2 * proc/fs/generic.c --- generic routines for the proc-fs
4 * This file contains generic proc-fs routines for handling
5 * directories and files.
7 * Copyright (C) 1991, 1992 Linus Torvalds.
8 * Copyright (C) 1997 Theodore Ts'o
11 #include <linux/errno.h>
12 #include <linux/time.h>
13 #include <linux/proc_fs.h>
14 #include <linux/stat.h>
16 #include <linux/module.h>
17 #include <linux/slab.h>
18 #include <linux/printk.h>
19 #include <linux/mount.h>
20 #include <linux/init.h>
21 #include <linux/idr.h>
22 #include <linux/namei.h>
23 #include <linux/bitops.h>
24 #include <linux/spinlock.h>
25 #include <linux/completion.h>
26 #include <asm/uaccess.h>
30 DEFINE_SPINLOCK(proc_subdir_lock
);
32 static int proc_match(unsigned int len
, const char *name
, struct proc_dir_entry
*de
)
34 if (de
->namelen
!= len
)
36 return !memcmp(name
, de
->name
, len
);
39 static int proc_notify_change(struct dentry
*dentry
, struct iattr
*iattr
)
41 struct inode
*inode
= dentry
->d_inode
;
42 struct proc_dir_entry
*de
= PDE(inode
);
45 error
= inode_change_ok(inode
, iattr
);
49 setattr_copy(inode
, iattr
);
50 mark_inode_dirty(inode
);
52 de
->uid
= inode
->i_uid
;
53 de
->gid
= inode
->i_gid
;
54 de
->mode
= inode
->i_mode
;
58 static int proc_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
61 struct inode
*inode
= dentry
->d_inode
;
62 struct proc_dir_entry
*de
= PROC_I(inode
)->pde
;
64 set_nlink(inode
, de
->nlink
);
66 generic_fillattr(inode
, stat
);
70 static const struct inode_operations proc_file_inode_operations
= {
71 .setattr
= proc_notify_change
,
75 * This function parses a name such as "tty/driver/serial", and
76 * returns the struct proc_dir_entry for "/proc/tty/driver", and
77 * returns "serial" in residual.
79 static int __xlate_proc_name(const char *name
, struct proc_dir_entry
**ret
,
80 const char **residual
)
82 const char *cp
= name
, *next
;
83 struct proc_dir_entry
*de
;
91 next
= strchr(cp
, '/');
96 for (de
= de
->subdir
; de
; de
= de
->next
) {
97 if (proc_match(len
, cp
, de
))
101 WARN(1, "name '%s'\n", name
);
111 static int xlate_proc_name(const char *name
, struct proc_dir_entry
**ret
,
112 const char **residual
)
116 spin_lock(&proc_subdir_lock
);
117 rv
= __xlate_proc_name(name
, ret
, residual
);
118 spin_unlock(&proc_subdir_lock
);
122 static DEFINE_IDA(proc_inum_ida
);
123 static DEFINE_SPINLOCK(proc_inum_lock
); /* protects the above */
125 #define PROC_DYNAMIC_FIRST 0xF0000000U
128 * Return an inode number between PROC_DYNAMIC_FIRST and
129 * 0xffffffff, or zero on failure.
131 int proc_alloc_inum(unsigned int *inum
)
137 if (!ida_pre_get(&proc_inum_ida
, GFP_KERNEL
))
140 spin_lock_irq(&proc_inum_lock
);
141 error
= ida_get_new(&proc_inum_ida
, &i
);
142 spin_unlock_irq(&proc_inum_lock
);
143 if (error
== -EAGAIN
)
148 if (i
> UINT_MAX
- PROC_DYNAMIC_FIRST
) {
149 spin_lock_irq(&proc_inum_lock
);
150 ida_remove(&proc_inum_ida
, i
);
151 spin_unlock_irq(&proc_inum_lock
);
154 *inum
= PROC_DYNAMIC_FIRST
+ i
;
158 void proc_free_inum(unsigned int inum
)
161 spin_lock_irqsave(&proc_inum_lock
, flags
);
162 ida_remove(&proc_inum_ida
, inum
- PROC_DYNAMIC_FIRST
);
163 spin_unlock_irqrestore(&proc_inum_lock
, flags
);
166 static void *proc_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
168 nd_set_link(nd
, __PDE_DATA(dentry
->d_inode
));
172 static const struct inode_operations proc_link_inode_operations
= {
173 .readlink
= generic_readlink
,
174 .follow_link
= proc_follow_link
,
178 * Don't create negative dentries here, return -ENOENT by hand
181 struct dentry
*proc_lookup_de(struct proc_dir_entry
*de
, struct inode
*dir
,
182 struct dentry
*dentry
)
186 spin_lock(&proc_subdir_lock
);
187 for (de
= de
->subdir
; de
; de
= de
->next
) {
188 if (de
->namelen
!= dentry
->d_name
.len
)
190 if (!memcmp(dentry
->d_name
.name
, de
->name
, de
->namelen
)) {
192 spin_unlock(&proc_subdir_lock
);
193 inode
= proc_get_inode(dir
->i_sb
, de
);
195 return ERR_PTR(-ENOMEM
);
196 d_set_d_op(dentry
, &simple_dentry_operations
);
197 d_add(dentry
, inode
);
201 spin_unlock(&proc_subdir_lock
);
202 return ERR_PTR(-ENOENT
);
205 struct dentry
*proc_lookup(struct inode
*dir
, struct dentry
*dentry
,
208 return proc_lookup_de(PDE(dir
), dir
, dentry
);
212 * This returns non-zero if at EOF, so that the /proc
213 * root directory can use this and check if it should
214 * continue with the <pid> entries..
216 * Note that the VFS-layer doesn't care about the return
217 * value of the readdir() call, as long as it's non-negative
220 int proc_readdir_de(struct proc_dir_entry
*de
, struct file
*file
,
221 struct dir_context
*ctx
)
225 if (!dir_emit_dots(file
, ctx
))
228 spin_lock(&proc_subdir_lock
);
233 spin_unlock(&proc_subdir_lock
);
243 struct proc_dir_entry
*next
;
245 spin_unlock(&proc_subdir_lock
);
246 if (!dir_emit(ctx
, de
->name
, de
->namelen
,
247 de
->low_ino
, de
->mode
>> 12)) {
251 spin_lock(&proc_subdir_lock
);
257 spin_unlock(&proc_subdir_lock
);
261 int proc_readdir(struct file
*file
, struct dir_context
*ctx
)
263 struct inode
*inode
= file_inode(file
);
265 return proc_readdir_de(PDE(inode
), file
, ctx
);
269 * These are the generic /proc directory operations. They
270 * use the in-memory "struct proc_dir_entry" tree to parse
271 * the /proc directory.
273 static const struct file_operations proc_dir_operations
= {
274 .llseek
= generic_file_llseek
,
275 .read
= generic_read_dir
,
276 .iterate
= proc_readdir
,
280 * proc directories can do almost nothing..
282 static const struct inode_operations proc_dir_inode_operations
= {
283 .lookup
= proc_lookup
,
284 .getattr
= proc_getattr
,
285 .setattr
= proc_notify_change
,
288 static int proc_register(struct proc_dir_entry
* dir
, struct proc_dir_entry
* dp
)
290 struct proc_dir_entry
*tmp
;
293 ret
= proc_alloc_inum(&dp
->low_ino
);
297 if (S_ISDIR(dp
->mode
)) {
298 dp
->proc_fops
= &proc_dir_operations
;
299 dp
->proc_iops
= &proc_dir_inode_operations
;
301 } else if (S_ISLNK(dp
->mode
)) {
302 dp
->proc_iops
= &proc_link_inode_operations
;
303 } else if (S_ISREG(dp
->mode
)) {
304 BUG_ON(dp
->proc_fops
== NULL
);
305 dp
->proc_iops
= &proc_file_inode_operations
;
311 spin_lock(&proc_subdir_lock
);
313 for (tmp
= dir
->subdir
; tmp
; tmp
= tmp
->next
)
314 if (strcmp(tmp
->name
, dp
->name
) == 0) {
315 WARN(1, "proc_dir_entry '%s/%s' already registered\n",
316 dir
->name
, dp
->name
);
320 dp
->next
= dir
->subdir
;
323 spin_unlock(&proc_subdir_lock
);
328 static struct proc_dir_entry
*__proc_create(struct proc_dir_entry
**parent
,
333 struct proc_dir_entry
*ent
= NULL
;
334 const char *fn
= name
;
337 /* make sure name is valid */
338 if (!name
|| !strlen(name
))
341 if (xlate_proc_name(name
, parent
, &fn
) != 0)
344 /* At this point there must not be any '/' characters beyond *fn */
350 ent
= kzalloc(sizeof(struct proc_dir_entry
) + len
+ 1, GFP_KERNEL
);
354 memcpy(ent
->name
, fn
, len
+ 1);
358 atomic_set(&ent
->count
, 1);
359 spin_lock_init(&ent
->pde_unload_lock
);
360 INIT_LIST_HEAD(&ent
->pde_openers
);
365 struct proc_dir_entry
*proc_symlink(const char *name
,
366 struct proc_dir_entry
*parent
, const char *dest
)
368 struct proc_dir_entry
*ent
;
370 ent
= __proc_create(&parent
, name
,
371 (S_IFLNK
| S_IRUGO
| S_IWUGO
| S_IXUGO
),1);
374 ent
->data
= kmalloc((ent
->size
=strlen(dest
))+1, GFP_KERNEL
);
376 strcpy((char*)ent
->data
,dest
);
377 if (proc_register(parent
, ent
) < 0) {
389 EXPORT_SYMBOL(proc_symlink
);
391 struct proc_dir_entry
*proc_mkdir_data(const char *name
, umode_t mode
,
392 struct proc_dir_entry
*parent
, void *data
)
394 struct proc_dir_entry
*ent
;
397 mode
= S_IRUGO
| S_IXUGO
;
399 ent
= __proc_create(&parent
, name
, S_IFDIR
| mode
, 2);
402 if (proc_register(parent
, ent
) < 0) {
409 EXPORT_SYMBOL_GPL(proc_mkdir_data
);
411 struct proc_dir_entry
*proc_mkdir_mode(const char *name
, umode_t mode
,
412 struct proc_dir_entry
*parent
)
414 return proc_mkdir_data(name
, mode
, parent
, NULL
);
416 EXPORT_SYMBOL(proc_mkdir_mode
);
418 struct proc_dir_entry
*proc_mkdir(const char *name
,
419 struct proc_dir_entry
*parent
)
421 return proc_mkdir_data(name
, 0, parent
, NULL
);
423 EXPORT_SYMBOL(proc_mkdir
);
425 struct proc_dir_entry
*proc_create_data(const char *name
, umode_t mode
,
426 struct proc_dir_entry
*parent
,
427 const struct file_operations
*proc_fops
,
430 struct proc_dir_entry
*pde
;
431 if ((mode
& S_IFMT
) == 0)
434 if (!S_ISREG(mode
)) {
435 WARN_ON(1); /* use proc_mkdir() */
439 if ((mode
& S_IALLUGO
) == 0)
441 pde
= __proc_create(&parent
, name
, mode
, 1);
444 pde
->proc_fops
= proc_fops
;
446 if (proc_register(parent
, pde
) < 0)
454 EXPORT_SYMBOL(proc_create_data
);
456 void proc_set_size(struct proc_dir_entry
*de
, loff_t size
)
460 EXPORT_SYMBOL(proc_set_size
);
462 void proc_set_user(struct proc_dir_entry
*de
, kuid_t uid
, kgid_t gid
)
467 EXPORT_SYMBOL(proc_set_user
);
469 static void free_proc_entry(struct proc_dir_entry
*de
)
471 proc_free_inum(de
->low_ino
);
473 if (S_ISLNK(de
->mode
))
478 void pde_put(struct proc_dir_entry
*pde
)
480 if (atomic_dec_and_test(&pde
->count
))
481 free_proc_entry(pde
);
485 * Remove a /proc entry and free it if it's not currently in use.
487 void remove_proc_entry(const char *name
, struct proc_dir_entry
*parent
)
489 struct proc_dir_entry
**p
;
490 struct proc_dir_entry
*de
= NULL
;
491 const char *fn
= name
;
494 spin_lock(&proc_subdir_lock
);
495 if (__xlate_proc_name(name
, &parent
, &fn
) != 0) {
496 spin_unlock(&proc_subdir_lock
);
501 for (p
= &parent
->subdir
; *p
; p
=&(*p
)->next
) {
502 if (proc_match(len
, fn
, *p
)) {
509 spin_unlock(&proc_subdir_lock
);
511 WARN(1, "name '%s'\n", name
);
515 proc_entry_rundown(de
);
517 if (S_ISDIR(de
->mode
))
520 WARN(de
->subdir
, "%s: removing non-empty directory "
521 "'%s/%s', leaking at least '%s'\n", __func__
,
522 de
->parent
->name
, de
->name
, de
->subdir
->name
);
525 EXPORT_SYMBOL(remove_proc_entry
);
527 int remove_proc_subtree(const char *name
, struct proc_dir_entry
*parent
)
529 struct proc_dir_entry
**p
;
530 struct proc_dir_entry
*root
= NULL
, *de
, *next
;
531 const char *fn
= name
;
534 spin_lock(&proc_subdir_lock
);
535 if (__xlate_proc_name(name
, &parent
, &fn
) != 0) {
536 spin_unlock(&proc_subdir_lock
);
541 for (p
= &parent
->subdir
; *p
; p
=&(*p
)->next
) {
542 if (proc_match(len
, fn
, *p
)) {
550 spin_unlock(&proc_subdir_lock
);
557 de
->subdir
= next
->next
;
562 spin_unlock(&proc_subdir_lock
);
564 proc_entry_rundown(de
);
566 if (S_ISDIR(de
->mode
))
573 spin_lock(&proc_subdir_lock
);
579 EXPORT_SYMBOL(remove_proc_subtree
);
581 void *proc_get_parent_data(const struct inode
*inode
)
583 struct proc_dir_entry
*de
= PDE(inode
);
584 return de
->parent
->data
;
586 EXPORT_SYMBOL_GPL(proc_get_parent_data
);
588 void proc_remove(struct proc_dir_entry
*de
)
591 remove_proc_subtree(de
->name
, de
->parent
);
593 EXPORT_SYMBOL(proc_remove
);
595 void *PDE_DATA(const struct inode
*inode
)
597 return __PDE_DATA(inode
);
599 EXPORT_SYMBOL(PDE_DATA
);