lustre/obdclass/genops.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; If not, see
  18  * http://www.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 1999, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2011, 2017, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  *
  31  * lustre/obdclass/genops.c
  32  *
  33  * These are the only exported functions, they provide some generic
  34  * infrastructure for managing object devices
  35  */
  36
  37 #define DEBUG_SUBSYSTEM S_CLASS
  38
  39 #include <linux/pid_namespace.h>
  40 #include <linux/workqueue.h>
  41 #include <lustre_compat.h>
  42 #include <obd_class.h>
  43 #include <lustre_log.h>
  44 #include <lprocfs_status.h>
  45 #include <lustre_disk.h>
  46 #include <lustre_kernelcomm.h>
  47
  48 DEFINE_RWLOCK(obd_dev_lock);
  49 static struct obd_device *obd_devs[MAX_OBD_DEVICES];
  50
  51 static struct kmem_cache *obd_device_cachep;
  52 static struct kobj_type class_ktype;
  53 static struct workqueue_struct *zombie_wq;
  54
  55 static void obd_zombie_export_add(struct obd_export *exp);
  56 static void obd_zombie_import_add(struct obd_import *imp);
  57 static void print_export_data(struct obd_export *exp,
  58                               const char *status, int locks, int debug_level);
  59
  60 static LIST_HEAD(obd_stale_exports);
  61 static DEFINE_SPINLOCK(obd_stale_export_lock);
  62 static atomic_t obd_stale_export_num = ATOMIC_INIT(0);
  63
  64 /*
  65  * support functions: we could use inter-module communication, but this
  66  * is more portable to other OS's
  67  */
  68 static struct obd_device *obd_device_alloc(void)
  69 {
  70         struct obd_device *obd;
  71
  72         OBD_SLAB_ALLOC_PTR_GFP(obd, obd_device_cachep, GFP_NOFS);
  73         if (obd != NULL) {
  74                 obd->obd_magic = OBD_DEVICE_MAGIC;
  75         }
  76         return obd;
  77 }
  78
  79 static void obd_device_free(struct obd_device *obd)
  80 {
  81         LASSERT(obd != NULL);
  82         LASSERTF(obd->obd_magic == OBD_DEVICE_MAGIC, "obd %p obd_magic %08x != %08x\n",
  83                  obd, obd->obd_magic, OBD_DEVICE_MAGIC);
  84         if (obd->obd_namespace != NULL) {
  85                 CERROR("obd %p: namespace %p was not properly cleaned up (obd_force=%d)!\n",
  86                        obd, obd->obd_namespace, obd->obd_force);
  87                 LBUG();
  88         }
  89         lu_ref_fini(&obd->obd_reference);
  90         OBD_SLAB_FREE_PTR(obd, obd_device_cachep);
  91 }
  92
  93 struct obd_type *class_search_type(const char *name)
  94 {
  95         struct kobject *kobj = kset_find_obj(lustre_kset, name);
  96
  97         if (kobj && kobj->ktype == &class_ktype)
  98                 return container_of(kobj, struct obd_type, typ_kobj);
  99
 100         kobject_put(kobj);
 101         return NULL;
 102 }
 103 EXPORT_SYMBOL(class_search_type);
 104
 105 struct obd_type *class_get_type(const char *name)
 106 {
 107         struct obd_type *type;
 108
 109         type = class_search_type(name);
 110 #ifdef HAVE_MODULE_LOADING_SUPPORT
 111         if (!type) {
 112                 const char *modname = name;
 113
 114 #ifdef HAVE_SERVER_SUPPORT
 115                 if (strcmp(modname, "obdfilter") == 0)
 116                         modname = "ofd";
 117
 118                 if (strcmp(modname, LUSTRE_LWP_NAME) == 0)
 119                         modname = LUSTRE_OSP_NAME;
 120
 121                 if (!strncmp(modname, LUSTRE_MDS_NAME, strlen(LUSTRE_MDS_NAME)))
 122                         modname = LUSTRE_MDT_NAME;
 123 #endif /* HAVE_SERVER_SUPPORT */
 124
 125                 if (!request_module("%s", modname)) {
 126                         CDEBUG(D_INFO, "Loaded module '%s'\n", modname);
 127                         type = class_search_type(name);
 128                 } else {
 129                         LCONSOLE_ERROR_MSG(0x158, "Can't load module '%s'\n",
 130                                            modname);
 131                 }
 132         }
 133 #endif
 134         if (type) {
 135                 if (try_module_get(type->typ_dt_ops->o_owner)) {
 136                         atomic_inc(&type->typ_refcnt);
 137                         /* class_search_type() returned a counted reference,
 138                          * but we don't need that count any more as
 139                          * we have one through typ_refcnt.
 140                          */
 141                         kobject_put(&type->typ_kobj);
 142                 } else {
 143                         kobject_put(&type->typ_kobj);
 144                         type = NULL;
 145                 }
 146         }
 147         return type;
 148 }
 149
 150 void class_put_type(struct obd_type *type)
 151 {
 152         LASSERT(type);
 153         module_put(type->typ_dt_ops->o_owner);
 154         atomic_dec(&type->typ_refcnt);
 155 }
 156
 157 static void class_sysfs_release(struct kobject *kobj)
 158 {
 159         struct obd_type *type = container_of(kobj, struct obd_type, typ_kobj);
 160
 161         debugfs_remove_recursive(type->typ_debugfs_entry);
 162         type->typ_debugfs_entry = NULL;
 163
 164         if (type->typ_lu)
 165                 lu_device_type_fini(type->typ_lu);
 166
 167 #ifdef CONFIG_PROC_FS
 168         if (type->typ_name && type->typ_procroot)
 169                 remove_proc_subtree(type->typ_name, proc_lustre_root);
 170 #endif
 171         OBD_FREE(type, sizeof(*type));
 172 }
 173
 174 static struct kobj_type class_ktype = {
 175         .sysfs_ops      = &lustre_sysfs_ops,
 176         .release        = class_sysfs_release,
 177 };
 178
 179 #ifdef HAVE_SERVER_SUPPORT
 180 struct obd_type *class_add_symlinks(const char *name, bool enable_proc)
 181 {
 182         struct dentry *symlink;
 183         struct obd_type *type;
 184         int rc;
 185
 186         type = class_search_type(name);
 187         if (type) {
 188                 kobject_put(&type->typ_kobj);
 189                 return ERR_PTR(-EEXIST);
 190         }
 191
 192         OBD_ALLOC(type, sizeof(*type));
 193         if (!type)
 194                 return ERR_PTR(-ENOMEM);
 195
 196         type->typ_kobj.kset = lustre_kset;
 197         rc = kobject_init_and_add(&type->typ_kobj, &class_ktype,
 198                                   &lustre_kset->kobj, "%s", name);
 199         if (rc)
 200                 return ERR_PTR(rc);
 201
 202         symlink = debugfs_create_dir(name, debugfs_lustre_root);
 203         type->typ_debugfs_entry = symlink;
 204         type->typ_sym_filter = true;
 205
 206         if (enable_proc) {
 207                 type->typ_procroot = lprocfs_register(name, proc_lustre_root,
 208                                                       NULL, NULL);
 209                 if (IS_ERR(type->typ_procroot)) {
 210                         CERROR("%s: can't create compat proc entry: %d\n",
 211                                name, (int)PTR_ERR(type->typ_procroot));
 212                         type->typ_procroot = NULL;
 213                 }
 214         }
 215
 216         return type;
 217 }
 218 EXPORT_SYMBOL(class_add_symlinks);
 219 #endif /* HAVE_SERVER_SUPPORT */
 220
 221 #define CLASS_MAX_NAME 1024
 222
 223 int class_register_type(const struct obd_ops *dt_ops,
 224                         const struct md_ops *md_ops,
 225                         bool enable_proc,
 226                         const char *name, struct lu_device_type *ldt)
 227 {
 228         struct obd_type *type;
 229         int rc;
 230
 231         ENTRY;
 232         /* sanity check */
 233         LASSERT(strnlen(name, CLASS_MAX_NAME) < CLASS_MAX_NAME);
 234
 235         type = class_search_type(name);
 236         if (type) {
 237 #ifdef HAVE_SERVER_SUPPORT
 238                 if (type->typ_sym_filter)
 239                         goto dir_exist;
 240 #endif /* HAVE_SERVER_SUPPORT */
 241                 kobject_put(&type->typ_kobj);
 242                 CDEBUG(D_IOCTL, "Type %s already registered\n", name);
 243                 RETURN(-EEXIST);
 244         }
 245
 246         OBD_ALLOC(type, sizeof(*type));
 247         if (type == NULL)
 248                 RETURN(-ENOMEM);
 249
 250         type->typ_lu = ldt ? OBD_LU_TYPE_SETUP : NULL;
 251         type->typ_kobj.kset = lustre_kset;
 252         kobject_init(&type->typ_kobj, &class_ktype);
 253 #ifdef HAVE_SERVER_SUPPORT
 254 dir_exist:
 255 #endif /* HAVE_SERVER_SUPPORT */
 256
 257         type->typ_dt_ops = dt_ops;
 258         type->typ_md_ops = md_ops;
 259
 260 #ifdef HAVE_SERVER_SUPPORT
 261         if (type->typ_sym_filter) {
 262                 type->typ_sym_filter = false;
 263                 kobject_put(&type->typ_kobj);
 264                 goto setup_ldt;
 265         }
 266 #endif
 267 #ifdef CONFIG_PROC_FS
 268         if (enable_proc && !type->typ_procroot) {
 269                 type->typ_procroot = lprocfs_register(name,
 270                                                       proc_lustre_root,
 271                                                       NULL, type);
 272                 if (IS_ERR(type->typ_procroot)) {
 273                         rc = PTR_ERR(type->typ_procroot);
 274                         type->typ_procroot = NULL;
 275                         GOTO(failed, rc);
 276                 }
 277         }
 278 #endif
 279         type->typ_debugfs_entry = debugfs_create_dir(name, debugfs_lustre_root);
 280
 281         rc = kobject_add(&type->typ_kobj, &lustre_kset->kobj, "%s", name);
 282         if (rc)
 283                 GOTO(failed, rc);
 284 #ifdef HAVE_SERVER_SUPPORT
 285 setup_ldt:
 286 #endif
 287         if (ldt) {
 288                 rc = lu_device_type_init(ldt);
 289                 smp_store_release(&type->typ_lu, rc ? NULL : ldt);
 290                 wake_up_var(&type->typ_lu);
 291                 if (rc)
 292                         GOTO(failed, rc);
 293         }
 294
 295         RETURN(0);
 296
 297 failed:
 298         kobject_put(&type->typ_kobj);
 299
 300         RETURN(rc);
 301 }
 302 EXPORT_SYMBOL(class_register_type);
 303
 304 int class_unregister_type(const char *name)
 305 {
 306         struct obd_type *type = class_search_type(name);
 307         int rc = 0;
 308         ENTRY;
 309
 310         if (!type) {
 311                 CERROR("unknown obd type\n");
 312                 RETURN(-EINVAL);
 313         }
 314
 315         if (atomic_read(&type->typ_refcnt)) {
 316                 CERROR("type %s has refcount (%d)\n", name,
 317                        atomic_read(&type->typ_refcnt));
 318                 /* This is a bad situation, let's make the best of it */
 319                 /* Remove ops, but leave the name for debugging */
 320                 type->typ_dt_ops = NULL;
 321                 type->typ_md_ops = NULL;
 322                 GOTO(out_put, rc = -EBUSY);
 323         }
 324
 325         /* Put the final ref */
 326         kobject_put(&type->typ_kobj);
 327 out_put:
 328         /* Put the ref returned by class_search_type() */
 329         kobject_put(&type->typ_kobj);
 330
 331         RETURN(rc);
 332 } /* class_unregister_type */
 333 EXPORT_SYMBOL(class_unregister_type);
 334
 335 /**
 336  * Create a new obd device.
 337  *
 338  * Allocate the new obd_device and initialize it.
 339  *
 340  * \param[in] type_name obd device type string.
 341  * \param[in] name      obd device name.
 342  * \param[in] uuid      obd device UUID
 343  *
 344  * \retval newdev         pointer to created obd_device
 345  * \retval ERR_PTR(errno) on error
 346  */
 347 struct obd_device *class_newdev(const char *type_name, const char *name,
 348                                 const char *uuid)
 349 {
 350         struct obd_device *newdev;
 351         struct obd_type *type = NULL;
 352         ENTRY;
 353
 354         if (strlen(name) >= MAX_OBD_NAME) {
 355                 CERROR("name/uuid must be < %u bytes long\n", MAX_OBD_NAME);
 356                 RETURN(ERR_PTR(-EINVAL));
 357         }
 358
 359         type = class_get_type(type_name);
 360         if (type == NULL){
 361                 CERROR("OBD: unknown type: %s\n", type_name);
 362                 RETURN(ERR_PTR(-ENODEV));
 363         }
 364
 365         newdev = obd_device_alloc();
 366         if (newdev == NULL) {
 367                 class_put_type(type);
 368                 RETURN(ERR_PTR(-ENOMEM));
 369         }
 370         LASSERT(newdev->obd_magic == OBD_DEVICE_MAGIC);
 371         strncpy(newdev->obd_name, name, sizeof(newdev->obd_name) - 1);
 372         newdev->obd_type = type;
 373         newdev->obd_minor = -1;
 374
 375         rwlock_init(&newdev->obd_pool_lock);
 376         newdev->obd_pool_limit = 0;
 377         newdev->obd_pool_slv = 0;
 378
 379         INIT_LIST_HEAD(&newdev->obd_exports);
 380         newdev->obd_num_exports = 0;
 381         newdev->obd_grant_check_threshold = 100;
 382         INIT_LIST_HEAD(&newdev->obd_unlinked_exports);
 383         INIT_LIST_HEAD(&newdev->obd_delayed_exports);
 384         INIT_LIST_HEAD(&newdev->obd_exports_timed);
 385         INIT_LIST_HEAD(&newdev->obd_nid_stats);
 386         spin_lock_init(&newdev->obd_nid_lock);
 387         spin_lock_init(&newdev->obd_dev_lock);
 388         mutex_init(&newdev->obd_dev_mutex);
 389         spin_lock_init(&newdev->obd_osfs_lock);
 390         /* newdev->obd_osfs_age must be set to a value in the distant
 391          * past to guarantee a fresh statfs is fetched on mount. */
 392         newdev->obd_osfs_age = ktime_get_seconds() - 1000;
 393
 394         /* XXX belongs in setup not attach  */
 395         init_rwsem(&newdev->obd_observer_link_sem);
 396         /* recovery data */
 397         spin_lock_init(&newdev->obd_recovery_task_lock);
 398         init_waitqueue_head(&newdev->obd_next_transno_waitq);
 399         init_waitqueue_head(&newdev->obd_evict_inprogress_waitq);
 400         INIT_LIST_HEAD(&newdev->obd_req_replay_queue);
 401         INIT_LIST_HEAD(&newdev->obd_lock_replay_queue);
 402         INIT_LIST_HEAD(&newdev->obd_final_req_queue);
 403         INIT_LIST_HEAD(&newdev->obd_evict_list);
 404         INIT_LIST_HEAD(&newdev->obd_lwp_list);
 405
 406         llog_group_init(&newdev->obd_olg);
 407         /* Detach drops this */
 408         atomic_set(&newdev->obd_refcount, 1);
 409         lu_ref_init(&newdev->obd_reference);
 410         lu_ref_add(&newdev->obd_reference, "newdev", newdev);
 411
 412         newdev->obd_conn_inprogress = 0;
 413
 414         strncpy(newdev->obd_uuid.uuid, uuid, UUID_MAX);
 415
 416         CDEBUG(D_IOCTL, "Allocate new device %s (%p)\n",
 417                newdev->obd_name, newdev);
 418
 419         return newdev;
 420 }
 421
 422 /**
 423  * Free obd device.
 424  *
 425  * \param[in] obd obd_device to be freed
 426  *
 427  * \retval none
 428  */
 429 void class_free_dev(struct obd_device *obd)
 430 {
 431         struct obd_type *obd_type = obd->obd_type;
 432
 433         LASSERTF(obd->obd_magic == OBD_DEVICE_MAGIC, "%p obd_magic %08x "
 434                  "!= %08x\n", obd, obd->obd_magic, OBD_DEVICE_MAGIC);
 435         LASSERTF(obd->obd_minor == -1 || obd_devs[obd->obd_minor] == obd,
 436                  "obd %p != obd_devs[%d] %p\n",
 437                  obd, obd->obd_minor, obd_devs[obd->obd_minor]);
 438         LASSERTF(atomic_read(&obd->obd_refcount) == 0,
 439                  "obd_refcount should be 0, not %d\n",
 440                  atomic_read(&obd->obd_refcount));
 441         LASSERT(obd_type != NULL);
 442
 443         CDEBUG(D_INFO, "Release obd device %s obd_type name = %s\n",
 444                obd->obd_name, obd->obd_type->typ_name);
 445
 446         CDEBUG(D_CONFIG, "finishing cleanup of obd %s (%s)\n",
 447                          obd->obd_name, obd->obd_uuid.uuid);
 448         if (obd->obd_stopping) {
 449                 int err;
 450
 451                 /* If we're not stopping, we were never set up */
 452                 err = obd_cleanup(obd);
 453                 if (err)
 454                         CERROR("Cleanup %s returned %d\n",
 455                                 obd->obd_name, err);
 456         }
 457
 458         obd_device_free(obd);
 459
 460         class_put_type(obd_type);
 461 }
 462
 463 /**
 464  * Unregister obd device.
 465  *
 466  * Free slot in obd_dev[] used by \a obd.
 467  *
 468  * \param[in] new_obd obd_device to be unregistered
 469  *
 470  * \retval none
 471  */
 472 void class_unregister_device(struct obd_device *obd)
 473 {
 474         write_lock(&obd_dev_lock);
 475         if (obd->obd_minor >= 0) {
 476                 LASSERT(obd_devs[obd->obd_minor] == obd);
 477                 obd_devs[obd->obd_minor] = NULL;
 478                 obd->obd_minor = -1;
 479         }
 480         write_unlock(&obd_dev_lock);
 481 }
 482
 483 /**
 484  * Register obd device.
 485  *
 486  * Find free slot in obd_devs[], fills it with \a new_obd.
 487  *
 488  * \param[in] new_obd obd_device to be registered
 489  *
 490  * \retval 0          success
 491  * \retval -EEXIST    device with this name is registered
 492  * \retval -EOVERFLOW obd_devs[] is full
 493  */
 494 int class_register_device(struct obd_device *new_obd)
 495 {
 496         int ret = 0;
 497         int i;
 498         int new_obd_minor = 0;
 499         bool minor_assign = false;
 500         bool retried = false;
 501
 502 again:
 503         write_lock(&obd_dev_lock);
 504         for (i = 0; i < class_devno_max(); i++) {
 505                 struct obd_device *obd = class_num2obd(i);
 506
 507                 if (obd != NULL &&
 508                     (strcmp(new_obd->obd_name, obd->obd_name) == 0)) {
 509
 510                         if (!retried) {
 511                                 write_unlock(&obd_dev_lock);
 512
 513                                 /* the obd_device could be waited to be
 514                                  * destroyed by the "obd_zombie_impexp_thread".
 515                                  */
 516                                 obd_zombie_barrier();
 517                                 retried = true;
 518                                 goto again;
 519                         }
 520
 521                         CERROR("%s: already exists, won't add\n",
 522                                obd->obd_name);
 523                         /* in case we found a free slot before duplicate */
 524                         minor_assign = false;
 525                         ret = -EEXIST;
 526                         break;
 527                 }
 528                 if (!minor_assign && obd == NULL) {
 529                         new_obd_minor = i;
 530                         minor_assign = true;
 531                 }
 532         }
 533
 534         if (minor_assign) {
 535                 new_obd->obd_minor = new_obd_minor;
 536                 LASSERTF(obd_devs[new_obd_minor] == NULL, "obd_devs[%d] "
 537                          "%p\n", new_obd_minor, obd_devs[new_obd_minor]);
 538                 obd_devs[new_obd_minor] = new_obd;
 539         } else {
 540                 if (ret == 0) {
 541                         ret = -EOVERFLOW;
 542                         CERROR("%s: all %u/%u devices used, increase "
 543                                "MAX_OBD_DEVICES: rc = %d\n", new_obd->obd_name,
 544                                i, class_devno_max(), ret);
 545                 }
 546         }
 547         write_unlock(&obd_dev_lock);
 548
 549         RETURN(ret);
 550 }
 551
 552 static int class_name2dev_nolock(const char *name)
 553 {
 554         int i;
 555
 556         if (!name)
 557                 return -1;
 558
 559         for (i = 0; i < class_devno_max(); i++) {
 560                 struct obd_device *obd = class_num2obd(i);
 561
 562                 if (obd && strcmp(name, obd->obd_name) == 0) {
 563                         /* Make sure we finished attaching before we give
 564                            out any references */
 565                         LASSERT(obd->obd_magic == OBD_DEVICE_MAGIC);
 566                         if (obd->obd_attached) {
 567                                 return i;
 568                         }
 569                         break;
 570                 }
 571         }
 572
 573         return -1;
 574 }
 575
 576 int class_name2dev(const char *name)
 577 {
 578         int i;
 579
 580         if (!name)
 581                 return -1;
 582
 583         read_lock(&obd_dev_lock);
 584         i = class_name2dev_nolock(name);
 585         read_unlock(&obd_dev_lock);
 586
 587         return i;
 588 }
 589 EXPORT_SYMBOL(class_name2dev);
 590
 591 struct obd_device *class_name2obd(const char *name)
 592 {
 593         int dev = class_name2dev(name);
 594
 595         if (dev < 0 || dev > class_devno_max())
 596                 return NULL;
 597         return class_num2obd(dev);
 598 }
 599 EXPORT_SYMBOL(class_name2obd);
 600
 601 int class_uuid2dev_nolock(struct obd_uuid *uuid)
 602 {
 603         int i;
 604
 605         for (i = 0; i < class_devno_max(); i++) {
 606                 struct obd_device *obd = class_num2obd(i);
 607
 608                 if (obd && obd_uuid_equals(uuid, &obd->obd_uuid)) {
 609                         LASSERT(obd->obd_magic == OBD_DEVICE_MAGIC);
 610                         return i;
 611                 }
 612         }
 613
 614         return -1;
 615 }
 616
 617 int class_uuid2dev(struct obd_uuid *uuid)
 618 {
 619         int i;
 620
 621         read_lock(&obd_dev_lock);
 622         i = class_uuid2dev_nolock(uuid);
 623         read_unlock(&obd_dev_lock);
 624
 625         return i;
 626 }
 627 EXPORT_SYMBOL(class_uuid2dev);
 628
 629 struct obd_device *class_uuid2obd(struct obd_uuid *uuid)
 630 {
 631         int dev = class_uuid2dev(uuid);
 632         if (dev < 0)
 633                 return NULL;
 634         return class_num2obd(dev);
 635 }
 636 EXPORT_SYMBOL(class_uuid2obd);
 637
 638 /**
 639  * Get obd device from ::obd_devs[]
 640  *
 641  * \param num [in] array index
 642  *
 643  * \retval NULL if ::obd_devs[\a num] does not contains an obd device
 644  *         otherwise return the obd device there.
 645  */
 646 struct obd_device *class_num2obd(int num)
 647 {
 648         struct obd_device *obd = NULL;
 649
 650         if (num < class_devno_max()) {
 651                 obd = obd_devs[num];
 652                 if (obd == NULL)
 653                         return NULL;
 654
 655                 LASSERTF(obd->obd_magic == OBD_DEVICE_MAGIC,
 656                          "%p obd_magic %08x != %08x\n",
 657                          obd, obd->obd_magic, OBD_DEVICE_MAGIC);
 658                 LASSERTF(obd->obd_minor == num,
 659                          "%p obd_minor %0d != %0d\n",
 660                          obd, obd->obd_minor, num);
 661         }
 662
 663         return obd;
 664 }
 665 EXPORT_SYMBOL(class_num2obd);
 666
 667 /**
 668  * Find obd in obd_dev[] by name or uuid.
 669  *
 670  * Increment obd's refcount if found.
 671  *
 672  * \param[in] str obd name or uuid
 673  *
 674  * \retval NULL    if not found
 675  * \retval target  pointer to found obd_device
 676  */
 677 struct obd_device *class_dev_by_str(const char *str)
 678 {
 679         struct obd_device *target = NULL;
 680         struct obd_uuid tgtuuid;
 681         int rc;
 682
 683         obd_str2uuid(&tgtuuid, str);
 684
 685         read_lock(&obd_dev_lock);
 686         rc = class_uuid2dev_nolock(&tgtuuid);
 687         if (rc < 0)
 688                 rc = class_name2dev_nolock(str);
 689
 690         if (rc >= 0)
 691                 target = class_num2obd(rc);
 692
 693         if (target != NULL)
 694                 class_incref(target, "find", current);
 695         read_unlock(&obd_dev_lock);
 696
 697         RETURN(target);
 698 }
 699 EXPORT_SYMBOL(class_dev_by_str);
 700
 701 /**
 702  * Get obd devices count. Device in any
 703  *    state are counted
 704  * \retval obd device count
 705  */
 706 int get_devices_count(void)
 707 {
 708         int index, max_index = class_devno_max(), dev_count = 0;
 709
 710         read_lock(&obd_dev_lock);
 711         for (index = 0; index <= max_index; index++) {
 712                 struct obd_device *obd = class_num2obd(index);
 713                 if (obd != NULL)
 714                         dev_count++;
 715         }
 716         read_unlock(&obd_dev_lock);
 717
 718         return dev_count;
 719 }
 720 EXPORT_SYMBOL(get_devices_count);
 721
 722 void class_obd_list(void)
 723 {
 724         char *status;
 725         int i;
 726
 727         read_lock(&obd_dev_lock);
 728         for (i = 0; i < class_devno_max(); i++) {
 729                 struct obd_device *obd = class_num2obd(i);
 730
 731                 if (obd == NULL)
 732                         continue;
 733                 if (obd->obd_stopping)
 734                         status = "ST";
 735                 else if (obd->obd_set_up)
 736                         status = "UP";
 737                 else if (obd->obd_attached)
 738                         status = "AT";
 739                 else
 740                         status = "--";
 741                 LCONSOLE(D_CONFIG, "%3d %s %s %s %s %d\n",
 742                          i, status, obd->obd_type->typ_name,
 743                          obd->obd_name, obd->obd_uuid.uuid,
 744                          atomic_read(&obd->obd_refcount));
 745         }
 746         read_unlock(&obd_dev_lock);
 747 }
 748
 749 /* Search for a client OBD connected to tgt_uuid.  If grp_uuid is
 750  * specified, then only the client with that uuid is returned,
 751  * otherwise any client connected to the tgt is returned.
 752  */
 753 struct obd_device *class_find_client_obd(struct obd_uuid *tgt_uuid,
 754                                          const char *type_name,
 755                                          struct obd_uuid *grp_uuid)
 756 {
 757         int i;
 758
 759         read_lock(&obd_dev_lock);
 760         for (i = 0; i < class_devno_max(); i++) {
 761                 struct obd_device *obd = class_num2obd(i);
 762
 763                 if (obd == NULL)
 764                         continue;
 765                 if ((strncmp(obd->obd_type->typ_name, type_name,
 766                              strlen(type_name)) == 0)) {
 767                         if (obd_uuid_equals(tgt_uuid,
 768                                             &obd->u.cli.cl_target_uuid) &&
 769                             ((grp_uuid)? obd_uuid_equals(grp_uuid,
 770                                                          &obd->obd_uuid) : 1)) {
 771                                 read_unlock(&obd_dev_lock);
 772                                 return obd;
 773                         }
 774                 }
 775         }
 776         read_unlock(&obd_dev_lock);
 777
 778         return NULL;
 779 }
 780 EXPORT_SYMBOL(class_find_client_obd);
 781
 782 /* Iterate the obd_device list looking devices have grp_uuid. Start
 783  * searching at *next, and if a device is found, the next index to look
 784  * at is saved in *next. If next is NULL, then the first matching device
 785  * will always be returned.
 786  */
 787 struct obd_device *class_devices_in_group(struct obd_uuid *grp_uuid, int *next)
 788 {
 789         int i;
 790
 791         if (next == NULL)
 792                 i = 0;
 793         else if (*next >= 0 && *next < class_devno_max())
 794                 i = *next;
 795         else
 796                 return NULL;
 797
 798         read_lock(&obd_dev_lock);
 799         for (; i < class_devno_max(); i++) {
 800                 struct obd_device *obd = class_num2obd(i);
 801
 802                 if (obd == NULL)
 803                         continue;
 804                 if (obd_uuid_equals(grp_uuid, &obd->obd_uuid)) {
 805                         if (next != NULL)
 806                                 *next = i+1;
 807                         read_unlock(&obd_dev_lock);
 808                         return obd;
 809                 }
 810         }
 811         read_unlock(&obd_dev_lock);
 812
 813         return NULL;
 814 }
 815 EXPORT_SYMBOL(class_devices_in_group);
 816
 817 /**
 818  * to notify sptlrpc log for \a fsname has changed, let every relevant OBD
 819  * adjust sptlrpc settings accordingly.
 820  */
 821 int class_notify_sptlrpc_conf(const char *fsname, int namelen)
 822 {
 823         struct obd_device  *obd;
 824         const char         *type;
 825         int                 i, rc = 0, rc2;
 826
 827         LASSERT(namelen > 0);
 828
 829         read_lock(&obd_dev_lock);
 830         for (i = 0; i < class_devno_max(); i++) {
 831                 obd = class_num2obd(i);
 832
 833                 if (obd == NULL || obd->obd_set_up == 0 || obd->obd_stopping)
 834                         continue;
 835
 836                 /* only notify mdc, osc, osp, lwp, mdt, ost
 837                  * because only these have a -sptlrpc llog */
 838                 type = obd->obd_type->typ_name;
 839                 if (strcmp(type, LUSTRE_MDC_NAME) != 0 &&
 840                     strcmp(type, LUSTRE_OSC_NAME) != 0 &&
 841                     strcmp(type, LUSTRE_OSP_NAME) != 0 &&
 842                     strcmp(type, LUSTRE_LWP_NAME) != 0 &&
 843                     strcmp(type, LUSTRE_MDT_NAME) != 0 &&
 844                     strcmp(type, LUSTRE_OST_NAME) != 0)
 845                         continue;
 846
 847                 if (strncmp(obd->obd_name, fsname, namelen))
 848                         continue;
 849
 850                 class_incref(obd, __FUNCTION__, obd);
 851                 read_unlock(&obd_dev_lock);
 852                 rc2 = obd_set_info_async(NULL, obd->obd_self_export,
 853                                          sizeof(KEY_SPTLRPC_CONF),
 854                                          KEY_SPTLRPC_CONF, 0, NULL, NULL);
 855                 rc = rc ? rc : rc2;
 856                 class_decref(obd, __FUNCTION__, obd);
 857                 read_lock(&obd_dev_lock);
 858         }
 859         read_unlock(&obd_dev_lock);
 860         return rc;
 861 }
 862 EXPORT_SYMBOL(class_notify_sptlrpc_conf);
 863
 864 void obd_cleanup_caches(void)
 865 {
 866         ENTRY;
 867         if (obd_device_cachep) {
 868                 kmem_cache_destroy(obd_device_cachep);
 869                 obd_device_cachep = NULL;
 870         }
 871
 872         EXIT;
 873 }
 874
 875 int obd_init_caches(void)
 876 {
 877         int rc;
 878         ENTRY;
 879
 880         LASSERT(obd_device_cachep == NULL);
 881         obd_device_cachep = kmem_cache_create_usercopy("ll_obd_dev_cache",
 882                                 sizeof(struct obd_device),
 883                                 0, 0, 0, sizeof(struct obd_device), NULL);
 884         if (!obd_device_cachep)
 885                 GOTO(out, rc = -ENOMEM);
 886
 887         RETURN(0);
 888 out:
 889         obd_cleanup_caches();
 890         RETURN(rc);
 891 }
 892
 893 static const char export_handle_owner[] = "export";
 894
 895 /* map connection to client */
 896 struct obd_export *class_conn2export(struct lustre_handle *conn)
 897 {
 898         struct obd_export *export;
 899         ENTRY;
 900
 901         if (!conn) {
 902                 CDEBUG(D_CACHE, "looking for null handle\n");
 903                 RETURN(NULL);
 904         }
 905
 906         if (conn->cookie == -1) {  /* this means assign a new connection */
 907                 CDEBUG(D_CACHE, "want a new connection\n");
 908                 RETURN(NULL);
 909         }
 910
 911         CDEBUG(D_INFO, "looking for export cookie %#llx\n", conn->cookie);
 912         export = class_handle2object(conn->cookie, export_handle_owner);
 913         RETURN(export);
 914 }
 915 EXPORT_SYMBOL(class_conn2export);
 916
 917 struct obd_device *class_exp2obd(struct obd_export *exp)
 918 {
 919         if (exp)
 920                 return exp->exp_obd;
 921         return NULL;
 922 }
 923 EXPORT_SYMBOL(class_exp2obd);
 924
 925 struct obd_import *class_exp2cliimp(struct obd_export *exp)
 926 {
 927         struct obd_device *obd = exp->exp_obd;
 928         if (obd == NULL)
 929                 return NULL;
 930         return obd->u.cli.cl_import;
 931 }
 932 EXPORT_SYMBOL(class_exp2cliimp);
 933
 934 /* Export management functions */
 935 static void class_export_destroy(struct obd_export *exp)
 936 {
 937         struct obd_device *obd = exp->exp_obd;
 938         ENTRY;
 939
 940         LASSERT(refcount_read(&exp->exp_handle.h_ref) == 0);
 941         LASSERT(obd != NULL);
 942
 943         CDEBUG(D_IOCTL, "destroying export %p/%s for %s\n", exp,
 944                exp->exp_client_uuid.uuid, obd->obd_name);
 945
 946         /* "Local" exports (lctl, LOV->{mdc,osc}) have no connection. */
 947         ptlrpc_connection_put(exp->exp_connection);
 948
 949         LASSERT(list_empty(&exp->exp_outstanding_replies));
 950         LASSERT(list_empty(&exp->exp_uncommitted_replies));
 951         LASSERT(list_empty(&exp->exp_req_replay_queue));
 952         LASSERT(list_empty(&exp->exp_hp_rpcs));
 953         obd_destroy_export(exp);
 954         /* self export doesn't hold a reference to an obd, although it
 955          * exists until freeing of the obd */
 956         if (exp != obd->obd_self_export)
 957                 class_decref(obd, "export", exp);
 958
 959         OBD_FREE_PRE(exp, sizeof(*exp), "rcu");
 960         kfree_rcu(exp, exp_handle.h_rcu);
 961         EXIT;
 962 }
 963
 964 struct obd_export *class_export_get(struct obd_export *exp)
 965 {
 966         refcount_inc(&exp->exp_handle.h_ref);
 967         CDEBUG(D_INFO, "GET export %p refcount=%d\n", exp,
 968                refcount_read(&exp->exp_handle.h_ref));
 969         return exp;
 970 }
 971 EXPORT_SYMBOL(class_export_get);
 972
 973 void class_export_put(struct obd_export *exp)
 974 {
 975         LASSERT(exp != NULL);
 976         LASSERT(refcount_read(&exp->exp_handle.h_ref) >  0);
 977         LASSERT(refcount_read(&exp->exp_handle.h_ref) < LI_POISON);
 978         CDEBUG(D_INFO, "PUTting export %p : new refcount %d\n", exp,
 979                refcount_read(&exp->exp_handle.h_ref) - 1);
 980
 981         if (refcount_dec_and_test(&exp->exp_handle.h_ref)) {
 982                 struct obd_device *obd = exp->exp_obd;
 983
 984                 CDEBUG(D_IOCTL, "final put %p/%s\n",
 985                        exp, exp->exp_client_uuid.uuid);
 986
 987                 /* release nid stat refererence */
 988                 lprocfs_exp_cleanup(exp);
 989
 990                 if (exp == obd->obd_self_export) {
 991                         /* self export should be destroyed without
 992                          * zombie thread as it doesn't hold a
 993                          * reference to obd and doesn't hold any
 994                          * resources */
 995                         class_export_destroy(exp);
 996                         /* self export is destroyed, no class
 997                          * references exist and it is safe to free
 998                          * obd */
 999                         class_free_dev(obd);
1000                 } else {
1001                         LASSERT(!list_empty(&exp->exp_obd_chain));
1002                         obd_zombie_export_add(exp);
1003                 }
1004
1005         }
1006 }
1007 EXPORT_SYMBOL(class_export_put);
1008
1009 static void obd_zombie_exp_cull(struct work_struct *ws)
1010 {
1011         struct obd_export *export;
1012
1013         export = container_of(ws, struct obd_export, exp_zombie_work);
1014         class_export_destroy(export);
1015 }
1016
1017 /* Creates a new export, adds it to the hash table, and returns a
1018  * pointer to it. The refcount is 2: one for the hash reference, and
1019  * one for the pointer returned by this function. */
1020 struct obd_export *__class_new_export(struct obd_device *obd,
1021                                       struct obd_uuid *cluuid, bool is_self)
1022 {
1023         struct obd_export *export;
1024         int rc = 0;
1025         ENTRY;
1026
1027         OBD_ALLOC_PTR(export);
1028         if (!export)
1029                 return ERR_PTR(-ENOMEM);
1030
1031         export->exp_conn_cnt = 0;
1032         export->exp_lock_hash = NULL;
1033         export->exp_flock_hash = NULL;
1034         /* 2 = class_handle_hash + last */
1035         refcount_set(&export->exp_handle.h_ref, 2);
1036         atomic_set(&export->exp_rpc_count, 0);
1037         atomic_set(&export->exp_cb_count, 0);
1038         atomic_set(&export->exp_locks_count, 0);
1039 #if LUSTRE_TRACKS_LOCK_EXP_REFS
1040         INIT_LIST_HEAD(&export->exp_locks_list);
1041         spin_lock_init(&export->exp_locks_list_guard);
1042 #endif
1043         atomic_set(&export->exp_replay_count, 0);
1044         export->exp_obd = obd;
1045         INIT_LIST_HEAD(&export->exp_outstanding_replies);
1046         spin_lock_init(&export->exp_uncommitted_replies_lock);
1047         INIT_LIST_HEAD(&export->exp_uncommitted_replies);
1048         INIT_LIST_HEAD(&export->exp_req_replay_queue);
1049         INIT_HLIST_NODE(&export->exp_handle.h_link);
1050         INIT_LIST_HEAD(&export->exp_hp_rpcs);
1051         INIT_LIST_HEAD(&export->exp_reg_rpcs);
1052         class_handle_hash(&export->exp_handle, export_handle_owner);
1053         export->exp_last_request_time = ktime_get_real_seconds();
1054         spin_lock_init(&export->exp_lock);
1055         spin_lock_init(&export->exp_rpc_lock);
1056         INIT_HLIST_NODE(&export->exp_gen_hash);
1057         spin_lock_init(&export->exp_bl_list_lock);
1058         INIT_LIST_HEAD(&export->exp_bl_list);
1059         INIT_LIST_HEAD(&export->exp_stale_list);
1060         INIT_WORK(&export->exp_zombie_work, obd_zombie_exp_cull);
1061
1062         export->exp_sp_peer = LUSTRE_SP_ANY;
1063         export->exp_flvr.sf_rpc = SPTLRPC_FLVR_INVALID;
1064         export->exp_client_uuid = *cluuid;
1065         obd_init_export(export);
1066
1067         at_init(&export->exp_bl_lock_at, obd_timeout, 0);
1068
1069         spin_lock(&obd->obd_dev_lock);
1070         if (!obd_uuid_equals(cluuid, &obd->obd_uuid)) {
1071                 /* shouldn't happen, but might race */
1072                 if (obd->obd_stopping)
1073                         GOTO(exit_unlock, rc = -ENODEV);
1074
1075                 rc = obd_uuid_add(obd, export);
1076                 if (rc != 0) {
1077                         LCONSOLE_WARN("%s: denying duplicate export for %s: rc = %d\n",
1078                                       obd->obd_name, cluuid->uuid, rc);
1079                         GOTO(exit_unlock, rc = -EALREADY);
1080                 }
1081         }
1082
1083         if (!is_self) {
1084                 class_incref(obd, "export", export);
1085                 list_add_tail(&export->exp_obd_chain_timed,
1086                               &obd->obd_exports_timed);
1087                 list_add(&export->exp_obd_chain, &obd->obd_exports);
1088                 obd->obd_num_exports++;
1089         } else {
1090                 INIT_LIST_HEAD(&export->exp_obd_chain_timed);
1091                 INIT_LIST_HEAD(&export->exp_obd_chain);
1092         }
1093         spin_unlock(&obd->obd_dev_lock);
1094         RETURN(export);
1095
1096 exit_unlock:
1097         spin_unlock(&obd->obd_dev_lock);
1098         class_handle_unhash(&export->exp_handle);
1099         obd_destroy_export(export);
1100         OBD_FREE_PTR(export);
1101         return ERR_PTR(rc);
1102 }
1103
1104 struct obd_export *class_new_export(struct obd_device *obd,
1105                                     struct obd_uuid *uuid)
1106 {
1107         return __class_new_export(obd, uuid, false);
1108 }
1109 EXPORT_SYMBOL(class_new_export);
1110
1111 struct obd_export *class_new_export_self(struct obd_device *obd,
1112                                          struct obd_uuid *uuid)
1113 {
1114         return __class_new_export(obd, uuid, true);
1115 }
1116
1117 void class_unlink_export(struct obd_export *exp)
1118 {
1119         class_handle_unhash(&exp->exp_handle);
1120
1121         if (exp->exp_obd->obd_self_export == exp) {
1122                 class_export_put(exp);
1123                 return;
1124         }
1125
1126         spin_lock(&exp->exp_obd->obd_dev_lock);
1127         /* delete an uuid-export hashitem from hashtables */
1128         if (exp != exp->exp_obd->obd_self_export)
1129                 obd_uuid_del(exp->exp_obd, exp);
1130
1131 #ifdef HAVE_SERVER_SUPPORT
1132         if (!hlist_unhashed(&exp->exp_gen_hash)) {
1133                 struct tg_export_data   *ted = &exp->exp_target_data;
1134                 struct cfs_hash         *hash;
1135
1136                 /* Because obd_gen_hash will not be released until
1137                  * class_cleanup(), so hash should never be NULL here */
1138                 hash = cfs_hash_getref(exp->exp_obd->obd_gen_hash);
1139                 LASSERT(hash != NULL);
1140                 cfs_hash_del(hash, &ted->ted_lcd->lcd_generation,
1141                              &exp->exp_gen_hash);
1142                 cfs_hash_putref(hash);
1143         }
1144 #endif /* HAVE_SERVER_SUPPORT */
1145
1146         list_move(&exp->exp_obd_chain, &exp->exp_obd->obd_unlinked_exports);
1147         list_del_init(&exp->exp_obd_chain_timed);
1148         exp->exp_obd->obd_num_exports--;
1149         spin_unlock(&exp->exp_obd->obd_dev_lock);
1150         atomic_inc(&obd_stale_export_num);
1151
1152         /* A reference is kept by obd_stale_exports list */
1153         obd_stale_export_put(exp);
1154 }
1155 EXPORT_SYMBOL(class_unlink_export);
1156
1157 /* Import management functions */
1158 static void obd_zombie_import_free(struct obd_import *imp)
1159 {
1160         struct obd_import_conn *imp_conn;
1161
1162         ENTRY;
1163         CDEBUG(D_IOCTL, "destroying import %p for %s\n", imp,
1164                imp->imp_obd->obd_name);
1165
1166         LASSERT(refcount_read(&imp->imp_refcount) == 0);
1167
1168         ptlrpc_connection_put(imp->imp_connection);
1169
1170         while ((imp_conn = list_first_entry_or_null(&imp->imp_conn_list,
1171                                                     struct obd_import_conn,
1172                                                     oic_item)) != NULL) {
1173                 list_del_init(&imp_conn->oic_item);
1174                 ptlrpc_connection_put(imp_conn->oic_conn);
1175                 OBD_FREE(imp_conn, sizeof(*imp_conn));
1176         }
1177
1178         LASSERT(imp->imp_sec == NULL);
1179         LASSERTF(atomic_read(&imp->imp_reqs) == 0, "%s: imp_reqs = %d\n",
1180                  imp->imp_obd->obd_name, atomic_read(&imp->imp_reqs));
1181         class_decref(imp->imp_obd, "import", imp);
1182         OBD_FREE_PTR(imp);
1183         EXIT;
1184 }
1185
1186 struct obd_import *class_import_get(struct obd_import *import)
1187 {
1188         refcount_inc(&import->imp_refcount);
1189         CDEBUG(D_INFO, "import %p refcount=%d obd=%s\n", import,
1190                refcount_read(&import->imp_refcount),
1191                import->imp_obd->obd_name);
1192         return import;
1193 }
1194 EXPORT_SYMBOL(class_import_get);
1195
1196 void class_import_put(struct obd_import *imp)
1197 {
1198         ENTRY;
1199
1200         LASSERT(refcount_read(&imp->imp_refcount) > 0);
1201
1202         CDEBUG(D_INFO, "import %p refcount=%d obd=%s\n", imp,
1203                refcount_read(&imp->imp_refcount) - 1,
1204                imp->imp_obd->obd_name);
1205
1206         if (refcount_dec_and_test(&imp->imp_refcount)) {
1207                 CDEBUG(D_INFO, "final put import %p\n", imp);
1208                 obd_zombie_import_add(imp);
1209         }
1210
1211         EXIT;
1212 }
1213 EXPORT_SYMBOL(class_import_put);
1214
1215 static void init_imp_at(struct imp_at *at) {
1216         int i;
1217         at_init(&at->iat_net_latency, 0, 0);
1218         for (i = 0; i < IMP_AT_MAX_PORTALS; i++) {
1219                 /* max service estimates are tracked on the server side, so
1220                    don't use the AT history here, just use the last reported
1221                    val. (But keep hist for proc histogram, worst_ever) */
1222                 at_init(&at->iat_service_estimate[i], INITIAL_CONNECT_TIMEOUT,
1223                         AT_FLG_NOHIST);
1224         }
1225 }
1226
1227 static void obd_zombie_imp_cull(struct work_struct *ws)
1228 {
1229         struct obd_import *import;
1230
1231         import = container_of(ws, struct obd_import, imp_zombie_work);
1232         obd_zombie_import_free(import);
1233 }
1234
1235 struct obd_import *class_new_import(struct obd_device *obd)
1236 {
1237         struct obd_import *imp;
1238         struct pid_namespace *curr_pid_ns = ll_task_pid_ns(current);
1239
1240         OBD_ALLOC(imp, sizeof(*imp));
1241         if (imp == NULL)
1242                 return NULL;
1243
1244         INIT_LIST_HEAD(&imp->imp_pinger_chain);
1245         INIT_LIST_HEAD(&imp->imp_replay_list);
1246         INIT_LIST_HEAD(&imp->imp_sending_list);
1247         INIT_LIST_HEAD(&imp->imp_delayed_list);
1248         INIT_LIST_HEAD(&imp->imp_committed_list);
1249         INIT_LIST_HEAD(&imp->imp_unreplied_list);
1250         imp->imp_known_replied_xid = 0;
1251         imp->imp_replay_cursor = &imp->imp_committed_list;
1252         spin_lock_init(&imp->imp_lock);
1253         imp->imp_last_success_conn = 0;
1254         imp->imp_state = LUSTRE_IMP_NEW;
1255         imp->imp_obd = class_incref(obd, "import", imp);
1256         rwlock_init(&imp->imp_sec_lock);
1257         init_waitqueue_head(&imp->imp_recovery_waitq);
1258         INIT_WORK(&imp->imp_zombie_work, obd_zombie_imp_cull);
1259
1260         if (curr_pid_ns && curr_pid_ns->child_reaper)
1261                 imp->imp_sec_refpid = curr_pid_ns->child_reaper->pid;
1262         else
1263                 imp->imp_sec_refpid = 1;
1264
1265         refcount_set(&imp->imp_refcount, 2);
1266         atomic_set(&imp->imp_unregistering, 0);
1267         atomic_set(&imp->imp_reqs, 0);
1268         atomic_set(&imp->imp_inflight, 0);
1269         atomic_set(&imp->imp_replay_inflight, 0);
1270         init_waitqueue_head(&imp->imp_replay_waitq);
1271         atomic_set(&imp->imp_inval_count, 0);
1272         INIT_LIST_HEAD(&imp->imp_conn_list);
1273         init_imp_at(&imp->imp_at);
1274
1275         /* the default magic is V2, will be used in connect RPC, and
1276          * then adjusted according to the flags in request/reply. */
1277         imp->imp_msg_magic = LUSTRE_MSG_MAGIC_V2;
1278
1279         return imp;
1280 }
1281 EXPORT_SYMBOL(class_new_import);
1282
1283 void class_destroy_import(struct obd_import *import)
1284 {
1285         LASSERT(import != NULL);
1286         LASSERT(import != LP_POISON);
1287
1288         spin_lock(&import->imp_lock);
1289         import->imp_generation++;
1290         spin_unlock(&import->imp_lock);
1291         class_import_put(import);
1292 }
1293 EXPORT_SYMBOL(class_destroy_import);
1294
1295 #if LUSTRE_TRACKS_LOCK_EXP_REFS
1296
1297 void __class_export_add_lock_ref(struct obd_export *exp, struct ldlm_lock *lock)
1298 {
1299         spin_lock(&exp->exp_locks_list_guard);
1300
1301         LASSERT(lock->l_exp_refs_nr >= 0);
1302
1303         if (lock->l_exp_refs_target != NULL &&
1304             lock->l_exp_refs_target != exp) {
1305                 LCONSOLE_WARN("setting export %p for lock %p which already has export %p\n",
1306                               exp, lock, lock->l_exp_refs_target);
1307         }
1308         if ((lock->l_exp_refs_nr ++) == 0) {
1309                 list_add(&lock->l_exp_refs_link, &exp->exp_locks_list);
1310                 lock->l_exp_refs_target = exp;
1311         }
1312         CDEBUG(D_INFO, "lock = %p, export = %p, refs = %u\n",
1313                lock, exp, lock->l_exp_refs_nr);
1314         spin_unlock(&exp->exp_locks_list_guard);
1315 }
1316 EXPORT_SYMBOL(__class_export_add_lock_ref);
1317
1318 void __class_export_del_lock_ref(struct obd_export *exp, struct ldlm_lock *lock)
1319 {
1320         spin_lock(&exp->exp_locks_list_guard);
1321         LASSERT(lock->l_exp_refs_nr > 0);
1322         if (lock->l_exp_refs_target != exp) {
1323                 LCONSOLE_WARN("lock %p, "
1324                               "mismatching export pointers: %p, %p\n",
1325                               lock, lock->l_exp_refs_target, exp);
1326         }
1327         if (-- lock->l_exp_refs_nr == 0) {
1328                 list_del_init(&lock->l_exp_refs_link);
1329                 lock->l_exp_refs_target = NULL;
1330         }
1331         CDEBUG(D_INFO, "lock = %p, export = %p, refs = %u\n",
1332                lock, exp, lock->l_exp_refs_nr);
1333         spin_unlock(&exp->exp_locks_list_guard);
1334 }
1335 EXPORT_SYMBOL(__class_export_del_lock_ref);
1336 #endif
1337
1338 /* A connection defines an export context in which preallocation can
1339    be managed. This releases the export pointer reference, and returns
1340    the export handle, so the export refcount is 1 when this function
1341    returns. */
1342 int class_connect(struct lustre_handle *conn, struct obd_device *obd,
1343                   struct obd_uuid *cluuid)
1344 {
1345         struct obd_export *export;
1346         LASSERT(conn != NULL);
1347         LASSERT(obd != NULL);
1348         LASSERT(cluuid != NULL);
1349         ENTRY;
1350
1351         export = class_new_export(obd, cluuid);
1352         if (IS_ERR(export))
1353                 RETURN(PTR_ERR(export));
1354
1355         conn->cookie = export->exp_handle.h_cookie;
1356         class_export_put(export);
1357
1358         CDEBUG(D_IOCTL, "connect: client %s, cookie %#llx\n",
1359                cluuid->uuid, conn->cookie);
1360         RETURN(0);
1361 }
1362 EXPORT_SYMBOL(class_connect);
1363
1364 /* if export is involved in recovery then clean up related things */
1365 static void class_export_recovery_cleanup(struct obd_export *exp)
1366 {
1367         struct obd_device *obd = exp->exp_obd;
1368
1369         spin_lock(&obd->obd_recovery_task_lock);
1370         if (obd->obd_recovering) {
1371                 if (exp->exp_in_recovery) {
1372                         spin_lock(&exp->exp_lock);
1373                         exp->exp_in_recovery = 0;
1374                         spin_unlock(&exp->exp_lock);
1375                         LASSERT_ATOMIC_POS(&obd->obd_connected_clients);
1376                         atomic_dec(&obd->obd_connected_clients);
1377                 }
1378
1379                 /* if called during recovery then should update
1380                  * obd_stale_clients counter,
1381                  * lightweight exports are not counted */
1382                 if ((exp_connect_flags(exp) & OBD_CONNECT_LIGHTWEIGHT) == 0)
1383                         exp->exp_obd->obd_stale_clients++;
1384         }
1385         spin_unlock(&obd->obd_recovery_task_lock);
1386
1387         spin_lock(&exp->exp_lock);
1388         /** Cleanup req replay fields */
1389         if (exp->exp_req_replay_needed) {
1390                 exp->exp_req_replay_needed = 0;
1391
1392                 LASSERT(atomic_read(&obd->obd_req_replay_clients));
1393                 atomic_dec(&obd->obd_req_replay_clients);
1394         }
1395
1396         /** Cleanup lock replay data */
1397         if (exp->exp_lock_replay_needed) {
1398                 exp->exp_lock_replay_needed = 0;
1399
1400                 LASSERT(atomic_read(&obd->obd_lock_replay_clients));
1401                 atomic_dec(&obd->obd_lock_replay_clients);
1402         }
1403         spin_unlock(&exp->exp_lock);
1404 }
1405
1406 /* This function removes 1-3 references from the export:
1407  * 1 - for export pointer passed
1408  * and if disconnect really need
1409  * 2 - removing from hash
1410  * 3 - in client_unlink_export
1411  * The export pointer passed to this function can destroyed */
1412 int class_disconnect(struct obd_export *export)
1413 {
1414         int already_disconnected;
1415         ENTRY;
1416
1417         if (export == NULL) {
1418                 CWARN("attempting to free NULL export %p\n", export);
1419                 RETURN(-EINVAL);
1420         }
1421
1422         spin_lock(&export->exp_lock);
1423         already_disconnected = export->exp_disconnected;
1424         export->exp_disconnected = 1;
1425 #ifdef HAVE_SERVER_SUPPORT
1426         /*  We hold references of export for uuid hash
1427          *  and nid_hash and export link at least. So
1428          *  it is safe to call rh*table_remove_fast in
1429          *  there.
1430          */
1431         obd_nid_del(export->exp_obd, export);
1432 #endif /* HAVE_SERVER_SUPPORT */
1433         spin_unlock(&export->exp_lock);
1434
1435         /* class_cleanup(), abort_recovery(), and class_fail_export()
1436          * all end up in here, and if any of them race we shouldn't
1437          * call extra class_export_puts(). */
1438         if (already_disconnected)
1439                 GOTO(no_disconn, already_disconnected);
1440
1441         CDEBUG(D_IOCTL, "disconnect: cookie %#llx\n",
1442                export->exp_handle.h_cookie);
1443
1444         class_export_recovery_cleanup(export);
1445         class_unlink_export(export);
1446 no_disconn:
1447         class_export_put(export);
1448         RETURN(0);
1449 }
1450 EXPORT_SYMBOL(class_disconnect);
1451
1452 /* Return non-zero for a fully connected export */
1453 int class_connected_export(struct obd_export *exp)
1454 {
1455         int connected = 0;
1456
1457         if (exp) {
1458                 spin_lock(&exp->exp_lock);
1459                 connected = (exp->exp_conn_cnt > 0) && !exp->exp_failed;
1460                 spin_unlock(&exp->exp_lock);
1461         }
1462         return connected;
1463 }
1464 EXPORT_SYMBOL(class_connected_export);
1465
1466 static void class_disconnect_export_list(struct list_head *list,
1467                                          enum obd_option flags)
1468 {
1469         int rc;
1470         struct obd_export *exp;
1471         ENTRY;
1472
1473         /* It's possible that an export may disconnect itself, but
1474          * nothing else will be added to this list.
1475          */
1476         while ((exp = list_first_entry_or_null(list, struct obd_export,
1477                                                exp_obd_chain)) != NULL) {
1478                 /* need for safe call CDEBUG after obd_disconnect */
1479                 class_export_get(exp);
1480
1481                 spin_lock(&exp->exp_lock);
1482                 exp->exp_flags = flags;
1483                 spin_unlock(&exp->exp_lock);
1484
1485                 if (obd_uuid_equals(&exp->exp_client_uuid,
1486                                     &exp->exp_obd->obd_uuid)) {
1487                         CDEBUG(D_HA,
1488                                "exp %p export uuid == obd uuid, don't discon\n",
1489                                exp);
1490                         /* Need to delete this now so we don't end up pointing
1491                          * to work_list later when this export is cleaned up. */
1492                         list_del_init(&exp->exp_obd_chain);
1493                         class_export_put(exp);
1494                         continue;
1495                 }
1496
1497                 class_export_get(exp);
1498                 CDEBUG(D_HA, "%s: disconnecting export at %s (%p), "
1499                        "last request at %lld\n",
1500                        exp->exp_obd->obd_name, obd_export_nid2str(exp),
1501                        exp, exp->exp_last_request_time);
1502                 /* release one export reference anyway */
1503                 rc = obd_disconnect(exp);
1504
1505                 CDEBUG(D_HA, "disconnected export at %s (%p): rc %d\n",
1506                        obd_export_nid2str(exp), exp, rc);
1507                 class_export_put(exp);
1508         }
1509         EXIT;
1510 }
1511
1512 void class_disconnect_exports(struct obd_device *obd)
1513 {
1514         LIST_HEAD(work_list);
1515         ENTRY;
1516
1517         /* Move all of the exports from obd_exports to a work list, en masse. */
1518         spin_lock(&obd->obd_dev_lock);
1519         list_splice_init(&obd->obd_exports, &work_list);
1520         list_splice_init(&obd->obd_delayed_exports, &work_list);
1521         spin_unlock(&obd->obd_dev_lock);
1522
1523         if (!list_empty(&work_list)) {
1524                 CDEBUG(D_HA, "OBD device %d (%p) has exports, "
1525                        "disconnecting them\n", obd->obd_minor, obd);
1526                 class_disconnect_export_list(&work_list,
1527                                              exp_flags_from_obd(obd));
1528         } else
1529                 CDEBUG(D_HA, "OBD device %d (%p) has no exports\n",
1530                        obd->obd_minor, obd);
1531         EXIT;
1532 }
1533 EXPORT_SYMBOL(class_disconnect_exports);
1534
1535 /* Remove exports that have not completed recovery.
1536  */
1537 void class_disconnect_stale_exports(struct obd_device *obd,
1538                                     int (*test_export)(struct obd_export *))
1539 {
1540         LIST_HEAD(work_list);
1541         struct obd_export *exp, *n;
1542         int evicted = 0;
1543         ENTRY;
1544
1545         spin_lock(&obd->obd_dev_lock);
1546         list_for_each_entry_safe(exp, n, &obd->obd_exports,
1547                                  exp_obd_chain) {
1548                 /* don't count self-export as client */
1549                 if (obd_uuid_equals(&exp->exp_client_uuid,
1550                                     &exp->exp_obd->obd_uuid))
1551                         continue;
1552
1553                 /* don't evict clients which have no slot in last_rcvd
1554                  * (e.g. lightweight connection) */
1555                 if (exp->exp_target_data.ted_lr_idx == -1)
1556                         continue;
1557
1558                 spin_lock(&exp->exp_lock);
1559                 if (exp->exp_failed || test_export(exp)) {
1560                         spin_unlock(&exp->exp_lock);
1561                         continue;
1562                 }
1563                 exp->exp_failed = 1;
1564                 spin_unlock(&exp->exp_lock);
1565
1566                 list_move(&exp->exp_obd_chain, &work_list);
1567                 evicted++;
1568                 CDEBUG(D_HA, "%s: disconnect stale client %s@%s\n",
1569                        obd->obd_name, exp->exp_client_uuid.uuid,
1570                        obd_export_nid2str(exp));
1571                 print_export_data(exp, "EVICTING", 0, D_HA);
1572         }
1573         spin_unlock(&obd->obd_dev_lock);
1574
1575         if (evicted)
1576                 LCONSOLE_WARN("%s: disconnecting %d stale clients\n",
1577                               obd->obd_name, evicted);
1578
1579         class_disconnect_export_list(&work_list, exp_flags_from_obd(obd) |
1580                                                  OBD_OPT_ABORT_RECOV);
1581         EXIT;
1582 }
1583 EXPORT_SYMBOL(class_disconnect_stale_exports);
1584
1585 void class_fail_export(struct obd_export *exp)
1586 {
1587         int rc, already_failed;
1588
1589         spin_lock(&exp->exp_lock);
1590         already_failed = exp->exp_failed;
1591         exp->exp_failed = 1;
1592         spin_unlock(&exp->exp_lock);
1593
1594         if (already_failed) {
1595                 CDEBUG(D_HA, "disconnecting dead export %p/%s; skipping\n",
1596                        exp, exp->exp_client_uuid.uuid);
1597                 return;
1598         }
1599
1600         CDEBUG(D_HA, "disconnecting export %p/%s\n",
1601                exp, exp->exp_client_uuid.uuid);
1602
1603         if (obd_dump_on_timeout)
1604                 libcfs_debug_dumplog();
1605
1606         /* need for safe call CDEBUG after obd_disconnect */
1607         class_export_get(exp);
1608
1609         /* Most callers into obd_disconnect are removing their own reference
1610          * (request, for example) in addition to the one from the hash table.
1611          * We don't have such a reference here, so make one. */
1612         class_export_get(exp);
1613         rc = obd_disconnect(exp);
1614         if (rc)
1615                 CERROR("disconnecting export %p failed: %d\n", exp, rc);
1616         else
1617                 CDEBUG(D_HA, "disconnected export %p/%s\n",
1618                        exp, exp->exp_client_uuid.uuid);
1619         class_export_put(exp);
1620 }
1621 EXPORT_SYMBOL(class_fail_export);
1622
1623 #ifdef HAVE_SERVER_SUPPORT
1624
1625 static int take_first(struct obd_export *exp, void *data)
1626 {
1627         struct obd_export **expp = data;
1628
1629         if (*expp)
1630                 /* already have one */
1631                 return 0;
1632         if (exp->exp_failed)
1633                 /* Don't want this one */
1634                 return 0;
1635         if (!refcount_inc_not_zero(&exp->exp_handle.h_ref))
1636                 /* Cannot get a ref on this one */
1637                 return 0;
1638         *expp = exp;
1639         return 1;
1640 }
1641
1642 int obd_export_evict_by_nid(struct obd_device *obd, const char *nid)
1643 {
1644         lnet_nid_t nid_key = libcfs_str2nid((char *)nid);
1645         struct obd_export *doomed_exp;
1646         int exports_evicted = 0;
1647
1648         spin_lock(&obd->obd_dev_lock);
1649         /* umount has run already, so evict thread should leave
1650          * its task to umount thread now */
1651         if (obd->obd_stopping) {
1652                 spin_unlock(&obd->obd_dev_lock);
1653                 return exports_evicted;
1654         }
1655         spin_unlock(&obd->obd_dev_lock);
1656
1657         doomed_exp = NULL;
1658         while (obd_nid_export_for_each(obd, nid_key,
1659                                        take_first, &doomed_exp) > 0) {
1660
1661                 LASSERTF(doomed_exp != obd->obd_self_export,
1662                          "self-export is hashed by NID?\n");
1663
1664                 LCONSOLE_WARN("%s: evicting %s (at %s) by administrative request\n",
1665                               obd->obd_name,
1666                               obd_uuid2str(&doomed_exp->exp_client_uuid),
1667                               obd_export_nid2str(doomed_exp));
1668
1669                 class_fail_export(doomed_exp);
1670                 class_export_put(doomed_exp);
1671                 exports_evicted++;
1672                 doomed_exp = NULL;
1673         }
1674
1675         if (!exports_evicted)
1676                 CDEBUG(D_HA,
1677                        "%s: can't disconnect NID '%s': no exports found\n",
1678                        obd->obd_name, nid);
1679         return exports_evicted;
1680 }
1681 EXPORT_SYMBOL(obd_export_evict_by_nid);
1682
1683 int obd_export_evict_by_uuid(struct obd_device *obd, const char *uuid)
1684 {
1685         struct obd_export *doomed_exp = NULL;
1686         struct obd_uuid doomed_uuid;
1687         int exports_evicted = 0;
1688
1689         spin_lock(&obd->obd_dev_lock);
1690         if (obd->obd_stopping) {
1691                 spin_unlock(&obd->obd_dev_lock);
1692                 return exports_evicted;
1693         }
1694         spin_unlock(&obd->obd_dev_lock);
1695
1696         obd_str2uuid(&doomed_uuid, uuid);
1697         if (obd_uuid_equals(&doomed_uuid, &obd->obd_uuid)) {
1698                 CERROR("%s: can't evict myself\n", obd->obd_name);
1699                 return exports_evicted;
1700         }
1701
1702         doomed_exp = obd_uuid_lookup(obd, &doomed_uuid);
1703         if (doomed_exp == NULL) {
1704                 CERROR("%s: can't disconnect %s: no exports found\n",
1705                        obd->obd_name, uuid);
1706         } else {
1707                 CWARN("%s: evicting %s at adminstrative request\n",
1708                        obd->obd_name, doomed_exp->exp_client_uuid.uuid);
1709                 class_fail_export(doomed_exp);
1710                 class_export_put(doomed_exp);
1711                 obd_uuid_del(obd, doomed_exp);
1712                 exports_evicted++;
1713         }
1714
1715         return exports_evicted;
1716 }
1717 #endif /* HAVE_SERVER_SUPPORT */
1718
1719 #if LUSTRE_TRACKS_LOCK_EXP_REFS
1720 void (*class_export_dump_hook)(struct obd_export*) = NULL;
1721 EXPORT_SYMBOL(class_export_dump_hook);
1722 #endif
1723
1724 static void print_export_data(struct obd_export *exp, const char *status,
1725                               int locks, int debug_level)
1726 {
1727         struct ptlrpc_reply_state *rs;
1728         struct ptlrpc_reply_state *first_reply = NULL;
1729         int nreplies = 0;
1730
1731         spin_lock(&exp->exp_lock);
1732         list_for_each_entry(rs, &exp->exp_outstanding_replies,
1733                             rs_exp_list) {
1734                 if (nreplies == 0)
1735                         first_reply = rs;
1736                 nreplies++;
1737         }
1738         spin_unlock(&exp->exp_lock);
1739
1740         CDEBUG(debug_level, "%s: %s %p %s %s %d (%d %d %d) %d %d %d %d: "
1741                "%p %s %llu stale:%d\n",
1742                exp->exp_obd->obd_name, status, exp, exp->exp_client_uuid.uuid,
1743                obd_export_nid2str(exp),
1744                refcount_read(&exp->exp_handle.h_ref),
1745                atomic_read(&exp->exp_rpc_count),
1746                atomic_read(&exp->exp_cb_count),
1747                atomic_read(&exp->exp_locks_count),
1748                exp->exp_disconnected, exp->exp_delayed, exp->exp_failed,
1749                nreplies, first_reply, nreplies > 3 ? "..." : "",
1750                exp->exp_last_committed, !list_empty(&exp->exp_stale_list));
1751 #if LUSTRE_TRACKS_LOCK_EXP_REFS
1752         if (locks && class_export_dump_hook != NULL)
1753                 class_export_dump_hook(exp);
1754 #endif
1755 }
1756
1757 void dump_exports(struct obd_device *obd, int locks, int debug_level)
1758 {
1759         struct obd_export *exp;
1760
1761         spin_lock(&obd->obd_dev_lock);
1762         list_for_each_entry(exp, &obd->obd_exports, exp_obd_chain)
1763                 print_export_data(exp, "ACTIVE", locks, debug_level);
1764         list_for_each_entry(exp, &obd->obd_unlinked_exports, exp_obd_chain)
1765                 print_export_data(exp, "UNLINKED", locks, debug_level);
1766         list_for_each_entry(exp, &obd->obd_delayed_exports, exp_obd_chain)
1767                 print_export_data(exp, "DELAYED", locks, debug_level);
1768         spin_unlock(&obd->obd_dev_lock);
1769 }
1770
1771 void obd_exports_barrier(struct obd_device *obd)
1772 {
1773         int waited = 2;
1774         LASSERT(list_empty(&obd->obd_exports));
1775         spin_lock(&obd->obd_dev_lock);
1776         while (!list_empty(&obd->obd_unlinked_exports)) {
1777                 spin_unlock(&obd->obd_dev_lock);
1778                 schedule_timeout_uninterruptible(cfs_time_seconds(waited));
1779                 if (waited > 5 && is_power_of_2(waited)) {
1780                         LCONSOLE_WARN("%s is waiting for obd_unlinked_exports "
1781                                       "more than %d seconds. "
1782                                       "The obd refcount = %d. Is it stuck?\n",
1783                                       obd->obd_name, waited,
1784                                       atomic_read(&obd->obd_refcount));
1785                         dump_exports(obd, 1, D_CONSOLE | D_WARNING);
1786                 }
1787                 waited *= 2;
1788                 spin_lock(&obd->obd_dev_lock);
1789         }
1790         spin_unlock(&obd->obd_dev_lock);
1791 }
1792 EXPORT_SYMBOL(obd_exports_barrier);
1793
1794 /**
1795  * Add export to the obd_zombe thread and notify it.
1796  */
1797 static void obd_zombie_export_add(struct obd_export *exp) {
1798         atomic_dec(&obd_stale_export_num);
1799         spin_lock(&exp->exp_obd->obd_dev_lock);
1800         LASSERT(!list_empty(&exp->exp_obd_chain));
1801         list_del_init(&exp->exp_obd_chain);
1802         spin_unlock(&exp->exp_obd->obd_dev_lock);
1803
1804         queue_work(zombie_wq, &exp->exp_zombie_work);
1805 }
1806
1807 /**
1808  * Add import to the obd_zombe thread and notify it.
1809  */
1810 static void obd_zombie_import_add(struct obd_import *imp) {
1811         LASSERT(imp->imp_sec == NULL);
1812
1813         queue_work(zombie_wq, &imp->imp_zombie_work);
1814 }
1815
1816 /**
1817  * wait when obd_zombie import/export queues become empty
1818  */
1819 void obd_zombie_barrier(void)
1820 {
1821         flush_workqueue(zombie_wq);
1822 }
1823 EXPORT_SYMBOL(obd_zombie_barrier);
1824
1825
1826 struct obd_export *obd_stale_export_get(void)
1827 {
1828         struct obd_export *exp = NULL;
1829         ENTRY;
1830
1831         spin_lock(&obd_stale_export_lock);
1832         if (!list_empty(&obd_stale_exports)) {
1833                 exp = list_first_entry(&obd_stale_exports,
1834                                        struct obd_export, exp_stale_list);
1835                 list_del_init(&exp->exp_stale_list);
1836         }
1837         spin_unlock(&obd_stale_export_lock);
1838
1839         if (exp) {
1840                 CDEBUG(D_DLMTRACE, "Get export %p: total %d\n", exp,
1841                        atomic_read(&obd_stale_export_num));
1842         }
1843         RETURN(exp);
1844 }
1845 EXPORT_SYMBOL(obd_stale_export_get);
1846
1847 void obd_stale_export_put(struct obd_export *exp)
1848 {
1849         ENTRY;
1850
1851         LASSERT(list_empty(&exp->exp_stale_list));
1852         if (exp->exp_lock_hash &&
1853             atomic_read(&exp->exp_lock_hash->hs_count)) {
1854                 CDEBUG(D_DLMTRACE, "Put export %p: total %d\n", exp,
1855                        atomic_read(&obd_stale_export_num));
1856
1857                 spin_lock_bh(&exp->exp_bl_list_lock);
1858                 spin_lock(&obd_stale_export_lock);
1859                 /* Add to the tail if there is no blocked locks,
1860                  * to the head otherwise. */
1861                 if (list_empty(&exp->exp_bl_list))
1862                         list_add_tail(&exp->exp_stale_list,
1863                                       &obd_stale_exports);
1864                 else
1865                         list_add(&exp->exp_stale_list,
1866                                  &obd_stale_exports);
1867
1868                 spin_unlock(&obd_stale_export_lock);
1869                 spin_unlock_bh(&exp->exp_bl_list_lock);
1870         } else {
1871                 class_export_put(exp);
1872         }
1873         EXIT;
1874 }
1875 EXPORT_SYMBOL(obd_stale_export_put);
1876
1877 /**
1878  * Adjust the position of the export in the stale list,
1879  * i.e. move to the head of the list if is needed.
1880  **/
1881 void obd_stale_export_adjust(struct obd_export *exp)
1882 {
1883         LASSERT(exp != NULL);
1884         spin_lock_bh(&exp->exp_bl_list_lock);
1885         spin_lock(&obd_stale_export_lock);
1886
1887         if (!list_empty(&exp->exp_stale_list) &&
1888             !list_empty(&exp->exp_bl_list))
1889                 list_move(&exp->exp_stale_list, &obd_stale_exports);
1890
1891         spin_unlock(&obd_stale_export_lock);
1892         spin_unlock_bh(&exp->exp_bl_list_lock);
1893 }
1894 EXPORT_SYMBOL(obd_stale_export_adjust);
1895
1896 /**
1897  * start destroy zombie import/export thread
1898  */
1899 int obd_zombie_impexp_init(void)
1900 {
1901         zombie_wq = cfs_cpt_bind_workqueue("obd_zombid", cfs_cpt_tab,
1902                                            0, CFS_CPT_ANY,
1903                                            cfs_cpt_number(cfs_cpt_tab));
1904
1905         return IS_ERR(zombie_wq) ? PTR_ERR(zombie_wq) : 0;
1906 }
1907
1908 /**
1909  * stop destroy zombie import/export thread
1910  */
1911 void obd_zombie_impexp_stop(void)
1912 {
1913         destroy_workqueue(zombie_wq);
1914         LASSERT(list_empty(&obd_stale_exports));
1915 }
1916
1917 /***** Kernel-userspace comm helpers *******/
1918
1919 /* Get length of entire message, including header */
1920 int kuc_len(int payload_len)
1921 {
1922         return sizeof(struct kuc_hdr) + payload_len;
1923 }
1924 EXPORT_SYMBOL(kuc_len);
1925
1926 /* Get a pointer to kuc header, given a ptr to the payload
1927  * @param p Pointer to payload area
1928  * @returns Pointer to kuc header
1929  */
1930 struct kuc_hdr * kuc_ptr(void *p)
1931 {
1932         struct kuc_hdr *lh = ((struct kuc_hdr *)p) - 1;
1933         LASSERT(lh->kuc_magic == KUC_MAGIC);
1934         return lh;
1935 }
1936 EXPORT_SYMBOL(kuc_ptr);
1937
1938 /* Alloc space for a message, and fill in header
1939  * @return Pointer to payload area
1940  */
1941 void *kuc_alloc(int payload_len, int transport, int type)
1942 {
1943         struct kuc_hdr *lh;
1944         int len = kuc_len(payload_len);
1945
1946         OBD_ALLOC(lh, len);
1947         if (lh == NULL)
1948                 return ERR_PTR(-ENOMEM);
1949
1950         lh->kuc_magic = KUC_MAGIC;
1951         lh->kuc_transport = transport;
1952         lh->kuc_msgtype = type;
1953         lh->kuc_msglen = len;
1954
1955         return (void *)(lh + 1);
1956 }
1957 EXPORT_SYMBOL(kuc_alloc);
1958
1959 /* Takes pointer to payload area */
1960 void kuc_free(void *p, int payload_len)
1961 {
1962         struct kuc_hdr *lh = kuc_ptr(p);
1963         OBD_FREE(lh, kuc_len(payload_len));
1964 }
1965 EXPORT_SYMBOL(kuc_free);
1966
1967 struct obd_request_slot_waiter {
1968         struct list_head        orsw_entry;
1969         wait_queue_head_t       orsw_waitq;
1970         bool                    orsw_signaled;
1971 };
1972
1973 static bool obd_request_slot_avail(struct client_obd *cli,
1974                                    struct obd_request_slot_waiter *orsw)
1975 {
1976         bool avail;
1977
1978         spin_lock(&cli->cl_loi_list_lock);
1979         avail = !!list_empty(&orsw->orsw_entry);
1980         spin_unlock(&cli->cl_loi_list_lock);
1981
1982         return avail;
1983 };
1984
1985 /*
1986  * For network flow control, the RPC sponsor needs to acquire a credit
1987  * before sending the RPC. The credits count for a connection is defined
1988  * by the "cl_max_rpcs_in_flight". If all the credits are occpuied, then
1989  * the subsequent RPC sponsors need to wait until others released their
1990  * credits, or the administrator increased the "cl_max_rpcs_in_flight".
1991  */
1992 int obd_get_request_slot(struct client_obd *cli)
1993 {
1994         struct obd_request_slot_waiter   orsw;
1995         int                              rc;
1996
1997         spin_lock(&cli->cl_loi_list_lock);
1998         if (cli->cl_rpcs_in_flight < cli->cl_max_rpcs_in_flight) {
1999                 cli->cl_rpcs_in_flight++;
2000                 spin_unlock(&cli->cl_loi_list_lock);
2001                 return 0;
2002         }
2003
2004         init_waitqueue_head(&orsw.orsw_waitq);
2005         list_add_tail(&orsw.orsw_entry, &cli->cl_flight_waiters);
2006         orsw.orsw_signaled = false;
2007         spin_unlock(&cli->cl_loi_list_lock);
2008
2009         rc = l_wait_event_abortable(orsw.orsw_waitq,
2010                                     obd_request_slot_avail(cli, &orsw) ||
2011                                     orsw.orsw_signaled);
2012
2013         /* Here, we must take the lock to avoid the on-stack 'orsw' to be
2014          * freed but other (such as obd_put_request_slot) is using it. */
2015         spin_lock(&cli->cl_loi_list_lock);
2016         if (rc != 0) {
2017                 if (!orsw.orsw_signaled) {
2018                         if (list_empty(&orsw.orsw_entry))
2019                                 cli->cl_rpcs_in_flight--;
2020                         else
2021                                 list_del(&orsw.orsw_entry);
2022                 }
2023                 rc = -EINTR;
2024         }
2025
2026         if (orsw.orsw_signaled) {
2027                 LASSERT(list_empty(&orsw.orsw_entry));
2028
2029                 rc = -EINTR;
2030         }
2031         spin_unlock(&cli->cl_loi_list_lock);
2032
2033         return rc;
2034 }
2035 EXPORT_SYMBOL(obd_get_request_slot);
2036
2037 void obd_put_request_slot(struct client_obd *cli)
2038 {
2039         struct obd_request_slot_waiter *orsw;
2040
2041         spin_lock(&cli->cl_loi_list_lock);
2042         cli->cl_rpcs_in_flight--;
2043
2044         /* If there is free slot, wakeup the first waiter. */
2045         if (!list_empty(&cli->cl_flight_waiters) &&
2046             likely(cli->cl_rpcs_in_flight < cli->cl_max_rpcs_in_flight)) {
2047                 orsw = list_first_entry(&cli->cl_flight_waiters,
2048                                         struct obd_request_slot_waiter,
2049                                         orsw_entry);
2050                 list_del_init(&orsw->orsw_entry);
2051                 cli->cl_rpcs_in_flight++;
2052                 wake_up(&orsw->orsw_waitq);
2053         }
2054         spin_unlock(&cli->cl_loi_list_lock);
2055 }
2056 EXPORT_SYMBOL(obd_put_request_slot);
2057
2058 __u32 obd_get_max_rpcs_in_flight(struct client_obd *cli)
2059 {
2060         return cli->cl_max_rpcs_in_flight;
2061 }
2062 EXPORT_SYMBOL(obd_get_max_rpcs_in_flight);
2063
2064 int obd_set_max_rpcs_in_flight(struct client_obd *cli, __u32 max)
2065 {
2066         struct obd_request_slot_waiter *orsw;
2067         __u32                           old;
2068         int                             diff;
2069         int                             i;
2070         int                             rc;
2071
2072         if (max > OBD_MAX_RIF_MAX || max < 1)
2073                 return -ERANGE;
2074
2075         CDEBUG(D_INFO, "%s: max = %hu max_mod = %u rif = %u\n",
2076                cli->cl_import->imp_obd->obd_name, max,
2077                cli->cl_max_mod_rpcs_in_flight, cli->cl_max_rpcs_in_flight);
2078
2079         if (strcmp(cli->cl_import->imp_obd->obd_type->typ_name,
2080                    LUSTRE_MDC_NAME) == 0) {
2081                 /* adjust max_mod_rpcs_in_flight to ensure it is always
2082                  * strictly lower that max_rpcs_in_flight */
2083                 if (max < 2) {
2084                         CERROR("%s: cannot set mdc.*.max_rpcs_in_flight=1\n",
2085                                cli->cl_import->imp_obd->obd_name);
2086                         return -ERANGE;
2087                 }
2088                 if (max <= cli->cl_max_mod_rpcs_in_flight) {
2089                         rc = obd_set_max_mod_rpcs_in_flight(cli, max - 1);
2090                         if (rc != 0)
2091                                 return rc;
2092                 }
2093         }
2094
2095         spin_lock(&cli->cl_loi_list_lock);
2096         old = cli->cl_max_rpcs_in_flight;
2097         cli->cl_max_rpcs_in_flight = max;
2098         client_adjust_max_dirty(cli);
2099
2100         diff = max - old;
2101
2102         /* We increase the max_rpcs_in_flight, then wakeup some waiters. */
2103         for (i = 0; i < diff; i++) {
2104                 orsw = list_first_entry_or_null(&cli->cl_loi_read_list,
2105                                                 struct obd_request_slot_waiter,
2106                                                 orsw_entry);
2107                 if (!orsw)
2108                         break;
2109
2110                 list_del_init(&orsw->orsw_entry);
2111                 cli->cl_rpcs_in_flight++;
2112                 wake_up(&orsw->orsw_waitq);
2113         }
2114         spin_unlock(&cli->cl_loi_list_lock);
2115
2116         return 0;
2117 }
2118 EXPORT_SYMBOL(obd_set_max_rpcs_in_flight);
2119
2120 __u16 obd_get_max_mod_rpcs_in_flight(struct client_obd *cli)
2121 {
2122         return cli->cl_max_mod_rpcs_in_flight;
2123 }
2124 EXPORT_SYMBOL(obd_get_max_mod_rpcs_in_flight);
2125
2126 int obd_set_max_mod_rpcs_in_flight(struct client_obd *cli, __u16 max)
2127 {
2128         struct obd_connect_data *ocd;
2129         __u16 maxmodrpcs;
2130         __u16 prev;
2131
2132         if (max > OBD_MAX_RIF_MAX || max < 1)
2133                 return -ERANGE;
2134
2135         ocd = &cli->cl_import->imp_connect_data;
2136         CDEBUG(D_INFO, "%s: max = %hu flags = %llx, max_mod = %u rif = %u\n",
2137                cli->cl_import->imp_obd->obd_name, max, ocd->ocd_connect_flags,
2138                ocd->ocd_maxmodrpcs, cli->cl_max_rpcs_in_flight);
2139
2140         if (max == OBD_MAX_RIF_MAX)
2141                 max = OBD_MAX_RIF_MAX - 1;
2142
2143         /* Cannot exceed or equal max_rpcs_in_flight.  If we are asked to
2144          * increase this value, also bump up max_rpcs_in_flight to match.
2145          */
2146         if (max >= cli->cl_max_rpcs_in_flight) {
2147                 CDEBUG(D_INFO,
2148                        "%s: increasing max_rpcs_in_flight=%hu to allow larger max_mod_rpcs_in_flight=%u\n",
2149                        cli->cl_import->imp_obd->obd_name, max + 1, max);
2150                 obd_set_max_rpcs_in_flight(cli, max + 1);
2151         }
2152
2153         /* cannot exceed max modify RPCs in flight supported by the server,
2154          * but verify ocd_connect_flags is at least initialized first.  If
2155          * not, allow it and fix value later in ptlrpc_connect_set_flags().
2156          */
2157         if (!ocd->ocd_connect_flags) {
2158                 maxmodrpcs = cli->cl_max_rpcs_in_flight - 1;
2159         } else if (ocd->ocd_connect_flags & OBD_CONNECT_MULTIMODRPCS) {
2160                 maxmodrpcs = ocd->ocd_maxmodrpcs;
2161                 if (maxmodrpcs == 0) { /* connection not finished yet */
2162                         maxmodrpcs = cli->cl_max_rpcs_in_flight - 1;
2163                         CDEBUG(D_INFO,
2164                                "%s: partial connect, assume maxmodrpcs=%hu\n",
2165                                cli->cl_import->imp_obd->obd_name, maxmodrpcs);
2166                 }
2167         } else {
2168                 maxmodrpcs = 1;
2169         }
2170         if (max > maxmodrpcs) {
2171                 CERROR("%s: can't set max_mod_rpcs_in_flight=%hu higher than ocd_maxmodrpcs=%hu returned by the server at connection\n",
2172                        cli->cl_import->imp_obd->obd_name,
2173                        max, maxmodrpcs);
2174                 return -ERANGE;
2175         }
2176
2177         spin_lock(&cli->cl_mod_rpcs_lock);
2178
2179         prev = cli->cl_max_mod_rpcs_in_flight;
2180         cli->cl_max_mod_rpcs_in_flight = max;
2181
2182         /* wakeup waiters if limit has been increased */
2183         if (cli->cl_max_mod_rpcs_in_flight > prev)
2184                 wake_up(&cli->cl_mod_rpcs_waitq);
2185
2186         spin_unlock(&cli->cl_mod_rpcs_lock);
2187
2188         return 0;
2189 }
2190 EXPORT_SYMBOL(obd_set_max_mod_rpcs_in_flight);
2191
2192 int obd_mod_rpc_stats_seq_show(struct client_obd *cli,
2193                                struct seq_file *seq)
2194 {
2195         unsigned long mod_tot = 0, mod_cum;
2196         int i;
2197
2198         spin_lock(&cli->cl_mod_rpcs_lock);
2199         lprocfs_stats_header(seq, ktime_get(), cli->cl_mod_rpcs_init, 25,
2200                              ":", true);
2201         seq_printf(seq, "modify_RPCs_in_flight:  %hu\n",
2202                    cli->cl_mod_rpcs_in_flight);
2203
2204         seq_printf(seq, "\n\t\t\tmodify\n");
2205         seq_printf(seq, "rpcs in flight        rpcs   %% cum %%\n");
2206
2207         mod_tot = lprocfs_oh_sum(&cli->cl_mod_rpcs_hist);
2208
2209         mod_cum = 0;
2210         for (i = 0; i < OBD_HIST_MAX; i++) {
2211                 unsigned long mod = cli->cl_mod_rpcs_hist.oh_buckets[i];
2212
2213                 mod_cum += mod;
2214                 seq_printf(seq, "%d:\t\t%10lu %3u %3u\n",
2215                            i, mod, pct(mod, mod_tot),
2216                            pct(mod_cum, mod_tot));
2217                 if (mod_cum == mod_tot)
2218                         break;
2219         }
2220
2221         spin_unlock(&cli->cl_mod_rpcs_lock);
2222
2223         return 0;
2224 }
2225 EXPORT_SYMBOL(obd_mod_rpc_stats_seq_show);
2226
2227 /* The number of modify RPCs sent in parallel is limited
2228  * because the server has a finite number of slots per client to
2229  * store request result and ensure reply reconstruction when needed.
2230  * On the client, this limit is stored in cl_max_mod_rpcs_in_flight
2231  * that takes into account server limit and cl_max_rpcs_in_flight
2232  * value.
2233  * On the MDC client, to avoid a potential deadlock (see Bugzilla 3462),
2234  * one close request is allowed above the maximum.
2235  */
2236 static inline bool obd_mod_rpc_slot_avail_locked(struct client_obd *cli,
2237                                                  bool close_req)
2238 {
2239         bool avail;
2240
2241         /* A slot is available if
2242          * - number of modify RPCs in flight is less than the max
2243          * - it's a close RPC and no other close request is in flight
2244          */
2245         avail = cli->cl_mod_rpcs_in_flight < cli->cl_max_mod_rpcs_in_flight ||
2246                 (close_req && cli->cl_close_rpcs_in_flight == 0);
2247
2248         return avail;
2249 }
2250
2251 static inline bool obd_mod_rpc_slot_avail(struct client_obd *cli,
2252                                          bool close_req)
2253 {
2254         bool avail;
2255
2256         spin_lock(&cli->cl_mod_rpcs_lock);
2257         avail = obd_mod_rpc_slot_avail_locked(cli, close_req);
2258         spin_unlock(&cli->cl_mod_rpcs_lock);
2259         return avail;
2260 }
2261
2262
2263 /* Get a modify RPC slot from the obd client @cli according
2264  * to the kind of operation @opc that is going to be sent
2265  * and the intent @it of the operation if it applies.
2266  * If the maximum number of modify RPCs in flight is reached
2267  * the thread is put to sleep.
2268  * Returns the tag to be set in the request message. Tag 0
2269  * is reserved for non-modifying requests.
2270  */
2271 __u16 obd_get_mod_rpc_slot(struct client_obd *cli, __u32 opc)
2272 {
2273         bool                    close_req = false;
2274         __u16                   i, max;
2275
2276         if (opc == MDS_CLOSE)
2277                 close_req = true;
2278
2279         do {
2280                 spin_lock(&cli->cl_mod_rpcs_lock);
2281                 max = cli->cl_max_mod_rpcs_in_flight;
2282                 if (obd_mod_rpc_slot_avail_locked(cli, close_req)) {
2283                         /* there is a slot available */
2284                         cli->cl_mod_rpcs_in_flight++;
2285                         if (close_req)
2286                                 cli->cl_close_rpcs_in_flight++;
2287                         lprocfs_oh_tally(&cli->cl_mod_rpcs_hist,
2288                                          cli->cl_mod_rpcs_in_flight);
2289                         /* find a free tag */
2290                         i = find_first_zero_bit(cli->cl_mod_tag_bitmap,
2291                                                 max + 1);
2292                         LASSERT(i < OBD_MAX_RIF_MAX);
2293                         LASSERT(!test_and_set_bit(i, cli->cl_mod_tag_bitmap));
2294                         spin_unlock(&cli->cl_mod_rpcs_lock);
2295                         /* tag 0 is reserved for non-modify RPCs */
2296
2297                         CDEBUG(D_RPCTRACE,
2298                                "%s: modify RPC slot %u is allocated opc %u, max %hu\n",
2299                                cli->cl_import->imp_obd->obd_name,
2300                                i + 1, opc, max);
2301
2302                         return i + 1;
2303                 }
2304                 spin_unlock(&cli->cl_mod_rpcs_lock);
2305
2306                 CDEBUG(D_RPCTRACE, "%s: sleeping for a modify RPC slot "
2307                        "opc %u, max %hu\n",
2308                        cli->cl_import->imp_obd->obd_name, opc, max);
2309
2310                 wait_event_idle_exclusive(cli->cl_mod_rpcs_waitq,
2311                                           obd_mod_rpc_slot_avail(cli,
2312                                                                  close_req));
2313         } while (true);
2314 }
2315 EXPORT_SYMBOL(obd_get_mod_rpc_slot);
2316
2317 /* Put a modify RPC slot from the obd client @cli according
2318  * to the kind of operation @opc that has been sent.
2319  */
2320 void obd_put_mod_rpc_slot(struct client_obd *cli, __u32 opc, __u16 tag)
2321 {
2322         bool                    close_req = false;
2323
2324         if (tag == 0)
2325                 return;
2326
2327         if (opc == MDS_CLOSE)
2328                 close_req = true;
2329
2330         spin_lock(&cli->cl_mod_rpcs_lock);
2331         cli->cl_mod_rpcs_in_flight--;
2332         if (close_req)
2333                 cli->cl_close_rpcs_in_flight--;
2334         /* release the tag in the bitmap */
2335         LASSERT(tag - 1 < OBD_MAX_RIF_MAX);
2336         LASSERT(test_and_clear_bit(tag - 1, cli->cl_mod_tag_bitmap) != 0);
2337         spin_unlock(&cli->cl_mod_rpcs_lock);
2338         /* LU-14741 - to prevent close RPCs stuck behind normal ones */
2339         if (close_req)
2340                 wake_up_all(&cli->cl_mod_rpcs_waitq);
2341         else
2342                 wake_up(&cli->cl_mod_rpcs_waitq);
2343 }
2344 EXPORT_SYMBOL(obd_put_mod_rpc_slot);
2345