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_sibling - 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 WARN(!(sd->s_flags & SYSFS_FLAG_REMOVED),
272 "sysfs: free using entry: %s/%s\n",
273 parent_sd ? parent_sd->s_name : "", sd->s_name);
275 if (sysfs_type(sd) == SYSFS_KOBJ_LINK)
276 sysfs_put(sd->s_symlink.target_sd);
277 if (sysfs_type(sd) & SYSFS_COPY_NAME)
279 if (sd->s_iattr && sd->s_iattr->ia_secdata)
280 security_release_secctx(sd->s_iattr->ia_secdata,
281 sd->s_iattr->ia_secdata_len);
283 sysfs_free_ino(sd->s_ino);
284 kmem_cache_free(sysfs_dir_cachep, sd);
287 if (sd && atomic_dec_and_test(&sd->s_count))
291 static int sysfs_dentry_delete(const struct dentry *dentry)
293 struct sysfs_dirent *sd = dentry->d_fsdata;
294 return !(sd && !(sd->s_flags & SYSFS_FLAG_REMOVED));
297 static int sysfs_dentry_revalidate(struct dentry *dentry, unsigned int flags)
299 struct sysfs_dirent *sd;
302 if (flags & LOOKUP_RCU)
305 sd = dentry->d_fsdata;
306 mutex_lock(&sysfs_mutex);
308 /* The sysfs dirent has been deleted */
309 if (sd->s_flags & SYSFS_FLAG_REMOVED)
312 /* The sysfs dirent has been moved? */
313 if (dentry->d_parent->d_fsdata != sd->s_parent)
316 /* The sysfs dirent has been renamed */
317 if (strcmp(dentry->d_name.name, sd->s_name) != 0)
320 /* The sysfs dirent has been moved to a different namespace */
321 type = KOBJ_NS_TYPE_NONE;
323 type = sysfs_ns_type(sd->s_parent);
324 if (type != KOBJ_NS_TYPE_NONE &&
325 sysfs_info(dentry->d_sb)->ns[type] != sd->s_ns)
329 mutex_unlock(&sysfs_mutex);
332 /* Remove the dentry from the dcache hashes.
333 * If this is a deleted dentry we use d_drop instead of d_delete
334 * so sysfs doesn't need to cope with negative dentries.
336 * If this is a dentry that has simply been renamed we
337 * use d_drop to remove it from the dcache lookup on its
338 * old parent. If this dentry persists later when a lookup
339 * is performed at its new name the dentry will be readded
340 * to the dcache hashes.
342 mutex_unlock(&sysfs_mutex);
343 shrink_submounts_and_drop(dentry);
348 static void sysfs_dentry_release(struct dentry *dentry)
350 sysfs_put(dentry->d_fsdata);
353 const struct dentry_operations sysfs_dentry_ops = {
354 .d_revalidate = sysfs_dentry_revalidate,
355 .d_delete = sysfs_dentry_delete,
356 .d_release = sysfs_dentry_release,
359 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
361 char *dup_name = NULL;
362 struct sysfs_dirent *sd;
364 if (type & SYSFS_COPY_NAME) {
365 name = dup_name = kstrdup(name, GFP_KERNEL);
370 sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL);
374 if (sysfs_alloc_ino(&sd->s_ino))
377 atomic_set(&sd->s_count, 1);
378 atomic_set(&sd->s_active, 0);
382 sd->s_flags = type | SYSFS_FLAG_REMOVED;
387 kmem_cache_free(sysfs_dir_cachep, sd);
394 * sysfs_addrm_start - prepare for sysfs_dirent add/remove
395 * @acxt: pointer to sysfs_addrm_cxt to be used
396 * @parent_sd: parent sysfs_dirent
398 * This function is called when the caller is about to add or
399 * remove sysfs_dirent under @parent_sd. This function acquires
400 * sysfs_mutex. @acxt is used to keep and pass context to
401 * other addrm functions.
404 * Kernel thread context (may sleep). sysfs_mutex is locked on
407 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
408 struct sysfs_dirent *parent_sd)
410 memset(acxt, 0, sizeof(*acxt));
411 acxt->parent_sd = parent_sd;
413 mutex_lock(&sysfs_mutex);
417 * __sysfs_add_one - add sysfs_dirent to parent without warning
418 * @acxt: addrm context to use
419 * @sd: sysfs_dirent to be added
421 * Get @acxt->parent_sd and set sd->s_parent to it and increment
422 * nlink of parent inode if @sd is a directory and link into the
423 * children list of the parent.
425 * This function should be called between calls to
426 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
427 * passed the same @acxt as passed to sysfs_addrm_start().
430 * Determined by sysfs_addrm_start().
433 * 0 on success, -EEXIST if entry with the given name already
436 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
438 struct sysfs_inode_attrs *ps_iattr;
441 if (!!sysfs_ns_type(acxt->parent_sd) != !!sd->s_ns) {
442 WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n",
443 sysfs_ns_type(acxt->parent_sd) ? "required" : "invalid",
444 acxt->parent_sd->s_name, sd->s_name);
448 sd->s_hash = sysfs_name_hash(sd->s_ns, sd->s_name);
449 sd->s_parent = sysfs_get(acxt->parent_sd);
451 ret = sysfs_link_sibling(sd);
455 /* Update timestamps on the parent */
456 ps_iattr = acxt->parent_sd->s_iattr;
458 struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
459 ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
462 /* Mark the entry added into directory tree */
463 sd->s_flags &= ~SYSFS_FLAG_REMOVED;
469 * sysfs_pathname - return full path to sysfs dirent
470 * @sd: sysfs_dirent whose path we want
471 * @path: caller allocated buffer of size PATH_MAX
473 * Gives the name "/" to the sysfs_root entry; any path returned
474 * is relative to wherever sysfs is mounted.
476 static char *sysfs_pathname(struct sysfs_dirent *sd, char *path)
479 sysfs_pathname(sd->s_parent, path);
480 strlcat(path, "/", PATH_MAX);
482 strlcat(path, sd->s_name, PATH_MAX);
487 * sysfs_add_one - add sysfs_dirent to parent
488 * @acxt: addrm context to use
489 * @sd: sysfs_dirent to be added
491 * Get @acxt->parent_sd and set sd->s_parent to it and increment
492 * nlink of parent inode if @sd is a directory and link into the
493 * children list of the parent.
495 * This function should be called between calls to
496 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
497 * passed the same @acxt as passed to sysfs_addrm_start().
500 * Determined by sysfs_addrm_start().
503 * 0 on success, -EEXIST if entry with the given name already
506 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
510 ret = __sysfs_add_one(acxt, sd);
511 if (ret == -EEXIST) {
512 char *path = kzalloc(PATH_MAX, GFP_KERNEL);
514 "sysfs: cannot create duplicate filename '%s'\n",
515 (path == NULL) ? sd->s_name
516 : (sysfs_pathname(acxt->parent_sd, path),
517 strlcat(path, "/", PATH_MAX),
518 strlcat(path, sd->s_name, PATH_MAX),
527 * sysfs_remove_one - remove sysfs_dirent from parent
528 * @acxt: addrm context to use
529 * @sd: sysfs_dirent to be removed
531 * Mark @sd removed and drop nlink of parent inode if @sd is a
532 * directory. @sd is unlinked from the children list.
534 * This function should be called between calls to
535 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
536 * passed the same @acxt as passed to sysfs_addrm_start().
539 * Determined by sysfs_addrm_start().
541 void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
543 struct sysfs_inode_attrs *ps_iattr;
545 BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED);
547 sysfs_unlink_sibling(sd);
549 /* Update timestamps on the parent */
550 ps_iattr = acxt->parent_sd->s_iattr;
552 struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
553 ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
556 sd->s_flags |= SYSFS_FLAG_REMOVED;
557 sd->u.removed_list = acxt->removed;
562 * sysfs_addrm_finish - finish up sysfs_dirent add/remove
563 * @acxt: addrm context to finish up
565 * Finish up sysfs_dirent add/remove. Resources acquired by
566 * sysfs_addrm_start() are released and removed sysfs_dirents are
570 * sysfs_mutex is released.
572 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
574 /* release resources acquired by sysfs_addrm_start() */
575 mutex_unlock(&sysfs_mutex);
577 /* kill removed sysfs_dirents */
578 while (acxt->removed) {
579 struct sysfs_dirent *sd = acxt->removed;
581 acxt->removed = sd->u.removed_list;
583 sysfs_deactivate(sd);
590 * sysfs_find_dirent - find sysfs_dirent with the given name
591 * @parent_sd: sysfs_dirent to search under
592 * @name: name to look for
594 * Look for sysfs_dirent with name @name under @parent_sd.
597 * mutex_lock(sysfs_mutex)
600 * Pointer to sysfs_dirent if found, NULL if not.
602 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
604 const unsigned char *name)
606 struct rb_node *node = parent_sd->s_dir.children.rb_node;
609 if (!!sysfs_ns_type(parent_sd) != !!ns) {
610 WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n",
611 sysfs_ns_type(parent_sd) ? "required" : "invalid",
612 parent_sd->s_name, name);
616 hash = sysfs_name_hash(ns, name);
618 struct sysfs_dirent *sd;
621 sd = to_sysfs_dirent(node);
622 result = sysfs_name_compare(hash, ns, name, sd);
624 node = node->rb_left;
626 node = node->rb_right;
634 * sysfs_get_dirent - find and get sysfs_dirent with the given name
635 * @parent_sd: sysfs_dirent to search under
636 * @name: name to look for
638 * Look for sysfs_dirent with name @name under @parent_sd and get
642 * Kernel thread context (may sleep). Grabs sysfs_mutex.
645 * Pointer to sysfs_dirent if found, NULL if not.
647 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
649 const unsigned char *name)
651 struct sysfs_dirent *sd;
653 mutex_lock(&sysfs_mutex);
654 sd = sysfs_find_dirent(parent_sd, ns, name);
656 mutex_unlock(&sysfs_mutex);
660 EXPORT_SYMBOL_GPL(sysfs_get_dirent);
662 static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
663 enum kobj_ns_type type, const void *ns, const char *name,
664 struct sysfs_dirent **p_sd)
666 umode_t mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
667 struct sysfs_addrm_cxt acxt;
668 struct sysfs_dirent *sd;
672 sd = sysfs_new_dirent(name, mode, SYSFS_DIR);
676 sd->s_flags |= (type << SYSFS_NS_TYPE_SHIFT);
678 sd->s_dir.kobj = kobj;
681 sysfs_addrm_start(&acxt, parent_sd);
682 rc = sysfs_add_one(&acxt, sd);
683 sysfs_addrm_finish(&acxt);
693 int sysfs_create_subdir(struct kobject *kobj, const char *name,
694 struct sysfs_dirent **p_sd)
696 return create_dir(kobj, kobj->sd,
697 KOBJ_NS_TYPE_NONE, NULL, name, p_sd);
701 * sysfs_read_ns_type: return associated ns_type
702 * @kobj: the kobject being queried
704 * Each kobject can be tagged with exactly one namespace type
705 * (i.e. network or user). Return the ns_type associated with
708 static enum kobj_ns_type sysfs_read_ns_type(struct kobject *kobj)
710 const struct kobj_ns_type_operations *ops;
711 enum kobj_ns_type type;
713 ops = kobj_child_ns_ops(kobj);
715 return KOBJ_NS_TYPE_NONE;
718 BUG_ON(type <= KOBJ_NS_TYPE_NONE);
719 BUG_ON(type >= KOBJ_NS_TYPES);
720 BUG_ON(!kobj_ns_type_registered(type));
726 * sysfs_create_dir - create a directory for an object.
727 * @kobj: object we're creating directory for.
729 int sysfs_create_dir(struct kobject *kobj)
731 enum kobj_ns_type type;
732 struct sysfs_dirent *parent_sd, *sd;
733 const void *ns = NULL;
739 parent_sd = kobj->parent->sd;
741 parent_sd = &sysfs_root;
746 if (sysfs_ns_type(parent_sd))
747 ns = kobj->ktype->namespace(kobj);
748 type = sysfs_read_ns_type(kobj);
750 error = create_dir(kobj, parent_sd, type, ns, kobject_name(kobj), &sd);
756 static struct dentry *sysfs_lookup(struct inode *dir, struct dentry *dentry,
759 struct dentry *ret = NULL;
760 struct dentry *parent = dentry->d_parent;
761 struct sysfs_dirent *parent_sd = parent->d_fsdata;
762 struct sysfs_dirent *sd;
764 enum kobj_ns_type type;
767 mutex_lock(&sysfs_mutex);
769 type = sysfs_ns_type(parent_sd);
770 ns = sysfs_info(dir->i_sb)->ns[type];
772 sd = sysfs_find_dirent(parent_sd, ns, dentry->d_name.name);
776 ret = ERR_PTR(-ENOENT);
779 dentry->d_fsdata = sysfs_get(sd);
781 /* attach dentry and inode */
782 inode = sysfs_get_inode(dir->i_sb, sd);
784 ret = ERR_PTR(-ENOMEM);
788 /* instantiate and hash dentry */
789 ret = d_materialise_unique(dentry, inode);
791 mutex_unlock(&sysfs_mutex);
795 const struct inode_operations sysfs_dir_inode_operations = {
796 .lookup = sysfs_lookup,
797 .permission = sysfs_permission,
798 .setattr = sysfs_setattr,
799 .getattr = sysfs_getattr,
800 .setxattr = sysfs_setxattr,
803 static void remove_dir(struct sysfs_dirent *sd)
805 struct sysfs_addrm_cxt acxt;
807 sysfs_addrm_start(&acxt, sd->s_parent);
808 sysfs_remove_one(&acxt, sd);
809 sysfs_addrm_finish(&acxt);
812 void sysfs_remove_subdir(struct sysfs_dirent *sd)
818 static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd)
820 struct sysfs_addrm_cxt acxt;
826 pr_debug("sysfs %s: removing dir\n", dir_sd->s_name);
827 sysfs_addrm_start(&acxt, dir_sd);
828 pos = rb_first(&dir_sd->s_dir.children);
830 struct sysfs_dirent *sd = to_sysfs_dirent(pos);
832 if (sysfs_type(sd) != SYSFS_DIR)
833 sysfs_remove_one(&acxt, sd);
835 sysfs_addrm_finish(&acxt);
841 * sysfs_remove_dir - remove an object's directory.
844 * The only thing special about this is that we remove any files in
845 * the directory before we remove the directory, and we've inlined
846 * what used to be sysfs_rmdir() below, instead of calling separately.
849 void sysfs_remove_dir(struct kobject *kobj)
851 struct sysfs_dirent *sd = kobj->sd;
853 spin_lock(&sysfs_assoc_lock);
855 spin_unlock(&sysfs_assoc_lock);
857 __sysfs_remove_dir(sd);
860 int sysfs_rename(struct sysfs_dirent *sd,
861 struct sysfs_dirent *new_parent_sd, const void *new_ns,
862 const char *new_name)
866 mutex_lock(&sysfs_mutex);
869 if ((sd->s_parent == new_parent_sd) && (sd->s_ns == new_ns) &&
870 (strcmp(sd->s_name, new_name) == 0))
871 goto out; /* nothing to rename */
874 if (sysfs_find_dirent(new_parent_sd, new_ns, new_name))
877 /* rename sysfs_dirent */
878 if (strcmp(sd->s_name, new_name) != 0) {
880 new_name = kstrdup(new_name, GFP_KERNEL);
885 sd->s_name = new_name;
889 * Move to the appropriate place in the appropriate directories rbtree.
891 sysfs_unlink_sibling(sd);
892 sysfs_get(new_parent_sd);
893 sysfs_put(sd->s_parent);
895 sd->s_hash = sysfs_name_hash(sd->s_ns, sd->s_name);
896 sd->s_parent = new_parent_sd;
897 sysfs_link_sibling(sd);
901 mutex_unlock(&sysfs_mutex);
905 int sysfs_rename_dir(struct kobject *kobj, const char *new_name)
907 struct sysfs_dirent *parent_sd = kobj->sd->s_parent;
908 const void *new_ns = NULL;
910 if (sysfs_ns_type(parent_sd))
911 new_ns = kobj->ktype->namespace(kobj);
913 return sysfs_rename(kobj->sd, parent_sd, new_ns, new_name);
916 int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj)
918 struct sysfs_dirent *sd = kobj->sd;
919 struct sysfs_dirent *new_parent_sd;
920 const void *new_ns = NULL;
922 BUG_ON(!sd->s_parent);
923 if (sysfs_ns_type(sd->s_parent))
924 new_ns = kobj->ktype->namespace(kobj);
925 new_parent_sd = new_parent_kobj && new_parent_kobj->sd ?
926 new_parent_kobj->sd : &sysfs_root;
928 return sysfs_rename(sd, new_parent_sd, new_ns, sd->s_name);
931 /* Relationship between s_mode and the DT_xxx types */
932 static inline unsigned char dt_type(struct sysfs_dirent *sd)
934 return (sd->s_mode >> 12) & 15;
937 static int sysfs_dir_release(struct inode *inode, struct file *filp)
939 sysfs_put(filp->private_data);
943 static struct sysfs_dirent *sysfs_dir_pos(const void *ns,
944 struct sysfs_dirent *parent_sd, loff_t hash, struct sysfs_dirent *pos)
947 int valid = !(pos->s_flags & SYSFS_FLAG_REMOVED) &&
948 pos->s_parent == parent_sd &&
954 if (!pos && (hash > 1) && (hash < INT_MAX)) {
955 struct rb_node *node = parent_sd->s_dir.children.rb_node;
957 pos = to_sysfs_dirent(node);
959 if (hash < pos->s_hash)
960 node = node->rb_left;
961 else if (hash > pos->s_hash)
962 node = node->rb_right;
967 /* Skip over entries in the wrong namespace */
968 while (pos && pos->s_ns != ns) {
969 struct rb_node *node = rb_next(&pos->s_rb);
973 pos = to_sysfs_dirent(node);
978 static struct sysfs_dirent *sysfs_dir_next_pos(const void *ns,
979 struct sysfs_dirent *parent_sd, ino_t ino, struct sysfs_dirent *pos)
981 pos = sysfs_dir_pos(ns, parent_sd, ino, pos);
984 struct rb_node *node = rb_next(&pos->s_rb);
988 pos = to_sysfs_dirent(node);
989 } while (pos && pos->s_ns != ns);
993 static int sysfs_readdir(struct file *file, struct dir_context *ctx)
995 struct dentry *dentry = file->f_path.dentry;
996 struct sysfs_dirent *parent_sd = dentry->d_fsdata;
997 struct sysfs_dirent *pos = file->private_data;
998 enum kobj_ns_type type;
1001 type = sysfs_ns_type(parent_sd);
1002 ns = sysfs_info(dentry->d_sb)->ns[type];
1004 if (!dir_emit_dots(file, ctx))
1006 mutex_lock(&sysfs_mutex);
1007 for (pos = sysfs_dir_pos(ns, parent_sd, ctx->pos, pos);
1009 pos = sysfs_dir_next_pos(ns, parent_sd, ctx->pos, pos)) {
1010 const char *name = pos->s_name;
1011 unsigned int type = dt_type(pos);
1012 int len = strlen(name);
1013 ino_t ino = pos->s_ino;
1014 ctx->pos = pos->s_hash;
1015 file->private_data = sysfs_get(pos);
1017 mutex_unlock(&sysfs_mutex);
1018 if (!dir_emit(ctx, name, len, ino, type))
1020 mutex_lock(&sysfs_mutex);
1022 mutex_unlock(&sysfs_mutex);
1023 file->private_data = NULL;
1028 static loff_t sysfs_dir_llseek(struct file *file, loff_t offset, int whence)
1030 struct inode *inode = file_inode(file);
1033 mutex_lock(&inode->i_mutex);
1034 ret = generic_file_llseek(file, offset, whence);
1035 mutex_unlock(&inode->i_mutex);
1040 const struct file_operations sysfs_dir_operations = {
1041 .read = generic_read_dir,
1042 .iterate = sysfs_readdir,
1043 .release = sysfs_dir_release,
1044 .llseek = sysfs_dir_llseek,