2 * inode.c - part of debugfs, a tiny little debug file system
4 * Copyright (C) 2004 Greg Kroah-Hartman <greg@kroah.com>
5 * Copyright (C) 2004 IBM Inc.
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.
11 * debugfs is for people to use instead of /proc or /sys.
12 * See ./Documentation/core-api/kernel-api.rst for more details.
16 #include <linux/module.h>
18 #include <linux/mount.h>
19 #include <linux/pagemap.h>
20 #include <linux/init.h>
21 #include <linux/kobject.h>
22 #include <linux/namei.h>
23 #include <linux/debugfs.h>
24 #include <linux/fsnotify.h>
25 #include <linux/string.h>
26 #include <linux/seq_file.h>
27 #include <linux/parser.h>
28 #include <linux/magic.h>
29 #include <linux/slab.h>
33 #define DEBUGFS_DEFAULT_MODE 0700
35 static struct vfsmount
*debugfs_mount
;
36 static int debugfs_mount_count
;
37 static bool debugfs_registered
;
39 static struct inode
*debugfs_get_inode(struct super_block
*sb
)
41 struct inode
*inode
= new_inode(sb
);
43 inode
->i_ino
= get_next_ino();
44 inode
->i_atime
= inode
->i_mtime
=
45 inode
->i_ctime
= current_time(inode
);
50 struct debugfs_mount_opts
{
63 static const match_table_t tokens
= {
66 {Opt_mode
, "mode=%o"},
70 struct debugfs_fs_info
{
71 struct debugfs_mount_opts mount_opts
;
74 static int debugfs_parse_options(char *data
, struct debugfs_mount_opts
*opts
)
76 substring_t args
[MAX_OPT_ARGS
];
83 opts
->mode
= DEBUGFS_DEFAULT_MODE
;
85 while ((p
= strsep(&data
, ",")) != NULL
) {
89 token
= match_token(p
, tokens
, args
);
92 if (match_int(&args
[0], &option
))
94 uid
= make_kuid(current_user_ns(), option
);
100 if (match_int(&args
[0], &option
))
102 gid
= make_kgid(current_user_ns(), option
);
108 if (match_octal(&args
[0], &option
))
110 opts
->mode
= option
& S_IALLUGO
;
113 * We might like to report bad mount options here;
114 * but traditionally debugfs has ignored all mount options
122 static int debugfs_apply_options(struct super_block
*sb
)
124 struct debugfs_fs_info
*fsi
= sb
->s_fs_info
;
125 struct inode
*inode
= d_inode(sb
->s_root
);
126 struct debugfs_mount_opts
*opts
= &fsi
->mount_opts
;
128 inode
->i_mode
&= ~S_IALLUGO
;
129 inode
->i_mode
|= opts
->mode
;
131 inode
->i_uid
= opts
->uid
;
132 inode
->i_gid
= opts
->gid
;
137 static int debugfs_remount(struct super_block
*sb
, int *flags
, char *data
)
140 struct debugfs_fs_info
*fsi
= sb
->s_fs_info
;
143 err
= debugfs_parse_options(data
, &fsi
->mount_opts
);
147 debugfs_apply_options(sb
);
153 static int debugfs_show_options(struct seq_file
*m
, struct dentry
*root
)
155 struct debugfs_fs_info
*fsi
= root
->d_sb
->s_fs_info
;
156 struct debugfs_mount_opts
*opts
= &fsi
->mount_opts
;
158 if (!uid_eq(opts
->uid
, GLOBAL_ROOT_UID
))
159 seq_printf(m
, ",uid=%u",
160 from_kuid_munged(&init_user_ns
, opts
->uid
));
161 if (!gid_eq(opts
->gid
, GLOBAL_ROOT_GID
))
162 seq_printf(m
, ",gid=%u",
163 from_kgid_munged(&init_user_ns
, opts
->gid
));
164 if (opts
->mode
!= DEBUGFS_DEFAULT_MODE
)
165 seq_printf(m
, ",mode=%o", opts
->mode
);
170 static void debugfs_evict_inode(struct inode
*inode
)
172 truncate_inode_pages_final(&inode
->i_data
);
174 if (S_ISLNK(inode
->i_mode
))
175 kfree(inode
->i_link
);
178 static const struct super_operations debugfs_super_operations
= {
179 .statfs
= simple_statfs
,
180 .remount_fs
= debugfs_remount
,
181 .show_options
= debugfs_show_options
,
182 .evict_inode
= debugfs_evict_inode
,
185 static void debugfs_release_dentry(struct dentry
*dentry
)
187 void *fsd
= dentry
->d_fsdata
;
189 if (!((unsigned long)fsd
& DEBUGFS_FSDATA_IS_REAL_FOPS_BIT
))
190 kfree(dentry
->d_fsdata
);
193 static struct vfsmount
*debugfs_automount(struct path
*path
)
195 debugfs_automount_t f
;
196 f
= (debugfs_automount_t
)path
->dentry
->d_fsdata
;
197 return f(path
->dentry
, d_inode(path
->dentry
)->i_private
);
200 static const struct dentry_operations debugfs_dops
= {
201 .d_delete
= always_delete_dentry
,
202 .d_release
= debugfs_release_dentry
,
203 .d_automount
= debugfs_automount
,
206 static int debug_fill_super(struct super_block
*sb
, void *data
, int silent
)
208 static const struct tree_descr debug_files
[] = {{""}};
209 struct debugfs_fs_info
*fsi
;
212 fsi
= kzalloc(sizeof(struct debugfs_fs_info
), GFP_KERNEL
);
219 err
= debugfs_parse_options(data
, &fsi
->mount_opts
);
223 err
= simple_fill_super(sb
, DEBUGFS_MAGIC
, debug_files
);
227 sb
->s_op
= &debugfs_super_operations
;
228 sb
->s_d_op
= &debugfs_dops
;
230 debugfs_apply_options(sb
);
236 sb
->s_fs_info
= NULL
;
240 static struct dentry
*debug_mount(struct file_system_type
*fs_type
,
241 int flags
, const char *dev_name
,
244 return mount_single(fs_type
, flags
, data
, debug_fill_super
);
247 static struct file_system_type debug_fs_type
= {
248 .owner
= THIS_MODULE
,
250 .mount
= debug_mount
,
251 .kill_sb
= kill_litter_super
,
253 MODULE_ALIAS_FS("debugfs");
256 * debugfs_lookup() - look up an existing debugfs file
257 * @name: a pointer to a string containing the name of the file to look up.
258 * @parent: a pointer to the parent dentry of the file.
260 * This function will return a pointer to a dentry if it succeeds. If the file
261 * doesn't exist or an error occurs, %NULL will be returned. The returned
262 * dentry must be passed to dput() when it is no longer needed.
264 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
267 struct dentry
*debugfs_lookup(const char *name
, struct dentry
*parent
)
269 struct dentry
*dentry
;
275 parent
= debugfs_mount
->mnt_root
;
277 inode_lock(d_inode(parent
));
278 dentry
= lookup_one_len(name
, parent
, strlen(name
));
279 inode_unlock(d_inode(parent
));
283 if (!d_really_is_positive(dentry
)) {
289 EXPORT_SYMBOL_GPL(debugfs_lookup
);
291 static struct dentry
*start_creating(const char *name
, struct dentry
*parent
)
293 struct dentry
*dentry
;
296 pr_debug("debugfs: creating file '%s'\n",name
);
301 error
= simple_pin_fs(&debug_fs_type
, &debugfs_mount
,
302 &debugfs_mount_count
);
304 return ERR_PTR(error
);
306 /* If the parent is not specified, we create it in the root.
307 * We need the root dentry to do this, which is in the super
308 * block. A pointer to that is in the struct vfsmount that we
312 parent
= debugfs_mount
->mnt_root
;
314 inode_lock(d_inode(parent
));
315 dentry
= lookup_one_len(name
, parent
, strlen(name
));
316 if (!IS_ERR(dentry
) && d_really_is_positive(dentry
)) {
318 dentry
= ERR_PTR(-EEXIST
);
321 if (IS_ERR(dentry
)) {
322 inode_unlock(d_inode(parent
));
323 simple_release_fs(&debugfs_mount
, &debugfs_mount_count
);
329 static struct dentry
*failed_creating(struct dentry
*dentry
)
331 inode_unlock(d_inode(dentry
->d_parent
));
333 simple_release_fs(&debugfs_mount
, &debugfs_mount_count
);
337 static struct dentry
*end_creating(struct dentry
*dentry
)
339 inode_unlock(d_inode(dentry
->d_parent
));
343 static struct dentry
*__debugfs_create_file(const char *name
, umode_t mode
,
344 struct dentry
*parent
, void *data
,
345 const struct file_operations
*proxy_fops
,
346 const struct file_operations
*real_fops
)
348 struct dentry
*dentry
;
351 if (!(mode
& S_IFMT
))
353 BUG_ON(!S_ISREG(mode
));
354 dentry
= start_creating(name
, parent
);
359 inode
= debugfs_get_inode(dentry
->d_sb
);
360 if (unlikely(!inode
))
361 return failed_creating(dentry
);
363 inode
->i_mode
= mode
;
364 inode
->i_private
= data
;
366 inode
->i_fop
= proxy_fops
;
367 dentry
->d_fsdata
= (void *)((unsigned long)real_fops
|
368 DEBUGFS_FSDATA_IS_REAL_FOPS_BIT
);
370 d_instantiate(dentry
, inode
);
371 fsnotify_create(d_inode(dentry
->d_parent
), dentry
);
372 return end_creating(dentry
);
376 * debugfs_create_file - create a file in the debugfs filesystem
377 * @name: a pointer to a string containing the name of the file to create.
378 * @mode: the permission that the file should have.
379 * @parent: a pointer to the parent dentry for this file. This should be a
380 * directory dentry if set. If this parameter is NULL, then the
381 * file will be created in the root of the debugfs filesystem.
382 * @data: a pointer to something that the caller will want to get to later
383 * on. The inode.i_private pointer will point to this value on
385 * @fops: a pointer to a struct file_operations that should be used for
388 * This is the basic "create a file" function for debugfs. It allows for a
389 * wide range of flexibility in creating a file, or a directory (if you want
390 * to create a directory, the debugfs_create_dir() function is
391 * recommended to be used instead.)
393 * This function will return a pointer to a dentry if it succeeds. This
394 * pointer must be passed to the debugfs_remove() function when the file is
395 * to be removed (no automatic cleanup happens if your module is unloaded,
396 * you are responsible here.) If an error occurs, %NULL will be returned.
398 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
401 struct dentry
*debugfs_create_file(const char *name
, umode_t mode
,
402 struct dentry
*parent
, void *data
,
403 const struct file_operations
*fops
)
406 return __debugfs_create_file(name
, mode
, parent
, data
,
407 fops
? &debugfs_full_proxy_file_operations
:
408 &debugfs_noop_file_operations
,
411 EXPORT_SYMBOL_GPL(debugfs_create_file
);
414 * debugfs_create_file_unsafe - create a file in the debugfs filesystem
415 * @name: a pointer to a string containing the name of the file to create.
416 * @mode: the permission that the file should have.
417 * @parent: a pointer to the parent dentry for this file. This should be a
418 * directory dentry if set. If this parameter is NULL, then the
419 * file will be created in the root of the debugfs filesystem.
420 * @data: a pointer to something that the caller will want to get to later
421 * on. The inode.i_private pointer will point to this value on
423 * @fops: a pointer to a struct file_operations that should be used for
426 * debugfs_create_file_unsafe() is completely analogous to
427 * debugfs_create_file(), the only difference being that the fops
428 * handed it will not get protected against file removals by the
431 * It is your responsibility to protect your struct file_operation
432 * methods against file removals by means of debugfs_use_file_start()
433 * and debugfs_use_file_finish(). ->open() is still protected by
436 * Any struct file_operations defined by means of
437 * DEFINE_DEBUGFS_ATTRIBUTE() is protected against file removals and
438 * thus, may be used here.
440 struct dentry
*debugfs_create_file_unsafe(const char *name
, umode_t mode
,
441 struct dentry
*parent
, void *data
,
442 const struct file_operations
*fops
)
445 return __debugfs_create_file(name
, mode
, parent
, data
,
446 fops
? &debugfs_open_proxy_file_operations
:
447 &debugfs_noop_file_operations
,
450 EXPORT_SYMBOL_GPL(debugfs_create_file_unsafe
);
453 * debugfs_create_file_size - create a file in the debugfs filesystem
454 * @name: a pointer to a string containing the name of the file to create.
455 * @mode: the permission that the file should have.
456 * @parent: a pointer to the parent dentry for this file. This should be a
457 * directory dentry if set. If this parameter is NULL, then the
458 * file will be created in the root of the debugfs filesystem.
459 * @data: a pointer to something that the caller will want to get to later
460 * on. The inode.i_private pointer will point to this value on
462 * @fops: a pointer to a struct file_operations that should be used for
464 * @file_size: initial file size
466 * This is the basic "create a file" function for debugfs. It allows for a
467 * wide range of flexibility in creating a file, or a directory (if you want
468 * to create a directory, the debugfs_create_dir() function is
469 * recommended to be used instead.)
471 * This function will return a pointer to a dentry if it succeeds. This
472 * pointer must be passed to the debugfs_remove() function when the file is
473 * to be removed (no automatic cleanup happens if your module is unloaded,
474 * you are responsible here.) If an error occurs, %NULL will be returned.
476 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
479 struct dentry
*debugfs_create_file_size(const char *name
, umode_t mode
,
480 struct dentry
*parent
, void *data
,
481 const struct file_operations
*fops
,
484 struct dentry
*de
= debugfs_create_file(name
, mode
, parent
, data
, fops
);
487 d_inode(de
)->i_size
= file_size
;
490 EXPORT_SYMBOL_GPL(debugfs_create_file_size
);
493 * debugfs_create_dir - create a directory in the debugfs filesystem
494 * @name: a pointer to a string containing the name of the directory to
496 * @parent: a pointer to the parent dentry for this file. This should be a
497 * directory dentry if set. If this parameter is NULL, then the
498 * directory will be created in the root of the debugfs filesystem.
500 * This function creates a directory in debugfs with the given name.
502 * This function will return a pointer to a dentry if it succeeds. This
503 * pointer must be passed to the debugfs_remove() function when the file is
504 * to be removed (no automatic cleanup happens if your module is unloaded,
505 * you are responsible here.) If an error occurs, %NULL will be returned.
507 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
510 struct dentry
*debugfs_create_dir(const char *name
, struct dentry
*parent
)
512 struct dentry
*dentry
= start_creating(name
, parent
);
518 inode
= debugfs_get_inode(dentry
->d_sb
);
519 if (unlikely(!inode
))
520 return failed_creating(dentry
);
522 inode
->i_mode
= S_IFDIR
| S_IRWXU
| S_IRUGO
| S_IXUGO
;
523 inode
->i_op
= &simple_dir_inode_operations
;
524 inode
->i_fop
= &simple_dir_operations
;
526 /* directory inodes start off with i_nlink == 2 (for "." entry) */
528 d_instantiate(dentry
, inode
);
529 inc_nlink(d_inode(dentry
->d_parent
));
530 fsnotify_mkdir(d_inode(dentry
->d_parent
), dentry
);
531 return end_creating(dentry
);
533 EXPORT_SYMBOL_GPL(debugfs_create_dir
);
536 * debugfs_create_automount - create automount point in the debugfs filesystem
537 * @name: a pointer to a string containing the name of the file to create.
538 * @parent: a pointer to the parent dentry for this file. This should be a
539 * directory dentry if set. If this parameter is NULL, then the
540 * file will be created in the root of the debugfs filesystem.
541 * @f: function to be called when pathname resolution steps on that one.
542 * @data: opaque argument to pass to f().
544 * @f should return what ->d_automount() would.
546 struct dentry
*debugfs_create_automount(const char *name
,
547 struct dentry
*parent
,
548 debugfs_automount_t f
,
551 struct dentry
*dentry
= start_creating(name
, parent
);
557 inode
= debugfs_get_inode(dentry
->d_sb
);
558 if (unlikely(!inode
))
559 return failed_creating(dentry
);
561 make_empty_dir_inode(inode
);
562 inode
->i_flags
|= S_AUTOMOUNT
;
563 inode
->i_private
= data
;
564 dentry
->d_fsdata
= (void *)f
;
565 /* directory inodes start off with i_nlink == 2 (for "." entry) */
567 d_instantiate(dentry
, inode
);
568 inc_nlink(d_inode(dentry
->d_parent
));
569 fsnotify_mkdir(d_inode(dentry
->d_parent
), dentry
);
570 return end_creating(dentry
);
572 EXPORT_SYMBOL(debugfs_create_automount
);
575 * debugfs_create_symlink- create a symbolic link in the debugfs filesystem
576 * @name: a pointer to a string containing the name of the symbolic link to
578 * @parent: a pointer to the parent dentry for this symbolic link. This
579 * should be a directory dentry if set. If this parameter is NULL,
580 * then the symbolic link will be created in the root of the debugfs
582 * @target: a pointer to a string containing the path to the target of the
585 * This function creates a symbolic link with the given name in debugfs that
586 * links to the given target path.
588 * This function will return a pointer to a dentry if it succeeds. This
589 * pointer must be passed to the debugfs_remove() function when the symbolic
590 * link is to be removed (no automatic cleanup happens if your module is
591 * unloaded, you are responsible here.) If an error occurs, %NULL will be
594 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
597 struct dentry
*debugfs_create_symlink(const char *name
, struct dentry
*parent
,
600 struct dentry
*dentry
;
602 char *link
= kstrdup(target
, GFP_KERNEL
);
606 dentry
= start_creating(name
, parent
);
607 if (IS_ERR(dentry
)) {
612 inode
= debugfs_get_inode(dentry
->d_sb
);
613 if (unlikely(!inode
)) {
615 return failed_creating(dentry
);
617 inode
->i_mode
= S_IFLNK
| S_IRWXUGO
;
618 inode
->i_op
= &simple_symlink_inode_operations
;
619 inode
->i_link
= link
;
620 d_instantiate(dentry
, inode
);
621 return end_creating(dentry
);
623 EXPORT_SYMBOL_GPL(debugfs_create_symlink
);
625 static void __debugfs_remove_file(struct dentry
*dentry
, struct dentry
*parent
)
627 struct debugfs_fsdata
*fsd
;
629 simple_unlink(d_inode(parent
), dentry
);
633 * Paired with the closing smp_mb() implied by a successful
634 * cmpxchg() in debugfs_file_get(): either
635 * debugfs_file_get() must see a dead dentry or we must see a
636 * debugfs_fsdata instance at ->d_fsdata here (or both).
639 fsd
= READ_ONCE(dentry
->d_fsdata
);
640 if ((unsigned long)fsd
& DEBUGFS_FSDATA_IS_REAL_FOPS_BIT
)
642 if (!refcount_dec_and_test(&fsd
->active_users
))
643 wait_for_completion(&fsd
->active_users_drained
);
646 static int __debugfs_remove(struct dentry
*dentry
, struct dentry
*parent
)
650 if (simple_positive(dentry
)) {
652 if (!d_is_reg(dentry
)) {
653 if (d_is_dir(dentry
))
654 ret
= simple_rmdir(d_inode(parent
), dentry
);
656 simple_unlink(d_inode(parent
), dentry
);
660 __debugfs_remove_file(dentry
, parent
);
668 * debugfs_remove - removes a file or directory from the debugfs filesystem
669 * @dentry: a pointer to a the dentry of the file or directory to be
670 * removed. If this parameter is NULL or an error value, nothing
673 * This function removes a file or directory in debugfs that was previously
674 * created with a call to another debugfs function (like
675 * debugfs_create_file() or variants thereof.)
677 * This function is required to be called in order for the file to be
678 * removed, no automatic cleanup of files will happen when a module is
679 * removed, you are responsible here.
681 void debugfs_remove(struct dentry
*dentry
)
683 struct dentry
*parent
;
686 if (IS_ERR_OR_NULL(dentry
))
689 parent
= dentry
->d_parent
;
690 inode_lock(d_inode(parent
));
691 ret
= __debugfs_remove(dentry
, parent
);
692 inode_unlock(d_inode(parent
));
694 simple_release_fs(&debugfs_mount
, &debugfs_mount_count
);
696 EXPORT_SYMBOL_GPL(debugfs_remove
);
699 * debugfs_remove_recursive - recursively removes a directory
700 * @dentry: a pointer to a the dentry of the directory to be removed. If this
701 * parameter is NULL or an error value, nothing will be done.
703 * This function recursively removes a directory tree in debugfs that
704 * was previously created with a call to another debugfs function
705 * (like debugfs_create_file() or variants thereof.)
707 * This function is required to be called in order for the file to be
708 * removed, no automatic cleanup of files will happen when a module is
709 * removed, you are responsible here.
711 void debugfs_remove_recursive(struct dentry
*dentry
)
713 struct dentry
*child
, *parent
;
715 if (IS_ERR_OR_NULL(dentry
))
720 inode_lock(d_inode(parent
));
723 * The parent->d_subdirs is protected by the d_lock. Outside that
724 * lock, the child can be unlinked and set to be freed which can
725 * use the d_u.d_child as the rcu head and corrupt this list.
727 spin_lock(&parent
->d_lock
);
728 list_for_each_entry(child
, &parent
->d_subdirs
, d_child
) {
729 if (!simple_positive(child
))
732 /* perhaps simple_empty(child) makes more sense */
733 if (!list_empty(&child
->d_subdirs
)) {
734 spin_unlock(&parent
->d_lock
);
735 inode_unlock(d_inode(parent
));
740 spin_unlock(&parent
->d_lock
);
742 if (!__debugfs_remove(child
, parent
))
743 simple_release_fs(&debugfs_mount
, &debugfs_mount_count
);
746 * The parent->d_lock protects agaist child from unlinking
747 * from d_subdirs. When releasing the parent->d_lock we can
748 * no longer trust that the next pointer is valid.
749 * Restart the loop. We'll skip this one with the
750 * simple_positive() check.
754 spin_unlock(&parent
->d_lock
);
756 inode_unlock(d_inode(parent
));
758 parent
= parent
->d_parent
;
759 inode_lock(d_inode(parent
));
765 if (!__debugfs_remove(child
, parent
))
766 simple_release_fs(&debugfs_mount
, &debugfs_mount_count
);
767 inode_unlock(d_inode(parent
));
769 EXPORT_SYMBOL_GPL(debugfs_remove_recursive
);
772 * debugfs_rename - rename a file/directory in the debugfs filesystem
773 * @old_dir: a pointer to the parent dentry for the renamed object. This
774 * should be a directory dentry.
775 * @old_dentry: dentry of an object to be renamed.
776 * @new_dir: a pointer to the parent dentry where the object should be
777 * moved. This should be a directory dentry.
778 * @new_name: a pointer to a string containing the target name.
780 * This function renames a file/directory in debugfs. The target must not
781 * exist for rename to succeed.
783 * This function will return a pointer to old_dentry (which is updated to
784 * reflect renaming) if it succeeds. If an error occurs, %NULL will be
787 * If debugfs is not enabled in the kernel, the value -%ENODEV will be
790 struct dentry
*debugfs_rename(struct dentry
*old_dir
, struct dentry
*old_dentry
,
791 struct dentry
*new_dir
, const char *new_name
)
794 struct dentry
*dentry
= NULL
, *trap
;
795 struct name_snapshot old_name
;
801 if (IS_ERR_OR_NULL(old_dentry
))
804 trap
= lock_rename(new_dir
, old_dir
);
805 /* Source or destination directories don't exist? */
806 if (d_really_is_negative(old_dir
) || d_really_is_negative(new_dir
))
808 /* Source does not exist, cyclic rename, or mountpoint? */
809 if (d_really_is_negative(old_dentry
) || old_dentry
== trap
||
810 d_mountpoint(old_dentry
))
812 dentry
= lookup_one_len(new_name
, new_dir
, strlen(new_name
));
813 /* Lookup failed, cyclic rename or target exists? */
814 if (IS_ERR(dentry
) || dentry
== trap
|| d_really_is_positive(dentry
))
817 take_dentry_name_snapshot(&old_name
, old_dentry
);
819 error
= simple_rename(d_inode(old_dir
), old_dentry
, d_inode(new_dir
),
822 release_dentry_name_snapshot(&old_name
);
825 d_move(old_dentry
, dentry
);
826 fsnotify_move(d_inode(old_dir
), d_inode(new_dir
), old_name
.name
,
827 d_is_dir(old_dentry
),
829 release_dentry_name_snapshot(&old_name
);
830 unlock_rename(new_dir
, old_dir
);
834 if (dentry
&& !IS_ERR(dentry
))
836 unlock_rename(new_dir
, old_dir
);
839 EXPORT_SYMBOL_GPL(debugfs_rename
);
842 * debugfs_initialized - Tells whether debugfs has been registered
844 bool debugfs_initialized(void)
846 return debugfs_registered
;
848 EXPORT_SYMBOL_GPL(debugfs_initialized
);
850 static int __init
debugfs_init(void)
854 retval
= sysfs_create_mount_point(kernel_kobj
, "debug");
858 retval
= register_filesystem(&debug_fs_type
);
860 sysfs_remove_mount_point(kernel_kobj
, "debug");
862 debugfs_registered
= true;
866 core_initcall(debugfs_init
);