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         obd->obd_type = NULL;
 216         //memset(obd, 0, sizeof(*obd));
 217         obd->obd_minor = minor;
 218         spin_unlock(&obd_dev_lock);
 219 }
 220
 221 int class_name2dev(char *name)
 222 {
 223         int i;
 224
 225         if (!name)
 226                 return -1;
 227
 228         spin_lock(&obd_dev_lock);
 229         for (i = 0; i < MAX_OBD_DEVICES; i++) {
 230                 struct obd_device *obd = &obd_dev[i];
 231                 if (obd->obd_name && strcmp(name, obd->obd_name) == 0) {
 232                         spin_unlock(&obd_dev_lock);
 233                         return i;
 234                 }
 235         }
 236         spin_unlock(&obd_dev_lock);
 237         return -1;
 238 }
 239
 240 struct obd_device *class_name2obd(char *name)
 241 {
 242         int dev = class_name2dev(name);
 243         if (dev < 0)
 244                 return NULL;
 245         return &obd_dev[dev];
 246 }
 247
 248 int class_uuid2dev(struct obd_uuid *uuid)
 249 {
 250         int i;
 251         spin_lock(&obd_dev_lock);
 252         for (i = 0; i < MAX_OBD_DEVICES; i++) {
 253                 struct obd_device *obd = &obd_dev[i];
 254                 if (obd_uuid_equals(uuid, &obd->obd_uuid)) {
 255                         spin_unlock(&obd_dev_lock);
 256                         return i;
 257                 }
 258         }
 259         spin_unlock(&obd_dev_lock);
 260         return -1;
 261 }
 262
 263 struct obd_device *class_uuid2obd(struct obd_uuid *uuid)
 264 {
 265         int dev = class_uuid2dev(uuid);
 266         if (dev < 0)
 267                 return NULL;
 268         return &obd_dev[dev];
 269 }
 270
 271 /* Search for a client OBD connected to tgt_uuid.  If grp_uuid is
 272    specified, then only the client with that uuid is returned,
 273    otherwise any client connected to the tgt is returned.
 274    If tgt_uuid is NULL, the lov with grp_uuid is returned. */
 275 struct obd_device *class_find_client_obd(struct obd_uuid *tgt_uuid,
 276                                          char *typ_name,
 277                                          struct obd_uuid *grp_uuid)
 278 {
 279         int i;
 280
 281         spin_lock(&obd_dev_lock);
 282         for (i = 0; i < MAX_OBD_DEVICES; i++) {
 283                 struct obd_device *obd = &obd_dev[i];
 284                 if (obd->obd_type == NULL)
 285                         continue;
 286                 if ((strncmp(obd->obd_type->typ_name, typ_name,
 287                              strlen(typ_name)) == 0)) {
 288                         struct client_obd *cli = &obd->u.cli;
 289                         struct obd_import *imp = cli->cl_import;
 290                         if (tgt_uuid == NULL) {
 291                                 LASSERT(grp_uuid);
 292                                 if (obd_uuid_equals(grp_uuid, &obd->obd_uuid)) {
 293                                         spin_unlock(&obd_dev_lock);
 294                                         return obd;
 295                                 }
 296                                 continue;
 297                         }
 298                         if (obd_uuid_equals(tgt_uuid, &imp->imp_target_uuid) &&
 299                             ((grp_uuid)? obd_uuid_equals(grp_uuid,
 300                                                          &obd->obd_uuid) : 1)) {
 301                                 spin_unlock(&obd_dev_lock);
 302                                 return obd;
 303                         }
 304                 }
 305         }
 306         spin_unlock(&obd_dev_lock);
 307         return NULL;
 308 }
 309
 310 /* Iterate the obd_device list looking devices have grp_uuid. Start
 311    searching at *next, and if a device is found, the next index to look
 312    it is saved in *next. If next is NULL, then the first matching device
 313    will always be returned. */
 314 struct obd_device *class_devices_in_group(struct obd_uuid *grp_uuid, int *next)
 315 {
 316         int i;
 317
 318         if (next == NULL)
 319                 i = 0;
 320         else if (*next >= 0 && *next < MAX_OBD_DEVICES)
 321                 i = *next;
 322         else
 323                 return NULL;
 324         spin_lock(&obd_dev_lock);
 325         for (; i < MAX_OBD_DEVICES; i++) {
 326                 struct obd_device *obd = &obd_dev[i];
 327                 if (obd->obd_type == NULL)
 328                         continue;
 329                 if (obd_uuid_equals(grp_uuid, &obd->obd_uuid)) {
 330                         if (next != NULL)
 331                                 *next = i+1;
 332                         spin_unlock(&obd_dev_lock);
 333                         return obd;
 334                 }
 335         }
 336
 337         spin_unlock(&obd_dev_lock);
 338         return NULL;
 339 }
 340
 341 void obd_cleanup_caches(void)
 342 {
 343         ENTRY;
 344         if (obdo_cachep) {
 345                 LASSERTF(kmem_cache_destroy(obdo_cachep) == 0,
 346                          "Cannot destory ll_obdo_cache\n");
 347                 obdo_cachep = NULL;
 348         }
 349         if (import_cachep) {
 350                 LASSERTF(kmem_cache_destroy(import_cachep) == 0,
 351                          "Cannot destory ll_import_cache\n");
 352                 import_cachep = NULL;
 353         }
 354         EXIT;
 355 }
 356
 357 int obd_init_caches(void)
 358 {
 359         ENTRY;
 360         LASSERT(obdo_cachep == NULL);
 361         obdo_cachep = kmem_cache_create("ll_obdo_cache", sizeof(struct obdo),
 362                                         0, 0, NULL, NULL);
 363         if (!obdo_cachep)
 364                 GOTO(out, -ENOMEM);
 365
 366         LASSERT(import_cachep == NULL);
 367         import_cachep = kmem_cache_create("ll_import_cache",
 368                                           sizeof(struct obd_import),
 369                                           0, 0, NULL, NULL);
 370         if (!import_cachep)
 371                 GOTO(out, -ENOMEM);
 372
 373         RETURN(0);
 374  out:
 375         obd_cleanup_caches();
 376         RETURN(-ENOMEM);
 377
 378 }
 379
 380 /* map connection to client */
 381 struct obd_export *class_conn2export(struct lustre_handle *conn)
 382 {
 383         struct obd_export *export;
 384         ENTRY;
 385
 386         if (!conn) {
 387                 CDEBUG(D_CACHE, "looking for null handle\n");
 388                 RETURN(NULL);
 389         }
 390
 391         if (conn->cookie == -1) {  /* this means assign a new connection */
 392                 CDEBUG(D_CACHE, "want a new connection\n");
 393                 RETURN(NULL);
 394         }
 395
 396         CDEBUG(D_IOCTL, "looking for export cookie "LPX64"\n", conn->cookie);
 397         export = class_handle2object(conn->cookie);
 398         RETURN(export);
 399 }
 400
 401 struct obd_device *class_exp2obd(struct obd_export *exp)
 402 {
 403         if (exp)
 404                 return exp->exp_obd;
 405         return NULL;
 406 }
 407
 408 struct obd_device *class_conn2obd(struct lustre_handle *conn)
 409 {
 410         struct obd_export *export;
 411         export = class_conn2export(conn);
 412         if (export) {
 413                 struct obd_device *obd = export->exp_obd;
 414                 class_export_put(export);
 415                 return obd;
 416         }
 417         return NULL;
 418 }
 419
 420 struct obd_import *class_exp2cliimp(struct obd_export *exp)
 421 {
 422         struct obd_device *obd = exp->exp_obd;
 423         if (obd == NULL)
 424                 return NULL;
 425         return obd->u.cli.cl_import;
 426 }
 427
 428 struct obd_import *class_conn2cliimp(struct lustre_handle *conn)
 429 {
 430         struct obd_device *obd = class_conn2obd(conn);
 431         if (obd == NULL)
 432                 return NULL;
 433         return obd->u.cli.cl_import;
 434 }
 435
 436 /* Export management functions */
 437 static void export_handle_addref(void *export)
 438 {
 439         class_export_get(export);
 440 }
 441
 442 void __class_export_put(struct obd_export *exp)
 443 {
 444         if (atomic_dec_and_test(&exp->exp_refcount)) {
 445                 struct obd_device *obd = exp->exp_obd;
 446                 CDEBUG(D_IOCTL, "destroying export %p/%s\n", exp,
 447                        exp->exp_client_uuid.uuid);
 448
 449                 LASSERT(obd != NULL);
 450
 451                 /* "Local" exports (lctl, LOV->{mdc,osc}) have no connection. */
 452                 if (exp->exp_connection)
 453                         ptlrpc_put_connection_superhack(exp->exp_connection);
 454
 455                 LASSERT(list_empty(&exp->exp_outstanding_replies));
 456                 LASSERT(list_empty(&exp->exp_handle.h_link));
 457                 obd_destroy_export(exp);
 458
 459                 OBD_FREE(exp, sizeof(*exp));
 460                 if (obd->obd_set_up) {
 461                         atomic_dec(&obd->obd_refcount);
 462                         wake_up(&obd->obd_refcount_waitq);
 463                 } else {
 464                         CERROR("removing export %p from obd %s (%p) -- OBD "
 465                                "not set up (refcount = %d)\n", exp,
 466                                obd->obd_name, obd,
 467                                atomic_read(&obd->obd_refcount));
 468                 }
 469         }
 470 }
 471
 472 /* Creates a new export, adds it to the hash table, and returns a
 473  * pointer to it. The refcount is 2: one for the hash reference, and
 474  * one for the pointer returned by this function. */
 475 struct obd_export *class_new_export(struct obd_device *obd)
 476 {
 477         struct obd_export *export;
 478
 479         OBD_ALLOC(export, sizeof(*export));
 480         if (!export) {
 481                 CERROR("no memory! (minor %d)\n", obd->obd_minor);
 482                 return NULL;
 483         }
 484
 485         export->exp_conn_cnt = 0;
 486         atomic_set(&export->exp_refcount, 2);
 487         atomic_set(&export->exp_rpc_count, 0);
 488         export->exp_obd = obd;
 489         export->exp_flags = 0;
 490         INIT_LIST_HEAD(&export->exp_outstanding_replies);
 491         /* XXX this should be in LDLM init */
 492         INIT_LIST_HEAD(&export->exp_ldlm_data.led_held_locks);
 493         spin_lock_init(&export->exp_ldlm_data.led_lock);
 494
 495         INIT_LIST_HEAD(&export->exp_handle.h_link);
 496         class_handle_hash(&export->exp_handle, export_handle_addref);
 497         spin_lock_init(&export->exp_lock);
 498
 499         spin_lock(&obd->obd_dev_lock);
 500         LASSERT(!obd->obd_stopping); /* shouldn't happen, but might race */
 501         atomic_inc(&obd->obd_refcount);
 502         list_add(&export->exp_obd_chain, &export->exp_obd->obd_exports);
 503         export->exp_obd->obd_num_exports++;
 504         spin_unlock(&obd->obd_dev_lock);
 505         export->exp_connected = 1;
 506         obd_init_export(export);
 507         return export;
 508 }
 509
 510 void class_unlink_export(struct obd_export *exp)
 511 {
 512         class_handle_unhash(&exp->exp_handle);
 513
 514         spin_lock(&exp->exp_obd->obd_dev_lock);
 515         list_del_init(&exp->exp_obd_chain);
 516         exp->exp_obd->obd_num_exports--;
 517         spin_unlock(&exp->exp_obd->obd_dev_lock);
 518
 519         class_export_put(exp);
 520 }
 521
 522 /* Import management functions */
 523 static void import_handle_addref(void *import)
 524 {
 525         class_import_get(import);
 526 }
 527
 528 struct obd_import *class_import_get(struct obd_import *import)
 529 {
 530         atomic_inc(&import->imp_refcount);
 531         CDEBUG(D_IOCTL, "import %p refcount=%d\n", import,
 532                atomic_read(&import->imp_refcount));
 533         return import;
 534 }
 535
 536 void class_import_put(struct obd_import *import)
 537 {
 538         ENTRY;
 539
 540         CDEBUG(D_IOCTL, "import %p refcount=%d\n", import,
 541                atomic_read(&import->imp_refcount) - 1);
 542
 543         LASSERT(atomic_read(&import->imp_refcount) > 0);
 544         LASSERT(atomic_read(&import->imp_refcount) < 0x5a5a5a);
 545
 546         if (!atomic_dec_and_test(&import->imp_refcount)) {
 547                 EXIT;
 548                 return;
 549         }
 550
 551         CDEBUG(D_IOCTL, "destroying import %p\n", import);
 552
 553         if (import->imp_connection)
 554                 ptlrpc_put_connection_superhack(import->imp_connection);
 555
 556         LASSERT(!import->imp_sec);
 557         while (!list_empty(&import->imp_conn_list)) {
 558                 struct obd_import_conn *imp_conn;
 559
 560                 imp_conn = list_entry(import->imp_conn_list.next,
 561                                       struct obd_import_conn, oic_item);
 562                 list_del(&imp_conn->oic_item);
 563                 if (imp_conn->oic_conn)
 564                         ptlrpc_put_connection_superhack(imp_conn->oic_conn);
 565                 OBD_FREE(imp_conn, sizeof(*imp_conn));
 566         }
 567
 568         LASSERT(list_empty(&import->imp_handle.h_link));
 569         OBD_FREE(import, sizeof(*import));
 570         EXIT;
 571 }
 572
 573 struct obd_import *class_new_import(void)
 574 {
 575         struct obd_import *imp;
 576
 577         OBD_ALLOC(imp, sizeof(*imp));
 578         if (imp == NULL)
 579                 return NULL;
 580
 581         INIT_LIST_HEAD(&imp->imp_replay_list);
 582         INIT_LIST_HEAD(&imp->imp_sending_list);
 583         INIT_LIST_HEAD(&imp->imp_delayed_list);
 584         INIT_LIST_HEAD(&imp->imp_rawrpc_list);
 585         spin_lock_init(&imp->imp_lock);
 586         imp->imp_conn_cnt = 0;
 587         imp->imp_max_transno = 0;
 588         imp->imp_peer_committed_transno = 0;
 589         imp->imp_state = LUSTRE_IMP_NEW;
 590         init_waitqueue_head(&imp->imp_recovery_waitq);
 591
 592         atomic_set(&imp->imp_refcount, 2);
 593         atomic_set(&imp->imp_inflight, 0);
 594         atomic_set(&imp->imp_replay_inflight, 0);
 595         INIT_LIST_HEAD(&imp->imp_conn_list);
 596         INIT_LIST_HEAD(&imp->imp_handle.h_link);
 597         class_handle_hash(&imp->imp_handle, import_handle_addref);
 598         imp->imp_waiting_ping_reply = 0;
 599
 600         return imp;
 601 }
 602
 603 void class_destroy_import(struct obd_import *import)
 604 {
 605         LASSERT(import != NULL);
 606         LASSERT(import != LP_POISON);
 607
 608         class_handle_unhash(&import->imp_handle);
 609
 610         /* Abort any inflight DLM requests and NULL out their (about to be
 611          * freed) import. */
 612         /* Invalidate all requests on import, would be better to call
 613            ptlrpc_set_import_active(imp, 0); */
 614         import->imp_generation++;
 615         ptlrpc_abort_inflight_superhack(import);
 616
 617         class_import_put(import);
 618 }
 619
 620 /* A connection defines an export context in which preallocation can
 621    be managed. This releases the export pointer reference, and returns
 622    the export handle, so the export refcount is 1 when this function
 623    returns. */
 624 int class_connect(struct lustre_handle *conn, struct obd_device *obd,
 625                   struct obd_uuid *cluuid)
 626 {
 627         struct obd_export *export;
 628         LASSERT(conn != NULL);
 629         LASSERT(obd != NULL);
 630         LASSERT(cluuid != NULL);
 631         ENTRY;
 632
 633         export = class_new_export(obd);
 634         if (export == NULL)
 635                 RETURN(-ENOMEM);
 636
 637         conn->cookie = export->exp_handle.h_cookie;
 638         memcpy(&export->exp_client_uuid, cluuid,
 639                sizeof(export->exp_client_uuid));
 640         class_export_put(export);
 641
 642         CDEBUG(D_IOCTL, "connect: client %s, cookie "LPX64"\n",
 643                cluuid->uuid, conn->cookie);
 644         RETURN(0);
 645 }
 646
 647 /* This function removes two references from the export: one for the
 648  * hash entry and one for the export pointer passed in.  The export
 649  * pointer passed to this function is destroyed should not be used
 650  * again. */
 651 int class_disconnect(struct obd_export *export, unsigned long flags)
 652 {
 653         ENTRY;
 654
 655         if (export == NULL) {
 656                 fixme();
 657                 CDEBUG(D_IOCTL, "attempting to free NULL export %p\n", export);
 658                 RETURN(-EINVAL);
 659         }
 660
 661         /* XXX this shouldn't have to be here, but double-disconnect will crash
 662          * otherwise, and sometimes double-disconnect happens.  abort_recovery,
 663          * for example. */
 664         if (list_empty(&export->exp_handle.h_link))
 665                 RETURN(0);
 666
 667         CDEBUG(D_IOCTL, "disconnect: cookie "LPX64"\n",
 668                export->exp_handle.h_cookie);
 669
 670         if (export->exp_handle.h_cookie == LL_POISON) {
 671                 CERROR("disconnecting freed export %p, ignoring\n", export);
 672         } else {
 673                 class_unlink_export(export);
 674                 class_export_put(export);
 675         }
 676         RETURN(0);
 677 }
 678
 679 static void class_disconnect_export_list(struct list_head *list, unsigned long flags)
 680 {
 681         struct obd_export *fake_exp, *exp;
 682         struct lustre_handle fake_conn;
 683         int rc;
 684         ENTRY;
 685
 686         /* Move all of the exports from obd_exports to a work list, en masse. */
 687         /* It's possible that an export may disconnect itself, but
 688          * nothing else will be added to this list. */
 689         while(!list_empty(list)) {
 690                 exp = list_entry(list->next, struct obd_export, exp_obd_chain);
 691                 class_export_get(exp);
 692
 693                 if (obd_uuid_equals(&exp->exp_client_uuid,
 694                                     &exp->exp_obd->obd_uuid)) {
 695                         CDEBUG(D_HA,
 696                                "exp %p export uuid == obd uuid, don't discon\n",
 697                                exp);
 698                         /*
 699                          * need to delete this now so we don't end up pointing
 700                          * to work_list later when this export is cleaned up.
 701                          */
 702                         list_del_init(&exp->exp_obd_chain);
 703                         class_export_put(exp);
 704                         continue;
 705                 }
 706
 707                 fake_conn.cookie = exp->exp_handle.h_cookie;
 708                 fake_exp = class_conn2export(&fake_conn);
 709                 if (!fake_exp) {
 710                         class_export_put(exp);
 711                         continue;
 712                 }
 713
 714                 rc = obd_disconnect(fake_exp, flags);
 715                 class_export_put(exp);
 716                 if (rc) {
 717                         CDEBUG(D_HA, "disconnecting export %p failed: %d\n",
 718                                exp, rc);
 719                 } else {
 720                         CDEBUG(D_HA, "export %p disconnected\n", exp);
 721                 }
 722         }
 723         EXIT;
 724 }
 725
 726 void class_disconnect_exports(struct obd_device *obd, unsigned long flags)
 727 {
 728         struct list_head work_list;
 729         ENTRY;
 730
 731         /* Move all of the exports from obd_exports to a work list, en masse. */
 732         spin_lock(&obd->obd_dev_lock);
 733         list_add(&work_list, &obd->obd_exports);
 734         list_del_init(&obd->obd_exports);
 735         spin_unlock(&obd->obd_dev_lock);
 736
 737         CDEBUG(D_HA, "OBD device %d (%p) has exports, "
 738                "disconnecting them\n", obd->obd_minor, obd);
 739         class_disconnect_export_list(&work_list, flags);
 740         EXIT;
 741 }
 742
 743 /* Remove exports that have not completed recovery.
 744  */
 745 int class_disconnect_stale_exports(struct obd_device *obd,
 746                                    int (*test_export)(struct obd_export *),
 747                                    unsigned long flags)
 748 {
 749         char str[PTL_NALFMT_SIZE];
 750         struct list_head work_list;
 751         struct list_head *pos, *n;
 752         struct obd_export *exp;
 753         int cnt = 0;
 754         ENTRY;
 755
 756         INIT_LIST_HEAD(&work_list);
 757         spin_lock(&obd->obd_dev_lock);
 758         list_for_each_safe(pos, n, &obd->obd_exports) {
 759                 exp = list_entry(pos, struct obd_export, exp_obd_chain);
 760                 if (test_export(exp))
 761                         continue;
 762                 list_del(&exp->exp_obd_chain);
 763                 list_add(&exp->exp_obd_chain, &work_list);
 764                 cnt++;
 765                 CDEBUG(D_ERROR, "%s: disconnect stale client %s@%s\n",
 766                        obd->obd_name, exp->exp_client_uuid.uuid,
 767                        exp->exp_connection == NULL ? "<unknown>" :
 768                        ptlrpc_peernid2str(&exp->exp_connection->c_peer, str));
 769         }
 770         spin_unlock(&obd->obd_dev_lock);
 771
 772         CDEBUG(D_ERROR, "%s: disconnecting %d stale clients\n",
 773                obd->obd_name, cnt);
 774         class_disconnect_export_list(&work_list, flags);
 775         RETURN(cnt);
 776 }
 777
 778
 779
 780 int oig_init(struct obd_io_group **oig_out)
 781 {
 782         struct obd_io_group *oig;
 783         ENTRY;
 784
 785         OBD_ALLOC(oig, sizeof(*oig));
 786         if (oig == NULL)
 787                 RETURN(-ENOMEM);
 788
 789         spin_lock_init(&oig->oig_lock);
 790         oig->oig_rc = 0;
 791         oig->oig_pending = 0;
 792         atomic_set(&oig->oig_refcount, 1);
 793         init_waitqueue_head(&oig->oig_waitq);
 794         INIT_LIST_HEAD(&oig->oig_occ_list);
 795
 796         *oig_out = oig;
 797         RETURN(0);
 798 };
 799
 800 static inline void oig_grab(struct obd_io_group *oig)
 801 {
 802         atomic_inc(&oig->oig_refcount);
 803 }
 804
 805 void oig_release(struct obd_io_group *oig)
 806 {
 807         if (atomic_dec_and_test(&oig->oig_refcount))
 808                 OBD_FREE(oig, sizeof(*oig));
 809 }
 810
 811 void oig_add_one(struct obd_io_group *oig, struct oig_callback_context *occ)
 812 {
 813         unsigned long flags;
 814         CDEBUG(D_CACHE, "oig %p ready to roll\n", oig);
 815         spin_lock_irqsave(&oig->oig_lock, flags);
 816         oig->oig_pending++;
 817         if (occ != NULL)
 818                 list_add_tail(&occ->occ_oig_item, &oig->oig_occ_list);
 819         spin_unlock_irqrestore(&oig->oig_lock, flags);
 820         oig_grab(oig);
 821 }
 822
 823 void oig_complete_one(struct obd_io_group *oig,
 824                       struct oig_callback_context *occ, int rc)
 825 {
 826         unsigned long flags;
 827         wait_queue_head_t *wake = NULL;
 828         int old_rc;
 829
 830         spin_lock_irqsave(&oig->oig_lock, flags);
 831
 832         if (occ != NULL)
 833                 list_del_init(&occ->occ_oig_item);
 834
 835         old_rc = oig->oig_rc;
 836         if (oig->oig_rc == 0 && rc != 0)
 837                 oig->oig_rc = rc;
 838
 839         if (--oig->oig_pending <= 0)
 840                 wake = &oig->oig_waitq;
 841
 842         spin_unlock_irqrestore(&oig->oig_lock, flags);
 843
 844         CDEBUG(D_CACHE, "oig %p completed, rc %d -> %d via %d, %d now "
 845                         "pending (racey)\n", oig, old_rc, oig->oig_rc, rc,
 846                         oig->oig_pending);
 847         if (wake)
 848                 wake_up(wake);
 849         oig_release(oig);
 850 }
 851
 852 static int oig_done(struct obd_io_group *oig)
 853 {
 854         unsigned long flags;
 855         int rc = 0;
 856         spin_lock_irqsave(&oig->oig_lock, flags);
 857         if (oig->oig_pending <= 0)
 858                 rc = 1;
 859         spin_unlock_irqrestore(&oig->oig_lock, flags);
 860         return rc;
 861 }
 862
 863 static void interrupted_oig(void *data)
 864 {
 865         struct obd_io_group *oig = data;
 866         struct oig_callback_context *occ;
 867         unsigned long flags;
 868
 869         spin_lock_irqsave(&oig->oig_lock, flags);
 870         /* We need to restart the processing each time we drop the lock, as
 871          * it is possible other threads called oig_complete_one() to remove
 872          * an entry elsewhere in the list while we dropped lock.  We need to
 873          * drop the lock because osc_ap_completion() calls oig_complete_one()
 874          * which re-gets this lock ;-) as well as a lock ordering issue. */
 875 restart:
 876         list_for_each_entry(occ, &oig->oig_occ_list, occ_oig_item) {
 877                 if (occ->interrupted)
 878                         continue;
 879                 occ->interrupted = 1;
 880                 spin_unlock_irqrestore(&oig->oig_lock, flags);
 881                 occ->occ_interrupted(occ);
 882                 spin_lock_irqsave(&oig->oig_lock, flags);
 883                 goto restart;
 884         }
 885         spin_unlock_irqrestore(&oig->oig_lock, flags);
 886 }
 887
 888 int oig_wait(struct obd_io_group *oig)
 889 {
 890         struct l_wait_info lwi = LWI_INTR(interrupted_oig, oig);
 891         int rc;
 892
 893         CDEBUG(D_CACHE, "waiting for oig %p\n", oig);
 894
 895         do {
 896                 rc = l_wait_event(oig->oig_waitq, oig_done(oig), &lwi);
 897                 LASSERTF(rc == 0 || rc == -EINTR, "rc: %d\n", rc);
 898                 /* we can't continue until the oig has emptied and stopped
 899                  * referencing state that the caller will free upon return */
 900                 if (rc == -EINTR)
 901                         lwi = (struct l_wait_info){ 0, };
 902         } while (rc == -EINTR);
 903
 904         LASSERTF(oig->oig_pending == 0,
 905                  "exiting oig_wait(oig = %p) with %d pending\n", oig,
 906                  oig->oig_pending);
 907
 908         CDEBUG(D_CACHE, "done waiting on oig %p rc %d\n", oig, oig->oig_rc);
 909         return oig->oig_rc;
 910 }