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 (c) 2002, 2010, Oracle and/or its affiliates. All rights reserved.
  30  * Use is subject to license terms.
  31  *
  32  * Copyright (c) 2010, 2011, Whamcloud, Inc.
  33  */
  34 /*
  35  * This file is part of Lustre, http://www.lustre.org/
  36  * Lustre is a trademark of Sun Microsystems, Inc.
  37  *
  38  * lustre/obdecho/echo.c
  39  *
  40  * Author: Peter Braam <braam@clusterfs.com>
  41  * Author: Andreas Dilger <adilger@clusterfs.com>
  42  */
  43
  44 #ifndef EXPORT_SYMTAB
  45 # define EXPORT_SYMTAB
  46 #endif
  47
  48 #define DEBUG_SUBSYSTEM S_ECHO
  49
  50 #include <obd_support.h>
  51 #include <obd_class.h>
  52 #include <lustre_debug.h>
  53 #include <lustre_dlm.h>
  54 #include <lprocfs_status.h>
  55
  56 #include "echo_internal.h"
  57
  58 /* The echo objid needs to be below 2^32, because regular FID numbers are
  59  * limited to 2^32 objects in f_oid for the FID_SEQ_ECHO range. b=23335 */
  60 #define ECHO_INIT_OID        0x10000000ULL
  61 #define ECHO_HANDLE_MAGIC    0xabcd0123fedc9876ULL
  62
  63 #define ECHO_PERSISTENT_PAGES (ECHO_PERSISTENT_SIZE >> CFS_PAGE_SHIFT)
  64 static cfs_page_t *echo_persistent_pages[ECHO_PERSISTENT_PAGES];
  65
  66 enum {
  67         LPROC_ECHO_READ_BYTES = 1,
  68         LPROC_ECHO_WRITE_BYTES = 2,
  69         LPROC_ECHO_LAST = LPROC_ECHO_WRITE_BYTES +1
  70 };
  71
  72 static int echo_connect(const struct lu_env *env,
  73                         struct obd_export **exp, struct obd_device *obd,
  74                         struct obd_uuid *cluuid, struct obd_connect_data *data,
  75                         void *localdata)
  76 {
  77         struct lustre_handle conn = { 0 };
  78         int rc;
  79
  80         data->ocd_connect_flags &= ECHO_CONNECT_SUPPORTED;
  81         rc = class_connect(&conn, obd, cluuid);
  82         if (rc) {
  83                 CERROR("can't connect %d\n", rc);
  84                 return rc;
  85         }
  86         *exp = class_conn2export(&conn);
  87
  88         return 0;
  89 }
  90
  91 static int echo_disconnect(struct obd_export *exp)
  92 {
  93         LASSERT (exp != NULL);
  94
  95         return server_disconnect_export(exp);
  96 }
  97
  98 static int echo_init_export(struct obd_export *exp)
  99 {
 100         return ldlm_init_export(exp);
 101 }
 102
 103 static int echo_destroy_export(struct obd_export *exp)
 104 {
 105         ENTRY;
 106
 107         target_destroy_export(exp);
 108         ldlm_destroy_export(exp);
 109
 110         RETURN(0);
 111 }
 112
 113  static __u64 echo_next_id(struct obd_device *obddev)
 114 {
 115         obd_id id;
 116
 117         cfs_spin_lock(&obddev->u.echo.eo_lock);
 118         id = ++obddev->u.echo.eo_lastino;
 119         cfs_spin_unlock(&obddev->u.echo.eo_lock);
 120
 121         return id;
 122 }
 123
 124 static int echo_create(struct obd_export *exp, struct obdo *oa,
 125                        struct lov_stripe_md **ea, struct obd_trans_info *oti)
 126 {
 127         struct obd_device *obd = class_exp2obd(exp);
 128
 129         if (!obd) {
 130                 CERROR("invalid client cookie "LPX64"\n",
 131                        exp->exp_handle.h_cookie);
 132                 return -EINVAL;
 133         }
 134
 135         if (!(oa->o_mode && S_IFMT)) {
 136                 CERROR("echo obd: no type!\n");
 137                 return -ENOENT;
 138         }
 139
 140         if (!(oa->o_valid & OBD_MD_FLTYPE)) {
 141                 CERROR("invalid o_valid "LPX64"\n", oa->o_valid);
 142                 return -EINVAL;
 143         }
 144
 145         oa->o_id = echo_next_id(obd);
 146         oa->o_valid = OBD_MD_FLID;
 147
 148         return 0;
 149 }
 150
 151 static int echo_destroy(struct obd_export *exp, struct obdo *oa,
 152                         struct lov_stripe_md *ea, struct obd_trans_info *oti,
 153                         struct obd_export *md_exp, void *capa)
 154 {
 155         struct obd_device *obd = class_exp2obd(exp);
 156
 157         ENTRY;
 158         if (!obd) {
 159                 CERROR("invalid client cookie "LPX64"\n",
 160                        exp->exp_handle.h_cookie);
 161                 RETURN(-EINVAL);
 162         }
 163
 164         if (!(oa->o_valid & OBD_MD_FLID)) {
 165                 CERROR("obdo missing FLID valid flag: "LPX64"\n", oa->o_valid);
 166                 RETURN(-EINVAL);
 167         }
 168
 169         if (oa->o_id > obd->u.echo.eo_lastino || oa->o_id < ECHO_INIT_OID) {
 170                 CERROR("bad destroy objid: "LPX64"\n", oa->o_id);
 171                 RETURN(-EINVAL);
 172         }
 173
 174         RETURN(0);
 175 }
 176
 177 static int echo_getattr(struct obd_export *exp, struct obd_info *oinfo)
 178 {
 179         struct obd_device *obd = class_exp2obd(exp);
 180         obd_id id = oinfo->oi_oa->o_id;
 181
 182         ENTRY;
 183         if (!obd) {
 184                 CERROR("invalid client cookie "LPX64"\n",
 185                        exp->exp_handle.h_cookie);
 186                 RETURN(-EINVAL);
 187         }
 188
 189         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 190                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 191                        oinfo->oi_oa->o_valid);
 192                 RETURN(-EINVAL);
 193         }
 194
 195         obdo_cpy_md(oinfo->oi_oa, &obd->u.echo.eo_oa, oinfo->oi_oa->o_valid);
 196         oinfo->oi_oa->o_id = id;
 197
 198         RETURN(0);
 199 }
 200
 201 static int echo_setattr(struct obd_export *exp, struct obd_info *oinfo,
 202                         struct obd_trans_info *oti)
 203 {
 204         struct obd_device *obd = class_exp2obd(exp);
 205
 206         ENTRY;
 207         if (!obd) {
 208                 CERROR("invalid client cookie "LPX64"\n",
 209                        exp->exp_handle.h_cookie);
 210                 RETURN(-EINVAL);
 211         }
 212
 213         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 214                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 215                        oinfo->oi_oa->o_valid);
 216                 RETURN(-EINVAL);
 217         }
 218
 219         memcpy(&obd->u.echo.eo_oa, oinfo->oi_oa, sizeof(*oinfo->oi_oa));
 220
 221         if (oinfo->oi_oa->o_id & 4) {
 222                 /* Save lock to force ACKed reply */
 223                 ldlm_lock_addref (&obd->u.echo.eo_nl_lock, LCK_NL);
 224                 oti->oti_ack_locks[0].mode = LCK_NL;
 225                 oti->oti_ack_locks[0].lock = obd->u.echo.eo_nl_lock;
 226         }
 227
 228         RETURN(0);
 229 }
 230
 231 static void
 232 echo_page_debug_setup(cfs_page_t *page, int rw, obd_id id,
 233                       __u64 offset, int len)
 234 {
 235         int   page_offset = offset & ~CFS_PAGE_MASK;
 236         char *addr        = ((char *)cfs_kmap(page)) + page_offset;
 237
 238         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 239                 CERROR("Unexpected block size %d\n", len);
 240
 241         while (len > 0) {
 242                 if (rw & OBD_BRW_READ)
 243                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 244                                           offset, id);
 245                 else
 246                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 247                                           0xecc0ecc0ecc0ecc0ULL,
 248                                           0xecc0ecc0ecc0ecc0ULL);
 249
 250                 addr   += OBD_ECHO_BLOCK_SIZE;
 251                 offset += OBD_ECHO_BLOCK_SIZE;
 252                 len    -= OBD_ECHO_BLOCK_SIZE;
 253         }
 254
 255         cfs_kunmap(page);
 256 }
 257
 258 static int
 259 echo_page_debug_check(cfs_page_t *page, obd_id id,
 260                       __u64 offset, int len)
 261 {
 262         int   page_offset = offset & ~CFS_PAGE_MASK;
 263         char *addr        = ((char *)cfs_kmap(page)) + page_offset;
 264         int   rc          = 0;
 265         int   rc2;
 266
 267         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 268                 CERROR("Unexpected block size %d\n", len);
 269
 270         while (len > 0) {
 271                 rc2 = block_debug_check("echo", addr, OBD_ECHO_BLOCK_SIZE,
 272                                         offset, id);
 273
 274                 if (rc2 != 0 && rc == 0)
 275                         rc = rc2;
 276
 277                 addr   += OBD_ECHO_BLOCK_SIZE;
 278                 offset += OBD_ECHO_BLOCK_SIZE;
 279                 len    -= OBD_ECHO_BLOCK_SIZE;
 280         }
 281
 282         cfs_kunmap(page);
 283
 284         return (rc);
 285 }
 286
 287 /* This allows us to verify that desc_private is passed unmolested */
 288 #define DESC_PRIV 0x10293847
 289
 290 static int echo_map_nb_to_lb(struct obdo *oa, struct obd_ioobj *obj,
 291                              struct niobuf_remote *nb, int *pages,
 292                              struct niobuf_local *lb, int cmd, int *left)
 293 {
 294         int gfp_mask = (obj->ioo_id & 1) ? CFS_ALLOC_HIGHUSER : CFS_ALLOC_STD;
 295         int ispersistent = obj->ioo_id == ECHO_PERSISTENT_OBJID;
 296         int debug_setup = (!ispersistent &&
 297                            (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 298                            (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 299         struct niobuf_local *res = lb;
 300         obd_off offset = nb->offset;
 301         int len = nb->len;
 302
 303         while (len > 0) {
 304                 int plen = CFS_PAGE_SIZE - (offset & (CFS_PAGE_SIZE-1));
 305                 if (len < plen)
 306                         plen = len;
 307
 308                 /* check for local buf overflow */
 309                 if (*left == 0)
 310                         return -EINVAL;
 311
 312                 res->offset = offset;
 313                 res->len = plen;
 314                 LASSERT((res->offset & ~CFS_PAGE_MASK) + res->len <= CFS_PAGE_SIZE);
 315
 316
 317                 if (ispersistent &&
 318                     (res->offset >> CFS_PAGE_SHIFT) < ECHO_PERSISTENT_PAGES) {
 319                         res->page = echo_persistent_pages[res->offset >>
 320                                 CFS_PAGE_SHIFT];
 321                         /* Take extra ref so __free_pages() can be called OK */
 322                         cfs_get_page (res->page);
 323                 } else {
 324                         OBD_PAGE_ALLOC(res->page, gfp_mask);
 325                         if (res->page == NULL) {
 326                                 CERROR("can't get page for id " LPU64"\n",
 327                                        obj->ioo_id);
 328                                 return -ENOMEM;
 329                         }
 330                 }
 331
 332                 CDEBUG(D_PAGE, "$$$$ get page %p @ "LPU64" for %d\n",
 333                        res->page, res->offset, res->len);
 334
 335                 if (cmd & OBD_BRW_READ)
 336                         res->rc = res->len;
 337
 338                 if (debug_setup)
 339                         echo_page_debug_setup(res->page, cmd, obj->ioo_id,
 340                                               res->offset, res->len);
 341
 342                 offset += plen;
 343                 len -= plen;
 344                 res++;
 345
 346                 (*left)--;
 347                 (*pages)++;
 348         }
 349
 350         return 0;
 351 }
 352
 353 static int echo_finalize_lb(struct obdo *oa, struct obd_ioobj *obj,
 354                             struct niobuf_remote *rb, int *pgs,
 355                             struct niobuf_local *lb, int verify)
 356 {
 357         struct niobuf_local *res = lb;
 358         obd_off start  = rb->offset >> CFS_PAGE_SHIFT;
 359         obd_off end    = (rb->offset + rb->len + CFS_PAGE_SIZE - 1) >> CFS_PAGE_SHIFT;
 360         int     count  = (int)(end - start);
 361         int     rc     = 0;
 362         int     i;
 363
 364         for (i = 0; i < count; i++, (*pgs) ++, res++) {
 365                 cfs_page_t *page = res->page;
 366                 void       *addr;
 367
 368                 if (page == NULL) {
 369                         CERROR("null page objid "LPU64":%p, buf %d/%d\n",
 370                                obj->ioo_id, page, i, obj->ioo_bufcnt);
 371                         return -EFAULT;
 372                 }
 373
 374                 addr = cfs_kmap(page);
 375
 376                 CDEBUG(D_PAGE, "$$$$ use page %p, addr %p@"LPU64"\n",
 377                        res->page, addr, res->offset);
 378
 379                 if (verify) {
 380                         int vrc = echo_page_debug_check(page, obj->ioo_id,
 381                                                         res->offset, res->len);
 382                         /* check all the pages always */
 383                         if (vrc != 0 && rc == 0)
 384                                 rc = vrc;
 385                 }
 386
 387                 cfs_kunmap(page);
 388                 /* NB see comment above regarding persistent pages */
 389                 OBD_PAGE_FREE(page);
 390         }
 391
 392         return rc;
 393 }
 394
 395 static int echo_preprw(int cmd, struct obd_export *export, struct obdo *oa,
 396                        int objcount, struct obd_ioobj *obj,
 397                        struct niobuf_remote *nb, int *pages,
 398                        struct niobuf_local *res, struct obd_trans_info *oti,
 399                        struct lustre_capa *unused)
 400 {
 401         struct obd_device *obd;
 402         int tot_bytes = 0;
 403         int rc = 0;
 404         int i, left;
 405         ENTRY;
 406
 407         obd = export->exp_obd;
 408         if (obd == NULL)
 409                 RETURN(-EINVAL);
 410
 411         /* Temp fix to stop falling foul of osc_announce_cached() */
 412         oa->o_valid &= ~(OBD_MD_FLBLOCKS | OBD_MD_FLGRANT);
 413
 414         memset(res, 0, sizeof(*res) * *pages);
 415
 416         CDEBUG(D_PAGE, "%s %d obdos with %d IOs\n",
 417                cmd == OBD_BRW_READ ? "reading" : "writing", objcount, *pages);
 418
 419         if (oti)
 420                 oti->oti_handle = (void *)DESC_PRIV;
 421
 422         left = *pages;
 423         *pages = 0;
 424
 425         for (i = 0; i < objcount; i++, obj++) {
 426                 int j;
 427
 428                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, nb++) {
 429
 430                         rc = echo_map_nb_to_lb(oa, obj, nb, pages,
 431                                                res + *pages, cmd, &left);
 432                         if (rc)
 433                                 GOTO(preprw_cleanup, rc);
 434
 435                         tot_bytes += nb->len;
 436                 }
 437         }
 438
 439         cfs_atomic_add(*pages, &obd->u.echo.eo_prep);
 440
 441         if (cmd & OBD_BRW_READ)
 442                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 443                                     tot_bytes);
 444         else
 445                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 446                                     tot_bytes);
 447
 448         CDEBUG(D_PAGE, "%d pages allocated after prep\n",
 449                cfs_atomic_read(&obd->u.echo.eo_prep));
 450
 451         RETURN(0);
 452
 453 preprw_cleanup:
 454         /* It is possible that we would rather handle errors by  allow
 455          * any already-set-up pages to complete, rather than tearing them
 456          * all down again.  I believe that this is what the in-kernel
 457          * prep/commit operations do.
 458          */
 459         CERROR("cleaning up %u pages (%d obdos)\n", *pages, objcount);
 460         for (i = 0; i < *pages; i++) {
 461                 cfs_kunmap(res[i].page);
 462                 /* NB if this is a persistent page, __free_pages will just
 463                  * lose the extra ref gained above */
 464                 OBD_PAGE_FREE(res[i].page);
 465                 res[i].page = NULL;
 466                 cfs_atomic_dec(&obd->u.echo.eo_prep);
 467         }
 468
 469         return rc;
 470 }
 471
 472 static int echo_commitrw(int cmd, struct obd_export *export, struct obdo *oa,
 473                          int objcount, struct obd_ioobj *obj,
 474                          struct niobuf_remote *rb, int niocount,
 475                          struct niobuf_local *res, struct obd_trans_info *oti,
 476                          int rc)
 477 {
 478         struct obd_device *obd;
 479         int pgs = 0;
 480         int i;
 481         ENTRY;
 482
 483         obd = export->exp_obd;
 484         if (obd == NULL)
 485                 RETURN(-EINVAL);
 486
 487         if (rc)
 488                 GOTO(commitrw_cleanup, rc);
 489
 490         if ((cmd & OBD_BRW_RWMASK) == OBD_BRW_READ) {
 491                 CDEBUG(D_PAGE, "reading %d obdos with %d IOs\n",
 492                        objcount, niocount);
 493         } else {
 494                 CDEBUG(D_PAGE, "writing %d obdos with %d IOs\n",
 495                        objcount, niocount);
 496         }
 497
 498         if (niocount && res == NULL) {
 499                 CERROR("NULL res niobuf with niocount %d\n", niocount);
 500                 RETURN(-EINVAL);
 501         }
 502
 503         LASSERT(oti == NULL || oti->oti_handle == (void *)DESC_PRIV);
 504
 505         for (i = 0; i < objcount; i++, obj++) {
 506                 int verify = (rc == 0 &&
 507                               obj->ioo_id != ECHO_PERSISTENT_OBJID &&
 508                               (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 509                               (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 510                 int j;
 511
 512                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, rb++) {
 513                         int vrc = echo_finalize_lb(oa, obj, rb, &pgs, &res[pgs], verify);
 514
 515                         if (vrc == 0)
 516                                 continue;
 517
 518                         if (vrc == -EFAULT)
 519                                 GOTO(commitrw_cleanup, rc = vrc);
 520
 521                         if (rc == 0)
 522                                 rc = vrc;
 523                 }
 524
 525         }
 526
 527         cfs_atomic_sub(pgs, &obd->u.echo.eo_prep);
 528
 529         CDEBUG(D_PAGE, "%d pages remain after commit\n",
 530                cfs_atomic_read(&obd->u.echo.eo_prep));
 531         RETURN(rc);
 532
 533 commitrw_cleanup:
 534         cfs_atomic_sub(pgs, &obd->u.echo.eo_prep);
 535
 536         CERROR("cleaning up %d pages (%d obdos)\n",
 537                niocount - pgs - 1, objcount);
 538
 539         while (pgs < niocount) {
 540                 cfs_page_t *page = res[pgs++].page;
 541
 542                 if (page == NULL)
 543                         continue;
 544
 545                 /* NB see comment above regarding persistent pages */
 546                 OBD_PAGE_FREE(page);
 547                 cfs_atomic_dec(&obd->u.echo.eo_prep);
 548         }
 549         return rc;
 550 }
 551
 552 static int echo_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
 553 {
 554         struct lprocfs_static_vars lvars;
 555         int                        rc;
 556         int                        lock_flags = 0;
 557         struct ldlm_res_id         res_id = {.name = {1}};
 558         char                       ns_name[48];
 559         ENTRY;
 560
 561         obd->u.echo.eo_obt.obt_magic = OBT_MAGIC;
 562         cfs_spin_lock_init(&obd->u.echo.eo_lock);
 563         obd->u.echo.eo_lastino = ECHO_INIT_OID;
 564
 565         sprintf(ns_name, "echotgt-%s", obd->obd_uuid.uuid);
 566         obd->obd_namespace = ldlm_namespace_new(obd, ns_name,
 567                                                 LDLM_NAMESPACE_SERVER,
 568                                                 LDLM_NAMESPACE_MODEST,
 569                                                 LDLM_NS_TYPE_OST);
 570         if (obd->obd_namespace == NULL) {
 571                 LBUG();
 572                 RETURN(-ENOMEM);
 573         }
 574
 575         rc = ldlm_cli_enqueue_local(obd->obd_namespace, &res_id, LDLM_PLAIN,
 576                                     NULL, LCK_NL, &lock_flags, NULL,
 577                                     ldlm_completion_ast, NULL, NULL, 0, NULL,
 578                                     &obd->u.echo.eo_nl_lock);
 579         LASSERT (rc == ELDLM_OK);
 580
 581         lprocfs_echo_init_vars(&lvars);
 582         if (lprocfs_obd_setup(obd, lvars.obd_vars) == 0 &&
 583             lprocfs_alloc_obd_stats(obd, LPROC_ECHO_LAST) == 0) {
 584                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 585                                      LPROCFS_CNTR_AVGMINMAX,
 586                                      "read_bytes", "bytes");
 587                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 588                                      LPROCFS_CNTR_AVGMINMAX,
 589                                      "write_bytes", "bytes");
 590         }
 591
 592         ptlrpc_init_client (LDLM_CB_REQUEST_PORTAL, LDLM_CB_REPLY_PORTAL,
 593                             "echo_ldlm_cb_client", &obd->obd_ldlm_client);
 594         RETURN(0);
 595 }
 596
 597 static int echo_cleanup(struct obd_device *obd)
 598 {
 599         int leaked;
 600         ENTRY;
 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         cfs_schedule_timeout_and_set_state(CFS_TASK_UNINT, cfs_time_seconds(1));
 610
 611         ldlm_namespace_free(obd->obd_namespace, NULL, obd->obd_force);
 612         obd->obd_namespace = NULL;
 613
 614         leaked = cfs_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         cfs_page_t *pg;
 651         int          i;
 652
 653         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++) {
 654                 int gfp_mask = (i < ECHO_PERSISTENT_PAGES/2) ?
 655                         CFS_ALLOC_STD : CFS_ALLOC_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 (cfs_kmap (pg), 0, CFS_PAGE_SIZE);
 664                 cfs_kunmap (pg);
 665
 666                 echo_persistent_pages[i] = pg;
 667         }
 668
 669         return (0);
 670 }