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
 339 void obd_cleanup_caches(void)
 340 {
 341         ENTRY;
 342         if (obdo_cachep) {
 343                 LASSERTF(kmem_cache_destroy(obdo_cachep) == 0,
 344                          "Cannot destory ll_obdo_cache\n");
 345                 obdo_cachep = NULL;
 346         }
 347         if (import_cachep) {
 348                 LASSERTF(kmem_cache_destroy(import_cachep) == 0,
 349                          "Cannot destory ll_import_cache\n");
 350                 import_cachep = NULL;
 351         }
 352         EXIT;
 353 }
 354
 355 int obd_init_caches(void)
 356 {
 357         ENTRY;
 358         LASSERT(obdo_cachep == NULL);
 359         obdo_cachep = kmem_cache_create("ll_obdo_cache", sizeof(struct obdo),
 360                                         0, 0, NULL, NULL);
 361         if (!obdo_cachep)
 362                 GOTO(out, -ENOMEM);
 363
 364         LASSERT(import_cachep == NULL);
 365         import_cachep = kmem_cache_create("ll_import_cache",
 366                                           sizeof(struct obd_import),
 367                                           0, 0, NULL, NULL);
 368         if (!import_cachep)
 369                 GOTO(out, -ENOMEM);
 370
 371         RETURN(0);
 372  out:
 373         obd_cleanup_caches();
 374         RETURN(-ENOMEM);
 375
 376 }
 377
 378 /* map connection to client */
 379 struct obd_export *class_conn2export(struct lustre_handle *conn)
 380 {
 381         struct obd_export *export;
 382         ENTRY;
 383
 384         if (!conn) {
 385                 CDEBUG(D_CACHE, "looking for null handle\n");
 386                 RETURN(NULL);
 387         }
 388
 389         if (conn->cookie == -1) {  /* this means assign a new connection */
 390                 CDEBUG(D_CACHE, "want a new connection\n");
 391                 RETURN(NULL);
 392         }
 393
 394         CDEBUG(D_IOCTL, "looking for export cookie "LPX64"\n", conn->cookie);
 395         export = class_handle2object(conn->cookie);
 396         RETURN(export);
 397 }
 398
 399 struct obd_device *class_exp2obd(struct obd_export *exp)
 400 {
 401         if (exp)
 402                 return exp->exp_obd;
 403         return NULL;
 404 }
 405
 406 struct obd_device *class_conn2obd(struct lustre_handle *conn)
 407 {
 408         struct obd_export *export;
 409         export = class_conn2export(conn);
 410         if (export) {
 411                 struct obd_device *obd = export->exp_obd;
 412                 class_export_put(export);
 413                 return obd;
 414         }
 415         return NULL;
 416 }
 417
 418 struct obd_import *class_exp2cliimp(struct obd_export *exp)
 419 {
 420         struct obd_device *obd = exp->exp_obd;
 421         if (obd == NULL)
 422                 return NULL;
 423         return obd->u.cli.cl_import;
 424 }
 425
 426 struct obd_import *class_conn2cliimp(struct lustre_handle *conn)
 427 {
 428         struct obd_device *obd = class_conn2obd(conn);
 429         if (obd == NULL)
 430                 return NULL;
 431         return obd->u.cli.cl_import;
 432 }
 433
 434 /* Export management functions */
 435 static void export_handle_addref(void *export)
 436 {
 437         class_export_get(export);
 438 }
 439
 440 void __class_export_put(struct obd_export *exp)
 441 {
 442         if (atomic_dec_and_test(&exp->exp_refcount)) {
 443                 struct obd_device *obd = exp->exp_obd;
 444                 CDEBUG(D_IOCTL, "destroying export %p/%s\n", exp,
 445                        exp->exp_client_uuid.uuid);
 446
 447                 LASSERT(obd != NULL);
 448
 449                 /* "Local" exports (lctl, LOV->{mdc,osc}) have no connection. */
 450                 if (exp->exp_connection)
 451                         ptlrpc_put_connection_superhack(exp->exp_connection);
 452
 453                 LASSERT(list_empty(&exp->exp_outstanding_replies));
 454                 LASSERT(list_empty(&exp->exp_handle.h_link));
 455                 obd_destroy_export(exp);
 456
 457                 OBD_FREE(exp, sizeof(*exp));
 458                 if (obd->obd_set_up) {
 459                         atomic_dec(&obd->obd_refcount);
 460                         wake_up(&obd->obd_refcount_waitq);
 461                 } else {
 462                         CERROR("removing export %p from obd %s (%p) -- OBD "
 463                                "not set up (refcount = %d)\n", exp,
 464                                obd->obd_name, obd,
 465                                atomic_read(&obd->obd_refcount));
 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         atomic_set(&export->exp_rpc_count, 0);
 486         export->exp_obd = obd;
 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         if (!atomic_dec_and_test(&import->imp_refcount)) {
 541                 EXIT;
 542                 return;
 543         }
 544
 545         CDEBUG(D_IOCTL, "destroying import %p\n", import);
 546
 547         ptlrpc_put_connection_superhack(import->imp_connection);
 548
 549         while (!list_empty(&import->imp_conn_list)) {
 550                 struct obd_import_conn *imp_conn;
 551
 552                 imp_conn = list_entry(import->imp_conn_list.next,
 553                                       struct obd_import_conn, oic_item);
 554                 list_del(&imp_conn->oic_item);
 555                 ptlrpc_put_connection_superhack(imp_conn->oic_conn);
 556                 OBD_FREE(imp_conn, sizeof(*imp_conn));
 557         }
 558
 559         LASSERT(list_empty(&import->imp_handle.h_link));
 560         OBD_FREE(import, sizeof(*import));
 561         EXIT;
 562 }
 563
 564 struct obd_import *class_new_import(void)
 565 {
 566         struct obd_import *imp;
 567
 568         OBD_ALLOC(imp, sizeof(*imp));
 569         if (imp == NULL)
 570                 return NULL;
 571
 572         INIT_LIST_HEAD(&imp->imp_replay_list);
 573         INIT_LIST_HEAD(&imp->imp_sending_list);
 574         INIT_LIST_HEAD(&imp->imp_delayed_list);
 575         spin_lock_init(&imp->imp_lock);
 576         imp->imp_conn_cnt = 0;
 577         imp->imp_max_transno = 0;
 578         imp->imp_peer_committed_transno = 0;
 579         imp->imp_state = LUSTRE_IMP_NEW;
 580         init_waitqueue_head(&imp->imp_recovery_waitq);
 581
 582         atomic_set(&imp->imp_refcount, 2);
 583         atomic_set(&imp->imp_inflight, 0);
 584         atomic_set(&imp->imp_replay_inflight, 0);
 585         INIT_LIST_HEAD(&imp->imp_conn_list);
 586         INIT_LIST_HEAD(&imp->imp_handle.h_link);
 587         class_handle_hash(&imp->imp_handle, import_handle_addref);
 588
 589         return imp;
 590 }
 591
 592 void class_destroy_import(struct obd_import *import)
 593 {
 594         LASSERT(import != NULL);
 595         LASSERT(import != LP_POISON);
 596
 597         class_handle_unhash(&import->imp_handle);
 598
 599         /* Abort any inflight DLM requests and NULL out their (about to be
 600          * freed) import. */
 601         /* Invalidate all requests on import, would be better to call
 602            ptlrpc_set_import_active(imp, 0); */
 603         import->imp_generation++;
 604         ptlrpc_abort_inflight_superhack(import);
 605
 606         class_import_put(import);
 607 }
 608
 609 /* A connection defines an export context in which preallocation can
 610    be managed. This releases the export pointer reference, and returns
 611    the export handle, so the export refcount is 1 when this function
 612    returns. */
 613 int class_connect(struct lustre_handle *conn, struct obd_device *obd,
 614                   struct obd_uuid *cluuid)
 615 {
 616         struct obd_export *export;
 617         LASSERT(conn != NULL);
 618         LASSERT(obd != NULL);
 619         LASSERT(cluuid != NULL);
 620         ENTRY;
 621
 622         export = class_new_export(obd);
 623         if (export == NULL)
 624                 RETURN(-ENOMEM);
 625
 626         conn->cookie = export->exp_handle.h_cookie;
 627         memcpy(&export->exp_client_uuid, cluuid,
 628                sizeof(export->exp_client_uuid));
 629         class_export_put(export);
 630
 631         CDEBUG(D_IOCTL, "connect: client %s, cookie "LPX64"\n",
 632                cluuid->uuid, conn->cookie);
 633         RETURN(0);
 634 }
 635
 636 /* This function removes two references from the export: one for the
 637  * hash entry and one for the export pointer passed in.  The export
 638  * pointer passed to this function is destroyed should not be used
 639  * again. */
 640 int class_disconnect(struct obd_export *export, int flags)
 641 {
 642         ENTRY;
 643
 644         if (export == NULL) {
 645                 fixme();
 646                 CDEBUG(D_IOCTL, "attempting to free NULL export %p\n", export);
 647                 RETURN(-EINVAL);
 648         }
 649
 650         /* XXX this shouldn't have to be here, but double-disconnect will crash
 651          * otherwise, and sometimes double-disconnect happens.  abort_recovery,
 652          * for example. */
 653         if (list_empty(&export->exp_handle.h_link))
 654                 RETURN(0);
 655
 656         CDEBUG(D_IOCTL, "disconnect: cookie "LPX64"\n",
 657                export->exp_handle.h_cookie);
 658
 659         if (export->exp_handle.h_cookie == 0x5a5a5a5a5a5a5a5a) {
 660                 CERROR("disconnecting freed export %p, ignoring\n", export);
 661         } else {
 662                 class_unlink_export(export);
 663                 class_export_put(export);
 664         }
 665         RETURN(0);
 666 }
 667
 668 static void  class_disconnect_export_list(struct list_head *list, int flags)
 669 {
 670         int rc;
 671         struct lustre_handle fake_conn;
 672         struct obd_export *fake_exp, *exp;
 673         ENTRY;
 674
 675         /* Move all of the exports from obd_exports to a work list, en masse. */
 676         /* It's possible that an export may disconnect itself, but
 677          * nothing else will be added to this list. */
 678         while(!list_empty(list)) {
 679                 exp = list_entry(list->next, struct obd_export, exp_obd_chain);
 680                 class_export_get(exp);
 681
 682                 if (obd_uuid_equals(&exp->exp_client_uuid,
 683                                     &exp->exp_obd->obd_uuid)) {
 684                         CDEBUG(D_HA,
 685                                "exp %p export uuid == obd uuid, don't discon\n",
 686                                exp);
 687                         /* Need to delete this now so we don't end up pointing
 688                          * to work_list later when this export is cleaned up. */
 689                         list_del_init(&exp->exp_obd_chain);
 690                         class_export_put(exp);
 691                         continue;
 692                 }
 693
 694                 fake_conn.cookie = exp->exp_handle.h_cookie;
 695                 fake_exp = class_conn2export(&fake_conn);
 696                 if (!fake_exp) {
 697                         class_export_put(exp);
 698                         continue;
 699                 }
 700                 rc = obd_disconnect(fake_exp, flags);
 701                 class_export_put(exp);
 702                 if (rc) {
 703                         CDEBUG(D_HA, "disconnecting export %p failed: %d\n",
 704                                exp, rc);
 705                 } else {
 706                         CDEBUG(D_HA, "export %p disconnected\n", exp);
 707                 }
 708         }
 709         EXIT;
 710 }
 711
 712 void class_disconnect_exports(struct obd_device *obd, int flags)
 713 {
 714         struct list_head work_list;
 715         ENTRY;
 716
 717         /* Move all of the exports from obd_exports to a work list, en masse. */
 718         spin_lock(&obd->obd_dev_lock);
 719         list_add(&work_list, &obd->obd_exports);
 720         list_del_init(&obd->obd_exports);
 721         spin_unlock(&obd->obd_dev_lock);
 722
 723         CDEBUG(D_HA, "OBD device %d (%p) has exports, "
 724                "disconnecting them\n", obd->obd_minor, obd);
 725         class_disconnect_export_list(&work_list, flags);
 726         EXIT;
 727 }
 728
 729 /* Remove exports that have not completed recovery.
 730  */
 731 void class_disconnect_stale_exports(struct obd_device *obd, int flags)
 732 {
 733         struct list_head work_list;
 734         struct list_head *pos, *n;
 735         struct obd_export *exp;
 736         int cnt = 0;
 737         ENTRY;
 738
 739         INIT_LIST_HEAD(&work_list);
 740         spin_lock(&obd->obd_dev_lock);
 741         list_for_each_safe(pos, n, &obd->obd_exports) {
 742                 exp = list_entry(pos, struct obd_export, exp_obd_chain);
 743                 if (exp->exp_replay_needed) {
 744                         list_del(&exp->exp_obd_chain);
 745                         list_add(&exp->exp_obd_chain, &work_list);
 746                         cnt++;
 747                 }
 748         }
 749         spin_unlock(&obd->obd_dev_lock);
 750
 751         CDEBUG(D_ERROR, "%s: disconnecting %d stale clients\n",
 752                obd->obd_name, cnt);
 753         class_disconnect_export_list(&work_list, flags);
 754         EXIT;
 755 }
 756
 757
 758
 759 int oig_init(struct obd_io_group **oig_out)
 760 {
 761         struct obd_io_group *oig;
 762         ENTRY;
 763
 764         OBD_ALLOC(oig, sizeof(*oig));
 765         if (oig == NULL)
 766                 RETURN(-ENOMEM);
 767
 768         spin_lock_init(&oig->oig_lock);
 769         oig->oig_rc = 0;
 770         oig->oig_pending = 0;
 771         atomic_set(&oig->oig_refcount, 1);
 772         init_waitqueue_head(&oig->oig_waitq);
 773         INIT_LIST_HEAD(&oig->oig_occ_list);
 774
 775         *oig_out = oig;
 776         RETURN(0);
 777 };
 778
 779 static inline void oig_grab(struct obd_io_group *oig)
 780 {
 781         atomic_inc(&oig->oig_refcount);
 782 }
 783 void oig_release(struct obd_io_group *oig)
 784 {
 785         if (atomic_dec_and_test(&oig->oig_refcount))
 786                 OBD_FREE(oig, sizeof(*oig));
 787 }
 788
 789 void oig_add_one(struct obd_io_group *oig, struct oig_callback_context *occ)
 790 {
 791         unsigned long flags;
 792         CDEBUG(D_CACHE, "oig %p ready to roll\n", oig);
 793         spin_lock_irqsave(&oig->oig_lock, flags);
 794         oig->oig_pending++;
 795         if (occ != NULL)
 796                 list_add_tail(&occ->occ_oig_item, &oig->oig_occ_list);
 797         spin_unlock_irqrestore(&oig->oig_lock, flags);
 798         oig_grab(oig);
 799 }
 800
 801 void oig_complete_one(struct obd_io_group *oig,
 802                       struct oig_callback_context *occ, int rc)
 803 {
 804         unsigned long flags;
 805         wait_queue_head_t *wake = NULL;
 806         int old_rc;
 807
 808         spin_lock_irqsave(&oig->oig_lock, flags);
 809
 810         if (occ != NULL)
 811                 list_del_init(&occ->occ_oig_item);
 812
 813         old_rc = oig->oig_rc;
 814         if (oig->oig_rc == 0 && rc != 0)
 815                 oig->oig_rc = rc;
 816
 817         if (--oig->oig_pending <= 0)
 818                 wake = &oig->oig_waitq;
 819
 820         spin_unlock_irqrestore(&oig->oig_lock, flags);
 821
 822         CDEBUG(D_CACHE, "oig %p completed, rc %d -> %d via %d, %d now "
 823                         "pending (racey)\n", oig, old_rc, oig->oig_rc, rc,
 824                         oig->oig_pending);
 825         if (wake)
 826                 wake_up(wake);
 827         oig_release(oig);
 828 }
 829
 830 static int oig_done(struct obd_io_group *oig)
 831 {
 832         unsigned long flags;
 833         int rc = 0;
 834         spin_lock_irqsave(&oig->oig_lock, flags);
 835         if (oig->oig_pending <= 0)
 836                 rc = 1;
 837         spin_unlock_irqrestore(&oig->oig_lock, flags);
 838         return rc;
 839 }
 840
 841 static void interrupted_oig(void *data)
 842 {
 843         struct obd_io_group *oig = data;
 844         struct oig_callback_context *occ;
 845         unsigned long flags;
 846
 847         spin_lock_irqsave(&oig->oig_lock, flags);
 848         /* We need to restart the processing each time we drop the lock, as
 849          * it is possible other threads called oig_complete_one() to remove
 850          * an entry elsewhere in the list while we dropped lock.  We need to
 851          * drop the lock because osc_ap_completion() calls oig_complete_one()
 852          * which re-gets this lock ;-) as well as a lock ordering issue. */
 853 restart:
 854         list_for_each_entry(occ, &oig->oig_occ_list, occ_oig_item) {
 855                 if (occ->interrupted)
 856                         continue;
 857                 occ->interrupted = 1;
 858                 spin_unlock_irqrestore(&oig->oig_lock, flags);
 859                 occ->occ_interrupted(occ);
 860                 spin_lock_irqsave(&oig->oig_lock, flags);
 861                 goto restart;
 862         }
 863         spin_unlock_irqrestore(&oig->oig_lock, flags);
 864 }
 865
 866 int oig_wait(struct obd_io_group *oig)
 867 {
 868         struct l_wait_info lwi = LWI_INTR(interrupted_oig, oig);
 869         int rc;
 870
 871         CDEBUG(D_CACHE, "waiting for oig %p\n", oig);
 872
 873         do {
 874                 rc = l_wait_event(oig->oig_waitq, oig_done(oig), &lwi);
 875                 LASSERTF(rc == 0 || rc == -EINTR, "rc: %d\n", rc);
 876                 /* we can't continue until the oig has emptied and stopped
 877                  * referencing state that the caller will free upon return */
 878                 if (rc == -EINTR)
 879                         lwi = (struct l_wait_info){ 0, };
 880         } while (rc == -EINTR);
 881
 882         LASSERTF(oig->oig_pending == 0,
 883                  "exiting oig_wait(oig = %p) with %d pending\n", oig,
 884                  oig->oig_pending);
 885
 886         CDEBUG(D_CACHE, "done waiting on oig %p rc %d\n", oig, oig->oig_rc);
 887         return oig->oig_rc;
 888 }