1 // SPDX-License-Identifier: GPL-2.0
3 * inode.c - part of debugfs, a tiny little debug file system
5 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
6 * Copyright (C) 2004 IBM Inc.
8 * debugfs is for people to use instead of /proc or /sys.
9 * See ./Documentation/core-api/kernel-api.rst for more details.
12 #include <linux/module.h>
14 #include <linux/mount.h>
15 #include <linux/pagemap.h>
16 #include <linux/init.h>
17 #include <linux/kobject.h>
18 #include <linux/namei.h>
19 #include <linux/debugfs.h>
20 #include <linux/fsnotify.h>
21 #include <linux/string.h>
22 #include <linux/seq_file.h>
23 #include <linux/parser.h>
24 #include <linux/magic.h>
25 #include <linux/slab.h>
29 #define DEBUGFS_DEFAULT_MODE 0700
31 static struct vfsmount
*debugfs_mount
;
32 static int debugfs_mount_count
;
33 static bool debugfs_registered
;
35 static struct inode
*debugfs_get_inode(struct super_block
*sb
)
37 struct inode
*inode
= new_inode(sb
);
39 inode
->i_ino
= get_next_ino();
40 inode
->i_atime
= inode
->i_mtime
=
41 inode
->i_ctime
= current_time(inode
);
46 struct debugfs_mount_opts
{
59 static const match_table_t tokens
= {
62 {Opt_mode
, "mode=%o"},
66 struct debugfs_fs_info
{
67 struct debugfs_mount_opts mount_opts
;
70 static int debugfs_parse_options(char *data
, struct debugfs_mount_opts
*opts
)
72 substring_t args
[MAX_OPT_ARGS
];
79 opts
->mode
= DEBUGFS_DEFAULT_MODE
;
81 while ((p
= strsep(&data
, ",")) != NULL
) {
85 token
= match_token(p
, tokens
, args
);
88 if (match_int(&args
[0], &option
))
90 uid
= make_kuid(current_user_ns(), option
);
96 if (match_int(&args
[0], &option
))
98 gid
= make_kgid(current_user_ns(), option
);
104 if (match_octal(&args
[0], &option
))
106 opts
->mode
= option
& S_IALLUGO
;
109 * We might like to report bad mount options here;
110 * but traditionally debugfs has ignored all mount options
118 static int debugfs_apply_options(struct super_block
*sb
)
120 struct debugfs_fs_info
*fsi
= sb
->s_fs_info
;
121 struct inode
*inode
= d_inode(sb
->s_root
);
122 struct debugfs_mount_opts
*opts
= &fsi
->mount_opts
;
124 inode
->i_mode
&= ~S_IALLUGO
;
125 inode
->i_mode
|= opts
->mode
;
127 inode
->i_uid
= opts
->uid
;
128 inode
->i_gid
= opts
->gid
;
133 static int debugfs_remount(struct super_block
*sb
, int *flags
, char *data
)
136 struct debugfs_fs_info
*fsi
= sb
->s_fs_info
;
139 err
= debugfs_parse_options(data
, &fsi
->mount_opts
);
143 debugfs_apply_options(sb
);
149 static int debugfs_show_options(struct seq_file
*m
, struct dentry
*root
)
151 struct debugfs_fs_info
*fsi
= root
->d_sb
->s_fs_info
;
152 struct debugfs_mount_opts
*opts
= &fsi
->mount_opts
;
154 if (!uid_eq(opts
->uid
, GLOBAL_ROOT_UID
))
155 seq_printf(m
, ",uid=%u",
156 from_kuid_munged(&init_user_ns
, opts
->uid
));
157 if (!gid_eq(opts
->gid
, GLOBAL_ROOT_GID
))
158 seq_printf(m
, ",gid=%u",
159 from_kgid_munged(&init_user_ns
, opts
->gid
));
160 if (opts
->mode
!= DEBUGFS_DEFAULT_MODE
)
161 seq_printf(m
, ",mode=%o", opts
->mode
);
166 static void debugfs_evict_inode(struct inode
*inode
)
168 truncate_inode_pages_final(&inode
->i_data
);
170 if (S_ISLNK(inode
->i_mode
))
171 kfree(inode
->i_link
);
174 static const struct super_operations debugfs_super_operations
= {
175 .statfs
= simple_statfs
,
176 .remount_fs
= debugfs_remount
,
177 .show_options
= debugfs_show_options
,
178 .evict_inode
= debugfs_evict_inode
,
181 static void debugfs_release_dentry(struct dentry
*dentry
)
183 void *fsd
= dentry
->d_fsdata
;
185 if (!((unsigned long)fsd
& DEBUGFS_FSDATA_IS_REAL_FOPS_BIT
))
186 kfree(dentry
->d_fsdata
);
189 static struct vfsmount
*debugfs_automount(struct path
*path
)
191 debugfs_automount_t f
;
192 f
= (debugfs_automount_t
)path
->dentry
->d_fsdata
;
193 return f(path
->dentry
, d_inode(path
->dentry
)->i_private
);
196 static const struct dentry_operations debugfs_dops
= {
197 .d_delete
= always_delete_dentry
,
198 .d_release
= debugfs_release_dentry
,
199 .d_automount
= debugfs_automount
,
202 static int debug_fill_super(struct super_block
*sb
, void *data
, int silent
)
204 static const struct tree_descr debug_files
[] = {{""}};
205 struct debugfs_fs_info
*fsi
;
208 fsi
= kzalloc(sizeof(struct debugfs_fs_info
), GFP_KERNEL
);
215 err
= debugfs_parse_options(data
, &fsi
->mount_opts
);
219 err
= simple_fill_super(sb
, DEBUGFS_MAGIC
, debug_files
);
223 sb
->s_op
= &debugfs_super_operations
;
224 sb
->s_d_op
= &debugfs_dops
;
226 debugfs_apply_options(sb
);
232 sb
->s_fs_info
= NULL
;
236 static struct dentry
*debug_mount(struct file_system_type
*fs_type
,
237 int flags
, const char *dev_name
,
240 return mount_single(fs_type
, flags
, data
, debug_fill_super
);
243 static struct file_system_type debug_fs_type
= {
244 .owner
= THIS_MODULE
,
246 .mount
= debug_mount
,
247 .kill_sb
= kill_litter_super
,
249 MODULE_ALIAS_FS("debugfs");
252 * debugfs_lookup() - look up an existing debugfs file
253 * @name: a pointer to a string containing the name of the file to look up.
254 * @parent: a pointer to the parent dentry of the file.
256 * This function will return a pointer to a dentry if it succeeds. If the file
257 * doesn't exist or an error occurs, %NULL will be returned. The returned
258 * dentry must be passed to dput() when it is no longer needed.
260 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
263 struct dentry
*debugfs_lookup(const char *name
, struct dentry
*parent
)
265 struct dentry
*dentry
;
271 parent
= debugfs_mount
->mnt_root
;
273 dentry
= lookup_one_len_unlocked(name
, parent
, strlen(name
));
276 if (!d_really_is_positive(dentry
)) {
282 EXPORT_SYMBOL_GPL(debugfs_lookup
);
284 static struct dentry
*start_creating(const char *name
, struct dentry
*parent
)
286 struct dentry
*dentry
;
289 pr_debug("debugfs: creating file '%s'\n",name
);
294 error
= simple_pin_fs(&debug_fs_type
, &debugfs_mount
,
295 &debugfs_mount_count
);
297 return ERR_PTR(error
);
299 /* If the parent is not specified, we create it in the root.
300 * We need the root dentry to do this, which is in the super
301 * block. A pointer to that is in the struct vfsmount that we
305 parent
= debugfs_mount
->mnt_root
;
307 inode_lock(d_inode(parent
));
308 dentry
= lookup_one_len(name
, parent
, strlen(name
));
309 if (!IS_ERR(dentry
) && d_really_is_positive(dentry
)) {
311 dentry
= ERR_PTR(-EEXIST
);
314 if (IS_ERR(dentry
)) {
315 inode_unlock(d_inode(parent
));
316 simple_release_fs(&debugfs_mount
, &debugfs_mount_count
);
322 static struct dentry
*failed_creating(struct dentry
*dentry
)
324 inode_unlock(d_inode(dentry
->d_parent
));
326 simple_release_fs(&debugfs_mount
, &debugfs_mount_count
);
330 static struct dentry
*end_creating(struct dentry
*dentry
)
332 inode_unlock(d_inode(dentry
->d_parent
));
336 static struct dentry
*__debugfs_create_file(const char *name
, umode_t mode
,
337 struct dentry
*parent
, void *data
,
338 const struct file_operations
*proxy_fops
,
339 const struct file_operations
*real_fops
)
341 struct dentry
*dentry
;
344 if (!(mode
& S_IFMT
))
346 BUG_ON(!S_ISREG(mode
));
347 dentry
= start_creating(name
, parent
);
352 inode
= debugfs_get_inode(dentry
->d_sb
);
353 if (unlikely(!inode
))
354 return failed_creating(dentry
);
356 inode
->i_mode
= mode
;
357 inode
->i_private
= data
;
359 inode
->i_fop
= proxy_fops
;
360 dentry
->d_fsdata
= (void *)((unsigned long)real_fops
|
361 DEBUGFS_FSDATA_IS_REAL_FOPS_BIT
);
363 d_instantiate(dentry
, inode
);
364 fsnotify_create(d_inode(dentry
->d_parent
), dentry
);
365 return end_creating(dentry
);
369 * debugfs_create_file - create a file in the debugfs filesystem
370 * @name: a pointer to a string containing the name of the file to create.
371 * @mode: the permission that the file should have.
372 * @parent: a pointer to the parent dentry for this file. This should be a
373 * directory dentry if set. If this parameter is NULL, then the
374 * file will be created in the root of the debugfs filesystem.
375 * @data: a pointer to something that the caller will want to get to later
376 * on. The inode.i_private pointer will point to this value on
378 * @fops: a pointer to a struct file_operations that should be used for
381 * This is the basic "create a file" function for debugfs. It allows for a
382 * wide range of flexibility in creating a file, or a directory (if you want
383 * to create a directory, the debugfs_create_dir() function is
384 * recommended to be used instead.)
386 * This function will return a pointer to a dentry if it succeeds. This
387 * pointer must be passed to the debugfs_remove() function when the file is
388 * to be removed (no automatic cleanup happens if your module is unloaded,
389 * you are responsible here.) If an error occurs, %NULL will be returned.
391 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
394 struct dentry
*debugfs_create_file(const char *name
, umode_t mode
,
395 struct dentry
*parent
, void *data
,
396 const struct file_operations
*fops
)
399 return __debugfs_create_file(name
, mode
, parent
, data
,
400 fops
? &debugfs_full_proxy_file_operations
:
401 &debugfs_noop_file_operations
,
404 EXPORT_SYMBOL_GPL(debugfs_create_file
);
407 * debugfs_create_file_unsafe - create a file in the debugfs filesystem
408 * @name: a pointer to a string containing the name of the file to create.
409 * @mode: the permission that the file should have.
410 * @parent: a pointer to the parent dentry for this file. This should be a
411 * directory dentry if set. If this parameter is NULL, then the
412 * file will be created in the root of the debugfs filesystem.
413 * @data: a pointer to something that the caller will want to get to later
414 * on. The inode.i_private pointer will point to this value on
416 * @fops: a pointer to a struct file_operations that should be used for
419 * debugfs_create_file_unsafe() is completely analogous to
420 * debugfs_create_file(), the only difference being that the fops
421 * handed it will not get protected against file removals by the
424 * It is your responsibility to protect your struct file_operation
425 * methods against file removals by means of debugfs_use_file_start()
426 * and debugfs_use_file_finish(). ->open() is still protected by
429 * Any struct file_operations defined by means of
430 * DEFINE_DEBUGFS_ATTRIBUTE() is protected against file removals and
431 * thus, may be used here.
433 struct dentry
*debugfs_create_file_unsafe(const char *name
, umode_t mode
,
434 struct dentry
*parent
, void *data
,
435 const struct file_operations
*fops
)
438 return __debugfs_create_file(name
, mode
, parent
, data
,
439 fops
? &debugfs_open_proxy_file_operations
:
440 &debugfs_noop_file_operations
,
443 EXPORT_SYMBOL_GPL(debugfs_create_file_unsafe
);
446 * debugfs_create_file_size - create a file in the debugfs filesystem
447 * @name: a pointer to a string containing the name of the file to create.
448 * @mode: the permission that the file should have.
449 * @parent: a pointer to the parent dentry for this file. This should be a
450 * directory dentry if set. If this parameter is NULL, then the
451 * file will be created in the root of the debugfs filesystem.
452 * @data: a pointer to something that the caller will want to get to later
453 * on. The inode.i_private pointer will point to this value on
455 * @fops: a pointer to a struct file_operations that should be used for
457 * @file_size: initial file size
459 * This is the basic "create a file" function for debugfs. It allows for a
460 * wide range of flexibility in creating a file, or a directory (if you want
461 * to create a directory, the debugfs_create_dir() function is
462 * recommended to be used instead.)
464 * This function will return a pointer to a dentry if it succeeds. This
465 * pointer must be passed to the debugfs_remove() function when the file is
466 * to be removed (no automatic cleanup happens if your module is unloaded,
467 * you are responsible here.) If an error occurs, %NULL will be returned.
469 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
472 struct dentry
*debugfs_create_file_size(const char *name
, umode_t mode
,
473 struct dentry
*parent
, void *data
,
474 const struct file_operations
*fops
,
477 struct dentry
*de
= debugfs_create_file(name
, mode
, parent
, data
, fops
);
480 d_inode(de
)->i_size
= file_size
;
483 EXPORT_SYMBOL_GPL(debugfs_create_file_size
);
486 * debugfs_create_dir - create a directory in the debugfs filesystem
487 * @name: a pointer to a string containing the name of the directory to
489 * @parent: a pointer to the parent dentry for this file. This should be a
490 * directory dentry if set. If this parameter is NULL, then the
491 * directory will be created in the root of the debugfs filesystem.
493 * This function creates a directory in debugfs with the given name.
495 * This function will return a pointer to a dentry if it succeeds. This
496 * pointer must be passed to the debugfs_remove() function when the file is
497 * to be removed (no automatic cleanup happens if your module is unloaded,
498 * you are responsible here.) If an error occurs, %NULL will be returned.
500 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
503 struct dentry
*debugfs_create_dir(const char *name
, struct dentry
*parent
)
505 struct dentry
*dentry
= start_creating(name
, parent
);
511 inode
= debugfs_get_inode(dentry
->d_sb
);
512 if (unlikely(!inode
))
513 return failed_creating(dentry
);
515 inode
->i_mode
= S_IFDIR
| S_IRWXU
| S_IRUGO
| S_IXUGO
;
516 inode
->i_op
= &simple_dir_inode_operations
;
517 inode
->i_fop
= &simple_dir_operations
;
519 /* directory inodes start off with i_nlink == 2 (for "." entry) */
521 d_instantiate(dentry
, inode
);
522 inc_nlink(d_inode(dentry
->d_parent
));
523 fsnotify_mkdir(d_inode(dentry
->d_parent
), dentry
);
524 return end_creating(dentry
);
526 EXPORT_SYMBOL_GPL(debugfs_create_dir
);
529 * debugfs_create_automount - create automount point in the debugfs filesystem
530 * @name: a pointer to a string containing the name of the file to create.
531 * @parent: a pointer to the parent dentry for this file. This should be a
532 * directory dentry if set. If this parameter is NULL, then the
533 * file will be created in the root of the debugfs filesystem.
534 * @f: function to be called when pathname resolution steps on that one.
535 * @data: opaque argument to pass to f().
537 * @f should return what ->d_automount() would.
539 struct dentry
*debugfs_create_automount(const char *name
,
540 struct dentry
*parent
,
541 debugfs_automount_t f
,
544 struct dentry
*dentry
= start_creating(name
, parent
);
550 inode
= debugfs_get_inode(dentry
->d_sb
);
551 if (unlikely(!inode
))
552 return failed_creating(dentry
);
554 make_empty_dir_inode(inode
);
555 inode
->i_flags
|= S_AUTOMOUNT
;
556 inode
->i_private
= data
;
557 dentry
->d_fsdata
= (void *)f
;
558 /* directory inodes start off with i_nlink == 2 (for "." entry) */
560 d_instantiate(dentry
, inode
);
561 inc_nlink(d_inode(dentry
->d_parent
));
562 fsnotify_mkdir(d_inode(dentry
->d_parent
), dentry
);
563 return end_creating(dentry
);
565 EXPORT_SYMBOL(debugfs_create_automount
);
568 * debugfs_create_symlink- create a symbolic link in the debugfs filesystem
569 * @name: a pointer to a string containing the name of the symbolic link to
571 * @parent: a pointer to the parent dentry for this symbolic link. This
572 * should be a directory dentry if set. If this parameter is NULL,
573 * then the symbolic link will be created in the root of the debugfs
575 * @target: a pointer to a string containing the path to the target of the
578 * This function creates a symbolic link with the given name in debugfs that
579 * links to the given target path.
581 * This function will return a pointer to a dentry if it succeeds. This
582 * pointer must be passed to the debugfs_remove() function when the symbolic
583 * link is to be removed (no automatic cleanup happens if your module is
584 * unloaded, you are responsible here.) If an error occurs, %NULL will be
587 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
590 struct dentry
*debugfs_create_symlink(const char *name
, struct dentry
*parent
,
593 struct dentry
*dentry
;
595 char *link
= kstrdup(target
, GFP_KERNEL
);
599 dentry
= start_creating(name
, parent
);
600 if (IS_ERR(dentry
)) {
605 inode
= debugfs_get_inode(dentry
->d_sb
);
606 if (unlikely(!inode
)) {
608 return failed_creating(dentry
);
610 inode
->i_mode
= S_IFLNK
| S_IRWXUGO
;
611 inode
->i_op
= &simple_symlink_inode_operations
;
612 inode
->i_link
= link
;
613 d_instantiate(dentry
, inode
);
614 return end_creating(dentry
);
616 EXPORT_SYMBOL_GPL(debugfs_create_symlink
);
618 static void __debugfs_remove_file(struct dentry
*dentry
, struct dentry
*parent
)
620 struct debugfs_fsdata
*fsd
;
622 simple_unlink(d_inode(parent
), dentry
);
626 * Paired with the closing smp_mb() implied by a successful
627 * cmpxchg() in debugfs_file_get(): either
628 * debugfs_file_get() must see a dead dentry or we must see a
629 * debugfs_fsdata instance at ->d_fsdata here (or both).
632 fsd
= READ_ONCE(dentry
->d_fsdata
);
633 if ((unsigned long)fsd
& DEBUGFS_FSDATA_IS_REAL_FOPS_BIT
)
635 if (!refcount_dec_and_test(&fsd
->active_users
))
636 wait_for_completion(&fsd
->active_users_drained
);
639 static int __debugfs_remove(struct dentry
*dentry
, struct dentry
*parent
)
643 if (simple_positive(dentry
)) {
645 if (!d_is_reg(dentry
)) {
646 if (d_is_dir(dentry
))
647 ret
= simple_rmdir(d_inode(parent
), dentry
);
649 simple_unlink(d_inode(parent
), dentry
);
653 __debugfs_remove_file(dentry
, parent
);
661 * debugfs_remove - removes a file or directory from the debugfs filesystem
662 * @dentry: a pointer to a the dentry of the file or directory to be
663 * removed. If this parameter is NULL or an error value, nothing
666 * This function removes a file or directory in debugfs that was previously
667 * created with a call to another debugfs function (like
668 * debugfs_create_file() or variants thereof.)
670 * This function is required to be called in order for the file to be
671 * removed, no automatic cleanup of files will happen when a module is
672 * removed, you are responsible here.
674 void debugfs_remove(struct dentry
*dentry
)
676 struct dentry
*parent
;
679 if (IS_ERR_OR_NULL(dentry
))
682 parent
= dentry
->d_parent
;
683 inode_lock(d_inode(parent
));
684 ret
= __debugfs_remove(dentry
, parent
);
685 inode_unlock(d_inode(parent
));
687 simple_release_fs(&debugfs_mount
, &debugfs_mount_count
);
689 EXPORT_SYMBOL_GPL(debugfs_remove
);
692 * debugfs_remove_recursive - recursively removes a directory
693 * @dentry: a pointer to a the dentry of the directory to be removed. If this
694 * parameter is NULL or an error value, nothing will be done.
696 * This function recursively removes a directory tree in debugfs that
697 * was previously created with a call to another debugfs function
698 * (like debugfs_create_file() or variants thereof.)
700 * This function is required to be called in order for the file to be
701 * removed, no automatic cleanup of files will happen when a module is
702 * removed, you are responsible here.
704 void debugfs_remove_recursive(struct dentry
*dentry
)
706 struct dentry
*child
, *parent
;
708 if (IS_ERR_OR_NULL(dentry
))
713 inode_lock(d_inode(parent
));
716 * The parent->d_subdirs is protected by the d_lock. Outside that
717 * lock, the child can be unlinked and set to be freed which can
718 * use the d_u.d_child as the rcu head and corrupt this list.
720 spin_lock(&parent
->d_lock
);
721 list_for_each_entry(child
, &parent
->d_subdirs
, d_child
) {
722 if (!simple_positive(child
))
725 /* perhaps simple_empty(child) makes more sense */
726 if (!list_empty(&child
->d_subdirs
)) {
727 spin_unlock(&parent
->d_lock
);
728 inode_unlock(d_inode(parent
));
733 spin_unlock(&parent
->d_lock
);
735 if (!__debugfs_remove(child
, parent
))
736 simple_release_fs(&debugfs_mount
, &debugfs_mount_count
);
739 * The parent->d_lock protects agaist child from unlinking
740 * from d_subdirs. When releasing the parent->d_lock we can
741 * no longer trust that the next pointer is valid.
742 * Restart the loop. We'll skip this one with the
743 * simple_positive() check.
747 spin_unlock(&parent
->d_lock
);
749 inode_unlock(d_inode(parent
));
751 parent
= parent
->d_parent
;
752 inode_lock(d_inode(parent
));
758 if (!__debugfs_remove(child
, parent
))
759 simple_release_fs(&debugfs_mount
, &debugfs_mount_count
);
760 inode_unlock(d_inode(parent
));
762 EXPORT_SYMBOL_GPL(debugfs_remove_recursive
);
765 * debugfs_rename - rename a file/directory in the debugfs filesystem
766 * @old_dir: a pointer to the parent dentry for the renamed object. This
767 * should be a directory dentry.
768 * @old_dentry: dentry of an object to be renamed.
769 * @new_dir: a pointer to the parent dentry where the object should be
770 * moved. This should be a directory dentry.
771 * @new_name: a pointer to a string containing the target name.
773 * This function renames a file/directory in debugfs. The target must not
774 * exist for rename to succeed.
776 * This function will return a pointer to old_dentry (which is updated to
777 * reflect renaming) if it succeeds. If an error occurs, %NULL will be
780 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
783 struct dentry
*debugfs_rename(struct dentry
*old_dir
, struct dentry
*old_dentry
,
784 struct dentry
*new_dir
, const char *new_name
)
787 struct dentry
*dentry
= NULL
, *trap
;
788 struct name_snapshot old_name
;
790 trap
= lock_rename(new_dir
, old_dir
);
791 /* Source or destination directories don't exist? */
792 if (d_really_is_negative(old_dir
) || d_really_is_negative(new_dir
))
794 /* Source does not exist, cyclic rename, or mountpoint? */
795 if (d_really_is_negative(old_dentry
) || old_dentry
== trap
||
796 d_mountpoint(old_dentry
))
798 dentry
= lookup_one_len(new_name
, new_dir
, strlen(new_name
));
799 /* Lookup failed, cyclic rename or target exists? */
800 if (IS_ERR(dentry
) || dentry
== trap
|| d_really_is_positive(dentry
))
803 take_dentry_name_snapshot(&old_name
, old_dentry
);
805 error
= simple_rename(d_inode(old_dir
), old_dentry
, d_inode(new_dir
),
808 release_dentry_name_snapshot(&old_name
);
811 d_move(old_dentry
, dentry
);
812 fsnotify_move(d_inode(old_dir
), d_inode(new_dir
), old_name
.name
,
813 d_is_dir(old_dentry
),
815 release_dentry_name_snapshot(&old_name
);
816 unlock_rename(new_dir
, old_dir
);
820 if (dentry
&& !IS_ERR(dentry
))
822 unlock_rename(new_dir
, old_dir
);
825 EXPORT_SYMBOL_GPL(debugfs_rename
);
828 * debugfs_initialized - Tells whether debugfs has been registered
830 bool debugfs_initialized(void)
832 return debugfs_registered
;
834 EXPORT_SYMBOL_GPL(debugfs_initialized
);
836 static int __init
debugfs_init(void)
840 retval
= sysfs_create_mount_point(kernel_kobj
, "debug");
844 retval
= register_filesystem(&debug_fs_type
);
846 sysfs_remove_mount_point(kernel_kobj
, "debug");
848 debugfs_registered
= true;
852 core_initcall(debugfs_init
);