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>
27 DEFINE_MUTEX(sysfs_mutex);
28 DEFINE_MUTEX(sysfs_rename_mutex);
29 DEFINE_SPINLOCK(sysfs_assoc_lock);
31 static DEFINE_SPINLOCK(sysfs_ino_lock);
32 static DEFINE_IDA(sysfs_ino_ida);
35 * sysfs_link_sibling - link sysfs_dirent into sibling list
36 * @sd: sysfs_dirent of interest
38 * Link @sd into its sibling list which starts from
39 * sd->s_parent->s_dir.children.
42 * mutex_lock(sysfs_mutex)
44 static void sysfs_link_sibling(struct sysfs_dirent *sd)
46 struct sysfs_dirent *parent_sd = sd->s_parent;
47 struct sysfs_dirent **pos;
49 BUG_ON(sd->s_sibling);
51 /* Store directory entries in order by ino. This allows
52 * readdir to properly restart without having to add a
53 * cursor into the s_dir.children list.
55 for (pos = &parent_sd->s_dir.children; *pos; pos = &(*pos)->s_sibling) {
56 if (sd->s_ino < (*pos)->s_ino)
64 * sysfs_unlink_sibling - unlink sysfs_dirent from sibling list
65 * @sd: sysfs_dirent of interest
67 * Unlink @sd from its sibling list which starts from
68 * sd->s_parent->s_dir.children.
71 * mutex_lock(sysfs_mutex)
73 static void sysfs_unlink_sibling(struct sysfs_dirent *sd)
75 struct sysfs_dirent **pos;
77 for (pos = &sd->s_parent->s_dir.children; *pos;
78 pos = &(*pos)->s_sibling) {
88 * sysfs_get_dentry - get dentry for the given sysfs_dirent
89 * @sd: sysfs_dirent of interest
91 * Get dentry for @sd. Dentry is looked up if currently not
92 * present. This function descends from the root looking up
93 * dentry for each step.
96 * mutex_lock(sysfs_rename_mutex)
99 * Pointer to found dentry on success, ERR_PTR() value on error.
101 struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd)
103 struct dentry *dentry = dget(sysfs_sb->s_root);
105 while (dentry->d_fsdata != sd) {
106 struct sysfs_dirent *cur;
107 struct dentry *parent;
109 /* find the first ancestor which hasn't been looked up */
111 while (cur->s_parent != dentry->d_fsdata)
116 mutex_lock(&parent->d_inode->i_mutex);
117 dentry = lookup_one_noperm(cur->s_name, parent);
118 mutex_unlock(&parent->d_inode->i_mutex);
128 * sysfs_get_active - get an active reference to sysfs_dirent
129 * @sd: sysfs_dirent to get an active reference to
131 * Get an active reference of @sd. This function is noop if @sd
135 * Pointer to @sd on success, NULL on failure.
137 static struct sysfs_dirent *sysfs_get_active(struct sysfs_dirent *sd)
145 v = atomic_read(&sd->s_active);
149 t = atomic_cmpxchg(&sd->s_active, v, v + 1);
160 * sysfs_put_active - put an active reference to sysfs_dirent
161 * @sd: sysfs_dirent to put an active reference to
163 * Put an active reference to @sd. This function is noop if @sd
166 static void sysfs_put_active(struct sysfs_dirent *sd)
168 struct completion *cmpl;
174 v = atomic_dec_return(&sd->s_active);
175 if (likely(v != SD_DEACTIVATED_BIAS))
178 /* atomic_dec_return() is a mb(), we'll always see the updated
181 cmpl = (void *)sd->s_sibling;
186 * sysfs_get_active_two - get active references to sysfs_dirent and parent
187 * @sd: sysfs_dirent of interest
189 * Get active reference to @sd and its parent. Parent's active
190 * reference is grabbed first. This function is noop if @sd is
194 * Pointer to @sd on success, NULL on failure.
196 struct sysfs_dirent *sysfs_get_active_two(struct sysfs_dirent *sd)
199 if (sd->s_parent && unlikely(!sysfs_get_active(sd->s_parent)))
201 if (unlikely(!sysfs_get_active(sd))) {
202 sysfs_put_active(sd->s_parent);
210 * sysfs_put_active_two - put active references to sysfs_dirent and parent
211 * @sd: sysfs_dirent of interest
213 * Put active references to @sd and its parent. This function is
214 * noop if @sd is NULL.
216 void sysfs_put_active_two(struct sysfs_dirent *sd)
219 sysfs_put_active(sd);
220 sysfs_put_active(sd->s_parent);
225 * sysfs_deactivate - deactivate sysfs_dirent
226 * @sd: sysfs_dirent to deactivate
228 * Deny new active references and drain existing ones.
230 static void sysfs_deactivate(struct sysfs_dirent *sd)
232 DECLARE_COMPLETION_ONSTACK(wait);
235 BUG_ON(sd->s_sibling || !(sd->s_flags & SYSFS_FLAG_REMOVED));
236 sd->s_sibling = (void *)&wait;
238 /* atomic_add_return() is a mb(), put_active() will always see
239 * the updated sd->s_sibling.
241 v = atomic_add_return(SD_DEACTIVATED_BIAS, &sd->s_active);
243 if (v != SD_DEACTIVATED_BIAS)
244 wait_for_completion(&wait);
246 sd->s_sibling = NULL;
249 static int sysfs_alloc_ino(ino_t *pino)
254 spin_lock(&sysfs_ino_lock);
255 rc = ida_get_new_above(&sysfs_ino_ida, 2, &ino);
256 spin_unlock(&sysfs_ino_lock);
259 if (ida_pre_get(&sysfs_ino_ida, GFP_KERNEL))
268 static void sysfs_free_ino(ino_t ino)
270 spin_lock(&sysfs_ino_lock);
271 ida_remove(&sysfs_ino_ida, ino);
272 spin_unlock(&sysfs_ino_lock);
275 void release_sysfs_dirent(struct sysfs_dirent * sd)
277 struct sysfs_dirent *parent_sd;
280 /* Moving/renaming is always done while holding reference.
281 * sd->s_parent won't change beneath us.
283 parent_sd = sd->s_parent;
285 if (sysfs_type(sd) == SYSFS_KOBJ_LINK)
286 sysfs_put(sd->s_symlink.target_sd);
287 if (sysfs_type(sd) & SYSFS_COPY_NAME)
289 if (sd->s_iattr && sd->s_iattr->ia_secdata)
290 security_release_secctx(sd->s_iattr->ia_secdata,
291 sd->s_iattr->ia_secdata_len);
293 sysfs_free_ino(sd->s_ino);
294 kmem_cache_free(sysfs_dir_cachep, sd);
297 if (sd && atomic_dec_and_test(&sd->s_count))
301 static int sysfs_dentry_delete(struct dentry *dentry)
303 struct sysfs_dirent *sd = dentry->d_fsdata;
304 return !!(sd->s_flags & SYSFS_FLAG_REMOVED);
307 static int sysfs_dentry_revalidate(struct dentry *dentry, struct nameidata *nd)
309 struct sysfs_dirent *sd = dentry->d_fsdata;
312 mutex_lock(&sysfs_mutex);
314 /* The sysfs dirent has been deleted */
315 if (sd->s_flags & SYSFS_FLAG_REMOVED)
318 mutex_unlock(&sysfs_mutex);
322 /* Remove the dentry from the dcache hashes.
323 * If this is a deleted dentry we use d_drop instead of d_delete
324 * so sysfs doesn't need to cope with negative dentries.
326 is_dir = (sysfs_type(sd) == SYSFS_DIR);
327 mutex_unlock(&sysfs_mutex);
329 /* If we have submounts we must allow the vfs caches
330 * to lie about the state of the filesystem to prevent
331 * leaks and other nasty things.
333 if (have_submounts(dentry))
335 shrink_dcache_parent(dentry);
341 static void sysfs_dentry_iput(struct dentry *dentry, struct inode *inode)
343 struct sysfs_dirent * sd = dentry->d_fsdata;
349 static const struct dentry_operations sysfs_dentry_ops = {
350 .d_revalidate = sysfs_dentry_revalidate,
351 .d_delete = sysfs_dentry_delete,
352 .d_iput = sysfs_dentry_iput,
355 struct sysfs_dirent *sysfs_new_dirent(const char *name, umode_t mode, int type)
357 char *dup_name = NULL;
358 struct sysfs_dirent *sd;
360 if (type & SYSFS_COPY_NAME) {
361 name = dup_name = kstrdup(name, GFP_KERNEL);
366 sd = kmem_cache_zalloc(sysfs_dir_cachep, GFP_KERNEL);
370 if (sysfs_alloc_ino(&sd->s_ino))
373 atomic_set(&sd->s_count, 1);
374 atomic_set(&sd->s_active, 0);
383 kmem_cache_free(sysfs_dir_cachep, sd);
389 static int sysfs_ilookup_test(struct inode *inode, void *arg)
391 struct sysfs_dirent *sd = arg;
392 return inode->i_ino == sd->s_ino;
396 * sysfs_addrm_start - prepare for sysfs_dirent add/remove
397 * @acxt: pointer to sysfs_addrm_cxt to be used
398 * @parent_sd: parent sysfs_dirent
400 * This function is called when the caller is about to add or
401 * remove sysfs_dirent under @parent_sd. This function acquires
402 * sysfs_mutex, grabs inode for @parent_sd if available and lock
403 * i_mutex of it. @acxt is used to keep and pass context to
404 * other addrm functions.
407 * Kernel thread context (may sleep). sysfs_mutex is locked on
408 * return. i_mutex of parent inode is locked on return if
411 void sysfs_addrm_start(struct sysfs_addrm_cxt *acxt,
412 struct sysfs_dirent *parent_sd)
416 memset(acxt, 0, sizeof(*acxt));
417 acxt->parent_sd = parent_sd;
419 /* Lookup parent inode. inode initialization is protected by
420 * sysfs_mutex, so inode existence can be determined by
421 * looking up inode while holding sysfs_mutex.
423 mutex_lock(&sysfs_mutex);
425 inode = ilookup5(sysfs_sb, parent_sd->s_ino, sysfs_ilookup_test,
428 WARN_ON(inode->i_state & I_NEW);
430 /* parent inode available */
431 acxt->parent_inode = inode;
433 /* sysfs_mutex is below i_mutex in lock hierarchy.
434 * First, trylock i_mutex. If fails, unlock
435 * sysfs_mutex and lock them in order.
437 if (!mutex_trylock(&inode->i_mutex)) {
438 mutex_unlock(&sysfs_mutex);
439 mutex_lock(&inode->i_mutex);
440 mutex_lock(&sysfs_mutex);
446 * __sysfs_add_one - add sysfs_dirent to parent without warning
447 * @acxt: addrm context to use
448 * @sd: sysfs_dirent to be added
450 * Get @acxt->parent_sd and set sd->s_parent to it and increment
451 * nlink of parent inode if @sd is a directory and link into the
452 * children list of the parent.
454 * This function should be called between calls to
455 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
456 * passed the same @acxt as passed to sysfs_addrm_start().
459 * Determined by sysfs_addrm_start().
462 * 0 on success, -EEXIST if entry with the given name already
465 int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
467 struct sysfs_inode_attrs *ps_iattr;
469 if (sysfs_find_dirent(acxt->parent_sd, sd->s_name))
472 sd->s_parent = sysfs_get(acxt->parent_sd);
474 if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode)
475 inc_nlink(acxt->parent_inode);
479 sysfs_link_sibling(sd);
481 /* Update timestamps on the parent */
482 ps_iattr = acxt->parent_sd->s_iattr;
484 struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
485 ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
492 * sysfs_pathname - return full path to sysfs dirent
493 * @sd: sysfs_dirent whose path we want
494 * @path: caller allocated buffer
496 * Gives the name "/" to the sysfs_root entry; any path returned
497 * is relative to wherever sysfs is mounted.
499 * XXX: does no error checking on @path size
501 static char *sysfs_pathname(struct sysfs_dirent *sd, char *path)
504 sysfs_pathname(sd->s_parent, path);
507 strcat(path, sd->s_name);
512 * sysfs_add_one - add sysfs_dirent to parent
513 * @acxt: addrm context to use
514 * @sd: sysfs_dirent to be added
516 * Get @acxt->parent_sd and set sd->s_parent to it and increment
517 * nlink of parent inode if @sd is a directory and link into the
518 * children list of the parent.
520 * This function should be called between calls to
521 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
522 * passed the same @acxt as passed to sysfs_addrm_start().
525 * Determined by sysfs_addrm_start().
528 * 0 on success, -EEXIST if entry with the given name already
531 int sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
535 ret = __sysfs_add_one(acxt, sd);
536 if (ret == -EEXIST) {
537 char *path = kzalloc(PATH_MAX, GFP_KERNEL);
539 "sysfs: cannot create duplicate filename '%s'\n",
540 (path == NULL) ? sd->s_name :
541 strcat(strcat(sysfs_pathname(acxt->parent_sd, path), "/"),
550 * sysfs_remove_one - remove sysfs_dirent from parent
551 * @acxt: addrm context to use
552 * @sd: sysfs_dirent to be removed
554 * Mark @sd removed and drop nlink of parent inode if @sd is a
555 * directory. @sd is unlinked from the children list.
557 * This function should be called between calls to
558 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
559 * passed the same @acxt as passed to sysfs_addrm_start().
562 * Determined by sysfs_addrm_start().
564 void sysfs_remove_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
566 struct sysfs_inode_attrs *ps_iattr;
568 BUG_ON(sd->s_flags & SYSFS_FLAG_REMOVED);
570 sysfs_unlink_sibling(sd);
572 /* Update timestamps on the parent */
573 ps_iattr = acxt->parent_sd->s_iattr;
575 struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
576 ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
579 sd->s_flags |= SYSFS_FLAG_REMOVED;
580 sd->s_sibling = acxt->removed;
583 if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode)
584 drop_nlink(acxt->parent_inode);
590 * sysfs_dec_nlink - Decrement link count for the specified sysfs_dirent
591 * @sd: target sysfs_dirent
593 * Decrement nlink for @sd. @sd must have been unlinked from its
594 * parent on entry to this function such that it can't be looked
597 static void sysfs_dec_nlink(struct sysfs_dirent *sd)
601 inode = ilookup(sysfs_sb, sd->s_ino);
605 /* adjust nlink and update timestamp */
606 mutex_lock(&inode->i_mutex);
608 inode->i_ctime = CURRENT_TIME;
610 if (sysfs_type(sd) == SYSFS_DIR)
613 mutex_unlock(&inode->i_mutex);
619 * sysfs_addrm_finish - finish up sysfs_dirent add/remove
620 * @acxt: addrm context to finish up
622 * Finish up sysfs_dirent add/remove. Resources acquired by
623 * sysfs_addrm_start() are released and removed sysfs_dirents are
624 * cleaned up. Timestamps on the parent inode are updated.
627 * All mutexes acquired by sysfs_addrm_start() are released.
629 void sysfs_addrm_finish(struct sysfs_addrm_cxt *acxt)
631 /* release resources acquired by sysfs_addrm_start() */
632 mutex_unlock(&sysfs_mutex);
633 if (acxt->parent_inode) {
634 struct inode *inode = acxt->parent_inode;
636 /* if added/removed, update timestamps on the parent */
638 inode->i_ctime = inode->i_mtime = CURRENT_TIME;
640 mutex_unlock(&inode->i_mutex);
644 /* kill removed sysfs_dirents */
645 while (acxt->removed) {
646 struct sysfs_dirent *sd = acxt->removed;
648 acxt->removed = sd->s_sibling;
649 sd->s_sibling = NULL;
652 sysfs_deactivate(sd);
659 * sysfs_find_dirent - find sysfs_dirent with the given name
660 * @parent_sd: sysfs_dirent to search under
661 * @name: name to look for
663 * Look for sysfs_dirent with name @name under @parent_sd.
666 * mutex_lock(sysfs_mutex)
669 * Pointer to sysfs_dirent if found, NULL if not.
671 struct sysfs_dirent *sysfs_find_dirent(struct sysfs_dirent *parent_sd,
672 const unsigned char *name)
674 struct sysfs_dirent *sd;
676 for (sd = parent_sd->s_dir.children; sd; sd = sd->s_sibling)
677 if (!strcmp(sd->s_name, name))
683 * sysfs_get_dirent - find and get sysfs_dirent with the given name
684 * @parent_sd: sysfs_dirent to search under
685 * @name: name to look for
687 * Look for sysfs_dirent with name @name under @parent_sd and get
691 * Kernel thread context (may sleep). Grabs sysfs_mutex.
694 * Pointer to sysfs_dirent if found, NULL if not.
696 struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
697 const unsigned char *name)
699 struct sysfs_dirent *sd;
701 mutex_lock(&sysfs_mutex);
702 sd = sysfs_find_dirent(parent_sd, name);
704 mutex_unlock(&sysfs_mutex);
708 EXPORT_SYMBOL_GPL(sysfs_get_dirent);
710 static int create_dir(struct kobject *kobj, struct sysfs_dirent *parent_sd,
711 const char *name, struct sysfs_dirent **p_sd)
713 umode_t mode = S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO;
714 struct sysfs_addrm_cxt acxt;
715 struct sysfs_dirent *sd;
719 sd = sysfs_new_dirent(name, mode, SYSFS_DIR);
722 sd->s_dir.kobj = kobj;
725 sysfs_addrm_start(&acxt, parent_sd);
726 rc = sysfs_add_one(&acxt, sd);
727 sysfs_addrm_finish(&acxt);
737 int sysfs_create_subdir(struct kobject *kobj, const char *name,
738 struct sysfs_dirent **p_sd)
740 return create_dir(kobj, kobj->sd, name, p_sd);
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 struct sysfs_dirent *parent_sd, *sd;
755 parent_sd = kobj->parent->sd;
757 parent_sd = &sysfs_root;
759 error = create_dir(kobj, parent_sd, kobject_name(kobj), &sd);
765 static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
766 struct nameidata *nd)
768 struct dentry *ret = NULL;
769 struct sysfs_dirent *parent_sd = dentry->d_parent->d_fsdata;
770 struct sysfs_dirent *sd;
773 mutex_lock(&sysfs_mutex);
775 sd = sysfs_find_dirent(parent_sd, dentry->d_name.name);
779 ret = ERR_PTR(-ENOENT);
783 /* attach dentry and inode */
784 inode = sysfs_get_inode(sd);
786 ret = ERR_PTR(-ENOMEM);
790 /* instantiate and hash dentry */
791 dentry->d_op = &sysfs_dentry_ops;
792 dentry->d_fsdata = sysfs_get(sd);
793 d_instantiate(dentry, inode);
797 mutex_unlock(&sysfs_mutex);
801 const struct inode_operations sysfs_dir_inode_operations = {
802 .lookup = sysfs_lookup,
803 .permission = sysfs_permission,
804 .setattr = sysfs_setattr,
805 .getattr = sysfs_getattr,
806 .setxattr = sysfs_setxattr,
809 static void remove_dir(struct sysfs_dirent *sd)
811 struct sysfs_addrm_cxt acxt;
813 sysfs_addrm_start(&acxt, sd->s_parent);
814 sysfs_remove_one(&acxt, sd);
815 sysfs_addrm_finish(&acxt);
818 void sysfs_remove_subdir(struct sysfs_dirent *sd)
824 static void __sysfs_remove_dir(struct sysfs_dirent *dir_sd)
826 struct sysfs_addrm_cxt acxt;
827 struct sysfs_dirent **pos;
832 pr_debug("sysfs %s: removing dir\n", dir_sd->s_name);
833 sysfs_addrm_start(&acxt, dir_sd);
834 pos = &dir_sd->s_dir.children;
836 struct sysfs_dirent *sd = *pos;
838 if (sysfs_type(sd) != SYSFS_DIR)
839 sysfs_remove_one(&acxt, sd);
841 pos = &(*pos)->s_sibling;
843 sysfs_addrm_finish(&acxt);
849 * sysfs_remove_dir - remove an object's directory.
852 * The only thing special about this is that we remove any files in
853 * the directory before we remove the directory, and we've inlined
854 * what used to be sysfs_rmdir() below, instead of calling separately.
857 void sysfs_remove_dir(struct kobject * kobj)
859 struct sysfs_dirent *sd = kobj->sd;
861 spin_lock(&sysfs_assoc_lock);
863 spin_unlock(&sysfs_assoc_lock);
865 __sysfs_remove_dir(sd);
868 int sysfs_rename_dir(struct kobject * kobj, const char *new_name)
870 struct sysfs_dirent *sd = kobj->sd;
871 struct dentry *parent = NULL;
872 struct dentry *old_dentry = NULL, *new_dentry = NULL;
873 const char *dup_name = NULL;
876 mutex_lock(&sysfs_rename_mutex);
879 if (strcmp(sd->s_name, new_name) == 0)
880 goto out; /* nothing to rename */
882 /* get the original dentry */
883 old_dentry = sysfs_get_dentry(sd);
884 if (IS_ERR(old_dentry)) {
885 error = PTR_ERR(old_dentry);
890 parent = old_dentry->d_parent;
892 /* lock parent and get dentry for new name */
893 mutex_lock(&parent->d_inode->i_mutex);
894 mutex_lock(&sysfs_mutex);
897 if (sysfs_find_dirent(sd->s_parent, new_name))
901 new_dentry = d_alloc_name(parent, new_name);
905 /* rename sysfs_dirent */
907 new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
911 dup_name = sd->s_name;
912 sd->s_name = new_name;
915 d_add(new_dentry, NULL);
916 d_move(old_dentry, new_dentry);
920 mutex_unlock(&sysfs_mutex);
921 mutex_unlock(&parent->d_inode->i_mutex);
926 mutex_unlock(&sysfs_rename_mutex);
930 int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj)
932 struct sysfs_dirent *sd = kobj->sd;
933 struct sysfs_dirent *new_parent_sd;
934 struct dentry *old_parent, *new_parent = NULL;
935 struct dentry *old_dentry = NULL, *new_dentry = NULL;
938 mutex_lock(&sysfs_rename_mutex);
939 BUG_ON(!sd->s_parent);
940 new_parent_sd = (new_parent_kobj && new_parent_kobj->sd) ?
941 new_parent_kobj->sd : &sysfs_root;
944 if (sd->s_parent == new_parent_sd)
945 goto out; /* nothing to move */
948 old_dentry = sysfs_get_dentry(sd);
949 if (IS_ERR(old_dentry)) {
950 error = PTR_ERR(old_dentry);
954 old_parent = old_dentry->d_parent;
956 new_parent = sysfs_get_dentry(new_parent_sd);
957 if (IS_ERR(new_parent)) {
958 error = PTR_ERR(new_parent);
964 mutex_lock(&old_parent->d_inode->i_mutex);
965 if (!mutex_trylock(&new_parent->d_inode->i_mutex)) {
966 mutex_unlock(&old_parent->d_inode->i_mutex);
969 mutex_lock(&sysfs_mutex);
972 if (sysfs_find_dirent(new_parent_sd, sd->s_name))
976 new_dentry = d_alloc_name(new_parent, sd->s_name);
981 d_add(new_dentry, NULL);
982 d_move(old_dentry, new_dentry);
984 /* Remove from old parent's list and insert into new parent's list. */
985 sysfs_unlink_sibling(sd);
986 sysfs_get(new_parent_sd);
987 drop_nlink(old_parent->d_inode);
988 sysfs_put(sd->s_parent);
989 sd->s_parent = new_parent_sd;
990 inc_nlink(new_parent->d_inode);
991 sysfs_link_sibling(sd);
994 mutex_unlock(&sysfs_mutex);
995 mutex_unlock(&new_parent->d_inode->i_mutex);
996 mutex_unlock(&old_parent->d_inode->i_mutex);
1001 mutex_unlock(&sysfs_rename_mutex);
1005 /* Relationship between s_mode and the DT_xxx types */
1006 static inline unsigned char dt_type(struct sysfs_dirent *sd)
1008 return (sd->s_mode >> 12) & 15;
1011 static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
1013 struct dentry *dentry = filp->f_path.dentry;
1014 struct sysfs_dirent * parent_sd = dentry->d_fsdata;
1015 struct sysfs_dirent *pos;
1018 if (filp->f_pos == 0) {
1019 ino = parent_sd->s_ino;
1020 if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) == 0)
1023 if (filp->f_pos == 1) {
1024 if (parent_sd->s_parent)
1025 ino = parent_sd->s_parent->s_ino;
1027 ino = parent_sd->s_ino;
1028 if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0)
1031 if ((filp->f_pos > 1) && (filp->f_pos < INT_MAX)) {
1032 mutex_lock(&sysfs_mutex);
1034 /* Skip the dentries we have already reported */
1035 pos = parent_sd->s_dir.children;
1036 while (pos && (filp->f_pos > pos->s_ino))
1037 pos = pos->s_sibling;
1039 for ( ; pos; pos = pos->s_sibling) {
1045 filp->f_pos = ino = pos->s_ino;
1047 if (filldir(dirent, name, len, filp->f_pos, ino,
1052 filp->f_pos = INT_MAX;
1053 mutex_unlock(&sysfs_mutex);
1059 const struct file_operations sysfs_dir_operations = {
1060 .read = generic_read_dir,
1061 .readdir = sysfs_readdir,
1062 .llseek = generic_file_llseek,