blob: 2edf34f2eb61136972e12e79714e36e4197e4ad8 [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>
Christoph Hellwig10257742010-06-04 11:30:02 +020015#include <linux/mm.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070016#include <linux/module.h>
Tejun Heo5a0e3ad2010-03-24 17:04:11 +090017#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/mount.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/init.h>
20#include <linux/idr.h>
21#include <linux/namei.h>
22#include <linux/bitops.h>
Steven Rostedt64a07bd2006-03-26 01:36:55 -080023#include <linux/spinlock.h>
Alexey Dobriyan786d7e12007-07-15 23:39:00 -070024#include <linux/completion.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <asm/uaccess.h>
26
Adrian Bunkfee781e2006-01-08 01:04:16 -080027#include "internal.h"
28
Steven Rostedt64a07bd2006-03-26 01:36:55 -080029DEFINE_SPINLOCK(proc_subdir_lock);
30
Alexey Dobriyan312ec7e2011-03-23 16:42:52 -070031static int proc_match(unsigned int len, const char *name, struct proc_dir_entry *de)
Linus Torvalds1da177e2005-04-16 15:20:36 -070032{
33 if (de->namelen != len)
34 return 0;
35 return !memcmp(name, de->name, len);
36}
37
Linus Torvalds1da177e2005-04-16 15:20:36 -070038/* buffer size is one page but our output routines use some slack for overruns */
39#define PROC_BLOCK_SIZE (PAGE_SIZE - 1024)
40
41static ssize_t
Alexey Dobriyan3dec7f52009-02-20 17:04:33 +030042__proc_file_read(struct file *file, char __user *buf, size_t nbytes,
Linus Torvalds1da177e2005-04-16 15:20:36 -070043 loff_t *ppos)
44{
Josef "Jeff" Sipek2fddfee2006-12-08 02:36:36 -080045 struct inode * inode = file->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070046 char *page;
47 ssize_t retval=0;
48 int eof=0;
49 ssize_t n, count;
50 char *start;
51 struct proc_dir_entry * dp;
Linus Torvalds8b90db02005-12-30 08:39:10 -080052 unsigned long long pos;
53
54 /*
55 * Gaah, please just use "seq_file" instead. The legacy /proc
56 * interfaces cut loff_t down to off_t for reads, and ignore
57 * the offset entirely for writes..
58 */
59 pos = *ppos;
60 if (pos > MAX_NON_LFS)
61 return 0;
62 if (nbytes > MAX_NON_LFS - pos)
63 nbytes = MAX_NON_LFS - pos;
Linus Torvalds1da177e2005-04-16 15:20:36 -070064
65 dp = PDE(inode);
Mel Gormane12ba742007-10-16 01:25:52 -070066 if (!(page = (char*) __get_free_page(GFP_TEMPORARY)))
Linus Torvalds1da177e2005-04-16 15:20:36 -070067 return -ENOMEM;
68
69 while ((nbytes > 0) && !eof) {
70 count = min_t(size_t, PROC_BLOCK_SIZE, nbytes);
71
72 start = NULL;
Alexey Dobriyan8731f142008-04-29 01:01:58 -070073 if (dp->read_proc) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070074 /*
75 * How to be a proc read function
76 * ------------------------------
77 * Prototype:
78 * int f(char *buffer, char **start, off_t offset,
79 * int count, int *peof, void *dat)
80 *
81 * Assume that the buffer is "count" bytes in size.
82 *
83 * If you know you have supplied all the data you
84 * have, set *peof.
85 *
86 * You have three ways to return data:
87 * 0) Leave *start = NULL. (This is the default.)
88 * Put the data of the requested offset at that
89 * offset within the buffer. Return the number (n)
90 * of bytes there are from the beginning of the
91 * buffer up to the last byte of data. If the
92 * number of supplied bytes (= n - offset) is
93 * greater than zero and you didn't signal eof
94 * and the reader is prepared to take more data
95 * you will be called again with the requested
96 * offset advanced by the number of bytes
97 * absorbed. This interface is useful for files
98 * no larger than the buffer.
99 * 1) Set *start = an unsigned long value less than
100 * the buffer address but greater than zero.
101 * Put the data of the requested offset at the
102 * beginning of the buffer. Return the number of
103 * bytes of data placed there. If this number is
104 * greater than zero and you didn't signal eof
105 * and the reader is prepared to take more data
106 * you will be called again with the requested
107 * offset advanced by *start. This interface is
108 * useful when you have a large file consisting
109 * of a series of blocks which you want to count
110 * and return as wholes.
111 * (Hack by Paul.Russell@rustcorp.com.au)
112 * 2) Set *start = an address within the buffer.
113 * Put the data of the requested offset at *start.
114 * Return the number of bytes of data placed there.
115 * If this number is greater than zero and you
116 * didn't signal eof and the reader is prepared to
117 * take more data you will be called again with the
118 * requested offset advanced by the number of bytes
119 * absorbed.
120 */
121 n = dp->read_proc(page, &start, *ppos,
122 count, &eof, dp->data);
123 } else
124 break;
125
126 if (n == 0) /* end of file */
127 break;
128 if (n < 0) { /* error */
129 if (retval == 0)
130 retval = n;
131 break;
132 }
133
134 if (start == NULL) {
135 if (n > PAGE_SIZE) {
136 printk(KERN_ERR
137 "proc_file_read: Apparent buffer overflow!\n");
138 n = PAGE_SIZE;
139 }
140 n -= *ppos;
141 if (n <= 0)
142 break;
143 if (n > count)
144 n = count;
145 start = page + *ppos;
146 } else if (start < page) {
147 if (n > PAGE_SIZE) {
148 printk(KERN_ERR
149 "proc_file_read: Apparent buffer overflow!\n");
150 n = PAGE_SIZE;
151 }
152 if (n > count) {
153 /*
154 * Don't reduce n because doing so might
155 * cut off part of a data block.
156 */
157 printk(KERN_WARNING
158 "proc_file_read: Read count exceeded\n");
159 }
160 } else /* start >= page */ {
161 unsigned long startoff = (unsigned long)(start - page);
162 if (n > (PAGE_SIZE - startoff)) {
163 printk(KERN_ERR
164 "proc_file_read: Apparent buffer overflow!\n");
165 n = PAGE_SIZE - startoff;
166 }
167 if (n > count)
168 n = count;
169 }
170
171 n -= copy_to_user(buf, start < page ? page : start, n);
172 if (n == 0) {
173 if (retval == 0)
174 retval = -EFAULT;
175 break;
176 }
177
178 *ppos += start < page ? (unsigned long)start : n;
179 nbytes -= n;
180 buf += n;
181 retval += n;
182 }
183 free_page((unsigned long) page);
184 return retval;
185}
186
187static ssize_t
Alexey Dobriyan3dec7f52009-02-20 17:04:33 +0300188proc_file_read(struct file *file, char __user *buf, size_t nbytes,
189 loff_t *ppos)
190{
191 struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
192 ssize_t rv = -EIO;
193
194 spin_lock(&pde->pde_unload_lock);
195 if (!pde->proc_fops) {
196 spin_unlock(&pde->pde_unload_lock);
197 return rv;
198 }
199 pde->pde_users++;
200 spin_unlock(&pde->pde_unload_lock);
201
202 rv = __proc_file_read(file, buf, nbytes, ppos);
203
204 pde_users_dec(pde);
205 return rv;
206}
207
208static ssize_t
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209proc_file_write(struct file *file, const char __user *buffer,
210 size_t count, loff_t *ppos)
211{
Alexey Dobriyan3dec7f52009-02-20 17:04:33 +0300212 struct proc_dir_entry *pde = PDE(file->f_path.dentry->d_inode);
213 ssize_t rv = -EIO;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214
Alexey Dobriyan3dec7f52009-02-20 17:04:33 +0300215 if (pde->write_proc) {
216 spin_lock(&pde->pde_unload_lock);
217 if (!pde->proc_fops) {
218 spin_unlock(&pde->pde_unload_lock);
219 return rv;
220 }
221 pde->pde_users++;
222 spin_unlock(&pde->pde_unload_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223
Alexey Dobriyan3dec7f52009-02-20 17:04:33 +0300224 /* FIXME: does this routine need ppos? probably... */
225 rv = pde->write_proc(file, buffer, count, pde->data);
226 pde_users_dec(pde);
227 }
228 return rv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700229}
230
231
232static loff_t
233proc_file_lseek(struct file *file, loff_t offset, int orig)
234{
Linus Torvalds8b90db02005-12-30 08:39:10 -0800235 loff_t retval = -EINVAL;
236 switch (orig) {
237 case 1:
238 offset += file->f_pos;
239 /* fallthrough */
240 case 0:
241 if (offset < 0 || offset > MAX_NON_LFS)
242 break;
243 file->f_pos = retval = offset;
244 }
245 return retval;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700246}
247
Alexey Dobriyan76df0c22008-02-08 04:18:27 -0800248static const struct file_operations proc_file_operations = {
249 .llseek = proc_file_lseek,
250 .read = proc_file_read,
251 .write = proc_file_write,
252};
253
Linus Torvalds1da177e2005-04-16 15:20:36 -0700254static int proc_notify_change(struct dentry *dentry, struct iattr *iattr)
255{
256 struct inode *inode = dentry->d_inode;
257 struct proc_dir_entry *de = PDE(inode);
258 int error;
259
260 error = inode_change_ok(inode, iattr);
261 if (error)
Christoph Hellwig10257742010-06-04 11:30:02 +0200262 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700263
Christoph Hellwig10257742010-06-04 11:30:02 +0200264 if ((iattr->ia_valid & ATTR_SIZE) &&
265 iattr->ia_size != i_size_read(inode)) {
266 error = vmtruncate(inode, iattr->ia_size);
267 if (error)
268 return error;
269 }
270
271 setattr_copy(inode, iattr);
272 mark_inode_dirty(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273
274 de->uid = inode->i_uid;
275 de->gid = inode->i_gid;
276 de->mode = inode->i_mode;
Christoph Hellwig10257742010-06-04 11:30:02 +0200277 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700278}
279
Miklos Szeredi2b579be2005-09-06 15:17:18 -0700280static int proc_getattr(struct vfsmount *mnt, struct dentry *dentry,
281 struct kstat *stat)
282{
283 struct inode *inode = dentry->d_inode;
284 struct proc_dir_entry *de = PROC_I(inode)->pde;
285 if (de && de->nlink)
Miklos Szeredibfe86842011-10-28 14:13:29 +0200286 set_nlink(inode, de->nlink);
Miklos Szeredi2b579be2005-09-06 15:17:18 -0700287
288 generic_fillattr(inode, stat);
289 return 0;
290}
291
Arjan van de Venc5ef1c42007-02-12 00:55:40 -0800292static const struct inode_operations proc_file_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700293 .setattr = proc_notify_change,
294};
295
296/*
297 * This function parses a name such as "tty/driver/serial", and
298 * returns the struct proc_dir_entry for "/proc/tty/driver", and
299 * returns "serial" in residual.
300 */
Alexey Dobriyane17a5762010-03-05 13:43:59 -0800301static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret,
302 const char **residual)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303{
304 const char *cp = name, *next;
305 struct proc_dir_entry *de;
Alexey Dobriyan312ec7e2011-03-23 16:42:52 -0700306 unsigned int len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700307
Alexey Dobriyan7cee4e02008-04-29 01:01:40 -0700308 de = *ret;
309 if (!de)
310 de = &proc_root;
311
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312 while (1) {
313 next = strchr(cp, '/');
314 if (!next)
315 break;
316
317 len = next - cp;
318 for (de = de->subdir; de ; de = de->next) {
319 if (proc_match(len, cp, de))
320 break;
321 }
Alexey Dobriyan12bac0d2010-03-05 13:44:00 -0800322 if (!de) {
323 WARN(1, "name '%s'\n", name);
Alexey Dobriyane17a5762010-03-05 13:43:59 -0800324 return -ENOENT;
Alexey Dobriyan12bac0d2010-03-05 13:44:00 -0800325 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700326 cp += len + 1;
327 }
328 *residual = cp;
329 *ret = de;
Alexey Dobriyane17a5762010-03-05 13:43:59 -0800330 return 0;
331}
332
333static int xlate_proc_name(const char *name, struct proc_dir_entry **ret,
334 const char **residual)
335{
336 int rv;
337
338 spin_lock(&proc_subdir_lock);
339 rv = __xlate_proc_name(name, ret, residual);
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800340 spin_unlock(&proc_subdir_lock);
Alexey Dobriyane17a5762010-03-05 13:43:59 -0800341 return rv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342}
343
Alexey Dobriyan9a185402008-07-26 11:21:37 +0400344static DEFINE_IDA(proc_inum_ida);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700345static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */
346
Alexey Dobriyan67935df2008-07-26 11:18:28 +0400347#define PROC_DYNAMIC_FIRST 0xF0000000U
Linus Torvalds1da177e2005-04-16 15:20:36 -0700348
349/*
350 * Return an inode number between PROC_DYNAMIC_FIRST and
351 * 0xffffffff, or zero on failure.
352 */
353static unsigned int get_inode_number(void)
354{
Alexey Dobriyan67935df2008-07-26 11:18:28 +0400355 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356 int error;
357
358retry:
Alexey Dobriyan9a185402008-07-26 11:21:37 +0400359 if (ida_pre_get(&proc_inum_ida, GFP_KERNEL) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360 return 0;
361
362 spin_lock(&proc_inum_lock);
Alexey Dobriyan9a185402008-07-26 11:21:37 +0400363 error = ida_get_new(&proc_inum_ida, &i);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700364 spin_unlock(&proc_inum_lock);
365 if (error == -EAGAIN)
366 goto retry;
367 else if (error)
368 return 0;
369
Alexey Dobriyan67935df2008-07-26 11:18:28 +0400370 if (i > UINT_MAX - PROC_DYNAMIC_FIRST) {
371 spin_lock(&proc_inum_lock);
Alexey Dobriyan9a185402008-07-26 11:21:37 +0400372 ida_remove(&proc_inum_ida, i);
Alexey Dobriyan67935df2008-07-26 11:18:28 +0400373 spin_unlock(&proc_inum_lock);
Alexey Dobriyancc996092008-08-02 07:30:48 +0400374 return 0;
Alexey Dobriyan67935df2008-07-26 11:18:28 +0400375 }
376 return PROC_DYNAMIC_FIRST + i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700377}
378
379static void release_inode_number(unsigned int inum)
380{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 spin_lock(&proc_inum_lock);
Alexey Dobriyan9a185402008-07-26 11:21:37 +0400382 ida_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700383 spin_unlock(&proc_inum_lock);
384}
385
Al Viro008b1502005-08-20 00:17:39 +0100386static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700387{
388 nd_set_link(nd, PDE(dentry->d_inode)->data);
Al Viro008b1502005-08-20 00:17:39 +0100389 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700390}
391
Arjan van de Venc5ef1c42007-02-12 00:55:40 -0800392static const struct inode_operations proc_link_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700393 .readlink = generic_readlink,
394 .follow_link = proc_follow_link,
395};
396
397/*
398 * As some entries in /proc are volatile, we want to
399 * get rid of unused dentries. This could be made
400 * smarter: we could keep a "volatile" flag in the
401 * inode to indicate which ones to keep.
402 */
Nick Pigginfe15ce42011-01-07 17:49:23 +1100403static int proc_delete_dentry(const struct dentry * dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404{
405 return 1;
406}
407
Al Virod72f71e2009-02-20 05:58:47 +0000408static const struct dentry_operations proc_dentry_operations =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409{
410 .d_delete = proc_delete_dentry,
411};
412
413/*
414 * Don't create negative dentries here, return -ENOENT by hand
415 * instead.
416 */
Pavel Emelyanove9720ac2008-03-07 11:08:40 -0800417struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir,
418 struct dentry *dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419{
420 struct inode *inode = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700421 int error = -ENOENT;
422
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800423 spin_lock(&proc_subdir_lock);
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700424 for (de = de->subdir; de ; de = de->next) {
425 if (de->namelen != dentry->d_name.len)
426 continue;
427 if (!memcmp(dentry->d_name.name, de->name, de->namelen)) {
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800428 pde_get(de);
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700429 spin_unlock(&proc_subdir_lock);
430 error = -EINVAL;
Alexey Dobriyan6d1b6e42011-01-12 17:00:33 -0800431 inode = proc_get_inode(dir->i_sb, de);
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700432 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700433 }
434 }
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800435 spin_unlock(&proc_subdir_lock);
Alexey Dobriyan4237e0d2008-02-08 04:18:27 -0800436out_unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700437
438 if (inode) {
Nick Pigginfb045ad2011-01-07 17:49:55 +1100439 d_set_d_op(dentry, &proc_dentry_operations);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 d_add(dentry, inode);
441 return NULL;
442 }
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700443 if (de)
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800444 pde_put(de);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 return ERR_PTR(error);
446}
447
Pavel Emelyanove9720ac2008-03-07 11:08:40 -0800448struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry,
449 struct nameidata *nd)
450{
451 return proc_lookup_de(PDE(dir), dir, dentry);
452}
453
Linus Torvalds1da177e2005-04-16 15:20:36 -0700454/*
455 * This returns non-zero if at EOF, so that the /proc
456 * root directory can use this and check if it should
457 * continue with the <pid> entries..
458 *
459 * Note that the VFS-layer doesn't care about the return
460 * value of the readdir() call, as long as it's non-negative
461 * for success..
462 */
Pavel Emelyanove9720ac2008-03-07 11:08:40 -0800463int proc_readdir_de(struct proc_dir_entry *de, struct file *filp, void *dirent,
464 filldir_t filldir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 unsigned int ino;
467 int i;
Josef "Jeff" Sipek2fddfee2006-12-08 02:36:36 -0800468 struct inode *inode = filp->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700469 int ret = 0;
470
Linus Torvalds1da177e2005-04-16 15:20:36 -0700471 ino = inode->i_ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 i = filp->f_pos;
473 switch (i) {
474 case 0:
475 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
476 goto out;
477 i++;
478 filp->f_pos++;
479 /* fall through */
480 case 1:
481 if (filldir(dirent, "..", 2, i,
Josef "Jeff" Sipek2fddfee2006-12-08 02:36:36 -0800482 parent_ino(filp->f_path.dentry),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483 DT_DIR) < 0)
484 goto out;
485 i++;
486 filp->f_pos++;
487 /* fall through */
488 default:
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800489 spin_lock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700490 de = de->subdir;
491 i -= 2;
492 for (;;) {
493 if (!de) {
494 ret = 1;
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800495 spin_unlock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496 goto out;
497 }
498 if (!i)
499 break;
500 de = de->next;
501 i--;
502 }
503
504 do {
Darrick J. Wong59cd0cb2007-05-08 00:25:47 -0700505 struct proc_dir_entry *next;
506
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800507 /* filldir passes info to user space */
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800508 pde_get(de);
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800509 spin_unlock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510 if (filldir(dirent, de->name, de->namelen, filp->f_pos,
Darrick J. Wong59cd0cb2007-05-08 00:25:47 -0700511 de->low_ino, de->mode >> 12) < 0) {
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800512 pde_put(de);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700513 goto out;
Darrick J. Wong59cd0cb2007-05-08 00:25:47 -0700514 }
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800515 spin_lock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700516 filp->f_pos++;
Darrick J. Wong59cd0cb2007-05-08 00:25:47 -0700517 next = de->next;
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800518 pde_put(de);
Darrick J. Wong59cd0cb2007-05-08 00:25:47 -0700519 de = next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 } while (de);
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800521 spin_unlock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522 }
523 ret = 1;
Alexey Dobriyanb4df2b92008-10-27 22:48:36 +0300524out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525 return ret;
526}
527
Pavel Emelyanove9720ac2008-03-07 11:08:40 -0800528int proc_readdir(struct file *filp, void *dirent, filldir_t filldir)
529{
530 struct inode *inode = filp->f_path.dentry->d_inode;
531
532 return proc_readdir_de(PDE(inode), filp, dirent, filldir);
533}
534
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535/*
536 * These are the generic /proc directory operations. They
537 * use the in-memory "struct proc_dir_entry" tree to parse
538 * the /proc directory.
539 */
Arjan van de Ven00977a52007-02-12 00:55:34 -0800540static const struct file_operations proc_dir_operations = {
Alexey Dobriyanb4df2b92008-10-27 22:48:36 +0300541 .llseek = generic_file_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700542 .read = generic_read_dir,
543 .readdir = proc_readdir,
544};
545
546/*
547 * proc directories can do almost nothing..
548 */
Arjan van de Venc5ef1c42007-02-12 00:55:40 -0800549static const struct inode_operations proc_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700550 .lookup = proc_lookup,
Miklos Szeredi2b579be2005-09-06 15:17:18 -0700551 .getattr = proc_getattr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 .setattr = proc_notify_change,
553};
554
555static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
556{
557 unsigned int i;
Zhang Rui94413d82008-02-08 04:18:29 -0800558 struct proc_dir_entry *tmp;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559
560 i = get_inode_number();
561 if (i == 0)
562 return -EAGAIN;
563 dp->low_ino = i;
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800564
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 if (S_ISDIR(dp->mode)) {
566 if (dp->proc_iops == NULL) {
567 dp->proc_fops = &proc_dir_operations;
568 dp->proc_iops = &proc_dir_inode_operations;
569 }
570 dir->nlink++;
571 } else if (S_ISLNK(dp->mode)) {
572 if (dp->proc_iops == NULL)
573 dp->proc_iops = &proc_link_inode_operations;
574 } else if (S_ISREG(dp->mode)) {
575 if (dp->proc_fops == NULL)
576 dp->proc_fops = &proc_file_operations;
577 if (dp->proc_iops == NULL)
578 dp->proc_iops = &proc_file_inode_operations;
579 }
Changli Gao99fc06d2007-07-15 23:40:09 -0700580
581 spin_lock(&proc_subdir_lock);
Zhang Rui94413d82008-02-08 04:18:29 -0800582
583 for (tmp = dir->subdir; tmp; tmp = tmp->next)
584 if (strcmp(tmp->name, dp->name) == 0) {
Arjan van de Ven6c2f91e2008-09-13 19:51:30 -0700585 WARN(1, KERN_WARNING "proc_dir_entry '%s/%s' already registered\n",
Alexey Dobriyan665020c2008-09-13 02:33:06 -0700586 dir->name, dp->name);
Zhang Rui94413d82008-02-08 04:18:29 -0800587 break;
588 }
589
Changli Gao99fc06d2007-07-15 23:40:09 -0700590 dp->next = dir->subdir;
591 dp->parent = dir;
592 dir->subdir = dp;
593 spin_unlock(&proc_subdir_lock);
594
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 return 0;
596}
597
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800598static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700599 const char *name,
Al Virod161a132011-07-24 03:36:29 -0400600 umode_t mode,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 nlink_t nlink)
602{
603 struct proc_dir_entry *ent = NULL;
604 const char *fn = name;
Alexey Dobriyan312ec7e2011-03-23 16:42:52 -0700605 unsigned int len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606
607 /* make sure name is valid */
608 if (!name || !strlen(name)) goto out;
609
Alexey Dobriyan7cee4e02008-04-29 01:01:40 -0700610 if (xlate_proc_name(name, parent, &fn) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611 goto out;
612
613 /* At this point there must not be any '/' characters beyond *fn */
614 if (strchr(fn, '/'))
615 goto out;
616
617 len = strlen(fn);
618
619 ent = kmalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL);
620 if (!ent) goto out;
621
622 memset(ent, 0, sizeof(struct proc_dir_entry));
David Howells09570f92011-07-27 21:47:03 +0300623 memcpy(ent->name, fn, len + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700624 ent->namelen = len;
625 ent->mode = mode;
626 ent->nlink = nlink;
Alexey Dobriyan5a622f22007-12-04 23:45:28 -0800627 atomic_set(&ent->count, 1);
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700628 ent->pde_users = 0;
629 spin_lock_init(&ent->pde_unload_lock);
630 ent->pde_unload_completion = NULL;
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700631 INIT_LIST_HEAD(&ent->pde_openers);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 out:
633 return ent;
634}
635
636struct proc_dir_entry *proc_symlink(const char *name,
637 struct proc_dir_entry *parent, const char *dest)
638{
639 struct proc_dir_entry *ent;
640
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800641 ent = __proc_create(&parent, name,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700642 (S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO),1);
643
644 if (ent) {
645 ent->data = kmalloc((ent->size=strlen(dest))+1, GFP_KERNEL);
646 if (ent->data) {
647 strcpy((char*)ent->data,dest);
648 if (proc_register(parent, ent) < 0) {
649 kfree(ent->data);
650 kfree(ent);
651 ent = NULL;
652 }
653 } else {
654 kfree(ent);
655 ent = NULL;
656 }
657 }
658 return ent;
659}
Helight.Xu587d4a12009-12-30 13:24:41 +0800660EXPORT_SYMBOL(proc_symlink);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661
Al Virod161a132011-07-24 03:36:29 -0400662struct proc_dir_entry *proc_mkdir_mode(const char *name, umode_t mode,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700663 struct proc_dir_entry *parent)
664{
665 struct proc_dir_entry *ent;
666
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800667 ent = __proc_create(&parent, name, S_IFDIR | mode, 2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700668 if (ent) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700669 if (proc_register(parent, ent) < 0) {
670 kfree(ent);
671 ent = NULL;
672 }
673 }
674 return ent;
675}
Alexey Dobriyan011159a2011-05-14 00:12:48 +0300676EXPORT_SYMBOL(proc_mkdir_mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700677
Denis V. Lunev78e92b92008-05-02 04:12:41 -0700678struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name,
679 struct proc_dir_entry *parent)
680{
681 struct proc_dir_entry *ent;
682
683 ent = __proc_create(&parent, name, S_IFDIR | S_IRUGO | S_IXUGO, 2);
684 if (ent) {
685 ent->data = net;
686 if (proc_register(parent, ent) < 0) {
687 kfree(ent);
688 ent = NULL;
689 }
690 }
691 return ent;
692}
693EXPORT_SYMBOL_GPL(proc_net_mkdir);
694
Linus Torvalds1da177e2005-04-16 15:20:36 -0700695struct proc_dir_entry *proc_mkdir(const char *name,
696 struct proc_dir_entry *parent)
697{
698 return proc_mkdir_mode(name, S_IRUGO | S_IXUGO, parent);
699}
Helight.Xu587d4a12009-12-30 13:24:41 +0800700EXPORT_SYMBOL(proc_mkdir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701
Al Virod161a132011-07-24 03:36:29 -0400702struct proc_dir_entry *create_proc_entry(const char *name, umode_t mode,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 struct proc_dir_entry *parent)
704{
705 struct proc_dir_entry *ent;
706 nlink_t nlink;
707
708 if (S_ISDIR(mode)) {
709 if ((mode & S_IALLUGO) == 0)
710 mode |= S_IRUGO | S_IXUGO;
711 nlink = 2;
712 } else {
713 if ((mode & S_IFMT) == 0)
714 mode |= S_IFREG;
715 if ((mode & S_IALLUGO) == 0)
716 mode |= S_IRUGO;
717 nlink = 1;
718 }
719
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800720 ent = __proc_create(&parent, name, mode, nlink);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700721 if (ent) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700722 if (proc_register(parent, ent) < 0) {
723 kfree(ent);
724 ent = NULL;
725 }
726 }
727 return ent;
728}
Helight.Xu587d4a12009-12-30 13:24:41 +0800729EXPORT_SYMBOL(create_proc_entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700730
Al Virod161a132011-07-24 03:36:29 -0400731struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
Denis V. Lunev59b74352008-04-29 01:02:00 -0700732 struct proc_dir_entry *parent,
733 const struct file_operations *proc_fops,
734 void *data)
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800735{
736 struct proc_dir_entry *pde;
737 nlink_t nlink;
738
739 if (S_ISDIR(mode)) {
740 if ((mode & S_IALLUGO) == 0)
741 mode |= S_IRUGO | S_IXUGO;
742 nlink = 2;
743 } else {
744 if ((mode & S_IFMT) == 0)
745 mode |= S_IFREG;
746 if ((mode & S_IALLUGO) == 0)
747 mode |= S_IRUGO;
748 nlink = 1;
749 }
750
751 pde = __proc_create(&parent, name, mode, nlink);
752 if (!pde)
753 goto out;
754 pde->proc_fops = proc_fops;
Denis V. Lunev59b74352008-04-29 01:02:00 -0700755 pde->data = data;
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800756 if (proc_register(parent, pde) < 0)
757 goto out_free;
758 return pde;
759out_free:
760 kfree(pde);
761out:
762 return NULL;
763}
Helight.Xu587d4a12009-12-30 13:24:41 +0800764EXPORT_SYMBOL(proc_create_data);
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800765
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800766static void free_proc_entry(struct proc_dir_entry *de)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700767{
Alexey Dobriyan6d1b6e42011-01-12 17:00:33 -0800768 release_inode_number(de->low_ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769
Alexey Dobriyanfd2cbe42008-02-08 04:18:28 -0800770 if (S_ISLNK(de->mode))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700771 kfree(de->data);
772 kfree(de);
773}
774
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800775void pde_put(struct proc_dir_entry *pde)
776{
777 if (atomic_dec_and_test(&pde->count))
778 free_proc_entry(pde);
779}
780
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781/*
782 * Remove a /proc entry and free it if it's not currently in use.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783 */
784void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
785{
786 struct proc_dir_entry **p;
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700787 struct proc_dir_entry *de = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 const char *fn = name;
Alexey Dobriyan312ec7e2011-03-23 16:42:52 -0700789 unsigned int len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700790
Alexey Dobriyane17a5762010-03-05 13:43:59 -0800791 spin_lock(&proc_subdir_lock);
792 if (__xlate_proc_name(name, &parent, &fn) != 0) {
793 spin_unlock(&proc_subdir_lock);
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700794 return;
Alexey Dobriyane17a5762010-03-05 13:43:59 -0800795 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700796 len = strlen(fn);
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800797
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 for (p = &parent->subdir; *p; p=&(*p)->next ) {
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700799 if (proc_match(len, fn, *p)) {
800 de = *p;
801 *p = de->next;
802 de->next = NULL;
803 break;
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700804 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805 }
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800806 spin_unlock(&proc_subdir_lock);
Alexey Dobriyan12bac0d2010-03-05 13:44:00 -0800807 if (!de) {
808 WARN(1, "name '%s'\n", name);
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700809 return;
Alexey Dobriyan12bac0d2010-03-05 13:44:00 -0800810 }
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700811
812 spin_lock(&de->pde_unload_lock);
813 /*
814 * Stop accepting new callers into module. If you're
815 * dynamically allocating ->proc_fops, save a pointer somewhere.
816 */
817 de->proc_fops = NULL;
818 /* Wait until all existing callers into module are done. */
819 if (de->pde_users > 0) {
820 DECLARE_COMPLETION_ONSTACK(c);
821
822 if (!de->pde_unload_completion)
823 de->pde_unload_completion = &c;
824
825 spin_unlock(&de->pde_unload_lock);
826
827 wait_for_completion(de->pde_unload_completion);
828
Alexey Dobriyan3740a202011-01-12 17:00:35 -0800829 spin_lock(&de->pde_unload_lock);
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700830 }
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700831
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700832 while (!list_empty(&de->pde_openers)) {
833 struct pde_opener *pdeo;
834
835 pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh);
836 list_del(&pdeo->lh);
837 spin_unlock(&de->pde_unload_lock);
838 pdeo->release(pdeo->inode, pdeo->file);
839 kfree(pdeo);
840 spin_lock(&de->pde_unload_lock);
841 }
842 spin_unlock(&de->pde_unload_lock);
843
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700844 if (S_ISDIR(de->mode))
845 parent->nlink--;
846 de->nlink = 0;
Arjan van de Ven267e2a92008-07-25 19:45:41 -0700847 WARN(de->subdir, KERN_WARNING "%s: removing non-empty directory "
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700848 "'%s/%s', leaking at least '%s'\n", __func__,
849 de->parent->name, de->name, de->subdir->name);
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800850 pde_put(de);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700851}
Helight.Xu587d4a12009-12-30 13:24:41 +0800852EXPORT_SYMBOL(remove_proc_entry);