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 md_ops *md_ops,
  95                         struct lprocfs_vars *vars, 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 (md_ops)
 116                 OBD_ALLOC(type->typ_md_ops, sizeof(*type->typ_md_ops));
 117         if (type->typ_ops == NULL || type->typ_name == NULL ||
 118                         (md_ops && type->typ_md_ops == NULL))
 119                 GOTO (failed, rc);
 120
 121         *(type->typ_ops) = *ops;
 122         if (md_ops)
 123                 *(type->typ_md_ops) = *md_ops;
 124         else
 125                 type->typ_md_ops = NULL;
 126         strcpy(type->typ_name, name);
 127
 128 #ifdef LPROCFS
 129         type->typ_procroot = lprocfs_register(type->typ_name, proc_lustre_root,
 130                                               vars, type);
 131 #endif
 132         if (IS_ERR(type->typ_procroot)) {
 133                 rc = PTR_ERR(type->typ_procroot);
 134                 type->typ_procroot = NULL;
 135                 GOTO (failed, rc);
 136         }
 137
 138         spin_lock(&obd_types_lock);
 139         list_add(&type->typ_chain, &obd_types);
 140         spin_unlock(&obd_types_lock);
 141
 142         RETURN (0);
 143
 144  failed:
 145         if (type->typ_name != NULL)
 146                 OBD_FREE(type->typ_name, strlen(name) + 1);
 147         if (type->typ_ops != NULL)
 148                 OBD_FREE (type->typ_ops, sizeof (*type->typ_ops));
 149         if (type->typ_md_ops != NULL)
 150                 OBD_FREE (type->typ_md_ops, sizeof (*type->typ_md_ops));
 151         OBD_FREE(type, sizeof(*type));
 152         RETURN(rc);
 153 }
 154
 155 int class_unregister_type(char *name)
 156 {
 157         struct obd_type *type = class_search_type(name);
 158         ENTRY;
 159
 160         if (!type) {
 161                 CERROR("unknown obd type\n");
 162                 RETURN(-EINVAL);
 163         }
 164
 165         if (type->typ_refcnt) {
 166                 CERROR("type %s has refcount (%d)\n", name, type->typ_refcnt);
 167                 /* This is a bad situation, let's make the best of it */
 168                 /* Remove ops, but leave the name for debugging */
 169                 OBD_FREE(type->typ_ops, sizeof(*type->typ_ops));
 170                 RETURN(-EBUSY);
 171         }
 172
 173         if (type->typ_procroot) {
 174                 lprocfs_remove(type->typ_procroot);
 175                 type->typ_procroot = NULL;
 176         }
 177
 178         spin_lock(&obd_types_lock);
 179         list_del(&type->typ_chain);
 180         spin_unlock(&obd_types_lock);
 181         OBD_FREE(type->typ_name, strlen(name) + 1);
 182         if (type->typ_ops != NULL)
 183                 OBD_FREE(type->typ_ops, sizeof(*type->typ_ops));
 184         if (type->typ_md_ops != NULL)
 185                 OBD_FREE (type->typ_md_ops, sizeof(*type->typ_md_ops));
 186         OBD_FREE(type, sizeof(*type));
 187         RETURN(0);
 188 } /* class_unregister_type */
 189
 190 struct obd_device *class_newdev(struct obd_type *type)
 191 {
 192         struct obd_device *result = NULL;
 193         int i;
 194
 195         spin_lock(&obd_dev_lock);
 196         for (i = 0 ; i < MAX_OBD_DEVICES && result == NULL; i++) {
 197                 struct obd_device *obd = &obd_dev[i];
 198                 if (!obd->obd_type) {
 199                         LASSERT(obd->obd_minor == i);
 200                         memset(obd, 0, sizeof(*obd));
 201                         obd->obd_minor = i;
 202                         obd->obd_type = type;
 203                         result = obd;
 204                 }
 205         }
 206         spin_unlock(&obd_dev_lock);
 207         return result;
 208 }
 209
 210 void class_release_dev(struct obd_device *obd)
 211 {
 212         int minor = obd->obd_minor;
 213
 214         spin_lock(&obd_dev_lock);
 215         memset(obd, 0, sizeof(*obd));
 216         obd->obd_minor = minor;
 217         spin_unlock(&obd_dev_lock);
 218 }
 219
 220 int class_name2dev(char *name)
 221 {
 222         int i;
 223
 224         if (!name)
 225                 return -1;
 226
 227         spin_lock(&obd_dev_lock);
 228         for (i = 0; i < MAX_OBD_DEVICES; i++) {
 229                 struct obd_device *obd = &obd_dev[i];
 230                 if (obd->obd_name && strcmp(name, obd->obd_name) == 0) {
 231                         spin_unlock(&obd_dev_lock);
 232                         return i;
 233                 }
 234         }
 235         spin_unlock(&obd_dev_lock);
 236         return -1;
 237 }
 238
 239 struct obd_device *class_name2obd(char *name)
 240 {
 241         int dev = class_name2dev(name);
 242         if (dev < 0)
 243                 return NULL;
 244         return &obd_dev[dev];
 245 }
 246
 247 int class_uuid2dev(struct obd_uuid *uuid)
 248 {
 249         int i;
 250         spin_lock(&obd_dev_lock);
 251         for (i = 0; i < MAX_OBD_DEVICES; i++) {
 252                 struct obd_device *obd = &obd_dev[i];
 253                 if (obd_uuid_equals(uuid, &obd->obd_uuid)) {
 254                         spin_unlock(&obd_dev_lock);
 255                         return i;
 256                 }
 257         }
 258         spin_unlock(&obd_dev_lock);
 259         return -1;
 260 }
 261
 262 struct obd_device *class_uuid2obd(struct obd_uuid *uuid)
 263 {
 264         int dev = class_uuid2dev(uuid);
 265         if (dev < 0)
 266                 return NULL;
 267         return &obd_dev[dev];
 268 }
 269
 270 /* Search for a client OBD connected to tgt_uuid.  If grp_uuid is
 271    specified, then only the client with that uuid is returned,
 272    otherwise any client connected to the tgt is returned.
 273    If tgt_uuid is NULL, the lov with grp_uuid is returned. */
 274 struct obd_device *class_find_client_obd(struct obd_uuid *tgt_uuid,
 275                                          char *typ_name,
 276                                          struct obd_uuid *grp_uuid)
 277 {
 278         int i;
 279
 280         spin_lock(&obd_dev_lock);
 281         for (i = 0; i < MAX_OBD_DEVICES; i++) {
 282                 struct obd_device *obd = &obd_dev[i];
 283                 if (obd->obd_type == NULL)
 284                         continue;
 285                 if ((strncmp(obd->obd_type->typ_name, typ_name,
 286                              strlen(typ_name)) == 0)) {
 287                         struct client_obd *cli = &obd->u.cli;
 288                         struct obd_import *imp = cli->cl_import;
 289                         if (tgt_uuid == NULL) {
 290                                 LASSERT(grp_uuid);
 291                                 if (obd_uuid_equals(grp_uuid, &obd->obd_uuid))
 292                                         return obd;
 293                                 continue;
 294                         }
 295                         if (obd_uuid_equals(tgt_uuid, &imp->imp_target_uuid) &&
 296                             ((grp_uuid)? obd_uuid_equals(grp_uuid,
 297                                                          &obd->obd_uuid) : 1)) {
 298                                 spin_unlock(&obd_dev_lock);
 299                                 return obd;
 300                         }
 301                 }
 302         }
 303         spin_unlock(&obd_dev_lock);
 304         return NULL;
 305 }
 306
 307 /* Iterate the obd_device list looking devices have grp_uuid. Start
 308    searching at *next, and if a device is found, the next index to look
 309    it is saved in *next. If next is NULL, then the first matching device
 310    will always be returned. */
 311 struct obd_device *class_devices_in_group(struct obd_uuid *grp_uuid, int *next)
 312 {
 313         int i;
 314
 315         if (next == NULL)
 316                 i = 0;
 317         else if (*next >= 0 && *next < MAX_OBD_DEVICES)
 318                 i = *next;
 319         else
 320                 return NULL;
 321         spin_lock(&obd_dev_lock);
 322         for (; i < MAX_OBD_DEVICES; i++) {
 323                 struct obd_device *obd = &obd_dev[i];
 324                 if (obd->obd_type == NULL)
 325                         continue;
 326                 if (obd_uuid_equals(grp_uuid, &obd->obd_uuid)) {
 327                         if (next != NULL)
 328                                 *next = i+1;
 329                         spin_unlock(&obd_dev_lock);
 330                         return obd;
 331                 }
 332         }
 333
 334         spin_unlock(&obd_dev_lock);
 335         return NULL;
 336 }
 337
 338 void obd_cleanup_caches(void)
 339 {
 340         ENTRY;
 341         if (obdo_cachep) {
 342                 LASSERTF(kmem_cache_destroy(obdo_cachep) == 0,
 343                          "Cannot destory ll_obdo_cache\n");
 344                 obdo_cachep = NULL;
 345         }
 346         if (import_cachep) {
 347                 LASSERTF(kmem_cache_destroy(import_cachep) == 0,
 348                          "Cannot destory ll_import_cache\n");
 349                 import_cachep = NULL;
 350         }
 351         EXIT;
 352 }
 353
 354 int obd_init_caches(void)
 355 {
 356         ENTRY;
 357         LASSERT(obdo_cachep == NULL);
 358         obdo_cachep = kmem_cache_create("ll_obdo_cache", sizeof(struct obdo),
 359                                         0, 0, NULL, NULL);
 360         if (!obdo_cachep)
 361                 GOTO(out, -ENOMEM);
 362
 363         LASSERT(import_cachep == NULL);
 364         import_cachep = kmem_cache_create("ll_import_cache",
 365                                           sizeof(struct obd_import),
 366                                           0, 0, NULL, NULL);
 367         if (!import_cachep)
 368                 GOTO(out, -ENOMEM);
 369
 370         RETURN(0);
 371  out:
 372         obd_cleanup_caches();
 373         RETURN(-ENOMEM);
 374
 375 }
 376
 377 /* map connection to client */
 378 struct obd_export *class_conn2export(struct lustre_handle *conn)
 379 {
 380         struct obd_export *export;
 381         ENTRY;
 382
 383         if (!conn) {
 384                 CDEBUG(D_CACHE, "looking for null handle\n");
 385                 RETURN(NULL);
 386         }
 387
 388         if (conn->cookie == -1) {  /* this means assign a new connection */
 389                 CDEBUG(D_CACHE, "want a new connection\n");
 390                 RETURN(NULL);
 391         }
 392
 393         CDEBUG(D_IOCTL, "looking for export cookie "LPX64"\n", conn->cookie);
 394         export = class_handle2object(conn->cookie);
 395         RETURN(export);
 396 }
 397
 398 struct obd_device *class_exp2obd(struct obd_export *exp)
 399 {
 400         if (exp)
 401                 return exp->exp_obd;
 402         return NULL;
 403 }
 404
 405 struct obd_device *class_conn2obd(struct lustre_handle *conn)
 406 {
 407         struct obd_export *export;
 408         export = class_conn2export(conn);
 409         if (export) {
 410                 struct obd_device *obd = export->exp_obd;
 411                 class_export_put(export);
 412                 return obd;
 413         }
 414         return NULL;
 415 }
 416
 417 struct obd_import *class_exp2cliimp(struct obd_export *exp)
 418 {
 419         struct obd_device *obd = exp->exp_obd;
 420         if (obd == NULL)
 421                 return NULL;
 422         return obd->u.cli.cl_import;
 423 }
 424
 425 struct obd_import *class_conn2cliimp(struct lustre_handle *conn)
 426 {
 427         struct obd_device *obd = class_conn2obd(conn);
 428         if (obd == NULL)
 429                 return NULL;
 430         return obd->u.cli.cl_import;
 431 }
 432
 433 /* Export management functions */
 434 static void export_handle_addref(void *export)
 435 {
 436         class_export_get(export);
 437 }
 438
 439 void __class_export_put(struct obd_export *exp)
 440 {
 441         if (atomic_dec_and_test(&exp->exp_refcount)) {
 442                 struct obd_device *obd = exp->exp_obd;
 443                 CDEBUG(D_IOCTL, "destroying export %p/%s\n", exp,
 444                        exp->exp_client_uuid.uuid);
 445
 446                 LASSERT(obd != NULL);
 447
 448                 /* "Local" exports (lctl, LOV->{mdc,osc}) have no connection. */
 449                 if (exp->exp_connection)
 450                         ptlrpc_put_connection_superhack(exp->exp_connection);
 451
 452                 LASSERT(list_empty(&exp->exp_outstanding_replies));
 453                 LASSERT(list_empty(&exp->exp_handle.h_link));
 454                 obd_destroy_export(exp);
 455
 456                 OBD_FREE(exp, sizeof(*exp));
 457                 if (obd->obd_set_up) {
 458                         atomic_dec(&obd->obd_refcount);
 459                         wake_up(&obd->obd_refcount_waitq);
 460                 } else {
 461                         CERROR("removing export %p from obd %s (%p) -- OBD "
 462                                "not set up (refcount = %d)\n", exp,
 463                                obd->obd_name, obd,
 464                                atomic_read(&obd->obd_refcount));
 465                 }
 466         }
 467 }
 468
 469 /* Creates a new export, adds it to the hash table, and returns a
 470  * pointer to it. The refcount is 2: one for the hash reference, and
 471  * one for the pointer returned by this function. */
 472 struct obd_export *class_new_export(struct obd_device *obd)
 473 {
 474         struct obd_export *export;
 475
 476         OBD_ALLOC(export, sizeof(*export));
 477         if (!export) {
 478                 CERROR("no memory! (minor %d)\n", obd->obd_minor);
 479                 return NULL;
 480         }
 481
 482         export->exp_conn_cnt = 0;
 483         atomic_set(&export->exp_refcount, 2);
 484         atomic_set(&export->exp_rpc_count, 0);
 485         export->exp_obd = obd;
 486         export->exp_flags = 0;
 487         INIT_LIST_HEAD(&export->exp_outstanding_replies);
 488         /* XXX this should be in LDLM init */
 489         INIT_LIST_HEAD(&export->exp_ldlm_data.led_held_locks);
 490
 491         INIT_LIST_HEAD(&export->exp_handle.h_link);
 492         class_handle_hash(&export->exp_handle, export_handle_addref);
 493         spin_lock_init(&export->exp_lock);
 494
 495         spin_lock(&obd->obd_dev_lock);
 496         LASSERT(!obd->obd_stopping); /* shouldn't happen, but might race */
 497         atomic_inc(&obd->obd_refcount);
 498         list_add(&export->exp_obd_chain, &export->exp_obd->obd_exports);
 499         export->exp_obd->obd_num_exports++;
 500         spin_unlock(&obd->obd_dev_lock);
 501         obd_init_export(export);
 502         return export;
 503 }
 504
 505 void class_unlink_export(struct obd_export *exp)
 506 {
 507         class_handle_unhash(&exp->exp_handle);
 508
 509         spin_lock(&exp->exp_obd->obd_dev_lock);
 510         list_del_init(&exp->exp_obd_chain);
 511         exp->exp_obd->obd_num_exports--;
 512         spin_unlock(&exp->exp_obd->obd_dev_lock);
 513
 514         class_export_put(exp);
 515 }
 516
 517 /* Import management functions */
 518 static void import_handle_addref(void *import)
 519 {
 520         class_import_get(import);
 521 }
 522
 523 struct obd_import *class_import_get(struct obd_import *import)
 524 {
 525         atomic_inc(&import->imp_refcount);
 526         CDEBUG(D_IOCTL, "import %p refcount=%d\n", import,
 527                atomic_read(&import->imp_refcount));
 528         return import;
 529 }
 530
 531 void class_import_put(struct obd_import *import)
 532 {
 533         ENTRY;
 534
 535         CDEBUG(D_IOCTL, "import %p refcount=%d\n", import,
 536                atomic_read(&import->imp_refcount) - 1);
 537
 538         LASSERT(atomic_read(&import->imp_refcount) > 0);
 539         LASSERT(atomic_read(&import->imp_refcount) < 0x5a5a5a);
 540
 541         if (!atomic_dec_and_test(&import->imp_refcount)) {
 542                 EXIT;
 543                 return;
 544         }
 545
 546         CDEBUG(D_IOCTL, "destroying import %p\n", import);
 547
 548         if (import->imp_connection)
 549                 ptlrpc_put_connection_superhack(import->imp_connection);
 550
 551         while (!list_empty(&import->imp_conn_list)) {
 552                 struct obd_import_conn *imp_conn;
 553
 554                 imp_conn = list_entry(import->imp_conn_list.next,
 555                                       struct obd_import_conn, oic_item);
 556                 list_del(&imp_conn->oic_item);
 557                 if (imp_conn->oic_conn)
 558                         ptlrpc_put_connection_superhack(imp_conn->oic_conn);
 559                 OBD_FREE(imp_conn, sizeof(*imp_conn));
 560         }
 561
 562         LASSERT(list_empty(&import->imp_handle.h_link));
 563         OBD_FREE(import, sizeof(*import));
 564         EXIT;
 565 }
 566
 567 struct obd_import *class_new_import(void)
 568 {
 569         struct obd_import *imp;
 570
 571         OBD_ALLOC(imp, sizeof(*imp));
 572         if (imp == NULL)
 573                 return NULL;
 574
 575         INIT_LIST_HEAD(&imp->imp_replay_list);
 576         INIT_LIST_HEAD(&imp->imp_sending_list);
 577         INIT_LIST_HEAD(&imp->imp_delayed_list);
 578         spin_lock_init(&imp->imp_lock);
 579         imp->imp_conn_cnt = 0;
 580         imp->imp_max_transno = 0;
 581         imp->imp_peer_committed_transno = 0;
 582         imp->imp_state = LUSTRE_IMP_NEW;
 583         init_waitqueue_head(&imp->imp_recovery_waitq);
 584
 585         atomic_set(&imp->imp_refcount, 2);
 586         atomic_set(&imp->imp_inflight, 0);
 587         atomic_set(&imp->imp_replay_inflight, 0);
 588         INIT_LIST_HEAD(&imp->imp_conn_list);
 589         INIT_LIST_HEAD(&imp->imp_handle.h_link);
 590         class_handle_hash(&imp->imp_handle, import_handle_addref);
 591
 592         return imp;
 593 }
 594
 595 void class_destroy_import(struct obd_import *import)
 596 {
 597         LASSERT(import != NULL);
 598         LASSERT(import != LP_POISON);
 599
 600         class_handle_unhash(&import->imp_handle);
 601
 602         /* Abort any inflight DLM requests and NULL out their (about to be
 603          * freed) import. */
 604         /* Invalidate all requests on import, would be better to call
 605            ptlrpc_set_import_active(imp, 0); */
 606         import->imp_generation++;
 607         ptlrpc_abort_inflight_superhack(import);
 608
 609         class_import_put(import);
 610 }
 611
 612 /* A connection defines an export context in which preallocation can
 613    be managed. This releases the export pointer reference, and returns
 614    the export handle, so the export refcount is 1 when this function
 615    returns. */
 616 int class_connect(struct lustre_handle *conn, struct obd_device *obd,
 617                   struct obd_uuid *cluuid)
 618 {
 619         struct obd_export *export;
 620         LASSERT(conn != NULL);
 621         LASSERT(obd != NULL);
 622         LASSERT(cluuid != NULL);
 623         ENTRY;
 624
 625         export = class_new_export(obd);
 626         if (export == NULL)
 627                 RETURN(-ENOMEM);
 628
 629         conn->cookie = export->exp_handle.h_cookie;
 630         memcpy(&export->exp_client_uuid, cluuid,
 631                sizeof(export->exp_client_uuid));
 632         class_export_put(export);
 633
 634         CDEBUG(D_IOCTL, "connect: client %s, cookie "LPX64"\n",
 635                cluuid->uuid, conn->cookie);
 636         RETURN(0);
 637 }
 638
 639 /* This function removes two references from the export: one for the
 640  * hash entry and one for the export pointer passed in.  The export
 641  * pointer passed to this function is destroyed should not be used
 642  * again. */
 643 int class_disconnect(struct obd_export *export, unsigned long flags)
 644 {
 645         ENTRY;
 646
 647         if (export == NULL) {
 648                 fixme();
 649                 CDEBUG(D_IOCTL, "attempting to free NULL export %p\n", export);
 650                 RETURN(-EINVAL);
 651         }
 652
 653         /* XXX this shouldn't have to be here, but double-disconnect will crash
 654          * otherwise, and sometimes double-disconnect happens.  abort_recovery,
 655          * for example. */
 656         if (list_empty(&export->exp_handle.h_link))
 657                 RETURN(0);
 658
 659         CDEBUG(D_IOCTL, "disconnect: cookie "LPX64"\n",
 660                export->exp_handle.h_cookie);
 661
 662         if (export->exp_handle.h_cookie == LL_POISON) {
 663                 CERROR("disconnecting freed export %p, ignoring\n", export);
 664         } else {
 665                 class_unlink_export(export);
 666                 class_export_put(export);
 667         }
 668         RETURN(0);
 669 }
 670
 671 static void class_disconnect_export_list(struct list_head *list, unsigned long flags)
 672 {
 673         struct obd_export *fake_exp, *exp;
 674         struct lustre_handle fake_conn;
 675         int rc;
 676         ENTRY;
 677
 678         /* Move all of the exports from obd_exports to a work list, en masse. */
 679         /* It's possible that an export may disconnect itself, but
 680          * nothing else will be added to this list. */
 681         while(!list_empty(list)) {
 682                 exp = list_entry(list->next, struct obd_export, exp_obd_chain);
 683                 class_export_get(exp);
 684
 685                 if (obd_uuid_equals(&exp->exp_client_uuid,
 686                                     &exp->exp_obd->obd_uuid)) {
 687                         CDEBUG(D_HA,
 688                                "exp %p export uuid == obd uuid, don't discon\n",
 689                                exp);
 690                         /*
 691                          * need to delete this now so we don't end up pointing
 692                          * to work_list later when this export is cleaned up.
 693                          */
 694                         list_del_init(&exp->exp_obd_chain);
 695                         class_export_put(exp);
 696                         continue;
 697                 }
 698
 699                 fake_conn.cookie = exp->exp_handle.h_cookie;
 700                 fake_exp = class_conn2export(&fake_conn);
 701                 if (!fake_exp) {
 702                         class_export_put(exp);
 703                         continue;
 704                 }
 705
 706                 rc = obd_disconnect(fake_exp, flags);
 707                 class_export_put(exp);
 708                 if (rc) {
 709                         CDEBUG(D_HA, "disconnecting export %p failed: %d\n",
 710                                exp, rc);
 711                 } else {
 712                         CDEBUG(D_HA, "export %p disconnected\n", exp);
 713                 }
 714         }
 715         EXIT;
 716 }
 717
 718 void class_disconnect_exports(struct obd_device *obd, unsigned long flags)
 719 {
 720         struct list_head work_list;
 721         ENTRY;
 722
 723         /* Move all of the exports from obd_exports to a work list, en masse. */
 724         spin_lock(&obd->obd_dev_lock);
 725         list_add(&work_list, &obd->obd_exports);
 726         list_del_init(&obd->obd_exports);
 727         spin_unlock(&obd->obd_dev_lock);
 728
 729         CDEBUG(D_HA, "OBD device %d (%p) has exports, "
 730                "disconnecting them\n", obd->obd_minor, obd);
 731         class_disconnect_export_list(&work_list, flags);
 732         EXIT;
 733 }
 734
 735 /* Remove exports that have not completed recovery.
 736  */
 737 void class_disconnect_stale_exports(struct obd_device *obd, unsigned long flags)
 738 {
 739         struct list_head work_list;
 740         struct list_head *pos, *n;
 741         struct obd_export *exp;
 742         int cnt = 0;
 743         ENTRY;
 744
 745         INIT_LIST_HEAD(&work_list);
 746         spin_lock(&obd->obd_dev_lock);
 747         list_for_each_safe(pos, n, &obd->obd_exports) {
 748                 exp = list_entry(pos, struct obd_export, exp_obd_chain);
 749                 if (exp->exp_replay_needed) {
 750                         list_del(&exp->exp_obd_chain);
 751                         list_add(&exp->exp_obd_chain, &work_list);
 752                         cnt++;
 753                 }
 754         }
 755         spin_unlock(&obd->obd_dev_lock);
 756
 757         CDEBUG(D_ERROR, "%s: disconnecting %d stale clients\n",
 758                obd->obd_name, cnt);
 759         class_disconnect_export_list(&work_list, flags);
 760         EXIT;
 761 }
 762
 763
 764
 765 int oig_init(struct obd_io_group **oig_out)
 766 {
 767         struct obd_io_group *oig;
 768         ENTRY;
 769
 770         OBD_ALLOC(oig, sizeof(*oig));
 771         if (oig == NULL)
 772                 RETURN(-ENOMEM);
 773
 774         spin_lock_init(&oig->oig_lock);
 775         oig->oig_rc = 0;
 776         oig->oig_pending = 0;
 777         atomic_set(&oig->oig_refcount, 1);
 778         init_waitqueue_head(&oig->oig_waitq);
 779         INIT_LIST_HEAD(&oig->oig_occ_list);
 780
 781         *oig_out = oig;
 782         RETURN(0);
 783 };
 784
 785 static inline void oig_grab(struct obd_io_group *oig)
 786 {
 787         atomic_inc(&oig->oig_refcount);
 788 }
 789 void oig_release(struct obd_io_group *oig)
 790 {
 791         if (atomic_dec_and_test(&oig->oig_refcount))
 792                 OBD_FREE(oig, sizeof(*oig));
 793 }
 794
 795 void oig_add_one(struct obd_io_group *oig, struct oig_callback_context *occ)
 796 {
 797         unsigned long flags;
 798         CDEBUG(D_CACHE, "oig %p ready to roll\n", oig);
 799         spin_lock_irqsave(&oig->oig_lock, flags);
 800         oig->oig_pending++;
 801         if (occ != NULL)
 802                 list_add_tail(&occ->occ_oig_item, &oig->oig_occ_list);
 803         spin_unlock_irqrestore(&oig->oig_lock, flags);
 804         oig_grab(oig);
 805 }
 806
 807 void oig_complete_one(struct obd_io_group *oig,
 808                       struct oig_callback_context *occ, int rc)
 809 {
 810         unsigned long flags;
 811         wait_queue_head_t *wake = NULL;
 812         int old_rc;
 813
 814         spin_lock_irqsave(&oig->oig_lock, flags);
 815
 816         if (occ != NULL)
 817                 list_del_init(&occ->occ_oig_item);
 818
 819         old_rc = oig->oig_rc;
 820         if (oig->oig_rc == 0 && rc != 0)
 821                 oig->oig_rc = rc;
 822
 823         if (--oig->oig_pending <= 0)
 824                 wake = &oig->oig_waitq;
 825
 826         spin_unlock_irqrestore(&oig->oig_lock, flags);
 827
 828         CDEBUG(D_CACHE, "oig %p completed, rc %d -> %d via %d, %d now "
 829                         "pending (racey)\n", oig, old_rc, oig->oig_rc, rc,
 830                         oig->oig_pending);
 831         if (wake)
 832                 wake_up(wake);
 833         oig_release(oig);
 834 }
 835
 836 static int oig_done(struct obd_io_group *oig)
 837 {
 838         unsigned long flags;
 839         int rc = 0;
 840         spin_lock_irqsave(&oig->oig_lock, flags);
 841         if (oig->oig_pending <= 0)
 842                 rc = 1;
 843         spin_unlock_irqrestore(&oig->oig_lock, flags);
 844         return rc;
 845 }
 846
 847 static void interrupted_oig(void *data)
 848 {
 849         struct obd_io_group *oig = data;
 850         struct oig_callback_context *occ;
 851         unsigned long flags;
 852
 853         spin_lock_irqsave(&oig->oig_lock, flags);
 854         /* We need to restart the processing each time we drop the lock, as
 855          * it is possible other threads called oig_complete_one() to remove
 856          * an entry elsewhere in the list while we dropped lock.  We need to
 857          * drop the lock because osc_ap_completion() calls oig_complete_one()
 858          * which re-gets this lock ;-) as well as a lock ordering issue. */
 859 restart:
 860         list_for_each_entry(occ, &oig->oig_occ_list, occ_oig_item) {
 861                 if (occ->interrupted)
 862                         continue;
 863                 occ->interrupted = 1;
 864                 spin_unlock_irqrestore(&oig->oig_lock, flags);
 865                 occ->occ_interrupted(occ);
 866                 spin_lock_irqsave(&oig->oig_lock, flags);
 867                 goto restart;
 868         }
 869         spin_unlock_irqrestore(&oig->oig_lock, flags);
 870 }
 871
 872 int oig_wait(struct obd_io_group *oig)
 873 {
 874         struct l_wait_info lwi = LWI_INTR(interrupted_oig, oig);
 875         int rc;
 876
 877         CDEBUG(D_CACHE, "waiting for oig %p\n", oig);
 878
 879         do {
 880                 rc = l_wait_event(oig->oig_waitq, oig_done(oig), &lwi);
 881                 LASSERTF(rc == 0 || rc == -EINTR, "rc: %d\n", rc);
 882                 /* we can't continue until the oig has emptied and stopped
 883                  * referencing state that the caller will free upon return */
 884                 if (rc == -EINTR)
 885                         lwi = (struct l_wait_info){ 0, };
 886         } while (rc == -EINTR);
 887
 888         LASSERTF(oig->oig_pending == 0,
 889                  "exiting oig_wait(oig = %p) with %d pending\n", oig,
 890                  oig->oig_pending);
 891
 892         CDEBUG(D_CACHE, "done waiting on oig %p rc %d\n", oig, oig->oig_rc);
 893         return oig->oig_rc;
 894 }