Pileus Git - ~andy/linux/blob - drivers/staging/lustre/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, 2012, Intel Corporation.
  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 #define DEBUG_SUBSYSTEM S_ECHO
  43
  44 #include <obd_support.h>
  45 #include <obd_class.h>
  46 #include <lustre_debug.h>
  47 #include <lustre_dlm.h>
  48 #include <lprocfs_status.h>
  49
  50 #include "echo_internal.h"
  51
  52 /* The echo objid needs to be below 2^32, because regular FID numbers are
  53  * limited to 2^32 objects in f_oid for the FID_SEQ_ECHO range. b=23335 */
  54 #define ECHO_INIT_OID   0x10000000ULL
  55 #define ECHO_HANDLE_MAGIC    0xabcd0123fedc9876ULL
  56
  57 #define ECHO_PERSISTENT_PAGES (ECHO_PERSISTENT_SIZE >> PAGE_CACHE_SHIFT)
  58 static struct page *echo_persistent_pages[ECHO_PERSISTENT_PAGES];
  59
  60 enum {
  61         LPROC_ECHO_READ_BYTES = 1,
  62         LPROC_ECHO_WRITE_BYTES = 2,
  63         LPROC_ECHO_LAST = LPROC_ECHO_WRITE_BYTES +1
  64 };
  65
  66 static int echo_connect(const struct lu_env *env,
  67                         struct obd_export **exp, struct obd_device *obd,
  68                         struct obd_uuid *cluuid, struct obd_connect_data *data,
  69                         void *localdata)
  70 {
  71         struct lustre_handle conn = { 0 };
  72         int rc;
  73
  74         data->ocd_connect_flags &= ECHO_CONNECT_SUPPORTED;
  75         rc = class_connect(&conn, obd, cluuid);
  76         if (rc) {
  77                 CERROR("can't connect %d\n", rc);
  78                 return rc;
  79         }
  80         *exp = class_conn2export(&conn);
  81
  82         return 0;
  83 }
  84
  85 static int echo_disconnect(struct obd_export *exp)
  86 {
  87         LASSERT (exp != NULL);
  88
  89         return server_disconnect_export(exp);
  90 }
  91
  92 static int echo_init_export(struct obd_export *exp)
  93 {
  94         return ldlm_init_export(exp);
  95 }
  96
  97 static int echo_destroy_export(struct obd_export *exp)
  98 {
  99         target_destroy_export(exp);
 100         ldlm_destroy_export(exp);
 101
 102         return 0;
 103 }
 104
 105  static __u64 echo_next_id(struct obd_device *obddev)
 106 {
 107         obd_id id;
 108
 109         spin_lock(&obddev->u.echo.eo_lock);
 110         id = ++obddev->u.echo.eo_lastino;
 111         spin_unlock(&obddev->u.echo.eo_lock);
 112
 113         return id;
 114 }
 115
 116 static int echo_create(const struct lu_env *env, struct obd_export *exp,
 117                        struct obdo *oa, struct lov_stripe_md **ea,
 118                        struct obd_trans_info *oti)
 119 {
 120         struct obd_device *obd = class_exp2obd(exp);
 121
 122         if (!obd) {
 123                 CERROR("invalid client cookie "LPX64"\n",
 124                        exp->exp_handle.h_cookie);
 125                 return -EINVAL;
 126         }
 127
 128         if (!(oa->o_mode && S_IFMT)) {
 129                 CERROR("echo obd: no type!\n");
 130                 return -ENOENT;
 131         }
 132
 133         if (!(oa->o_valid & OBD_MD_FLTYPE)) {
 134                 CERROR("invalid o_valid "LPX64"\n", oa->o_valid);
 135                 return -EINVAL;
 136         }
 137
 138         ostid_set_seq_echo(&oa->o_oi);
 139         ostid_set_id(&oa->o_oi, echo_next_id(obd));
 140         oa->o_valid = OBD_MD_FLID;
 141
 142         return 0;
 143 }
 144
 145 static int echo_destroy(const struct lu_env *env, struct obd_export *exp,
 146                         struct obdo *oa, struct lov_stripe_md *ea,
 147                         struct obd_trans_info *oti, struct obd_export *md_exp,
 148                         void *capa)
 149 {
 150         struct obd_device *obd = class_exp2obd(exp);
 151
 152         if (!obd) {
 153                 CERROR("invalid client cookie "LPX64"\n",
 154                        exp->exp_handle.h_cookie);
 155                 return -EINVAL;
 156         }
 157
 158         if (!(oa->o_valid & OBD_MD_FLID)) {
 159                 CERROR("obdo missing FLID valid flag: "LPX64"\n", oa->o_valid);
 160                 return -EINVAL;
 161         }
 162
 163         if (ostid_id(&oa->o_oi) > obd->u.echo.eo_lastino ||
 164             ostid_id(&oa->o_oi) < ECHO_INIT_OID) {
 165                 CERROR("bad destroy objid: "DOSTID"\n", POSTID(&oa->o_oi));
 166                 return -EINVAL;
 167         }
 168
 169         return 0;
 170 }
 171
 172 static int echo_getattr(const struct lu_env *env, struct obd_export *exp,
 173                         struct obd_info *oinfo)
 174 {
 175         struct obd_device *obd = class_exp2obd(exp);
 176         obd_id id = ostid_id(&oinfo->oi_oa->o_oi);
 177
 178         if (!obd) {
 179                 CERROR("invalid client cookie "LPX64"\n",
 180                        exp->exp_handle.h_cookie);
 181                 return -EINVAL;
 182         }
 183
 184         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 185                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 186                        oinfo->oi_oa->o_valid);
 187                 return -EINVAL;
 188         }
 189
 190         obdo_cpy_md(oinfo->oi_oa, &obd->u.echo.eo_oa, oinfo->oi_oa->o_valid);
 191         ostid_set_seq_echo(&oinfo->oi_oa->o_oi);
 192         ostid_set_id(&oinfo->oi_oa->o_oi, id);
 193
 194         return 0;
 195 }
 196
 197 static int echo_setattr(const struct lu_env *env, struct obd_export *exp,
 198                         struct obd_info *oinfo, struct obd_trans_info *oti)
 199 {
 200         struct obd_device *obd = class_exp2obd(exp);
 201
 202         if (!obd) {
 203                 CERROR("invalid client cookie "LPX64"\n",
 204                        exp->exp_handle.h_cookie);
 205                 return -EINVAL;
 206         }
 207
 208         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 209                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 210                        oinfo->oi_oa->o_valid);
 211                 return -EINVAL;
 212         }
 213
 214         memcpy(&obd->u.echo.eo_oa, oinfo->oi_oa, sizeof(*oinfo->oi_oa));
 215
 216         if (ostid_id(&oinfo->oi_oa->o_oi) & 4) {
 217                 /* Save lock to force ACKed reply */
 218                 ldlm_lock_addref (&obd->u.echo.eo_nl_lock, LCK_NL);
 219                 oti->oti_ack_locks[0].mode = LCK_NL;
 220                 oti->oti_ack_locks[0].lock = obd->u.echo.eo_nl_lock;
 221         }
 222
 223         return 0;
 224 }
 225
 226 static void
 227 echo_page_debug_setup(struct page *page, int rw, obd_id id,
 228                       __u64 offset, int len)
 229 {
 230         int   page_offset = offset & ~CFS_PAGE_MASK;
 231         char *addr      = ((char *)kmap(page)) + page_offset;
 232
 233         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 234                 CERROR("Unexpected block size %d\n", len);
 235
 236         while (len > 0) {
 237                 if (rw & OBD_BRW_READ)
 238                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 239                                           offset, id);
 240                 else
 241                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 242                                           0xecc0ecc0ecc0ecc0ULL,
 243                                           0xecc0ecc0ecc0ecc0ULL);
 244
 245                 addr   += OBD_ECHO_BLOCK_SIZE;
 246                 offset += OBD_ECHO_BLOCK_SIZE;
 247                 len    -= OBD_ECHO_BLOCK_SIZE;
 248         }
 249
 250         kunmap(page);
 251 }
 252
 253 static int
 254 echo_page_debug_check(struct page *page, obd_id id,
 255                       __u64 offset, int len)
 256 {
 257         int   page_offset = offset & ~CFS_PAGE_MASK;
 258         char *addr      = ((char *)kmap(page)) + page_offset;
 259         int   rc          = 0;
 260         int   rc2;
 261
 262         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 263                 CERROR("Unexpected block size %d\n", len);
 264
 265         while (len > 0) {
 266                 rc2 = block_debug_check("echo", addr, OBD_ECHO_BLOCK_SIZE,
 267                                         offset, id);
 268
 269                 if (rc2 != 0 && rc == 0)
 270                         rc = rc2;
 271
 272                 addr   += OBD_ECHO_BLOCK_SIZE;
 273                 offset += OBD_ECHO_BLOCK_SIZE;
 274                 len    -= OBD_ECHO_BLOCK_SIZE;
 275         }
 276
 277         kunmap(page);
 278
 279         return (rc);
 280 }
 281
 282 /* This allows us to verify that desc_private is passed unmolested */
 283 #define DESC_PRIV 0x10293847
 284
 285 static int echo_map_nb_to_lb(struct obdo *oa, struct obd_ioobj *obj,
 286                              struct niobuf_remote *nb, int *pages,
 287                              struct niobuf_local *lb, int cmd, int *left)
 288 {
 289         int gfp_mask = (ostid_id(&obj->ioo_oid) & 1) ?
 290                         GFP_HIGHUSER : GFP_IOFS;
 291         int ispersistent = ostid_id(&obj->ioo_oid) == ECHO_PERSISTENT_OBJID;
 292         int debug_setup = (!ispersistent &&
 293                            (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 294                            (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 295         struct niobuf_local *res = lb;
 296         obd_off offset = nb->offset;
 297         int len = nb->len;
 298
 299         while (len > 0) {
 300                 int plen = PAGE_CACHE_SIZE - (offset & (PAGE_CACHE_SIZE-1));
 301                 if (len < plen)
 302                         plen = len;
 303
 304                 /* check for local buf overflow */
 305                 if (*left == 0)
 306                         return -EINVAL;
 307
 308                 res->lnb_file_offset = offset;
 309                 res->len = plen;
 310                 LASSERT((res->lnb_file_offset & ~CFS_PAGE_MASK) + res->len <=
 311                         PAGE_CACHE_SIZE);
 312
 313                 if (ispersistent &&
 314                     ((res->lnb_file_offset >> PAGE_CACHE_SHIFT) <
 315                       ECHO_PERSISTENT_PAGES)) {
 316                         res->page =
 317                                 echo_persistent_pages[res->lnb_file_offset >>
 318                                                       PAGE_CACHE_SHIFT];
 319                         /* Take extra ref so __free_pages() can be called OK */
 320                         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 " DOSTID"\n",
 325                                        POSTID(&obj->ioo_oid));
 326                                 return -ENOMEM;
 327                         }
 328                 }
 329
 330                 CDEBUG(D_PAGE, "$$$$ get page %p @ "LPU64" for %d\n",
 331                        res->page, res->lnb_file_offset, res->len);
 332
 333                 if (cmd & OBD_BRW_READ)
 334                         res->rc = res->len;
 335
 336                 if (debug_setup)
 337                         echo_page_debug_setup(res->page, cmd,
 338                                               ostid_id(&obj->ioo_oid),
 339                                               res->lnb_file_offset, res->len);
 340
 341                 offset += plen;
 342                 len -= plen;
 343                 res++;
 344
 345                 (*left)--;
 346                 (*pages)++;
 347         }
 348
 349         return 0;
 350 }
 351
 352 static int echo_finalize_lb(struct obdo *oa, struct obd_ioobj *obj,
 353                             struct niobuf_remote *rb, int *pgs,
 354                             struct niobuf_local *lb, int verify)
 355 {
 356         struct niobuf_local *res = lb;
 357         obd_off start  = rb->offset >> PAGE_CACHE_SHIFT;
 358         obd_off end    = (rb->offset + rb->len + PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
 359         int     count  = (int)(end - start);
 360         int     rc     = 0;
 361         int     i;
 362
 363         for (i = 0; i < count; i++, (*pgs) ++, res++) {
 364                 struct page *page = res->page;
 365                 void       *addr;
 366
 367                 if (page == NULL) {
 368                         CERROR("null page objid "LPU64":%p, buf %d/%d\n",
 369                                ostid_id(&obj->ioo_oid), page, i,
 370                                obj->ioo_bufcnt);
 371                         return -EFAULT;
 372                 }
 373
 374                 addr = kmap(page);
 375
 376                 CDEBUG(D_PAGE, "$$$$ use page %p, addr %p@"LPU64"\n",
 377                        res->page, addr, res->lnb_file_offset);
 378
 379                 if (verify) {
 380                         int vrc = echo_page_debug_check(page,
 381                                                         ostid_id(&obj->ioo_oid),
 382                                                         res->lnb_file_offset,
 383                                                         res->len);
 384                         /* check all the pages always */
 385                         if (vrc != 0 && rc == 0)
 386                                 rc = vrc;
 387                 }
 388
 389                 kunmap(page);
 390                 /* NB see comment above regarding persistent pages */
 391                 OBD_PAGE_FREE(page);
 392         }
 393
 394         return rc;
 395 }
 396
 397 static int echo_preprw(const struct lu_env *env, int cmd,
 398                        struct obd_export *export, struct obdo *oa,
 399                        int objcount, struct obd_ioobj *obj,
 400                        struct niobuf_remote *nb, int *pages,
 401                        struct niobuf_local *res, struct obd_trans_info *oti,
 402                        struct lustre_capa *unused)
 403 {
 404         struct obd_device *obd;
 405         int tot_bytes = 0;
 406         int rc = 0;
 407         int i, left;
 408
 409         obd = export->exp_obd;
 410         if (obd == NULL)
 411                 return -EINVAL;
 412
 413         /* Temp fix to stop falling foul of osc_announce_cached() */
 414         oa->o_valid &= ~(OBD_MD_FLBLOCKS | OBD_MD_FLGRANT);
 415
 416         memset(res, 0, sizeof(*res) * *pages);
 417
 418         CDEBUG(D_PAGE, "%s %d obdos with %d IOs\n",
 419                cmd == OBD_BRW_READ ? "reading" : "writing", objcount, *pages);
 420
 421         if (oti)
 422                 oti->oti_handle = (void *)DESC_PRIV;
 423
 424         left = *pages;
 425         *pages = 0;
 426
 427         for (i = 0; i < objcount; i++, obj++) {
 428                 int j;
 429
 430                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, nb++) {
 431
 432                         rc = echo_map_nb_to_lb(oa, obj, nb, pages,
 433                                                res + *pages, cmd, &left);
 434                         if (rc)
 435                                 GOTO(preprw_cleanup, rc);
 436
 437                         tot_bytes += nb->len;
 438                 }
 439         }
 440
 441         atomic_add(*pages, &obd->u.echo.eo_prep);
 442
 443         if (cmd & OBD_BRW_READ)
 444                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 445                                     tot_bytes);
 446         else
 447                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 448                                     tot_bytes);
 449
 450         CDEBUG(D_PAGE, "%d pages allocated after prep\n",
 451                atomic_read(&obd->u.echo.eo_prep));
 452
 453         return 0;
 454
 455 preprw_cleanup:
 456         /* It is possible that we would rather handle errors by  allow
 457          * any already-set-up pages to complete, rather than tearing them
 458          * all down again.  I believe that this is what the in-kernel
 459          * prep/commit operations do.
 460          */
 461         CERROR("cleaning up %u pages (%d obdos)\n", *pages, objcount);
 462         for (i = 0; i < *pages; i++) {
 463                 kunmap(res[i].page);
 464                 /* NB if this is a persistent page, __free_pages will just
 465                  * lose the extra ref gained above */
 466                 OBD_PAGE_FREE(res[i].page);
 467                 res[i].page = NULL;
 468                 atomic_dec(&obd->u.echo.eo_prep);
 469         }
 470
 471         return rc;
 472 }
 473
 474 static int echo_commitrw(const struct lu_env *env, int cmd,
 475                          struct obd_export *export, struct obdo *oa,
 476                          int objcount, struct obd_ioobj *obj,
 477                          struct niobuf_remote *rb, int niocount,
 478                          struct niobuf_local *res, struct obd_trans_info *oti,
 479                          int rc)
 480 {
 481         struct obd_device *obd;
 482         int pgs = 0;
 483         int i;
 484
 485         obd = export->exp_obd;
 486         if (obd == NULL)
 487                 return -EINVAL;
 488
 489         if (rc)
 490                 GOTO(commitrw_cleanup, rc);
 491
 492         if ((cmd & OBD_BRW_RWMASK) == OBD_BRW_READ) {
 493                 CDEBUG(D_PAGE, "reading %d obdos with %d IOs\n",
 494                        objcount, niocount);
 495         } else {
 496                 CDEBUG(D_PAGE, "writing %d obdos with %d IOs\n",
 497                        objcount, niocount);
 498         }
 499
 500         if (niocount && res == NULL) {
 501                 CERROR("NULL res niobuf with niocount %d\n", niocount);
 502                 return -EINVAL;
 503         }
 504
 505         LASSERT(oti == NULL || oti->oti_handle == (void *)DESC_PRIV);
 506
 507         for (i = 0; i < objcount; i++, obj++) {
 508                 int verify = (rc == 0 &&
 509                              ostid_id(&obj->ioo_oid) != ECHO_PERSISTENT_OBJID &&
 510                               (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 511                               (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 512                 int j;
 513
 514                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, rb++) {
 515                         int vrc = echo_finalize_lb(oa, obj, rb, &pgs, &res[pgs],
 516                                                    verify);
 517                         if (vrc == 0)
 518                                 continue;
 519
 520                         if (vrc == -EFAULT)
 521                                 GOTO(commitrw_cleanup, rc = vrc);
 522
 523                         if (rc == 0)
 524                                 rc = vrc;
 525                 }
 526
 527         }
 528
 529         atomic_sub(pgs, &obd->u.echo.eo_prep);
 530
 531         CDEBUG(D_PAGE, "%d pages remain after commit\n",
 532                atomic_read(&obd->u.echo.eo_prep));
 533         return rc;
 534
 535 commitrw_cleanup:
 536         atomic_sub(pgs, &obd->u.echo.eo_prep);
 537
 538         CERROR("cleaning up %d pages (%d obdos)\n",
 539                niocount - pgs - 1, objcount);
 540
 541         while (pgs < niocount) {
 542                 struct page *page = res[pgs++].page;
 543
 544                 if (page == NULL)
 545                         continue;
 546
 547                 /* NB see comment above regarding persistent pages */
 548                 OBD_PAGE_FREE(page);
 549                 atomic_dec(&obd->u.echo.eo_prep);
 550         }
 551         return rc;
 552 }
 553
 554 static int echo_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
 555 {
 556         struct lprocfs_static_vars lvars;
 557         int                     rc;
 558         __u64                 lock_flags = 0;
 559         struct ldlm_res_id       res_id = {.name = {1}};
 560         char                   ns_name[48];
 561
 562         obd->u.echo.eo_obt.obt_magic = OBT_MAGIC;
 563         spin_lock_init(&obd->u.echo.eo_lock);
 564         obd->u.echo.eo_lastino = ECHO_INIT_OID;
 565
 566         sprintf(ns_name, "echotgt-%s", obd->obd_uuid.uuid);
 567         obd->obd_namespace = ldlm_namespace_new(obd, ns_name,
 568                                                 LDLM_NAMESPACE_SERVER,
 569                                                 LDLM_NAMESPACE_MODEST,
 570                                                 LDLM_NS_TYPE_OST);
 571         if (obd->obd_namespace == NULL) {
 572                 LBUG();
 573                 return -ENOMEM;
 574         }
 575
 576         rc = ldlm_cli_enqueue_local(obd->obd_namespace, &res_id, LDLM_PLAIN,
 577                                     NULL, LCK_NL, &lock_flags, NULL,
 578                                     ldlm_completion_ast, NULL, NULL, 0,
 579                                     LVB_T_NONE, NULL, &obd->u.echo.eo_nl_lock);
 580         LASSERT (rc == ELDLM_OK);
 581
 582         lprocfs_echo_init_vars(&lvars);
 583         if (lprocfs_obd_setup(obd, lvars.obd_vars) == 0 &&
 584             lprocfs_alloc_obd_stats(obd, LPROC_ECHO_LAST) == 0) {
 585                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 586                                      LPROCFS_CNTR_AVGMINMAX,
 587                                      "read_bytes", "bytes");
 588                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 589                                      LPROCFS_CNTR_AVGMINMAX,
 590                                      "write_bytes", "bytes");
 591         }
 592
 593         ptlrpc_init_client (LDLM_CB_REQUEST_PORTAL, LDLM_CB_REPLY_PORTAL,
 594                             "echo_ldlm_cb_client", &obd->obd_ldlm_client);
 595         return 0;
 596 }
 597
 598 static int echo_cleanup(struct obd_device *obd)
 599 {
 600         int leaked;
 601
 602         lprocfs_obd_cleanup(obd);
 603         lprocfs_free_obd_stats(obd);
 604
 605         ldlm_lock_decref(&obd->u.echo.eo_nl_lock, LCK_NL);
 606
 607         /* XXX Bug 3413; wait for a bit to ensure the BL callback has
 608          * happened before calling ldlm_namespace_free() */
 609         schedule_timeout_and_set_state(TASK_UNINTERRUPTIBLE, cfs_time_seconds(1));
 610
 611         ldlm_namespace_free(obd->obd_namespace, NULL, obd->obd_force);
 612         obd->obd_namespace = NULL;
 613
 614         leaked = atomic_read(&obd->u.echo.eo_prep);
 615         if (leaked != 0)
 616                 CERROR("%d prep/commitrw pages leaked\n", leaked);
 617
 618         return 0;
 619 }
 620
 621 struct obd_ops echo_obd_ops = {
 622         .o_owner           = THIS_MODULE,
 623         .o_connect       = echo_connect,
 624         .o_disconnect      = echo_disconnect,
 625         .o_init_export     = echo_init_export,
 626         .o_destroy_export  = echo_destroy_export,
 627         .o_create         = echo_create,
 628         .o_destroy       = echo_destroy,
 629         .o_getattr       = echo_getattr,
 630         .o_setattr       = echo_setattr,
 631         .o_preprw         = echo_preprw,
 632         .o_commitrw     = echo_commitrw,
 633         .o_setup           = echo_setup,
 634         .o_cleanup       = echo_cleanup
 635 };
 636
 637 void echo_persistent_pages_fini(void)
 638 {
 639         int     i;
 640
 641         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++)
 642                 if (echo_persistent_pages[i] != NULL) {
 643                         OBD_PAGE_FREE(echo_persistent_pages[i]);
 644                         echo_persistent_pages[i] = NULL;
 645                 }
 646 }
 647
 648 int echo_persistent_pages_init(void)
 649 {
 650         struct page *pg;
 651         int       i;
 652
 653         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++) {
 654                 int gfp_mask = (i < ECHO_PERSISTENT_PAGES/2) ?
 655                         GFP_IOFS : GFP_HIGHUSER;
 656
 657                 OBD_PAGE_ALLOC(pg, gfp_mask);
 658                 if (pg == NULL) {
 659                         echo_persistent_pages_fini ();
 660                         return (-ENOMEM);
 661                 }
 662
 663                 memset (kmap (pg), 0, PAGE_CACHE_SIZE);
 664                 kunmap (pg);
 665
 666                 echo_persistent_pages[i] = pg;
 667         }
 668
 669         return (0);
 670 }