Commit | Line | Data |
---|---|---|
1da177e4 LT |
1 | /* |
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> | |
630d9c47 | 9 | #include <linux/export.h> |
1da177e4 LT |
10 | #include <linux/seq_file.h> |
11 | #include <linux/slab.h> | |
adb37c4c | 12 | #include <linux/cred.h> |
1da177e4 LT |
13 | |
14 | #include <asm/uaccess.h> | |
15 | #include <asm/page.h> | |
16 | ||
e075f591 KH |
17 | |
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 | */ | |
23 | static bool seq_overflow(struct seq_file *m) | |
24 | { | |
25 | return m->count == m->size; | |
26 | } | |
27 | ||
28 | static void seq_set_overflow(struct seq_file *m) | |
29 | { | |
30 | m->count = m->size; | |
31 | } | |
32 | ||
1da177e4 LT |
33 | /** |
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. | |
521b5d0c | 45 | * Returning SEQ_SKIP means "discard this element and move on". |
1da177e4 | 46 | */ |
15ad7cdc | 47 | int seq_open(struct file *file, const struct seq_operations *op) |
1da177e4 | 48 | { |
1abe77b0 AV |
49 | 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 | } | |
1da177e4 | 57 | memset(p, 0, sizeof(*p)); |
0ac1759a | 58 | mutex_init(&p->lock); |
1da177e4 | 59 | p->op = op; |
adb37c4c EB |
60 | #ifdef CONFIG_USER_NS |
61 | p->user_ns = file->f_cred->user_ns; | |
62 | #endif | |
1da177e4 LT |
63 | |
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 | ||
8f19d472 EB |
71 | /* |
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; | |
1da177e4 LT |
81 | return 0; |
82 | } | |
83 | EXPORT_SYMBOL(seq_open); | |
84 | ||
33da8892 EB |
85 | static 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 | } | |
e075f591 | 115 | if (seq_overflow(m)) |
33da8892 EB |
116 | 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); | |
f01d1d54 | 133 | m->index = index; |
33da8892 EB |
134 | return error; |
135 | ||
136 | Eoverflow: | |
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 | ||
1da177e4 LT |
143 | /** |
144 | * seq_read - ->read() method for sequential files. | |
67be2dd1 MW |
145 | * @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 | |
1da177e4 LT |
149 | * |
150 | * Ready-made ->f_op->read() | |
151 | */ | |
152 | ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) | |
153 | { | |
8209e2f4 | 154 | struct seq_file *m = file->private_data; |
1da177e4 LT |
155 | size_t copied = 0; |
156 | loff_t pos; | |
157 | size_t n; | |
158 | void *p; | |
159 | int err = 0; | |
160 | ||
0ac1759a | 161 | mutex_lock(&m->lock); |
8f19d472 | 162 | |
7904ac84 EC |
163 | /* |
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; | |
175 | ||
8f19d472 EB |
176 | /* Don't assume *ppos is where we left it */ |
177 | if (unlikely(*ppos != m->read_pos)) { | |
8f19d472 EB |
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; | |
7904ac84 EC |
187 | } else { |
188 | m->read_pos = *ppos; | |
8f19d472 EB |
189 | } |
190 | } | |
191 | ||
1da177e4 LT |
192 | /* 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; | |
3c15d166 VN |
209 | if (!m->count) { |
210 | m->from = 0; | |
1da177e4 | 211 | m->index++; |
3c15d166 | 212 | } |
1da177e4 LT |
213 | if (!size) |
214 | goto Done; | |
215 | } | |
216 | /* we need at least one record in buffer */ | |
4cdfe84b AV |
217 | pos = m->index; |
218 | p = m->op->start(m, &pos); | |
1da177e4 | 219 | while (1) { |
1da177e4 LT |
220 | err = PTR_ERR(p); |
221 | if (!p || IS_ERR(p)) | |
222 | break; | |
223 | err = m->op->show(m, p); | |
521b5d0c | 224 | if (err < 0) |
1da177e4 | 225 | break; |
521b5d0c AV |
226 | if (unlikely(err)) |
227 | m->count = 0; | |
4cdfe84b AV |
228 | if (unlikely(!m->count)) { |
229 | p = m->op->next(m, p, &pos); | |
230 | m->index = pos; | |
231 | continue; | |
232 | } | |
1da177e4 LT |
233 | if (m->count < m->size) |
234 | goto Fill; | |
235 | m->op->stop(m, p); | |
236 | kfree(m->buf); | |
237 | m->buf = kmalloc(m->size <<= 1, GFP_KERNEL); | |
238 | if (!m->buf) | |
239 | goto Enomem; | |
240 | m->count = 0; | |
241 | m->version = 0; | |
4cdfe84b AV |
242 | pos = m->index; |
243 | p = m->op->start(m, &pos); | |
1da177e4 LT |
244 | } |
245 | m->op->stop(m, p); | |
246 | m->count = 0; | |
247 | goto Done; | |
248 | Fill: | |
249 | /* they want more? let's try to get some more */ | |
250 | while (m->count < size) { | |
251 | size_t offs = m->count; | |
252 | loff_t next = pos; | |
253 | p = m->op->next(m, p, &next); | |
254 | if (!p || IS_ERR(p)) { | |
255 | err = PTR_ERR(p); | |
256 | break; | |
257 | } | |
258 | err = m->op->show(m, p); | |
e075f591 | 259 | if (seq_overflow(m) || err) { |
1da177e4 | 260 | m->count = offs; |
521b5d0c AV |
261 | if (likely(err <= 0)) |
262 | break; | |
1da177e4 LT |
263 | } |
264 | pos = next; | |
265 | } | |
266 | m->op->stop(m, p); | |
267 | n = min(m->count, size); | |
268 | err = copy_to_user(buf, m->buf, n); | |
269 | if (err) | |
270 | goto Efault; | |
271 | copied += n; | |
272 | m->count -= n; | |
273 | if (m->count) | |
274 | m->from = n; | |
275 | else | |
276 | pos++; | |
277 | m->index = pos; | |
278 | Done: | |
279 | if (!copied) | |
280 | copied = err; | |
8f19d472 | 281 | else { |
1da177e4 | 282 | *ppos += copied; |
8f19d472 EB |
283 | m->read_pos += copied; |
284 | } | |
1da177e4 | 285 | file->f_version = m->version; |
0ac1759a | 286 | mutex_unlock(&m->lock); |
1da177e4 LT |
287 | return copied; |
288 | Enomem: | |
289 | err = -ENOMEM; | |
290 | goto Done; | |
291 | Efault: | |
292 | err = -EFAULT; | |
293 | goto Done; | |
294 | } | |
295 | EXPORT_SYMBOL(seq_read); | |
296 | ||
1da177e4 LT |
297 | /** |
298 | * seq_lseek - ->llseek() method for sequential files. | |
67be2dd1 MW |
299 | * @file: the file in question |
300 | * @offset: new position | |
254adaa4 | 301 | * @whence: 0 for absolute, 1 for relative position |
1da177e4 LT |
302 | * |
303 | * Ready-made ->f_op->llseek() | |
304 | */ | |
965c8e59 | 305 | loff_t seq_lseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 306 | { |
8209e2f4 | 307 | struct seq_file *m = file->private_data; |
16abef0e | 308 | loff_t retval = -EINVAL; |
1da177e4 | 309 | |
0ac1759a | 310 | mutex_lock(&m->lock); |
1da177e4 | 311 | m->version = file->f_version; |
965c8e59 | 312 | switch (whence) { |
5e62adef AM |
313 | case SEEK_CUR: |
314 | offset += file->f_pos; | |
315 | case SEEK_SET: | |
316 | if (offset < 0) | |
317 | break; | |
318 | retval = offset; | |
319 | if (offset != m->read_pos) { | |
320 | while ((retval = traverse(m, offset)) == -EAGAIN) | |
321 | ; | |
322 | if (retval) { | |
323 | /* with extreme prejudice... */ | |
324 | file->f_pos = 0; | |
325 | m->read_pos = 0; | |
326 | m->version = 0; | |
327 | m->index = 0; | |
328 | m->count = 0; | |
329 | } else { | |
330 | m->read_pos = offset; | |
331 | retval = file->f_pos = offset; | |
1da177e4 | 332 | } |
dad483b7 GZ |
333 | } else { |
334 | file->f_pos = offset; | |
5e62adef | 335 | } |
1da177e4 | 336 | } |
1da177e4 | 337 | file->f_version = m->version; |
00c5746d | 338 | mutex_unlock(&m->lock); |
1da177e4 LT |
339 | return retval; |
340 | } | |
341 | EXPORT_SYMBOL(seq_lseek); | |
342 | ||
343 | /** | |
344 | * seq_release - free the structures associated with sequential file. | |
345 | * @file: file in question | |
6131ffaa | 346 | * @inode: its inode |
1da177e4 LT |
347 | * |
348 | * Frees the structures associated with sequential file; can be used | |
349 | * as ->f_op->release() if you don't have private data to destroy. | |
350 | */ | |
351 | int seq_release(struct inode *inode, struct file *file) | |
352 | { | |
8209e2f4 | 353 | struct seq_file *m = file->private_data; |
1da177e4 LT |
354 | kfree(m->buf); |
355 | kfree(m); | |
356 | return 0; | |
357 | } | |
358 | EXPORT_SYMBOL(seq_release); | |
359 | ||
360 | /** | |
361 | * seq_escape - print string into buffer, escaping some characters | |
362 | * @m: target buffer | |
363 | * @s: string | |
364 | * @esc: set of characters that need escaping | |
365 | * | |
366 | * Puts string into buffer, replacing each occurrence of character from | |
367 | * @esc with usual octal escape. Returns 0 in case of success, -1 - in | |
368 | * case of overflow. | |
369 | */ | |
370 | int seq_escape(struct seq_file *m, const char *s, const char *esc) | |
371 | { | |
372 | char *end = m->buf + m->size; | |
373 | char *p; | |
374 | char c; | |
375 | ||
376 | for (p = m->buf + m->count; (c = *s) != '\0' && p < end; s++) { | |
377 | if (!strchr(esc, c)) { | |
378 | *p++ = c; | |
379 | continue; | |
380 | } | |
381 | if (p + 3 < end) { | |
382 | *p++ = '\\'; | |
383 | *p++ = '0' + ((c & 0300) >> 6); | |
384 | *p++ = '0' + ((c & 070) >> 3); | |
385 | *p++ = '0' + (c & 07); | |
386 | continue; | |
387 | } | |
e075f591 | 388 | seq_set_overflow(m); |
1da177e4 LT |
389 | return -1; |
390 | } | |
391 | m->count = p - m->buf; | |
392 | return 0; | |
393 | } | |
394 | EXPORT_SYMBOL(seq_escape); | |
395 | ||
a4808147 | 396 | int seq_vprintf(struct seq_file *m, const char *f, va_list args) |
1da177e4 | 397 | { |
1da177e4 LT |
398 | int len; |
399 | ||
400 | if (m->count < m->size) { | |
1da177e4 | 401 | len = vsnprintf(m->buf + m->count, m->size - m->count, f, args); |
1da177e4 LT |
402 | if (m->count + len < m->size) { |
403 | m->count += len; | |
404 | return 0; | |
405 | } | |
406 | } | |
e075f591 | 407 | seq_set_overflow(m); |
1da177e4 LT |
408 | return -1; |
409 | } | |
a4808147 SW |
410 | EXPORT_SYMBOL(seq_vprintf); |
411 | ||
412 | int seq_printf(struct seq_file *m, const char *f, ...) | |
413 | { | |
414 | int ret; | |
415 | va_list args; | |
416 | ||
417 | va_start(args, f); | |
418 | ret = seq_vprintf(m, f, args); | |
419 | va_end(args); | |
420 | ||
421 | return ret; | |
422 | } | |
1da177e4 LT |
423 | EXPORT_SYMBOL(seq_printf); |
424 | ||
74e2f334 | 425 | /** |
958086d1 TE |
426 | * mangle_path - mangle and copy path to buffer beginning |
427 | * @s: buffer start | |
428 | * @p: beginning of path in above buffer | |
429 | * @esc: set of characters that need escaping | |
74e2f334 TE |
430 | * |
431 | * Copy the path from @p to @s, replacing each occurrence of character from | |
432 | * @esc with usual octal escape. | |
433 | * Returns pointer past last written character in @s, or NULL in case of | |
434 | * failure. | |
435 | */ | |
8c9379e9 | 436 | char *mangle_path(char *s, const char *p, const char *esc) |
6092d048 RP |
437 | { |
438 | while (s <= p) { | |
439 | char c = *p++; | |
440 | if (!c) { | |
441 | return s; | |
442 | } else if (!strchr(esc, c)) { | |
443 | *s++ = c; | |
444 | } else if (s + 4 > p) { | |
445 | break; | |
446 | } else { | |
447 | *s++ = '\\'; | |
448 | *s++ = '0' + ((c & 0300) >> 6); | |
449 | *s++ = '0' + ((c & 070) >> 3); | |
450 | *s++ = '0' + (c & 07); | |
451 | } | |
452 | } | |
453 | return NULL; | |
454 | } | |
604094f4 | 455 | EXPORT_SYMBOL(mangle_path); |
6092d048 | 456 | |
52afeefb AV |
457 | /** |
458 | * seq_path - seq_file interface to print a pathname | |
459 | * @m: the seq_file handle | |
460 | * @path: the struct path to print | |
461 | * @esc: set of characters to escape in the output | |
462 | * | |
463 | * return the absolute path of 'path', as represented by the | |
464 | * dentry / mnt pair in the path parameter. | |
6092d048 | 465 | */ |
8c9379e9 | 466 | int seq_path(struct seq_file *m, const struct path *path, const char *esc) |
1da177e4 | 467 | { |
f8439806 MS |
468 | char *buf; |
469 | size_t size = seq_get_buf(m, &buf); | |
470 | int res = -1; | |
471 | ||
472 | if (size) { | |
473 | char *p = d_path(path, buf, size); | |
1da177e4 | 474 | if (!IS_ERR(p)) { |
f8439806 MS |
475 | char *end = mangle_path(buf, p, esc); |
476 | if (end) | |
477 | res = end - buf; | |
1da177e4 LT |
478 | } |
479 | } | |
f8439806 MS |
480 | seq_commit(m, res); |
481 | ||
482 | return res; | |
1da177e4 LT |
483 | } |
484 | EXPORT_SYMBOL(seq_path); | |
485 | ||
9d1bc601 MS |
486 | /* |
487 | * Same as seq_path, but relative to supplied root. | |
9d1bc601 | 488 | */ |
8c9379e9 AV |
489 | int seq_path_root(struct seq_file *m, const struct path *path, |
490 | const struct path *root, const char *esc) | |
9d1bc601 | 491 | { |
f8439806 MS |
492 | char *buf; |
493 | size_t size = seq_get_buf(m, &buf); | |
494 | int res = -ENAMETOOLONG; | |
495 | ||
496 | if (size) { | |
9d1bc601 MS |
497 | char *p; |
498 | ||
f8439806 | 499 | p = __d_path(path, root, buf, size); |
02125a82 AV |
500 | if (!p) |
501 | return SEQ_SKIP; | |
f8439806 | 502 | res = PTR_ERR(p); |
9d1bc601 | 503 | if (!IS_ERR(p)) { |
f8439806 MS |
504 | char *end = mangle_path(buf, p, esc); |
505 | if (end) | |
506 | res = end - buf; | |
507 | else | |
508 | res = -ENAMETOOLONG; | |
9d1bc601 MS |
509 | } |
510 | } | |
f8439806 MS |
511 | seq_commit(m, res); |
512 | ||
02125a82 | 513 | return res < 0 && res != -ENAMETOOLONG ? res : 0; |
9d1bc601 MS |
514 | } |
515 | ||
6092d048 RP |
516 | /* |
517 | * returns the path of the 'dentry' from the root of its filesystem. | |
518 | */ | |
8c9379e9 | 519 | int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc) |
6092d048 | 520 | { |
f8439806 MS |
521 | char *buf; |
522 | size_t size = seq_get_buf(m, &buf); | |
523 | int res = -1; | |
524 | ||
525 | if (size) { | |
526 | char *p = dentry_path(dentry, buf, size); | |
6092d048 | 527 | if (!IS_ERR(p)) { |
f8439806 MS |
528 | char *end = mangle_path(buf, p, esc); |
529 | if (end) | |
530 | res = end - buf; | |
6092d048 RP |
531 | } |
532 | } | |
f8439806 MS |
533 | seq_commit(m, res); |
534 | ||
535 | return res; | |
6092d048 RP |
536 | } |
537 | ||
cb78a0ce RR |
538 | int seq_bitmap(struct seq_file *m, const unsigned long *bits, |
539 | unsigned int nr_bits) | |
50ac2d69 | 540 | { |
85dd030e LJ |
541 | if (m->count < m->size) { |
542 | int len = bitmap_scnprintf(m->buf + m->count, | |
543 | m->size - m->count, bits, nr_bits); | |
544 | if (m->count + len < m->size) { | |
545 | m->count += len; | |
546 | return 0; | |
547 | } | |
50ac2d69 | 548 | } |
e075f591 | 549 | seq_set_overflow(m); |
50ac2d69 AD |
550 | return -1; |
551 | } | |
85dd030e | 552 | EXPORT_SYMBOL(seq_bitmap); |
50ac2d69 | 553 | |
af76aba0 | 554 | int seq_bitmap_list(struct seq_file *m, const unsigned long *bits, |
3eda2011 LJ |
555 | unsigned int nr_bits) |
556 | { | |
557 | if (m->count < m->size) { | |
558 | int len = bitmap_scnlistprintf(m->buf + m->count, | |
559 | m->size - m->count, bits, nr_bits); | |
560 | if (m->count + len < m->size) { | |
561 | m->count += len; | |
562 | return 0; | |
563 | } | |
564 | } | |
e075f591 | 565 | seq_set_overflow(m); |
3eda2011 LJ |
566 | return -1; |
567 | } | |
568 | EXPORT_SYMBOL(seq_bitmap_list); | |
569 | ||
1da177e4 LT |
570 | static void *single_start(struct seq_file *p, loff_t *pos) |
571 | { | |
572 | return NULL + (*pos == 0); | |
573 | } | |
574 | ||
575 | static void *single_next(struct seq_file *p, void *v, loff_t *pos) | |
576 | { | |
577 | ++*pos; | |
578 | return NULL; | |
579 | } | |
580 | ||
581 | static void single_stop(struct seq_file *p, void *v) | |
582 | { | |
583 | } | |
584 | ||
585 | int single_open(struct file *file, int (*show)(struct seq_file *, void *), | |
586 | void *data) | |
587 | { | |
588 | struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL); | |
589 | int res = -ENOMEM; | |
590 | ||
591 | if (op) { | |
592 | op->start = single_start; | |
593 | op->next = single_next; | |
594 | op->stop = single_stop; | |
595 | op->show = show; | |
596 | res = seq_open(file, op); | |
597 | if (!res) | |
598 | ((struct seq_file *)file->private_data)->private = data; | |
599 | else | |
600 | kfree(op); | |
601 | } | |
602 | return res; | |
603 | } | |
604 | EXPORT_SYMBOL(single_open); | |
605 | ||
2043f495 AV |
606 | int single_open_size(struct file *file, int (*show)(struct seq_file *, void *), |
607 | void *data, size_t size) | |
608 | { | |
609 | char *buf = kmalloc(size, GFP_KERNEL); | |
610 | int ret; | |
611 | if (!buf) | |
612 | return -ENOMEM; | |
613 | ret = single_open(file, show, data); | |
614 | if (ret) { | |
615 | kfree(buf); | |
616 | return ret; | |
617 | } | |
618 | ((struct seq_file *)file->private_data)->buf = buf; | |
619 | ((struct seq_file *)file->private_data)->size = size; | |
620 | return 0; | |
621 | } | |
622 | EXPORT_SYMBOL(single_open_size); | |
623 | ||
1da177e4 LT |
624 | int single_release(struct inode *inode, struct file *file) |
625 | { | |
15ad7cdc | 626 | const struct seq_operations *op = ((struct seq_file *)file->private_data)->op; |
1da177e4 LT |
627 | int res = seq_release(inode, file); |
628 | kfree(op); | |
629 | return res; | |
630 | } | |
631 | EXPORT_SYMBOL(single_release); | |
632 | ||
633 | int seq_release_private(struct inode *inode, struct file *file) | |
634 | { | |
635 | struct seq_file *seq = file->private_data; | |
636 | ||
637 | kfree(seq->private); | |
638 | seq->private = NULL; | |
639 | return seq_release(inode, file); | |
640 | } | |
641 | EXPORT_SYMBOL(seq_release_private); | |
642 | ||
39699037 PE |
643 | void *__seq_open_private(struct file *f, const struct seq_operations *ops, |
644 | int psize) | |
645 | { | |
646 | int rc; | |
647 | void *private; | |
648 | struct seq_file *seq; | |
649 | ||
650 | private = kzalloc(psize, GFP_KERNEL); | |
651 | if (private == NULL) | |
652 | goto out; | |
653 | ||
654 | rc = seq_open(f, ops); | |
655 | if (rc < 0) | |
656 | goto out_free; | |
657 | ||
658 | seq = f->private_data; | |
659 | seq->private = private; | |
660 | return private; | |
661 | ||
662 | out_free: | |
663 | kfree(private); | |
664 | out: | |
665 | return NULL; | |
666 | } | |
667 | EXPORT_SYMBOL(__seq_open_private); | |
668 | ||
669 | int seq_open_private(struct file *filp, const struct seq_operations *ops, | |
670 | int psize) | |
671 | { | |
672 | return __seq_open_private(filp, ops, psize) ? 0 : -ENOMEM; | |
673 | } | |
674 | EXPORT_SYMBOL(seq_open_private); | |
675 | ||
1da177e4 LT |
676 | int seq_putc(struct seq_file *m, char c) |
677 | { | |
678 | if (m->count < m->size) { | |
679 | m->buf[m->count++] = c; | |
680 | return 0; | |
681 | } | |
682 | return -1; | |
683 | } | |
684 | EXPORT_SYMBOL(seq_putc); | |
685 | ||
686 | int seq_puts(struct seq_file *m, const char *s) | |
687 | { | |
688 | int len = strlen(s); | |
689 | if (m->count + len < m->size) { | |
690 | memcpy(m->buf + m->count, s, len); | |
691 | m->count += len; | |
692 | return 0; | |
693 | } | |
e075f591 | 694 | seq_set_overflow(m); |
1da177e4 LT |
695 | return -1; |
696 | } | |
697 | EXPORT_SYMBOL(seq_puts); | |
bcf67e16 | 698 | |
1ac101a5 KH |
699 | /* |
700 | * A helper routine for putting decimal numbers without rich format of printf(). | |
701 | * only 'unsigned long long' is supported. | |
702 | * This routine will put one byte delimiter + number into seq_file. | |
703 | * This routine is very quick when you show lots of numbers. | |
704 | * In usual cases, it will be better to use seq_printf(). It's easier to read. | |
705 | */ | |
706 | int seq_put_decimal_ull(struct seq_file *m, char delimiter, | |
707 | unsigned long long num) | |
708 | { | |
709 | int len; | |
710 | ||
711 | if (m->count + 2 >= m->size) /* we'll write 2 bytes at least */ | |
712 | goto overflow; | |
713 | ||
bda7bad6 KH |
714 | if (delimiter) |
715 | m->buf[m->count++] = delimiter; | |
1ac101a5 KH |
716 | |
717 | if (num < 10) { | |
718 | m->buf[m->count++] = num + '0'; | |
719 | return 0; | |
720 | } | |
721 | ||
722 | len = num_to_str(m->buf + m->count, m->size - m->count, num); | |
723 | if (!len) | |
724 | goto overflow; | |
725 | m->count += len; | |
726 | return 0; | |
727 | overflow: | |
e075f591 | 728 | seq_set_overflow(m); |
1ac101a5 KH |
729 | return -1; |
730 | } | |
731 | EXPORT_SYMBOL(seq_put_decimal_ull); | |
732 | ||
bda7bad6 KH |
733 | int seq_put_decimal_ll(struct seq_file *m, char delimiter, |
734 | long long num) | |
735 | { | |
736 | if (num < 0) { | |
737 | if (m->count + 3 >= m->size) { | |
e075f591 | 738 | seq_set_overflow(m); |
bda7bad6 KH |
739 | return -1; |
740 | } | |
741 | if (delimiter) | |
742 | m->buf[m->count++] = delimiter; | |
743 | num = -num; | |
744 | delimiter = '-'; | |
745 | } | |
746 | return seq_put_decimal_ull(m, delimiter, num); | |
747 | ||
748 | } | |
749 | EXPORT_SYMBOL(seq_put_decimal_ll); | |
750 | ||
0b923606 PO |
751 | /** |
752 | * seq_write - write arbitrary data to buffer | |
753 | * @seq: seq_file identifying the buffer to which data should be written | |
754 | * @data: data address | |
755 | * @len: number of bytes | |
756 | * | |
757 | * Return 0 on success, non-zero otherwise. | |
758 | */ | |
759 | int seq_write(struct seq_file *seq, const void *data, size_t len) | |
760 | { | |
761 | if (seq->count + len < seq->size) { | |
762 | memcpy(seq->buf + seq->count, data, len); | |
763 | seq->count += len; | |
764 | return 0; | |
765 | } | |
e075f591 | 766 | seq_set_overflow(seq); |
0b923606 PO |
767 | return -1; |
768 | } | |
769 | EXPORT_SYMBOL(seq_write); | |
770 | ||
bcf67e16 PE |
771 | struct list_head *seq_list_start(struct list_head *head, loff_t pos) |
772 | { | |
773 | struct list_head *lh; | |
774 | ||
775 | list_for_each(lh, head) | |
776 | if (pos-- == 0) | |
777 | return lh; | |
778 | ||
779 | return NULL; | |
780 | } | |
bcf67e16 PE |
781 | EXPORT_SYMBOL(seq_list_start); |
782 | ||
783 | struct list_head *seq_list_start_head(struct list_head *head, loff_t pos) | |
784 | { | |
785 | if (!pos) | |
786 | return head; | |
787 | ||
788 | return seq_list_start(head, pos - 1); | |
789 | } | |
bcf67e16 PE |
790 | EXPORT_SYMBOL(seq_list_start_head); |
791 | ||
792 | struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos) | |
793 | { | |
794 | struct list_head *lh; | |
795 | ||
796 | lh = ((struct list_head *)v)->next; | |
797 | ++*ppos; | |
798 | return lh == head ? NULL : lh; | |
799 | } | |
bcf67e16 | 800 | EXPORT_SYMBOL(seq_list_next); |
66655de6 LZ |
801 | |
802 | /** | |
803 | * seq_hlist_start - start an iteration of a hlist | |
804 | * @head: the head of the hlist | |
805 | * @pos: the start position of the sequence | |
806 | * | |
807 | * Called at seq_file->op->start(). | |
808 | */ | |
809 | struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos) | |
810 | { | |
811 | struct hlist_node *node; | |
812 | ||
813 | hlist_for_each(node, head) | |
814 | if (pos-- == 0) | |
815 | return node; | |
816 | return NULL; | |
817 | } | |
818 | EXPORT_SYMBOL(seq_hlist_start); | |
819 | ||
820 | /** | |
821 | * seq_hlist_start_head - start an iteration of a hlist | |
822 | * @head: the head of the hlist | |
823 | * @pos: the start position of the sequence | |
824 | * | |
825 | * Called at seq_file->op->start(). Call this function if you want to | |
826 | * print a header at the top of the output. | |
827 | */ | |
828 | struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos) | |
829 | { | |
830 | if (!pos) | |
831 | return SEQ_START_TOKEN; | |
832 | ||
833 | return seq_hlist_start(head, pos - 1); | |
834 | } | |
835 | EXPORT_SYMBOL(seq_hlist_start_head); | |
836 | ||
837 | /** | |
838 | * seq_hlist_next - move to the next position of the hlist | |
839 | * @v: the current iterator | |
840 | * @head: the head of the hlist | |
138860b9 | 841 | * @ppos: the current position |
66655de6 LZ |
842 | * |
843 | * Called at seq_file->op->next(). | |
844 | */ | |
845 | struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head, | |
846 | loff_t *ppos) | |
847 | { | |
848 | struct hlist_node *node = v; | |
849 | ||
850 | ++*ppos; | |
851 | if (v == SEQ_START_TOKEN) | |
852 | return head->first; | |
853 | else | |
854 | return node->next; | |
855 | } | |
856 | EXPORT_SYMBOL(seq_hlist_next); | |
1cc52327 | 857 | |
858 | /** | |
859 | * seq_hlist_start_rcu - start an iteration of a hlist protected by RCU | |
860 | * @head: the head of the hlist | |
861 | * @pos: the start position of the sequence | |
862 | * | |
863 | * Called at seq_file->op->start(). | |
864 | * | |
865 | * This list-traversal primitive may safely run concurrently with | |
866 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
867 | * as long as the traversal is guarded by rcu_read_lock(). | |
868 | */ | |
869 | struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head, | |
870 | loff_t pos) | |
871 | { | |
872 | struct hlist_node *node; | |
873 | ||
874 | __hlist_for_each_rcu(node, head) | |
875 | if (pos-- == 0) | |
876 | return node; | |
877 | return NULL; | |
878 | } | |
879 | EXPORT_SYMBOL(seq_hlist_start_rcu); | |
880 | ||
881 | /** | |
882 | * seq_hlist_start_head_rcu - start an iteration of a hlist protected by RCU | |
883 | * @head: the head of the hlist | |
884 | * @pos: the start position of the sequence | |
885 | * | |
886 | * Called at seq_file->op->start(). Call this function if you want to | |
887 | * print a header at the top of the output. | |
888 | * | |
889 | * This list-traversal primitive may safely run concurrently with | |
890 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
891 | * as long as the traversal is guarded by rcu_read_lock(). | |
892 | */ | |
893 | struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, | |
894 | loff_t pos) | |
895 | { | |
896 | if (!pos) | |
897 | return SEQ_START_TOKEN; | |
898 | ||
899 | return seq_hlist_start_rcu(head, pos - 1); | |
900 | } | |
901 | EXPORT_SYMBOL(seq_hlist_start_head_rcu); | |
902 | ||
903 | /** | |
904 | * seq_hlist_next_rcu - move to the next position of the hlist protected by RCU | |
905 | * @v: the current iterator | |
906 | * @head: the head of the hlist | |
138860b9 | 907 | * @ppos: the current position |
1cc52327 | 908 | * |
909 | * Called at seq_file->op->next(). | |
910 | * | |
911 | * This list-traversal primitive may safely run concurrently with | |
912 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
913 | * as long as the traversal is guarded by rcu_read_lock(). | |
914 | */ | |
915 | struct hlist_node *seq_hlist_next_rcu(void *v, | |
916 | struct hlist_head *head, | |
917 | loff_t *ppos) | |
918 | { | |
919 | struct hlist_node *node = v; | |
920 | ||
921 | ++*ppos; | |
922 | if (v == SEQ_START_TOKEN) | |
923 | return rcu_dereference(head->first); | |
924 | else | |
925 | return rcu_dereference(node->next); | |
926 | } | |
927 | EXPORT_SYMBOL(seq_hlist_next_rcu); |