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 obd_export **exp, struct obd_device *obd,
  70                         struct obd_uuid *cluuid, struct obd_connect_data *data,
  71                         void *localdata)
  72 {
  73         struct lustre_handle conn = { 0 };
  74         int rc;
  75
  76         data->ocd_connect_flags &= ECHO_CONNECT_SUPPORTED;
  77         rc = class_connect(&conn, obd, cluuid);
  78         if (rc) {
  79                 CERROR("can't connect %d\n", rc);
  80                 return rc;
  81         }
  82         *exp = class_conn2export(&conn);
  83
  84         return 0;
  85 }
  86
  87 static int echo_disconnect(struct obd_export *exp)
  88 {
  89         LASSERT (exp != NULL);
  90
  91         ldlm_cancel_locks_for_export(exp);
  92
  93         /* complete all outstanding replies */
  94         spin_lock(&exp->exp_lock);
  95         while (!list_empty(&exp->exp_outstanding_replies)) {
  96                 struct ptlrpc_reply_state *rs =
  97                         list_entry(exp->exp_outstanding_replies.next,
  98                                    struct ptlrpc_reply_state, rs_exp_list);
  99                 struct ptlrpc_service *svc = rs->rs_service;
 100
 101                 spin_lock(&svc->srv_lock);
 102                 list_del_init(&rs->rs_exp_list);
 103                 spin_lock(&rs->rs_lock);
 104                 ptlrpc_schedule_difficult_reply(rs);
 105                 spin_unlock(&rs->rs_lock);
 106                 spin_unlock(&svc->srv_lock);
 107         }
 108         spin_unlock(&exp->exp_lock);
 109
 110         return class_disconnect(exp);
 111 }
 112
 113 static int echo_init_export(struct obd_export *exp)
 114 {
 115         return ldlm_init_export(exp);
 116 }
 117
 118 static int echo_destroy_export(struct obd_export *exp)
 119 {
 120         ENTRY;
 121
 122         target_destroy_export(exp);
 123         ldlm_destroy_export(exp);
 124
 125         RETURN(0);
 126 }
 127
 128  static __u64 echo_next_id(struct obd_device *obddev)
 129 {
 130         obd_id id;
 131
 132         spin_lock(&obddev->u.echo.eo_lock);
 133         id = ++obddev->u.echo.eo_lastino;
 134         spin_unlock(&obddev->u.echo.eo_lock);
 135
 136         return id;
 137 }
 138
 139 int echo_create(struct obd_export *exp, struct obdo *oa,
 140                 struct lov_stripe_md **ea, struct obd_trans_info *oti)
 141 {
 142         struct obd_device *obd = class_exp2obd(exp);
 143
 144         if (!obd) {
 145                 CERROR("invalid client cookie "LPX64"\n",
 146                        exp->exp_handle.h_cookie);
 147                 return -EINVAL;
 148         }
 149
 150         if (!(oa->o_mode && S_IFMT)) {
 151                 CERROR("echo obd: no type!\n");
 152                 return -ENOENT;
 153         }
 154
 155         if (!(oa->o_valid & OBD_MD_FLTYPE)) {
 156                 CERROR("invalid o_valid "LPX64"\n", oa->o_valid);
 157                 return -EINVAL;
 158         }
 159
 160         oa->o_id = echo_next_id(obd);
 161         oa->o_valid = OBD_MD_FLID;
 162
 163         return 0;
 164 }
 165
 166 int echo_destroy(struct obd_export *exp, struct obdo *oa,
 167                  struct lov_stripe_md *ea, struct obd_trans_info *oti,
 168                  struct obd_export *md_exp, void *capa)
 169 {
 170         struct obd_device *obd = class_exp2obd(exp);
 171
 172         ENTRY;
 173         if (!obd) {
 174                 CERROR("invalid client cookie "LPX64"\n",
 175                        exp->exp_handle.h_cookie);
 176                 RETURN(-EINVAL);
 177         }
 178
 179         if (!(oa->o_valid & OBD_MD_FLID)) {
 180                 CERROR("obdo missing FLID valid flag: "LPX64"\n", oa->o_valid);
 181                 RETURN(-EINVAL);
 182         }
 183
 184         if (oa->o_id > obd->u.echo.eo_lastino || oa->o_id < ECHO_INIT_OBJID) {
 185                 CERROR("bad destroy objid: "LPX64"\n", oa->o_id);
 186                 RETURN(-EINVAL);
 187         }
 188
 189         RETURN(0);
 190 }
 191
 192 static int echo_getattr(struct obd_export *exp, struct obd_info *oinfo)
 193 {
 194         struct obd_device *obd = class_exp2obd(exp);
 195         obd_id id = oinfo->oi_oa->o_id;
 196
 197         ENTRY;
 198         if (!obd) {
 199                 CERROR("invalid client cookie "LPX64"\n",
 200                        exp->exp_handle.h_cookie);
 201                 RETURN(-EINVAL);
 202         }
 203
 204         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 205                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 206                        oinfo->oi_oa->o_valid);
 207                 RETURN(-EINVAL);
 208         }
 209
 210         obdo_cpy_md(oinfo->oi_oa, &obd->u.echo.eo_oa, oinfo->oi_oa->o_valid);
 211         oinfo->oi_oa->o_id = id;
 212
 213         RETURN(0);
 214 }
 215
 216 static int echo_setattr(struct obd_export *exp, struct obd_info *oinfo,
 217                         struct obd_trans_info *oti)
 218 {
 219         struct obd_device *obd = class_exp2obd(exp);
 220
 221         ENTRY;
 222         if (!obd) {
 223                 CERROR("invalid client cookie "LPX64"\n",
 224                        exp->exp_handle.h_cookie);
 225                 RETURN(-EINVAL);
 226         }
 227
 228         if (!(oinfo->oi_oa->o_valid & OBD_MD_FLID)) {
 229                 CERROR("obdo missing FLID valid flag: "LPX64"\n",
 230                        oinfo->oi_oa->o_valid);
 231                 RETURN(-EINVAL);
 232         }
 233
 234         memcpy(&obd->u.echo.eo_oa, oinfo->oi_oa, sizeof(*oinfo->oi_oa));
 235
 236         if (oinfo->oi_oa->o_id & 4) {
 237                 /* Save lock to force ACKed reply */
 238                 ldlm_lock_addref (&obd->u.echo.eo_nl_lock, LCK_NL);
 239                 oti->oti_ack_locks[0].mode = LCK_NL;
 240                 oti->oti_ack_locks[0].lock = obd->u.echo.eo_nl_lock;
 241         }
 242
 243         RETURN(0);
 244 }
 245
 246 static void
 247 echo_page_debug_setup(cfs_page_t *page, int rw, obd_id id,
 248                       __u64 offset, int len)
 249 {
 250         int   page_offset = offset & ~CFS_PAGE_MASK;
 251         char *addr        = ((char *)cfs_kmap(page)) + page_offset;
 252
 253         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 254                 CERROR("Unexpected block size %d\n", len);
 255
 256         while (len > 0) {
 257                 if (rw & OBD_BRW_READ)
 258                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 259                                           offset, id);
 260                 else
 261                         block_debug_setup(addr, OBD_ECHO_BLOCK_SIZE,
 262                                           0xecc0ecc0ecc0ecc0ULL,
 263                                           0xecc0ecc0ecc0ecc0ULL);
 264
 265                 addr   += OBD_ECHO_BLOCK_SIZE;
 266                 offset += OBD_ECHO_BLOCK_SIZE;
 267                 len    -= OBD_ECHO_BLOCK_SIZE;
 268         }
 269
 270         cfs_kunmap(page);
 271 }
 272
 273 static int
 274 echo_page_debug_check(cfs_page_t *page, obd_id id,
 275                       __u64 offset, int len)
 276 {
 277         int   page_offset = offset & ~CFS_PAGE_MASK;
 278         char *addr        = ((char *)cfs_kmap(page)) + page_offset;
 279         int   rc          = 0;
 280         int   rc2;
 281
 282         if (len % OBD_ECHO_BLOCK_SIZE != 0)
 283                 CERROR("Unexpected block size %d\n", len);
 284
 285         while (len > 0) {
 286                 rc2 = block_debug_check("echo", addr, OBD_ECHO_BLOCK_SIZE,
 287                                         offset, id);
 288
 289                 if (rc2 != 0 && rc == 0)
 290                         rc = rc2;
 291
 292                 addr   += OBD_ECHO_BLOCK_SIZE;
 293                 offset += OBD_ECHO_BLOCK_SIZE;
 294                 len    -= OBD_ECHO_BLOCK_SIZE;
 295         }
 296
 297         cfs_kunmap(page);
 298
 299         return (rc);
 300 }
 301
 302 /* This allows us to verify that desc_private is passed unmolested */
 303 #define DESC_PRIV 0x10293847
 304
 305 static int echo_map_nb_to_lb(struct obdo *oa, struct obd_ioobj *obj,
 306                              struct niobuf_remote *nb, int *pages,
 307                              struct niobuf_local *lb, int cmd, int *left)
 308 {
 309         int gfp_mask = (obj->ioo_id & 1) ? CFS_ALLOC_HIGHUSER : CFS_ALLOC_STD;
 310         int ispersistent = obj->ioo_id == ECHO_PERSISTENT_OBJID;
 311         int debug_setup = (!ispersistent &&
 312                            (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 313                            (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 314         struct niobuf_local *res = lb;
 315         obd_off offset = nb->offset;
 316         int len = nb->len;
 317
 318         while (len > 0) {
 319                 int plen = CFS_PAGE_SIZE - (offset & (CFS_PAGE_SIZE-1));
 320                 if (len < plen)
 321                         plen = len;
 322
 323                 /* check for local buf overflow */
 324                 if (*left == 0)
 325                         return -EINVAL;
 326
 327                 res->offset = offset;
 328                 res->len = plen;
 329                 LASSERT((res->offset & ~CFS_PAGE_MASK) + res->len <= CFS_PAGE_SIZE);
 330
 331
 332                 if (ispersistent &&
 333                     (res->offset >> CFS_PAGE_SHIFT) < ECHO_PERSISTENT_PAGES) {
 334                         res->page = echo_persistent_pages[res->offset >>
 335                                 CFS_PAGE_SHIFT];
 336                         /* Take extra ref so __free_pages() can be called OK */
 337                         cfs_get_page (res->page);
 338                 } else {
 339                         OBD_PAGE_ALLOC(res->page, gfp_mask);
 340                         if (res->page == NULL) {
 341                                 CERROR("can't get page for id " LPU64"\n",
 342                                        obj->ioo_id);
 343                                 return -ENOMEM;
 344                         }
 345                 }
 346
 347                 CDEBUG(D_PAGE, "$$$$ get page %p @ "LPU64" for %d\n",
 348                        res->page, res->offset, res->len);
 349
 350                 if (cmd & OBD_BRW_READ)
 351                         res->rc = res->len;
 352
 353                 if (debug_setup)
 354                         echo_page_debug_setup(res->page, cmd, obj->ioo_id,
 355                                               res->offset, res->len);
 356
 357                 offset += plen;
 358                 len -= plen;
 359                 res++;
 360
 361                 (*left)--;
 362                 (*pages)++;
 363         }
 364
 365         return 0;
 366 }
 367
 368 int echo_preprw(int cmd, struct obd_export *export, struct obdo *oa,
 369                 int objcount, struct obd_ioobj *obj, struct niobuf_remote *nb,
 370                 int *pages, struct niobuf_local *res,
 371                 struct obd_trans_info *oti, struct lustre_capa *unused)
 372 {
 373         struct obd_device *obd;
 374         struct niobuf_local *r = res;
 375         int tot_bytes = 0;
 376         int rc = 0;
 377         int i, left;
 378         ENTRY;
 379
 380         obd = export->exp_obd;
 381         if (obd == NULL)
 382                 RETURN(-EINVAL);
 383
 384         /* Temp fix to stop falling foul of osc_announce_cached() */
 385         oa->o_valid &= ~(OBD_MD_FLBLOCKS | OBD_MD_FLGRANT);
 386
 387         memset(res, 0, sizeof(*res) * *pages);
 388
 389         CDEBUG(D_PAGE, "%s %d obdos with %d IOs\n",
 390                cmd == OBD_BRW_READ ? "reading" : "writing", objcount, *pages);
 391
 392         if (oti)
 393                 oti->oti_handle = (void *)DESC_PRIV;
 394
 395         left = *pages;
 396         *pages = 0;
 397
 398         for (i = 0; i < objcount; i++, obj++) {
 399                 int j;
 400
 401                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, nb++, r++) {
 402
 403                         rc = echo_map_nb_to_lb(oa, obj, nb, pages,
 404                                                res + *pages, cmd, &left);
 405                         if (rc)
 406                                 GOTO(preprw_cleanup, rc);
 407
 408                         tot_bytes += nb->len;
 409                 }
 410         }
 411
 412         atomic_add(*pages, &obd->u.echo.eo_prep);
 413
 414         if (cmd & OBD_BRW_READ)
 415                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 416                                     tot_bytes);
 417         else
 418                 lprocfs_counter_add(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 419                                     tot_bytes);
 420
 421         CDEBUG(D_PAGE, "%d pages allocated after prep\n",
 422                atomic_read(&obd->u.echo.eo_prep));
 423
 424         RETURN(0);
 425
 426 preprw_cleanup:
 427         /* It is possible that we would rather handle errors by  allow
 428          * any already-set-up pages to complete, rather than tearing them
 429          * all down again.  I believe that this is what the in-kernel
 430          * prep/commit operations do.
 431          */
 432         CERROR("cleaning up %u pages (%d obdos)\n", *pages, objcount);
 433         for (i = 0; i < *pages; i++) {
 434                 cfs_kunmap(res[i].page);
 435                 /* NB if this is a persistent page, __free_pages will just
 436                  * lose the extra ref gained above */
 437                 OBD_PAGE_FREE(res[i].page);
 438                 res[i].page = NULL;
 439                 atomic_dec(&obd->u.echo.eo_prep);
 440         }
 441
 442         return rc;
 443 }
 444
 445 int echo_commitrw(int cmd, struct obd_export *export, struct obdo *oa,
 446                   int objcount, struct obd_ioobj *obj,
 447                   struct niobuf_remote *rb, int niocount,
 448                   struct niobuf_local *res, struct obd_trans_info *oti, int rc)
 449 {
 450         struct obd_device *obd;
 451         struct niobuf_local *r = res;
 452         int i, vrc = 0;
 453         ENTRY;
 454
 455         obd = export->exp_obd;
 456         if (obd == NULL)
 457                 RETURN(-EINVAL);
 458
 459         if (rc)
 460                 GOTO(commitrw_cleanup, rc);
 461
 462         if ((cmd & OBD_BRW_RWMASK) == OBD_BRW_READ) {
 463                 CDEBUG(D_PAGE, "reading %d obdos with %d IOs\n",
 464                        objcount, niocount);
 465         } else {
 466                 CDEBUG(D_PAGE, "writing %d obdos with %d IOs\n",
 467                        objcount, niocount);
 468         }
 469
 470         if (niocount && !r) {
 471                 CERROR("NULL res niobuf with niocount %d\n", niocount);
 472                 RETURN(-EINVAL);
 473         }
 474
 475         LASSERT(oti == NULL || oti->oti_handle == (void *)DESC_PRIV);
 476
 477         for (i = 0; i < objcount; i++, obj++) {
 478                 int verify = (rc == 0 &&
 479                               obj->ioo_id != ECHO_PERSISTENT_OBJID &&
 480                               (oa->o_valid & OBD_MD_FLFLAGS) != 0 &&
 481                               (oa->o_flags & OBD_FL_DEBUG_CHECK) != 0);
 482                 int j;
 483
 484                 for (j = 0 ; j < obj->ioo_bufcnt ; j++, r++) {
 485                         cfs_page_t *page = r->page;
 486                         void *addr;
 487
 488                         if (page == NULL) {
 489                                 CERROR("null page objid "LPU64":%p, buf %d/%d\n",
 490                                        obj->ioo_id, page, j, obj->ioo_bufcnt);
 491                                 GOTO(commitrw_cleanup, rc = -EFAULT);
 492                         }
 493
 494                         addr = cfs_kmap(page);
 495
 496                         CDEBUG(D_PAGE, "$$$$ use page %p, addr %p@"LPU64"\n",
 497                                r->page, addr, r->offset);
 498
 499                         if (verify) {
 500                                 vrc = echo_page_debug_check(page, obj->ioo_id,
 501                                                             r->offset, r->len);
 502                                 /* check all the pages always */
 503                                 if (vrc != 0 && rc == 0)
 504                                         rc = vrc;
 505                         }
 506
 507                         cfs_kunmap(page);
 508                         /* NB see comment above regarding persistent pages */
 509                         OBD_PAGE_FREE(page);
 510                         atomic_dec(&obd->u.echo.eo_prep);
 511                 }
 512         }
 513         CDEBUG(D_PAGE, "%d pages remain after commit\n",
 514                atomic_read(&obd->u.echo.eo_prep));
 515         RETURN(rc);
 516
 517 commitrw_cleanup:
 518         CERROR("cleaning up %ld pages (%d obdos)\n",
 519                niocount - (long)(r - res) - 1, objcount);
 520         while (++r < res + niocount) {
 521                 cfs_page_t *page = r->page;
 522
 523                 /* NB see comment above regarding persistent pages */
 524                 OBD_PAGE_FREE(page);
 525                 atomic_dec(&obd->u.echo.eo_prep);
 526         }
 527         return rc;
 528 }
 529
 530 static int echo_setup(struct obd_device *obd, struct lustre_cfg *lcfg)
 531 {
 532         struct lprocfs_static_vars lvars;
 533         int                        rc;
 534         int                        lock_flags = 0;
 535         struct ldlm_res_id         res_id = {.name = {1}};
 536         ENTRY;
 537
 538         spin_lock_init(&obd->u.echo.eo_lock);
 539         obd->u.echo.eo_lastino = ECHO_INIT_OBJID;
 540
 541         obd->obd_namespace = ldlm_namespace_new(obd, "echo-tgt",
 542                                                 LDLM_NAMESPACE_SERVER,
 543                                                 LDLM_NAMESPACE_MODEST);
 544         if (obd->obd_namespace == NULL) {
 545                 LBUG();
 546                 RETURN(-ENOMEM);
 547         }
 548
 549         rc = ldlm_cli_enqueue_local(obd->obd_namespace, &res_id, LDLM_PLAIN,
 550                                     NULL, LCK_NL, &lock_flags, NULL,
 551                                     ldlm_completion_ast, NULL, NULL,
 552                                     0, NULL, NULL, &obd->u.echo.eo_nl_lock);
 553         LASSERT (rc == ELDLM_OK);
 554
 555         lprocfs_echo_init_vars(&lvars);
 556         if (lprocfs_obd_setup(obd, lvars.obd_vars) == 0 &&
 557             lprocfs_alloc_obd_stats(obd, LPROC_ECHO_LAST) == 0) {
 558                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_READ_BYTES,
 559                                      LPROCFS_CNTR_AVGMINMAX,
 560                                      "read_bytes", "bytes");
 561                 lprocfs_counter_init(obd->obd_stats, LPROC_ECHO_WRITE_BYTES,
 562                                      LPROCFS_CNTR_AVGMINMAX,
 563                                      "write_bytes", "bytes");
 564         }
 565
 566         ptlrpc_init_client (LDLM_CB_REQUEST_PORTAL, LDLM_CB_REPLY_PORTAL,
 567                             "echo_ldlm_cb_client", &obd->obd_ldlm_client);
 568         RETURN(0);
 569 }
 570
 571 static int echo_cleanup(struct obd_device *obd)
 572 {
 573         int leaked;
 574         ENTRY;
 575
 576         lprocfs_obd_cleanup(obd);
 577         lprocfs_free_obd_stats(obd);
 578
 579         ldlm_lock_decref (&obd->u.echo.eo_nl_lock, LCK_NL);
 580
 581         /* XXX Bug 3413; wait for a bit to ensure the BL callback has
 582          * happened before calling ldlm_namespace_free() */
 583         cfs_schedule_timeout (CFS_TASK_UNINT, cfs_time_seconds(1));
 584
 585         ldlm_namespace_free(obd->obd_namespace, NULL, obd->obd_force);
 586         obd->obd_namespace = NULL;
 587
 588         leaked = atomic_read(&obd->u.echo.eo_prep);
 589         if (leaked != 0)
 590                 CERROR("%d prep/commitrw pages leaked\n", leaked);
 591
 592         RETURN(0);
 593 }
 594
 595 static struct obd_ops echo_obd_ops = {
 596         .o_owner           = THIS_MODULE,
 597         .o_connect         = echo_connect,
 598         .o_disconnect      = echo_disconnect,
 599         .o_init_export     = echo_init_export,
 600         .o_destroy_export  = echo_destroy_export,
 601         .o_create          = echo_create,
 602         .o_destroy         = echo_destroy,
 603         .o_getattr         = echo_getattr,
 604         .o_setattr         = echo_setattr,
 605         .o_preprw          = echo_preprw,
 606         .o_commitrw        = echo_commitrw,
 607         .o_setup           = echo_setup,
 608         .o_cleanup         = echo_cleanup
 609 };
 610
 611 extern int echo_client_init(void);
 612 extern void echo_client_exit(void);
 613
 614 static void
 615 echo_persistent_pages_fini (void)
 616 {
 617         int     i;
 618
 619         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++)
 620                 if (echo_persistent_pages[i] != NULL) {
 621                         OBD_PAGE_FREE(echo_persistent_pages[i]);
 622                         echo_persistent_pages[i] = NULL;
 623                 }
 624 }
 625
 626 static int
 627 echo_persistent_pages_init (void)
 628 {
 629         cfs_page_t *pg;
 630         int          i;
 631
 632         for (i = 0; i < ECHO_PERSISTENT_PAGES; i++) {
 633                 int gfp_mask = (i < ECHO_PERSISTENT_PAGES/2) ?
 634                         CFS_ALLOC_STD : CFS_ALLOC_HIGHUSER;
 635
 636                 OBD_PAGE_ALLOC(pg, gfp_mask);
 637                 if (pg == NULL) {
 638                         echo_persistent_pages_fini ();
 639                         return (-ENOMEM);
 640                 }
 641
 642                 memset (cfs_kmap (pg), 0, CFS_PAGE_SIZE);
 643                 cfs_kunmap (pg);
 644
 645                 echo_persistent_pages[i] = pg;
 646         }
 647
 648         return (0);
 649 }
 650
 651 static int __init obdecho_init(void)
 652 {
 653         struct lprocfs_static_vars lvars;
 654         int rc;
 655
 656         ENTRY;
 657         LCONSOLE_INFO("Echo OBD driver; http://www.lustre.org/\n");
 658
 659         LASSERT(CFS_PAGE_SIZE % OBD_ECHO_BLOCK_SIZE == 0);
 660
 661         lprocfs_echo_init_vars(&lvars);
 662
 663         rc = echo_persistent_pages_init ();
 664         if (rc != 0)
 665                 goto failed_0;
 666
 667         rc = class_register_type(&echo_obd_ops, NULL, lvars.module_vars,
 668                                  LUSTRE_ECHO_NAME, NULL);
 669         if (rc != 0)
 670                 goto failed_1;
 671
 672         rc = echo_client_init();
 673         if (rc == 0)
 674                 RETURN (0);
 675
 676         class_unregister_type(LUSTRE_ECHO_NAME);
 677  failed_1:
 678         echo_persistent_pages_fini ();
 679  failed_0:
 680         RETURN(rc);
 681 }
 682
 683 static void /*__exit*/ obdecho_exit(void)
 684 {
 685         echo_client_exit();
 686         class_unregister_type(LUSTRE_ECHO_NAME);
 687         echo_persistent_pages_fini ();
 688 }
 689
 690 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 691 MODULE_DESCRIPTION("Lustre Testing Echo OBD driver");
 692 MODULE_LICENSE("GPL");
 693
 694 cfs_module(obdecho, "1.0.0", obdecho_init, obdecho_exit);