blob: 3f2f1c45b7b6bf4abf6ac9bbaddd3e24f456171a [file] [log] [blame]
Joel Becker24ef1812008-01-29 17:37:32 -08001/* -*- 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 *
Joel Becker1c520df2009-06-19 15:14:13 -07009 * Copyright (C) 2007, 2009 Oracle. All rights reserved.
Joel Becker24ef1812008-01-29 17:37:32 -080010 *
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
Joel Becker286eaa92008-02-01 15:03:57 -080021#include <linux/list.h>
22#include <linux/spinlock.h>
23#include <linux/module.h>
Joel Becker4670c462008-02-01 14:39:35 -080024#include <linux/slab.h>
Joel Becker6953b4c2008-01-29 16:59:56 -080025#include <linux/kmod.h>
Joel Becker74ae4e12008-01-31 23:56:17 -080026#include <linux/fs.h>
27#include <linux/kobject.h>
28#include <linux/sysfs.h>
Joel Becker3878f112008-05-30 15:30:49 -070029#include <linux/sysctl.h>
Joel Becker4670c462008-02-01 14:39:35 -080030
Joel Becker9c6c8772008-02-01 15:17:30 -080031#include "ocfs2_fs.h"
32
Joel Becker24ef1812008-01-29 17:37:32 -080033#include "stackglue.h"
34
Joel Becker9c6c8772008-02-01 15:17:30 -080035#define OCFS2_STACK_PLUGIN_O2CB "o2cb"
36#define OCFS2_STACK_PLUGIN_USER "user"
Joel Becker9f9a99f2008-05-30 15:43:58 -070037#define OCFS2_MAX_HB_CTL_PATH 256
Joel Becker9c6c8772008-02-01 15:17:30 -080038
Joel Becker286eaa92008-02-01 15:03:57 -080039static struct ocfs2_locking_protocol *lproto;
40static DEFINE_SPINLOCK(ocfs2_stack_lock);
41static LIST_HEAD(ocfs2_stack_list);
Joel Becker9c6c8772008-02-01 15:17:30 -080042static char cluster_stack_name[OCFS2_STACK_LABEL_LEN + 1];
Joel Becker9f9a99f2008-05-30 15:43:58 -070043static char ocfs2_hb_ctl_path[OCFS2_MAX_HB_CTL_PATH] = "/sbin/ocfs2_hb_ctl";
Joel Becker286eaa92008-02-01 15:03:57 -080044
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 */
49static struct ocfs2_stack_plugin *active_stack;
50
51static 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
Joel Becker9c6c8772008-02-01 15:17:30 -080065static int ocfs2_stack_driver_request(const char *stack_name,
66 const char *plugin_name)
Joel Becker286eaa92008-02-01 15:03:57 -080067{
68 int rc;
69 struct ocfs2_stack_plugin *p;
70
71 spin_lock(&ocfs2_stack_lock);
72
Joel Becker9c6c8772008-02-01 15:17:30 -080073 /*
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
Joel Becker286eaa92008-02-01 15:03:57 -080082 if (active_stack) {
83 /*
84 * If the active stack isn't the one we want, it cannot
85 * be selected right now.
86 */
Joel Becker9c6c8772008-02-01 15:17:30 -080087 if (!strcmp(active_stack->sp_name, plugin_name))
Joel Becker286eaa92008-02-01 15:03:57 -080088 rc = 0;
89 else
90 rc = -EBUSY;
91 goto out;
92 }
93
Joel Becker9c6c8772008-02-01 15:17:30 -080094 p = ocfs2_stack_lookup(plugin_name);
Joel Becker286eaa92008-02-01 15:03:57 -080095 if (!p || !try_module_get(p->sp_owner)) {
96 rc = -ENOENT;
97 goto out;
98 }
99
Joel Becker286eaa92008-02-01 15:03:57 -0800100 active_stack = p;
Joel Becker286eaa92008-02-01 15:03:57 -0800101 rc = 0;
102
103out:
Joel Beckerd6817cd2008-08-22 14:30:10 -0700104 /* If we found it, pin it */
105 if (!rc)
106 active_stack->sp_count++;
107
Joel Becker286eaa92008-02-01 15:03:57 -0800108 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 */
Joel Becker9c6c8772008-02-01 15:17:30 -0800117static int ocfs2_stack_driver_get(const char *stack_name)
Joel Becker286eaa92008-02-01 15:03:57 -0800118{
119 int rc;
Joel Becker9c6c8772008-02-01 15:17:30 -0800120 char *plugin_name = OCFS2_STACK_PLUGIN_O2CB;
Joel Becker286eaa92008-02-01 15:03:57 -0800121
Joel Becker9c6c8772008-02-01 15:17:30 -0800122 /*
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);
Joel Becker286eaa92008-02-01 15:03:57 -0800141 if (rc == -ENOENT) {
Joel Becker9c6c8772008-02-01 15:17:30 -0800142 request_module("ocfs2_stack_%s", plugin_name);
143 rc = ocfs2_stack_driver_request(stack_name, plugin_name);
Joel Becker286eaa92008-02-01 15:03:57 -0800144 }
145
146 if (rc == -ENOENT) {
147 printk(KERN_ERR
148 "ocfs2: Cluster stack driver \"%s\" cannot be found\n",
Joel Becker9c6c8772008-02-01 15:17:30 -0800149 plugin_name);
Joel Becker286eaa92008-02-01 15:03:57 -0800150 } else if (rc == -EBUSY) {
151 printk(KERN_ERR
Joel Becker9c6c8772008-02-01 15:17:30 -0800152 "ocfs2: A different cluster stack is in use\n");
Joel Becker286eaa92008-02-01 15:03:57 -0800153 }
154
155 return rc;
156}
157
158static 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
172int 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}
193EXPORT_SYMBOL_GPL(ocfs2_stack_glue_register);
194
195void 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}
214EXPORT_SYMBOL_GPL(ocfs2_stack_glue_unregister);
215
216void 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}
232EXPORT_SYMBOL_GPL(ocfs2_stack_glue_set_locking_protocol);
Joel Becker24ef1812008-01-29 17:37:32 -0800233
Joel Becker24ef1812008-01-29 17:37:32 -0800234
David Teiglandcf4d8d72008-02-20 14:29:27 -0800235/*
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 */
Joel Becker553aa7e2008-02-01 14:51:03 -0800242int 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,
David Teiglandcf4d8d72008-02-20 14:29:27 -0800248 struct ocfs2_lock_res *astarg)
Joel Becker553aa7e2008-02-01 14:51:03 -0800249{
Joel Becker286eaa92008-02-01 15:03:57 -0800250 BUG_ON(lproto == NULL);
Joel Becker553aa7e2008-02-01 14:51:03 -0800251
Joel Becker286eaa92008-02-01 15:03:57 -0800252 return active_stack->sp_ops->dlm_lock(conn, mode, lksb, flags,
253 name, namelen, astarg);
Joel Becker24ef1812008-01-29 17:37:32 -0800254}
Joel Becker286eaa92008-02-01 15:03:57 -0800255EXPORT_SYMBOL_GPL(ocfs2_dlm_lock);
Joel Becker24ef1812008-01-29 17:37:32 -0800256
Joel Becker553aa7e2008-02-01 14:51:03 -0800257int ocfs2_dlm_unlock(struct ocfs2_cluster_connection *conn,
258 union ocfs2_dlm_lksb *lksb,
259 u32 flags,
David Teiglandcf4d8d72008-02-20 14:29:27 -0800260 struct ocfs2_lock_res *astarg)
Joel Becker553aa7e2008-02-01 14:51:03 -0800261{
Joel Becker286eaa92008-02-01 15:03:57 -0800262 BUG_ON(lproto == NULL);
Joel Becker553aa7e2008-02-01 14:51:03 -0800263
Joel Becker286eaa92008-02-01 15:03:57 -0800264 return active_stack->sp_ops->dlm_unlock(conn, lksb, flags, astarg);
Joel Becker8f2c9c12008-02-01 12:16:57 -0800265}
Joel Becker286eaa92008-02-01 15:03:57 -0800266EXPORT_SYMBOL_GPL(ocfs2_dlm_unlock);
Joel Becker8f2c9c12008-02-01 12:16:57 -0800267
Joel Becker553aa7e2008-02-01 14:51:03 -0800268int ocfs2_dlm_lock_status(union ocfs2_dlm_lksb *lksb)
269{
Joel Becker286eaa92008-02-01 15:03:57 -0800270 return active_stack->sp_ops->lock_status(lksb);
Joel Becker553aa7e2008-02-01 14:51:03 -0800271}
Joel Becker286eaa92008-02-01 15:03:57 -0800272EXPORT_SYMBOL_GPL(ocfs2_dlm_lock_status);
Joel Becker553aa7e2008-02-01 14:51:03 -0800273
Joel Becker1c520df2009-06-19 15:14:13 -0700274int ocfs2_dlm_lvb_valid(union ocfs2_dlm_lksb *lksb)
275{
276 return active_stack->sp_ops->lvb_valid(lksb);
277}
278EXPORT_SYMBOL_GPL(ocfs2_dlm_lvb_valid);
279
Joel Becker553aa7e2008-02-01 14:51:03 -0800280void *ocfs2_dlm_lvb(union ocfs2_dlm_lksb *lksb)
281{
Joel Becker286eaa92008-02-01 15:03:57 -0800282 return active_stack->sp_ops->lock_lvb(lksb);
Joel Beckercf0acdc2008-01-29 16:59:55 -0800283}
Joel Becker286eaa92008-02-01 15:03:57 -0800284EXPORT_SYMBOL_GPL(ocfs2_dlm_lvb);
Joel Beckercf0acdc2008-01-29 16:59:55 -0800285
Joel Becker553aa7e2008-02-01 14:51:03 -0800286void ocfs2_dlm_dump_lksb(union ocfs2_dlm_lksb *lksb)
287{
Joel Becker286eaa92008-02-01 15:03:57 -0800288 active_stack->sp_ops->dump_lksb(lksb);
Joel Becker553aa7e2008-02-01 14:51:03 -0800289}
Joel Becker286eaa92008-02-01 15:03:57 -0800290EXPORT_SYMBOL_GPL(ocfs2_dlm_dump_lksb);
Joel Becker553aa7e2008-02-01 14:51:03 -0800291
Mark Fasheh53da4932008-07-21 14:29:16 -0700292int ocfs2_stack_supports_plocks(void)
293{
Mark Fasheh009d3752008-10-06 16:16:08 -0700294 return active_stack && active_stack->sp_ops->plock;
Mark Fasheh53da4932008-07-21 14:29:16 -0700295}
296EXPORT_SYMBOL_GPL(ocfs2_stack_supports_plocks);
297
298/*
299 * ocfs2_plock() can only be safely called if
300 * ocfs2_stack_supports_plocks() returned true
301 */
302int ocfs2_plock(struct ocfs2_cluster_connection *conn, u64 ino,
303 struct file *file, int cmd, struct file_lock *fl)
304{
305 WARN_ON_ONCE(active_stack->sp_ops->plock == NULL);
306 if (active_stack->sp_ops->plock)
307 return active_stack->sp_ops->plock(conn, ino, file, cmd, fl);
308 return -EOPNOTSUPP;
309}
310EXPORT_SYMBOL_GPL(ocfs2_plock);
311
Joel Becker9c6c8772008-02-01 15:17:30 -0800312int ocfs2_cluster_connect(const char *stack_name,
313 const char *group,
Joel Becker4670c462008-02-01 14:39:35 -0800314 int grouplen,
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;
Joel Becker4670c462008-02-01 14:39:35 -0800322
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 new_conn = kzalloc(sizeof(struct ocfs2_cluster_connection),
333 GFP_KERNEL);
334 if (!new_conn) {
335 rc = -ENOMEM;
336 goto out;
337 }
338
339 memcpy(new_conn->cc_name, group, grouplen);
340 new_conn->cc_namelen = grouplen;
341 new_conn->cc_recovery_handler = recovery_handler;
342 new_conn->cc_recovery_data = recovery_data;
343
344 /* Start the new connection at our maximum compatibility level */
Joel Becker286eaa92008-02-01 15:03:57 -0800345 new_conn->cc_version = lproto->lp_max_version;
Joel Becker4670c462008-02-01 14:39:35 -0800346
Joel Becker286eaa92008-02-01 15:03:57 -0800347 /* This will pin the stack driver if successful */
Joel Becker9c6c8772008-02-01 15:17:30 -0800348 rc = ocfs2_stack_driver_get(stack_name);
Joel Becker286eaa92008-02-01 15:03:57 -0800349 if (rc)
350 goto out_free;
351
352 rc = active_stack->sp_ops->connect(new_conn);
Joel Becker553aa7e2008-02-01 14:51:03 -0800353 if (rc) {
Joel Becker286eaa92008-02-01 15:03:57 -0800354 ocfs2_stack_driver_put();
Joel Becker4670c462008-02-01 14:39:35 -0800355 goto out_free;
356 }
357
Joel Becker4670c462008-02-01 14:39:35 -0800358 *conn = new_conn;
359
360out_free:
Joel Becker553aa7e2008-02-01 14:51:03 -0800361 if (rc)
Joel Becker4670c462008-02-01 14:39:35 -0800362 kfree(new_conn);
Joel Becker4670c462008-02-01 14:39:35 -0800363
364out:
365 return rc;
366}
Joel Becker286eaa92008-02-01 15:03:57 -0800367EXPORT_SYMBOL_GPL(ocfs2_cluster_connect);
Joel Becker4670c462008-02-01 14:39:35 -0800368
Joel Becker286eaa92008-02-01 15:03:57 -0800369/* If hangup_pending is 0, the stack driver will be dropped */
370int ocfs2_cluster_disconnect(struct ocfs2_cluster_connection *conn,
371 int hangup_pending)
Joel Becker553aa7e2008-02-01 14:51:03 -0800372{
373 int ret;
374
375 BUG_ON(conn == NULL);
376
Joel Becker2c394502008-05-30 15:58:26 -0700377 ret = active_stack->sp_ops->disconnect(conn);
Joel Becker553aa7e2008-02-01 14:51:03 -0800378
379 /* XXX Should we free it anyway? */
Joel Becker286eaa92008-02-01 15:03:57 -0800380 if (!ret) {
Joel Becker553aa7e2008-02-01 14:51:03 -0800381 kfree(conn);
Joel Becker286eaa92008-02-01 15:03:57 -0800382 if (!hangup_pending)
383 ocfs2_stack_driver_put();
384 }
Joel Becker553aa7e2008-02-01 14:51:03 -0800385
386 return ret;
387}
Joel Becker286eaa92008-02-01 15:03:57 -0800388EXPORT_SYMBOL_GPL(ocfs2_cluster_disconnect);
Joel Becker553aa7e2008-02-01 14:51:03 -0800389
Joel Becker9f9a99f2008-05-30 15:43:58 -0700390/*
391 * Leave the group for this filesystem. This is executed by a userspace
392 * program (stored in ocfs2_hb_ctl_path).
393 */
394static void ocfs2_leave_group(const char *group)
395{
396 int ret;
397 char *argv[5], *envp[3];
398
399 argv[0] = ocfs2_hb_ctl_path;
400 argv[1] = "-K";
401 argv[2] = "-u";
402 argv[3] = (char *)group;
403 argv[4] = NULL;
404
405 /* minimal command environment taken from cpu_run_sbin_hotplug */
406 envp[0] = "HOME=/";
407 envp[1] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
408 envp[2] = NULL;
409
410 ret = call_usermodehelper(argv[0], argv, envp, UMH_WAIT_PROC);
411 if (ret < 0) {
412 printk(KERN_ERR
413 "ocfs2: Error %d running user helper "
414 "\"%s %s %s %s\"\n",
415 ret, argv[0], argv[1], argv[2], argv[3]);
416 }
417}
418
419/*
420 * Hangup is a required post-umount. ocfs2-tools software expects the
421 * filesystem to call "ocfs2_hb_ctl" during unmount. This happens
422 * regardless of whether the DLM got started, so we can't do it
423 * in ocfs2_cluster_disconnect(). The ocfs2_leave_group() function does
424 * the actual work.
425 */
Joel Becker6953b4c2008-01-29 16:59:56 -0800426void ocfs2_cluster_hangup(const char *group, int grouplen)
427{
428 BUG_ON(group == NULL);
429 BUG_ON(group[grouplen] != '\0');
430
Joel Becker9f9a99f2008-05-30 15:43:58 -0700431 ocfs2_leave_group(group);
432
Joel Becker286eaa92008-02-01 15:03:57 -0800433 /* cluster_disconnect() was called with hangup_pending==1 */
434 ocfs2_stack_driver_put();
Joel Becker19fdb622008-01-30 15:38:24 -0800435}
Joel Becker286eaa92008-02-01 15:03:57 -0800436EXPORT_SYMBOL_GPL(ocfs2_cluster_hangup);
Joel Becker19fdb622008-01-30 15:38:24 -0800437
Joel Becker553aa7e2008-02-01 14:51:03 -0800438int ocfs2_cluster_this_node(unsigned int *node)
439{
Joel Becker286eaa92008-02-01 15:03:57 -0800440 return active_stack->sp_ops->this_node(node);
Joel Becker553aa7e2008-02-01 14:51:03 -0800441}
Joel Becker286eaa92008-02-01 15:03:57 -0800442EXPORT_SYMBOL_GPL(ocfs2_cluster_this_node);
Joel Becker553aa7e2008-02-01 14:51:03 -0800443
Joel Becker286eaa92008-02-01 15:03:57 -0800444
Joel Becker74ae4e12008-01-31 23:56:17 -0800445/*
446 * Sysfs bits
447 */
448
449static ssize_t ocfs2_max_locking_protocol_show(struct kobject *kobj,
450 struct kobj_attribute *attr,
451 char *buf)
452{
453 ssize_t ret = 0;
454
455 spin_lock(&ocfs2_stack_lock);
456 if (lproto)
457 ret = snprintf(buf, PAGE_SIZE, "%u.%u\n",
458 lproto->lp_max_version.pv_major,
459 lproto->lp_max_version.pv_minor);
460 spin_unlock(&ocfs2_stack_lock);
461
462 return ret;
463}
464
465static struct kobj_attribute ocfs2_attr_max_locking_protocol =
466 __ATTR(max_locking_protocol, S_IFREG | S_IRUGO,
467 ocfs2_max_locking_protocol_show, NULL);
468
469static ssize_t ocfs2_loaded_cluster_plugins_show(struct kobject *kobj,
470 struct kobj_attribute *attr,
471 char *buf)
472{
473 ssize_t ret = 0, total = 0, remain = PAGE_SIZE;
474 struct ocfs2_stack_plugin *p;
475
476 spin_lock(&ocfs2_stack_lock);
477 list_for_each_entry(p, &ocfs2_stack_list, sp_list) {
478 ret = snprintf(buf, remain, "%s\n",
479 p->sp_name);
480 if (ret < 0) {
481 total = ret;
482 break;
483 }
484 if (ret == remain) {
485 /* snprintf() didn't fit */
486 total = -E2BIG;
487 break;
488 }
489 total += ret;
490 remain -= ret;
491 }
492 spin_unlock(&ocfs2_stack_lock);
493
494 return total;
495}
496
497static struct kobj_attribute ocfs2_attr_loaded_cluster_plugins =
498 __ATTR(loaded_cluster_plugins, S_IFREG | S_IRUGO,
499 ocfs2_loaded_cluster_plugins_show, NULL);
500
501static ssize_t ocfs2_active_cluster_plugin_show(struct kobject *kobj,
502 struct kobj_attribute *attr,
503 char *buf)
504{
505 ssize_t ret = 0;
506
507 spin_lock(&ocfs2_stack_lock);
508 if (active_stack) {
509 ret = snprintf(buf, PAGE_SIZE, "%s\n",
510 active_stack->sp_name);
511 if (ret == PAGE_SIZE)
512 ret = -E2BIG;
513 }
514 spin_unlock(&ocfs2_stack_lock);
515
516 return ret;
517}
518
519static struct kobj_attribute ocfs2_attr_active_cluster_plugin =
520 __ATTR(active_cluster_plugin, S_IFREG | S_IRUGO,
521 ocfs2_active_cluster_plugin_show, NULL);
522
Joel Becker9c6c8772008-02-01 15:17:30 -0800523static ssize_t ocfs2_cluster_stack_show(struct kobject *kobj,
524 struct kobj_attribute *attr,
525 char *buf)
526{
527 ssize_t ret;
528 spin_lock(&ocfs2_stack_lock);
529 ret = snprintf(buf, PAGE_SIZE, "%s\n", cluster_stack_name);
530 spin_unlock(&ocfs2_stack_lock);
531
532 return ret;
533}
534
535static ssize_t ocfs2_cluster_stack_store(struct kobject *kobj,
536 struct kobj_attribute *attr,
537 const char *buf, size_t count)
538{
539 size_t len = count;
540 ssize_t ret;
541
542 if (len == 0)
543 return len;
544
545 if (buf[len - 1] == '\n')
546 len--;
547
548 if ((len != OCFS2_STACK_LABEL_LEN) ||
549 (strnlen(buf, len) != len))
550 return -EINVAL;
551
552 spin_lock(&ocfs2_stack_lock);
553 if (active_stack) {
554 if (!strncmp(buf, cluster_stack_name, len))
555 ret = count;
556 else
557 ret = -EBUSY;
558 } else {
559 memcpy(cluster_stack_name, buf, len);
560 ret = count;
561 }
562 spin_unlock(&ocfs2_stack_lock);
563
564 return ret;
565}
566
567
568static struct kobj_attribute ocfs2_attr_cluster_stack =
569 __ATTR(cluster_stack, S_IFREG | S_IRUGO | S_IWUSR,
570 ocfs2_cluster_stack_show,
571 ocfs2_cluster_stack_store);
572
Joel Becker74ae4e12008-01-31 23:56:17 -0800573static struct attribute *ocfs2_attrs[] = {
574 &ocfs2_attr_max_locking_protocol.attr,
575 &ocfs2_attr_loaded_cluster_plugins.attr,
576 &ocfs2_attr_active_cluster_plugin.attr,
Joel Becker9c6c8772008-02-01 15:17:30 -0800577 &ocfs2_attr_cluster_stack.attr,
Joel Becker74ae4e12008-01-31 23:56:17 -0800578 NULL,
579};
580
581static struct attribute_group ocfs2_attr_group = {
582 .attrs = ocfs2_attrs,
583};
584
585static struct kset *ocfs2_kset;
586
587static void ocfs2_sysfs_exit(void)
588{
589 kset_unregister(ocfs2_kset);
590}
591
592static int ocfs2_sysfs_init(void)
593{
594 int ret;
595
596 ocfs2_kset = kset_create_and_add("ocfs2", NULL, fs_kobj);
597 if (!ocfs2_kset)
598 return -ENOMEM;
599
600 ret = sysfs_create_group(&ocfs2_kset->kobj, &ocfs2_attr_group);
601 if (ret)
602 goto error;
603
604 return 0;
605
606error:
607 kset_unregister(ocfs2_kset);
608 return ret;
609}
610
Joel Becker3878f112008-05-30 15:30:49 -0700611/*
612 * Sysctl bits
613 *
614 * The sysctl lives at /proc/sys/fs/ocfs2/nm/hb_ctl_path. The 'nm' doesn't
615 * make as much sense in a multiple cluster stack world, but it's safer
616 * and easier to preserve the name.
617 */
618
619#define FS_OCFS2_NM 1
620
Joel Becker3878f112008-05-30 15:30:49 -0700621static ctl_table ocfs2_nm_table[] = {
622 {
623 .ctl_name = 1,
624 .procname = "hb_ctl_path",
625 .data = ocfs2_hb_ctl_path,
626 .maxlen = OCFS2_MAX_HB_CTL_PATH,
627 .mode = 0644,
628 .proc_handler = &proc_dostring,
629 .strategy = &sysctl_string,
630 },
631 { .ctl_name = 0 }
632};
633
634static ctl_table ocfs2_mod_table[] = {
635 {
636 .ctl_name = FS_OCFS2_NM,
637 .procname = "nm",
638 .data = NULL,
639 .maxlen = 0,
640 .mode = 0555,
641 .child = ocfs2_nm_table
642 },
643 { .ctl_name = 0}
644};
645
646static ctl_table ocfs2_kern_table[] = {
647 {
648 .ctl_name = FS_OCFS2,
649 .procname = "ocfs2",
650 .data = NULL,
651 .maxlen = 0,
652 .mode = 0555,
653 .child = ocfs2_mod_table
654 },
655 { .ctl_name = 0}
656};
657
658static ctl_table ocfs2_root_table[] = {
659 {
660 .ctl_name = CTL_FS,
661 .procname = "fs",
662 .data = NULL,
663 .maxlen = 0,
664 .mode = 0555,
665 .child = ocfs2_kern_table
666 },
667 { .ctl_name = 0 }
668};
669
670static struct ctl_table_header *ocfs2_table_header = NULL;
671
Joel Becker3878f112008-05-30 15:30:49 -0700672
673/*
674 * Initialization
675 */
676
Joel Becker286eaa92008-02-01 15:03:57 -0800677static int __init ocfs2_stack_glue_init(void)
Joel Becker24ef1812008-01-29 17:37:32 -0800678{
Joel Becker9c6c8772008-02-01 15:17:30 -0800679 strcpy(cluster_stack_name, OCFS2_STACK_PLUGIN_O2CB);
680
Joel Becker3878f112008-05-30 15:30:49 -0700681 ocfs2_table_header = register_sysctl_table(ocfs2_root_table);
682 if (!ocfs2_table_header) {
683 printk(KERN_ERR
684 "ocfs2 stack glue: unable to register sysctl\n");
685 return -ENOMEM; /* or something. */
686 }
687
Joel Becker74ae4e12008-01-31 23:56:17 -0800688 return ocfs2_sysfs_init();
Joel Becker24ef1812008-01-29 17:37:32 -0800689}
690
Joel Becker286eaa92008-02-01 15:03:57 -0800691static void __exit ocfs2_stack_glue_exit(void)
692{
693 lproto = NULL;
Joel Becker74ae4e12008-01-31 23:56:17 -0800694 ocfs2_sysfs_exit();
Joel Becker3878f112008-05-30 15:30:49 -0700695 if (ocfs2_table_header)
696 unregister_sysctl_table(ocfs2_table_header);
Joel Becker286eaa92008-02-01 15:03:57 -0800697}
698
699MODULE_AUTHOR("Oracle");
700MODULE_DESCRIPTION("ocfs2 cluter stack glue layer");
701MODULE_LICENSE("GPL");
702module_init(ocfs2_stack_glue_init);
703module_exit(ocfs2_stack_glue_exit);