blob: 774c1eb7f1c926c73a7018ae47d9cfb03f75da76 [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>
11#include <linux/slab.h>
Eric W. Biedermanadb37c42012-05-23 18:01:20 -060012#include <linux/cred.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070013
14#include <asm/uaccess.h>
15#include <asm/page.h>
16
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -070017
18/*
19 * seq_files have a buffer which can may overflow. When this happens a larger
20 * buffer is reallocated and all the data will be printed again.
21 * The overflow state is true when m->count == m->size.
22 */
23static bool seq_overflow(struct seq_file *m)
24{
25 return m->count == m->size;
26}
27
28static void seq_set_overflow(struct seq_file *m)
29{
30 m->count = m->size;
31}
32
Linus Torvalds1da177e2005-04-16 15:20:36 -070033/**
34 * seq_open - initialize sequential file
35 * @file: file we initialize
36 * @op: method table describing the sequence
37 *
38 * seq_open() sets @file, associating it with a sequence described
39 * by @op. @op->start() sets the iterator up and returns the first
40 * element of sequence. @op->stop() shuts it down. @op->next()
41 * returns the next element of sequence. @op->show() prints element
42 * into the buffer. In case of error ->start() and ->next() return
43 * ERR_PTR(error). In the end of sequence they return %NULL. ->show()
44 * returns 0 in case of success and negative number in case of error.
Al Viro521b5d02008-03-28 00:46:41 -040045 * Returning SEQ_SKIP means "discard this element and move on".
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 */
Helge Deller15ad7cd2006-12-06 20:40:36 -080047int seq_open(struct file *file, const struct seq_operations *op)
Linus Torvalds1da177e2005-04-16 15:20:36 -070048{
Al Viro1abe77b2005-11-07 17:15:34 -050049 struct seq_file *p = file->private_data;
50
51 if (!p) {
52 p = kmalloc(sizeof(*p), GFP_KERNEL);
53 if (!p)
54 return -ENOMEM;
55 file->private_data = p;
56 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070057 memset(p, 0, sizeof(*p));
Ingo Molnar0ac17592006-03-23 03:00:37 -080058 mutex_init(&p->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 p->op = op;
Eric W. Biedermanadb37c42012-05-23 18:01:20 -060060#ifdef CONFIG_USER_NS
61 p->user_ns = file->f_cred->user_ns;
62#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
64 /*
65 * Wrappers around seq_open(e.g. swaps_open) need to be
66 * aware of this. If they set f_version themselves, they
67 * should call seq_open first and then set f_version.
68 */
69 file->f_version = 0;
70
Eric Biederman8f19d472009-02-18 14:48:16 -080071 /*
72 * seq_files support lseek() and pread(). They do not implement
73 * write() at all, but we clear FMODE_PWRITE here for historical
74 * reasons.
75 *
76 * If a client of seq_files a) implements file.write() and b) wishes to
77 * support pwrite() then that client will need to implement its own
78 * file.open() which calls seq_open() and then sets FMODE_PWRITE.
79 */
80 file->f_mode &= ~FMODE_PWRITE;
Linus Torvalds1da177e2005-04-16 15:20:36 -070081 return 0;
82}
83EXPORT_SYMBOL(seq_open);
84
Eric Biederman33da8892009-02-04 15:12:25 -080085static int traverse(struct seq_file *m, loff_t offset)
86{
87 loff_t pos = 0, index;
88 int error = 0;
89 void *p;
90
91 m->version = 0;
92 index = 0;
93 m->count = m->from = 0;
94 if (!offset) {
95 m->index = index;
96 return 0;
97 }
98 if (!m->buf) {
99 m->buf = kmalloc(m->size = PAGE_SIZE, GFP_KERNEL);
100 if (!m->buf)
101 return -ENOMEM;
102 }
103 p = m->op->start(m, &index);
104 while (p) {
105 error = PTR_ERR(p);
106 if (IS_ERR(p))
107 break;
108 error = m->op->show(m, p);
109 if (error < 0)
110 break;
111 if (unlikely(error)) {
112 error = 0;
113 m->count = 0;
114 }
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700115 if (seq_overflow(m))
Eric Biederman33da8892009-02-04 15:12:25 -0800116 goto Eoverflow;
117 if (pos + m->count > offset) {
118 m->from = offset - pos;
119 m->count -= m->from;
120 m->index = index;
121 break;
122 }
123 pos += m->count;
124 m->count = 0;
125 if (pos == offset) {
126 index++;
127 m->index = index;
128 break;
129 }
130 p = m->op->next(m, p, &index);
131 }
132 m->op->stop(m, p);
Alexey Dobriyanf01d1d52009-02-06 00:30:05 +0300133 m->index = index;
Eric Biederman33da8892009-02-04 15:12:25 -0800134 return error;
135
136Eoverflow:
137 m->op->stop(m, p);
138 kfree(m->buf);
139 m->buf = kmalloc(m->size <<= 1, GFP_KERNEL);
140 return !m->buf ? -ENOMEM : -EAGAIN;
141}
142
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143/**
144 * seq_read - ->read() method for sequential files.
Martin Waitz67be2dd2005-05-01 08:59:26 -0700145 * @file: the file to read from
146 * @buf: the buffer to read to
147 * @size: the maximum number of bytes to read
148 * @ppos: the current position in the file
Linus Torvalds1da177e2005-04-16 15:20:36 -0700149 *
150 * Ready-made ->f_op->read()
151 */
152ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos)
153{
Joe Perches8209e2f2010-09-04 18:52:49 -0700154 struct seq_file *m = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700155 size_t copied = 0;
156 loff_t pos;
157 size_t n;
158 void *p;
159 int err = 0;
160
Ingo Molnar0ac17592006-03-23 03:00:37 -0800161 mutex_lock(&m->lock);
Eric Biederman8f19d472009-02-18 14:48:16 -0800162
Linus Torvalds1da177e2005-04-16 15:20:36 -0700163 /*
164 * seq_file->op->..m_start/m_stop/m_next may do special actions
165 * or optimisations based on the file->f_version, so we want to
166 * pass the file->f_version to those methods.
167 *
168 * seq_file->version is just copy of f_version, and seq_file
169 * methods can treat it simply as file version.
170 * It is copied in first and copied out after all operations.
171 * It is convenient to have it as part of structure to avoid the
172 * need of passing another argument to all the seq_file methods.
173 */
174 m->version = file->f_version;
Earl Chew7904ac82012-03-21 16:33:43 -0700175
176 /* Don't assume *ppos is where we left it */
177 if (unlikely(*ppos != m->read_pos)) {
178 while ((err = traverse(m, *ppos)) == -EAGAIN)
179 ;
180 if (err) {
181 /* With prejudice... */
182 m->read_pos = 0;
183 m->version = 0;
184 m->index = 0;
185 m->count = 0;
186 goto Done;
187 } else {
188 m->read_pos = *ppos;
189 }
190 }
191
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 /* grab buffer if we didn't have one */
193 if (!m->buf) {
194 m->buf = kmalloc(m->size = PAGE_SIZE, GFP_KERNEL);
195 if (!m->buf)
196 goto Enomem;
197 }
198 /* if not empty - flush it first */
199 if (m->count) {
200 n = min(m->count, size);
201 err = copy_to_user(buf, m->buf + m->from, n);
202 if (err)
203 goto Efault;
204 m->count -= n;
205 m->from += n;
206 size -= n;
207 buf += n;
208 copied += n;
209 if (!m->count)
210 m->index++;
211 if (!size)
212 goto Done;
213 }
214 /* we need at least one record in buffer */
Al Viro4cdfe842008-08-24 07:45:33 -0400215 pos = m->index;
216 p = m->op->start(m, &pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217 while (1) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218 err = PTR_ERR(p);
219 if (!p || IS_ERR(p))
220 break;
221 err = m->op->show(m, p);
Al Viro521b5d02008-03-28 00:46:41 -0400222 if (err < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 break;
Al Viro521b5d02008-03-28 00:46:41 -0400224 if (unlikely(err))
225 m->count = 0;
Al Viro4cdfe842008-08-24 07:45:33 -0400226 if (unlikely(!m->count)) {
227 p = m->op->next(m, p, &pos);
228 m->index = pos;
229 continue;
230 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700231 if (m->count < m->size)
232 goto Fill;
233 m->op->stop(m, p);
234 kfree(m->buf);
235 m->buf = kmalloc(m->size <<= 1, GFP_KERNEL);
236 if (!m->buf)
237 goto Enomem;
238 m->count = 0;
239 m->version = 0;
Al Viro4cdfe842008-08-24 07:45:33 -0400240 pos = m->index;
241 p = m->op->start(m, &pos);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700242 }
243 m->op->stop(m, p);
244 m->count = 0;
245 goto Done;
246Fill:
247 /* they want more? let's try to get some more */
248 while (m->count < size) {
249 size_t offs = m->count;
250 loff_t next = pos;
251 p = m->op->next(m, p, &next);
252 if (!p || IS_ERR(p)) {
253 err = PTR_ERR(p);
254 break;
255 }
256 err = m->op->show(m, p);
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700257 if (seq_overflow(m) || err) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700258 m->count = offs;
Al Viro521b5d02008-03-28 00:46:41 -0400259 if (likely(err <= 0))
260 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 }
262 pos = next;
263 }
264 m->op->stop(m, p);
265 n = min(m->count, size);
266 err = copy_to_user(buf, m->buf, n);
267 if (err)
268 goto Efault;
269 copied += n;
270 m->count -= n;
271 if (m->count)
272 m->from = n;
273 else
274 pos++;
275 m->index = pos;
276Done:
277 if (!copied)
278 copied = err;
Eric Biederman8f19d472009-02-18 14:48:16 -0800279 else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 *ppos += copied;
Eric Biederman8f19d472009-02-18 14:48:16 -0800281 m->read_pos += copied;
282 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700283 file->f_version = m->version;
Ingo Molnar0ac17592006-03-23 03:00:37 -0800284 mutex_unlock(&m->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700285 return copied;
286Enomem:
287 err = -ENOMEM;
288 goto Done;
289Efault:
290 err = -EFAULT;
291 goto Done;
292}
293EXPORT_SYMBOL(seq_read);
294
Linus Torvalds1da177e2005-04-16 15:20:36 -0700295/**
296 * seq_lseek - ->llseek() method for sequential files.
Martin Waitz67be2dd2005-05-01 08:59:26 -0700297 * @file: the file in question
298 * @offset: new position
Randy Dunlap254adaa2013-01-09 17:13:00 -0800299 * @whence: 0 for absolute, 1 for relative position
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300 *
301 * Ready-made ->f_op->llseek()
302 */
Andrew Morton965c8e52012-12-17 15:59:39 -0800303loff_t seq_lseek(struct file *file, loff_t offset, int whence)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304{
Joe Perches8209e2f2010-09-04 18:52:49 -0700305 struct seq_file *m = file->private_data;
David Sterba16abef02008-04-22 15:09:22 +0200306 loff_t retval = -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307
Ingo Molnar0ac17592006-03-23 03:00:37 -0800308 mutex_lock(&m->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700309 m->version = file->f_version;
Andrew Morton965c8e52012-12-17 15:59:39 -0800310 switch (whence) {
Andrew Morton5e62ade2013-02-27 17:03:22 -0800311 case SEEK_CUR:
312 offset += file->f_pos;
313 case SEEK_SET:
314 if (offset < 0)
315 break;
316 retval = offset;
317 if (offset != m->read_pos) {
318 while ((retval = traverse(m, offset)) == -EAGAIN)
319 ;
320 if (retval) {
321 /* with extreme prejudice... */
322 file->f_pos = 0;
323 m->read_pos = 0;
324 m->version = 0;
325 m->index = 0;
326 m->count = 0;
327 } else {
328 m->read_pos = offset;
329 retval = file->f_pos = offset;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 }
Andrew Morton5e62ade2013-02-27 17:03:22 -0800331 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700332 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700333 file->f_version = m->version;
Alexey Dobriyan00c57462007-07-15 23:40:22 -0700334 mutex_unlock(&m->lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335 return retval;
336}
337EXPORT_SYMBOL(seq_lseek);
338
339/**
340 * seq_release - free the structures associated with sequential file.
341 * @file: file in question
Al Viro6131ffa2013-02-27 16:59:05 -0500342 * @inode: its inode
Linus Torvalds1da177e2005-04-16 15:20:36 -0700343 *
344 * Frees the structures associated with sequential file; can be used
345 * as ->f_op->release() if you don't have private data to destroy.
346 */
347int seq_release(struct inode *inode, struct file *file)
348{
Joe Perches8209e2f2010-09-04 18:52:49 -0700349 struct seq_file *m = file->private_data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700350 kfree(m->buf);
351 kfree(m);
352 return 0;
353}
354EXPORT_SYMBOL(seq_release);
355
356/**
357 * seq_escape - print string into buffer, escaping some characters
358 * @m: target buffer
359 * @s: string
360 * @esc: set of characters that need escaping
361 *
362 * Puts string into buffer, replacing each occurrence of character from
363 * @esc with usual octal escape. Returns 0 in case of success, -1 - in
364 * case of overflow.
365 */
366int seq_escape(struct seq_file *m, const char *s, const char *esc)
367{
368 char *end = m->buf + m->size;
369 char *p;
370 char c;
371
372 for (p = m->buf + m->count; (c = *s) != '\0' && p < end; s++) {
373 if (!strchr(esc, c)) {
374 *p++ = c;
375 continue;
376 }
377 if (p + 3 < end) {
378 *p++ = '\\';
379 *p++ = '0' + ((c & 0300) >> 6);
380 *p++ = '0' + ((c & 070) >> 3);
381 *p++ = '0' + (c & 07);
382 continue;
383 }
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700384 seq_set_overflow(m);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385 return -1;
386 }
387 m->count = p - m->buf;
388 return 0;
389}
390EXPORT_SYMBOL(seq_escape);
391
Steven Whitehousea4808142012-06-11 13:16:35 +0100392int seq_vprintf(struct seq_file *m, const char *f, va_list args)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700394 int len;
395
396 if (m->count < m->size) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700397 len = vsnprintf(m->buf + m->count, m->size - m->count, f, args);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398 if (m->count + len < m->size) {
399 m->count += len;
400 return 0;
401 }
402 }
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700403 seq_set_overflow(m);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404 return -1;
405}
Steven Whitehousea4808142012-06-11 13:16:35 +0100406EXPORT_SYMBOL(seq_vprintf);
407
408int seq_printf(struct seq_file *m, const char *f, ...)
409{
410 int ret;
411 va_list args;
412
413 va_start(args, f);
414 ret = seq_vprintf(m, f, args);
415 va_end(args);
416
417 return ret;
418}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419EXPORT_SYMBOL(seq_printf);
420
Török Edwin74e2f332008-11-22 13:28:48 +0200421/**
Török Edwin958086d2008-11-23 23:24:53 +0200422 * mangle_path - mangle and copy path to buffer beginning
423 * @s: buffer start
424 * @p: beginning of path in above buffer
425 * @esc: set of characters that need escaping
Török Edwin74e2f332008-11-22 13:28:48 +0200426 *
427 * Copy the path from @p to @s, replacing each occurrence of character from
428 * @esc with usual octal escape.
429 * Returns pointer past last written character in @s, or NULL in case of
430 * failure.
431 */
Al Viro8c9379e2011-12-08 20:18:57 -0500432char *mangle_path(char *s, const char *p, const char *esc)
Ram Pai6092d042008-03-27 13:06:20 +0100433{
434 while (s <= p) {
435 char c = *p++;
436 if (!c) {
437 return s;
438 } else if (!strchr(esc, c)) {
439 *s++ = c;
440 } else if (s + 4 > p) {
441 break;
442 } else {
443 *s++ = '\\';
444 *s++ = '0' + ((c & 0300) >> 6);
445 *s++ = '0' + ((c & 070) >> 3);
446 *s++ = '0' + (c & 07);
447 }
448 }
449 return NULL;
450}
Ingo Molnar604094f2008-11-28 18:03:22 +0100451EXPORT_SYMBOL(mangle_path);
Ram Pai6092d042008-03-27 13:06:20 +0100452
Arjan van de Ven52afeef2008-12-01 14:35:00 -0800453/**
454 * seq_path - seq_file interface to print a pathname
455 * @m: the seq_file handle
456 * @path: the struct path to print
457 * @esc: set of characters to escape in the output
458 *
459 * return the absolute path of 'path', as represented by the
460 * dentry / mnt pair in the path parameter.
Ram Pai6092d042008-03-27 13:06:20 +0100461 */
Al Viro8c9379e2011-12-08 20:18:57 -0500462int seq_path(struct seq_file *m, const struct path *path, const char *esc)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463{
Miklos Szeredif8439802009-09-21 14:48:36 +0200464 char *buf;
465 size_t size = seq_get_buf(m, &buf);
466 int res = -1;
467
468 if (size) {
469 char *p = d_path(path, buf, size);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 if (!IS_ERR(p)) {
Miklos Szeredif8439802009-09-21 14:48:36 +0200471 char *end = mangle_path(buf, p, esc);
472 if (end)
473 res = end - buf;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700474 }
475 }
Miklos Szeredif8439802009-09-21 14:48:36 +0200476 seq_commit(m, res);
477
478 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479}
480EXPORT_SYMBOL(seq_path);
481
Ram Pai6092d042008-03-27 13:06:20 +0100482/*
Miklos Szeredi9d1bc6012008-03-27 13:06:21 +0100483 * Same as seq_path, but relative to supplied root.
Miklos Szeredi9d1bc6012008-03-27 13:06:21 +0100484 */
Al Viro8c9379e2011-12-08 20:18:57 -0500485int seq_path_root(struct seq_file *m, const struct path *path,
486 const struct path *root, const char *esc)
Miklos Szeredi9d1bc6012008-03-27 13:06:21 +0100487{
Miklos Szeredif8439802009-09-21 14:48:36 +0200488 char *buf;
489 size_t size = seq_get_buf(m, &buf);
490 int res = -ENAMETOOLONG;
491
492 if (size) {
Miklos Szeredi9d1bc6012008-03-27 13:06:21 +0100493 char *p;
494
Miklos Szeredif8439802009-09-21 14:48:36 +0200495 p = __d_path(path, root, buf, size);
Al Viro02125a82011-12-05 08:43:34 -0500496 if (!p)
497 return SEQ_SKIP;
Miklos Szeredif8439802009-09-21 14:48:36 +0200498 res = PTR_ERR(p);
Miklos Szeredi9d1bc6012008-03-27 13:06:21 +0100499 if (!IS_ERR(p)) {
Miklos Szeredif8439802009-09-21 14:48:36 +0200500 char *end = mangle_path(buf, p, esc);
501 if (end)
502 res = end - buf;
503 else
504 res = -ENAMETOOLONG;
Miklos Szeredi9d1bc6012008-03-27 13:06:21 +0100505 }
506 }
Miklos Szeredif8439802009-09-21 14:48:36 +0200507 seq_commit(m, res);
508
Al Viro02125a82011-12-05 08:43:34 -0500509 return res < 0 && res != -ENAMETOOLONG ? res : 0;
Miklos Szeredi9d1bc6012008-03-27 13:06:21 +0100510}
511
512/*
Ram Pai6092d042008-03-27 13:06:20 +0100513 * returns the path of the 'dentry' from the root of its filesystem.
514 */
Al Viro8c9379e2011-12-08 20:18:57 -0500515int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc)
Ram Pai6092d042008-03-27 13:06:20 +0100516{
Miklos Szeredif8439802009-09-21 14:48:36 +0200517 char *buf;
518 size_t size = seq_get_buf(m, &buf);
519 int res = -1;
520
521 if (size) {
522 char *p = dentry_path(dentry, buf, size);
Ram Pai6092d042008-03-27 13:06:20 +0100523 if (!IS_ERR(p)) {
Miklos Szeredif8439802009-09-21 14:48:36 +0200524 char *end = mangle_path(buf, p, esc);
525 if (end)
526 res = end - buf;
Ram Pai6092d042008-03-27 13:06:20 +0100527 }
528 }
Miklos Szeredif8439802009-09-21 14:48:36 +0200529 seq_commit(m, res);
530
531 return res;
Ram Pai6092d042008-03-27 13:06:20 +0100532}
533
Rusty Russellcb78a0c2008-12-30 09:05:14 +1030534int seq_bitmap(struct seq_file *m, const unsigned long *bits,
535 unsigned int nr_bits)
Alexey Dobriyan50ac2d62008-08-12 15:09:02 -0700536{
Lai Jiangshan85dd0302008-10-18 20:28:18 -0700537 if (m->count < m->size) {
538 int len = bitmap_scnprintf(m->buf + m->count,
539 m->size - m->count, bits, nr_bits);
540 if (m->count + len < m->size) {
541 m->count += len;
542 return 0;
543 }
Alexey Dobriyan50ac2d62008-08-12 15:09:02 -0700544 }
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700545 seq_set_overflow(m);
Alexey Dobriyan50ac2d62008-08-12 15:09:02 -0700546 return -1;
547}
Lai Jiangshan85dd0302008-10-18 20:28:18 -0700548EXPORT_SYMBOL(seq_bitmap);
Alexey Dobriyan50ac2d62008-08-12 15:09:02 -0700549
Rusty Russellaf76aba2009-03-30 22:05:11 -0600550int seq_bitmap_list(struct seq_file *m, const unsigned long *bits,
Lai Jiangshan3eda2012008-10-18 20:28:19 -0700551 unsigned int nr_bits)
552{
553 if (m->count < m->size) {
554 int len = bitmap_scnlistprintf(m->buf + m->count,
555 m->size - m->count, bits, nr_bits);
556 if (m->count + len < m->size) {
557 m->count += len;
558 return 0;
559 }
560 }
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700561 seq_set_overflow(m);
Lai Jiangshan3eda2012008-10-18 20:28:19 -0700562 return -1;
563}
564EXPORT_SYMBOL(seq_bitmap_list);
565
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566static void *single_start(struct seq_file *p, loff_t *pos)
567{
568 return NULL + (*pos == 0);
569}
570
571static void *single_next(struct seq_file *p, void *v, loff_t *pos)
572{
573 ++*pos;
574 return NULL;
575}
576
577static void single_stop(struct seq_file *p, void *v)
578{
579}
580
581int single_open(struct file *file, int (*show)(struct seq_file *, void *),
582 void *data)
583{
584 struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL);
585 int res = -ENOMEM;
586
587 if (op) {
588 op->start = single_start;
589 op->next = single_next;
590 op->stop = single_stop;
591 op->show = show;
592 res = seq_open(file, op);
593 if (!res)
594 ((struct seq_file *)file->private_data)->private = data;
595 else
596 kfree(op);
597 }
598 return res;
599}
600EXPORT_SYMBOL(single_open);
601
Al Viro2043f492013-03-31 13:43:23 -0400602int single_open_size(struct file *file, int (*show)(struct seq_file *, void *),
603 void *data, size_t size)
604{
605 char *buf = kmalloc(size, GFP_KERNEL);
606 int ret;
607 if (!buf)
608 return -ENOMEM;
609 ret = single_open(file, show, data);
610 if (ret) {
611 kfree(buf);
612 return ret;
613 }
614 ((struct seq_file *)file->private_data)->buf = buf;
615 ((struct seq_file *)file->private_data)->size = size;
616 return 0;
617}
618EXPORT_SYMBOL(single_open_size);
619
Linus Torvalds1da177e2005-04-16 15:20:36 -0700620int single_release(struct inode *inode, struct file *file)
621{
Helge Deller15ad7cd2006-12-06 20:40:36 -0800622 const struct seq_operations *op = ((struct seq_file *)file->private_data)->op;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700623 int res = seq_release(inode, file);
624 kfree(op);
625 return res;
626}
627EXPORT_SYMBOL(single_release);
628
629int seq_release_private(struct inode *inode, struct file *file)
630{
631 struct seq_file *seq = file->private_data;
632
633 kfree(seq->private);
634 seq->private = NULL;
635 return seq_release(inode, file);
636}
637EXPORT_SYMBOL(seq_release_private);
638
Pavel Emelyanov39699032007-10-10 02:28:42 -0700639void *__seq_open_private(struct file *f, const struct seq_operations *ops,
640 int psize)
641{
642 int rc;
643 void *private;
644 struct seq_file *seq;
645
646 private = kzalloc(psize, GFP_KERNEL);
647 if (private == NULL)
648 goto out;
649
650 rc = seq_open(f, ops);
651 if (rc < 0)
652 goto out_free;
653
654 seq = f->private_data;
655 seq->private = private;
656 return private;
657
658out_free:
659 kfree(private);
660out:
661 return NULL;
662}
663EXPORT_SYMBOL(__seq_open_private);
664
665int seq_open_private(struct file *filp, const struct seq_operations *ops,
666 int psize)
667{
668 return __seq_open_private(filp, ops, psize) ? 0 : -ENOMEM;
669}
670EXPORT_SYMBOL(seq_open_private);
671
Linus Torvalds1da177e2005-04-16 15:20:36 -0700672int seq_putc(struct seq_file *m, char c)
673{
674 if (m->count < m->size) {
675 m->buf[m->count++] = c;
676 return 0;
677 }
678 return -1;
679}
680EXPORT_SYMBOL(seq_putc);
681
682int seq_puts(struct seq_file *m, const char *s)
683{
684 int len = strlen(s);
685 if (m->count + len < m->size) {
686 memcpy(m->buf + m->count, s, len);
687 m->count += len;
688 return 0;
689 }
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700690 seq_set_overflow(m);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700691 return -1;
692}
693EXPORT_SYMBOL(seq_puts);
Pavel Emelianovbcf67e12007-07-10 17:22:26 -0700694
KAMEZAWA Hiroyuki1ac101a2012-03-23 15:02:54 -0700695/*
696 * A helper routine for putting decimal numbers without rich format of printf().
697 * only 'unsigned long long' is supported.
698 * This routine will put one byte delimiter + number into seq_file.
699 * This routine is very quick when you show lots of numbers.
700 * In usual cases, it will be better to use seq_printf(). It's easier to read.
701 */
702int seq_put_decimal_ull(struct seq_file *m, char delimiter,
703 unsigned long long num)
704{
705 int len;
706
707 if (m->count + 2 >= m->size) /* we'll write 2 bytes at least */
708 goto overflow;
709
KAMEZAWA Hiroyukibda7bad2012-03-23 15:02:54 -0700710 if (delimiter)
711 m->buf[m->count++] = delimiter;
KAMEZAWA Hiroyuki1ac101a2012-03-23 15:02:54 -0700712
713 if (num < 10) {
714 m->buf[m->count++] = num + '0';
715 return 0;
716 }
717
718 len = num_to_str(m->buf + m->count, m->size - m->count, num);
719 if (!len)
720 goto overflow;
721 m->count += len;
722 return 0;
723overflow:
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700724 seq_set_overflow(m);
KAMEZAWA Hiroyuki1ac101a2012-03-23 15:02:54 -0700725 return -1;
726}
727EXPORT_SYMBOL(seq_put_decimal_ull);
728
KAMEZAWA Hiroyukibda7bad2012-03-23 15:02:54 -0700729int seq_put_decimal_ll(struct seq_file *m, char delimiter,
730 long long num)
731{
732 if (num < 0) {
733 if (m->count + 3 >= m->size) {
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700734 seq_set_overflow(m);
KAMEZAWA Hiroyukibda7bad2012-03-23 15:02:54 -0700735 return -1;
736 }
737 if (delimiter)
738 m->buf[m->count++] = delimiter;
739 num = -num;
740 delimiter = '-';
741 }
742 return seq_put_decimal_ull(m, delimiter, num);
743
744}
745EXPORT_SYMBOL(seq_put_decimal_ll);
746
Peter Oberparleiter0b923602009-06-17 16:28:05 -0700747/**
748 * seq_write - write arbitrary data to buffer
749 * @seq: seq_file identifying the buffer to which data should be written
750 * @data: data address
751 * @len: number of bytes
752 *
753 * Return 0 on success, non-zero otherwise.
754 */
755int seq_write(struct seq_file *seq, const void *data, size_t len)
756{
757 if (seq->count + len < seq->size) {
758 memcpy(seq->buf + seq->count, data, len);
759 seq->count += len;
760 return 0;
761 }
KAMEZAWA Hiroyukie075f592012-03-23 15:02:55 -0700762 seq_set_overflow(seq);
Peter Oberparleiter0b923602009-06-17 16:28:05 -0700763 return -1;
764}
765EXPORT_SYMBOL(seq_write);
766
Pavel Emelianovbcf67e12007-07-10 17:22:26 -0700767struct list_head *seq_list_start(struct list_head *head, loff_t pos)
768{
769 struct list_head *lh;
770
771 list_for_each(lh, head)
772 if (pos-- == 0)
773 return lh;
774
775 return NULL;
776}
Pavel Emelianovbcf67e12007-07-10 17:22:26 -0700777EXPORT_SYMBOL(seq_list_start);
778
779struct list_head *seq_list_start_head(struct list_head *head, loff_t pos)
780{
781 if (!pos)
782 return head;
783
784 return seq_list_start(head, pos - 1);
785}
Pavel Emelianovbcf67e12007-07-10 17:22:26 -0700786EXPORT_SYMBOL(seq_list_start_head);
787
788struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos)
789{
790 struct list_head *lh;
791
792 lh = ((struct list_head *)v)->next;
793 ++*ppos;
794 return lh == head ? NULL : lh;
795}
Pavel Emelianovbcf67e12007-07-10 17:22:26 -0700796EXPORT_SYMBOL(seq_list_next);
Li Zefan66655de2010-02-08 23:18:22 +0000797
798/**
799 * seq_hlist_start - start an iteration of a hlist
800 * @head: the head of the hlist
801 * @pos: the start position of the sequence
802 *
803 * Called at seq_file->op->start().
804 */
805struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos)
806{
807 struct hlist_node *node;
808
809 hlist_for_each(node, head)
810 if (pos-- == 0)
811 return node;
812 return NULL;
813}
814EXPORT_SYMBOL(seq_hlist_start);
815
816/**
817 * seq_hlist_start_head - start an iteration of a hlist
818 * @head: the head of the hlist
819 * @pos: the start position of the sequence
820 *
821 * Called at seq_file->op->start(). Call this function if you want to
822 * print a header at the top of the output.
823 */
824struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos)
825{
826 if (!pos)
827 return SEQ_START_TOKEN;
828
829 return seq_hlist_start(head, pos - 1);
830}
831EXPORT_SYMBOL(seq_hlist_start_head);
832
833/**
834 * seq_hlist_next - move to the next position of the hlist
835 * @v: the current iterator
836 * @head: the head of the hlist
Randy Dunlap138860b2010-03-04 09:37:12 -0800837 * @ppos: the current position
Li Zefan66655de2010-02-08 23:18:22 +0000838 *
839 * Called at seq_file->op->next().
840 */
841struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head,
842 loff_t *ppos)
843{
844 struct hlist_node *node = v;
845
846 ++*ppos;
847 if (v == SEQ_START_TOKEN)
848 return head->first;
849 else
850 return node->next;
851}
852EXPORT_SYMBOL(seq_hlist_next);
stephen hemminger1cc52322010-02-22 07:57:17 +0000853
854/**
855 * seq_hlist_start_rcu - start an iteration of a hlist protected by RCU
856 * @head: the head of the hlist
857 * @pos: the start position of the sequence
858 *
859 * Called at seq_file->op->start().
860 *
861 * This list-traversal primitive may safely run concurrently with
862 * the _rcu list-mutation primitives such as hlist_add_head_rcu()
863 * as long as the traversal is guarded by rcu_read_lock().
864 */
865struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head,
866 loff_t pos)
867{
868 struct hlist_node *node;
869
870 __hlist_for_each_rcu(node, head)
871 if (pos-- == 0)
872 return node;
873 return NULL;
874}
875EXPORT_SYMBOL(seq_hlist_start_rcu);
876
877/**
878 * seq_hlist_start_head_rcu - start an iteration of a hlist protected by RCU
879 * @head: the head of the hlist
880 * @pos: the start position of the sequence
881 *
882 * Called at seq_file->op->start(). Call this function if you want to
883 * print a header at the top of the output.
884 *
885 * This list-traversal primitive may safely run concurrently with
886 * the _rcu list-mutation primitives such as hlist_add_head_rcu()
887 * as long as the traversal is guarded by rcu_read_lock().
888 */
889struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head,
890 loff_t pos)
891{
892 if (!pos)
893 return SEQ_START_TOKEN;
894
895 return seq_hlist_start_rcu(head, pos - 1);
896}
897EXPORT_SYMBOL(seq_hlist_start_head_rcu);
898
899/**
900 * seq_hlist_next_rcu - move to the next position of the hlist protected by RCU
901 * @v: the current iterator
902 * @head: the head of the hlist
Randy Dunlap138860b2010-03-04 09:37:12 -0800903 * @ppos: the current position
stephen hemminger1cc52322010-02-22 07:57:17 +0000904 *
905 * Called at seq_file->op->next().
906 *
907 * This list-traversal primitive may safely run concurrently with
908 * the _rcu list-mutation primitives such as hlist_add_head_rcu()
909 * as long as the traversal is guarded by rcu_read_lock().
910 */
911struct hlist_node *seq_hlist_next_rcu(void *v,
912 struct hlist_head *head,
913 loff_t *ppos)
914{
915 struct hlist_node *node = v;
916
917 ++*ppos;
918 if (v == SEQ_START_TOKEN)
919 return rcu_dereference(head->first);
920 else
921 return rcu_dereference(node->next);
922}
923EXPORT_SYMBOL(seq_hlist_next_rcu);