;
 530
 531         obd->obd_namespace = ldlm_namespace_new(obd, "echo-tgt",
 532                                                 LDLM_NAMESPACE_SERVER,
 533                                                 LDLM_NAMESPACE_MODEST);
 534         if (obd->obd_namespace == NULL) {
 535                 LBUG();
 536                 RETURN(-ENOMEM);
 537         }
 538
 539         rc = ldlm_cli_enqueue_local(obd->obd_namespace, &res_id, LDLM_PLAIN,
 540                                     NULL, LCK_NL, &lock_flags, NULL,
 541                                     ldlm_completion_ast, NULL, NULL,
 542                                     0, NULL, NULL, &obd->u.echo.eo_nl_lock);
 543         LASSERT (rc == ELDLM_OK);
 544
 545         lprocfs_echo_init_vars(&lvars);
 546         if (lprocfs_obd_setup(obd, lvars.obd_vars) == 0 &&
 547             lprocfs_alloc_obd_stats(obd, LPROC_ECHO_LAST) == 0) {
 548                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 549                                      LPROCFS_CNTR_AVGMINMAX,
 550                                      "read_bytes", "bytes");
 551                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 552                                      LPROCFS_CNTR_AVGMINMAX,
 553                                      "write_bytes", "bytes");
 554         }
 555
 556         ptlrpc_init_client (LDLM_CB_REQUEST_PORTAL, LDLM_CB_REPLY_PORTAL,
 557                             "echo_ldlm_cb_client", &obd->obd_ldlm_client);
 558         RETURN(0);
 559 }
 560
 561 static int echo_cleanup(struct obd_device *obd)
 562 {
 563         int leaked;
 564         ENTRY;
 565
 566         lprocfs_obd_cleanup(obd);
 567         lprocfs_free_obd_stats(obd);
 568
 569         ldlm_lock_decref (&obd->u.echo.eo_nl_lock, LCK_NL);
 570
 571         /* XXX Bug 3413; wait for a bit to ensure the BL callback has
 572          * happened before calling ldlm_namespace_free() */
 573         cfs_schedule_timeout (CFS_TASK_UNINT, cfs_time_seconds(1));
 574
 575         ldlm_namespace_free(obd->obd_namespace, NULL, obd->obd_force);
 576         obd->obd_namespace = NULL;
 577
 578         leaked = atomic_read(&obd->u.echo.eo_prep);
 579         if (leaked != 0)
 580                 CERROR("%d prep/commitrw pages leaked\n", leaked);
 581
 582         RETURN(0);
 583 }
 584
 585 static struct obd_ops echo_obd_ops = {
 586         .o_owner           = THIS_MODULE,
 587         .o_connect         = echo_connect,
 588         .o_disconnect      = echo_disconnect,
 589         .o_init_export     = echo_init_export,
 590         .o_destroy_export  = echo_destroy_export,
 591         .o_create          = echo_create,
 592         .o_destroy         = echo_destroy,
 593         .o_getattr         = echo_getattr,
 594         .o_setattr         = echo_setattr,
 595         .o_preprw          = echo_preprw,
 596         .o_commitrw        = echo_commitrw,
 597         .o_setup           = echo_setup,
 598         .o_cleanup         = echo_cleanup
 599 };
 600
 601 extern int echo_client_init(void);
 602 extern void echo_client_exit(void);
 603
 604 static void
 605 echo_persistent_pages_fini (void)
 606 {
 607         int     i;
 608
 609         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++)
 610                 if (echo_persistent_pages[i] != NULL) {
 611                         OBD_PAGE_FREE(echo_persistent_pages[i]);
 612                         echo_persistent_pages[i] = NULL;
 613                 }
 614 }
 615
 616 static int
 617 echo_persistent_pages_init (void)
 618 {
 619         cfs_page_t *pg;
 620         int          i;
 621
 622         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++) {
 623                 int gfp_mask = (i < ECHO_PERSISTENT_PAGES/2) ?
 624                         CFS_ALLOC_STD : CFS_ALLOC_HIGHUSER;
 625
 626                 OBD_PAGE_ALLOC(pg, gfp_mask);
 627                 if (pg == NULL) {
 628                         echo_persistent_pages_fini ();
 629                         return (-ENOMEM);
 630                 }
 631
 632                 memset (cfs_kmap (pg), 0, CFS_PAGE_SIZE);
 633                 cfs_kunmap (pg);
 634
 635                 echo_persistent_pages[i] = pg;
 636         }
 637
 638         return (0);
 639 }
 640
 641 static int __init obdecho_init(void)
 642 {
 643         struct lprocfs_static_vars lvars;
 644         int rc;
 645
 646         ENTRY;
 647         LCONSOLE_INFO("Echo OBD driver; http://www.lustre.org/\n");
 648
 649         LASSERT(CFS_PAGE_SIZE % OBD_ECHO_BLOCK_SIZE == 0);
 650
 651         lprocfs_echo_init_vars(&lvars);
 652
 653         rc = echo_persistent_pages_init ();
 654         if (rc != 0)
 655                 goto failed_0;
 656
 657         rc = class_register_type(&echo_obd_ops, NULL, lvars.module_vars,
 658                                  LUSTRE_ECHO_NAME, NULL);
 659         if (rc != 0)
 660                 goto failed_1;
 661
 662         rc = echo_client_init();
 663         if (rc == 0)
 664                 RETURN (0);
 665
 666         class_unregister_type(LUSTRE_ECHO_NAME);
 667  failed_1:
 668         echo_persistent_pages_fini ();
 669  failed_0:
 670         RETURN(rc);
 671 }
 672
 673 static void /*__exit*/ obdecho_exit(void)
 674 {
 675         echo_client_exit();
 676         class_unregister_type(LUSTRE_ECHO_NAME);
 677         echo_persistent_pages_fini ();
 678 }
 679
 680 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 681 MODULE_DESCRIPTION("Lustre Testing Echo OBD driver");
 682 MODULE_LICENSE("GPL");
 683
 684 cfs_module(obdecho, "1.0.0", obdecho_init, obdecho_exit);