blob: 76ddae83daa58e2b086dd286c847c47de71f1124 [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 setattr_copy(inode, iattr);
265 mark_inode_dirty(inode);
Marco Stornelli46f69552012-12-15 11:48:48 +0100266
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267 de->uid = inode->i_uid;
268 de->gid = inode->i_gid;
269 de->mode = inode->i_mode;
Christoph Hellwig10257742010-06-04 11:30:02 +0200270 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700271}
272
Miklos Szeredi2b579be2005-09-06 15:17:18 -0700273static int proc_getattr(struct vfsmount *mnt, struct dentry *dentry,
274 struct kstat *stat)
275{
276 struct inode *inode = dentry->d_inode;
277 struct proc_dir_entry *de = PROC_I(inode)->pde;
278 if (de && de->nlink)
Miklos Szeredibfe86842011-10-28 14:13:29 +0200279 set_nlink(inode, de->nlink);
Miklos Szeredi2b579be2005-09-06 15:17:18 -0700280
281 generic_fillattr(inode, stat);
282 return 0;
283}
284
Arjan van de Venc5ef1c42007-02-12 00:55:40 -0800285static const struct inode_operations proc_file_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700286 .setattr = proc_notify_change,
287};
288
289/*
290 * This function parses a name such as "tty/driver/serial", and
291 * returns the struct proc_dir_entry for "/proc/tty/driver", and
292 * returns "serial" in residual.
293 */
Alexey Dobriyane17a5762010-03-05 13:43:59 -0800294static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret,
295 const char **residual)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296{
297 const char *cp = name, *next;
298 struct proc_dir_entry *de;
Alexey Dobriyan312ec7e2011-03-23 16:42:52 -0700299 unsigned int len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700300
Alexey Dobriyan7cee4e02008-04-29 01:01:40 -0700301 de = *ret;
302 if (!de)
303 de = &proc_root;
304
Linus Torvalds1da177e2005-04-16 15:20:36 -0700305 while (1) {
306 next = strchr(cp, '/');
307 if (!next)
308 break;
309
310 len = next - cp;
311 for (de = de->subdir; de ; de = de->next) {
312 if (proc_match(len, cp, de))
313 break;
314 }
Alexey Dobriyan12bac0d2010-03-05 13:44:00 -0800315 if (!de) {
316 WARN(1, "name '%s'\n", name);
Alexey Dobriyane17a5762010-03-05 13:43:59 -0800317 return -ENOENT;
Alexey Dobriyan12bac0d2010-03-05 13:44:00 -0800318 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319 cp += len + 1;
320 }
321 *residual = cp;
322 *ret = de;
Alexey Dobriyane17a5762010-03-05 13:43:59 -0800323 return 0;
324}
325
326static int xlate_proc_name(const char *name, struct proc_dir_entry **ret,
327 const char **residual)
328{
329 int rv;
330
331 spin_lock(&proc_subdir_lock);
332 rv = __xlate_proc_name(name, ret, residual);
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800333 spin_unlock(&proc_subdir_lock);
Alexey Dobriyane17a5762010-03-05 13:43:59 -0800334 return rv;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700335}
336
Alexey Dobriyan9a185402008-07-26 11:21:37 +0400337static DEFINE_IDA(proc_inum_ida);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700338static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */
339
Alexey Dobriyan67935df2008-07-26 11:18:28 +0400340#define PROC_DYNAMIC_FIRST 0xF0000000U
Linus Torvalds1da177e2005-04-16 15:20:36 -0700341
342/*
343 * Return an inode number between PROC_DYNAMIC_FIRST and
344 * 0xffffffff, or zero on failure.
345 */
Eric W. Biederman33d6dce2011-06-17 13:33:20 -0700346int proc_alloc_inum(unsigned int *inum)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700347{
Alexey Dobriyan67935df2008-07-26 11:18:28 +0400348 unsigned int i;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700349 int error;
350
351retry:
Eric W. Biederman33d6dce2011-06-17 13:33:20 -0700352 if (!ida_pre_get(&proc_inum_ida, GFP_KERNEL))
353 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700354
Eric W. Biedermandfb2ea42012-12-21 20:38:00 -0800355 spin_lock_irq(&proc_inum_lock);
Alexey Dobriyan9a185402008-07-26 11:21:37 +0400356 error = ida_get_new(&proc_inum_ida, &i);
Eric W. Biedermandfb2ea42012-12-21 20:38:00 -0800357 spin_unlock_irq(&proc_inum_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700358 if (error == -EAGAIN)
359 goto retry;
360 else if (error)
Eric W. Biederman33d6dce2011-06-17 13:33:20 -0700361 return error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700362
Alexey Dobriyan67935df2008-07-26 11:18:28 +0400363 if (i > UINT_MAX - PROC_DYNAMIC_FIRST) {
Eric W. Biedermandfb2ea42012-12-21 20:38:00 -0800364 spin_lock_irq(&proc_inum_lock);
Alexey Dobriyan9a185402008-07-26 11:21:37 +0400365 ida_remove(&proc_inum_ida, i);
Eric W. Biedermandfb2ea42012-12-21 20:38:00 -0800366 spin_unlock_irq(&proc_inum_lock);
Eric W. Biederman33d6dce2011-06-17 13:33:20 -0700367 return -ENOSPC;
Alexey Dobriyan67935df2008-07-26 11:18:28 +0400368 }
Eric W. Biederman33d6dce2011-06-17 13:33:20 -0700369 *inum = PROC_DYNAMIC_FIRST + i;
370 return 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371}
372
Eric W. Biederman33d6dce2011-06-17 13:33:20 -0700373void proc_free_inum(unsigned int inum)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700374{
Eric W. Biedermandfb2ea42012-12-21 20:38:00 -0800375 unsigned long flags;
376 spin_lock_irqsave(&proc_inum_lock, flags);
Alexey Dobriyan9a185402008-07-26 11:21:37 +0400377 ida_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST);
Eric W. Biedermandfb2ea42012-12-21 20:38:00 -0800378 spin_unlock_irqrestore(&proc_inum_lock, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700379}
380
Al Viro008b1502005-08-20 00:17:39 +0100381static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700382{
383 nd_set_link(nd, PDE(dentry->d_inode)->data);
Al Viro008b1502005-08-20 00:17:39 +0100384 return NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700385}
386
Arjan van de Venc5ef1c42007-02-12 00:55:40 -0800387static const struct inode_operations proc_link_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700388 .readlink = generic_readlink,
389 .follow_link = proc_follow_link,
390};
391
392/*
393 * As some entries in /proc are volatile, we want to
394 * get rid of unused dentries. This could be made
395 * smarter: we could keep a "volatile" flag in the
396 * inode to indicate which ones to keep.
397 */
Nick Pigginfe15ce42011-01-07 17:49:23 +1100398static int proc_delete_dentry(const struct dentry * dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399{
400 return 1;
401}
402
Al Virod72f71e2009-02-20 05:58:47 +0000403static const struct dentry_operations proc_dentry_operations =
Linus Torvalds1da177e2005-04-16 15:20:36 -0700404{
405 .d_delete = proc_delete_dentry,
406};
407
408/*
409 * Don't create negative dentries here, return -ENOENT by hand
410 * instead.
411 */
Pavel Emelyanove9720ac2008-03-07 11:08:40 -0800412struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir,
413 struct dentry *dentry)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414{
415 struct inode *inode = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700416 int error = -ENOENT;
417
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800418 spin_lock(&proc_subdir_lock);
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700419 for (de = de->subdir; de ; de = de->next) {
420 if (de->namelen != dentry->d_name.len)
421 continue;
422 if (!memcmp(dentry->d_name.name, de->name, de->namelen)) {
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800423 pde_get(de);
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700424 spin_unlock(&proc_subdir_lock);
yan620727502012-10-04 17:15:38 -0700425 error = -ENOMEM;
Alexey Dobriyan6d1b6e42011-01-12 17:00:33 -0800426 inode = proc_get_inode(dir->i_sb, de);
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700427 goto out_unlock;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700428 }
429 }
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800430 spin_unlock(&proc_subdir_lock);
Alexey Dobriyan4237e0d2008-02-08 04:18:27 -0800431out_unlock:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432
433 if (inode) {
Nick Pigginfb045ad2011-01-07 17:49:55 +1100434 d_set_d_op(dentry, &proc_dentry_operations);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700435 d_add(dentry, inode);
436 return NULL;
437 }
Alexey Dobriyan5e971dc2008-04-29 01:01:41 -0700438 if (de)
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800439 pde_put(de);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 return ERR_PTR(error);
441}
442
Pavel Emelyanove9720ac2008-03-07 11:08:40 -0800443struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry,
Al Viro00cd8dd2012-06-10 17:13:09 -0400444 unsigned int flags)
Pavel Emelyanove9720ac2008-03-07 11:08:40 -0800445{
446 return proc_lookup_de(PDE(dir), dir, dentry);
447}
448
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449/*
450 * This returns non-zero if at EOF, so that the /proc
451 * root directory can use this and check if it should
452 * continue with the <pid> entries..
453 *
454 * Note that the VFS-layer doesn't care about the return
455 * value of the readdir() call, as long as it's non-negative
456 * for success..
457 */
Pavel Emelyanove9720ac2008-03-07 11:08:40 -0800458int proc_readdir_de(struct proc_dir_entry *de, struct file *filp, void *dirent,
459 filldir_t filldir)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700460{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700461 unsigned int ino;
462 int i;
Josef "Jeff" Sipek2fddfee2006-12-08 02:36:36 -0800463 struct inode *inode = filp->f_path.dentry->d_inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700464 int ret = 0;
465
Linus Torvalds1da177e2005-04-16 15:20:36 -0700466 ino = inode->i_ino;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 i = filp->f_pos;
468 switch (i) {
469 case 0:
470 if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0)
471 goto out;
472 i++;
473 filp->f_pos++;
474 /* fall through */
475 case 1:
476 if (filldir(dirent, "..", 2, i,
Josef "Jeff" Sipek2fddfee2006-12-08 02:36:36 -0800477 parent_ino(filp->f_path.dentry),
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478 DT_DIR) < 0)
479 goto out;
480 i++;
481 filp->f_pos++;
482 /* fall through */
483 default:
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800484 spin_lock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 de = de->subdir;
486 i -= 2;
487 for (;;) {
488 if (!de) {
489 ret = 1;
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800490 spin_unlock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700491 goto out;
492 }
493 if (!i)
494 break;
495 de = de->next;
496 i--;
497 }
498
499 do {
Darrick J. Wong59cd0cb2007-05-08 00:25:47 -0700500 struct proc_dir_entry *next;
501
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800502 /* filldir passes info to user space */
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800503 pde_get(de);
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800504 spin_unlock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505 if (filldir(dirent, de->name, de->namelen, filp->f_pos,
Darrick J. Wong59cd0cb2007-05-08 00:25:47 -0700506 de->low_ino, de->mode >> 12) < 0) {
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800507 pde_put(de);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 goto out;
Darrick J. Wong59cd0cb2007-05-08 00:25:47 -0700509 }
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800510 spin_lock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700511 filp->f_pos++;
Darrick J. Wong59cd0cb2007-05-08 00:25:47 -0700512 next = de->next;
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800513 pde_put(de);
Darrick J. Wong59cd0cb2007-05-08 00:25:47 -0700514 de = next;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700515 } while (de);
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800516 spin_unlock(&proc_subdir_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700517 }
518 ret = 1;
Alexey Dobriyanb4df2b92008-10-27 22:48:36 +0300519out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700520 return ret;
521}
522
Pavel Emelyanove9720ac2008-03-07 11:08:40 -0800523int proc_readdir(struct file *filp, void *dirent, filldir_t filldir)
524{
525 struct inode *inode = filp->f_path.dentry->d_inode;
526
527 return proc_readdir_de(PDE(inode), filp, dirent, filldir);
528}
529
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530/*
531 * These are the generic /proc directory operations. They
532 * use the in-memory "struct proc_dir_entry" tree to parse
533 * the /proc directory.
534 */
Arjan van de Ven00977a52007-02-12 00:55:34 -0800535static const struct file_operations proc_dir_operations = {
Alexey Dobriyanb4df2b92008-10-27 22:48:36 +0300536 .llseek = generic_file_llseek,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 .read = generic_read_dir,
538 .readdir = proc_readdir,
539};
540
541/*
542 * proc directories can do almost nothing..
543 */
Arjan van de Venc5ef1c42007-02-12 00:55:40 -0800544static const struct inode_operations proc_dir_inode_operations = {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700545 .lookup = proc_lookup,
Miklos Szeredi2b579be2005-09-06 15:17:18 -0700546 .getattr = proc_getattr,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547 .setattr = proc_notify_change,
548};
549
550static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
551{
Zhang Rui94413d82008-02-08 04:18:29 -0800552 struct proc_dir_entry *tmp;
Eric W. Biederman33d6dce2011-06-17 13:33:20 -0700553 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554
Eric W. Biederman33d6dce2011-06-17 13:33:20 -0700555 ret = proc_alloc_inum(&dp->low_ino);
556 if (ret)
557 return ret;
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800558
Linus Torvalds1da177e2005-04-16 15:20:36 -0700559 if (S_ISDIR(dp->mode)) {
560 if (dp->proc_iops == NULL) {
561 dp->proc_fops = &proc_dir_operations;
562 dp->proc_iops = &proc_dir_inode_operations;
563 }
564 dir->nlink++;
565 } else if (S_ISLNK(dp->mode)) {
566 if (dp->proc_iops == NULL)
567 dp->proc_iops = &proc_link_inode_operations;
568 } else if (S_ISREG(dp->mode)) {
569 if (dp->proc_fops == NULL)
570 dp->proc_fops = &proc_file_operations;
571 if (dp->proc_iops == NULL)
572 dp->proc_iops = &proc_file_inode_operations;
573 }
Changli Gao99fc06d2007-07-15 23:40:09 -0700574
575 spin_lock(&proc_subdir_lock);
Zhang Rui94413d82008-02-08 04:18:29 -0800576
577 for (tmp = dir->subdir; tmp; tmp = tmp->next)
578 if (strcmp(tmp->name, dp->name) == 0) {
Arjan van de Ven6c2f91e2008-09-13 19:51:30 -0700579 WARN(1, KERN_WARNING "proc_dir_entry '%s/%s' already registered\n",
Alexey Dobriyan665020c2008-09-13 02:33:06 -0700580 dir->name, dp->name);
Zhang Rui94413d82008-02-08 04:18:29 -0800581 break;
582 }
583
Changli Gao99fc06d2007-07-15 23:40:09 -0700584 dp->next = dir->subdir;
585 dp->parent = dir;
586 dir->subdir = dp;
587 spin_unlock(&proc_subdir_lock);
588
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589 return 0;
590}
591
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800592static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593 const char *name,
Al Virod161a132011-07-24 03:36:29 -0400594 umode_t mode,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700595 nlink_t nlink)
596{
597 struct proc_dir_entry *ent = NULL;
598 const char *fn = name;
Alexey Dobriyan312ec7e2011-03-23 16:42:52 -0700599 unsigned int len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700600
601 /* make sure name is valid */
yan17baa2a2012-10-04 17:15:43 -0700602 if (!name || !strlen(name))
603 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604
Alexey Dobriyan7cee4e02008-04-29 01:01:40 -0700605 if (xlate_proc_name(name, parent, &fn) != 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606 goto out;
607
608 /* At this point there must not be any '/' characters beyond *fn */
609 if (strchr(fn, '/'))
610 goto out;
611
612 len = strlen(fn);
613
yan17baa2a2012-10-04 17:15:43 -0700614 ent = kzalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL);
615 if (!ent)
616 goto out;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700617
David Howells09570f92011-07-27 21:47:03 +0300618 memcpy(ent->name, fn, len + 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700619 ent->namelen = len;
620 ent->mode = mode;
621 ent->nlink = nlink;
Alexey Dobriyan5a622f22007-12-04 23:45:28 -0800622 atomic_set(&ent->count, 1);
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700623 spin_lock_init(&ent->pde_unload_lock);
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700624 INIT_LIST_HEAD(&ent->pde_openers);
yan17baa2a2012-10-04 17:15:43 -0700625out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700626 return ent;
627}
628
629struct proc_dir_entry *proc_symlink(const char *name,
630 struct proc_dir_entry *parent, const char *dest)
631{
632 struct proc_dir_entry *ent;
633
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800634 ent = __proc_create(&parent, name,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700635 (S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO),1);
636
637 if (ent) {
638 ent->data = kmalloc((ent->size=strlen(dest))+1, GFP_KERNEL);
639 if (ent->data) {
640 strcpy((char*)ent->data,dest);
641 if (proc_register(parent, ent) < 0) {
642 kfree(ent->data);
643 kfree(ent);
644 ent = NULL;
645 }
646 } else {
647 kfree(ent);
648 ent = NULL;
649 }
650 }
651 return ent;
652}
Helight.Xu587d4a12009-12-30 13:24:41 +0800653EXPORT_SYMBOL(proc_symlink);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654
Al Virod161a132011-07-24 03:36:29 -0400655struct proc_dir_entry *proc_mkdir_mode(const char *name, umode_t mode,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700656 struct proc_dir_entry *parent)
657{
658 struct proc_dir_entry *ent;
659
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800660 ent = __proc_create(&parent, name, S_IFDIR | mode, 2);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700661 if (ent) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700662 if (proc_register(parent, ent) < 0) {
663 kfree(ent);
664 ent = NULL;
665 }
666 }
667 return ent;
668}
Alexey Dobriyan011159a2011-05-14 00:12:48 +0300669EXPORT_SYMBOL(proc_mkdir_mode);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700670
Denis V. Lunev78e92b92008-05-02 04:12:41 -0700671struct proc_dir_entry *proc_net_mkdir(struct net *net, const char *name,
672 struct proc_dir_entry *parent)
673{
674 struct proc_dir_entry *ent;
675
676 ent = __proc_create(&parent, name, S_IFDIR | S_IRUGO | S_IXUGO, 2);
677 if (ent) {
678 ent->data = net;
679 if (proc_register(parent, ent) < 0) {
680 kfree(ent);
681 ent = NULL;
682 }
683 }
684 return ent;
685}
686EXPORT_SYMBOL_GPL(proc_net_mkdir);
687
Linus Torvalds1da177e2005-04-16 15:20:36 -0700688struct proc_dir_entry *proc_mkdir(const char *name,
689 struct proc_dir_entry *parent)
690{
691 return proc_mkdir_mode(name, S_IRUGO | S_IXUGO, parent);
692}
Helight.Xu587d4a12009-12-30 13:24:41 +0800693EXPORT_SYMBOL(proc_mkdir);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700694
Al Virod161a132011-07-24 03:36:29 -0400695struct proc_dir_entry *create_proc_entry(const char *name, umode_t mode,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696 struct proc_dir_entry *parent)
697{
698 struct proc_dir_entry *ent;
699 nlink_t nlink;
700
701 if (S_ISDIR(mode)) {
702 if ((mode & S_IALLUGO) == 0)
703 mode |= S_IRUGO | S_IXUGO;
704 nlink = 2;
705 } else {
706 if ((mode & S_IFMT) == 0)
707 mode |= S_IFREG;
708 if ((mode & S_IALLUGO) == 0)
709 mode |= S_IRUGO;
710 nlink = 1;
711 }
712
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800713 ent = __proc_create(&parent, name, mode, nlink);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 if (ent) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700715 if (proc_register(parent, ent) < 0) {
716 kfree(ent);
717 ent = NULL;
718 }
719 }
720 return ent;
721}
Helight.Xu587d4a12009-12-30 13:24:41 +0800722EXPORT_SYMBOL(create_proc_entry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700723
Al Virod161a132011-07-24 03:36:29 -0400724struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
Denis V. Lunev59b74352008-04-29 01:02:00 -0700725 struct proc_dir_entry *parent,
726 const struct file_operations *proc_fops,
727 void *data)
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800728{
729 struct proc_dir_entry *pde;
730 nlink_t nlink;
731
732 if (S_ISDIR(mode)) {
733 if ((mode & S_IALLUGO) == 0)
734 mode |= S_IRUGO | S_IXUGO;
735 nlink = 2;
736 } else {
737 if ((mode & S_IFMT) == 0)
738 mode |= S_IFREG;
739 if ((mode & S_IALLUGO) == 0)
740 mode |= S_IRUGO;
741 nlink = 1;
742 }
743
744 pde = __proc_create(&parent, name, mode, nlink);
745 if (!pde)
746 goto out;
747 pde->proc_fops = proc_fops;
Denis V. Lunev59b74352008-04-29 01:02:00 -0700748 pde->data = data;
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800749 if (proc_register(parent, pde) < 0)
750 goto out_free;
751 return pde;
752out_free:
753 kfree(pde);
754out:
755 return NULL;
756}
Helight.Xu587d4a12009-12-30 13:24:41 +0800757EXPORT_SYMBOL(proc_create_data);
Alexey Dobriyan2d3a4e32008-02-08 04:18:37 -0800758
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800759static void free_proc_entry(struct proc_dir_entry *de)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700760{
Eric W. Biederman33d6dce2011-06-17 13:33:20 -0700761 proc_free_inum(de->low_ino);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700762
Alexey Dobriyanfd2cbe42008-02-08 04:18:28 -0800763 if (S_ISLNK(de->mode))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700764 kfree(de->data);
765 kfree(de);
766}
767
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800768void pde_put(struct proc_dir_entry *pde)
769{
770 if (atomic_dec_and_test(&pde->count))
771 free_proc_entry(pde);
772}
773
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774/*
775 * Remove a /proc entry and free it if it's not currently in use.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700776 */
777void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
778{
779 struct proc_dir_entry **p;
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700780 struct proc_dir_entry *de = NULL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700781 const char *fn = name;
Alexey Dobriyan312ec7e2011-03-23 16:42:52 -0700782 unsigned int len;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700783
Alexey Dobriyane17a5762010-03-05 13:43:59 -0800784 spin_lock(&proc_subdir_lock);
785 if (__xlate_proc_name(name, &parent, &fn) != 0) {
786 spin_unlock(&proc_subdir_lock);
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700787 return;
Alexey Dobriyane17a5762010-03-05 13:43:59 -0800788 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700789 len = strlen(fn);
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800790
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 for (p = &parent->subdir; *p; p=&(*p)->next ) {
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700792 if (proc_match(len, fn, *p)) {
793 de = *p;
794 *p = de->next;
795 de->next = NULL;
796 break;
Alexey Dobriyan786d7e12007-07-15 23:39:00 -0700797 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 }
Steven Rostedt64a07bd2006-03-26 01:36:55 -0800799 spin_unlock(&proc_subdir_lock);
Alexey Dobriyan12bac0d2010-03-05 13:44:00 -0800800 if (!de) {
801 WARN(1, "name '%s'\n", name);
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700802 return;
Alexey Dobriyan12bac0d2010-03-05 13:44:00 -0800803 }
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700804
805 spin_lock(&de->pde_unload_lock);
806 /*
807 * Stop accepting new callers into module. If you're
808 * dynamically allocating ->proc_fops, save a pointer somewhere.
809 */
810 de->proc_fops = NULL;
811 /* Wait until all existing callers into module are done. */
812 if (de->pde_users > 0) {
813 DECLARE_COMPLETION_ONSTACK(c);
814
815 if (!de->pde_unload_completion)
816 de->pde_unload_completion = &c;
817
818 spin_unlock(&de->pde_unload_lock);
819
820 wait_for_completion(de->pde_unload_completion);
821
Alexey Dobriyan3740a202011-01-12 17:00:35 -0800822 spin_lock(&de->pde_unload_lock);
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700823 }
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700824
Alexey Dobriyan881adb82008-07-25 01:48:29 -0700825 while (!list_empty(&de->pde_openers)) {
826 struct pde_opener *pdeo;
827
828 pdeo = list_first_entry(&de->pde_openers, struct pde_opener, lh);
829 list_del(&pdeo->lh);
830 spin_unlock(&de->pde_unload_lock);
831 pdeo->release(pdeo->inode, pdeo->file);
832 kfree(pdeo);
833 spin_lock(&de->pde_unload_lock);
834 }
835 spin_unlock(&de->pde_unload_lock);
836
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700837 if (S_ISDIR(de->mode))
838 parent->nlink--;
839 de->nlink = 0;
Arjan van de Ven267e2a92008-07-25 19:45:41 -0700840 WARN(de->subdir, KERN_WARNING "%s: removing non-empty directory "
Alexey Dobriyanf649d6d2008-04-29 01:01:39 -0700841 "'%s/%s', leaking at least '%s'\n", __func__,
842 de->parent->name, de->name, de->subdir->name);
Alexey Dobriyan135d5652009-12-15 16:45:39 -0800843 pde_put(de);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700844}
Helight.Xu587d4a12009-12-30 13:24:41 +0800845EXPORT_SYMBOL(remove_proc_entry);