lustre/obdecho/echo.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2010, 2011, Whamcloud, Inc.
  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 /* The echo objid needs to be below 2^32, because regular FID numbers are
  57  * limited to 2^32 objects in f_oid for the FID_SEQ_ECHO range. b=23335 */
  58 #define ECHO_INIT_OID        0x10000000ULL
  59 #define ECHO_HANDLE_MAGIC    0xabcd0123fedc9876ULL
  60
  61 #define ECHO_PERSISTENT_PAGES (ECHO_PERSISTENT_SIZE >> CFS_PAGE_SHIFT)
  62 static cfs_page_t *echo_persistent_pages[ECHO_PERSISTENT_PAGES];
  63
  64 enum {
  65         LPROC_ECHO_READ_BYTES = 1,
  66         LPROC_ECHO_WRITE_BYTES = 2,
  67         LPROC_ECHO_LAST = LPROC_ECHO_WRITE_BYTES +1
  68 };
  69
  70 static int echo_connect(const struct lu_env *env,
  71                         struct obd_export **exp, struct obd_device *obd,
  72                         struct obd_uuid *cluuid, struct obd_connect_data *data,
  73                         void *localdata)
  74 {
  75         struct lustre_handle conn = { 0 };
  76         int rc;
  77
  78         data->ocd_connect_flags &= ECHO_CONNECT_SUPPORTED;
  79         rc = class_connect(&conn, obd, cluuid);
  80         if (rc) {
  81                 CERROR("can't connect %d\n", rc);
  82                 return rc;
  83         }
  84         *exp = class_conn2export(&conn);
  85
  86         return 0;
  87 }
  88
  89 static int echo_disconnect(struct obd_export *exp)
  90 {
  91         LASSERT (exp != NULL);
  92
  93         return server_disconnect_export(exp);
  94 }
  95
  96 static int echo_init_export(struct obd_export *exp)
  97 {
  98         return ldlm_init_export(exp);
  99 }
 100
 101 static int echo_destroy_export(struct obd_export *exp)
 102 {
 103         ENTRY;
 104
 105         target_destroy_export(exp);
 106         ldlm_destroy_export(exp);
 107
 108         RETURN(0);
 109 }
 110
 111  static __u64 echo_next_id(struct obd_device *obddev)
 112 {
 113         obd_id id;
 114
 115         cfs_spin_lock(&obddev->u.echo.eo_lock);
 116         id = ++obddev->u.echo.eo_lastino;
 117         cfs_spin_unlock(&obddev->u.echo.eo_lock);
 118
 119         return id;
 120 }
 121
 122 static int echo_create(struct obd_export *exp, struct obdo *oa,
 123                        struct lov_stripe_md **ea, struct obd_trans_info *oti)
 124 {
 125         struct obd_device *obd = class_exp2obd(exp);
 126
 127         if (!obd) {
 128                 CERROR("invalid client cookie "LPX64"\n",
 129                        exp->exp_handle.h_cookie);
 130                 return -EINVAL;
 131         }
 132
 133         if (!(oa->o_mode && S_IFMT)) {
 134                 CERROR("echo obd: no type!\n");
 135                 return -ENOENT;
 136         }
 137
 138         if (!(oa->o_valid & OBD_MD_FLTYPE)) {
 139                 CERROR("invalid o_valid "LPX64"\n", oa->o_valid);
 140                 return -EINVAL;
 141         }
 142
 143         oa->o_id = echo_next_id(obd);
 144         oa->o_valid = OBD_MD_FLID;
 145
 146         return 0;
 147 }
 148
 149 static int echo_destroy(struct obd_export *exp, struct obdo *oa,
 150                         struct lov_stripe_md *ea, struct obd_trans_info *oti,
 151                         struct obd_export *md_exp, void *capa)
 152 {
 153         struct obd_device *obd = class_exp2obd(exp);
 154
 155         ENTRY;
 156         if (!obd) {
 157                 CERROR("invalid client cookie "LPX64"\n",
 158                        exp->exp_handle.h_cookie);
 159                 RETURN(-EINVAL);
 160         }
 161
 162         if (!(oa->o_valid & OBD_MD_FLID)) {
 163                 CERROR("obdo missing FLID valid flag: "LPX64"\n", oa->o_valid);
 164                 RETURN(-EINVAL);
 165         }
 166
 167         if (oa->o_id > obd->u.echo.eo_lastino || oa->o_id < ECHO_INIT_OID) {
 168                 CERROR("bad destroy objid: "LPX64"\n", oa->o_id);
 169                 RETURN(-EINVAL);
 170         }
 171
 172         RETURN(0);
 173 }
 174
 175 static int echo_getattr(struct obd_export *exp, struct obd_info *oinfo)
 176 {
 177         struct obd_device *obd = class_exp2obd(exp);
 178         obd_id id = oinfo->oi_oa->o_id;
 179
 180         ENTRY;
 181         if (!obd) {
 182                 CERROR("invalid client cookie "LPX64"\n",
 183                        exp->exp_handle.h_cookie);
 184                 RETURN(-EINVAL);
 185         }
 186
 187         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 188                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 189                        oinfo->oi_oa->o_valid);
 190                 RETURN(-EINVAL);
 191         }
 192
 193         obdo_cpy_md(oinfo->oi_oa, &obd->u.echo.eo_oa, oinfo->oi_oa->o_valid);
 194         oinfo->oi_oa->o_id = id;
 195
 196         RETURN(0);
 197 }
 198
 199 static int echo_setattr(struct obd_export *exp, struct obd_info *oinfo,
 200                         struct obd_trans_info *oti)
 201 {
 202         struct obd_device *obd = class_exp2obd(exp);
 203
 204         ENTRY;
 205         if (!obd) {
 206                 CERROR("invalid client cookie "LPX64"\n",
 207                        exp->exp_handle.h_cookie);
 208                 RETURN(-EINVAL);
 209         }
 210
 211         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 212                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 213                        oinfo->oi_oa->o_valid);
 214                 RETURN(-EINVAL);
 215         }
 216
 217         memcpy(&obd->u.echo.eo_oa, oinfo->oi_oa, sizeof(*oinfo->oi_oa));
 218
 219         if (oinfo->oi_oa->o_id & 4) {
 220                 /* Save lock to force ACKed reply */
 221                 ldlm_lock_addref (&obd->u.echo.eo_nl_lock, LCK_NL);
 222                 oti->oti_ack_locks[0].mode = LCK_NL;
 223                 oti->oti_ack_locks[0].lock = obd->u.echo.eo_nl_lock;
 224         }
 225
 226         RETURN(0);
 227 }
 228
 229 static void
 230 echo_page_debug_setup(cfs_page_t *page, int rw, obd_id id,
 231                       __u64 offset, int len)
 232 {
 233         int   page_offset = offset & ~CFS_PAGE_MASK;
 234         char *addr        = ((char *)cfs_kmap(page)) + page_offset;
 235
 236         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 237                 CERROR("Unexpected block size %d\n", len);
 238
 239         while (len > 0) {
 240                 if (rw & OBD_BRW_READ)
 241                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 242                                           offset, id);
 243                 else
 244                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 245                                           0xecc0ecc0ecc0ecc0ULL,
 246                                           0xecc0ecc0ecc0ecc0ULL);
 247
 248                 addr   += OBD_ECHO_BLOCK_SIZE;
 249                 offset += OBD_ECHO_BLOCK_SIZE;
 250                 len    -= OBD_ECHO_BLOCK_SIZE;
 251         }
 252
 253         cfs_kunmap(page);
 254 }
 255
 256 static int
 257 echo_page_debug_check(cfs_page_t *page, obd_id id,
 258                       __u64 offset, int len)
 259 {
 260         int   page_offset = offset & ~CFS_PAGE_MASK;
 261         char *addr        = ((char *)cfs_kmap(page)) + page_offset;
 262         int   rc          = 0;
 263         int   rc2;
 264
 265         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 266                 CERROR("Unexpected block size %d\n", len);
 267
 268         while (len > 0) {
 269                 rc2 = block_debug_check("echo", addr, OBD_ECHO_BLOCK_SIZE,
 270                                         offset, id);
 271
 272                 if (rc2 != 0 && rc == 0)
 273                         rc = rc2;
 274
 275                 addr   += OBD_ECHO_BLOCK_SIZE;
 276                 offset += OBD_ECHO_BLOCK_SIZE;
 277                 len    -= OBD_ECHO_BLOCK_SIZE;
 278         }
 279
 280         cfs_kunmap(page);
 281
 282         return (rc);
 283 }
 284
 285 /* This allows us to verify that desc_private is passed unmolested */
 286 #define DESC_PRIV 0x10293847
 287
 288 static int echo_map_nb_to_lb(struct obdo *oa, struct obd_ioobj *obj,
 289                              struct niobuf_remote *nb, int *pages,
 290                              struct niobuf_local *lb, int cmd, int *left)
 291 {
 292         int gfp_mask = (obj->ioo_id & 1) ? CFS_ALLOC_HIGHUSER : CFS_ALLOC_STD;
 293         int ispersistent = obj->ioo_id == ECHO_PERSISTENT_OBJID;
 294         int debug_setup = (!ispersistent &&
 295                            (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 296                            (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 297         struct niobuf_local *res = lb;
 298         obd_off offset = nb->offset;
 299         int len = nb->len;
 300
 301         while (len > 0) {
 302                 int plen = CFS_PAGE_SIZE - (offset & (CFS_PAGE_SIZE-1));
 303                 if (len < plen)
 304                         plen = len;
 305
 306                 /* check for local buf overflow */
 307                 if (*left == 0)
 308                         return -EINVAL;
 309
 310                 res->offset = offset;
 311                 res->len = plen;
 312                 LASSERT((res->offset & ~CFS_PAGE_MASK) + res->len <= CFS_PAGE_SIZE);
 313
 314
 315                 if (ispersistent &&
 316                     (res->offset >> CFS_PAGE_SHIFT) < ECHO_PERSISTENT_PAGES) {
 317                         res->page = echo_persistent_pages[res->offset >>
 318                                 CFS_PAGE_SHIFT];
 319                         /* Take extra ref so __free_pages() can be called OK */
 320                         cfs_get_page (res->page);
 321                 } else {
 322                         OBD_PAGE_ALLOC(res->page, gfp_mask);
 323                         if (res->page == NULL) {
 324                                 CERROR("can't get page for id " LPU64"\n",
 325                                        obj->ioo_id);
 326                                 return -ENOMEM;
 327                         }
 328                 }
 329
 330                 CDEBUG(D_PAGE, "$$$$ get page %p @ "LPU64" for %d\n",
 331                        res->page, res->offset, res->len);
 332
 333                 if (cmd & OBD_BRW_READ)
 334                         res->rc = res->len;
 335
 336                 if (debug_setup)
 337                         echo_page_debug_setup(res->page, cmd, obj->ioo_id,
 338                                               res->offset, res->len);
 339
 340                 offset += plen;
 341                 len -= plen;
 342                 res++;
 343
 344                 (*left)--;
 345                 (*pages)++;
 346         }
 347
 348         return 0;
 349 }
 350
 351 static int echo_finalize_lb(struct obdo *oa, struct obd_ioobj *obj,
 352                             struct niobuf_remote *rb, int *pgs,
 353                             struct niobuf_local *lb, int verify)
 354 {
 355         struct niobuf_local *res = lb;
 356         obd_off start  = rb->offset >> CFS_PAGE_SHIFT;
 357         obd_off end    = (rb->offset + rb->len + CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT;
 358         int     count  = (int)(end - start);
 359         int     rc     = 0;
 360         int     i;
 361
 362         for (i = 0; i < count; i++, (*pgs) ++, res++) {
 363                 cfs_page_t *page = res->page;
 364                 void       *addr;
 365
 366                 if (page == NULL) {
 367                         CERROR("null page objid "LPU64":%p, buf %d/%d\n",
 368                                obj->ioo_id, page, i, obj->ioo_bufcnt);
 369                         return -EFAULT;
 370                 }
 371
 372                 addr = cfs_kmap(page);
 373
 374                 CDEBUG(D_PAGE, "$$$$ use page %p, addr %p@"LPU64"\n",
 375                        res->page, addr, res->offset);
 376
 377                 if (verify) {
 378                         int vrc = echo_page_debug_check(page, obj->ioo_id,
 379                                                         res->offset, res->len);
 380                         /* check all the pages always */
 381                         if (vrc != 0 && rc == 0)
 382                                 rc = vrc;
 383                 }
 384
 385                 cfs_kunmap(page);
 386                 /* NB see comment above regarding persistent pages */
 387                 OBD_PAGE_FREE(page);
 388         }
 389
 390         return rc;
 391 }
 392
 393 static int echo_preprw(int cmd, struct obd_export *export, struct obdo *oa,
 394                        int objcount, struct obd_ioobj *obj,
 395                        struct niobuf_remote *nb, int *pages,
 396                        struct niobuf_local *res, struct obd_trans_info *oti,
 397                        struct lustre_capa *unused)
 398 {
 399         struct obd_device *obd;
 400         int tot_bytes = 0;
 401         int rc = 0;
 402         int i, left;
 403         ENTRY;
 404
 405         obd = export->exp_obd;
 406         if (obd == NULL)
 407                 RETURN(-EINVAL);
 408
 409         /* Temp fix to stop falling foul of osc_announce_cached() */
 410         oa->o_valid &= ~(OBD_MD_FLBLOCKS | OBD_MD_FLGRANT);
 411
 412         memset(res, 0, sizeof(*res) * *pages);
 413
 414         CDEBUG(D_PAGE, "%s %d obdos with %d IOs\n",
 415                cmd == OBD_BRW_READ ? "reading" : "writing", objcount, *pages);
 416
 417         if (oti)
 418                 oti->oti_handle = (void *)DESC_PRIV;
 419
 420         left = *pages;
 421         *pages = 0;
 422
 423         for (i = 0; i < objcount; i++, obj++) {
 424                 int j;
 425
 426                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, nb++) {
 427
 428                         rc = echo_map_nb_to_lb(oa, obj, nb, pages,
 429                                                res + *pages, cmd, &left);
 430                         if (rc)
 431                                 GOTO(preprw_cleanup, rc);
 432
 433                         tot_bytes += nb->len;
 434                 }
 435         }
 436
 437         cfs_atomic_add(*pages, &obd->u.echo.eo_prep);
 438
 439         if (cmd & OBD_BRW_READ)
 440                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 441                                     tot_bytes);
 442         else
 443                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 444                                     tot_bytes);
 445
 446         CDEBUG(D_PAGE, "%d pages allocated after prep\n",
 447                cfs_atomic_read(&obd->u.echo.eo_prep));
 448
 449         RETURN(0);
 450
 451 preprw_cleanup:
 452         /* It is possible that we would rather handle errors by  allow
 453          * any already-set-up pages to complete, rather than tearing them
 454          * all down again.  I believe that this is what the in-kernel
 455          * prep/commit operations do.
 456          */
 457         CERROR("cleaning up %u pages (%d obdos)\n", *pages, objcount);
 458         for (i = 0; i < *pages; i++) {
 459                 cfs_kunmap(res[i].page);
 460                 /* NB if this is a persistent page, __free_pages will just
 461                  * lose the extra ref gained above */
 462                 OBD_PAGE_FREE(res[i].page);
 463                 res[i].page = NULL;
 464                 cfs_atomic_dec(&obd->u.echo.eo_prep);
 465         }
 466
 467         return rc;
 468 }
 469
 470 static int echo_commitrw(int cmd, struct obd_export *export, struct obdo *oa,
 471                          int objcount, struct obd_ioobj *obj,
 472                          struct niobuf_remote *rb, int niocount,
 473                          struct niobuf_local *res, struct obd_trans_info *oti,
 474                          int rc)
 475 {
 476         struct obd_device *obd;
 477         int pgs = 0;
 478         int i;
 479         ENTRY;
 480
 481         obd = export->exp_obd;
 482         if (obd == NULL)
 483                 RETURN(-EINVAL);
 484
 485         if (rc)
 486                 GOTO(commitrw_cleanup, rc);
 487
 488         if ((cmd & OBD_BRW_RWMASK) == OBD_BRW_READ) {
 489                 CDEBUG(D_PAGE, "reading %d obdos with %d IOs\n",
 490                        objcount, niocount);
 491         } else {
 492                 CDEBUG(D_PAGE, "writing %d obdos with %d IOs\n",
 493                        objcount, niocount);
 494         }
 495
 496         if (niocount && res == NULL) {
 497                 CERROR("NULL res niobuf with niocount %d\n", niocount);
 498                 RETURN(-EINVAL);
 499         }
 500
 501         LASSERT(oti == NULL || oti->oti_handle == (void *)DESC_PRIV);
 502
 503         for (i = 0; i < objcount; i++, obj++) {
 504                 int verify = (rc == 0 &&
 505                               obj->ioo_id != ECHO_PERSISTENT_OBJID &&
 506                               (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 507                               (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 508                 int j;
 509
 510                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, rb++) {
 511                         int vrc = echo_finalize_lb(oa, obj, rb, &pgs, &res[pgs], verify);
 512
 513                         if (vrc == 0)
 514                                 continue;
 515
 516                         if (vrc == -EFAULT)
 517                                 GOTO(commitrw_cleanup, rc = vrc);
 518
 519                         if (rc == 0)
 520                                 rc = vrc;
 521                 }
 522
 523         }
 524
 525         cfs_atomic_sub(pgs, &obd->u.echo.eo_prep);
 526
 527         CDEBUG(D_PAGE, "%d pages remain after commit\n",
 528                cfs_atomic_read(&obd->u.echo.eo_prep));
 529         RETURN(rc);
 530
 531 commitrw_cleanup:
 532         cfs_atomic_sub(pgs, &obd->u.echo.eo_prep);
 533
 534         CERROR("cleaning up %d pages (%d obdos)\n",
 535                niocount - pgs - 1, objcount);
 536
 537         while (pgs < niocount) {
 538                 cfs_page_t *page = res[pgs++].page;
 539
 540                 if (page == NULL)
 541                         continue;
 542
 543                 /* NB see comment above regarding persistent pages */
 544                 OBD_PAGE_FREE(page);
 545                 cfs_atomic_dec(&obd->u.echo.eo_prep);
 546         }
 547         return rc;
 548 }
 549
 550 static int echo_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
 551 {
 552         struct lprocfs_static_vars lvars;
 553         int                        rc;
 554         int                        lock_flags = 0;
 555         struct ldlm_res_id         res_id = {.name = {1}};
 556         char                       ns_name[48];
 557         ENTRY;
 558
 559         obd->u.echo.eo_obt.obt_magic = OBT_MAGIC;
 560         cfs_spin_lock_init(&obd->u.echo.eo_lock);
 561         obd->u.echo.eo_lastino = ECHO_INIT_OID;
 562
 563         sprintf(ns_name, "echotgt-%s", obd->obd_uuid.uuid);
 564         obd->obd_namespace = ldlm_namespace_new(obd, ns_name,
 565                                                 LDLM_NAMESPACE_SERVER,
 566                                                 LDLM_NAMESPACE_MODEST,
 567                                                 LDLM_NS_TYPE_OST);
 568         if (obd->obd_namespace == NULL) {
 569                 LBUG();
 570                 RETURN(-ENOMEM);
 571         }
 572
 573         rc = ldlm_cli_enqueue_local(obd->obd_namespace, &res_id, LDLM_PLAIN,
 574                                     NULL, LCK_NL, &lock_flags, NULL,
 575                                     ldlm_completion_ast, NULL, NULL, 0, NULL,
 576                                     &obd->u.echo.eo_nl_lock);
 577         LASSERT (rc == ELDLM_OK);
 578
 579         lprocfs_echo_init_vars(&lvars);
 580         if (lprocfs_obd_setup(obd, lvars.obd_vars) == 0 &&
 581             lprocfs_alloc_obd_stats(obd, LPROC_ECHO_LAST) == 0) {
 582                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 583                                      LPROCFS_CNTR_AVGMINMAX,
 584                                      "read_bytes", "bytes");
 585                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 586                                      LPROCFS_CNTR_AVGMINMAX,
 587                                      "write_bytes", "bytes");
 588         }
 589
 590         ptlrpc_init_client (LDLM_CB_REQUEST_PORTAL, LDLM_CB_REPLY_PORTAL,
 591                             "echo_ldlm_cb_client", &obd->obd_ldlm_client);
 592         RETURN(0);
 593 }
 594
 595 static int echo_cleanup(struct obd_device *obd)
 596 {
 597         int leaked;
 598         ENTRY;
 599
 600         lprocfs_obd_cleanup(obd);
 601         lprocfs_free_obd_stats(obd);
 602
 603         ldlm_lock_decref(&obd->u.echo.eo_nl_lock, LCK_NL);
 604
 605         /* XXX Bug 3413; wait for a bit to ensure the BL callback has
 606          * happened before calling ldlm_namespace_free() */
 607         cfs_schedule_timeout_and_set_state(CFS_TASK_UNINT, cfs_time_seconds(1));
 608
 609         ldlm_namespace_free(obd->obd_namespace, NULL, obd->obd_force);
 610         obd->obd_namespace = NULL;
 611
 612         leaked = cfs_atomic_read(&obd->u.echo.eo_prep);
 613         if (leaked != 0)
 614                 CERROR("%d prep/commitrw pages leaked\n", leaked);
 615
 616         RETURN(0);
 617 }
 618
 619 struct obd_ops echo_obd_ops = {
 620         .o_owner           = THIS_MODULE,
 621         .o_connect         = echo_connect,
 622         .o_disconnect      = echo_disconnect,
 623         .o_init_export     = echo_init_export,
 624         .o_destroy_export  = echo_destroy_export,
 625         .o_create          = echo_create,
 626         .o_destroy         = echo_destroy,
 627         .o_getattr         = echo_getattr,
 628         .o_setattr         = echo_setattr,
 629         .o_preprw          = echo_preprw,
 630         .o_commitrw        = echo_commitrw,
 631         .o_setup           = echo_setup,
 632         .o_cleanup         = echo_cleanup
 633 };
 634
 635 void echo_persistent_pages_fini(void)
 636 {
 637         int     i;
 638
 639         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++)
 640                 if (echo_persistent_pages[i] != NULL) {
 641                         OBD_PAGE_FREE(echo_persistent_pages[i]);
 642                         echo_persistent_pages[i] = NULL;
 643                 }
 644 }
 645
 646 int echo_persistent_pages_init(void)
 647 {
 648         cfs_page_t *pg;
 649         int          i;
 650
 651         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++) {
 652                 int gfp_mask = (i < ECHO_PERSISTENT_PAGES/2) ?
 653                         CFS_ALLOC_STD : CFS_ALLOC_HIGHUSER;
 654
 655                 OBD_PAGE_ALLOC(pg, gfp_mask);
 656                 if (pg == NULL) {
 657                         echo_persistent_pages_fini ();
 658                         return (-ENOMEM);
 659                 }
 660
 661                 memset (cfs_kmap (pg), 0, CFS_PAGE_SIZE);
 662                 cfs_kunmap (pg);
 663
 664                 echo_persistent_pages[i] = pg;
 665         }
 666
 667         return (0);
 668 }