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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * proc/fs/generic.c --- generic routines for the proc-fs | |
3 | * | |
4 | * This file contains generic proc-fs routines for handling | |
5 | * directories and files. | |
6 | * | |
7 | * Copyright (C) 1991, 1992 Linus Torvalds. | |
8 | * Copyright (C) 1997 Theodore Ts'o | |
9 | */ | |
10 | ||
11 | #include <linux/errno.h> | |
12 | #include <linux/time.h> | |
13 | #include <linux/proc_fs.h> | |
14 | #include <linux/stat.h> | |
15 | #include <linux/module.h> | |
16 | #include <linux/mount.h> | |
17 | #include <linux/smp_lock.h> | |
18 | #include <linux/init.h> | |
19 | #include <linux/idr.h> | |
20 | #include <linux/namei.h> | |
21 | #include <linux/bitops.h> | |
64a07bd8 | 22 | #include <linux/spinlock.h> |
786d7e16 | 23 | #include <linux/completion.h> |
1da177e4 LT |
24 | #include <asm/uaccess.h> |
25 | ||
fee781e6 AB |
26 | #include "internal.h" |
27 | ||
64a07bd8 SR |
28 | DEFINE_SPINLOCK(proc_subdir_lock); |
29 | ||
77b14db5 | 30 | static int proc_match(int len, const char *name, struct proc_dir_entry *de) |
1da177e4 LT |
31 | { |
32 | if (de->namelen != len) | |
33 | return 0; | |
34 | return !memcmp(name, de->name, len); | |
35 | } | |
36 | ||
1da177e4 LT |
37 | /* buffer size is one page but our output routines use some slack for overruns */ |
38 | #define PROC_BLOCK_SIZE (PAGE_SIZE - 1024) | |
39 | ||
40 | static ssize_t | |
41 | proc_file_read(struct file *file, char __user *buf, size_t nbytes, | |
42 | loff_t *ppos) | |
43 | { | |
2fddfeef | 44 | struct inode * inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
45 | char *page; |
46 | ssize_t retval=0; | |
47 | int eof=0; | |
48 | ssize_t n, count; | |
49 | char *start; | |
50 | struct proc_dir_entry * dp; | |
8b90db0d LT |
51 | unsigned long long pos; |
52 | ||
53 | /* | |
54 | * Gaah, please just use "seq_file" instead. The legacy /proc | |
55 | * interfaces cut loff_t down to off_t for reads, and ignore | |
56 | * the offset entirely for writes.. | |
57 | */ | |
58 | pos = *ppos; | |
59 | if (pos > MAX_NON_LFS) | |
60 | return 0; | |
61 | if (nbytes > MAX_NON_LFS - pos) | |
62 | nbytes = MAX_NON_LFS - pos; | |
1da177e4 LT |
63 | |
64 | dp = PDE(inode); | |
e12ba74d | 65 | if (!(page = (char*) __get_free_page(GFP_TEMPORARY))) |
1da177e4 LT |
66 | return -ENOMEM; |
67 | ||
68 | while ((nbytes > 0) && !eof) { | |
69 | count = min_t(size_t, PROC_BLOCK_SIZE, nbytes); | |
70 | ||
71 | start = NULL; | |
72 | if (dp->get_info) { | |
73 | /* Handle old net routines */ | |
74 | n = dp->get_info(page, &start, *ppos, count); | |
75 | if (n < count) | |
76 | eof = 1; | |
77 | } else if (dp->read_proc) { | |
78 | /* | |
79 | * How to be a proc read function | |
80 | * ------------------------------ | |
81 | * Prototype: | |
82 | * int f(char *buffer, char **start, off_t offset, | |
83 | * int count, int *peof, void *dat) | |
84 | * | |
85 | * Assume that the buffer is "count" bytes in size. | |
86 | * | |
87 | * If you know you have supplied all the data you | |
88 | * have, set *peof. | |
89 | * | |
90 | * You have three ways to return data: | |
91 | * 0) Leave *start = NULL. (This is the default.) | |
92 | * Put the data of the requested offset at that | |
93 | * offset within the buffer. Return the number (n) | |
94 | * of bytes there are from the beginning of the | |
95 | * buffer up to the last byte of data. If the | |
96 | * number of supplied bytes (= n - offset) is | |
97 | * greater than zero and you didn't signal eof | |
98 | * and the reader is prepared to take more data | |
99 | * you will be called again with the requested | |
100 | * offset advanced by the number of bytes | |
101 | * absorbed. This interface is useful for files | |
102 | * no larger than the buffer. | |
103 | * 1) Set *start = an unsigned long value less than | |
104 | * the buffer address but greater than zero. | |
105 | * Put the data of the requested offset at the | |
106 | * beginning of the buffer. Return the number of | |
107 | * bytes of data placed there. If this number is | |
108 | * greater than zero and you didn't signal eof | |
109 | * and the reader is prepared to take more data | |
110 | * you will be called again with the requested | |
111 | * offset advanced by *start. This interface is | |
112 | * useful when you have a large file consisting | |
113 | * of a series of blocks which you want to count | |
114 | * and return as wholes. | |
115 | * (Hack by Paul.Russell@rustcorp.com.au) | |
116 | * 2) Set *start = an address within the buffer. | |
117 | * Put the data of the requested offset at *start. | |
118 | * Return the number of bytes of data placed there. | |
119 | * If this number is greater than zero and you | |
120 | * didn't signal eof and the reader is prepared to | |
121 | * take more data you will be called again with the | |
122 | * requested offset advanced by the number of bytes | |
123 | * absorbed. | |
124 | */ | |
125 | n = dp->read_proc(page, &start, *ppos, | |
126 | count, &eof, dp->data); | |
127 | } else | |
128 | break; | |
129 | ||
130 | if (n == 0) /* end of file */ | |
131 | break; | |
132 | if (n < 0) { /* error */ | |
133 | if (retval == 0) | |
134 | retval = n; | |
135 | break; | |
136 | } | |
137 | ||
138 | if (start == NULL) { | |
139 | if (n > PAGE_SIZE) { | |
140 | printk(KERN_ERR | |
141 | "proc_file_read: Apparent buffer overflow!\n"); | |
142 | n = PAGE_SIZE; | |
143 | } | |
144 | n -= *ppos; | |
145 | if (n <= 0) | |
146 | break; | |
147 | if (n > count) | |
148 | n = count; | |
149 | start = page + *ppos; | |
150 | } else if (start < page) { | |
151 | if (n > PAGE_SIZE) { | |
152 | printk(KERN_ERR | |
153 | "proc_file_read: Apparent buffer overflow!\n"); | |
154 | n = PAGE_SIZE; | |
155 | } | |
156 | if (n > count) { | |
157 | /* | |
158 | * Don't reduce n because doing so might | |
159 | * cut off part of a data block. | |
160 | */ | |
161 | printk(KERN_WARNING | |
162 | "proc_file_read: Read count exceeded\n"); | |
163 | } | |
164 | } else /* start >= page */ { | |
165 | unsigned long startoff = (unsigned long)(start - page); | |
166 | if (n > (PAGE_SIZE - startoff)) { | |
167 | printk(KERN_ERR | |
168 | "proc_file_read: Apparent buffer overflow!\n"); | |
169 | n = PAGE_SIZE - startoff; | |
170 | } | |
171 | if (n > count) | |
172 | n = count; | |
173 | } | |
174 | ||
175 | n -= copy_to_user(buf, start < page ? page : start, n); | |
176 | if (n == 0) { | |
177 | if (retval == 0) | |
178 | retval = -EFAULT; | |
179 | break; | |
180 | } | |
181 | ||
182 | *ppos += start < page ? (unsigned long)start : n; | |
183 | nbytes -= n; | |
184 | buf += n; | |
185 | retval += n; | |
186 | } | |
187 | free_page((unsigned long) page); | |
188 | return retval; | |
189 | } | |
190 | ||
191 | static ssize_t | |
192 | proc_file_write(struct file *file, const char __user *buffer, | |
193 | size_t count, loff_t *ppos) | |
194 | { | |
2fddfeef | 195 | struct inode *inode = file->f_path.dentry->d_inode; |
1da177e4 LT |
196 | struct proc_dir_entry * dp; |
197 | ||
198 | dp = PDE(inode); | |
199 | ||
200 | if (!dp->write_proc) | |
201 | return -EIO; | |
202 | ||
203 | /* FIXME: does this routine need ppos? probably... */ | |
204 | return dp->write_proc(file, buffer, count, dp->data); | |
205 | } | |
206 | ||
207 | ||
208 | static loff_t | |
209 | proc_file_lseek(struct file *file, loff_t offset, int orig) | |
210 | { | |
8b90db0d LT |
211 | loff_t retval = -EINVAL; |
212 | switch (orig) { | |
213 | case 1: | |
214 | offset += file->f_pos; | |
215 | /* fallthrough */ | |
216 | case 0: | |
217 | if (offset < 0 || offset > MAX_NON_LFS) | |
218 | break; | |
219 | file->f_pos = retval = offset; | |
220 | } | |
221 | return retval; | |
1da177e4 LT |
222 | } |
223 | ||
76df0c25 AD |
224 | static const struct file_operations proc_file_operations = { |
225 | .llseek = proc_file_lseek, | |
226 | .read = proc_file_read, | |
227 | .write = proc_file_write, | |
228 | }; | |
229 | ||
1da177e4 LT |
230 | static int proc_notify_change(struct dentry *dentry, struct iattr *iattr) |
231 | { | |
232 | struct inode *inode = dentry->d_inode; | |
233 | struct proc_dir_entry *de = PDE(inode); | |
234 | int error; | |
235 | ||
236 | error = inode_change_ok(inode, iattr); | |
237 | if (error) | |
238 | goto out; | |
239 | ||
240 | error = inode_setattr(inode, iattr); | |
241 | if (error) | |
242 | goto out; | |
243 | ||
244 | de->uid = inode->i_uid; | |
245 | de->gid = inode->i_gid; | |
246 | de->mode = inode->i_mode; | |
247 | out: | |
248 | return error; | |
249 | } | |
250 | ||
2b579bee MS |
251 | static int proc_getattr(struct vfsmount *mnt, struct dentry *dentry, |
252 | struct kstat *stat) | |
253 | { | |
254 | struct inode *inode = dentry->d_inode; | |
255 | struct proc_dir_entry *de = PROC_I(inode)->pde; | |
256 | if (de && de->nlink) | |
257 | inode->i_nlink = de->nlink; | |
258 | ||
259 | generic_fillattr(inode, stat); | |
260 | return 0; | |
261 | } | |
262 | ||
c5ef1c42 | 263 | static const struct inode_operations proc_file_inode_operations = { |
1da177e4 LT |
264 | .setattr = proc_notify_change, |
265 | }; | |
266 | ||
267 | /* | |
268 | * This function parses a name such as "tty/driver/serial", and | |
269 | * returns the struct proc_dir_entry for "/proc/tty/driver", and | |
270 | * returns "serial" in residual. | |
271 | */ | |
272 | static int xlate_proc_name(const char *name, | |
273 | struct proc_dir_entry **ret, const char **residual) | |
274 | { | |
275 | const char *cp = name, *next; | |
276 | struct proc_dir_entry *de; | |
277 | int len; | |
64a07bd8 | 278 | int rtn = 0; |
1da177e4 | 279 | |
64a07bd8 | 280 | spin_lock(&proc_subdir_lock); |
1da177e4 LT |
281 | de = &proc_root; |
282 | while (1) { | |
283 | next = strchr(cp, '/'); | |
284 | if (!next) | |
285 | break; | |
286 | ||
287 | len = next - cp; | |
288 | for (de = de->subdir; de ; de = de->next) { | |
289 | if (proc_match(len, cp, de)) | |
290 | break; | |
291 | } | |
64a07bd8 SR |
292 | if (!de) { |
293 | rtn = -ENOENT; | |
294 | goto out; | |
295 | } | |
1da177e4 LT |
296 | cp += len + 1; |
297 | } | |
298 | *residual = cp; | |
299 | *ret = de; | |
64a07bd8 SR |
300 | out: |
301 | spin_unlock(&proc_subdir_lock); | |
302 | return rtn; | |
1da177e4 LT |
303 | } |
304 | ||
305 | static DEFINE_IDR(proc_inum_idr); | |
306 | static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */ | |
307 | ||
308 | #define PROC_DYNAMIC_FIRST 0xF0000000UL | |
309 | ||
310 | /* | |
311 | * Return an inode number between PROC_DYNAMIC_FIRST and | |
312 | * 0xffffffff, or zero on failure. | |
313 | */ | |
314 | static unsigned int get_inode_number(void) | |
315 | { | |
316 | int i, inum = 0; | |
317 | int error; | |
318 | ||
319 | retry: | |
320 | if (idr_pre_get(&proc_inum_idr, GFP_KERNEL) == 0) | |
321 | return 0; | |
322 | ||
323 | spin_lock(&proc_inum_lock); | |
324 | error = idr_get_new(&proc_inum_idr, NULL, &i); | |
325 | spin_unlock(&proc_inum_lock); | |
326 | if (error == -EAGAIN) | |
327 | goto retry; | |
328 | else if (error) | |
329 | return 0; | |
330 | ||
331 | inum = (i & MAX_ID_MASK) + PROC_DYNAMIC_FIRST; | |
332 | ||
333 | /* inum will never be more than 0xf0ffffff, so no check | |
334 | * for overflow. | |
335 | */ | |
336 | ||
337 | return inum; | |
338 | } | |
339 | ||
340 | static void release_inode_number(unsigned int inum) | |
341 | { | |
342 | int id = (inum - PROC_DYNAMIC_FIRST) | ~MAX_ID_MASK; | |
343 | ||
344 | spin_lock(&proc_inum_lock); | |
345 | idr_remove(&proc_inum_idr, id); | |
346 | spin_unlock(&proc_inum_lock); | |
347 | } | |
348 | ||
008b150a | 349 | static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd) |
1da177e4 LT |
350 | { |
351 | nd_set_link(nd, PDE(dentry->d_inode)->data); | |
008b150a | 352 | return NULL; |
1da177e4 LT |
353 | } |
354 | ||
c5ef1c42 | 355 | static const struct inode_operations proc_link_inode_operations = { |
1da177e4 LT |
356 | .readlink = generic_readlink, |
357 | .follow_link = proc_follow_link, | |
358 | }; | |
359 | ||
360 | /* | |
361 | * As some entries in /proc are volatile, we want to | |
362 | * get rid of unused dentries. This could be made | |
363 | * smarter: we could keep a "volatile" flag in the | |
364 | * inode to indicate which ones to keep. | |
365 | */ | |
366 | static int proc_delete_dentry(struct dentry * dentry) | |
367 | { | |
368 | return 1; | |
369 | } | |
370 | ||
371 | static struct dentry_operations proc_dentry_operations = | |
372 | { | |
373 | .d_delete = proc_delete_dentry, | |
374 | }; | |
375 | ||
376 | /* | |
377 | * Don't create negative dentries here, return -ENOENT by hand | |
378 | * instead. | |
379 | */ | |
380 | struct dentry *proc_lookup(struct inode * dir, struct dentry *dentry, struct nameidata *nd) | |
381 | { | |
382 | struct inode *inode = NULL; | |
383 | struct proc_dir_entry * de; | |
384 | int error = -ENOENT; | |
385 | ||
386 | lock_kernel(); | |
64a07bd8 | 387 | spin_lock(&proc_subdir_lock); |
1da177e4 LT |
388 | de = PDE(dir); |
389 | if (de) { | |
390 | for (de = de->subdir; de ; de = de->next) { | |
391 | if (de->namelen != dentry->d_name.len) | |
392 | continue; | |
393 | if (!memcmp(dentry->d_name.name, de->name, de->namelen)) { | |
2b1e300a | 394 | unsigned int ino; |
1da177e4 | 395 | |
2b1e300a EB |
396 | if (de->shadow_proc) |
397 | de = de->shadow_proc(current, de); | |
398 | ino = de->low_ino; | |
7695650a | 399 | de_get(de); |
64a07bd8 | 400 | spin_unlock(&proc_subdir_lock); |
1da177e4 LT |
401 | error = -EINVAL; |
402 | inode = proc_get_inode(dir->i_sb, ino, de); | |
4237e0d3 | 403 | goto out_unlock; |
1da177e4 LT |
404 | } |
405 | } | |
406 | } | |
64a07bd8 | 407 | spin_unlock(&proc_subdir_lock); |
4237e0d3 | 408 | out_unlock: |
1da177e4 LT |
409 | unlock_kernel(); |
410 | ||
411 | if (inode) { | |
412 | dentry->d_op = &proc_dentry_operations; | |
413 | d_add(dentry, inode); | |
414 | return NULL; | |
415 | } | |
7695650a | 416 | de_put(de); |
1da177e4 LT |
417 | return ERR_PTR(error); |
418 | } | |
419 | ||
420 | /* | |
421 | * This returns non-zero if at EOF, so that the /proc | |
422 | * root directory can use this and check if it should | |
423 | * continue with the <pid> entries.. | |
424 | * | |
425 | * Note that the VFS-layer doesn't care about the return | |
426 | * value of the readdir() call, as long as it's non-negative | |
427 | * for success.. | |
428 | */ | |
429 | int proc_readdir(struct file * filp, | |
430 | void * dirent, filldir_t filldir) | |
431 | { | |
432 | struct proc_dir_entry * de; | |
433 | unsigned int ino; | |
434 | int i; | |
2fddfeef | 435 | struct inode *inode = filp->f_path.dentry->d_inode; |
1da177e4 LT |
436 | int ret = 0; |
437 | ||
438 | lock_kernel(); | |
439 | ||
440 | ino = inode->i_ino; | |
441 | de = PDE(inode); | |
442 | if (!de) { | |
443 | ret = -EINVAL; | |
444 | goto out; | |
445 | } | |
446 | i = filp->f_pos; | |
447 | switch (i) { | |
448 | case 0: | |
449 | if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) | |
450 | goto out; | |
451 | i++; | |
452 | filp->f_pos++; | |
453 | /* fall through */ | |
454 | case 1: | |
455 | if (filldir(dirent, "..", 2, i, | |
2fddfeef | 456 | parent_ino(filp->f_path.dentry), |
1da177e4 LT |
457 | DT_DIR) < 0) |
458 | goto out; | |
459 | i++; | |
460 | filp->f_pos++; | |
461 | /* fall through */ | |
462 | default: | |
64a07bd8 | 463 | spin_lock(&proc_subdir_lock); |
1da177e4 LT |
464 | de = de->subdir; |
465 | i -= 2; | |
466 | for (;;) { | |
467 | if (!de) { | |
468 | ret = 1; | |
64a07bd8 | 469 | spin_unlock(&proc_subdir_lock); |
1da177e4 LT |
470 | goto out; |
471 | } | |
472 | if (!i) | |
473 | break; | |
474 | de = de->next; | |
475 | i--; | |
476 | } | |
477 | ||
478 | do { | |
59cd0cbc DW |
479 | struct proc_dir_entry *next; |
480 | ||
64a07bd8 | 481 | /* filldir passes info to user space */ |
59cd0cbc | 482 | de_get(de); |
64a07bd8 | 483 | spin_unlock(&proc_subdir_lock); |
1da177e4 | 484 | if (filldir(dirent, de->name, de->namelen, filp->f_pos, |
59cd0cbc DW |
485 | de->low_ino, de->mode >> 12) < 0) { |
486 | de_put(de); | |
1da177e4 | 487 | goto out; |
59cd0cbc | 488 | } |
64a07bd8 | 489 | spin_lock(&proc_subdir_lock); |
1da177e4 | 490 | filp->f_pos++; |
59cd0cbc DW |
491 | next = de->next; |
492 | de_put(de); | |
493 | de = next; | |
1da177e4 | 494 | } while (de); |
64a07bd8 | 495 | spin_unlock(&proc_subdir_lock); |
1da177e4 LT |
496 | } |
497 | ret = 1; | |
498 | out: unlock_kernel(); | |
499 | return ret; | |
500 | } | |
501 | ||
502 | /* | |
503 | * These are the generic /proc directory operations. They | |
504 | * use the in-memory "struct proc_dir_entry" tree to parse | |
505 | * the /proc directory. | |
506 | */ | |
00977a59 | 507 | static const struct file_operations proc_dir_operations = { |
1da177e4 LT |
508 | .read = generic_read_dir, |
509 | .readdir = proc_readdir, | |
510 | }; | |
511 | ||
512 | /* | |
513 | * proc directories can do almost nothing.. | |
514 | */ | |
c5ef1c42 | 515 | static const struct inode_operations proc_dir_inode_operations = { |
1da177e4 | 516 | .lookup = proc_lookup, |
2b579bee | 517 | .getattr = proc_getattr, |
1da177e4 LT |
518 | .setattr = proc_notify_change, |
519 | }; | |
520 | ||
521 | static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp) | |
522 | { | |
523 | unsigned int i; | |
94413d88 | 524 | struct proc_dir_entry *tmp; |
1da177e4 LT |
525 | |
526 | i = get_inode_number(); | |
527 | if (i == 0) | |
528 | return -EAGAIN; | |
529 | dp->low_ino = i; | |
64a07bd8 | 530 | |
1da177e4 LT |
531 | if (S_ISDIR(dp->mode)) { |
532 | if (dp->proc_iops == NULL) { | |
533 | dp->proc_fops = &proc_dir_operations; | |
534 | dp->proc_iops = &proc_dir_inode_operations; | |
535 | } | |
536 | dir->nlink++; | |
537 | } else if (S_ISLNK(dp->mode)) { | |
538 | if (dp->proc_iops == NULL) | |
539 | dp->proc_iops = &proc_link_inode_operations; | |
540 | } else if (S_ISREG(dp->mode)) { | |
541 | if (dp->proc_fops == NULL) | |
542 | dp->proc_fops = &proc_file_operations; | |
543 | if (dp->proc_iops == NULL) | |
544 | dp->proc_iops = &proc_file_inode_operations; | |
545 | } | |
99fc06df CG |
546 | |
547 | spin_lock(&proc_subdir_lock); | |
94413d88 ZR |
548 | |
549 | for (tmp = dir->subdir; tmp; tmp = tmp->next) | |
550 | if (strcmp(tmp->name, dp->name) == 0) { | |
551 | printk(KERN_WARNING "proc_dir_entry '%s' already " | |
552 | "registered\n", dp->name); | |
553 | dump_stack(); | |
554 | break; | |
555 | } | |
556 | ||
99fc06df CG |
557 | dp->next = dir->subdir; |
558 | dp->parent = dir; | |
559 | dir->subdir = dp; | |
560 | spin_unlock(&proc_subdir_lock); | |
561 | ||
1da177e4 LT |
562 | return 0; |
563 | } | |
564 | ||
2d3a4e36 | 565 | static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent, |
1da177e4 LT |
566 | const char *name, |
567 | mode_t mode, | |
568 | nlink_t nlink) | |
569 | { | |
570 | struct proc_dir_entry *ent = NULL; | |
571 | const char *fn = name; | |
572 | int len; | |
573 | ||
574 | /* make sure name is valid */ | |
575 | if (!name || !strlen(name)) goto out; | |
576 | ||
577 | if (!(*parent) && xlate_proc_name(name, parent, &fn) != 0) | |
578 | goto out; | |
579 | ||
580 | /* At this point there must not be any '/' characters beyond *fn */ | |
581 | if (strchr(fn, '/')) | |
582 | goto out; | |
583 | ||
584 | len = strlen(fn); | |
585 | ||
586 | ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL); | |
587 | if (!ent) goto out; | |
588 | ||
589 | memset(ent, 0, sizeof(struct proc_dir_entry)); | |
590 | memcpy(((char *) ent) + sizeof(struct proc_dir_entry), fn, len + 1); | |
591 | ent->name = ((char *) ent) + sizeof(*ent); | |
592 | ent->namelen = len; | |
593 | ent->mode = mode; | |
594 | ent->nlink = nlink; | |
5a622f2d | 595 | atomic_set(&ent->count, 1); |
786d7e16 AD |
596 | ent->pde_users = 0; |
597 | spin_lock_init(&ent->pde_unload_lock); | |
598 | ent->pde_unload_completion = NULL; | |
1da177e4 LT |
599 | out: |
600 | return ent; | |
601 | } | |
602 | ||
603 | struct proc_dir_entry *proc_symlink(const char *name, | |
604 | struct proc_dir_entry *parent, const char *dest) | |
605 | { | |
606 | struct proc_dir_entry *ent; | |
607 | ||
2d3a4e36 | 608 | ent = __proc_create(&parent, name, |
1da177e4 LT |
609 | (S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO),1); |
610 | ||
611 | if (ent) { | |
612 | ent->data = kmalloc((ent->size=strlen(dest))+1, GFP_KERNEL); | |
613 | if (ent->data) { | |
614 | strcpy((char*)ent->data,dest); | |
615 | if (proc_register(parent, ent) < 0) { | |
616 | kfree(ent->data); | |
617 | kfree(ent); | |
618 | ent = NULL; | |
619 | } | |
620 | } else { | |
621 | kfree(ent); | |
622 | ent = NULL; | |
623 | } | |
624 | } | |
625 | return ent; | |
626 | } | |
627 | ||
628 | struct proc_dir_entry *proc_mkdir_mode(const char *name, mode_t mode, | |
629 | struct proc_dir_entry *parent) | |
630 | { | |
631 | struct proc_dir_entry *ent; | |
632 | ||
2d3a4e36 | 633 | ent = __proc_create(&parent, name, S_IFDIR | mode, 2); |
1da177e4 | 634 | if (ent) { |
1da177e4 LT |
635 | if (proc_register(parent, ent) < 0) { |
636 | kfree(ent); | |
637 | ent = NULL; | |
638 | } | |
639 | } | |
640 | return ent; | |
641 | } | |
642 | ||
643 | struct proc_dir_entry *proc_mkdir(const char *name, | |
644 | struct proc_dir_entry *parent) | |
645 | { | |
646 | return proc_mkdir_mode(name, S_IRUGO | S_IXUGO, parent); | |
647 | } | |
648 | ||
649 | struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode, | |
650 | struct proc_dir_entry *parent) | |
651 | { | |
652 | struct proc_dir_entry *ent; | |
653 | nlink_t nlink; | |
654 | ||
655 | if (S_ISDIR(mode)) { | |
656 | if ((mode & S_IALLUGO) == 0) | |
657 | mode |= S_IRUGO | S_IXUGO; | |
658 | nlink = 2; | |
659 | } else { | |
660 | if ((mode & S_IFMT) == 0) | |
661 | mode |= S_IFREG; | |
662 | if ((mode & S_IALLUGO) == 0) | |
663 | mode |= S_IRUGO; | |
664 | nlink = 1; | |
665 | } | |
666 | ||
2d3a4e36 | 667 | ent = __proc_create(&parent, name, mode, nlink); |
1da177e4 | 668 | if (ent) { |
1da177e4 LT |
669 | if (proc_register(parent, ent) < 0) { |
670 | kfree(ent); | |
671 | ent = NULL; | |
672 | } | |
673 | } | |
674 | return ent; | |
675 | } | |
676 | ||
2d3a4e36 AD |
677 | struct proc_dir_entry *proc_create(const char *name, mode_t mode, |
678 | struct proc_dir_entry *parent, | |
679 | const struct file_operations *proc_fops) | |
680 | { | |
681 | struct proc_dir_entry *pde; | |
682 | nlink_t nlink; | |
683 | ||
684 | if (S_ISDIR(mode)) { | |
685 | if ((mode & S_IALLUGO) == 0) | |
686 | mode |= S_IRUGO | S_IXUGO; | |
687 | nlink = 2; | |
688 | } else { | |
689 | if ((mode & S_IFMT) == 0) | |
690 | mode |= S_IFREG; | |
691 | if ((mode & S_IALLUGO) == 0) | |
692 | mode |= S_IRUGO; | |
693 | nlink = 1; | |
694 | } | |
695 | ||
696 | pde = __proc_create(&parent, name, mode, nlink); | |
697 | if (!pde) | |
698 | goto out; | |
699 | pde->proc_fops = proc_fops; | |
700 | if (proc_register(parent, pde) < 0) | |
701 | goto out_free; | |
702 | return pde; | |
703 | out_free: | |
704 | kfree(pde); | |
705 | out: | |
706 | return NULL; | |
707 | } | |
708 | ||
1da177e4 LT |
709 | void free_proc_entry(struct proc_dir_entry *de) |
710 | { | |
711 | unsigned int ino = de->low_ino; | |
712 | ||
713 | if (ino < PROC_DYNAMIC_FIRST) | |
714 | return; | |
715 | ||
716 | release_inode_number(ino); | |
717 | ||
fd2cbe48 | 718 | if (S_ISLNK(de->mode)) |
1da177e4 LT |
719 | kfree(de->data); |
720 | kfree(de); | |
721 | } | |
722 | ||
723 | /* | |
724 | * Remove a /proc entry and free it if it's not currently in use. | |
1da177e4 LT |
725 | */ |
726 | void remove_proc_entry(const char *name, struct proc_dir_entry *parent) | |
727 | { | |
728 | struct proc_dir_entry **p; | |
729 | struct proc_dir_entry *de; | |
730 | const char *fn = name; | |
731 | int len; | |
732 | ||
733 | if (!parent && xlate_proc_name(name, &parent, &fn) != 0) | |
734 | goto out; | |
735 | len = strlen(fn); | |
64a07bd8 SR |
736 | |
737 | spin_lock(&proc_subdir_lock); | |
1da177e4 LT |
738 | for (p = &parent->subdir; *p; p=&(*p)->next ) { |
739 | if (!proc_match(len, fn, *p)) | |
740 | continue; | |
741 | de = *p; | |
742 | *p = de->next; | |
743 | de->next = NULL; | |
786d7e16 AD |
744 | |
745 | spin_lock(&de->pde_unload_lock); | |
746 | /* | |
747 | * Stop accepting new callers into module. If you're | |
748 | * dynamically allocating ->proc_fops, save a pointer somewhere. | |
749 | */ | |
750 | de->proc_fops = NULL; | |
751 | /* Wait until all existing callers into module are done. */ | |
752 | if (de->pde_users > 0) { | |
753 | DECLARE_COMPLETION_ONSTACK(c); | |
754 | ||
755 | if (!de->pde_unload_completion) | |
756 | de->pde_unload_completion = &c; | |
757 | ||
758 | spin_unlock(&de->pde_unload_lock); | |
759 | spin_unlock(&proc_subdir_lock); | |
760 | ||
761 | wait_for_completion(de->pde_unload_completion); | |
762 | ||
763 | spin_lock(&proc_subdir_lock); | |
764 | goto continue_removing; | |
765 | } | |
766 | spin_unlock(&de->pde_unload_lock); | |
767 | ||
768 | continue_removing: | |
1da177e4 LT |
769 | if (S_ISDIR(de->mode)) |
770 | parent->nlink--; | |
1da177e4 LT |
771 | de->nlink = 0; |
772 | WARN_ON(de->subdir); | |
5a622f2d | 773 | if (atomic_dec_and_test(&de->count)) |
1da177e4 | 774 | free_proc_entry(de); |
1da177e4 LT |
775 | break; |
776 | } | |
64a07bd8 | 777 | spin_unlock(&proc_subdir_lock); |
1da177e4 LT |
778 | out: |
779 | return; | |
780 | } |