blob: d22438ef7674870ad4987b9c2eb11555057e4dc8 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * file.c - part of debugfs, a tiny little debug file system
3 *
4 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
5 * Copyright (C) 2004 IBM Inc.
6 *
7 * This program is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU General Public License version
9 * 2 as published by the Free Software Foundation.
10 *
11 * debugfs is for people to use instead of /proc or /sys.
12 * See Documentation/DocBook/kernel-api for more details.
13 *
14 */
15
16/* uncomment to get debug messages from the debug filesystem, ah the irony. */
17/* #define DEBUG */
18
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/module.h>
20#include <linux/fs.h>
21#include <linux/mount.h>
22#include <linux/pagemap.h>
23#include <linux/init.h>
Randy Dunlap4d8ebdd2006-11-25 11:09:26 -080024#include <linux/kobject.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/namei.h>
26#include <linux/debugfs.h>
Mathieu Desnoyers4f365572006-11-24 13:45:37 -050027#include <linux/fsnotify.h>
Peter Oberparleiter66f54962007-02-13 12:13:54 +010028#include <linux/string.h>
Mimi Zohar92562922008-10-07 14:00:12 -040029#include <linux/magic.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070030
Linus Torvalds1da177e2005-04-16 15:20:36 -070031static struct vfsmount *debugfs_mount;
32static int debugfs_mount_count;
Frederic Weisbeckerc0f92ba2009-03-22 23:10:44 +010033static bool debugfs_registered;
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
35static struct inode *debugfs_get_inode(struct super_block *sb, int mode, dev_t dev)
36{
37 struct inode *inode = new_inode(sb);
38
39 if (inode) {
40 inode->i_mode = mode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041 inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME;
42 switch (mode & S_IFMT) {
43 default:
44 init_special_inode(inode, mode, dev);
45 break;
46 case S_IFREG:
47 inode->i_fop = &debugfs_file_operations;
48 break;
Peter Oberparleiter66f54962007-02-13 12:13:54 +010049 case S_IFLNK:
50 inode->i_op = &debugfs_link_operations;
51 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -070052 case S_IFDIR:
53 inode->i_op = &simple_dir_inode_operations;
54 inode->i_fop = &simple_dir_operations;
55
Mathieu Desnoyersbafb2322006-11-24 13:46:30 -050056 /* directory inodes start off with i_nlink == 2
57 * (for "." entry) */
Dave Hansend8c76e62006-09-30 23:29:04 -070058 inc_nlink(inode);
Linus Torvalds1da177e2005-04-16 15:20:36 -070059 break;
60 }
61 }
62 return inode;
63}
64
65/* SMP-safe */
66static int debugfs_mknod(struct inode *dir, struct dentry *dentry,
67 int mode, dev_t dev)
68{
Jens Axboe71601e22006-06-08 10:26:39 +020069 struct inode *inode;
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 int error = -EPERM;
71
72 if (dentry->d_inode)
73 return -EEXIST;
74
Jens Axboe71601e22006-06-08 10:26:39 +020075 inode = debugfs_get_inode(dir->i_sb, mode, dev);
Linus Torvalds1da177e2005-04-16 15:20:36 -070076 if (inode) {
77 d_instantiate(dentry, inode);
78 dget(dentry);
79 error = 0;
80 }
81 return error;
82}
83
84static int debugfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
85{
86 int res;
87
88 mode = (mode & (S_IRWXUGO | S_ISVTX)) | S_IFDIR;
89 res = debugfs_mknod(dir, dentry, mode, 0);
Mathieu Desnoyers4f365572006-11-24 13:45:37 -050090 if (!res) {
Dave Hansend8c76e62006-09-30 23:29:04 -070091 inc_nlink(dir);
Mathieu Desnoyers4f365572006-11-24 13:45:37 -050092 fsnotify_mkdir(dir, dentry);
93 }
Linus Torvalds1da177e2005-04-16 15:20:36 -070094 return res;
95}
96
Peter Oberparleiter66f54962007-02-13 12:13:54 +010097static int debugfs_link(struct inode *dir, struct dentry *dentry, int mode)
98{
99 mode = (mode & S_IALLUGO) | S_IFLNK;
100 return debugfs_mknod(dir, dentry, mode, 0);
101}
102
Linus Torvalds1da177e2005-04-16 15:20:36 -0700103static int debugfs_create(struct inode *dir, struct dentry *dentry, int mode)
104{
Mathieu Desnoyers4f365572006-11-24 13:45:37 -0500105 int res;
106
Linus Torvalds1da177e2005-04-16 15:20:36 -0700107 mode = (mode & S_IALLUGO) | S_IFREG;
Mathieu Desnoyers4f365572006-11-24 13:45:37 -0500108 res = debugfs_mknod(dir, dentry, mode, 0);
109 if (!res)
110 fsnotify_create(dir, dentry);
111 return res;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700112}
113
114static inline int debugfs_positive(struct dentry *dentry)
115{
116 return dentry->d_inode && !d_unhashed(dentry);
117}
118
119static int debug_fill_super(struct super_block *sb, void *data, int silent)
120{
121 static struct tree_descr debug_files[] = {{""}};
122
123 return simple_fill_super(sb, DEBUGFS_MAGIC, debug_files);
124}
125
David Howells454e2392006-06-23 02:02:57 -0700126static int debug_get_sb(struct file_system_type *fs_type,
127 int flags, const char *dev_name,
128 void *data, struct vfsmount *mnt)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700129{
David Howells454e2392006-06-23 02:02:57 -0700130 return get_sb_single(fs_type, flags, data, debug_fill_super, mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700131}
132
133static struct file_system_type debug_fs_type = {
134 .owner = THIS_MODULE,
135 .name = "debugfs",
136 .get_sb = debug_get_sb,
137 .kill_sb = kill_litter_super,
138};
139
140static int debugfs_create_by_name(const char *name, mode_t mode,
141 struct dentry *parent,
142 struct dentry **dentry)
143{
144 int error = 0;
145
146 /* If the parent is not specified, we create it in the root.
147 * We need the root dentry to do this, which is in the super
148 * block. A pointer to that is in the struct vfsmount that we
149 * have around.
150 */
Mathieu Desnoyersbafb2322006-11-24 13:46:30 -0500151 if (!parent) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700152 if (debugfs_mount && debugfs_mount->mnt_sb) {
153 parent = debugfs_mount->mnt_sb->s_root;
154 }
155 }
156 if (!parent) {
157 pr_debug("debugfs: Ah! can not find a parent!\n");
158 return -EFAULT;
159 }
160
161 *dentry = NULL;
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800162 mutex_lock(&parent->d_inode->i_mutex);
Christoph Hellwig5f45f1a2005-06-23 00:09:12 -0700163 *dentry = lookup_one_len(name, parent, strlen(name));
Akinobu Mita7bb03862006-10-19 12:24:42 +0900164 if (!IS_ERR(*dentry)) {
Peter Oberparleiter66f54962007-02-13 12:13:54 +0100165 switch (mode & S_IFMT) {
166 case S_IFDIR:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700167 error = debugfs_mkdir(parent->d_inode, *dentry, mode);
Peter Oberparleiter66f54962007-02-13 12:13:54 +0100168 break;
169 case S_IFLNK:
170 error = debugfs_link(parent->d_inode, *dentry, mode);
171 break;
172 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173 error = debugfs_create(parent->d_inode, *dentry, mode);
Peter Oberparleiter66f54962007-02-13 12:13:54 +0100174 break;
175 }
Mathieu Desnoyers65c33332006-11-24 13:50:09 -0500176 dput(*dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700177 } else
Akinobu Mita7bb03862006-10-19 12:24:42 +0900178 error = PTR_ERR(*dentry);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800179 mutex_unlock(&parent->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700180
181 return error;
182}
183
184/**
185 * debugfs_create_file - create a file in the debugfs filesystem
Linus Torvalds1da177e2005-04-16 15:20:36 -0700186 * @name: a pointer to a string containing the name of the file to create.
187 * @mode: the permission that the file should have
188 * @parent: a pointer to the parent dentry for this file. This should be a
189 * directory dentry if set. If this paramater is NULL, then the
190 * file will be created in the root of the debugfs filesystem.
191 * @data: a pointer to something that the caller will want to get to later
Theodore Ts'o8e18e292006-09-27 01:50:46 -0700192 * on. The inode.i_private pointer will point to this value on
Linus Torvalds1da177e2005-04-16 15:20:36 -0700193 * the open() call.
194 * @fops: a pointer to a struct file_operations that should be used for
195 * this file.
196 *
197 * This is the basic "create a file" function for debugfs. It allows for a
198 * wide range of flexibility in createing a file, or a directory (if you
199 * want to create a directory, the debugfs_create_dir() function is
200 * recommended to be used instead.)
201 *
202 * This function will return a pointer to a dentry if it succeeds. This
203 * pointer must be passed to the debugfs_remove() function when the file is
204 * to be removed (no automatic cleanup happens if your module is unloaded,
Randy Dunlap6468b3a2006-07-20 08:16:42 -0700205 * you are responsible here.) If an error occurs, %NULL will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700206 *
Randy Dunlap6468b3a2006-07-20 08:16:42 -0700207 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
Cornelia Huck873760f2007-02-14 07:57:47 +0100208 * returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700209 */
210struct dentry *debugfs_create_file(const char *name, mode_t mode,
211 struct dentry *parent, void *data,
Arjan van de Ven99ac48f2006-03-28 01:56:41 -0800212 const struct file_operations *fops)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700213{
214 struct dentry *dentry = NULL;
215 int error;
216
217 pr_debug("debugfs: creating file '%s'\n",name);
218
Mathieu Desnoyers63223a02006-11-24 13:48:19 -0500219 error = simple_pin_fs(&debug_fs_type, &debugfs_mount,
220 &debugfs_mount_count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700221 if (error)
222 goto exit;
223
224 error = debugfs_create_by_name(name, mode, parent, &dentry);
225 if (error) {
226 dentry = NULL;
Mathieu Desnoyers63223a02006-11-24 13:48:19 -0500227 simple_release_fs(&debugfs_mount, &debugfs_mount_count);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700228 goto exit;
229 }
230
231 if (dentry->d_inode) {
232 if (data)
Theodore Ts'o8e18e292006-09-27 01:50:46 -0700233 dentry->d_inode->i_private = data;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234 if (fops)
235 dentry->d_inode->i_fop = fops;
236 }
237exit:
238 return dentry;
239}
240EXPORT_SYMBOL_GPL(debugfs_create_file);
241
242/**
243 * debugfs_create_dir - create a directory in the debugfs filesystem
Linus Torvalds1da177e2005-04-16 15:20:36 -0700244 * @name: a pointer to a string containing the name of the directory to
245 * create.
246 * @parent: a pointer to the parent dentry for this file. This should be a
247 * directory dentry if set. If this paramater is NULL, then the
248 * directory will be created in the root of the debugfs filesystem.
249 *
250 * This function creates a directory in debugfs with the given name.
251 *
252 * This function will return a pointer to a dentry if it succeeds. This
253 * pointer must be passed to the debugfs_remove() function when the file is
254 * to be removed (no automatic cleanup happens if your module is unloaded,
Randy Dunlap6468b3a2006-07-20 08:16:42 -0700255 * you are responsible here.) If an error occurs, %NULL will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700256 *
Randy Dunlap6468b3a2006-07-20 08:16:42 -0700257 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
Cornelia Huck873760f2007-02-14 07:57:47 +0100258 * returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700259 */
260struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
261{
262 return debugfs_create_file(name,
263 S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
264 parent, NULL, NULL);
265}
266EXPORT_SYMBOL_GPL(debugfs_create_dir);
267
268/**
Peter Oberparleiter66f54962007-02-13 12:13:54 +0100269 * debugfs_create_symlink- create a symbolic link in the debugfs filesystem
270 * @name: a pointer to a string containing the name of the symbolic link to
271 * create.
272 * @parent: a pointer to the parent dentry for this symbolic link. This
273 * should be a directory dentry if set. If this paramater is NULL,
274 * then the symbolic link will be created in the root of the debugfs
275 * filesystem.
276 * @target: a pointer to a string containing the path to the target of the
277 * symbolic link.
278 *
279 * This function creates a symbolic link with the given name in debugfs that
280 * links to the given target path.
281 *
282 * This function will return a pointer to a dentry if it succeeds. This
283 * pointer must be passed to the debugfs_remove() function when the symbolic
284 * link is to be removed (no automatic cleanup happens if your module is
285 * unloaded, you are responsible here.) If an error occurs, %NULL will be
286 * returned.
287 *
288 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
Cornelia Huck873760f2007-02-14 07:57:47 +0100289 * returned.
Peter Oberparleiter66f54962007-02-13 12:13:54 +0100290 */
291struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
292 const char *target)
293{
294 struct dentry *result;
295 char *link;
296
297 link = kstrdup(target, GFP_KERNEL);
298 if (!link)
299 return NULL;
300
301 result = debugfs_create_file(name, S_IFLNK | S_IRWXUGO, parent, link,
302 NULL);
303 if (!result)
304 kfree(link);
305 return result;
306}
307EXPORT_SYMBOL_GPL(debugfs_create_symlink);
308
Haavard Skinnemoen9505e632008-07-01 15:14:51 +0200309static void __debugfs_remove(struct dentry *dentry, struct dentry *parent)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310{
Mathieu Desnoyers65c33332006-11-24 13:50:09 -0500311 int ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700312
Linus Torvalds1da177e2005-04-16 15:20:36 -0700313 if (debugfs_positive(dentry)) {
314 if (dentry->d_inode) {
Mathieu Desnoyers29a7f3a2006-11-24 13:51:14 -0500315 dget(dentry);
Peter Oberparleiter66f54962007-02-13 12:13:54 +0100316 switch (dentry->d_inode->i_mode & S_IFMT) {
317 case S_IFDIR:
Mathieu Desnoyers65c33332006-11-24 13:50:09 -0500318 ret = simple_rmdir(parent->d_inode, dentry);
Peter Oberparleiter66f54962007-02-13 12:13:54 +0100319 break;
320 case S_IFLNK:
321 kfree(dentry->d_inode->i_private);
322 /* fall through */
323 default:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 simple_unlink(parent->d_inode, dentry);
Peter Oberparleiter66f54962007-02-13 12:13:54 +0100325 break;
326 }
Mathieu Desnoyers29a7f3a2006-11-24 13:51:14 -0500327 if (!ret)
328 d_delete(dentry);
329 dput(dentry);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700330 }
331 }
Haavard Skinnemoen9505e632008-07-01 15:14:51 +0200332}
333
334/**
335 * debugfs_remove - removes a file or directory from the debugfs filesystem
336 * @dentry: a pointer to a the dentry of the file or directory to be
337 * removed.
338 *
339 * This function removes a file or directory in debugfs that was previously
340 * created with a call to another debugfs function (like
341 * debugfs_create_file() or variants thereof.)
342 *
343 * This function is required to be called in order for the file to be
344 * removed, no automatic cleanup of files will happen when a module is
345 * removed, you are responsible here.
346 */
347void debugfs_remove(struct dentry *dentry)
348{
349 struct dentry *parent;
350
351 if (!dentry)
352 return;
353
354 parent = dentry->d_parent;
355 if (!parent || !parent->d_inode)
356 return;
357
358 mutex_lock(&parent->d_inode->i_mutex);
359 __debugfs_remove(dentry, parent);
Jes Sorensen1b1dcc12006-01-09 15:59:24 -0800360 mutex_unlock(&parent->d_inode->i_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700361 simple_release_fs(&debugfs_mount, &debugfs_mount_count);
362}
363EXPORT_SYMBOL_GPL(debugfs_remove);
364
Jan Karacfc94cd2007-05-09 13:19:52 +0200365/**
Haavard Skinnemoen9505e632008-07-01 15:14:51 +0200366 * debugfs_remove_recursive - recursively removes a directory
367 * @dentry: a pointer to a the dentry of the directory to be removed.
368 *
369 * This function recursively removes a directory tree in debugfs that
370 * was previously created with a call to another debugfs function
371 * (like debugfs_create_file() or variants thereof.)
372 *
373 * This function is required to be called in order for the file to be
374 * removed, no automatic cleanup of files will happen when a module is
375 * removed, you are responsible here.
376 */
377void debugfs_remove_recursive(struct dentry *dentry)
378{
379 struct dentry *child;
380 struct dentry *parent;
381
382 if (!dentry)
383 return;
384
385 parent = dentry->d_parent;
386 if (!parent || !parent->d_inode)
387 return;
388
389 parent = dentry;
390 mutex_lock(&parent->d_inode->i_mutex);
391
392 while (1) {
393 /*
394 * When all dentries under "parent" has been removed,
395 * walk up the tree until we reach our starting point.
396 */
397 if (list_empty(&parent->d_subdirs)) {
398 mutex_unlock(&parent->d_inode->i_mutex);
399 if (parent == dentry)
400 break;
401 parent = parent->d_parent;
402 mutex_lock(&parent->d_inode->i_mutex);
403 }
404 child = list_entry(parent->d_subdirs.next, struct dentry,
405 d_u.d_child);
Steven Rostedt56a83cc2009-04-25 00:39:40 -0400406 next_sibling:
Haavard Skinnemoen9505e632008-07-01 15:14:51 +0200407
408 /*
409 * If "child" isn't empty, walk down the tree and
410 * remove all its descendants first.
411 */
412 if (!list_empty(&child->d_subdirs)) {
413 mutex_unlock(&parent->d_inode->i_mutex);
414 parent = child;
415 mutex_lock(&parent->d_inode->i_mutex);
416 continue;
417 }
418 __debugfs_remove(child, parent);
419 if (parent->d_subdirs.next == &child->d_u.d_child) {
420 /*
Steven Rostedt56a83cc2009-04-25 00:39:40 -0400421 * Try the next sibling.
422 */
423 if (child->d_u.d_child.next != &parent->d_subdirs) {
424 child = list_entry(child->d_u.d_child.next,
425 struct dentry,
426 d_u.d_child);
427 goto next_sibling;
428 }
429
430 /*
Haavard Skinnemoen9505e632008-07-01 15:14:51 +0200431 * Avoid infinite loop if we fail to remove
432 * one dentry.
433 */
434 mutex_unlock(&parent->d_inode->i_mutex);
435 break;
436 }
437 simple_release_fs(&debugfs_mount, &debugfs_mount_count);
438 }
439
440 parent = dentry->d_parent;
441 mutex_lock(&parent->d_inode->i_mutex);
442 __debugfs_remove(dentry, parent);
443 mutex_unlock(&parent->d_inode->i_mutex);
444 simple_release_fs(&debugfs_mount, &debugfs_mount_count);
445}
446EXPORT_SYMBOL_GPL(debugfs_remove_recursive);
447
448/**
Jan Karacfc94cd2007-05-09 13:19:52 +0200449 * debugfs_rename - rename a file/directory in the debugfs filesystem
450 * @old_dir: a pointer to the parent dentry for the renamed object. This
451 * should be a directory dentry.
452 * @old_dentry: dentry of an object to be renamed.
453 * @new_dir: a pointer to the parent dentry where the object should be
454 * moved. This should be a directory dentry.
455 * @new_name: a pointer to a string containing the target name.
456 *
457 * This function renames a file/directory in debugfs. The target must not
458 * exist for rename to succeed.
459 *
460 * This function will return a pointer to old_dentry (which is updated to
461 * reflect renaming) if it succeeds. If an error occurs, %NULL will be
462 * returned.
463 *
464 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
465 * returned.
466 */
467struct dentry *debugfs_rename(struct dentry *old_dir, struct dentry *old_dentry,
468 struct dentry *new_dir, const char *new_name)
469{
470 int error;
471 struct dentry *dentry = NULL, *trap;
472 const char *old_name;
473
474 trap = lock_rename(new_dir, old_dir);
475 /* Source or destination directories don't exist? */
476 if (!old_dir->d_inode || !new_dir->d_inode)
477 goto exit;
478 /* Source does not exist, cyclic rename, or mountpoint? */
479 if (!old_dentry->d_inode || old_dentry == trap ||
480 d_mountpoint(old_dentry))
481 goto exit;
482 dentry = lookup_one_len(new_name, new_dir, strlen(new_name));
483 /* Lookup failed, cyclic rename or target exists? */
484 if (IS_ERR(dentry) || dentry == trap || dentry->d_inode)
485 goto exit;
486
487 old_name = fsnotify_oldname_init(old_dentry->d_name.name);
488
489 error = simple_rename(old_dir->d_inode, old_dentry, new_dir->d_inode,
490 dentry);
491 if (error) {
492 fsnotify_oldname_free(old_name);
493 goto exit;
494 }
495 d_move(old_dentry, dentry);
496 fsnotify_move(old_dir->d_inode, new_dir->d_inode, old_name,
497 old_dentry->d_name.name, S_ISDIR(old_dentry->d_inode->i_mode),
Al Viro5a190ae2007-06-07 12:19:32 -0400498 NULL, old_dentry);
Jan Karacfc94cd2007-05-09 13:19:52 +0200499 fsnotify_oldname_free(old_name);
500 unlock_rename(new_dir, old_dir);
501 dput(dentry);
502 return old_dentry;
503exit:
504 if (dentry && !IS_ERR(dentry))
505 dput(dentry);
506 unlock_rename(new_dir, old_dir);
507 return NULL;
508}
509EXPORT_SYMBOL_GPL(debugfs_rename);
510
Frederic Weisbeckerc0f92ba2009-03-22 23:10:44 +0100511/**
512 * debugfs_initialized - Tells whether debugfs has been registered
513 */
514bool debugfs_initialized(void)
515{
516 return debugfs_registered;
517}
518EXPORT_SYMBOL_GPL(debugfs_initialized);
519
520
Greg Kroah-Hartman191e1862007-10-29 20:13:17 +0100521static struct kobject *debug_kobj;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700522
523static int __init debugfs_init(void)
524{
525 int retval;
526
Greg Kroah-Hartman0ff21e42007-11-06 10:36:58 -0800527 debug_kobj = kobject_create_and_add("debug", kernel_kobj);
Greg Kroah-Hartman191e1862007-10-29 20:13:17 +0100528 if (!debug_kobj)
529 return -EINVAL;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530
531 retval = register_filesystem(&debug_fs_type);
532 if (retval)
Greg Kroah-Hartman197b12d2007-12-20 08:13:05 -0800533 kobject_put(debug_kobj);
Frederic Weisbeckerc0f92ba2009-03-22 23:10:44 +0100534 else
535 debugfs_registered = true;
536
Linus Torvalds1da177e2005-04-16 15:20:36 -0700537 return retval;
538}
539
540static void __exit debugfs_exit(void)
541{
Frederic Weisbeckerc0f92ba2009-03-22 23:10:44 +0100542 debugfs_registered = false;
543
Linus Torvalds1da177e2005-04-16 15:20:36 -0700544 simple_release_fs(&debugfs_mount, &debugfs_mount_count);
545 unregister_filesystem(&debug_fs_type);
Greg Kroah-Hartman197b12d2007-12-20 08:13:05 -0800546 kobject_put(debug_kobj);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547}
548
549core_initcall(debugfs_init);
550module_exit(debugfs_exit);
551MODULE_LICENSE("GPL");
552