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 Lustre, http://www.lustre.org.
   7  *
   8  *   Lustre is free software; you can redistribute it and/or
   9  *   modify it under the terms of version 2 of the GNU General Public
  10  *   License as published by the Free Software Foundation.
  11  *
  12  *   Lustre is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with Lustre; if not, write to the Free Software
  19  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  *
  21  * These are the only exported functions, they provide some generic
  22  * infrastructure for managing object devices
  23  */
  24
  25 #define DEBUG_SUBSYSTEM S_CLASS
  26 #ifdef __KERNEL__
  27 #include <linux/kmod.h>   /* for request_module() */
  28 #include <linux/module.h>
  29 #include <linux/obd_class.h>
  30 #include <linux/random.h>
  31 #include <linux/slab.h>
  32 #include <linux/pagemap.h>
  33 #else
  34 #include <liblustre.h>
  35 #include <linux/obd_class.h>
  36 #include <linux/obd.h>
  37 #endif
  38 #include <linux/lprocfs_status.h>
  39
  40 extern struct list_head obd_types;
  41 static spinlock_t obd_types_lock = SPIN_LOCK_UNLOCKED;
  42 kmem_cache_t *obdo_cachep = NULL;
  43 kmem_cache_t *import_cachep = NULL;
  44
  45 int (*ptlrpc_put_connection_superhack)(struct ptlrpc_connection *c);
  46 void (*ptlrpc_abort_inflight_superhack)(struct obd_import *imp);
  47
  48 /*
  49  * support functions: we could use inter-module communication, but this
  50  * is more portable to other OS's
  51  */
  52 static struct obd_type *class_search_type(char *name)
  53 {
  54         struct list_head *tmp;
  55         struct obd_type *type;
  56
  57         spin_lock(&obd_types_lock);
  58         list_for_each(tmp, &obd_types) {
  59                 type = list_entry(tmp, struct obd_type, typ_chain);
  60                 if (strlen(type->typ_name) == strlen(name) &&
  61                     strcmp(type->typ_name, name) == 0) {
  62                         spin_unlock(&obd_types_lock);
  63                         return type;
  64                 }
  65         }
  66         spin_unlock(&obd_types_lock);
  67         return NULL;
  68 }
  69
  70 struct obd_type *class_get_type(char *name)
  71 {
  72         struct obd_type *type = class_search_type(name);
  73
  74 #ifdef CONFIG_KMOD
  75         if (!type) {
  76                 if (!request_module(name)) {
  77                         CDEBUG(D_INFO, "Loaded module '%s'\n", name);
  78                         type = class_search_type(name);
  79                 } else
  80                         CDEBUG(D_INFO, "Can't load module '%s'\n", name);
  81         }
  82 #endif
  83         if (type)
  84                 try_module_get(type->typ_ops->o_owner);
  85         return type;
  86 }
  87
  88 void class_put_type(struct obd_type *type)
  89 {
  90         LASSERT(type);
  91         module_put(type->typ_ops->o_owner);
  92 }
  93
  94 int class_register_type(struct obd_ops *ops, struct lprocfs_vars *vars,
  95                         char *name)
  96 {
  97         struct obd_type *type;
  98         int rc = 0;
  99         ENTRY;
 100
 101         LASSERT(strnlen(name, 1024) < 1024);    /* sanity check */
 102
 103         if (class_search_type(name)) {
 104                 CDEBUG(D_IOCTL, "Type %s already registered\n", name);
 105                 RETURN(-EEXIST);
 106         }
 107
 108         rc = -ENOMEM;
 109         OBD_ALLOC(type, sizeof(*type));
 110         if (type == NULL)
 111                 RETURN(rc);
 112
 113         OBD_ALLOC(type->typ_ops, sizeof(*type->typ_ops));
 114         OBD_ALLOC(type->typ_name, strlen(name) + 1);
 115         if (type->typ_ops == NULL || type->typ_name == NULL)
 116                 GOTO (failed, rc);
 117
 118         *(type->typ_ops) = *ops;
 119         strcpy(type->typ_name, name);
 120
 121 #ifdef LPROCFS
 122         type->typ_procroot = lprocfs_register(type->typ_name, proc_lustre_root,
 123                                               vars, type);
 124 #endif
 125         if (IS_ERR(type->typ_procroot)) {
 126                 rc = PTR_ERR(type->typ_procroot);
 127                 type->typ_procroot = NULL;
 128                 GOTO (failed, rc);
 129         }
 130
 131         spin_lock(&obd_types_lock);
 132         list_add(&type->typ_chain, &obd_types);
 133         spin_unlock(&obd_types_lock);
 134
 135         RETURN (0);
 136
 137  failed:
 138         if (type->typ_name != NULL)
 139                 OBD_FREE(type->typ_name, strlen(name) + 1);
 140         if (type->typ_ops != NULL)
 141                 OBD_FREE (type->typ_ops, sizeof (*type->typ_ops));
 142         OBD_FREE(type, sizeof(*type));
 143         RETURN(rc);
 144 }
 145
 146 int class_unregister_type(char *name)
 147 {
 148         struct obd_type *type = class_search_type(name);
 149         ENTRY;
 150
 151         if (!type) {
 152                 CERROR("unknown obd type\n");
 153                 RETURN(-EINVAL);
 154         }
 155
 156         if (type->typ_refcnt) {
 157                 CERROR("type %s has refcount (%d)\n", name, type->typ_refcnt);
 158                 /* This is a bad situation, let's make the best of it */
 159                 /* Remove ops, but leave the name for debugging */
 160                 OBD_FREE(type->typ_ops, sizeof(*type->typ_ops));
 161                 RETURN(-EBUSY);
 162         }
 163
 164         if (type->typ_procroot) {
 165                 lprocfs_remove(type->typ_procroot);
 166                 type->typ_procroot = NULL;
 167         }
 168
 169         spin_lock(&obd_types_lock);
 170         list_del(&type->typ_chain);
 171         spin_unlock(&obd_types_lock);
 172         OBD_FREE(type->typ_name, strlen(name) + 1);
 173         if (type->typ_ops != NULL)
 174                 OBD_FREE(type->typ_ops, sizeof(*type->typ_ops));
 175         OBD_FREE(type, sizeof(*type));
 176         RETURN(0);
 177 } /* class_unregister_type */
 178
 179 struct obd_device *class_newdev(struct obd_type *type, char *name)
 180 {
 181         struct obd_device *result = NULL;
 182         int i;
 183
 184         spin_lock(&obd_dev_lock);
 185         for (i = 0 ; i < MAX_OBD_DEVICES; i++) {
 186                 struct obd_device *obd = &obd_dev[i];
 187                 if (obd->obd_name && (strcmp(name, obd->obd_name) == 0)) {
 188                         CERROR("Device %s already exists, won't add\n", name);
 189                         if (result) {
 190                                 result->obd_type = NULL;
 191                                 result->obd_name = NULL;
 192                                 result = NULL;
 193                         }
 194                         break;
 195                 }
 196                 if (!result && !obd->obd_type) {
 197                         LASSERT(obd->obd_minor == i);
 198                         memset(obd, 0, sizeof(*obd));
 199                         obd->obd_minor = i;
 200                         obd->obd_type = type;
 201                         obd->obd_name = name;
 202                         CDEBUG(D_IOCTL, "Adding new device %s\n",
 203                                obd->obd_name);
 204                         result = obd;
 205                 }
 206         }
 207         spin_unlock(&obd_dev_lock);
 208         return result;
 209 }
 210
 211 void class_release_dev(struct obd_device *obd)
 212 {
 213         int minor = obd->obd_minor;
 214
 215         spin_lock(&obd_dev_lock);
 216         obd->obd_type = NULL;
 217         //memset(obd, 0, sizeof(*obd));
 218         obd->obd_minor = minor;
 219         spin_unlock(&obd_dev_lock);
 220 }
 221
 222 int class_name2dev(char *name)
 223 {
 224         int i;
 225
 226         if (!name)
 227                 return -1;
 228
 229         spin_lock(&obd_dev_lock);
 230         for (i = 0; i < MAX_OBD_DEVICES; i++) {
 231                 struct obd_device *obd = &obd_dev[i];
 232                 if (obd->obd_name && strcmp(name, obd->obd_name) == 0) {
 233                         /* Make sure we finished attaching before we give
 234                            out any references */
 235                         if (obd->obd_attached) {
 236                                 spin_unlock(&obd_dev_lock);
 237                                 return i;
 238                         }
 239                         break;
 240                 }
 241         }
 242         spin_unlock(&obd_dev_lock);
 243
 244         return -1;
 245 }
 246
 247 struct obd_device *class_name2obd(char *name)
 248 {
 249         int dev = class_name2dev(name);
 250         if (dev < 0)
 251                 return NULL;
 252         return &obd_dev[dev];
 253 }
 254
 255 int class_uuid2dev(struct obd_uuid *uuid)
 256 {
 257         int i;
 258
 259         spin_lock(&obd_dev_lock);
 260         for (i = 0; i < MAX_OBD_DEVICES; i++) {
 261                 struct obd_device *obd = &obd_dev[i];
 262                 if (obd_uuid_equals(uuid, &obd->obd_uuid)) {
 263                         spin_unlock(&obd_dev_lock);
 264                         return i;
 265                 }
 266         }
 267         spin_unlock(&obd_dev_lock);
 268
 269         return -1;
 270 }
 271
 272 struct obd_device *class_uuid2obd(struct obd_uuid *uuid)
 273 {
 274         int dev = class_uuid2dev(uuid);
 275         if (dev < 0)
 276                 return NULL;
 277         return &obd_dev[dev];
 278 }
 279
 280 /* Search for a client OBD connected to tgt_uuid.  If grp_uuid is
 281    specified, then only the client with that uuid is returned,
 282    otherwise any client connected to the tgt is returned. */
 283 struct obd_device * class_find_client_obd(struct obd_uuid *tgt_uuid,
 284                                           char * typ_name,
 285                                           struct obd_uuid *grp_uuid)
 286 {
 287         int i;
 288
 289         spin_lock(&obd_dev_lock);
 290         for (i = 0; i < MAX_OBD_DEVICES; i++) {
 291                 struct obd_device *obd = &obd_dev[i];
 292                 if (obd->obd_type == NULL)
 293                         continue;
 294                 if ((strncmp(obd->obd_type->typ_name, typ_name,
 295                              strlen(typ_name)) == 0)) {
 296                         struct client_obd *cli = &obd->u.cli;
 297                         struct obd_import *imp = cli->cl_import;
 298                         if (obd_uuid_equals(tgt_uuid, &imp->imp_target_uuid) &&
 299                             ((grp_uuid)? obd_uuid_equals(grp_uuid,
 300                                                          &obd->obd_uuid) : 1)) {
 301                                 spin_unlock(&obd_dev_lock);
 302                                 return obd;
 303                         }
 304                 }
 305         }
 306         spin_unlock(&obd_dev_lock);
 307
 308         return NULL;
 309 }
 310
 311 /* Iterate the obd_device list looking devices have grp_uuid. Start
 312    searching at *next, and if a device is found, the next index to look
 313    it is saved in *next. If next is NULL, then the first matching device
 314    will always be returned. */
 315 struct obd_device * class_devices_in_group(struct obd_uuid *grp_uuid, int *next)
 316 {
 317         int i;
 318
 319         if (next == NULL)
 320                 i = 0;
 321         else if (*next >= 0 && *next < MAX_OBD_DEVICES)
 322                 i = *next;
 323         else
 324                 return NULL;
 325
 326         spin_lock(&obd_dev_lock);
 327         for (; i < MAX_OBD_DEVICES; i++) {
 328                 struct obd_device *obd = &obd_dev[i];
 329                 if (obd->obd_type == NULL)
 330                         continue;
 331                 if (obd_uuid_equals(grp_uuid, &obd->obd_uuid)) {
 332                         if (next != NULL)
 333                                 *next = i+1;
 334                         spin_unlock(&obd_dev_lock);
 335                         return obd;
 336                 }
 337         }
 338         spin_unlock(&obd_dev_lock);
 339
 340         return NULL;
 341 }
 342
 343
 344 void obd_cleanup_caches(void)
 345 {
 346         ENTRY;
 347         if (obdo_cachep) {
 348                 LASSERTF(kmem_cache_destroy(obdo_cachep) == 0,
 349                          "Cannot destory ll_obdo_cache\n");
 350                 obdo_cachep = NULL;
 351         }
 352         if (import_cachep) {
 353                 LASSERTF(kmem_cache_destroy(import_cachep) == 0,
 354                          "Cannot destory ll_import_cache\n");
 355                 import_cachep = NULL;
 356         }
 357         EXIT;
 358 }
 359
 360 int obd_init_caches(void)
 361 {
 362         ENTRY;
 363         LASSERT(obdo_cachep == NULL);
 364         obdo_cachep = kmem_cache_create("ll_obdo_cache", sizeof(struct obdo),
 365                                         0, 0, NULL, NULL);
 366         if (!obdo_cachep)
 367                 GOTO(out, -ENOMEM);
 368
 369         LASSERT(import_cachep == NULL);
 370         import_cachep = kmem_cache_create("ll_import_cache",
 371                                           sizeof(struct obd_import),
 372                                           0, 0, NULL, NULL);
 373         if (!import_cachep)
 374                 GOTO(out, -ENOMEM);
 375
 376         RETURN(0);
 377  out:
 378         obd_cleanup_caches();
 379         RETURN(-ENOMEM);
 380
 381 }
 382
 383 /* map connection to client */
 384 struct obd_export *class_conn2export(struct lustre_handle *conn)
 385 {
 386         struct obd_export *export;
 387         ENTRY;
 388
 389         if (!conn) {
 390                 CDEBUG(D_CACHE, "looking for null handle\n");
 391                 RETURN(NULL);
 392         }
 393
 394         if (conn->cookie == -1) {  /* this means assign a new connection */
 395                 CDEBUG(D_CACHE, "want a new connection\n");
 396                 RETURN(NULL);
 397         }
 398
 399         CDEBUG(D_IOCTL, "looking for export cookie "LPX64"\n", conn->cookie);
 400         export = class_handle2object(conn->cookie);
 401         RETURN(export);
 402 }
 403
 404 struct obd_device *class_exp2obd(struct obd_export *exp)
 405 {
 406         if (exp)
 407                 return exp->exp_obd;
 408         return NULL;
 409 }
 410
 411 struct obd_device *class_conn2obd(struct lustre_handle *conn)
 412 {
 413         struct obd_export *export;
 414         export = class_conn2export(conn);
 415         if (export) {
 416                 struct obd_device *obd = export->exp_obd;
 417                 class_export_put(export);
 418                 return obd;
 419         }
 420         return NULL;
 421 }
 422
 423 struct obd_import *class_exp2cliimp(struct obd_export *exp)
 424 {
 425         struct obd_device *obd = exp->exp_obd;
 426         if (obd == NULL)
 427                 return NULL;
 428         return obd->u.cli.cl_import;
 429 }
 430
 431 struct obd_import *class_conn2cliimp(struct lustre_handle *conn)
 432 {
 433         struct obd_device *obd = class_conn2obd(conn);
 434         if (obd == NULL)
 435                 return NULL;
 436         return obd->u.cli.cl_import;
 437 }
 438
 439 /* Export management functions */
 440 static void export_handle_addref(void *export)
 441 {
 442         class_export_get(export);
 443 }
 444
 445 void __class_export_put(struct obd_export *exp)
 446 {
 447         if (atomic_dec_and_test(&exp->exp_refcount)) {
 448                 struct obd_device *obd = exp->exp_obd;
 449                 CDEBUG(D_IOCTL, "destroying export %p/%s\n", exp,
 450                        exp->exp_client_uuid.uuid);
 451
 452                 LASSERT(obd != NULL);
 453
 454                 /* "Local" exports (lctl, LOV->{mdc,osc}) have no connection. */
 455                 if (exp->exp_connection)
 456                         ptlrpc_put_connection_superhack(exp->exp_connection);
 457
 458                 LASSERT(list_empty(&exp->exp_outstanding_replies));
 459                 LASSERT(list_empty(&exp->exp_handle.h_link));
 460                 obd_destroy_export(exp);
 461
 462                 OBD_FREE(exp, sizeof(*exp));
 463                 if (obd->obd_set_up) {
 464                         atomic_dec(&obd->obd_refcount);
 465                         wake_up(&obd->obd_refcount_waitq);
 466                 }
 467         }
 468 }
 469
 470 /* Creates a new export, adds it to the hash table, and returns a
 471  * pointer to it. The refcount is 2: one for the hash reference, and
 472  * one for the pointer returned by this function. */
 473 struct obd_export *class_new_export(struct obd_device *obd)
 474 {
 475         struct obd_export *export;
 476
 477         OBD_ALLOC(export, sizeof(*export));
 478         if (!export) {
 479                 CERROR("no memory! (minor %d)\n", obd->obd_minor);
 480                 return NULL;
 481         }
 482
 483         export->exp_conn_cnt = 0;
 484         atomic_set(&export->exp_refcount, 2);
 485         export->exp_obd = obd;
 486         INIT_LIST_HEAD(&export->exp_outstanding_replies);
 487         /* XXX this should be in LDLM init */
 488         INIT_LIST_HEAD(&export->exp_ldlm_data.led_held_locks);
 489
 490         INIT_LIST_HEAD(&export->exp_handle.h_link);
 491         class_handle_hash(&export->exp_handle, export_handle_addref);
 492         spin_lock_init(&export->exp_lock);
 493
 494         spin_lock(&obd->obd_dev_lock);
 495         LASSERT(!obd->obd_stopping); /* shouldn't happen, but might race */
 496         atomic_inc(&obd->obd_refcount);
 497         list_add(&export->exp_obd_chain, &export->exp_obd->obd_exports);
 498         export->exp_obd->obd_num_exports++;
 499         spin_unlock(&obd->obd_dev_lock);
 500         obd_init_export(export);
 501         return export;
 502 }
 503
 504 void class_unlink_export(struct obd_export *exp)
 505 {
 506         class_handle_unhash(&exp->exp_handle);
 507
 508         spin_lock(&exp->exp_obd->obd_dev_lock);
 509         list_del_init(&exp->exp_obd_chain);
 510         exp->exp_obd->obd_num_exports--;
 511         spin_unlock(&exp->exp_obd->obd_dev_lock);
 512
 513         class_export_put(exp);
 514 }
 515
 516 /* Import management functions */
 517 static void import_handle_addref(void *import)
 518 {
 519         class_import_get(import);
 520 }
 521
 522 struct obd_import *class_import_get(struct obd_import *import)
 523 {
 524         atomic_inc(&import->imp_refcount);
 525         CDEBUG(D_IOCTL, "import %p refcount=%d\n", import,
 526                atomic_read(&import->imp_refcount));
 527         return import;
 528 }
 529
 530 void class_import_put(struct obd_import *import)
 531 {
 532         ENTRY;
 533
 534         CDEBUG(D_IOCTL, "import %p refcount=%d\n", import,
 535                atomic_read(&import->imp_refcount) - 1);
 536
 537         LASSERT(atomic_read(&import->imp_refcount) > 0);
 538         LASSERT(atomic_read(&import->imp_refcount) < 0x5a5a5a);
 539         if (!atomic_dec_and_test(&import->imp_refcount)) {
 540                 EXIT;
 541                 return;
 542         }
 543
 544         CDEBUG(D_IOCTL, "destroying import %p\n", import);
 545
 546         ptlrpc_put_connection_superhack(import->imp_connection);
 547
 548         LASSERT(list_empty(&import->imp_handle.h_link));
 549         OBD_FREE(import, sizeof(*import));
 550         EXIT;
 551 }
 552
 553 struct obd_import *class_new_import(void)
 554 {
 555         struct obd_import *imp;
 556
 557         OBD_ALLOC(imp, sizeof(*imp));
 558         if (imp == NULL)
 559                 return NULL;
 560
 561         INIT_LIST_HEAD(&imp->imp_replay_list);
 562         INIT_LIST_HEAD(&imp->imp_sending_list);
 563         INIT_LIST_HEAD(&imp->imp_delayed_list);
 564         spin_lock_init(&imp->imp_lock);
 565         imp->imp_conn_cnt = 0;
 566         imp->imp_max_transno = 0;
 567         imp->imp_peer_committed_transno = 0;
 568         imp->imp_state = LUSTRE_IMP_NEW;
 569         init_waitqueue_head(&imp->imp_recovery_waitq);
 570
 571         atomic_set(&imp->imp_refcount, 2);
 572         atomic_set(&imp->imp_inflight, 0);
 573         atomic_set(&imp->imp_replay_inflight, 0);
 574         INIT_LIST_HEAD(&imp->imp_handle.h_link);
 575         class_handle_hash(&imp->imp_handle, import_handle_addref);
 576
 577         return imp;
 578 }
 579
 580 void class_destroy_import(struct obd_import *import)
 581 {
 582         LASSERT(import != NULL);
 583         LASSERT(import != LP_POISON);
 584
 585         class_handle_unhash(&import->imp_handle);
 586
 587         /* Abort any inflight DLM requests and NULL out their (about to be
 588          * freed) import. */
 589         /* Invalidate all requests on import, would be better to call
 590            ptlrpc_set_import_active(imp, 0); */
 591         import->imp_generation++;
 592         ptlrpc_abort_inflight_superhack(import);
 593
 594         class_import_put(import);
 595 }
 596
 597 /* A connection defines an export context in which preallocation can
 598    be managed. This releases the export pointer reference, and returns
 599    the export handle, so the export refcount is 1 when this function
 600    returns. */
 601 int class_connect(struct lustre_handle *conn, struct obd_device *obd,
 602                   struct obd_uuid *cluuid)
 603 {
 604         struct obd_export *export;
 605         LASSERT(conn != NULL);
 606         LASSERT(obd != NULL);
 607         LASSERT(cluuid != NULL);
 608         ENTRY;
 609
 610         export = class_new_export(obd);
 611         if (export == NULL)
 612                 RETURN(-ENOMEM);
 613
 614         conn->cookie = export->exp_handle.h_cookie;
 615         memcpy(&export->exp_client_uuid, cluuid,
 616                sizeof(export->exp_client_uuid));
 617         class_export_put(export);
 618
 619         CDEBUG(D_IOCTL, "connect: client %s, cookie "LPX64"\n",
 620                cluuid->uuid, conn->cookie);
 621         RETURN(0);
 622 }
 623
 624 /* This function removes two references from the export: one for the
 625  * hash entry and one for the export pointer passed in.  The export
 626  * pointer passed to this function is destroyed should not be used
 627  * again. */
 628 int class_disconnect(struct obd_export *export, int flags)
 629 {
 630         ENTRY;
 631
 632         if (export == NULL) {
 633                 fixme();
 634                 CDEBUG(D_IOCTL, "attempting to free NULL export %p\n", export);
 635                 RETURN(-EINVAL);
 636         }
 637
 638         /* XXX this shouldn't have to be here, but double-disconnect will crash
 639          * otherwise, and sometimes double-disconnect happens.  abort_recovery,
 640          * for example. */
 641         if (list_empty(&export->exp_handle.h_link))
 642                 RETURN(0);
 643
 644         CDEBUG(D_IOCTL, "disconnect: cookie "LPX64"\n",
 645                export->exp_handle.h_cookie);
 646
 647         class_unlink_export(export);
 648         class_export_put(export);
 649         RETURN(0);
 650 }
 651
 652 static void  class_disconnect_export_list(struct list_head *list, int flags)
 653 {
 654         int rc;
 655         struct lustre_handle fake_conn;
 656         struct obd_export *fake_exp, *exp;
 657         ENTRY;
 658
 659         /* It's possible that an export may disconnect itself, but
 660          * nothing else will be added to this list. */
 661         while(!list_empty(list)) {
 662                 exp = list_entry(list->next, struct obd_export, exp_obd_chain);
 663                 class_export_get(exp);
 664
 665                 if (obd_uuid_equals(&exp->exp_client_uuid,
 666                                     &exp->exp_obd->obd_uuid)) {
 667                         CDEBUG(D_HA,
 668                                "exp %p export uuid == obd uuid, don't discon\n",
 669                                exp);
 670                         /* Need to delete this now so we don't end up pointing
 671                          * to work_list later when this export is cleaned up. */
 672                         list_del_init(&exp->exp_obd_chain);
 673                         class_export_put(exp);
 674                         continue;
 675                 }
 676
 677                 fake_conn.cookie = exp->exp_handle.h_cookie;
 678                 fake_exp = class_conn2export(&fake_conn);
 679                 if (!fake_exp) {
 680                         class_export_put(exp);
 681                         continue;
 682                 }
 683                 rc = obd_disconnect(fake_exp, flags);
 684                 class_export_put(exp);
 685                 if (rc) {
 686                         CDEBUG(D_HA, "disconnecting export %p failed: %d\n",
 687                                exp, rc);
 688                 } else {
 689                         CDEBUG(D_HA, "export %p disconnected\n", exp);
 690                 }
 691         }
 692         EXIT;
 693 }
 694
 695 void class_disconnect_exports(struct obd_device *obd, int flags)
 696 {
 697         struct list_head work_list;
 698         ENTRY;
 699
 700         /* Move all of the exports from obd_exports to a work list, en masse. */
 701         spin_lock(&obd->obd_dev_lock);
 702         list_add(&work_list, &obd->obd_exports);
 703         list_del_init(&obd->obd_exports);
 704         spin_unlock(&obd->obd_dev_lock);
 705
 706         CDEBUG(D_HA, "OBD device %d (%p) has exports, "
 707                "disconnecting them\n", obd->obd_minor, obd);
 708         class_disconnect_export_list(&work_list, flags);
 709         EXIT;
 710 }
 711
 712 /* Remove exports that have not completed recovery.
 713  */
 714 void class_disconnect_stale_exports(struct obd_device *obd, int flags)
 715 {
 716         struct list_head work_list;
 717         struct list_head *pos, *n;
 718         struct obd_export *exp;
 719         int cnt = 0;
 720         ENTRY;
 721
 722         INIT_LIST_HEAD(&work_list);
 723         spin_lock(&obd->obd_dev_lock);
 724         list_for_each_safe(pos, n, &obd->obd_exports) {
 725                 exp = list_entry(pos, struct obd_export, exp_obd_chain);
 726                 if (exp->exp_replay_needed) {
 727                         list_del(&exp->exp_obd_chain);
 728                         list_add(&exp->exp_obd_chain, &work_list);
 729                         cnt++;
 730                 }
 731         }
 732         spin_unlock(&obd->obd_dev_lock);
 733
 734         CDEBUG(D_ERROR, "%s: disconnecting %d stale clients\n",
 735                obd->obd_name, cnt);
 736         class_disconnect_export_list(&work_list, flags);
 737         EXIT;
 738 }
 739
 740 int oig_init(struct obd_io_group **oig_out)
 741 {
 742         struct obd_io_group *oig;
 743         ENTRY;
 744
 745         OBD_ALLOC(oig, sizeof(*oig));
 746         if (oig == NULL)
 747                 RETURN(-ENOMEM);
 748
 749         spin_lock_init(&oig->oig_lock);
 750         oig->oig_rc = 0;
 751         oig->oig_pending = 0;
 752         atomic_set(&oig->oig_refcount, 1);
 753         init_waitqueue_head(&oig->oig_waitq);
 754         INIT_LIST_HEAD(&oig->oig_occ_list);
 755
 756         *oig_out = oig;
 757         RETURN(0);
 758 };
 759
 760 static inline void oig_grab(struct obd_io_group *oig)
 761 {
 762         atomic_inc(&oig->oig_refcount);
 763 }
 764 void oig_release(struct obd_io_group *oig)
 765 {
 766         if (atomic_dec_and_test(&oig->oig_refcount))
 767                 OBD_FREE(oig, sizeof(*oig));
 768 }
 769
 770 void oig_add_one(struct obd_io_group *oig,
 771                   struct oig_callback_context *occ)
 772 {
 773         unsigned long flags;
 774         CDEBUG(D_CACHE, "oig %p ready to roll\n", oig);
 775         spin_lock_irqsave(&oig->oig_lock, flags);
 776         oig->oig_pending++;
 777         if (occ != NULL)
 778                 list_add_tail(&occ->occ_oig_item, &oig->oig_occ_list);
 779         spin_unlock_irqrestore(&oig->oig_lock, flags);
 780         oig_grab(oig);
 781 }
 782
 783 void oig_complete_one(struct obd_io_group *oig,
 784                       struct oig_callback_context *occ, int rc)
 785 {
 786         unsigned long flags;
 787         wait_queue_head_t *wake = NULL;
 788         int old_rc;
 789
 790         spin_lock_irqsave(&oig->oig_lock, flags);
 791
 792         if (occ != NULL)
 793                 list_del_init(&occ->occ_oig_item);
 794
 795         old_rc = oig->oig_rc;
 796         if (oig->oig_rc == 0 && rc != 0)
 797                 oig->oig_rc = rc;
 798
 799         if (--oig->oig_pending <= 0)
 800                 wake = &oig->oig_waitq;
 801
 802         spin_unlock_irqrestore(&oig->oig_lock, flags);
 803
 804         CDEBUG(D_CACHE, "oig %p completed, rc %d -> %d via %d, %d now "
 805                         "pending (racey)\n", oig, old_rc, oig->oig_rc, rc,
 806                         oig->oig_pending);
 807         if (wake)
 808                 wake_up(wake);
 809         oig_release(oig);
 810 }
 811
 812 static int oig_done(struct obd_io_group *oig)
 813 {
 814         unsigned long flags;
 815         int rc = 0;
 816         spin_lock_irqsave(&oig->oig_lock, flags);
 817         if (oig->oig_pending <= 0)
 818                 rc = 1;
 819         spin_unlock_irqrestore(&oig->oig_lock, flags);
 820         return rc;
 821 }
 822
 823 static void interrupted_oig(void *data)
 824 {
 825         struct obd_io_group *oig = data;
 826         struct oig_callback_context *occ;
 827         unsigned long flags;
 828
 829         spin_lock_irqsave(&oig->oig_lock, flags);
 830         /* We need to restart the processing each time we drop the lock, as
 831          * it is possible other threads called oig_complete_one() to remove
 832          * an entry elsewhere in the list while we dropped lock.  We need to
 833          * drop the lock because osc_ap_completion() calls oig_complete_one()
 834          * which re-gets this lock ;-) as well as a lock ordering issue. */
 835 restart:
 836         list_for_each_entry(occ, &oig->oig_occ_list, occ_oig_item) {
 837                 if (occ->interrupted)
 838                         continue;
 839                 occ->interrupted = 1;
 840                 spin_unlock_irqrestore(&oig->oig_lock, flags);
 841                 occ->occ_interrupted(occ);
 842                 spin_lock_irqsave(&oig->oig_lock, flags);
 843                 goto restart;
 844         }
 845         spin_unlock_irqrestore(&oig->oig_lock, flags);
 846 }
 847
 848 int oig_wait(struct obd_io_group *oig)
 849 {
 850         struct l_wait_info lwi = LWI_INTR(interrupted_oig, oig);
 851         int rc;
 852
 853         CDEBUG(D_CACHE, "waiting for oig %p\n", oig);
 854
 855         do {
 856                 rc = l_wait_event(oig->oig_waitq, oig_done(oig), &lwi);
 857                 LASSERTF(rc == 0 || rc == -EINTR, "rc: %d\n", rc);
 858                 /* we can't continue until the oig has emptied and stopped
 859                  * referencing state that the caller will free upon return */
 860                 if (rc == -EINTR)
 861                         lwi = (struct l_wait_info){ 0, };
 862         } while (rc == -EINTR);
 863
 864         LASSERTF(oig->oig_pending == 0,
 865                  "exiting oig_wait(oig = %p) with %d pending\n", oig,
 866                  oig->oig_pending);
 867
 868         CDEBUG(D_CACHE, "done waiting on oig %p rc %d\n", oig, oig->oig_rc);
 869         return oig->oig_rc;
 870 }