2 * fs/sysfs/dir.c - sysfs core and dir operation implementation
4 * Copyright (c) 2001-3 Patrick Mochel
5 * Copyright (c) 2007 SUSE Linux Products GmbH
6 * Copyright (c) 2007 Tejun Heo <teheo@suse.de>
8 * This file is released under the GPLv2.
10 * Please see Documentation/filesystems/sysfs.txt for more information.
16 #include <linux/mount.h>
17 #include <linux/module.h>
18 #include <linux/kobject.h>
19 #include <linux/namei.h>
20 #include <linux/idr.h>
21 #include <linux/completion.h>
22 #include <linux/mutex.h>
23 #include <linux/slab.h>
24 #include <linux/security.h>
25 #include <linux/hash.h>
28 DEFINE_MUTEX(sysfs_mutex
);
29 DEFINE_SPINLOCK(sysfs_assoc_lock
);
31 #define to_sysfs_dirent(X) rb_entry((X), struct sysfs_dirent, s_rb);
33 static DEFINE_SPINLOCK(sysfs_ino_lock
);
34 static DEFINE_IDA(sysfs_ino_ida
);
38 * @ns: Namespace tag to hash
39 * @name: Null terminated string to hash
41 * Returns 31 bit hash of ns + name (so it fits in an off_t )
43 static unsigned int sysfs_name_hash(const void *ns
, const char *name
)
45 unsigned long hash
= init_name_hash();
46 unsigned int len
= strlen(name
);
48 hash
= partial_name_hash(*name
++, hash
);
49 hash
= ( end_name_hash(hash
) ^ hash_ptr( (void *)ns
, 31 ) );
51 /* Reserve hash numbers 0, 1 and INT_MAX for magic directory entries */
59 static int sysfs_name_compare(unsigned int hash
, const void *ns
,
60 const char *name
, const struct sysfs_dirent
*sd
)
62 if (hash
!= sd
->s_hash
)
63 return hash
- sd
->s_hash
;
66 return strcmp(name
, sd
->s_name
);
69 static int sysfs_sd_compare(const struct sysfs_dirent
*left
,
70 const struct sysfs_dirent
*right
)
72 return sysfs_name_compare(left
->s_hash
, left
->s_ns
, left
->s_name
,
77 * sysfs_link_subling - link sysfs_dirent into sibling rbtree
78 * @sd: sysfs_dirent of interest
80 * Link @sd into its sibling rbtree which starts from
81 * sd->s_parent->s_dir.children.
84 * mutex_lock(sysfs_mutex)
87 * 0 on susccess -EEXIST on failure.
89 static int sysfs_link_sibling(struct sysfs_dirent
*sd
)
91 struct rb_node
**node
= &sd
->s_parent
->s_dir
.children
.rb_node
;
92 struct rb_node
*parent
= NULL
;
94 if (sysfs_type(sd
) == SYSFS_DIR
)
95 sd
->s_parent
->s_dir
.subdirs
++;
98 struct sysfs_dirent
*pos
;
101 pos
= to_sysfs_dirent(*node
);
103 result
= sysfs_sd_compare(sd
, pos
);
105 node
= &pos
->s_rb
.rb_left
;
107 node
= &pos
->s_rb
.rb_right
;
111 /* add new node and rebalance the tree */
112 rb_link_node(&sd
->s_rb
, parent
, node
);
113 rb_insert_color(&sd
->s_rb
, &sd
->s_parent
->s_dir
.children
);
118 * sysfs_unlink_sibling - unlink sysfs_dirent from sibling rbtree
119 * @sd: sysfs_dirent of interest
121 * Unlink @sd from its sibling rbtree which starts from
122 * sd->s_parent->s_dir.children.
125 * mutex_lock(sysfs_mutex)
127 static void sysfs_unlink_sibling(struct sysfs_dirent
*sd
)
129 if (sysfs_type(sd
) == SYSFS_DIR
)
130 sd
->s_parent
->s_dir
.subdirs
--;
132 rb_erase(&sd
->s_rb
, &sd
->s_parent
->s_dir
.children
);
135 #ifdef CONFIG_DEBUG_LOCK_ALLOC
137 /* Test for attributes that want to ignore lockdep for read-locking */
138 static bool ignore_lockdep(struct sysfs_dirent
*sd
)
140 return sysfs_type(sd
) == SYSFS_KOBJ_ATTR
&&
141 sd
->s_attr
.attr
->ignore_lockdep
;
146 static inline bool ignore_lockdep(struct sysfs_dirent
*sd
)
154 * sysfs_get_active - get an active reference to sysfs_dirent
155 * @sd: sysfs_dirent to get an active reference to
157 * Get an active reference of @sd. This function is noop if @sd
161 * Pointer to @sd on success, NULL on failure.
163 struct sysfs_dirent
*sysfs_get_active(struct sysfs_dirent
*sd
)
171 v
= atomic_read(&sd
->s_active
);
175 t
= atomic_cmpxchg(&sd
->s_active
, v
, v
+ 1);
184 if (likely(!ignore_lockdep(sd
)))
185 rwsem_acquire_read(&sd
->dep_map
, 0, 1, _RET_IP_
);
190 * sysfs_put_active - put an active reference to sysfs_dirent
191 * @sd: sysfs_dirent to put an active reference to
193 * Put an active reference to @sd. This function is noop if @sd
196 void sysfs_put_active(struct sysfs_dirent
*sd
)
203 if (likely(!ignore_lockdep(sd
)))
204 rwsem_release(&sd
->dep_map
, 1, _RET_IP_
);
205 v
= atomic_dec_return(&sd
->s_active
);
206 if (likely(v
!= SD_DEACTIVATED_BIAS
))
209 /* atomic_dec_return() is a mb(), we'll always see the updated
212 complete(sd
->u
.completion
);
216 * sysfs_deactivate - deactivate sysfs_dirent
217 * @sd: sysfs_dirent to deactivate
219 * Deny new active references and drain existing ones.
221 static void sysfs_deactivate(struct sysfs_dirent
*sd
)
223 DECLARE_COMPLETION_ONSTACK(wait
);
226 BUG_ON(!(sd
->s_flags
& SYSFS_FLAG_REMOVED
));
228 if (!(sysfs_type(sd
) & SYSFS_ACTIVE_REF
))
231 sd
->u
.completion
= (void *)&wait
;
233 rwsem_acquire(&sd
->dep_map
, 0, 0, _RET_IP_
);
234 /* atomic_add_return() is a mb(), put_active() will always see
235 * the updated sd->u.completion.
237 v
= atomic_add_return(SD_DEACTIVATED_BIAS
, &sd
->s_active
);
239 if (v
!= SD_DEACTIVATED_BIAS
) {
240 lock_contended(&sd
->dep_map
, _RET_IP_
);
241 wait_for_completion(&wait
);
244 lock_acquired(&sd
->dep_map
, _RET_IP_
);
245 rwsem_release(&sd
->dep_map
, 1, _RET_IP_
);
248 static int sysfs_alloc_ino(unsigned int *pino
)
253 spin_lock(&sysfs_ino_lock
);
254 rc
= ida_get_new_above(&sysfs_ino_ida
, 2, &ino
);
255 spin_unlock(&sysfs_ino_lock
);
258 if (ida_pre_get(&sysfs_ino_ida
, GFP_KERNEL
))
267 static void sysfs_free_ino(unsigned int ino
)
269 spin_lock(&sysfs_ino_lock
);
270 ida_remove(&sysfs_ino_ida
, ino
);
271 spin_unlock(&sysfs_ino_lock
);
274 void release_sysfs_dirent(struct sysfs_dirent
* sd
)
276 struct sysfs_dirent
*parent_sd
;
279 /* Moving/renaming is always done while holding reference.
280 * sd->s_parent won't change beneath us.
282 parent_sd
= sd
->s_parent
;
284 if (sysfs_type(sd
) == SYSFS_KOBJ_LINK
)
285 sysfs_put(sd
->s_symlink
.target_sd
);
286 if (sysfs_type(sd
) & SYSFS_COPY_NAME
)
288 if (sd
->s_iattr
&& sd
->s_iattr
->ia_secdata
)
289 security_release_secctx(sd
->s_iattr
->ia_secdata
,
290 sd
->s_iattr
->ia_secdata_len
);
292 sysfs_free_ino(sd
->s_ino
);
293 kmem_cache_free(sysfs_dir_cachep
, sd
);
296 if (sd
&& atomic_dec_and_test(&sd
->s_count
))
300 static int sysfs_dentry_delete(const struct dentry
*dentry
)
302 struct sysfs_dirent
*sd
= dentry
->d_fsdata
;
303 return !!(sd
->s_flags
& SYSFS_FLAG_REMOVED
);
306 static int sysfs_dentry_revalidate(struct dentry
*dentry
, struct nameidata
*nd
)
308 struct sysfs_dirent
*sd
;
311 if (nd
->flags
& LOOKUP_RCU
)
314 sd
= dentry
->d_fsdata
;
315 mutex_lock(&sysfs_mutex
);
317 /* The sysfs dirent has been deleted */
318 if (sd
->s_flags
& SYSFS_FLAG_REMOVED
)
321 /* The sysfs dirent has been moved? */
322 if (dentry
->d_parent
->d_fsdata
!= sd
->s_parent
)
325 /* The sysfs dirent has been renamed */
326 if (strcmp(dentry
->d_name
.name
, sd
->s_name
) != 0)
329 mutex_unlock(&sysfs_mutex
);
333 /* Remove the dentry from the dcache hashes.
334 * If this is a deleted dentry we use d_drop instead of d_delete
335 * so sysfs doesn't need to cope with negative dentries.
337 * If this is a dentry that has simply been renamed we
338 * use d_drop to remove it from the dcache lookup on its
339 * old parent. If this dentry persists later when a lookup
340 * is performed at its new name the dentry will be readded
341 * to the dcache hashes.
343 is_dir
= (sysfs_type(sd
) == SYSFS_DIR
);
344 mutex_unlock(&sysfs_mutex
);
346 /* If we have submounts we must allow the vfs caches
347 * to lie about the state of the filesystem to prevent
348 * leaks and other nasty things.
350 if (have_submounts(dentry
))
352 shrink_dcache_parent(dentry
);
358 static void sysfs_dentry_iput(struct dentry
*dentry
, struct inode
*inode
)
360 struct sysfs_dirent
* sd
= dentry
->d_fsdata
;
366 static const struct dentry_operations sysfs_dentry_ops
= {
367 .d_revalidate
= sysfs_dentry_revalidate
,
368 .d_delete
= sysfs_dentry_delete
,
369 .d_iput
= sysfs_dentry_iput
,
372 struct sysfs_dirent
*sysfs_new_dirent(const char *name
, umode_t mode
, int type
)
374 char *dup_name
= NULL
;
375 struct sysfs_dirent
*sd
;
377 if (type
& SYSFS_COPY_NAME
) {
378 name
= dup_name
= kstrdup(name
, GFP_KERNEL
);
383 sd
= kmem_cache_zalloc(sysfs_dir_cachep
, GFP_KERNEL
);
387 if (sysfs_alloc_ino(&sd
->s_ino
))
390 atomic_set(&sd
->s_count
, 1);
391 atomic_set(&sd
->s_active
, 0);
400 kmem_cache_free(sysfs_dir_cachep
, sd
);
407 * sysfs_addrm_start - prepare for sysfs_dirent add/remove
408 * @acxt: pointer to sysfs_addrm_cxt to be used
409 * @parent_sd: parent sysfs_dirent
411 * This function is called when the caller is about to add or
412 * remove sysfs_dirent under @parent_sd. This function acquires
413 * sysfs_mutex. @acxt is used to keep and pass context to
414 * other addrm functions.
417 * Kernel thread context (may sleep). sysfs_mutex is locked on
420 void sysfs_addrm_start(struct sysfs_addrm_cxt
*acxt
,
421 struct sysfs_dirent
*parent_sd
)
423 memset(acxt
, 0, sizeof(*acxt
));
424 acxt
->parent_sd
= parent_sd
;
426 mutex_lock(&sysfs_mutex
);
430 * __sysfs_add_one - add sysfs_dirent to parent without warning
431 * @acxt: addrm context to use
432 * @sd: sysfs_dirent to be added
434 * Get @acxt->parent_sd and set sd->s_parent to it and increment
435 * nlink of parent inode if @sd is a directory and link into the
436 * children list of the parent.
438 * This function should be called between calls to
439 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
440 * passed the same @acxt as passed to sysfs_addrm_start().
443 * Determined by sysfs_addrm_start().
446 * 0 on success, -EEXIST if entry with the given name already
449 int __sysfs_add_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
451 struct sysfs_inode_attrs
*ps_iattr
;
454 if (!!sysfs_ns_type(acxt
->parent_sd
) != !!sd
->s_ns
) {
455 WARN(1, KERN_WARNING
"sysfs: ns %s in '%s' for '%s'\n",
456 sysfs_ns_type(acxt
->parent_sd
)? "required": "invalid",
457 acxt
->parent_sd
->s_name
, sd
->s_name
);
461 sd
->s_hash
= sysfs_name_hash(sd
->s_ns
, sd
->s_name
);
462 sd
->s_parent
= sysfs_get(acxt
->parent_sd
);
464 ret
= sysfs_link_sibling(sd
);
468 /* Update timestamps on the parent */
469 ps_iattr
= acxt
->parent_sd
->s_iattr
;
471 struct iattr
*ps_iattrs
= &ps_iattr
->ia_iattr
;
472 ps_iattrs
->ia_ctime
= ps_iattrs
->ia_mtime
= CURRENT_TIME
;
479 * sysfs_pathname - return full path to sysfs dirent
480 * @sd: sysfs_dirent whose path we want
481 * @path: caller allocated buffer
483 * Gives the name "/" to the sysfs_root entry; any path returned
484 * is relative to wherever sysfs is mounted.
486 * XXX: does no error checking on @path size
488 static char *sysfs_pathname(struct sysfs_dirent
*sd
, char *path
)
491 sysfs_pathname(sd
->s_parent
, path
);
494 strcat(path
, sd
->s_name
);
499 * sysfs_add_one - add sysfs_dirent to parent
500 * @acxt: addrm context to use
501 * @sd: sysfs_dirent to be added
503 * Get @acxt->parent_sd and set sd->s_parent to it and increment
504 * nlink of parent inode if @sd is a directory and link into the
505 * children list of the parent.
507 * This function should be called between calls to
508 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
509 * passed the same @acxt as passed to sysfs_addrm_start().
512 * Determined by sysfs_addrm_start().
515 * 0 on success, -EEXIST if entry with the given name already
518 int sysfs_add_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
522 ret
= __sysfs_add_one(acxt
, sd
);
523 if (ret
== -EEXIST
) {
524 char *path
= kzalloc(PATH_MAX
, GFP_KERNEL
);
526 "sysfs: cannot create duplicate filename '%s'\n",
527 (path
== NULL
) ? sd
->s_name
:
528 strcat(strcat(sysfs_pathname(acxt
->parent_sd
, path
), "/"),
537 * sysfs_remove_one - remove sysfs_dirent from parent
538 * @acxt: addrm context to use
539 * @sd: sysfs_dirent to be removed
541 * Mark @sd removed and drop nlink of parent inode if @sd is a
542 * directory. @sd is unlinked from the children list.
544 * This function should be called between calls to
545 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
546 * passed the same @acxt as passed to sysfs_addrm_start().
549 * Determined by sysfs_addrm_start().
551 void sysfs_remove_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
553 struct sysfs_inode_attrs
*ps_iattr
;
555 BUG_ON(sd
->s_flags
& SYSFS_FLAG_REMOVED
);
557 sysfs_unlink_sibling(sd
);
559 /* Update timestamps on the parent */
560 ps_iattr
= acxt
->parent_sd
->s_iattr
;
562 struct iattr
*ps_iattrs
= &ps_iattr
->ia_iattr
;
563 ps_iattrs
->ia_ctime
= ps_iattrs
->ia_mtime
= CURRENT_TIME
;
566 sd
->s_flags
|= SYSFS_FLAG_REMOVED
;
567 sd
->u
.removed_list
= acxt
->removed
;
572 * sysfs_addrm_finish - finish up sysfs_dirent add/remove
573 * @acxt: addrm context to finish up
575 * Finish up sysfs_dirent add/remove. Resources acquired by
576 * sysfs_addrm_start() are released and removed sysfs_dirents are
580 * sysfs_mutex is released.
582 void sysfs_addrm_finish(struct sysfs_addrm_cxt
*acxt
)
584 /* release resources acquired by sysfs_addrm_start() */
585 mutex_unlock(&sysfs_mutex
);
587 /* kill removed sysfs_dirents */
588 while (acxt
->removed
) {
589 struct sysfs_dirent
*sd
= acxt
->removed
;
591 acxt
->removed
= sd
->u
.removed_list
;
593 sysfs_deactivate(sd
);
600 * sysfs_find_dirent - find sysfs_dirent with the given name
601 * @parent_sd: sysfs_dirent to search under
602 * @name: name to look for
604 * Look for sysfs_dirent with name @name under @parent_sd.
607 * mutex_lock(sysfs_mutex)
610 * Pointer to sysfs_dirent if found, NULL if not.
612 struct sysfs_dirent
*sysfs_find_dirent(struct sysfs_dirent
*parent_sd
,
614 const unsigned char *name
)
616 struct rb_node
*node
= parent_sd
->s_dir
.children
.rb_node
;
619 if (!!sysfs_ns_type(parent_sd
) != !!ns
) {
620 WARN(1, KERN_WARNING
"sysfs: ns %s in '%s' for '%s'\n",
621 sysfs_ns_type(parent_sd
)? "required": "invalid",
622 parent_sd
->s_name
, name
);
626 hash
= sysfs_name_hash(ns
, name
);
628 struct sysfs_dirent
*sd
;
631 sd
= to_sysfs_dirent(node
);
632 result
= sysfs_name_compare(hash
, ns
, name
, sd
);
634 node
= node
->rb_left
;
636 node
= node
->rb_right
;
644 * sysfs_get_dirent - find and get sysfs_dirent with the given name
645 * @parent_sd: sysfs_dirent to search under
646 * @name: name to look for
648 * Look for sysfs_dirent with name @name under @parent_sd and get
652 * Kernel thread context (may sleep). Grabs sysfs_mutex.
655 * Pointer to sysfs_dirent if found, NULL if not.
657 struct sysfs_dirent
*sysfs_get_dirent(struct sysfs_dirent
*parent_sd
,
659 const unsigned char *name
)
661 struct sysfs_dirent
*sd
;
663 mutex_lock(&sysfs_mutex
);
664 sd
= sysfs_find_dirent(parent_sd
, ns
, name
);
666 mutex_unlock(&sysfs_mutex
);
670 EXPORT_SYMBOL_GPL(sysfs_get_dirent
);
672 static int create_dir(struct kobject
*kobj
, struct sysfs_dirent
*parent_sd
,
673 enum kobj_ns_type type
, const void *ns
, const char *name
,
674 struct sysfs_dirent
**p_sd
)
676 umode_t mode
= S_IFDIR
| S_IRWXU
| S_IRUGO
| S_IXUGO
;
677 struct sysfs_addrm_cxt acxt
;
678 struct sysfs_dirent
*sd
;
682 sd
= sysfs_new_dirent(name
, mode
, SYSFS_DIR
);
686 sd
->s_flags
|= (type
<< SYSFS_NS_TYPE_SHIFT
);
688 sd
->s_dir
.kobj
= kobj
;
691 sysfs_addrm_start(&acxt
, parent_sd
);
692 rc
= sysfs_add_one(&acxt
, sd
);
693 sysfs_addrm_finish(&acxt
);
703 int sysfs_create_subdir(struct kobject
*kobj
, const char *name
,
704 struct sysfs_dirent
**p_sd
)
706 return create_dir(kobj
, kobj
->sd
,
707 KOBJ_NS_TYPE_NONE
, NULL
, name
, p_sd
);
711 * sysfs_read_ns_type: return associated ns_type
712 * @kobj: the kobject being queried
714 * Each kobject can be tagged with exactly one namespace type
715 * (i.e. network or user). Return the ns_type associated with
718 static enum kobj_ns_type
sysfs_read_ns_type(struct kobject
*kobj
)
720 const struct kobj_ns_type_operations
*ops
;
721 enum kobj_ns_type type
;
723 ops
= kobj_child_ns_ops(kobj
);
725 return KOBJ_NS_TYPE_NONE
;
728 BUG_ON(type
<= KOBJ_NS_TYPE_NONE
);
729 BUG_ON(type
>= KOBJ_NS_TYPES
);
730 BUG_ON(!kobj_ns_type_registered(type
));
736 * sysfs_create_dir - create a directory for an object.
737 * @kobj: object we're creating directory for.
739 int sysfs_create_dir(struct kobject
* kobj
)
741 enum kobj_ns_type type
;
742 struct sysfs_dirent
*parent_sd
, *sd
;
743 const void *ns
= NULL
;
749 parent_sd
= kobj
->parent
->sd
;
751 parent_sd
= &sysfs_root
;
756 if (sysfs_ns_type(parent_sd
))
757 ns
= kobj
->ktype
->namespace(kobj
);
758 type
= sysfs_read_ns_type(kobj
);
760 error
= create_dir(kobj
, parent_sd
, type
, ns
, kobject_name(kobj
), &sd
);
766 static struct dentry
* sysfs_lookup(struct inode
*dir
, struct dentry
*dentry
,
767 struct nameidata
*nd
)
769 struct dentry
*ret
= NULL
;
770 struct dentry
*parent
= dentry
->d_parent
;
771 struct sysfs_dirent
*parent_sd
= parent
->d_fsdata
;
772 struct sysfs_dirent
*sd
;
774 enum kobj_ns_type type
;
777 mutex_lock(&sysfs_mutex
);
779 type
= sysfs_ns_type(parent_sd
);
780 ns
= sysfs_info(dir
->i_sb
)->ns
[type
];
782 sd
= sysfs_find_dirent(parent_sd
, ns
, dentry
->d_name
.name
);
786 ret
= ERR_PTR(-ENOENT
);
790 /* attach dentry and inode */
791 inode
= sysfs_get_inode(dir
->i_sb
, sd
);
793 ret
= ERR_PTR(-ENOMEM
);
797 /* instantiate and hash dentry */
798 ret
= d_find_alias(inode
);
800 d_set_d_op(dentry
, &sysfs_dentry_ops
);
801 dentry
->d_fsdata
= sysfs_get(sd
);
802 d_add(dentry
, inode
);
809 mutex_unlock(&sysfs_mutex
);
813 const struct inode_operations sysfs_dir_inode_operations
= {
814 .lookup
= sysfs_lookup
,
815 .permission
= sysfs_permission
,
816 .setattr
= sysfs_setattr
,
817 .getattr
= sysfs_getattr
,
818 .setxattr
= sysfs_setxattr
,
821 static void remove_dir(struct sysfs_dirent
*sd
)
823 struct sysfs_addrm_cxt acxt
;
825 sysfs_addrm_start(&acxt
, sd
->s_parent
);
826 sysfs_remove_one(&acxt
, sd
);
827 sysfs_addrm_finish(&acxt
);
830 void sysfs_remove_subdir(struct sysfs_dirent
*sd
)
836 static void __sysfs_remove_dir(struct sysfs_dirent
*dir_sd
)
838 struct sysfs_addrm_cxt acxt
;
844 pr_debug("sysfs %s: removing dir\n", dir_sd
->s_name
);
845 sysfs_addrm_start(&acxt
, dir_sd
);
846 pos
= rb_first(&dir_sd
->s_dir
.children
);
848 struct sysfs_dirent
*sd
= to_sysfs_dirent(pos
);
850 if (sysfs_type(sd
) != SYSFS_DIR
)
851 sysfs_remove_one(&acxt
, sd
);
853 sysfs_addrm_finish(&acxt
);
859 * sysfs_remove_dir - remove an object's directory.
862 * The only thing special about this is that we remove any files in
863 * the directory before we remove the directory, and we've inlined
864 * what used to be sysfs_rmdir() below, instead of calling separately.
867 void sysfs_remove_dir(struct kobject
* kobj
)
869 struct sysfs_dirent
*sd
= kobj
->sd
;
871 spin_lock(&sysfs_assoc_lock
);
873 spin_unlock(&sysfs_assoc_lock
);
875 __sysfs_remove_dir(sd
);
878 int sysfs_rename(struct sysfs_dirent
*sd
,
879 struct sysfs_dirent
*new_parent_sd
, const void *new_ns
,
880 const char *new_name
)
884 mutex_lock(&sysfs_mutex
);
887 if ((sd
->s_parent
== new_parent_sd
) && (sd
->s_ns
== new_ns
) &&
888 (strcmp(sd
->s_name
, new_name
) == 0))
889 goto out
; /* nothing to rename */
892 if (sysfs_find_dirent(new_parent_sd
, new_ns
, new_name
))
895 /* rename sysfs_dirent */
896 if (strcmp(sd
->s_name
, new_name
) != 0) {
898 new_name
= kstrdup(new_name
, GFP_KERNEL
);
903 sd
->s_name
= new_name
;
906 /* Move to the appropriate place in the appropriate directories rbtree. */
907 sysfs_unlink_sibling(sd
);
908 sysfs_get(new_parent_sd
);
909 sysfs_put(sd
->s_parent
);
911 sd
->s_hash
= sysfs_name_hash(sd
->s_ns
, sd
->s_name
);
912 sd
->s_parent
= new_parent_sd
;
913 sysfs_link_sibling(sd
);
917 mutex_unlock(&sysfs_mutex
);
921 int sysfs_rename_dir(struct kobject
*kobj
, const char *new_name
)
923 struct sysfs_dirent
*parent_sd
= kobj
->sd
->s_parent
;
924 const void *new_ns
= NULL
;
926 if (sysfs_ns_type(parent_sd
))
927 new_ns
= kobj
->ktype
->namespace(kobj
);
929 return sysfs_rename(kobj
->sd
, parent_sd
, new_ns
, new_name
);
932 int sysfs_move_dir(struct kobject
*kobj
, struct kobject
*new_parent_kobj
)
934 struct sysfs_dirent
*sd
= kobj
->sd
;
935 struct sysfs_dirent
*new_parent_sd
;
936 const void *new_ns
= NULL
;
938 BUG_ON(!sd
->s_parent
);
939 if (sysfs_ns_type(sd
->s_parent
))
940 new_ns
= kobj
->ktype
->namespace(kobj
);
941 new_parent_sd
= new_parent_kobj
&& new_parent_kobj
->sd
?
942 new_parent_kobj
->sd
: &sysfs_root
;
944 return sysfs_rename(sd
, new_parent_sd
, new_ns
, sd
->s_name
);
947 /* Relationship between s_mode and the DT_xxx types */
948 static inline unsigned char dt_type(struct sysfs_dirent
*sd
)
950 return (sd
->s_mode
>> 12) & 15;
953 static int sysfs_dir_release(struct inode
*inode
, struct file
*filp
)
955 sysfs_put(filp
->private_data
);
959 static struct sysfs_dirent
*sysfs_dir_pos(const void *ns
,
960 struct sysfs_dirent
*parent_sd
, loff_t hash
, struct sysfs_dirent
*pos
)
963 int valid
= !(pos
->s_flags
& SYSFS_FLAG_REMOVED
) &&
964 pos
->s_parent
== parent_sd
&&
970 if (!pos
&& (hash
> 1) && (hash
< INT_MAX
)) {
971 struct rb_node
*node
= parent_sd
->s_dir
.children
.rb_node
;
973 pos
= to_sysfs_dirent(node
);
975 if (hash
< pos
->s_hash
)
976 node
= node
->rb_left
;
977 else if (hash
> pos
->s_hash
)
978 node
= node
->rb_right
;
983 /* Skip over entries in the wrong namespace */
984 while (pos
&& pos
->s_ns
!= ns
) {
985 struct rb_node
*node
= rb_next(&pos
->s_rb
);
989 pos
= to_sysfs_dirent(node
);
994 static struct sysfs_dirent
*sysfs_dir_next_pos(const void *ns
,
995 struct sysfs_dirent
*parent_sd
, ino_t ino
, struct sysfs_dirent
*pos
)
997 pos
= sysfs_dir_pos(ns
, parent_sd
, ino
, pos
);
999 struct rb_node
*node
= rb_next(&pos
->s_rb
);
1003 pos
= to_sysfs_dirent(node
);
1004 } while (pos
&& pos
->s_ns
!= ns
);
1008 static int sysfs_readdir(struct file
* filp
, void * dirent
, filldir_t filldir
)
1010 struct dentry
*dentry
= filp
->f_path
.dentry
;
1011 struct sysfs_dirent
* parent_sd
= dentry
->d_fsdata
;
1012 struct sysfs_dirent
*pos
= filp
->private_data
;
1013 enum kobj_ns_type type
;
1017 type
= sysfs_ns_type(parent_sd
);
1018 ns
= sysfs_info(dentry
->d_sb
)->ns
[type
];
1020 if (filp
->f_pos
== 0) {
1021 ino
= parent_sd
->s_ino
;
1022 if (filldir(dirent
, ".", 1, filp
->f_pos
, ino
, DT_DIR
) == 0)
1025 if (filp
->f_pos
== 1) {
1026 if (parent_sd
->s_parent
)
1027 ino
= parent_sd
->s_parent
->s_ino
;
1029 ino
= parent_sd
->s_ino
;
1030 if (filldir(dirent
, "..", 2, filp
->f_pos
, ino
, DT_DIR
) == 0)
1033 mutex_lock(&sysfs_mutex
);
1034 for (pos
= sysfs_dir_pos(ns
, parent_sd
, filp
->f_pos
, pos
);
1036 pos
= sysfs_dir_next_pos(ns
, parent_sd
, filp
->f_pos
, pos
)) {
1044 type
= dt_type(pos
);
1045 filp
->f_pos
= pos
->s_hash
;
1046 filp
->private_data
= sysfs_get(pos
);
1048 mutex_unlock(&sysfs_mutex
);
1049 ret
= filldir(dirent
, name
, len
, filp
->f_pos
, ino
, type
);
1050 mutex_lock(&sysfs_mutex
);
1054 mutex_unlock(&sysfs_mutex
);
1055 if ((filp
->f_pos
> 1) && !pos
) { /* EOF */
1056 filp
->f_pos
= INT_MAX
;
1057 filp
->private_data
= NULL
;
1063 const struct file_operations sysfs_dir_operations
= {
1064 .read
= generic_read_dir
,
1065 .readdir
= sysfs_readdir
,
1066 .release
= sysfs_dir_release
,
1067 .llseek
= generic_file_llseek
,