xref: /openbmc/linux/fs/dlm/debug_fs.c (revision 643d1f7f)
1 /******************************************************************************
2 *******************************************************************************
3 **
4 **  Copyright (C) 2005 Red Hat, Inc.  All rights reserved.
5 **
6 **  This copyrighted material is made available to anyone wishing to use,
7 **  modify, copy, or redistribute it subject to the terms and conditions
8 **  of the GNU General Public License v.2.
9 **
10 *******************************************************************************
11 ******************************************************************************/
12 
13 #include <linux/pagemap.h>
14 #include <linux/seq_file.h>
15 #include <linux/module.h>
16 #include <linux/ctype.h>
17 #include <linux/debugfs.h>
18 
19 #include "dlm_internal.h"
20 #include "lock.h"
21 
22 #define DLM_DEBUG_BUF_LEN 4096
23 static char debug_buf[DLM_DEBUG_BUF_LEN];
24 static struct mutex debug_buf_lock;
25 
26 static struct dentry *dlm_root;
27 
28 struct rsb_iter {
29 	int entry;
30 	int locks;
31 	int header;
32 	struct dlm_ls *ls;
33 	struct list_head *next;
34 	struct dlm_rsb *rsb;
35 };
36 
37 /*
38  * dump all rsb's in the lockspace hash table
39  */
40 
41 static char *print_lockmode(int mode)
42 {
43 	switch (mode) {
44 	case DLM_LOCK_IV:
45 		return "--";
46 	case DLM_LOCK_NL:
47 		return "NL";
48 	case DLM_LOCK_CR:
49 		return "CR";
50 	case DLM_LOCK_CW:
51 		return "CW";
52 	case DLM_LOCK_PR:
53 		return "PR";
54 	case DLM_LOCK_PW:
55 		return "PW";
56 	case DLM_LOCK_EX:
57 		return "EX";
58 	default:
59 		return "??";
60 	}
61 }
62 
63 static void print_resource_lock(struct seq_file *s, struct dlm_lkb *lkb,
64 				struct dlm_rsb *res)
65 {
66 	seq_printf(s, "%08x %s", lkb->lkb_id, print_lockmode(lkb->lkb_grmode));
67 
68 	if (lkb->lkb_status == DLM_LKSTS_CONVERT
69 	    || lkb->lkb_status == DLM_LKSTS_WAITING)
70 		seq_printf(s, " (%s)", print_lockmode(lkb->lkb_rqmode));
71 
72 	if (lkb->lkb_nodeid) {
73 		if (lkb->lkb_nodeid != res->res_nodeid)
74 			seq_printf(s, " Remote: %3d %08x", lkb->lkb_nodeid,
75 				   lkb->lkb_remid);
76 		else
77 			seq_printf(s, " Master:     %08x", lkb->lkb_remid);
78 	}
79 
80 	if (lkb->lkb_wait_type)
81 		seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
82 
83 	seq_printf(s, "\n");
84 }
85 
86 static int print_resource(struct dlm_rsb *res, struct seq_file *s)
87 {
88 	struct dlm_lkb *lkb;
89 	int i, lvblen = res->res_ls->ls_lvblen, recover_list, root_list;
90 
91 	lock_rsb(res);
92 
93 	seq_printf(s, "\nResource %p Name (len=%d) \"", res, res->res_length);
94 	for (i = 0; i < res->res_length; i++) {
95 		if (isprint(res->res_name[i]))
96 			seq_printf(s, "%c", res->res_name[i]);
97 		else
98 			seq_printf(s, "%c", '.');
99 	}
100 	if (res->res_nodeid > 0)
101 		seq_printf(s, "\"  \nLocal Copy, Master is node %d\n",
102 			   res->res_nodeid);
103 	else if (res->res_nodeid == 0)
104 		seq_printf(s, "\"  \nMaster Copy\n");
105 	else if (res->res_nodeid == -1)
106 		seq_printf(s, "\"  \nLooking up master (lkid %x)\n",
107 			   res->res_first_lkid);
108 	else
109 		seq_printf(s, "\"  \nInvalid master %d\n", res->res_nodeid);
110 
111 	/* Print the LVB: */
112 	if (res->res_lvbptr) {
113 		seq_printf(s, "LVB: ");
114 		for (i = 0; i < lvblen; i++) {
115 			if (i == lvblen / 2)
116 				seq_printf(s, "\n     ");
117 			seq_printf(s, "%02x ",
118 				   (unsigned char) res->res_lvbptr[i]);
119 		}
120 		if (rsb_flag(res, RSB_VALNOTVALID))
121 			seq_printf(s, " (INVALID)");
122 		seq_printf(s, "\n");
123 	}
124 
125 	root_list = !list_empty(&res->res_root_list);
126 	recover_list = !list_empty(&res->res_recover_list);
127 
128 	if (root_list || recover_list) {
129 		seq_printf(s, "Recovery: root %d recover %d flags %lx "
130 			   "count %d\n", root_list, recover_list,
131 			   res->res_flags, res->res_recover_locks_count);
132 	}
133 
134 	/* Print the locks attached to this resource */
135 	seq_printf(s, "Granted Queue\n");
136 	list_for_each_entry(lkb, &res->res_grantqueue, lkb_statequeue)
137 		print_resource_lock(s, lkb, res);
138 
139 	seq_printf(s, "Conversion Queue\n");
140 	list_for_each_entry(lkb, &res->res_convertqueue, lkb_statequeue)
141 		print_resource_lock(s, lkb, res);
142 
143 	seq_printf(s, "Waiting Queue\n");
144 	list_for_each_entry(lkb, &res->res_waitqueue, lkb_statequeue)
145 		print_resource_lock(s, lkb, res);
146 
147 	if (list_empty(&res->res_lookup))
148 		goto out;
149 
150 	seq_printf(s, "Lookup Queue\n");
151 	list_for_each_entry(lkb, &res->res_lookup, lkb_rsb_lookup) {
152 		seq_printf(s, "%08x %s", lkb->lkb_id,
153 			   print_lockmode(lkb->lkb_rqmode));
154 		if (lkb->lkb_wait_type)
155 			seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
156 		seq_printf(s, "\n");
157 	}
158  out:
159 	unlock_rsb(res);
160 	return 0;
161 }
162 
163 static void print_lock(struct seq_file *s, struct dlm_lkb *lkb, struct dlm_rsb *r)
164 {
165 	struct dlm_user_args *ua;
166 	unsigned int waiting = 0;
167 	uint64_t xid = 0;
168 
169 	if (lkb->lkb_flags & DLM_IFL_USER) {
170 		ua = (struct dlm_user_args *) lkb->lkb_astparam;
171 		if (ua)
172 			xid = ua->xid;
173 	}
174 
175 	if (lkb->lkb_timestamp)
176 		waiting = jiffies_to_msecs(jiffies - lkb->lkb_timestamp);
177 
178 	/* id nodeid remid pid xid exflags flags sts grmode rqmode time_ms
179 	   r_nodeid r_len r_name */
180 
181 	seq_printf(s, "%x %d %x %u %llu %x %x %d %d %d %u %u %d \"%s\"\n",
182 		   lkb->lkb_id,
183 		   lkb->lkb_nodeid,
184 		   lkb->lkb_remid,
185 		   lkb->lkb_ownpid,
186 		   (unsigned long long)xid,
187 		   lkb->lkb_exflags,
188 		   lkb->lkb_flags,
189 		   lkb->lkb_status,
190 		   lkb->lkb_grmode,
191 		   lkb->lkb_rqmode,
192 		   waiting,
193 		   r->res_nodeid,
194 		   r->res_length,
195 		   r->res_name);
196 }
197 
198 static int print_locks(struct dlm_rsb *r, struct seq_file *s)
199 {
200 	struct dlm_lkb *lkb;
201 
202 	lock_rsb(r);
203 
204 	list_for_each_entry(lkb, &r->res_grantqueue, lkb_statequeue)
205 		print_lock(s, lkb, r);
206 
207 	list_for_each_entry(lkb, &r->res_convertqueue, lkb_statequeue)
208 		print_lock(s, lkb, r);
209 
210 	list_for_each_entry(lkb, &r->res_waitqueue, lkb_statequeue)
211 		print_lock(s, lkb, r);
212 
213 	unlock_rsb(r);
214 	return 0;
215 }
216 
217 static int rsb_iter_next(struct rsb_iter *ri)
218 {
219 	struct dlm_ls *ls = ri->ls;
220 	int i;
221 
222 	if (!ri->next) {
223  top:
224 		/* Find the next non-empty hash bucket */
225 		for (i = ri->entry; i < ls->ls_rsbtbl_size; i++) {
226 			read_lock(&ls->ls_rsbtbl[i].lock);
227 			if (!list_empty(&ls->ls_rsbtbl[i].list)) {
228 				ri->next = ls->ls_rsbtbl[i].list.next;
229 				ri->rsb = list_entry(ri->next, struct dlm_rsb,
230 							res_hashchain);
231 				dlm_hold_rsb(ri->rsb);
232 				read_unlock(&ls->ls_rsbtbl[i].lock);
233 				break;
234 			}
235 			read_unlock(&ls->ls_rsbtbl[i].lock);
236                 }
237 		ri->entry = i;
238 
239 		if (ri->entry >= ls->ls_rsbtbl_size)
240 			return 1;
241 	} else {
242 		struct dlm_rsb *old = ri->rsb;
243 		i = ri->entry;
244 		read_lock(&ls->ls_rsbtbl[i].lock);
245 		ri->next = ri->next->next;
246 		if (ri->next->next == ls->ls_rsbtbl[i].list.next) {
247 			/* End of list - move to next bucket */
248 			ri->next = NULL;
249 			ri->entry++;
250 			read_unlock(&ls->ls_rsbtbl[i].lock);
251 			dlm_put_rsb(old);
252 			goto top;
253                 }
254 		ri->rsb = list_entry(ri->next, struct dlm_rsb, res_hashchain);
255 		dlm_hold_rsb(ri->rsb);
256 		read_unlock(&ls->ls_rsbtbl[i].lock);
257 		dlm_put_rsb(old);
258 	}
259 
260 	return 0;
261 }
262 
263 static void rsb_iter_free(struct rsb_iter *ri)
264 {
265 	kfree(ri);
266 }
267 
268 static struct rsb_iter *rsb_iter_init(struct dlm_ls *ls)
269 {
270 	struct rsb_iter *ri;
271 
272 	ri = kzalloc(sizeof *ri, GFP_KERNEL);
273 	if (!ri)
274 		return NULL;
275 
276 	ri->ls = ls;
277 	ri->entry = 0;
278 	ri->next = NULL;
279 
280 	if (rsb_iter_next(ri)) {
281 		rsb_iter_free(ri);
282 		return NULL;
283 	}
284 
285 	return ri;
286 }
287 
288 static void *rsb_seq_start(struct seq_file *file, loff_t *pos)
289 {
290 	struct rsb_iter *ri;
291 	loff_t n = *pos;
292 
293 	ri = rsb_iter_init(file->private);
294 	if (!ri)
295 		return NULL;
296 
297 	while (n--) {
298 		if (rsb_iter_next(ri)) {
299 			rsb_iter_free(ri);
300 			return NULL;
301 		}
302 	}
303 
304 	return ri;
305 }
306 
307 static void *rsb_seq_next(struct seq_file *file, void *iter_ptr, loff_t *pos)
308 {
309 	struct rsb_iter *ri = iter_ptr;
310 
311 	(*pos)++;
312 
313 	if (rsb_iter_next(ri)) {
314 		rsb_iter_free(ri);
315 		return NULL;
316 	}
317 
318 	return ri;
319 }
320 
321 static void rsb_seq_stop(struct seq_file *file, void *iter_ptr)
322 {
323 	/* nothing for now */
324 }
325 
326 static int rsb_seq_show(struct seq_file *file, void *iter_ptr)
327 {
328 	struct rsb_iter *ri = iter_ptr;
329 
330 	if (ri->locks) {
331 		if (ri->header) {
332 			seq_printf(file, "id nodeid remid pid xid exflags flags "
333 					 "sts grmode rqmode time_ms r_nodeid "
334 					 "r_len r_name\n");
335 			ri->header = 0;
336 		}
337 		print_locks(ri->rsb, file);
338 	} else {
339 		print_resource(ri->rsb, file);
340 	}
341 
342 	return 0;
343 }
344 
345 static struct seq_operations rsb_seq_ops = {
346 	.start = rsb_seq_start,
347 	.next  = rsb_seq_next,
348 	.stop  = rsb_seq_stop,
349 	.show  = rsb_seq_show,
350 };
351 
352 static int rsb_open(struct inode *inode, struct file *file)
353 {
354 	struct seq_file *seq;
355 	int ret;
356 
357 	ret = seq_open(file, &rsb_seq_ops);
358 	if (ret)
359 		return ret;
360 
361 	seq = file->private_data;
362 	seq->private = inode->i_private;
363 
364 	return 0;
365 }
366 
367 static const struct file_operations rsb_fops = {
368 	.owner   = THIS_MODULE,
369 	.open    = rsb_open,
370 	.read    = seq_read,
371 	.llseek  = seq_lseek,
372 	.release = seq_release
373 };
374 
375 /*
376  * Dump state in compact per-lock listing
377  */
378 
379 static struct rsb_iter *locks_iter_init(struct dlm_ls *ls, loff_t *pos)
380 {
381 	struct rsb_iter *ri;
382 
383 	ri = kzalloc(sizeof *ri, GFP_KERNEL);
384 	if (!ri)
385 		return NULL;
386 
387 	ri->ls = ls;
388 	ri->entry = 0;
389 	ri->next = NULL;
390 	ri->locks = 1;
391 
392 	if (*pos == 0)
393 		ri->header = 1;
394 
395 	if (rsb_iter_next(ri)) {
396 		rsb_iter_free(ri);
397 		return NULL;
398 	}
399 
400 	return ri;
401 }
402 
403 static void *locks_seq_start(struct seq_file *file, loff_t *pos)
404 {
405 	struct rsb_iter *ri;
406 	loff_t n = *pos;
407 
408 	ri = locks_iter_init(file->private, pos);
409 	if (!ri)
410 		return NULL;
411 
412 	while (n--) {
413 		if (rsb_iter_next(ri)) {
414 			rsb_iter_free(ri);
415 			return NULL;
416 		}
417 	}
418 
419 	return ri;
420 }
421 
422 static struct seq_operations locks_seq_ops = {
423 	.start = locks_seq_start,
424 	.next  = rsb_seq_next,
425 	.stop  = rsb_seq_stop,
426 	.show  = rsb_seq_show,
427 };
428 
429 static int locks_open(struct inode *inode, struct file *file)
430 {
431 	struct seq_file *seq;
432 	int ret;
433 
434 	ret = seq_open(file, &locks_seq_ops);
435 	if (ret)
436 		return ret;
437 
438 	seq = file->private_data;
439 	seq->private = inode->i_private;
440 
441 	return 0;
442 }
443 
444 static const struct file_operations locks_fops = {
445 	.owner   = THIS_MODULE,
446 	.open    = locks_open,
447 	.read    = seq_read,
448 	.llseek  = seq_lseek,
449 	.release = seq_release
450 };
451 
452 /*
453  * dump lkb's on the ls_waiters list
454  */
455 
456 static int waiters_open(struct inode *inode, struct file *file)
457 {
458 	file->private_data = inode->i_private;
459 	return 0;
460 }
461 
462 static ssize_t waiters_read(struct file *file, char __user *userbuf,
463 			    size_t count, loff_t *ppos)
464 {
465 	struct dlm_ls *ls = file->private_data;
466 	struct dlm_lkb *lkb;
467 	size_t len = DLM_DEBUG_BUF_LEN, pos = 0, ret, rv;
468 
469 	mutex_lock(&debug_buf_lock);
470 	mutex_lock(&ls->ls_waiters_mutex);
471 	memset(debug_buf, 0, sizeof(debug_buf));
472 
473 	list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
474 		ret = snprintf(debug_buf + pos, len - pos, "%x %d %d %s\n",
475 			       lkb->lkb_id, lkb->lkb_wait_type,
476 			       lkb->lkb_nodeid, lkb->lkb_resource->res_name);
477 		if (ret >= len - pos)
478 			break;
479 		pos += ret;
480 	}
481 	mutex_unlock(&ls->ls_waiters_mutex);
482 
483 	rv = simple_read_from_buffer(userbuf, count, ppos, debug_buf, pos);
484 	mutex_unlock(&debug_buf_lock);
485 	return rv;
486 }
487 
488 static const struct file_operations waiters_fops = {
489 	.owner   = THIS_MODULE,
490 	.open    = waiters_open,
491 	.read    = waiters_read
492 };
493 
494 int dlm_create_debug_file(struct dlm_ls *ls)
495 {
496 	char name[DLM_LOCKSPACE_LEN+8];
497 
498 	ls->ls_debug_rsb_dentry = debugfs_create_file(ls->ls_name,
499 						      S_IFREG | S_IRUGO,
500 						      dlm_root,
501 						      ls,
502 						      &rsb_fops);
503 	if (!ls->ls_debug_rsb_dentry)
504 		return -ENOMEM;
505 
506 	memset(name, 0, sizeof(name));
507 	snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_waiters", ls->ls_name);
508 
509 	ls->ls_debug_waiters_dentry = debugfs_create_file(name,
510 							  S_IFREG | S_IRUGO,
511 							  dlm_root,
512 							  ls,
513 							  &waiters_fops);
514 	if (!ls->ls_debug_waiters_dentry) {
515 		debugfs_remove(ls->ls_debug_rsb_dentry);
516 		return -ENOMEM;
517 	}
518 
519 	memset(name, 0, sizeof(name));
520 	snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_locks", ls->ls_name);
521 
522 	ls->ls_debug_locks_dentry = debugfs_create_file(name,
523 							S_IFREG | S_IRUGO,
524 							dlm_root,
525 							ls,
526 							&locks_fops);
527 	if (!ls->ls_debug_locks_dentry) {
528 		debugfs_remove(ls->ls_debug_waiters_dentry);
529 		debugfs_remove(ls->ls_debug_rsb_dentry);
530 		return -ENOMEM;
531 	}
532 
533 	return 0;
534 }
535 
536 void dlm_delete_debug_file(struct dlm_ls *ls)
537 {
538 	if (ls->ls_debug_rsb_dentry)
539 		debugfs_remove(ls->ls_debug_rsb_dentry);
540 	if (ls->ls_debug_waiters_dentry)
541 		debugfs_remove(ls->ls_debug_waiters_dentry);
542 	if (ls->ls_debug_locks_dentry)
543 		debugfs_remove(ls->ls_debug_locks_dentry);
544 }
545 
546 int dlm_register_debugfs(void)
547 {
548 	mutex_init(&debug_buf_lock);
549 	dlm_root = debugfs_create_dir("dlm", NULL);
550 	return dlm_root ? 0 : -ENOMEM;
551 }
552 
553 void dlm_unregister_debugfs(void)
554 {
555 	debugfs_remove(dlm_root);
556 }
557 
558