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1/* -*- 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>
21#include <linux/fs.h>
22#include <linux/miscdevice.h>
23#include <linux/mutex.h>
24#include <linux/slab.h>
25#include <linux/reboot.h>
26#include <asm/uaccess.h>
27
28#include "stackglue.h"
29
30#include <linux/dlm_plock.h>
31
32/*
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
40 * 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 *
45 * The T01 protocol has three messages. First is the "SETN" message.
46 * 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 *
55 * 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
65 * ocfs2_user_plugin.sp_max_proto.pv_major, and the minor number
66 * must be less than or equal to ...sp_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:
71 *
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.
79 */
80
81/*
82 * 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
87
88/* Handshake states */
89#define OCFS2_CONTROL_HANDSHAKE_INVALID (0)
90#define OCFS2_CONTROL_HANDSHAKE_READ (1)
91#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
98#define OCFS2_CONTROL_MESSAGE_SETVERSION_OP "SETV"
99#define OCFS2_CONTROL_MESSAGE_SETVERSION_TOTAL_LEN 11
100#define OCFS2_CONTROL_MESSAGE_DOWN_OP "DOWN"
101#define OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN 47
102#define OCFS2_TEXT_UUID_LEN 32
103#define OCFS2_CONTROL_MESSAGE_VERNUM_LEN 2
104#define OCFS2_CONTROL_MESSAGE_NODENUM_LEN 8
105
106/*
107 * 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
115struct ocfs2_control_private {
116 struct list_head op_list;
117 int op_state;
118 int op_this_node;
119 struct ocfs2_protocol_version op_proto;
120};
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
130/* 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
140/* 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;
153 struct ocfs2_control_message_setv u_setv;
154 struct ocfs2_control_message_down u_down;
155};
156
157static struct ocfs2_stack_plugin ocfs2_user_plugin;
158
159static atomic_t ocfs2_control_opened;
160static int ocfs2_control_this_node = -1;
161static struct ocfs2_protocol_version running_proto;
162
163static LIST_HEAD(ocfs2_live_connection_list);
164static LIST_HEAD(ocfs2_control_private_list);
165static DEFINE_MUTEX(ocfs2_control_lock);
166
167static 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
180static 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 NULL;
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
246static int ocfs2_control_cfu(void *target, size_t target_len,
247 const char __user *buf, size_t count)
248{
249 /* The T01 expects write(2) calls to have exactly one command */
250 if ((count != target_len) ||
251 (count > sizeof(union ocfs2_control_message)))
252 return -EINVAL;
253
254 if (copy_from_user(target, buf, target_len))
255 return -EFAULT;
256
257 return 0;
258}
259
260static ssize_t ocfs2_control_validate_protocol(struct file *file,
261 const char __user *buf,
262 size_t count)
263{
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);
269 if (ret)
270 return ret;
271
272 if (strncmp(kbuf, OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN))
273 return -EINVAL;
274
275 ocfs2_control_set_handshake_state(file,
276 OCFS2_CONTROL_HANDSHAKE_PROTOCOL);
277
278 return count;
279}
280
281static 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
298/*
299 * Called whenever configuration elements are sent to /dev/ocfs2_control.
300 * If all configuration elements are present, try to set the global
301 * 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.
304 */
305static int ocfs2_control_install_private(struct file *file)
306{
307 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
313 mutex_lock(&ocfs2_control_lock);
314
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)) {
319 rc = -EINVAL;
320 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:
339 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
351static 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
365static int ocfs2_control_do_setnode_msg(struct file *file,
366 struct ocfs2_control_message_setn *msg)
367{
368 long nodenum;
369 char *ptr = NULL;
370 struct ocfs2_control_private *p = file->private_data;
371
372 if (ocfs2_control_get_handshake_state(file) !=
373 OCFS2_CONTROL_HANDSHAKE_PROTOCOL)
374 return -EINVAL;
375
376 if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_SETNODE_OP,
377 OCFS2_CONTROL_MESSAGE_OP_LEN))
378 return -EINVAL;
379
380 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
396static 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 =
403 &ocfs2_user_plugin.sp_max_proto;
404
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
446static 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);
466 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
473 ocfs2_control_send_down(msg->uuid, nodenum);
474
475 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);
498 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);
502 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;
511}
512
513static ssize_t ocfs2_control_write(struct file *file,
514 const char __user *buf,
515 size_t count,
516 loff_t *ppos)
517{
518 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:
526 ret = ocfs2_control_validate_protocol(file, buf,
527 count);
528 break;
529
530 case OCFS2_CONTROL_HANDSHAKE_PROTOCOL:
531 case OCFS2_CONTROL_HANDSHAKE_VALID:
532 ret = ocfs2_control_message(file, buf, count);
533 break;
534
535 default:
536 BUG();
537 ret = -EIO;
538 break;
539 }
540
541 return ret;
542}
543
544/*
545 * This is a naive version. If we ever have a new protocol, we'll expand
546 * it. Probably using seq_file.
547 */
548static ssize_t ocfs2_control_read(struct file *file,
549 char __user *buf,
550 size_t count,
551 loff_t *ppos)
552{
553 ssize_t ret;
554
555 ret = simple_read_from_buffer(buf, count, ppos,
556 OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN);
557
558 /* Have we read the whole protocol list? */
559 if (ret > 0 && *ppos >= OCFS2_CONTROL_PROTO_LEN)
560 ocfs2_control_set_handshake_state(file,
561 OCFS2_CONTROL_HANDSHAKE_READ);
562
563 return ret;
564}
565
566static int ocfs2_control_release(struct inode *inode, struct file *file)
567{
568 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
576 if (atomic_dec_and_test(&ocfs2_control_opened)) {
577 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 }
585 /*
586 * Last valid close clears the node number and resets
587 * the locking protocol version
588 */
589 ocfs2_control_this_node = -1;
590 running_proto.pv_major = 0;
591 running_proto.pv_major = 0;
592 }
593
594out:
595 list_del_init(&p->op_list);
596 file->private_data = NULL;
597
598 mutex_unlock(&ocfs2_control_lock);
599
600 kfree(p);
601
602 return 0;
603}
604
605static int ocfs2_control_open(struct inode *inode, struct file *file)
606{
607 struct ocfs2_control_private *p;
608
609 p = kzalloc(sizeof(struct ocfs2_control_private), GFP_KERNEL);
610 if (!p)
611 return -ENOMEM;
612 p->op_this_node = -1;
613
614 mutex_lock(&ocfs2_control_lock);
615 file->private_data = p;
616 list_add(&p->op_list, &ocfs2_control_private_list);
617 mutex_unlock(&ocfs2_control_lock);
618
619 return 0;
620}
621
622static const struct file_operations ocfs2_control_fops = {
623 .open = ocfs2_control_open,
624 .release = ocfs2_control_release,
625 .read = ocfs2_control_read,
626 .write = ocfs2_control_write,
627 .owner = THIS_MODULE,
628 .llseek = default_llseek,
629};
630
631static struct miscdevice ocfs2_control_device = {
632 .minor = MISC_DYNAMIC_MINOR,
633 .name = "ocfs2_control",
634 .fops = &ocfs2_control_fops,
635};
636
637static int ocfs2_control_init(void)
638{
639 int rc;
640
641 atomic_set(&ocfs2_control_opened, 0);
642
643 rc = misc_register(&ocfs2_control_device);
644 if (rc)
645 printk(KERN_ERR
646 "ocfs2: Unable to register ocfs2_control device "
647 "(errno %d)\n",
648 -rc);
649
650 return rc;
651}
652
653static void ocfs2_control_exit(void)
654{
655 int rc;
656
657 rc = misc_deregister(&ocfs2_control_device);
658 if (rc)
659 printk(KERN_ERR
660 "ocfs2: Unable to deregister ocfs2_control device "
661 "(errno %d)\n",
662 -rc);
663}
664
665static void fsdlm_lock_ast_wrapper(void *astarg)
666{
667 struct ocfs2_dlm_lksb *lksb = astarg;
668 int status = lksb->lksb_fsdlm.sb_status;
669
670 /*
671 * For now we're punting on the issue of other non-standard errors
672 * where we can't tell if the unlock_ast or lock_ast should be called.
673 * The main "other error" that's possible is EINVAL which means the
674 * function was called with invalid args, which shouldn't be possible
675 * since the caller here is under our control. Other non-standard
676 * errors probably fall into the same category, or otherwise are fatal
677 * which means we can't carry on anyway.
678 */
679
680 if (status == -DLM_EUNLOCK || status == -DLM_ECANCEL)
681 lksb->lksb_conn->cc_proto->lp_unlock_ast(lksb, 0);
682 else
683 lksb->lksb_conn->cc_proto->lp_lock_ast(lksb);
684}
685
686static void fsdlm_blocking_ast_wrapper(void *astarg, int level)
687{
688 struct ocfs2_dlm_lksb *lksb = astarg;
689
690 lksb->lksb_conn->cc_proto->lp_blocking_ast(lksb, level);
691}
692
693static int user_dlm_lock(struct ocfs2_cluster_connection *conn,
694 int mode,
695 struct ocfs2_dlm_lksb *lksb,
696 u32 flags,
697 void *name,
698 unsigned int namelen)
699{
700 int ret;
701
702 if (!lksb->lksb_fsdlm.sb_lvbptr)
703 lksb->lksb_fsdlm.sb_lvbptr = (char *)lksb +
704 sizeof(struct dlm_lksb);
705
706 ret = dlm_lock(conn->cc_lockspace, mode, &lksb->lksb_fsdlm,
707 flags|DLM_LKF_NODLCKWT, name, namelen, 0,
708 fsdlm_lock_ast_wrapper, lksb,
709 fsdlm_blocking_ast_wrapper);
710 return ret;
711}
712
713static int user_dlm_unlock(struct ocfs2_cluster_connection *conn,
714 struct ocfs2_dlm_lksb *lksb,
715 u32 flags)
716{
717 int ret;
718
719 ret = dlm_unlock(conn->cc_lockspace, lksb->lksb_fsdlm.sb_lkid,
720 flags, &lksb->lksb_fsdlm, lksb);
721 return ret;
722}
723
724static int user_dlm_lock_status(struct ocfs2_dlm_lksb *lksb)
725{
726 return lksb->lksb_fsdlm.sb_status;
727}
728
729static int user_dlm_lvb_valid(struct ocfs2_dlm_lksb *lksb)
730{
731 int invalid = lksb->lksb_fsdlm.sb_flags & DLM_SBF_VALNOTVALID;
732
733 return !invalid;
734}
735
736static void *user_dlm_lvb(struct ocfs2_dlm_lksb *lksb)
737{
738 if (!lksb->lksb_fsdlm.sb_lvbptr)
739 lksb->lksb_fsdlm.sb_lvbptr = (char *)lksb +
740 sizeof(struct dlm_lksb);
741 return (void *)(lksb->lksb_fsdlm.sb_lvbptr);
742}
743
744static void user_dlm_dump_lksb(struct ocfs2_dlm_lksb *lksb)
745{
746}
747
748static int user_plock(struct ocfs2_cluster_connection *conn,
749 u64 ino,
750 struct file *file,
751 int cmd,
752 struct file_lock *fl)
753{
754 /*
755 * This more or less just demuxes the plock request into any
756 * one of three dlm calls.
757 *
758 * Internally, fs/dlm will pass these to a misc device, which
759 * a userspace daemon will read and write to.
760 *
761 * For now, cancel requests (which happen internally only),
762 * are turned into unlocks. Most of this function taken from
763 * gfs2_lock.
764 */
765
766 if (cmd == F_CANCELLK) {
767 cmd = F_SETLK;
768 fl->fl_type = F_UNLCK;
769 }
770
771 if (IS_GETLK(cmd))
772 return dlm_posix_get(conn->cc_lockspace, ino, file, fl);
773 else if (fl->fl_type == F_UNLCK)
774 return dlm_posix_unlock(conn->cc_lockspace, ino, file, fl);
775 else
776 return dlm_posix_lock(conn->cc_lockspace, ino, file, cmd, fl);
777}
778
779/*
780 * Compare a requested locking protocol version against the current one.
781 *
782 * If the major numbers are different, they are incompatible.
783 * If the current minor is greater than the request, they are incompatible.
784 * If the current minor is less than or equal to the request, they are
785 * compatible, and the requester should run at the current minor version.
786 */
787static int fs_protocol_compare(struct ocfs2_protocol_version *existing,
788 struct ocfs2_protocol_version *request)
789{
790 if (existing->pv_major != request->pv_major)
791 return 1;
792
793 if (existing->pv_minor > request->pv_minor)
794 return 1;
795
796 if (existing->pv_minor < request->pv_minor)
797 request->pv_minor = existing->pv_minor;
798
799 return 0;
800}
801
802static int user_cluster_connect(struct ocfs2_cluster_connection *conn)
803{
804 dlm_lockspace_t *fsdlm;
805 struct ocfs2_live_connection *uninitialized_var(control);
806 int rc = 0;
807
808 BUG_ON(conn == NULL);
809
810 rc = ocfs2_live_connection_new(conn, &control);
811 if (rc)
812 goto out;
813
814 /*
815 * running_proto must have been set before we allowed any mounts
816 * to proceed.
817 */
818 if (fs_protocol_compare(&running_proto, &conn->cc_version)) {
819 printk(KERN_ERR
820 "Unable to mount with fs locking protocol version "
821 "%u.%u because the userspace control daemon has "
822 "negotiated %u.%u\n",
823 conn->cc_version.pv_major, conn->cc_version.pv_minor,
824 running_proto.pv_major, running_proto.pv_minor);
825 rc = -EPROTO;
826 ocfs2_live_connection_drop(control);
827 goto out;
828 }
829
830 rc = dlm_new_lockspace(conn->cc_name, NULL, DLM_LSFL_FS, DLM_LVB_LEN,
831 NULL, NULL, NULL, &fsdlm);
832 if (rc) {
833 ocfs2_live_connection_drop(control);
834 goto out;
835 }
836
837 conn->cc_private = control;
838 conn->cc_lockspace = fsdlm;
839out:
840 return rc;
841}
842
843static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn)
844{
845 dlm_release_lockspace(conn->cc_lockspace, 2);
846 conn->cc_lockspace = NULL;
847 ocfs2_live_connection_drop(conn->cc_private);
848 conn->cc_private = NULL;
849 return 0;
850}
851
852static int user_cluster_this_node(unsigned int *this_node)
853{
854 int rc;
855
856 rc = ocfs2_control_get_this_node();
857 if (rc < 0)
858 return rc;
859
860 *this_node = rc;
861 return 0;
862}
863
864static struct ocfs2_stack_operations ocfs2_user_plugin_ops = {
865 .connect = user_cluster_connect,
866 .disconnect = user_cluster_disconnect,
867 .this_node = user_cluster_this_node,
868 .dlm_lock = user_dlm_lock,
869 .dlm_unlock = user_dlm_unlock,
870 .lock_status = user_dlm_lock_status,
871 .lvb_valid = user_dlm_lvb_valid,
872 .lock_lvb = user_dlm_lvb,
873 .plock = user_plock,
874 .dump_lksb = user_dlm_dump_lksb,
875};
876
877static struct ocfs2_stack_plugin ocfs2_user_plugin = {
878 .sp_name = "user",
879 .sp_ops = &ocfs2_user_plugin_ops,
880 .sp_owner = THIS_MODULE,
881};
882
883
884static int __init ocfs2_user_plugin_init(void)
885{
886 int rc;
887
888 rc = ocfs2_control_init();
889 if (!rc) {
890 rc = ocfs2_stack_glue_register(&ocfs2_user_plugin);
891 if (rc)
892 ocfs2_control_exit();
893 }
894
895 return rc;
896}
897
898static void __exit ocfs2_user_plugin_exit(void)
899{
900 ocfs2_stack_glue_unregister(&ocfs2_user_plugin);
901 ocfs2_control_exit();
902}
903
904MODULE_AUTHOR("Oracle");
905MODULE_DESCRIPTION("ocfs2 driver for userspace cluster stacks");
906MODULE_LICENSE("GPL");
907module_init(ocfs2_user_plugin_init);
908module_exit(ocfs2_user_plugin_exit);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * stack_user.c
4 *
5 * Code which interfaces ocfs2 with fs/dlm and a userspace stack.
6 *
7 * Copyright (C) 2007 Oracle. All rights reserved.
8 */
9
10#include <linux/module.h>
11#include <linux/fs.h>
12#include <linux/miscdevice.h>
13#include <linux/mutex.h>
14#include <linux/slab.h>
15#include <linux/reboot.h>
16#include <linux/sched.h>
17#include <linux/uaccess.h>
18
19#include "stackglue.h"
20
21#include <linux/dlm_plock.h>
22
23/*
24 * The control protocol starts with a handshake. Until the handshake
25 * is complete, the control device will fail all write(2)s.
26 *
27 * The handshake is simple. First, the client reads until EOF. Each line
28 * of output is a supported protocol tag. All protocol tags are a single
29 * character followed by a two hex digit version number. Currently the
30 * only things supported is T01, for "Text-base version 0x01". Next, the
31 * client writes the version they would like to use, including the newline.
32 * Thus, the protocol tag is 'T01\n'. If the version tag written is
33 * unknown, -EINVAL is returned. Once the negotiation is complete, the
34 * client can start sending messages.
35 *
36 * The T01 protocol has three messages. First is the "SETN" message.
37 * It has the following syntax:
38 *
39 * SETN<space><8-char-hex-nodenum><newline>
40 *
41 * This is 14 characters.
42 *
43 * The "SETN" message must be the first message following the protocol.
44 * It tells ocfs2_control the local node number.
45 *
46 * Next comes the "SETV" message. It has the following syntax:
47 *
48 * SETV<space><2-char-hex-major><space><2-char-hex-minor><newline>
49 *
50 * This is 11 characters.
51 *
52 * The "SETV" message sets the filesystem locking protocol version as
53 * negotiated by the client. The client negotiates based on the maximum
54 * version advertised in /sys/fs/ocfs2/max_locking_protocol. The major
55 * number from the "SETV" message must match
56 * ocfs2_user_plugin.sp_max_proto.pv_major, and the minor number
57 * must be less than or equal to ...sp_max_version.pv_minor.
58 *
59 * Once this information has been set, mounts will be allowed. From this
60 * point on, the "DOWN" message can be sent for node down notification.
61 * It has the following syntax:
62 *
63 * DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline>
64 *
65 * eg:
66 *
67 * DOWN 632A924FDD844190BDA93C0DF6B94899 00000001\n
68 *
69 * This is 47 characters.
70 */
71
72/*
73 * Whether or not the client has done the handshake.
74 * For now, we have just one protocol version.
75 */
76#define OCFS2_CONTROL_PROTO "T01\n"
77#define OCFS2_CONTROL_PROTO_LEN 4
78
79/* Handshake states */
80#define OCFS2_CONTROL_HANDSHAKE_INVALID (0)
81#define OCFS2_CONTROL_HANDSHAKE_READ (1)
82#define OCFS2_CONTROL_HANDSHAKE_PROTOCOL (2)
83#define OCFS2_CONTROL_HANDSHAKE_VALID (3)
84
85/* Messages */
86#define OCFS2_CONTROL_MESSAGE_OP_LEN 4
87#define OCFS2_CONTROL_MESSAGE_SETNODE_OP "SETN"
88#define OCFS2_CONTROL_MESSAGE_SETNODE_TOTAL_LEN 14
89#define OCFS2_CONTROL_MESSAGE_SETVERSION_OP "SETV"
90#define OCFS2_CONTROL_MESSAGE_SETVERSION_TOTAL_LEN 11
91#define OCFS2_CONTROL_MESSAGE_DOWN_OP "DOWN"
92#define OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN 47
93#define OCFS2_TEXT_UUID_LEN 32
94#define OCFS2_CONTROL_MESSAGE_VERNUM_LEN 2
95#define OCFS2_CONTROL_MESSAGE_NODENUM_LEN 8
96#define VERSION_LOCK "version_lock"
97
98enum ocfs2_connection_type {
99 WITH_CONTROLD,
100 NO_CONTROLD
101};
102
103/*
104 * ocfs2_live_connection is refcounted because the filesystem and
105 * miscdevice sides can detach in different order. Let's just be safe.
106 */
107struct ocfs2_live_connection {
108 struct list_head oc_list;
109 struct ocfs2_cluster_connection *oc_conn;
110 enum ocfs2_connection_type oc_type;
111 atomic_t oc_this_node;
112 int oc_our_slot;
113 struct dlm_lksb oc_version_lksb;
114 char oc_lvb[DLM_LVB_LEN];
115 struct completion oc_sync_wait;
116 wait_queue_head_t oc_wait;
117};
118
119struct ocfs2_control_private {
120 struct list_head op_list;
121 int op_state;
122 int op_this_node;
123 struct ocfs2_protocol_version op_proto;
124};
125
126/* SETN<space><8-char-hex-nodenum><newline> */
127struct ocfs2_control_message_setn {
128 char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
129 char space;
130 char nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN];
131 char newline;
132};
133
134/* SETV<space><2-char-hex-major><space><2-char-hex-minor><newline> */
135struct ocfs2_control_message_setv {
136 char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
137 char space1;
138 char major[OCFS2_CONTROL_MESSAGE_VERNUM_LEN];
139 char space2;
140 char minor[OCFS2_CONTROL_MESSAGE_VERNUM_LEN];
141 char newline;
142};
143
144/* DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline> */
145struct ocfs2_control_message_down {
146 char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
147 char space1;
148 char uuid[OCFS2_TEXT_UUID_LEN];
149 char space2;
150 char nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN];
151 char newline;
152};
153
154union ocfs2_control_message {
155 char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
156 struct ocfs2_control_message_setn u_setn;
157 struct ocfs2_control_message_setv u_setv;
158 struct ocfs2_control_message_down u_down;
159};
160
161static struct ocfs2_stack_plugin ocfs2_user_plugin;
162
163static atomic_t ocfs2_control_opened;
164static int ocfs2_control_this_node = -1;
165static struct ocfs2_protocol_version running_proto;
166
167static LIST_HEAD(ocfs2_live_connection_list);
168static LIST_HEAD(ocfs2_control_private_list);
169static DEFINE_MUTEX(ocfs2_control_lock);
170
171static inline void ocfs2_control_set_handshake_state(struct file *file,
172 int state)
173{
174 struct ocfs2_control_private *p = file->private_data;
175 p->op_state = state;
176}
177
178static inline int ocfs2_control_get_handshake_state(struct file *file)
179{
180 struct ocfs2_control_private *p = file->private_data;
181 return p->op_state;
182}
183
184static struct ocfs2_live_connection *ocfs2_connection_find(const char *name)
185{
186 size_t len = strlen(name);
187 struct ocfs2_live_connection *c;
188
189 BUG_ON(!mutex_is_locked(&ocfs2_control_lock));
190
191 list_for_each_entry(c, &ocfs2_live_connection_list, oc_list) {
192 if ((c->oc_conn->cc_namelen == len) &&
193 !strncmp(c->oc_conn->cc_name, name, len))
194 return c;
195 }
196
197 return NULL;
198}
199
200/*
201 * ocfs2_live_connection structures are created underneath the ocfs2
202 * mount path. Since the VFS prevents multiple calls to
203 * fill_super(), we can't get dupes here.
204 */
205static int ocfs2_live_connection_attach(struct ocfs2_cluster_connection *conn,
206 struct ocfs2_live_connection *c)
207{
208 int rc = 0;
209
210 mutex_lock(&ocfs2_control_lock);
211 c->oc_conn = conn;
212
213 if ((c->oc_type == NO_CONTROLD) || atomic_read(&ocfs2_control_opened))
214 list_add(&c->oc_list, &ocfs2_live_connection_list);
215 else {
216 printk(KERN_ERR
217 "ocfs2: Userspace control daemon is not present\n");
218 rc = -ESRCH;
219 }
220
221 mutex_unlock(&ocfs2_control_lock);
222 return rc;
223}
224
225/*
226 * This function disconnects the cluster connection from ocfs2_control.
227 * Afterwards, userspace can't affect the cluster connection.
228 */
229static void ocfs2_live_connection_drop(struct ocfs2_live_connection *c)
230{
231 mutex_lock(&ocfs2_control_lock);
232 list_del_init(&c->oc_list);
233 c->oc_conn = NULL;
234 mutex_unlock(&ocfs2_control_lock);
235
236 kfree(c);
237}
238
239static int ocfs2_control_cfu(void *target, size_t target_len,
240 const char __user *buf, size_t count)
241{
242 /* The T01 expects write(2) calls to have exactly one command */
243 if ((count != target_len) ||
244 (count > sizeof(union ocfs2_control_message)))
245 return -EINVAL;
246
247 if (copy_from_user(target, buf, target_len))
248 return -EFAULT;
249
250 return 0;
251}
252
253static ssize_t ocfs2_control_validate_protocol(struct file *file,
254 const char __user *buf,
255 size_t count)
256{
257 ssize_t ret;
258 char kbuf[OCFS2_CONTROL_PROTO_LEN];
259
260 ret = ocfs2_control_cfu(kbuf, OCFS2_CONTROL_PROTO_LEN,
261 buf, count);
262 if (ret)
263 return ret;
264
265 if (strncmp(kbuf, OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN))
266 return -EINVAL;
267
268 ocfs2_control_set_handshake_state(file,
269 OCFS2_CONTROL_HANDSHAKE_PROTOCOL);
270
271 return count;
272}
273
274static void ocfs2_control_send_down(const char *uuid,
275 int nodenum)
276{
277 struct ocfs2_live_connection *c;
278
279 mutex_lock(&ocfs2_control_lock);
280
281 c = ocfs2_connection_find(uuid);
282 if (c) {
283 BUG_ON(c->oc_conn == NULL);
284 c->oc_conn->cc_recovery_handler(nodenum,
285 c->oc_conn->cc_recovery_data);
286 }
287
288 mutex_unlock(&ocfs2_control_lock);
289}
290
291/*
292 * Called whenever configuration elements are sent to /dev/ocfs2_control.
293 * If all configuration elements are present, try to set the global
294 * values. If there is a problem, return an error. Skip any missing
295 * elements, and only bump ocfs2_control_opened when we have all elements
296 * and are successful.
297 */
298static int ocfs2_control_install_private(struct file *file)
299{
300 int rc = 0;
301 int set_p = 1;
302 struct ocfs2_control_private *p = file->private_data;
303
304 BUG_ON(p->op_state != OCFS2_CONTROL_HANDSHAKE_PROTOCOL);
305
306 mutex_lock(&ocfs2_control_lock);
307
308 if (p->op_this_node < 0) {
309 set_p = 0;
310 } else if ((ocfs2_control_this_node >= 0) &&
311 (ocfs2_control_this_node != p->op_this_node)) {
312 rc = -EINVAL;
313 goto out_unlock;
314 }
315
316 if (!p->op_proto.pv_major) {
317 set_p = 0;
318 } else if (!list_empty(&ocfs2_live_connection_list) &&
319 ((running_proto.pv_major != p->op_proto.pv_major) ||
320 (running_proto.pv_minor != p->op_proto.pv_minor))) {
321 rc = -EINVAL;
322 goto out_unlock;
323 }
324
325 if (set_p) {
326 ocfs2_control_this_node = p->op_this_node;
327 running_proto.pv_major = p->op_proto.pv_major;
328 running_proto.pv_minor = p->op_proto.pv_minor;
329 }
330
331out_unlock:
332 mutex_unlock(&ocfs2_control_lock);
333
334 if (!rc && set_p) {
335 /* We set the global values successfully */
336 atomic_inc(&ocfs2_control_opened);
337 ocfs2_control_set_handshake_state(file,
338 OCFS2_CONTROL_HANDSHAKE_VALID);
339 }
340
341 return rc;
342}
343
344static int ocfs2_control_get_this_node(void)
345{
346 int rc;
347
348 mutex_lock(&ocfs2_control_lock);
349 if (ocfs2_control_this_node < 0)
350 rc = -EINVAL;
351 else
352 rc = ocfs2_control_this_node;
353 mutex_unlock(&ocfs2_control_lock);
354
355 return rc;
356}
357
358static int ocfs2_control_do_setnode_msg(struct file *file,
359 struct ocfs2_control_message_setn *msg)
360{
361 long nodenum;
362 char *ptr = NULL;
363 struct ocfs2_control_private *p = file->private_data;
364
365 if (ocfs2_control_get_handshake_state(file) !=
366 OCFS2_CONTROL_HANDSHAKE_PROTOCOL)
367 return -EINVAL;
368
369 if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_SETNODE_OP,
370 OCFS2_CONTROL_MESSAGE_OP_LEN))
371 return -EINVAL;
372
373 if ((msg->space != ' ') || (msg->newline != '\n'))
374 return -EINVAL;
375 msg->space = msg->newline = '\0';
376
377 nodenum = simple_strtol(msg->nodestr, &ptr, 16);
378 if (!ptr || *ptr)
379 return -EINVAL;
380
381 if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) ||
382 (nodenum > INT_MAX) || (nodenum < 0))
383 return -ERANGE;
384 p->op_this_node = nodenum;
385
386 return ocfs2_control_install_private(file);
387}
388
389static int ocfs2_control_do_setversion_msg(struct file *file,
390 struct ocfs2_control_message_setv *msg)
391{
392 long major, minor;
393 char *ptr = NULL;
394 struct ocfs2_control_private *p = file->private_data;
395 struct ocfs2_protocol_version *max =
396 &ocfs2_user_plugin.sp_max_proto;
397
398 if (ocfs2_control_get_handshake_state(file) !=
399 OCFS2_CONTROL_HANDSHAKE_PROTOCOL)
400 return -EINVAL;
401
402 if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_SETVERSION_OP,
403 OCFS2_CONTROL_MESSAGE_OP_LEN))
404 return -EINVAL;
405
406 if ((msg->space1 != ' ') || (msg->space2 != ' ') ||
407 (msg->newline != '\n'))
408 return -EINVAL;
409 msg->space1 = msg->space2 = msg->newline = '\0';
410
411 major = simple_strtol(msg->major, &ptr, 16);
412 if (!ptr || *ptr)
413 return -EINVAL;
414 minor = simple_strtol(msg->minor, &ptr, 16);
415 if (!ptr || *ptr)
416 return -EINVAL;
417
418 /*
419 * The major must be between 1 and 255, inclusive. The minor
420 * must be between 0 and 255, inclusive. The version passed in
421 * must be within the maximum version supported by the filesystem.
422 */
423 if ((major == LONG_MIN) || (major == LONG_MAX) ||
424 (major > (u8)-1) || (major < 1))
425 return -ERANGE;
426 if ((minor == LONG_MIN) || (minor == LONG_MAX) ||
427 (minor > (u8)-1) || (minor < 0))
428 return -ERANGE;
429 if ((major != max->pv_major) ||
430 (minor > max->pv_minor))
431 return -EINVAL;
432
433 p->op_proto.pv_major = major;
434 p->op_proto.pv_minor = minor;
435
436 return ocfs2_control_install_private(file);
437}
438
439static int ocfs2_control_do_down_msg(struct file *file,
440 struct ocfs2_control_message_down *msg)
441{
442 long nodenum;
443 char *p = NULL;
444
445 if (ocfs2_control_get_handshake_state(file) !=
446 OCFS2_CONTROL_HANDSHAKE_VALID)
447 return -EINVAL;
448
449 if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_DOWN_OP,
450 OCFS2_CONTROL_MESSAGE_OP_LEN))
451 return -EINVAL;
452
453 if ((msg->space1 != ' ') || (msg->space2 != ' ') ||
454 (msg->newline != '\n'))
455 return -EINVAL;
456 msg->space1 = msg->space2 = msg->newline = '\0';
457
458 nodenum = simple_strtol(msg->nodestr, &p, 16);
459 if (!p || *p)
460 return -EINVAL;
461
462 if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) ||
463 (nodenum > INT_MAX) || (nodenum < 0))
464 return -ERANGE;
465
466 ocfs2_control_send_down(msg->uuid, nodenum);
467
468 return 0;
469}
470
471static ssize_t ocfs2_control_message(struct file *file,
472 const char __user *buf,
473 size_t count)
474{
475 ssize_t ret;
476 union ocfs2_control_message msg;
477
478 /* Try to catch padding issues */
479 WARN_ON(offsetof(struct ocfs2_control_message_down, uuid) !=
480 (sizeof(msg.u_down.tag) + sizeof(msg.u_down.space1)));
481
482 memset(&msg, 0, sizeof(union ocfs2_control_message));
483 ret = ocfs2_control_cfu(&msg, count, buf, count);
484 if (ret)
485 goto out;
486
487 if ((count == OCFS2_CONTROL_MESSAGE_SETNODE_TOTAL_LEN) &&
488 !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_SETNODE_OP,
489 OCFS2_CONTROL_MESSAGE_OP_LEN))
490 ret = ocfs2_control_do_setnode_msg(file, &msg.u_setn);
491 else if ((count == OCFS2_CONTROL_MESSAGE_SETVERSION_TOTAL_LEN) &&
492 !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_SETVERSION_OP,
493 OCFS2_CONTROL_MESSAGE_OP_LEN))
494 ret = ocfs2_control_do_setversion_msg(file, &msg.u_setv);
495 else if ((count == OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN) &&
496 !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_DOWN_OP,
497 OCFS2_CONTROL_MESSAGE_OP_LEN))
498 ret = ocfs2_control_do_down_msg(file, &msg.u_down);
499 else
500 ret = -EINVAL;
501
502out:
503 return ret ? ret : count;
504}
505
506static ssize_t ocfs2_control_write(struct file *file,
507 const char __user *buf,
508 size_t count,
509 loff_t *ppos)
510{
511 ssize_t ret;
512
513 switch (ocfs2_control_get_handshake_state(file)) {
514 case OCFS2_CONTROL_HANDSHAKE_INVALID:
515 ret = -EINVAL;
516 break;
517
518 case OCFS2_CONTROL_HANDSHAKE_READ:
519 ret = ocfs2_control_validate_protocol(file, buf,
520 count);
521 break;
522
523 case OCFS2_CONTROL_HANDSHAKE_PROTOCOL:
524 case OCFS2_CONTROL_HANDSHAKE_VALID:
525 ret = ocfs2_control_message(file, buf, count);
526 break;
527
528 default:
529 BUG();
530 ret = -EIO;
531 break;
532 }
533
534 return ret;
535}
536
537/*
538 * This is a naive version. If we ever have a new protocol, we'll expand
539 * it. Probably using seq_file.
540 */
541static ssize_t ocfs2_control_read(struct file *file,
542 char __user *buf,
543 size_t count,
544 loff_t *ppos)
545{
546 ssize_t ret;
547
548 ret = simple_read_from_buffer(buf, count, ppos,
549 OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN);
550
551 /* Have we read the whole protocol list? */
552 if (ret > 0 && *ppos >= OCFS2_CONTROL_PROTO_LEN)
553 ocfs2_control_set_handshake_state(file,
554 OCFS2_CONTROL_HANDSHAKE_READ);
555
556 return ret;
557}
558
559static int ocfs2_control_release(struct inode *inode, struct file *file)
560{
561 struct ocfs2_control_private *p = file->private_data;
562
563 mutex_lock(&ocfs2_control_lock);
564
565 if (ocfs2_control_get_handshake_state(file) !=
566 OCFS2_CONTROL_HANDSHAKE_VALID)
567 goto out;
568
569 if (atomic_dec_and_test(&ocfs2_control_opened)) {
570 if (!list_empty(&ocfs2_live_connection_list)) {
571 /* XXX: Do bad things! */
572 printk(KERN_ERR
573 "ocfs2: Unexpected release of ocfs2_control!\n"
574 " Loss of cluster connection requires "
575 "an emergency restart!\n");
576 emergency_restart();
577 }
578 /*
579 * Last valid close clears the node number and resets
580 * the locking protocol version
581 */
582 ocfs2_control_this_node = -1;
583 running_proto.pv_major = 0;
584 running_proto.pv_minor = 0;
585 }
586
587out:
588 list_del_init(&p->op_list);
589 file->private_data = NULL;
590
591 mutex_unlock(&ocfs2_control_lock);
592
593 kfree(p);
594
595 return 0;
596}
597
598static int ocfs2_control_open(struct inode *inode, struct file *file)
599{
600 struct ocfs2_control_private *p;
601
602 p = kzalloc(sizeof(struct ocfs2_control_private), GFP_KERNEL);
603 if (!p)
604 return -ENOMEM;
605 p->op_this_node = -1;
606
607 mutex_lock(&ocfs2_control_lock);
608 file->private_data = p;
609 list_add(&p->op_list, &ocfs2_control_private_list);
610 mutex_unlock(&ocfs2_control_lock);
611
612 return 0;
613}
614
615static const struct file_operations ocfs2_control_fops = {
616 .open = ocfs2_control_open,
617 .release = ocfs2_control_release,
618 .read = ocfs2_control_read,
619 .write = ocfs2_control_write,
620 .owner = THIS_MODULE,
621 .llseek = default_llseek,
622};
623
624static struct miscdevice ocfs2_control_device = {
625 .minor = MISC_DYNAMIC_MINOR,
626 .name = "ocfs2_control",
627 .fops = &ocfs2_control_fops,
628};
629
630static int ocfs2_control_init(void)
631{
632 int rc;
633
634 atomic_set(&ocfs2_control_opened, 0);
635
636 rc = misc_register(&ocfs2_control_device);
637 if (rc)
638 printk(KERN_ERR
639 "ocfs2: Unable to register ocfs2_control device "
640 "(errno %d)\n",
641 -rc);
642
643 return rc;
644}
645
646static void ocfs2_control_exit(void)
647{
648 misc_deregister(&ocfs2_control_device);
649}
650
651static void fsdlm_lock_ast_wrapper(void *astarg)
652{
653 struct ocfs2_dlm_lksb *lksb = astarg;
654 int status = lksb->lksb_fsdlm.sb_status;
655
656 /*
657 * For now we're punting on the issue of other non-standard errors
658 * where we can't tell if the unlock_ast or lock_ast should be called.
659 * The main "other error" that's possible is EINVAL which means the
660 * function was called with invalid args, which shouldn't be possible
661 * since the caller here is under our control. Other non-standard
662 * errors probably fall into the same category, or otherwise are fatal
663 * which means we can't carry on anyway.
664 */
665
666 if (status == -DLM_EUNLOCK || status == -DLM_ECANCEL)
667 lksb->lksb_conn->cc_proto->lp_unlock_ast(lksb, 0);
668 else
669 lksb->lksb_conn->cc_proto->lp_lock_ast(lksb);
670}
671
672static void fsdlm_blocking_ast_wrapper(void *astarg, int level)
673{
674 struct ocfs2_dlm_lksb *lksb = astarg;
675
676 lksb->lksb_conn->cc_proto->lp_blocking_ast(lksb, level);
677}
678
679static int user_dlm_lock(struct ocfs2_cluster_connection *conn,
680 int mode,
681 struct ocfs2_dlm_lksb *lksb,
682 u32 flags,
683 void *name,
684 unsigned int namelen)
685{
686 int ret;
687
688 if (!lksb->lksb_fsdlm.sb_lvbptr)
689 lksb->lksb_fsdlm.sb_lvbptr = (char *)lksb +
690 sizeof(struct dlm_lksb);
691
692 ret = dlm_lock(conn->cc_lockspace, mode, &lksb->lksb_fsdlm,
693 flags|DLM_LKF_NODLCKWT, name, namelen, 0,
694 fsdlm_lock_ast_wrapper, lksb,
695 fsdlm_blocking_ast_wrapper);
696 return ret;
697}
698
699static int user_dlm_unlock(struct ocfs2_cluster_connection *conn,
700 struct ocfs2_dlm_lksb *lksb,
701 u32 flags)
702{
703 int ret;
704
705 ret = dlm_unlock(conn->cc_lockspace, lksb->lksb_fsdlm.sb_lkid,
706 flags, &lksb->lksb_fsdlm, lksb);
707 return ret;
708}
709
710static int user_dlm_lock_status(struct ocfs2_dlm_lksb *lksb)
711{
712 return lksb->lksb_fsdlm.sb_status;
713}
714
715static int user_dlm_lvb_valid(struct ocfs2_dlm_lksb *lksb)
716{
717 int invalid = lksb->lksb_fsdlm.sb_flags & DLM_SBF_VALNOTVALID;
718
719 return !invalid;
720}
721
722static void *user_dlm_lvb(struct ocfs2_dlm_lksb *lksb)
723{
724 if (!lksb->lksb_fsdlm.sb_lvbptr)
725 lksb->lksb_fsdlm.sb_lvbptr = (char *)lksb +
726 sizeof(struct dlm_lksb);
727 return (void *)(lksb->lksb_fsdlm.sb_lvbptr);
728}
729
730static void user_dlm_dump_lksb(struct ocfs2_dlm_lksb *lksb)
731{
732}
733
734static int user_plock(struct ocfs2_cluster_connection *conn,
735 u64 ino,
736 struct file *file,
737 int cmd,
738 struct file_lock *fl)
739{
740 /*
741 * This more or less just demuxes the plock request into any
742 * one of three dlm calls.
743 *
744 * Internally, fs/dlm will pass these to a misc device, which
745 * a userspace daemon will read and write to.
746 *
747 * For now, cancel requests (which happen internally only),
748 * are turned into unlocks. Most of this function taken from
749 * gfs2_lock.
750 */
751
752 if (cmd == F_CANCELLK) {
753 cmd = F_SETLK;
754 fl->fl_type = F_UNLCK;
755 }
756
757 if (IS_GETLK(cmd))
758 return dlm_posix_get(conn->cc_lockspace, ino, file, fl);
759 else if (fl->fl_type == F_UNLCK)
760 return dlm_posix_unlock(conn->cc_lockspace, ino, file, fl);
761 else
762 return dlm_posix_lock(conn->cc_lockspace, ino, file, cmd, fl);
763}
764
765/*
766 * Compare a requested locking protocol version against the current one.
767 *
768 * If the major numbers are different, they are incompatible.
769 * If the current minor is greater than the request, they are incompatible.
770 * If the current minor is less than or equal to the request, they are
771 * compatible, and the requester should run at the current minor version.
772 */
773static int fs_protocol_compare(struct ocfs2_protocol_version *existing,
774 struct ocfs2_protocol_version *request)
775{
776 if (existing->pv_major != request->pv_major)
777 return 1;
778
779 if (existing->pv_minor > request->pv_minor)
780 return 1;
781
782 if (existing->pv_minor < request->pv_minor)
783 request->pv_minor = existing->pv_minor;
784
785 return 0;
786}
787
788static void lvb_to_version(char *lvb, struct ocfs2_protocol_version *ver)
789{
790 struct ocfs2_protocol_version *pv =
791 (struct ocfs2_protocol_version *)lvb;
792 /*
793 * ocfs2_protocol_version has two u8 variables, so we don't
794 * need any endian conversion.
795 */
796 ver->pv_major = pv->pv_major;
797 ver->pv_minor = pv->pv_minor;
798}
799
800static void version_to_lvb(struct ocfs2_protocol_version *ver, char *lvb)
801{
802 struct ocfs2_protocol_version *pv =
803 (struct ocfs2_protocol_version *)lvb;
804 /*
805 * ocfs2_protocol_version has two u8 variables, so we don't
806 * need any endian conversion.
807 */
808 pv->pv_major = ver->pv_major;
809 pv->pv_minor = ver->pv_minor;
810}
811
812static void sync_wait_cb(void *arg)
813{
814 struct ocfs2_cluster_connection *conn = arg;
815 struct ocfs2_live_connection *lc = conn->cc_private;
816 complete(&lc->oc_sync_wait);
817}
818
819static int sync_unlock(struct ocfs2_cluster_connection *conn,
820 struct dlm_lksb *lksb, char *name)
821{
822 int error;
823 struct ocfs2_live_connection *lc = conn->cc_private;
824
825 error = dlm_unlock(conn->cc_lockspace, lksb->sb_lkid, 0, lksb, conn);
826 if (error) {
827 printk(KERN_ERR "%s lkid %x error %d\n",
828 name, lksb->sb_lkid, error);
829 return error;
830 }
831
832 wait_for_completion(&lc->oc_sync_wait);
833
834 if (lksb->sb_status != -DLM_EUNLOCK) {
835 printk(KERN_ERR "%s lkid %x status %d\n",
836 name, lksb->sb_lkid, lksb->sb_status);
837 return -1;
838 }
839 return 0;
840}
841
842static int sync_lock(struct ocfs2_cluster_connection *conn,
843 int mode, uint32_t flags,
844 struct dlm_lksb *lksb, char *name)
845{
846 int error, status;
847 struct ocfs2_live_connection *lc = conn->cc_private;
848
849 error = dlm_lock(conn->cc_lockspace, mode, lksb, flags,
850 name, strlen(name),
851 0, sync_wait_cb, conn, NULL);
852 if (error) {
853 printk(KERN_ERR "%s lkid %x flags %x mode %d error %d\n",
854 name, lksb->sb_lkid, flags, mode, error);
855 return error;
856 }
857
858 wait_for_completion(&lc->oc_sync_wait);
859
860 status = lksb->sb_status;
861
862 if (status && status != -EAGAIN) {
863 printk(KERN_ERR "%s lkid %x flags %x mode %d status %d\n",
864 name, lksb->sb_lkid, flags, mode, status);
865 }
866
867 return status;
868}
869
870
871static int version_lock(struct ocfs2_cluster_connection *conn, int mode,
872 int flags)
873{
874 struct ocfs2_live_connection *lc = conn->cc_private;
875 return sync_lock(conn, mode, flags,
876 &lc->oc_version_lksb, VERSION_LOCK);
877}
878
879static int version_unlock(struct ocfs2_cluster_connection *conn)
880{
881 struct ocfs2_live_connection *lc = conn->cc_private;
882 return sync_unlock(conn, &lc->oc_version_lksb, VERSION_LOCK);
883}
884
885/* get_protocol_version()
886 *
887 * To exchange ocfs2 versioning, we use the LVB of the version dlm lock.
888 * The algorithm is:
889 * 1. Attempt to take the lock in EX mode (non-blocking).
890 * 2. If successful (which means it is the first mount), write the
891 * version number and downconvert to PR lock.
892 * 3. If unsuccessful (returns -EAGAIN), read the version from the LVB after
893 * taking the PR lock.
894 */
895
896static int get_protocol_version(struct ocfs2_cluster_connection *conn)
897{
898 int ret;
899 struct ocfs2_live_connection *lc = conn->cc_private;
900 struct ocfs2_protocol_version pv;
901
902 running_proto.pv_major =
903 ocfs2_user_plugin.sp_max_proto.pv_major;
904 running_proto.pv_minor =
905 ocfs2_user_plugin.sp_max_proto.pv_minor;
906
907 lc->oc_version_lksb.sb_lvbptr = lc->oc_lvb;
908 ret = version_lock(conn, DLM_LOCK_EX,
909 DLM_LKF_VALBLK|DLM_LKF_NOQUEUE);
910 if (!ret) {
911 conn->cc_version.pv_major = running_proto.pv_major;
912 conn->cc_version.pv_minor = running_proto.pv_minor;
913 version_to_lvb(&running_proto, lc->oc_lvb);
914 version_lock(conn, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
915 } else if (ret == -EAGAIN) {
916 ret = version_lock(conn, DLM_LOCK_PR, DLM_LKF_VALBLK);
917 if (ret)
918 goto out;
919 lvb_to_version(lc->oc_lvb, &pv);
920
921 if ((pv.pv_major != running_proto.pv_major) ||
922 (pv.pv_minor > running_proto.pv_minor)) {
923 ret = -EINVAL;
924 goto out;
925 }
926
927 conn->cc_version.pv_major = pv.pv_major;
928 conn->cc_version.pv_minor = pv.pv_minor;
929 }
930out:
931 return ret;
932}
933
934static void user_recover_prep(void *arg)
935{
936}
937
938static void user_recover_slot(void *arg, struct dlm_slot *slot)
939{
940 struct ocfs2_cluster_connection *conn = arg;
941 printk(KERN_INFO "ocfs2: Node %d/%d down. Initiating recovery.\n",
942 slot->nodeid, slot->slot);
943 conn->cc_recovery_handler(slot->nodeid, conn->cc_recovery_data);
944
945}
946
947static void user_recover_done(void *arg, struct dlm_slot *slots,
948 int num_slots, int our_slot,
949 uint32_t generation)
950{
951 struct ocfs2_cluster_connection *conn = arg;
952 struct ocfs2_live_connection *lc = conn->cc_private;
953 int i;
954
955 for (i = 0; i < num_slots; i++)
956 if (slots[i].slot == our_slot) {
957 atomic_set(&lc->oc_this_node, slots[i].nodeid);
958 break;
959 }
960
961 lc->oc_our_slot = our_slot;
962 wake_up(&lc->oc_wait);
963}
964
965static const struct dlm_lockspace_ops ocfs2_ls_ops = {
966 .recover_prep = user_recover_prep,
967 .recover_slot = user_recover_slot,
968 .recover_done = user_recover_done,
969};
970
971static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn)
972{
973 version_unlock(conn);
974 dlm_release_lockspace(conn->cc_lockspace, 2);
975 conn->cc_lockspace = NULL;
976 ocfs2_live_connection_drop(conn->cc_private);
977 conn->cc_private = NULL;
978 return 0;
979}
980
981static int user_cluster_connect(struct ocfs2_cluster_connection *conn)
982{
983 dlm_lockspace_t *fsdlm;
984 struct ocfs2_live_connection *lc;
985 int rc, ops_rv;
986
987 BUG_ON(conn == NULL);
988
989 lc = kzalloc(sizeof(struct ocfs2_live_connection), GFP_KERNEL);
990 if (!lc)
991 return -ENOMEM;
992
993 init_waitqueue_head(&lc->oc_wait);
994 init_completion(&lc->oc_sync_wait);
995 atomic_set(&lc->oc_this_node, 0);
996 conn->cc_private = lc;
997 lc->oc_type = NO_CONTROLD;
998
999 rc = dlm_new_lockspace(conn->cc_name, conn->cc_cluster_name,
1000 DLM_LSFL_FS | DLM_LSFL_NEWEXCL, DLM_LVB_LEN,
1001 &ocfs2_ls_ops, conn, &ops_rv, &fsdlm);
1002 if (rc) {
1003 if (rc == -EEXIST || rc == -EPROTO)
1004 printk(KERN_ERR "ocfs2: Unable to create the "
1005 "lockspace %s (%d), because a ocfs2-tools "
1006 "program is running on this file system "
1007 "with the same name lockspace\n",
1008 conn->cc_name, rc);
1009 goto out;
1010 }
1011
1012 if (ops_rv == -EOPNOTSUPP) {
1013 lc->oc_type = WITH_CONTROLD;
1014 printk(KERN_NOTICE "ocfs2: You seem to be using an older "
1015 "version of dlm_controld and/or ocfs2-tools."
1016 " Please consider upgrading.\n");
1017 } else if (ops_rv) {
1018 rc = ops_rv;
1019 goto out;
1020 }
1021 conn->cc_lockspace = fsdlm;
1022
1023 rc = ocfs2_live_connection_attach(conn, lc);
1024 if (rc)
1025 goto out;
1026
1027 if (lc->oc_type == NO_CONTROLD) {
1028 rc = get_protocol_version(conn);
1029 if (rc) {
1030 printk(KERN_ERR "ocfs2: Could not determine"
1031 " locking version\n");
1032 user_cluster_disconnect(conn);
1033 goto out;
1034 }
1035 wait_event(lc->oc_wait, (atomic_read(&lc->oc_this_node) > 0));
1036 }
1037
1038 /*
1039 * running_proto must have been set before we allowed any mounts
1040 * to proceed.
1041 */
1042 if (fs_protocol_compare(&running_proto, &conn->cc_version)) {
1043 printk(KERN_ERR
1044 "Unable to mount with fs locking protocol version "
1045 "%u.%u because negotiated protocol is %u.%u\n",
1046 conn->cc_version.pv_major, conn->cc_version.pv_minor,
1047 running_proto.pv_major, running_proto.pv_minor);
1048 rc = -EPROTO;
1049 ocfs2_live_connection_drop(lc);
1050 lc = NULL;
1051 }
1052
1053out:
1054 if (rc)
1055 kfree(lc);
1056 return rc;
1057}
1058
1059
1060static int user_cluster_this_node(struct ocfs2_cluster_connection *conn,
1061 unsigned int *this_node)
1062{
1063 int rc;
1064 struct ocfs2_live_connection *lc = conn->cc_private;
1065
1066 if (lc->oc_type == WITH_CONTROLD)
1067 rc = ocfs2_control_get_this_node();
1068 else if (lc->oc_type == NO_CONTROLD)
1069 rc = atomic_read(&lc->oc_this_node);
1070 else
1071 rc = -EINVAL;
1072
1073 if (rc < 0)
1074 return rc;
1075
1076 *this_node = rc;
1077 return 0;
1078}
1079
1080static struct ocfs2_stack_operations ocfs2_user_plugin_ops = {
1081 .connect = user_cluster_connect,
1082 .disconnect = user_cluster_disconnect,
1083 .this_node = user_cluster_this_node,
1084 .dlm_lock = user_dlm_lock,
1085 .dlm_unlock = user_dlm_unlock,
1086 .lock_status = user_dlm_lock_status,
1087 .lvb_valid = user_dlm_lvb_valid,
1088 .lock_lvb = user_dlm_lvb,
1089 .plock = user_plock,
1090 .dump_lksb = user_dlm_dump_lksb,
1091};
1092
1093static struct ocfs2_stack_plugin ocfs2_user_plugin = {
1094 .sp_name = "user",
1095 .sp_ops = &ocfs2_user_plugin_ops,
1096 .sp_owner = THIS_MODULE,
1097};
1098
1099
1100static int __init ocfs2_user_plugin_init(void)
1101{
1102 int rc;
1103
1104 rc = ocfs2_control_init();
1105 if (!rc) {
1106 rc = ocfs2_stack_glue_register(&ocfs2_user_plugin);
1107 if (rc)
1108 ocfs2_control_exit();
1109 }
1110
1111 return rc;
1112}
1113
1114static void __exit ocfs2_user_plugin_exit(void)
1115{
1116 ocfs2_stack_glue_unregister(&ocfs2_user_plugin);
1117 ocfs2_control_exit();
1118}
1119
1120MODULE_AUTHOR("Oracle");
1121MODULE_DESCRIPTION("ocfs2 driver for userspace cluster stacks");
1122MODULE_LICENSE("GPL");
1123module_init(ocfs2_user_plugin_init);
1124module_exit(ocfs2_user_plugin_exit);