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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 | 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 | ||
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 | */ | |
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 | ||
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 | ||
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 | ||
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 | ||
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 | */ | |
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | */ | |
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 | ||
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 */ | |
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 */ | |
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 | */ | |
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 | */ | |
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
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 | ||
612 | static void ocfs2_sysfs_exit(void) | |
613 | { | |
614 | kset_unregister(ocfs2_kset); | |
615 | } | |
616 | ||
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 | ||
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 | ||
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); |