Btrfs: avoid deadlocks during reservations in btrfs_truncate_block
[cascardo/linux.git] / net / batman-adv / debugfs.c
1 /* Copyright (C) 2010-2016  B.A.T.M.A.N. contributors:
2  *
3  * Marek Lindner
4  *
5  * This program is free software; you can redistribute it and/or
6  * modify it under the terms of version 2 of the GNU General Public
7  * License as published by the Free Software Foundation.
8  *
9  * This program is distributed in the hope that it will be useful, but
10  * WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12  * General Public License for more details.
13  *
14  * You should have received a copy of the GNU General Public License
15  * along with this program; if not, see <http://www.gnu.org/licenses/>.
16  */
17
18 #include "debugfs.h"
19 #include "main.h"
20
21 #include <linux/compiler.h>
22 #include <linux/debugfs.h>
23 #include <linux/device.h>
24 #include <linux/errno.h>
25 #include <linux/export.h>
26 #include <linux/fcntl.h>
27 #include <linux/fs.h>
28 #include <linux/jiffies.h>
29 #include <linux/kernel.h>
30 #include <linux/module.h>
31 #include <linux/netdevice.h>
32 #include <linux/poll.h>
33 #include <linux/printk.h>
34 #include <linux/sched.h> /* for linux/wait.h */
35 #include <linux/seq_file.h>
36 #include <linux/slab.h>
37 #include <linux/spinlock.h>
38 #include <linux/stat.h>
39 #include <linux/stddef.h>
40 #include <linux/stringify.h>
41 #include <linux/sysfs.h>
42 #include <linux/types.h>
43 #include <linux/uaccess.h>
44 #include <linux/wait.h>
45 #include <stdarg.h>
46
47 #include "bridge_loop_avoidance.h"
48 #include "distributed-arp-table.h"
49 #include "gateway_client.h"
50 #include "icmp_socket.h"
51 #include "network-coding.h"
52 #include "originator.h"
53 #include "translation-table.h"
54
55 static struct dentry *batadv_debugfs;
56
57 #ifdef CONFIG_BATMAN_ADV_DEBUG
58 #define BATADV_LOG_BUFF_MASK (batadv_log_buff_len - 1)
59
60 static const int batadv_log_buff_len = BATADV_LOG_BUF_LEN;
61
62 static char *batadv_log_char_addr(struct batadv_priv_debug_log *debug_log,
63                                   size_t idx)
64 {
65         return &debug_log->log_buff[idx & BATADV_LOG_BUFF_MASK];
66 }
67
68 static void batadv_emit_log_char(struct batadv_priv_debug_log *debug_log,
69                                  char c)
70 {
71         char *char_addr;
72
73         char_addr = batadv_log_char_addr(debug_log, debug_log->log_end);
74         *char_addr = c;
75         debug_log->log_end++;
76
77         if (debug_log->log_end - debug_log->log_start > batadv_log_buff_len)
78                 debug_log->log_start = debug_log->log_end - batadv_log_buff_len;
79 }
80
81 __printf(2, 3)
82 static int batadv_fdebug_log(struct batadv_priv_debug_log *debug_log,
83                              const char *fmt, ...)
84 {
85         va_list args;
86         static char debug_log_buf[256];
87         char *p;
88
89         if (!debug_log)
90                 return 0;
91
92         spin_lock_bh(&debug_log->lock);
93         va_start(args, fmt);
94         vscnprintf(debug_log_buf, sizeof(debug_log_buf), fmt, args);
95         va_end(args);
96
97         for (p = debug_log_buf; *p != 0; p++)
98                 batadv_emit_log_char(debug_log, *p);
99
100         spin_unlock_bh(&debug_log->lock);
101
102         wake_up(&debug_log->queue_wait);
103
104         return 0;
105 }
106
107 int batadv_debug_log(struct batadv_priv *bat_priv, const char *fmt, ...)
108 {
109         va_list args;
110         char tmp_log_buf[256];
111
112         va_start(args, fmt);
113         vscnprintf(tmp_log_buf, sizeof(tmp_log_buf), fmt, args);
114         batadv_fdebug_log(bat_priv->debug_log, "[%10u] %s",
115                           jiffies_to_msecs(jiffies), tmp_log_buf);
116         va_end(args);
117
118         return 0;
119 }
120
121 static int batadv_log_open(struct inode *inode, struct file *file)
122 {
123         if (!try_module_get(THIS_MODULE))
124                 return -EBUSY;
125
126         nonseekable_open(inode, file);
127         file->private_data = inode->i_private;
128         return 0;
129 }
130
131 static int batadv_log_release(struct inode *inode, struct file *file)
132 {
133         module_put(THIS_MODULE);
134         return 0;
135 }
136
137 static bool batadv_log_empty(struct batadv_priv_debug_log *debug_log)
138 {
139         return !(debug_log->log_start - debug_log->log_end);
140 }
141
142 static ssize_t batadv_log_read(struct file *file, char __user *buf,
143                                size_t count, loff_t *ppos)
144 {
145         struct batadv_priv *bat_priv = file->private_data;
146         struct batadv_priv_debug_log *debug_log = bat_priv->debug_log;
147         int error, i = 0;
148         char *char_addr;
149         char c;
150
151         if ((file->f_flags & O_NONBLOCK) && batadv_log_empty(debug_log))
152                 return -EAGAIN;
153
154         if (!buf)
155                 return -EINVAL;
156
157         if (count == 0)
158                 return 0;
159
160         if (!access_ok(VERIFY_WRITE, buf, count))
161                 return -EFAULT;
162
163         error = wait_event_interruptible(debug_log->queue_wait,
164                                          (!batadv_log_empty(debug_log)));
165
166         if (error)
167                 return error;
168
169         spin_lock_bh(&debug_log->lock);
170
171         while ((!error) && (i < count) &&
172                (debug_log->log_start != debug_log->log_end)) {
173                 char_addr = batadv_log_char_addr(debug_log,
174                                                  debug_log->log_start);
175                 c = *char_addr;
176
177                 debug_log->log_start++;
178
179                 spin_unlock_bh(&debug_log->lock);
180
181                 error = __put_user(c, buf);
182
183                 spin_lock_bh(&debug_log->lock);
184
185                 buf++;
186                 i++;
187         }
188
189         spin_unlock_bh(&debug_log->lock);
190
191         if (!error)
192                 return i;
193
194         return error;
195 }
196
197 static unsigned int batadv_log_poll(struct file *file, poll_table *wait)
198 {
199         struct batadv_priv *bat_priv = file->private_data;
200         struct batadv_priv_debug_log *debug_log = bat_priv->debug_log;
201
202         poll_wait(file, &debug_log->queue_wait, wait);
203
204         if (!batadv_log_empty(debug_log))
205                 return POLLIN | POLLRDNORM;
206
207         return 0;
208 }
209
210 static const struct file_operations batadv_log_fops = {
211         .open           = batadv_log_open,
212         .release        = batadv_log_release,
213         .read           = batadv_log_read,
214         .poll           = batadv_log_poll,
215         .llseek         = no_llseek,
216 };
217
218 static int batadv_debug_log_setup(struct batadv_priv *bat_priv)
219 {
220         struct dentry *d;
221
222         if (!bat_priv->debug_dir)
223                 goto err;
224
225         bat_priv->debug_log = kzalloc(sizeof(*bat_priv->debug_log), GFP_ATOMIC);
226         if (!bat_priv->debug_log)
227                 goto err;
228
229         spin_lock_init(&bat_priv->debug_log->lock);
230         init_waitqueue_head(&bat_priv->debug_log->queue_wait);
231
232         d = debugfs_create_file("log", S_IFREG | S_IRUSR,
233                                 bat_priv->debug_dir, bat_priv,
234                                 &batadv_log_fops);
235         if (!d)
236                 goto err;
237
238         return 0;
239
240 err:
241         return -ENOMEM;
242 }
243
244 static void batadv_debug_log_cleanup(struct batadv_priv *bat_priv)
245 {
246         kfree(bat_priv->debug_log);
247         bat_priv->debug_log = NULL;
248 }
249 #else /* CONFIG_BATMAN_ADV_DEBUG */
250 static int batadv_debug_log_setup(struct batadv_priv *bat_priv)
251 {
252         return 0;
253 }
254
255 static void batadv_debug_log_cleanup(struct batadv_priv *bat_priv)
256 {
257 }
258 #endif
259
260 static int batadv_algorithms_open(struct inode *inode, struct file *file)
261 {
262         return single_open(file, batadv_algo_seq_print_text, NULL);
263 }
264
265 static int neighbors_open(struct inode *inode, struct file *file)
266 {
267         struct net_device *net_dev = (struct net_device *)inode->i_private;
268
269         return single_open(file, batadv_hardif_neigh_seq_print_text, net_dev);
270 }
271
272 static int batadv_originators_open(struct inode *inode, struct file *file)
273 {
274         struct net_device *net_dev = (struct net_device *)inode->i_private;
275
276         return single_open(file, batadv_orig_seq_print_text, net_dev);
277 }
278
279 /**
280  * batadv_originators_hardif_open - handles debugfs output for the
281  *  originator table of an hard interface
282  * @inode: inode pointer to debugfs file
283  * @file: pointer to the seq_file
284  *
285  * Return: 0 on success or negative error number in case of failure
286  */
287 static int batadv_originators_hardif_open(struct inode *inode,
288                                           struct file *file)
289 {
290         struct net_device *net_dev = (struct net_device *)inode->i_private;
291
292         return single_open(file, batadv_orig_hardif_seq_print_text, net_dev);
293 }
294
295 static int batadv_gateways_open(struct inode *inode, struct file *file)
296 {
297         struct net_device *net_dev = (struct net_device *)inode->i_private;
298
299         return single_open(file, batadv_gw_client_seq_print_text, net_dev);
300 }
301
302 static int batadv_transtable_global_open(struct inode *inode, struct file *file)
303 {
304         struct net_device *net_dev = (struct net_device *)inode->i_private;
305
306         return single_open(file, batadv_tt_global_seq_print_text, net_dev);
307 }
308
309 #ifdef CONFIG_BATMAN_ADV_BLA
310 static int batadv_bla_claim_table_open(struct inode *inode, struct file *file)
311 {
312         struct net_device *net_dev = (struct net_device *)inode->i_private;
313
314         return single_open(file, batadv_bla_claim_table_seq_print_text,
315                            net_dev);
316 }
317
318 static int batadv_bla_backbone_table_open(struct inode *inode,
319                                           struct file *file)
320 {
321         struct net_device *net_dev = (struct net_device *)inode->i_private;
322
323         return single_open(file, batadv_bla_backbone_table_seq_print_text,
324                            net_dev);
325 }
326
327 #endif
328
329 #ifdef CONFIG_BATMAN_ADV_DAT
330 /**
331  * batadv_dat_cache_open - Prepare file handler for reads from dat_chache
332  * @inode: inode which was opened
333  * @file: file handle to be initialized
334  *
335  * Return: 0 on success or negative error number in case of failure
336  */
337 static int batadv_dat_cache_open(struct inode *inode, struct file *file)
338 {
339         struct net_device *net_dev = (struct net_device *)inode->i_private;
340
341         return single_open(file, batadv_dat_cache_seq_print_text, net_dev);
342 }
343 #endif
344
345 static int batadv_transtable_local_open(struct inode *inode, struct file *file)
346 {
347         struct net_device *net_dev = (struct net_device *)inode->i_private;
348
349         return single_open(file, batadv_tt_local_seq_print_text, net_dev);
350 }
351
352 struct batadv_debuginfo {
353         struct attribute attr;
354         const struct file_operations fops;
355 };
356
357 #ifdef CONFIG_BATMAN_ADV_NC
358 static int batadv_nc_nodes_open(struct inode *inode, struct file *file)
359 {
360         struct net_device *net_dev = (struct net_device *)inode->i_private;
361
362         return single_open(file, batadv_nc_nodes_seq_print_text, net_dev);
363 }
364 #endif
365
366 #define BATADV_DEBUGINFO(_name, _mode, _open)           \
367 struct batadv_debuginfo batadv_debuginfo_##_name = {    \
368         .attr = {                                       \
369                 .name = __stringify(_name),             \
370                 .mode = _mode,                          \
371         },                                              \
372         .fops = {                                       \
373                 .owner = THIS_MODULE,                   \
374                 .open = _open,                          \
375                 .read   = seq_read,                     \
376                 .llseek = seq_lseek,                    \
377                 .release = single_release,              \
378         },                                              \
379 }
380
381 /* the following attributes are general and therefore they will be directly
382  * placed in the BATADV_DEBUGFS_SUBDIR subdirectory of debugfs
383  */
384 static BATADV_DEBUGINFO(routing_algos, S_IRUGO, batadv_algorithms_open);
385
386 static struct batadv_debuginfo *batadv_general_debuginfos[] = {
387         &batadv_debuginfo_routing_algos,
388         NULL,
389 };
390
391 /* The following attributes are per soft interface */
392 static BATADV_DEBUGINFO(neighbors, S_IRUGO, neighbors_open);
393 static BATADV_DEBUGINFO(originators, S_IRUGO, batadv_originators_open);
394 static BATADV_DEBUGINFO(gateways, S_IRUGO, batadv_gateways_open);
395 static BATADV_DEBUGINFO(transtable_global, S_IRUGO,
396                         batadv_transtable_global_open);
397 #ifdef CONFIG_BATMAN_ADV_BLA
398 static BATADV_DEBUGINFO(bla_claim_table, S_IRUGO, batadv_bla_claim_table_open);
399 static BATADV_DEBUGINFO(bla_backbone_table, S_IRUGO,
400                         batadv_bla_backbone_table_open);
401 #endif
402 #ifdef CONFIG_BATMAN_ADV_DAT
403 static BATADV_DEBUGINFO(dat_cache, S_IRUGO, batadv_dat_cache_open);
404 #endif
405 static BATADV_DEBUGINFO(transtable_local, S_IRUGO,
406                         batadv_transtable_local_open);
407 #ifdef CONFIG_BATMAN_ADV_NC
408 static BATADV_DEBUGINFO(nc_nodes, S_IRUGO, batadv_nc_nodes_open);
409 #endif
410
411 static struct batadv_debuginfo *batadv_mesh_debuginfos[] = {
412         &batadv_debuginfo_neighbors,
413         &batadv_debuginfo_originators,
414         &batadv_debuginfo_gateways,
415         &batadv_debuginfo_transtable_global,
416 #ifdef CONFIG_BATMAN_ADV_BLA
417         &batadv_debuginfo_bla_claim_table,
418         &batadv_debuginfo_bla_backbone_table,
419 #endif
420 #ifdef CONFIG_BATMAN_ADV_DAT
421         &batadv_debuginfo_dat_cache,
422 #endif
423         &batadv_debuginfo_transtable_local,
424 #ifdef CONFIG_BATMAN_ADV_NC
425         &batadv_debuginfo_nc_nodes,
426 #endif
427         NULL,
428 };
429
430 #define BATADV_HARDIF_DEBUGINFO(_name, _mode, _open)            \
431 struct batadv_debuginfo batadv_hardif_debuginfo_##_name = {     \
432         .attr = {                                               \
433                 .name = __stringify(_name),                     \
434                 .mode = _mode,                                  \
435         },                                                      \
436         .fops = {                                               \
437                 .owner = THIS_MODULE,                           \
438                 .open = _open,                                  \
439                 .read   = seq_read,                             \
440                 .llseek = seq_lseek,                            \
441                 .release = single_release,                      \
442         },                                                      \
443 }
444
445 static BATADV_HARDIF_DEBUGINFO(originators, S_IRUGO,
446                                batadv_originators_hardif_open);
447
448 static struct batadv_debuginfo *batadv_hardif_debuginfos[] = {
449         &batadv_hardif_debuginfo_originators,
450         NULL,
451 };
452
453 void batadv_debugfs_init(void)
454 {
455         struct batadv_debuginfo **bat_debug;
456         struct dentry *file;
457
458         batadv_debugfs = debugfs_create_dir(BATADV_DEBUGFS_SUBDIR, NULL);
459         if (batadv_debugfs == ERR_PTR(-ENODEV))
460                 batadv_debugfs = NULL;
461
462         if (!batadv_debugfs)
463                 goto err;
464
465         for (bat_debug = batadv_general_debuginfos; *bat_debug; ++bat_debug) {
466                 file = debugfs_create_file(((*bat_debug)->attr).name,
467                                            S_IFREG | ((*bat_debug)->attr).mode,
468                                            batadv_debugfs, NULL,
469                                            &(*bat_debug)->fops);
470                 if (!file) {
471                         pr_err("Can't add general debugfs file: %s\n",
472                                ((*bat_debug)->attr).name);
473                         goto err;
474                 }
475         }
476
477         return;
478 err:
479         debugfs_remove_recursive(batadv_debugfs);
480         batadv_debugfs = NULL;
481 }
482
483 void batadv_debugfs_destroy(void)
484 {
485         debugfs_remove_recursive(batadv_debugfs);
486         batadv_debugfs = NULL;
487 }
488
489 /**
490  * batadv_debugfs_add_hardif - creates the base directory for a hard interface
491  *  in debugfs.
492  * @hard_iface: hard interface which should be added.
493  *
494  * Return: 0 on success or negative error number in case of failure
495  */
496 int batadv_debugfs_add_hardif(struct batadv_hard_iface *hard_iface)
497 {
498         struct batadv_debuginfo **bat_debug;
499         struct dentry *file;
500
501         if (!batadv_debugfs)
502                 goto out;
503
504         hard_iface->debug_dir = debugfs_create_dir(hard_iface->net_dev->name,
505                                                    batadv_debugfs);
506         if (!hard_iface->debug_dir)
507                 goto out;
508
509         for (bat_debug = batadv_hardif_debuginfos; *bat_debug; ++bat_debug) {
510                 file = debugfs_create_file(((*bat_debug)->attr).name,
511                                            S_IFREG | ((*bat_debug)->attr).mode,
512                                            hard_iface->debug_dir,
513                                            hard_iface->net_dev,
514                                            &(*bat_debug)->fops);
515                 if (!file)
516                         goto rem_attr;
517         }
518
519         return 0;
520 rem_attr:
521         debugfs_remove_recursive(hard_iface->debug_dir);
522         hard_iface->debug_dir = NULL;
523 out:
524         return -ENOMEM;
525 }
526
527 /**
528  * batadv_debugfs_del_hardif - delete the base directory for a hard interface
529  *  in debugfs.
530  * @hard_iface: hard interface which is deleted.
531  */
532 void batadv_debugfs_del_hardif(struct batadv_hard_iface *hard_iface)
533 {
534         if (batadv_debugfs) {
535                 debugfs_remove_recursive(hard_iface->debug_dir);
536                 hard_iface->debug_dir = NULL;
537         }
538 }
539
540 int batadv_debugfs_add_meshif(struct net_device *dev)
541 {
542         struct batadv_priv *bat_priv = netdev_priv(dev);
543         struct batadv_debuginfo **bat_debug;
544         struct dentry *file;
545
546         if (!batadv_debugfs)
547                 goto out;
548
549         bat_priv->debug_dir = debugfs_create_dir(dev->name, batadv_debugfs);
550         if (!bat_priv->debug_dir)
551                 goto out;
552
553         if (batadv_socket_setup(bat_priv) < 0)
554                 goto rem_attr;
555
556         if (batadv_debug_log_setup(bat_priv) < 0)
557                 goto rem_attr;
558
559         for (bat_debug = batadv_mesh_debuginfos; *bat_debug; ++bat_debug) {
560                 file = debugfs_create_file(((*bat_debug)->attr).name,
561                                            S_IFREG | ((*bat_debug)->attr).mode,
562                                            bat_priv->debug_dir,
563                                            dev, &(*bat_debug)->fops);
564                 if (!file) {
565                         batadv_err(dev, "Can't add debugfs file: %s/%s\n",
566                                    dev->name, ((*bat_debug)->attr).name);
567                         goto rem_attr;
568                 }
569         }
570
571         if (batadv_nc_init_debugfs(bat_priv) < 0)
572                 goto rem_attr;
573
574         return 0;
575 rem_attr:
576         debugfs_remove_recursive(bat_priv->debug_dir);
577         bat_priv->debug_dir = NULL;
578 out:
579         return -ENOMEM;
580 }
581
582 void batadv_debugfs_del_meshif(struct net_device *dev)
583 {
584         struct batadv_priv *bat_priv = netdev_priv(dev);
585
586         batadv_debug_log_cleanup(bat_priv);
587
588         if (batadv_debugfs) {
589                 debugfs_remove_recursive(bat_priv->debug_dir);
590                 bat_priv->debug_dir = NULL;
591         }
592 }