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Commit | Line | Data |
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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> | |
9 | #include <linux/export.h> | |
10 | #include <linux/seq_file.h> | |
11 | #include <linux/vmalloc.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/cred.h> | |
14 | #include <linux/mm.h> | |
15 | ||
16 | #include <asm/uaccess.h> | |
17 | #include <asm/page.h> | |
18 | ||
19 | ||
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 | */ | |
25 | static bool seq_overflow(struct seq_file *m) | |
26 | { | |
27 | return m->count == m->size; | |
28 | } | |
29 | ||
30 | static void seq_set_overflow(struct seq_file *m) | |
31 | { | |
32 | m->count = m->size; | |
33 | } | |
34 | ||
35 | static 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 | ||
45 | /** | |
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. | |
57 | * Returning SEQ_SKIP means "discard this element and move on". | |
58 | */ | |
59 | int seq_open(struct file *file, const struct seq_operations *op) | |
60 | { | |
61 | 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 | } | |
69 | memset(p, 0, sizeof(*p)); | |
70 | mutex_init(&p->lock); | |
71 | p->op = op; | |
72 | #ifdef CONFIG_USER_NS | |
73 | p->user_ns = file->f_cred->user_ns; | |
74 | #endif | |
75 | ||
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 | ||
83 | /* | |
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; | |
93 | return 0; | |
94 | } | |
95 | EXPORT_SYMBOL(seq_open); | |
96 | ||
97 | static 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) { | |
111 | m->buf = seq_buf_alloc(m->size = PAGE_SIZE); | |
112 | 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 | } | |
127 | if (seq_overflow(m)) | |
128 | 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); | |
145 | m->index = index; | |
146 | return error; | |
147 | ||
148 | Eoverflow: | |
149 | m->op->stop(m, p); | |
150 | kvfree(m->buf); | |
151 | m->count = 0; | |
152 | m->buf = seq_buf_alloc(m->size <<= 1); | |
153 | return !m->buf ? -ENOMEM : -EAGAIN; | |
154 | } | |
155 | ||
156 | /** | |
157 | * seq_read - ->read() method for sequential files. | |
158 | * @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 | |
162 | * | |
163 | * Ready-made ->f_op->read() | |
164 | */ | |
165 | ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) | |
166 | { | |
167 | struct seq_file *m = file->private_data; | |
168 | size_t copied = 0; | |
169 | loff_t pos; | |
170 | size_t n; | |
171 | void *p; | |
172 | int err = 0; | |
173 | ||
174 | mutex_lock(&m->lock); | |
175 | ||
176 | /* | |
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; | |
188 | ||
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 | ||
205 | /* grab buffer if we didn't have one */ | |
206 | if (!m->buf) { | |
207 | m->buf = seq_buf_alloc(m->size = PAGE_SIZE); | |
208 | 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 */ | |
228 | pos = m->index; | |
229 | p = m->op->start(m, &pos); | |
230 | while (1) { | |
231 | err = PTR_ERR(p); | |
232 | if (!p || IS_ERR(p)) | |
233 | break; | |
234 | err = m->op->show(m, p); | |
235 | if (err < 0) | |
236 | break; | |
237 | if (unlikely(err)) | |
238 | m->count = 0; | |
239 | if (unlikely(!m->count)) { | |
240 | p = m->op->next(m, p, &pos); | |
241 | m->index = pos; | |
242 | continue; | |
243 | } | |
244 | if (m->count < m->size) | |
245 | goto Fill; | |
246 | m->op->stop(m, p); | |
247 | kvfree(m->buf); | |
248 | m->count = 0; | |
249 | m->buf = seq_buf_alloc(m->size <<= 1); | |
250 | if (!m->buf) | |
251 | goto Enomem; | |
252 | m->version = 0; | |
253 | pos = m->index; | |
254 | p = m->op->start(m, &pos); | |
255 | } | |
256 | m->op->stop(m, p); | |
257 | m->count = 0; | |
258 | goto Done; | |
259 | Fill: | |
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); | |
270 | if (seq_overflow(m) || err) { | |
271 | m->count = offs; | |
272 | if (likely(err <= 0)) | |
273 | break; | |
274 | } | |
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; | |
289 | Done: | |
290 | if (!copied) | |
291 | copied = err; | |
292 | else { | |
293 | *ppos += copied; | |
294 | m->read_pos += copied; | |
295 | } | |
296 | file->f_version = m->version; | |
297 | mutex_unlock(&m->lock); | |
298 | return copied; | |
299 | Enomem: | |
300 | err = -ENOMEM; | |
301 | goto Done; | |
302 | Efault: | |
303 | err = -EFAULT; | |
304 | goto Done; | |
305 | } | |
306 | EXPORT_SYMBOL(seq_read); | |
307 | ||
308 | /** | |
309 | * seq_lseek - ->llseek() method for sequential files. | |
310 | * @file: the file in question | |
311 | * @offset: new position | |
312 | * @whence: 0 for absolute, 1 for relative position | |
313 | * | |
314 | * Ready-made ->f_op->llseek() | |
315 | */ | |
316 | loff_t seq_lseek(struct file *file, loff_t offset, int whence) | |
317 | { | |
318 | struct seq_file *m = file->private_data; | |
319 | loff_t retval = -EINVAL; | |
320 | ||
321 | mutex_lock(&m->lock); | |
322 | m->version = file->f_version; | |
323 | switch (whence) { | |
324 | 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; | |
343 | } | |
344 | } else { | |
345 | file->f_pos = offset; | |
346 | } | |
347 | } | |
348 | file->f_version = m->version; | |
349 | mutex_unlock(&m->lock); | |
350 | return retval; | |
351 | } | |
352 | EXPORT_SYMBOL(seq_lseek); | |
353 | ||
354 | /** | |
355 | * seq_release - free the structures associated with sequential file. | |
356 | * @file: file in question | |
357 | * @inode: its inode | |
358 | * | |
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 | */ | |
362 | int seq_release(struct inode *inode, struct file *file) | |
363 | { | |
364 | struct seq_file *m = file->private_data; | |
365 | kvfree(m->buf); | |
366 | kfree(m); | |
367 | return 0; | |
368 | } | |
369 | EXPORT_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 | */ | |
381 | int 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 | } | |
399 | seq_set_overflow(m); | |
400 | return -1; | |
401 | } | |
402 | m->count = p - m->buf; | |
403 | return 0; | |
404 | } | |
405 | EXPORT_SYMBOL(seq_escape); | |
406 | ||
407 | int seq_vprintf(struct seq_file *m, const char *f, va_list args) | |
408 | { | |
409 | int len; | |
410 | ||
411 | if (m->count < m->size) { | |
412 | len = vsnprintf(m->buf + m->count, m->size - m->count, f, args); | |
413 | if (m->count + len < m->size) { | |
414 | m->count += len; | |
415 | return 0; | |
416 | } | |
417 | } | |
418 | seq_set_overflow(m); | |
419 | return -1; | |
420 | } | |
421 | EXPORT_SYMBOL(seq_vprintf); | |
422 | ||
423 | int 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 | } | |
434 | EXPORT_SYMBOL(seq_printf); | |
435 | ||
436 | /** | |
437 | * 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 | |
441 | * | |
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 | */ | |
447 | char *mangle_path(char *s, const char *p, const char *esc) | |
448 | { | |
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 | } | |
466 | EXPORT_SYMBOL(mangle_path); | |
467 | ||
468 | /** | |
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. | |
476 | */ | |
477 | int seq_path(struct seq_file *m, const struct path *path, const char *esc) | |
478 | { | |
479 | 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); | |
485 | if (!IS_ERR(p)) { | |
486 | char *end = mangle_path(buf, p, esc); | |
487 | if (end) | |
488 | res = end - buf; | |
489 | } | |
490 | } | |
491 | seq_commit(m, res); | |
492 | ||
493 | return res; | |
494 | } | |
495 | EXPORT_SYMBOL(seq_path); | |
496 | ||
497 | /* | |
498 | * Same as seq_path, but relative to supplied root. | |
499 | */ | |
500 | int seq_path_root(struct seq_file *m, const struct path *path, | |
501 | const struct path *root, const char *esc) | |
502 | { | |
503 | char *buf; | |
504 | size_t size = seq_get_buf(m, &buf); | |
505 | int res = -ENAMETOOLONG; | |
506 | ||
507 | if (size) { | |
508 | char *p; | |
509 | ||
510 | p = __d_path(path, root, buf, size); | |
511 | if (!p) | |
512 | return SEQ_SKIP; | |
513 | res = PTR_ERR(p); | |
514 | if (!IS_ERR(p)) { | |
515 | char *end = mangle_path(buf, p, esc); | |
516 | if (end) | |
517 | res = end - buf; | |
518 | else | |
519 | res = -ENAMETOOLONG; | |
520 | } | |
521 | } | |
522 | seq_commit(m, res); | |
523 | ||
524 | return res < 0 && res != -ENAMETOOLONG ? res : 0; | |
525 | } | |
526 | ||
527 | /* | |
528 | * returns the path of the 'dentry' from the root of its filesystem. | |
529 | */ | |
530 | int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc) | |
531 | { | |
532 | 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); | |
538 | if (!IS_ERR(p)) { | |
539 | char *end = mangle_path(buf, p, esc); | |
540 | if (end) | |
541 | res = end - buf; | |
542 | } | |
543 | } | |
544 | seq_commit(m, res); | |
545 | ||
546 | return res; | |
547 | } | |
548 | ||
549 | int seq_bitmap(struct seq_file *m, const unsigned long *bits, | |
550 | unsigned int nr_bits) | |
551 | { | |
552 | 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 | } | |
559 | } | |
560 | seq_set_overflow(m); | |
561 | return -1; | |
562 | } | |
563 | EXPORT_SYMBOL(seq_bitmap); | |
564 | ||
565 | int seq_bitmap_list(struct seq_file *m, const unsigned long *bits, | |
566 | 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 | } | |
576 | seq_set_overflow(m); | |
577 | return -1; | |
578 | } | |
579 | EXPORT_SYMBOL(seq_bitmap_list); | |
580 | ||
581 | static void *single_start(struct seq_file *p, loff_t *pos) | |
582 | { | |
583 | return NULL + (*pos == 0); | |
584 | } | |
585 | ||
586 | static void *single_next(struct seq_file *p, void *v, loff_t *pos) | |
587 | { | |
588 | ++*pos; | |
589 | return NULL; | |
590 | } | |
591 | ||
592 | static void single_stop(struct seq_file *p, void *v) | |
593 | { | |
594 | } | |
595 | ||
596 | int 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 | } | |
615 | EXPORT_SYMBOL(single_open); | |
616 | ||
617 | int single_open_size(struct file *file, int (*show)(struct seq_file *, void *), | |
618 | void *data, size_t size) | |
619 | { | |
620 | char *buf = seq_buf_alloc(size); | |
621 | int ret; | |
622 | if (!buf) | |
623 | return -ENOMEM; | |
624 | ret = single_open(file, show, data); | |
625 | if (ret) { | |
626 | kvfree(buf); | |
627 | 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 | } | |
633 | EXPORT_SYMBOL(single_open_size); | |
634 | ||
635 | int single_release(struct inode *inode, struct file *file) | |
636 | { | |
637 | const struct seq_operations *op = ((struct seq_file *)file->private_data)->op; | |
638 | int res = seq_release(inode, file); | |
639 | kfree(op); | |
640 | return res; | |
641 | } | |
642 | EXPORT_SYMBOL(single_release); | |
643 | ||
644 | int 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 | } | |
652 | EXPORT_SYMBOL(seq_release_private); | |
653 | ||
654 | void *__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 | ||
673 | out_free: | |
674 | kfree(private); | |
675 | out: | |
676 | return NULL; | |
677 | } | |
678 | EXPORT_SYMBOL(__seq_open_private); | |
679 | ||
680 | int 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 | } | |
685 | EXPORT_SYMBOL(seq_open_private); | |
686 | ||
687 | int 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 | } | |
695 | EXPORT_SYMBOL(seq_putc); | |
696 | ||
697 | int 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 | } | |
705 | seq_set_overflow(m); | |
706 | return -1; | |
707 | } | |
708 | EXPORT_SYMBOL(seq_puts); | |
709 | ||
710 | /* | |
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 | */ | |
717 | int 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 | ||
725 | if (delimiter) | |
726 | m->buf[m->count++] = delimiter; | |
727 | ||
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; | |
738 | overflow: | |
739 | seq_set_overflow(m); | |
740 | return -1; | |
741 | } | |
742 | EXPORT_SYMBOL(seq_put_decimal_ull); | |
743 | ||
744 | int 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) { | |
749 | seq_set_overflow(m); | |
750 | 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 | } | |
760 | EXPORT_SYMBOL(seq_put_decimal_ll); | |
761 | ||
762 | /** | |
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 | */ | |
770 | int 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 | } | |
777 | seq_set_overflow(seq); | |
778 | return -1; | |
779 | } | |
780 | EXPORT_SYMBOL(seq_write); | |
781 | ||
782 | /** | |
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 | */ | |
787 | void 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 | } | |
795 | EXPORT_SYMBOL(seq_pad); | |
796 | ||
797 | struct 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 | } | |
807 | EXPORT_SYMBOL(seq_list_start); | |
808 | ||
809 | struct 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 | } | |
816 | EXPORT_SYMBOL(seq_list_start_head); | |
817 | ||
818 | struct 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 | } | |
826 | EXPORT_SYMBOL(seq_list_next); | |
827 | ||
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 | */ | |
835 | struct 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 | } | |
844 | EXPORT_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 | */ | |
854 | struct 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 | } | |
861 | EXPORT_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 | |
867 | * @ppos: the current position | |
868 | * | |
869 | * Called at seq_file->op->next(). | |
870 | */ | |
871 | struct 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 | } | |
882 | EXPORT_SYMBOL(seq_hlist_next); | |
883 | ||
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 | */ | |
895 | struct 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 | } | |
905 | EXPORT_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 | */ | |
919 | struct 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 | } | |
927 | EXPORT_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 | |
933 | * @ppos: the current position | |
934 | * | |
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 | */ | |
941 | struct 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 | } | |
953 | EXPORT_SYMBOL(seq_hlist_next_rcu); | |
954 | ||
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 | */ | |
963 | struct hlist_node * | |
964 | seq_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 | } | |
976 | EXPORT_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 | */ | |
987 | struct hlist_node * | |
988 | seq_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 | } | |
1007 | EXPORT_SYMBOL(seq_hlist_next_percpu); |