xref: /linux/fs/dlm/config.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
1 /******************************************************************************
2 *******************************************************************************
3 **
4 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
5 **  Copyright (C) 2004-2011 Red Hat, Inc.  All rights reserved.
6 **
7 **  This copyrighted material is made available to anyone wishing to use,
8 **  modify, copy, or redistribute it subject to the terms and conditions
9 **  of the GNU General Public License v.2.
10 **
11 *******************************************************************************
12 ******************************************************************************/
13 
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/configfs.h>
17 #include <linux/slab.h>
18 #include <linux/in.h>
19 #include <linux/in6.h>
20 #include <linux/dlmconstants.h>
21 #include <net/ipv6.h>
22 #include <net/sock.h>
23 
24 #include "config.h"
25 #include "lowcomms.h"
26 
27 /*
28  * /config/dlm/<cluster>/spaces/<space>/nodes/<node>/nodeid
29  * /config/dlm/<cluster>/spaces/<space>/nodes/<node>/weight
30  * /config/dlm/<cluster>/comms/<comm>/nodeid
31  * /config/dlm/<cluster>/comms/<comm>/local
32  * /config/dlm/<cluster>/comms/<comm>/addr      (write only)
33  * /config/dlm/<cluster>/comms/<comm>/addr_list (read only)
34  * The <cluster> level is useless, but I haven't figured out how to avoid it.
35  */
36 
37 static struct config_group *space_list;
38 static struct config_group *comm_list;
39 static struct dlm_comm *local_comm;
40 static uint32_t dlm_comm_count;
41 
42 struct dlm_clusters;
43 struct dlm_cluster;
44 struct dlm_spaces;
45 struct dlm_space;
46 struct dlm_comms;
47 struct dlm_comm;
48 struct dlm_nodes;
49 struct dlm_node;
50 
51 static struct config_group *make_cluster(struct config_group *, const char *);
52 static void drop_cluster(struct config_group *, struct config_item *);
53 static void release_cluster(struct config_item *);
54 static struct config_group *make_space(struct config_group *, const char *);
55 static void drop_space(struct config_group *, struct config_item *);
56 static void release_space(struct config_item *);
57 static struct config_item *make_comm(struct config_group *, const char *);
58 static void drop_comm(struct config_group *, struct config_item *);
59 static void release_comm(struct config_item *);
60 static struct config_item *make_node(struct config_group *, const char *);
61 static void drop_node(struct config_group *, struct config_item *);
62 static void release_node(struct config_item *);
63 
64 static ssize_t show_cluster(struct config_item *i, struct configfs_attribute *a,
65 			    char *buf);
66 static ssize_t store_cluster(struct config_item *i,
67 			     struct configfs_attribute *a,
68 			     const char *buf, size_t len);
69 static ssize_t show_comm(struct config_item *i, struct configfs_attribute *a,
70 			 char *buf);
71 static ssize_t store_comm(struct config_item *i, struct configfs_attribute *a,
72 			  const char *buf, size_t len);
73 static ssize_t show_node(struct config_item *i, struct configfs_attribute *a,
74 			 char *buf);
75 static ssize_t store_node(struct config_item *i, struct configfs_attribute *a,
76 			  const char *buf, size_t len);
77 
78 static ssize_t comm_nodeid_read(struct dlm_comm *cm, char *buf);
79 static ssize_t comm_nodeid_write(struct dlm_comm *cm, const char *buf,
80 				size_t len);
81 static ssize_t comm_local_read(struct dlm_comm *cm, char *buf);
82 static ssize_t comm_local_write(struct dlm_comm *cm, const char *buf,
83 				size_t len);
84 static ssize_t comm_addr_write(struct dlm_comm *cm, const char *buf,
85 				size_t len);
86 static ssize_t comm_addr_list_read(struct dlm_comm *cm, char *buf);
87 static ssize_t node_nodeid_read(struct dlm_node *nd, char *buf);
88 static ssize_t node_nodeid_write(struct dlm_node *nd, const char *buf,
89 				size_t len);
90 static ssize_t node_weight_read(struct dlm_node *nd, char *buf);
91 static ssize_t node_weight_write(struct dlm_node *nd, const char *buf,
92 				size_t len);
93 
94 struct dlm_cluster {
95 	struct config_group group;
96 	unsigned int cl_tcp_port;
97 	unsigned int cl_buffer_size;
98 	unsigned int cl_rsbtbl_size;
99 	unsigned int cl_recover_timer;
100 	unsigned int cl_toss_secs;
101 	unsigned int cl_scan_secs;
102 	unsigned int cl_log_debug;
103 	unsigned int cl_protocol;
104 	unsigned int cl_timewarn_cs;
105 	unsigned int cl_waitwarn_us;
106 	unsigned int cl_new_rsb_count;
107 	unsigned int cl_recover_callbacks;
108 	char cl_cluster_name[DLM_LOCKSPACE_LEN];
109 };
110 
111 enum {
112 	CLUSTER_ATTR_TCP_PORT = 0,
113 	CLUSTER_ATTR_BUFFER_SIZE,
114 	CLUSTER_ATTR_RSBTBL_SIZE,
115 	CLUSTER_ATTR_RECOVER_TIMER,
116 	CLUSTER_ATTR_TOSS_SECS,
117 	CLUSTER_ATTR_SCAN_SECS,
118 	CLUSTER_ATTR_LOG_DEBUG,
119 	CLUSTER_ATTR_PROTOCOL,
120 	CLUSTER_ATTR_TIMEWARN_CS,
121 	CLUSTER_ATTR_WAITWARN_US,
122 	CLUSTER_ATTR_NEW_RSB_COUNT,
123 	CLUSTER_ATTR_RECOVER_CALLBACKS,
124 	CLUSTER_ATTR_CLUSTER_NAME,
125 };
126 
127 struct cluster_attribute {
128 	struct configfs_attribute attr;
129 	ssize_t (*show)(struct dlm_cluster *, char *);
130 	ssize_t (*store)(struct dlm_cluster *, const char *, size_t);
131 };
132 
133 static ssize_t cluster_cluster_name_read(struct dlm_cluster *cl, char *buf)
134 {
135 	return sprintf(buf, "%s\n", cl->cl_cluster_name);
136 }
137 
138 static ssize_t cluster_cluster_name_write(struct dlm_cluster *cl,
139 					  const char *buf, size_t len)
140 {
141 	strlcpy(dlm_config.ci_cluster_name, buf,
142 				sizeof(dlm_config.ci_cluster_name));
143 	strlcpy(cl->cl_cluster_name, buf, sizeof(cl->cl_cluster_name));
144 	return len;
145 }
146 
147 static struct cluster_attribute cluster_attr_cluster_name = {
148 	.attr   = { .ca_owner = THIS_MODULE,
149                     .ca_name = "cluster_name",
150                     .ca_mode = S_IRUGO | S_IWUSR },
151 	.show   = cluster_cluster_name_read,
152 	.store  = cluster_cluster_name_write,
153 };
154 
155 static ssize_t cluster_set(struct dlm_cluster *cl, unsigned int *cl_field,
156 			   int *info_field, int check_zero,
157 			   const char *buf, size_t len)
158 {
159 	unsigned int x;
160 
161 	if (!capable(CAP_SYS_ADMIN))
162 		return -EPERM;
163 
164 	x = simple_strtoul(buf, NULL, 0);
165 
166 	if (check_zero && !x)
167 		return -EINVAL;
168 
169 	*cl_field = x;
170 	*info_field = x;
171 
172 	return len;
173 }
174 
175 #define CLUSTER_ATTR(name, check_zero)                                        \
176 static ssize_t name##_write(struct dlm_cluster *cl, const char *buf, size_t len) \
177 {                                                                             \
178 	return cluster_set(cl, &cl->cl_##name, &dlm_config.ci_##name,         \
179 			   check_zero, buf, len);                             \
180 }                                                                             \
181 static ssize_t name##_read(struct dlm_cluster *cl, char *buf)                 \
182 {                                                                             \
183 	return snprintf(buf, PAGE_SIZE, "%u\n", cl->cl_##name);               \
184 }                                                                             \
185 static struct cluster_attribute cluster_attr_##name =                         \
186 __CONFIGFS_ATTR(name, 0644, name##_read, name##_write)
187 
188 CLUSTER_ATTR(tcp_port, 1);
189 CLUSTER_ATTR(buffer_size, 1);
190 CLUSTER_ATTR(rsbtbl_size, 1);
191 CLUSTER_ATTR(recover_timer, 1);
192 CLUSTER_ATTR(toss_secs, 1);
193 CLUSTER_ATTR(scan_secs, 1);
194 CLUSTER_ATTR(log_debug, 0);
195 CLUSTER_ATTR(protocol, 0);
196 CLUSTER_ATTR(timewarn_cs, 1);
197 CLUSTER_ATTR(waitwarn_us, 0);
198 CLUSTER_ATTR(new_rsb_count, 0);
199 CLUSTER_ATTR(recover_callbacks, 0);
200 
201 static struct configfs_attribute *cluster_attrs[] = {
202 	[CLUSTER_ATTR_TCP_PORT] = &cluster_attr_tcp_port.attr,
203 	[CLUSTER_ATTR_BUFFER_SIZE] = &cluster_attr_buffer_size.attr,
204 	[CLUSTER_ATTR_RSBTBL_SIZE] = &cluster_attr_rsbtbl_size.attr,
205 	[CLUSTER_ATTR_RECOVER_TIMER] = &cluster_attr_recover_timer.attr,
206 	[CLUSTER_ATTR_TOSS_SECS] = &cluster_attr_toss_secs.attr,
207 	[CLUSTER_ATTR_SCAN_SECS] = &cluster_attr_scan_secs.attr,
208 	[CLUSTER_ATTR_LOG_DEBUG] = &cluster_attr_log_debug.attr,
209 	[CLUSTER_ATTR_PROTOCOL] = &cluster_attr_protocol.attr,
210 	[CLUSTER_ATTR_TIMEWARN_CS] = &cluster_attr_timewarn_cs.attr,
211 	[CLUSTER_ATTR_WAITWARN_US] = &cluster_attr_waitwarn_us.attr,
212 	[CLUSTER_ATTR_NEW_RSB_COUNT] = &cluster_attr_new_rsb_count.attr,
213 	[CLUSTER_ATTR_RECOVER_CALLBACKS] = &cluster_attr_recover_callbacks.attr,
214 	[CLUSTER_ATTR_CLUSTER_NAME] = &cluster_attr_cluster_name.attr,
215 	NULL,
216 };
217 
218 enum {
219 	COMM_ATTR_NODEID = 0,
220 	COMM_ATTR_LOCAL,
221 	COMM_ATTR_ADDR,
222 	COMM_ATTR_ADDR_LIST,
223 };
224 
225 struct comm_attribute {
226 	struct configfs_attribute attr;
227 	ssize_t (*show)(struct dlm_comm *, char *);
228 	ssize_t (*store)(struct dlm_comm *, const char *, size_t);
229 };
230 
231 static struct comm_attribute comm_attr_nodeid = {
232 	.attr   = { .ca_owner = THIS_MODULE,
233                     .ca_name = "nodeid",
234                     .ca_mode = S_IRUGO | S_IWUSR },
235 	.show   = comm_nodeid_read,
236 	.store  = comm_nodeid_write,
237 };
238 
239 static struct comm_attribute comm_attr_local = {
240 	.attr   = { .ca_owner = THIS_MODULE,
241                     .ca_name = "local",
242                     .ca_mode = S_IRUGO | S_IWUSR },
243 	.show   = comm_local_read,
244 	.store  = comm_local_write,
245 };
246 
247 static struct comm_attribute comm_attr_addr = {
248 	.attr   = { .ca_owner = THIS_MODULE,
249                     .ca_name = "addr",
250                     .ca_mode = S_IWUSR },
251 	.store  = comm_addr_write,
252 };
253 
254 static struct comm_attribute comm_attr_addr_list = {
255 	.attr   = { .ca_owner = THIS_MODULE,
256                     .ca_name = "addr_list",
257                     .ca_mode = S_IRUGO },
258 	.show   = comm_addr_list_read,
259 };
260 
261 static struct configfs_attribute *comm_attrs[] = {
262 	[COMM_ATTR_NODEID] = &comm_attr_nodeid.attr,
263 	[COMM_ATTR_LOCAL] = &comm_attr_local.attr,
264 	[COMM_ATTR_ADDR] = &comm_attr_addr.attr,
265 	[COMM_ATTR_ADDR_LIST] = &comm_attr_addr_list.attr,
266 	NULL,
267 };
268 
269 enum {
270 	NODE_ATTR_NODEID = 0,
271 	NODE_ATTR_WEIGHT,
272 };
273 
274 struct node_attribute {
275 	struct configfs_attribute attr;
276 	ssize_t (*show)(struct dlm_node *, char *);
277 	ssize_t (*store)(struct dlm_node *, const char *, size_t);
278 };
279 
280 static struct node_attribute node_attr_nodeid = {
281 	.attr   = { .ca_owner = THIS_MODULE,
282                     .ca_name = "nodeid",
283                     .ca_mode = S_IRUGO | S_IWUSR },
284 	.show   = node_nodeid_read,
285 	.store  = node_nodeid_write,
286 };
287 
288 static struct node_attribute node_attr_weight = {
289 	.attr   = { .ca_owner = THIS_MODULE,
290                     .ca_name = "weight",
291                     .ca_mode = S_IRUGO | S_IWUSR },
292 	.show   = node_weight_read,
293 	.store  = node_weight_write,
294 };
295 
296 static struct configfs_attribute *node_attrs[] = {
297 	[NODE_ATTR_NODEID] = &node_attr_nodeid.attr,
298 	[NODE_ATTR_WEIGHT] = &node_attr_weight.attr,
299 	NULL,
300 };
301 
302 struct dlm_clusters {
303 	struct configfs_subsystem subsys;
304 };
305 
306 struct dlm_spaces {
307 	struct config_group ss_group;
308 };
309 
310 struct dlm_space {
311 	struct config_group group;
312 	struct list_head members;
313 	struct mutex members_lock;
314 	int members_count;
315 };
316 
317 struct dlm_comms {
318 	struct config_group cs_group;
319 };
320 
321 struct dlm_comm {
322 	struct config_item item;
323 	int seq;
324 	int nodeid;
325 	int local;
326 	int addr_count;
327 	struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT];
328 };
329 
330 struct dlm_nodes {
331 	struct config_group ns_group;
332 };
333 
334 struct dlm_node {
335 	struct config_item item;
336 	struct list_head list; /* space->members */
337 	int nodeid;
338 	int weight;
339 	int new;
340 	int comm_seq; /* copy of cm->seq when nd->nodeid is set */
341 };
342 
343 static struct configfs_group_operations clusters_ops = {
344 	.make_group = make_cluster,
345 	.drop_item = drop_cluster,
346 };
347 
348 static struct configfs_item_operations cluster_ops = {
349 	.release = release_cluster,
350 	.show_attribute = show_cluster,
351 	.store_attribute = store_cluster,
352 };
353 
354 static struct configfs_group_operations spaces_ops = {
355 	.make_group = make_space,
356 	.drop_item = drop_space,
357 };
358 
359 static struct configfs_item_operations space_ops = {
360 	.release = release_space,
361 };
362 
363 static struct configfs_group_operations comms_ops = {
364 	.make_item = make_comm,
365 	.drop_item = drop_comm,
366 };
367 
368 static struct configfs_item_operations comm_ops = {
369 	.release = release_comm,
370 	.show_attribute = show_comm,
371 	.store_attribute = store_comm,
372 };
373 
374 static struct configfs_group_operations nodes_ops = {
375 	.make_item = make_node,
376 	.drop_item = drop_node,
377 };
378 
379 static struct configfs_item_operations node_ops = {
380 	.release = release_node,
381 	.show_attribute = show_node,
382 	.store_attribute = store_node,
383 };
384 
385 static struct config_item_type clusters_type = {
386 	.ct_group_ops = &clusters_ops,
387 	.ct_owner = THIS_MODULE,
388 };
389 
390 static struct config_item_type cluster_type = {
391 	.ct_item_ops = &cluster_ops,
392 	.ct_attrs = cluster_attrs,
393 	.ct_owner = THIS_MODULE,
394 };
395 
396 static struct config_item_type spaces_type = {
397 	.ct_group_ops = &spaces_ops,
398 	.ct_owner = THIS_MODULE,
399 };
400 
401 static struct config_item_type space_type = {
402 	.ct_item_ops = &space_ops,
403 	.ct_owner = THIS_MODULE,
404 };
405 
406 static struct config_item_type comms_type = {
407 	.ct_group_ops = &comms_ops,
408 	.ct_owner = THIS_MODULE,
409 };
410 
411 static struct config_item_type comm_type = {
412 	.ct_item_ops = &comm_ops,
413 	.ct_attrs = comm_attrs,
414 	.ct_owner = THIS_MODULE,
415 };
416 
417 static struct config_item_type nodes_type = {
418 	.ct_group_ops = &nodes_ops,
419 	.ct_owner = THIS_MODULE,
420 };
421 
422 static struct config_item_type node_type = {
423 	.ct_item_ops = &node_ops,
424 	.ct_attrs = node_attrs,
425 	.ct_owner = THIS_MODULE,
426 };
427 
428 static struct dlm_cluster *config_item_to_cluster(struct config_item *i)
429 {
430 	return i ? container_of(to_config_group(i), struct dlm_cluster, group) :
431 		   NULL;
432 }
433 
434 static struct dlm_space *config_item_to_space(struct config_item *i)
435 {
436 	return i ? container_of(to_config_group(i), struct dlm_space, group) :
437 		   NULL;
438 }
439 
440 static struct dlm_comm *config_item_to_comm(struct config_item *i)
441 {
442 	return i ? container_of(i, struct dlm_comm, item) : NULL;
443 }
444 
445 static struct dlm_node *config_item_to_node(struct config_item *i)
446 {
447 	return i ? container_of(i, struct dlm_node, item) : NULL;
448 }
449 
450 static struct config_group *make_cluster(struct config_group *g,
451 					 const char *name)
452 {
453 	struct dlm_cluster *cl = NULL;
454 	struct dlm_spaces *sps = NULL;
455 	struct dlm_comms *cms = NULL;
456 	void *gps = NULL;
457 
458 	cl = kzalloc(sizeof(struct dlm_cluster), GFP_NOFS);
459 	gps = kcalloc(3, sizeof(struct config_group *), GFP_NOFS);
460 	sps = kzalloc(sizeof(struct dlm_spaces), GFP_NOFS);
461 	cms = kzalloc(sizeof(struct dlm_comms), GFP_NOFS);
462 
463 	if (!cl || !gps || !sps || !cms)
464 		goto fail;
465 
466 	config_group_init_type_name(&cl->group, name, &cluster_type);
467 	config_group_init_type_name(&sps->ss_group, "spaces", &spaces_type);
468 	config_group_init_type_name(&cms->cs_group, "comms", &comms_type);
469 
470 	cl->group.default_groups = gps;
471 	cl->group.default_groups[0] = &sps->ss_group;
472 	cl->group.default_groups[1] = &cms->cs_group;
473 	cl->group.default_groups[2] = NULL;
474 
475 	cl->cl_tcp_port = dlm_config.ci_tcp_port;
476 	cl->cl_buffer_size = dlm_config.ci_buffer_size;
477 	cl->cl_rsbtbl_size = dlm_config.ci_rsbtbl_size;
478 	cl->cl_recover_timer = dlm_config.ci_recover_timer;
479 	cl->cl_toss_secs = dlm_config.ci_toss_secs;
480 	cl->cl_scan_secs = dlm_config.ci_scan_secs;
481 	cl->cl_log_debug = dlm_config.ci_log_debug;
482 	cl->cl_protocol = dlm_config.ci_protocol;
483 	cl->cl_timewarn_cs = dlm_config.ci_timewarn_cs;
484 	cl->cl_waitwarn_us = dlm_config.ci_waitwarn_us;
485 	cl->cl_new_rsb_count = dlm_config.ci_new_rsb_count;
486 	cl->cl_recover_callbacks = dlm_config.ci_recover_callbacks;
487 	memcpy(cl->cl_cluster_name, dlm_config.ci_cluster_name,
488 	       DLM_LOCKSPACE_LEN);
489 
490 	space_list = &sps->ss_group;
491 	comm_list = &cms->cs_group;
492 	return &cl->group;
493 
494  fail:
495 	kfree(cl);
496 	kfree(gps);
497 	kfree(sps);
498 	kfree(cms);
499 	return ERR_PTR(-ENOMEM);
500 }
501 
502 static void drop_cluster(struct config_group *g, struct config_item *i)
503 {
504 	struct dlm_cluster *cl = config_item_to_cluster(i);
505 	struct config_item *tmp;
506 	int j;
507 
508 	for (j = 0; cl->group.default_groups[j]; j++) {
509 		tmp = &cl->group.default_groups[j]->cg_item;
510 		cl->group.default_groups[j] = NULL;
511 		config_item_put(tmp);
512 	}
513 
514 	space_list = NULL;
515 	comm_list = NULL;
516 
517 	config_item_put(i);
518 }
519 
520 static void release_cluster(struct config_item *i)
521 {
522 	struct dlm_cluster *cl = config_item_to_cluster(i);
523 	kfree(cl->group.default_groups);
524 	kfree(cl);
525 }
526 
527 static struct config_group *make_space(struct config_group *g, const char *name)
528 {
529 	struct dlm_space *sp = NULL;
530 	struct dlm_nodes *nds = NULL;
531 	void *gps = NULL;
532 
533 	sp = kzalloc(sizeof(struct dlm_space), GFP_NOFS);
534 	gps = kcalloc(2, sizeof(struct config_group *), GFP_NOFS);
535 	nds = kzalloc(sizeof(struct dlm_nodes), GFP_NOFS);
536 
537 	if (!sp || !gps || !nds)
538 		goto fail;
539 
540 	config_group_init_type_name(&sp->group, name, &space_type);
541 	config_group_init_type_name(&nds->ns_group, "nodes", &nodes_type);
542 
543 	sp->group.default_groups = gps;
544 	sp->group.default_groups[0] = &nds->ns_group;
545 	sp->group.default_groups[1] = NULL;
546 
547 	INIT_LIST_HEAD(&sp->members);
548 	mutex_init(&sp->members_lock);
549 	sp->members_count = 0;
550 	return &sp->group;
551 
552  fail:
553 	kfree(sp);
554 	kfree(gps);
555 	kfree(nds);
556 	return ERR_PTR(-ENOMEM);
557 }
558 
559 static void drop_space(struct config_group *g, struct config_item *i)
560 {
561 	struct dlm_space *sp = config_item_to_space(i);
562 	struct config_item *tmp;
563 	int j;
564 
565 	/* assert list_empty(&sp->members) */
566 
567 	for (j = 0; sp->group.default_groups[j]; j++) {
568 		tmp = &sp->group.default_groups[j]->cg_item;
569 		sp->group.default_groups[j] = NULL;
570 		config_item_put(tmp);
571 	}
572 
573 	config_item_put(i);
574 }
575 
576 static void release_space(struct config_item *i)
577 {
578 	struct dlm_space *sp = config_item_to_space(i);
579 	kfree(sp->group.default_groups);
580 	kfree(sp);
581 }
582 
583 static struct config_item *make_comm(struct config_group *g, const char *name)
584 {
585 	struct dlm_comm *cm;
586 
587 	cm = kzalloc(sizeof(struct dlm_comm), GFP_NOFS);
588 	if (!cm)
589 		return ERR_PTR(-ENOMEM);
590 
591 	config_item_init_type_name(&cm->item, name, &comm_type);
592 
593 	cm->seq = dlm_comm_count++;
594 	if (!cm->seq)
595 		cm->seq = dlm_comm_count++;
596 
597 	cm->nodeid = -1;
598 	cm->local = 0;
599 	cm->addr_count = 0;
600 	return &cm->item;
601 }
602 
603 static void drop_comm(struct config_group *g, struct config_item *i)
604 {
605 	struct dlm_comm *cm = config_item_to_comm(i);
606 	if (local_comm == cm)
607 		local_comm = NULL;
608 	dlm_lowcomms_close(cm->nodeid);
609 	while (cm->addr_count--)
610 		kfree(cm->addr[cm->addr_count]);
611 	config_item_put(i);
612 }
613 
614 static void release_comm(struct config_item *i)
615 {
616 	struct dlm_comm *cm = config_item_to_comm(i);
617 	kfree(cm);
618 }
619 
620 static struct config_item *make_node(struct config_group *g, const char *name)
621 {
622 	struct dlm_space *sp = config_item_to_space(g->cg_item.ci_parent);
623 	struct dlm_node *nd;
624 
625 	nd = kzalloc(sizeof(struct dlm_node), GFP_NOFS);
626 	if (!nd)
627 		return ERR_PTR(-ENOMEM);
628 
629 	config_item_init_type_name(&nd->item, name, &node_type);
630 	nd->nodeid = -1;
631 	nd->weight = 1;  /* default weight of 1 if none is set */
632 	nd->new = 1;     /* set to 0 once it's been read by dlm_nodeid_list() */
633 
634 	mutex_lock(&sp->members_lock);
635 	list_add(&nd->list, &sp->members);
636 	sp->members_count++;
637 	mutex_unlock(&sp->members_lock);
638 
639 	return &nd->item;
640 }
641 
642 static void drop_node(struct config_group *g, struct config_item *i)
643 {
644 	struct dlm_space *sp = config_item_to_space(g->cg_item.ci_parent);
645 	struct dlm_node *nd = config_item_to_node(i);
646 
647 	mutex_lock(&sp->members_lock);
648 	list_del(&nd->list);
649 	sp->members_count--;
650 	mutex_unlock(&sp->members_lock);
651 
652 	config_item_put(i);
653 }
654 
655 static void release_node(struct config_item *i)
656 {
657 	struct dlm_node *nd = config_item_to_node(i);
658 	kfree(nd);
659 }
660 
661 static struct dlm_clusters clusters_root = {
662 	.subsys = {
663 		.su_group = {
664 			.cg_item = {
665 				.ci_namebuf = "dlm",
666 				.ci_type = &clusters_type,
667 			},
668 		},
669 	},
670 };
671 
672 int __init dlm_config_init(void)
673 {
674 	config_group_init(&clusters_root.subsys.su_group);
675 	mutex_init(&clusters_root.subsys.su_mutex);
676 	return configfs_register_subsystem(&clusters_root.subsys);
677 }
678 
679 void dlm_config_exit(void)
680 {
681 	configfs_unregister_subsystem(&clusters_root.subsys);
682 }
683 
684 /*
685  * Functions for user space to read/write attributes
686  */
687 
688 static ssize_t show_cluster(struct config_item *i, struct configfs_attribute *a,
689 			    char *buf)
690 {
691 	struct dlm_cluster *cl = config_item_to_cluster(i);
692 	struct cluster_attribute *cla =
693 			container_of(a, struct cluster_attribute, attr);
694 	return cla->show ? cla->show(cl, buf) : 0;
695 }
696 
697 static ssize_t store_cluster(struct config_item *i,
698 			     struct configfs_attribute *a,
699 			     const char *buf, size_t len)
700 {
701 	struct dlm_cluster *cl = config_item_to_cluster(i);
702 	struct cluster_attribute *cla =
703 		container_of(a, struct cluster_attribute, attr);
704 	return cla->store ? cla->store(cl, buf, len) : -EINVAL;
705 }
706 
707 static ssize_t show_comm(struct config_item *i, struct configfs_attribute *a,
708 			 char *buf)
709 {
710 	struct dlm_comm *cm = config_item_to_comm(i);
711 	struct comm_attribute *cma =
712 			container_of(a, struct comm_attribute, attr);
713 	return cma->show ? cma->show(cm, buf) : 0;
714 }
715 
716 static ssize_t store_comm(struct config_item *i, struct configfs_attribute *a,
717 			  const char *buf, size_t len)
718 {
719 	struct dlm_comm *cm = config_item_to_comm(i);
720 	struct comm_attribute *cma =
721 		container_of(a, struct comm_attribute, attr);
722 	return cma->store ? cma->store(cm, buf, len) : -EINVAL;
723 }
724 
725 static ssize_t comm_nodeid_read(struct dlm_comm *cm, char *buf)
726 {
727 	return sprintf(buf, "%d\n", cm->nodeid);
728 }
729 
730 static ssize_t comm_nodeid_write(struct dlm_comm *cm, const char *buf,
731 				 size_t len)
732 {
733 	cm->nodeid = simple_strtol(buf, NULL, 0);
734 	return len;
735 }
736 
737 static ssize_t comm_local_read(struct dlm_comm *cm, char *buf)
738 {
739 	return sprintf(buf, "%d\n", cm->local);
740 }
741 
742 static ssize_t comm_local_write(struct dlm_comm *cm, const char *buf,
743 				size_t len)
744 {
745 	cm->local= simple_strtol(buf, NULL, 0);
746 	if (cm->local && !local_comm)
747 		local_comm = cm;
748 	return len;
749 }
750 
751 static ssize_t comm_addr_write(struct dlm_comm *cm, const char *buf, size_t len)
752 {
753 	struct sockaddr_storage *addr;
754 	int rv;
755 
756 	if (len != sizeof(struct sockaddr_storage))
757 		return -EINVAL;
758 
759 	if (cm->addr_count >= DLM_MAX_ADDR_COUNT)
760 		return -ENOSPC;
761 
762 	addr = kzalloc(sizeof(*addr), GFP_NOFS);
763 	if (!addr)
764 		return -ENOMEM;
765 
766 	memcpy(addr, buf, len);
767 
768 	rv = dlm_lowcomms_addr(cm->nodeid, addr, len);
769 	if (rv) {
770 		kfree(addr);
771 		return rv;
772 	}
773 
774 	cm->addr[cm->addr_count++] = addr;
775 	return len;
776 }
777 
778 static ssize_t comm_addr_list_read(struct dlm_comm *cm, char *buf)
779 {
780 	ssize_t s;
781 	ssize_t allowance;
782 	int i;
783 	struct sockaddr_storage *addr;
784 	struct sockaddr_in *addr_in;
785 	struct sockaddr_in6 *addr_in6;
786 
787 	/* Taken from ip6_addr_string() defined in lib/vsprintf.c */
788 	char buf0[sizeof("AF_INET6	xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255\n")];
789 
790 
791 	/* Derived from SIMPLE_ATTR_SIZE of fs/configfs/file.c */
792 	allowance = 4096;
793 	buf[0] = '\0';
794 
795 	for (i = 0; i < cm->addr_count; i++) {
796 		addr = cm->addr[i];
797 
798 		switch(addr->ss_family) {
799 		case AF_INET:
800 			addr_in = (struct sockaddr_in *)addr;
801 			s = sprintf(buf0, "AF_INET	%pI4\n", &addr_in->sin_addr.s_addr);
802 			break;
803 		case AF_INET6:
804 			addr_in6 = (struct sockaddr_in6 *)addr;
805 			s = sprintf(buf0, "AF_INET6	%pI6\n", &addr_in6->sin6_addr);
806 			break;
807 		default:
808 			s = sprintf(buf0, "%s\n", "<UNKNOWN>");
809 			break;
810 		}
811 		allowance -= s;
812 		if (allowance >= 0)
813 			strcat(buf, buf0);
814 		else {
815 			allowance += s;
816 			break;
817 		}
818 	}
819 	return 4096 - allowance;
820 }
821 
822 static ssize_t show_node(struct config_item *i, struct configfs_attribute *a,
823 			 char *buf)
824 {
825 	struct dlm_node *nd = config_item_to_node(i);
826 	struct node_attribute *nda =
827 			container_of(a, struct node_attribute, attr);
828 	return nda->show ? nda->show(nd, buf) : 0;
829 }
830 
831 static ssize_t store_node(struct config_item *i, struct configfs_attribute *a,
832 			  const char *buf, size_t len)
833 {
834 	struct dlm_node *nd = config_item_to_node(i);
835 	struct node_attribute *nda =
836 		container_of(a, struct node_attribute, attr);
837 	return nda->store ? nda->store(nd, buf, len) : -EINVAL;
838 }
839 
840 static ssize_t node_nodeid_read(struct dlm_node *nd, char *buf)
841 {
842 	return sprintf(buf, "%d\n", nd->nodeid);
843 }
844 
845 static ssize_t node_nodeid_write(struct dlm_node *nd, const char *buf,
846 				 size_t len)
847 {
848 	uint32_t seq = 0;
849 	nd->nodeid = simple_strtol(buf, NULL, 0);
850 	dlm_comm_seq(nd->nodeid, &seq);
851 	nd->comm_seq = seq;
852 	return len;
853 }
854 
855 static ssize_t node_weight_read(struct dlm_node *nd, char *buf)
856 {
857 	return sprintf(buf, "%d\n", nd->weight);
858 }
859 
860 static ssize_t node_weight_write(struct dlm_node *nd, const char *buf,
861 				 size_t len)
862 {
863 	nd->weight = simple_strtol(buf, NULL, 0);
864 	return len;
865 }
866 
867 /*
868  * Functions for the dlm to get the info that's been configured
869  */
870 
871 static struct dlm_space *get_space(char *name)
872 {
873 	struct config_item *i;
874 
875 	if (!space_list)
876 		return NULL;
877 
878 	mutex_lock(&space_list->cg_subsys->su_mutex);
879 	i = config_group_find_item(space_list, name);
880 	mutex_unlock(&space_list->cg_subsys->su_mutex);
881 
882 	return config_item_to_space(i);
883 }
884 
885 static void put_space(struct dlm_space *sp)
886 {
887 	config_item_put(&sp->group.cg_item);
888 }
889 
890 static struct dlm_comm *get_comm(int nodeid)
891 {
892 	struct config_item *i;
893 	struct dlm_comm *cm = NULL;
894 	int found = 0;
895 
896 	if (!comm_list)
897 		return NULL;
898 
899 	mutex_lock(&clusters_root.subsys.su_mutex);
900 
901 	list_for_each_entry(i, &comm_list->cg_children, ci_entry) {
902 		cm = config_item_to_comm(i);
903 
904 		if (cm->nodeid != nodeid)
905 			continue;
906 		found = 1;
907 		config_item_get(i);
908 		break;
909 	}
910 	mutex_unlock(&clusters_root.subsys.su_mutex);
911 
912 	if (!found)
913 		cm = NULL;
914 	return cm;
915 }
916 
917 static void put_comm(struct dlm_comm *cm)
918 {
919 	config_item_put(&cm->item);
920 }
921 
922 /* caller must free mem */
923 int dlm_config_nodes(char *lsname, struct dlm_config_node **nodes_out,
924 		     int *count_out)
925 {
926 	struct dlm_space *sp;
927 	struct dlm_node *nd;
928 	struct dlm_config_node *nodes, *node;
929 	int rv, count;
930 
931 	sp = get_space(lsname);
932 	if (!sp)
933 		return -EEXIST;
934 
935 	mutex_lock(&sp->members_lock);
936 	if (!sp->members_count) {
937 		rv = -EINVAL;
938 		printk(KERN_ERR "dlm: zero members_count\n");
939 		goto out;
940 	}
941 
942 	count = sp->members_count;
943 
944 	nodes = kcalloc(count, sizeof(struct dlm_config_node), GFP_NOFS);
945 	if (!nodes) {
946 		rv = -ENOMEM;
947 		goto out;
948 	}
949 
950 	node = nodes;
951 	list_for_each_entry(nd, &sp->members, list) {
952 		node->nodeid = nd->nodeid;
953 		node->weight = nd->weight;
954 		node->new = nd->new;
955 		node->comm_seq = nd->comm_seq;
956 		node++;
957 
958 		nd->new = 0;
959 	}
960 
961 	*count_out = count;
962 	*nodes_out = nodes;
963 	rv = 0;
964  out:
965 	mutex_unlock(&sp->members_lock);
966 	put_space(sp);
967 	return rv;
968 }
969 
970 int dlm_comm_seq(int nodeid, uint32_t *seq)
971 {
972 	struct dlm_comm *cm = get_comm(nodeid);
973 	if (!cm)
974 		return -EEXIST;
975 	*seq = cm->seq;
976 	put_comm(cm);
977 	return 0;
978 }
979 
980 int dlm_our_nodeid(void)
981 {
982 	return local_comm ? local_comm->nodeid : 0;
983 }
984 
985 /* num 0 is first addr, num 1 is second addr */
986 int dlm_our_addr(struct sockaddr_storage *addr, int num)
987 {
988 	if (!local_comm)
989 		return -1;
990 	if (num + 1 > local_comm->addr_count)
991 		return -1;
992 	memcpy(addr, local_comm->addr[num], sizeof(*addr));
993 	return 0;
994 }
995 
996 /* Config file defaults */
997 #define DEFAULT_TCP_PORT       21064
998 #define DEFAULT_BUFFER_SIZE     4096
999 #define DEFAULT_RSBTBL_SIZE     1024
1000 #define DEFAULT_RECOVER_TIMER      5
1001 #define DEFAULT_TOSS_SECS         10
1002 #define DEFAULT_SCAN_SECS          5
1003 #define DEFAULT_LOG_DEBUG          0
1004 #define DEFAULT_PROTOCOL           0
1005 #define DEFAULT_TIMEWARN_CS      500 /* 5 sec = 500 centiseconds */
1006 #define DEFAULT_WAITWARN_US	   0
1007 #define DEFAULT_NEW_RSB_COUNT    128
1008 #define DEFAULT_RECOVER_CALLBACKS  0
1009 #define DEFAULT_CLUSTER_NAME      ""
1010 
1011 struct dlm_config_info dlm_config = {
1012 	.ci_tcp_port = DEFAULT_TCP_PORT,
1013 	.ci_buffer_size = DEFAULT_BUFFER_SIZE,
1014 	.ci_rsbtbl_size = DEFAULT_RSBTBL_SIZE,
1015 	.ci_recover_timer = DEFAULT_RECOVER_TIMER,
1016 	.ci_toss_secs = DEFAULT_TOSS_SECS,
1017 	.ci_scan_secs = DEFAULT_SCAN_SECS,
1018 	.ci_log_debug = DEFAULT_LOG_DEBUG,
1019 	.ci_protocol = DEFAULT_PROTOCOL,
1020 	.ci_timewarn_cs = DEFAULT_TIMEWARN_CS,
1021 	.ci_waitwarn_us = DEFAULT_WAITWARN_US,
1022 	.ci_new_rsb_count = DEFAULT_NEW_RSB_COUNT,
1023 	.ci_recover_callbacks = DEFAULT_RECOVER_CALLBACKS,
1024 	.ci_cluster_name = DEFAULT_CLUSTER_NAME
1025 };
1026 
1027