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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 <linux/sched.h>
27#include <asm/uaccess.h>
28
29#include "stackglue.h"
30
31#include <linux/dlm_plock.h>
32
33/*
34 * The control protocol starts with a handshake. Until the handshake
35 * is complete, the control device will fail all write(2)s.
36 *
37 * The handshake is simple. First, the client reads until EOF. Each line
38 * of output is a supported protocol tag. All protocol tags are a single
39 * character followed by a two hex digit version number. Currently the
40 * only things supported is T01, for "Text-base version 0x01". Next, the
41 * client writes the version they would like to use, including the newline.
42 * Thus, the protocol tag is 'T01\n'. If the version tag written is
43 * unknown, -EINVAL is returned. Once the negotiation is complete, the
44 * client can start sending messages.
45 *
46 * The T01 protocol has three messages. First is the "SETN" message.
47 * It has the following syntax:
48 *
49 * SETN<space><8-char-hex-nodenum><newline>
50 *
51 * This is 14 characters.
52 *
53 * The "SETN" message must be the first message following the protocol.
54 * It tells ocfs2_control the local node number.
55 *
56 * Next comes the "SETV" message. It has the following syntax:
57 *
58 * SETV<space><2-char-hex-major><space><2-char-hex-minor><newline>
59 *
60 * This is 11 characters.
61 *
62 * The "SETV" message sets the filesystem locking protocol version as
63 * negotiated by the client. The client negotiates based on the maximum
64 * version advertised in /sys/fs/ocfs2/max_locking_protocol. The major
65 * number from the "SETV" message must match
66 * ocfs2_user_plugin.sp_max_proto.pv_major, and the minor number
67 * must be less than or equal to ...sp_max_version.pv_minor.
68 *
69 * Once this information has been set, mounts will be allowed. From this
70 * point on, the "DOWN" message can be sent for node down notification.
71 * It has the following syntax:
72 *
73 * DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline>
74 *
75 * eg:
76 *
77 * DOWN 632A924FDD844190BDA93C0DF6B94899 00000001\n
78 *
79 * This is 47 characters.
80 */
81
82/*
83 * Whether or not the client has done the handshake.
84 * For now, we have just one protocol version.
85 */
86#define OCFS2_CONTROL_PROTO "T01\n"
87#define OCFS2_CONTROL_PROTO_LEN 4
88
89/* Handshake states */
90#define OCFS2_CONTROL_HANDSHAKE_INVALID (0)
91#define OCFS2_CONTROL_HANDSHAKE_READ (1)
92#define OCFS2_CONTROL_HANDSHAKE_PROTOCOL (2)
93#define OCFS2_CONTROL_HANDSHAKE_VALID (3)
94
95/* Messages */
96#define OCFS2_CONTROL_MESSAGE_OP_LEN 4
97#define OCFS2_CONTROL_MESSAGE_SETNODE_OP "SETN"
98#define OCFS2_CONTROL_MESSAGE_SETNODE_TOTAL_LEN 14
99#define OCFS2_CONTROL_MESSAGE_SETVERSION_OP "SETV"
100#define OCFS2_CONTROL_MESSAGE_SETVERSION_TOTAL_LEN 11
101#define OCFS2_CONTROL_MESSAGE_DOWN_OP "DOWN"
102#define OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN 47
103#define OCFS2_TEXT_UUID_LEN 32
104#define OCFS2_CONTROL_MESSAGE_VERNUM_LEN 2
105#define OCFS2_CONTROL_MESSAGE_NODENUM_LEN 8
106#define VERSION_LOCK "version_lock"
107
108enum ocfs2_connection_type {
109 WITH_CONTROLD,
110 NO_CONTROLD
111};
112
113/*
114 * ocfs2_live_connection is refcounted because the filesystem and
115 * miscdevice sides can detach in different order. Let's just be safe.
116 */
117struct ocfs2_live_connection {
118 struct list_head oc_list;
119 struct ocfs2_cluster_connection *oc_conn;
120 enum ocfs2_connection_type oc_type;
121 atomic_t oc_this_node;
122 int oc_our_slot;
123 struct dlm_lksb oc_version_lksb;
124 char oc_lvb[DLM_LVB_LEN];
125 struct completion oc_sync_wait;
126 wait_queue_head_t oc_wait;
127};
128
129struct ocfs2_control_private {
130 struct list_head op_list;
131 int op_state;
132 int op_this_node;
133 struct ocfs2_protocol_version op_proto;
134};
135
136/* SETN<space><8-char-hex-nodenum><newline> */
137struct ocfs2_control_message_setn {
138 char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
139 char space;
140 char nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN];
141 char newline;
142};
143
144/* SETV<space><2-char-hex-major><space><2-char-hex-minor><newline> */
145struct ocfs2_control_message_setv {
146 char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
147 char space1;
148 char major[OCFS2_CONTROL_MESSAGE_VERNUM_LEN];
149 char space2;
150 char minor[OCFS2_CONTROL_MESSAGE_VERNUM_LEN];
151 char newline;
152};
153
154/* DOWN<space><32-char-cap-hex-uuid><space><8-char-hex-nodenum><newline> */
155struct ocfs2_control_message_down {
156 char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
157 char space1;
158 char uuid[OCFS2_TEXT_UUID_LEN];
159 char space2;
160 char nodestr[OCFS2_CONTROL_MESSAGE_NODENUM_LEN];
161 char newline;
162};
163
164union ocfs2_control_message {
165 char tag[OCFS2_CONTROL_MESSAGE_OP_LEN];
166 struct ocfs2_control_message_setn u_setn;
167 struct ocfs2_control_message_setv u_setv;
168 struct ocfs2_control_message_down u_down;
169};
170
171static struct ocfs2_stack_plugin ocfs2_user_plugin;
172
173static atomic_t ocfs2_control_opened;
174static int ocfs2_control_this_node = -1;
175static struct ocfs2_protocol_version running_proto;
176
177static LIST_HEAD(ocfs2_live_connection_list);
178static LIST_HEAD(ocfs2_control_private_list);
179static DEFINE_MUTEX(ocfs2_control_lock);
180
181static inline void ocfs2_control_set_handshake_state(struct file *file,
182 int state)
183{
184 struct ocfs2_control_private *p = file->private_data;
185 p->op_state = state;
186}
187
188static inline int ocfs2_control_get_handshake_state(struct file *file)
189{
190 struct ocfs2_control_private *p = file->private_data;
191 return p->op_state;
192}
193
194static struct ocfs2_live_connection *ocfs2_connection_find(const char *name)
195{
196 size_t len = strlen(name);
197 struct ocfs2_live_connection *c;
198
199 BUG_ON(!mutex_is_locked(&ocfs2_control_lock));
200
201 list_for_each_entry(c, &ocfs2_live_connection_list, oc_list) {
202 if ((c->oc_conn->cc_namelen == len) &&
203 !strncmp(c->oc_conn->cc_name, name, len))
204 return c;
205 }
206
207 return NULL;
208}
209
210/*
211 * ocfs2_live_connection structures are created underneath the ocfs2
212 * mount path. Since the VFS prevents multiple calls to
213 * fill_super(), we can't get dupes here.
214 */
215static int ocfs2_live_connection_attach(struct ocfs2_cluster_connection *conn,
216 struct ocfs2_live_connection *c)
217{
218 int rc = 0;
219
220 mutex_lock(&ocfs2_control_lock);
221 c->oc_conn = conn;
222
223 if ((c->oc_type == NO_CONTROLD) || atomic_read(&ocfs2_control_opened))
224 list_add(&c->oc_list, &ocfs2_live_connection_list);
225 else {
226 printk(KERN_ERR
227 "ocfs2: Userspace control daemon is not present\n");
228 rc = -ESRCH;
229 }
230
231 mutex_unlock(&ocfs2_control_lock);
232 return rc;
233}
234
235/*
236 * This function disconnects the cluster connection from ocfs2_control.
237 * Afterwards, userspace can't affect the cluster connection.
238 */
239static void ocfs2_live_connection_drop(struct ocfs2_live_connection *c)
240{
241 mutex_lock(&ocfs2_control_lock);
242 list_del_init(&c->oc_list);
243 c->oc_conn = NULL;
244 mutex_unlock(&ocfs2_control_lock);
245
246 kfree(c);
247}
248
249static int ocfs2_control_cfu(void *target, size_t target_len,
250 const char __user *buf, size_t count)
251{
252 /* The T01 expects write(2) calls to have exactly one command */
253 if ((count != target_len) ||
254 (count > sizeof(union ocfs2_control_message)))
255 return -EINVAL;
256
257 if (copy_from_user(target, buf, target_len))
258 return -EFAULT;
259
260 return 0;
261}
262
263static ssize_t ocfs2_control_validate_protocol(struct file *file,
264 const char __user *buf,
265 size_t count)
266{
267 ssize_t ret;
268 char kbuf[OCFS2_CONTROL_PROTO_LEN];
269
270 ret = ocfs2_control_cfu(kbuf, OCFS2_CONTROL_PROTO_LEN,
271 buf, count);
272 if (ret)
273 return ret;
274
275 if (strncmp(kbuf, OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN))
276 return -EINVAL;
277
278 ocfs2_control_set_handshake_state(file,
279 OCFS2_CONTROL_HANDSHAKE_PROTOCOL);
280
281 return count;
282}
283
284static void ocfs2_control_send_down(const char *uuid,
285 int nodenum)
286{
287 struct ocfs2_live_connection *c;
288
289 mutex_lock(&ocfs2_control_lock);
290
291 c = ocfs2_connection_find(uuid);
292 if (c) {
293 BUG_ON(c->oc_conn == NULL);
294 c->oc_conn->cc_recovery_handler(nodenum,
295 c->oc_conn->cc_recovery_data);
296 }
297
298 mutex_unlock(&ocfs2_control_lock);
299}
300
301/*
302 * Called whenever configuration elements are sent to /dev/ocfs2_control.
303 * If all configuration elements are present, try to set the global
304 * values. If there is a problem, return an error. Skip any missing
305 * elements, and only bump ocfs2_control_opened when we have all elements
306 * and are successful.
307 */
308static int ocfs2_control_install_private(struct file *file)
309{
310 int rc = 0;
311 int set_p = 1;
312 struct ocfs2_control_private *p = file->private_data;
313
314 BUG_ON(p->op_state != OCFS2_CONTROL_HANDSHAKE_PROTOCOL);
315
316 mutex_lock(&ocfs2_control_lock);
317
318 if (p->op_this_node < 0) {
319 set_p = 0;
320 } else if ((ocfs2_control_this_node >= 0) &&
321 (ocfs2_control_this_node != p->op_this_node)) {
322 rc = -EINVAL;
323 goto out_unlock;
324 }
325
326 if (!p->op_proto.pv_major) {
327 set_p = 0;
328 } else if (!list_empty(&ocfs2_live_connection_list) &&
329 ((running_proto.pv_major != p->op_proto.pv_major) ||
330 (running_proto.pv_minor != p->op_proto.pv_minor))) {
331 rc = -EINVAL;
332 goto out_unlock;
333 }
334
335 if (set_p) {
336 ocfs2_control_this_node = p->op_this_node;
337 running_proto.pv_major = p->op_proto.pv_major;
338 running_proto.pv_minor = p->op_proto.pv_minor;
339 }
340
341out_unlock:
342 mutex_unlock(&ocfs2_control_lock);
343
344 if (!rc && set_p) {
345 /* We set the global values successfully */
346 atomic_inc(&ocfs2_control_opened);
347 ocfs2_control_set_handshake_state(file,
348 OCFS2_CONTROL_HANDSHAKE_VALID);
349 }
350
351 return rc;
352}
353
354static int ocfs2_control_get_this_node(void)
355{
356 int rc;
357
358 mutex_lock(&ocfs2_control_lock);
359 if (ocfs2_control_this_node < 0)
360 rc = -EINVAL;
361 else
362 rc = ocfs2_control_this_node;
363 mutex_unlock(&ocfs2_control_lock);
364
365 return rc;
366}
367
368static int ocfs2_control_do_setnode_msg(struct file *file,
369 struct ocfs2_control_message_setn *msg)
370{
371 long nodenum;
372 char *ptr = NULL;
373 struct ocfs2_control_private *p = file->private_data;
374
375 if (ocfs2_control_get_handshake_state(file) !=
376 OCFS2_CONTROL_HANDSHAKE_PROTOCOL)
377 return -EINVAL;
378
379 if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_SETNODE_OP,
380 OCFS2_CONTROL_MESSAGE_OP_LEN))
381 return -EINVAL;
382
383 if ((msg->space != ' ') || (msg->newline != '\n'))
384 return -EINVAL;
385 msg->space = msg->newline = '\0';
386
387 nodenum = simple_strtol(msg->nodestr, &ptr, 16);
388 if (!ptr || *ptr)
389 return -EINVAL;
390
391 if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) ||
392 (nodenum > INT_MAX) || (nodenum < 0))
393 return -ERANGE;
394 p->op_this_node = nodenum;
395
396 return ocfs2_control_install_private(file);
397}
398
399static int ocfs2_control_do_setversion_msg(struct file *file,
400 struct ocfs2_control_message_setv *msg)
401 {
402 long major, minor;
403 char *ptr = NULL;
404 struct ocfs2_control_private *p = file->private_data;
405 struct ocfs2_protocol_version *max =
406 &ocfs2_user_plugin.sp_max_proto;
407
408 if (ocfs2_control_get_handshake_state(file) !=
409 OCFS2_CONTROL_HANDSHAKE_PROTOCOL)
410 return -EINVAL;
411
412 if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_SETVERSION_OP,
413 OCFS2_CONTROL_MESSAGE_OP_LEN))
414 return -EINVAL;
415
416 if ((msg->space1 != ' ') || (msg->space2 != ' ') ||
417 (msg->newline != '\n'))
418 return -EINVAL;
419 msg->space1 = msg->space2 = msg->newline = '\0';
420
421 major = simple_strtol(msg->major, &ptr, 16);
422 if (!ptr || *ptr)
423 return -EINVAL;
424 minor = simple_strtol(msg->minor, &ptr, 16);
425 if (!ptr || *ptr)
426 return -EINVAL;
427
428 /*
429 * The major must be between 1 and 255, inclusive. The minor
430 * must be between 0 and 255, inclusive. The version passed in
431 * must be within the maximum version supported by the filesystem.
432 */
433 if ((major == LONG_MIN) || (major == LONG_MAX) ||
434 (major > (u8)-1) || (major < 1))
435 return -ERANGE;
436 if ((minor == LONG_MIN) || (minor == LONG_MAX) ||
437 (minor > (u8)-1) || (minor < 0))
438 return -ERANGE;
439 if ((major != max->pv_major) ||
440 (minor > max->pv_minor))
441 return -EINVAL;
442
443 p->op_proto.pv_major = major;
444 p->op_proto.pv_minor = minor;
445
446 return ocfs2_control_install_private(file);
447}
448
449static int ocfs2_control_do_down_msg(struct file *file,
450 struct ocfs2_control_message_down *msg)
451{
452 long nodenum;
453 char *p = NULL;
454
455 if (ocfs2_control_get_handshake_state(file) !=
456 OCFS2_CONTROL_HANDSHAKE_VALID)
457 return -EINVAL;
458
459 if (strncmp(msg->tag, OCFS2_CONTROL_MESSAGE_DOWN_OP,
460 OCFS2_CONTROL_MESSAGE_OP_LEN))
461 return -EINVAL;
462
463 if ((msg->space1 != ' ') || (msg->space2 != ' ') ||
464 (msg->newline != '\n'))
465 return -EINVAL;
466 msg->space1 = msg->space2 = msg->newline = '\0';
467
468 nodenum = simple_strtol(msg->nodestr, &p, 16);
469 if (!p || *p)
470 return -EINVAL;
471
472 if ((nodenum == LONG_MIN) || (nodenum == LONG_MAX) ||
473 (nodenum > INT_MAX) || (nodenum < 0))
474 return -ERANGE;
475
476 ocfs2_control_send_down(msg->uuid, nodenum);
477
478 return 0;
479}
480
481static ssize_t ocfs2_control_message(struct file *file,
482 const char __user *buf,
483 size_t count)
484{
485 ssize_t ret;
486 union ocfs2_control_message msg;
487
488 /* Try to catch padding issues */
489 WARN_ON(offsetof(struct ocfs2_control_message_down, uuid) !=
490 (sizeof(msg.u_down.tag) + sizeof(msg.u_down.space1)));
491
492 memset(&msg, 0, sizeof(union ocfs2_control_message));
493 ret = ocfs2_control_cfu(&msg, count, buf, count);
494 if (ret)
495 goto out;
496
497 if ((count == OCFS2_CONTROL_MESSAGE_SETNODE_TOTAL_LEN) &&
498 !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_SETNODE_OP,
499 OCFS2_CONTROL_MESSAGE_OP_LEN))
500 ret = ocfs2_control_do_setnode_msg(file, &msg.u_setn);
501 else if ((count == OCFS2_CONTROL_MESSAGE_SETVERSION_TOTAL_LEN) &&
502 !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_SETVERSION_OP,
503 OCFS2_CONTROL_MESSAGE_OP_LEN))
504 ret = ocfs2_control_do_setversion_msg(file, &msg.u_setv);
505 else if ((count == OCFS2_CONTROL_MESSAGE_DOWN_TOTAL_LEN) &&
506 !strncmp(msg.tag, OCFS2_CONTROL_MESSAGE_DOWN_OP,
507 OCFS2_CONTROL_MESSAGE_OP_LEN))
508 ret = ocfs2_control_do_down_msg(file, &msg.u_down);
509 else
510 ret = -EINVAL;
511
512out:
513 return ret ? ret : count;
514}
515
516static ssize_t ocfs2_control_write(struct file *file,
517 const char __user *buf,
518 size_t count,
519 loff_t *ppos)
520{
521 ssize_t ret;
522
523 switch (ocfs2_control_get_handshake_state(file)) {
524 case OCFS2_CONTROL_HANDSHAKE_INVALID:
525 ret = -EINVAL;
526 break;
527
528 case OCFS2_CONTROL_HANDSHAKE_READ:
529 ret = ocfs2_control_validate_protocol(file, buf,
530 count);
531 break;
532
533 case OCFS2_CONTROL_HANDSHAKE_PROTOCOL:
534 case OCFS2_CONTROL_HANDSHAKE_VALID:
535 ret = ocfs2_control_message(file, buf, count);
536 break;
537
538 default:
539 BUG();
540 ret = -EIO;
541 break;
542 }
543
544 return ret;
545}
546
547/*
548 * This is a naive version. If we ever have a new protocol, we'll expand
549 * it. Probably using seq_file.
550 */
551static ssize_t ocfs2_control_read(struct file *file,
552 char __user *buf,
553 size_t count,
554 loff_t *ppos)
555{
556 ssize_t ret;
557
558 ret = simple_read_from_buffer(buf, count, ppos,
559 OCFS2_CONTROL_PROTO, OCFS2_CONTROL_PROTO_LEN);
560
561 /* Have we read the whole protocol list? */
562 if (ret > 0 && *ppos >= OCFS2_CONTROL_PROTO_LEN)
563 ocfs2_control_set_handshake_state(file,
564 OCFS2_CONTROL_HANDSHAKE_READ);
565
566 return ret;
567}
568
569static int ocfs2_control_release(struct inode *inode, struct file *file)
570{
571 struct ocfs2_control_private *p = file->private_data;
572
573 mutex_lock(&ocfs2_control_lock);
574
575 if (ocfs2_control_get_handshake_state(file) !=
576 OCFS2_CONTROL_HANDSHAKE_VALID)
577 goto out;
578
579 if (atomic_dec_and_test(&ocfs2_control_opened)) {
580 if (!list_empty(&ocfs2_live_connection_list)) {
581 /* XXX: Do bad things! */
582 printk(KERN_ERR
583 "ocfs2: Unexpected release of ocfs2_control!\n"
584 " Loss of cluster connection requires "
585 "an emergency restart!\n");
586 emergency_restart();
587 }
588 /*
589 * Last valid close clears the node number and resets
590 * the locking protocol version
591 */
592 ocfs2_control_this_node = -1;
593 running_proto.pv_major = 0;
594 running_proto.pv_major = 0;
595 }
596
597out:
598 list_del_init(&p->op_list);
599 file->private_data = NULL;
600
601 mutex_unlock(&ocfs2_control_lock);
602
603 kfree(p);
604
605 return 0;
606}
607
608static int ocfs2_control_open(struct inode *inode, struct file *file)
609{
610 struct ocfs2_control_private *p;
611
612 p = kzalloc(sizeof(struct ocfs2_control_private), GFP_KERNEL);
613 if (!p)
614 return -ENOMEM;
615 p->op_this_node = -1;
616
617 mutex_lock(&ocfs2_control_lock);
618 file->private_data = p;
619 list_add(&p->op_list, &ocfs2_control_private_list);
620 mutex_unlock(&ocfs2_control_lock);
621
622 return 0;
623}
624
625static const struct file_operations ocfs2_control_fops = {
626 .open = ocfs2_control_open,
627 .release = ocfs2_control_release,
628 .read = ocfs2_control_read,
629 .write = ocfs2_control_write,
630 .owner = THIS_MODULE,
631 .llseek = default_llseek,
632};
633
634static struct miscdevice ocfs2_control_device = {
635 .minor = MISC_DYNAMIC_MINOR,
636 .name = "ocfs2_control",
637 .fops = &ocfs2_control_fops,
638};
639
640static int ocfs2_control_init(void)
641{
642 int rc;
643
644 atomic_set(&ocfs2_control_opened, 0);
645
646 rc = misc_register(&ocfs2_control_device);
647 if (rc)
648 printk(KERN_ERR
649 "ocfs2: Unable to register ocfs2_control device "
650 "(errno %d)\n",
651 -rc);
652
653 return rc;
654}
655
656static void ocfs2_control_exit(void)
657{
658 int rc;
659
660 rc = misc_deregister(&ocfs2_control_device);
661 if (rc)
662 printk(KERN_ERR
663 "ocfs2: Unable to deregister ocfs2_control device "
664 "(errno %d)\n",
665 -rc);
666}
667
668static void fsdlm_lock_ast_wrapper(void *astarg)
669{
670 struct ocfs2_dlm_lksb *lksb = astarg;
671 int status = lksb->lksb_fsdlm.sb_status;
672
673 /*
674 * For now we're punting on the issue of other non-standard errors
675 * where we can't tell if the unlock_ast or lock_ast should be called.
676 * The main "other error" that's possible is EINVAL which means the
677 * function was called with invalid args, which shouldn't be possible
678 * since the caller here is under our control. Other non-standard
679 * errors probably fall into the same category, or otherwise are fatal
680 * which means we can't carry on anyway.
681 */
682
683 if (status == -DLM_EUNLOCK || status == -DLM_ECANCEL)
684 lksb->lksb_conn->cc_proto->lp_unlock_ast(lksb, 0);
685 else
686 lksb->lksb_conn->cc_proto->lp_lock_ast(lksb);
687}
688
689static void fsdlm_blocking_ast_wrapper(void *astarg, int level)
690{
691 struct ocfs2_dlm_lksb *lksb = astarg;
692
693 lksb->lksb_conn->cc_proto->lp_blocking_ast(lksb, level);
694}
695
696static int user_dlm_lock(struct ocfs2_cluster_connection *conn,
697 int mode,
698 struct ocfs2_dlm_lksb *lksb,
699 u32 flags,
700 void *name,
701 unsigned int namelen)
702{
703 int ret;
704
705 if (!lksb->lksb_fsdlm.sb_lvbptr)
706 lksb->lksb_fsdlm.sb_lvbptr = (char *)lksb +
707 sizeof(struct dlm_lksb);
708
709 ret = dlm_lock(conn->cc_lockspace, mode, &lksb->lksb_fsdlm,
710 flags|DLM_LKF_NODLCKWT, name, namelen, 0,
711 fsdlm_lock_ast_wrapper, lksb,
712 fsdlm_blocking_ast_wrapper);
713 return ret;
714}
715
716static int user_dlm_unlock(struct ocfs2_cluster_connection *conn,
717 struct ocfs2_dlm_lksb *lksb,
718 u32 flags)
719{
720 int ret;
721
722 ret = dlm_unlock(conn->cc_lockspace, lksb->lksb_fsdlm.sb_lkid,
723 flags, &lksb->lksb_fsdlm, lksb);
724 return ret;
725}
726
727static int user_dlm_lock_status(struct ocfs2_dlm_lksb *lksb)
728{
729 return lksb->lksb_fsdlm.sb_status;
730}
731
732static int user_dlm_lvb_valid(struct ocfs2_dlm_lksb *lksb)
733{
734 int invalid = lksb->lksb_fsdlm.sb_flags & DLM_SBF_VALNOTVALID;
735
736 return !invalid;
737}
738
739static void *user_dlm_lvb(struct ocfs2_dlm_lksb *lksb)
740{
741 if (!lksb->lksb_fsdlm.sb_lvbptr)
742 lksb->lksb_fsdlm.sb_lvbptr = (char *)lksb +
743 sizeof(struct dlm_lksb);
744 return (void *)(lksb->lksb_fsdlm.sb_lvbptr);
745}
746
747static void user_dlm_dump_lksb(struct ocfs2_dlm_lksb *lksb)
748{
749}
750
751static int user_plock(struct ocfs2_cluster_connection *conn,
752 u64 ino,
753 struct file *file,
754 int cmd,
755 struct file_lock *fl)
756{
757 /*
758 * This more or less just demuxes the plock request into any
759 * one of three dlm calls.
760 *
761 * Internally, fs/dlm will pass these to a misc device, which
762 * a userspace daemon will read and write to.
763 *
764 * For now, cancel requests (which happen internally only),
765 * are turned into unlocks. Most of this function taken from
766 * gfs2_lock.
767 */
768
769 if (cmd == F_CANCELLK) {
770 cmd = F_SETLK;
771 fl->fl_type = F_UNLCK;
772 }
773
774 if (IS_GETLK(cmd))
775 return dlm_posix_get(conn->cc_lockspace, ino, file, fl);
776 else if (fl->fl_type == F_UNLCK)
777 return dlm_posix_unlock(conn->cc_lockspace, ino, file, fl);
778 else
779 return dlm_posix_lock(conn->cc_lockspace, ino, file, cmd, fl);
780}
781
782/*
783 * Compare a requested locking protocol version against the current one.
784 *
785 * If the major numbers are different, they are incompatible.
786 * If the current minor is greater than the request, they are incompatible.
787 * If the current minor is less than or equal to the request, they are
788 * compatible, and the requester should run at the current minor version.
789 */
790static int fs_protocol_compare(struct ocfs2_protocol_version *existing,
791 struct ocfs2_protocol_version *request)
792{
793 if (existing->pv_major != request->pv_major)
794 return 1;
795
796 if (existing->pv_minor > request->pv_minor)
797 return 1;
798
799 if (existing->pv_minor < request->pv_minor)
800 request->pv_minor = existing->pv_minor;
801
802 return 0;
803}
804
805static void lvb_to_version(char *lvb, struct ocfs2_protocol_version *ver)
806{
807 struct ocfs2_protocol_version *pv =
808 (struct ocfs2_protocol_version *)lvb;
809 /*
810 * ocfs2_protocol_version has two u8 variables, so we don't
811 * need any endian conversion.
812 */
813 ver->pv_major = pv->pv_major;
814 ver->pv_minor = pv->pv_minor;
815}
816
817static void version_to_lvb(struct ocfs2_protocol_version *ver, char *lvb)
818{
819 struct ocfs2_protocol_version *pv =
820 (struct ocfs2_protocol_version *)lvb;
821 /*
822 * ocfs2_protocol_version has two u8 variables, so we don't
823 * need any endian conversion.
824 */
825 pv->pv_major = ver->pv_major;
826 pv->pv_minor = ver->pv_minor;
827}
828
829static void sync_wait_cb(void *arg)
830{
831 struct ocfs2_cluster_connection *conn = arg;
832 struct ocfs2_live_connection *lc = conn->cc_private;
833 complete(&lc->oc_sync_wait);
834}
835
836static int sync_unlock(struct ocfs2_cluster_connection *conn,
837 struct dlm_lksb *lksb, char *name)
838{
839 int error;
840 struct ocfs2_live_connection *lc = conn->cc_private;
841
842 error = dlm_unlock(conn->cc_lockspace, lksb->sb_lkid, 0, lksb, conn);
843 if (error) {
844 printk(KERN_ERR "%s lkid %x error %d\n",
845 name, lksb->sb_lkid, error);
846 return error;
847 }
848
849 wait_for_completion(&lc->oc_sync_wait);
850
851 if (lksb->sb_status != -DLM_EUNLOCK) {
852 printk(KERN_ERR "%s lkid %x status %d\n",
853 name, lksb->sb_lkid, lksb->sb_status);
854 return -1;
855 }
856 return 0;
857}
858
859static int sync_lock(struct ocfs2_cluster_connection *conn,
860 int mode, uint32_t flags,
861 struct dlm_lksb *lksb, char *name)
862{
863 int error, status;
864 struct ocfs2_live_connection *lc = conn->cc_private;
865
866 error = dlm_lock(conn->cc_lockspace, mode, lksb, flags,
867 name, strlen(name),
868 0, sync_wait_cb, conn, NULL);
869 if (error) {
870 printk(KERN_ERR "%s lkid %x flags %x mode %d error %d\n",
871 name, lksb->sb_lkid, flags, mode, error);
872 return error;
873 }
874
875 wait_for_completion(&lc->oc_sync_wait);
876
877 status = lksb->sb_status;
878
879 if (status && status != -EAGAIN) {
880 printk(KERN_ERR "%s lkid %x flags %x mode %d status %d\n",
881 name, lksb->sb_lkid, flags, mode, status);
882 }
883
884 return status;
885}
886
887
888static int version_lock(struct ocfs2_cluster_connection *conn, int mode,
889 int flags)
890{
891 struct ocfs2_live_connection *lc = conn->cc_private;
892 return sync_lock(conn, mode, flags,
893 &lc->oc_version_lksb, VERSION_LOCK);
894}
895
896static int version_unlock(struct ocfs2_cluster_connection *conn)
897{
898 struct ocfs2_live_connection *lc = conn->cc_private;
899 return sync_unlock(conn, &lc->oc_version_lksb, VERSION_LOCK);
900}
901
902/* get_protocol_version()
903 *
904 * To exchange ocfs2 versioning, we use the LVB of the version dlm lock.
905 * The algorithm is:
906 * 1. Attempt to take the lock in EX mode (non-blocking).
907 * 2. If successful (which means it is the first mount), write the
908 * version number and downconvert to PR lock.
909 * 3. If unsuccessful (returns -EAGAIN), read the version from the LVB after
910 * taking the PR lock.
911 */
912
913static int get_protocol_version(struct ocfs2_cluster_connection *conn)
914{
915 int ret;
916 struct ocfs2_live_connection *lc = conn->cc_private;
917 struct ocfs2_protocol_version pv;
918
919 running_proto.pv_major =
920 ocfs2_user_plugin.sp_max_proto.pv_major;
921 running_proto.pv_minor =
922 ocfs2_user_plugin.sp_max_proto.pv_minor;
923
924 lc->oc_version_lksb.sb_lvbptr = lc->oc_lvb;
925 ret = version_lock(conn, DLM_LOCK_EX,
926 DLM_LKF_VALBLK|DLM_LKF_NOQUEUE);
927 if (!ret) {
928 conn->cc_version.pv_major = running_proto.pv_major;
929 conn->cc_version.pv_minor = running_proto.pv_minor;
930 version_to_lvb(&running_proto, lc->oc_lvb);
931 version_lock(conn, DLM_LOCK_PR, DLM_LKF_CONVERT|DLM_LKF_VALBLK);
932 } else if (ret == -EAGAIN) {
933 ret = version_lock(conn, DLM_LOCK_PR, DLM_LKF_VALBLK);
934 if (ret)
935 goto out;
936 lvb_to_version(lc->oc_lvb, &pv);
937
938 if ((pv.pv_major != running_proto.pv_major) ||
939 (pv.pv_minor > running_proto.pv_minor)) {
940 ret = -EINVAL;
941 goto out;
942 }
943
944 conn->cc_version.pv_major = pv.pv_major;
945 conn->cc_version.pv_minor = pv.pv_minor;
946 }
947out:
948 return ret;
949}
950
951static void user_recover_prep(void *arg)
952{
953}
954
955static void user_recover_slot(void *arg, struct dlm_slot *slot)
956{
957 struct ocfs2_cluster_connection *conn = arg;
958 printk(KERN_INFO "ocfs2: Node %d/%d down. Initiating recovery.\n",
959 slot->nodeid, slot->slot);
960 conn->cc_recovery_handler(slot->nodeid, conn->cc_recovery_data);
961
962}
963
964static void user_recover_done(void *arg, struct dlm_slot *slots,
965 int num_slots, int our_slot,
966 uint32_t generation)
967{
968 struct ocfs2_cluster_connection *conn = arg;
969 struct ocfs2_live_connection *lc = conn->cc_private;
970 int i;
971
972 for (i = 0; i < num_slots; i++)
973 if (slots[i].slot == our_slot) {
974 atomic_set(&lc->oc_this_node, slots[i].nodeid);
975 break;
976 }
977
978 lc->oc_our_slot = our_slot;
979 wake_up(&lc->oc_wait);
980}
981
982static const struct dlm_lockspace_ops ocfs2_ls_ops = {
983 .recover_prep = user_recover_prep,
984 .recover_slot = user_recover_slot,
985 .recover_done = user_recover_done,
986};
987
988static int user_cluster_disconnect(struct ocfs2_cluster_connection *conn)
989{
990 version_unlock(conn);
991 dlm_release_lockspace(conn->cc_lockspace, 2);
992 conn->cc_lockspace = NULL;
993 ocfs2_live_connection_drop(conn->cc_private);
994 conn->cc_private = NULL;
995 return 0;
996}
997
998static int user_cluster_connect(struct ocfs2_cluster_connection *conn)
999{
1000 dlm_lockspace_t *fsdlm;
1001 struct ocfs2_live_connection *lc;
1002 int rc, ops_rv;
1003
1004 BUG_ON(conn == NULL);
1005
1006 lc = kzalloc(sizeof(struct ocfs2_live_connection), GFP_KERNEL);
1007 if (!lc) {
1008 rc = -ENOMEM;
1009 goto out;
1010 }
1011
1012 init_waitqueue_head(&lc->oc_wait);
1013 init_completion(&lc->oc_sync_wait);
1014 atomic_set(&lc->oc_this_node, 0);
1015 conn->cc_private = lc;
1016 lc->oc_type = NO_CONTROLD;
1017
1018 rc = dlm_new_lockspace(conn->cc_name, conn->cc_cluster_name,
1019 DLM_LSFL_FS, DLM_LVB_LEN,
1020 &ocfs2_ls_ops, conn, &ops_rv, &fsdlm);
1021 if (rc)
1022 goto out;
1023
1024 if (ops_rv == -EOPNOTSUPP) {
1025 lc->oc_type = WITH_CONTROLD;
1026 printk(KERN_NOTICE "ocfs2: You seem to be using an older "
1027 "version of dlm_controld and/or ocfs2-tools."
1028 " Please consider upgrading.\n");
1029 } else if (ops_rv) {
1030 rc = ops_rv;
1031 goto out;
1032 }
1033 conn->cc_lockspace = fsdlm;
1034
1035 rc = ocfs2_live_connection_attach(conn, lc);
1036 if (rc)
1037 goto out;
1038
1039 if (lc->oc_type == NO_CONTROLD) {
1040 rc = get_protocol_version(conn);
1041 if (rc) {
1042 printk(KERN_ERR "ocfs2: Could not determine"
1043 " locking version\n");
1044 user_cluster_disconnect(conn);
1045 goto out;
1046 }
1047 wait_event(lc->oc_wait, (atomic_read(&lc->oc_this_node) > 0));
1048 }
1049
1050 /*
1051 * running_proto must have been set before we allowed any mounts
1052 * to proceed.
1053 */
1054 if (fs_protocol_compare(&running_proto, &conn->cc_version)) {
1055 printk(KERN_ERR
1056 "Unable to mount with fs locking protocol version "
1057 "%u.%u because negotiated protocol is %u.%u\n",
1058 conn->cc_version.pv_major, conn->cc_version.pv_minor,
1059 running_proto.pv_major, running_proto.pv_minor);
1060 rc = -EPROTO;
1061 ocfs2_live_connection_drop(lc);
1062 lc = NULL;
1063 }
1064
1065out:
1066 if (rc && lc)
1067 kfree(lc);
1068 return rc;
1069}
1070
1071
1072static int user_cluster_this_node(struct ocfs2_cluster_connection *conn,
1073 unsigned int *this_node)
1074{
1075 int rc;
1076 struct ocfs2_live_connection *lc = conn->cc_private;
1077
1078 if (lc->oc_type == WITH_CONTROLD)
1079 rc = ocfs2_control_get_this_node();
1080 else if (lc->oc_type == NO_CONTROLD)
1081 rc = atomic_read(&lc->oc_this_node);
1082 else
1083 rc = -EINVAL;
1084
1085 if (rc < 0)
1086 return rc;
1087
1088 *this_node = rc;
1089 return 0;
1090}
1091
1092static struct ocfs2_stack_operations ocfs2_user_plugin_ops = {
1093 .connect = user_cluster_connect,
1094 .disconnect = user_cluster_disconnect,
1095 .this_node = user_cluster_this_node,
1096 .dlm_lock = user_dlm_lock,
1097 .dlm_unlock = user_dlm_unlock,
1098 .lock_status = user_dlm_lock_status,
1099 .lvb_valid = user_dlm_lvb_valid,
1100 .lock_lvb = user_dlm_lvb,
1101 .plock = user_plock,
1102 .dump_lksb = user_dlm_dump_lksb,
1103};
1104
1105static struct ocfs2_stack_plugin ocfs2_user_plugin = {
1106 .sp_name = "user",
1107 .sp_ops = &ocfs2_user_plugin_ops,
1108 .sp_owner = THIS_MODULE,
1109};
1110
1111
1112static int __init ocfs2_user_plugin_init(void)
1113{
1114 int rc;
1115
1116 rc = ocfs2_control_init();
1117 if (!rc) {
1118 rc = ocfs2_stack_glue_register(&ocfs2_user_plugin);
1119 if (rc)
1120 ocfs2_control_exit();
1121 }
1122
1123 return rc;
1124}
1125
1126static void __exit ocfs2_user_plugin_exit(void)
1127{
1128 ocfs2_stack_glue_unregister(&ocfs2_user_plugin);
1129 ocfs2_control_exit();
1130}
1131
1132MODULE_AUTHOR("Oracle");
1133MODULE_DESCRIPTION("ocfs2 driver for userspace cluster stacks");
1134MODULE_LICENSE("GPL");
1135module_init(ocfs2_user_plugin_init);
1136module_exit(ocfs2_user_plugin_exit);
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, strlen(conn->cc_name),
831 &fsdlm, DLM_LSFL_FS, DLM_LVB_LEN);
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);