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
);
136 * sysfs_get_active - get an active reference to sysfs_dirent
137 * @sd: sysfs_dirent to get an active reference to
139 * Get an active reference of @sd. This function is noop if @sd
143 * Pointer to @sd on success, NULL on failure.
145 struct sysfs_dirent
*sysfs_get_active(struct sysfs_dirent
*sd
)
153 v
= atomic_read(&sd
->s_active
);
157 t
= atomic_cmpxchg(&sd
->s_active
, v
, v
+ 1);
158 if (likely(t
== v
)) {
159 rwsem_acquire_read(&sd
->dep_map
, 0, 1, _RET_IP_
);
170 * sysfs_put_active - put an active reference to sysfs_dirent
171 * @sd: sysfs_dirent to put an active reference to
173 * Put an active reference to @sd. This function is noop if @sd
176 void sysfs_put_active(struct sysfs_dirent
*sd
)
183 rwsem_release(&sd
->dep_map
, 1, _RET_IP_
);
184 v
= atomic_dec_return(&sd
->s_active
);
185 if (likely(v
!= SD_DEACTIVATED_BIAS
))
188 /* atomic_dec_return() is a mb(), we'll always see the updated
191 complete(sd
->u
.completion
);
195 * sysfs_deactivate - deactivate sysfs_dirent
196 * @sd: sysfs_dirent to deactivate
198 * Deny new active references and drain existing ones.
200 static void sysfs_deactivate(struct sysfs_dirent
*sd
)
202 DECLARE_COMPLETION_ONSTACK(wait
);
205 BUG_ON(!(sd
->s_flags
& SYSFS_FLAG_REMOVED
));
207 if (!(sysfs_type(sd
) & SYSFS_ACTIVE_REF
))
210 sd
->u
.completion
= (void *)&wait
;
212 rwsem_acquire(&sd
->dep_map
, 0, 0, _RET_IP_
);
213 /* atomic_add_return() is a mb(), put_active() will always see
214 * the updated sd->u.completion.
216 v
= atomic_add_return(SD_DEACTIVATED_BIAS
, &sd
->s_active
);
218 if (v
!= SD_DEACTIVATED_BIAS
) {
219 lock_contended(&sd
->dep_map
, _RET_IP_
);
220 wait_for_completion(&wait
);
223 lock_acquired(&sd
->dep_map
, _RET_IP_
);
224 rwsem_release(&sd
->dep_map
, 1, _RET_IP_
);
227 static int sysfs_alloc_ino(unsigned int *pino
)
232 spin_lock(&sysfs_ino_lock
);
233 rc
= ida_get_new_above(&sysfs_ino_ida
, 2, &ino
);
234 spin_unlock(&sysfs_ino_lock
);
237 if (ida_pre_get(&sysfs_ino_ida
, GFP_KERNEL
))
246 static void sysfs_free_ino(unsigned int ino
)
248 spin_lock(&sysfs_ino_lock
);
249 ida_remove(&sysfs_ino_ida
, ino
);
250 spin_unlock(&sysfs_ino_lock
);
253 void release_sysfs_dirent(struct sysfs_dirent
* sd
)
255 struct sysfs_dirent
*parent_sd
;
258 /* Moving/renaming is always done while holding reference.
259 * sd->s_parent won't change beneath us.
261 parent_sd
= sd
->s_parent
;
263 if (sysfs_type(sd
) == SYSFS_KOBJ_LINK
)
264 sysfs_put(sd
->s_symlink
.target_sd
);
265 if (sysfs_type(sd
) & SYSFS_COPY_NAME
)
267 if (sd
->s_iattr
&& sd
->s_iattr
->ia_secdata
)
268 security_release_secctx(sd
->s_iattr
->ia_secdata
,
269 sd
->s_iattr
->ia_secdata_len
);
271 sysfs_free_ino(sd
->s_ino
);
272 kmem_cache_free(sysfs_dir_cachep
, sd
);
275 if (sd
&& atomic_dec_and_test(&sd
->s_count
))
279 static int sysfs_dentry_delete(const struct dentry
*dentry
)
281 struct sysfs_dirent
*sd
= dentry
->d_fsdata
;
282 return !!(sd
->s_flags
& SYSFS_FLAG_REMOVED
);
285 static int sysfs_dentry_revalidate(struct dentry
*dentry
, struct nameidata
*nd
)
287 struct sysfs_dirent
*sd
;
290 if (nd
->flags
& LOOKUP_RCU
)
293 sd
= dentry
->d_fsdata
;
294 mutex_lock(&sysfs_mutex
);
296 /* The sysfs dirent has been deleted */
297 if (sd
->s_flags
& SYSFS_FLAG_REMOVED
)
300 /* The sysfs dirent has been moved? */
301 if (dentry
->d_parent
->d_fsdata
!= sd
->s_parent
)
304 /* The sysfs dirent has been renamed */
305 if (strcmp(dentry
->d_name
.name
, sd
->s_name
) != 0)
308 mutex_unlock(&sysfs_mutex
);
312 /* Remove the dentry from the dcache hashes.
313 * If this is a deleted dentry we use d_drop instead of d_delete
314 * so sysfs doesn't need to cope with negative dentries.
316 * If this is a dentry that has simply been renamed we
317 * use d_drop to remove it from the dcache lookup on its
318 * old parent. If this dentry persists later when a lookup
319 * is performed at its new name the dentry will be readded
320 * to the dcache hashes.
322 is_dir
= (sysfs_type(sd
) == SYSFS_DIR
);
323 mutex_unlock(&sysfs_mutex
);
325 /* If we have submounts we must allow the vfs caches
326 * to lie about the state of the filesystem to prevent
327 * leaks and other nasty things.
329 if (have_submounts(dentry
))
331 shrink_dcache_parent(dentry
);
337 static void sysfs_dentry_iput(struct dentry
*dentry
, struct inode
*inode
)
339 struct sysfs_dirent
* sd
= dentry
->d_fsdata
;
345 static const struct dentry_operations sysfs_dentry_ops
= {
346 .d_revalidate
= sysfs_dentry_revalidate
,
347 .d_delete
= sysfs_dentry_delete
,
348 .d_iput
= sysfs_dentry_iput
,
351 struct sysfs_dirent
*sysfs_new_dirent(const char *name
, umode_t mode
, int type
)
353 char *dup_name
= NULL
;
354 struct sysfs_dirent
*sd
;
356 if (type
& SYSFS_COPY_NAME
) {
357 name
= dup_name
= kstrdup(name
, GFP_KERNEL
);
362 sd
= kmem_cache_zalloc(sysfs_dir_cachep
, GFP_KERNEL
);
366 if (sysfs_alloc_ino(&sd
->s_ino
))
369 atomic_set(&sd
->s_count
, 1);
370 atomic_set(&sd
->s_active
, 0);
379 kmem_cache_free(sysfs_dir_cachep
, sd
);
386 * sysfs_addrm_start - prepare for sysfs_dirent add/remove
387 * @acxt: pointer to sysfs_addrm_cxt to be used
388 * @parent_sd: parent sysfs_dirent
390 * This function is called when the caller is about to add or
391 * remove sysfs_dirent under @parent_sd. This function acquires
392 * sysfs_mutex. @acxt is used to keep and pass context to
393 * other addrm functions.
396 * Kernel thread context (may sleep). sysfs_mutex is locked on
399 void sysfs_addrm_start(struct sysfs_addrm_cxt
*acxt
,
400 struct sysfs_dirent
*parent_sd
)
402 memset(acxt
, 0, sizeof(*acxt
));
403 acxt
->parent_sd
= parent_sd
;
405 mutex_lock(&sysfs_mutex
);
409 * __sysfs_add_one - add sysfs_dirent to parent without warning
410 * @acxt: addrm context to use
411 * @sd: sysfs_dirent to be added
413 * Get @acxt->parent_sd and set sd->s_parent to it and increment
414 * nlink of parent inode if @sd is a directory and link into the
415 * children list of the parent.
417 * This function should be called between calls to
418 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
419 * passed the same @acxt as passed to sysfs_addrm_start().
422 * Determined by sysfs_addrm_start().
425 * 0 on success, -EEXIST if entry with the given name already
428 int __sysfs_add_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
430 struct sysfs_inode_attrs
*ps_iattr
;
433 if (!!sysfs_ns_type(acxt
->parent_sd
) != !!sd
->s_ns
) {
434 WARN(1, KERN_WARNING
"sysfs: ns %s in '%s' for '%s'\n",
435 sysfs_ns_type(acxt
->parent_sd
)? "required": "invalid",
436 acxt
->parent_sd
->s_name
, sd
->s_name
);
440 sd
->s_hash
= sysfs_name_hash(sd
->s_ns
, sd
->s_name
);
441 sd
->s_parent
= sysfs_get(acxt
->parent_sd
);
443 ret
= sysfs_link_sibling(sd
);
447 /* Update timestamps on the parent */
448 ps_iattr
= acxt
->parent_sd
->s_iattr
;
450 struct iattr
*ps_iattrs
= &ps_iattr
->ia_iattr
;
451 ps_iattrs
->ia_ctime
= ps_iattrs
->ia_mtime
= CURRENT_TIME
;
458 * sysfs_pathname - return full path to sysfs dirent
459 * @sd: sysfs_dirent whose path we want
460 * @path: caller allocated buffer
462 * Gives the name "/" to the sysfs_root entry; any path returned
463 * is relative to wherever sysfs is mounted.
465 * XXX: does no error checking on @path size
467 static char *sysfs_pathname(struct sysfs_dirent
*sd
, char *path
)
470 sysfs_pathname(sd
->s_parent
, path
);
473 strcat(path
, sd
->s_name
);
478 * sysfs_add_one - add sysfs_dirent to parent
479 * @acxt: addrm context to use
480 * @sd: sysfs_dirent to be added
482 * Get @acxt->parent_sd and set sd->s_parent to it and increment
483 * nlink of parent inode if @sd is a directory and link into the
484 * children list of the parent.
486 * This function should be called between calls to
487 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
488 * passed the same @acxt as passed to sysfs_addrm_start().
491 * Determined by sysfs_addrm_start().
494 * 0 on success, -EEXIST if entry with the given name already
497 int sysfs_add_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
501 ret
= __sysfs_add_one(acxt
, sd
);
502 if (ret
== -EEXIST
) {
503 char *path
= kzalloc(PATH_MAX
, GFP_KERNEL
);
505 "sysfs: cannot create duplicate filename '%s'\n",
506 (path
== NULL
) ? sd
->s_name
:
507 strcat(strcat(sysfs_pathname(acxt
->parent_sd
, path
), "/"),
516 * sysfs_remove_one - remove sysfs_dirent from parent
517 * @acxt: addrm context to use
518 * @sd: sysfs_dirent to be removed
520 * Mark @sd removed and drop nlink of parent inode if @sd is a
521 * directory. @sd is unlinked from the children list.
523 * This function should be called between calls to
524 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
525 * passed the same @acxt as passed to sysfs_addrm_start().
528 * Determined by sysfs_addrm_start().
530 void sysfs_remove_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
532 struct sysfs_inode_attrs
*ps_iattr
;
534 BUG_ON(sd
->s_flags
& SYSFS_FLAG_REMOVED
);
536 sysfs_unlink_sibling(sd
);
538 /* Update timestamps on the parent */
539 ps_iattr
= acxt
->parent_sd
->s_iattr
;
541 struct iattr
*ps_iattrs
= &ps_iattr
->ia_iattr
;
542 ps_iattrs
->ia_ctime
= ps_iattrs
->ia_mtime
= CURRENT_TIME
;
545 sd
->s_flags
|= SYSFS_FLAG_REMOVED
;
546 sd
->u
.removed_list
= acxt
->removed
;
551 * sysfs_addrm_finish - finish up sysfs_dirent add/remove
552 * @acxt: addrm context to finish up
554 * Finish up sysfs_dirent add/remove. Resources acquired by
555 * sysfs_addrm_start() are released and removed sysfs_dirents are
559 * sysfs_mutex is released.
561 void sysfs_addrm_finish(struct sysfs_addrm_cxt
*acxt
)
563 /* release resources acquired by sysfs_addrm_start() */
564 mutex_unlock(&sysfs_mutex
);
566 /* kill removed sysfs_dirents */
567 while (acxt
->removed
) {
568 struct sysfs_dirent
*sd
= acxt
->removed
;
570 acxt
->removed
= sd
->u
.removed_list
;
572 sysfs_deactivate(sd
);
579 * sysfs_find_dirent - find sysfs_dirent with the given name
580 * @parent_sd: sysfs_dirent to search under
581 * @name: name to look for
583 * Look for sysfs_dirent with name @name under @parent_sd.
586 * mutex_lock(sysfs_mutex)
589 * Pointer to sysfs_dirent if found, NULL if not.
591 struct sysfs_dirent
*sysfs_find_dirent(struct sysfs_dirent
*parent_sd
,
593 const unsigned char *name
)
595 struct rb_node
*node
= parent_sd
->s_dir
.children
.rb_node
;
598 if (!!sysfs_ns_type(parent_sd
) != !!ns
) {
599 WARN(1, KERN_WARNING
"sysfs: ns %s in '%s' for '%s'\n",
600 sysfs_ns_type(parent_sd
)? "required": "invalid",
601 parent_sd
->s_name
, name
);
605 hash
= sysfs_name_hash(ns
, name
);
607 struct sysfs_dirent
*sd
;
610 sd
= to_sysfs_dirent(node
);
611 result
= sysfs_name_compare(hash
, ns
, name
, sd
);
613 node
= node
->rb_left
;
615 node
= node
->rb_right
;
623 * sysfs_get_dirent - find and get sysfs_dirent with the given name
624 * @parent_sd: sysfs_dirent to search under
625 * @name: name to look for
627 * Look for sysfs_dirent with name @name under @parent_sd and get
631 * Kernel thread context (may sleep). Grabs sysfs_mutex.
634 * Pointer to sysfs_dirent if found, NULL if not.
636 struct sysfs_dirent
*sysfs_get_dirent(struct sysfs_dirent
*parent_sd
,
638 const unsigned char *name
)
640 struct sysfs_dirent
*sd
;
642 mutex_lock(&sysfs_mutex
);
643 sd
= sysfs_find_dirent(parent_sd
, ns
, name
);
645 mutex_unlock(&sysfs_mutex
);
649 EXPORT_SYMBOL_GPL(sysfs_get_dirent
);
651 static int create_dir(struct kobject
*kobj
, struct sysfs_dirent
*parent_sd
,
652 enum kobj_ns_type type
, const void *ns
, const char *name
,
653 struct sysfs_dirent
**p_sd
)
655 umode_t mode
= S_IFDIR
| S_IRWXU
| S_IRUGO
| S_IXUGO
;
656 struct sysfs_addrm_cxt acxt
;
657 struct sysfs_dirent
*sd
;
661 sd
= sysfs_new_dirent(name
, mode
, SYSFS_DIR
);
665 sd
->s_flags
|= (type
<< SYSFS_NS_TYPE_SHIFT
);
667 sd
->s_dir
.kobj
= kobj
;
670 sysfs_addrm_start(&acxt
, parent_sd
);
671 rc
= sysfs_add_one(&acxt
, sd
);
672 sysfs_addrm_finish(&acxt
);
682 int sysfs_create_subdir(struct kobject
*kobj
, const char *name
,
683 struct sysfs_dirent
**p_sd
)
685 return create_dir(kobj
, kobj
->sd
,
686 KOBJ_NS_TYPE_NONE
, NULL
, name
, p_sd
);
690 * sysfs_read_ns_type: return associated ns_type
691 * @kobj: the kobject being queried
693 * Each kobject can be tagged with exactly one namespace type
694 * (i.e. network or user). Return the ns_type associated with
697 static enum kobj_ns_type
sysfs_read_ns_type(struct kobject
*kobj
)
699 const struct kobj_ns_type_operations
*ops
;
700 enum kobj_ns_type type
;
702 ops
= kobj_child_ns_ops(kobj
);
704 return KOBJ_NS_TYPE_NONE
;
707 BUG_ON(type
<= KOBJ_NS_TYPE_NONE
);
708 BUG_ON(type
>= KOBJ_NS_TYPES
);
709 BUG_ON(!kobj_ns_type_registered(type
));
715 * sysfs_create_dir - create a directory for an object.
716 * @kobj: object we're creating directory for.
718 int sysfs_create_dir(struct kobject
* kobj
)
720 enum kobj_ns_type type
;
721 struct sysfs_dirent
*parent_sd
, *sd
;
722 const void *ns
= NULL
;
728 parent_sd
= kobj
->parent
->sd
;
730 parent_sd
= &sysfs_root
;
732 if (sysfs_ns_type(parent_sd
))
733 ns
= kobj
->ktype
->namespace(kobj
);
734 type
= sysfs_read_ns_type(kobj
);
736 error
= create_dir(kobj
, parent_sd
, type
, ns
, kobject_name(kobj
), &sd
);
742 static struct dentry
* sysfs_lookup(struct inode
*dir
, struct dentry
*dentry
,
743 struct nameidata
*nd
)
745 struct dentry
*ret
= NULL
;
746 struct dentry
*parent
= dentry
->d_parent
;
747 struct sysfs_dirent
*parent_sd
= parent
->d_fsdata
;
748 struct sysfs_dirent
*sd
;
750 enum kobj_ns_type type
;
753 mutex_lock(&sysfs_mutex
);
755 type
= sysfs_ns_type(parent_sd
);
756 ns
= sysfs_info(dir
->i_sb
)->ns
[type
];
758 sd
= sysfs_find_dirent(parent_sd
, ns
, dentry
->d_name
.name
);
762 ret
= ERR_PTR(-ENOENT
);
766 /* attach dentry and inode */
767 inode
= sysfs_get_inode(dir
->i_sb
, sd
);
769 ret
= ERR_PTR(-ENOMEM
);
773 /* instantiate and hash dentry */
774 ret
= d_find_alias(inode
);
776 d_set_d_op(dentry
, &sysfs_dentry_ops
);
777 dentry
->d_fsdata
= sysfs_get(sd
);
778 d_add(dentry
, inode
);
785 mutex_unlock(&sysfs_mutex
);
789 const struct inode_operations sysfs_dir_inode_operations
= {
790 .lookup
= sysfs_lookup
,
791 .permission
= sysfs_permission
,
792 .setattr
= sysfs_setattr
,
793 .getattr
= sysfs_getattr
,
794 .setxattr
= sysfs_setxattr
,
797 static void remove_dir(struct sysfs_dirent
*sd
)
799 struct sysfs_addrm_cxt acxt
;
801 sysfs_addrm_start(&acxt
, sd
->s_parent
);
802 sysfs_remove_one(&acxt
, sd
);
803 sysfs_addrm_finish(&acxt
);
806 void sysfs_remove_subdir(struct sysfs_dirent
*sd
)
812 static void __sysfs_remove_dir(struct sysfs_dirent
*dir_sd
)
814 struct sysfs_addrm_cxt acxt
;
820 pr_debug("sysfs %s: removing dir\n", dir_sd
->s_name
);
821 sysfs_addrm_start(&acxt
, dir_sd
);
822 pos
= rb_first(&dir_sd
->s_dir
.children
);
824 struct sysfs_dirent
*sd
= to_sysfs_dirent(pos
);
826 if (sysfs_type(sd
) != SYSFS_DIR
)
827 sysfs_remove_one(&acxt
, sd
);
829 sysfs_addrm_finish(&acxt
);
835 * sysfs_remove_dir - remove an object's directory.
838 * The only thing special about this is that we remove any files in
839 * the directory before we remove the directory, and we've inlined
840 * what used to be sysfs_rmdir() below, instead of calling separately.
843 void sysfs_remove_dir(struct kobject
* kobj
)
845 struct sysfs_dirent
*sd
= kobj
->sd
;
847 spin_lock(&sysfs_assoc_lock
);
849 spin_unlock(&sysfs_assoc_lock
);
851 __sysfs_remove_dir(sd
);
854 int sysfs_rename(struct sysfs_dirent
*sd
,
855 struct sysfs_dirent
*new_parent_sd
, const void *new_ns
,
856 const char *new_name
)
858 const char *dup_name
= NULL
;
861 mutex_lock(&sysfs_mutex
);
864 if ((sd
->s_parent
== new_parent_sd
) && (sd
->s_ns
== new_ns
) &&
865 (strcmp(sd
->s_name
, new_name
) == 0))
866 goto out
; /* nothing to rename */
869 if (sysfs_find_dirent(new_parent_sd
, new_ns
, new_name
))
872 /* rename sysfs_dirent */
873 if (strcmp(sd
->s_name
, new_name
) != 0) {
875 new_name
= dup_name
= kstrdup(new_name
, GFP_KERNEL
);
879 dup_name
= sd
->s_name
;
880 sd
->s_name
= new_name
;
883 /* Move to the appropriate place in the appropriate directories rbtree. */
884 sysfs_unlink_sibling(sd
);
885 sysfs_get(new_parent_sd
);
886 sysfs_put(sd
->s_parent
);
888 sd
->s_hash
= sysfs_name_hash(sd
->s_ns
, sd
->s_name
);
889 sd
->s_parent
= new_parent_sd
;
890 sysfs_link_sibling(sd
);
894 mutex_unlock(&sysfs_mutex
);
899 int sysfs_rename_dir(struct kobject
*kobj
, const char *new_name
)
901 struct sysfs_dirent
*parent_sd
= kobj
->sd
->s_parent
;
902 const void *new_ns
= NULL
;
904 if (sysfs_ns_type(parent_sd
))
905 new_ns
= kobj
->ktype
->namespace(kobj
);
907 return sysfs_rename(kobj
->sd
, parent_sd
, new_ns
, new_name
);
910 int sysfs_move_dir(struct kobject
*kobj
, struct kobject
*new_parent_kobj
)
912 struct sysfs_dirent
*sd
= kobj
->sd
;
913 struct sysfs_dirent
*new_parent_sd
;
914 const void *new_ns
= NULL
;
916 BUG_ON(!sd
->s_parent
);
917 if (sysfs_ns_type(sd
->s_parent
))
918 new_ns
= kobj
->ktype
->namespace(kobj
);
919 new_parent_sd
= new_parent_kobj
&& new_parent_kobj
->sd
?
920 new_parent_kobj
->sd
: &sysfs_root
;
922 return sysfs_rename(sd
, new_parent_sd
, new_ns
, sd
->s_name
);
925 /* Relationship between s_mode and the DT_xxx types */
926 static inline unsigned char dt_type(struct sysfs_dirent
*sd
)
928 return (sd
->s_mode
>> 12) & 15;
931 static int sysfs_dir_release(struct inode
*inode
, struct file
*filp
)
933 sysfs_put(filp
->private_data
);
937 static struct sysfs_dirent
*sysfs_dir_pos(const void *ns
,
938 struct sysfs_dirent
*parent_sd
, loff_t hash
, struct sysfs_dirent
*pos
)
941 int valid
= !(pos
->s_flags
& SYSFS_FLAG_REMOVED
) &&
942 pos
->s_parent
== parent_sd
&&
948 if (!pos
&& (hash
> 1) && (hash
< INT_MAX
)) {
949 struct rb_node
*node
= parent_sd
->s_dir
.children
.rb_node
;
951 pos
= to_sysfs_dirent(node
);
953 if (hash
< pos
->s_hash
)
954 node
= node
->rb_left
;
955 else if (hash
> pos
->s_hash
)
956 node
= node
->rb_right
;
961 /* Skip over entries in the wrong namespace */
962 while (pos
&& pos
->s_ns
!= ns
) {
963 struct rb_node
*node
= rb_next(&pos
->s_rb
);
967 pos
= to_sysfs_dirent(node
);
972 static struct sysfs_dirent
*sysfs_dir_next_pos(const void *ns
,
973 struct sysfs_dirent
*parent_sd
, ino_t ino
, struct sysfs_dirent
*pos
)
975 pos
= sysfs_dir_pos(ns
, parent_sd
, ino
, pos
);
977 struct rb_node
*node
= rb_next(&pos
->s_rb
);
981 pos
= to_sysfs_dirent(node
);
982 } while (pos
&& pos
->s_ns
!= ns
);
986 static int sysfs_readdir(struct file
* filp
, void * dirent
, filldir_t filldir
)
988 struct dentry
*dentry
= filp
->f_path
.dentry
;
989 struct sysfs_dirent
* parent_sd
= dentry
->d_fsdata
;
990 struct sysfs_dirent
*pos
= filp
->private_data
;
991 enum kobj_ns_type type
;
995 type
= sysfs_ns_type(parent_sd
);
996 ns
= sysfs_info(dentry
->d_sb
)->ns
[type
];
998 if (filp
->f_pos
== 0) {
999 ino
= parent_sd
->s_ino
;
1000 if (filldir(dirent
, ".", 1, filp
->f_pos
, ino
, DT_DIR
) == 0)
1003 if (filp
->f_pos
== 1) {
1004 if (parent_sd
->s_parent
)
1005 ino
= parent_sd
->s_parent
->s_ino
;
1007 ino
= parent_sd
->s_ino
;
1008 if (filldir(dirent
, "..", 2, filp
->f_pos
, ino
, DT_DIR
) == 0)
1011 mutex_lock(&sysfs_mutex
);
1012 for (pos
= sysfs_dir_pos(ns
, parent_sd
, filp
->f_pos
, pos
);
1014 pos
= sysfs_dir_next_pos(ns
, parent_sd
, filp
->f_pos
, pos
)) {
1022 type
= dt_type(pos
);
1023 filp
->f_pos
= pos
->s_hash
;
1024 filp
->private_data
= sysfs_get(pos
);
1026 mutex_unlock(&sysfs_mutex
);
1027 ret
= filldir(dirent
, name
, len
, filp
->f_pos
, ino
, type
);
1028 mutex_lock(&sysfs_mutex
);
1032 mutex_unlock(&sysfs_mutex
);
1033 if ((filp
->f_pos
> 1) && !pos
) { /* EOF */
1034 filp
->f_pos
= INT_MAX
;
1035 filp
->private_data
= NULL
;
1041 const struct file_operations sysfs_dir_operations
= {
1042 .read
= generic_read_dir
,
1043 .readdir
= sysfs_readdir
,
1044 .release
= sysfs_dir_release
,
1045 .llseek
= generic_file_llseek
,