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
;
312 if (nd
->flags
& LOOKUP_RCU
)
315 sd
= dentry
->d_fsdata
;
316 mutex_lock(&sysfs_mutex
);
318 /* The sysfs dirent has been deleted */
319 if (sd
->s_flags
& SYSFS_FLAG_REMOVED
)
322 /* The sysfs dirent has been moved? */
323 if (dentry
->d_parent
->d_fsdata
!= sd
->s_parent
)
326 /* The sysfs dirent has been renamed */
327 if (strcmp(dentry
->d_name
.name
, sd
->s_name
) != 0)
330 /* The sysfs dirent has been moved to a different namespace */
331 type
= KOBJ_NS_TYPE_NONE
;
333 type
= sysfs_ns_type(sd
->s_parent
);
334 if (type
&& (sysfs_info(dentry
->d_sb
)->ns
[type
] != sd
->s_ns
))
337 mutex_unlock(&sysfs_mutex
);
341 /* Remove the dentry from the dcache hashes.
342 * If this is a deleted dentry we use d_drop instead of d_delete
343 * so sysfs doesn't need to cope with negative dentries.
345 * If this is a dentry that has simply been renamed we
346 * use d_drop to remove it from the dcache lookup on its
347 * old parent. If this dentry persists later when a lookup
348 * is performed at its new name the dentry will be readded
349 * to the dcache hashes.
351 is_dir
= (sysfs_type(sd
) == SYSFS_DIR
);
352 mutex_unlock(&sysfs_mutex
);
354 /* If we have submounts we must allow the vfs caches
355 * to lie about the state of the filesystem to prevent
356 * leaks and other nasty things.
358 if (have_submounts(dentry
))
360 shrink_dcache_parent(dentry
);
366 static void sysfs_dentry_iput(struct dentry
*dentry
, struct inode
*inode
)
368 struct sysfs_dirent
* sd
= dentry
->d_fsdata
;
374 static const struct dentry_operations sysfs_dentry_ops
= {
375 .d_revalidate
= sysfs_dentry_revalidate
,
376 .d_delete
= sysfs_dentry_delete
,
377 .d_iput
= sysfs_dentry_iput
,
380 struct sysfs_dirent
*sysfs_new_dirent(const char *name
, umode_t mode
, int type
)
382 char *dup_name
= NULL
;
383 struct sysfs_dirent
*sd
;
385 if (type
& SYSFS_COPY_NAME
) {
386 name
= dup_name
= kstrdup(name
, GFP_KERNEL
);
391 sd
= kmem_cache_zalloc(sysfs_dir_cachep
, GFP_KERNEL
);
395 if (sysfs_alloc_ino(&sd
->s_ino
))
398 atomic_set(&sd
->s_count
, 1);
399 atomic_set(&sd
->s_active
, 0);
408 kmem_cache_free(sysfs_dir_cachep
, sd
);
415 * sysfs_addrm_start - prepare for sysfs_dirent add/remove
416 * @acxt: pointer to sysfs_addrm_cxt to be used
417 * @parent_sd: parent sysfs_dirent
419 * This function is called when the caller is about to add or
420 * remove sysfs_dirent under @parent_sd. This function acquires
421 * sysfs_mutex. @acxt is used to keep and pass context to
422 * other addrm functions.
425 * Kernel thread context (may sleep). sysfs_mutex is locked on
428 void sysfs_addrm_start(struct sysfs_addrm_cxt
*acxt
,
429 struct sysfs_dirent
*parent_sd
)
431 memset(acxt
, 0, sizeof(*acxt
));
432 acxt
->parent_sd
= parent_sd
;
434 mutex_lock(&sysfs_mutex
);
438 * __sysfs_add_one - add sysfs_dirent to parent without warning
439 * @acxt: addrm context to use
440 * @sd: sysfs_dirent to be added
442 * Get @acxt->parent_sd and set sd->s_parent to it and increment
443 * nlink of parent inode if @sd is a directory and link into the
444 * children list of the parent.
446 * This function should be called between calls to
447 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
448 * passed the same @acxt as passed to sysfs_addrm_start().
451 * Determined by sysfs_addrm_start().
454 * 0 on success, -EEXIST if entry with the given name already
457 int __sysfs_add_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
459 struct sysfs_inode_attrs
*ps_iattr
;
462 if (!!sysfs_ns_type(acxt
->parent_sd
) != !!sd
->s_ns
) {
463 WARN(1, KERN_WARNING
"sysfs: ns %s in '%s' for '%s'\n",
464 sysfs_ns_type(acxt
->parent_sd
)? "required": "invalid",
465 acxt
->parent_sd
->s_name
, sd
->s_name
);
469 sd
->s_hash
= sysfs_name_hash(sd
->s_ns
, sd
->s_name
);
470 sd
->s_parent
= sysfs_get(acxt
->parent_sd
);
472 ret
= sysfs_link_sibling(sd
);
476 /* Update timestamps on the parent */
477 ps_iattr
= acxt
->parent_sd
->s_iattr
;
479 struct iattr
*ps_iattrs
= &ps_iattr
->ia_iattr
;
480 ps_iattrs
->ia_ctime
= ps_iattrs
->ia_mtime
= CURRENT_TIME
;
487 * sysfs_pathname - return full path to sysfs dirent
488 * @sd: sysfs_dirent whose path we want
489 * @path: caller allocated buffer
491 * Gives the name "/" to the sysfs_root entry; any path returned
492 * is relative to wherever sysfs is mounted.
494 * XXX: does no error checking on @path size
496 static char *sysfs_pathname(struct sysfs_dirent
*sd
, char *path
)
499 sysfs_pathname(sd
->s_parent
, path
);
502 strcat(path
, sd
->s_name
);
507 * sysfs_add_one - add sysfs_dirent to parent
508 * @acxt: addrm context to use
509 * @sd: sysfs_dirent to be added
511 * Get @acxt->parent_sd and set sd->s_parent to it and increment
512 * nlink of parent inode if @sd is a directory and link into the
513 * children list of the parent.
515 * This function should be called between calls to
516 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
517 * passed the same @acxt as passed to sysfs_addrm_start().
520 * Determined by sysfs_addrm_start().
523 * 0 on success, -EEXIST if entry with the given name already
526 int sysfs_add_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
530 ret
= __sysfs_add_one(acxt
, sd
);
531 if (ret
== -EEXIST
) {
532 char *path
= kzalloc(PATH_MAX
, GFP_KERNEL
);
534 "sysfs: cannot create duplicate filename '%s'\n",
535 (path
== NULL
) ? sd
->s_name
:
536 strcat(strcat(sysfs_pathname(acxt
->parent_sd
, path
), "/"),
545 * sysfs_remove_one - remove sysfs_dirent from parent
546 * @acxt: addrm context to use
547 * @sd: sysfs_dirent to be removed
549 * Mark @sd removed and drop nlink of parent inode if @sd is a
550 * directory. @sd is unlinked from the children list.
552 * This function should be called between calls to
553 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
554 * passed the same @acxt as passed to sysfs_addrm_start().
557 * Determined by sysfs_addrm_start().
559 void sysfs_remove_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
561 struct sysfs_inode_attrs
*ps_iattr
;
563 BUG_ON(sd
->s_flags
& SYSFS_FLAG_REMOVED
);
565 sysfs_unlink_sibling(sd
);
567 /* Update timestamps on the parent */
568 ps_iattr
= acxt
->parent_sd
->s_iattr
;
570 struct iattr
*ps_iattrs
= &ps_iattr
->ia_iattr
;
571 ps_iattrs
->ia_ctime
= ps_iattrs
->ia_mtime
= CURRENT_TIME
;
574 sd
->s_flags
|= SYSFS_FLAG_REMOVED
;
575 sd
->u
.removed_list
= acxt
->removed
;
580 * sysfs_addrm_finish - finish up sysfs_dirent add/remove
581 * @acxt: addrm context to finish up
583 * Finish up sysfs_dirent add/remove. Resources acquired by
584 * sysfs_addrm_start() are released and removed sysfs_dirents are
588 * sysfs_mutex is released.
590 void sysfs_addrm_finish(struct sysfs_addrm_cxt
*acxt
)
592 /* release resources acquired by sysfs_addrm_start() */
593 mutex_unlock(&sysfs_mutex
);
595 /* kill removed sysfs_dirents */
596 while (acxt
->removed
) {
597 struct sysfs_dirent
*sd
= acxt
->removed
;
599 acxt
->removed
= sd
->u
.removed_list
;
601 sysfs_deactivate(sd
);
608 * sysfs_find_dirent - find sysfs_dirent with the given name
609 * @parent_sd: sysfs_dirent to search under
610 * @name: name to look for
612 * Look for sysfs_dirent with name @name under @parent_sd.
615 * mutex_lock(sysfs_mutex)
618 * Pointer to sysfs_dirent if found, NULL if not.
620 struct sysfs_dirent
*sysfs_find_dirent(struct sysfs_dirent
*parent_sd
,
622 const unsigned char *name
)
624 struct rb_node
*node
= parent_sd
->s_dir
.children
.rb_node
;
627 if (!!sysfs_ns_type(parent_sd
) != !!ns
) {
628 WARN(1, KERN_WARNING
"sysfs: ns %s in '%s' for '%s'\n",
629 sysfs_ns_type(parent_sd
)? "required": "invalid",
630 parent_sd
->s_name
, name
);
634 hash
= sysfs_name_hash(ns
, name
);
636 struct sysfs_dirent
*sd
;
639 sd
= to_sysfs_dirent(node
);
640 result
= sysfs_name_compare(hash
, ns
, name
, sd
);
642 node
= node
->rb_left
;
644 node
= node
->rb_right
;
652 * sysfs_get_dirent - find and get sysfs_dirent with the given name
653 * @parent_sd: sysfs_dirent to search under
654 * @name: name to look for
656 * Look for sysfs_dirent with name @name under @parent_sd and get
660 * Kernel thread context (may sleep). Grabs sysfs_mutex.
663 * Pointer to sysfs_dirent if found, NULL if not.
665 struct sysfs_dirent
*sysfs_get_dirent(struct sysfs_dirent
*parent_sd
,
667 const unsigned char *name
)
669 struct sysfs_dirent
*sd
;
671 mutex_lock(&sysfs_mutex
);
672 sd
= sysfs_find_dirent(parent_sd
, ns
, name
);
674 mutex_unlock(&sysfs_mutex
);
678 EXPORT_SYMBOL_GPL(sysfs_get_dirent
);
680 static int create_dir(struct kobject
*kobj
, struct sysfs_dirent
*parent_sd
,
681 enum kobj_ns_type type
, const void *ns
, const char *name
,
682 struct sysfs_dirent
**p_sd
)
684 umode_t mode
= S_IFDIR
| S_IRWXU
| S_IRUGO
| S_IXUGO
;
685 struct sysfs_addrm_cxt acxt
;
686 struct sysfs_dirent
*sd
;
690 sd
= sysfs_new_dirent(name
, mode
, SYSFS_DIR
);
694 sd
->s_flags
|= (type
<< SYSFS_NS_TYPE_SHIFT
);
696 sd
->s_dir
.kobj
= kobj
;
699 sysfs_addrm_start(&acxt
, parent_sd
);
700 rc
= sysfs_add_one(&acxt
, sd
);
701 sysfs_addrm_finish(&acxt
);
711 int sysfs_create_subdir(struct kobject
*kobj
, const char *name
,
712 struct sysfs_dirent
**p_sd
)
714 return create_dir(kobj
, kobj
->sd
,
715 KOBJ_NS_TYPE_NONE
, NULL
, name
, p_sd
);
719 * sysfs_read_ns_type: return associated ns_type
720 * @kobj: the kobject being queried
722 * Each kobject can be tagged with exactly one namespace type
723 * (i.e. network or user). Return the ns_type associated with
726 static enum kobj_ns_type
sysfs_read_ns_type(struct kobject
*kobj
)
728 const struct kobj_ns_type_operations
*ops
;
729 enum kobj_ns_type type
;
731 ops
= kobj_child_ns_ops(kobj
);
733 return KOBJ_NS_TYPE_NONE
;
736 BUG_ON(type
<= KOBJ_NS_TYPE_NONE
);
737 BUG_ON(type
>= KOBJ_NS_TYPES
);
738 BUG_ON(!kobj_ns_type_registered(type
));
744 * sysfs_create_dir - create a directory for an object.
745 * @kobj: object we're creating directory for.
747 int sysfs_create_dir(struct kobject
* kobj
)
749 enum kobj_ns_type type
;
750 struct sysfs_dirent
*parent_sd
, *sd
;
751 const void *ns
= NULL
;
757 parent_sd
= kobj
->parent
->sd
;
759 parent_sd
= &sysfs_root
;
764 if (sysfs_ns_type(parent_sd
))
765 ns
= kobj
->ktype
->namespace(kobj
);
766 type
= sysfs_read_ns_type(kobj
);
768 error
= create_dir(kobj
, parent_sd
, type
, ns
, kobject_name(kobj
), &sd
);
774 static struct dentry
* sysfs_lookup(struct inode
*dir
, struct dentry
*dentry
,
775 struct nameidata
*nd
)
777 struct dentry
*ret
= NULL
;
778 struct dentry
*parent
= dentry
->d_parent
;
779 struct sysfs_dirent
*parent_sd
= parent
->d_fsdata
;
780 struct sysfs_dirent
*sd
;
782 enum kobj_ns_type type
;
785 mutex_lock(&sysfs_mutex
);
787 type
= sysfs_ns_type(parent_sd
);
788 ns
= sysfs_info(dir
->i_sb
)->ns
[type
];
790 sd
= sysfs_find_dirent(parent_sd
, ns
, dentry
->d_name
.name
);
794 ret
= ERR_PTR(-ENOENT
);
798 /* attach dentry and inode */
799 inode
= sysfs_get_inode(dir
->i_sb
, sd
);
801 ret
= ERR_PTR(-ENOMEM
);
805 /* instantiate and hash dentry */
806 ret
= d_find_alias(inode
);
808 d_set_d_op(dentry
, &sysfs_dentry_ops
);
809 dentry
->d_fsdata
= sysfs_get(sd
);
810 d_add(dentry
, inode
);
817 mutex_unlock(&sysfs_mutex
);
821 const struct inode_operations sysfs_dir_inode_operations
= {
822 .lookup
= sysfs_lookup
,
823 .permission
= sysfs_permission
,
824 .setattr
= sysfs_setattr
,
825 .getattr
= sysfs_getattr
,
826 .setxattr
= sysfs_setxattr
,
829 static void remove_dir(struct sysfs_dirent
*sd
)
831 struct sysfs_addrm_cxt acxt
;
833 sysfs_addrm_start(&acxt
, sd
->s_parent
);
834 sysfs_remove_one(&acxt
, sd
);
835 sysfs_addrm_finish(&acxt
);
838 void sysfs_remove_subdir(struct sysfs_dirent
*sd
)
844 static void __sysfs_remove_dir(struct sysfs_dirent
*dir_sd
)
846 struct sysfs_addrm_cxt acxt
;
852 pr_debug("sysfs %s: removing dir\n", dir_sd
->s_name
);
853 sysfs_addrm_start(&acxt
, dir_sd
);
854 pos
= rb_first(&dir_sd
->s_dir
.children
);
856 struct sysfs_dirent
*sd
= to_sysfs_dirent(pos
);
858 if (sysfs_type(sd
) != SYSFS_DIR
)
859 sysfs_remove_one(&acxt
, sd
);
861 sysfs_addrm_finish(&acxt
);
867 * sysfs_remove_dir - remove an object's directory.
870 * The only thing special about this is that we remove any files in
871 * the directory before we remove the directory, and we've inlined
872 * what used to be sysfs_rmdir() below, instead of calling separately.
875 void sysfs_remove_dir(struct kobject
* kobj
)
877 struct sysfs_dirent
*sd
= kobj
->sd
;
879 spin_lock(&sysfs_assoc_lock
);
881 spin_unlock(&sysfs_assoc_lock
);
883 __sysfs_remove_dir(sd
);
886 int sysfs_rename(struct sysfs_dirent
*sd
,
887 struct sysfs_dirent
*new_parent_sd
, const void *new_ns
,
888 const char *new_name
)
892 mutex_lock(&sysfs_mutex
);
895 if ((sd
->s_parent
== new_parent_sd
) && (sd
->s_ns
== new_ns
) &&
896 (strcmp(sd
->s_name
, new_name
) == 0))
897 goto out
; /* nothing to rename */
900 if (sysfs_find_dirent(new_parent_sd
, new_ns
, new_name
))
903 /* rename sysfs_dirent */
904 if (strcmp(sd
->s_name
, new_name
) != 0) {
906 new_name
= kstrdup(new_name
, GFP_KERNEL
);
911 sd
->s_name
= new_name
;
914 /* Move to the appropriate place in the appropriate directories rbtree. */
915 sysfs_unlink_sibling(sd
);
916 sysfs_get(new_parent_sd
);
917 sysfs_put(sd
->s_parent
);
919 sd
->s_hash
= sysfs_name_hash(sd
->s_ns
, sd
->s_name
);
920 sd
->s_parent
= new_parent_sd
;
921 sysfs_link_sibling(sd
);
925 mutex_unlock(&sysfs_mutex
);
929 int sysfs_rename_dir(struct kobject
*kobj
, const char *new_name
)
931 struct sysfs_dirent
*parent_sd
= kobj
->sd
->s_parent
;
932 const void *new_ns
= NULL
;
934 if (sysfs_ns_type(parent_sd
))
935 new_ns
= kobj
->ktype
->namespace(kobj
);
937 return sysfs_rename(kobj
->sd
, parent_sd
, new_ns
, new_name
);
940 int sysfs_move_dir(struct kobject
*kobj
, struct kobject
*new_parent_kobj
)
942 struct sysfs_dirent
*sd
= kobj
->sd
;
943 struct sysfs_dirent
*new_parent_sd
;
944 const void *new_ns
= NULL
;
946 BUG_ON(!sd
->s_parent
);
947 if (sysfs_ns_type(sd
->s_parent
))
948 new_ns
= kobj
->ktype
->namespace(kobj
);
949 new_parent_sd
= new_parent_kobj
&& new_parent_kobj
->sd
?
950 new_parent_kobj
->sd
: &sysfs_root
;
952 return sysfs_rename(sd
, new_parent_sd
, new_ns
, sd
->s_name
);
955 /* Relationship between s_mode and the DT_xxx types */
956 static inline unsigned char dt_type(struct sysfs_dirent
*sd
)
958 return (sd
->s_mode
>> 12) & 15;
961 static int sysfs_dir_release(struct inode
*inode
, struct file
*filp
)
963 sysfs_put(filp
->private_data
);
967 static struct sysfs_dirent
*sysfs_dir_pos(const void *ns
,
968 struct sysfs_dirent
*parent_sd
, loff_t hash
, struct sysfs_dirent
*pos
)
971 int valid
= !(pos
->s_flags
& SYSFS_FLAG_REMOVED
) &&
972 pos
->s_parent
== parent_sd
&&
978 if (!pos
&& (hash
> 1) && (hash
< INT_MAX
)) {
979 struct rb_node
*node
= parent_sd
->s_dir
.children
.rb_node
;
981 pos
= to_sysfs_dirent(node
);
983 if (hash
< pos
->s_hash
)
984 node
= node
->rb_left
;
985 else if (hash
> pos
->s_hash
)
986 node
= node
->rb_right
;
991 /* Skip over entries in the wrong namespace */
992 while (pos
&& pos
->s_ns
!= ns
) {
993 struct rb_node
*node
= rb_next(&pos
->s_rb
);
997 pos
= to_sysfs_dirent(node
);
1002 static struct sysfs_dirent
*sysfs_dir_next_pos(const void *ns
,
1003 struct sysfs_dirent
*parent_sd
, ino_t ino
, struct sysfs_dirent
*pos
)
1005 pos
= sysfs_dir_pos(ns
, parent_sd
, ino
, pos
);
1007 struct rb_node
*node
= rb_next(&pos
->s_rb
);
1011 pos
= to_sysfs_dirent(node
);
1012 } while (pos
&& pos
->s_ns
!= ns
);
1016 static int sysfs_readdir(struct file
* filp
, void * dirent
, filldir_t filldir
)
1018 struct dentry
*dentry
= filp
->f_path
.dentry
;
1019 struct sysfs_dirent
* parent_sd
= dentry
->d_fsdata
;
1020 struct sysfs_dirent
*pos
= filp
->private_data
;
1021 enum kobj_ns_type type
;
1025 type
= sysfs_ns_type(parent_sd
);
1026 ns
= sysfs_info(dentry
->d_sb
)->ns
[type
];
1028 if (filp
->f_pos
== 0) {
1029 ino
= parent_sd
->s_ino
;
1030 if (filldir(dirent
, ".", 1, filp
->f_pos
, ino
, DT_DIR
) == 0)
1033 if (filp
->f_pos
== 1) {
1034 if (parent_sd
->s_parent
)
1035 ino
= parent_sd
->s_parent
->s_ino
;
1037 ino
= parent_sd
->s_ino
;
1038 if (filldir(dirent
, "..", 2, filp
->f_pos
, ino
, DT_DIR
) == 0)
1041 mutex_lock(&sysfs_mutex
);
1042 for (pos
= sysfs_dir_pos(ns
, parent_sd
, filp
->f_pos
, pos
);
1044 pos
= sysfs_dir_next_pos(ns
, parent_sd
, filp
->f_pos
, pos
)) {
1052 type
= dt_type(pos
);
1053 filp
->f_pos
= pos
->s_hash
;
1054 filp
->private_data
= sysfs_get(pos
);
1056 mutex_unlock(&sysfs_mutex
);
1057 ret
= filldir(dirent
, name
, len
, filp
->f_pos
, ino
, type
);
1058 mutex_lock(&sysfs_mutex
);
1062 mutex_unlock(&sysfs_mutex
);
1063 if ((filp
->f_pos
> 1) && !pos
) { /* EOF */
1064 filp
->f_pos
= INT_MAX
;
1065 filp
->private_data
= NULL
;
1071 const struct file_operations sysfs_dir_operations
= {
1072 .read
= generic_read_dir
,
1073 .readdir
= sysfs_readdir
,
1074 .release
= sysfs_dir_release
,
1075 .llseek
= generic_file_llseek
,