lustre/obdclass/genops.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  *  Copyright (c) 2001-2003 Cluster File Systems, Inc.
   5  *
   6  *   This file is part of the Lustre file system, http://www.lustre.org
   7  *   Lustre is a trademark of Cluster File Systems, Inc.
   8  *
   9  *   You may have signed or agreed to another license before downloading
  10  *   this software.  If so, you are bound by the terms and conditions
  11  *   of that agreement, and the following does not apply to you.  See the
  12  *   LICENSE file included with this distribution for more information.
  13  *
  14  *   If you did not agree to a different license, then this copy of Lustre
  15  *   is open source software; you can redistribute it and/or modify it
  16  *   under the terms of version 2 of the GNU General Public License as
  17  *   published by the Free Software Foundation.
  18  *
  19  *   In either case, Lustre is distributed in the hope that it will be
  20  *   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  21  *   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  *   license text for more details.
  23  *
  24  * These are the only exported functions, they provide some generic
  25  * infrastructure for managing object devices
  26  */
  27
  28 #define DEBUG_SUBSYSTEM S_CLASS
  29 #ifndef __KERNEL__
  30 #include <liblustre.h>
  31 #endif
  32 #include <obd_ost.h>
  33 #include <obd_class.h>
  34 #include <lprocfs_status.h>
  35
  36 extern struct list_head obd_types;
  37 spinlock_t obd_types_lock;
  38
  39 cfs_mem_cache_t *obd_device_cachep;
  40 cfs_mem_cache_t *obdo_cachep;
  41 EXPORT_SYMBOL(obdo_cachep);
  42 cfs_mem_cache_t *import_cachep;
  43
  44 struct list_head  obd_zombie_imports;
  45 struct list_head  obd_zombie_exports;
  46 spinlock_t        obd_zombie_impexp_lock;
  47 void            (*obd_zombie_impexp_notify)(void) = NULL;
  48 EXPORT_SYMBOL(obd_zombie_impexp_notify);
  49
  50
  51 int (*ptlrpc_put_connection_superhack)(struct ptlrpc_connection *c);
  52
  53 /*
  54  * support functions: we could use inter-module communication, but this
  55  * is more portable to other OS's
  56  */
  57 static struct obd_device *obd_device_alloc(void)
  58 {
  59         struct obd_device *obd;
  60
  61         OBD_SLAB_ALLOC_PTR(obd, obd_device_cachep);
  62         if (obd != NULL) {
  63                 obd->obd_magic = OBD_DEVICE_MAGIC;
  64         }
  65         return obd;
  66 }
  67 EXPORT_SYMBOL(obd_device_alloc);
  68
  69 static void obd_device_free(struct obd_device *obd)
  70 {
  71         LASSERT(obd != NULL);
  72         LASSERTF(obd->obd_magic == OBD_DEVICE_MAGIC, "obd %p obd_magic %08x != %08x\n",
  73                  obd, obd->obd_magic, OBD_DEVICE_MAGIC);
  74         OBD_SLAB_FREE_PTR(obd, obd_device_cachep);
  75 }
  76 EXPORT_SYMBOL(obd_device_free);
  77
  78 struct obd_type *class_search_type(const char *name)
  79 {
  80         struct list_head *tmp;
  81         struct obd_type *type;
  82
  83         spin_lock(&obd_types_lock);
  84         list_for_each(tmp, &obd_types) {
  85                 type = list_entry(tmp, struct obd_type, typ_chain);
  86                 if (strcmp(type->typ_name, name) == 0) {
  87                         spin_unlock(&obd_types_lock);
  88                         return type;
  89                 }
  90         }
  91         spin_unlock(&obd_types_lock);
  92         return NULL;
  93 }
  94
  95 struct obd_type *class_get_type(const char *name)
  96 {
  97         struct obd_type *type = class_search_type(name);
  98
  99 #ifdef CONFIG_KMOD
 100         if (!type) {
 101                 const char *modname = name;
 102                 if (!request_module(modname)) {
 103                         CDEBUG(D_INFO, "Loaded module '%s'\n", modname);
 104                         type = class_search_type(name);
 105                 } else {
 106                         LCONSOLE_ERROR_MSG(0x158, "Can't load module '%s'\n",
 107                                            modname);
 108                 }
 109         }
 110 #endif
 111         if (type) {
 112                 spin_lock(&type->obd_type_lock);
 113                 type->typ_refcnt++;
 114                 try_module_get(type->typ_dt_ops->o_owner);
 115                 spin_unlock(&type->obd_type_lock);
 116         }
 117         return type;
 118 }
 119
 120 void class_put_type(struct obd_type *type)
 121 {
 122         LASSERT(type);
 123         spin_lock(&type->obd_type_lock);
 124         type->typ_refcnt--;
 125         module_put(type->typ_dt_ops->o_owner);
 126         spin_unlock(&type->obd_type_lock);
 127 }
 128
 129 #define CLASS_MAX_NAME 1024
 130
 131 int class_register_type(struct obd_ops *dt_ops, struct md_ops *md_ops,
 132                         struct lprocfs_vars *vars, const char *name,
 133                         struct lu_device_type *ldt)
 134 {
 135         struct obd_type *type;
 136         int rc = 0;
 137         ENTRY;
 138
 139         /* sanity check */
 140         LASSERT(strnlen(name, CLASS_MAX_NAME) < CLASS_MAX_NAME);
 141
 142         if (class_search_type(name)) {
 143                 CDEBUG(D_IOCTL, "Type %s already registered\n", name);
 144                 RETURN(-EEXIST);
 145         }
 146
 147         rc = -ENOMEM;
 148         OBD_ALLOC(type, sizeof(*type));
 149         if (type == NULL)
 150                 RETURN(rc);
 151
 152         OBD_ALLOC_PTR(type->typ_dt_ops);
 153         OBD_ALLOC_PTR(type->typ_md_ops);
 154         OBD_ALLOC(type->typ_name, strlen(name) + 1);
 155
 156         if (type->typ_dt_ops == NULL ||
 157             type->typ_md_ops == NULL ||
 158             type->typ_name == NULL)
 159                 GOTO (failed, rc);
 160
 161         *(type->typ_dt_ops) = *dt_ops;
 162         /* md_ops is optional */
 163         if (md_ops)
 164                 *(type->typ_md_ops) = *md_ops;
 165         strcpy(type->typ_name, name);
 166         spin_lock_init(&type->obd_type_lock);
 167
 168 #ifdef LPROCFS
 169         type->typ_procroot = lprocfs_register(type->typ_name, proc_lustre_root,
 170                                               vars, type);
 171         if (IS_ERR(type->typ_procroot)) {
 172                 rc = PTR_ERR(type->typ_procroot);
 173                 type->typ_procroot = NULL;
 174                 GOTO (failed, rc);
 175         }
 176 #endif
 177         if (ldt != NULL) {
 178                 type->typ_lu = ldt;
 179                 rc = ldt->ldt_ops->ldto_init(ldt);
 180                 if (rc != 0)
 181                         GOTO (failed, rc);
 182         }
 183
 184         spin_lock(&obd_types_lock);
 185         list_add(&type->typ_chain, &obd_types);
 186         spin_unlock(&obd_types_lock);
 187
 188         RETURN (0);
 189
 190  failed:
 191         if (type->typ_name != NULL)
 192                 OBD_FREE(type->typ_name, strlen(name) + 1);
 193         if (type->typ_md_ops != NULL)
 194                 OBD_FREE_PTR(type->typ_md_ops);
 195         if (type->typ_dt_ops != NULL)
 196                 OBD_FREE_PTR(type->typ_dt_ops);
 197         OBD_FREE(type, sizeof(*type));
 198         RETURN(rc);
 199 }
 200
 201 int class_unregister_type(const char *name)
 202 {
 203         struct obd_type *type = class_search_type(name);
 204         ENTRY;
 205
 206         if (!type) {
 207                 CERROR("unknown obd type\n");
 208                 RETURN(-EINVAL);
 209         }
 210
 211         if (type->typ_refcnt) {
 212                 CERROR("type %s has refcount (%d)\n", name, type->typ_refcnt);
 213                 /* This is a bad situation, let's make the best of it */
 214                 /* Remove ops, but leave the name for debugging */
 215                 OBD_FREE_PTR(type->typ_dt_ops);
 216                 OBD_FREE_PTR(type->typ_md_ops);
 217                 RETURN(-EBUSY);
 218         }
 219
 220         if (type->typ_procroot) {
 221                 lprocfs_remove(&type->typ_procroot);
 222         }
 223
 224         if (type->typ_lu)
 225                 type->typ_lu->ldt_ops->ldto_fini(type->typ_lu);
 226
 227         spin_lock(&obd_types_lock);
 228         list_del(&type->typ_chain);
 229         spin_unlock(&obd_types_lock);
 230         OBD_FREE(type->typ_name, strlen(name) + 1);
 231         if (type->typ_dt_ops != NULL)
 232                 OBD_FREE_PTR(type->typ_dt_ops);
 233         if (type->typ_md_ops != NULL)
 234                 OBD_FREE_PTR(type->typ_md_ops);
 235         OBD_FREE(type, sizeof(*type));
 236         RETURN(0);
 237 } /* class_unregister_type */
 238
 239 struct obd_device *class_newdev(const char *type_name, const char *name)
 240 {
 241         struct obd_device *result = NULL;
 242         struct obd_device *newdev;
 243         struct obd_type *type = NULL;
 244         int i;
 245         int new_obd_minor = 0;
 246
 247         if (strlen(name) > MAX_OBD_NAME) {
 248                 CERROR("name/uuid must be < %u bytes long\n", MAX_OBD_NAME);
 249                 RETURN(ERR_PTR(-EINVAL));
 250         }
 251
 252         type = class_get_type(type_name);
 253         if (type == NULL){
 254                 CERROR("OBD: unknown type: %s\n", type_name);
 255                 RETURN(ERR_PTR(-ENODEV));
 256         }
 257
 258         newdev = obd_device_alloc();
 259         if (newdev == NULL) {
 260                 class_put_type(type);
 261                 RETURN(ERR_PTR(-ENOMEM));
 262         }
 263         LASSERT(newdev->obd_magic == OBD_DEVICE_MAGIC);
 264
 265         spin_lock(&obd_dev_lock);
 266         for (i = 0; i < class_devno_max(); i++) {
 267                 struct obd_device *obd = class_num2obd(i);
 268                 if (obd && obd->obd_name &&
 269                     (strcmp(name, obd->obd_name) == 0)) {
 270                         CERROR("Device %s already exists, won't add\n", name);
 271                         if (result) {
 272                                 LASSERTF(result->obd_magic == OBD_DEVICE_MAGIC,
 273                                          "%p obd_magic %08x != %08x\n", result,
 274                                          result->obd_magic, OBD_DEVICE_MAGIC);
 275                                 LASSERTF(result->obd_minor == new_obd_minor,
 276                                          "%p obd_minor %d != %d\n", result,
 277                                          result->obd_minor, new_obd_minor);
 278
 279                                 obd_devs[result->obd_minor] = NULL;
 280                                 result->obd_name[0]='\0';
 281                          }
 282                         result = ERR_PTR(-EEXIST);
 283                         break;
 284                 }
 285                 if (!result && !obd) {
 286                         result = newdev;
 287                         result->obd_minor = i;
 288                         new_obd_minor = i;
 289                         result->obd_type = type;
 290                         memcpy(result->obd_name, name, strlen(name));
 291                         obd_devs[i] = result;
 292                 }
 293         }
 294         spin_unlock(&obd_dev_lock);
 295
 296         if (result == NULL && i >= class_devno_max()) {
 297                 CERROR("all %u OBD devices used, increase MAX_OBD_DEVICES\n",
 298                        class_devno_max());
 299                 result = ERR_PTR(-EOVERFLOW);
 300         }
 301
 302         if (IS_ERR(result)) {
 303                 obd_device_free(newdev);
 304                 class_put_type(type);
 305         } else {
 306                 CDEBUG(D_IOCTL, "Adding new device %s (%p)\n",
 307                        result->obd_name, result);
 308         }
 309         return result;
 310 }
 311
 312 void class_release_dev(struct obd_device *obd)
 313 {
 314         struct obd_type *obd_type = obd->obd_type;
 315
 316         LASSERTF(obd->obd_magic == OBD_DEVICE_MAGIC, "%p obd_magic %08x != %08x\n",
 317                  obd, obd->obd_magic, OBD_DEVICE_MAGIC);
 318         LASSERTF(obd == obd_devs[obd->obd_minor], "obd %p != obd_devs[%d] %p\n",
 319                  obd, obd->obd_minor, obd_devs[obd->obd_minor]);
 320         LASSERT(obd_type != NULL);
 321
 322         CDEBUG(D_INFO, "Release obd device %s obd_type name =%s\n",
 323                obd->obd_name,obd->obd_type->typ_name);
 324
 325         spin_lock(&obd_dev_lock);
 326         obd_devs[obd->obd_minor] = NULL;
 327         spin_unlock(&obd_dev_lock);
 328         obd_device_free(obd);
 329
 330         class_put_type(obd_type);
 331 }
 332
 333 int class_name2dev(const char *name)
 334 {
 335         int i;
 336
 337         if (!name)
 338                 return -1;
 339
 340         spin_lock(&obd_dev_lock);
 341         for (i = 0; i < class_devno_max(); i++) {
 342                 struct obd_device *obd = class_num2obd(i);
 343                 if (obd && obd->obd_name && strcmp(name, obd->obd_name) == 0) {
 344                         /* Make sure we finished attaching before we give
 345                            out any references */
 346                         LASSERT(obd->obd_magic == OBD_DEVICE_MAGIC);
 347                         if (obd->obd_attached) {
 348                                 spin_unlock(&obd_dev_lock);
 349                                 return i;
 350                         }
 351                         break;
 352                 }
 353         }
 354         spin_unlock(&obd_dev_lock);
 355
 356         return -1;
 357 }
 358
 359 struct obd_device *class_name2obd(const char *name)
 360 {
 361         int dev = class_name2dev(name);
 362
 363         if (dev < 0 || dev > class_devno_max())
 364                 return NULL;
 365         return class_num2obd(dev);
 366 }
 367
 368 int class_uuid2dev(struct obd_uuid *uuid)
 369 {
 370         int i;
 371
 372         spin_lock(&obd_dev_lock);
 373         for (i = 0; i < class_devno_max(); i++) {
 374                 struct obd_device *obd = class_num2obd(i);
 375                 if (obd && obd_uuid_equals(uuid, &obd->obd_uuid)) {
 376                         LASSERT(obd->obd_magic == OBD_DEVICE_MAGIC);
 377                         spin_unlock(&obd_dev_lock);
 378                         return i;
 379                 }
 380         }
 381         spin_unlock(&obd_dev_lock);
 382
 383         return -1;
 384 }
 385
 386 struct obd_device *class_uuid2obd(struct obd_uuid *uuid)
 387 {
 388         int dev = class_uuid2dev(uuid);
 389         if (dev < 0)
 390                 return NULL;
 391         return class_num2obd(dev);
 392 }
 393
 394 struct obd_device *class_num2obd(int num)
 395 {
 396         struct obd_device *obd = NULL;
 397
 398         if (num < class_devno_max()) {
 399                 obd = obd_devs[num];
 400                 if (obd == NULL) {
 401                         return NULL;
 402                 }
 403
 404                 LASSERTF(obd->obd_magic == OBD_DEVICE_MAGIC,
 405                          "%p obd_magic %08x != %08x\n",
 406                          obd, obd->obd_magic, OBD_DEVICE_MAGIC);
 407                 LASSERTF(obd->obd_minor == num,
 408                          "%p obd_minor %0d != %0d\n",
 409                          obd, obd->obd_minor, num);
 410         }
 411
 412         return obd;
 413 }
 414
 415 void class_obd_list(void)
 416 {
 417         char *status;
 418         int i;
 419
 420         spin_lock(&obd_dev_lock);
 421         for (i = 0; i < class_devno_max(); i++) {
 422                 struct obd_device *obd = class_num2obd(i);
 423                 if (obd == NULL)
 424                         continue;
 425                 if (obd->obd_stopping)
 426                         status = "ST";
 427                 else if (obd->obd_set_up)
 428                         status = "UP";
 429                 else if (obd->obd_attached)
 430                         status = "AT";
 431                 else
 432                         status = "--";
 433                 LCONSOLE(D_CONFIG, "%3d %s %s %s %s %d\n",
 434                          i, status, obd->obd_type->typ_name,
 435                          obd->obd_name, obd->obd_uuid.uuid,
 436                          atomic_read(&obd->obd_refcount));
 437         }
 438         spin_unlock(&obd_dev_lock);
 439         return;
 440 }
 441
 442 /* Search for a client OBD connected to tgt_uuid.  If grp_uuid is
 443    specified, then only the client with that uuid is returned,
 444    otherwise any client connected to the tgt is returned. */
 445 struct obd_device * class_find_client_obd(struct obd_uuid *tgt_uuid,
 446                                           const char * typ_name,
 447                                           struct obd_uuid *grp_uuid)
 448 {
 449         int i;
 450
 451         spin_lock(&obd_dev_lock);
 452         for (i = 0; i < class_devno_max(); i++) {
 453                 struct obd_device *obd = class_num2obd(i);
 454                 if (obd == NULL)
 455                         continue;
 456                 if ((strncmp(obd->obd_type->typ_name, typ_name,
 457                              strlen(typ_name)) == 0)) {
 458                         if (obd_uuid_equals(tgt_uuid,
 459                                             &obd->u.cli.cl_target_uuid) &&
 460                             ((grp_uuid)? obd_uuid_equals(grp_uuid,
 461                                                          &obd->obd_uuid) : 1)) {
 462                                 spin_unlock(&obd_dev_lock);
 463                                 return obd;
 464                         }
 465                 }
 466         }
 467         spin_unlock(&obd_dev_lock);
 468
 469         return NULL;
 470 }
 471
 472 struct obd_device *class_find_client_notype(struct obd_uuid *tgt_uuid,
 473                                             struct obd_uuid *grp_uuid)
 474 {
 475         struct obd_device *obd;
 476
 477         obd = class_find_client_obd(tgt_uuid, LUSTRE_MDC_NAME, NULL);
 478         if (!obd)
 479                 obd = class_find_client_obd(tgt_uuid, LUSTRE_OSC_NAME,
 480                                             grp_uuid);
 481         return obd;
 482 }
 483
 484 /* Iterate the obd_device list looking devices have grp_uuid. Start
 485    searching at *next, and if a device is found, the next index to look
 486    at is saved in *next. If next is NULL, then the first matching device
 487    will always be returned. */
 488 struct obd_device * class_devices_in_group(struct obd_uuid *grp_uuid, int *next)
 489 {
 490         int i;
 491
 492         if (next == NULL)
 493                 i = 0;
 494         else if (*next >= 0 && *next < class_devno_max())
 495                 i = *next;
 496         else
 497                 return NULL;
 498
 499         spin_lock(&obd_dev_lock);
 500         for (; i < class_devno_max(); i++) {
 501                 struct obd_device *obd = class_num2obd(i);
 502                 if (obd == NULL)
 503                         continue;
 504                 if (obd_uuid_equals(grp_uuid, &obd->obd_uuid)) {
 505                         if (next != NULL)
 506                                 *next = i+1;
 507                         spin_unlock(&obd_dev_lock);
 508                         return obd;
 509                 }
 510         }
 511         spin_unlock(&obd_dev_lock);
 512
 513         return NULL;
 514 }
 515
 516
 517 void obd_cleanup_caches(void)
 518 {
 519         int rc;
 520
 521         ENTRY;
 522         if (obd_device_cachep) {
 523                 rc = cfs_mem_cache_destroy(obd_device_cachep);
 524                 LASSERTF(rc == 0, "Cannot destropy ll_obd_device_cache: rc %d\n", rc);
 525                 obd_device_cachep = NULL;
 526         }
 527         if (obdo_cachep) {
 528                 rc = cfs_mem_cache_destroy(obdo_cachep);
 529                 LASSERTF(rc == 0, "Cannot destory ll_obdo_cache\n");
 530                 obdo_cachep = NULL;
 531         }
 532         if (import_cachep) {
 533                 rc = cfs_mem_cache_destroy(import_cachep);
 534                 LASSERTF(rc == 0, "Cannot destory ll_import_cache\n");
 535                 import_cachep = NULL;
 536         }
 537         if (capa_cachep) {
 538                 rc = cfs_mem_cache_destroy(capa_cachep);
 539                 LASSERTF(rc == 0, "Cannot destory capa_cache\n");
 540                 capa_cachep = NULL;
 541         }
 542         EXIT;
 543 }
 544
 545 int obd_init_caches(void)
 546 {
 547         ENTRY;
 548
 549         LASSERT(obd_device_cachep == NULL);
 550         obd_device_cachep = cfs_mem_cache_create("ll_obd_dev_cache",
 551                                               sizeof(struct obd_device), 0, 0);
 552         if (!obd_device_cachep)
 553                 GOTO(out, -ENOMEM);
 554
 555         LASSERT(obdo_cachep == NULL);
 556         obdo_cachep = cfs_mem_cache_create("ll_obdo_cache", sizeof(struct obdo),
 557                                         0, 0);
 558         if (!obdo_cachep)
 559                 GOTO(out, -ENOMEM);
 560
 561         LASSERT(import_cachep == NULL);
 562         import_cachep = cfs_mem_cache_create("ll_import_cache",
 563                                           sizeof(struct obd_import),
 564                                           0, 0);
 565         if (!import_cachep)
 566                 GOTO(out, -ENOMEM);
 567
 568         LASSERT(capa_cachep == NULL);
 569         capa_cachep = cfs_mem_cache_create("capa_cache",
 570                                            sizeof(struct obd_capa), 0, 0);
 571         if (!capa_cachep)
 572                 GOTO(out, -ENOMEM);
 573
 574         RETURN(0);
 575  out:
 576         obd_cleanup_caches();
 577         RETURN(-ENOMEM);
 578
 579 }
 580
 581 /* map connection to client */
 582 struct obd_export *class_conn2export(struct lustre_handle *conn)
 583 {
 584         struct obd_export *export;
 585         ENTRY;
 586
 587         if (!conn) {
 588                 CDEBUG(D_CACHE, "looking for null handle\n");
 589                 RETURN(NULL);
 590         }
 591
 592         if (conn->cookie == -1) {  /* this means assign a new connection */
 593                 CDEBUG(D_CACHE, "want a new connection\n");
 594                 RETURN(NULL);
 595         }
 596
 597         CDEBUG(D_INFO, "looking for export cookie "LPX64"\n", conn->cookie);
 598         export = class_handle2object(conn->cookie);
 599         RETURN(export);
 600 }
 601
 602 struct obd_device *class_exp2obd(struct obd_export *exp)
 603 {
 604         if (exp)
 605                 return exp->exp_obd;
 606         return NULL;
 607 }
 608
 609 struct obd_device *class_conn2obd(struct lustre_handle *conn)
 610 {
 611         struct obd_export *export;
 612         export = class_conn2export(conn);
 613         if (export) {
 614                 struct obd_device *obd = export->exp_obd;
 615                 class_export_put(export);
 616                 return obd;
 617         }
 618         return NULL;
 619 }
 620
 621 struct obd_import *class_exp2cliimp(struct obd_export *exp)
 622 {
 623         struct obd_device *obd = exp->exp_obd;
 624         if (obd == NULL)
 625                 return NULL;
 626         return obd->u.cli.cl_import;
 627 }
 628
 629 struct obd_import *class_conn2cliimp(struct lustre_handle *conn)
 630 {
 631         struct obd_device *obd = class_conn2obd(conn);
 632         if (obd == NULL)
 633                 return NULL;
 634         return obd->u.cli.cl_import;
 635 }
 636
 637 /* Export management functions */
 638 static void export_handle_addref(void *export)
 639 {
 640         class_export_get(export);
 641 }
 642
 643 void __class_export_put(struct obd_export *exp)
 644 {
 645         if (atomic_dec_and_test(&exp->exp_refcount)) {
 646                 LASSERT (list_empty(&exp->exp_obd_chain));
 647
 648                 CDEBUG(D_IOCTL, "final put %p/%s\n",
 649                        exp, exp->exp_client_uuid.uuid);
 650
 651                 spin_lock(&obd_zombie_impexp_lock);
 652                 list_add(&exp->exp_obd_chain, &obd_zombie_exports);
 653                 spin_unlock(&obd_zombie_impexp_lock);
 654
 655                 if (obd_zombie_impexp_notify != NULL)
 656                         obd_zombie_impexp_notify();
 657         }
 658 }
 659 EXPORT_SYMBOL(__class_export_put);
 660
 661 void class_export_destroy(struct obd_export *exp)
 662 {
 663         struct obd_device *obd = exp->exp_obd;
 664         ENTRY;
 665
 666         LASSERT (atomic_read(&exp->exp_refcount) == 0);
 667
 668         CDEBUG(D_IOCTL, "destroying export %p/%s for %s\n", exp,
 669                exp->exp_client_uuid.uuid, obd->obd_name);
 670
 671         LASSERT(obd != NULL);
 672
 673         /* "Local" exports (lctl, LOV->{mdc,osc}) have no connection. */
 674         if (exp->exp_connection)
 675                 ptlrpc_put_connection_superhack(exp->exp_connection);
 676
 677         LASSERT(list_empty(&exp->exp_outstanding_replies));
 678         obd_destroy_export(exp);
 679
 680         OBD_FREE_RCU(exp, sizeof(*exp), &exp->exp_handle);
 681         class_decref(obd);
 682         EXIT;
 683 }
 684
 685 /* Creates a new export, adds it to the hash table, and returns a
 686  * pointer to it. The refcount is 2: one for the hash reference, and
 687  * one for the pointer returned by this function. */
 688 struct obd_export *class_new_export(struct obd_device *obd,
 689                                     struct obd_uuid *cluuid)
 690 {
 691         struct obd_export *export, *tmp;
 692
 693         OBD_ALLOC(export, sizeof(*export));
 694         if (!export)
 695                 return ERR_PTR(-ENOMEM);
 696
 697         export->exp_conn_cnt = 0;
 698         atomic_set(&export->exp_refcount, 2);
 699         atomic_set(&export->exp_rpc_count, 0);
 700         export->exp_obd = obd;
 701         CFS_INIT_LIST_HEAD(&export->exp_outstanding_replies);
 702         /* XXX this should be in LDLM init */
 703         CFS_INIT_LIST_HEAD(&export->exp_ldlm_data.led_held_locks);
 704         spin_lock_init(&export->exp_ldlm_data.led_lock);
 705
 706         CFS_INIT_LIST_HEAD(&export->exp_handle.h_link);
 707         class_handle_hash(&export->exp_handle, export_handle_addref);
 708         export->exp_last_request_time = CURRENT_SECONDS;
 709         spin_lock_init(&export->exp_lock);
 710
 711         export->exp_client_uuid = *cluuid;
 712         obd_init_export(export);
 713
 714         spin_lock(&obd->obd_dev_lock);
 715         if (!obd_uuid_equals(cluuid, &obd->obd_uuid)) {
 716                 list_for_each_entry(tmp, &obd->obd_exports, exp_obd_chain) {
 717                         if (obd_uuid_equals(cluuid, &tmp->exp_client_uuid)) {
 718                                 spin_unlock(&obd->obd_dev_lock);
 719                                 CWARN("%s: denying duplicate export for %s\n",
 720                                       obd->obd_name, cluuid->uuid);
 721                                 class_handle_unhash(&export->exp_handle);
 722                                 OBD_FREE_PTR(export);
 723                                 return ERR_PTR(-EALREADY);
 724                         }
 725                 }
 726         }
 727         LASSERT(!obd->obd_stopping); /* shouldn't happen, but might race */
 728         class_incref(obd);
 729         list_add(&export->exp_obd_chain, &export->exp_obd->obd_exports);
 730         list_add_tail(&export->exp_obd_chain_timed,
 731                       &export->exp_obd->obd_exports_timed);
 732         export->exp_obd->obd_num_exports++;
 733         spin_unlock(&obd->obd_dev_lock);
 734
 735         return export;
 736 }
 737 EXPORT_SYMBOL(class_new_export);
 738
 739 void class_unlink_export(struct obd_export *exp)
 740 {
 741         class_handle_unhash(&exp->exp_handle);
 742
 743         spin_lock(&exp->exp_obd->obd_dev_lock);
 744         list_del_init(&exp->exp_obd_chain);
 745         list_del_init(&exp->exp_obd_chain_timed);
 746         exp->exp_obd->obd_num_exports--;
 747         spin_unlock(&exp->exp_obd->obd_dev_lock);
 748
 749         class_export_put(exp);
 750 }
 751 EXPORT_SYMBOL(class_unlink_export);
 752
 753 /* Import management functions */
 754 static void import_handle_addref(void *import)
 755 {
 756         class_import_get(import);
 757 }
 758
 759 struct obd_import *class_import_get(struct obd_import *import)
 760 {
 761         LASSERT(atomic_read(&import->imp_refcount) >= 0);
 762         LASSERT(atomic_read(&import->imp_refcount) < 0x5a5a5a);
 763         atomic_inc(&import->imp_refcount);
 764         CDEBUG(D_INFO, "import %p refcount=%d\n", import,
 765                atomic_read(&import->imp_refcount));
 766         return import;
 767 }
 768 EXPORT_SYMBOL(class_import_get);
 769
 770 void class_import_put(struct obd_import *import)
 771 {
 772         ENTRY;
 773
 774         CDEBUG(D_INFO, "import %p refcount=%d\n", import,
 775                atomic_read(&import->imp_refcount) - 1);
 776
 777         LASSERT(atomic_read(&import->imp_refcount) > 0);
 778         LASSERT(atomic_read(&import->imp_refcount) < 0x5a5a5a);
 779         LASSERT(list_empty(&import->imp_zombie_chain));
 780
 781         if (atomic_dec_and_test(&import->imp_refcount)) {
 782
 783                 CDEBUG(D_INFO, "final put import %p\n", import);
 784
 785                 spin_lock(&obd_zombie_impexp_lock);
 786                 list_add(&import->imp_zombie_chain, &obd_zombie_imports);
 787                 spin_unlock(&obd_zombie_impexp_lock);
 788
 789                 if (obd_zombie_impexp_notify != NULL)
 790                         obd_zombie_impexp_notify();
 791         }
 792
 793         EXIT;
 794 }
 795
 796 void class_import_destroy(struct obd_import *import)
 797 {
 798         ENTRY;
 799
 800         CDEBUG(D_IOCTL, "destroying import %p for %s\n", import,
 801                 import->imp_obd->obd_name);
 802
 803         LASSERT(atomic_read(&import->imp_refcount) == 0);
 804
 805         ptlrpc_put_connection_superhack(import->imp_connection);
 806
 807         while (!list_empty(&import->imp_conn_list)) {
 808                 struct obd_import_conn *imp_conn;
 809
 810                 imp_conn = list_entry(import->imp_conn_list.next,
 811                                       struct obd_import_conn, oic_item);
 812                 list_del(&imp_conn->oic_item);
 813                 ptlrpc_put_connection_superhack(imp_conn->oic_conn);
 814                 OBD_FREE(imp_conn, sizeof(*imp_conn));
 815         }
 816
 817         LASSERT(import->imp_sec == NULL);
 818         class_decref(import->imp_obd);
 819         OBD_FREE_RCU(import, sizeof(*import), &import->imp_handle);
 820         EXIT;
 821 }
 822 EXPORT_SYMBOL(class_import_put);
 823
 824 struct obd_import *class_new_import(struct obd_device *obd)
 825 {
 826         struct obd_import *imp;
 827
 828         OBD_ALLOC(imp, sizeof(*imp));
 829         if (imp == NULL)
 830                 return NULL;
 831
 832         CFS_INIT_LIST_HEAD(&imp->imp_zombie_chain);
 833         CFS_INIT_LIST_HEAD(&imp->imp_replay_list);
 834         CFS_INIT_LIST_HEAD(&imp->imp_sending_list);
 835         CFS_INIT_LIST_HEAD(&imp->imp_delayed_list);
 836         spin_lock_init(&imp->imp_lock);
 837         imp->imp_last_success_conn = 0;
 838         imp->imp_state = LUSTRE_IMP_NEW;
 839         imp->imp_obd = class_incref(obd);
 840         cfs_waitq_init(&imp->imp_recovery_waitq);
 841
 842         atomic_set(&imp->imp_refcount, 2);
 843         atomic_set(&imp->imp_inflight, 0);
 844         atomic_set(&imp->imp_replay_inflight, 0);
 845         atomic_set(&imp->imp_inval_count, 0);
 846         CFS_INIT_LIST_HEAD(&imp->imp_conn_list);
 847         CFS_INIT_LIST_HEAD(&imp->imp_handle.h_link);
 848         class_handle_hash(&imp->imp_handle, import_handle_addref);
 849
 850         /* the default magic is V1, will be used in connect RPC, and
 851          * then adjusted according to the flags in request/reply. */
 852         imp->imp_msg_magic = LUSTRE_MSG_MAGIC_V1;
 853
 854         return imp;
 855 }
 856 EXPORT_SYMBOL(class_new_import);
 857
 858 void class_destroy_import(struct obd_import *import)
 859 {
 860         LASSERT(import != NULL);
 861         LASSERT(import != LP_POISON);
 862
 863         class_handle_unhash(&import->imp_handle);
 864
 865         spin_lock(&import->imp_lock);
 866         import->imp_generation++;
 867         spin_unlock(&import->imp_lock);
 868         class_import_put(import);
 869 }
 870 EXPORT_SYMBOL(class_destroy_import);
 871
 872 /* A connection defines an export context in which preallocation can
 873    be managed. This releases the export pointer reference, and returns
 874    the export handle, so the export refcount is 1 when this function
 875    returns. */
 876 int class_connect(struct lustre_handle *conn, struct obd_device *obd,
 877                   struct obd_uuid *cluuid)
 878 {
 879         struct obd_export *export;
 880         LASSERT(conn != NULL);
 881         LASSERT(obd != NULL);
 882         LASSERT(cluuid != NULL);
 883         ENTRY;
 884
 885         export = class_new_export(obd, cluuid);
 886         if (IS_ERR(export))
 887                 RETURN(PTR_ERR(export));
 888
 889         conn->cookie = export->exp_handle.h_cookie;
 890         class_export_put(export);
 891
 892         CDEBUG(D_IOCTL, "connect: client %s, cookie "LPX64"\n",
 893                cluuid->uuid, conn->cookie);
 894         RETURN(0);
 895 }
 896 EXPORT_SYMBOL(class_connect);
 897
 898 /* if export is involved in recovery then clean up related things */
 899 void class_export_recovery_cleanup(struct obd_export *exp)
 900 {
 901         struct obd_device *obd = exp->exp_obd;
 902
 903         spin_lock_bh(&obd->obd_processing_task_lock);
 904         if (obd->obd_recovering && exp->exp_in_recovery) {
 905                 spin_lock(&exp->exp_lock);
 906                 exp->exp_in_recovery = 0;
 907                 spin_unlock(&exp->exp_lock);
 908                 obd->obd_connected_clients--;
 909                 /* each connected client is counted as recoverable */
 910                 obd->obd_recoverable_clients--;
 911                 if (exp->exp_req_replay_needed) {
 912                         spin_lock(&exp->exp_lock);
 913                         exp->exp_req_replay_needed = 0;
 914                         spin_unlock(&exp->exp_lock);
 915                         LASSERT(atomic_read(&obd->obd_req_replay_clients));
 916                         atomic_dec(&obd->obd_req_replay_clients);
 917                 }
 918                 if (exp->exp_lock_replay_needed) {
 919                         spin_lock(&exp->exp_lock);
 920                         exp->exp_lock_replay_needed = 0;
 921                         spin_unlock(&exp->exp_lock);
 922                         LASSERT(atomic_read(&obd->obd_lock_replay_clients));
 923                         atomic_dec(&obd->obd_lock_replay_clients);
 924                 }
 925         }
 926         spin_unlock_bh(&obd->obd_processing_task_lock);
 927 }
 928
 929 /* This function removes two references from the export: one for the
 930  * hash entry and one for the export pointer passed in.  The export
 931  * pointer passed to this function is destroyed should not be used
 932  * again. */
 933 int class_disconnect(struct obd_export *export)
 934 {
 935         int already_disconnected;
 936         ENTRY;
 937
 938         if (export == NULL) {
 939                 fixme();
 940                 CDEBUG(D_IOCTL, "attempting to free NULL export %p\n", export);
 941                 RETURN(-EINVAL);
 942         }
 943
 944         spin_lock(&export->exp_lock);
 945         already_disconnected = export->exp_disconnected;
 946         export->exp_disconnected = 1;
 947         spin_unlock(&export->exp_lock);
 948
 949         /* class_cleanup(), abort_recovery(), and class_fail_export()
 950          * all end up in here, and if any of them race we shouldn't
 951          * call extra class_export_puts(). */
 952         if (already_disconnected)
 953                 RETURN(0);
 954
 955         CDEBUG(D_IOCTL, "disconnect: cookie "LPX64"\n",
 956                export->exp_handle.h_cookie);
 957
 958         class_export_recovery_cleanup(export);
 959         class_unlink_export(export);
 960         class_export_put(export);
 961         RETURN(0);
 962 }
 963
 964 static void class_disconnect_export_list(struct list_head *list, int flags)
 965 {
 966         int rc;
 967         struct lustre_handle fake_conn;
 968         struct obd_export *fake_exp, *exp;
 969         ENTRY;
 970
 971         /* It's possible that an export may disconnect itself, but
 972          * nothing else will be added to this list. */
 973         while (!list_empty(list)) {
 974                 exp = list_entry(list->next, struct obd_export, exp_obd_chain);
 975                 class_export_get(exp);
 976
 977                 spin_lock(&exp->exp_lock);
 978                 exp->exp_flags = flags;
 979                 spin_unlock(&exp->exp_lock);
 980
 981                 if (obd_uuid_equals(&exp->exp_client_uuid,
 982                                     &exp->exp_obd->obd_uuid)) {
 983                         CDEBUG(D_HA,
 984                                "exp %p export uuid == obd uuid, don't discon\n",
 985                                exp);
 986                         /* Need to delete this now so we don't end up pointing
 987                          * to work_list later when this export is cleaned up. */
 988                         list_del_init(&exp->exp_obd_chain);
 989                         class_export_put(exp);
 990                         continue;
 991                 }
 992
 993                 fake_conn.cookie = exp->exp_handle.h_cookie;
 994                 fake_exp = class_conn2export(&fake_conn);
 995                 if (!fake_exp) {
 996                         class_export_put(exp);
 997                         continue;
 998                 }
 999
1000                 spin_lock(&fake_exp->exp_lock);
1001                 fake_exp->exp_flags = flags;
1002                 spin_unlock(&fake_exp->exp_lock);
1003
1004                 rc = obd_disconnect(fake_exp);
1005                 class_export_put(exp);
1006                 if (rc) {
1007                         CDEBUG(D_HA, "disconnecting export %p failed: %d\n",
1008                                exp, rc);
1009                 } else {
1010                         CDEBUG(D_HA, "export %p disconnected\n", exp);
1011                 }
1012         }
1013         EXIT;
1014 }
1015
1016 static inline int get_exp_flags_from_obd(struct obd_device *obd)
1017 {
1018         return ((obd->obd_fail ? OBD_OPT_FAILOVER : 0) |
1019                 (obd->obd_force ? OBD_OPT_FORCE : 0));
1020 }
1021
1022 void class_disconnect_exports(struct obd_device *obd)
1023 {
1024         struct list_head work_list;
1025         ENTRY;
1026
1027         /* Move all of the exports from obd_exports to a work list, en masse. */
1028         spin_lock(&obd->obd_dev_lock);
1029         list_add(&work_list, &obd->obd_exports);
1030         list_del_init(&obd->obd_exports);
1031         spin_unlock(&obd->obd_dev_lock);
1032
1033         if (!list_empty(&work_list)) {
1034                 CDEBUG(D_HA, "OBD device %d (%p) has exports, "
1035                        "disconnecting them\n", obd->obd_minor, obd);
1036                 class_disconnect_export_list(&work_list,
1037                                              get_exp_flags_from_obd(obd));
1038         } else
1039                 CDEBUG(D_HA, "OBD device %d (%p) has no exports\n",
1040                        obd->obd_minor, obd);
1041         EXIT;
1042 }
1043 EXPORT_SYMBOL(class_disconnect_exports);
1044
1045 /* Remove exports that have not completed recovery.
1046  */
1047 int class_disconnect_stale_exports(struct obd_device *obd,
1048                                    int (*test_export)(struct obd_export *))
1049 {
1050         struct list_head work_list;
1051         struct list_head *pos, *n;
1052         struct obd_export *exp;
1053         int cnt = 0;
1054         ENTRY;
1055
1056         CFS_INIT_LIST_HEAD(&work_list);
1057         spin_lock(&obd->obd_dev_lock);
1058         list_for_each_safe(pos, n, &obd->obd_exports) {
1059                 exp = list_entry(pos, struct obd_export, exp_obd_chain);
1060                 if (test_export(exp))
1061                         continue;
1062
1063                 list_del(&exp->exp_obd_chain);
1064                 list_add(&exp->exp_obd_chain, &work_list);
1065                 /* don't count self-export as client */
1066                 if (obd_uuid_equals(&exp->exp_client_uuid,
1067                                      &exp->exp_obd->obd_uuid))
1068                         continue;
1069
1070                 cnt++;
1071                 CDEBUG(D_ERROR, "%s: disconnect stale client %s@%s\n",
1072                        obd->obd_name, exp->exp_client_uuid.uuid,
1073                        exp->exp_connection == NULL ? "<unknown>" :
1074                        libcfs_nid2str(exp->exp_connection->c_peer.nid));
1075         }
1076         spin_unlock(&obd->obd_dev_lock);
1077
1078         CDEBUG(D_ERROR, "%s: disconnecting %d stale clients\n",
1079                obd->obd_name, cnt);
1080         class_disconnect_export_list(&work_list, get_exp_flags_from_obd(obd));
1081         RETURN(cnt);
1082 }
1083 EXPORT_SYMBOL(class_disconnect_stale_exports);
1084
1085 int oig_init(struct obd_io_group **oig_out)
1086 {
1087         struct obd_io_group *oig;
1088         ENTRY;
1089
1090         OBD_ALLOC(oig, sizeof(*oig));
1091         if (oig == NULL)
1092                 RETURN(-ENOMEM);
1093
1094         spin_lock_init(&oig->oig_lock);
1095         oig->oig_rc = 0;
1096         oig->oig_pending = 0;
1097         atomic_set(&oig->oig_refcount, 1);
1098         cfs_waitq_init(&oig->oig_waitq);
1099         CFS_INIT_LIST_HEAD(&oig->oig_occ_list);
1100
1101         *oig_out = oig;
1102         RETURN(0);
1103 };
1104 EXPORT_SYMBOL(oig_init);
1105
1106 static inline void oig_grab(struct obd_io_group *oig)
1107 {
1108         atomic_inc(&oig->oig_refcount);
1109 }
1110
1111 void oig_release(struct obd_io_group *oig)
1112 {
1113         if (atomic_dec_and_test(&oig->oig_refcount))
1114                 OBD_FREE(oig, sizeof(*oig));
1115 }
1116 EXPORT_SYMBOL(oig_release);
1117
1118 int oig_add_one(struct obd_io_group *oig, struct oig_callback_context *occ)
1119 {
1120         int rc = 0;
1121         CDEBUG(D_CACHE, "oig %p ready to roll\n", oig);
1122         spin_lock(&oig->oig_lock);
1123         if (oig->oig_rc) {
1124                 rc = oig->oig_rc;
1125         } else {
1126                 oig->oig_pending++;
1127                 if (occ != NULL)
1128                         list_add_tail(&occ->occ_oig_item, &oig->oig_occ_list);
1129         }
1130         spin_unlock(&oig->oig_lock);
1131         oig_grab(oig);
1132
1133         return rc;
1134 }
1135 EXPORT_SYMBOL(oig_add_one);
1136
1137 void oig_complete_one(struct obd_io_group *oig,
1138                       struct oig_callback_context *occ, int rc)
1139 {
1140         cfs_waitq_t *wake = NULL;
1141         int old_rc;
1142
1143         spin_lock(&oig->oig_lock);
1144
1145         if (occ != NULL)
1146                 list_del_init(&occ->occ_oig_item);
1147
1148         old_rc = oig->oig_rc;
1149         if (oig->oig_rc == 0 && rc != 0)
1150                 oig->oig_rc = rc;
1151
1152         if (--oig->oig_pending <= 0)
1153                 wake = &oig->oig_waitq;
1154
1155         spin_unlock(&oig->oig_lock);
1156
1157         CDEBUG(D_CACHE, "oig %p completed, rc %d -> %d via %d, %d now "
1158                         "pending (racey)\n", oig, old_rc, oig->oig_rc, rc,
1159                         oig->oig_pending);
1160         if (wake)
1161                 cfs_waitq_signal(wake);
1162         oig_release(oig);
1163 }
1164 EXPORT_SYMBOL(oig_complete_one);
1165
1166 static int oig_done(struct obd_io_group *oig)
1167 {
1168         int rc = 0;
1169         spin_lock(&oig->oig_lock);
1170         if (oig->oig_pending <= 0)
1171                 rc = 1;
1172         spin_unlock(&oig->oig_lock);
1173         return rc;
1174 }
1175
1176 static void interrupted_oig(void *data)
1177 {
1178         struct obd_io_group *oig = data;
1179         struct oig_callback_context *occ;
1180
1181         spin_lock(&oig->oig_lock);
1182         /* We need to restart the processing each time we drop the lock, as
1183          * it is possible other threads called oig_complete_one() to remove
1184          * an entry elsewhere in the list while we dropped lock.  We need to
1185          * drop the lock because osc_ap_completion() calls oig_complete_one()
1186          * which re-gets this lock ;-) as well as a lock ordering issue. */
1187 restart:
1188         list_for_each_entry(occ, &oig->oig_occ_list, occ_oig_item) {
1189                 if (occ->interrupted)
1190                         continue;
1191                 occ->interrupted = 1;
1192                 spin_unlock(&oig->oig_lock);
1193                 occ->occ_interrupted(occ);
1194                 spin_lock(&oig->oig_lock);
1195                 goto restart;
1196         }
1197         spin_unlock(&oig->oig_lock);
1198 }
1199
1200 int oig_wait(struct obd_io_group *oig)
1201 {
1202         struct l_wait_info lwi = LWI_INTR(interrupted_oig, oig);
1203         int rc;
1204
1205         CDEBUG(D_CACHE, "waiting for oig %p\n", oig);
1206
1207         do {
1208                 rc = l_wait_event(oig->oig_waitq, oig_done(oig), &lwi);
1209                 LASSERTF(rc == 0 || rc == -EINTR, "rc: %d\n", rc);
1210                 /* we can't continue until the oig has emptied and stopped
1211                  * referencing state that the caller will free upon return */
1212                 if (rc == -EINTR)
1213                         lwi = (struct l_wait_info){ 0, };
1214         } while (rc == -EINTR);
1215
1216         LASSERTF(oig->oig_pending == 0,
1217                  "exiting oig_wait(oig = %p) with %d pending\n", oig,
1218                  oig->oig_pending);
1219
1220         CDEBUG(D_CACHE, "done waiting on oig %p rc %d\n", oig, oig->oig_rc);
1221         return oig->oig_rc;
1222 }
1223 EXPORT_SYMBOL(oig_wait);
1224
1225 void class_fail_export(struct obd_export *exp)
1226 {
1227         int rc, already_failed;
1228
1229         spin_lock(&exp->exp_lock);
1230         already_failed = exp->exp_failed;
1231         exp->exp_failed = 1;
1232         spin_unlock(&exp->exp_lock);
1233
1234         if (already_failed) {
1235                 CDEBUG(D_HA, "disconnecting dead export %p/%s; skipping\n",
1236                        exp, exp->exp_client_uuid.uuid);
1237                 return;
1238         }
1239
1240         CDEBUG(D_HA, "disconnecting export %p/%s\n",
1241                exp, exp->exp_client_uuid.uuid);
1242
1243         if (obd_dump_on_timeout)
1244                 libcfs_debug_dumplog();
1245
1246         /* Most callers into obd_disconnect are removing their own reference
1247          * (request, for example) in addition to the one from the hash table.
1248          * We don't have such a reference here, so make one. */
1249         class_export_get(exp);
1250         rc = obd_disconnect(exp);
1251         if (rc)
1252                 CERROR("disconnecting export %p failed: %d\n", exp, rc);
1253         else
1254                 CDEBUG(D_HA, "disconnected export %p/%s\n",
1255                        exp, exp->exp_client_uuid.uuid);
1256 }
1257 EXPORT_SYMBOL(class_fail_export);
1258
1259 char *obd_export_nid2str(struct obd_export *exp)
1260 {
1261         if (exp->exp_connection != NULL)
1262                 return libcfs_nid2str(exp->exp_connection->c_peer.nid);
1263
1264         return "(no nid)";
1265 }
1266 EXPORT_SYMBOL(obd_export_nid2str);
1267
1268 #define EVICT_BATCH 32
1269 int obd_export_evict_by_nid(struct obd_device *obd, const char *nid)
1270 {
1271         struct obd_export *doomed_exp[EVICT_BATCH] = { NULL };
1272         struct list_head *p;
1273         int exports_evicted = 0, num_to_evict = 0, i;
1274
1275 search_again:
1276         spin_lock(&obd->obd_dev_lock);
1277         list_for_each(p, &obd->obd_exports) {
1278                 doomed_exp[num_to_evict] = list_entry(p, struct obd_export,
1279                                                       exp_obd_chain);
1280                 if (strcmp(obd_export_nid2str(doomed_exp[num_to_evict]),
1281                            nid) == 0) {
1282                         class_export_get(doomed_exp[num_to_evict]);
1283                         if (++num_to_evict == EVICT_BATCH)
1284                                 break;
1285                 }
1286         }
1287         spin_unlock(&obd->obd_dev_lock);
1288
1289         for (i = 0; i < num_to_evict; i++) {
1290                 exports_evicted++;
1291                 CWARN("%s: evict NID '%s' (%s) #%d at adminstrative request\n",
1292                        obd->obd_name, nid, doomed_exp[i]->exp_client_uuid.uuid,
1293                        exports_evicted);
1294                 class_fail_export(doomed_exp[i]);
1295                 class_export_put(doomed_exp[i]);
1296         }
1297         if (num_to_evict == EVICT_BATCH) {
1298                 num_to_evict = 0;
1299                 goto search_again;
1300         }
1301
1302         if (!exports_evicted)
1303                 CDEBUG(D_HA,"%s: can't disconnect NID '%s': no exports found\n",
1304                        obd->obd_name, nid);
1305         return exports_evicted;
1306 }
1307 EXPORT_SYMBOL(obd_export_evict_by_nid);
1308
1309 int obd_export_evict_by_uuid(struct obd_device *obd, const char *uuid)
1310 {
1311         struct obd_export *doomed_exp = NULL;
1312         struct list_head *p;
1313         struct obd_uuid doomed;
1314         int exports_evicted = 0;
1315
1316         obd_str2uuid(&doomed, uuid);
1317
1318         spin_lock(&obd->obd_dev_lock);
1319         list_for_each(p, &obd->obd_exports) {
1320                 doomed_exp = list_entry(p, struct obd_export, exp_obd_chain);
1321
1322                 if (obd_uuid_equals(&doomed, &doomed_exp->exp_client_uuid)) {
1323                         class_export_get(doomed_exp);
1324                         break;
1325                 }
1326                 doomed_exp = NULL;
1327         }
1328         spin_unlock(&obd->obd_dev_lock);
1329
1330         if (doomed_exp == NULL) {
1331                 CERROR("%s: can't disconnect %s: no exports found\n",
1332                        obd->obd_name, uuid);
1333         } else {
1334                 CWARN("%s: evicting %s at adminstrative request\n",
1335                        obd->obd_name, doomed_exp->exp_client_uuid.uuid);
1336                 class_fail_export(doomed_exp);
1337                 class_export_put(doomed_exp);
1338                 exports_evicted++;
1339         }
1340
1341         return exports_evicted;
1342 }
1343 EXPORT_SYMBOL(obd_export_evict_by_uuid);
1344
1345 void obd_zombie_impexp_cull(void)
1346 {
1347         struct obd_import *import;
1348         struct obd_export *export;
1349         ENTRY;
1350
1351         do {
1352                 spin_lock (&obd_zombie_impexp_lock);
1353
1354                 import = NULL;
1355                 if (!list_empty(&obd_zombie_imports)) {
1356                         import = list_entry(obd_zombie_imports.next,
1357                                             struct obd_import,
1358                                             imp_zombie_chain);
1359                         list_del(&import->imp_zombie_chain);
1360                 }
1361
1362                 export = NULL;
1363                 if (!list_empty(&obd_zombie_exports)) {
1364                         export = list_entry(obd_zombie_exports.next,
1365                                             struct obd_export,
1366                                             exp_obd_chain);
1367                         list_del_init(&export->exp_obd_chain);
1368                 }
1369
1370                 spin_unlock(&obd_zombie_impexp_lock);
1371
1372                 if (import != NULL)
1373                         class_import_destroy(import);
1374
1375                 if (export != NULL)
1376                         class_export_destroy(export);
1377
1378         } while (import != NULL || export != NULL);
1379         EXIT;
1380 }
1381 EXPORT_SYMBOL(obd_zombie_impexp_cull);
1382
1383 void obd_zombie_impexp_init(void)
1384 {
1385         INIT_LIST_HEAD(&obd_zombie_imports);
1386         INIT_LIST_HEAD(&obd_zombie_exports);
1387         spin_lock_init(&obd_zombie_impexp_lock);
1388 }
1389