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
21#define DLM_DEBUG_BUF_LEN 4096
22static char debug_buf[DLM_DEBUG_BUF_LEN];
23static struct mutex debug_buf_lock;
24
25static struct dentry *dlm_root;
26
27struct rsb_iter {
28	int entry;
29	struct dlm_ls *ls;
30	struct list_head *next;
31	struct dlm_rsb *rsb;
32};
33
34/*
35 * dump all rsb's in the lockspace hash table
36 */
37
38static char *print_lockmode(int mode)
39{
40	switch (mode) {
41	case DLM_LOCK_IV:
42		return "--";
43	case DLM_LOCK_NL:
44		return "NL";
45	case DLM_LOCK_CR:
46		return "CR";
47	case DLM_LOCK_CW:
48		return "CW";
49	case DLM_LOCK_PR:
50		return "PR";
51	case DLM_LOCK_PW:
52		return "PW";
53	case DLM_LOCK_EX:
54		return "EX";
55	default:
56		return "??";
57	}
58}
59
60static void print_lock(struct seq_file *s, struct dlm_lkb *lkb,
61		       struct dlm_rsb *res)
62{
63	seq_printf(s, "%08x %s", lkb->lkb_id, print_lockmode(lkb->lkb_grmode));
64
65	if (lkb->lkb_status == DLM_LKSTS_CONVERT
66	    || lkb->lkb_status == DLM_LKSTS_WAITING)
67		seq_printf(s, " (%s)", print_lockmode(lkb->lkb_rqmode));
68
69	if (lkb->lkb_nodeid) {
70		if (lkb->lkb_nodeid != res->res_nodeid)
71			seq_printf(s, " Remote: %3d %08x", lkb->lkb_nodeid,
72				   lkb->lkb_remid);
73		else
74			seq_printf(s, " Master:     %08x", lkb->lkb_remid);
75	}
76
77	if (lkb->lkb_wait_type)
78		seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
79
80	seq_printf(s, "\n");
81}
82
83static int print_resource(struct dlm_rsb *res, struct seq_file *s)
84{
85	struct dlm_lkb *lkb;
86	int i, lvblen = res->res_ls->ls_lvblen, recover_list, root_list;
87
88	seq_printf(s, "\nResource %p Name (len=%d) \"", res, res->res_length);
89	for (i = 0; i < res->res_length; i++) {
90		if (isprint(res->res_name[i]))
91			seq_printf(s, "%c", res->res_name[i]);
92		else
93			seq_printf(s, "%c", '.');
94	}
95	if (res->res_nodeid > 0)
96		seq_printf(s, "\"  \nLocal Copy, Master is node %d\n",
97			   res->res_nodeid);
98	else if (res->res_nodeid == 0)
99		seq_printf(s, "\"  \nMaster Copy\n");
100	else if (res->res_nodeid == -1)
101		seq_printf(s, "\"  \nLooking up master (lkid %x)\n",
102			   res->res_first_lkid);
103	else
104		seq_printf(s, "\"  \nInvalid master %d\n", res->res_nodeid);
105
106	/* Print the LVB: */
107	if (res->res_lvbptr) {
108		seq_printf(s, "LVB: ");
109		for (i = 0; i < lvblen; i++) {
110			if (i == lvblen / 2)
111				seq_printf(s, "\n     ");
112			seq_printf(s, "%02x ",
113				   (unsigned char) res->res_lvbptr[i]);
114		}
115		if (rsb_flag(res, RSB_VALNOTVALID))
116			seq_printf(s, " (INVALID)");
117		seq_printf(s, "\n");
118	}
119
120	root_list = !list_empty(&res->res_root_list);
121	recover_list = !list_empty(&res->res_recover_list);
122
123	if (root_list || recover_list) {
124		seq_printf(s, "Recovery: root %d recover %d flags %lx "
125			   "count %d\n", root_list, recover_list,
126			   res->res_flags, res->res_recover_locks_count);
127	}
128
129	/* Print the locks attached to this resource */
130	seq_printf(s, "Granted Queue\n");
131	list_for_each_entry(lkb, &res->res_grantqueue, lkb_statequeue)
132		print_lock(s, lkb, res);
133
134	seq_printf(s, "Conversion Queue\n");
135	list_for_each_entry(lkb, &res->res_convertqueue, lkb_statequeue)
136		print_lock(s, lkb, res);
137
138	seq_printf(s, "Waiting Queue\n");
139	list_for_each_entry(lkb, &res->res_waitqueue, lkb_statequeue)
140		print_lock(s, lkb, res);
141
142	if (list_empty(&res->res_lookup))
143		goto out;
144
145	seq_printf(s, "Lookup Queue\n");
146	list_for_each_entry(lkb, &res->res_lookup, lkb_rsb_lookup) {
147		seq_printf(s, "%08x %s", lkb->lkb_id,
148			   print_lockmode(lkb->lkb_rqmode));
149		if (lkb->lkb_wait_type)
150			seq_printf(s, " wait_type: %d", lkb->lkb_wait_type);
151		seq_printf(s, "\n");
152	}
153 out:
154	return 0;
155}
156
157static int rsb_iter_next(struct rsb_iter *ri)
158{
159	struct dlm_ls *ls = ri->ls;
160	int i;
161
162	if (!ri->next) {
163 top:
164		/* Find the next non-empty hash bucket */
165		for (i = ri->entry; i < ls->ls_rsbtbl_size; i++) {
166			read_lock(&ls->ls_rsbtbl[i].lock);
167			if (!list_empty(&ls->ls_rsbtbl[i].list)) {
168				ri->next = ls->ls_rsbtbl[i].list.next;
169				read_unlock(&ls->ls_rsbtbl[i].lock);
170				break;
171			}
172			read_unlock(&ls->ls_rsbtbl[i].lock);
173                }
174		ri->entry = i;
175
176		if (ri->entry >= ls->ls_rsbtbl_size)
177			return 1;
178	} else {
179		i = ri->entry;
180		read_lock(&ls->ls_rsbtbl[i].lock);
181		ri->next = ri->next->next;
182		if (ri->next->next == ls->ls_rsbtbl[i].list.next) {
183			/* End of list - move to next bucket */
184			ri->next = NULL;
185			ri->entry++;
186			read_unlock(&ls->ls_rsbtbl[i].lock);
187			goto top;
188                }
189		read_unlock(&ls->ls_rsbtbl[i].lock);
190	}
191	ri->rsb = list_entry(ri->next, struct dlm_rsb, res_hashchain);
192
193	return 0;
194}
195
196static void rsb_iter_free(struct rsb_iter *ri)
197{
198	kfree(ri);
199}
200
201static struct rsb_iter *rsb_iter_init(struct dlm_ls *ls)
202{
203	struct rsb_iter *ri;
204
205	ri = kmalloc(sizeof *ri, GFP_KERNEL);
206	if (!ri)
207		return NULL;
208
209	ri->ls = ls;
210	ri->entry = 0;
211	ri->next = NULL;
212
213	if (rsb_iter_next(ri)) {
214		rsb_iter_free(ri);
215		return NULL;
216	}
217
218	return ri;
219}
220
221static void *rsb_seq_start(struct seq_file *file, loff_t *pos)
222{
223	struct rsb_iter *ri;
224	loff_t n = *pos;
225
226	ri = rsb_iter_init(file->private);
227	if (!ri)
228		return NULL;
229
230	while (n--) {
231		if (rsb_iter_next(ri)) {
232			rsb_iter_free(ri);
233			return NULL;
234		}
235	}
236
237	return ri;
238}
239
240static void *rsb_seq_next(struct seq_file *file, void *iter_ptr, loff_t *pos)
241{
242	struct rsb_iter *ri = iter_ptr;
243
244	(*pos)++;
245
246	if (rsb_iter_next(ri)) {
247		rsb_iter_free(ri);
248		return NULL;
249	}
250
251	return ri;
252}
253
254static void rsb_seq_stop(struct seq_file *file, void *iter_ptr)
255{
256	/* nothing for now */
257}
258
259static int rsb_seq_show(struct seq_file *file, void *iter_ptr)
260{
261	struct rsb_iter *ri = iter_ptr;
262
263	print_resource(ri->rsb, file);
264
265	return 0;
266}
267
268static struct seq_operations rsb_seq_ops = {
269	.start = rsb_seq_start,
270	.next  = rsb_seq_next,
271	.stop  = rsb_seq_stop,
272	.show  = rsb_seq_show,
273};
274
275static int rsb_open(struct inode *inode, struct file *file)
276{
277	struct seq_file *seq;
278	int ret;
279
280	ret = seq_open(file, &rsb_seq_ops);
281	if (ret)
282		return ret;
283
284	seq = file->private_data;
285	seq->private = inode->i_private;
286
287	return 0;
288}
289
290static const struct file_operations rsb_fops = {
291	.owner   = THIS_MODULE,
292	.open    = rsb_open,
293	.read    = seq_read,
294	.llseek  = seq_lseek,
295	.release = seq_release
296};
297
298/*
299 * dump lkb's on the ls_waiters list
300 */
301
302static int waiters_open(struct inode *inode, struct file *file)
303{
304	file->private_data = inode->i_private;
305	return 0;
306}
307
308static ssize_t waiters_read(struct file *file, char __user *userbuf,
309			    size_t count, loff_t *ppos)
310{
311	struct dlm_ls *ls = file->private_data;
312	struct dlm_lkb *lkb;
313	size_t len = DLM_DEBUG_BUF_LEN, pos = 0, ret, rv;
314
315	mutex_lock(&debug_buf_lock);
316	mutex_lock(&ls->ls_waiters_mutex);
317	memset(debug_buf, 0, sizeof(debug_buf));
318
319	list_for_each_entry(lkb, &ls->ls_waiters, lkb_wait_reply) {
320		ret = snprintf(debug_buf + pos, len - pos, "%x %d %d %s\n",
321			       lkb->lkb_id, lkb->lkb_wait_type,
322			       lkb->lkb_nodeid, lkb->lkb_resource->res_name);
323		if (ret >= len - pos)
324			break;
325		pos += ret;
326	}
327	mutex_unlock(&ls->ls_waiters_mutex);
328
329	rv = simple_read_from_buffer(userbuf, count, ppos, debug_buf, pos);
330	mutex_unlock(&debug_buf_lock);
331	return rv;
332}
333
334static const struct file_operations waiters_fops = {
335	.owner   = THIS_MODULE,
336	.open    = waiters_open,
337	.read    = waiters_read
338};
339
340int dlm_create_debug_file(struct dlm_ls *ls)
341{
342	char name[DLM_LOCKSPACE_LEN+8];
343
344	ls->ls_debug_rsb_dentry = debugfs_create_file(ls->ls_name,
345						      S_IFREG | S_IRUGO,
346						      dlm_root,
347						      ls,
348						      &rsb_fops);
349	if (!ls->ls_debug_rsb_dentry)
350		return -ENOMEM;
351
352	memset(name, 0, sizeof(name));
353	snprintf(name, DLM_LOCKSPACE_LEN+8, "%s_waiters", ls->ls_name);
354
355	ls->ls_debug_waiters_dentry = debugfs_create_file(name,
356							  S_IFREG | S_IRUGO,
357							  dlm_root,
358							  ls,
359							  &waiters_fops);
360	if (!ls->ls_debug_waiters_dentry) {
361		debugfs_remove(ls->ls_debug_rsb_dentry);
362		return -ENOMEM;
363	}
364
365	return 0;
366}
367
368void dlm_delete_debug_file(struct dlm_ls *ls)
369{
370	if (ls->ls_debug_rsb_dentry)
371		debugfs_remove(ls->ls_debug_rsb_dentry);
372	if (ls->ls_debug_waiters_dentry)
373		debugfs_remove(ls->ls_debug_waiters_dentry);
374}
375
376int dlm_register_debugfs(void)
377{
378	mutex_init(&debug_buf_lock);
379	dlm_root = debugfs_create_dir("dlm", NULL);
380	return dlm_root ? 0 : -ENOMEM;
381}
382
383void dlm_unregister_debugfs(void)
384{
385	debugfs_remove(dlm_root);
386}
387