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24ef1815 JB |
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 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 | ||
286eaa95 JB |
21 | #include <linux/list.h> |
22 | #include <linux/spinlock.h> | |
23 | #include <linux/module.h> | |
4670c46d | 24 | #include <linux/slab.h> |
6953b4c0 | 25 | #include <linux/kmod.h> |
74ae4e10 JB |
26 | #include <linux/fs.h> |
27 | #include <linux/kobject.h> | |
28 | #include <linux/sysfs.h> | |
3878f110 | 29 | #include <linux/sysctl.h> |
4670c46d | 30 | |
9c6c877c JB |
31 | #include "ocfs2_fs.h" |
32 | ||
286eaa95 | 33 | #include "stackglue.h" |
4670c46d | 34 | |
9c6c877c JB |
35 | #define OCFS2_STACK_PLUGIN_O2CB "o2cb" |
36 | #define OCFS2_STACK_PLUGIN_USER "user" | |
9f9a99f4 | 37 | #define OCFS2_MAX_HB_CTL_PATH 256 |
9c6c877c | 38 | |
286eaa95 JB |
39 | static struct ocfs2_locking_protocol *lproto; |
40 | static DEFINE_SPINLOCK(ocfs2_stack_lock); | |
41 | static LIST_HEAD(ocfs2_stack_list); | |
9c6c877c | 42 | static char cluster_stack_name[OCFS2_STACK_LABEL_LEN + 1]; |
9f9a99f4 | 43 | static char ocfs2_hb_ctl_path[OCFS2_MAX_HB_CTL_PATH] = "/sbin/ocfs2_hb_ctl"; |
19fdb624 | 44 | |
286eaa95 JB |
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 | ||
9c6c877c JB |
65 | static int ocfs2_stack_driver_request(const char *stack_name, |
66 | const char *plugin_name) | |
286eaa95 JB |
67 | { |
68 | int rc; | |
69 | struct ocfs2_stack_plugin *p; | |
70 | ||
71 | spin_lock(&ocfs2_stack_lock); | |
72 | ||
9c6c877c JB |
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 | ||
286eaa95 JB |
82 | if (active_stack) { |
83 | /* | |
84 | * If the active stack isn't the one we want, it cannot | |
85 | * be selected right now. | |
86 | */ | |
9c6c877c | 87 | if (!strcmp(active_stack->sp_name, plugin_name)) |
286eaa95 JB |
88 | rc = 0; |
89 | else | |
90 | rc = -EBUSY; | |
91 | goto out; | |
92 | } | |
93 | ||
9c6c877c | 94 | p = ocfs2_stack_lookup(plugin_name); |
286eaa95 JB |
95 | if (!p || !try_module_get(p->sp_owner)) { |
96 | rc = -ENOENT; | |
97 | goto out; | |
98 | } | |
99 | ||
286eaa95 | 100 | active_stack = p; |
286eaa95 JB |
101 | rc = 0; |
102 | ||
103 | out: | |
d6817cdb JB |
104 | /* If we found it, pin it */ |
105 | if (!rc) | |
106 | active_stack->sp_count++; | |
107 | ||
286eaa95 JB |
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 | */ | |
9c6c877c | 117 | static int ocfs2_stack_driver_get(const char *stack_name) |
286eaa95 JB |
118 | { |
119 | int rc; | |
9c6c877c JB |
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 | } | |
286eaa95 | 135 | |
9c6c877c JB |
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); | |
286eaa95 | 141 | if (rc == -ENOENT) { |
9c6c877c JB |
142 | request_module("ocfs2_stack_%s", plugin_name); |
143 | rc = ocfs2_stack_driver_request(stack_name, plugin_name); | |
286eaa95 JB |
144 | } |
145 | ||
146 | if (rc == -ENOENT) { | |
147 | printk(KERN_ERR | |
148 | "ocfs2: Cluster stack driver \"%s\" cannot be found\n", | |
9c6c877c | 149 | plugin_name); |
286eaa95 JB |
150 | } else if (rc == -EBUSY) { |
151 | printk(KERN_ERR | |
9c6c877c | 152 | "ocfs2: A different cluster stack is in use\n"); |
286eaa95 JB |
153 | } |
154 | ||
155 | return rc; | |
156 | } | |
24ef1815 | 157 | |
286eaa95 JB |
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_proto = lproto; | |
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_locking_protocol(struct ocfs2_locking_protocol *proto) | |
217 | { | |
218 | struct ocfs2_stack_plugin *p; | |
219 | ||
220 | BUG_ON(proto == NULL); | |
221 | ||
222 | spin_lock(&ocfs2_stack_lock); | |
223 | BUG_ON(active_stack != NULL); | |
224 | ||
225 | lproto = proto; | |
226 | list_for_each_entry(p, &ocfs2_stack_list, sp_list) { | |
227 | p->sp_proto = lproto; | |
228 | } | |
229 | ||
230 | spin_unlock(&ocfs2_stack_lock); | |
231 | } | |
232 | EXPORT_SYMBOL_GPL(ocfs2_stack_glue_set_locking_protocol); | |
7431cd7e | 233 | |
24ef1815 | 234 | |
cf4d8d75 DT |
235 | /* |
236 | * The ocfs2_dlm_lock() and ocfs2_dlm_unlock() functions take | |
237 | * "struct ocfs2_lock_res *astarg" instead of "void *astarg" because the | |
238 | * underlying stack plugins need to pilfer the lksb off of the lock_res. | |
239 | * If some other structure needs to be passed as an astarg, the plugins | |
240 | * will need to be given a different avenue to the lksb. | |
241 | */ | |
553aa7e4 JB |
242 | int ocfs2_dlm_lock(struct ocfs2_cluster_connection *conn, |
243 | int mode, | |
244 | union ocfs2_dlm_lksb *lksb, | |
245 | u32 flags, | |
246 | void *name, | |
247 | unsigned int namelen, | |
cf4d8d75 | 248 | struct ocfs2_lock_res *astarg) |
553aa7e4 | 249 | { |
286eaa95 | 250 | BUG_ON(lproto == NULL); |
bd3e7610 | 251 | |
286eaa95 JB |
252 | return active_stack->sp_ops->dlm_lock(conn, mode, lksb, flags, |
253 | name, namelen, astarg); | |
24ef1815 | 254 | } |
286eaa95 | 255 | EXPORT_SYMBOL_GPL(ocfs2_dlm_lock); |
24ef1815 | 256 | |
553aa7e4 JB |
257 | int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn, |
258 | union ocfs2_dlm_lksb *lksb, | |
259 | u32 flags, | |
cf4d8d75 | 260 | struct ocfs2_lock_res *astarg) |
553aa7e4 | 261 | { |
286eaa95 | 262 | BUG_ON(lproto == NULL); |
553aa7e4 | 263 | |
286eaa95 | 264 | return active_stack->sp_ops->dlm_unlock(conn, lksb, flags, astarg); |
8f2c9c1b | 265 | } |
286eaa95 | 266 | EXPORT_SYMBOL_GPL(ocfs2_dlm_unlock); |
8f2c9c1b | 267 | |
553aa7e4 JB |
268 | int ocfs2_dlm_lock_status(union ocfs2_dlm_lksb *lksb) |
269 | { | |
286eaa95 | 270 | return active_stack->sp_ops->lock_status(lksb); |
553aa7e4 | 271 | } |
286eaa95 | 272 | EXPORT_SYMBOL_GPL(ocfs2_dlm_lock_status); |
553aa7e4 | 273 | |
8f2c9c1b JB |
274 | /* |
275 | * Why don't we cast to ocfs2_meta_lvb? The "clean" answer is that we | |
276 | * don't cast at the glue level. The real answer is that the header | |
277 | * ordering is nigh impossible. | |
278 | */ | |
553aa7e4 JB |
279 | void *ocfs2_dlm_lvb(union ocfs2_dlm_lksb *lksb) |
280 | { | |
286eaa95 | 281 | return active_stack->sp_ops->lock_lvb(lksb); |
cf0acdcd | 282 | } |
286eaa95 | 283 | EXPORT_SYMBOL_GPL(ocfs2_dlm_lvb); |
cf0acdcd | 284 | |
553aa7e4 JB |
285 | void ocfs2_dlm_dump_lksb(union ocfs2_dlm_lksb *lksb) |
286 | { | |
286eaa95 | 287 | active_stack->sp_ops->dump_lksb(lksb); |
553aa7e4 | 288 | } |
286eaa95 | 289 | EXPORT_SYMBOL_GPL(ocfs2_dlm_dump_lksb); |
553aa7e4 | 290 | |
53da4939 MF |
291 | int ocfs2_stack_supports_plocks(void) |
292 | { | |
009d3750 | 293 | return active_stack && active_stack->sp_ops->plock; |
53da4939 MF |
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 | ||
9c6c877c JB |
311 | int ocfs2_cluster_connect(const char *stack_name, |
312 | const char *group, | |
4670c46d JB |
313 | int grouplen, |
314 | void (*recovery_handler)(int node_num, | |
315 | void *recovery_data), | |
316 | void *recovery_data, | |
317 | struct ocfs2_cluster_connection **conn) | |
318 | { | |
319 | int rc = 0; | |
320 | struct ocfs2_cluster_connection *new_conn; | |
4670c46d JB |
321 | |
322 | BUG_ON(group == NULL); | |
323 | BUG_ON(conn == NULL); | |
324 | BUG_ON(recovery_handler == NULL); | |
325 | ||
326 | if (grouplen > GROUP_NAME_MAX) { | |
327 | rc = -EINVAL; | |
328 | goto out; | |
329 | } | |
330 | ||
331 | new_conn = kzalloc(sizeof(struct ocfs2_cluster_connection), | |
332 | GFP_KERNEL); | |
333 | if (!new_conn) { | |
334 | rc = -ENOMEM; | |
335 | goto out; | |
336 | } | |
337 | ||
338 | memcpy(new_conn->cc_name, group, grouplen); | |
339 | new_conn->cc_namelen = grouplen; | |
340 | new_conn->cc_recovery_handler = recovery_handler; | |
341 | new_conn->cc_recovery_data = recovery_data; | |
342 | ||
343 | /* Start the new connection at our maximum compatibility level */ | |
286eaa95 JB |
344 | new_conn->cc_version = lproto->lp_max_version; |
345 | ||
346 | /* This will pin the stack driver if successful */ | |
9c6c877c | 347 | rc = ocfs2_stack_driver_get(stack_name); |
286eaa95 JB |
348 | if (rc) |
349 | goto out_free; | |
4670c46d | 350 | |
286eaa95 | 351 | rc = active_stack->sp_ops->connect(new_conn); |
553aa7e4 | 352 | if (rc) { |
286eaa95 | 353 | ocfs2_stack_driver_put(); |
4670c46d JB |
354 | goto out_free; |
355 | } | |
356 | ||
4670c46d JB |
357 | *conn = new_conn; |
358 | ||
359 | out_free: | |
553aa7e4 | 360 | if (rc) |
4670c46d | 361 | kfree(new_conn); |
4670c46d JB |
362 | |
363 | out: | |
364 | return rc; | |
365 | } | |
286eaa95 | 366 | EXPORT_SYMBOL_GPL(ocfs2_cluster_connect); |
4670c46d | 367 | |
286eaa95 JB |
368 | /* If hangup_pending is 0, the stack driver will be dropped */ |
369 | int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn, | |
370 | int hangup_pending) | |
553aa7e4 JB |
371 | { |
372 | int ret; | |
373 | ||
374 | BUG_ON(conn == NULL); | |
375 | ||
2c39450b | 376 | ret = active_stack->sp_ops->disconnect(conn); |
553aa7e4 JB |
377 | |
378 | /* XXX Should we free it anyway? */ | |
286eaa95 | 379 | if (!ret) { |
553aa7e4 | 380 | kfree(conn); |
286eaa95 JB |
381 | if (!hangup_pending) |
382 | ocfs2_stack_driver_put(); | |
383 | } | |
553aa7e4 JB |
384 | |
385 | return ret; | |
386 | } | |
286eaa95 | 387 | EXPORT_SYMBOL_GPL(ocfs2_cluster_disconnect); |
553aa7e4 | 388 | |
9f9a99f4 JB |
389 | /* |
390 | * Leave the group for this filesystem. This is executed by a userspace | |
391 | * program (stored in ocfs2_hb_ctl_path). | |
392 | */ | |
393 | static void ocfs2_leave_group(const char *group) | |
394 | { | |
395 | int ret; | |
396 | char *argv[5], *envp[3]; | |
397 | ||
398 | argv[0] = ocfs2_hb_ctl_path; | |
399 | argv[1] = "-K"; | |
400 | argv[2] = "-u"; | |
401 | argv[3] = (char *)group; | |
402 | argv[4] = NULL; | |
403 | ||
404 | /* minimal command environment taken from cpu_run_sbin_hotplug */ | |
405 | envp[0] = "HOME=/"; | |
406 | envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; | |
407 | envp[2] = NULL; | |
408 | ||
409 | ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC); | |
410 | if (ret < 0) { | |
411 | printk(KERN_ERR | |
412 | "ocfs2: Error %d running user helper " | |
413 | "\"%s %s %s %s\"\n", | |
414 | ret, argv[0], argv[1], argv[2], argv[3]); | |
415 | } | |
416 | } | |
417 | ||
418 | /* | |
419 | * Hangup is a required post-umount. ocfs2-tools software expects the | |
420 | * filesystem to call "ocfs2_hb_ctl" during unmount. This happens | |
421 | * regardless of whether the DLM got started, so we can't do it | |
422 | * in ocfs2_cluster_disconnect(). The ocfs2_leave_group() function does | |
423 | * the actual work. | |
424 | */ | |
6953b4c0 JB |
425 | void ocfs2_cluster_hangup(const char *group, int grouplen) |
426 | { | |
427 | BUG_ON(group == NULL); | |
428 | BUG_ON(group[grouplen] != '\0'); | |
429 | ||
9f9a99f4 JB |
430 | ocfs2_leave_group(group); |
431 | ||
286eaa95 JB |
432 | /* cluster_disconnect() was called with hangup_pending==1 */ |
433 | ocfs2_stack_driver_put(); | |
19fdb624 | 434 | } |
286eaa95 | 435 | EXPORT_SYMBOL_GPL(ocfs2_cluster_hangup); |
19fdb624 | 436 | |
553aa7e4 JB |
437 | int ocfs2_cluster_this_node(unsigned int *node) |
438 | { | |
286eaa95 | 439 | return active_stack->sp_ops->this_node(node); |
553aa7e4 | 440 | } |
286eaa95 | 441 | EXPORT_SYMBOL_GPL(ocfs2_cluster_this_node); |
553aa7e4 | 442 | |
286eaa95 | 443 | |
74ae4e10 JB |
444 | /* |
445 | * Sysfs bits | |
446 | */ | |
447 | ||
448 | static ssize_t ocfs2_max_locking_protocol_show(struct kobject *kobj, | |
449 | struct kobj_attribute *attr, | |
450 | char *buf) | |
451 | { | |
452 | ssize_t ret = 0; | |
453 | ||
454 | spin_lock(&ocfs2_stack_lock); | |
455 | if (lproto) | |
456 | ret = snprintf(buf, PAGE_SIZE, "%u.%u\n", | |
457 | lproto->lp_max_version.pv_major, | |
458 | lproto->lp_max_version.pv_minor); | |
459 | spin_unlock(&ocfs2_stack_lock); | |
460 | ||
461 | return ret; | |
462 | } | |
463 | ||
464 | static struct kobj_attribute ocfs2_attr_max_locking_protocol = | |
465 | __ATTR(max_locking_protocol, S_IFREG | S_IRUGO, | |
466 | ocfs2_max_locking_protocol_show, NULL); | |
467 | ||
468 | static ssize_t ocfs2_loaded_cluster_plugins_show(struct kobject *kobj, | |
469 | struct kobj_attribute *attr, | |
470 | char *buf) | |
24ef1815 | 471 | { |
74ae4e10 JB |
472 | ssize_t ret = 0, total = 0, remain = PAGE_SIZE; |
473 | struct ocfs2_stack_plugin *p; | |
474 | ||
475 | spin_lock(&ocfs2_stack_lock); | |
476 | list_for_each_entry(p, &ocfs2_stack_list, sp_list) { | |
477 | ret = snprintf(buf, remain, "%s\n", | |
478 | p->sp_name); | |
479 | if (ret < 0) { | |
480 | total = ret; | |
481 | break; | |
482 | } | |
483 | if (ret == remain) { | |
484 | /* snprintf() didn't fit */ | |
485 | total = -E2BIG; | |
486 | break; | |
487 | } | |
488 | total += ret; | |
489 | remain -= ret; | |
490 | } | |
491 | spin_unlock(&ocfs2_stack_lock); | |
492 | ||
493 | return total; | |
494 | } | |
495 | ||
496 | static struct kobj_attribute ocfs2_attr_loaded_cluster_plugins = | |
497 | __ATTR(loaded_cluster_plugins, S_IFREG | S_IRUGO, | |
498 | ocfs2_loaded_cluster_plugins_show, NULL); | |
499 | ||
500 | static ssize_t ocfs2_active_cluster_plugin_show(struct kobject *kobj, | |
501 | struct kobj_attribute *attr, | |
502 | char *buf) | |
503 | { | |
504 | ssize_t ret = 0; | |
505 | ||
506 | spin_lock(&ocfs2_stack_lock); | |
507 | if (active_stack) { | |
508 | ret = snprintf(buf, PAGE_SIZE, "%s\n", | |
509 | active_stack->sp_name); | |
510 | if (ret == PAGE_SIZE) | |
511 | ret = -E2BIG; | |
512 | } | |
513 | spin_unlock(&ocfs2_stack_lock); | |
514 | ||
515 | return ret; | |
516 | } | |
517 | ||
518 | static struct kobj_attribute ocfs2_attr_active_cluster_plugin = | |
519 | __ATTR(active_cluster_plugin, S_IFREG | S_IRUGO, | |
520 | ocfs2_active_cluster_plugin_show, NULL); | |
521 | ||
9c6c877c JB |
522 | static ssize_t ocfs2_cluster_stack_show(struct kobject *kobj, |
523 | struct kobj_attribute *attr, | |
524 | char *buf) | |
525 | { | |
526 | ssize_t ret; | |
527 | spin_lock(&ocfs2_stack_lock); | |
528 | ret = snprintf(buf, PAGE_SIZE, "%s\n", cluster_stack_name); | |
529 | spin_unlock(&ocfs2_stack_lock); | |
530 | ||
531 | return ret; | |
532 | } | |
533 | ||
534 | static ssize_t ocfs2_cluster_stack_store(struct kobject *kobj, | |
535 | struct kobj_attribute *attr, | |
536 | const char *buf, size_t count) | |
537 | { | |
538 | size_t len = count; | |
539 | ssize_t ret; | |
540 | ||
541 | if (len == 0) | |
542 | return len; | |
543 | ||
544 | if (buf[len - 1] == '\n') | |
545 | len--; | |
546 | ||
547 | if ((len != OCFS2_STACK_LABEL_LEN) || | |
548 | (strnlen(buf, len) != len)) | |
549 | return -EINVAL; | |
550 | ||
551 | spin_lock(&ocfs2_stack_lock); | |
552 | if (active_stack) { | |
553 | if (!strncmp(buf, cluster_stack_name, len)) | |
554 | ret = count; | |
555 | else | |
556 | ret = -EBUSY; | |
557 | } else { | |
558 | memcpy(cluster_stack_name, buf, len); | |
559 | ret = count; | |
560 | } | |
561 | spin_unlock(&ocfs2_stack_lock); | |
562 | ||
563 | return ret; | |
564 | } | |
565 | ||
566 | ||
567 | static struct kobj_attribute ocfs2_attr_cluster_stack = | |
568 | __ATTR(cluster_stack, S_IFREG | S_IRUGO | S_IWUSR, | |
569 | ocfs2_cluster_stack_show, | |
570 | ocfs2_cluster_stack_store); | |
571 | ||
74ae4e10 JB |
572 | static struct attribute *ocfs2_attrs[] = { |
573 | &ocfs2_attr_max_locking_protocol.attr, | |
574 | &ocfs2_attr_loaded_cluster_plugins.attr, | |
575 | &ocfs2_attr_active_cluster_plugin.attr, | |
9c6c877c | 576 | &ocfs2_attr_cluster_stack.attr, |
74ae4e10 JB |
577 | NULL, |
578 | }; | |
579 | ||
580 | static struct attribute_group ocfs2_attr_group = { | |
581 | .attrs = ocfs2_attrs, | |
582 | }; | |
583 | ||
584 | static struct kset *ocfs2_kset; | |
585 | ||
586 | static void ocfs2_sysfs_exit(void) | |
587 | { | |
588 | kset_unregister(ocfs2_kset); | |
589 | } | |
590 | ||
591 | static int ocfs2_sysfs_init(void) | |
592 | { | |
593 | int ret; | |
594 | ||
595 | ocfs2_kset = kset_create_and_add("ocfs2", NULL, fs_kobj); | |
596 | if (!ocfs2_kset) | |
597 | return -ENOMEM; | |
598 | ||
599 | ret = sysfs_create_group(&ocfs2_kset->kobj, &ocfs2_attr_group); | |
600 | if (ret) | |
601 | goto error; | |
602 | ||
286eaa95 | 603 | return 0; |
74ae4e10 JB |
604 | |
605 | error: | |
606 | kset_unregister(ocfs2_kset); | |
607 | return ret; | |
608 | } | |
609 | ||
3878f110 JB |
610 | /* |
611 | * Sysctl bits | |
612 | * | |
613 | * The sysctl lives at /proc/sys/fs/ocfs2/nm/hb_ctl_path. The 'nm' doesn't | |
614 | * make as much sense in a multiple cluster stack world, but it's safer | |
615 | * and easier to preserve the name. | |
616 | */ | |
617 | ||
618 | #define FS_OCFS2_NM 1 | |
619 | ||
3878f110 JB |
620 | static ctl_table ocfs2_nm_table[] = { |
621 | { | |
622 | .ctl_name = 1, | |
623 | .procname = "hb_ctl_path", | |
624 | .data = ocfs2_hb_ctl_path, | |
625 | .maxlen = OCFS2_MAX_HB_CTL_PATH, | |
626 | .mode = 0644, | |
627 | .proc_handler = &proc_dostring, | |
628 | .strategy = &sysctl_string, | |
629 | }, | |
630 | { .ctl_name = 0 } | |
631 | }; | |
632 | ||
633 | static ctl_table ocfs2_mod_table[] = { | |
634 | { | |
635 | .ctl_name = FS_OCFS2_NM, | |
636 | .procname = "nm", | |
637 | .data = NULL, | |
638 | .maxlen = 0, | |
639 | .mode = 0555, | |
640 | .child = ocfs2_nm_table | |
641 | }, | |
642 | { .ctl_name = 0} | |
643 | }; | |
644 | ||
645 | static ctl_table ocfs2_kern_table[] = { | |
646 | { | |
647 | .ctl_name = FS_OCFS2, | |
648 | .procname = "ocfs2", | |
649 | .data = NULL, | |
650 | .maxlen = 0, | |
651 | .mode = 0555, | |
652 | .child = ocfs2_mod_table | |
653 | }, | |
654 | { .ctl_name = 0} | |
655 | }; | |
656 | ||
657 | static ctl_table ocfs2_root_table[] = { | |
658 | { | |
659 | .ctl_name = CTL_FS, | |
660 | .procname = "fs", | |
661 | .data = NULL, | |
662 | .maxlen = 0, | |
663 | .mode = 0555, | |
664 | .child = ocfs2_kern_table | |
665 | }, | |
666 | { .ctl_name = 0 } | |
667 | }; | |
668 | ||
669 | static struct ctl_table_header *ocfs2_table_header = NULL; | |
670 | ||
3878f110 JB |
671 | |
672 | /* | |
673 | * Initialization | |
674 | */ | |
675 | ||
74ae4e10 JB |
676 | static int __init ocfs2_stack_glue_init(void) |
677 | { | |
9c6c877c JB |
678 | strcpy(cluster_stack_name, OCFS2_STACK_PLUGIN_O2CB); |
679 | ||
3878f110 JB |
680 | ocfs2_table_header = register_sysctl_table(ocfs2_root_table); |
681 | if (!ocfs2_table_header) { | |
682 | printk(KERN_ERR | |
683 | "ocfs2 stack glue: unable to register sysctl\n"); | |
684 | return -ENOMEM; /* or something. */ | |
685 | } | |
686 | ||
74ae4e10 | 687 | return ocfs2_sysfs_init(); |
286eaa95 | 688 | } |
24ef1815 | 689 | |
286eaa95 JB |
690 | static void __exit ocfs2_stack_glue_exit(void) |
691 | { | |
692 | lproto = NULL; | |
74ae4e10 | 693 | ocfs2_sysfs_exit(); |
3878f110 JB |
694 | if (ocfs2_table_header) |
695 | unregister_sysctl_table(ocfs2_table_header); | |
24ef1815 JB |
696 | } |
697 | ||
286eaa95 JB |
698 | MODULE_AUTHOR("Oracle"); |
699 | MODULE_DESCRIPTION("ocfs2 cluter stack glue layer"); | |
700 | MODULE_LICENSE("GPL"); | |
701 | module_init(ocfs2_stack_glue_init); | |
702 | module_exit(ocfs2_stack_glue_exit); |