xref: /linux/fs/ocfs2/dlm/dlmdebug.c (revision 22d55f02b8922a097cd4be1e2f131dfa7ef65901)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* -*- mode: c; c-basic-offset: 8; -*-
3  * vim: noexpandtab sw=8 ts=8 sts=0:
4  *
5  * dlmdebug.c
6  *
7  * debug functionality for the dlm
8  *
9  * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
10  */
11 
12 #include <linux/types.h>
13 #include <linux/slab.h>
14 #include <linux/highmem.h>
15 #include <linux/sysctl.h>
16 #include <linux/spinlock.h>
17 #include <linux/debugfs.h>
18 #include <linux/export.h>
19 
20 #include "cluster/heartbeat.h"
21 #include "cluster/nodemanager.h"
22 #include "cluster/tcp.h"
23 
24 #include "dlmapi.h"
25 #include "dlmcommon.h"
26 #include "dlmdomain.h"
27 #include "dlmdebug.h"
28 
29 #define MLOG_MASK_PREFIX ML_DLM
30 #include "cluster/masklog.h"
31 
32 static int stringify_lockname(const char *lockname, int locklen, char *buf,
33 			      int len);
34 
35 void dlm_print_one_lock_resource(struct dlm_lock_resource *res)
36 {
37 	spin_lock(&res->spinlock);
38 	__dlm_print_one_lock_resource(res);
39 	spin_unlock(&res->spinlock);
40 }
41 
42 static void dlm_print_lockres_refmap(struct dlm_lock_resource *res)
43 {
44 	int bit;
45 	assert_spin_locked(&res->spinlock);
46 
47 	printk("  refmap nodes: [ ");
48 	bit = 0;
49 	while (1) {
50 		bit = find_next_bit(res->refmap, O2NM_MAX_NODES, bit);
51 		if (bit >= O2NM_MAX_NODES)
52 			break;
53 		printk("%u ", bit);
54 		bit++;
55 	}
56 	printk("], inflight=%u\n", res->inflight_locks);
57 }
58 
59 static void __dlm_print_lock(struct dlm_lock *lock)
60 {
61 	spin_lock(&lock->spinlock);
62 
63 	printk("    type=%d, conv=%d, node=%u, cookie=%u:%llu, "
64 	       "ref=%u, ast=(empty=%c,pend=%c), bast=(empty=%c,pend=%c), "
65 	       "pending=(conv=%c,lock=%c,cancel=%c,unlock=%c)\n",
66 	       lock->ml.type, lock->ml.convert_type, lock->ml.node,
67 	       dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
68 	       dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
69 	       kref_read(&lock->lock_refs),
70 	       (list_empty(&lock->ast_list) ? 'y' : 'n'),
71 	       (lock->ast_pending ? 'y' : 'n'),
72 	       (list_empty(&lock->bast_list) ? 'y' : 'n'),
73 	       (lock->bast_pending ? 'y' : 'n'),
74 	       (lock->convert_pending ? 'y' : 'n'),
75 	       (lock->lock_pending ? 'y' : 'n'),
76 	       (lock->cancel_pending ? 'y' : 'n'),
77 	       (lock->unlock_pending ? 'y' : 'n'));
78 
79 	spin_unlock(&lock->spinlock);
80 }
81 
82 void __dlm_print_one_lock_resource(struct dlm_lock_resource *res)
83 {
84 	struct dlm_lock *lock;
85 	char buf[DLM_LOCKID_NAME_MAX];
86 
87 	assert_spin_locked(&res->spinlock);
88 
89 	stringify_lockname(res->lockname.name, res->lockname.len,
90 			   buf, sizeof(buf));
91 	printk("lockres: %s, owner=%u, state=%u\n",
92 	       buf, res->owner, res->state);
93 	printk("  last used: %lu, refcnt: %u, on purge list: %s\n",
94 	       res->last_used, kref_read(&res->refs),
95 	       list_empty(&res->purge) ? "no" : "yes");
96 	printk("  on dirty list: %s, on reco list: %s, "
97 	       "migrating pending: %s\n",
98 	       list_empty(&res->dirty) ? "no" : "yes",
99 	       list_empty(&res->recovering) ? "no" : "yes",
100 	       res->migration_pending ? "yes" : "no");
101 	printk("  inflight locks: %d, asts reserved: %d\n",
102 	       res->inflight_locks, atomic_read(&res->asts_reserved));
103 	dlm_print_lockres_refmap(res);
104 	printk("  granted queue:\n");
105 	list_for_each_entry(lock, &res->granted, list) {
106 		__dlm_print_lock(lock);
107 	}
108 	printk("  converting queue:\n");
109 	list_for_each_entry(lock, &res->converting, list) {
110 		__dlm_print_lock(lock);
111 	}
112 	printk("  blocked queue:\n");
113 	list_for_each_entry(lock, &res->blocked, list) {
114 		__dlm_print_lock(lock);
115 	}
116 }
117 
118 void dlm_print_one_lock(struct dlm_lock *lockid)
119 {
120 	dlm_print_one_lock_resource(lockid->lockres);
121 }
122 EXPORT_SYMBOL_GPL(dlm_print_one_lock);
123 
124 static const char *dlm_errnames[] = {
125 	[DLM_NORMAL] =			"DLM_NORMAL",
126 	[DLM_GRANTED] =			"DLM_GRANTED",
127 	[DLM_DENIED] =			"DLM_DENIED",
128 	[DLM_DENIED_NOLOCKS] =		"DLM_DENIED_NOLOCKS",
129 	[DLM_WORKING] =			"DLM_WORKING",
130 	[DLM_BLOCKED] =			"DLM_BLOCKED",
131 	[DLM_BLOCKED_ORPHAN] =		"DLM_BLOCKED_ORPHAN",
132 	[DLM_DENIED_GRACE_PERIOD] =	"DLM_DENIED_GRACE_PERIOD",
133 	[DLM_SYSERR] =			"DLM_SYSERR",
134 	[DLM_NOSUPPORT] =		"DLM_NOSUPPORT",
135 	[DLM_CANCELGRANT] =		"DLM_CANCELGRANT",
136 	[DLM_IVLOCKID] =		"DLM_IVLOCKID",
137 	[DLM_SYNC] =			"DLM_SYNC",
138 	[DLM_BADTYPE] =			"DLM_BADTYPE",
139 	[DLM_BADRESOURCE] =		"DLM_BADRESOURCE",
140 	[DLM_MAXHANDLES] =		"DLM_MAXHANDLES",
141 	[DLM_NOCLINFO] =		"DLM_NOCLINFO",
142 	[DLM_NOLOCKMGR] =		"DLM_NOLOCKMGR",
143 	[DLM_NOPURGED] =		"DLM_NOPURGED",
144 	[DLM_BADARGS] =			"DLM_BADARGS",
145 	[DLM_VOID] =			"DLM_VOID",
146 	[DLM_NOTQUEUED] =		"DLM_NOTQUEUED",
147 	[DLM_IVBUFLEN] =		"DLM_IVBUFLEN",
148 	[DLM_CVTUNGRANT] =		"DLM_CVTUNGRANT",
149 	[DLM_BADPARAM] =		"DLM_BADPARAM",
150 	[DLM_VALNOTVALID] =		"DLM_VALNOTVALID",
151 	[DLM_REJECTED] =		"DLM_REJECTED",
152 	[DLM_ABORT] =			"DLM_ABORT",
153 	[DLM_CANCEL] =			"DLM_CANCEL",
154 	[DLM_IVRESHANDLE] =		"DLM_IVRESHANDLE",
155 	[DLM_DEADLOCK] =		"DLM_DEADLOCK",
156 	[DLM_DENIED_NOASTS] =		"DLM_DENIED_NOASTS",
157 	[DLM_FORWARD] =			"DLM_FORWARD",
158 	[DLM_TIMEOUT] =			"DLM_TIMEOUT",
159 	[DLM_IVGROUPID] =		"DLM_IVGROUPID",
160 	[DLM_VERS_CONFLICT] =		"DLM_VERS_CONFLICT",
161 	[DLM_BAD_DEVICE_PATH] =		"DLM_BAD_DEVICE_PATH",
162 	[DLM_NO_DEVICE_PERMISSION] =	"DLM_NO_DEVICE_PERMISSION",
163 	[DLM_NO_CONTROL_DEVICE ] =	"DLM_NO_CONTROL_DEVICE ",
164 	[DLM_RECOVERING] =		"DLM_RECOVERING",
165 	[DLM_MIGRATING] =		"DLM_MIGRATING",
166 	[DLM_MAXSTATS] =		"DLM_MAXSTATS",
167 };
168 
169 static const char *dlm_errmsgs[] = {
170 	[DLM_NORMAL] = 			"request in progress",
171 	[DLM_GRANTED] = 		"request granted",
172 	[DLM_DENIED] = 			"request denied",
173 	[DLM_DENIED_NOLOCKS] = 		"request denied, out of system resources",
174 	[DLM_WORKING] = 		"async request in progress",
175 	[DLM_BLOCKED] = 		"lock request blocked",
176 	[DLM_BLOCKED_ORPHAN] = 		"lock request blocked by a orphan lock",
177 	[DLM_DENIED_GRACE_PERIOD] = 	"topological change in progress",
178 	[DLM_SYSERR] = 			"system error",
179 	[DLM_NOSUPPORT] = 		"unsupported",
180 	[DLM_CANCELGRANT] = 		"can't cancel convert: already granted",
181 	[DLM_IVLOCKID] = 		"bad lockid",
182 	[DLM_SYNC] = 			"synchronous request granted",
183 	[DLM_BADTYPE] = 		"bad resource type",
184 	[DLM_BADRESOURCE] = 		"bad resource handle",
185 	[DLM_MAXHANDLES] = 		"no more resource handles",
186 	[DLM_NOCLINFO] = 		"can't contact cluster manager",
187 	[DLM_NOLOCKMGR] = 		"can't contact lock manager",
188 	[DLM_NOPURGED] = 		"can't contact purge daemon",
189 	[DLM_BADARGS] = 		"bad api args",
190 	[DLM_VOID] = 			"no status",
191 	[DLM_NOTQUEUED] = 		"NOQUEUE was specified and request failed",
192 	[DLM_IVBUFLEN] = 		"invalid resource name length",
193 	[DLM_CVTUNGRANT] = 		"attempted to convert ungranted lock",
194 	[DLM_BADPARAM] = 		"invalid lock mode specified",
195 	[DLM_VALNOTVALID] = 		"value block has been invalidated",
196 	[DLM_REJECTED] = 		"request rejected, unrecognized client",
197 	[DLM_ABORT] = 			"blocked lock request cancelled",
198 	[DLM_CANCEL] = 			"conversion request cancelled",
199 	[DLM_IVRESHANDLE] = 		"invalid resource handle",
200 	[DLM_DEADLOCK] = 		"deadlock recovery refused this request",
201 	[DLM_DENIED_NOASTS] = 		"failed to allocate AST",
202 	[DLM_FORWARD] = 		"request must wait for primary's response",
203 	[DLM_TIMEOUT] = 		"timeout value for lock has expired",
204 	[DLM_IVGROUPID] = 		"invalid group specification",
205 	[DLM_VERS_CONFLICT] = 		"version conflicts prevent request handling",
206 	[DLM_BAD_DEVICE_PATH] = 	"Locks device does not exist or path wrong",
207 	[DLM_NO_DEVICE_PERMISSION] = 	"Client has insufficient perms for device",
208 	[DLM_NO_CONTROL_DEVICE] = 	"Cannot set options on opened device ",
209 	[DLM_RECOVERING] = 		"lock resource being recovered",
210 	[DLM_MIGRATING] = 		"lock resource being migrated",
211 	[DLM_MAXSTATS] = 		"invalid error number",
212 };
213 
214 const char *dlm_errmsg(enum dlm_status err)
215 {
216 	if (err >= DLM_MAXSTATS || err < 0)
217 		return dlm_errmsgs[DLM_MAXSTATS];
218 	return dlm_errmsgs[err];
219 }
220 EXPORT_SYMBOL_GPL(dlm_errmsg);
221 
222 const char *dlm_errname(enum dlm_status err)
223 {
224 	if (err >= DLM_MAXSTATS || err < 0)
225 		return dlm_errnames[DLM_MAXSTATS];
226 	return dlm_errnames[err];
227 }
228 EXPORT_SYMBOL_GPL(dlm_errname);
229 
230 /* NOTE: This function converts a lockname into a string. It uses knowledge
231  * of the format of the lockname that should be outside the purview of the dlm.
232  * We are adding only to make dlm debugging slightly easier.
233  *
234  * For more on lockname formats, please refer to dlmglue.c and ocfs2_lockid.h.
235  */
236 static int stringify_lockname(const char *lockname, int locklen, char *buf,
237 			      int len)
238 {
239 	int out = 0;
240 	__be64 inode_blkno_be;
241 
242 #define OCFS2_DENTRY_LOCK_INO_START	18
243 	if (*lockname == 'N') {
244 		memcpy((__be64 *)&inode_blkno_be,
245 		       (char *)&lockname[OCFS2_DENTRY_LOCK_INO_START],
246 		       sizeof(__be64));
247 		out += snprintf(buf + out, len - out, "%.*s%08x",
248 				OCFS2_DENTRY_LOCK_INO_START - 1, lockname,
249 				(unsigned int)be64_to_cpu(inode_blkno_be));
250 	} else
251 		out += snprintf(buf + out, len - out, "%.*s",
252 				locklen, lockname);
253 	return out;
254 }
255 
256 static int stringify_nodemap(unsigned long *nodemap, int maxnodes,
257 			     char *buf, int len)
258 {
259 	int out = 0;
260 	int i = -1;
261 
262 	while ((i = find_next_bit(nodemap, maxnodes, i + 1)) < maxnodes)
263 		out += snprintf(buf + out, len - out, "%d ", i);
264 
265 	return out;
266 }
267 
268 static int dump_mle(struct dlm_master_list_entry *mle, char *buf, int len)
269 {
270 	int out = 0;
271 	char *mle_type;
272 
273 	if (mle->type == DLM_MLE_BLOCK)
274 		mle_type = "BLK";
275 	else if (mle->type == DLM_MLE_MASTER)
276 		mle_type = "MAS";
277 	else
278 		mle_type = "MIG";
279 
280 	out += stringify_lockname(mle->mname, mle->mnamelen, buf + out, len - out);
281 	out += snprintf(buf + out, len - out,
282 			"\t%3s\tmas=%3u\tnew=%3u\tevt=%1d\tuse=%1d\tref=%3d\n",
283 			mle_type, mle->master, mle->new_master,
284 			!list_empty(&mle->hb_events),
285 			!!mle->inuse,
286 			kref_read(&mle->mle_refs));
287 
288 	out += snprintf(buf + out, len - out, "Maybe=");
289 	out += stringify_nodemap(mle->maybe_map, O2NM_MAX_NODES,
290 				 buf + out, len - out);
291 	out += snprintf(buf + out, len - out, "\n");
292 
293 	out += snprintf(buf + out, len - out, "Vote=");
294 	out += stringify_nodemap(mle->vote_map, O2NM_MAX_NODES,
295 				 buf + out, len - out);
296 	out += snprintf(buf + out, len - out, "\n");
297 
298 	out += snprintf(buf + out, len - out, "Response=");
299 	out += stringify_nodemap(mle->response_map, O2NM_MAX_NODES,
300 				 buf + out, len - out);
301 	out += snprintf(buf + out, len - out, "\n");
302 
303 	out += snprintf(buf + out, len - out, "Node=");
304 	out += stringify_nodemap(mle->node_map, O2NM_MAX_NODES,
305 				 buf + out, len - out);
306 	out += snprintf(buf + out, len - out, "\n");
307 
308 	out += snprintf(buf + out, len - out, "\n");
309 
310 	return out;
311 }
312 
313 void dlm_print_one_mle(struct dlm_master_list_entry *mle)
314 {
315 	char *buf;
316 
317 	buf = (char *) get_zeroed_page(GFP_ATOMIC);
318 	if (buf) {
319 		dump_mle(mle, buf, PAGE_SIZE - 1);
320 		free_page((unsigned long)buf);
321 	}
322 }
323 
324 #ifdef CONFIG_DEBUG_FS
325 
326 static struct dentry *dlm_debugfs_root;
327 
328 #define DLM_DEBUGFS_DIR				"o2dlm"
329 #define DLM_DEBUGFS_DLM_STATE			"dlm_state"
330 #define DLM_DEBUGFS_LOCKING_STATE		"locking_state"
331 #define DLM_DEBUGFS_MLE_STATE			"mle_state"
332 #define DLM_DEBUGFS_PURGE_LIST			"purge_list"
333 
334 /* begin - utils funcs */
335 static int debug_release(struct inode *inode, struct file *file)
336 {
337 	free_page((unsigned long)file->private_data);
338 	return 0;
339 }
340 
341 static ssize_t debug_read(struct file *file, char __user *buf,
342 			  size_t nbytes, loff_t *ppos)
343 {
344 	return simple_read_from_buffer(buf, nbytes, ppos, file->private_data,
345 				       i_size_read(file->f_mapping->host));
346 }
347 /* end - util funcs */
348 
349 /* begin - purge list funcs */
350 static int debug_purgelist_print(struct dlm_ctxt *dlm, char *buf, int len)
351 {
352 	struct dlm_lock_resource *res;
353 	int out = 0;
354 	unsigned long total = 0;
355 
356 	out += snprintf(buf + out, len - out,
357 			"Dumping Purgelist for Domain: %s\n", dlm->name);
358 
359 	spin_lock(&dlm->spinlock);
360 	list_for_each_entry(res, &dlm->purge_list, purge) {
361 		++total;
362 		if (len - out < 100)
363 			continue;
364 		spin_lock(&res->spinlock);
365 		out += stringify_lockname(res->lockname.name,
366 					  res->lockname.len,
367 					  buf + out, len - out);
368 		out += snprintf(buf + out, len - out, "\t%ld\n",
369 				(jiffies - res->last_used)/HZ);
370 		spin_unlock(&res->spinlock);
371 	}
372 	spin_unlock(&dlm->spinlock);
373 
374 	out += snprintf(buf + out, len - out, "Total on list: %lu\n", total);
375 
376 	return out;
377 }
378 
379 static int debug_purgelist_open(struct inode *inode, struct file *file)
380 {
381 	struct dlm_ctxt *dlm = inode->i_private;
382 	char *buf = NULL;
383 
384 	buf = (char *) get_zeroed_page(GFP_NOFS);
385 	if (!buf)
386 		goto bail;
387 
388 	i_size_write(inode, debug_purgelist_print(dlm, buf, PAGE_SIZE - 1));
389 
390 	file->private_data = buf;
391 
392 	return 0;
393 bail:
394 	return -ENOMEM;
395 }
396 
397 static const struct file_operations debug_purgelist_fops = {
398 	.open =		debug_purgelist_open,
399 	.release =	debug_release,
400 	.read =		debug_read,
401 	.llseek =	generic_file_llseek,
402 };
403 /* end - purge list funcs */
404 
405 /* begin - debug mle funcs */
406 static int debug_mle_print(struct dlm_ctxt *dlm, char *buf, int len)
407 {
408 	struct dlm_master_list_entry *mle;
409 	struct hlist_head *bucket;
410 	int i, out = 0;
411 	unsigned long total = 0, longest = 0, bucket_count = 0;
412 
413 	out += snprintf(buf + out, len - out,
414 			"Dumping MLEs for Domain: %s\n", dlm->name);
415 
416 	spin_lock(&dlm->master_lock);
417 	for (i = 0; i < DLM_HASH_BUCKETS; i++) {
418 		bucket = dlm_master_hash(dlm, i);
419 		hlist_for_each_entry(mle, bucket, master_hash_node) {
420 			++total;
421 			++bucket_count;
422 			if (len - out < 200)
423 				continue;
424 			out += dump_mle(mle, buf + out, len - out);
425 		}
426 		longest = max(longest, bucket_count);
427 		bucket_count = 0;
428 	}
429 	spin_unlock(&dlm->master_lock);
430 
431 	out += snprintf(buf + out, len - out,
432 			"Total: %lu, Longest: %lu\n", total, longest);
433 	return out;
434 }
435 
436 static int debug_mle_open(struct inode *inode, struct file *file)
437 {
438 	struct dlm_ctxt *dlm = inode->i_private;
439 	char *buf = NULL;
440 
441 	buf = (char *) get_zeroed_page(GFP_NOFS);
442 	if (!buf)
443 		goto bail;
444 
445 	i_size_write(inode, debug_mle_print(dlm, buf, PAGE_SIZE - 1));
446 
447 	file->private_data = buf;
448 
449 	return 0;
450 bail:
451 	return -ENOMEM;
452 }
453 
454 static const struct file_operations debug_mle_fops = {
455 	.open =		debug_mle_open,
456 	.release =	debug_release,
457 	.read =		debug_read,
458 	.llseek =	generic_file_llseek,
459 };
460 
461 /* end - debug mle funcs */
462 
463 /* begin - debug lockres funcs */
464 static int dump_lock(struct dlm_lock *lock, int list_type, char *buf, int len)
465 {
466 	int out;
467 
468 #define DEBUG_LOCK_VERSION	1
469 	spin_lock(&lock->spinlock);
470 	out = snprintf(buf, len, "LOCK:%d,%d,%d,%d,%d,%d:%lld,%d,%d,%d,%d,%d,"
471 		       "%d,%d,%d,%d\n",
472 		       DEBUG_LOCK_VERSION,
473 		       list_type, lock->ml.type, lock->ml.convert_type,
474 		       lock->ml.node,
475 		       dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
476 		       dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
477 		       !list_empty(&lock->ast_list),
478 		       !list_empty(&lock->bast_list),
479 		       lock->ast_pending, lock->bast_pending,
480 		       lock->convert_pending, lock->lock_pending,
481 		       lock->cancel_pending, lock->unlock_pending,
482 		       kref_read(&lock->lock_refs));
483 	spin_unlock(&lock->spinlock);
484 
485 	return out;
486 }
487 
488 static int dump_lockres(struct dlm_lock_resource *res, char *buf, int len)
489 {
490 	struct dlm_lock *lock;
491 	int i;
492 	int out = 0;
493 
494 	out += snprintf(buf + out, len - out, "NAME:");
495 	out += stringify_lockname(res->lockname.name, res->lockname.len,
496 				  buf + out, len - out);
497 	out += snprintf(buf + out, len - out, "\n");
498 
499 #define DEBUG_LRES_VERSION	1
500 	out += snprintf(buf + out, len - out,
501 			"LRES:%d,%d,%d,%ld,%d,%d,%d,%d,%d,%d,%d\n",
502 			DEBUG_LRES_VERSION,
503 			res->owner, res->state, res->last_used,
504 			!list_empty(&res->purge),
505 			!list_empty(&res->dirty),
506 			!list_empty(&res->recovering),
507 			res->inflight_locks, res->migration_pending,
508 			atomic_read(&res->asts_reserved),
509 			kref_read(&res->refs));
510 
511 	/* refmap */
512 	out += snprintf(buf + out, len - out, "RMAP:");
513 	out += stringify_nodemap(res->refmap, O2NM_MAX_NODES,
514 				 buf + out, len - out);
515 	out += snprintf(buf + out, len - out, "\n");
516 
517 	/* lvb */
518 	out += snprintf(buf + out, len - out, "LVBX:");
519 	for (i = 0; i < DLM_LVB_LEN; i++)
520 		out += snprintf(buf + out, len - out,
521 					"%02x", (unsigned char)res->lvb[i]);
522 	out += snprintf(buf + out, len - out, "\n");
523 
524 	/* granted */
525 	list_for_each_entry(lock, &res->granted, list)
526 		out += dump_lock(lock, 0, buf + out, len - out);
527 
528 	/* converting */
529 	list_for_each_entry(lock, &res->converting, list)
530 		out += dump_lock(lock, 1, buf + out, len - out);
531 
532 	/* blocked */
533 	list_for_each_entry(lock, &res->blocked, list)
534 		out += dump_lock(lock, 2, buf + out, len - out);
535 
536 	out += snprintf(buf + out, len - out, "\n");
537 
538 	return out;
539 }
540 
541 static void *lockres_seq_start(struct seq_file *m, loff_t *pos)
542 {
543 	struct debug_lockres *dl = m->private;
544 	struct dlm_ctxt *dlm = dl->dl_ctxt;
545 	struct dlm_lock_resource *oldres = dl->dl_res;
546 	struct dlm_lock_resource *res = NULL;
547 	struct list_head *track_list;
548 
549 	spin_lock(&dlm->track_lock);
550 	if (oldres)
551 		track_list = &oldres->tracking;
552 	else {
553 		track_list = &dlm->tracking_list;
554 		if (list_empty(track_list)) {
555 			dl = NULL;
556 			spin_unlock(&dlm->track_lock);
557 			goto bail;
558 		}
559 	}
560 
561 	list_for_each_entry(res, track_list, tracking) {
562 		if (&res->tracking == &dlm->tracking_list)
563 			res = NULL;
564 		else
565 			dlm_lockres_get(res);
566 		break;
567 	}
568 	spin_unlock(&dlm->track_lock);
569 
570 	if (oldres)
571 		dlm_lockres_put(oldres);
572 
573 	dl->dl_res = res;
574 
575 	if (res) {
576 		spin_lock(&res->spinlock);
577 		dump_lockres(res, dl->dl_buf, dl->dl_len - 1);
578 		spin_unlock(&res->spinlock);
579 	} else
580 		dl = NULL;
581 
582 bail:
583 	/* passed to seq_show */
584 	return dl;
585 }
586 
587 static void lockres_seq_stop(struct seq_file *m, void *v)
588 {
589 }
590 
591 static void *lockres_seq_next(struct seq_file *m, void *v, loff_t *pos)
592 {
593 	return NULL;
594 }
595 
596 static int lockres_seq_show(struct seq_file *s, void *v)
597 {
598 	struct debug_lockres *dl = (struct debug_lockres *)v;
599 
600 	seq_printf(s, "%s", dl->dl_buf);
601 
602 	return 0;
603 }
604 
605 static const struct seq_operations debug_lockres_ops = {
606 	.start =	lockres_seq_start,
607 	.stop =		lockres_seq_stop,
608 	.next =		lockres_seq_next,
609 	.show =		lockres_seq_show,
610 };
611 
612 static int debug_lockres_open(struct inode *inode, struct file *file)
613 {
614 	struct dlm_ctxt *dlm = inode->i_private;
615 	struct debug_lockres *dl;
616 	void *buf;
617 
618 	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
619 	if (!buf)
620 		goto bail;
621 
622 	dl = __seq_open_private(file, &debug_lockres_ops, sizeof(*dl));
623 	if (!dl)
624 		goto bailfree;
625 
626 	dl->dl_len = PAGE_SIZE;
627 	dl->dl_buf = buf;
628 
629 	dlm_grab(dlm);
630 	dl->dl_ctxt = dlm;
631 
632 	return 0;
633 
634 bailfree:
635 	kfree(buf);
636 bail:
637 	mlog_errno(-ENOMEM);
638 	return -ENOMEM;
639 }
640 
641 static int debug_lockres_release(struct inode *inode, struct file *file)
642 {
643 	struct seq_file *seq = file->private_data;
644 	struct debug_lockres *dl = (struct debug_lockres *)seq->private;
645 
646 	if (dl->dl_res)
647 		dlm_lockres_put(dl->dl_res);
648 	dlm_put(dl->dl_ctxt);
649 	kfree(dl->dl_buf);
650 	return seq_release_private(inode, file);
651 }
652 
653 static const struct file_operations debug_lockres_fops = {
654 	.open =		debug_lockres_open,
655 	.release =	debug_lockres_release,
656 	.read =		seq_read,
657 	.llseek =	seq_lseek,
658 };
659 /* end - debug lockres funcs */
660 
661 /* begin - debug state funcs */
662 static int debug_state_print(struct dlm_ctxt *dlm, char *buf, int len)
663 {
664 	int out = 0;
665 	struct dlm_reco_node_data *node;
666 	char *state;
667 	int cur_mles = 0, tot_mles = 0;
668 	int i;
669 
670 	spin_lock(&dlm->spinlock);
671 
672 	switch (dlm->dlm_state) {
673 	case DLM_CTXT_NEW:
674 		state = "NEW"; break;
675 	case DLM_CTXT_JOINED:
676 		state = "JOINED"; break;
677 	case DLM_CTXT_IN_SHUTDOWN:
678 		state = "SHUTDOWN"; break;
679 	case DLM_CTXT_LEAVING:
680 		state = "LEAVING"; break;
681 	default:
682 		state = "UNKNOWN"; break;
683 	}
684 
685 	/* Domain: xxxxxxxxxx  Key: 0xdfbac769 */
686 	out += snprintf(buf + out, len - out,
687 			"Domain: %s  Key: 0x%08x  Protocol: %d.%d\n",
688 			dlm->name, dlm->key, dlm->dlm_locking_proto.pv_major,
689 			dlm->dlm_locking_proto.pv_minor);
690 
691 	/* Thread Pid: xxx  Node: xxx  State: xxxxx */
692 	out += snprintf(buf + out, len - out,
693 			"Thread Pid: %d  Node: %d  State: %s\n",
694 			task_pid_nr(dlm->dlm_thread_task), dlm->node_num, state);
695 
696 	/* Number of Joins: xxx  Joining Node: xxx */
697 	out += snprintf(buf + out, len - out,
698 			"Number of Joins: %d  Joining Node: %d\n",
699 			dlm->num_joins, dlm->joining_node);
700 
701 	/* Domain Map: xx xx xx */
702 	out += snprintf(buf + out, len - out, "Domain Map: ");
703 	out += stringify_nodemap(dlm->domain_map, O2NM_MAX_NODES,
704 				 buf + out, len - out);
705 	out += snprintf(buf + out, len - out, "\n");
706 
707 	/* Exit Domain Map: xx xx xx */
708 	out += snprintf(buf + out, len - out, "Exit Domain Map: ");
709 	out += stringify_nodemap(dlm->exit_domain_map, O2NM_MAX_NODES,
710 				 buf + out, len - out);
711 	out += snprintf(buf + out, len - out, "\n");
712 
713 	/* Live Map: xx xx xx */
714 	out += snprintf(buf + out, len - out, "Live Map: ");
715 	out += stringify_nodemap(dlm->live_nodes_map, O2NM_MAX_NODES,
716 				 buf + out, len - out);
717 	out += snprintf(buf + out, len - out, "\n");
718 
719 	/* Lock Resources: xxx (xxx) */
720 	out += snprintf(buf + out, len - out,
721 			"Lock Resources: %d (%d)\n",
722 			atomic_read(&dlm->res_cur_count),
723 			atomic_read(&dlm->res_tot_count));
724 
725 	for (i = 0; i < DLM_MLE_NUM_TYPES; ++i)
726 		tot_mles += atomic_read(&dlm->mle_tot_count[i]);
727 
728 	for (i = 0; i < DLM_MLE_NUM_TYPES; ++i)
729 		cur_mles += atomic_read(&dlm->mle_cur_count[i]);
730 
731 	/* MLEs: xxx (xxx) */
732 	out += snprintf(buf + out, len - out,
733 			"MLEs: %d (%d)\n", cur_mles, tot_mles);
734 
735 	/*  Blocking: xxx (xxx) */
736 	out += snprintf(buf + out, len - out,
737 			"  Blocking: %d (%d)\n",
738 			atomic_read(&dlm->mle_cur_count[DLM_MLE_BLOCK]),
739 			atomic_read(&dlm->mle_tot_count[DLM_MLE_BLOCK]));
740 
741 	/*  Mastery: xxx (xxx) */
742 	out += snprintf(buf + out, len - out,
743 			"  Mastery: %d (%d)\n",
744 			atomic_read(&dlm->mle_cur_count[DLM_MLE_MASTER]),
745 			atomic_read(&dlm->mle_tot_count[DLM_MLE_MASTER]));
746 
747 	/*  Migration: xxx (xxx) */
748 	out += snprintf(buf + out, len - out,
749 			"  Migration: %d (%d)\n",
750 			atomic_read(&dlm->mle_cur_count[DLM_MLE_MIGRATION]),
751 			atomic_read(&dlm->mle_tot_count[DLM_MLE_MIGRATION]));
752 
753 	/* Lists: Dirty=Empty  Purge=InUse  PendingASTs=Empty  ... */
754 	out += snprintf(buf + out, len - out,
755 			"Lists: Dirty=%s  Purge=%s  PendingASTs=%s  "
756 			"PendingBASTs=%s\n",
757 			(list_empty(&dlm->dirty_list) ? "Empty" : "InUse"),
758 			(list_empty(&dlm->purge_list) ? "Empty" : "InUse"),
759 			(list_empty(&dlm->pending_asts) ? "Empty" : "InUse"),
760 			(list_empty(&dlm->pending_basts) ? "Empty" : "InUse"));
761 
762 	/* Purge Count: xxx  Refs: xxx */
763 	out += snprintf(buf + out, len - out,
764 			"Purge Count: %d  Refs: %d\n", dlm->purge_count,
765 			kref_read(&dlm->dlm_refs));
766 
767 	/* Dead Node: xxx */
768 	out += snprintf(buf + out, len - out,
769 			"Dead Node: %d\n", dlm->reco.dead_node);
770 
771 	/* What about DLM_RECO_STATE_FINALIZE? */
772 	if (dlm->reco.state == DLM_RECO_STATE_ACTIVE)
773 		state = "ACTIVE";
774 	else
775 		state = "INACTIVE";
776 
777 	/* Recovery Pid: xxxx  Master: xxx  State: xxxx */
778 	out += snprintf(buf + out, len - out,
779 			"Recovery Pid: %d  Master: %d  State: %s\n",
780 			task_pid_nr(dlm->dlm_reco_thread_task),
781 			dlm->reco.new_master, state);
782 
783 	/* Recovery Map: xx xx */
784 	out += snprintf(buf + out, len - out, "Recovery Map: ");
785 	out += stringify_nodemap(dlm->recovery_map, O2NM_MAX_NODES,
786 				 buf + out, len - out);
787 	out += snprintf(buf + out, len - out, "\n");
788 
789 	/* Recovery Node State: */
790 	out += snprintf(buf + out, len - out, "Recovery Node State:\n");
791 	list_for_each_entry(node, &dlm->reco.node_data, list) {
792 		switch (node->state) {
793 		case DLM_RECO_NODE_DATA_INIT:
794 			state = "INIT";
795 			break;
796 		case DLM_RECO_NODE_DATA_REQUESTING:
797 			state = "REQUESTING";
798 			break;
799 		case DLM_RECO_NODE_DATA_DEAD:
800 			state = "DEAD";
801 			break;
802 		case DLM_RECO_NODE_DATA_RECEIVING:
803 			state = "RECEIVING";
804 			break;
805 		case DLM_RECO_NODE_DATA_REQUESTED:
806 			state = "REQUESTED";
807 			break;
808 		case DLM_RECO_NODE_DATA_DONE:
809 			state = "DONE";
810 			break;
811 		case DLM_RECO_NODE_DATA_FINALIZE_SENT:
812 			state = "FINALIZE-SENT";
813 			break;
814 		default:
815 			state = "BAD";
816 			break;
817 		}
818 		out += snprintf(buf + out, len - out, "\t%u - %s\n",
819 				node->node_num, state);
820 	}
821 
822 	spin_unlock(&dlm->spinlock);
823 
824 	return out;
825 }
826 
827 static int debug_state_open(struct inode *inode, struct file *file)
828 {
829 	struct dlm_ctxt *dlm = inode->i_private;
830 	char *buf = NULL;
831 
832 	buf = (char *) get_zeroed_page(GFP_NOFS);
833 	if (!buf)
834 		goto bail;
835 
836 	i_size_write(inode, debug_state_print(dlm, buf, PAGE_SIZE - 1));
837 
838 	file->private_data = buf;
839 
840 	return 0;
841 bail:
842 	return -ENOMEM;
843 }
844 
845 static const struct file_operations debug_state_fops = {
846 	.open =		debug_state_open,
847 	.release =	debug_release,
848 	.read =		debug_read,
849 	.llseek =	generic_file_llseek,
850 };
851 /* end  - debug state funcs */
852 
853 /* files in subroot */
854 int dlm_debug_init(struct dlm_ctxt *dlm)
855 {
856 	struct dlm_debug_ctxt *dc = dlm->dlm_debug_ctxt;
857 
858 	/* for dumping dlm_ctxt */
859 	dc->debug_state_dentry = debugfs_create_file(DLM_DEBUGFS_DLM_STATE,
860 						     S_IFREG|S_IRUSR,
861 						     dlm->dlm_debugfs_subroot,
862 						     dlm, &debug_state_fops);
863 	if (!dc->debug_state_dentry) {
864 		mlog_errno(-ENOMEM);
865 		goto bail;
866 	}
867 
868 	/* for dumping lockres */
869 	dc->debug_lockres_dentry =
870 			debugfs_create_file(DLM_DEBUGFS_LOCKING_STATE,
871 					    S_IFREG|S_IRUSR,
872 					    dlm->dlm_debugfs_subroot,
873 					    dlm, &debug_lockres_fops);
874 	if (!dc->debug_lockres_dentry) {
875 		mlog_errno(-ENOMEM);
876 		goto bail;
877 	}
878 
879 	/* for dumping mles */
880 	dc->debug_mle_dentry = debugfs_create_file(DLM_DEBUGFS_MLE_STATE,
881 						   S_IFREG|S_IRUSR,
882 						   dlm->dlm_debugfs_subroot,
883 						   dlm, &debug_mle_fops);
884 	if (!dc->debug_mle_dentry) {
885 		mlog_errno(-ENOMEM);
886 		goto bail;
887 	}
888 
889 	/* for dumping lockres on the purge list */
890 	dc->debug_purgelist_dentry =
891 			debugfs_create_file(DLM_DEBUGFS_PURGE_LIST,
892 					    S_IFREG|S_IRUSR,
893 					    dlm->dlm_debugfs_subroot,
894 					    dlm, &debug_purgelist_fops);
895 	if (!dc->debug_purgelist_dentry) {
896 		mlog_errno(-ENOMEM);
897 		goto bail;
898 	}
899 
900 	return 0;
901 
902 bail:
903 	return -ENOMEM;
904 }
905 
906 void dlm_debug_shutdown(struct dlm_ctxt *dlm)
907 {
908 	struct dlm_debug_ctxt *dc = dlm->dlm_debug_ctxt;
909 
910 	if (dc) {
911 		debugfs_remove(dc->debug_purgelist_dentry);
912 		debugfs_remove(dc->debug_mle_dentry);
913 		debugfs_remove(dc->debug_lockres_dentry);
914 		debugfs_remove(dc->debug_state_dentry);
915 		kfree(dc);
916 		dc = NULL;
917 	}
918 }
919 
920 /* subroot - domain dir */
921 int dlm_create_debugfs_subroot(struct dlm_ctxt *dlm)
922 {
923 	dlm->dlm_debugfs_subroot = debugfs_create_dir(dlm->name,
924 						      dlm_debugfs_root);
925 	if (!dlm->dlm_debugfs_subroot) {
926 		mlog_errno(-ENOMEM);
927 		goto bail;
928 	}
929 
930 	dlm->dlm_debug_ctxt = kzalloc(sizeof(struct dlm_debug_ctxt),
931 				      GFP_KERNEL);
932 	if (!dlm->dlm_debug_ctxt) {
933 		mlog_errno(-ENOMEM);
934 		goto bail;
935 	}
936 
937 	return 0;
938 bail:
939 	dlm_destroy_debugfs_subroot(dlm);
940 	return -ENOMEM;
941 }
942 
943 void dlm_destroy_debugfs_subroot(struct dlm_ctxt *dlm)
944 {
945 	debugfs_remove(dlm->dlm_debugfs_subroot);
946 }
947 
948 /* debugfs root */
949 int dlm_create_debugfs_root(void)
950 {
951 	dlm_debugfs_root = debugfs_create_dir(DLM_DEBUGFS_DIR, NULL);
952 	if (!dlm_debugfs_root) {
953 		mlog_errno(-ENOMEM);
954 		return -ENOMEM;
955 	}
956 	return 0;
957 }
958 
959 void dlm_destroy_debugfs_root(void)
960 {
961 	debugfs_remove(dlm_debugfs_root);
962 }
963 #endif	/* CONFIG_DEBUG_FS */
964