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
)
168 if (!atomic_inc_unless_negative(&sd
->s_active
))
171 if (likely(!ignore_lockdep(sd
)))
172 rwsem_acquire_read(&sd
->dep_map
, 0, 1, _RET_IP_
);
177 * sysfs_put_active - put an active reference to sysfs_dirent
178 * @sd: sysfs_dirent to put an active reference to
180 * Put an active reference to @sd. This function is noop if @sd
183 void sysfs_put_active(struct sysfs_dirent
*sd
)
190 if (likely(!ignore_lockdep(sd
)))
191 rwsem_release(&sd
->dep_map
, 1, _RET_IP_
);
192 v
= atomic_dec_return(&sd
->s_active
);
193 if (likely(v
!= SD_DEACTIVATED_BIAS
))
196 /* atomic_dec_return() is a mb(), we'll always see the updated
199 complete(sd
->u
.completion
);
203 * sysfs_deactivate - deactivate sysfs_dirent
204 * @sd: sysfs_dirent to deactivate
206 * Deny new active references and drain existing ones.
208 static void sysfs_deactivate(struct sysfs_dirent
*sd
)
210 DECLARE_COMPLETION_ONSTACK(wait
);
213 BUG_ON(!(sd
->s_flags
& SYSFS_FLAG_REMOVED
));
215 if (!(sysfs_type(sd
) & SYSFS_ACTIVE_REF
))
218 sd
->u
.completion
= (void *)&wait
;
220 rwsem_acquire(&sd
->dep_map
, 0, 0, _RET_IP_
);
221 /* atomic_add_return() is a mb(), put_active() will always see
222 * the updated sd->u.completion.
224 v
= atomic_add_return(SD_DEACTIVATED_BIAS
, &sd
->s_active
);
226 if (v
!= SD_DEACTIVATED_BIAS
) {
227 lock_contended(&sd
->dep_map
, _RET_IP_
);
228 wait_for_completion(&wait
);
231 lock_acquired(&sd
->dep_map
, _RET_IP_
);
232 rwsem_release(&sd
->dep_map
, 1, _RET_IP_
);
235 static int sysfs_alloc_ino(unsigned int *pino
)
240 spin_lock(&sysfs_ino_lock
);
241 rc
= ida_get_new_above(&sysfs_ino_ida
, 2, &ino
);
242 spin_unlock(&sysfs_ino_lock
);
245 if (ida_pre_get(&sysfs_ino_ida
, GFP_KERNEL
))
254 static void sysfs_free_ino(unsigned int ino
)
256 spin_lock(&sysfs_ino_lock
);
257 ida_remove(&sysfs_ino_ida
, ino
);
258 spin_unlock(&sysfs_ino_lock
);
261 void release_sysfs_dirent(struct sysfs_dirent
* sd
)
263 struct sysfs_dirent
*parent_sd
;
266 /* Moving/renaming is always done while holding reference.
267 * sd->s_parent won't change beneath us.
269 parent_sd
= sd
->s_parent
;
271 if (sysfs_type(sd
) == SYSFS_KOBJ_LINK
)
272 sysfs_put(sd
->s_symlink
.target_sd
);
273 if (sysfs_type(sd
) & SYSFS_COPY_NAME
)
275 if (sd
->s_iattr
&& sd
->s_iattr
->ia_secdata
)
276 security_release_secctx(sd
->s_iattr
->ia_secdata
,
277 sd
->s_iattr
->ia_secdata_len
);
279 sysfs_free_ino(sd
->s_ino
);
280 kmem_cache_free(sysfs_dir_cachep
, sd
);
283 if (sd
&& atomic_dec_and_test(&sd
->s_count
))
287 static int sysfs_dentry_delete(const struct dentry
*dentry
)
289 struct sysfs_dirent
*sd
= dentry
->d_fsdata
;
290 return !(sd
&& !(sd
->s_flags
& SYSFS_FLAG_REMOVED
));
293 static int sysfs_dentry_revalidate(struct dentry
*dentry
, unsigned int flags
)
295 struct sysfs_dirent
*sd
;
299 if (flags
& LOOKUP_RCU
)
302 sd
= dentry
->d_fsdata
;
303 mutex_lock(&sysfs_mutex
);
305 /* The sysfs dirent has been deleted */
306 if (sd
->s_flags
& SYSFS_FLAG_REMOVED
)
309 /* The sysfs dirent has been moved? */
310 if (dentry
->d_parent
->d_fsdata
!= sd
->s_parent
)
313 /* The sysfs dirent has been renamed */
314 if (strcmp(dentry
->d_name
.name
, sd
->s_name
) != 0)
317 /* The sysfs dirent has been moved to a different namespace */
318 type
= KOBJ_NS_TYPE_NONE
;
320 type
= sysfs_ns_type(sd
->s_parent
);
321 if (type
!= KOBJ_NS_TYPE_NONE
&&
322 sysfs_info(dentry
->d_sb
)->ns
[type
] != sd
->s_ns
)
326 mutex_unlock(&sysfs_mutex
);
330 /* Remove the dentry from the dcache hashes.
331 * If this is a deleted dentry we use d_drop instead of d_delete
332 * so sysfs doesn't need to cope with negative dentries.
334 * If this is a dentry that has simply been renamed we
335 * use d_drop to remove it from the dcache lookup on its
336 * old parent. If this dentry persists later when a lookup
337 * is performed at its new name the dentry will be readded
338 * to the dcache hashes.
340 is_dir
= (sysfs_type(sd
) == SYSFS_DIR
);
341 mutex_unlock(&sysfs_mutex
);
343 /* If we have submounts we must allow the vfs caches
344 * to lie about the state of the filesystem to prevent
345 * leaks and other nasty things.
347 if (have_submounts(dentry
))
349 shrink_dcache_parent(dentry
);
355 static void sysfs_dentry_release(struct dentry
*dentry
)
357 sysfs_put(dentry
->d_fsdata
);
360 const struct dentry_operations sysfs_dentry_ops
= {
361 .d_revalidate
= sysfs_dentry_revalidate
,
362 .d_delete
= sysfs_dentry_delete
,
363 .d_release
= sysfs_dentry_release
,
366 struct sysfs_dirent
*sysfs_new_dirent(const char *name
, umode_t mode
, int type
)
368 char *dup_name
= NULL
;
369 struct sysfs_dirent
*sd
;
371 if (type
& SYSFS_COPY_NAME
) {
372 name
= dup_name
= kstrdup(name
, GFP_KERNEL
);
377 sd
= kmem_cache_zalloc(sysfs_dir_cachep
, GFP_KERNEL
);
381 if (sysfs_alloc_ino(&sd
->s_ino
))
384 atomic_set(&sd
->s_count
, 1);
385 atomic_set(&sd
->s_active
, 0);
394 kmem_cache_free(sysfs_dir_cachep
, sd
);
401 * sysfs_addrm_start - prepare for sysfs_dirent add/remove
402 * @acxt: pointer to sysfs_addrm_cxt to be used
403 * @parent_sd: parent sysfs_dirent
405 * This function is called when the caller is about to add or
406 * remove sysfs_dirent under @parent_sd. This function acquires
407 * sysfs_mutex. @acxt is used to keep and pass context to
408 * other addrm functions.
411 * Kernel thread context (may sleep). sysfs_mutex is locked on
414 void sysfs_addrm_start(struct sysfs_addrm_cxt
*acxt
,
415 struct sysfs_dirent
*parent_sd
)
417 memset(acxt
, 0, sizeof(*acxt
));
418 acxt
->parent_sd
= parent_sd
;
420 mutex_lock(&sysfs_mutex
);
424 * __sysfs_add_one - add sysfs_dirent to parent without warning
425 * @acxt: addrm context to use
426 * @sd: sysfs_dirent to be added
428 * Get @acxt->parent_sd and set sd->s_parent to it and increment
429 * nlink of parent inode if @sd is a directory and link into the
430 * children list of the parent.
432 * This function should be called between calls to
433 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
434 * passed the same @acxt as passed to sysfs_addrm_start().
437 * Determined by sysfs_addrm_start().
440 * 0 on success, -EEXIST if entry with the given name already
443 int __sysfs_add_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
445 struct sysfs_inode_attrs
*ps_iattr
;
448 if (!!sysfs_ns_type(acxt
->parent_sd
) != !!sd
->s_ns
) {
449 WARN(1, KERN_WARNING
"sysfs: ns %s in '%s' for '%s'\n",
450 sysfs_ns_type(acxt
->parent_sd
)? "required": "invalid",
451 acxt
->parent_sd
->s_name
, sd
->s_name
);
455 sd
->s_hash
= sysfs_name_hash(sd
->s_ns
, sd
->s_name
);
456 sd
->s_parent
= sysfs_get(acxt
->parent_sd
);
458 ret
= sysfs_link_sibling(sd
);
462 /* Update timestamps on the parent */
463 ps_iattr
= acxt
->parent_sd
->s_iattr
;
465 struct iattr
*ps_iattrs
= &ps_iattr
->ia_iattr
;
466 ps_iattrs
->ia_ctime
= ps_iattrs
->ia_mtime
= CURRENT_TIME
;
473 * sysfs_pathname - return full path to sysfs dirent
474 * @sd: sysfs_dirent whose path we want
475 * @path: caller allocated buffer of size PATH_MAX
477 * Gives the name "/" to the sysfs_root entry; any path returned
478 * is relative to wherever sysfs is mounted.
480 static char *sysfs_pathname(struct sysfs_dirent
*sd
, char *path
)
483 sysfs_pathname(sd
->s_parent
, path
);
484 strlcat(path
, "/", PATH_MAX
);
486 strlcat(path
, sd
->s_name
, PATH_MAX
);
491 * sysfs_add_one - add sysfs_dirent to parent
492 * @acxt: addrm context to use
493 * @sd: sysfs_dirent to be added
495 * Get @acxt->parent_sd and set sd->s_parent to it and increment
496 * nlink of parent inode if @sd is a directory and link into the
497 * children list of the parent.
499 * This function should be called between calls to
500 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
501 * passed the same @acxt as passed to sysfs_addrm_start().
504 * Determined by sysfs_addrm_start().
507 * 0 on success, -EEXIST if entry with the given name already
510 int sysfs_add_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
514 ret
= __sysfs_add_one(acxt
, sd
);
515 if (ret
== -EEXIST
) {
516 char *path
= kzalloc(PATH_MAX
, GFP_KERNEL
);
518 "sysfs: cannot create duplicate filename '%s'\n",
519 (path
== NULL
) ? sd
->s_name
520 : (sysfs_pathname(acxt
->parent_sd
, path
),
521 strlcat(path
, "/", PATH_MAX
),
522 strlcat(path
, sd
->s_name
, PATH_MAX
),
531 * sysfs_remove_one - remove sysfs_dirent from parent
532 * @acxt: addrm context to use
533 * @sd: sysfs_dirent to be removed
535 * Mark @sd removed and drop nlink of parent inode if @sd is a
536 * directory. @sd is unlinked from the children list.
538 * This function should be called between calls to
539 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
540 * passed the same @acxt as passed to sysfs_addrm_start().
543 * Determined by sysfs_addrm_start().
545 void sysfs_remove_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
547 struct sysfs_inode_attrs
*ps_iattr
;
549 BUG_ON(sd
->s_flags
& SYSFS_FLAG_REMOVED
);
551 sysfs_unlink_sibling(sd
);
553 /* Update timestamps on the parent */
554 ps_iattr
= acxt
->parent_sd
->s_iattr
;
556 struct iattr
*ps_iattrs
= &ps_iattr
->ia_iattr
;
557 ps_iattrs
->ia_ctime
= ps_iattrs
->ia_mtime
= CURRENT_TIME
;
560 sd
->s_flags
|= SYSFS_FLAG_REMOVED
;
561 sd
->u
.removed_list
= acxt
->removed
;
566 * sysfs_addrm_finish - finish up sysfs_dirent add/remove
567 * @acxt: addrm context to finish up
569 * Finish up sysfs_dirent add/remove. Resources acquired by
570 * sysfs_addrm_start() are released and removed sysfs_dirents are
574 * sysfs_mutex is released.
576 void sysfs_addrm_finish(struct sysfs_addrm_cxt
*acxt
)
578 /* release resources acquired by sysfs_addrm_start() */
579 mutex_unlock(&sysfs_mutex
);
581 /* kill removed sysfs_dirents */
582 while (acxt
->removed
) {
583 struct sysfs_dirent
*sd
= acxt
->removed
;
585 acxt
->removed
= sd
->u
.removed_list
;
587 sysfs_deactivate(sd
);
594 * sysfs_find_dirent - find sysfs_dirent with the given name
595 * @parent_sd: sysfs_dirent to search under
596 * @name: name to look for
598 * Look for sysfs_dirent with name @name under @parent_sd.
601 * mutex_lock(sysfs_mutex)
604 * Pointer to sysfs_dirent if found, NULL if not.
606 struct sysfs_dirent
*sysfs_find_dirent(struct sysfs_dirent
*parent_sd
,
608 const unsigned char *name
)
610 struct rb_node
*node
= parent_sd
->s_dir
.children
.rb_node
;
613 if (!!sysfs_ns_type(parent_sd
) != !!ns
) {
614 WARN(1, KERN_WARNING
"sysfs: ns %s in '%s' for '%s'\n",
615 sysfs_ns_type(parent_sd
)? "required": "invalid",
616 parent_sd
->s_name
, name
);
620 hash
= sysfs_name_hash(ns
, name
);
622 struct sysfs_dirent
*sd
;
625 sd
= to_sysfs_dirent(node
);
626 result
= sysfs_name_compare(hash
, ns
, name
, sd
);
628 node
= node
->rb_left
;
630 node
= node
->rb_right
;
638 * sysfs_get_dirent - find and get sysfs_dirent with the given name
639 * @parent_sd: sysfs_dirent to search under
640 * @name: name to look for
642 * Look for sysfs_dirent with name @name under @parent_sd and get
646 * Kernel thread context (may sleep). Grabs sysfs_mutex.
649 * Pointer to sysfs_dirent if found, NULL if not.
651 struct sysfs_dirent
*sysfs_get_dirent(struct sysfs_dirent
*parent_sd
,
653 const unsigned char *name
)
655 struct sysfs_dirent
*sd
;
657 mutex_lock(&sysfs_mutex
);
658 sd
= sysfs_find_dirent(parent_sd
, ns
, name
);
660 mutex_unlock(&sysfs_mutex
);
664 EXPORT_SYMBOL_GPL(sysfs_get_dirent
);
666 static int create_dir(struct kobject
*kobj
, struct sysfs_dirent
*parent_sd
,
667 enum kobj_ns_type type
, const void *ns
, const char *name
,
668 struct sysfs_dirent
**p_sd
)
670 umode_t mode
= S_IFDIR
| S_IRWXU
| S_IRUGO
| S_IXUGO
;
671 struct sysfs_addrm_cxt acxt
;
672 struct sysfs_dirent
*sd
;
676 sd
= sysfs_new_dirent(name
, mode
, SYSFS_DIR
);
680 sd
->s_flags
|= (type
<< SYSFS_NS_TYPE_SHIFT
);
682 sd
->s_dir
.kobj
= kobj
;
685 sysfs_addrm_start(&acxt
, parent_sd
);
686 rc
= sysfs_add_one(&acxt
, sd
);
687 sysfs_addrm_finish(&acxt
);
697 int sysfs_create_subdir(struct kobject
*kobj
, const char *name
,
698 struct sysfs_dirent
**p_sd
)
700 return create_dir(kobj
, kobj
->sd
,
701 KOBJ_NS_TYPE_NONE
, NULL
, name
, p_sd
);
705 * sysfs_read_ns_type: return associated ns_type
706 * @kobj: the kobject being queried
708 * Each kobject can be tagged with exactly one namespace type
709 * (i.e. network or user). Return the ns_type associated with
712 static enum kobj_ns_type
sysfs_read_ns_type(struct kobject
*kobj
)
714 const struct kobj_ns_type_operations
*ops
;
715 enum kobj_ns_type type
;
717 ops
= kobj_child_ns_ops(kobj
);
719 return KOBJ_NS_TYPE_NONE
;
722 BUG_ON(type
<= KOBJ_NS_TYPE_NONE
);
723 BUG_ON(type
>= KOBJ_NS_TYPES
);
724 BUG_ON(!kobj_ns_type_registered(type
));
730 * sysfs_create_dir - create a directory for an object.
731 * @kobj: object we're creating directory for.
733 int sysfs_create_dir(struct kobject
* kobj
)
735 enum kobj_ns_type type
;
736 struct sysfs_dirent
*parent_sd
, *sd
;
737 const void *ns
= NULL
;
743 parent_sd
= kobj
->parent
->sd
;
745 parent_sd
= &sysfs_root
;
750 if (sysfs_ns_type(parent_sd
))
751 ns
= kobj
->ktype
->namespace(kobj
);
752 type
= sysfs_read_ns_type(kobj
);
754 error
= create_dir(kobj
, parent_sd
, type
, ns
, kobject_name(kobj
), &sd
);
760 static struct dentry
* sysfs_lookup(struct inode
*dir
, struct dentry
*dentry
,
763 struct dentry
*ret
= NULL
;
764 struct dentry
*parent
= dentry
->d_parent
;
765 struct sysfs_dirent
*parent_sd
= parent
->d_fsdata
;
766 struct sysfs_dirent
*sd
;
768 enum kobj_ns_type type
;
771 mutex_lock(&sysfs_mutex
);
773 type
= sysfs_ns_type(parent_sd
);
774 ns
= sysfs_info(dir
->i_sb
)->ns
[type
];
776 sd
= sysfs_find_dirent(parent_sd
, ns
, dentry
->d_name
.name
);
780 ret
= ERR_PTR(-ENOENT
);
783 dentry
->d_fsdata
= sysfs_get(sd
);
785 /* attach dentry and inode */
786 inode
= sysfs_get_inode(dir
->i_sb
, sd
);
788 ret
= ERR_PTR(-ENOMEM
);
792 /* instantiate and hash dentry */
793 ret
= d_materialise_unique(dentry
, inode
);
795 mutex_unlock(&sysfs_mutex
);
799 const struct inode_operations sysfs_dir_inode_operations
= {
800 .lookup
= sysfs_lookup
,
801 .permission
= sysfs_permission
,
802 .setattr
= sysfs_setattr
,
803 .getattr
= sysfs_getattr
,
804 .setxattr
= sysfs_setxattr
,
807 static void remove_dir(struct sysfs_dirent
*sd
)
809 struct sysfs_addrm_cxt acxt
;
811 sysfs_addrm_start(&acxt
, sd
->s_parent
);
812 sysfs_remove_one(&acxt
, sd
);
813 sysfs_addrm_finish(&acxt
);
816 void sysfs_remove_subdir(struct sysfs_dirent
*sd
)
822 static void __sysfs_remove_dir(struct sysfs_dirent
*dir_sd
)
824 struct sysfs_addrm_cxt acxt
;
830 pr_debug("sysfs %s: removing dir\n", dir_sd
->s_name
);
831 sysfs_addrm_start(&acxt
, dir_sd
);
832 pos
= rb_first(&dir_sd
->s_dir
.children
);
834 struct sysfs_dirent
*sd
= to_sysfs_dirent(pos
);
836 if (sysfs_type(sd
) != SYSFS_DIR
)
837 sysfs_remove_one(&acxt
, sd
);
839 sysfs_addrm_finish(&acxt
);
845 * sysfs_remove_dir - remove an object's directory.
848 * The only thing special about this is that we remove any files in
849 * the directory before we remove the directory, and we've inlined
850 * what used to be sysfs_rmdir() below, instead of calling separately.
853 void sysfs_remove_dir(struct kobject
* kobj
)
855 struct sysfs_dirent
*sd
= kobj
->sd
;
857 spin_lock(&sysfs_assoc_lock
);
859 spin_unlock(&sysfs_assoc_lock
);
861 __sysfs_remove_dir(sd
);
864 int sysfs_rename(struct sysfs_dirent
*sd
,
865 struct sysfs_dirent
*new_parent_sd
, const void *new_ns
,
866 const char *new_name
)
870 mutex_lock(&sysfs_mutex
);
873 if ((sd
->s_parent
== new_parent_sd
) && (sd
->s_ns
== new_ns
) &&
874 (strcmp(sd
->s_name
, new_name
) == 0))
875 goto out
; /* nothing to rename */
878 if (sysfs_find_dirent(new_parent_sd
, new_ns
, new_name
))
881 /* rename sysfs_dirent */
882 if (strcmp(sd
->s_name
, new_name
) != 0) {
884 new_name
= kstrdup(new_name
, GFP_KERNEL
);
889 sd
->s_name
= new_name
;
892 /* Move to the appropriate place in the appropriate directories rbtree. */
893 sysfs_unlink_sibling(sd
);
894 sysfs_get(new_parent_sd
);
895 sysfs_put(sd
->s_parent
);
897 sd
->s_hash
= sysfs_name_hash(sd
->s_ns
, sd
->s_name
);
898 sd
->s_parent
= new_parent_sd
;
899 sysfs_link_sibling(sd
);
903 mutex_unlock(&sysfs_mutex
);
907 int sysfs_rename_dir(struct kobject
*kobj
, const char *new_name
)
909 struct sysfs_dirent
*parent_sd
= kobj
->sd
->s_parent
;
910 const void *new_ns
= NULL
;
912 if (sysfs_ns_type(parent_sd
))
913 new_ns
= kobj
->ktype
->namespace(kobj
);
915 return sysfs_rename(kobj
->sd
, parent_sd
, new_ns
, new_name
);
918 int sysfs_move_dir(struct kobject
*kobj
, struct kobject
*new_parent_kobj
)
920 struct sysfs_dirent
*sd
= kobj
->sd
;
921 struct sysfs_dirent
*new_parent_sd
;
922 const void *new_ns
= NULL
;
924 BUG_ON(!sd
->s_parent
);
925 if (sysfs_ns_type(sd
->s_parent
))
926 new_ns
= kobj
->ktype
->namespace(kobj
);
927 new_parent_sd
= new_parent_kobj
&& new_parent_kobj
->sd
?
928 new_parent_kobj
->sd
: &sysfs_root
;
930 return sysfs_rename(sd
, new_parent_sd
, new_ns
, sd
->s_name
);
933 /* Relationship between s_mode and the DT_xxx types */
934 static inline unsigned char dt_type(struct sysfs_dirent
*sd
)
936 return (sd
->s_mode
>> 12) & 15;
939 static int sysfs_dir_release(struct inode
*inode
, struct file
*filp
)
941 sysfs_put(filp
->private_data
);
945 static struct sysfs_dirent
*sysfs_dir_pos(const void *ns
,
946 struct sysfs_dirent
*parent_sd
, loff_t hash
, struct sysfs_dirent
*pos
)
949 int valid
= !(pos
->s_flags
& SYSFS_FLAG_REMOVED
) &&
950 pos
->s_parent
== parent_sd
&&
956 if (!pos
&& (hash
> 1) && (hash
< INT_MAX
)) {
957 struct rb_node
*node
= parent_sd
->s_dir
.children
.rb_node
;
959 pos
= to_sysfs_dirent(node
);
961 if (hash
< pos
->s_hash
)
962 node
= node
->rb_left
;
963 else if (hash
> pos
->s_hash
)
964 node
= node
->rb_right
;
969 /* Skip over entries in the wrong namespace */
970 while (pos
&& pos
->s_ns
!= ns
) {
971 struct rb_node
*node
= rb_next(&pos
->s_rb
);
975 pos
= to_sysfs_dirent(node
);
980 static struct sysfs_dirent
*sysfs_dir_next_pos(const void *ns
,
981 struct sysfs_dirent
*parent_sd
, ino_t ino
, struct sysfs_dirent
*pos
)
983 pos
= sysfs_dir_pos(ns
, parent_sd
, ino
, pos
);
985 struct rb_node
*node
= rb_next(&pos
->s_rb
);
989 pos
= to_sysfs_dirent(node
);
990 } while (pos
&& pos
->s_ns
!= ns
);
994 static int sysfs_readdir(struct file
* filp
, void * dirent
, filldir_t filldir
)
996 struct dentry
*dentry
= filp
->f_path
.dentry
;
997 struct sysfs_dirent
* parent_sd
= dentry
->d_fsdata
;
998 struct sysfs_dirent
*pos
= filp
->private_data
;
999 enum kobj_ns_type type
;
1004 type
= sysfs_ns_type(parent_sd
);
1005 ns
= sysfs_info(dentry
->d_sb
)->ns
[type
];
1007 if (filp
->f_pos
== 0) {
1008 ino
= parent_sd
->s_ino
;
1009 if (filldir(dirent
, ".", 1, filp
->f_pos
, ino
, DT_DIR
) == 0)
1014 if (filp
->f_pos
== 1) {
1015 if (parent_sd
->s_parent
)
1016 ino
= parent_sd
->s_parent
->s_ino
;
1018 ino
= parent_sd
->s_ino
;
1019 if (filldir(dirent
, "..", 2, filp
->f_pos
, ino
, DT_DIR
) == 0)
1024 mutex_lock(&sysfs_mutex
);
1026 for (pos
= sysfs_dir_pos(ns
, parent_sd
, filp
->f_pos
, pos
);
1028 pos
= sysfs_dir_next_pos(ns
, parent_sd
, filp
->f_pos
, pos
)) {
1036 type
= dt_type(pos
);
1037 off
= filp
->f_pos
= pos
->s_hash
;
1038 filp
->private_data
= sysfs_get(pos
);
1040 mutex_unlock(&sysfs_mutex
);
1041 ret
= filldir(dirent
, name
, len
, off
, ino
, type
);
1042 mutex_lock(&sysfs_mutex
);
1046 mutex_unlock(&sysfs_mutex
);
1048 /* don't reference last entry if its refcount is dropped */
1050 filp
->private_data
= NULL
;
1052 /* EOF and not changed as 0 or 1 in read/write path */
1053 if (off
== filp
->f_pos
&& off
> 1)
1054 filp
->f_pos
= INT_MAX
;
1059 static loff_t
sysfs_dir_llseek(struct file
*file
, loff_t offset
, int whence
)
1061 struct inode
*inode
= file_inode(file
);
1064 mutex_lock(&inode
->i_mutex
);
1065 ret
= generic_file_llseek(file
, offset
, whence
);
1066 mutex_unlock(&inode
->i_mutex
);
1071 const struct file_operations sysfs_dir_operations
= {
1072 .read
= generic_read_dir
,
1073 .readdir
= sysfs_readdir
,
1074 .release
= sysfs_dir_release
,
1075 .llseek
= sysfs_dir_llseek
,