blob: bca0f81eb6876fba681f3db8dedd9788887e93b5 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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>
Steven Rostedt64a07bd2006-03-26 01:36:55 -080022#include <linux/spinlock.h>
Alexey Dobriyan786d7e12007-07-15 23:39:00 -070023#include <linux/completion.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070024#include <asm/uaccess.h>
25
Adrian Bunkfee781e2006-01-08 01:04:16 -080026#include "internal.h"
27
Steven Rostedt64a07bd2006-03-26 01:36:55 -080028DEFINE_SPINLOCK(proc_subdir_lock);
29
Eric W. Biederman77b14db2007-02-14 00:34:12 -080030static int proc_match(int len, const char *name, struct proc_dir_entry *de)
Linus Torvalds1da177e2005-04-16 15:20:36 -070031{
32 if (de->namelen != len)
33 return 0;
34 return !memcmp(name, de->name, len);
35}
36
Linus Torvalds1da177e2005-04-16 15:20:36 -070037/* buffer size is one page but our output routines use some slack for overruns */
38#define PROC_BLOCK_SIZE (PAGE_SIZE - 1024)
39
40static ssize_t
41proc_file_read(struct file *file, char __user *buf, size_t nbytes,
42 loff_t *ppos)
43{
Josef "Jeff" Sipek2fddfee2006-12-08 02:36:36 -080044 struct inode * inode = file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070045 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;
Linus Torvalds8b90db02005-12-30 08:39:10 -080051 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;
Linus Torvalds1da177e2005-04-16 15:20:36 -070063
64 dp = PDE(inode);
Mel Gormane12ba742007-10-16 01:25:52 -070065 if (!(page = (char*) __get_free_page(GFP_TEMPORARY)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070066 return -ENOMEM;
67
68 while ((nbytes > 0) && !eof) {
69 count = min_t(size_t, PROC_BLOCK_SIZE, nbytes);
70
71 start = NULL;
Alexey Dobriyan8731f142008-04-29 01:01:58 -070072 if (dp->read_proc) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 /*
74 * How to be a proc read function
75 * ------------------------------
76 * Prototype:
77 * int f(char *buffer, char **start, off_t offset,
78 * int count, int *peof, void *dat)
79 *
80 * Assume that the buffer is "count" bytes in size.
81 *
82 * If you know you have supplied all the data you
83 * have, set *peof.
84 *
85 * You have three ways to return data:
86 * 0) Leave *start = NULL. (This is the default.)
87 * Put the data of the requested offset at that
88 * offset within the buffer. Return the number (n)
89 * of bytes there are from the beginning of the
90 * buffer up to the last byte of data. If the
91 * number of supplied bytes (= n - offset) is
92 * greater than zero and you didn't signal eof
93 * and the reader is prepared to take more data
94 * you will be called again with the requested
95 * offset advanced by the number of bytes
96 * absorbed. This interface is useful for files
97 * no larger than the buffer.
98 * 1) Set *start = an unsigned long value less than
99 * the buffer address but greater than zero.
100 * Put the data of the requested offset at the
101 * beginning of the buffer. Return the number of
102 * bytes of data placed there. If this number is
103 * greater than zero and you didn't signal eof
104 * and the reader is prepared to take more data
105 * you will be called again with the requested
106 * offset advanced by *start. This interface is
107 * useful when you have a large file consisting
108 * of a series of blocks which you want to count
109 * and return as wholes.
110 * (Hack by Paul.Russell@rustcorp.com.au)
111 * 2) Set *start = an address within the buffer.
112 * Put the data of the requested offset at *start.
113 * Return the number of bytes of data placed there.
114 * If this number is greater than zero and you
115 * didn't signal eof and the reader is prepared to
116 * take more data you will be called again with the
117 * requested offset advanced by the number of bytes
118 * absorbed.
119 */
120 n = dp->read_proc(page, &start, *ppos,
121 count, &eof, dp->data);
122 } else
123 break;
124
125 if (n == 0) /* end of file */
126 break;
127 if (n < 0) { /* error */
128 if (retval == 0)
129 retval = n;
130 break;
131 }
132
133 if (start == NULL) {
134 if (n > PAGE_SIZE) {
135 printk(KERN_ERR
136 "proc_file_read: Apparent buffer overflow!\n");
137 n = PAGE_SIZE;
138 }
139 n -= *ppos;
140 if (n <= 0)
141 break;
142 if (n > count)
143 n = count;
144 start = page + *ppos;
145 } else if (start < page) {
146 if (n > PAGE_SIZE) {
147 printk(KERN_ERR
148 "proc_file_read: Apparent buffer overflow!\n");
149 n = PAGE_SIZE;
150 }
151 if (n > count) {
152 /*
153 * Don't reduce n because doing so might
154 * cut off part of a data block.
155 */
156 printk(KERN_WARNING
157 "proc_file_read: Read count exceeded\n");
158 }
159 } else /* start >= page */ {
160 unsigned long startoff = (unsigned long)(start - page);
161 if (n > (PAGE_SIZE - startoff)) {
162 printk(KERN_ERR
163 "proc_file_read: Apparent buffer overflow!\n");
164 n = PAGE_SIZE - startoff;
165 }
166 if (n > count)
167 n = count;
168 }
169
170 n -= copy_to_user(buf, start < page ? page : start, n);
171 if (n == 0) {
172 if (retval == 0)
173 retval = -EFAULT;
174 break;
175 }
176
177 *ppos += start < page ? (unsigned long)start : n;
178 nbytes -= n;
179 buf += n;
180 retval += n;
181 }
182 free_page((unsigned long) page);
183 return retval;
184}
185
186static ssize_t
187proc_file_write(struct file *file, const char __user *buffer,
188 size_t count, loff_t *ppos)
189{
Josef "Jeff" Sipek2fddfee2006-12-08 02:36:36 -0800190 struct inode *inode = file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700191 struct proc_dir_entry * dp;
192
193 dp = PDE(inode);
194
195 if (!dp->write_proc)
196 return -EIO;
197
198 /* FIXME: does this routine need ppos? probably... */
199 return dp->write_proc(file, buffer, count, dp->data);
200}
201
202
203static loff_t
204proc_file_lseek(struct file *file, loff_t offset, int orig)
205{
Linus Torvalds8b90db02005-12-30 08:39:10 -0800206 loff_t retval = -EINVAL;
207 switch (orig) {
208 case 1:
209 offset += file->f_pos;
210 /* fallthrough */
211 case 0:
212 if (offset < 0 || offset > MAX_NON_LFS)
213 break;
214 file->f_pos = retval = offset;
215 }
216 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700217}
218
Alexey Dobriyan76df0c22008-02-08 04:18:27 -0800219static const struct file_operations proc_file_operations = {
220 .llseek = proc_file_lseek,
221 .read = proc_file_read,
222 .write = proc_file_write,
223};
224
Linus Torvalds1da177e2005-04-16 15:20:36 -0700225static int proc_notify_change(struct dentry *dentry, struct iattr *iattr)
226{
227 struct inode *inode = dentry->d_inode;
228 struct proc_dir_entry *de = PDE(inode);
229 int error;
230
231 error = inode_change_ok(inode, iattr);
232 if (error)
233 goto out;
234
235 error = inode_setattr(inode, iattr);
236 if (error)
237 goto out;
238
239 de->uid = inode->i_uid;
240 de->gid = inode->i_gid;
241 de->mode = inode->i_mode;
242out:
243 return error;
244}
245
Miklos Szeredi2b579be2005-09-06 15:17:18 -0700246static int proc_getattr(struct vfsmount *mnt, struct dentry *dentry,
247 struct kstat *stat)
248{
249 struct inode *inode = dentry->d_inode;
250 struct proc_dir_entry *de = PROC_I(inode)->pde;
251 if (de && de->nlink)
252 inode->i_nlink = de->nlink;
253
254 generic_fillattr(inode, stat);
255 return 0;
256}
257
Arjan van de Venc5ef1c42007-02-12 00:55:40 -0800258static const struct inode_operations proc_file_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 .setattr = proc_notify_change,
260};
261
262/*
263 * This function parses a name such as "tty/driver/serial", and
264 * returns the struct proc_dir_entry for "/proc/tty/driver", and
265 * returns "serial" in residual.
266 */
267static int xlate_proc_name(const char *name,
268 struct proc_dir_entry **ret, const char **residual)
269{
270 const char *cp = name, *next;
271 struct proc_dir_entry *de;
272 int len;
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800273 int rtn = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700274
Alexey Dobriyan7cee4e02008-04-29 01:01:40 -0700275 de = *ret;
276 if (!de)
277 de = &proc_root;
278
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800279 spin_lock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700280 while (1) {
281 next = strchr(cp, '/');
282 if (!next)
283 break;
284
285 len = next - cp;
286 for (de = de->subdir; de ; de = de->next) {
287 if (proc_match(len, cp, de))
288 break;
289 }
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800290 if (!de) {
291 rtn = -ENOENT;
292 goto out;
293 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700294 cp += len + 1;
295 }
296 *residual = cp;
297 *ret = de;
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800298out:
299 spin_unlock(&proc_subdir_lock);
300 return rtn;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301}
302
Alexey Dobriyan9a185402008-07-26 11:21:37 +0400303static DEFINE_IDA(proc_inum_ida);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700304static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */
305
Alexey Dobriyan67935df2008-07-26 11:18:28 +0400306#define PROC_DYNAMIC_FIRST 0xF0000000U
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307
308/*
309 * Return an inode number between PROC_DYNAMIC_FIRST and
310 * 0xffffffff, or zero on failure.
311 */
312static unsigned int get_inode_number(void)
313{
Alexey Dobriyan67935df2008-07-26 11:18:28 +0400314 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700315 int error;
316
317retry:
Alexey Dobriyan9a185402008-07-26 11:21:37 +0400318 if (ida_pre_get(&proc_inum_ida, GFP_KERNEL) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 return 0;
320
321 spin_lock(&proc_inum_lock);
Alexey Dobriyan9a185402008-07-26 11:21:37 +0400322 error = ida_get_new(&proc_inum_ida, &i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700323 spin_unlock(&proc_inum_lock);
324 if (error == -EAGAIN)
325 goto retry;
326 else if (error)
327 return 0;
328
Alexey Dobriyan67935df2008-07-26 11:18:28 +0400329 if (i > UINT_MAX - PROC_DYNAMIC_FIRST) {
330 spin_lock(&proc_inum_lock);
Alexey Dobriyan9a185402008-07-26 11:21:37 +0400331 ida_remove(&proc_inum_ida, i);
Alexey Dobriyan67935df2008-07-26 11:18:28 +0400332 spin_unlock(&proc_inum_lock);
Alexey Dobriyancc996092008-08-02 07:30:48 +0400333 return 0;
Alexey Dobriyan67935df2008-07-26 11:18:28 +0400334 }
335 return PROC_DYNAMIC_FIRST + i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336}
337
338static void release_inode_number(unsigned int inum)
339{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340 spin_lock(&proc_inum_lock);
Alexey Dobriyan9a185402008-07-26 11:21:37 +0400341 ida_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 spin_unlock(&proc_inum_lock);
343}
344
Al Viro008b1502005-08-20 00:17:39 +0100345static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346{
347 nd_set_link(nd, PDE(dentry->d_inode)->data);
Al Viro008b1502005-08-20 00:17:39 +0100348 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349}
350
Arjan van de Venc5ef1c42007-02-12 00:55:40 -0800351static const struct inode_operations proc_link_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700352 .readlink = generic_readlink,
353 .follow_link = proc_follow_link,
354};
355
356/*
357 * As some entries in /proc are volatile, we want to
358 * get rid of unused dentries. This could be made
359 * smarter: we could keep a "volatile" flag in the
360 * inode to indicate which ones to keep.
361 */
362static int proc_delete_dentry(struct dentry * dentry)
363{
364 return 1;
365}
366
367static struct dentry_operations proc_dentry_operations =
368{
369 .d_delete = proc_delete_dentry,
370};
371
372/*
373 * Don't create negative dentries here, return -ENOENT by hand
374 * instead.
375 */
Pavel Emelyanove9720ac2008-03-07 11:08:40 -0800376struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir,
377 struct dentry *dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700378{
379 struct inode *inode = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 int error = -ENOENT;
381
382 lock_kernel();
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800383 spin_lock(&proc_subdir_lock);
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700384 for (de = de->subdir; de ; de = de->next) {
385 if (de->namelen != dentry->d_name.len)
386 continue;
387 if (!memcmp(dentry->d_name.name, de->name, de->namelen)) {
388 unsigned int ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700390 ino = de->low_ino;
391 de_get(de);
392 spin_unlock(&proc_subdir_lock);
393 error = -EINVAL;
394 inode = proc_get_inode(dir->i_sb, ino, de);
395 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396 }
397 }
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800398 spin_unlock(&proc_subdir_lock);
Alexey Dobriyan4237e0d2008-02-08 04:18:27 -0800399out_unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700400 unlock_kernel();
401
402 if (inode) {
403 dentry->d_op = &proc_dentry_operations;
404 d_add(dentry, inode);
405 return NULL;
406 }
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700407 if (de)
408 de_put(de);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409 return ERR_PTR(error);
410}
411
Pavel Emelyanove9720ac2008-03-07 11:08:40 -0800412struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry,
413 struct nameidata *nd)
414{
415 return proc_lookup_de(PDE(dir), dir, dentry);
416}
417
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418/*
419 * This returns non-zero if at EOF, so that the /proc
420 * root directory can use this and check if it should
421 * continue with the <pid> entries..
422 *
423 * Note that the VFS-layer doesn't care about the return
424 * value of the readdir() call, as long as it's non-negative
425 * for success..
426 */
Pavel Emelyanove9720ac2008-03-07 11:08:40 -0800427int proc_readdir_de(struct proc_dir_entry *de, struct file *filp, void *dirent,
428 filldir_t filldir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430 unsigned int ino;
431 int i;
Josef "Jeff" Sipek2fddfee2006-12-08 02:36:36 -0800432 struct inode *inode = filp->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 int ret = 0;
434
435 lock_kernel();
436
437 ino = inode->i_ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700438 i = filp->f_pos;
439 switch (i) {
440 case 0:
441 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
442 goto out;
443 i++;
444 filp->f_pos++;
445 /* fall through */
446 case 1:
447 if (filldir(dirent, "..", 2, i,
Josef "Jeff" Sipek2fddfee2006-12-08 02:36:36 -0800448 parent_ino(filp->f_path.dentry),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449 DT_DIR) < 0)
450 goto out;
451 i++;
452 filp->f_pos++;
453 /* fall through */
454 default:
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800455 spin_lock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456 de = de->subdir;
457 i -= 2;
458 for (;;) {
459 if (!de) {
460 ret = 1;
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800461 spin_unlock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700462 goto out;
463 }
464 if (!i)
465 break;
466 de = de->next;
467 i--;
468 }
469
470 do {
Darrick J. Wong59cd0cb2007-05-08 00:25:47 -0700471 struct proc_dir_entry *next;
472
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800473 /* filldir passes info to user space */
Darrick J. Wong59cd0cb2007-05-08 00:25:47 -0700474 de_get(de);
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800475 spin_unlock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 if (filldir(dirent, de->name, de->namelen, filp->f_pos,
Darrick J. Wong59cd0cb2007-05-08 00:25:47 -0700477 de->low_ino, de->mode >> 12) < 0) {
478 de_put(de);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700479 goto out;
Darrick J. Wong59cd0cb2007-05-08 00:25:47 -0700480 }
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800481 spin_lock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700482 filp->f_pos++;
Darrick J. Wong59cd0cb2007-05-08 00:25:47 -0700483 next = de->next;
484 de_put(de);
485 de = next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700486 } while (de);
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800487 spin_unlock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488 }
489 ret = 1;
490out: unlock_kernel();
491 return ret;
492}
493
Pavel Emelyanove9720ac2008-03-07 11:08:40 -0800494int proc_readdir(struct file *filp, void *dirent, filldir_t filldir)
495{
496 struct inode *inode = filp->f_path.dentry->d_inode;
497
498 return proc_readdir_de(PDE(inode), filp, dirent, filldir);
499}
500
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501/*
502 * These are the generic /proc directory operations. They
503 * use the in-memory "struct proc_dir_entry" tree to parse
504 * the /proc directory.
505 */
Arjan van de Ven00977a52007-02-12 00:55:34 -0800506static const struct file_operations proc_dir_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700507 .read = generic_read_dir,
508 .readdir = proc_readdir,
509};
510
511/*
512 * proc directories can do almost nothing..
513 */
Arjan van de Venc5ef1c42007-02-12 00:55:40 -0800514static const struct inode_operations proc_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 .lookup = proc_lookup,
Miklos Szeredi2b579be2005-09-06 15:17:18 -0700516 .getattr = proc_getattr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 .setattr = proc_notify_change,
518};
519
520static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
521{
522 unsigned int i;
Zhang Rui94413d82008-02-08 04:18:29 -0800523 struct proc_dir_entry *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700524
525 i = get_inode_number();
526 if (i == 0)
527 return -EAGAIN;
528 dp->low_ino = i;
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800529
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 if (S_ISDIR(dp->mode)) {
531 if (dp->proc_iops == NULL) {
532 dp->proc_fops = &proc_dir_operations;
533 dp->proc_iops = &proc_dir_inode_operations;
534 }
535 dir->nlink++;
536 } else if (S_ISLNK(dp->mode)) {
537 if (dp->proc_iops == NULL)
538 dp->proc_iops = &proc_link_inode_operations;
539 } else if (S_ISREG(dp->mode)) {
540 if (dp->proc_fops == NULL)
541 dp->proc_fops = &proc_file_operations;
542 if (dp->proc_iops == NULL)
543 dp->proc_iops = &proc_file_inode_operations;
544 }
Changli Gao99fc06d2007-07-15 23:40:09 -0700545
546 spin_lock(&proc_subdir_lock);
Zhang Rui94413d82008-02-08 04:18:29 -0800547
548 for (tmp = dir->subdir; tmp; tmp = tmp->next)
549 if (strcmp(tmp->name, dp->name) == 0) {
550 printk(KERN_WARNING "proc_dir_entry '%s' already "
551 "registered\n", dp->name);
552 dump_stack();
553 break;
554 }
555
Changli Gao99fc06d2007-07-15 23:40:09 -0700556 dp->next = dir->subdir;
557 dp->parent = dir;
558 dir->subdir = dp;
559 spin_unlock(&proc_subdir_lock);
560
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561 return 0;
562}
563
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800564static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 const char *name,
566 mode_t mode,
567 nlink_t nlink)
568{
569 struct proc_dir_entry *ent = NULL;
570 const char *fn = name;
571 int len;
572
573 /* make sure name is valid */
574 if (!name || !strlen(name)) goto out;
575
Alexey Dobriyan7cee4e02008-04-29 01:01:40 -0700576 if (xlate_proc_name(name, parent, &fn) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577 goto out;
578
579 /* At this point there must not be any '/' characters beyond *fn */
580 if (strchr(fn, '/'))
581 goto out;
582
583 len = strlen(fn);
584
585 ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL);
586 if (!ent) goto out;
587
588 memset(ent, 0, sizeof(struct proc_dir_entry));
589 memcpy(((char *) ent) + sizeof(struct proc_dir_entry), fn, len + 1);
590 ent->name = ((char *) ent) + sizeof(*ent);
591 ent->namelen = len;
592 ent->mode = mode;
593 ent->nlink = nlink;
Alexey Dobriyan5a622f22007-12-04 23:45:28 -0800594 atomic_set(&ent->count, 1);
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700595 ent->pde_users = 0;
596 spin_lock_init(&ent->pde_unload_lock);
597 ent->pde_unload_completion = NULL;
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700598 INIT_LIST_HEAD(&ent->pde_openers);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 out:
600 return ent;
601}
602
603struct 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
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800608 ent = __proc_create(&parent, name,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 (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
628struct 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
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800633 ent = __proc_create(&parent, name, S_IFDIR | mode, 2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700634 if (ent) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 if (proc_register(parent, ent) < 0) {
636 kfree(ent);
637 ent = NULL;
638 }
639 }
640 return ent;
641}
642
Denis V. Lunev78e92b92008-05-02 04:12:41 -0700643struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name,
644 struct proc_dir_entry *parent)
645{
646 struct proc_dir_entry *ent;
647
648 ent = __proc_create(&parent, name, S_IFDIR | S_IRUGO | S_IXUGO, 2);
649 if (ent) {
650 ent->data = net;
651 if (proc_register(parent, ent) < 0) {
652 kfree(ent);
653 ent = NULL;
654 }
655 }
656 return ent;
657}
658EXPORT_SYMBOL_GPL(proc_net_mkdir);
659
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660struct proc_dir_entry *proc_mkdir(const char *name,
661 struct proc_dir_entry *parent)
662{
663 return proc_mkdir_mode(name, S_IRUGO | S_IXUGO, parent);
664}
665
666struct proc_dir_entry *create_proc_entry(const char *name, mode_t mode,
667 struct proc_dir_entry *parent)
668{
669 struct proc_dir_entry *ent;
670 nlink_t nlink;
671
672 if (S_ISDIR(mode)) {
673 if ((mode & S_IALLUGO) == 0)
674 mode |= S_IRUGO | S_IXUGO;
675 nlink = 2;
676 } else {
677 if ((mode & S_IFMT) == 0)
678 mode |= S_IFREG;
679 if ((mode & S_IALLUGO) == 0)
680 mode |= S_IRUGO;
681 nlink = 1;
682 }
683
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800684 ent = __proc_create(&parent, name, mode, nlink);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700685 if (ent) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700686 if (proc_register(parent, ent) < 0) {
687 kfree(ent);
688 ent = NULL;
689 }
690 }
691 return ent;
692}
693
Denis V. Lunev59b74352008-04-29 01:02:00 -0700694struct proc_dir_entry *proc_create_data(const char *name, mode_t mode,
695 struct proc_dir_entry *parent,
696 const struct file_operations *proc_fops,
697 void *data)
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800698{
699 struct proc_dir_entry *pde;
700 nlink_t nlink;
701
702 if (S_ISDIR(mode)) {
703 if ((mode & S_IALLUGO) == 0)
704 mode |= S_IRUGO | S_IXUGO;
705 nlink = 2;
706 } else {
707 if ((mode & S_IFMT) == 0)
708 mode |= S_IFREG;
709 if ((mode & S_IALLUGO) == 0)
710 mode |= S_IRUGO;
711 nlink = 1;
712 }
713
714 pde = __proc_create(&parent, name, mode, nlink);
715 if (!pde)
716 goto out;
717 pde->proc_fops = proc_fops;
Denis V. Lunev59b74352008-04-29 01:02:00 -0700718 pde->data = data;
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800719 if (proc_register(parent, pde) < 0)
720 goto out_free;
721 return pde;
722out_free:
723 kfree(pde);
724out:
725 return NULL;
726}
727
Linus Torvalds1da177e2005-04-16 15:20:36 -0700728void free_proc_entry(struct proc_dir_entry *de)
729{
730 unsigned int ino = de->low_ino;
731
732 if (ino < PROC_DYNAMIC_FIRST)
733 return;
734
735 release_inode_number(ino);
736
Alexey Dobriyanfd2cbe42008-02-08 04:18:28 -0800737 if (S_ISLNK(de->mode))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738 kfree(de->data);
739 kfree(de);
740}
741
742/*
743 * Remove a /proc entry and free it if it's not currently in use.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744 */
745void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
746{
747 struct proc_dir_entry **p;
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700748 struct proc_dir_entry *de = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749 const char *fn = name;
750 int len;
751
Alexey Dobriyan7cee4e02008-04-29 01:01:40 -0700752 if (xlate_proc_name(name, &parent, &fn) != 0)
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700753 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700754 len = strlen(fn);
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800755
756 spin_lock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700757 for (p = &parent->subdir; *p; p=&(*p)->next ) {
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700758 if (proc_match(len, fn, *p)) {
759 de = *p;
760 *p = de->next;
761 de->next = NULL;
762 break;
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700763 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 }
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800765 spin_unlock(&proc_subdir_lock);
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700766 if (!de)
767 return;
768
769 spin_lock(&de->pde_unload_lock);
770 /*
771 * Stop accepting new callers into module. If you're
772 * dynamically allocating ->proc_fops, save a pointer somewhere.
773 */
774 de->proc_fops = NULL;
775 /* Wait until all existing callers into module are done. */
776 if (de->pde_users > 0) {
777 DECLARE_COMPLETION_ONSTACK(c);
778
779 if (!de->pde_unload_completion)
780 de->pde_unload_completion = &c;
781
782 spin_unlock(&de->pde_unload_lock);
783
784 wait_for_completion(de->pde_unload_completion);
785
786 goto continue_removing;
787 }
788 spin_unlock(&de->pde_unload_lock);
789
790continue_removing:
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700791 spin_lock(&de->pde_unload_lock);
792 while (!list_empty(&de->pde_openers)) {
793 struct pde_opener *pdeo;
794
795 pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh);
796 list_del(&pdeo->lh);
797 spin_unlock(&de->pde_unload_lock);
798 pdeo->release(pdeo->inode, pdeo->file);
799 kfree(pdeo);
800 spin_lock(&de->pde_unload_lock);
801 }
802 spin_unlock(&de->pde_unload_lock);
803
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700804 if (S_ISDIR(de->mode))
805 parent->nlink--;
806 de->nlink = 0;
Arjan van de Ven267e2a92008-07-25 19:45:41 -0700807 WARN(de->subdir, KERN_WARNING "%s: removing non-empty directory "
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700808 "'%s/%s', leaking at least '%s'\n", __func__,
809 de->parent->name, de->name, de->subdir->name);
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700810 if (atomic_dec_and_test(&de->count))
811 free_proc_entry(de);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700812}