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