blob: 353fc35c6748db228172b8476c42ecac8027261c [file] [log] [blame]
Joel Becker8adf0532007-11-28 14:38:40 -08001/* -*- mode: c; c-basic-offset: 8; -*-
2 * vim: noexpandtab sw=8 ts=8 sts=0:
3 *
4 * stack_user.c
5 *
6 * Code which interfaces ocfs2 with fs/dlm and a userspace stack.
7 *
8 * Copyright (C) 2007 Oracle. All rights reserved.
9 *
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public
12 * License as published by the Free Software Foundation, version 2.
13 *
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
17 * General Public License for more details.
18 */
19
20#include <linux/module.h>
Joel Becker6427a722008-02-18 19:23:28 -080021#include <linux/fs.h>
22#include <linux/miscdevice.h>
23#include <linux/mutex.h>
Arnd Bergmannb7fdf9f2008-05-20 19:16:28 +020024#include <linux/smp_lock.h>
Joel Becker6427a722008-02-18 19:23:28 -080025#include <linux/reboot.h>
Joel Becker462c7e62008-02-18 19:40:12 -080026#include <asm/uaccess.h>
Joel Becker8adf0532007-11-28 14:38:40 -080027
David Teiglandcf4d8d72008-02-20 14:29:27 -080028#include "ocfs2.h" /* For struct ocfs2_lock_res */
Joel Becker8adf0532007-11-28 14:38:40 -080029#include "stackglue.h"
30
31
Joel Becker6427a722008-02-18 19:23:28 -080032/*
33 * The control protocol starts with a handshake. Until the handshake
34 * is complete, the control device will fail all write(2)s.
35 *
36 * The handshake is simple. First, the client reads until EOF. Each line
37 * of output is a supported protocol tag. All protocol tags are a single
38 * character followed by a two hex digit version number. Currently the
39 * only things supported is T01, for "Text-base version 0x01". Next, the
Joel Beckerde870ef2008-02-18 17:07:09 -080040 * client writes the version they would like to use, including the newline.
41 * Thus, the protocol tag is 'T01\n'. If the version tag written is
42 * unknown, -EINVAL is returned. Once the negotiation is complete, the
43 * client can start sending messages.
44 *
Joel Beckerd4b95ee2008-02-20 15:39:44 -080045 * The T01 protocol has three messages. First is the "SETN" message.
Joel Becker3cfd4ab2008-02-20 14:44:34 -080046 * It has the following syntax:
47 *
48 * SETN<space><8-char-hex-nodenum><newline>
49 *
50 * This is 14 characters.
51 *
52 * The "SETN" message must be the first message following the protocol.
53 * It tells ocfs2_control the local node number.
54 *
Joel Beckerd4b95ee2008-02-20 15:39:44 -080055 * Next comes the "SETV" message. It has the following syntax:
56 *
57 * SETV<space><2-char-hex-major><space><2-char-hex-minor><newline>
58 *
59 * This is 11 characters.
60 *
61 * The "SETV" message sets the filesystem locking protocol version as
62 * negotiated by the client. The client negotiates based on the maximum
63 * version advertised in /sys/fs/ocfs2/max_locking_protocol. The major
64 * number from the "SETV" message must match
Joel Beckera12630b2008-05-09 18:49:29 -070065 * ocfs2_user_plugin.sp_proto->lp_max_version.pv_major, and the minor number
Joel Beckerd4b95ee2008-02-20 15:39:44 -080066 * must be less than or equal to ...->lp_max_version.pv_minor.
67 *
68 * Once this information has been set, mounts will be allowed. From this
69 * point on, the "DOWN" message can be sent for node down notification.
70 * It has the following syntax:
Joel Beckerde870ef2008-02-18 17:07:09 -080071 *
72 * DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline>
73 *
74 * eg:
75 *
76 * DOWN 632A924FDD844190BDA93C0DF6B94899 00000001\n
77 *
78 * This is 47 characters.
Joel Becker6427a722008-02-18 19:23:28 -080079 */
80
81/*
Joel Becker462c7e62008-02-18 19:40:12 -080082 * Whether or not the client has done the handshake.
83 * For now, we have just one protocol version.
84 */
85#define OCFS2_CONTROL_PROTO "T01\n"
86#define OCFS2_CONTROL_PROTO_LEN 4
Joel Becker3cfd4ab2008-02-20 14:44:34 -080087
88/* Handshake states */
Joel Becker462c7e62008-02-18 19:40:12 -080089#define OCFS2_CONTROL_HANDSHAKE_INVALID (0)
90#define OCFS2_CONTROL_HANDSHAKE_READ (1)
Joel Becker3cfd4ab2008-02-20 14:44:34 -080091#define OCFS2_CONTROL_HANDSHAKE_PROTOCOL (2)
92#define OCFS2_CONTROL_HANDSHAKE_VALID (3)
93
94/* Messages */
95#define OCFS2_CONTROL_MESSAGE_OP_LEN 4
96#define OCFS2_CONTROL_MESSAGE_SETNODE_OP "SETN"
97#define OCFS2_CONTROL_MESSAGE_SETNODE_TOTAL_LEN 14
Joel Beckerd4b95ee2008-02-20 15:39:44 -080098#define OCFS2_CONTROL_MESSAGE_SETVERSION_OP "SETV"
99#define OCFS2_CONTROL_MESSAGE_SETVERSION_TOTAL_LEN 11
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800100#define OCFS2_CONTROL_MESSAGE_DOWN_OP "DOWN"
Joel Beckerde870ef2008-02-18 17:07:09 -0800101#define OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN 47
102#define OCFS2_TEXT_UUID_LEN 32
Joel Beckerd4b95ee2008-02-20 15:39:44 -0800103#define OCFS2_CONTROL_MESSAGE_VERNUM_LEN 2
Joel Beckerde870ef2008-02-18 17:07:09 -0800104#define OCFS2_CONTROL_MESSAGE_NODENUM_LEN 8
Joel Becker462c7e62008-02-18 19:40:12 -0800105
106/*
Joel Becker6427a722008-02-18 19:23:28 -0800107 * ocfs2_live_connection is refcounted because the filesystem and
108 * miscdevice sides can detach in different order. Let's just be safe.
109 */
110struct ocfs2_live_connection {
111 struct list_head oc_list;
112 struct ocfs2_cluster_connection *oc_conn;
113};
114
Joel Becker462c7e62008-02-18 19:40:12 -0800115struct ocfs2_control_private {
116 struct list_head op_list;
117 int op_state;
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800118 int op_this_node;
Joel Beckerd4b95ee2008-02-20 15:39:44 -0800119 struct ocfs2_protocol_version op_proto;
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800120};
121
122/* SETN<space><8-char-hex-nodenum><newline> */
123struct ocfs2_control_message_setn {
124 char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
125 char space;
126 char nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN];
127 char newline;
128};
129
Joel Beckerd4b95ee2008-02-20 15:39:44 -0800130/* SETV<space><2-char-hex-major><space><2-char-hex-minor><newline> */
131struct ocfs2_control_message_setv {
132 char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
133 char space1;
134 char major[OCFS2_CONTROL_MESSAGE_VERNUM_LEN];
135 char space2;
136 char minor[OCFS2_CONTROL_MESSAGE_VERNUM_LEN];
137 char newline;
138};
139
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800140/* DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline> */
141struct ocfs2_control_message_down {
142 char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
143 char space1;
144 char uuid[OCFS2_TEXT_UUID_LEN];
145 char space2;
146 char nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN];
147 char newline;
148};
149
150union ocfs2_control_message {
151 char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
152 struct ocfs2_control_message_setn u_setn;
Joel Beckerd4b95ee2008-02-20 15:39:44 -0800153 struct ocfs2_control_message_setv u_setv;
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800154 struct ocfs2_control_message_down u_down;
Joel Becker462c7e62008-02-18 19:40:12 -0800155};
156
Joel Beckera12630b2008-05-09 18:49:29 -0700157static struct ocfs2_stack_plugin ocfs2_user_plugin;
David Teiglandcf4d8d72008-02-20 14:29:27 -0800158
Joel Becker6427a722008-02-18 19:23:28 -0800159static atomic_t ocfs2_control_opened;
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800160static int ocfs2_control_this_node = -1;
Joel Beckerd4b95ee2008-02-20 15:39:44 -0800161static struct ocfs2_protocol_version running_proto;
Joel Becker6427a722008-02-18 19:23:28 -0800162
163static LIST_HEAD(ocfs2_live_connection_list);
Joel Becker462c7e62008-02-18 19:40:12 -0800164static LIST_HEAD(ocfs2_control_private_list);
Joel Becker6427a722008-02-18 19:23:28 -0800165static DEFINE_MUTEX(ocfs2_control_lock);
166
Joel Becker462c7e62008-02-18 19:40:12 -0800167static inline void ocfs2_control_set_handshake_state(struct file *file,
168 int state)
169{
170 struct ocfs2_control_private *p = file->private_data;
171 p->op_state = state;
172}
173
174static inline int ocfs2_control_get_handshake_state(struct file *file)
175{
176 struct ocfs2_control_private *p = file->private_data;
177 return p->op_state;
178}
179
Joel Becker6427a722008-02-18 19:23:28 -0800180static struct ocfs2_live_connection *ocfs2_connection_find(const char *name)
181{
182 size_t len = strlen(name);
183 struct ocfs2_live_connection *c;
184
185 BUG_ON(!mutex_is_locked(&ocfs2_control_lock));
186
187 list_for_each_entry(c, &ocfs2_live_connection_list, oc_list) {
188 if ((c->oc_conn->cc_namelen == len) &&
189 !strncmp(c->oc_conn->cc_name, name, len))
190 return c;
191 }
192
193 return c;
194}
195
196/*
197 * ocfs2_live_connection structures are created underneath the ocfs2
198 * mount path. Since the VFS prevents multiple calls to
199 * fill_super(), we can't get dupes here.
200 */
201static int ocfs2_live_connection_new(struct ocfs2_cluster_connection *conn,
202 struct ocfs2_live_connection **c_ret)
203{
204 int rc = 0;
205 struct ocfs2_live_connection *c;
206
207 c = kzalloc(sizeof(struct ocfs2_live_connection), GFP_KERNEL);
208 if (!c)
209 return -ENOMEM;
210
211 mutex_lock(&ocfs2_control_lock);
212 c->oc_conn = conn;
213
214 if (atomic_read(&ocfs2_control_opened))
215 list_add(&c->oc_list, &ocfs2_live_connection_list);
216 else {
217 printk(KERN_ERR
218 "ocfs2: Userspace control daemon is not present\n");
219 rc = -ESRCH;
220 }
221
222 mutex_unlock(&ocfs2_control_lock);
223
224 if (!rc)
225 *c_ret = c;
226 else
227 kfree(c);
228
229 return rc;
230}
231
232/*
233 * This function disconnects the cluster connection from ocfs2_control.
234 * Afterwards, userspace can't affect the cluster connection.
235 */
236static void ocfs2_live_connection_drop(struct ocfs2_live_connection *c)
237{
238 mutex_lock(&ocfs2_control_lock);
239 list_del_init(&c->oc_list);
240 c->oc_conn = NULL;
241 mutex_unlock(&ocfs2_control_lock);
242
243 kfree(c);
244}
245
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800246static int ocfs2_control_cfu(void *target, size_t target_len,
247 const char __user *buf, size_t count)
Joel Becker462c7e62008-02-18 19:40:12 -0800248{
249 /* The T01 expects write(2) calls to have exactly one command */
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800250 if ((count != target_len) ||
251 (count > sizeof(union ocfs2_control_message)))
Joel Becker462c7e62008-02-18 19:40:12 -0800252 return -EINVAL;
253
254 if (copy_from_user(target, buf, target_len))
255 return -EFAULT;
256
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800257 return 0;
Joel Becker462c7e62008-02-18 19:40:12 -0800258}
259
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800260static ssize_t ocfs2_control_validate_protocol(struct file *file,
261 const char __user *buf,
262 size_t count)
Joel Becker462c7e62008-02-18 19:40:12 -0800263{
264 ssize_t ret;
265 char kbuf[OCFS2_CONTROL_PROTO_LEN];
266
267 ret = ocfs2_control_cfu(kbuf, OCFS2_CONTROL_PROTO_LEN,
268 buf, count);
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800269 if (ret)
Joel Becker462c7e62008-02-18 19:40:12 -0800270 return ret;
271
272 if (strncmp(kbuf, OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN))
273 return -EINVAL;
274
Joel Becker462c7e62008-02-18 19:40:12 -0800275 ocfs2_control_set_handshake_state(file,
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800276 OCFS2_CONTROL_HANDSHAKE_PROTOCOL);
Joel Becker462c7e62008-02-18 19:40:12 -0800277
278 return count;
279}
280
Joel Beckerde870ef2008-02-18 17:07:09 -0800281static void ocfs2_control_send_down(const char *uuid,
282 int nodenum)
283{
284 struct ocfs2_live_connection *c;
285
286 mutex_lock(&ocfs2_control_lock);
287
288 c = ocfs2_connection_find(uuid);
289 if (c) {
290 BUG_ON(c->oc_conn == NULL);
291 c->oc_conn->cc_recovery_handler(nodenum,
292 c->oc_conn->cc_recovery_data);
293 }
294
295 mutex_unlock(&ocfs2_control_lock);
296}
297
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800298/*
299 * Called whenever configuration elements are sent to /dev/ocfs2_control.
300 * If all configuration elements are present, try to set the global
Joel Beckerd4b95ee2008-02-20 15:39:44 -0800301 * values. If there is a problem, return an error. Skip any missing
302 * elements, and only bump ocfs2_control_opened when we have all elements
303 * and are successful.
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800304 */
305static int ocfs2_control_install_private(struct file *file)
Joel Beckerde870ef2008-02-18 17:07:09 -0800306{
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800307 int rc = 0;
308 int set_p = 1;
309 struct ocfs2_control_private *p = file->private_data;
310
311 BUG_ON(p->op_state != OCFS2_CONTROL_HANDSHAKE_PROTOCOL);
312
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800313 mutex_lock(&ocfs2_control_lock);
Joel Beckerd4b95ee2008-02-20 15:39:44 -0800314
315 if (p->op_this_node < 0) {
316 set_p = 0;
317 } else if ((ocfs2_control_this_node >= 0) &&
318 (ocfs2_control_this_node != p->op_this_node)) {
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800319 rc = -EINVAL;
Joel Beckerd4b95ee2008-02-20 15:39:44 -0800320 goto out_unlock;
321 }
322
323 if (!p->op_proto.pv_major) {
324 set_p = 0;
325 } else if (!list_empty(&ocfs2_live_connection_list) &&
326 ((running_proto.pv_major != p->op_proto.pv_major) ||
327 (running_proto.pv_minor != p->op_proto.pv_minor))) {
328 rc = -EINVAL;
329 goto out_unlock;
330 }
331
332 if (set_p) {
333 ocfs2_control_this_node = p->op_this_node;
334 running_proto.pv_major = p->op_proto.pv_major;
335 running_proto.pv_minor = p->op_proto.pv_minor;
336 }
337
338out_unlock:
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800339 mutex_unlock(&ocfs2_control_lock);
340
341 if (!rc && set_p) {
342 /* We set the global values successfully */
343 atomic_inc(&ocfs2_control_opened);
344 ocfs2_control_set_handshake_state(file,
345 OCFS2_CONTROL_HANDSHAKE_VALID);
346 }
347
348 return rc;
349}
350
David Teiglandcf4d8d72008-02-20 14:29:27 -0800351static int ocfs2_control_get_this_node(void)
352{
353 int rc;
354
355 mutex_lock(&ocfs2_control_lock);
356 if (ocfs2_control_this_node < 0)
357 rc = -EINVAL;
358 else
359 rc = ocfs2_control_this_node;
360 mutex_unlock(&ocfs2_control_lock);
361
362 return rc;
363}
364
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800365static int ocfs2_control_do_setnode_msg(struct file *file,
366 struct ocfs2_control_message_setn *msg)
367{
Joel Beckerde870ef2008-02-18 17:07:09 -0800368 long nodenum;
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800369 char *ptr = NULL;
370 struct ocfs2_control_private *p = file->private_data;
Joel Beckerde870ef2008-02-18 17:07:09 -0800371
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800372 if (ocfs2_control_get_handshake_state(file) !=
373 OCFS2_CONTROL_HANDSHAKE_PROTOCOL)
Joel Beckerde870ef2008-02-18 17:07:09 -0800374 return -EINVAL;
375
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800376 if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_SETNODE_OP,
377 OCFS2_CONTROL_MESSAGE_OP_LEN))
Joel Beckerde870ef2008-02-18 17:07:09 -0800378 return -EINVAL;
Joel Beckerde870ef2008-02-18 17:07:09 -0800379
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800380 if ((msg->space != ' ') || (msg->newline != '\n'))
381 return -EINVAL;
382 msg->space = msg->newline = '\0';
383
384 nodenum = simple_strtol(msg->nodestr, &ptr, 16);
385 if (!ptr || *ptr)
386 return -EINVAL;
387
388 if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) ||
389 (nodenum > INT_MAX) || (nodenum < 0))
390 return -ERANGE;
391 p->op_this_node = nodenum;
392
393 return ocfs2_control_install_private(file);
394}
395
Joel Beckerd4b95ee2008-02-20 15:39:44 -0800396static int ocfs2_control_do_setversion_msg(struct file *file,
397 struct ocfs2_control_message_setv *msg)
398 {
399 long major, minor;
400 char *ptr = NULL;
401 struct ocfs2_control_private *p = file->private_data;
402 struct ocfs2_protocol_version *max =
Joel Beckera12630b2008-05-09 18:49:29 -0700403 &ocfs2_user_plugin.sp_proto->lp_max_version;
Joel Beckerd4b95ee2008-02-20 15:39:44 -0800404
405 if (ocfs2_control_get_handshake_state(file) !=
406 OCFS2_CONTROL_HANDSHAKE_PROTOCOL)
407 return -EINVAL;
408
409 if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_SETVERSION_OP,
410 OCFS2_CONTROL_MESSAGE_OP_LEN))
411 return -EINVAL;
412
413 if ((msg->space1 != ' ') || (msg->space2 != ' ') ||
414 (msg->newline != '\n'))
415 return -EINVAL;
416 msg->space1 = msg->space2 = msg->newline = '\0';
417
418 major = simple_strtol(msg->major, &ptr, 16);
419 if (!ptr || *ptr)
420 return -EINVAL;
421 minor = simple_strtol(msg->minor, &ptr, 16);
422 if (!ptr || *ptr)
423 return -EINVAL;
424
425 /*
426 * The major must be between 1 and 255, inclusive. The minor
427 * must be between 0 and 255, inclusive. The version passed in
428 * must be within the maximum version supported by the filesystem.
429 */
430 if ((major == LONG_MIN) || (major == LONG_MAX) ||
431 (major > (u8)-1) || (major < 1))
432 return -ERANGE;
433 if ((minor == LONG_MIN) || (minor == LONG_MAX) ||
434 (minor > (u8)-1) || (minor < 0))
435 return -ERANGE;
436 if ((major != max->pv_major) ||
437 (minor > max->pv_minor))
438 return -EINVAL;
439
440 p->op_proto.pv_major = major;
441 p->op_proto.pv_minor = minor;
442
443 return ocfs2_control_install_private(file);
444}
445
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800446static int ocfs2_control_do_down_msg(struct file *file,
447 struct ocfs2_control_message_down *msg)
448{
449 long nodenum;
450 char *p = NULL;
451
452 if (ocfs2_control_get_handshake_state(file) !=
453 OCFS2_CONTROL_HANDSHAKE_VALID)
454 return -EINVAL;
455
456 if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_DOWN_OP,
457 OCFS2_CONTROL_MESSAGE_OP_LEN))
458 return -EINVAL;
459
460 if ((msg->space1 != ' ') || (msg->space2 != ' ') ||
461 (msg->newline != '\n'))
462 return -EINVAL;
463 msg->space1 = msg->space2 = msg->newline = '\0';
464
465 nodenum = simple_strtol(msg->nodestr, &p, 16);
Joel Beckerde870ef2008-02-18 17:07:09 -0800466 if (!p || *p)
467 return -EINVAL;
468
469 if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) ||
470 (nodenum > INT_MAX) || (nodenum < 0))
471 return -ERANGE;
472
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800473 ocfs2_control_send_down(msg->uuid, nodenum);
Joel Beckerde870ef2008-02-18 17:07:09 -0800474
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800475 return 0;
476}
477
478static ssize_t ocfs2_control_message(struct file *file,
479 const char __user *buf,
480 size_t count)
481{
482 ssize_t ret;
483 union ocfs2_control_message msg;
484
485 /* Try to catch padding issues */
486 WARN_ON(offsetof(struct ocfs2_control_message_down, uuid) !=
487 (sizeof(msg.u_down.tag) + sizeof(msg.u_down.space1)));
488
489 memset(&msg, 0, sizeof(union ocfs2_control_message));
490 ret = ocfs2_control_cfu(&msg, count, buf, count);
491 if (ret)
492 goto out;
493
494 if ((count == OCFS2_CONTROL_MESSAGE_SETNODE_TOTAL_LEN) &&
495 !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_SETNODE_OP,
496 OCFS2_CONTROL_MESSAGE_OP_LEN))
497 ret = ocfs2_control_do_setnode_msg(file, &msg.u_setn);
Joel Beckerd4b95ee2008-02-20 15:39:44 -0800498 else if ((count == OCFS2_CONTROL_MESSAGE_SETVERSION_TOTAL_LEN) &&
499 !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_SETVERSION_OP,
500 OCFS2_CONTROL_MESSAGE_OP_LEN))
501 ret = ocfs2_control_do_setversion_msg(file, &msg.u_setv);
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800502 else if ((count == OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN) &&
503 !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_DOWN_OP,
504 OCFS2_CONTROL_MESSAGE_OP_LEN))
505 ret = ocfs2_control_do_down_msg(file, &msg.u_down);
506 else
507 ret = -EINVAL;
508
509out:
510 return ret ? ret : count;
Joel Beckerde870ef2008-02-18 17:07:09 -0800511}
Joel Becker6427a722008-02-18 19:23:28 -0800512
513static ssize_t ocfs2_control_write(struct file *file,
514 const char __user *buf,
515 size_t count,
516 loff_t *ppos)
Joel Becker8adf0532007-11-28 14:38:40 -0800517{
Joel Becker462c7e62008-02-18 19:40:12 -0800518 ssize_t ret;
519
520 switch (ocfs2_control_get_handshake_state(file)) {
521 case OCFS2_CONTROL_HANDSHAKE_INVALID:
522 ret = -EINVAL;
523 break;
524
525 case OCFS2_CONTROL_HANDSHAKE_READ:
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800526 ret = ocfs2_control_validate_protocol(file, buf,
527 count);
Joel Becker462c7e62008-02-18 19:40:12 -0800528 break;
529
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800530 case OCFS2_CONTROL_HANDSHAKE_PROTOCOL:
Joel Becker462c7e62008-02-18 19:40:12 -0800531 case OCFS2_CONTROL_HANDSHAKE_VALID:
Joel Beckerde870ef2008-02-18 17:07:09 -0800532 ret = ocfs2_control_message(file, buf, count);
Joel Becker462c7e62008-02-18 19:40:12 -0800533 break;
534
535 default:
536 BUG();
537 ret = -EIO;
538 break;
539 }
540
541 return ret;
Joel Becker8adf0532007-11-28 14:38:40 -0800542}
543
Joel Becker462c7e62008-02-18 19:40:12 -0800544/*
545 * This is a naive version. If we ever have a new protocol, we'll expand
546 * it. Probably using seq_file.
547 */
Joel Becker6427a722008-02-18 19:23:28 -0800548static ssize_t ocfs2_control_read(struct file *file,
549 char __user *buf,
550 size_t count,
551 loff_t *ppos)
552{
Akinobu Mita7600c722008-06-09 16:34:23 -0700553 ssize_t ret;
Joel Becker462c7e62008-02-18 19:40:12 -0800554
Akinobu Mita7600c722008-06-09 16:34:23 -0700555 ret = simple_read_from_buffer(buf, count, ppos,
556 OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN);
Joel Becker462c7e62008-02-18 19:40:12 -0800557
558 /* Have we read the whole protocol list? */
Akinobu Mita7600c722008-06-09 16:34:23 -0700559 if (ret > 0 && *ppos >= OCFS2_CONTROL_PROTO_LEN)
Joel Becker462c7e62008-02-18 19:40:12 -0800560 ocfs2_control_set_handshake_state(file,
561 OCFS2_CONTROL_HANDSHAKE_READ);
562
Akinobu Mita7600c722008-06-09 16:34:23 -0700563 return ret;
Joel Becker6427a722008-02-18 19:23:28 -0800564}
565
566static int ocfs2_control_release(struct inode *inode, struct file *file)
567{
Joel Becker462c7e62008-02-18 19:40:12 -0800568 struct ocfs2_control_private *p = file->private_data;
569
570 mutex_lock(&ocfs2_control_lock);
571
572 if (ocfs2_control_get_handshake_state(file) !=
573 OCFS2_CONTROL_HANDSHAKE_VALID)
574 goto out;
575
Joel Becker6427a722008-02-18 19:23:28 -0800576 if (atomic_dec_and_test(&ocfs2_control_opened)) {
Joel Becker6427a722008-02-18 19:23:28 -0800577 if (!list_empty(&ocfs2_live_connection_list)) {
578 /* XXX: Do bad things! */
579 printk(KERN_ERR
580 "ocfs2: Unexpected release of ocfs2_control!\n"
581 " Loss of cluster connection requires "
582 "an emergency restart!\n");
583 emergency_restart();
584 }
Joel Beckerd4b95ee2008-02-20 15:39:44 -0800585 /*
586 * Last valid close clears the node number and resets
587 * the locking protocol version
588 */
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800589 ocfs2_control_this_node = -1;
Joel Beckerd4b95ee2008-02-20 15:39:44 -0800590 running_proto.pv_major = 0;
591 running_proto.pv_major = 0;
Joel Becker6427a722008-02-18 19:23:28 -0800592 }
593
Joel Becker462c7e62008-02-18 19:40:12 -0800594out:
595 list_del_init(&p->op_list);
596 file->private_data = NULL;
597
598 mutex_unlock(&ocfs2_control_lock);
599
600 kfree(p);
601
Joel Becker6427a722008-02-18 19:23:28 -0800602 return 0;
603}
604
605static int ocfs2_control_open(struct inode *inode, struct file *file)
606{
Joel Becker462c7e62008-02-18 19:40:12 -0800607 struct ocfs2_control_private *p;
608
609 p = kzalloc(sizeof(struct ocfs2_control_private), GFP_KERNEL);
610 if (!p)
611 return -ENOMEM;
Joel Becker3cfd4ab2008-02-20 14:44:34 -0800612 p->op_this_node = -1;
Joel Becker462c7e62008-02-18 19:40:12 -0800613
Arnd Bergmannb7fdf9f2008-05-20 19:16:28 +0200614 lock_kernel();
Joel Becker462c7e62008-02-18 19:40:12 -0800615 mutex_lock(&ocfs2_control_lock);
616 file->private_data = p;
617 list_add(&p->op_list, &ocfs2_control_private_list);
618 mutex_unlock(&ocfs2_control_lock);
Arnd Bergmannb7fdf9f2008-05-20 19:16:28 +0200619 unlock_kernel();
Joel Becker6427a722008-02-18 19:23:28 -0800620
621 return 0;
622}
623
624static const struct file_operations ocfs2_control_fops = {
625 .open = ocfs2_control_open,
626 .release = ocfs2_control_release,
627 .read = ocfs2_control_read,
628 .write = ocfs2_control_write,
629 .owner = THIS_MODULE,
630};
631
Adrian Bunk4d8755b2008-04-21 11:49:26 +0300632static struct miscdevice ocfs2_control_device = {
Joel Becker6427a722008-02-18 19:23:28 -0800633 .minor = MISC_DYNAMIC_MINOR,
634 .name = "ocfs2_control",
635 .fops = &ocfs2_control_fops,
636};
637
638static int ocfs2_control_init(void)
639{
640 int rc;
641
642 atomic_set(&ocfs2_control_opened, 0);
643
644 rc = misc_register(&ocfs2_control_device);
645 if (rc)
646 printk(KERN_ERR
647 "ocfs2: Unable to register ocfs2_control device "
648 "(errno %d)\n",
649 -rc);
650
651 return rc;
652}
653
654static void ocfs2_control_exit(void)
655{
656 int rc;
657
658 rc = misc_deregister(&ocfs2_control_device);
659 if (rc)
660 printk(KERN_ERR
661 "ocfs2: Unable to deregister ocfs2_control device "
662 "(errno %d)\n",
663 -rc);
664}
665
David Teiglandcf4d8d72008-02-20 14:29:27 -0800666static struct dlm_lksb *fsdlm_astarg_to_lksb(void *astarg)
667{
668 struct ocfs2_lock_res *res = astarg;
669 return &res->l_lksb.lksb_fsdlm;
670}
671
672static void fsdlm_lock_ast_wrapper(void *astarg)
673{
674 struct dlm_lksb *lksb = fsdlm_astarg_to_lksb(astarg);
675 int status = lksb->sb_status;
676
Joel Beckera12630b2008-05-09 18:49:29 -0700677 BUG_ON(ocfs2_user_plugin.sp_proto == NULL);
David Teiglandcf4d8d72008-02-20 14:29:27 -0800678
679 /*
680 * For now we're punting on the issue of other non-standard errors
681 * where we can't tell if the unlock_ast or lock_ast should be called.
682 * The main "other error" that's possible is EINVAL which means the
683 * function was called with invalid args, which shouldn't be possible
684 * since the caller here is under our control. Other non-standard
685 * errors probably fall into the same category, or otherwise are fatal
686 * which means we can't carry on anyway.
687 */
688
689 if (status == -DLM_EUNLOCK || status == -DLM_ECANCEL)
Joel Beckera12630b2008-05-09 18:49:29 -0700690 ocfs2_user_plugin.sp_proto->lp_unlock_ast(astarg, 0);
David Teiglandcf4d8d72008-02-20 14:29:27 -0800691 else
Joel Beckera12630b2008-05-09 18:49:29 -0700692 ocfs2_user_plugin.sp_proto->lp_lock_ast(astarg);
David Teiglandcf4d8d72008-02-20 14:29:27 -0800693}
694
695static void fsdlm_blocking_ast_wrapper(void *astarg, int level)
696{
Joel Beckera12630b2008-05-09 18:49:29 -0700697 BUG_ON(ocfs2_user_plugin.sp_proto == NULL);
David Teiglandcf4d8d72008-02-20 14:29:27 -0800698
Joel Beckera12630b2008-05-09 18:49:29 -0700699 ocfs2_user_plugin.sp_proto->lp_blocking_ast(astarg, level);
David Teiglandcf4d8d72008-02-20 14:29:27 -0800700}
701
702static int user_dlm_lock(struct ocfs2_cluster_connection *conn,
703 int mode,
704 union ocfs2_dlm_lksb *lksb,
705 u32 flags,
706 void *name,
707 unsigned int namelen,
708 void *astarg)
709{
710 int ret;
711
712 if (!lksb->lksb_fsdlm.sb_lvbptr)
713 lksb->lksb_fsdlm.sb_lvbptr = (char *)lksb +
714 sizeof(struct dlm_lksb);
715
716 ret = dlm_lock(conn->cc_lockspace, mode, &lksb->lksb_fsdlm,
717 flags|DLM_LKF_NODLCKWT, name, namelen, 0,
718 fsdlm_lock_ast_wrapper, astarg,
719 fsdlm_blocking_ast_wrapper);
720 return ret;
721}
722
723static int user_dlm_unlock(struct ocfs2_cluster_connection *conn,
724 union ocfs2_dlm_lksb *lksb,
725 u32 flags,
726 void *astarg)
727{
728 int ret;
729
730 ret = dlm_unlock(conn->cc_lockspace, lksb->lksb_fsdlm.sb_lkid,
731 flags, &lksb->lksb_fsdlm, astarg);
732 return ret;
733}
734
735static int user_dlm_lock_status(union ocfs2_dlm_lksb *lksb)
736{
737 return lksb->lksb_fsdlm.sb_status;
738}
739
740static void *user_dlm_lvb(union ocfs2_dlm_lksb *lksb)
741{
742 return (void *)(lksb->lksb_fsdlm.sb_lvbptr);
743}
744
745static void user_dlm_dump_lksb(union ocfs2_dlm_lksb *lksb)
746{
747}
748
749/*
750 * Compare a requested locking protocol version against the current one.
751 *
752 * If the major numbers are different, they are incompatible.
753 * If the current minor is greater than the request, they are incompatible.
754 * If the current minor is less than or equal to the request, they are
755 * compatible, and the requester should run at the current minor version.
756 */
757static int fs_protocol_compare(struct ocfs2_protocol_version *existing,
758 struct ocfs2_protocol_version *request)
759{
760 if (existing->pv_major != request->pv_major)
761 return 1;
762
763 if (existing->pv_minor > request->pv_minor)
764 return 1;
765
766 if (existing->pv_minor < request->pv_minor)
767 request->pv_minor = existing->pv_minor;
768
769 return 0;
770}
771
772static int user_cluster_connect(struct ocfs2_cluster_connection *conn)
773{
774 dlm_lockspace_t *fsdlm;
775 struct ocfs2_live_connection *control;
776 int rc = 0;
777
778 BUG_ON(conn == NULL);
779
780 rc = ocfs2_live_connection_new(conn, &control);
781 if (rc)
782 goto out;
783
784 /*
785 * running_proto must have been set before we allowed any mounts
786 * to proceed.
787 */
788 if (fs_protocol_compare(&running_proto, &conn->cc_version)) {
789 printk(KERN_ERR
790 "Unable to mount with fs locking protocol version "
791 "%u.%u because the userspace control daemon has "
792 "negotiated %u.%u\n",
793 conn->cc_version.pv_major, conn->cc_version.pv_minor,
794 running_proto.pv_major, running_proto.pv_minor);
795 rc = -EPROTO;
796 ocfs2_live_connection_drop(control);
797 goto out;
798 }
799
800 rc = dlm_new_lockspace(conn->cc_name, strlen(conn->cc_name),
801 &fsdlm, DLM_LSFL_FS, DLM_LVB_LEN);
802 if (rc) {
803 ocfs2_live_connection_drop(control);
804 goto out;
805 }
806
807 conn->cc_private = control;
808 conn->cc_lockspace = fsdlm;
809out:
810 return rc;
811}
812
Joel Becker2c394502008-05-30 15:58:26 -0700813static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn)
David Teiglandcf4d8d72008-02-20 14:29:27 -0800814{
815 dlm_release_lockspace(conn->cc_lockspace, 2);
816 conn->cc_lockspace = NULL;
817 ocfs2_live_connection_drop(conn->cc_private);
818 conn->cc_private = NULL;
819 return 0;
820}
821
822static int user_cluster_this_node(unsigned int *this_node)
823{
824 int rc;
825
826 rc = ocfs2_control_get_this_node();
827 if (rc < 0)
828 return rc;
829
830 *this_node = rc;
831 return 0;
832}
833
Joel Beckera12630b2008-05-09 18:49:29 -0700834static struct ocfs2_stack_operations ocfs2_user_plugin_ops = {
David Teiglandcf4d8d72008-02-20 14:29:27 -0800835 .connect = user_cluster_connect,
836 .disconnect = user_cluster_disconnect,
837 .this_node = user_cluster_this_node,
838 .dlm_lock = user_dlm_lock,
839 .dlm_unlock = user_dlm_unlock,
840 .lock_status = user_dlm_lock_status,
841 .lock_lvb = user_dlm_lvb,
842 .dump_lksb = user_dlm_dump_lksb,
843};
844
Joel Beckera12630b2008-05-09 18:49:29 -0700845static struct ocfs2_stack_plugin ocfs2_user_plugin = {
David Teiglandcf4d8d72008-02-20 14:29:27 -0800846 .sp_name = "user",
Joel Beckera12630b2008-05-09 18:49:29 -0700847 .sp_ops = &ocfs2_user_plugin_ops,
David Teiglandcf4d8d72008-02-20 14:29:27 -0800848 .sp_owner = THIS_MODULE,
849};
850
851
Joel Beckera12630b2008-05-09 18:49:29 -0700852static int __init ocfs2_user_plugin_init(void)
Joel Becker6427a722008-02-18 19:23:28 -0800853{
David Teiglandcf4d8d72008-02-20 14:29:27 -0800854 int rc;
855
856 rc = ocfs2_control_init();
857 if (!rc) {
Joel Beckera12630b2008-05-09 18:49:29 -0700858 rc = ocfs2_stack_glue_register(&ocfs2_user_plugin);
David Teiglandcf4d8d72008-02-20 14:29:27 -0800859 if (rc)
860 ocfs2_control_exit();
861 }
862
863 return rc;
Joel Becker6427a722008-02-18 19:23:28 -0800864}
865
Joel Beckera12630b2008-05-09 18:49:29 -0700866static void __exit ocfs2_user_plugin_exit(void)
Joel Becker8adf0532007-11-28 14:38:40 -0800867{
Joel Beckera12630b2008-05-09 18:49:29 -0700868 ocfs2_stack_glue_unregister(&ocfs2_user_plugin);
Joel Becker6427a722008-02-18 19:23:28 -0800869 ocfs2_control_exit();
Joel Becker8adf0532007-11-28 14:38:40 -0800870}
871
872MODULE_AUTHOR("Oracle");
873MODULE_DESCRIPTION("ocfs2 driver for userspace cluster stacks");
874MODULE_LICENSE("GPL");
Joel Beckera12630b2008-05-09 18:49:29 -0700875module_init(ocfs2_user_plugin_init);
876module_exit(ocfs2_user_plugin_exit);