kernel/fs/ocfs2/stackglue.c

   1 /* -*- mode: c; c-basic-offset: 8; -*-
   2  * vim: noexpandtab sw=8 ts=8 sts=0:
   3  *
   4  * stackglue.c
   5  *
   6  * Code which implements an OCFS2 specific interface to underlying
   7  * cluster stacks.
   8  *
   9  * Copyright (C) 2007, 2009 Oracle.  All rights reserved.
  10  *
  11  * This program is free software; you can redistribute it and/or
  12  * modify it under the terms of the GNU General Public
  13  * License as published by the Free Software Foundation, version 2.
  14  *
  15  * This program is distributed in the hope that it will be useful,
  16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  18  * General Public License for more details.
  19  */
  20
  21 #include <linux/list.h>
  22 #include <linux/spinlock.h>
  23 #include <linux/module.h>
  24 #include <linux/slab.h>
  25 #include <linux/kmod.h>
  26 #include <linux/fs.h>
  27 #include <linux/kobject.h>
  28 #include <linux/sysfs.h>
  29 #include <linux/sysctl.h>
  30
  31 #include "ocfs2_fs.h"
  32
  33 #include "stackglue.h"
  34
  35 #define OCFS2_STACK_PLUGIN_O2CB         "o2cb"
  36 #define OCFS2_STACK_PLUGIN_USER         "user"
  37 #define OCFS2_MAX_HB_CTL_PATH           256
  38
  39 static struct ocfs2_protocol_version locking_max_version;
  40 static DEFINE_SPINLOCK(ocfs2_stack_lock);
  41 static LIST_HEAD(ocfs2_stack_list);
  42 static char cluster_stack_name[OCFS2_STACK_LABEL_LEN + 1];
  43 static char ocfs2_hb_ctl_path[OCFS2_MAX_HB_CTL_PATH] = "/sbin/ocfs2_hb_ctl";
  44
  45 /*
  46  * The stack currently in use.  If not null, active_stack->sp_count > 0,
  47  * the module is pinned, and the locking protocol cannot be changed.
  48  */
  49 static struct ocfs2_stack_plugin *active_stack;
  50
  51 inline int ocfs2_is_o2cb_active(void)
  52 {
  53         return !strcmp(active_stack->sp_name, OCFS2_STACK_PLUGIN_O2CB);
  54 }
  55 EXPORT_SYMBOL_GPL(ocfs2_is_o2cb_active);
  56
  57 static struct ocfs2_stack_plugin *ocfs2_stack_lookup(const char *name)
  58 {
  59         struct ocfs2_stack_plugin *p;
  60
  61         assert_spin_locked(&ocfs2_stack_lock);
  62
  63         list_for_each_entry(p, &ocfs2_stack_list, sp_list) {
  64                 if (!strcmp(p->sp_name, name))
  65                         return p;
  66         }
  67
  68         return NULL;
  69 }
  70
  71 static int ocfs2_stack_driver_request(const char *stack_name,
  72                                       const char *plugin_name)
  73 {
  74         int rc;
  75         struct ocfs2_stack_plugin *p;
  76
  77         spin_lock(&ocfs2_stack_lock);
  78
  79         /*
  80          * If the stack passed by the filesystem isn't the selected one,
  81          * we can't continue.
  82          */
  83         if (strcmp(stack_name, cluster_stack_name)) {
  84                 rc = -EBUSY;
  85                 goto out;
  86         }
  87
  88         if (active_stack) {
  89                 /*
  90                  * If the active stack isn't the one we want, it cannot
  91                  * be selected right now.
  92                  */
  93                 if (!strcmp(active_stack->sp_name, plugin_name))
  94                         rc = 0;
  95                 else
  96                         rc = -EBUSY;
  97                 goto out;
  98         }
  99
 100         p = ocfs2_stack_lookup(plugin_name);
 101         if (!p || !try_module_get(p->sp_owner)) {
 102                 rc = -ENOENT;
 103                 goto out;
 104         }
 105
 106         active_stack = p;
 107         rc = 0;
 108
 109 out:
 110         /* If we found it, pin it */
 111         if (!rc)
 112                 active_stack->sp_count++;
 113
 114         spin_unlock(&ocfs2_stack_lock);
 115         return rc;
 116 }
 117
 118 /*
 119  * This function looks up the appropriate stack and makes it active.  If
 120  * there is no stack, it tries to load it.  It will fail if the stack still
 121  * cannot be found.  It will also fail if a different stack is in use.
 122  */
 123 static int ocfs2_stack_driver_get(const char *stack_name)
 124 {
 125         int rc;
 126         char *plugin_name = OCFS2_STACK_PLUGIN_O2CB;
 127
 128         /*
 129          * Classic stack does not pass in a stack name.  This is
 130          * compatible with older tools as well.
 131          */
 132         if (!stack_name || !*stack_name)
 133                 stack_name = OCFS2_STACK_PLUGIN_O2CB;
 134
 135         if (strlen(stack_name) != OCFS2_STACK_LABEL_LEN) {
 136                 printk(KERN_ERR
 137                        "ocfs2 passed an invalid cluster stack label: \"%s\"\n",
 138                        stack_name);
 139                 return -EINVAL;
 140         }
 141
 142         /* Anything that isn't the classic stack is a user stack */
 143         if (strcmp(stack_name, OCFS2_STACK_PLUGIN_O2CB))
 144                 plugin_name = OCFS2_STACK_PLUGIN_USER;
 145
 146         rc = ocfs2_stack_driver_request(stack_name, plugin_name);
 147         if (rc == -ENOENT) {
 148                 request_module("ocfs2_stack_%s", plugin_name);
 149                 rc = ocfs2_stack_driver_request(stack_name, plugin_name);
 150         }
 151
 152         if (rc == -ENOENT) {
 153                 printk(KERN_ERR
 154                        "ocfs2: Cluster stack driver \"%s\" cannot be found\n",
 155                        plugin_name);
 156         } else if (rc == -EBUSY) {
 157                 printk(KERN_ERR
 158                        "ocfs2: A different cluster stack is in use\n");
 159         }
 160
 161         return rc;
 162 }
 163
 164 static void ocfs2_stack_driver_put(void)
 165 {
 166         spin_lock(&ocfs2_stack_lock);
 167         BUG_ON(active_stack == NULL);
 168         BUG_ON(active_stack->sp_count == 0);
 169
 170         active_stack->sp_count--;
 171         if (!active_stack->sp_count) {
 172                 module_put(active_stack->sp_owner);
 173                 active_stack = NULL;
 174         }
 175         spin_unlock(&ocfs2_stack_lock);
 176 }
 177
 178 int ocfs2_stack_glue_register(struct ocfs2_stack_plugin *plugin)
 179 {
 180         int rc;
 181
 182         spin_lock(&ocfs2_stack_lock);
 183         if (!ocfs2_stack_lookup(plugin->sp_name)) {
 184                 plugin->sp_count = 0;
 185                 plugin->sp_max_proto = locking_max_version;
 186                 list_add(&plugin->sp_list, &ocfs2_stack_list);
 187                 printk(KERN_INFO "ocfs2: Registered cluster interface %s\n",
 188                        plugin->sp_name);
 189                 rc = 0;
 190         } else {
 191                 printk(KERN_ERR "ocfs2: Stack \"%s\" already registered\n",
 192                        plugin->sp_name);
 193                 rc = -EEXIST;
 194         }
 195         spin_unlock(&ocfs2_stack_lock);
 196
 197         return rc;
 198 }
 199 EXPORT_SYMBOL_GPL(ocfs2_stack_glue_register);
 200
 201 void ocfs2_stack_glue_unregister(struct ocfs2_stack_plugin *plugin)
 202 {
 203         struct ocfs2_stack_plugin *p;
 204
 205         spin_lock(&ocfs2_stack_lock);
 206         p = ocfs2_stack_lookup(plugin->sp_name);
 207         if (p) {
 208                 BUG_ON(p != plugin);
 209                 BUG_ON(plugin == active_stack);
 210                 BUG_ON(plugin->sp_count != 0);
 211                 list_del_init(&plugin->sp_list);
 212                 printk(KERN_INFO "ocfs2: Unregistered cluster interface %s\n",
 213                        plugin->sp_name);
 214         } else {
 215                 printk(KERN_ERR "Stack \"%s\" is not registered\n",
 216                        plugin->sp_name);
 217         }
 218         spin_unlock(&ocfs2_stack_lock);
 219 }
 220 EXPORT_SYMBOL_GPL(ocfs2_stack_glue_unregister);
 221
 222 void ocfs2_stack_glue_set_max_proto_version(struct ocfs2_protocol_version *max_proto)
 223 {
 224         struct ocfs2_stack_plugin *p;
 225
 226         spin_lock(&ocfs2_stack_lock);
 227         if (memcmp(max_proto, &locking_max_version,
 228                    sizeof(struct ocfs2_protocol_version))) {
 229                 BUG_ON(locking_max_version.pv_major != 0);
 230
 231                 locking_max_version = *max_proto;
 232                 list_for_each_entry(p, &ocfs2_stack_list, sp_list) {
 233                         p->sp_max_proto = locking_max_version;
 234                 }
 235         }
 236         spin_unlock(&ocfs2_stack_lock);
 237 }
 238 EXPORT_SYMBOL_GPL(ocfs2_stack_glue_set_max_proto_version);
 239
 240
 241 /*
 242  * The ocfs2_dlm_lock() and ocfs2_dlm_unlock() functions take no argument
 243  * for the ast and bast functions.  They will pass the lksb to the ast
 244  * and bast.  The caller can wrap the lksb with their own structure to
 245  * get more information.
 246  */
 247 int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn,
 248                    int mode,
 249                    struct ocfs2_dlm_lksb *lksb,
 250                    u32 flags,
 251                    void *name,
 252                    unsigned int namelen)
 253 {
 254         if (!lksb->lksb_conn)
 255                 lksb->lksb_conn = conn;
 256         else
 257                 BUG_ON(lksb->lksb_conn != conn);
 258         return active_stack->sp_ops->dlm_lock(conn, mode, lksb, flags,
 259                                               name, namelen);
 260 }
 261 EXPORT_SYMBOL_GPL(ocfs2_dlm_lock);
 262
 263 int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
 264                      struct ocfs2_dlm_lksb *lksb,
 265                      u32 flags)
 266 {
 267         BUG_ON(lksb->lksb_conn == NULL);
 268
 269         return active_stack->sp_ops->dlm_unlock(conn, lksb, flags);
 270 }
 271 EXPORT_SYMBOL_GPL(ocfs2_dlm_unlock);
 272
 273 int ocfs2_dlm_lock_status(struct ocfs2_dlm_lksb *lksb)
 274 {
 275         return active_stack->sp_ops->lock_status(lksb);
 276 }
 277 EXPORT_SYMBOL_GPL(ocfs2_dlm_lock_status);
 278
 279 int ocfs2_dlm_lvb_valid(struct ocfs2_dlm_lksb *lksb)
 280 {
 281         return active_stack->sp_ops->lvb_valid(lksb);
 282 }
 283 EXPORT_SYMBOL_GPL(ocfs2_dlm_lvb_valid);
 284
 285 void *ocfs2_dlm_lvb(struct ocfs2_dlm_lksb *lksb)
 286 {
 287         return active_stack->sp_ops->lock_lvb(lksb);
 288 }
 289 EXPORT_SYMBOL_GPL(ocfs2_dlm_lvb);
 290
 291 void ocfs2_dlm_dump_lksb(struct ocfs2_dlm_lksb *lksb)
 292 {
 293         active_stack->sp_ops->dump_lksb(lksb);
 294 }
 295 EXPORT_SYMBOL_GPL(ocfs2_dlm_dump_lksb);
 296
 297 int ocfs2_stack_supports_plocks(void)
 298 {
 299         return active_stack && active_stack->sp_ops->plock;
 300 }
 301 EXPORT_SYMBOL_GPL(ocfs2_stack_supports_plocks);
 302
 303 /*
 304  * ocfs2_plock() can only be safely called if
 305  * ocfs2_stack_supports_plocks() returned true
 306  */
 307 int ocfs2_plock(struct ocfs2_cluster_connection *conn, u64 ino,
 308                 struct file *file, int cmd, struct file_lock *fl)
 309 {
 310         WARN_ON_ONCE(active_stack->sp_ops->plock == NULL);
 311         if (active_stack->sp_ops->plock)
 312                 return active_stack->sp_ops->plock(conn, ino, file, cmd, fl);
 313         return -EOPNOTSUPP;
 314 }
 315 EXPORT_SYMBOL_GPL(ocfs2_plock);
 316
 317 int ocfs2_cluster_connect(const char *stack_name,
 318                           const char *cluster_name,
 319                           int cluster_name_len,
 320                           const char *group,
 321                           int grouplen,
 322                           struct ocfs2_locking_protocol *lproto,
 323                           void (*recovery_handler)(int node_num,
 324                                                    void *recovery_data),
 325                           void *recovery_data,
 326                           struct ocfs2_cluster_connection **conn)
 327 {
 328         int rc = 0;
 329         struct ocfs2_cluster_connection *new_conn;
 330
 331         BUG_ON(group == NULL);
 332         BUG_ON(conn == NULL);
 333         BUG_ON(recovery_handler == NULL);
 334
 335         if (grouplen > GROUP_NAME_MAX) {
 336                 rc = -EINVAL;
 337                 goto out;
 338         }
 339
 340         if (memcmp(&lproto->lp_max_version, &locking_max_version,
 341                    sizeof(struct ocfs2_protocol_version))) {
 342                 rc = -EINVAL;
 343                 goto out;
 344         }
 345
 346         new_conn = kzalloc(sizeof(struct ocfs2_cluster_connection),
 347                            GFP_KERNEL);
 348         if (!new_conn) {
 349                 rc = -ENOMEM;
 350                 goto out;
 351         }
 352
 353         strlcpy(new_conn->cc_name, group, GROUP_NAME_MAX + 1);
 354         new_conn->cc_namelen = grouplen;
 355         if (cluster_name_len)
 356                 strlcpy(new_conn->cc_cluster_name, cluster_name,
 357                         CLUSTER_NAME_MAX + 1);
 358         new_conn->cc_cluster_name_len = cluster_name_len;
 359         new_conn->cc_recovery_handler = recovery_handler;
 360         new_conn->cc_recovery_data = recovery_data;
 361
 362         new_conn->cc_proto = lproto;
 363         /* Start the new connection at our maximum compatibility level */
 364         new_conn->cc_version = lproto->lp_max_version;
 365
 366         /* This will pin the stack driver if successful */
 367         rc = ocfs2_stack_driver_get(stack_name);
 368         if (rc)
 369                 goto out_free;
 370
 371         rc = active_stack->sp_ops->connect(new_conn);
 372         if (rc) {
 373                 ocfs2_stack_driver_put();
 374                 goto out_free;
 375         }
 376
 377         *conn = new_conn;
 378
 379 out_free:
 380         if (rc)
 381                 kfree(new_conn);
 382
 383 out:
 384         return rc;
 385 }
 386 EXPORT_SYMBOL_GPL(ocfs2_cluster_connect);
 387
 388 /* The caller will ensure all nodes have the same cluster stack */
 389 int ocfs2_cluster_connect_agnostic(const char *group,
 390                                    int grouplen,
 391                                    struct ocfs2_locking_protocol *lproto,
 392                                    void (*recovery_handler)(int node_num,
 393                                                             void *recovery_data),
 394                                    void *recovery_data,
 395                                    struct ocfs2_cluster_connection **conn)
 396 {
 397         char *stack_name = NULL;
 398
 399         if (cluster_stack_name[0])
 400                 stack_name = cluster_stack_name;
 401         return ocfs2_cluster_connect(stack_name, NULL, 0, group, grouplen,
 402                                      lproto, recovery_handler, recovery_data,
 403                                      conn);
 404 }
 405 EXPORT_SYMBOL_GPL(ocfs2_cluster_connect_agnostic);
 406
 407 /* If hangup_pending is 0, the stack driver will be dropped */
 408 int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,
 409                              int hangup_pending)
 410 {
 411         int ret;
 412
 413         BUG_ON(conn == NULL);
 414
 415         ret = active_stack->sp_ops->disconnect(conn);
 416
 417         /* XXX Should we free it anyway? */
 418         if (!ret) {
 419                 kfree(conn);
 420                 if (!hangup_pending)
 421                         ocfs2_stack_driver_put();
 422         }
 423
 424         return ret;
 425 }
 426 EXPORT_SYMBOL_GPL(ocfs2_cluster_disconnect);
 427
 428 /*
 429  * Leave the group for this filesystem.  This is executed by a userspace
 430  * program (stored in ocfs2_hb_ctl_path).
 431  */
 432 static void ocfs2_leave_group(const char *group)
 433 {
 434         int ret;
 435         char *argv[5], *envp[3];
 436
 437         argv[0] = ocfs2_hb_ctl_path;
 438         argv[1] = "-K";
 439         argv[2] = "-u";
 440         argv[3] = (char *)group;
 441         argv[4] = NULL;
 442
 443         /* minimal command environment taken from cpu_run_sbin_hotplug */
 444         envp[0] = "HOME=/";
 445         envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
 446         envp[2] = NULL;
 447
 448         ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
 449         if (ret < 0) {
 450                 printk(KERN_ERR
 451                        "ocfs2: Error %d running user helper "
 452                        "\"%s %s %s %s\"\n",
 453                        ret, argv[0], argv[1], argv[2], argv[3]);
 454         }
 455 }
 456
 457 /*
 458  * Hangup is a required post-umount.  ocfs2-tools software expects the
 459  * filesystem to call "ocfs2_hb_ctl" during unmount.  This happens
 460  * regardless of whether the DLM got started, so we can't do it
 461  * in ocfs2_cluster_disconnect().  The ocfs2_leave_group() function does
 462  * the actual work.
 463  */
 464 void ocfs2_cluster_hangup(const char *group, int grouplen)
 465 {
 466         BUG_ON(group == NULL);
 467         BUG_ON(group[grouplen] != '\0');
 468
 469         ocfs2_leave_group(group);
 470
 471         /* cluster_disconnect() was called with hangup_pending==1 */
 472         ocfs2_stack_driver_put();
 473 }
 474 EXPORT_SYMBOL_GPL(ocfs2_cluster_hangup);
 475
 476 int ocfs2_cluster_this_node(struct ocfs2_cluster_connection *conn,
 477                             unsigned int *node)
 478 {
 479         return active_stack->sp_ops->this_node(conn, node);
 480 }
 481 EXPORT_SYMBOL_GPL(ocfs2_cluster_this_node);
 482
 483
 484 /*
 485  * Sysfs bits
 486  */
 487
 488 static ssize_t ocfs2_max_locking_protocol_show(struct kobject *kobj,
 489                                                struct kobj_attribute *attr,
 490                                                char *buf)
 491 {
 492         ssize_t ret = 0;
 493
 494         spin_lock(&ocfs2_stack_lock);
 495         if (locking_max_version.pv_major)
 496                 ret = snprintf(buf, PAGE_SIZE, "%u.%u\n",
 497                                locking_max_version.pv_major,
 498                                locking_max_version.pv_minor);
 499         spin_unlock(&ocfs2_stack_lock);
 500
 501         return ret;
 502 }
 503
 504 static struct kobj_attribute ocfs2_attr_max_locking_protocol =
 505         __ATTR(max_locking_protocol, S_IRUGO,
 506                ocfs2_max_locking_protocol_show, NULL);
 507
 508 static ssize_t ocfs2_loaded_cluster_plugins_show(struct kobject *kobj,
 509                                                  struct kobj_attribute *attr,
 510                                                  char *buf)
 511 {
 512         ssize_t ret = 0, total = 0, remain = PAGE_SIZE;
 513         struct ocfs2_stack_plugin *p;
 514
 515         spin_lock(&ocfs2_stack_lock);
 516         list_for_each_entry(p, &ocfs2_stack_list, sp_list) {
 517                 ret = snprintf(buf, remain, "%s\n",
 518                                p->sp_name);
 519                 if (ret < 0) {
 520                         total = ret;
 521                         break;
 522                 }
 523                 if (ret == remain) {
 524                         /* snprintf() didn't fit */
 525                         total = -E2BIG;
 526                         break;
 527                 }
 528                 total += ret;
 529                 remain -= ret;
 530         }
 531         spin_unlock(&ocfs2_stack_lock);
 532
 533         return total;
 534 }
 535
 536 static struct kobj_attribute ocfs2_attr_loaded_cluster_plugins =
 537         __ATTR(loaded_cluster_plugins, S_IRUGO,
 538                ocfs2_loaded_cluster_plugins_show, NULL);
 539
 540 static ssize_t ocfs2_active_cluster_plugin_show(struct kobject *kobj,
 541                                                 struct kobj_attribute *attr,
 542                                                 char *buf)
 543 {
 544         ssize_t ret = 0;
 545
 546         spin_lock(&ocfs2_stack_lock);
 547         if (active_stack) {
 548                 ret = snprintf(buf, PAGE_SIZE, "%s\n",
 549                                active_stack->sp_name);
 550                 if (ret == PAGE_SIZE)
 551                         ret = -E2BIG;
 552         }
 553         spin_unlock(&ocfs2_stack_lock);
 554
 555         return ret;
 556 }
 557
 558 static struct kobj_attribute ocfs2_attr_active_cluster_plugin =
 559         __ATTR(active_cluster_plugin, S_IRUGO,
 560                ocfs2_active_cluster_plugin_show, NULL);
 561
 562 static ssize_t ocfs2_cluster_stack_show(struct kobject *kobj,
 563                                         struct kobj_attribute *attr,
 564                                         char *buf)
 565 {
 566         ssize_t ret;
 567         spin_lock(&ocfs2_stack_lock);
 568         ret = snprintf(buf, PAGE_SIZE, "%s\n", cluster_stack_name);
 569         spin_unlock(&ocfs2_stack_lock);
 570
 571         return ret;
 572 }
 573
 574 static ssize_t ocfs2_cluster_stack_store(struct kobject *kobj,
 575                                          struct kobj_attribute *attr,
 576                                          const char *buf, size_t count)
 577 {
 578         size_t len = count;
 579         ssize_t ret;
 580
 581         if (len == 0)
 582                 return len;
 583
 584         if (buf[len - 1] == '\n')
 585                 len--;
 586
 587         if ((len != OCFS2_STACK_LABEL_LEN) ||
 588             (strnlen(buf, len) != len))
 589                 return -EINVAL;
 590
 591         spin_lock(&ocfs2_stack_lock);
 592         if (active_stack) {
 593                 if (!strncmp(buf, cluster_stack_name, len))
 594                         ret = count;
 595                 else
 596                         ret = -EBUSY;
 597         } else {
 598                 memcpy(cluster_stack_name, buf, len);
 599                 ret = count;
 600         }
 601         spin_unlock(&ocfs2_stack_lock);
 602
 603         return ret;
 604 }
 605
 606
 607 static struct kobj_attribute ocfs2_attr_cluster_stack =
 608         __ATTR(cluster_stack, S_IRUGO | S_IWUSR,
 609                ocfs2_cluster_stack_show,
 610                ocfs2_cluster_stack_store);
 611
 612
 613
 614 static ssize_t ocfs2_dlm_recover_show(struct kobject *kobj,
 615                                         struct kobj_attribute *attr,
 616                                         char *buf)
 617 {
 618         return snprintf(buf, PAGE_SIZE, "1\n");
 619 }
 620
 621 static struct kobj_attribute ocfs2_attr_dlm_recover_support =
 622         __ATTR(dlm_recover_callback_support, S_IRUGO,
 623                ocfs2_dlm_recover_show, NULL);
 624
 625 static struct attribute *ocfs2_attrs[] = {
 626         &ocfs2_attr_max_locking_protocol.attr,
 627         &ocfs2_attr_loaded_cluster_plugins.attr,
 628         &ocfs2_attr_active_cluster_plugin.attr,
 629         &ocfs2_attr_cluster_stack.attr,
 630         &ocfs2_attr_dlm_recover_support.attr,
 631         NULL,
 632 };
 633
 634 static struct attribute_group ocfs2_attr_group = {
 635         .attrs = ocfs2_attrs,
 636 };
 637
 638 static struct kset *ocfs2_kset;
 639
 640 static void ocfs2_sysfs_exit(void)
 641 {
 642         kset_unregister(ocfs2_kset);
 643 }
 644
 645 static int ocfs2_sysfs_init(void)
 646 {
 647         int ret;
 648
 649         ocfs2_kset = kset_create_and_add("ocfs2", NULL, fs_kobj);
 650         if (!ocfs2_kset)
 651                 return -ENOMEM;
 652
 653         ret = sysfs_create_group(&ocfs2_kset->kobj, &ocfs2_attr_group);
 654         if (ret)
 655                 goto error;
 656
 657         return 0;
 658
 659 error:
 660         kset_unregister(ocfs2_kset);
 661         return ret;
 662 }
 663
 664 /*
 665  * Sysctl bits
 666  *
 667  * The sysctl lives at /proc/sys/fs/ocfs2/nm/hb_ctl_path.  The 'nm' doesn't
 668  * make as much sense in a multiple cluster stack world, but it's safer
 669  * and easier to preserve the name.
 670  */
 671
 672 #define FS_OCFS2_NM             1
 673
 674 static struct ctl_table ocfs2_nm_table[] = {
 675         {
 676                 .procname       = "hb_ctl_path",
 677                 .data           = ocfs2_hb_ctl_path,
 678                 .maxlen         = OCFS2_MAX_HB_CTL_PATH,
 679                 .mode           = 0644,
 680                 .proc_handler   = proc_dostring,
 681         },
 682         { }
 683 };
 684
 685 static struct ctl_table ocfs2_mod_table[] = {
 686         {
 687                 .procname       = "nm",
 688                 .data           = NULL,
 689                 .maxlen         = 0,
 690                 .mode           = 0555,
 691                 .child          = ocfs2_nm_table
 692         },
 693         { }
 694 };
 695
 696 static struct ctl_table ocfs2_kern_table[] = {
 697         {
 698                 .procname       = "ocfs2",
 699                 .data           = NULL,
 700                 .maxlen         = 0,
 701                 .mode           = 0555,
 702                 .child          = ocfs2_mod_table
 703         },
 704         { }
 705 };
 706
 707 static struct ctl_table ocfs2_root_table[] = {
 708         {
 709                 .procname       = "fs",
 710                 .data           = NULL,
 711                 .maxlen         = 0,
 712                 .mode           = 0555,
 713                 .child          = ocfs2_kern_table
 714         },
 715         { }
 716 };
 717
 718 static struct ctl_table_header *ocfs2_table_header;
 719
 720
 721 /*
 722  * Initialization
 723  */
 724
 725 static int __init ocfs2_stack_glue_init(void)
 726 {
 727         strcpy(cluster_stack_name, OCFS2_STACK_PLUGIN_O2CB);
 728
 729         ocfs2_table_header = register_sysctl_table(ocfs2_root_table);
 730         if (!ocfs2_table_header) {
 731                 printk(KERN_ERR
 732                        "ocfs2 stack glue: unable to register sysctl\n");
 733                 return -ENOMEM; /* or something. */
 734         }
 735
 736         return ocfs2_sysfs_init();
 737 }
 738
 739 static void __exit ocfs2_stack_glue_exit(void)
 740 {
 741         memset(&locking_max_version, 0,
 742                sizeof(struct ocfs2_protocol_version));
 743         locking_max_version.pv_major = 0;
 744         locking_max_version.pv_minor = 0;
 745         ocfs2_sysfs_exit();
 746         if (ocfs2_table_header)
 747                 unregister_sysctl_table(ocfs2_table_header);
 748 }
 749
 750 MODULE_AUTHOR("Oracle");
 751 MODULE_DESCRIPTION("ocfs2 cluter stack glue layer");
 752 MODULE_LICENSE("GPL");
 753 module_init(ocfs2_stack_glue_init);
 754 module_exit(ocfs2_stack_glue_exit);