]>
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 | 10 | #include <linux/seq_file.h> |
058504ed | 11 | #include <linux/vmalloc.h> |
1da177e4 | 12 | #include <linux/slab.h> |
adb37c4c | 13 | #include <linux/cred.h> |
058504ed | 14 | #include <linux/mm.h> |
37607102 | 15 | #include <linux/printk.h> |
1da177e4 LT |
16 | |
17 | #include <asm/uaccess.h> | |
18 | #include <asm/page.h> | |
19 | ||
e075f591 KH |
20 | static void seq_set_overflow(struct seq_file *m) |
21 | { | |
22 | m->count = m->size; | |
23 | } | |
24 | ||
058504ed HC |
25 | static void *seq_buf_alloc(unsigned long size) |
26 | { | |
27 | void *buf; | |
28 | ||
5cec38ac DR |
29 | /* |
30 | * __GFP_NORETRY to avoid oom-killings with high-order allocations - | |
31 | * it's better to fall back to vmalloc() than to kill things. | |
32 | */ | |
33 | buf = kmalloc(size, GFP_KERNEL | __GFP_NORETRY | __GFP_NOWARN); | |
058504ed HC |
34 | if (!buf && size > PAGE_SIZE) |
35 | buf = vmalloc(size); | |
36 | return buf; | |
37 | } | |
38 | ||
1da177e4 LT |
39 | /** |
40 | * seq_open - initialize sequential file | |
41 | * @file: file we initialize | |
42 | * @op: method table describing the sequence | |
43 | * | |
44 | * seq_open() sets @file, associating it with a sequence described | |
45 | * by @op. @op->start() sets the iterator up and returns the first | |
46 | * element of sequence. @op->stop() shuts it down. @op->next() | |
47 | * returns the next element of sequence. @op->show() prints element | |
48 | * into the buffer. In case of error ->start() and ->next() return | |
49 | * ERR_PTR(error). In the end of sequence they return %NULL. ->show() | |
50 | * returns 0 in case of success and negative number in case of error. | |
521b5d0c | 51 | * Returning SEQ_SKIP means "discard this element and move on". |
460b865e YD |
52 | * Note: seq_open() will allocate a struct seq_file and store its |
53 | * pointer in @file->private_data. This pointer should not be modified. | |
1da177e4 | 54 | */ |
15ad7cdc | 55 | int seq_open(struct file *file, const struct seq_operations *op) |
1da177e4 | 56 | { |
189f9841 YD |
57 | struct seq_file *p; |
58 | ||
59 | WARN_ON(file->private_data); | |
60 | ||
61 | p = kzalloc(sizeof(*p), GFP_KERNEL); | |
62 | if (!p) | |
63 | return -ENOMEM; | |
64 | ||
65 | file->private_data = p; | |
1abe77b0 | 66 | |
0ac1759a | 67 | mutex_init(&p->lock); |
1da177e4 | 68 | p->op = op; |
adb37c4c EB |
69 | #ifdef CONFIG_USER_NS |
70 | p->user_ns = file->f_cred->user_ns; | |
71 | #endif | |
1da177e4 LT |
72 | |
73 | /* | |
74 | * Wrappers around seq_open(e.g. swaps_open) need to be | |
75 | * aware of this. If they set f_version themselves, they | |
76 | * should call seq_open first and then set f_version. | |
77 | */ | |
78 | file->f_version = 0; | |
79 | ||
8f19d472 EB |
80 | /* |
81 | * seq_files support lseek() and pread(). They do not implement | |
82 | * write() at all, but we clear FMODE_PWRITE here for historical | |
83 | * reasons. | |
84 | * | |
85 | * If a client of seq_files a) implements file.write() and b) wishes to | |
86 | * support pwrite() then that client will need to implement its own | |
87 | * file.open() which calls seq_open() and then sets FMODE_PWRITE. | |
88 | */ | |
89 | file->f_mode &= ~FMODE_PWRITE; | |
1da177e4 LT |
90 | return 0; |
91 | } | |
92 | EXPORT_SYMBOL(seq_open); | |
93 | ||
33da8892 EB |
94 | static int traverse(struct seq_file *m, loff_t offset) |
95 | { | |
96 | loff_t pos = 0, index; | |
97 | int error = 0; | |
98 | void *p; | |
99 | ||
100 | m->version = 0; | |
101 | index = 0; | |
102 | m->count = m->from = 0; | |
103 | if (!offset) { | |
104 | m->index = index; | |
105 | return 0; | |
106 | } | |
107 | if (!m->buf) { | |
058504ed | 108 | m->buf = seq_buf_alloc(m->size = PAGE_SIZE); |
33da8892 EB |
109 | if (!m->buf) |
110 | return -ENOMEM; | |
111 | } | |
112 | p = m->op->start(m, &index); | |
113 | while (p) { | |
114 | error = PTR_ERR(p); | |
115 | if (IS_ERR(p)) | |
116 | break; | |
117 | error = m->op->show(m, p); | |
118 | if (error < 0) | |
119 | break; | |
120 | if (unlikely(error)) { | |
121 | error = 0; | |
122 | m->count = 0; | |
123 | } | |
1f33c41c | 124 | if (seq_has_overflowed(m)) |
33da8892 EB |
125 | goto Eoverflow; |
126 | if (pos + m->count > offset) { | |
127 | m->from = offset - pos; | |
128 | m->count -= m->from; | |
129 | m->index = index; | |
130 | break; | |
131 | } | |
132 | pos += m->count; | |
133 | m->count = 0; | |
134 | if (pos == offset) { | |
135 | index++; | |
136 | m->index = index; | |
137 | break; | |
138 | } | |
139 | p = m->op->next(m, p, &index); | |
140 | } | |
141 | m->op->stop(m, p); | |
f01d1d54 | 142 | m->index = index; |
33da8892 EB |
143 | return error; |
144 | ||
145 | Eoverflow: | |
146 | m->op->stop(m, p); | |
058504ed | 147 | kvfree(m->buf); |
801a7605 | 148 | m->count = 0; |
058504ed | 149 | m->buf = seq_buf_alloc(m->size <<= 1); |
33da8892 EB |
150 | return !m->buf ? -ENOMEM : -EAGAIN; |
151 | } | |
152 | ||
1da177e4 LT |
153 | /** |
154 | * seq_read - ->read() method for sequential files. | |
67be2dd1 MW |
155 | * @file: the file to read from |
156 | * @buf: the buffer to read to | |
157 | * @size: the maximum number of bytes to read | |
158 | * @ppos: the current position in the file | |
1da177e4 LT |
159 | * |
160 | * Ready-made ->f_op->read() | |
161 | */ | |
162 | ssize_t seq_read(struct file *file, char __user *buf, size_t size, loff_t *ppos) | |
163 | { | |
8209e2f4 | 164 | struct seq_file *m = file->private_data; |
1da177e4 LT |
165 | size_t copied = 0; |
166 | loff_t pos; | |
167 | size_t n; | |
168 | void *p; | |
169 | int err = 0; | |
170 | ||
0ac1759a | 171 | mutex_lock(&m->lock); |
8f19d472 | 172 | |
7904ac84 EC |
173 | /* |
174 | * seq_file->op->..m_start/m_stop/m_next may do special actions | |
175 | * or optimisations based on the file->f_version, so we want to | |
176 | * pass the file->f_version to those methods. | |
177 | * | |
178 | * seq_file->version is just copy of f_version, and seq_file | |
179 | * methods can treat it simply as file version. | |
180 | * It is copied in first and copied out after all operations. | |
181 | * It is convenient to have it as part of structure to avoid the | |
182 | * need of passing another argument to all the seq_file methods. | |
183 | */ | |
184 | m->version = file->f_version; | |
185 | ||
8f19d472 EB |
186 | /* Don't assume *ppos is where we left it */ |
187 | if (unlikely(*ppos != m->read_pos)) { | |
8f19d472 EB |
188 | while ((err = traverse(m, *ppos)) == -EAGAIN) |
189 | ; | |
190 | if (err) { | |
191 | /* With prejudice... */ | |
192 | m->read_pos = 0; | |
193 | m->version = 0; | |
194 | m->index = 0; | |
195 | m->count = 0; | |
196 | goto Done; | |
7904ac84 EC |
197 | } else { |
198 | m->read_pos = *ppos; | |
8f19d472 EB |
199 | } |
200 | } | |
201 | ||
1da177e4 LT |
202 | /* grab buffer if we didn't have one */ |
203 | if (!m->buf) { | |
058504ed | 204 | m->buf = seq_buf_alloc(m->size = PAGE_SIZE); |
1da177e4 LT |
205 | if (!m->buf) |
206 | goto Enomem; | |
207 | } | |
208 | /* if not empty - flush it first */ | |
209 | if (m->count) { | |
210 | n = min(m->count, size); | |
211 | err = copy_to_user(buf, m->buf + m->from, n); | |
212 | if (err) | |
213 | goto Efault; | |
214 | m->count -= n; | |
215 | m->from += n; | |
216 | size -= n; | |
217 | buf += n; | |
218 | copied += n; | |
219 | if (!m->count) | |
220 | m->index++; | |
221 | if (!size) | |
222 | goto Done; | |
223 | } | |
224 | /* we need at least one record in buffer */ | |
4cdfe84b AV |
225 | pos = m->index; |
226 | p = m->op->start(m, &pos); | |
1da177e4 | 227 | while (1) { |
1da177e4 LT |
228 | err = PTR_ERR(p); |
229 | if (!p || IS_ERR(p)) | |
230 | break; | |
231 | err = m->op->show(m, p); | |
521b5d0c | 232 | if (err < 0) |
1da177e4 | 233 | break; |
521b5d0c AV |
234 | if (unlikely(err)) |
235 | m->count = 0; | |
4cdfe84b AV |
236 | if (unlikely(!m->count)) { |
237 | p = m->op->next(m, p, &pos); | |
238 | m->index = pos; | |
239 | continue; | |
240 | } | |
1da177e4 LT |
241 | if (m->count < m->size) |
242 | goto Fill; | |
243 | m->op->stop(m, p); | |
058504ed | 244 | kvfree(m->buf); |
801a7605 | 245 | m->count = 0; |
058504ed | 246 | m->buf = seq_buf_alloc(m->size <<= 1); |
1da177e4 LT |
247 | if (!m->buf) |
248 | goto Enomem; | |
1da177e4 | 249 | m->version = 0; |
4cdfe84b AV |
250 | pos = m->index; |
251 | p = m->op->start(m, &pos); | |
1da177e4 LT |
252 | } |
253 | m->op->stop(m, p); | |
254 | m->count = 0; | |
255 | goto Done; | |
256 | Fill: | |
257 | /* they want more? let's try to get some more */ | |
258 | while (m->count < size) { | |
259 | size_t offs = m->count; | |
260 | loff_t next = pos; | |
261 | p = m->op->next(m, p, &next); | |
262 | if (!p || IS_ERR(p)) { | |
263 | err = PTR_ERR(p); | |
264 | break; | |
265 | } | |
266 | err = m->op->show(m, p); | |
1f33c41c | 267 | if (seq_has_overflowed(m) || err) { |
1da177e4 | 268 | m->count = offs; |
521b5d0c AV |
269 | if (likely(err <= 0)) |
270 | break; | |
1da177e4 LT |
271 | } |
272 | pos = next; | |
273 | } | |
274 | m->op->stop(m, p); | |
275 | n = min(m->count, size); | |
276 | err = copy_to_user(buf, m->buf, n); | |
277 | if (err) | |
278 | goto Efault; | |
279 | copied += n; | |
280 | m->count -= n; | |
281 | if (m->count) | |
282 | m->from = n; | |
283 | else | |
284 | pos++; | |
285 | m->index = pos; | |
286 | Done: | |
287 | if (!copied) | |
288 | copied = err; | |
8f19d472 | 289 | else { |
1da177e4 | 290 | *ppos += copied; |
8f19d472 EB |
291 | m->read_pos += copied; |
292 | } | |
1da177e4 | 293 | file->f_version = m->version; |
0ac1759a | 294 | mutex_unlock(&m->lock); |
1da177e4 LT |
295 | return copied; |
296 | Enomem: | |
297 | err = -ENOMEM; | |
298 | goto Done; | |
299 | Efault: | |
300 | err = -EFAULT; | |
301 | goto Done; | |
302 | } | |
303 | EXPORT_SYMBOL(seq_read); | |
304 | ||
1da177e4 LT |
305 | /** |
306 | * seq_lseek - ->llseek() method for sequential files. | |
67be2dd1 MW |
307 | * @file: the file in question |
308 | * @offset: new position | |
254adaa4 | 309 | * @whence: 0 for absolute, 1 for relative position |
1da177e4 LT |
310 | * |
311 | * Ready-made ->f_op->llseek() | |
312 | */ | |
965c8e59 | 313 | loff_t seq_lseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 314 | { |
8209e2f4 | 315 | struct seq_file *m = file->private_data; |
16abef0e | 316 | loff_t retval = -EINVAL; |
1da177e4 | 317 | |
0ac1759a | 318 | mutex_lock(&m->lock); |
1da177e4 | 319 | m->version = file->f_version; |
965c8e59 | 320 | switch (whence) { |
5e62adef AM |
321 | case SEEK_CUR: |
322 | offset += file->f_pos; | |
323 | case SEEK_SET: | |
324 | if (offset < 0) | |
325 | break; | |
326 | retval = offset; | |
327 | if (offset != m->read_pos) { | |
328 | while ((retval = traverse(m, offset)) == -EAGAIN) | |
329 | ; | |
330 | if (retval) { | |
331 | /* with extreme prejudice... */ | |
332 | file->f_pos = 0; | |
333 | m->read_pos = 0; | |
334 | m->version = 0; | |
335 | m->index = 0; | |
336 | m->count = 0; | |
337 | } else { | |
338 | m->read_pos = offset; | |
339 | retval = file->f_pos = offset; | |
1da177e4 | 340 | } |
05e16745 GZ |
341 | } else { |
342 | file->f_pos = offset; | |
5e62adef | 343 | } |
1da177e4 | 344 | } |
1da177e4 | 345 | file->f_version = m->version; |
00c5746d | 346 | mutex_unlock(&m->lock); |
1da177e4 LT |
347 | return retval; |
348 | } | |
349 | EXPORT_SYMBOL(seq_lseek); | |
350 | ||
351 | /** | |
352 | * seq_release - free the structures associated with sequential file. | |
353 | * @file: file in question | |
6131ffaa | 354 | * @inode: its inode |
1da177e4 LT |
355 | * |
356 | * Frees the structures associated with sequential file; can be used | |
357 | * as ->f_op->release() if you don't have private data to destroy. | |
358 | */ | |
359 | int seq_release(struct inode *inode, struct file *file) | |
360 | { | |
8209e2f4 | 361 | struct seq_file *m = file->private_data; |
058504ed | 362 | kvfree(m->buf); |
1da177e4 LT |
363 | kfree(m); |
364 | return 0; | |
365 | } | |
366 | EXPORT_SYMBOL(seq_release); | |
367 | ||
368 | /** | |
369 | * seq_escape - print string into buffer, escaping some characters | |
370 | * @m: target buffer | |
371 | * @s: string | |
372 | * @esc: set of characters that need escaping | |
373 | * | |
374 | * Puts string into buffer, replacing each occurrence of character from | |
375 | * @esc with usual octal escape. Returns 0 in case of success, -1 - in | |
376 | * case of overflow. | |
377 | */ | |
378 | int seq_escape(struct seq_file *m, const char *s, const char *esc) | |
379 | { | |
380 | char *end = m->buf + m->size; | |
381 | char *p; | |
382 | char c; | |
383 | ||
384 | for (p = m->buf + m->count; (c = *s) != '\0' && p < end; s++) { | |
385 | if (!strchr(esc, c)) { | |
386 | *p++ = c; | |
387 | continue; | |
388 | } | |
389 | if (p + 3 < end) { | |
390 | *p++ = '\\'; | |
391 | *p++ = '0' + ((c & 0300) >> 6); | |
392 | *p++ = '0' + ((c & 070) >> 3); | |
393 | *p++ = '0' + (c & 07); | |
394 | continue; | |
395 | } | |
e075f591 | 396 | seq_set_overflow(m); |
1da177e4 LT |
397 | return -1; |
398 | } | |
399 | m->count = p - m->buf; | |
400 | return 0; | |
401 | } | |
402 | EXPORT_SYMBOL(seq_escape); | |
403 | ||
a4808147 | 404 | int seq_vprintf(struct seq_file *m, const char *f, va_list args) |
1da177e4 | 405 | { |
1da177e4 LT |
406 | int len; |
407 | ||
408 | if (m->count < m->size) { | |
1da177e4 | 409 | len = vsnprintf(m->buf + m->count, m->size - m->count, f, args); |
1da177e4 LT |
410 | if (m->count + len < m->size) { |
411 | m->count += len; | |
412 | return 0; | |
413 | } | |
414 | } | |
e075f591 | 415 | seq_set_overflow(m); |
1da177e4 LT |
416 | return -1; |
417 | } | |
a4808147 SW |
418 | EXPORT_SYMBOL(seq_vprintf); |
419 | ||
420 | int seq_printf(struct seq_file *m, const char *f, ...) | |
421 | { | |
422 | int ret; | |
423 | va_list args; | |
424 | ||
425 | va_start(args, f); | |
426 | ret = seq_vprintf(m, f, args); | |
427 | va_end(args); | |
428 | ||
429 | return ret; | |
430 | } | |
1da177e4 LT |
431 | EXPORT_SYMBOL(seq_printf); |
432 | ||
74e2f334 | 433 | /** |
958086d1 TE |
434 | * mangle_path - mangle and copy path to buffer beginning |
435 | * @s: buffer start | |
436 | * @p: beginning of path in above buffer | |
437 | * @esc: set of characters that need escaping | |
74e2f334 TE |
438 | * |
439 | * Copy the path from @p to @s, replacing each occurrence of character from | |
440 | * @esc with usual octal escape. | |
441 | * Returns pointer past last written character in @s, or NULL in case of | |
442 | * failure. | |
443 | */ | |
8c9379e9 | 444 | char *mangle_path(char *s, const char *p, const char *esc) |
6092d048 RP |
445 | { |
446 | while (s <= p) { | |
447 | char c = *p++; | |
448 | if (!c) { | |
449 | return s; | |
450 | } else if (!strchr(esc, c)) { | |
451 | *s++ = c; | |
452 | } else if (s + 4 > p) { | |
453 | break; | |
454 | } else { | |
455 | *s++ = '\\'; | |
456 | *s++ = '0' + ((c & 0300) >> 6); | |
457 | *s++ = '0' + ((c & 070) >> 3); | |
458 | *s++ = '0' + (c & 07); | |
459 | } | |
460 | } | |
461 | return NULL; | |
462 | } | |
604094f4 | 463 | EXPORT_SYMBOL(mangle_path); |
6092d048 | 464 | |
52afeefb AV |
465 | /** |
466 | * seq_path - seq_file interface to print a pathname | |
467 | * @m: the seq_file handle | |
468 | * @path: the struct path to print | |
469 | * @esc: set of characters to escape in the output | |
470 | * | |
471 | * return the absolute path of 'path', as represented by the | |
472 | * dentry / mnt pair in the path parameter. | |
6092d048 | 473 | */ |
8c9379e9 | 474 | int seq_path(struct seq_file *m, const struct path *path, const char *esc) |
1da177e4 | 475 | { |
f8439806 MS |
476 | char *buf; |
477 | size_t size = seq_get_buf(m, &buf); | |
478 | int res = -1; | |
479 | ||
480 | if (size) { | |
481 | char *p = d_path(path, buf, size); | |
1da177e4 | 482 | if (!IS_ERR(p)) { |
f8439806 MS |
483 | char *end = mangle_path(buf, p, esc); |
484 | if (end) | |
485 | res = end - buf; | |
1da177e4 LT |
486 | } |
487 | } | |
f8439806 MS |
488 | seq_commit(m, res); |
489 | ||
490 | return res; | |
1da177e4 LT |
491 | } |
492 | EXPORT_SYMBOL(seq_path); | |
493 | ||
2726d566 MS |
494 | /** |
495 | * seq_file_path - seq_file interface to print a pathname of a file | |
496 | * @m: the seq_file handle | |
497 | * @file: the struct file to print | |
498 | * @esc: set of characters to escape in the output | |
499 | * | |
500 | * return the absolute path to the file. | |
501 | */ | |
502 | int seq_file_path(struct seq_file *m, struct file *file, const char *esc) | |
503 | { | |
504 | return seq_path(m, &file->f_path, esc); | |
505 | } | |
506 | EXPORT_SYMBOL(seq_file_path); | |
507 | ||
9d1bc601 MS |
508 | /* |
509 | * Same as seq_path, but relative to supplied root. | |
9d1bc601 | 510 | */ |
8c9379e9 AV |
511 | int seq_path_root(struct seq_file *m, const struct path *path, |
512 | const struct path *root, const char *esc) | |
9d1bc601 | 513 | { |
f8439806 MS |
514 | char *buf; |
515 | size_t size = seq_get_buf(m, &buf); | |
516 | int res = -ENAMETOOLONG; | |
517 | ||
518 | if (size) { | |
9d1bc601 MS |
519 | char *p; |
520 | ||
f8439806 | 521 | p = __d_path(path, root, buf, size); |
02125a82 AV |
522 | if (!p) |
523 | return SEQ_SKIP; | |
f8439806 | 524 | res = PTR_ERR(p); |
9d1bc601 | 525 | if (!IS_ERR(p)) { |
f8439806 MS |
526 | char *end = mangle_path(buf, p, esc); |
527 | if (end) | |
528 | res = end - buf; | |
529 | else | |
530 | res = -ENAMETOOLONG; | |
9d1bc601 MS |
531 | } |
532 | } | |
f8439806 MS |
533 | seq_commit(m, res); |
534 | ||
02125a82 | 535 | return res < 0 && res != -ENAMETOOLONG ? res : 0; |
9d1bc601 MS |
536 | } |
537 | ||
6092d048 RP |
538 | /* |
539 | * returns the path of the 'dentry' from the root of its filesystem. | |
540 | */ | |
8c9379e9 | 541 | int seq_dentry(struct seq_file *m, struct dentry *dentry, const char *esc) |
6092d048 | 542 | { |
f8439806 MS |
543 | char *buf; |
544 | size_t size = seq_get_buf(m, &buf); | |
545 | int res = -1; | |
546 | ||
547 | if (size) { | |
548 | char *p = dentry_path(dentry, buf, size); | |
6092d048 | 549 | if (!IS_ERR(p)) { |
f8439806 MS |
550 | char *end = mangle_path(buf, p, esc); |
551 | if (end) | |
552 | res = end - buf; | |
6092d048 RP |
553 | } |
554 | } | |
f8439806 MS |
555 | seq_commit(m, res); |
556 | ||
557 | return res; | |
6092d048 | 558 | } |
c8d3fe02 | 559 | EXPORT_SYMBOL(seq_dentry); |
6092d048 | 560 | |
1da177e4 LT |
561 | static void *single_start(struct seq_file *p, loff_t *pos) |
562 | { | |
563 | return NULL + (*pos == 0); | |
564 | } | |
565 | ||
566 | static void *single_next(struct seq_file *p, void *v, loff_t *pos) | |
567 | { | |
568 | ++*pos; | |
569 | return NULL; | |
570 | } | |
571 | ||
572 | static void single_stop(struct seq_file *p, void *v) | |
573 | { | |
574 | } | |
575 | ||
576 | int single_open(struct file *file, int (*show)(struct seq_file *, void *), | |
577 | void *data) | |
578 | { | |
579 | struct seq_operations *op = kmalloc(sizeof(*op), GFP_KERNEL); | |
580 | int res = -ENOMEM; | |
581 | ||
582 | if (op) { | |
583 | op->start = single_start; | |
584 | op->next = single_next; | |
585 | op->stop = single_stop; | |
586 | op->show = show; | |
587 | res = seq_open(file, op); | |
588 | if (!res) | |
589 | ((struct seq_file *)file->private_data)->private = data; | |
590 | else | |
591 | kfree(op); | |
592 | } | |
593 | return res; | |
594 | } | |
595 | EXPORT_SYMBOL(single_open); | |
596 | ||
2043f495 AV |
597 | int single_open_size(struct file *file, int (*show)(struct seq_file *, void *), |
598 | void *data, size_t size) | |
599 | { | |
058504ed | 600 | char *buf = seq_buf_alloc(size); |
2043f495 AV |
601 | int ret; |
602 | if (!buf) | |
603 | return -ENOMEM; | |
604 | ret = single_open(file, show, data); | |
605 | if (ret) { | |
058504ed | 606 | kvfree(buf); |
2043f495 AV |
607 | return ret; |
608 | } | |
609 | ((struct seq_file *)file->private_data)->buf = buf; | |
610 | ((struct seq_file *)file->private_data)->size = size; | |
611 | return 0; | |
612 | } | |
613 | EXPORT_SYMBOL(single_open_size); | |
614 | ||
1da177e4 LT |
615 | int single_release(struct inode *inode, struct file *file) |
616 | { | |
15ad7cdc | 617 | const struct seq_operations *op = ((struct seq_file *)file->private_data)->op; |
1da177e4 LT |
618 | int res = seq_release(inode, file); |
619 | kfree(op); | |
620 | return res; | |
621 | } | |
622 | EXPORT_SYMBOL(single_release); | |
623 | ||
624 | int seq_release_private(struct inode *inode, struct file *file) | |
625 | { | |
626 | struct seq_file *seq = file->private_data; | |
627 | ||
628 | kfree(seq->private); | |
629 | seq->private = NULL; | |
630 | return seq_release(inode, file); | |
631 | } | |
632 | EXPORT_SYMBOL(seq_release_private); | |
633 | ||
39699037 PE |
634 | void *__seq_open_private(struct file *f, const struct seq_operations *ops, |
635 | int psize) | |
636 | { | |
637 | int rc; | |
638 | void *private; | |
639 | struct seq_file *seq; | |
640 | ||
641 | private = kzalloc(psize, GFP_KERNEL); | |
642 | if (private == NULL) | |
643 | goto out; | |
644 | ||
645 | rc = seq_open(f, ops); | |
646 | if (rc < 0) | |
647 | goto out_free; | |
648 | ||
649 | seq = f->private_data; | |
650 | seq->private = private; | |
651 | return private; | |
652 | ||
653 | out_free: | |
654 | kfree(private); | |
655 | out: | |
656 | return NULL; | |
657 | } | |
658 | EXPORT_SYMBOL(__seq_open_private); | |
659 | ||
660 | int seq_open_private(struct file *filp, const struct seq_operations *ops, | |
661 | int psize) | |
662 | { | |
663 | return __seq_open_private(filp, ops, psize) ? 0 : -ENOMEM; | |
664 | } | |
665 | EXPORT_SYMBOL(seq_open_private); | |
666 | ||
1da177e4 LT |
667 | int seq_putc(struct seq_file *m, char c) |
668 | { | |
669 | if (m->count < m->size) { | |
670 | m->buf[m->count++] = c; | |
671 | return 0; | |
672 | } | |
673 | return -1; | |
674 | } | |
675 | EXPORT_SYMBOL(seq_putc); | |
676 | ||
677 | int seq_puts(struct seq_file *m, const char *s) | |
678 | { | |
679 | int len = strlen(s); | |
680 | if (m->count + len < m->size) { | |
681 | memcpy(m->buf + m->count, s, len); | |
682 | m->count += len; | |
683 | return 0; | |
684 | } | |
e075f591 | 685 | seq_set_overflow(m); |
1da177e4 LT |
686 | return -1; |
687 | } | |
688 | EXPORT_SYMBOL(seq_puts); | |
bcf67e16 | 689 | |
1ac101a5 KH |
690 | /* |
691 | * A helper routine for putting decimal numbers without rich format of printf(). | |
692 | * only 'unsigned long long' is supported. | |
693 | * This routine will put one byte delimiter + number into seq_file. | |
694 | * This routine is very quick when you show lots of numbers. | |
695 | * In usual cases, it will be better to use seq_printf(). It's easier to read. | |
696 | */ | |
697 | int seq_put_decimal_ull(struct seq_file *m, char delimiter, | |
698 | unsigned long long num) | |
699 | { | |
700 | int len; | |
701 | ||
702 | if (m->count + 2 >= m->size) /* we'll write 2 bytes at least */ | |
703 | goto overflow; | |
704 | ||
bda7bad6 KH |
705 | if (delimiter) |
706 | m->buf[m->count++] = delimiter; | |
1ac101a5 KH |
707 | |
708 | if (num < 10) { | |
709 | m->buf[m->count++] = num + '0'; | |
710 | return 0; | |
711 | } | |
712 | ||
713 | len = num_to_str(m->buf + m->count, m->size - m->count, num); | |
714 | if (!len) | |
715 | goto overflow; | |
716 | m->count += len; | |
717 | return 0; | |
718 | overflow: | |
e075f591 | 719 | seq_set_overflow(m); |
1ac101a5 KH |
720 | return -1; |
721 | } | |
722 | EXPORT_SYMBOL(seq_put_decimal_ull); | |
723 | ||
bda7bad6 KH |
724 | int seq_put_decimal_ll(struct seq_file *m, char delimiter, |
725 | long long num) | |
726 | { | |
727 | if (num < 0) { | |
728 | if (m->count + 3 >= m->size) { | |
e075f591 | 729 | seq_set_overflow(m); |
bda7bad6 KH |
730 | return -1; |
731 | } | |
732 | if (delimiter) | |
733 | m->buf[m->count++] = delimiter; | |
734 | num = -num; | |
735 | delimiter = '-'; | |
736 | } | |
737 | return seq_put_decimal_ull(m, delimiter, num); | |
738 | ||
739 | } | |
740 | EXPORT_SYMBOL(seq_put_decimal_ll); | |
741 | ||
0b923606 PO |
742 | /** |
743 | * seq_write - write arbitrary data to buffer | |
744 | * @seq: seq_file identifying the buffer to which data should be written | |
745 | * @data: data address | |
746 | * @len: number of bytes | |
747 | * | |
748 | * Return 0 on success, non-zero otherwise. | |
749 | */ | |
750 | int seq_write(struct seq_file *seq, const void *data, size_t len) | |
751 | { | |
752 | if (seq->count + len < seq->size) { | |
753 | memcpy(seq->buf + seq->count, data, len); | |
754 | seq->count += len; | |
755 | return 0; | |
756 | } | |
e075f591 | 757 | seq_set_overflow(seq); |
0b923606 PO |
758 | return -1; |
759 | } | |
760 | EXPORT_SYMBOL(seq_write); | |
761 | ||
839cc2a9 TH |
762 | /** |
763 | * seq_pad - write padding spaces to buffer | |
764 | * @m: seq_file identifying the buffer to which data should be written | |
765 | * @c: the byte to append after padding if non-zero | |
766 | */ | |
767 | void seq_pad(struct seq_file *m, char c) | |
768 | { | |
769 | int size = m->pad_until - m->count; | |
770 | if (size > 0) | |
771 | seq_printf(m, "%*s", size, ""); | |
772 | if (c) | |
773 | seq_putc(m, c); | |
774 | } | |
775 | EXPORT_SYMBOL(seq_pad); | |
776 | ||
37607102 AS |
777 | /* A complete analogue of print_hex_dump() */ |
778 | void seq_hex_dump(struct seq_file *m, const char *prefix_str, int prefix_type, | |
779 | int rowsize, int groupsize, const void *buf, size_t len, | |
780 | bool ascii) | |
781 | { | |
782 | const u8 *ptr = buf; | |
783 | int i, linelen, remaining = len; | |
784 | int ret; | |
785 | ||
786 | if (rowsize != 16 && rowsize != 32) | |
787 | rowsize = 16; | |
788 | ||
789 | for (i = 0; i < len && !seq_has_overflowed(m); i += rowsize) { | |
790 | linelen = min(remaining, rowsize); | |
791 | remaining -= rowsize; | |
792 | ||
793 | switch (prefix_type) { | |
794 | case DUMP_PREFIX_ADDRESS: | |
795 | seq_printf(m, "%s%p: ", prefix_str, ptr + i); | |
796 | break; | |
797 | case DUMP_PREFIX_OFFSET: | |
798 | seq_printf(m, "%s%.8x: ", prefix_str, i); | |
799 | break; | |
800 | default: | |
801 | seq_printf(m, "%s", prefix_str); | |
802 | break; | |
803 | } | |
804 | ||
805 | ret = hex_dump_to_buffer(ptr + i, linelen, rowsize, groupsize, | |
806 | m->buf + m->count, m->size - m->count, | |
807 | ascii); | |
808 | if (ret >= m->size - m->count) { | |
809 | seq_set_overflow(m); | |
810 | } else { | |
811 | m->count += ret; | |
812 | seq_putc(m, '\n'); | |
813 | } | |
814 | } | |
815 | } | |
816 | EXPORT_SYMBOL(seq_hex_dump); | |
817 | ||
bcf67e16 PE |
818 | struct list_head *seq_list_start(struct list_head *head, loff_t pos) |
819 | { | |
820 | struct list_head *lh; | |
821 | ||
822 | list_for_each(lh, head) | |
823 | if (pos-- == 0) | |
824 | return lh; | |
825 | ||
826 | return NULL; | |
827 | } | |
bcf67e16 PE |
828 | EXPORT_SYMBOL(seq_list_start); |
829 | ||
830 | struct list_head *seq_list_start_head(struct list_head *head, loff_t pos) | |
831 | { | |
832 | if (!pos) | |
833 | return head; | |
834 | ||
835 | return seq_list_start(head, pos - 1); | |
836 | } | |
bcf67e16 PE |
837 | EXPORT_SYMBOL(seq_list_start_head); |
838 | ||
839 | struct list_head *seq_list_next(void *v, struct list_head *head, loff_t *ppos) | |
840 | { | |
841 | struct list_head *lh; | |
842 | ||
843 | lh = ((struct list_head *)v)->next; | |
844 | ++*ppos; | |
845 | return lh == head ? NULL : lh; | |
846 | } | |
bcf67e16 | 847 | EXPORT_SYMBOL(seq_list_next); |
66655de6 LZ |
848 | |
849 | /** | |
850 | * seq_hlist_start - start an iteration of a hlist | |
851 | * @head: the head of the hlist | |
852 | * @pos: the start position of the sequence | |
853 | * | |
854 | * Called at seq_file->op->start(). | |
855 | */ | |
856 | struct hlist_node *seq_hlist_start(struct hlist_head *head, loff_t pos) | |
857 | { | |
858 | struct hlist_node *node; | |
859 | ||
860 | hlist_for_each(node, head) | |
861 | if (pos-- == 0) | |
862 | return node; | |
863 | return NULL; | |
864 | } | |
865 | EXPORT_SYMBOL(seq_hlist_start); | |
866 | ||
867 | /** | |
868 | * seq_hlist_start_head - start an iteration of a hlist | |
869 | * @head: the head of the hlist | |
870 | * @pos: the start position of the sequence | |
871 | * | |
872 | * Called at seq_file->op->start(). Call this function if you want to | |
873 | * print a header at the top of the output. | |
874 | */ | |
875 | struct hlist_node *seq_hlist_start_head(struct hlist_head *head, loff_t pos) | |
876 | { | |
877 | if (!pos) | |
878 | return SEQ_START_TOKEN; | |
879 | ||
880 | return seq_hlist_start(head, pos - 1); | |
881 | } | |
882 | EXPORT_SYMBOL(seq_hlist_start_head); | |
883 | ||
884 | /** | |
885 | * seq_hlist_next - move to the next position of the hlist | |
886 | * @v: the current iterator | |
887 | * @head: the head of the hlist | |
138860b9 | 888 | * @ppos: the current position |
66655de6 LZ |
889 | * |
890 | * Called at seq_file->op->next(). | |
891 | */ | |
892 | struct hlist_node *seq_hlist_next(void *v, struct hlist_head *head, | |
893 | loff_t *ppos) | |
894 | { | |
895 | struct hlist_node *node = v; | |
896 | ||
897 | ++*ppos; | |
898 | if (v == SEQ_START_TOKEN) | |
899 | return head->first; | |
900 | else | |
901 | return node->next; | |
902 | } | |
903 | EXPORT_SYMBOL(seq_hlist_next); | |
1cc52327 | 904 | |
905 | /** | |
906 | * seq_hlist_start_rcu - start an iteration of a hlist protected by RCU | |
907 | * @head: the head of the hlist | |
908 | * @pos: the start position of the sequence | |
909 | * | |
910 | * Called at seq_file->op->start(). | |
911 | * | |
912 | * This list-traversal primitive may safely run concurrently with | |
913 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
914 | * as long as the traversal is guarded by rcu_read_lock(). | |
915 | */ | |
916 | struct hlist_node *seq_hlist_start_rcu(struct hlist_head *head, | |
917 | loff_t pos) | |
918 | { | |
919 | struct hlist_node *node; | |
920 | ||
921 | __hlist_for_each_rcu(node, head) | |
922 | if (pos-- == 0) | |
923 | return node; | |
924 | return NULL; | |
925 | } | |
926 | EXPORT_SYMBOL(seq_hlist_start_rcu); | |
927 | ||
928 | /** | |
929 | * seq_hlist_start_head_rcu - start an iteration of a hlist protected by RCU | |
930 | * @head: the head of the hlist | |
931 | * @pos: the start position of the sequence | |
932 | * | |
933 | * Called at seq_file->op->start(). Call this function if you want to | |
934 | * print a header at the top of the output. | |
935 | * | |
936 | * This list-traversal primitive may safely run concurrently with | |
937 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
938 | * as long as the traversal is guarded by rcu_read_lock(). | |
939 | */ | |
940 | struct hlist_node *seq_hlist_start_head_rcu(struct hlist_head *head, | |
941 | loff_t pos) | |
942 | { | |
943 | if (!pos) | |
944 | return SEQ_START_TOKEN; | |
945 | ||
946 | return seq_hlist_start_rcu(head, pos - 1); | |
947 | } | |
948 | EXPORT_SYMBOL(seq_hlist_start_head_rcu); | |
949 | ||
950 | /** | |
951 | * seq_hlist_next_rcu - move to the next position of the hlist protected by RCU | |
952 | * @v: the current iterator | |
953 | * @head: the head of the hlist | |
138860b9 | 954 | * @ppos: the current position |
1cc52327 | 955 | * |
956 | * Called at seq_file->op->next(). | |
957 | * | |
958 | * This list-traversal primitive may safely run concurrently with | |
959 | * the _rcu list-mutation primitives such as hlist_add_head_rcu() | |
960 | * as long as the traversal is guarded by rcu_read_lock(). | |
961 | */ | |
962 | struct hlist_node *seq_hlist_next_rcu(void *v, | |
963 | struct hlist_head *head, | |
964 | loff_t *ppos) | |
965 | { | |
966 | struct hlist_node *node = v; | |
967 | ||
968 | ++*ppos; | |
969 | if (v == SEQ_START_TOKEN) | |
970 | return rcu_dereference(head->first); | |
971 | else | |
972 | return rcu_dereference(node->next); | |
973 | } | |
974 | EXPORT_SYMBOL(seq_hlist_next_rcu); | |
0bc77381 JL |
975 | |
976 | /** | |
977 | * seq_hlist_start_precpu - start an iteration of a percpu hlist array | |
978 | * @head: pointer to percpu array of struct hlist_heads | |
979 | * @cpu: pointer to cpu "cursor" | |
980 | * @pos: start position of sequence | |
981 | * | |
982 | * Called at seq_file->op->start(). | |
983 | */ | |
984 | struct hlist_node * | |
985 | seq_hlist_start_percpu(struct hlist_head __percpu *head, int *cpu, loff_t pos) | |
986 | { | |
987 | struct hlist_node *node; | |
988 | ||
989 | for_each_possible_cpu(*cpu) { | |
990 | hlist_for_each(node, per_cpu_ptr(head, *cpu)) { | |
991 | if (pos-- == 0) | |
992 | return node; | |
993 | } | |
994 | } | |
995 | return NULL; | |
996 | } | |
997 | EXPORT_SYMBOL(seq_hlist_start_percpu); | |
998 | ||
999 | /** | |
1000 | * seq_hlist_next_percpu - move to the next position of the percpu hlist array | |
1001 | * @v: pointer to current hlist_node | |
1002 | * @head: pointer to percpu array of struct hlist_heads | |
1003 | * @cpu: pointer to cpu "cursor" | |
1004 | * @pos: start position of sequence | |
1005 | * | |
1006 | * Called at seq_file->op->next(). | |
1007 | */ | |
1008 | struct hlist_node * | |
1009 | seq_hlist_next_percpu(void *v, struct hlist_head __percpu *head, | |
1010 | int *cpu, loff_t *pos) | |
1011 | { | |
1012 | struct hlist_node *node = v; | |
1013 | ||
1014 | ++*pos; | |
1015 | ||
1016 | if (node->next) | |
1017 | return node->next; | |
1018 | ||
1019 | for (*cpu = cpumask_next(*cpu, cpu_possible_mask); *cpu < nr_cpu_ids; | |
1020 | *cpu = cpumask_next(*cpu, cpu_possible_mask)) { | |
1021 | struct hlist_head *bucket = per_cpu_ptr(head, *cpu); | |
1022 | ||
1023 | if (!hlist_empty(bucket)) | |
1024 | return bucket->first; | |
1025 | } | |
1026 | return NULL; | |
1027 | } | |
1028 | EXPORT_SYMBOL(seq_hlist_next_percpu); |