xref: /openbmc/linux/fs/ocfs2/dlm/dlmdebug.c (revision 9a29f5fc)
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * dlmdebug.c
4  *
5  * debug functionality for the dlm
6  *
7  * Copyright (C) 2004, 2008 Oracle.  All rights reserved.
8  */
9 
10 #include <linux/types.h>
11 #include <linux/slab.h>
12 #include <linux/highmem.h>
13 #include <linux/sysctl.h>
14 #include <linux/spinlock.h>
15 #include <linux/debugfs.h>
16 #include <linux/export.h>
17 
18 #include "../cluster/heartbeat.h"
19 #include "../cluster/nodemanager.h"
20 #include "../cluster/tcp.h"
21 
22 #include "dlmapi.h"
23 #include "dlmcommon.h"
24 #include "dlmdomain.h"
25 #include "dlmdebug.h"
26 
27 #define MLOG_MASK_PREFIX ML_DLM
28 #include "../cluster/masklog.h"
29 
30 static int stringify_lockname(const char *lockname, int locklen, char *buf,
31 			      int len);
32 
33 void dlm_print_one_lock_resource(struct dlm_lock_resource *res)
34 {
35 	spin_lock(&res->spinlock);
36 	__dlm_print_one_lock_resource(res);
37 	spin_unlock(&res->spinlock);
38 }
39 
40 static void dlm_print_lockres_refmap(struct dlm_lock_resource *res)
41 {
42 	int bit;
43 	assert_spin_locked(&res->spinlock);
44 
45 	printk("  refmap nodes: [ ");
46 	bit = 0;
47 	while (1) {
48 		bit = find_next_bit(res->refmap, O2NM_MAX_NODES, bit);
49 		if (bit >= O2NM_MAX_NODES)
50 			break;
51 		printk("%u ", bit);
52 		bit++;
53 	}
54 	printk("], inflight=%u\n", res->inflight_locks);
55 }
56 
57 static void __dlm_print_lock(struct dlm_lock *lock)
58 {
59 	spin_lock(&lock->spinlock);
60 
61 	printk("    type=%d, conv=%d, node=%u, cookie=%u:%llu, "
62 	       "ref=%u, ast=(empty=%c,pend=%c), bast=(empty=%c,pend=%c), "
63 	       "pending=(conv=%c,lock=%c,cancel=%c,unlock=%c)\n",
64 	       lock->ml.type, lock->ml.convert_type, lock->ml.node,
65 	       dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
66 	       dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
67 	       kref_read(&lock->lock_refs),
68 	       (list_empty(&lock->ast_list) ? 'y' : 'n'),
69 	       (lock->ast_pending ? 'y' : 'n'),
70 	       (list_empty(&lock->bast_list) ? 'y' : 'n'),
71 	       (lock->bast_pending ? 'y' : 'n'),
72 	       (lock->convert_pending ? 'y' : 'n'),
73 	       (lock->lock_pending ? 'y' : 'n'),
74 	       (lock->cancel_pending ? 'y' : 'n'),
75 	       (lock->unlock_pending ? 'y' : 'n'));
76 
77 	spin_unlock(&lock->spinlock);
78 }
79 
80 void __dlm_print_one_lock_resource(struct dlm_lock_resource *res)
81 {
82 	struct dlm_lock *lock;
83 	char buf[DLM_LOCKID_NAME_MAX];
84 
85 	assert_spin_locked(&res->spinlock);
86 
87 	stringify_lockname(res->lockname.name, res->lockname.len,
88 			   buf, sizeof(buf));
89 	printk("lockres: %s, owner=%u, state=%u\n",
90 	       buf, res->owner, res->state);
91 	printk("  last used: %lu, refcnt: %u, on purge list: %s\n",
92 	       res->last_used, kref_read(&res->refs),
93 	       list_empty(&res->purge) ? "no" : "yes");
94 	printk("  on dirty list: %s, on reco list: %s, "
95 	       "migrating pending: %s\n",
96 	       list_empty(&res->dirty) ? "no" : "yes",
97 	       list_empty(&res->recovering) ? "no" : "yes",
98 	       res->migration_pending ? "yes" : "no");
99 	printk("  inflight locks: %d, asts reserved: %d\n",
100 	       res->inflight_locks, atomic_read(&res->asts_reserved));
101 	dlm_print_lockres_refmap(res);
102 	printk("  granted queue:\n");
103 	list_for_each_entry(lock, &res->granted, list) {
104 		__dlm_print_lock(lock);
105 	}
106 	printk("  converting queue:\n");
107 	list_for_each_entry(lock, &res->converting, list) {
108 		__dlm_print_lock(lock);
109 	}
110 	printk("  blocked queue:\n");
111 	list_for_each_entry(lock, &res->blocked, list) {
112 		__dlm_print_lock(lock);
113 	}
114 }
115 
116 void dlm_print_one_lock(struct dlm_lock *lockid)
117 {
118 	dlm_print_one_lock_resource(lockid->lockres);
119 }
120 EXPORT_SYMBOL_GPL(dlm_print_one_lock);
121 
122 static const char *dlm_errnames[] = {
123 	[DLM_NORMAL] =			"DLM_NORMAL",
124 	[DLM_GRANTED] =			"DLM_GRANTED",
125 	[DLM_DENIED] =			"DLM_DENIED",
126 	[DLM_DENIED_NOLOCKS] =		"DLM_DENIED_NOLOCKS",
127 	[DLM_WORKING] =			"DLM_WORKING",
128 	[DLM_BLOCKED] =			"DLM_BLOCKED",
129 	[DLM_BLOCKED_ORPHAN] =		"DLM_BLOCKED_ORPHAN",
130 	[DLM_DENIED_GRACE_PERIOD] =	"DLM_DENIED_GRACE_PERIOD",
131 	[DLM_SYSERR] =			"DLM_SYSERR",
132 	[DLM_NOSUPPORT] =		"DLM_NOSUPPORT",
133 	[DLM_CANCELGRANT] =		"DLM_CANCELGRANT",
134 	[DLM_IVLOCKID] =		"DLM_IVLOCKID",
135 	[DLM_SYNC] =			"DLM_SYNC",
136 	[DLM_BADTYPE] =			"DLM_BADTYPE",
137 	[DLM_BADRESOURCE] =		"DLM_BADRESOURCE",
138 	[DLM_MAXHANDLES] =		"DLM_MAXHANDLES",
139 	[DLM_NOCLINFO] =		"DLM_NOCLINFO",
140 	[DLM_NOLOCKMGR] =		"DLM_NOLOCKMGR",
141 	[DLM_NOPURGED] =		"DLM_NOPURGED",
142 	[DLM_BADARGS] =			"DLM_BADARGS",
143 	[DLM_VOID] =			"DLM_VOID",
144 	[DLM_NOTQUEUED] =		"DLM_NOTQUEUED",
145 	[DLM_IVBUFLEN] =		"DLM_IVBUFLEN",
146 	[DLM_CVTUNGRANT] =		"DLM_CVTUNGRANT",
147 	[DLM_BADPARAM] =		"DLM_BADPARAM",
148 	[DLM_VALNOTVALID] =		"DLM_VALNOTVALID",
149 	[DLM_REJECTED] =		"DLM_REJECTED",
150 	[DLM_ABORT] =			"DLM_ABORT",
151 	[DLM_CANCEL] =			"DLM_CANCEL",
152 	[DLM_IVRESHANDLE] =		"DLM_IVRESHANDLE",
153 	[DLM_DEADLOCK] =		"DLM_DEADLOCK",
154 	[DLM_DENIED_NOASTS] =		"DLM_DENIED_NOASTS",
155 	[DLM_FORWARD] =			"DLM_FORWARD",
156 	[DLM_TIMEOUT] =			"DLM_TIMEOUT",
157 	[DLM_IVGROUPID] =		"DLM_IVGROUPID",
158 	[DLM_VERS_CONFLICT] =		"DLM_VERS_CONFLICT",
159 	[DLM_BAD_DEVICE_PATH] =		"DLM_BAD_DEVICE_PATH",
160 	[DLM_NO_DEVICE_PERMISSION] =	"DLM_NO_DEVICE_PERMISSION",
161 	[DLM_NO_CONTROL_DEVICE ] =	"DLM_NO_CONTROL_DEVICE ",
162 	[DLM_RECOVERING] =		"DLM_RECOVERING",
163 	[DLM_MIGRATING] =		"DLM_MIGRATING",
164 	[DLM_MAXSTATS] =		"DLM_MAXSTATS",
165 };
166 
167 static const char *dlm_errmsgs[] = {
168 	[DLM_NORMAL] = 			"request in progress",
169 	[DLM_GRANTED] = 		"request granted",
170 	[DLM_DENIED] = 			"request denied",
171 	[DLM_DENIED_NOLOCKS] = 		"request denied, out of system resources",
172 	[DLM_WORKING] = 		"async request in progress",
173 	[DLM_BLOCKED] = 		"lock request blocked",
174 	[DLM_BLOCKED_ORPHAN] = 		"lock request blocked by a orphan lock",
175 	[DLM_DENIED_GRACE_PERIOD] = 	"topological change in progress",
176 	[DLM_SYSERR] = 			"system error",
177 	[DLM_NOSUPPORT] = 		"unsupported",
178 	[DLM_CANCELGRANT] = 		"can't cancel convert: already granted",
179 	[DLM_IVLOCKID] = 		"bad lockid",
180 	[DLM_SYNC] = 			"synchronous request granted",
181 	[DLM_BADTYPE] = 		"bad resource type",
182 	[DLM_BADRESOURCE] = 		"bad resource handle",
183 	[DLM_MAXHANDLES] = 		"no more resource handles",
184 	[DLM_NOCLINFO] = 		"can't contact cluster manager",
185 	[DLM_NOLOCKMGR] = 		"can't contact lock manager",
186 	[DLM_NOPURGED] = 		"can't contact purge daemon",
187 	[DLM_BADARGS] = 		"bad api args",
188 	[DLM_VOID] = 			"no status",
189 	[DLM_NOTQUEUED] = 		"NOQUEUE was specified and request failed",
190 	[DLM_IVBUFLEN] = 		"invalid resource name length",
191 	[DLM_CVTUNGRANT] = 		"attempted to convert ungranted lock",
192 	[DLM_BADPARAM] = 		"invalid lock mode specified",
193 	[DLM_VALNOTVALID] = 		"value block has been invalidated",
194 	[DLM_REJECTED] = 		"request rejected, unrecognized client",
195 	[DLM_ABORT] = 			"blocked lock request cancelled",
196 	[DLM_CANCEL] = 			"conversion request cancelled",
197 	[DLM_IVRESHANDLE] = 		"invalid resource handle",
198 	[DLM_DEADLOCK] = 		"deadlock recovery refused this request",
199 	[DLM_DENIED_NOASTS] = 		"failed to allocate AST",
200 	[DLM_FORWARD] = 		"request must wait for primary's response",
201 	[DLM_TIMEOUT] = 		"timeout value for lock has expired",
202 	[DLM_IVGROUPID] = 		"invalid group specification",
203 	[DLM_VERS_CONFLICT] = 		"version conflicts prevent request handling",
204 	[DLM_BAD_DEVICE_PATH] = 	"Locks device does not exist or path wrong",
205 	[DLM_NO_DEVICE_PERMISSION] = 	"Client has insufficient perms for device",
206 	[DLM_NO_CONTROL_DEVICE] = 	"Cannot set options on opened device ",
207 	[DLM_RECOVERING] = 		"lock resource being recovered",
208 	[DLM_MIGRATING] = 		"lock resource being migrated",
209 	[DLM_MAXSTATS] = 		"invalid error number",
210 };
211 
212 const char *dlm_errmsg(enum dlm_status err)
213 {
214 	if (err >= DLM_MAXSTATS || err < 0)
215 		return dlm_errmsgs[DLM_MAXSTATS];
216 	return dlm_errmsgs[err];
217 }
218 EXPORT_SYMBOL_GPL(dlm_errmsg);
219 
220 const char *dlm_errname(enum dlm_status err)
221 {
222 	if (err >= DLM_MAXSTATS || err < 0)
223 		return dlm_errnames[DLM_MAXSTATS];
224 	return dlm_errnames[err];
225 }
226 EXPORT_SYMBOL_GPL(dlm_errname);
227 
228 /* NOTE: This function converts a lockname into a string. It uses knowledge
229  * of the format of the lockname that should be outside the purview of the dlm.
230  * We are adding only to make dlm debugging slightly easier.
231  *
232  * For more on lockname formats, please refer to dlmglue.c and ocfs2_lockid.h.
233  */
234 static int stringify_lockname(const char *lockname, int locklen, char *buf,
235 			      int len)
236 {
237 	int out = 0;
238 	__be64 inode_blkno_be;
239 
240 #define OCFS2_DENTRY_LOCK_INO_START	18
241 	if (*lockname == 'N') {
242 		memcpy((__be64 *)&inode_blkno_be,
243 		       (char *)&lockname[OCFS2_DENTRY_LOCK_INO_START],
244 		       sizeof(__be64));
245 		out += scnprintf(buf + out, len - out, "%.*s%08x",
246 				OCFS2_DENTRY_LOCK_INO_START - 1, lockname,
247 				(unsigned int)be64_to_cpu(inode_blkno_be));
248 	} else
249 		out += scnprintf(buf + out, len - out, "%.*s",
250 				locklen, lockname);
251 	return out;
252 }
253 
254 static int stringify_nodemap(unsigned long *nodemap, int maxnodes,
255 			     char *buf, int len)
256 {
257 	int out = 0;
258 	int i = -1;
259 
260 	while ((i = find_next_bit(nodemap, maxnodes, i + 1)) < maxnodes)
261 		out += scnprintf(buf + out, len - out, "%d ", i);
262 
263 	return out;
264 }
265 
266 static int dump_mle(struct dlm_master_list_entry *mle, char *buf, int len)
267 {
268 	int out = 0;
269 	char *mle_type;
270 
271 	if (mle->type == DLM_MLE_BLOCK)
272 		mle_type = "BLK";
273 	else if (mle->type == DLM_MLE_MASTER)
274 		mle_type = "MAS";
275 	else
276 		mle_type = "MIG";
277 
278 	out += stringify_lockname(mle->mname, mle->mnamelen, buf + out, len - out);
279 	out += scnprintf(buf + out, len - out,
280 			"\t%3s\tmas=%3u\tnew=%3u\tevt=%1d\tuse=%1d\tref=%3d\n",
281 			mle_type, mle->master, mle->new_master,
282 			!list_empty(&mle->hb_events),
283 			!!mle->inuse,
284 			kref_read(&mle->mle_refs));
285 
286 	out += scnprintf(buf + out, len - out, "Maybe=");
287 	out += stringify_nodemap(mle->maybe_map, O2NM_MAX_NODES,
288 				 buf + out, len - out);
289 	out += scnprintf(buf + out, len - out, "\n");
290 
291 	out += scnprintf(buf + out, len - out, "Vote=");
292 	out += stringify_nodemap(mle->vote_map, O2NM_MAX_NODES,
293 				 buf + out, len - out);
294 	out += scnprintf(buf + out, len - out, "\n");
295 
296 	out += scnprintf(buf + out, len - out, "Response=");
297 	out += stringify_nodemap(mle->response_map, O2NM_MAX_NODES,
298 				 buf + out, len - out);
299 	out += scnprintf(buf + out, len - out, "\n");
300 
301 	out += scnprintf(buf + out, len - out, "Node=");
302 	out += stringify_nodemap(mle->node_map, O2NM_MAX_NODES,
303 				 buf + out, len - out);
304 	out += scnprintf(buf + out, len - out, "\n");
305 
306 	out += scnprintf(buf + out, len - out, "\n");
307 
308 	return out;
309 }
310 
311 void dlm_print_one_mle(struct dlm_master_list_entry *mle)
312 {
313 	char *buf;
314 
315 	buf = (char *) get_zeroed_page(GFP_ATOMIC);
316 	if (buf) {
317 		dump_mle(mle, buf, PAGE_SIZE - 1);
318 		free_page((unsigned long)buf);
319 	}
320 }
321 
322 #ifdef CONFIG_DEBUG_FS
323 
324 static struct dentry *dlm_debugfs_root;
325 
326 #define DLM_DEBUGFS_DIR				"o2dlm"
327 #define DLM_DEBUGFS_DLM_STATE			"dlm_state"
328 #define DLM_DEBUGFS_LOCKING_STATE		"locking_state"
329 #define DLM_DEBUGFS_MLE_STATE			"mle_state"
330 #define DLM_DEBUGFS_PURGE_LIST			"purge_list"
331 
332 /* begin - utils funcs */
333 static int debug_release(struct inode *inode, struct file *file)
334 {
335 	free_page((unsigned long)file->private_data);
336 	return 0;
337 }
338 
339 static ssize_t debug_read(struct file *file, char __user *buf,
340 			  size_t nbytes, loff_t *ppos)
341 {
342 	return simple_read_from_buffer(buf, nbytes, ppos, file->private_data,
343 				       i_size_read(file->f_mapping->host));
344 }
345 /* end - util funcs */
346 
347 /* begin - purge list funcs */
348 static int debug_purgelist_print(struct dlm_ctxt *dlm, char *buf, int len)
349 {
350 	struct dlm_lock_resource *res;
351 	int out = 0;
352 	unsigned long total = 0;
353 
354 	out += scnprintf(buf + out, len - out,
355 			"Dumping Purgelist for Domain: %s\n", dlm->name);
356 
357 	spin_lock(&dlm->spinlock);
358 	list_for_each_entry(res, &dlm->purge_list, purge) {
359 		++total;
360 		if (len - out < 100)
361 			continue;
362 		spin_lock(&res->spinlock);
363 		out += stringify_lockname(res->lockname.name,
364 					  res->lockname.len,
365 					  buf + out, len - out);
366 		out += scnprintf(buf + out, len - out, "\t%ld\n",
367 				(jiffies - res->last_used)/HZ);
368 		spin_unlock(&res->spinlock);
369 	}
370 	spin_unlock(&dlm->spinlock);
371 
372 	out += scnprintf(buf + out, len - out, "Total on list: %lu\n", total);
373 
374 	return out;
375 }
376 
377 static int debug_purgelist_open(struct inode *inode, struct file *file)
378 {
379 	struct dlm_ctxt *dlm = inode->i_private;
380 	char *buf = NULL;
381 
382 	buf = (char *) get_zeroed_page(GFP_NOFS);
383 	if (!buf)
384 		goto bail;
385 
386 	i_size_write(inode, debug_purgelist_print(dlm, buf, PAGE_SIZE - 1));
387 
388 	file->private_data = buf;
389 
390 	return 0;
391 bail:
392 	return -ENOMEM;
393 }
394 
395 static const struct file_operations debug_purgelist_fops = {
396 	.open =		debug_purgelist_open,
397 	.release =	debug_release,
398 	.read =		debug_read,
399 	.llseek =	generic_file_llseek,
400 };
401 /* end - purge list funcs */
402 
403 /* begin - debug mle funcs */
404 static int debug_mle_print(struct dlm_ctxt *dlm, char *buf, int len)
405 {
406 	struct dlm_master_list_entry *mle;
407 	struct hlist_head *bucket;
408 	int i, out = 0;
409 	unsigned long total = 0, longest = 0, bucket_count = 0;
410 
411 	out += scnprintf(buf + out, len - out,
412 			"Dumping MLEs for Domain: %s\n", dlm->name);
413 
414 	spin_lock(&dlm->master_lock);
415 	for (i = 0; i < DLM_HASH_BUCKETS; i++) {
416 		bucket = dlm_master_hash(dlm, i);
417 		hlist_for_each_entry(mle, bucket, master_hash_node) {
418 			++total;
419 			++bucket_count;
420 			if (len - out < 200)
421 				continue;
422 			out += dump_mle(mle, buf + out, len - out);
423 		}
424 		longest = max(longest, bucket_count);
425 		bucket_count = 0;
426 	}
427 	spin_unlock(&dlm->master_lock);
428 
429 	out += scnprintf(buf + out, len - out,
430 			"Total: %lu, Longest: %lu\n", total, longest);
431 	return out;
432 }
433 
434 static int debug_mle_open(struct inode *inode, struct file *file)
435 {
436 	struct dlm_ctxt *dlm = inode->i_private;
437 	char *buf = NULL;
438 
439 	buf = (char *) get_zeroed_page(GFP_NOFS);
440 	if (!buf)
441 		goto bail;
442 
443 	i_size_write(inode, debug_mle_print(dlm, buf, PAGE_SIZE - 1));
444 
445 	file->private_data = buf;
446 
447 	return 0;
448 bail:
449 	return -ENOMEM;
450 }
451 
452 static const struct file_operations debug_mle_fops = {
453 	.open =		debug_mle_open,
454 	.release =	debug_release,
455 	.read =		debug_read,
456 	.llseek =	generic_file_llseek,
457 };
458 
459 /* end - debug mle funcs */
460 
461 /* begin - debug lockres funcs */
462 static int dump_lock(struct dlm_lock *lock, int list_type, char *buf, int len)
463 {
464 	int out;
465 
466 #define DEBUG_LOCK_VERSION	1
467 	spin_lock(&lock->spinlock);
468 	out = scnprintf(buf, len, "LOCK:%d,%d,%d,%d,%d,%d:%lld,%d,%d,%d,%d,%d,"
469 		       "%d,%d,%d,%d\n",
470 		       DEBUG_LOCK_VERSION,
471 		       list_type, lock->ml.type, lock->ml.convert_type,
472 		       lock->ml.node,
473 		       dlm_get_lock_cookie_node(be64_to_cpu(lock->ml.cookie)),
474 		       dlm_get_lock_cookie_seq(be64_to_cpu(lock->ml.cookie)),
475 		       !list_empty(&lock->ast_list),
476 		       !list_empty(&lock->bast_list),
477 		       lock->ast_pending, lock->bast_pending,
478 		       lock->convert_pending, lock->lock_pending,
479 		       lock->cancel_pending, lock->unlock_pending,
480 		       kref_read(&lock->lock_refs));
481 	spin_unlock(&lock->spinlock);
482 
483 	return out;
484 }
485 
486 static int dump_lockres(struct dlm_lock_resource *res, char *buf, int len)
487 {
488 	struct dlm_lock *lock;
489 	int i;
490 	int out = 0;
491 
492 	out += scnprintf(buf + out, len - out, "NAME:");
493 	out += stringify_lockname(res->lockname.name, res->lockname.len,
494 				  buf + out, len - out);
495 	out += scnprintf(buf + out, len - out, "\n");
496 
497 #define DEBUG_LRES_VERSION	1
498 	out += scnprintf(buf + out, len - out,
499 			"LRES:%d,%d,%d,%ld,%d,%d,%d,%d,%d,%d,%d\n",
500 			DEBUG_LRES_VERSION,
501 			res->owner, res->state, res->last_used,
502 			!list_empty(&res->purge),
503 			!list_empty(&res->dirty),
504 			!list_empty(&res->recovering),
505 			res->inflight_locks, res->migration_pending,
506 			atomic_read(&res->asts_reserved),
507 			kref_read(&res->refs));
508 
509 	/* refmap */
510 	out += scnprintf(buf + out, len - out, "RMAP:");
511 	out += stringify_nodemap(res->refmap, O2NM_MAX_NODES,
512 				 buf + out, len - out);
513 	out += scnprintf(buf + out, len - out, "\n");
514 
515 	/* lvb */
516 	out += scnprintf(buf + out, len - out, "LVBX:");
517 	for (i = 0; i < DLM_LVB_LEN; i++)
518 		out += scnprintf(buf + out, len - out,
519 					"%02x", (unsigned char)res->lvb[i]);
520 	out += scnprintf(buf + out, len - out, "\n");
521 
522 	/* granted */
523 	list_for_each_entry(lock, &res->granted, list)
524 		out += dump_lock(lock, 0, buf + out, len - out);
525 
526 	/* converting */
527 	list_for_each_entry(lock, &res->converting, list)
528 		out += dump_lock(lock, 1, buf + out, len - out);
529 
530 	/* blocked */
531 	list_for_each_entry(lock, &res->blocked, list)
532 		out += dump_lock(lock, 2, buf + out, len - out);
533 
534 	out += scnprintf(buf + out, len - out, "\n");
535 
536 	return out;
537 }
538 
539 static void *lockres_seq_start(struct seq_file *m, loff_t *pos)
540 {
541 	struct debug_lockres *dl = m->private;
542 	struct dlm_ctxt *dlm = dl->dl_ctxt;
543 	struct dlm_lock_resource *oldres = dl->dl_res;
544 	struct dlm_lock_resource *res = NULL, *iter;
545 	struct list_head *track_list;
546 
547 	spin_lock(&dlm->track_lock);
548 	if (oldres)
549 		track_list = &oldres->tracking;
550 	else {
551 		track_list = &dlm->tracking_list;
552 		if (list_empty(track_list)) {
553 			dl = NULL;
554 			spin_unlock(&dlm->track_lock);
555 			goto bail;
556 		}
557 	}
558 
559 	list_for_each_entry(iter, track_list, tracking) {
560 		if (&iter->tracking != &dlm->tracking_list) {
561 			dlm_lockres_get(iter);
562 			res = iter;
563 		}
564 		break;
565 	}
566 	spin_unlock(&dlm->track_lock);
567 
568 	if (oldres)
569 		dlm_lockres_put(oldres);
570 
571 	dl->dl_res = res;
572 
573 	if (res) {
574 		spin_lock(&res->spinlock);
575 		dump_lockres(res, dl->dl_buf, dl->dl_len - 1);
576 		spin_unlock(&res->spinlock);
577 	} else
578 		dl = NULL;
579 
580 bail:
581 	/* passed to seq_show */
582 	return dl;
583 }
584 
585 static void lockres_seq_stop(struct seq_file *m, void *v)
586 {
587 }
588 
589 static void *lockres_seq_next(struct seq_file *m, void *v, loff_t *pos)
590 {
591 	return NULL;
592 }
593 
594 static int lockres_seq_show(struct seq_file *s, void *v)
595 {
596 	struct debug_lockres *dl = (struct debug_lockres *)v;
597 
598 	seq_printf(s, "%s", dl->dl_buf);
599 
600 	return 0;
601 }
602 
603 static const struct seq_operations debug_lockres_ops = {
604 	.start =	lockres_seq_start,
605 	.stop =		lockres_seq_stop,
606 	.next =		lockres_seq_next,
607 	.show =		lockres_seq_show,
608 };
609 
610 static int debug_lockres_open(struct inode *inode, struct file *file)
611 {
612 	struct dlm_ctxt *dlm = inode->i_private;
613 	struct debug_lockres *dl;
614 	void *buf;
615 
616 	buf = kmalloc(PAGE_SIZE, GFP_KERNEL);
617 	if (!buf)
618 		goto bail;
619 
620 	dl = __seq_open_private(file, &debug_lockres_ops, sizeof(*dl));
621 	if (!dl)
622 		goto bailfree;
623 
624 	dl->dl_len = PAGE_SIZE;
625 	dl->dl_buf = buf;
626 
627 	dlm_grab(dlm);
628 	dl->dl_ctxt = dlm;
629 
630 	return 0;
631 
632 bailfree:
633 	kfree(buf);
634 bail:
635 	mlog_errno(-ENOMEM);
636 	return -ENOMEM;
637 }
638 
639 static int debug_lockres_release(struct inode *inode, struct file *file)
640 {
641 	struct seq_file *seq = file->private_data;
642 	struct debug_lockres *dl = (struct debug_lockres *)seq->private;
643 
644 	if (dl->dl_res)
645 		dlm_lockres_put(dl->dl_res);
646 	dlm_put(dl->dl_ctxt);
647 	kfree(dl->dl_buf);
648 	return seq_release_private(inode, file);
649 }
650 
651 static const struct file_operations debug_lockres_fops = {
652 	.open =		debug_lockres_open,
653 	.release =	debug_lockres_release,
654 	.read =		seq_read,
655 	.llseek =	seq_lseek,
656 };
657 /* end - debug lockres funcs */
658 
659 /* begin - debug state funcs */
660 static int debug_state_print(struct dlm_ctxt *dlm, char *buf, int len)
661 {
662 	int out = 0;
663 	struct dlm_reco_node_data *node;
664 	char *state;
665 	int cur_mles = 0, tot_mles = 0;
666 	int i;
667 
668 	spin_lock(&dlm->spinlock);
669 
670 	switch (dlm->dlm_state) {
671 	case DLM_CTXT_NEW:
672 		state = "NEW"; break;
673 	case DLM_CTXT_JOINED:
674 		state = "JOINED"; break;
675 	case DLM_CTXT_IN_SHUTDOWN:
676 		state = "SHUTDOWN"; break;
677 	case DLM_CTXT_LEAVING:
678 		state = "LEAVING"; break;
679 	default:
680 		state = "UNKNOWN"; break;
681 	}
682 
683 	/* Domain: xxxxxxxxxx  Key: 0xdfbac769 */
684 	out += scnprintf(buf + out, len - out,
685 			"Domain: %s  Key: 0x%08x  Protocol: %d.%d\n",
686 			dlm->name, dlm->key, dlm->dlm_locking_proto.pv_major,
687 			dlm->dlm_locking_proto.pv_minor);
688 
689 	/* Thread Pid: xxx  Node: xxx  State: xxxxx */
690 	out += scnprintf(buf + out, len - out,
691 			"Thread Pid: %d  Node: %d  State: %s\n",
692 			task_pid_nr(dlm->dlm_thread_task), dlm->node_num, state);
693 
694 	/* Number of Joins: xxx  Joining Node: xxx */
695 	out += scnprintf(buf + out, len - out,
696 			"Number of Joins: %d  Joining Node: %d\n",
697 			dlm->num_joins, dlm->joining_node);
698 
699 	/* Domain Map: xx xx xx */
700 	out += scnprintf(buf + out, len - out, "Domain Map: ");
701 	out += stringify_nodemap(dlm->domain_map, O2NM_MAX_NODES,
702 				 buf + out, len - out);
703 	out += scnprintf(buf + out, len - out, "\n");
704 
705 	/* Exit Domain Map: xx xx xx */
706 	out += scnprintf(buf + out, len - out, "Exit Domain Map: ");
707 	out += stringify_nodemap(dlm->exit_domain_map, O2NM_MAX_NODES,
708 				 buf + out, len - out);
709 	out += scnprintf(buf + out, len - out, "\n");
710 
711 	/* Live Map: xx xx xx */
712 	out += scnprintf(buf + out, len - out, "Live Map: ");
713 	out += stringify_nodemap(dlm->live_nodes_map, O2NM_MAX_NODES,
714 				 buf + out, len - out);
715 	out += scnprintf(buf + out, len - out, "\n");
716 
717 	/* Lock Resources: xxx (xxx) */
718 	out += scnprintf(buf + out, len - out,
719 			"Lock Resources: %d (%d)\n",
720 			atomic_read(&dlm->res_cur_count),
721 			atomic_read(&dlm->res_tot_count));
722 
723 	for (i = 0; i < DLM_MLE_NUM_TYPES; ++i)
724 		tot_mles += atomic_read(&dlm->mle_tot_count[i]);
725 
726 	for (i = 0; i < DLM_MLE_NUM_TYPES; ++i)
727 		cur_mles += atomic_read(&dlm->mle_cur_count[i]);
728 
729 	/* MLEs: xxx (xxx) */
730 	out += scnprintf(buf + out, len - out,
731 			"MLEs: %d (%d)\n", cur_mles, tot_mles);
732 
733 	/*  Blocking: xxx (xxx) */
734 	out += scnprintf(buf + out, len - out,
735 			"  Blocking: %d (%d)\n",
736 			atomic_read(&dlm->mle_cur_count[DLM_MLE_BLOCK]),
737 			atomic_read(&dlm->mle_tot_count[DLM_MLE_BLOCK]));
738 
739 	/*  Mastery: xxx (xxx) */
740 	out += scnprintf(buf + out, len - out,
741 			"  Mastery: %d (%d)\n",
742 			atomic_read(&dlm->mle_cur_count[DLM_MLE_MASTER]),
743 			atomic_read(&dlm->mle_tot_count[DLM_MLE_MASTER]));
744 
745 	/*  Migration: xxx (xxx) */
746 	out += scnprintf(buf + out, len - out,
747 			"  Migration: %d (%d)\n",
748 			atomic_read(&dlm->mle_cur_count[DLM_MLE_MIGRATION]),
749 			atomic_read(&dlm->mle_tot_count[DLM_MLE_MIGRATION]));
750 
751 	/* Lists: Dirty=Empty  Purge=InUse  PendingASTs=Empty  ... */
752 	out += scnprintf(buf + out, len - out,
753 			"Lists: Dirty=%s  Purge=%s  PendingASTs=%s  "
754 			"PendingBASTs=%s\n",
755 			(list_empty(&dlm->dirty_list) ? "Empty" : "InUse"),
756 			(list_empty(&dlm->purge_list) ? "Empty" : "InUse"),
757 			(list_empty(&dlm->pending_asts) ? "Empty" : "InUse"),
758 			(list_empty(&dlm->pending_basts) ? "Empty" : "InUse"));
759 
760 	/* Purge Count: xxx  Refs: xxx */
761 	out += scnprintf(buf + out, len - out,
762 			"Purge Count: %d  Refs: %d\n", dlm->purge_count,
763 			kref_read(&dlm->dlm_refs));
764 
765 	/* Dead Node: xxx */
766 	out += scnprintf(buf + out, len - out,
767 			"Dead Node: %d\n", dlm->reco.dead_node);
768 
769 	/* What about DLM_RECO_STATE_FINALIZE? */
770 	if (dlm->reco.state == DLM_RECO_STATE_ACTIVE)
771 		state = "ACTIVE";
772 	else
773 		state = "INACTIVE";
774 
775 	/* Recovery Pid: xxxx  Master: xxx  State: xxxx */
776 	out += scnprintf(buf + out, len - out,
777 			"Recovery Pid: %d  Master: %d  State: %s\n",
778 			task_pid_nr(dlm->dlm_reco_thread_task),
779 			dlm->reco.new_master, state);
780 
781 	/* Recovery Map: xx xx */
782 	out += scnprintf(buf + out, len - out, "Recovery Map: ");
783 	out += stringify_nodemap(dlm->recovery_map, O2NM_MAX_NODES,
784 				 buf + out, len - out);
785 	out += scnprintf(buf + out, len - out, "\n");
786 
787 	/* Recovery Node State: */
788 	out += scnprintf(buf + out, len - out, "Recovery Node State:\n");
789 	list_for_each_entry(node, &dlm->reco.node_data, list) {
790 		switch (node->state) {
791 		case DLM_RECO_NODE_DATA_INIT:
792 			state = "INIT";
793 			break;
794 		case DLM_RECO_NODE_DATA_REQUESTING:
795 			state = "REQUESTING";
796 			break;
797 		case DLM_RECO_NODE_DATA_DEAD:
798 			state = "DEAD";
799 			break;
800 		case DLM_RECO_NODE_DATA_RECEIVING:
801 			state = "RECEIVING";
802 			break;
803 		case DLM_RECO_NODE_DATA_REQUESTED:
804 			state = "REQUESTED";
805 			break;
806 		case DLM_RECO_NODE_DATA_DONE:
807 			state = "DONE";
808 			break;
809 		case DLM_RECO_NODE_DATA_FINALIZE_SENT:
810 			state = "FINALIZE-SENT";
811 			break;
812 		default:
813 			state = "BAD";
814 			break;
815 		}
816 		out += scnprintf(buf + out, len - out, "\t%u - %s\n",
817 				node->node_num, state);
818 	}
819 
820 	spin_unlock(&dlm->spinlock);
821 
822 	return out;
823 }
824 
825 static int debug_state_open(struct inode *inode, struct file *file)
826 {
827 	struct dlm_ctxt *dlm = inode->i_private;
828 	char *buf = NULL;
829 
830 	buf = (char *) get_zeroed_page(GFP_NOFS);
831 	if (!buf)
832 		goto bail;
833 
834 	i_size_write(inode, debug_state_print(dlm, buf, PAGE_SIZE - 1));
835 
836 	file->private_data = buf;
837 
838 	return 0;
839 bail:
840 	return -ENOMEM;
841 }
842 
843 static const struct file_operations debug_state_fops = {
844 	.open =		debug_state_open,
845 	.release =	debug_release,
846 	.read =		debug_read,
847 	.llseek =	generic_file_llseek,
848 };
849 /* end  - debug state funcs */
850 
851 /* files in subroot */
852 void dlm_debug_init(struct dlm_ctxt *dlm)
853 {
854 	/* for dumping dlm_ctxt */
855 	debugfs_create_file(DLM_DEBUGFS_DLM_STATE, S_IFREG|S_IRUSR,
856 			    dlm->dlm_debugfs_subroot, dlm, &debug_state_fops);
857 
858 	/* for dumping lockres */
859 	debugfs_create_file(DLM_DEBUGFS_LOCKING_STATE, S_IFREG|S_IRUSR,
860 			    dlm->dlm_debugfs_subroot, dlm, &debug_lockres_fops);
861 
862 	/* for dumping mles */
863 	debugfs_create_file(DLM_DEBUGFS_MLE_STATE, S_IFREG|S_IRUSR,
864 			    dlm->dlm_debugfs_subroot, dlm, &debug_mle_fops);
865 
866 	/* for dumping lockres on the purge list */
867 	debugfs_create_file(DLM_DEBUGFS_PURGE_LIST, S_IFREG|S_IRUSR,
868 			    dlm->dlm_debugfs_subroot, dlm,
869 			    &debug_purgelist_fops);
870 }
871 
872 /* subroot - domain dir */
873 void dlm_create_debugfs_subroot(struct dlm_ctxt *dlm)
874 {
875 	dlm->dlm_debugfs_subroot = debugfs_create_dir(dlm->name,
876 						      dlm_debugfs_root);
877 }
878 
879 void dlm_destroy_debugfs_subroot(struct dlm_ctxt *dlm)
880 {
881 	debugfs_remove_recursive(dlm->dlm_debugfs_subroot);
882 }
883 
884 /* debugfs root */
885 void dlm_create_debugfs_root(void)
886 {
887 	dlm_debugfs_root = debugfs_create_dir(DLM_DEBUGFS_DIR, NULL);
888 }
889 
890 void dlm_destroy_debugfs_root(void)
891 {
892 	debugfs_remove(dlm_debugfs_root);
893 }
894 #endif	/* CONFIG_DEBUG_FS */
895