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1/*
2 * proc/fs/generic.c --- generic routines for the proc-fs
3 *
4 * This file contains generic proc-fs routines for handling
5 * directories and files.
6 *
7 * Copyright (C) 1991, 1992 Linus Torvalds.
8 * Copyright (C) 1997 Theodore Ts'o
9 */
10
11#include <linux/errno.h>
12#include <linux/time.h>
13#include <linux/proc_fs.h>
14#include <linux/stat.h>
15#include <linux/mm.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/bitops.h>
23#include <linux/spinlock.h>
24#include <linux/completion.h>
25#include <asm/uaccess.h>
26
27#include "internal.h"
28
29static DEFINE_RWLOCK(proc_subdir_lock);
30
31static int proc_match(unsigned int len, const char *name, struct proc_dir_entry *de)
32{
33 if (len < de->namelen)
34 return -1;
35 if (len > de->namelen)
36 return 1;
37
38 return memcmp(name, de->name, len);
39}
40
41static struct proc_dir_entry *pde_subdir_first(struct proc_dir_entry *dir)
42{
43 return rb_entry_safe(rb_first(&dir->subdir), struct proc_dir_entry,
44 subdir_node);
45}
46
47static struct proc_dir_entry *pde_subdir_next(struct proc_dir_entry *dir)
48{
49 return rb_entry_safe(rb_next(&dir->subdir_node), struct proc_dir_entry,
50 subdir_node);
51}
52
53static struct proc_dir_entry *pde_subdir_find(struct proc_dir_entry *dir,
54 const char *name,
55 unsigned int len)
56{
57 struct rb_node *node = dir->subdir.rb_node;
58
59 while (node) {
60 struct proc_dir_entry *de = container_of(node,
61 struct proc_dir_entry,
62 subdir_node);
63 int result = proc_match(len, name, de);
64
65 if (result < 0)
66 node = node->rb_left;
67 else if (result > 0)
68 node = node->rb_right;
69 else
70 return de;
71 }
72 return NULL;
73}
74
75static bool pde_subdir_insert(struct proc_dir_entry *dir,
76 struct proc_dir_entry *de)
77{
78 struct rb_root *root = &dir->subdir;
79 struct rb_node **new = &root->rb_node, *parent = NULL;
80
81 /* Figure out where to put new node */
82 while (*new) {
83 struct proc_dir_entry *this =
84 container_of(*new, struct proc_dir_entry, subdir_node);
85 int result = proc_match(de->namelen, de->name, this);
86
87 parent = *new;
88 if (result < 0)
89 new = &(*new)->rb_left;
90 else if (result > 0)
91 new = &(*new)->rb_right;
92 else
93 return false;
94 }
95
96 /* Add new node and rebalance tree. */
97 rb_link_node(&de->subdir_node, parent, new);
98 rb_insert_color(&de->subdir_node, root);
99 return true;
100}
101
102static int proc_notify_change(struct dentry *dentry, struct iattr *iattr)
103{
104 struct inode *inode = d_inode(dentry);
105 struct proc_dir_entry *de = PDE(inode);
106 int error;
107
108 error = inode_change_ok(inode, iattr);
109 if (error)
110 return error;
111
112 setattr_copy(inode, iattr);
113 mark_inode_dirty(inode);
114
115 proc_set_user(de, inode->i_uid, inode->i_gid);
116 de->mode = inode->i_mode;
117 return 0;
118}
119
120static int proc_getattr(struct vfsmount *mnt, struct dentry *dentry,
121 struct kstat *stat)
122{
123 struct inode *inode = d_inode(dentry);
124 struct proc_dir_entry *de = PDE(inode);
125 if (de && de->nlink)
126 set_nlink(inode, de->nlink);
127
128 generic_fillattr(inode, stat);
129 return 0;
130}
131
132static const struct inode_operations proc_file_inode_operations = {
133 .setattr = proc_notify_change,
134};
135
136/*
137 * This function parses a name such as "tty/driver/serial", and
138 * returns the struct proc_dir_entry for "/proc/tty/driver", and
139 * returns "serial" in residual.
140 */
141static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret,
142 const char **residual)
143{
144 const char *cp = name, *next;
145 struct proc_dir_entry *de;
146 unsigned int len;
147
148 de = *ret;
149 if (!de)
150 de = &proc_root;
151
152 while (1) {
153 next = strchr(cp, '/');
154 if (!next)
155 break;
156
157 len = next - cp;
158 de = pde_subdir_find(de, cp, len);
159 if (!de) {
160 WARN(1, "name '%s'\n", name);
161 return -ENOENT;
162 }
163 cp += len + 1;
164 }
165 *residual = cp;
166 *ret = de;
167 return 0;
168}
169
170static int xlate_proc_name(const char *name, struct proc_dir_entry **ret,
171 const char **residual)
172{
173 int rv;
174
175 read_lock(&proc_subdir_lock);
176 rv = __xlate_proc_name(name, ret, residual);
177 read_unlock(&proc_subdir_lock);
178 return rv;
179}
180
181static DEFINE_IDA(proc_inum_ida);
182static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */
183
184#define PROC_DYNAMIC_FIRST 0xF0000000U
185
186/*
187 * Return an inode number between PROC_DYNAMIC_FIRST and
188 * 0xffffffff, or zero on failure.
189 */
190int proc_alloc_inum(unsigned int *inum)
191{
192 unsigned int i;
193 int error;
194
195retry:
196 if (!ida_pre_get(&proc_inum_ida, GFP_KERNEL))
197 return -ENOMEM;
198
199 spin_lock_irq(&proc_inum_lock);
200 error = ida_get_new(&proc_inum_ida, &i);
201 spin_unlock_irq(&proc_inum_lock);
202 if (error == -EAGAIN)
203 goto retry;
204 else if (error)
205 return error;
206
207 if (i > UINT_MAX - PROC_DYNAMIC_FIRST) {
208 spin_lock_irq(&proc_inum_lock);
209 ida_remove(&proc_inum_ida, i);
210 spin_unlock_irq(&proc_inum_lock);
211 return -ENOSPC;
212 }
213 *inum = PROC_DYNAMIC_FIRST + i;
214 return 0;
215}
216
217void proc_free_inum(unsigned int inum)
218{
219 unsigned long flags;
220 spin_lock_irqsave(&proc_inum_lock, flags);
221 ida_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST);
222 spin_unlock_irqrestore(&proc_inum_lock, flags);
223}
224
225/*
226 * Don't create negative dentries here, return -ENOENT by hand
227 * instead.
228 */
229struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir,
230 struct dentry *dentry)
231{
232 struct inode *inode;
233
234 read_lock(&proc_subdir_lock);
235 de = pde_subdir_find(de, dentry->d_name.name, dentry->d_name.len);
236 if (de) {
237 pde_get(de);
238 read_unlock(&proc_subdir_lock);
239 inode = proc_get_inode(dir->i_sb, de);
240 if (!inode)
241 return ERR_PTR(-ENOMEM);
242 d_set_d_op(dentry, &simple_dentry_operations);
243 d_add(dentry, inode);
244 return NULL;
245 }
246 read_unlock(&proc_subdir_lock);
247 return ERR_PTR(-ENOENT);
248}
249
250struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry,
251 unsigned int flags)
252{
253 return proc_lookup_de(PDE(dir), dir, dentry);
254}
255
256/*
257 * This returns non-zero if at EOF, so that the /proc
258 * root directory can use this and check if it should
259 * continue with the <pid> entries..
260 *
261 * Note that the VFS-layer doesn't care about the return
262 * value of the readdir() call, as long as it's non-negative
263 * for success..
264 */
265int proc_readdir_de(struct proc_dir_entry *de, struct file *file,
266 struct dir_context *ctx)
267{
268 int i;
269
270 if (!dir_emit_dots(file, ctx))
271 return 0;
272
273 read_lock(&proc_subdir_lock);
274 de = pde_subdir_first(de);
275 i = ctx->pos - 2;
276 for (;;) {
277 if (!de) {
278 read_unlock(&proc_subdir_lock);
279 return 0;
280 }
281 if (!i)
282 break;
283 de = pde_subdir_next(de);
284 i--;
285 }
286
287 do {
288 struct proc_dir_entry *next;
289 pde_get(de);
290 read_unlock(&proc_subdir_lock);
291 if (!dir_emit(ctx, de->name, de->namelen,
292 de->low_ino, de->mode >> 12)) {
293 pde_put(de);
294 return 0;
295 }
296 read_lock(&proc_subdir_lock);
297 ctx->pos++;
298 next = pde_subdir_next(de);
299 pde_put(de);
300 de = next;
301 } while (de);
302 read_unlock(&proc_subdir_lock);
303 return 1;
304}
305
306int proc_readdir(struct file *file, struct dir_context *ctx)
307{
308 struct inode *inode = file_inode(file);
309
310 return proc_readdir_de(PDE(inode), file, ctx);
311}
312
313/*
314 * These are the generic /proc directory operations. They
315 * use the in-memory "struct proc_dir_entry" tree to parse
316 * the /proc directory.
317 */
318static const struct file_operations proc_dir_operations = {
319 .llseek = generic_file_llseek,
320 .read = generic_read_dir,
321 .iterate = proc_readdir,
322};
323
324/*
325 * proc directories can do almost nothing..
326 */
327static const struct inode_operations proc_dir_inode_operations = {
328 .lookup = proc_lookup,
329 .getattr = proc_getattr,
330 .setattr = proc_notify_change,
331};
332
333static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
334{
335 int ret;
336
337 ret = proc_alloc_inum(&dp->low_ino);
338 if (ret)
339 return ret;
340
341 write_lock(&proc_subdir_lock);
342 dp->parent = dir;
343 if (pde_subdir_insert(dir, dp) == false) {
344 WARN(1, "proc_dir_entry '%s/%s' already registered\n",
345 dir->name, dp->name);
346 write_unlock(&proc_subdir_lock);
347 proc_free_inum(dp->low_ino);
348 return -EEXIST;
349 }
350 write_unlock(&proc_subdir_lock);
351
352 return 0;
353}
354
355static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
356 const char *name,
357 umode_t mode,
358 nlink_t nlink)
359{
360 struct proc_dir_entry *ent = NULL;
361 const char *fn;
362 struct qstr qstr;
363
364 if (xlate_proc_name(name, parent, &fn) != 0)
365 goto out;
366 qstr.name = fn;
367 qstr.len = strlen(fn);
368 if (qstr.len == 0 || qstr.len >= 256) {
369 WARN(1, "name len %u\n", qstr.len);
370 return NULL;
371 }
372 if (*parent == &proc_root && name_to_int(&qstr) != ~0U) {
373 WARN(1, "create '/proc/%s' by hand\n", qstr.name);
374 return NULL;
375 }
376 if (is_empty_pde(*parent)) {
377 WARN(1, "attempt to add to permanently empty directory");
378 return NULL;
379 }
380
381 ent = kzalloc(sizeof(struct proc_dir_entry) + qstr.len + 1, GFP_KERNEL);
382 if (!ent)
383 goto out;
384
385 memcpy(ent->name, fn, qstr.len + 1);
386 ent->namelen = qstr.len;
387 ent->mode = mode;
388 ent->nlink = nlink;
389 ent->subdir = RB_ROOT;
390 atomic_set(&ent->count, 1);
391 spin_lock_init(&ent->pde_unload_lock);
392 INIT_LIST_HEAD(&ent->pde_openers);
393out:
394 return ent;
395}
396
397struct proc_dir_entry *proc_symlink(const char *name,
398 struct proc_dir_entry *parent, const char *dest)
399{
400 struct proc_dir_entry *ent;
401
402 ent = __proc_create(&parent, name,
403 (S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO),1);
404
405 if (ent) {
406 ent->data = kmalloc((ent->size=strlen(dest))+1, GFP_KERNEL);
407 if (ent->data) {
408 strcpy((char*)ent->data,dest);
409 ent->proc_iops = &proc_link_inode_operations;
410 if (proc_register(parent, ent) < 0) {
411 kfree(ent->data);
412 kfree(ent);
413 ent = NULL;
414 }
415 } else {
416 kfree(ent);
417 ent = NULL;
418 }
419 }
420 return ent;
421}
422EXPORT_SYMBOL(proc_symlink);
423
424struct proc_dir_entry *proc_mkdir_data(const char *name, umode_t mode,
425 struct proc_dir_entry *parent, void *data)
426{
427 struct proc_dir_entry *ent;
428
429 if (mode == 0)
430 mode = S_IRUGO | S_IXUGO;
431
432 ent = __proc_create(&parent, name, S_IFDIR | mode, 2);
433 if (ent) {
434 ent->data = data;
435 ent->proc_fops = &proc_dir_operations;
436 ent->proc_iops = &proc_dir_inode_operations;
437 parent->nlink++;
438 if (proc_register(parent, ent) < 0) {
439 kfree(ent);
440 parent->nlink--;
441 ent = NULL;
442 }
443 }
444 return ent;
445}
446EXPORT_SYMBOL_GPL(proc_mkdir_data);
447
448struct proc_dir_entry *proc_mkdir_mode(const char *name, umode_t mode,
449 struct proc_dir_entry *parent)
450{
451 return proc_mkdir_data(name, mode, parent, NULL);
452}
453EXPORT_SYMBOL(proc_mkdir_mode);
454
455struct proc_dir_entry *proc_mkdir(const char *name,
456 struct proc_dir_entry *parent)
457{
458 return proc_mkdir_data(name, 0, parent, NULL);
459}
460EXPORT_SYMBOL(proc_mkdir);
461
462struct proc_dir_entry *proc_create_mount_point(const char *name)
463{
464 umode_t mode = S_IFDIR | S_IRUGO | S_IXUGO;
465 struct proc_dir_entry *ent, *parent = NULL;
466
467 ent = __proc_create(&parent, name, mode, 2);
468 if (ent) {
469 ent->data = NULL;
470 ent->proc_fops = NULL;
471 ent->proc_iops = NULL;
472 if (proc_register(parent, ent) < 0) {
473 kfree(ent);
474 parent->nlink--;
475 ent = NULL;
476 }
477 }
478 return ent;
479}
480
481struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
482 struct proc_dir_entry *parent,
483 const struct file_operations *proc_fops,
484 void *data)
485{
486 struct proc_dir_entry *pde;
487 if ((mode & S_IFMT) == 0)
488 mode |= S_IFREG;
489
490 if (!S_ISREG(mode)) {
491 WARN_ON(1); /* use proc_mkdir() */
492 return NULL;
493 }
494
495 BUG_ON(proc_fops == NULL);
496
497 if ((mode & S_IALLUGO) == 0)
498 mode |= S_IRUGO;
499 pde = __proc_create(&parent, name, mode, 1);
500 if (!pde)
501 goto out;
502 pde->proc_fops = proc_fops;
503 pde->data = data;
504 pde->proc_iops = &proc_file_inode_operations;
505 if (proc_register(parent, pde) < 0)
506 goto out_free;
507 return pde;
508out_free:
509 kfree(pde);
510out:
511 return NULL;
512}
513EXPORT_SYMBOL(proc_create_data);
514
515void proc_set_size(struct proc_dir_entry *de, loff_t size)
516{
517 de->size = size;
518}
519EXPORT_SYMBOL(proc_set_size);
520
521void proc_set_user(struct proc_dir_entry *de, kuid_t uid, kgid_t gid)
522{
523 de->uid = uid;
524 de->gid = gid;
525}
526EXPORT_SYMBOL(proc_set_user);
527
528static void free_proc_entry(struct proc_dir_entry *de)
529{
530 proc_free_inum(de->low_ino);
531
532 if (S_ISLNK(de->mode))
533 kfree(de->data);
534 kfree(de);
535}
536
537void pde_put(struct proc_dir_entry *pde)
538{
539 if (atomic_dec_and_test(&pde->count))
540 free_proc_entry(pde);
541}
542
543/*
544 * Remove a /proc entry and free it if it's not currently in use.
545 */
546void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
547{
548 struct proc_dir_entry *de = NULL;
549 const char *fn = name;
550 unsigned int len;
551
552 write_lock(&proc_subdir_lock);
553 if (__xlate_proc_name(name, &parent, &fn) != 0) {
554 write_unlock(&proc_subdir_lock);
555 return;
556 }
557 len = strlen(fn);
558
559 de = pde_subdir_find(parent, fn, len);
560 if (de)
561 rb_erase(&de->subdir_node, &parent->subdir);
562 write_unlock(&proc_subdir_lock);
563 if (!de) {
564 WARN(1, "name '%s'\n", name);
565 return;
566 }
567
568 proc_entry_rundown(de);
569
570 if (S_ISDIR(de->mode))
571 parent->nlink--;
572 de->nlink = 0;
573 WARN(pde_subdir_first(de),
574 "%s: removing non-empty directory '%s/%s', leaking at least '%s'\n",
575 __func__, de->parent->name, de->name, pde_subdir_first(de)->name);
576 pde_put(de);
577}
578EXPORT_SYMBOL(remove_proc_entry);
579
580int remove_proc_subtree(const char *name, struct proc_dir_entry *parent)
581{
582 struct proc_dir_entry *root = NULL, *de, *next;
583 const char *fn = name;
584 unsigned int len;
585
586 write_lock(&proc_subdir_lock);
587 if (__xlate_proc_name(name, &parent, &fn) != 0) {
588 write_unlock(&proc_subdir_lock);
589 return -ENOENT;
590 }
591 len = strlen(fn);
592
593 root = pde_subdir_find(parent, fn, len);
594 if (!root) {
595 write_unlock(&proc_subdir_lock);
596 return -ENOENT;
597 }
598 rb_erase(&root->subdir_node, &parent->subdir);
599
600 de = root;
601 while (1) {
602 next = pde_subdir_first(de);
603 if (next) {
604 rb_erase(&next->subdir_node, &de->subdir);
605 de = next;
606 continue;
607 }
608 write_unlock(&proc_subdir_lock);
609
610 proc_entry_rundown(de);
611 next = de->parent;
612 if (S_ISDIR(de->mode))
613 next->nlink--;
614 de->nlink = 0;
615 if (de == root)
616 break;
617 pde_put(de);
618
619 write_lock(&proc_subdir_lock);
620 de = next;
621 }
622 pde_put(root);
623 return 0;
624}
625EXPORT_SYMBOL(remove_proc_subtree);
626
627void *proc_get_parent_data(const struct inode *inode)
628{
629 struct proc_dir_entry *de = PDE(inode);
630 return de->parent->data;
631}
632EXPORT_SYMBOL_GPL(proc_get_parent_data);
633
634void proc_remove(struct proc_dir_entry *de)
635{
636 if (de)
637 remove_proc_subtree(de->name, de->parent);
638}
639EXPORT_SYMBOL(proc_remove);
640
641void *PDE_DATA(const struct inode *inode)
642{
643 return __PDE_DATA(inode);
644}
645EXPORT_SYMBOL(PDE_DATA);
1/*
2 * proc/fs/generic.c --- generic routines for the proc-fs
3 *
4 * This file contains generic proc-fs routines for handling
5 * directories and files.
6 *
7 * Copyright (C) 1991, 1992 Linus Torvalds.
8 * Copyright (C) 1997 Theodore Ts'o
9 */
10
11#include <linux/errno.h>
12#include <linux/time.h>
13#include <linux/proc_fs.h>
14#include <linux/stat.h>
15#include <linux/mm.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>
27
28#include "internal.h"
29
30DEFINE_SPINLOCK(proc_subdir_lock);
31
32static int proc_match(unsigned int len, const char *name, struct proc_dir_entry *de)
33{
34 if (de->namelen != len)
35 return 0;
36 return !memcmp(name, de->name, len);
37}
38
39static int proc_notify_change(struct dentry *dentry, struct iattr *iattr)
40{
41 struct inode *inode = dentry->d_inode;
42 struct proc_dir_entry *de = PDE(inode);
43 int error;
44
45 error = inode_change_ok(inode, iattr);
46 if (error)
47 return error;
48
49 setattr_copy(inode, iattr);
50 mark_inode_dirty(inode);
51
52 proc_set_user(de, inode->i_uid, inode->i_gid);
53 de->mode = inode->i_mode;
54 return 0;
55}
56
57static int proc_getattr(struct vfsmount *mnt, struct dentry *dentry,
58 struct kstat *stat)
59{
60 struct inode *inode = dentry->d_inode;
61 struct proc_dir_entry *de = PROC_I(inode)->pde;
62 if (de && de->nlink)
63 set_nlink(inode, de->nlink);
64
65 generic_fillattr(inode, stat);
66 return 0;
67}
68
69static const struct inode_operations proc_file_inode_operations = {
70 .setattr = proc_notify_change,
71};
72
73/*
74 * This function parses a name such as "tty/driver/serial", and
75 * returns the struct proc_dir_entry for "/proc/tty/driver", and
76 * returns "serial" in residual.
77 */
78static int __xlate_proc_name(const char *name, struct proc_dir_entry **ret,
79 const char **residual)
80{
81 const char *cp = name, *next;
82 struct proc_dir_entry *de;
83 unsigned int len;
84
85 de = *ret;
86 if (!de)
87 de = &proc_root;
88
89 while (1) {
90 next = strchr(cp, '/');
91 if (!next)
92 break;
93
94 len = next - cp;
95 for (de = de->subdir; de ; de = de->next) {
96 if (proc_match(len, cp, de))
97 break;
98 }
99 if (!de) {
100 WARN(1, "name '%s'\n", name);
101 return -ENOENT;
102 }
103 cp += len + 1;
104 }
105 *residual = cp;
106 *ret = de;
107 return 0;
108}
109
110static int xlate_proc_name(const char *name, struct proc_dir_entry **ret,
111 const char **residual)
112{
113 int rv;
114
115 spin_lock(&proc_subdir_lock);
116 rv = __xlate_proc_name(name, ret, residual);
117 spin_unlock(&proc_subdir_lock);
118 return rv;
119}
120
121static DEFINE_IDA(proc_inum_ida);
122static DEFINE_SPINLOCK(proc_inum_lock); /* protects the above */
123
124#define PROC_DYNAMIC_FIRST 0xF0000000U
125
126/*
127 * Return an inode number between PROC_DYNAMIC_FIRST and
128 * 0xffffffff, or zero on failure.
129 */
130int proc_alloc_inum(unsigned int *inum)
131{
132 unsigned int i;
133 int error;
134
135retry:
136 if (!ida_pre_get(&proc_inum_ida, GFP_KERNEL))
137 return -ENOMEM;
138
139 spin_lock_irq(&proc_inum_lock);
140 error = ida_get_new(&proc_inum_ida, &i);
141 spin_unlock_irq(&proc_inum_lock);
142 if (error == -EAGAIN)
143 goto retry;
144 else if (error)
145 return error;
146
147 if (i > UINT_MAX - PROC_DYNAMIC_FIRST) {
148 spin_lock_irq(&proc_inum_lock);
149 ida_remove(&proc_inum_ida, i);
150 spin_unlock_irq(&proc_inum_lock);
151 return -ENOSPC;
152 }
153 *inum = PROC_DYNAMIC_FIRST + i;
154 return 0;
155}
156
157void proc_free_inum(unsigned int inum)
158{
159 unsigned long flags;
160 spin_lock_irqsave(&proc_inum_lock, flags);
161 ida_remove(&proc_inum_ida, inum - PROC_DYNAMIC_FIRST);
162 spin_unlock_irqrestore(&proc_inum_lock, flags);
163}
164
165static void *proc_follow_link(struct dentry *dentry, struct nameidata *nd)
166{
167 nd_set_link(nd, __PDE_DATA(dentry->d_inode));
168 return NULL;
169}
170
171static const struct inode_operations proc_link_inode_operations = {
172 .readlink = generic_readlink,
173 .follow_link = proc_follow_link,
174};
175
176/*
177 * Don't create negative dentries here, return -ENOENT by hand
178 * instead.
179 */
180struct dentry *proc_lookup_de(struct proc_dir_entry *de, struct inode *dir,
181 struct dentry *dentry)
182{
183 struct inode *inode;
184
185 spin_lock(&proc_subdir_lock);
186 for (de = de->subdir; de ; de = de->next) {
187 if (de->namelen != dentry->d_name.len)
188 continue;
189 if (!memcmp(dentry->d_name.name, de->name, de->namelen)) {
190 pde_get(de);
191 spin_unlock(&proc_subdir_lock);
192 inode = proc_get_inode(dir->i_sb, de);
193 if (!inode)
194 return ERR_PTR(-ENOMEM);
195 d_set_d_op(dentry, &simple_dentry_operations);
196 d_add(dentry, inode);
197 return NULL;
198 }
199 }
200 spin_unlock(&proc_subdir_lock);
201 return ERR_PTR(-ENOENT);
202}
203
204struct dentry *proc_lookup(struct inode *dir, struct dentry *dentry,
205 unsigned int flags)
206{
207 return proc_lookup_de(PDE(dir), dir, dentry);
208}
209
210/*
211 * This returns non-zero if at EOF, so that the /proc
212 * root directory can use this and check if it should
213 * continue with the <pid> entries..
214 *
215 * Note that the VFS-layer doesn't care about the return
216 * value of the readdir() call, as long as it's non-negative
217 * for success..
218 */
219int proc_readdir_de(struct proc_dir_entry *de, struct file *file,
220 struct dir_context *ctx)
221{
222 int i;
223
224 if (!dir_emit_dots(file, ctx))
225 return 0;
226
227 spin_lock(&proc_subdir_lock);
228 de = de->subdir;
229 i = ctx->pos - 2;
230 for (;;) {
231 if (!de) {
232 spin_unlock(&proc_subdir_lock);
233 return 0;
234 }
235 if (!i)
236 break;
237 de = de->next;
238 i--;
239 }
240
241 do {
242 struct proc_dir_entry *next;
243 pde_get(de);
244 spin_unlock(&proc_subdir_lock);
245 if (!dir_emit(ctx, de->name, de->namelen,
246 de->low_ino, de->mode >> 12)) {
247 pde_put(de);
248 return 0;
249 }
250 spin_lock(&proc_subdir_lock);
251 ctx->pos++;
252 next = de->next;
253 pde_put(de);
254 de = next;
255 } while (de);
256 spin_unlock(&proc_subdir_lock);
257 return 1;
258}
259
260int proc_readdir(struct file *file, struct dir_context *ctx)
261{
262 struct inode *inode = file_inode(file);
263
264 return proc_readdir_de(PDE(inode), file, ctx);
265}
266
267/*
268 * These are the generic /proc directory operations. They
269 * use the in-memory "struct proc_dir_entry" tree to parse
270 * the /proc directory.
271 */
272static const struct file_operations proc_dir_operations = {
273 .llseek = generic_file_llseek,
274 .read = generic_read_dir,
275 .iterate = proc_readdir,
276};
277
278/*
279 * proc directories can do almost nothing..
280 */
281static const struct inode_operations proc_dir_inode_operations = {
282 .lookup = proc_lookup,
283 .getattr = proc_getattr,
284 .setattr = proc_notify_change,
285};
286
287static int proc_register(struct proc_dir_entry * dir, struct proc_dir_entry * dp)
288{
289 struct proc_dir_entry *tmp;
290 int ret;
291
292 ret = proc_alloc_inum(&dp->low_ino);
293 if (ret)
294 return ret;
295
296 if (S_ISDIR(dp->mode)) {
297 dp->proc_fops = &proc_dir_operations;
298 dp->proc_iops = &proc_dir_inode_operations;
299 dir->nlink++;
300 } else if (S_ISLNK(dp->mode)) {
301 dp->proc_iops = &proc_link_inode_operations;
302 } else if (S_ISREG(dp->mode)) {
303 BUG_ON(dp->proc_fops == NULL);
304 dp->proc_iops = &proc_file_inode_operations;
305 } else {
306 WARN_ON(1);
307 return -EINVAL;
308 }
309
310 spin_lock(&proc_subdir_lock);
311
312 for (tmp = dir->subdir; tmp; tmp = tmp->next)
313 if (strcmp(tmp->name, dp->name) == 0) {
314 WARN(1, "proc_dir_entry '%s/%s' already registered\n",
315 dir->name, dp->name);
316 break;
317 }
318
319 dp->next = dir->subdir;
320 dp->parent = dir;
321 dir->subdir = dp;
322 spin_unlock(&proc_subdir_lock);
323
324 return 0;
325}
326
327static struct proc_dir_entry *__proc_create(struct proc_dir_entry **parent,
328 const char *name,
329 umode_t mode,
330 nlink_t nlink)
331{
332 struct proc_dir_entry *ent = NULL;
333 const char *fn = name;
334 unsigned int len;
335
336 /* make sure name is valid */
337 if (!name || !strlen(name))
338 goto out;
339
340 if (xlate_proc_name(name, parent, &fn) != 0)
341 goto out;
342
343 /* At this point there must not be any '/' characters beyond *fn */
344 if (strchr(fn, '/'))
345 goto out;
346
347 len = strlen(fn);
348
349 ent = kzalloc(sizeof(struct proc_dir_entry) + len + 1, GFP_KERNEL);
350 if (!ent)
351 goto out;
352
353 memcpy(ent->name, fn, len + 1);
354 ent->namelen = len;
355 ent->mode = mode;
356 ent->nlink = nlink;
357 atomic_set(&ent->count, 1);
358 spin_lock_init(&ent->pde_unload_lock);
359 INIT_LIST_HEAD(&ent->pde_openers);
360out:
361 return ent;
362}
363
364struct proc_dir_entry *proc_symlink(const char *name,
365 struct proc_dir_entry *parent, const char *dest)
366{
367 struct proc_dir_entry *ent;
368
369 ent = __proc_create(&parent, name,
370 (S_IFLNK | S_IRUGO | S_IWUGO | S_IXUGO),1);
371
372 if (ent) {
373 ent->data = kmalloc((ent->size=strlen(dest))+1, GFP_KERNEL);
374 if (ent->data) {
375 strcpy((char*)ent->data,dest);
376 if (proc_register(parent, ent) < 0) {
377 kfree(ent->data);
378 kfree(ent);
379 ent = NULL;
380 }
381 } else {
382 kfree(ent);
383 ent = NULL;
384 }
385 }
386 return ent;
387}
388EXPORT_SYMBOL(proc_symlink);
389
390struct proc_dir_entry *proc_mkdir_data(const char *name, umode_t mode,
391 struct proc_dir_entry *parent, void *data)
392{
393 struct proc_dir_entry *ent;
394
395 if (mode == 0)
396 mode = S_IRUGO | S_IXUGO;
397
398 ent = __proc_create(&parent, name, S_IFDIR | mode, 2);
399 if (ent) {
400 ent->data = data;
401 if (proc_register(parent, ent) < 0) {
402 kfree(ent);
403 ent = NULL;
404 }
405 }
406 return ent;
407}
408EXPORT_SYMBOL_GPL(proc_mkdir_data);
409
410struct proc_dir_entry *proc_mkdir_mode(const char *name, umode_t mode,
411 struct proc_dir_entry *parent)
412{
413 return proc_mkdir_data(name, mode, parent, NULL);
414}
415EXPORT_SYMBOL(proc_mkdir_mode);
416
417struct proc_dir_entry *proc_mkdir(const char *name,
418 struct proc_dir_entry *parent)
419{
420 return proc_mkdir_data(name, 0, parent, NULL);
421}
422EXPORT_SYMBOL(proc_mkdir);
423
424struct proc_dir_entry *proc_create_data(const char *name, umode_t mode,
425 struct proc_dir_entry *parent,
426 const struct file_operations *proc_fops,
427 void *data)
428{
429 struct proc_dir_entry *pde;
430 if ((mode & S_IFMT) == 0)
431 mode |= S_IFREG;
432
433 if (!S_ISREG(mode)) {
434 WARN_ON(1); /* use proc_mkdir() */
435 return NULL;
436 }
437
438 if ((mode & S_IALLUGO) == 0)
439 mode |= S_IRUGO;
440 pde = __proc_create(&parent, name, mode, 1);
441 if (!pde)
442 goto out;
443 pde->proc_fops = proc_fops;
444 pde->data = data;
445 if (proc_register(parent, pde) < 0)
446 goto out_free;
447 return pde;
448out_free:
449 kfree(pde);
450out:
451 return NULL;
452}
453EXPORT_SYMBOL(proc_create_data);
454
455void proc_set_size(struct proc_dir_entry *de, loff_t size)
456{
457 de->size = size;
458}
459EXPORT_SYMBOL(proc_set_size);
460
461void proc_set_user(struct proc_dir_entry *de, kuid_t uid, kgid_t gid)
462{
463 de->uid = uid;
464 de->gid = gid;
465}
466EXPORT_SYMBOL(proc_set_user);
467
468static void free_proc_entry(struct proc_dir_entry *de)
469{
470 proc_free_inum(de->low_ino);
471
472 if (S_ISLNK(de->mode))
473 kfree(de->data);
474 kfree(de);
475}
476
477void pde_put(struct proc_dir_entry *pde)
478{
479 if (atomic_dec_and_test(&pde->count))
480 free_proc_entry(pde);
481}
482
483/*
484 * Remove a /proc entry and free it if it's not currently in use.
485 */
486void remove_proc_entry(const char *name, struct proc_dir_entry *parent)
487{
488 struct proc_dir_entry **p;
489 struct proc_dir_entry *de = NULL;
490 const char *fn = name;
491 unsigned int len;
492
493 spin_lock(&proc_subdir_lock);
494 if (__xlate_proc_name(name, &parent, &fn) != 0) {
495 spin_unlock(&proc_subdir_lock);
496 return;
497 }
498 len = strlen(fn);
499
500 for (p = &parent->subdir; *p; p=&(*p)->next ) {
501 if (proc_match(len, fn, *p)) {
502 de = *p;
503 *p = de->next;
504 de->next = NULL;
505 break;
506 }
507 }
508 spin_unlock(&proc_subdir_lock);
509 if (!de) {
510 WARN(1, "name '%s'\n", name);
511 return;
512 }
513
514 proc_entry_rundown(de);
515
516 if (S_ISDIR(de->mode))
517 parent->nlink--;
518 de->nlink = 0;
519 WARN(de->subdir, "%s: removing non-empty directory "
520 "'%s/%s', leaking at least '%s'\n", __func__,
521 de->parent->name, de->name, de->subdir->name);
522 pde_put(de);
523}
524EXPORT_SYMBOL(remove_proc_entry);
525
526int remove_proc_subtree(const char *name, struct proc_dir_entry *parent)
527{
528 struct proc_dir_entry **p;
529 struct proc_dir_entry *root = NULL, *de, *next;
530 const char *fn = name;
531 unsigned int len;
532
533 spin_lock(&proc_subdir_lock);
534 if (__xlate_proc_name(name, &parent, &fn) != 0) {
535 spin_unlock(&proc_subdir_lock);
536 return -ENOENT;
537 }
538 len = strlen(fn);
539
540 for (p = &parent->subdir; *p; p=&(*p)->next ) {
541 if (proc_match(len, fn, *p)) {
542 root = *p;
543 *p = root->next;
544 root->next = NULL;
545 break;
546 }
547 }
548 if (!root) {
549 spin_unlock(&proc_subdir_lock);
550 return -ENOENT;
551 }
552 de = root;
553 while (1) {
554 next = de->subdir;
555 if (next) {
556 de->subdir = next->next;
557 next->next = NULL;
558 de = next;
559 continue;
560 }
561 spin_unlock(&proc_subdir_lock);
562
563 proc_entry_rundown(de);
564 next = de->parent;
565 if (S_ISDIR(de->mode))
566 next->nlink--;
567 de->nlink = 0;
568 if (de == root)
569 break;
570 pde_put(de);
571
572 spin_lock(&proc_subdir_lock);
573 de = next;
574 }
575 pde_put(root);
576 return 0;
577}
578EXPORT_SYMBOL(remove_proc_subtree);
579
580void *proc_get_parent_data(const struct inode *inode)
581{
582 struct proc_dir_entry *de = PDE(inode);
583 return de->parent->data;
584}
585EXPORT_SYMBOL_GPL(proc_get_parent_data);
586
587void proc_remove(struct proc_dir_entry *de)
588{
589 if (de)
590 remove_proc_subtree(de->name, de->parent);
591}
592EXPORT_SYMBOL(proc_remove);
593
594void *PDE_DATA(const struct inode *inode)
595{
596 return __PDE_DATA(inode);
597}
598EXPORT_SYMBOL(PDE_DATA);