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  * Lustre is a trademark of Sun Microsystems, Inc.
  31  *
  32  * lustre/obdclass/genops.c
  33  *
  34  * These are the only exported functions, they provide some generic
  35  * infrastructure for managing object devices
  36  */
  37
  38 #define DEBUG_SUBSYSTEM S_CLASS
  39
  40 #include <linux/pid_namespace.h>
  41 #include <linux/workqueue.h>
  42 #include <lustre_compat.h>
  43 #include <obd_class.h>
  44 #include <lustre_log.h>
  45 #include <lprocfs_status.h>
  46 #include <lustre_disk.h>
  47 #include <lustre_kernelcomm.h>
  48
  49 DEFINE_RWLOCK(obd_dev_lock);
  50 static struct obd_device *obd_devs[MAX_OBD_DEVICES];
  51
  52 static struct kmem_cache *obd_device_cachep;
  53 static struct kobj_type class_ktype;
  54 static struct workqueue_struct *zombie_wq;
  55
  56 static void obd_zombie_export_add(struct obd_export *exp);
  57 static void obd_zombie_import_add(struct obd_import *imp);
  58 static void print_export_data(struct obd_export *exp,
  59                               const char *status, int locks, int debug_level);
  60
  61 static LIST_HEAD(obd_stale_exports);
  62 static DEFINE_SPINLOCK(obd_stale_export_lock);
  63 static atomic_t obd_stale_export_num = ATOMIC_INIT(0);
  64
  65 int (*ptlrpc_put_connection_superhack)(struct ptlrpc_connection *c);
  66 EXPORT_SYMBOL(ptlrpc_put_connection_superhack);
  67
  68 /*
  69  * support functions: we could use inter-module communication, but this
  70  * is more portable to other OS's
  71  */
  72 static struct obd_device *obd_device_alloc(void)
  73 {
  74         struct obd_device *obd;
  75
  76         OBD_SLAB_ALLOC_PTR_GFP(obd, obd_device_cachep, GFP_NOFS);
  77         if (obd != NULL) {
  78                 obd->obd_magic = OBD_DEVICE_MAGIC;
  79         }
  80         return obd;
  81 }
  82
  83 static void obd_device_free(struct obd_device *obd)
  84 {
  85         LASSERT(obd != NULL);
  86         LASSERTF(obd->obd_magic == OBD_DEVICE_MAGIC, "obd %p obd_magic %08x != %08x\n",
  87                  obd, obd->obd_magic, OBD_DEVICE_MAGIC);
  88         if (obd->obd_namespace != NULL) {
  89                 CERROR("obd %p: namespace %p was not properly cleaned up (obd_force=%d)!\n",
  90                        obd, obd->obd_namespace, obd->obd_force);
  91                 LBUG();
  92         }
  93         lu_ref_fini(&obd->obd_reference);
  94         OBD_SLAB_FREE_PTR(obd, obd_device_cachep);
  95 }
  96
  97 struct obd_type *class_search_type(const char *name)
  98 {
  99         struct kobject *kobj = kset_find_obj(lustre_kset, name);
 100
 101         if (kobj && kobj->ktype == &class_ktype)
 102                 return container_of(kobj, struct obd_type, typ_kobj);
 103
 104         kobject_put(kobj);
 105         return NULL;
 106 }
 107 EXPORT_SYMBOL(class_search_type);
 108
 109 struct obd_type *class_get_type(const char *name)
 110 {
 111         struct obd_type *type;
 112
 113         type = class_search_type(name);
 114 #ifdef HAVE_MODULE_LOADING_SUPPORT
 115         if (!type) {
 116                 const char *modname = name;
 117
 118 #ifdef HAVE_SERVER_SUPPORT
 119                 if (strcmp(modname, "obdfilter") == 0)
 120                         modname = "ofd";
 121
 122                 if (strcmp(modname, LUSTRE_LWP_NAME) == 0)
 123                         modname = LUSTRE_OSP_NAME;
 124
 125                 if (!strncmp(modname, LUSTRE_MDS_NAME, strlen(LUSTRE_MDS_NAME)))
 126                         modname = LUSTRE_MDT_NAME;
 127 #endif /* HAVE_SERVER_SUPPORT */
 128
 129                 if (!request_module("%s", modname)) {
 130                         CDEBUG(D_INFO, "Loaded module '%s'\n", modname);
 131                         type = class_search_type(name);
 132                 } else {
 133                         LCONSOLE_ERROR_MSG(0x158, "Can't load module '%s'\n",
 134                                            modname);
 135                 }
 136         }
 137 #endif
 138         if (type) {
 139                 if (try_module_get(type->typ_dt_ops->o_owner)) {
 140                         atomic_inc(&type->typ_refcnt);
 141                         /* class_search_type() returned a counted reference,
 142                          * but we don't need that count any more as
 143                          * we have one through typ_refcnt.
 144                          */
 145                         kobject_put(&type->typ_kobj);
 146                 } else {
 147                         kobject_put(&type->typ_kobj);
 148                         type = NULL;
 149                 }
 150         }
 151         return type;
 152 }
 153
 154 void class_put_type(struct obd_type *type)
 155 {
 156         LASSERT(type);
 157         module_put(type->typ_dt_ops->o_owner);
 158         atomic_dec(&type->typ_refcnt);
 159 }
 160
 161 static void class_sysfs_release(struct kobject *kobj)
 162 {
 163         struct obd_type *type = container_of(kobj, struct obd_type, typ_kobj);
 164
 165         debugfs_remove_recursive(type->typ_debugfs_entry);
 166         type->typ_debugfs_entry = NULL;
 167
 168         if (type->typ_lu)
 169                 lu_device_type_fini(type->typ_lu);
 170
 171 #ifdef CONFIG_PROC_FS
 172         if (type->typ_name && type->typ_procroot)
 173                 remove_proc_subtree(type->typ_name, proc_lustre_root);
 174 #endif
 175         OBD_FREE(type, sizeof(*type));
 176 }
 177
 178 static struct kobj_type class_ktype = {
 179         .sysfs_ops      = &lustre_sysfs_ops,
 180         .release        = class_sysfs_release,
 181 };
 182
 183 #ifdef HAVE_SERVER_SUPPORT
 184 struct obd_type *class_add_symlinks(const char *name, bool enable_proc)
 185 {
 186         struct dentry *symlink;
 187         struct obd_type *type;
 188         int rc;
 189
 190         type = class_search_type(name);
 191         if (type) {
 192                 kobject_put(&type->typ_kobj);
 193                 return ERR_PTR(-EEXIST);
 194         }
 195
 196         OBD_ALLOC(type, sizeof(*type));
 197         if (!type)
 198                 return ERR_PTR(-ENOMEM);
 199
 200         type->typ_kobj.kset = lustre_kset;
 201         rc = kobject_init_and_add(&type->typ_kobj, &class_ktype,
 202                                   &lustre_kset->kobj, "%s", name);
 203         if (rc)
 204                 return ERR_PTR(rc);
 205
 206         symlink = debugfs_create_dir(name, debugfs_lustre_root);
 207         type->typ_debugfs_entry = symlink;
 208         type->typ_sym_filter = true;
 209
 210         if (enable_proc) {
 211                 type->typ_procroot = lprocfs_register(name, proc_lustre_root,
 212                                                       NULL, NULL);
 213                 if (IS_ERR(type->typ_procroot)) {
 214                         CERROR("%s: can't create compat proc entry: %d\n",
 215                                name, (int)PTR_ERR(type->typ_procroot));
 216                         type->typ_procroot = NULL;
 217                 }
 218         }
 219
 220         return type;
 221 }
 222 EXPORT_SYMBOL(class_add_symlinks);
 223 #endif /* HAVE_SERVER_SUPPORT */
 224
 225 #define CLASS_MAX_NAME 1024
 226
 227 int class_register_type(const struct obd_ops *dt_ops,
 228                         const struct md_ops *md_ops,
 229                         bool enable_proc, struct lprocfs_vars *vars,
 230                         const char *name, struct lu_device_type *ldt)
 231 {
 232         struct obd_type *type;
 233         int rc;
 234
 235         ENTRY;
 236         /* sanity check */
 237         LASSERT(strnlen(name, CLASS_MAX_NAME) < CLASS_MAX_NAME);
 238
 239         type = class_search_type(name);
 240         if (type) {
 241 #ifdef HAVE_SERVER_SUPPORT
 242                 if (type->typ_sym_filter)
 243                         goto dir_exist;
 244 #endif /* HAVE_SERVER_SUPPORT */
 245                 kobject_put(&type->typ_kobj);
 246                 CDEBUG(D_IOCTL, "Type %s already registered\n", name);
 247                 RETURN(-EEXIST);
 248         }
 249
 250         OBD_ALLOC(type, sizeof(*type));
 251         if (type == NULL)
 252                 RETURN(-ENOMEM);
 253
 254         type->typ_lu = ldt ? OBD_LU_TYPE_SETUP : NULL;
 255         type->typ_kobj.kset = lustre_kset;
 256         kobject_init(&type->typ_kobj, &class_ktype);
 257 #ifdef HAVE_SERVER_SUPPORT
 258 dir_exist:
 259 #endif /* HAVE_SERVER_SUPPORT */
 260
 261         type->typ_dt_ops = dt_ops;
 262         type->typ_md_ops = md_ops;
 263
 264 #ifdef HAVE_SERVER_SUPPORT
 265         if (type->typ_sym_filter) {
 266                 type->typ_sym_filter = false;
 267                 kobject_put(&type->typ_kobj);
 268                 goto setup_ldt;
 269         }
 270 #endif
 271 #ifdef CONFIG_PROC_FS
 272         if (enable_proc && !type->typ_procroot) {
 273                 type->typ_procroot = lprocfs_register(name,
 274                                                       proc_lustre_root,
 275                                                       NULL, type);
 276                 if (IS_ERR(type->typ_procroot)) {
 277                         rc = PTR_ERR(type->typ_procroot);
 278                         type->typ_procroot = NULL;
 279                         GOTO(failed, rc);
 280                 }
 281         }
 282 #endif
 283         type->typ_debugfs_entry = debugfs_create_dir(name, debugfs_lustre_root);
 284         ldebugfs_add_vars(type->typ_debugfs_entry, vars, type);
 285
 286         rc = kobject_add(&type->typ_kobj, &lustre_kset->kobj, "%s", name);
 287         if (rc)
 288                 GOTO(failed, rc);
 289 #ifdef HAVE_SERVER_SUPPORT
 290 setup_ldt:
 291 #endif
 292         if (ldt) {
 293                 rc = lu_device_type_init(ldt);
 294                 smp_store_release(&type->typ_lu, rc ? NULL : ldt);
 295                 wake_up_var(&type->typ_lu);
 296                 if (rc)
 297                         GOTO(failed, rc);
 298         }
 299
 300         RETURN(0);
 301
 302 failed:
 303         kobject_put(&type->typ_kobj);
 304
 305         RETURN(rc);
 306 }
 307 EXPORT_SYMBOL(class_register_type);
 308
 309 int class_unregister_type(const char *name)
 310 {
 311         struct obd_type *type = class_search_type(name);
 312         int rc = 0;
 313         ENTRY;
 314
 315         if (!type) {
 316                 CERROR("unknown obd type\n");
 317                 RETURN(-EINVAL);
 318         }
 319
 320         if (atomic_read(&type->typ_refcnt)) {
 321                 CERROR("type %s has refcount (%d)\n", name,
 322                        atomic_read(&type->typ_refcnt));
 323                 /* This is a bad situation, let's make the best of it */
 324                 /* Remove ops, but leave the name for debugging */
 325                 type->typ_dt_ops = NULL;
 326                 type->typ_md_ops = NULL;
 327                 GOTO(out_put, rc = -EBUSY);
 328         }
 329
 330         /* Put the final ref */
 331         kobject_put(&type->typ_kobj);
 332 out_put:
 333         /* Put the ref returned by class_search_type() */
 334         kobject_put(&type->typ_kobj);
 335
 336         RETURN(rc);
 337 } /* class_unregister_type */
 338 EXPORT_SYMBOL(class_unregister_type);
 339
 340 /**
 341  * Create a new obd device.
 342  *
 343  * Allocate the new obd_device and initialize it.
 344  *
 345  * \param[in] type_name obd device type string.
 346  * \param[in] name      obd device name.
 347  * \param[in] uuid      obd device UUID
 348  *
 349  * \retval newdev         pointer to created obd_device
 350  * \retval ERR_PTR(errno) on error
 351  */
 352 struct obd_device *class_newdev(const char *type_name, const char *name,
 353                                 const char *uuid)
 354 {
 355         struct obd_device *newdev;
 356         struct obd_type *type = NULL;
 357         ENTRY;
 358
 359         if (strlen(name) >= MAX_OBD_NAME) {
 360                 CERROR("name/uuid must be < %u bytes long\n", MAX_OBD_NAME);
 361                 RETURN(ERR_PTR(-EINVAL));
 362         }
 363
 364         type = class_get_type(type_name);
 365         if (type == NULL){
 366                 CERROR("OBD: unknown type: %s\n", type_name);
 367                 RETURN(ERR_PTR(-ENODEV));
 368         }
 369
 370         newdev = obd_device_alloc();
 371         if (newdev == NULL) {
 372                 class_put_type(type);
 373                 RETURN(ERR_PTR(-ENOMEM));
 374         }
 375         LASSERT(newdev->obd_magic == OBD_DEVICE_MAGIC);
 376         strncpy(newdev->obd_name, name, sizeof(newdev->obd_name) - 1);
 377         newdev->obd_type = type;
 378         newdev->obd_minor = -1;
 379
 380         rwlock_init(&newdev->obd_pool_lock);
 381         newdev->obd_pool_limit = 0;
 382         newdev->obd_pool_slv = 0;
 383
 384         INIT_LIST_HEAD(&newdev->obd_exports);
 385         INIT_LIST_HEAD(&newdev->obd_unlinked_exports);
 386         INIT_LIST_HEAD(&newdev->obd_delayed_exports);
 387         INIT_LIST_HEAD(&newdev->obd_exports_timed);
 388         INIT_LIST_HEAD(&newdev->obd_nid_stats);
 389         spin_lock_init(&newdev->obd_nid_lock);
 390         spin_lock_init(&newdev->obd_dev_lock);
 391         mutex_init(&newdev->obd_dev_mutex);
 392         spin_lock_init(&newdev->obd_osfs_lock);
 393         /* newdev->obd_osfs_age must be set to a value in the distant
 394          * past to guarantee a fresh statfs is fetched on mount. */
 395         newdev->obd_osfs_age = ktime_get_seconds() - 1000;
 396
 397         /* XXX belongs in setup not attach  */
 398         init_rwsem(&newdev->obd_observer_link_sem);
 399         /* recovery data */
 400         spin_lock_init(&newdev->obd_recovery_task_lock);
 401         init_waitqueue_head(&newdev->obd_next_transno_waitq);
 402         init_waitqueue_head(&newdev->obd_evict_inprogress_waitq);
 403         INIT_LIST_HEAD(&newdev->obd_req_replay_queue);
 404         INIT_LIST_HEAD(&newdev->obd_lock_replay_queue);
 405         INIT_LIST_HEAD(&newdev->obd_final_req_queue);
 406         INIT_LIST_HEAD(&newdev->obd_evict_list);
 407         INIT_LIST_HEAD(&newdev->obd_lwp_list);
 408
 409         llog_group_init(&newdev->obd_olg);
 410         /* Detach drops this */
 411         atomic_set(&newdev->obd_refcount, 1);
 412         lu_ref_init(&newdev->obd_reference);
 413         lu_ref_add(&newdev->obd_reference, "newdev", newdev);
 414
 415         newdev->obd_conn_inprogress = 0;
 416
 417         strncpy(newdev->obd_uuid.uuid, uuid, UUID_MAX);
 418
 419         CDEBUG(D_IOCTL, "Allocate new device %s (%p)\n",
 420                newdev->obd_name, newdev);
 421
 422         return newdev;
 423 }
 424
 425 /**
 426  * Free obd device.
 427  *
 428  * \param[in] obd obd_device to be freed
 429  *
 430  * \retval none
 431  */
 432 void class_free_dev(struct obd_device *obd)
 433 {
 434         struct obd_type *obd_type = obd->obd_type;
 435
 436         LASSERTF(obd->obd_magic == OBD_DEVICE_MAGIC, "%p obd_magic %08x "
 437                  "!= %08x\n", obd, obd->obd_magic, OBD_DEVICE_MAGIC);
 438         LASSERTF(obd->obd_minor == -1 || obd_devs[obd->obd_minor] == obd,
 439                  "obd %p != obd_devs[%d] %p\n",
 440                  obd, obd->obd_minor, obd_devs[obd->obd_minor]);
 441         LASSERTF(atomic_read(&obd->obd_refcount) == 0,
 442                  "obd_refcount should be 0, not %d\n",
 443                  atomic_read(&obd->obd_refcount));
 444         LASSERT(obd_type != NULL);
 445
 446         CDEBUG(D_INFO, "Release obd device %s obd_type name = %s\n",
 447                obd->obd_name, obd->obd_type->typ_name);
 448
 449         CDEBUG(D_CONFIG, "finishing cleanup of obd %s (%s)\n",
 450                          obd->obd_name, obd->obd_uuid.uuid);
 451         if (obd->obd_stopping) {
 452                 int err;
 453
 454                 /* If we're not stopping, we were never set up */
 455                 err = obd_cleanup(obd);
 456                 if (err)
 457                         CERROR("Cleanup %s returned %d\n",
 458                                 obd->obd_name, err);
 459         }
 460
 461         obd_device_free(obd);
 462
 463         class_put_type(obd_type);
 464 }
 465
 466 /**
 467  * Unregister obd device.
 468  *
 469  * Free slot in obd_dev[] used by \a obd.
 470  *
 471  * \param[in] new_obd obd_device to be unregistered
 472  *
 473  * \retval none
 474  */
 475 void class_unregister_device(struct obd_device *obd)
 476 {
 477         write_lock(&obd_dev_lock);
 478         if (obd->obd_minor >= 0) {
 479                 LASSERT(obd_devs[obd->obd_minor] == obd);
 480                 obd_devs[obd->obd_minor] = NULL;
 481                 obd->obd_minor = -1;
 482         }
 483         write_unlock(&obd_dev_lock);
 484 }
 485
 486 /**
 487  * Register obd device.
 488  *
 489  * Find free slot in obd_devs[], fills it with \a new_obd.
 490  *
 491  * \param[in] new_obd obd_device to be registered
 492  *
 493  * \retval 0          success
 494  * \retval -EEXIST    device with this name is registered
 495  * \retval -EOVERFLOW obd_devs[] is full
 496  */
 497 int class_register_device(struct obd_device *new_obd)
 498 {
 499         int ret = 0;
 500         int i;
 501         int new_obd_minor = 0;
 502         bool minor_assign = false;
 503         bool retried = false;
 504
 505 again:
 506         write_lock(&obd_dev_lock);
 507         for (i = 0; i < class_devno_max(); i++) {
 508                 struct obd_device *obd = class_num2obd(i);
 509
 510                 if (obd != NULL &&
 511                     (strcmp(new_obd->obd_name, obd->obd_name) == 0)) {
 512
 513                         if (!retried) {
 514                                 write_unlock(&obd_dev_lock);
 515
 516                                 /* the obd_device could be waited to be
 517                                  * destroyed by the "obd_zombie_impexp_thread".
 518                                  */
 519                                 obd_zombie_barrier();
 520                                 retried = true;
 521                                 goto again;
 522                         }
 523
 524                         CERROR("%s: already exists, won't add\n",
 525                                obd->obd_name);
 526                         /* in case we found a free slot before duplicate */
 527                         minor_assign = false;
 528                         ret = -EEXIST;
 529                         break;
 530                 }
 531                 if (!minor_assign && obd == NULL) {
 532                         new_obd_minor = i;
 533                         minor_assign = true;
 534                 }
 535         }
 536
 537         if (minor_assign) {
 538                 new_obd->obd_minor = new_obd_minor;
 539                 LASSERTF(obd_devs[new_obd_minor] == NULL, "obd_devs[%d] "
 540                          "%p\n", new_obd_minor, obd_devs[new_obd_minor]);
 541                 obd_devs[new_obd_minor] = new_obd;
 542         } else {
 543                 if (ret == 0) {
 544                         ret = -EOVERFLOW;
 545                         CERROR("%s: all %u/%u devices used, increase "
 546                                "MAX_OBD_DEVICES: rc = %d\n", new_obd->obd_name,
 547                                i, class_devno_max(), ret);
 548                 }
 549         }
 550         write_unlock(&obd_dev_lock);
 551
 552         RETURN(ret);
 553 }
 554
 555 static int class_name2dev_nolock(const char *name)
 556 {
 557         int i;
 558
 559         if (!name)
 560                 return -1;
 561
 562         for (i = 0; i < class_devno_max(); i++) {
 563                 struct obd_device *obd = class_num2obd(i);
 564
 565                 if (obd && strcmp(name, obd->obd_name) == 0) {
 566                         /* Make sure we finished attaching before we give
 567                            out any references */
 568                         LASSERT(obd->obd_magic == OBD_DEVICE_MAGIC);
 569                         if (obd->obd_attached) {
 570                                 return i;
 571                         }
 572                         break;
 573                 }
 574         }
 575
 576         return -1;
 577 }
 578
 579 int class_name2dev(const char *name)
 580 {
 581         int i;
 582
 583         if (!name)
 584                 return -1;
 585
 586         read_lock(&obd_dev_lock);
 587         i = class_name2dev_nolock(name);
 588         read_unlock(&obd_dev_lock);
 589
 590         return i;
 591 }
 592 EXPORT_SYMBOL(class_name2dev);
 593
 594 struct obd_device *class_name2obd(const char *name)
 595 {
 596         int dev = class_name2dev(name);
 597
 598         if (dev < 0 || dev > class_devno_max())
 599                 return NULL;
 600         return class_num2obd(dev);
 601 }
 602 EXPORT_SYMBOL(class_name2obd);
 603
 604 int class_uuid2dev_nolock(struct obd_uuid *uuid)
 605 {
 606         int i;
 607
 608         for (i = 0; i < class_devno_max(); i++) {
 609                 struct obd_device *obd = class_num2obd(i);
 610
 611                 if (obd && obd_uuid_equals(uuid, &obd->obd_uuid)) {
 612                         LASSERT(obd->obd_magic == OBD_DEVICE_MAGIC);
 613                         return i;
 614                 }
 615         }
 616
 617         return -1;
 618 }
 619
 620 int class_uuid2dev(struct obd_uuid *uuid)
 621 {
 622         int i;
 623
 624         read_lock(&obd_dev_lock);
 625         i = class_uuid2dev_nolock(uuid);
 626         read_unlock(&obd_dev_lock);
 627
 628         return i;
 629 }
 630 EXPORT_SYMBOL(class_uuid2dev);
 631
 632 struct obd_device *class_uuid2obd(struct obd_uuid *uuid)
 633 {
 634         int dev = class_uuid2dev(uuid);
 635         if (dev < 0)
 636                 return NULL;
 637         return class_num2obd(dev);
 638 }
 639 EXPORT_SYMBOL(class_uuid2obd);
 640
 641 /**
 642  * Get obd device from ::obd_devs[]
 643  *
 644  * \param num [in] array index
 645  *
 646  * \retval NULL if ::obd_devs[\a num] does not contains an obd device
 647  *         otherwise return the obd device there.
 648  */
 649 struct obd_device *class_num2obd(int num)
 650 {
 651         struct obd_device *obd = NULL;
 652
 653         if (num < class_devno_max()) {
 654                 obd = obd_devs[num];
 655                 if (obd == NULL)
 656                         return NULL;
 657
 658                 LASSERTF(obd->obd_magic == OBD_DEVICE_MAGIC,
 659                          "%p obd_magic %08x != %08x\n",
 660                          obd, obd->obd_magic, OBD_DEVICE_MAGIC);
 661                 LASSERTF(obd->obd_minor == num,
 662                          "%p obd_minor %0d != %0d\n",
 663                          obd, obd->obd_minor, num);
 664         }
 665
 666         return obd;
 667 }
 668
 669 /**
 670  * Find obd in obd_dev[] by name or uuid.
 671  *
 672  * Increment obd's refcount if found.
 673  *
 674  * \param[in] str obd name or uuid
 675  *
 676  * \retval NULL    if not found
 677  * \retval target  pointer to found obd_device
 678  */
 679 struct obd_device *class_dev_by_str(const char *str)
 680 {
 681         struct obd_device *target = NULL;
 682         struct obd_uuid tgtuuid;
 683         int rc;
 684
 685         obd_str2uuid(&tgtuuid, str);
 686
 687         read_lock(&obd_dev_lock);
 688         rc = class_uuid2dev_nolock(&tgtuuid);
 689         if (rc < 0)
 690                 rc = class_name2dev_nolock(str);
 691
 692         if (rc >= 0)
 693                 target = class_num2obd(rc);
 694
 695         if (target != NULL)
 696                 class_incref(target, "find", current);
 697         read_unlock(&obd_dev_lock);
 698
 699         RETURN(target);
 700 }
 701 EXPORT_SYMBOL(class_dev_by_str);
 702
 703 /**
 704  * Get obd devices count. Device in any
 705  *    state are counted
 706  * \retval obd device count
 707  */
 708 int get_devices_count(void)
 709 {
 710         int index, max_index = class_devno_max(), dev_count = 0;
 711
 712         read_lock(&obd_dev_lock);
 713         for (index = 0; index <= max_index; index++) {
 714                 struct obd_device *obd = class_num2obd(index);
 715                 if (obd != NULL)
 716                         dev_count++;
 717         }
 718         read_unlock(&obd_dev_lock);
 719
 720         return dev_count;
 721 }
 722 EXPORT_SYMBOL(get_devices_count);
 723
 724 void class_obd_list(void)
 725 {
 726         char *status;
 727         int i;
 728
 729         read_lock(&obd_dev_lock);
 730         for (i = 0; i < class_devno_max(); i++) {
 731                 struct obd_device *obd = class_num2obd(i);
 732
 733                 if (obd == NULL)
 734                         continue;
 735                 if (obd->obd_stopping)
 736                         status = "ST";
 737                 else if (obd->obd_set_up)
 738                         status = "UP";
 739                 else if (obd->obd_attached)
 740                         status = "AT";
 741                 else
 742                         status = "--";
 743                 LCONSOLE(D_CONFIG, "%3d %s %s %s %s %d\n",
 744                          i, status, obd->obd_type->typ_name,
 745                          obd->obd_name, obd->obd_uuid.uuid,
 746                          atomic_read(&obd->obd_refcount));
 747         }
 748         read_unlock(&obd_dev_lock);
 749 }
 750
 751 /* Search for a client OBD connected to tgt_uuid.  If grp_uuid is
 752  * specified, then only the client with that uuid is returned,
 753  * otherwise any client connected to the tgt is returned.
 754  */
 755 struct obd_device *class_find_client_obd(struct obd_uuid *tgt_uuid,
 756                                          const char *type_name,
 757                                          struct obd_uuid *grp_uuid)
 758 {
 759         int i;
 760
 761         read_lock(&obd_dev_lock);
 762         for (i = 0; i < class_devno_max(); i++) {
 763                 struct obd_device *obd = class_num2obd(i);
 764
 765                 if (obd == NULL)
 766                         continue;
 767                 if ((strncmp(obd->obd_type->typ_name, type_name,
 768                              strlen(type_name)) == 0)) {
 769                         if (obd_uuid_equals(tgt_uuid,
 770                                             &obd->u.cli.cl_target_uuid) &&
 771                             ((grp_uuid)? obd_uuid_equals(grp_uuid,
 772                                                          &obd->obd_uuid) : 1)) {
 773                                 read_unlock(&obd_dev_lock);
 774                                 return obd;
 775                         }
 776                 }
 777         }
 778         read_unlock(&obd_dev_lock);
 779
 780         return NULL;
 781 }
 782 EXPORT_SYMBOL(class_find_client_obd);
 783
 784 /* Iterate the obd_device list looking devices have grp_uuid. Start
 785  * searching at *next, and if a device is found, the next index to look
 786  * at is saved in *next. If next is NULL, then the first matching device
 787  * will always be returned.
 788  */
 789 struct obd_device *class_devices_in_group(struct obd_uuid *grp_uuid, int *next)
 790 {
 791         int i;
 792
 793         if (next == NULL)
 794                 i = 0;
 795         else if (*next >= 0 && *next < class_devno_max())
 796                 i = *next;
 797         else
 798                 return NULL;
 799
 800         read_lock(&obd_dev_lock);
 801         for (; i < class_devno_max(); i++) {
 802                 struct obd_device *obd = class_num2obd(i);
 803
 804                 if (obd == NULL)
 805                         continue;
 806                 if (obd_uuid_equals(grp_uuid, &obd->obd_uuid)) {
 807                         if (next != NULL)
 808                                 *next = i+1;
 809                         read_unlock(&obd_dev_lock);
 810                         return obd;
 811                 }
 812         }
 813         read_unlock(&obd_dev_lock);
 814
 815         return NULL;
 816 }
 817 EXPORT_SYMBOL(class_devices_in_group);
 818
 819 /**
 820  * to notify sptlrpc log for \a fsname has changed, let every relevant OBD
 821  * adjust sptlrpc settings accordingly.
 822  */
 823 int class_notify_sptlrpc_conf(const char *fsname, int namelen)
 824 {
 825         struct obd_device  *obd;
 826         const char         *type;
 827         int                 i, rc = 0, rc2;
 828
 829         LASSERT(namelen > 0);
 830
 831         read_lock(&obd_dev_lock);
 832         for (i = 0; i < class_devno_max(); i++) {
 833                 obd = class_num2obd(i);
 834
 835                 if (obd == NULL || obd->obd_set_up == 0 || obd->obd_stopping)
 836                         continue;
 837
 838                 /* only notify mdc, osc, osp, lwp, mdt, ost
 839                  * because only these have a -sptlrpc llog */
 840                 type = obd->obd_type->typ_name;
 841                 if (strcmp(type, LUSTRE_MDC_NAME) != 0 &&
 842                     strcmp(type, LUSTRE_OSC_NAME) != 0 &&
 843                     strcmp(type, LUSTRE_OSP_NAME) != 0 &&
 844                     strcmp(type, LUSTRE_LWP_NAME) != 0 &&
 845                     strcmp(type, LUSTRE_MDT_NAME) != 0 &&
 846                     strcmp(type, LUSTRE_OST_NAME) != 0)
 847                         continue;
 848
 849                 if (strncmp(obd->obd_name, fsname, namelen))
 850                         continue;
 851
 852                 class_incref(obd, __FUNCTION__, obd);
 853                 read_unlock(&obd_dev_lock);
 854                 rc2 = obd_set_info_async(NULL, obd->obd_self_export,
 855                                          sizeof(KEY_SPTLRPC_CONF),
 856                                          KEY_SPTLRPC_CONF, 0, NULL, NULL);
 857                 rc = rc ? rc : rc2;
 858                 class_decref(obd, __FUNCTION__, obd);
 859                 read_lock(&obd_dev_lock);
 860         }
 861         read_unlock(&obd_dev_lock);
 862         return rc;
 863 }
 864 EXPORT_SYMBOL(class_notify_sptlrpc_conf);
 865
 866 void obd_cleanup_caches(void)
 867 {
 868         ENTRY;
 869         if (obd_device_cachep) {
 870                 kmem_cache_destroy(obd_device_cachep);
 871                 obd_device_cachep = NULL;
 872         }
 873
 874         EXIT;
 875 }
 876
 877 int obd_init_caches(void)
 878 {
 879         int rc;
 880         ENTRY;
 881
 882         LASSERT(obd_device_cachep == NULL);
 883         obd_device_cachep = kmem_cache_create_usercopy("ll_obd_dev_cache",
 884                                 sizeof(struct obd_device),
 885                                 0, 0, 0, sizeof(struct obd_device), NULL);
 886         if (!obd_device_cachep)
 887                 GOTO(out, rc = -ENOMEM);
 888
 889         RETURN(0);
 890 out:
 891         obd_cleanup_caches();
 892         RETURN(rc);
 893 }
 894
 895 static const char export_handle_owner[] = "export";
 896
 897 /* map connection to client */
 898 struct obd_export *class_conn2export(struct lustre_handle *conn)
 899 {
 900         struct obd_export *export;
 901         ENTRY;
 902
 903         if (!conn) {
 904                 CDEBUG(D_CACHE, "looking for null handle\n");
 905                 RETURN(NULL);
 906         }
 907
 908         if (conn->cookie == -1) {  /* this means assign a new connection */
 909                 CDEBUG(D_CACHE, "want a new connection\n");
 910                 RETURN(NULL);
 911         }
 912
 913         CDEBUG(D_INFO, "looking for export cookie %#llx\n", conn->cookie);
 914         export = class_handle2object(conn->cookie, export_handle_owner);
 915         RETURN(export);
 916 }
 917 EXPORT_SYMBOL(class_conn2export);
 918
 919 struct obd_device *class_exp2obd(struct obd_export *exp)
 920 {
 921         if (exp)
 922                 return exp->exp_obd;
 923         return NULL;
 924 }
 925 EXPORT_SYMBOL(class_exp2obd);
 926
 927 struct obd_import *class_exp2cliimp(struct obd_export *exp)
 928 {
 929         struct obd_device *obd = exp->exp_obd;
 930         if (obd == NULL)
 931                 return NULL;
 932         return obd->u.cli.cl_import;
 933 }
 934 EXPORT_SYMBOL(class_exp2cliimp);
 935
 936 /* Export management functions */
 937 static void class_export_destroy(struct obd_export *exp)
 938 {
 939         struct obd_device *obd = exp->exp_obd;
 940         ENTRY;
 941
 942         LASSERT(refcount_read(&exp->exp_handle.h_ref) == 0);
 943         LASSERT(obd != NULL);
 944
 945         CDEBUG(D_IOCTL, "destroying export %p/%s for %s\n", exp,
 946                exp->exp_client_uuid.uuid, obd->obd_name);
 947
 948         /* "Local" exports (lctl, LOV->{mdc,osc}) have no connection. */
 949         if (exp->exp_connection)
 950                 ptlrpc_put_connection_superhack(exp->exp_connection);
 951
 952         LASSERT(list_empty(&exp->exp_outstanding_replies));
 953         LASSERT(list_empty(&exp->exp_uncommitted_replies));
 954         LASSERT(list_empty(&exp->exp_req_replay_queue));
 955         LASSERT(list_empty(&exp->exp_hp_rpcs));
 956         obd_destroy_export(exp);
 957         /* self export doesn't hold a reference to an obd, although it
 958          * exists until freeing of the obd */
 959         if (exp != obd->obd_self_export)
 960                 class_decref(obd, "export", exp);
 961
 962         OBD_FREE_PRE(exp, sizeof(*exp), "rcu");
 963         kfree_rcu(exp, exp_handle.h_rcu);
 964         EXIT;
 965 }
 966
 967 struct obd_export *class_export_get(struct obd_export *exp)
 968 {
 969         refcount_inc(&exp->exp_handle.h_ref);
 970         CDEBUG(D_INFO, "GET export %p refcount=%d\n", exp,
 971                refcount_read(&exp->exp_handle.h_ref));
 972         return exp;
 973 }
 974 EXPORT_SYMBOL(class_export_get);
 975
 976 void class_export_put(struct obd_export *exp)
 977 {
 978         LASSERT(exp != NULL);
 979         LASSERT(refcount_read(&exp->exp_handle.h_ref) >  0);
 980         LASSERT(refcount_read(&exp->exp_handle.h_ref) < LI_POISON);
 981         CDEBUG(D_INFO, "PUTting export %p : new refcount %d\n", exp,
 982                refcount_read(&exp->exp_handle.h_ref) - 1);
 983
 984         if (refcount_dec_and_test(&exp->exp_handle.h_ref)) {
 985                 struct obd_device *obd = exp->exp_obd;
 986
 987                 CDEBUG(D_IOCTL, "final put %p/%s\n",
 988                        exp, exp->exp_client_uuid.uuid);
 989
 990                 /* release nid stat refererence */
 991                 lprocfs_exp_cleanup(exp);
 992
 993                 if (exp == obd->obd_self_export) {
 994                         /* self export should be destroyed without
 995                          * zombie thread as it doesn't hold a
 996                          * reference to obd and doesn't hold any
 997                          * resources */
 998                         class_export_destroy(exp);
 999                         /* self export is destroyed, no class
1000                          * references exist and it is safe to free
1001                          * obd */
1002                         class_free_dev(obd);
1003                 } else {
1004                         LASSERT(!list_empty(&exp->exp_obd_chain));
1005                         obd_zombie_export_add(exp);
1006                 }
1007
1008         }
1009 }
1010 EXPORT_SYMBOL(class_export_put);
1011
1012 static void obd_zombie_exp_cull(struct work_struct *ws)
1013 {
1014         struct obd_export *export;
1015
1016         export = container_of(ws, struct obd_export, exp_zombie_work);
1017         class_export_destroy(export);
1018 }
1019
1020 /* Creates a new export, adds it to the hash table, and returns a
1021  * pointer to it. The refcount is 2: one for the hash reference, and
1022  * one for the pointer returned by this function. */
1023 struct obd_export *__class_new_export(struct obd_device *obd,
1024                                       struct obd_uuid *cluuid, bool is_self)
1025 {
1026         struct obd_export *export;
1027         int rc = 0;
1028         ENTRY;
1029
1030         OBD_ALLOC_PTR(export);
1031         if (!export)
1032                 return ERR_PTR(-ENOMEM);
1033
1034         export->exp_conn_cnt = 0;
1035         export->exp_lock_hash = NULL;
1036         export->exp_flock_hash = NULL;
1037         /* 2 = class_handle_hash + last */
1038         refcount_set(&export->exp_handle.h_ref, 2);
1039         atomic_set(&export->exp_rpc_count, 0);
1040         atomic_set(&export->exp_cb_count, 0);
1041         atomic_set(&export->exp_locks_count, 0);
1042 #if LUSTRE_TRACKS_LOCK_EXP_REFS
1043         INIT_LIST_HEAD(&export->exp_locks_list);
1044         spin_lock_init(&export->exp_locks_list_guard);
1045 #endif
1046         atomic_set(&export->exp_replay_count, 0);
1047         export->exp_obd = obd;
1048         INIT_LIST_HEAD(&export->exp_outstanding_replies);
1049         spin_lock_init(&export->exp_uncommitted_replies_lock);
1050         INIT_LIST_HEAD(&export->exp_uncommitted_replies);
1051         INIT_LIST_HEAD(&export->exp_req_replay_queue);
1052         INIT_HLIST_NODE(&export->exp_handle.h_link);
1053         INIT_LIST_HEAD(&export->exp_hp_rpcs);
1054         INIT_LIST_HEAD(&export->exp_reg_rpcs);
1055         class_handle_hash(&export->exp_handle, export_handle_owner);
1056         export->exp_last_request_time = ktime_get_real_seconds();
1057         spin_lock_init(&export->exp_lock);
1058         spin_lock_init(&export->exp_rpc_lock);
1059         INIT_HLIST_NODE(&export->exp_nid_hash);
1060         INIT_HLIST_NODE(&export->exp_gen_hash);
1061         spin_lock_init(&export->exp_bl_list_lock);
1062         INIT_LIST_HEAD(&export->exp_bl_list);
1063         INIT_LIST_HEAD(&export->exp_stale_list);
1064         INIT_WORK(&export->exp_zombie_work, obd_zombie_exp_cull);
1065
1066         export->exp_sp_peer = LUSTRE_SP_ANY;
1067         export->exp_flvr.sf_rpc = SPTLRPC_FLVR_INVALID;
1068         export->exp_client_uuid = *cluuid;
1069         obd_init_export(export);
1070
1071         at_init(&export->exp_bl_lock_at, obd_timeout, 0);
1072
1073         spin_lock(&obd->obd_dev_lock);
1074         if (!obd_uuid_equals(cluuid, &obd->obd_uuid)) {
1075                 /* shouldn't happen, but might race */
1076                 if (obd->obd_stopping)
1077                         GOTO(exit_unlock, rc = -ENODEV);
1078
1079                 rc = obd_uuid_add(obd, export);
1080                 if (rc != 0) {
1081                         LCONSOLE_WARN("%s: denying duplicate export for %s: rc = %d\n",
1082                                       obd->obd_name, cluuid->uuid, rc);
1083                         GOTO(exit_unlock, rc = -EALREADY);
1084                 }
1085         }
1086
1087         if (!is_self) {
1088                 class_incref(obd, "export", export);
1089                 list_add_tail(&export->exp_obd_chain_timed,
1090                               &obd->obd_exports_timed);
1091                 list_add(&export->exp_obd_chain, &obd->obd_exports);
1092                 obd->obd_num_exports++;
1093         } else {
1094                 INIT_LIST_HEAD(&export->exp_obd_chain_timed);
1095                 INIT_LIST_HEAD(&export->exp_obd_chain);
1096         }
1097         spin_unlock(&obd->obd_dev_lock);
1098         RETURN(export);
1099
1100 exit_unlock:
1101         spin_unlock(&obd->obd_dev_lock);
1102         class_handle_unhash(&export->exp_handle);
1103         obd_destroy_export(export);
1104         OBD_FREE_PTR(export);
1105         return ERR_PTR(rc);
1106 }
1107
1108 struct obd_export *class_new_export(struct obd_device *obd,
1109                                     struct obd_uuid *uuid)
1110 {
1111         return __class_new_export(obd, uuid, false);
1112 }
1113 EXPORT_SYMBOL(class_new_export);
1114
1115 struct obd_export *class_new_export_self(struct obd_device *obd,
1116                                          struct obd_uuid *uuid)
1117 {
1118         return __class_new_export(obd, uuid, true);
1119 }
1120
1121 void class_unlink_export(struct obd_export *exp)
1122 {
1123         class_handle_unhash(&exp->exp_handle);
1124
1125         if (exp->exp_obd->obd_self_export == exp) {
1126                 class_export_put(exp);
1127                 return;
1128         }
1129
1130         spin_lock(&exp->exp_obd->obd_dev_lock);
1131         /* delete an uuid-export hashitem from hashtables */
1132         if (exp != exp->exp_obd->obd_self_export)
1133                 obd_uuid_del(exp->exp_obd, exp);
1134
1135 #ifdef HAVE_SERVER_SUPPORT
1136         if (!hlist_unhashed(&exp->exp_gen_hash)) {
1137                 struct tg_export_data   *ted = &exp->exp_target_data;
1138                 struct cfs_hash         *hash;
1139
1140                 /* Because obd_gen_hash will not be released until
1141                  * class_cleanup(), so hash should never be NULL here */
1142                 hash = cfs_hash_getref(exp->exp_obd->obd_gen_hash);
1143                 LASSERT(hash != NULL);
1144                 cfs_hash_del(hash, &ted->ted_lcd->lcd_generation,
1145                              &exp->exp_gen_hash);
1146                 cfs_hash_putref(hash);
1147         }
1148 #endif /* HAVE_SERVER_SUPPORT */
1149
1150         list_move(&exp->exp_obd_chain, &exp->exp_obd->obd_unlinked_exports);
1151         list_del_init(&exp->exp_obd_chain_timed);
1152         exp->exp_obd->obd_num_exports--;
1153         spin_unlock(&exp->exp_obd->obd_dev_lock);
1154         atomic_inc(&obd_stale_export_num);
1155
1156         /* A reference is kept by obd_stale_exports list */
1157         obd_stale_export_put(exp);
1158 }
1159 EXPORT_SYMBOL(class_unlink_export);
1160
1161 /* Import management functions */
1162 static void obd_zombie_import_free(struct obd_import *imp)
1163 {
1164         ENTRY;
1165
1166         CDEBUG(D_IOCTL, "destroying import %p for %s\n", imp,
1167                 imp->imp_obd->obd_name);
1168
1169         LASSERT(refcount_read(&imp->imp_refcount) == 0);
1170
1171         ptlrpc_put_connection_superhack(imp->imp_connection);
1172
1173         while (!list_empty(&imp->imp_conn_list)) {
1174                 struct obd_import_conn *imp_conn;
1175
1176                 imp_conn = list_first_entry(&imp->imp_conn_list,
1177                                             struct obd_import_conn, oic_item);
1178                 list_del_init(&imp_conn->oic_item);
1179                 ptlrpc_put_connection_superhack(imp_conn->oic_conn);
1180                 OBD_FREE(imp_conn, sizeof(*imp_conn));
1181         }
1182
1183         LASSERT(imp->imp_sec == NULL);
1184         LASSERTF(atomic_read(&imp->imp_reqs) == 0, "%s: imp_reqs = %d\n",
1185                  imp->imp_obd->obd_name, atomic_read(&imp->imp_reqs));
1186         class_decref(imp->imp_obd, "import", imp);
1187         OBD_FREE_PTR(imp);
1188         EXIT;
1189 }
1190
1191 struct obd_import *class_import_get(struct obd_import *import)
1192 {
1193         refcount_inc(&import->imp_refcount);
1194         CDEBUG(D_INFO, "import %p refcount=%d obd=%s\n", import,
1195                refcount_read(&import->imp_refcount),
1196                import->imp_obd->obd_name);
1197         return import;
1198 }
1199 EXPORT_SYMBOL(class_import_get);
1200
1201 void class_import_put(struct obd_import *imp)
1202 {
1203         ENTRY;
1204
1205         LASSERT(refcount_read(&imp->imp_refcount) > 0);
1206
1207         CDEBUG(D_INFO, "import %p refcount=%d obd=%s\n", imp,
1208                refcount_read(&imp->imp_refcount) - 1,
1209                imp->imp_obd->obd_name);
1210
1211         if (refcount_dec_and_test(&imp->imp_refcount)) {
1212                 CDEBUG(D_INFO, "final put import %p\n", imp);
1213                 obd_zombie_import_add(imp);
1214         }
1215
1216         EXIT;
1217 }
1218 EXPORT_SYMBOL(class_import_put);
1219
1220 static void init_imp_at(struct imp_at *at) {
1221         int i;
1222         at_init(&at->iat_net_latency, 0, 0);
1223         for (i = 0; i < IMP_AT_MAX_PORTALS; i++) {
1224                 /* max service estimates are tracked on the server side, so
1225                    don't use the AT history here, just use the last reported
1226                    val. (But keep hist for proc histogram, worst_ever) */
1227                 at_init(&at->iat_service_estimate[i], INITIAL_CONNECT_TIMEOUT,
1228                         AT_FLG_NOHIST);
1229         }
1230 }
1231
1232 static void obd_zombie_imp_cull(struct work_struct *ws)
1233 {
1234         struct obd_import *import;
1235
1236         import = container_of(ws, struct obd_import, imp_zombie_work);
1237         obd_zombie_import_free(import);
1238 }
1239
1240 struct obd_import *class_new_import(struct obd_device *obd)
1241 {
1242         struct obd_import *imp;
1243         struct pid_namespace *curr_pid_ns = ll_task_pid_ns(current);
1244
1245         OBD_ALLOC(imp, sizeof(*imp));
1246         if (imp == NULL)
1247                 return NULL;
1248
1249         INIT_LIST_HEAD(&imp->imp_pinger_chain);
1250         INIT_LIST_HEAD(&imp->imp_replay_list);
1251         INIT_LIST_HEAD(&imp->imp_sending_list);
1252         INIT_LIST_HEAD(&imp->imp_delayed_list);
1253         INIT_LIST_HEAD(&imp->imp_committed_list);
1254         INIT_LIST_HEAD(&imp->imp_unreplied_list);
1255         imp->imp_known_replied_xid = 0;
1256         imp->imp_replay_cursor = &imp->imp_committed_list;
1257         spin_lock_init(&imp->imp_lock);
1258         imp->imp_last_success_conn = 0;
1259         imp->imp_state = LUSTRE_IMP_NEW;
1260         imp->imp_obd = class_incref(obd, "import", imp);
1261         rwlock_init(&imp->imp_sec_lock);
1262         init_waitqueue_head(&imp->imp_recovery_waitq);
1263         INIT_WORK(&imp->imp_zombie_work, obd_zombie_imp_cull);
1264
1265         if (curr_pid_ns && curr_pid_ns->child_reaper)
1266                 imp->imp_sec_refpid = curr_pid_ns->child_reaper->pid;
1267         else
1268                 imp->imp_sec_refpid = 1;
1269
1270         refcount_set(&imp->imp_refcount, 2);
1271         atomic_set(&imp->imp_unregistering, 0);
1272         atomic_set(&imp->imp_reqs, 0);
1273         atomic_set(&imp->imp_inflight, 0);
1274         atomic_set(&imp->imp_replay_inflight, 0);
1275         atomic_set(&imp->imp_inval_count, 0);
1276         INIT_LIST_HEAD(&imp->imp_conn_list);
1277         init_imp_at(&imp->imp_at);
1278
1279         /* the default magic is V2, will be used in connect RPC, and
1280          * then adjusted according to the flags in request/reply. */
1281         imp->imp_msg_magic = LUSTRE_MSG_MAGIC_V2;
1282
1283         return imp;
1284 }
1285 EXPORT_SYMBOL(class_new_import);
1286
1287 void class_destroy_import(struct obd_import *import)
1288 {
1289         LASSERT(import != NULL);
1290         LASSERT(import != LP_POISON);
1291
1292         spin_lock(&import->imp_lock);
1293         import->imp_generation++;
1294         spin_unlock(&import->imp_lock);
1295         class_import_put(import);
1296 }
1297 EXPORT_SYMBOL(class_destroy_import);
1298
1299 #if LUSTRE_TRACKS_LOCK_EXP_REFS
1300
1301 void __class_export_add_lock_ref(struct obd_export *exp, struct ldlm_lock *lock)
1302 {
1303         spin_lock(&exp->exp_locks_list_guard);
1304
1305         LASSERT(lock->l_exp_refs_nr >= 0);
1306
1307         if (lock->l_exp_refs_target != NULL &&
1308             lock->l_exp_refs_target != exp) {
1309                 LCONSOLE_WARN("setting export %p for lock %p which already has export %p\n",
1310                               exp, lock, lock->l_exp_refs_target);
1311         }
1312         if ((lock->l_exp_refs_nr ++) == 0) {
1313                 list_add(&lock->l_exp_refs_link, &exp->exp_locks_list);
1314                 lock->l_exp_refs_target = exp;
1315         }
1316         CDEBUG(D_INFO, "lock = %p, export = %p, refs = %u\n",
1317                lock, exp, lock->l_exp_refs_nr);
1318         spin_unlock(&exp->exp_locks_list_guard);
1319 }
1320 EXPORT_SYMBOL(__class_export_add_lock_ref);
1321
1322 void __class_export_del_lock_ref(struct obd_export *exp, struct ldlm_lock *lock)
1323 {
1324         spin_lock(&exp->exp_locks_list_guard);
1325         LASSERT(lock->l_exp_refs_nr > 0);
1326         if (lock->l_exp_refs_target != exp) {
1327                 LCONSOLE_WARN("lock %p, "
1328                               "mismatching export pointers: %p, %p\n",
1329                               lock, lock->l_exp_refs_target, exp);
1330         }
1331         if (-- lock->l_exp_refs_nr == 0) {
1332                 list_del_init(&lock->l_exp_refs_link);
1333                 lock->l_exp_refs_target = NULL;
1334         }
1335         CDEBUG(D_INFO, "lock = %p, export = %p, refs = %u\n",
1336                lock, exp, lock->l_exp_refs_nr);
1337         spin_unlock(&exp->exp_locks_list_guard);
1338 }
1339 EXPORT_SYMBOL(__class_export_del_lock_ref);
1340 #endif
1341
1342 /* A connection defines an export context in which preallocation can
1343    be managed. This releases the export pointer reference, and returns
1344    the export handle, so the export refcount is 1 when this function
1345    returns. */
1346 int class_connect(struct lustre_handle *conn, struct obd_device *obd,
1347                   struct obd_uuid *cluuid)
1348 {
1349         struct obd_export *export;
1350         LASSERT(conn != NULL);
1351         LASSERT(obd != NULL);
1352         LASSERT(cluuid != NULL);
1353         ENTRY;
1354
1355         export = class_new_export(obd, cluuid);
1356         if (IS_ERR(export))
1357                 RETURN(PTR_ERR(export));
1358
1359         conn->cookie = export->exp_handle.h_cookie;
1360         class_export_put(export);
1361
1362         CDEBUG(D_IOCTL, "connect: client %s, cookie %#llx\n",
1363                cluuid->uuid, conn->cookie);
1364         RETURN(0);
1365 }
1366 EXPORT_SYMBOL(class_connect);
1367
1368 /* if export is involved in recovery then clean up related things */
1369 static void class_export_recovery_cleanup(struct obd_export *exp)
1370 {
1371         struct obd_device *obd = exp->exp_obd;
1372
1373         spin_lock(&obd->obd_recovery_task_lock);
1374         if (obd->obd_recovering) {
1375                 if (exp->exp_in_recovery) {
1376                         spin_lock(&exp->exp_lock);
1377                         exp->exp_in_recovery = 0;
1378                         spin_unlock(&exp->exp_lock);
1379                         LASSERT_ATOMIC_POS(&obd->obd_connected_clients);
1380                         atomic_dec(&obd->obd_connected_clients);
1381                 }
1382
1383                 /* if called during recovery then should update
1384                  * obd_stale_clients counter,
1385                  * lightweight exports are not counted */
1386                 if ((exp_connect_flags(exp) & OBD_CONNECT_LIGHTWEIGHT) == 0)
1387                         exp->exp_obd->obd_stale_clients++;
1388         }
1389         spin_unlock(&obd->obd_recovery_task_lock);
1390
1391         spin_lock(&exp->exp_lock);
1392         /** Cleanup req replay fields */
1393         if (exp->exp_req_replay_needed) {
1394                 exp->exp_req_replay_needed = 0;
1395
1396                 LASSERT(atomic_read(&obd->obd_req_replay_clients));
1397                 atomic_dec(&obd->obd_req_replay_clients);
1398         }
1399
1400         /** Cleanup lock replay data */
1401         if (exp->exp_lock_replay_needed) {
1402                 exp->exp_lock_replay_needed = 0;
1403
1404                 LASSERT(atomic_read(&obd->obd_lock_replay_clients));
1405                 atomic_dec(&obd->obd_lock_replay_clients);
1406         }
1407         spin_unlock(&exp->exp_lock);
1408 }
1409
1410 /* This function removes 1-3 references from the export:
1411  * 1 - for export pointer passed
1412  * and if disconnect really need
1413  * 2 - removing from hash
1414  * 3 - in client_unlink_export
1415  * The export pointer passed to this function can destroyed */
1416 int class_disconnect(struct obd_export *export)
1417 {
1418         int already_disconnected;
1419         ENTRY;
1420
1421         if (export == NULL) {
1422                 CWARN("attempting to free NULL export %p\n", export);
1423                 RETURN(-EINVAL);
1424         }
1425
1426         spin_lock(&export->exp_lock);
1427         already_disconnected = export->exp_disconnected;
1428         export->exp_disconnected = 1;
1429         /*  We hold references of export for uuid hash
1430          *  and nid_hash and export link at least. So
1431          *  it is safe to call cfs_hash_del in there.  */
1432         if (!hlist_unhashed(&export->exp_nid_hash))
1433                 cfs_hash_del(export->exp_obd->obd_nid_hash,
1434                              &export->exp_connection->c_peer.nid,
1435                              &export->exp_nid_hash);
1436         spin_unlock(&export->exp_lock);
1437
1438         /* class_cleanup(), abort_recovery(), and class_fail_export()
1439          * all end up in here, and if any of them race we shouldn't
1440          * call extra class_export_puts(). */
1441         if (already_disconnected) {
1442                 LASSERT(hlist_unhashed(&export->exp_nid_hash));
1443                 GOTO(no_disconn, already_disconnected);
1444         }
1445
1446         CDEBUG(D_IOCTL, "disconnect: cookie %#llx\n",
1447                export->exp_handle.h_cookie);
1448
1449         class_export_recovery_cleanup(export);
1450         class_unlink_export(export);
1451 no_disconn:
1452         class_export_put(export);
1453         RETURN(0);
1454 }
1455 EXPORT_SYMBOL(class_disconnect);
1456
1457 /* Return non-zero for a fully connected export */
1458 int class_connected_export(struct obd_export *exp)
1459 {
1460         int connected = 0;
1461
1462         if (exp) {
1463                 spin_lock(&exp->exp_lock);
1464                 connected = (exp->exp_conn_cnt > 0) && !exp->exp_failed;
1465                 spin_unlock(&exp->exp_lock);
1466         }
1467         return connected;
1468 }
1469 EXPORT_SYMBOL(class_connected_export);
1470
1471 static void class_disconnect_export_list(struct list_head *list,
1472                                          enum obd_option flags)
1473 {
1474         int rc;
1475         struct obd_export *exp;
1476         ENTRY;
1477
1478         /* It's possible that an export may disconnect itself, but
1479          * nothing else will be added to this list. */
1480         while (!list_empty(list)) {
1481                 exp = list_first_entry(list, struct obd_export,
1482                                        exp_obd_chain);
1483                 /* need for safe call CDEBUG after obd_disconnect */
1484                 class_export_get(exp);
1485
1486                 spin_lock(&exp->exp_lock);
1487                 exp->exp_flags = flags;
1488                 spin_unlock(&exp->exp_lock);
1489
1490                 if (obd_uuid_equals(&exp->exp_client_uuid,
1491                                     &exp->exp_obd->obd_uuid)) {
1492                         CDEBUG(D_HA,
1493                                "exp %p export uuid == obd uuid, don't discon\n",
1494                                exp);
1495                         /* Need to delete this now so we don't end up pointing
1496                          * to work_list later when this export is cleaned up. */
1497                         list_del_init(&exp->exp_obd_chain);
1498                         class_export_put(exp);
1499                         continue;
1500                 }
1501
1502                 class_export_get(exp);
1503                 CDEBUG(D_HA, "%s: disconnecting export at %s (%p), "
1504                        "last request at %lld\n",
1505                        exp->exp_obd->obd_name, obd_export_nid2str(exp),
1506                        exp, exp->exp_last_request_time);
1507                 /* release one export reference anyway */
1508                 rc = obd_disconnect(exp);
1509
1510                 CDEBUG(D_HA, "disconnected export at %s (%p): rc %d\n",
1511                        obd_export_nid2str(exp), exp, rc);
1512                 class_export_put(exp);
1513         }
1514         EXIT;
1515 }
1516
1517 void class_disconnect_exports(struct obd_device *obd)
1518 {
1519         LIST_HEAD(work_list);
1520         ENTRY;
1521
1522         /* Move all of the exports from obd_exports to a work list, en masse. */
1523         spin_lock(&obd->obd_dev_lock);
1524         list_splice_init(&obd->obd_exports, &work_list);
1525         list_splice_init(&obd->obd_delayed_exports, &work_list);
1526         spin_unlock(&obd->obd_dev_lock);
1527
1528         if (!list_empty(&work_list)) {
1529                 CDEBUG(D_HA, "OBD device %d (%p) has exports, "
1530                        "disconnecting them\n", obd->obd_minor, obd);
1531                 class_disconnect_export_list(&work_list,
1532                                              exp_flags_from_obd(obd));
1533         } else
1534                 CDEBUG(D_HA, "OBD device %d (%p) has no exports\n",
1535                        obd->obd_minor, obd);
1536         EXIT;
1537 }
1538 EXPORT_SYMBOL(class_disconnect_exports);
1539
1540 /* Remove exports that have not completed recovery.
1541  */
1542 void class_disconnect_stale_exports(struct obd_device *obd,
1543                                     int (*test_export)(struct obd_export *))
1544 {
1545         LIST_HEAD(work_list);
1546         struct obd_export *exp, *n;
1547         int evicted = 0;
1548         ENTRY;
1549
1550         spin_lock(&obd->obd_dev_lock);
1551         list_for_each_entry_safe(exp, n, &obd->obd_exports,
1552                                  exp_obd_chain) {
1553                 /* don't count self-export as client */
1554                 if (obd_uuid_equals(&exp->exp_client_uuid,
1555                                     &exp->exp_obd->obd_uuid))
1556                         continue;
1557
1558                 /* don't evict clients which have no slot in last_rcvd
1559                  * (e.g. lightweight connection) */
1560                 if (exp->exp_target_data.ted_lr_idx == -1)
1561                         continue;
1562
1563                 spin_lock(&exp->exp_lock);
1564                 if (exp->exp_failed || test_export(exp)) {
1565                         spin_unlock(&exp->exp_lock);
1566                         continue;
1567                 }
1568                 exp->exp_failed = 1;
1569                 spin_unlock(&exp->exp_lock);
1570
1571                 list_move(&exp->exp_obd_chain, &work_list);
1572                 evicted++;
1573                 CDEBUG(D_HA, "%s: disconnect stale client %s@%s\n",
1574                        obd->obd_name, exp->exp_client_uuid.uuid,
1575                        obd_export_nid2str(exp));
1576                 print_export_data(exp, "EVICTING", 0, D_HA);
1577         }
1578         spin_unlock(&obd->obd_dev_lock);
1579
1580         if (evicted)
1581                 LCONSOLE_WARN("%s: disconnecting %d stale clients\n",
1582                               obd->obd_name, evicted);
1583
1584         class_disconnect_export_list(&work_list, exp_flags_from_obd(obd) |
1585                                                  OBD_OPT_ABORT_RECOV);
1586         EXIT;
1587 }
1588 EXPORT_SYMBOL(class_disconnect_stale_exports);
1589
1590 void class_fail_export(struct obd_export *exp)
1591 {
1592         int rc, already_failed;
1593
1594         spin_lock(&exp->exp_lock);
1595         already_failed = exp->exp_failed;
1596         exp->exp_failed = 1;
1597         spin_unlock(&exp->exp_lock);
1598
1599         if (already_failed) {
1600                 CDEBUG(D_HA, "disconnecting dead export %p/%s; skipping\n",
1601                        exp, exp->exp_client_uuid.uuid);
1602                 return;
1603         }
1604
1605         CDEBUG(D_HA, "disconnecting export %p/%s\n",
1606                exp, exp->exp_client_uuid.uuid);
1607
1608         if (obd_dump_on_timeout)
1609                 libcfs_debug_dumplog();
1610
1611         /* need for safe call CDEBUG after obd_disconnect */
1612         class_export_get(exp);
1613
1614         /* Most callers into obd_disconnect are removing their own reference
1615          * (request, for example) in addition to the one from the hash table.
1616          * We don't have such a reference here, so make one. */
1617         class_export_get(exp);
1618         rc = obd_disconnect(exp);
1619         if (rc)
1620                 CERROR("disconnecting export %p failed: %d\n", exp, rc);
1621         else
1622                 CDEBUG(D_HA, "disconnected export %p/%s\n",
1623                        exp, exp->exp_client_uuid.uuid);
1624         class_export_put(exp);
1625 }
1626 EXPORT_SYMBOL(class_fail_export);
1627
1628 int obd_export_evict_by_nid(struct obd_device *obd, const char *nid)
1629 {
1630         struct cfs_hash *nid_hash;
1631         struct obd_export *doomed_exp = NULL;
1632         int exports_evicted = 0;
1633
1634         lnet_nid_t nid_key = libcfs_str2nid((char *)nid);
1635
1636         spin_lock(&obd->obd_dev_lock);
1637         /* umount has run already, so evict thread should leave
1638          * its task to umount thread now */
1639         if (obd->obd_stopping) {
1640                 spin_unlock(&obd->obd_dev_lock);
1641                 return exports_evicted;
1642         }
1643         nid_hash = obd->obd_nid_hash;
1644         cfs_hash_getref(nid_hash);
1645         spin_unlock(&obd->obd_dev_lock);
1646
1647         do {
1648                 doomed_exp = cfs_hash_lookup(nid_hash, &nid_key);
1649                 if (doomed_exp == NULL)
1650                         break;
1651
1652                 LASSERTF(doomed_exp->exp_connection->c_peer.nid == nid_key,
1653                          "nid %s found, wanted nid %s, requested nid %s\n",
1654                          obd_export_nid2str(doomed_exp),
1655                          libcfs_nid2str(nid_key), nid);
1656                 LASSERTF(doomed_exp != obd->obd_self_export,
1657                          "self-export is hashed by NID?\n");
1658                 exports_evicted++;
1659                 LCONSOLE_WARN("%s: evicting %s (at %s) by administrative "
1660                               "request\n", obd->obd_name,
1661                               obd_uuid2str(&doomed_exp->exp_client_uuid),
1662                               obd_export_nid2str(doomed_exp));
1663                 class_fail_export(doomed_exp);
1664                 class_export_put(doomed_exp);
1665         } while (1);
1666
1667         cfs_hash_putref(nid_hash);
1668
1669         if (!exports_evicted)
1670                 CDEBUG(D_HA,"%s: can't disconnect NID '%s': no exports found\n",
1671                        obd->obd_name, nid);
1672         return exports_evicted;
1673 }
1674 EXPORT_SYMBOL(obd_export_evict_by_nid);
1675
1676 #ifdef HAVE_SERVER_SUPPORT
1677 int obd_export_evict_by_uuid(struct obd_device *obd, const char *uuid)
1678 {
1679         struct obd_export *doomed_exp = NULL;
1680         struct obd_uuid doomed_uuid;
1681         int exports_evicted = 0;
1682
1683         spin_lock(&obd->obd_dev_lock);
1684         if (obd->obd_stopping) {
1685                 spin_unlock(&obd->obd_dev_lock);
1686                 return exports_evicted;
1687         }
1688         spin_unlock(&obd->obd_dev_lock);
1689
1690         obd_str2uuid(&doomed_uuid, uuid);
1691         if (obd_uuid_equals(&doomed_uuid, &obd->obd_uuid)) {
1692                 CERROR("%s: can't evict myself\n", obd->obd_name);
1693                 return exports_evicted;
1694         }
1695
1696         doomed_exp = obd_uuid_lookup(obd, &doomed_uuid);
1697         if (doomed_exp == NULL) {
1698                 CERROR("%s: can't disconnect %s: no exports found\n",
1699                        obd->obd_name, uuid);
1700         } else {
1701                 CWARN("%s: evicting %s at adminstrative request\n",
1702                        obd->obd_name, doomed_exp->exp_client_uuid.uuid);
1703                 class_fail_export(doomed_exp);
1704                 class_export_put(doomed_exp);
1705                 obd_uuid_del(obd, doomed_exp);
1706                 exports_evicted++;
1707         }
1708
1709         return exports_evicted;
1710 }
1711 #endif /* HAVE_SERVER_SUPPORT */
1712
1713 #if LUSTRE_TRACKS_LOCK_EXP_REFS
1714 void (*class_export_dump_hook)(struct obd_export*) = NULL;
1715 EXPORT_SYMBOL(class_export_dump_hook);
1716 #endif
1717
1718 static void print_export_data(struct obd_export *exp, const char *status,
1719                               int locks, int debug_level)
1720 {
1721         struct ptlrpc_reply_state *rs;
1722         struct ptlrpc_reply_state *first_reply = NULL;
1723         int nreplies = 0;
1724
1725         spin_lock(&exp->exp_lock);
1726         list_for_each_entry(rs, &exp->exp_outstanding_replies,
1727                             rs_exp_list) {
1728                 if (nreplies == 0)
1729                         first_reply = rs;
1730                 nreplies++;
1731         }
1732         spin_unlock(&exp->exp_lock);
1733
1734         CDEBUG(debug_level, "%s: %s %p %s %s %d (%d %d %d) %d %d %d %d: "
1735                "%p %s %llu stale:%d\n",
1736                exp->exp_obd->obd_name, status, exp, exp->exp_client_uuid.uuid,
1737                obd_export_nid2str(exp),
1738                refcount_read(&exp->exp_handle.h_ref),
1739                atomic_read(&exp->exp_rpc_count),
1740                atomic_read(&exp->exp_cb_count),
1741                atomic_read(&exp->exp_locks_count),
1742                exp->exp_disconnected, exp->exp_delayed, exp->exp_failed,
1743                nreplies, first_reply, nreplies > 3 ? "..." : "",
1744                exp->exp_last_committed, !list_empty(&exp->exp_stale_list));
1745 #if LUSTRE_TRACKS_LOCK_EXP_REFS
1746         if (locks && class_export_dump_hook != NULL)
1747                 class_export_dump_hook(exp);
1748 #endif
1749 }
1750
1751 void dump_exports(struct obd_device *obd, int locks, int debug_level)
1752 {
1753         struct obd_export *exp;
1754
1755         spin_lock(&obd->obd_dev_lock);
1756         list_for_each_entry(exp, &obd->obd_exports, exp_obd_chain)
1757                 print_export_data(exp, "ACTIVE", locks, debug_level);
1758         list_for_each_entry(exp, &obd->obd_unlinked_exports, exp_obd_chain)
1759                 print_export_data(exp, "UNLINKED", locks, debug_level);
1760         list_for_each_entry(exp, &obd->obd_delayed_exports, exp_obd_chain)
1761                 print_export_data(exp, "DELAYED", locks, debug_level);
1762         spin_unlock(&obd->obd_dev_lock);
1763 }
1764
1765 void obd_exports_barrier(struct obd_device *obd)
1766 {
1767         int waited = 2;
1768         LASSERT(list_empty(&obd->obd_exports));
1769         spin_lock(&obd->obd_dev_lock);
1770         while (!list_empty(&obd->obd_unlinked_exports)) {
1771                 spin_unlock(&obd->obd_dev_lock);
1772                 schedule_timeout_uninterruptible(cfs_time_seconds(waited));
1773                 if (waited > 5 && is_power_of_2(waited)) {
1774                         LCONSOLE_WARN("%s is waiting for obd_unlinked_exports "
1775                                       "more than %d seconds. "
1776                                       "The obd refcount = %d. Is it stuck?\n",
1777                                       obd->obd_name, waited,
1778                                       atomic_read(&obd->obd_refcount));
1779                         dump_exports(obd, 1, D_CONSOLE | D_WARNING);
1780                 }
1781                 waited *= 2;
1782                 spin_lock(&obd->obd_dev_lock);
1783         }
1784         spin_unlock(&obd->obd_dev_lock);
1785 }
1786 EXPORT_SYMBOL(obd_exports_barrier);
1787
1788 /**
1789  * Add export to the obd_zombe thread and notify it.
1790  */
1791 static void obd_zombie_export_add(struct obd_export *exp) {
1792         atomic_dec(&obd_stale_export_num);
1793         spin_lock(&exp->exp_obd->obd_dev_lock);
1794         LASSERT(!list_empty(&exp->exp_obd_chain));
1795         list_del_init(&exp->exp_obd_chain);
1796         spin_unlock(&exp->exp_obd->obd_dev_lock);
1797
1798         queue_work(zombie_wq, &exp->exp_zombie_work);
1799 }
1800
1801 /**
1802  * Add import to the obd_zombe thread and notify it.
1803  */
1804 static void obd_zombie_import_add(struct obd_import *imp) {
1805         LASSERT(imp->imp_sec == NULL);
1806
1807         queue_work(zombie_wq, &imp->imp_zombie_work);
1808 }
1809
1810 /**
1811  * wait when obd_zombie import/export queues become empty
1812  */
1813 void obd_zombie_barrier(void)
1814 {
1815         flush_workqueue(zombie_wq);
1816 }
1817 EXPORT_SYMBOL(obd_zombie_barrier);
1818
1819
1820 struct obd_export *obd_stale_export_get(void)
1821 {
1822         struct obd_export *exp = NULL;
1823         ENTRY;
1824
1825         spin_lock(&obd_stale_export_lock);
1826         if (!list_empty(&obd_stale_exports)) {
1827                 exp = list_first_entry(&obd_stale_exports,
1828                                        struct obd_export, exp_stale_list);
1829                 list_del_init(&exp->exp_stale_list);
1830         }
1831         spin_unlock(&obd_stale_export_lock);
1832
1833         if (exp) {
1834                 CDEBUG(D_DLMTRACE, "Get export %p: total %d\n", exp,
1835                        atomic_read(&obd_stale_export_num));
1836         }
1837         RETURN(exp);
1838 }
1839 EXPORT_SYMBOL(obd_stale_export_get);
1840
1841 void obd_stale_export_put(struct obd_export *exp)
1842 {
1843         ENTRY;
1844
1845         LASSERT(list_empty(&exp->exp_stale_list));
1846         if (exp->exp_lock_hash &&
1847             atomic_read(&exp->exp_lock_hash->hs_count)) {
1848                 CDEBUG(D_DLMTRACE, "Put export %p: total %d\n", exp,
1849                        atomic_read(&obd_stale_export_num));
1850
1851                 spin_lock_bh(&exp->exp_bl_list_lock);
1852                 spin_lock(&obd_stale_export_lock);
1853                 /* Add to the tail if there is no blocked locks,
1854                  * to the head otherwise. */
1855                 if (list_empty(&exp->exp_bl_list))
1856                         list_add_tail(&exp->exp_stale_list,
1857                                       &obd_stale_exports);
1858                 else
1859                         list_add(&exp->exp_stale_list,
1860                                  &obd_stale_exports);
1861
1862                 spin_unlock(&obd_stale_export_lock);
1863                 spin_unlock_bh(&exp->exp_bl_list_lock);
1864         } else {
1865                 class_export_put(exp);
1866         }
1867         EXIT;
1868 }
1869 EXPORT_SYMBOL(obd_stale_export_put);
1870
1871 /**
1872  * Adjust the position of the export in the stale list,
1873  * i.e. move to the head of the list if is needed.
1874  **/
1875 void obd_stale_export_adjust(struct obd_export *exp)
1876 {
1877         LASSERT(exp != NULL);
1878         spin_lock_bh(&exp->exp_bl_list_lock);
1879         spin_lock(&obd_stale_export_lock);
1880
1881         if (!list_empty(&exp->exp_stale_list) &&
1882             !list_empty(&exp->exp_bl_list))
1883                 list_move(&exp->exp_stale_list, &obd_stale_exports);
1884
1885         spin_unlock(&obd_stale_export_lock);
1886         spin_unlock_bh(&exp->exp_bl_list_lock);
1887 }
1888 EXPORT_SYMBOL(obd_stale_export_adjust);
1889
1890 /**
1891  * start destroy zombie import/export thread
1892  */
1893 int obd_zombie_impexp_init(void)
1894 {
1895         zombie_wq = alloc_workqueue("obd_zombid", 0, 0);
1896         if (!zombie_wq)
1897                 return -ENOMEM;
1898
1899         return 0;
1900 }
1901
1902 /**
1903  * stop destroy zombie import/export thread
1904  */
1905 void obd_zombie_impexp_stop(void)
1906 {
1907         destroy_workqueue(zombie_wq);
1908         LASSERT(list_empty(&obd_stale_exports));
1909 }
1910
1911 /***** Kernel-userspace comm helpers *******/
1912
1913 /* Get length of entire message, including header */
1914 int kuc_len(int payload_len)
1915 {
1916         return sizeof(struct kuc_hdr) + payload_len;
1917 }
1918 EXPORT_SYMBOL(kuc_len);
1919
1920 /* Get a pointer to kuc header, given a ptr to the payload
1921  * @param p Pointer to payload area
1922  * @returns Pointer to kuc header
1923  */
1924 struct kuc_hdr * kuc_ptr(void *p)
1925 {
1926         struct kuc_hdr *lh = ((struct kuc_hdr *)p) - 1;
1927         LASSERT(lh->kuc_magic == KUC_MAGIC);
1928         return lh;
1929 }
1930 EXPORT_SYMBOL(kuc_ptr);
1931
1932 /* Alloc space for a message, and fill in header
1933  * @return Pointer to payload area
1934  */
1935 void *kuc_alloc(int payload_len, int transport, int type)
1936 {
1937         struct kuc_hdr *lh;
1938         int len = kuc_len(payload_len);
1939
1940         OBD_ALLOC(lh, len);
1941         if (lh == NULL)
1942                 return ERR_PTR(-ENOMEM);
1943
1944         lh->kuc_magic = KUC_MAGIC;
1945         lh->kuc_transport = transport;
1946         lh->kuc_msgtype = type;
1947         lh->kuc_msglen = len;
1948
1949         return (void *)(lh + 1);
1950 }
1951 EXPORT_SYMBOL(kuc_alloc);
1952
1953 /* Takes pointer to payload area */
1954 void kuc_free(void *p, int payload_len)
1955 {
1956         struct kuc_hdr *lh = kuc_ptr(p);
1957         OBD_FREE(lh, kuc_len(payload_len));
1958 }
1959 EXPORT_SYMBOL(kuc_free);
1960
1961 struct obd_request_slot_waiter {
1962         struct list_head        orsw_entry;
1963         wait_queue_head_t       orsw_waitq;
1964         bool                    orsw_signaled;
1965 };
1966
1967 static bool obd_request_slot_avail(struct client_obd *cli,
1968                                    struct obd_request_slot_waiter *orsw)
1969 {
1970         bool avail;
1971
1972         spin_lock(&cli->cl_loi_list_lock);
1973         avail = !!list_empty(&orsw->orsw_entry);
1974         spin_unlock(&cli->cl_loi_list_lock);
1975
1976         return avail;
1977 };
1978
1979 /*
1980  * For network flow control, the RPC sponsor needs to acquire a credit
1981  * before sending the RPC. The credits count for a connection is defined
1982  * by the "cl_max_rpcs_in_flight". If all the credits are occpuied, then
1983  * the subsequent RPC sponsors need to wait until others released their
1984  * credits, or the administrator increased the "cl_max_rpcs_in_flight".
1985  */
1986 int obd_get_request_slot(struct client_obd *cli)
1987 {
1988         struct obd_request_slot_waiter   orsw;
1989         int                              rc;
1990
1991         spin_lock(&cli->cl_loi_list_lock);
1992         if (cli->cl_rpcs_in_flight < cli->cl_max_rpcs_in_flight) {
1993                 cli->cl_rpcs_in_flight++;
1994                 spin_unlock(&cli->cl_loi_list_lock);
1995                 return 0;
1996         }
1997
1998         init_waitqueue_head(&orsw.orsw_waitq);
1999         list_add_tail(&orsw.orsw_entry, &cli->cl_flight_waiters);
2000         orsw.orsw_signaled = false;
2001         spin_unlock(&cli->cl_loi_list_lock);
2002
2003         rc = l_wait_event_abortable(orsw.orsw_waitq,
2004                                     obd_request_slot_avail(cli, &orsw) ||
2005                                     orsw.orsw_signaled);
2006
2007         /* Here, we must take the lock to avoid the on-stack 'orsw' to be
2008          * freed but other (such as obd_put_request_slot) is using it. */
2009         spin_lock(&cli->cl_loi_list_lock);
2010         if (rc != 0) {
2011                 if (!orsw.orsw_signaled) {
2012                         if (list_empty(&orsw.orsw_entry))
2013                                 cli->cl_rpcs_in_flight--;
2014                         else
2015                                 list_del(&orsw.orsw_entry);
2016                 }
2017                 rc = -EINTR;
2018         }
2019
2020         if (orsw.orsw_signaled) {
2021                 LASSERT(list_empty(&orsw.orsw_entry));
2022
2023                 rc = -EINTR;
2024         }
2025         spin_unlock(&cli->cl_loi_list_lock);
2026
2027         return rc;
2028 }
2029 EXPORT_SYMBOL(obd_get_request_slot);
2030
2031 void obd_put_request_slot(struct client_obd *cli)
2032 {
2033         struct obd_request_slot_waiter *orsw;
2034
2035         spin_lock(&cli->cl_loi_list_lock);
2036         cli->cl_rpcs_in_flight--;
2037
2038         /* If there is free slot, wakeup the first waiter. */
2039         if (!list_empty(&cli->cl_flight_waiters) &&
2040             likely(cli->cl_rpcs_in_flight < cli->cl_max_rpcs_in_flight)) {
2041                 orsw = list_first_entry(&cli->cl_flight_waiters,
2042                                         struct obd_request_slot_waiter,
2043                                         orsw_entry);
2044                 list_del_init(&orsw->orsw_entry);
2045                 cli->cl_rpcs_in_flight++;
2046                 wake_up(&orsw->orsw_waitq);
2047         }
2048         spin_unlock(&cli->cl_loi_list_lock);
2049 }
2050 EXPORT_SYMBOL(obd_put_request_slot);
2051
2052 __u32 obd_get_max_rpcs_in_flight(struct client_obd *cli)
2053 {
2054         return cli->cl_max_rpcs_in_flight;
2055 }
2056 EXPORT_SYMBOL(obd_get_max_rpcs_in_flight);
2057
2058 int obd_set_max_rpcs_in_flight(struct client_obd *cli, __u32 max)
2059 {
2060         struct obd_request_slot_waiter *orsw;
2061         __u32                           old;
2062         int                             diff;
2063         int                             i;
2064         const char *type_name;
2065         int                             rc;
2066
2067         if (max > OBD_MAX_RIF_MAX || max < 1)
2068                 return -ERANGE;
2069
2070         type_name = cli->cl_import->imp_obd->obd_type->typ_name;
2071         if (strcmp(type_name, LUSTRE_MDC_NAME) == 0) {
2072                 /* adjust max_mod_rpcs_in_flight to ensure it is always
2073                  * strictly lower that max_rpcs_in_flight */
2074                 if (max < 2) {
2075                         CERROR("%s: cannot set max_rpcs_in_flight to 1 "
2076                                "because it must be higher than "
2077                                "max_mod_rpcs_in_flight value",
2078                                cli->cl_import->imp_obd->obd_name);
2079                         return -ERANGE;
2080                 }
2081                 if (max <= cli->cl_max_mod_rpcs_in_flight) {
2082                         rc = obd_set_max_mod_rpcs_in_flight(cli, max - 1);
2083                         if (rc != 0)
2084                                 return rc;
2085                 }
2086         }
2087
2088         spin_lock(&cli->cl_loi_list_lock);
2089         old = cli->cl_max_rpcs_in_flight;
2090         cli->cl_max_rpcs_in_flight = max;
2091         client_adjust_max_dirty(cli);
2092
2093         diff = max - old;
2094
2095         /* We increase the max_rpcs_in_flight, then wakeup some waiters. */
2096         for (i = 0; i < diff; i++) {
2097                 if (list_empty(&cli->cl_flight_waiters))
2098                         break;
2099
2100                 orsw = list_first_entry(&cli->cl_flight_waiters,
2101                                         struct obd_request_slot_waiter,
2102                                         orsw_entry);
2103                 list_del_init(&orsw->orsw_entry);
2104                 cli->cl_rpcs_in_flight++;
2105                 wake_up(&orsw->orsw_waitq);
2106         }
2107         spin_unlock(&cli->cl_loi_list_lock);
2108
2109         return 0;
2110 }
2111 EXPORT_SYMBOL(obd_set_max_rpcs_in_flight);
2112
2113 __u16 obd_get_max_mod_rpcs_in_flight(struct client_obd *cli)
2114 {
2115         return cli->cl_max_mod_rpcs_in_flight;
2116 }
2117 EXPORT_SYMBOL(obd_get_max_mod_rpcs_in_flight);
2118
2119 int obd_set_max_mod_rpcs_in_flight(struct client_obd *cli, __u16 max)
2120 {
2121         struct obd_connect_data *ocd;
2122         __u16 maxmodrpcs;
2123         __u16 prev;
2124
2125         if (max > OBD_MAX_RIF_MAX || max < 1)
2126                 return -ERANGE;
2127
2128         /* cannot exceed or equal max_rpcs_in_flight */
2129         if (max >= cli->cl_max_rpcs_in_flight) {
2130                 CERROR("%s: can't set max_mod_rpcs_in_flight to a value (%hu) "
2131                        "higher or equal to max_rpcs_in_flight value (%u)\n",
2132                        cli->cl_import->imp_obd->obd_name,
2133                        max, cli->cl_max_rpcs_in_flight);
2134                 return -ERANGE;
2135         }
2136
2137         /* cannot exceed max modify RPCs in flight supported by the server */
2138         ocd = &cli->cl_import->imp_connect_data;
2139         if (ocd->ocd_connect_flags & OBD_CONNECT_MULTIMODRPCS)
2140                 maxmodrpcs = ocd->ocd_maxmodrpcs;
2141         else
2142                 maxmodrpcs = 1;
2143         if (max > maxmodrpcs) {
2144                 CERROR("%s: can't set max_mod_rpcs_in_flight to a value (%hu) "
2145                        "higher than max_mod_rpcs_per_client value (%hu) "
2146                        "returned by the server at connection\n",
2147                        cli->cl_import->imp_obd->obd_name,
2148                        max, maxmodrpcs);
2149                 return -ERANGE;
2150         }
2151
2152         spin_lock(&cli->cl_mod_rpcs_lock);
2153
2154         prev = cli->cl_max_mod_rpcs_in_flight;
2155         cli->cl_max_mod_rpcs_in_flight = max;
2156
2157         /* wakeup waiters if limit has been increased */
2158         if (cli->cl_max_mod_rpcs_in_flight > prev)
2159                 wake_up(&cli->cl_mod_rpcs_waitq);
2160
2161         spin_unlock(&cli->cl_mod_rpcs_lock);
2162
2163         return 0;
2164 }
2165 EXPORT_SYMBOL(obd_set_max_mod_rpcs_in_flight);
2166
2167 int obd_mod_rpc_stats_seq_show(struct client_obd *cli,
2168                                struct seq_file *seq)
2169 {
2170         unsigned long mod_tot = 0, mod_cum;
2171         struct timespec64 now;
2172         int i;
2173
2174         ktime_get_real_ts64(&now);
2175
2176         spin_lock(&cli->cl_mod_rpcs_lock);
2177
2178         seq_printf(seq, "snapshot_time:         %llu.%9lu (secs.nsecs)\n",
2179                    (s64)now.tv_sec, now.tv_nsec);
2180         seq_printf(seq, "modify_RPCs_in_flight:  %hu\n",
2181                    cli->cl_mod_rpcs_in_flight);
2182
2183         seq_printf(seq, "\n\t\t\tmodify\n");
2184         seq_printf(seq, "rpcs in flight        rpcs   %% cum %%\n");
2185
2186         mod_tot = lprocfs_oh_sum(&cli->cl_mod_rpcs_hist);
2187
2188         mod_cum = 0;
2189         for (i = 0; i < OBD_HIST_MAX; i++) {
2190                 unsigned long mod = cli->cl_mod_rpcs_hist.oh_buckets[i];
2191                 mod_cum += mod;
2192                 seq_printf(seq, "%d:\t\t%10lu %3u %3u\n",
2193                            i, mod, pct(mod, mod_tot),
2194                            pct(mod_cum, mod_tot));
2195                 if (mod_cum == mod_tot)
2196                         break;
2197         }
2198
2199         spin_unlock(&cli->cl_mod_rpcs_lock);
2200
2201         return 0;
2202 }
2203 EXPORT_SYMBOL(obd_mod_rpc_stats_seq_show);
2204
2205 /* The number of modify RPCs sent in parallel is limited
2206  * because the server has a finite number of slots per client to
2207  * store request result and ensure reply reconstruction when needed.
2208  * On the client, this limit is stored in cl_max_mod_rpcs_in_flight
2209  * that takes into account server limit and cl_max_rpcs_in_flight
2210  * value.
2211  * On the MDC client, to avoid a potential deadlock (see Bugzilla 3462),
2212  * one close request is allowed above the maximum.
2213  */
2214 static inline bool obd_mod_rpc_slot_avail_locked(struct client_obd *cli,
2215                                                  bool close_req)
2216 {
2217         bool avail;
2218
2219         /* A slot is available if
2220          * - number of modify RPCs in flight is less than the max
2221          * - it's a close RPC and no other close request is in flight
2222          */
2223         avail = cli->cl_mod_rpcs_in_flight < cli->cl_max_mod_rpcs_in_flight ||
2224                 (close_req && cli->cl_close_rpcs_in_flight == 0);
2225
2226         return avail;
2227 }
2228
2229 static inline bool obd_mod_rpc_slot_avail(struct client_obd *cli,
2230                                          bool close_req)
2231 {
2232         bool avail;
2233
2234         spin_lock(&cli->cl_mod_rpcs_lock);
2235         avail = obd_mod_rpc_slot_avail_locked(cli, close_req);
2236         spin_unlock(&cli->cl_mod_rpcs_lock);
2237         return avail;
2238 }
2239
2240
2241 /* Get a modify RPC slot from the obd client @cli according
2242  * to the kind of operation @opc that is going to be sent
2243  * and the intent @it of the operation if it applies.
2244  * If the maximum number of modify RPCs in flight is reached
2245  * the thread is put to sleep.
2246  * Returns the tag to be set in the request message. Tag 0
2247  * is reserved for non-modifying requests.
2248  */
2249 __u16 obd_get_mod_rpc_slot(struct client_obd *cli, __u32 opc)
2250 {
2251         bool                    close_req = false;
2252         __u16                   i, max;
2253
2254         if (opc == MDS_CLOSE)
2255                 close_req = true;
2256
2257         do {
2258                 spin_lock(&cli->cl_mod_rpcs_lock);
2259                 max = cli->cl_max_mod_rpcs_in_flight;
2260                 if (obd_mod_rpc_slot_avail_locked(cli, close_req)) {
2261                         /* there is a slot available */
2262                         cli->cl_mod_rpcs_in_flight++;
2263                         if (close_req)
2264                                 cli->cl_close_rpcs_in_flight++;
2265                         lprocfs_oh_tally(&cli->cl_mod_rpcs_hist,
2266                                          cli->cl_mod_rpcs_in_flight);
2267                         /* find a free tag */
2268                         i = find_first_zero_bit(cli->cl_mod_tag_bitmap,
2269                                                 max + 1);
2270                         LASSERT(i < OBD_MAX_RIF_MAX);
2271                         LASSERT(!test_and_set_bit(i, cli->cl_mod_tag_bitmap));
2272                         spin_unlock(&cli->cl_mod_rpcs_lock);
2273                         /* tag 0 is reserved for non-modify RPCs */
2274
2275                         CDEBUG(D_RPCTRACE,
2276                                "%s: modify RPC slot %u is allocated opc %u, max %hu\n",
2277                                cli->cl_import->imp_obd->obd_name,
2278                                i + 1, opc, max);
2279
2280                         return i + 1;
2281                 }
2282                 spin_unlock(&cli->cl_mod_rpcs_lock);
2283
2284                 CDEBUG(D_RPCTRACE, "%s: sleeping for a modify RPC slot "
2285                        "opc %u, max %hu\n",
2286                        cli->cl_import->imp_obd->obd_name, opc, max);
2287
2288                 wait_event_idle_exclusive(cli->cl_mod_rpcs_waitq,
2289                                           obd_mod_rpc_slot_avail(cli,
2290                                                                  close_req));
2291         } while (true);
2292 }
2293 EXPORT_SYMBOL(obd_get_mod_rpc_slot);
2294
2295 /* Put a modify RPC slot from the obd client @cli according
2296  * to the kind of operation @opc that has been sent.
2297  */
2298 void obd_put_mod_rpc_slot(struct client_obd *cli, __u32 opc, __u16 tag)
2299 {
2300         bool                    close_req = false;
2301
2302         if (tag == 0)
2303                 return;
2304
2305         if (opc == MDS_CLOSE)
2306                 close_req = true;
2307
2308         spin_lock(&cli->cl_mod_rpcs_lock);
2309         cli->cl_mod_rpcs_in_flight--;
2310         if (close_req)
2311                 cli->cl_close_rpcs_in_flight--;
2312         /* release the tag in the bitmap */
2313         LASSERT(tag - 1 < OBD_MAX_RIF_MAX);
2314         LASSERT(test_and_clear_bit(tag - 1, cli->cl_mod_tag_bitmap) != 0);
2315         spin_unlock(&cli->cl_mod_rpcs_lock);
2316         wake_up(&cli->cl_mod_rpcs_waitq);
2317 }
2318 EXPORT_SYMBOL(obd_put_mod_rpc_slot);
2319