blob: 3857b720cb1b258a3964ae4a3557094087eaa2ed [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * linux/fs/seq_file.c
3 *
4 * helper functions for making synthetic files from sequences of records.
5 * initial implementation -- AV, Oct 2001.
6 */
7
8#include <linux/fs.h>
Paul Gortmaker630d9c42011-11-16 23:57:37 -05009#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070010#include <linux/seq_file.h>
Heiko Carstens058504e2014-07-02 15:22:37 -070011#include <linux/vmalloc.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070012#include <linux/slab.h>
Eric W. Biedermanadb37c42012-05-23 18:01:20 -060013#include <linux/cred.h>
Heiko Carstens058504e2014-07-02 15:22:37 -070014#include <linux/mm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015
16#include <asm/uaccess.h>
17#include <asm/page.h>
18
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -070019
20/*
21 * seq_files have a buffer which can may overflow. When this happens a larger
22 * buffer is reallocated and all the data will be printed again.
23 * The overflow state is true when m->count == m->size.
24 */
25static bool seq_overflow(struct seq_file *m)
26{
27 return m->count == m->size;
28}
29
30static void seq_set_overflow(struct seq_file *m)
31{
32 m->count = m->size;
33}
34
Heiko Carstens058504e2014-07-02 15:22:37 -070035static void *seq_buf_alloc(unsigned long size)
36{
37 void *buf;
38
39 buf = kmalloc(size, GFP_KERNEL | __GFP_NOWARN);
40 if (!buf && size > PAGE_SIZE)
41 buf = vmalloc(size);
42 return buf;
43}
44
Linus Torvalds1da177e2005-04-16 15:20:36 -070045/**
46 * seq_open - initialize sequential file
47 * @file: file we initialize
48 * @op: method table describing the sequence
49 *
50 * seq_open() sets @file, associating it with a sequence described
51 * by @op. @op->start() sets the iterator up and returns the first
52 * element of sequence. @op->stop() shuts it down. @op->next()
53 * returns the next element of sequence. @op->show() prints element
54 * into the buffer. In case of error ->start() and ->next() return
55 * ERR_PTR(error). In the end of sequence they return %NULL. ->show()
56 * returns 0 in case of success and negative number in case of error.
Al Viro521b5d02008-03-28 00:46:41 -040057 * Returning SEQ_SKIP means "discard this element and move on".
Linus Torvalds1da177e2005-04-16 15:20:36 -070058 */
Helge Deller15ad7cd2006-12-06 20:40:36 -080059int seq_open(struct file *file, const struct seq_operations *op)
Linus Torvalds1da177e2005-04-16 15:20:36 -070060{
Al Viro1abe77b2005-11-07 17:15:34 -050061 struct seq_file *p = file->private_data;
62
63 if (!p) {
64 p = kmalloc(sizeof(*p), GFP_KERNEL);
65 if (!p)
66 return -ENOMEM;
67 file->private_data = p;
68 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 memset(p, 0, sizeof(*p));
Ingo Molnar0ac17592006-03-23 03:00:37 -080070 mutex_init(&p->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070071 p->op = op;
Eric W. Biedermanadb37c42012-05-23 18:01:20 -060072#ifdef CONFIG_USER_NS
73 p->user_ns = file->f_cred->user_ns;
74#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070075
76 /*
77 * Wrappers around seq_open(e.g. swaps_open) need to be
78 * aware of this. If they set f_version themselves, they
79 * should call seq_open first and then set f_version.
80 */
81 file->f_version = 0;
82
Eric Biederman8f19d472009-02-18 14:48:16 -080083 /*
84 * seq_files support lseek() and pread(). They do not implement
85 * write() at all, but we clear FMODE_PWRITE here for historical
86 * reasons.
87 *
88 * If a client of seq_files a) implements file.write() and b) wishes to
89 * support pwrite() then that client will need to implement its own
90 * file.open() which calls seq_open() and then sets FMODE_PWRITE.
91 */
92 file->f_mode &= ~FMODE_PWRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -070093 return 0;
94}
95EXPORT_SYMBOL(seq_open);
96
Eric Biederman33da8892009-02-04 15:12:25 -080097static int traverse(struct seq_file *m, loff_t offset)
98{
99 loff_t pos = 0, index;
100 int error = 0;
101 void *p;
102
103 m->version = 0;
104 index = 0;
105 m->count = m->from = 0;
106 if (!offset) {
107 m->index = index;
108 return 0;
109 }
110 if (!m->buf) {
Heiko Carstens058504e2014-07-02 15:22:37 -0700111 m->buf = seq_buf_alloc(m->size = PAGE_SIZE);
Eric Biederman33da8892009-02-04 15:12:25 -0800112 if (!m->buf)
113 return -ENOMEM;
114 }
115 p = m->op->start(m, &index);
116 while (p) {
117 error = PTR_ERR(p);
118 if (IS_ERR(p))
119 break;
120 error = m->op->show(m, p);
121 if (error < 0)
122 break;
123 if (unlikely(error)) {
124 error = 0;
125 m->count = 0;
126 }
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700127 if (seq_overflow(m))
Eric Biederman33da8892009-02-04 15:12:25 -0800128 goto Eoverflow;
129 if (pos + m->count > offset) {
130 m->from = offset - pos;
131 m->count -= m->from;
132 m->index = index;
133 break;
134 }
135 pos += m->count;
136 m->count = 0;
137 if (pos == offset) {
138 index++;
139 m->index = index;
140 break;
141 }
142 p = m->op->next(m, p, &index);
143 }
144 m->op->stop(m, p);
Alexey Dobriyanf01d1d52009-02-06 00:30:05 +0300145 m->index = index;
Eric Biederman33da8892009-02-04 15:12:25 -0800146 return error;
147
148Eoverflow:
149 m->op->stop(m, p);
Heiko Carstens058504e2014-07-02 15:22:37 -0700150 kvfree(m->buf);
Al Viro801a7602013-11-19 01:20:43 +0000151 m->count = 0;
Heiko Carstens058504e2014-07-02 15:22:37 -0700152 m->buf = seq_buf_alloc(m->size <<= 1);
Eric Biederman33da8892009-02-04 15:12:25 -0800153 return !m->buf ? -ENOMEM : -EAGAIN;
154}
155
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156/**
157 * seq_read - ->read() method for sequential files.
Martin Waitz67be2dd2005-05-01 08:59:26 -0700158 * @file: the file to read from
159 * @buf: the buffer to read to
160 * @size: the maximum number of bytes to read
161 * @ppos: the current position in the file
Linus Torvalds1da177e2005-04-16 15:20:36 -0700162 *
163 * Ready-made ->f_op->read()
164 */
165ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
166{
Joe Perches8209e2f2010-09-04 18:52:49 -0700167 struct seq_file *m = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168 size_t copied = 0;
169 loff_t pos;
170 size_t n;
171 void *p;
172 int err = 0;
173
Ingo Molnar0ac17592006-03-23 03:00:37 -0800174 mutex_lock(&m->lock);
Eric Biederman8f19d472009-02-18 14:48:16 -0800175
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 /*
177 * seq_file->op->..m_start/m_stop/m_next may do special actions
178 * or optimisations based on the file->f_version, so we want to
179 * pass the file->f_version to those methods.
180 *
181 * seq_file->version is just copy of f_version, and seq_file
182 * methods can treat it simply as file version.
183 * It is copied in first and copied out after all operations.
184 * It is convenient to have it as part of structure to avoid the
185 * need of passing another argument to all the seq_file methods.
186 */
187 m->version = file->f_version;
Earl Chew7904ac82012-03-21 16:33:43 -0700188
189 /* Don't assume *ppos is where we left it */
190 if (unlikely(*ppos != m->read_pos)) {
191 while ((err = traverse(m, *ppos)) == -EAGAIN)
192 ;
193 if (err) {
194 /* With prejudice... */
195 m->read_pos = 0;
196 m->version = 0;
197 m->index = 0;
198 m->count = 0;
199 goto Done;
200 } else {
201 m->read_pos = *ppos;
202 }
203 }
204
Linus Torvalds1da177e2005-04-16 15:20:36 -0700205 /* grab buffer if we didn't have one */
206 if (!m->buf) {
Heiko Carstens058504e2014-07-02 15:22:37 -0700207 m->buf = seq_buf_alloc(m->size = PAGE_SIZE);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700208 if (!m->buf)
209 goto Enomem;
210 }
211 /* if not empty - flush it first */
212 if (m->count) {
213 n = min(m->count, size);
214 err = copy_to_user(buf, m->buf + m->from, n);
215 if (err)
216 goto Efault;
217 m->count -= n;
218 m->from += n;
219 size -= n;
220 buf += n;
221 copied += n;
222 if (!m->count)
223 m->index++;
224 if (!size)
225 goto Done;
226 }
227 /* we need at least one record in buffer */
Al Viro4cdfe842008-08-24 07:45:33 -0400228 pos = m->index;
229 p = m->op->start(m, &pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230 while (1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 err = PTR_ERR(p);
232 if (!p || IS_ERR(p))
233 break;
234 err = m->op->show(m, p);
Al Viro521b5d02008-03-28 00:46:41 -0400235 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700236 break;
Al Viro521b5d02008-03-28 00:46:41 -0400237 if (unlikely(err))
238 m->count = 0;
Al Viro4cdfe842008-08-24 07:45:33 -0400239 if (unlikely(!m->count)) {
240 p = m->op->next(m, p, &pos);
241 m->index = pos;
242 continue;
243 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 if (m->count < m->size)
245 goto Fill;
246 m->op->stop(m, p);
Heiko Carstens058504e2014-07-02 15:22:37 -0700247 kvfree(m->buf);
Al Viro801a7602013-11-19 01:20:43 +0000248 m->count = 0;
Heiko Carstens058504e2014-07-02 15:22:37 -0700249 m->buf = seq_buf_alloc(m->size <<= 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 if (!m->buf)
251 goto Enomem;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 m->version = 0;
Al Viro4cdfe842008-08-24 07:45:33 -0400253 pos = m->index;
254 p = m->op->start(m, &pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700255 }
256 m->op->stop(m, p);
257 m->count = 0;
258 goto Done;
259Fill:
260 /* they want more? let's try to get some more */
261 while (m->count < size) {
262 size_t offs = m->count;
263 loff_t next = pos;
264 p = m->op->next(m, p, &next);
265 if (!p || IS_ERR(p)) {
266 err = PTR_ERR(p);
267 break;
268 }
269 err = m->op->show(m, p);
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700270 if (seq_overflow(m) || err) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271 m->count = offs;
Al Viro521b5d02008-03-28 00:46:41 -0400272 if (likely(err <= 0))
273 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274 }
275 pos = next;
276 }
277 m->op->stop(m, p);
278 n = min(m->count, size);
279 err = copy_to_user(buf, m->buf, n);
280 if (err)
281 goto Efault;
282 copied += n;
283 m->count -= n;
284 if (m->count)
285 m->from = n;
286 else
287 pos++;
288 m->index = pos;
289Done:
290 if (!copied)
291 copied = err;
Eric Biederman8f19d472009-02-18 14:48:16 -0800292 else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 *ppos += copied;
Eric Biederman8f19d472009-02-18 14:48:16 -0800294 m->read_pos += copied;
295 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296 file->f_version = m->version;
Ingo Molnar0ac17592006-03-23 03:00:37 -0800297 mutex_unlock(&m->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 return copied;
299Enomem:
300 err = -ENOMEM;
301 goto Done;
302Efault:
303 err = -EFAULT;
304 goto Done;
305}
306EXPORT_SYMBOL(seq_read);
307
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308/**
309 * seq_lseek - ->llseek() method for sequential files.
Martin Waitz67be2dd2005-05-01 08:59:26 -0700310 * @file: the file in question
311 * @offset: new position
Randy Dunlap254adaa2013-01-09 17:13:00 -0800312 * @whence: 0 for absolute, 1 for relative position
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 *
314 * Ready-made ->f_op->llseek()
315 */
Andrew Morton965c8e52012-12-17 15:59:39 -0800316loff_t seq_lseek(struct file *file, loff_t offset, int whence)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317{
Joe Perches8209e2f2010-09-04 18:52:49 -0700318 struct seq_file *m = file->private_data;
David Sterba16abef02008-04-22 15:09:22 +0200319 loff_t retval = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320
Ingo Molnar0ac17592006-03-23 03:00:37 -0800321 mutex_lock(&m->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 m->version = file->f_version;
Andrew Morton965c8e52012-12-17 15:59:39 -0800323 switch (whence) {
Andrew Morton5e62ade2013-02-27 17:03:22 -0800324 case SEEK_CUR:
325 offset += file->f_pos;
326 case SEEK_SET:
327 if (offset < 0)
328 break;
329 retval = offset;
330 if (offset != m->read_pos) {
331 while ((retval = traverse(m, offset)) == -EAGAIN)
332 ;
333 if (retval) {
334 /* with extreme prejudice... */
335 file->f_pos = 0;
336 m->read_pos = 0;
337 m->version = 0;
338 m->index = 0;
339 m->count = 0;
340 } else {
341 m->read_pos = offset;
342 retval = file->f_pos = offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 }
Gu Zheng05e16742013-10-25 18:15:06 +0800344 } else {
345 file->f_pos = offset;
Andrew Morton5e62ade2013-02-27 17:03:22 -0800346 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348 file->f_version = m->version;
Alexey Dobriyan00c57462007-07-15 23:40:22 -0700349 mutex_unlock(&m->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 return retval;
351}
352EXPORT_SYMBOL(seq_lseek);
353
354/**
355 * seq_release - free the structures associated with sequential file.
356 * @file: file in question
Al Viro6131ffa2013-02-27 16:59:05 -0500357 * @inode: its inode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 *
359 * Frees the structures associated with sequential file; can be used
360 * as ->f_op->release() if you don't have private data to destroy.
361 */
362int seq_release(struct inode *inode, struct file *file)
363{
Joe Perches8209e2f2010-09-04 18:52:49 -0700364 struct seq_file *m = file->private_data;
Heiko Carstens058504e2014-07-02 15:22:37 -0700365 kvfree(m->buf);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 kfree(m);
367 return 0;
368}
369EXPORT_SYMBOL(seq_release);
370
371/**
372 * seq_escape - print string into buffer, escaping some characters
373 * @m: target buffer
374 * @s: string
375 * @esc: set of characters that need escaping
376 *
377 * Puts string into buffer, replacing each occurrence of character from
378 * @esc with usual octal escape. Returns 0 in case of success, -1 - in
379 * case of overflow.
380 */
381int seq_escape(struct seq_file *m, const char *s, const char *esc)
382{
383 char *end = m->buf + m->size;
384 char *p;
385 char c;
386
387 for (p = m->buf + m->count; (c = *s) != '\0' && p < end; s++) {
388 if (!strchr(esc, c)) {
389 *p++ = c;
390 continue;
391 }
392 if (p + 3 < end) {
393 *p++ = '\\';
394 *p++ = '0' + ((c & 0300) >> 6);
395 *p++ = '0' + ((c & 070) >> 3);
396 *p++ = '0' + (c & 07);
397 continue;
398 }
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700399 seq_set_overflow(m);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 return -1;
401 }
402 m->count = p - m->buf;
403 return 0;
404}
405EXPORT_SYMBOL(seq_escape);
406
Steven Whitehousea4808142012-06-11 13:16:35 +0100407int seq_vprintf(struct seq_file *m, const char *f, va_list args)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700408{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 int len;
410
411 if (m->count < m->size) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700412 len = vsnprintf(m->buf + m->count, m->size - m->count, f, args);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700413 if (m->count + len < m->size) {
414 m->count += len;
415 return 0;
416 }
417 }
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700418 seq_set_overflow(m);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419 return -1;
420}
Steven Whitehousea4808142012-06-11 13:16:35 +0100421EXPORT_SYMBOL(seq_vprintf);
422
423int seq_printf(struct seq_file *m, const char *f, ...)
424{
425 int ret;
426 va_list args;
427
428 va_start(args, f);
429 ret = seq_vprintf(m, f, args);
430 va_end(args);
431
432 return ret;
433}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700434EXPORT_SYMBOL(seq_printf);
435
Török Edwin74e2f332008-11-22 13:28:48 +0200436/**
Török Edwin958086d2008-11-23 23:24:53 +0200437 * mangle_path - mangle and copy path to buffer beginning
438 * @s: buffer start
439 * @p: beginning of path in above buffer
440 * @esc: set of characters that need escaping
Török Edwin74e2f332008-11-22 13:28:48 +0200441 *
442 * Copy the path from @p to @s, replacing each occurrence of character from
443 * @esc with usual octal escape.
444 * Returns pointer past last written character in @s, or NULL in case of
445 * failure.
446 */
Al Viro8c9379e2011-12-08 20:18:57 -0500447char *mangle_path(char *s, const char *p, const char *esc)
Ram Pai6092d042008-03-27 13:06:20 +0100448{
449 while (s <= p) {
450 char c = *p++;
451 if (!c) {
452 return s;
453 } else if (!strchr(esc, c)) {
454 *s++ = c;
455 } else if (s + 4 > p) {
456 break;
457 } else {
458 *s++ = '\\';
459 *s++ = '0' + ((c & 0300) >> 6);
460 *s++ = '0' + ((c & 070) >> 3);
461 *s++ = '0' + (c & 07);
462 }
463 }
464 return NULL;
465}
Ingo Molnar604094f2008-11-28 18:03:22 +0100466EXPORT_SYMBOL(mangle_path);
Ram Pai6092d042008-03-27 13:06:20 +0100467
Arjan van de Ven52afeef2008-12-01 14:35:00 -0800468/**
469 * seq_path - seq_file interface to print a pathname
470 * @m: the seq_file handle
471 * @path: the struct path to print
472 * @esc: set of characters to escape in the output
473 *
474 * return the absolute path of 'path', as represented by the
475 * dentry / mnt pair in the path parameter.
Ram Pai6092d042008-03-27 13:06:20 +0100476 */
Al Viro8c9379e2011-12-08 20:18:57 -0500477int seq_path(struct seq_file *m, const struct path *path, const char *esc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478{
Miklos Szeredif8439802009-09-21 14:48:36 +0200479 char *buf;
480 size_t size = seq_get_buf(m, &buf);
481 int res = -1;
482
483 if (size) {
484 char *p = d_path(path, buf, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 if (!IS_ERR(p)) {
Miklos Szeredif8439802009-09-21 14:48:36 +0200486 char *end = mangle_path(buf, p, esc);
487 if (end)
488 res = end - buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700489 }
490 }
Miklos Szeredif8439802009-09-21 14:48:36 +0200491 seq_commit(m, res);
492
493 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700494}
495EXPORT_SYMBOL(seq_path);
496
Ram Pai6092d042008-03-27 13:06:20 +0100497/*
Miklos Szeredi9d1bc6012008-03-27 13:06:21 +0100498 * Same as seq_path, but relative to supplied root.
Miklos Szeredi9d1bc6012008-03-27 13:06:21 +0100499 */
Al Viro8c9379e2011-12-08 20:18:57 -0500500int seq_path_root(struct seq_file *m, const struct path *path,
501 const struct path *root, const char *esc)
Miklos Szeredi9d1bc6012008-03-27 13:06:21 +0100502{
Miklos Szeredif8439802009-09-21 14:48:36 +0200503 char *buf;
504 size_t size = seq_get_buf(m, &buf);
505 int res = -ENAMETOOLONG;
506
507 if (size) {
Miklos Szeredi9d1bc6012008-03-27 13:06:21 +0100508 char *p;
509
Miklos Szeredif8439802009-09-21 14:48:36 +0200510 p = __d_path(path, root, buf, size);
Al Viro02125a82011-12-05 08:43:34 -0500511 if (!p)
512 return SEQ_SKIP;
Miklos Szeredif8439802009-09-21 14:48:36 +0200513 res = PTR_ERR(p);
Miklos Szeredi9d1bc6012008-03-27 13:06:21 +0100514 if (!IS_ERR(p)) {
Miklos Szeredif8439802009-09-21 14:48:36 +0200515 char *end = mangle_path(buf, p, esc);
516 if (end)
517 res = end - buf;
518 else
519 res = -ENAMETOOLONG;
Miklos Szeredi9d1bc6012008-03-27 13:06:21 +0100520 }
521 }
Miklos Szeredif8439802009-09-21 14:48:36 +0200522 seq_commit(m, res);
523
Al Viro02125a82011-12-05 08:43:34 -0500524 return res < 0 && res != -ENAMETOOLONG ? res : 0;
Miklos Szeredi9d1bc6012008-03-27 13:06:21 +0100525}
526
527/*
Ram Pai6092d042008-03-27 13:06:20 +0100528 * returns the path of the 'dentry' from the root of its filesystem.
529 */
Al Viro8c9379e2011-12-08 20:18:57 -0500530int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc)
Ram Pai6092d042008-03-27 13:06:20 +0100531{
Miklos Szeredif8439802009-09-21 14:48:36 +0200532 char *buf;
533 size_t size = seq_get_buf(m, &buf);
534 int res = -1;
535
536 if (size) {
537 char *p = dentry_path(dentry, buf, size);
Ram Pai6092d042008-03-27 13:06:20 +0100538 if (!IS_ERR(p)) {
Miklos Szeredif8439802009-09-21 14:48:36 +0200539 char *end = mangle_path(buf, p, esc);
540 if (end)
541 res = end - buf;
Ram Pai6092d042008-03-27 13:06:20 +0100542 }
543 }
Miklos Szeredif8439802009-09-21 14:48:36 +0200544 seq_commit(m, res);
545
546 return res;
Ram Pai6092d042008-03-27 13:06:20 +0100547}
548
Rusty Russellcb78a0c2008-12-30 09:05:14 +1030549int seq_bitmap(struct seq_file *m, const unsigned long *bits,
550 unsigned int nr_bits)
Alexey Dobriyan50ac2d62008-08-12 15:09:02 -0700551{
Lai Jiangshan85dd0302008-10-18 20:28:18 -0700552 if (m->count < m->size) {
553 int len = bitmap_scnprintf(m->buf + m->count,
554 m->size - m->count, bits, nr_bits);
555 if (m->count + len < m->size) {
556 m->count += len;
557 return 0;
558 }
Alexey Dobriyan50ac2d62008-08-12 15:09:02 -0700559 }
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700560 seq_set_overflow(m);
Alexey Dobriyan50ac2d62008-08-12 15:09:02 -0700561 return -1;
562}
Lai Jiangshan85dd0302008-10-18 20:28:18 -0700563EXPORT_SYMBOL(seq_bitmap);
Alexey Dobriyan50ac2d62008-08-12 15:09:02 -0700564
Rusty Russellaf76aba2009-03-30 22:05:11 -0600565int seq_bitmap_list(struct seq_file *m, const unsigned long *bits,
Lai Jiangshan3eda2012008-10-18 20:28:19 -0700566 unsigned int nr_bits)
567{
568 if (m->count < m->size) {
569 int len = bitmap_scnlistprintf(m->buf + m->count,
570 m->size - m->count, bits, nr_bits);
571 if (m->count + len < m->size) {
572 m->count += len;
573 return 0;
574 }
575 }
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700576 seq_set_overflow(m);
Lai Jiangshan3eda2012008-10-18 20:28:19 -0700577 return -1;
578}
579EXPORT_SYMBOL(seq_bitmap_list);
580
Linus Torvalds1da177e2005-04-16 15:20:36 -0700581static void *single_start(struct seq_file *p, loff_t *pos)
582{
583 return NULL + (*pos == 0);
584}
585
586static void *single_next(struct seq_file *p, void *v, loff_t *pos)
587{
588 ++*pos;
589 return NULL;
590}
591
592static void single_stop(struct seq_file *p, void *v)
593{
594}
595
596int single_open(struct file *file, int (*show)(struct seq_file *, void *),
597 void *data)
598{
599 struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL);
600 int res = -ENOMEM;
601
602 if (op) {
603 op->start = single_start;
604 op->next = single_next;
605 op->stop = single_stop;
606 op->show = show;
607 res = seq_open(file, op);
608 if (!res)
609 ((struct seq_file *)file->private_data)->private = data;
610 else
611 kfree(op);
612 }
613 return res;
614}
615EXPORT_SYMBOL(single_open);
616
Al Viro2043f492013-03-31 13:43:23 -0400617int single_open_size(struct file *file, int (*show)(struct seq_file *, void *),
618 void *data, size_t size)
619{
Heiko Carstens058504e2014-07-02 15:22:37 -0700620 char *buf = seq_buf_alloc(size);
Al Viro2043f492013-03-31 13:43:23 -0400621 int ret;
622 if (!buf)
623 return -ENOMEM;
624 ret = single_open(file, show, data);
625 if (ret) {
Heiko Carstens058504e2014-07-02 15:22:37 -0700626 kvfree(buf);
Al Viro2043f492013-03-31 13:43:23 -0400627 return ret;
628 }
629 ((struct seq_file *)file->private_data)->buf = buf;
630 ((struct seq_file *)file->private_data)->size = size;
631 return 0;
632}
633EXPORT_SYMBOL(single_open_size);
634
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635int single_release(struct inode *inode, struct file *file)
636{
Helge Deller15ad7cd2006-12-06 20:40:36 -0800637 const struct seq_operations *op = ((struct seq_file *)file->private_data)->op;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 int res = seq_release(inode, file);
639 kfree(op);
640 return res;
641}
642EXPORT_SYMBOL(single_release);
643
644int seq_release_private(struct inode *inode, struct file *file)
645{
646 struct seq_file *seq = file->private_data;
647
648 kfree(seq->private);
649 seq->private = NULL;
650 return seq_release(inode, file);
651}
652EXPORT_SYMBOL(seq_release_private);
653
Pavel Emelyanov39699032007-10-10 02:28:42 -0700654void *__seq_open_private(struct file *f, const struct seq_operations *ops,
655 int psize)
656{
657 int rc;
658 void *private;
659 struct seq_file *seq;
660
661 private = kzalloc(psize, GFP_KERNEL);
662 if (private == NULL)
663 goto out;
664
665 rc = seq_open(f, ops);
666 if (rc < 0)
667 goto out_free;
668
669 seq = f->private_data;
670 seq->private = private;
671 return private;
672
673out_free:
674 kfree(private);
675out:
676 return NULL;
677}
678EXPORT_SYMBOL(__seq_open_private);
679
680int seq_open_private(struct file *filp, const struct seq_operations *ops,
681 int psize)
682{
683 return __seq_open_private(filp, ops, psize) ? 0 : -ENOMEM;
684}
685EXPORT_SYMBOL(seq_open_private);
686
Linus Torvalds1da177e2005-04-16 15:20:36 -0700687int seq_putc(struct seq_file *m, char c)
688{
689 if (m->count < m->size) {
690 m->buf[m->count++] = c;
691 return 0;
692 }
693 return -1;
694}
695EXPORT_SYMBOL(seq_putc);
696
697int seq_puts(struct seq_file *m, const char *s)
698{
699 int len = strlen(s);
700 if (m->count + len < m->size) {
701 memcpy(m->buf + m->count, s, len);
702 m->count += len;
703 return 0;
704 }
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700705 seq_set_overflow(m);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700706 return -1;
707}
708EXPORT_SYMBOL(seq_puts);
Pavel Emelianovbcf67e12007-07-10 17:22:26 -0700709
KAMEZAWA Hiroyuki1ac101a2012-03-23 15:02:54 -0700710/*
711 * A helper routine for putting decimal numbers without rich format of printf().
712 * only 'unsigned long long' is supported.
713 * This routine will put one byte delimiter + number into seq_file.
714 * This routine is very quick when you show lots of numbers.
715 * In usual cases, it will be better to use seq_printf(). It's easier to read.
716 */
717int seq_put_decimal_ull(struct seq_file *m, char delimiter,
718 unsigned long long num)
719{
720 int len;
721
722 if (m->count + 2 >= m->size) /* we'll write 2 bytes at least */
723 goto overflow;
724
KAMEZAWA Hiroyukibda7bad2012-03-23 15:02:54 -0700725 if (delimiter)
726 m->buf[m->count++] = delimiter;
KAMEZAWA Hiroyuki1ac101a2012-03-23 15:02:54 -0700727
728 if (num < 10) {
729 m->buf[m->count++] = num + '0';
730 return 0;
731 }
732
733 len = num_to_str(m->buf + m->count, m->size - m->count, num);
734 if (!len)
735 goto overflow;
736 m->count += len;
737 return 0;
738overflow:
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700739 seq_set_overflow(m);
KAMEZAWA Hiroyuki1ac101a2012-03-23 15:02:54 -0700740 return -1;
741}
742EXPORT_SYMBOL(seq_put_decimal_ull);
743
KAMEZAWA Hiroyukibda7bad2012-03-23 15:02:54 -0700744int seq_put_decimal_ll(struct seq_file *m, char delimiter,
745 long long num)
746{
747 if (num < 0) {
748 if (m->count + 3 >= m->size) {
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700749 seq_set_overflow(m);
KAMEZAWA Hiroyukibda7bad2012-03-23 15:02:54 -0700750 return -1;
751 }
752 if (delimiter)
753 m->buf[m->count++] = delimiter;
754 num = -num;
755 delimiter = '-';
756 }
757 return seq_put_decimal_ull(m, delimiter, num);
758
759}
760EXPORT_SYMBOL(seq_put_decimal_ll);
761
Peter Oberparleiter0b923602009-06-17 16:28:05 -0700762/**
763 * seq_write - write arbitrary data to buffer
764 * @seq: seq_file identifying the buffer to which data should be written
765 * @data: data address
766 * @len: number of bytes
767 *
768 * Return 0 on success, non-zero otherwise.
769 */
770int seq_write(struct seq_file *seq, const void *data, size_t len)
771{
772 if (seq->count + len < seq->size) {
773 memcpy(seq->buf + seq->count, data, len);
774 seq->count += len;
775 return 0;
776 }
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700777 seq_set_overflow(seq);
Peter Oberparleiter0b923602009-06-17 16:28:05 -0700778 return -1;
779}
780EXPORT_SYMBOL(seq_write);
781
Tetsuo Handa839cc2a2013-11-14 14:31:56 -0800782/**
783 * seq_pad - write padding spaces to buffer
784 * @m: seq_file identifying the buffer to which data should be written
785 * @c: the byte to append after padding if non-zero
786 */
787void seq_pad(struct seq_file *m, char c)
788{
789 int size = m->pad_until - m->count;
790 if (size > 0)
791 seq_printf(m, "%*s", size, "");
792 if (c)
793 seq_putc(m, c);
794}
795EXPORT_SYMBOL(seq_pad);
796
Pavel Emelianovbcf67e12007-07-10 17:22:26 -0700797struct list_head *seq_list_start(struct list_head *head, loff_t pos)
798{
799 struct list_head *lh;
800
801 list_for_each(lh, head)
802 if (pos-- == 0)
803 return lh;
804
805 return NULL;
806}
Pavel Emelianovbcf67e12007-07-10 17:22:26 -0700807EXPORT_SYMBOL(seq_list_start);
808
809struct list_head *seq_list_start_head(struct list_head *head, loff_t pos)
810{
811 if (!pos)
812 return head;
813
814 return seq_list_start(head, pos - 1);
815}
Pavel Emelianovbcf67e12007-07-10 17:22:26 -0700816EXPORT_SYMBOL(seq_list_start_head);
817
818struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos)
819{
820 struct list_head *lh;
821
822 lh = ((struct list_head *)v)->next;
823 ++*ppos;
824 return lh == head ? NULL : lh;
825}
Pavel Emelianovbcf67e12007-07-10 17:22:26 -0700826EXPORT_SYMBOL(seq_list_next);
Li Zefan66655de2010-02-08 23:18:22 +0000827
828/**
829 * seq_hlist_start - start an iteration of a hlist
830 * @head: the head of the hlist
831 * @pos: the start position of the sequence
832 *
833 * Called at seq_file->op->start().
834 */
835struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos)
836{
837 struct hlist_node *node;
838
839 hlist_for_each(node, head)
840 if (pos-- == 0)
841 return node;
842 return NULL;
843}
844EXPORT_SYMBOL(seq_hlist_start);
845
846/**
847 * seq_hlist_start_head - start an iteration of a hlist
848 * @head: the head of the hlist
849 * @pos: the start position of the sequence
850 *
851 * Called at seq_file->op->start(). Call this function if you want to
852 * print a header at the top of the output.
853 */
854struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos)
855{
856 if (!pos)
857 return SEQ_START_TOKEN;
858
859 return seq_hlist_start(head, pos - 1);
860}
861EXPORT_SYMBOL(seq_hlist_start_head);
862
863/**
864 * seq_hlist_next - move to the next position of the hlist
865 * @v: the current iterator
866 * @head: the head of the hlist
Randy Dunlap138860b2010-03-04 09:37:12 -0800867 * @ppos: the current position
Li Zefan66655de2010-02-08 23:18:22 +0000868 *
869 * Called at seq_file->op->next().
870 */
871struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
872 loff_t *ppos)
873{
874 struct hlist_node *node = v;
875
876 ++*ppos;
877 if (v == SEQ_START_TOKEN)
878 return head->first;
879 else
880 return node->next;
881}
882EXPORT_SYMBOL(seq_hlist_next);
stephen hemminger1cc52322010-02-22 07:57:17 +0000883
884/**
885 * seq_hlist_start_rcu - start an iteration of a hlist protected by RCU
886 * @head: the head of the hlist
887 * @pos: the start position of the sequence
888 *
889 * Called at seq_file->op->start().
890 *
891 * This list-traversal primitive may safely run concurrently with
892 * the _rcu list-mutation primitives such as hlist_add_head_rcu()
893 * as long as the traversal is guarded by rcu_read_lock().
894 */
895struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head,
896 loff_t pos)
897{
898 struct hlist_node *node;
899
900 __hlist_for_each_rcu(node, head)
901 if (pos-- == 0)
902 return node;
903 return NULL;
904}
905EXPORT_SYMBOL(seq_hlist_start_rcu);
906
907/**
908 * seq_hlist_start_head_rcu - start an iteration of a hlist protected by RCU
909 * @head: the head of the hlist
910 * @pos: the start position of the sequence
911 *
912 * Called at seq_file->op->start(). Call this function if you want to
913 * print a header at the top of the output.
914 *
915 * This list-traversal primitive may safely run concurrently with
916 * the _rcu list-mutation primitives such as hlist_add_head_rcu()
917 * as long as the traversal is guarded by rcu_read_lock().
918 */
919struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head,
920 loff_t pos)
921{
922 if (!pos)
923 return SEQ_START_TOKEN;
924
925 return seq_hlist_start_rcu(head, pos - 1);
926}
927EXPORT_SYMBOL(seq_hlist_start_head_rcu);
928
929/**
930 * seq_hlist_next_rcu - move to the next position of the hlist protected by RCU
931 * @v: the current iterator
932 * @head: the head of the hlist
Randy Dunlap138860b2010-03-04 09:37:12 -0800933 * @ppos: the current position
stephen hemminger1cc52322010-02-22 07:57:17 +0000934 *
935 * Called at seq_file->op->next().
936 *
937 * This list-traversal primitive may safely run concurrently with
938 * the _rcu list-mutation primitives such as hlist_add_head_rcu()
939 * as long as the traversal is guarded by rcu_read_lock().
940 */
941struct hlist_node *seq_hlist_next_rcu(void *v,
942 struct hlist_head *head,
943 loff_t *ppos)
944{
945 struct hlist_node *node = v;
946
947 ++*ppos;
948 if (v == SEQ_START_TOKEN)
949 return rcu_dereference(head->first);
950 else
951 return rcu_dereference(node->next);
952}
953EXPORT_SYMBOL(seq_hlist_next_rcu);
Jeff Layton0bc77382013-06-21 08:58:21 -0400954
955/**
956 * seq_hlist_start_precpu - start an iteration of a percpu hlist array
957 * @head: pointer to percpu array of struct hlist_heads
958 * @cpu: pointer to cpu "cursor"
959 * @pos: start position of sequence
960 *
961 * Called at seq_file->op->start().
962 */
963struct hlist_node *
964seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos)
965{
966 struct hlist_node *node;
967
968 for_each_possible_cpu(*cpu) {
969 hlist_for_each(node, per_cpu_ptr(head, *cpu)) {
970 if (pos-- == 0)
971 return node;
972 }
973 }
974 return NULL;
975}
976EXPORT_SYMBOL(seq_hlist_start_percpu);
977
978/**
979 * seq_hlist_next_percpu - move to the next position of the percpu hlist array
980 * @v: pointer to current hlist_node
981 * @head: pointer to percpu array of struct hlist_heads
982 * @cpu: pointer to cpu "cursor"
983 * @pos: start position of sequence
984 *
985 * Called at seq_file->op->next().
986 */
987struct hlist_node *
988seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head,
989 int *cpu, loff_t *pos)
990{
991 struct hlist_node *node = v;
992
993 ++*pos;
994
995 if (node->next)
996 return node->next;
997
998 for (*cpu = cpumask_next(*cpu, cpu_possible_mask); *cpu < nr_cpu_ids;
999 *cpu = cpumask_next(*cpu, cpu_possible_mask)) {
1000 struct hlist_head *bucket = per_cpu_ptr(head, *cpu);
1001
1002 if (!hlist_empty(bucket))
1003 return bucket->first;
1004 }
1005 return NULL;
1006}
1007EXPORT_SYMBOL(seq_hlist_next_percpu);