xref: /openbmc/linux/fs/dlm/config.c (revision 726ccdba)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /******************************************************************************
3 *******************************************************************************
4 **
5 **  Copyright (C) Sistina Software, Inc.  1997-2003  All rights reserved.
6 **  Copyright (C) 2004-2011 Red Hat, Inc.  All rights reserved.
7 **
8 **
9 *******************************************************************************
10 ******************************************************************************/
11 
12 #include <linux/kernel.h>
13 #include <linux/init.h>
14 #include <linux/configfs.h>
15 #include <linux/slab.h>
16 #include <linux/in.h>
17 #include <linux/in6.h>
18 #include <linux/dlmconstants.h>
19 #include <net/ipv6.h>
20 #include <net/sock.h>
21 
22 #include "config.h"
23 #include "midcomms.h"
24 #include "lowcomms.h"
25 
26 /*
27  * /config/dlm/<cluster>/spaces/<space>/nodes/<node>/nodeid
28  * /config/dlm/<cluster>/spaces/<space>/nodes/<node>/weight
29  * /config/dlm/<cluster>/comms/<comm>/nodeid
30  * /config/dlm/<cluster>/comms/<comm>/local
31  * /config/dlm/<cluster>/comms/<comm>/addr      (write only)
32  * /config/dlm/<cluster>/comms/<comm>/addr_list (read only)
33  * The <cluster> level is useless, but I haven't figured out how to avoid it.
34  */
35 
36 static struct config_group *space_list;
37 static struct config_group *comm_list;
38 static struct dlm_comm *local_comm;
39 static uint32_t dlm_comm_count;
40 
41 struct dlm_clusters;
42 struct dlm_cluster;
43 struct dlm_spaces;
44 struct dlm_space;
45 struct dlm_comms;
46 struct dlm_comm;
47 struct dlm_nodes;
48 struct dlm_node;
49 
50 static struct config_group *make_cluster(struct config_group *, const char *);
51 static void drop_cluster(struct config_group *, struct config_item *);
52 static void release_cluster(struct config_item *);
53 static struct config_group *make_space(struct config_group *, const char *);
54 static void drop_space(struct config_group *, struct config_item *);
55 static void release_space(struct config_item *);
56 static struct config_item *make_comm(struct config_group *, const char *);
57 static void drop_comm(struct config_group *, struct config_item *);
58 static void release_comm(struct config_item *);
59 static struct config_item *make_node(struct config_group *, const char *);
60 static void drop_node(struct config_group *, struct config_item *);
61 static void release_node(struct config_item *);
62 
63 static struct configfs_attribute *comm_attrs[];
64 static struct configfs_attribute *node_attrs[];
65 
66 struct dlm_cluster {
67 	struct config_group group;
68 	unsigned int cl_tcp_port;
69 	unsigned int cl_buffer_size;
70 	unsigned int cl_rsbtbl_size;
71 	unsigned int cl_recover_timer;
72 	unsigned int cl_toss_secs;
73 	unsigned int cl_scan_secs;
74 	unsigned int cl_log_debug;
75 	unsigned int cl_log_info;
76 	unsigned int cl_protocol;
77 	unsigned int cl_mark;
78 	unsigned int cl_new_rsb_count;
79 	unsigned int cl_recover_callbacks;
80 	char cl_cluster_name[DLM_LOCKSPACE_LEN];
81 
82 	struct dlm_spaces *sps;
83 	struct dlm_comms *cms;
84 };
85 
86 static struct dlm_cluster *config_item_to_cluster(struct config_item *i)
87 {
88 	return i ? container_of(to_config_group(i), struct dlm_cluster, group) :
89 		   NULL;
90 }
91 
92 enum {
93 	CLUSTER_ATTR_TCP_PORT = 0,
94 	CLUSTER_ATTR_BUFFER_SIZE,
95 	CLUSTER_ATTR_RSBTBL_SIZE,
96 	CLUSTER_ATTR_RECOVER_TIMER,
97 	CLUSTER_ATTR_TOSS_SECS,
98 	CLUSTER_ATTR_SCAN_SECS,
99 	CLUSTER_ATTR_LOG_DEBUG,
100 	CLUSTER_ATTR_LOG_INFO,
101 	CLUSTER_ATTR_PROTOCOL,
102 	CLUSTER_ATTR_MARK,
103 	CLUSTER_ATTR_NEW_RSB_COUNT,
104 	CLUSTER_ATTR_RECOVER_CALLBACKS,
105 	CLUSTER_ATTR_CLUSTER_NAME,
106 };
107 
108 static ssize_t cluster_cluster_name_show(struct config_item *item, char *buf)
109 {
110 	struct dlm_cluster *cl = config_item_to_cluster(item);
111 	return sprintf(buf, "%s\n", cl->cl_cluster_name);
112 }
113 
114 static ssize_t cluster_cluster_name_store(struct config_item *item,
115 					  const char *buf, size_t len)
116 {
117 	struct dlm_cluster *cl = config_item_to_cluster(item);
118 
119 	strlcpy(dlm_config.ci_cluster_name, buf,
120 				sizeof(dlm_config.ci_cluster_name));
121 	strlcpy(cl->cl_cluster_name, buf, sizeof(cl->cl_cluster_name));
122 	return len;
123 }
124 
125 CONFIGFS_ATTR(cluster_, cluster_name);
126 
127 static ssize_t cluster_set(struct dlm_cluster *cl, unsigned int *cl_field,
128 			   int *info_field, int (*check_cb)(unsigned int x),
129 			   const char *buf, size_t len)
130 {
131 	unsigned int x;
132 	int rc;
133 
134 	if (!capable(CAP_SYS_ADMIN))
135 		return -EPERM;
136 	rc = kstrtouint(buf, 0, &x);
137 	if (rc)
138 		return rc;
139 
140 	if (check_cb) {
141 		rc = check_cb(x);
142 		if (rc)
143 			return rc;
144 	}
145 
146 	*cl_field = x;
147 	*info_field = x;
148 
149 	return len;
150 }
151 
152 #define CLUSTER_ATTR(name, check_cb)                                          \
153 static ssize_t cluster_##name##_store(struct config_item *item, \
154 		const char *buf, size_t len) \
155 {                                                                             \
156 	struct dlm_cluster *cl = config_item_to_cluster(item);		      \
157 	return cluster_set(cl, &cl->cl_##name, &dlm_config.ci_##name,         \
158 			   check_cb, buf, len);                               \
159 }                                                                             \
160 static ssize_t cluster_##name##_show(struct config_item *item, char *buf)     \
161 {                                                                             \
162 	struct dlm_cluster *cl = config_item_to_cluster(item);		      \
163 	return snprintf(buf, PAGE_SIZE, "%u\n", cl->cl_##name);               \
164 }                                                                             \
165 CONFIGFS_ATTR(cluster_, name);
166 
167 static int dlm_check_protocol_and_dlm_running(unsigned int x)
168 {
169 	switch (x) {
170 	case 0:
171 		/* TCP */
172 		break;
173 	case 1:
174 		/* SCTP */
175 		break;
176 	default:
177 		return -EINVAL;
178 	}
179 
180 	if (dlm_lowcomms_is_running())
181 		return -EBUSY;
182 
183 	return 0;
184 }
185 
186 static int dlm_check_zero_and_dlm_running(unsigned int x)
187 {
188 	if (!x)
189 		return -EINVAL;
190 
191 	if (dlm_lowcomms_is_running())
192 		return -EBUSY;
193 
194 	return 0;
195 }
196 
197 static int dlm_check_zero(unsigned int x)
198 {
199 	if (!x)
200 		return -EINVAL;
201 
202 	return 0;
203 }
204 
205 static int dlm_check_buffer_size(unsigned int x)
206 {
207 	if (x < DLM_MAX_SOCKET_BUFSIZE)
208 		return -EINVAL;
209 
210 	return 0;
211 }
212 
213 CLUSTER_ATTR(tcp_port, dlm_check_zero_and_dlm_running);
214 CLUSTER_ATTR(buffer_size, dlm_check_buffer_size);
215 CLUSTER_ATTR(rsbtbl_size, dlm_check_zero);
216 CLUSTER_ATTR(recover_timer, dlm_check_zero);
217 CLUSTER_ATTR(toss_secs, dlm_check_zero);
218 CLUSTER_ATTR(scan_secs, dlm_check_zero);
219 CLUSTER_ATTR(log_debug, NULL);
220 CLUSTER_ATTR(log_info, NULL);
221 CLUSTER_ATTR(protocol, dlm_check_protocol_and_dlm_running);
222 CLUSTER_ATTR(mark, NULL);
223 CLUSTER_ATTR(new_rsb_count, NULL);
224 CLUSTER_ATTR(recover_callbacks, NULL);
225 
226 static struct configfs_attribute *cluster_attrs[] = {
227 	[CLUSTER_ATTR_TCP_PORT] = &cluster_attr_tcp_port,
228 	[CLUSTER_ATTR_BUFFER_SIZE] = &cluster_attr_buffer_size,
229 	[CLUSTER_ATTR_RSBTBL_SIZE] = &cluster_attr_rsbtbl_size,
230 	[CLUSTER_ATTR_RECOVER_TIMER] = &cluster_attr_recover_timer,
231 	[CLUSTER_ATTR_TOSS_SECS] = &cluster_attr_toss_secs,
232 	[CLUSTER_ATTR_SCAN_SECS] = &cluster_attr_scan_secs,
233 	[CLUSTER_ATTR_LOG_DEBUG] = &cluster_attr_log_debug,
234 	[CLUSTER_ATTR_LOG_INFO] = &cluster_attr_log_info,
235 	[CLUSTER_ATTR_PROTOCOL] = &cluster_attr_protocol,
236 	[CLUSTER_ATTR_MARK] = &cluster_attr_mark,
237 	[CLUSTER_ATTR_NEW_RSB_COUNT] = &cluster_attr_new_rsb_count,
238 	[CLUSTER_ATTR_RECOVER_CALLBACKS] = &cluster_attr_recover_callbacks,
239 	[CLUSTER_ATTR_CLUSTER_NAME] = &cluster_attr_cluster_name,
240 	NULL,
241 };
242 
243 enum {
244 	COMM_ATTR_NODEID = 0,
245 	COMM_ATTR_LOCAL,
246 	COMM_ATTR_ADDR,
247 	COMM_ATTR_ADDR_LIST,
248 	COMM_ATTR_MARK,
249 };
250 
251 enum {
252 	NODE_ATTR_NODEID = 0,
253 	NODE_ATTR_WEIGHT,
254 };
255 
256 struct dlm_clusters {
257 	struct configfs_subsystem subsys;
258 };
259 
260 struct dlm_spaces {
261 	struct config_group ss_group;
262 };
263 
264 struct dlm_space {
265 	struct config_group group;
266 	struct list_head members;
267 	struct mutex members_lock;
268 	int members_count;
269 	struct dlm_nodes *nds;
270 };
271 
272 struct dlm_comms {
273 	struct config_group cs_group;
274 };
275 
276 struct dlm_comm {
277 	struct config_item item;
278 	int seq;
279 	int nodeid;
280 	int local;
281 	int addr_count;
282 	unsigned int mark;
283 	struct sockaddr_storage *addr[DLM_MAX_ADDR_COUNT];
284 };
285 
286 struct dlm_nodes {
287 	struct config_group ns_group;
288 };
289 
290 struct dlm_node {
291 	struct config_item item;
292 	struct list_head list; /* space->members */
293 	int nodeid;
294 	int weight;
295 	int new;
296 	int comm_seq; /* copy of cm->seq when nd->nodeid is set */
297 };
298 
299 static struct configfs_group_operations clusters_ops = {
300 	.make_group = make_cluster,
301 	.drop_item = drop_cluster,
302 };
303 
304 static struct configfs_item_operations cluster_ops = {
305 	.release = release_cluster,
306 };
307 
308 static struct configfs_group_operations spaces_ops = {
309 	.make_group = make_space,
310 	.drop_item = drop_space,
311 };
312 
313 static struct configfs_item_operations space_ops = {
314 	.release = release_space,
315 };
316 
317 static struct configfs_group_operations comms_ops = {
318 	.make_item = make_comm,
319 	.drop_item = drop_comm,
320 };
321 
322 static struct configfs_item_operations comm_ops = {
323 	.release = release_comm,
324 };
325 
326 static struct configfs_group_operations nodes_ops = {
327 	.make_item = make_node,
328 	.drop_item = drop_node,
329 };
330 
331 static struct configfs_item_operations node_ops = {
332 	.release = release_node,
333 };
334 
335 static const struct config_item_type clusters_type = {
336 	.ct_group_ops = &clusters_ops,
337 	.ct_owner = THIS_MODULE,
338 };
339 
340 static const struct config_item_type cluster_type = {
341 	.ct_item_ops = &cluster_ops,
342 	.ct_attrs = cluster_attrs,
343 	.ct_owner = THIS_MODULE,
344 };
345 
346 static const struct config_item_type spaces_type = {
347 	.ct_group_ops = &spaces_ops,
348 	.ct_owner = THIS_MODULE,
349 };
350 
351 static const struct config_item_type space_type = {
352 	.ct_item_ops = &space_ops,
353 	.ct_owner = THIS_MODULE,
354 };
355 
356 static const struct config_item_type comms_type = {
357 	.ct_group_ops = &comms_ops,
358 	.ct_owner = THIS_MODULE,
359 };
360 
361 static const struct config_item_type comm_type = {
362 	.ct_item_ops = &comm_ops,
363 	.ct_attrs = comm_attrs,
364 	.ct_owner = THIS_MODULE,
365 };
366 
367 static const struct config_item_type nodes_type = {
368 	.ct_group_ops = &nodes_ops,
369 	.ct_owner = THIS_MODULE,
370 };
371 
372 static const struct config_item_type node_type = {
373 	.ct_item_ops = &node_ops,
374 	.ct_attrs = node_attrs,
375 	.ct_owner = THIS_MODULE,
376 };
377 
378 static struct dlm_space *config_item_to_space(struct config_item *i)
379 {
380 	return i ? container_of(to_config_group(i), struct dlm_space, group) :
381 		   NULL;
382 }
383 
384 static struct dlm_comm *config_item_to_comm(struct config_item *i)
385 {
386 	return i ? container_of(i, struct dlm_comm, item) : NULL;
387 }
388 
389 static struct dlm_node *config_item_to_node(struct config_item *i)
390 {
391 	return i ? container_of(i, struct dlm_node, item) : NULL;
392 }
393 
394 static struct config_group *make_cluster(struct config_group *g,
395 					 const char *name)
396 {
397 	struct dlm_cluster *cl = NULL;
398 	struct dlm_spaces *sps = NULL;
399 	struct dlm_comms *cms = NULL;
400 
401 	cl = kzalloc(sizeof(struct dlm_cluster), GFP_NOFS);
402 	sps = kzalloc(sizeof(struct dlm_spaces), GFP_NOFS);
403 	cms = kzalloc(sizeof(struct dlm_comms), GFP_NOFS);
404 
405 	if (!cl || !sps || !cms)
406 		goto fail;
407 
408 	cl->sps = sps;
409 	cl->cms = cms;
410 
411 	config_group_init_type_name(&cl->group, name, &cluster_type);
412 	config_group_init_type_name(&sps->ss_group, "spaces", &spaces_type);
413 	config_group_init_type_name(&cms->cs_group, "comms", &comms_type);
414 
415 	configfs_add_default_group(&sps->ss_group, &cl->group);
416 	configfs_add_default_group(&cms->cs_group, &cl->group);
417 
418 	cl->cl_tcp_port = dlm_config.ci_tcp_port;
419 	cl->cl_buffer_size = dlm_config.ci_buffer_size;
420 	cl->cl_rsbtbl_size = dlm_config.ci_rsbtbl_size;
421 	cl->cl_recover_timer = dlm_config.ci_recover_timer;
422 	cl->cl_toss_secs = dlm_config.ci_toss_secs;
423 	cl->cl_scan_secs = dlm_config.ci_scan_secs;
424 	cl->cl_log_debug = dlm_config.ci_log_debug;
425 	cl->cl_log_info = dlm_config.ci_log_info;
426 	cl->cl_protocol = dlm_config.ci_protocol;
427 	cl->cl_new_rsb_count = dlm_config.ci_new_rsb_count;
428 	cl->cl_recover_callbacks = dlm_config.ci_recover_callbacks;
429 	memcpy(cl->cl_cluster_name, dlm_config.ci_cluster_name,
430 	       DLM_LOCKSPACE_LEN);
431 
432 	space_list = &sps->ss_group;
433 	comm_list = &cms->cs_group;
434 	return &cl->group;
435 
436  fail:
437 	kfree(cl);
438 	kfree(sps);
439 	kfree(cms);
440 	return ERR_PTR(-ENOMEM);
441 }
442 
443 static void drop_cluster(struct config_group *g, struct config_item *i)
444 {
445 	struct dlm_cluster *cl = config_item_to_cluster(i);
446 
447 	configfs_remove_default_groups(&cl->group);
448 
449 	space_list = NULL;
450 	comm_list = NULL;
451 
452 	config_item_put(i);
453 }
454 
455 static void release_cluster(struct config_item *i)
456 {
457 	struct dlm_cluster *cl = config_item_to_cluster(i);
458 
459 	kfree(cl->sps);
460 	kfree(cl->cms);
461 	kfree(cl);
462 }
463 
464 static struct config_group *make_space(struct config_group *g, const char *name)
465 {
466 	struct dlm_space *sp = NULL;
467 	struct dlm_nodes *nds = NULL;
468 
469 	sp = kzalloc(sizeof(struct dlm_space), GFP_NOFS);
470 	nds = kzalloc(sizeof(struct dlm_nodes), GFP_NOFS);
471 
472 	if (!sp || !nds)
473 		goto fail;
474 
475 	config_group_init_type_name(&sp->group, name, &space_type);
476 
477 	config_group_init_type_name(&nds->ns_group, "nodes", &nodes_type);
478 	configfs_add_default_group(&nds->ns_group, &sp->group);
479 
480 	INIT_LIST_HEAD(&sp->members);
481 	mutex_init(&sp->members_lock);
482 	sp->members_count = 0;
483 	sp->nds = nds;
484 	return &sp->group;
485 
486  fail:
487 	kfree(sp);
488 	kfree(nds);
489 	return ERR_PTR(-ENOMEM);
490 }
491 
492 static void drop_space(struct config_group *g, struct config_item *i)
493 {
494 	struct dlm_space *sp = config_item_to_space(i);
495 
496 	/* assert list_empty(&sp->members) */
497 
498 	configfs_remove_default_groups(&sp->group);
499 	config_item_put(i);
500 }
501 
502 static void release_space(struct config_item *i)
503 {
504 	struct dlm_space *sp = config_item_to_space(i);
505 	kfree(sp->nds);
506 	kfree(sp);
507 }
508 
509 static struct config_item *make_comm(struct config_group *g, const char *name)
510 {
511 	struct dlm_comm *cm;
512 
513 	cm = kzalloc(sizeof(struct dlm_comm), GFP_NOFS);
514 	if (!cm)
515 		return ERR_PTR(-ENOMEM);
516 
517 	config_item_init_type_name(&cm->item, name, &comm_type);
518 
519 	cm->seq = dlm_comm_count++;
520 	if (!cm->seq)
521 		cm->seq = dlm_comm_count++;
522 
523 	cm->nodeid = -1;
524 	cm->local = 0;
525 	cm->addr_count = 0;
526 	cm->mark = 0;
527 	return &cm->item;
528 }
529 
530 static void drop_comm(struct config_group *g, struct config_item *i)
531 {
532 	struct dlm_comm *cm = config_item_to_comm(i);
533 	if (local_comm == cm)
534 		local_comm = NULL;
535 	dlm_midcomms_close(cm->nodeid);
536 	while (cm->addr_count--)
537 		kfree(cm->addr[cm->addr_count]);
538 	config_item_put(i);
539 }
540 
541 static void release_comm(struct config_item *i)
542 {
543 	struct dlm_comm *cm = config_item_to_comm(i);
544 	kfree(cm);
545 }
546 
547 static struct config_item *make_node(struct config_group *g, const char *name)
548 {
549 	struct dlm_space *sp = config_item_to_space(g->cg_item.ci_parent);
550 	struct dlm_node *nd;
551 
552 	nd = kzalloc(sizeof(struct dlm_node), GFP_NOFS);
553 	if (!nd)
554 		return ERR_PTR(-ENOMEM);
555 
556 	config_item_init_type_name(&nd->item, name, &node_type);
557 	nd->nodeid = -1;
558 	nd->weight = 1;  /* default weight of 1 if none is set */
559 	nd->new = 1;     /* set to 0 once it's been read by dlm_nodeid_list() */
560 
561 	mutex_lock(&sp->members_lock);
562 	list_add(&nd->list, &sp->members);
563 	sp->members_count++;
564 	mutex_unlock(&sp->members_lock);
565 
566 	return &nd->item;
567 }
568 
569 static void drop_node(struct config_group *g, struct config_item *i)
570 {
571 	struct dlm_space *sp = config_item_to_space(g->cg_item.ci_parent);
572 	struct dlm_node *nd = config_item_to_node(i);
573 
574 	mutex_lock(&sp->members_lock);
575 	list_del(&nd->list);
576 	sp->members_count--;
577 	mutex_unlock(&sp->members_lock);
578 
579 	config_item_put(i);
580 }
581 
582 static void release_node(struct config_item *i)
583 {
584 	struct dlm_node *nd = config_item_to_node(i);
585 	kfree(nd);
586 }
587 
588 static struct dlm_clusters clusters_root = {
589 	.subsys = {
590 		.su_group = {
591 			.cg_item = {
592 				.ci_namebuf = "dlm",
593 				.ci_type = &clusters_type,
594 			},
595 		},
596 	},
597 };
598 
599 int __init dlm_config_init(void)
600 {
601 	config_group_init(&clusters_root.subsys.su_group);
602 	mutex_init(&clusters_root.subsys.su_mutex);
603 	return configfs_register_subsystem(&clusters_root.subsys);
604 }
605 
606 void dlm_config_exit(void)
607 {
608 	configfs_unregister_subsystem(&clusters_root.subsys);
609 }
610 
611 /*
612  * Functions for user space to read/write attributes
613  */
614 
615 static ssize_t comm_nodeid_show(struct config_item *item, char *buf)
616 {
617 	return sprintf(buf, "%d\n", config_item_to_comm(item)->nodeid);
618 }
619 
620 static ssize_t comm_nodeid_store(struct config_item *item, const char *buf,
621 				 size_t len)
622 {
623 	int rc = kstrtoint(buf, 0, &config_item_to_comm(item)->nodeid);
624 
625 	if (rc)
626 		return rc;
627 	return len;
628 }
629 
630 static ssize_t comm_local_show(struct config_item *item, char *buf)
631 {
632 	return sprintf(buf, "%d\n", config_item_to_comm(item)->local);
633 }
634 
635 static ssize_t comm_local_store(struct config_item *item, const char *buf,
636 				size_t len)
637 {
638 	struct dlm_comm *cm = config_item_to_comm(item);
639 	int rc = kstrtoint(buf, 0, &cm->local);
640 
641 	if (rc)
642 		return rc;
643 	if (cm->local && !local_comm)
644 		local_comm = cm;
645 	return len;
646 }
647 
648 static ssize_t comm_addr_store(struct config_item *item, const char *buf,
649 		size_t len)
650 {
651 	struct dlm_comm *cm = config_item_to_comm(item);
652 	struct sockaddr_storage *addr;
653 	int rv;
654 
655 	if (len != sizeof(struct sockaddr_storage))
656 		return -EINVAL;
657 
658 	if (cm->addr_count >= DLM_MAX_ADDR_COUNT)
659 		return -ENOSPC;
660 
661 	addr = kzalloc(sizeof(*addr), GFP_NOFS);
662 	if (!addr)
663 		return -ENOMEM;
664 
665 	memcpy(addr, buf, len);
666 
667 	rv = dlm_lowcomms_addr(cm->nodeid, addr, len);
668 	if (rv) {
669 		kfree(addr);
670 		return rv;
671 	}
672 
673 	cm->addr[cm->addr_count++] = addr;
674 	return len;
675 }
676 
677 static ssize_t comm_addr_list_show(struct config_item *item, char *buf)
678 {
679 	struct dlm_comm *cm = config_item_to_comm(item);
680 	ssize_t s;
681 	ssize_t allowance;
682 	int i;
683 	struct sockaddr_storage *addr;
684 	struct sockaddr_in *addr_in;
685 	struct sockaddr_in6 *addr_in6;
686 
687 	/* Taken from ip6_addr_string() defined in lib/vsprintf.c */
688 	char buf0[sizeof("AF_INET6	xxxx:xxxx:xxxx:xxxx:xxxx:xxxx:255.255.255.255\n")];
689 
690 
691 	/* Derived from SIMPLE_ATTR_SIZE of fs/configfs/file.c */
692 	allowance = 4096;
693 	buf[0] = '\0';
694 
695 	for (i = 0; i < cm->addr_count; i++) {
696 		addr = cm->addr[i];
697 
698 		switch(addr->ss_family) {
699 		case AF_INET:
700 			addr_in = (struct sockaddr_in *)addr;
701 			s = sprintf(buf0, "AF_INET	%pI4\n", &addr_in->sin_addr.s_addr);
702 			break;
703 		case AF_INET6:
704 			addr_in6 = (struct sockaddr_in6 *)addr;
705 			s = sprintf(buf0, "AF_INET6	%pI6\n", &addr_in6->sin6_addr);
706 			break;
707 		default:
708 			s = sprintf(buf0, "%s\n", "<UNKNOWN>");
709 			break;
710 		}
711 		allowance -= s;
712 		if (allowance >= 0)
713 			strcat(buf, buf0);
714 		else {
715 			allowance += s;
716 			break;
717 		}
718 	}
719 	return 4096 - allowance;
720 }
721 
722 static ssize_t comm_mark_show(struct config_item *item, char *buf)
723 {
724 	return sprintf(buf, "%u\n", config_item_to_comm(item)->mark);
725 }
726 
727 static ssize_t comm_mark_store(struct config_item *item, const char *buf,
728 			       size_t len)
729 {
730 	struct dlm_comm *comm;
731 	unsigned int mark;
732 	int rc;
733 
734 	rc = kstrtouint(buf, 0, &mark);
735 	if (rc)
736 		return rc;
737 
738 	if (mark == 0)
739 		mark = dlm_config.ci_mark;
740 
741 	comm = config_item_to_comm(item);
742 	rc = dlm_lowcomms_nodes_set_mark(comm->nodeid, mark);
743 	if (rc)
744 		return rc;
745 
746 	comm->mark = mark;
747 	return len;
748 }
749 
750 CONFIGFS_ATTR(comm_, nodeid);
751 CONFIGFS_ATTR(comm_, local);
752 CONFIGFS_ATTR(comm_, mark);
753 CONFIGFS_ATTR_WO(comm_, addr);
754 CONFIGFS_ATTR_RO(comm_, addr_list);
755 
756 static struct configfs_attribute *comm_attrs[] = {
757 	[COMM_ATTR_NODEID] = &comm_attr_nodeid,
758 	[COMM_ATTR_LOCAL] = &comm_attr_local,
759 	[COMM_ATTR_ADDR] = &comm_attr_addr,
760 	[COMM_ATTR_ADDR_LIST] = &comm_attr_addr_list,
761 	[COMM_ATTR_MARK] = &comm_attr_mark,
762 	NULL,
763 };
764 
765 static ssize_t node_nodeid_show(struct config_item *item, char *buf)
766 {
767 	return sprintf(buf, "%d\n", config_item_to_node(item)->nodeid);
768 }
769 
770 static ssize_t node_nodeid_store(struct config_item *item, const char *buf,
771 				 size_t len)
772 {
773 	struct dlm_node *nd = config_item_to_node(item);
774 	uint32_t seq = 0;
775 	int rc = kstrtoint(buf, 0, &nd->nodeid);
776 
777 	if (rc)
778 		return rc;
779 	dlm_comm_seq(nd->nodeid, &seq);
780 	nd->comm_seq = seq;
781 	return len;
782 }
783 
784 static ssize_t node_weight_show(struct config_item *item, char *buf)
785 {
786 	return sprintf(buf, "%d\n", config_item_to_node(item)->weight);
787 }
788 
789 static ssize_t node_weight_store(struct config_item *item, const char *buf,
790 				 size_t len)
791 {
792 	int rc = kstrtoint(buf, 0, &config_item_to_node(item)->weight);
793 
794 	if (rc)
795 		return rc;
796 	return len;
797 }
798 
799 CONFIGFS_ATTR(node_, nodeid);
800 CONFIGFS_ATTR(node_, weight);
801 
802 static struct configfs_attribute *node_attrs[] = {
803 	[NODE_ATTR_NODEID] = &node_attr_nodeid,
804 	[NODE_ATTR_WEIGHT] = &node_attr_weight,
805 	NULL,
806 };
807 
808 /*
809  * Functions for the dlm to get the info that's been configured
810  */
811 
812 static struct dlm_space *get_space(char *name)
813 {
814 	struct config_item *i;
815 
816 	if (!space_list)
817 		return NULL;
818 
819 	mutex_lock(&space_list->cg_subsys->su_mutex);
820 	i = config_group_find_item(space_list, name);
821 	mutex_unlock(&space_list->cg_subsys->su_mutex);
822 
823 	return config_item_to_space(i);
824 }
825 
826 static void put_space(struct dlm_space *sp)
827 {
828 	config_item_put(&sp->group.cg_item);
829 }
830 
831 static struct dlm_comm *get_comm(int nodeid)
832 {
833 	struct config_item *i;
834 	struct dlm_comm *cm = NULL;
835 	int found = 0;
836 
837 	if (!comm_list)
838 		return NULL;
839 
840 	mutex_lock(&clusters_root.subsys.su_mutex);
841 
842 	list_for_each_entry(i, &comm_list->cg_children, ci_entry) {
843 		cm = config_item_to_comm(i);
844 
845 		if (cm->nodeid != nodeid)
846 			continue;
847 		found = 1;
848 		config_item_get(i);
849 		break;
850 	}
851 	mutex_unlock(&clusters_root.subsys.su_mutex);
852 
853 	if (!found)
854 		cm = NULL;
855 	return cm;
856 }
857 
858 static void put_comm(struct dlm_comm *cm)
859 {
860 	config_item_put(&cm->item);
861 }
862 
863 /* caller must free mem */
864 int dlm_config_nodes(char *lsname, struct dlm_config_node **nodes_out,
865 		     int *count_out)
866 {
867 	struct dlm_space *sp;
868 	struct dlm_node *nd;
869 	struct dlm_config_node *nodes, *node;
870 	int rv, count;
871 
872 	sp = get_space(lsname);
873 	if (!sp)
874 		return -EEXIST;
875 
876 	mutex_lock(&sp->members_lock);
877 	if (!sp->members_count) {
878 		rv = -EINVAL;
879 		printk(KERN_ERR "dlm: zero members_count\n");
880 		goto out;
881 	}
882 
883 	count = sp->members_count;
884 
885 	nodes = kcalloc(count, sizeof(struct dlm_config_node), GFP_NOFS);
886 	if (!nodes) {
887 		rv = -ENOMEM;
888 		goto out;
889 	}
890 
891 	node = nodes;
892 	list_for_each_entry(nd, &sp->members, list) {
893 		node->nodeid = nd->nodeid;
894 		node->weight = nd->weight;
895 		node->new = nd->new;
896 		node->comm_seq = nd->comm_seq;
897 		node++;
898 
899 		nd->new = 0;
900 	}
901 
902 	*count_out = count;
903 	*nodes_out = nodes;
904 	rv = 0;
905  out:
906 	mutex_unlock(&sp->members_lock);
907 	put_space(sp);
908 	return rv;
909 }
910 
911 int dlm_comm_seq(int nodeid, uint32_t *seq)
912 {
913 	struct dlm_comm *cm = get_comm(nodeid);
914 	if (!cm)
915 		return -EEXIST;
916 	*seq = cm->seq;
917 	put_comm(cm);
918 	return 0;
919 }
920 
921 int dlm_our_nodeid(void)
922 {
923 	return local_comm ? local_comm->nodeid : 0;
924 }
925 
926 /* num 0 is first addr, num 1 is second addr */
927 int dlm_our_addr(struct sockaddr_storage *addr, int num)
928 {
929 	if (!local_comm)
930 		return -1;
931 	if (num + 1 > local_comm->addr_count)
932 		return -1;
933 	memcpy(addr, local_comm->addr[num], sizeof(*addr));
934 	return 0;
935 }
936 
937 /* Config file defaults */
938 #define DEFAULT_TCP_PORT       21064
939 #define DEFAULT_RSBTBL_SIZE     1024
940 #define DEFAULT_RECOVER_TIMER      5
941 #define DEFAULT_TOSS_SECS         10
942 #define DEFAULT_SCAN_SECS          5
943 #define DEFAULT_LOG_DEBUG          0
944 #define DEFAULT_LOG_INFO           1
945 #define DEFAULT_PROTOCOL           DLM_PROTO_TCP
946 #define DEFAULT_MARK               0
947 #define DEFAULT_NEW_RSB_COUNT    128
948 #define DEFAULT_RECOVER_CALLBACKS  0
949 #define DEFAULT_CLUSTER_NAME      ""
950 
951 struct dlm_config_info dlm_config = {
952 	.ci_tcp_port = DEFAULT_TCP_PORT,
953 	.ci_buffer_size = DLM_MAX_SOCKET_BUFSIZE,
954 	.ci_rsbtbl_size = DEFAULT_RSBTBL_SIZE,
955 	.ci_recover_timer = DEFAULT_RECOVER_TIMER,
956 	.ci_toss_secs = DEFAULT_TOSS_SECS,
957 	.ci_scan_secs = DEFAULT_SCAN_SECS,
958 	.ci_log_debug = DEFAULT_LOG_DEBUG,
959 	.ci_log_info = DEFAULT_LOG_INFO,
960 	.ci_protocol = DEFAULT_PROTOCOL,
961 	.ci_mark = DEFAULT_MARK,
962 	.ci_new_rsb_count = DEFAULT_NEW_RSB_COUNT,
963 	.ci_recover_callbacks = DEFAULT_RECOVER_CALLBACKS,
964 	.ci_cluster_name = DEFAULT_CLUSTER_NAME
965 };
966 
967