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(int *dev)
 180 {
 181         struct obd_device *result = NULL;
 182         int i;
 183
 184         for (i = 0 ; i < MAX_OBD_DEVICES ; i++) {
 185                 struct obd_device *obd = &obd_dev[i];
 186                 if (!obd->obd_type) {
 187                         result = obd;
 188                         if (dev)
 189                                 *dev = i;
 190                         break;
 191                 }
 192         }
 193         return result;
 194 }
 195
 196 int class_name2dev(char *name)
 197 {
 198         int i;
 199
 200         if (!name)
 201                 return -1;
 202
 203         for (i = 0; i < MAX_OBD_DEVICES; i++) {
 204                 struct obd_device *obd = &obd_dev[i];
 205                 if (obd->obd_name && strcmp(name, obd->obd_name) == 0)
 206                         return i;
 207         }
 208
 209         return -1;
 210 }
 211
 212 struct obd_device *class_name2obd(char *name)
 213 {
 214         int dev = class_name2dev(name);
 215         if (dev < 0)
 216                 return NULL;
 217         return &obd_dev[dev];
 218 }
 219
 220 int class_uuid2dev(struct obd_uuid *uuid)
 221 {
 222         int i;
 223
 224         for (i = 0; i < MAX_OBD_DEVICES; i++) {
 225                 struct obd_device *obd = &obd_dev[i];
 226                 if (obd_uuid_equals(uuid, &obd->obd_uuid))
 227                         return i;
 228         }
 229
 230         return -1;
 231 }
 232
 233 struct obd_device *class_uuid2obd(struct obd_uuid *uuid)
 234 {
 235         int dev = class_uuid2dev(uuid);
 236         if (dev < 0)
 237                 return NULL;
 238         return &obd_dev[dev];
 239 }
 240
 241 /* Search for a client OBD connected to tgt_uuid.  If grp_uuid is
 242    specified, then only the client with that uuid is returned,
 243    otherwise any client connected to the tgt is returned. */
 244 struct obd_device * class_find_client_obd(struct obd_uuid *tgt_uuid,
 245                                           char * typ_name,
 246                                           struct obd_uuid *grp_uuid)
 247 {
 248         int i;
 249
 250         for (i = 0; i < MAX_OBD_DEVICES; i++) {
 251                 struct obd_device *obd = &obd_dev[i];
 252                 if (obd->obd_type == NULL)
 253                         continue;
 254                 if ((strncmp(obd->obd_type->typ_name, typ_name,
 255                              strlen(typ_name)) == 0)) {
 256                         struct client_obd *cli = &obd->u.cli;
 257                         struct obd_import *imp = cli->cl_import;
 258                         if (obd_uuid_equals(tgt_uuid, &imp->imp_target_uuid) &&
 259                             ((grp_uuid)? obd_uuid_equals(grp_uuid,
 260                                                         &obd->obd_uuid) : 1)) {
 261                                 return obd;
 262                         }
 263                 }
 264         }
 265
 266         return NULL;
 267 }
 268
 269 void obd_cleanup_caches(void)
 270 {
 271         int rc;
 272         ENTRY;
 273         if (obdo_cachep) {
 274                 rc = kmem_cache_destroy(obdo_cachep);
 275                 if (rc)
 276                         CERROR("Cannot destory ll_obdo_cache\n");
 277                 obdo_cachep = NULL;
 278         }
 279         if (import_cachep) {
 280                 rc = kmem_cache_destroy(import_cachep);
 281                 if (rc)
 282                         CERROR("Cannot destory ll_import_cache\n");
 283                 import_cachep = NULL;
 284         }
 285         EXIT;
 286 }
 287
 288 int obd_init_caches(void)
 289 {
 290         ENTRY;
 291         LASSERT(obdo_cachep == NULL);
 292         obdo_cachep = kmem_cache_create("ll_obdo_cache", sizeof(struct obdo),
 293                                         0, 0, NULL, NULL);
 294         if (!obdo_cachep)
 295                 GOTO(out, -ENOMEM);
 296
 297         LASSERT(import_cachep == NULL);
 298         import_cachep = kmem_cache_create("ll_import_cache",
 299                                           sizeof(struct obd_import),
 300                                           0, 0, NULL, NULL);
 301         if (!import_cachep)
 302                 GOTO(out, -ENOMEM);
 303
 304         RETURN(0);
 305  out:
 306         obd_cleanup_caches();
 307         RETURN(-ENOMEM);
 308
 309 }
 310
 311 /* map connection to client */
 312 struct obd_export *class_conn2export(struct lustre_handle *conn)
 313 {
 314         struct obd_export *export;
 315         ENTRY;
 316
 317         if (!conn) {
 318                 CDEBUG(D_CACHE, "looking for null handle\n");
 319                 RETURN(NULL);
 320         }
 321
 322         if (conn->cookie == -1) {  /* this means assign a new connection */
 323                 CDEBUG(D_CACHE, "want a new connection\n");
 324                 RETURN(NULL);
 325         }
 326
 327         CDEBUG(D_IOCTL, "looking for export cookie "LPX64"\n", conn->cookie);
 328         export = class_handle2object(conn->cookie);
 329         RETURN(export);
 330 }
 331
 332 struct obd_device *class_exp2obd(struct obd_export *exp)
 333 {
 334         if (exp)
 335                 return exp->exp_obd;
 336         return NULL;
 337 }
 338
 339 struct obd_device *class_conn2obd(struct lustre_handle *conn)
 340 {
 341         struct obd_export *export;
 342         export = class_conn2export(conn);
 343         if (export) {
 344                 struct obd_device *obd = export->exp_obd;
 345                 class_export_put(export);
 346                 return obd;
 347         }
 348         return NULL;
 349 }
 350
 351 struct obd_import *class_exp2cliimp(struct obd_export *exp)
 352 {
 353         struct obd_device *obd = exp->exp_obd;
 354         if (obd == NULL)
 355                 return NULL;
 356         return obd->u.cli.cl_import;
 357 }
 358
 359 struct obd_import *class_conn2cliimp(struct lustre_handle *conn)
 360 {
 361         struct obd_device *obd = class_conn2obd(conn);
 362         if (obd == NULL)
 363                 return NULL;
 364         return obd->u.cli.cl_import;
 365 }
 366
 367
 368 /* Export management functions */
 369 static void export_handle_addref(void *export)
 370 {
 371         class_export_get(export);
 372 }
 373
 374 void __class_export_put(struct obd_export *exp)
 375 {
 376         if (atomic_dec_and_test(&exp->exp_refcount)) {
 377                 struct obd_device *obd = exp->exp_obd;
 378                 CDEBUG(D_IOCTL, "destroying export %p/%s\n", exp,
 379                        exp->exp_client_uuid.uuid);
 380
 381                 LASSERT(obd != NULL);
 382
 383                 /* "Local" exports (lctl, LOV->{mdc,osc}) have no connection. */
 384                 if (exp->exp_connection)
 385                         ptlrpc_put_connection_superhack(exp->exp_connection);
 386
 387                 LASSERT(list_empty(&exp->exp_handle.h_link));
 388                 obd_destroy_export(exp);
 389
 390                 OBD_FREE(exp, sizeof(*exp));
 391                 if (obd->obd_set_up) {
 392                         atomic_dec(&obd->obd_refcount);
 393                         wake_up(&obd->obd_refcount_waitq);
 394                 }
 395         }
 396 }
 397
 398 /* Creates a new export, adds it to the hash table, and returns a
 399  * pointer to it. The refcount is 2: one for the hash reference, and
 400  * one for the pointer returned by this function. */
 401 struct obd_export *class_new_export(struct obd_device *obd)
 402 {
 403         struct obd_export *export;
 404
 405         OBD_ALLOC(export, sizeof(*export));
 406         if (!export) {
 407                 CERROR("no memory! (minor %d)\n", obd->obd_minor);
 408                 return NULL;
 409         }
 410
 411         export->exp_conn_cnt = 0;
 412         atomic_set(&export->exp_refcount, 2);
 413         export->exp_obd = obd;
 414         /* XXX this should be in LDLM init */
 415         INIT_LIST_HEAD(&export->exp_ldlm_data.led_held_locks);
 416
 417         INIT_LIST_HEAD(&export->exp_handle.h_link);
 418         class_handle_hash(&export->exp_handle, export_handle_addref);
 419         spin_lock_init(&export->exp_lock);
 420
 421         spin_lock(&obd->obd_dev_lock);
 422         LASSERT(!obd->obd_stopping); /* shouldn't happen, but might race */
 423         atomic_inc(&obd->obd_refcount);
 424         list_add(&export->exp_obd_chain, &export->exp_obd->obd_exports);
 425         export->exp_obd->obd_num_exports++;
 426         spin_unlock(&obd->obd_dev_lock);
 427         obd_init_export(export);
 428         return export;
 429 }
 430
 431 void class_unlink_export(struct obd_export *exp)
 432 {
 433         class_handle_unhash(&exp->exp_handle);
 434
 435         spin_lock(&exp->exp_obd->obd_dev_lock);
 436         list_del_init(&exp->exp_obd_chain);
 437         exp->exp_obd->obd_num_exports--;
 438         spin_unlock(&exp->exp_obd->obd_dev_lock);
 439
 440         class_export_put(exp);
 441 }
 442
 443 /* Import management functions */
 444 static void import_handle_addref(void *import)
 445 {
 446         class_import_get(import);
 447 }
 448
 449 struct obd_import *class_import_get(struct obd_import *import)
 450 {
 451         atomic_inc(&import->imp_refcount);
 452         CDEBUG(D_IOCTL, "import %p refcount=%d\n", import,
 453                atomic_read(&import->imp_refcount));
 454         return import;
 455 }
 456
 457 void class_import_put(struct obd_import *import)
 458 {
 459         ENTRY;
 460
 461         CDEBUG(D_IOCTL, "import %p refcount=%d\n", import,
 462                atomic_read(&import->imp_refcount) - 1);
 463
 464         LASSERT(atomic_read(&import->imp_refcount) > 0);
 465         LASSERT(atomic_read(&import->imp_refcount) < 0x5a5a5a);
 466         if (!atomic_dec_and_test(&import->imp_refcount)) {
 467                 EXIT;
 468                 return;
 469         }
 470
 471         CDEBUG(D_IOCTL, "destroying import %p\n", import);
 472
 473         ptlrpc_put_connection_superhack(import->imp_connection);
 474
 475         LASSERT(list_empty(&import->imp_handle.h_link));
 476         OBD_FREE(import, sizeof(*import));
 477         EXIT;
 478 }
 479
 480 struct obd_import *class_new_import(void)
 481 {
 482         struct obd_import *imp;
 483
 484         OBD_ALLOC(imp, sizeof(*imp));
 485         if (imp == NULL)
 486                 return NULL;
 487
 488         INIT_LIST_HEAD(&imp->imp_replay_list);
 489         INIT_LIST_HEAD(&imp->imp_sending_list);
 490         INIT_LIST_HEAD(&imp->imp_delayed_list);
 491         spin_lock_init(&imp->imp_lock);
 492         imp->imp_conn_cnt = 0;
 493         imp->imp_max_transno = 0;
 494         imp->imp_peer_committed_transno = 0;
 495         imp->imp_state = LUSTRE_IMP_NEW;
 496         sema_init(&imp->imp_recovery_sem, 1);
 497
 498         atomic_set(&imp->imp_refcount, 2);
 499         INIT_LIST_HEAD(&imp->imp_handle.h_link);
 500         class_handle_hash(&imp->imp_handle, import_handle_addref);
 501
 502         return imp;
 503 }
 504
 505 void class_destroy_import(struct obd_import *import)
 506 {
 507         LASSERT(import != NULL);
 508         LASSERT((unsigned long)import != 0x5a5a5a5a);
 509
 510         class_handle_unhash(&import->imp_handle);
 511
 512         /* Abort any inflight DLM requests and NULL out their (about to be
 513          * freed) import. */
 514         /* Invalidate all requests on import, would be better to call
 515            ptlrpc_set_import_active(imp, 0); */
 516         import->imp_generation++;
 517         ptlrpc_abort_inflight_superhack(import);
 518
 519         class_import_put(import);
 520 }
 521
 522 /* A connection defines an export context in which preallocation can
 523    be managed. This releases the export pointer reference, and returns
 524    the export handle, so the export refcount is 1 when this function
 525    returns. */
 526 int class_connect(struct lustre_handle *conn, struct obd_device *obd,
 527                   struct obd_uuid *cluuid)
 528 {
 529         struct obd_export *export;
 530         LASSERT(conn != NULL);
 531         LASSERT(obd != NULL);
 532         LASSERT(cluuid != NULL);
 533         ENTRY;
 534
 535         export = class_new_export(obd);
 536         if (export == NULL)
 537                 RETURN(-ENOMEM);
 538
 539         conn->cookie = export->exp_handle.h_cookie;
 540         memcpy(&export->exp_client_uuid, cluuid,
 541                sizeof(export->exp_client_uuid));
 542         class_export_put(export);
 543
 544         CDEBUG(D_IOCTL, "connect: client %s, cookie "LPX64"\n",
 545                cluuid->uuid, conn->cookie);
 546         RETURN(0);
 547 }
 548
 549 /* This function removes two references from the export: one for the
 550  * hash entry and one for the export pointer passed in.  The export
 551  * pointer passed to this function is destroyed should not be used
 552  * again. */
 553 int class_disconnect(struct obd_export *export, int flags)
 554 {
 555         ENTRY;
 556
 557         if (export == NULL) {
 558                 fixme();
 559                 CDEBUG(D_IOCTL, "disconnect: attempting to free "
 560                        "null export %p\n", export);
 561                 RETURN(-EINVAL);
 562         }
 563
 564         /* XXX this shouldn't have to be here, but double-disconnect will crash
 565          * otherwise, and sometimes double-disconnect happens.  abort_recovery,
 566          * for example. */
 567         if (list_empty(&export->exp_handle.h_link))
 568                 RETURN(0);
 569
 570         CDEBUG(D_IOCTL, "disconnect: cookie "LPX64"\n",
 571                export->exp_handle.h_cookie);
 572
 573         class_unlink_export(export);
 574         class_export_put(export);
 575         RETURN(0);
 576 }
 577
 578 void class_disconnect_exports(struct obd_device *obd, int flags)
 579 {
 580         int rc;
 581         struct list_head *tmp, *n, work_list;
 582         struct lustre_handle fake_conn;
 583         struct obd_export *fake_exp, *exp;
 584         ENTRY;
 585
 586         /* Move all of the exports from obd_exports to a work list, en masse. */
 587         spin_lock(&obd->obd_dev_lock);
 588         list_add(&work_list, &obd->obd_exports);
 589         list_del_init(&obd->obd_exports);
 590         spin_unlock(&obd->obd_dev_lock);
 591
 592         CDEBUG(D_IOCTL, "OBD device %d (%p) has exports, "
 593                "disconnecting them\n", obd->obd_minor, obd);
 594         list_for_each_safe(tmp, n, &work_list) {
 595                 exp = list_entry(tmp, struct obd_export, exp_obd_chain);
 596                 class_export_get(exp);
 597
 598                 if (obd_uuid_equals(&exp->exp_client_uuid,
 599                                     &exp->exp_obd->obd_uuid)) {
 600                         CDEBUG(D_IOCTL,
 601                                "exp %p export uuid == obd uuid, don't discon\n",
 602                                exp);
 603                         class_export_put(exp);
 604                         continue;
 605                 }
 606
 607                 fake_conn.cookie = exp->exp_handle.h_cookie;
 608                 fake_exp = class_conn2export(&fake_conn);
 609                 if (!fake_exp) {
 610                         class_export_put(exp);
 611                         continue;
 612                 }
 613                 rc = obd_disconnect(fake_exp, flags);
 614                 class_export_put(exp);
 615                 if (rc) {
 616                         CDEBUG(D_IOCTL, "disconnecting export %p failed: %d\n",
 617                                exp, rc);
 618                 } else {
 619                         CDEBUG(D_IOCTL, "export %p disconnected\n", exp);
 620                 }
 621         }
 622         EXIT;
 623 }
 624
 625 void osic_init(struct obd_sync_io_container **osic_out)
 626 {
 627         struct obd_sync_io_container *osic;
 628         OBD_ALLOC(osic, sizeof(*osic));
 629         spin_lock_init(&osic->osic_lock);
 630         osic->osic_rc = 0;
 631         osic->osic_pending = 0;
 632         atomic_set(&osic->osic_refcount, 1);
 633         init_waitqueue_head(&osic->osic_waitq);
 634         INIT_LIST_HEAD(&osic->osic_occ_list);
 635         *osic_out = osic;
 636 };
 637
 638 static inline void osic_grab(struct obd_sync_io_container *osic)
 639 {
 640         atomic_inc(&osic->osic_refcount);
 641 }
 642 void osic_release(struct obd_sync_io_container *osic)
 643 {
 644         if (atomic_dec_and_test(&osic->osic_refcount))
 645                 OBD_FREE(osic, sizeof(*osic));
 646 }
 647
 648 void osic_add_one(struct obd_sync_io_container *osic,
 649                   struct osic_callback_context *occ)
 650 {
 651         unsigned long flags;
 652         CDEBUG(D_CACHE, "osic %p ready to roll\n", osic);
 653         spin_lock_irqsave(&osic->osic_lock, flags);
 654         osic->osic_pending++;
 655         if (occ != NULL)
 656                 list_add_tail(&occ->occ_osic_item, &osic->osic_occ_list);
 657         spin_unlock_irqrestore(&osic->osic_lock, flags);
 658         osic_grab(osic);
 659 }
 660
 661 void osic_complete_one(struct obd_sync_io_container *osic,
 662                        struct osic_callback_context *occ, int rc)
 663 {
 664         unsigned long flags;
 665         wait_queue_head_t *wake = NULL;
 666         int old_rc;
 667
 668         spin_lock_irqsave(&osic->osic_lock, flags);
 669
 670         if (occ != NULL)
 671                 list_del_init(&occ->occ_osic_item);
 672
 673         old_rc = osic->osic_rc;
 674         if (osic->osic_rc == 0 && rc != 0)
 675                 osic->osic_rc = rc;
 676
 677         if (--osic->osic_pending <= 0)
 678                 wake = &osic->osic_waitq;
 679
 680         spin_unlock_irqrestore(&osic->osic_lock, flags);
 681
 682         CDEBUG(D_CACHE, "osic %p completed, rc %d -> %d via %d, %d now "
 683                         "pending (racey)\n", osic, old_rc, osic->osic_rc, rc,
 684                         osic->osic_pending);
 685         if (wake)
 686                 wake_up(wake);
 687         osic_release(osic);
 688 }
 689
 690 static int osic_done(struct obd_sync_io_container *osic)
 691 {
 692         unsigned long flags;
 693         int rc = 0;
 694         spin_lock_irqsave(&osic->osic_lock, flags);
 695         if (osic->osic_pending <= 0)
 696                 rc = 1;
 697         spin_unlock_irqrestore(&osic->osic_lock, flags);
 698         return rc;
 699 }
 700
 701 static void interrupted_osic(void *data)
 702 {
 703         struct obd_sync_io_container *osic = data;
 704         struct list_head *pos;
 705         struct osic_callback_context *occ;
 706         unsigned long flags;
 707
 708         spin_lock_irqsave(&osic->osic_lock, flags);
 709         list_for_each(pos, &osic->osic_occ_list) {
 710                 occ = list_entry(pos, struct osic_callback_context,
 711                                  occ_osic_item);
 712                 occ->occ_interrupted(occ);
 713         }
 714         spin_unlock_irqrestore(&osic->osic_lock, flags);
 715 }
 716
 717 int osic_wait(struct obd_sync_io_container *osic)
 718 {
 719         struct l_wait_info lwi = LWI_INTR(interrupted_osic, osic);
 720         int rc;
 721
 722         CDEBUG(D_CACHE, "waiting for osic %p\n", osic);
 723
 724         do {
 725                 rc = l_wait_event(osic->osic_waitq, osic_done(osic), &lwi);
 726                 LASSERTF(rc == 0 || rc == -EINTR, "rc: %d\n", rc);
 727                 /* we can't continue until the osic has emptied and stopped
 728                  * referencing state that the caller will free upon return */
 729                 if (rc == -EINTR)
 730                         lwi = (struct l_wait_info){ 0, };
 731         } while (rc == -EINTR);
 732
 733         LASSERTF(osic->osic_pending == 0,
 734                  "exiting osic_wait(osic = %p) with %d pending\n", osic,
 735                  osic->osic_pending);
 736
 737         CDEBUG(D_CACHE, "done waiting on osic %p\n", osic);
 738         return osic->osic_rc;
 739 }