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>
26 DEFINE_MUTEX(sysfs_mutex
);
27 DEFINE_MUTEX(sysfs_rename_mutex
);
28 DEFINE_SPINLOCK(sysfs_assoc_lock
);
30 static DEFINE_SPINLOCK(sysfs_ino_lock
);
31 static DEFINE_IDA(sysfs_ino_ida
);
34 * sysfs_link_sibling - link sysfs_dirent into sibling list
35 * @sd: sysfs_dirent of interest
37 * Link @sd into its sibling list which starts from
38 * sd->s_parent->s_dir.children.
41 * mutex_lock(sysfs_mutex)
43 static void sysfs_link_sibling(struct sysfs_dirent
*sd
)
45 struct sysfs_dirent
*parent_sd
= sd
->s_parent
;
46 struct sysfs_dirent
**pos
;
48 BUG_ON(sd
->s_sibling
);
50 /* Store directory entries in order by ino. This allows
51 * readdir to properly restart without having to add a
52 * cursor into the s_dir.children list.
54 for (pos
= &parent_sd
->s_dir
.children
; *pos
; pos
= &(*pos
)->s_sibling
) {
55 if (sd
->s_ino
< (*pos
)->s_ino
)
63 * sysfs_unlink_sibling - unlink sysfs_dirent from sibling list
64 * @sd: sysfs_dirent of interest
66 * Unlink @sd from its sibling list which starts from
67 * sd->s_parent->s_dir.children.
70 * mutex_lock(sysfs_mutex)
72 static void sysfs_unlink_sibling(struct sysfs_dirent
*sd
)
74 struct sysfs_dirent
**pos
;
76 for (pos
= &sd
->s_parent
->s_dir
.children
; *pos
;
77 pos
= &(*pos
)->s_sibling
) {
87 * sysfs_get_dentry - get dentry for the given sysfs_dirent
88 * @sd: sysfs_dirent of interest
90 * Get dentry for @sd. Dentry is looked up if currently not
91 * present. This function descends from the root looking up
92 * dentry for each step.
95 * mutex_lock(sysfs_rename_mutex)
98 * Pointer to found dentry on success, ERR_PTR() value on error.
100 struct dentry
*sysfs_get_dentry(struct sysfs_dirent
*sd
)
102 struct dentry
*dentry
= dget(sysfs_sb
->s_root
);
104 while (dentry
->d_fsdata
!= sd
) {
105 struct sysfs_dirent
*cur
;
106 struct dentry
*parent
;
108 /* find the first ancestor which hasn't been looked up */
110 while (cur
->s_parent
!= dentry
->d_fsdata
)
115 mutex_lock(&parent
->d_inode
->i_mutex
);
116 dentry
= lookup_one_noperm(cur
->s_name
, parent
);
117 mutex_unlock(&parent
->d_inode
->i_mutex
);
127 * sysfs_get_active - get an active reference to sysfs_dirent
128 * @sd: sysfs_dirent to get an active reference to
130 * Get an active reference of @sd. This function is noop if @sd
134 * Pointer to @sd on success, NULL on failure.
136 static struct sysfs_dirent
*sysfs_get_active(struct sysfs_dirent
*sd
)
144 v
= atomic_read(&sd
->s_active
);
148 t
= atomic_cmpxchg(&sd
->s_active
, v
, v
+ 1);
159 * sysfs_put_active - put an active reference to sysfs_dirent
160 * @sd: sysfs_dirent to put an active reference to
162 * Put an active reference to @sd. This function is noop if @sd
165 static void sysfs_put_active(struct sysfs_dirent
*sd
)
167 struct completion
*cmpl
;
173 v
= atomic_dec_return(&sd
->s_active
);
174 if (likely(v
!= SD_DEACTIVATED_BIAS
))
177 /* atomic_dec_return() is a mb(), we'll always see the updated
180 cmpl
= (void *)sd
->s_sibling
;
185 * sysfs_get_active_two - get active references to sysfs_dirent and parent
186 * @sd: sysfs_dirent of interest
188 * Get active reference to @sd and its parent. Parent's active
189 * reference is grabbed first. This function is noop if @sd is
193 * Pointer to @sd on success, NULL on failure.
195 struct sysfs_dirent
*sysfs_get_active_two(struct sysfs_dirent
*sd
)
198 if (sd
->s_parent
&& unlikely(!sysfs_get_active(sd
->s_parent
)))
200 if (unlikely(!sysfs_get_active(sd
))) {
201 sysfs_put_active(sd
->s_parent
);
209 * sysfs_put_active_two - put active references to sysfs_dirent and parent
210 * @sd: sysfs_dirent of interest
212 * Put active references to @sd and its parent. This function is
213 * noop if @sd is NULL.
215 void sysfs_put_active_two(struct sysfs_dirent
*sd
)
218 sysfs_put_active(sd
);
219 sysfs_put_active(sd
->s_parent
);
224 * sysfs_deactivate - deactivate sysfs_dirent
225 * @sd: sysfs_dirent to deactivate
227 * Deny new active references and drain existing ones.
229 static void sysfs_deactivate(struct sysfs_dirent
*sd
)
231 DECLARE_COMPLETION_ONSTACK(wait
);
234 BUG_ON(sd
->s_sibling
|| !(sd
->s_flags
& SYSFS_FLAG_REMOVED
));
235 sd
->s_sibling
= (void *)&wait
;
237 /* atomic_add_return() is a mb(), put_active() will always see
238 * the updated sd->s_sibling.
240 v
= atomic_add_return(SD_DEACTIVATED_BIAS
, &sd
->s_active
);
242 if (v
!= SD_DEACTIVATED_BIAS
)
243 wait_for_completion(&wait
);
245 sd
->s_sibling
= NULL
;
248 static int sysfs_alloc_ino(ino_t
*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(ino_t 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
)
289 sysfs_free_ino(sd
->s_ino
);
290 kmem_cache_free(sysfs_dir_cachep
, sd
);
293 if (sd
&& atomic_dec_and_test(&sd
->s_count
))
297 static void sysfs_d_iput(struct dentry
* dentry
, struct inode
* inode
)
299 struct sysfs_dirent
* sd
= dentry
->d_fsdata
;
305 static struct dentry_operations sysfs_dentry_ops
= {
306 .d_iput
= sysfs_d_iput
,
309 struct sysfs_dirent
*sysfs_new_dirent(const char *name
, umode_t mode
, int type
)
311 char *dup_name
= NULL
;
312 struct sysfs_dirent
*sd
;
314 if (type
& SYSFS_COPY_NAME
) {
315 name
= dup_name
= kstrdup(name
, GFP_KERNEL
);
320 sd
= kmem_cache_zalloc(sysfs_dir_cachep
, GFP_KERNEL
);
324 if (sysfs_alloc_ino(&sd
->s_ino
))
327 atomic_set(&sd
->s_count
, 1);
328 atomic_set(&sd
->s_active
, 0);
337 kmem_cache_free(sysfs_dir_cachep
, sd
);
343 static int sysfs_ilookup_test(struct inode
*inode
, void *arg
)
345 struct sysfs_dirent
*sd
= arg
;
346 return inode
->i_ino
== sd
->s_ino
;
350 * sysfs_addrm_start - prepare for sysfs_dirent add/remove
351 * @acxt: pointer to sysfs_addrm_cxt to be used
352 * @parent_sd: parent sysfs_dirent
354 * This function is called when the caller is about to add or
355 * remove sysfs_dirent under @parent_sd. This function acquires
356 * sysfs_mutex, grabs inode for @parent_sd if available and lock
357 * i_mutex of it. @acxt is used to keep and pass context to
358 * other addrm functions.
361 * Kernel thread context (may sleep). sysfs_mutex is locked on
362 * return. i_mutex of parent inode is locked on return if
365 void sysfs_addrm_start(struct sysfs_addrm_cxt
*acxt
,
366 struct sysfs_dirent
*parent_sd
)
370 memset(acxt
, 0, sizeof(*acxt
));
371 acxt
->parent_sd
= parent_sd
;
373 /* Lookup parent inode. inode initialization is protected by
374 * sysfs_mutex, so inode existence can be determined by
375 * looking up inode while holding sysfs_mutex.
377 mutex_lock(&sysfs_mutex
);
379 inode
= ilookup5(sysfs_sb
, parent_sd
->s_ino
, sysfs_ilookup_test
,
382 WARN_ON(inode
->i_state
& I_NEW
);
384 /* parent inode available */
385 acxt
->parent_inode
= inode
;
387 /* sysfs_mutex is below i_mutex in lock hierarchy.
388 * First, trylock i_mutex. If fails, unlock
389 * sysfs_mutex and lock them in order.
391 if (!mutex_trylock(&inode
->i_mutex
)) {
392 mutex_unlock(&sysfs_mutex
);
393 mutex_lock(&inode
->i_mutex
);
394 mutex_lock(&sysfs_mutex
);
400 * __sysfs_add_one - add sysfs_dirent to parent without warning
401 * @acxt: addrm context to use
402 * @sd: sysfs_dirent to be added
404 * Get @acxt->parent_sd and set sd->s_parent to it and increment
405 * nlink of parent inode if @sd is a directory and link into the
406 * children list of the parent.
408 * This function should be called between calls to
409 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
410 * passed the same @acxt as passed to sysfs_addrm_start().
413 * Determined by sysfs_addrm_start().
416 * 0 on success, -EEXIST if entry with the given name already
419 int __sysfs_add_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
421 if (sysfs_find_dirent(acxt
->parent_sd
, sd
->s_name
))
424 sd
->s_parent
= sysfs_get(acxt
->parent_sd
);
426 if (sysfs_type(sd
) == SYSFS_DIR
&& acxt
->parent_inode
)
427 inc_nlink(acxt
->parent_inode
);
431 sysfs_link_sibling(sd
);
437 * sysfs_pathname - return full path to sysfs dirent
438 * @sd: sysfs_dirent whose path we want
439 * @path: caller allocated buffer
441 * Gives the name "/" to the sysfs_root entry; any path returned
442 * is relative to wherever sysfs is mounted.
444 * XXX: does no error checking on @path size
446 static char *sysfs_pathname(struct sysfs_dirent
*sd
, char *path
)
449 sysfs_pathname(sd
->s_parent
, path
);
452 strcat(path
, sd
->s_name
);
457 * sysfs_add_one - add sysfs_dirent to parent
458 * @acxt: addrm context to use
459 * @sd: sysfs_dirent to be added
461 * Get @acxt->parent_sd and set sd->s_parent to it and increment
462 * nlink of parent inode if @sd is a directory and link into the
463 * children list of the parent.
465 * This function should be called between calls to
466 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
467 * passed the same @acxt as passed to sysfs_addrm_start().
470 * Determined by sysfs_addrm_start().
473 * 0 on success, -EEXIST if entry with the given name already
476 int sysfs_add_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
480 ret
= __sysfs_add_one(acxt
, sd
);
481 if (ret
== -EEXIST
) {
482 char *path
= kzalloc(PATH_MAX
, GFP_KERNEL
);
484 "sysfs: cannot create duplicate filename '%s'\n",
485 (path
== NULL
) ? sd
->s_name
:
486 strcat(strcat(sysfs_pathname(acxt
->parent_sd
, path
), "/"),
495 * sysfs_remove_one - remove sysfs_dirent from parent
496 * @acxt: addrm context to use
497 * @sd: sysfs_dirent to be removed
499 * Mark @sd removed and drop nlink of parent inode if @sd is a
500 * directory. @sd is unlinked from the children list.
502 * This function should be called between calls to
503 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
504 * passed the same @acxt as passed to sysfs_addrm_start().
507 * Determined by sysfs_addrm_start().
509 void sysfs_remove_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
511 BUG_ON(sd
->s_flags
& SYSFS_FLAG_REMOVED
);
513 sysfs_unlink_sibling(sd
);
515 sd
->s_flags
|= SYSFS_FLAG_REMOVED
;
516 sd
->s_sibling
= acxt
->removed
;
519 if (sysfs_type(sd
) == SYSFS_DIR
&& acxt
->parent_inode
)
520 drop_nlink(acxt
->parent_inode
);
526 * sysfs_drop_dentry - drop dentry for the specified sysfs_dirent
527 * @sd: target sysfs_dirent
529 * Drop dentry for @sd. @sd must have been unlinked from its
530 * parent on entry to this function such that it can't be looked
533 static void sysfs_drop_dentry(struct sysfs_dirent
*sd
)
536 struct dentry
*dentry
;
538 inode
= ilookup(sysfs_sb
, sd
->s_ino
);
542 /* Drop any existing dentries associated with sd.
544 * For the dentry to be properly freed we need to grab a
545 * reference to the dentry under the dcache lock, unhash it,
546 * and then put it. The playing with the dentry count allows
547 * dput to immediately free the dentry if it is not in use.
550 spin_lock(&dcache_lock
);
551 list_for_each_entry(dentry
, &inode
->i_dentry
, d_alias
) {
552 if (d_unhashed(dentry
))
555 spin_lock(&dentry
->d_lock
);
557 spin_unlock(&dentry
->d_lock
);
558 spin_unlock(&dcache_lock
);
562 spin_unlock(&dcache_lock
);
564 /* adjust nlink and update timestamp */
565 mutex_lock(&inode
->i_mutex
);
567 inode
->i_ctime
= CURRENT_TIME
;
569 if (sysfs_type(sd
) == SYSFS_DIR
)
572 mutex_unlock(&inode
->i_mutex
);
578 * sysfs_addrm_finish - finish up sysfs_dirent add/remove
579 * @acxt: addrm context to finish up
581 * Finish up sysfs_dirent add/remove. Resources acquired by
582 * sysfs_addrm_start() are released and removed sysfs_dirents are
583 * cleaned up. Timestamps on the parent inode are updated.
586 * All mutexes acquired by sysfs_addrm_start() are released.
588 void sysfs_addrm_finish(struct sysfs_addrm_cxt
*acxt
)
590 /* release resources acquired by sysfs_addrm_start() */
591 mutex_unlock(&sysfs_mutex
);
592 if (acxt
->parent_inode
) {
593 struct inode
*inode
= acxt
->parent_inode
;
595 /* if added/removed, update timestamps on the parent */
597 inode
->i_ctime
= inode
->i_mtime
= CURRENT_TIME
;
599 mutex_unlock(&inode
->i_mutex
);
603 /* kill removed sysfs_dirents */
604 while (acxt
->removed
) {
605 struct sysfs_dirent
*sd
= acxt
->removed
;
607 acxt
->removed
= sd
->s_sibling
;
608 sd
->s_sibling
= NULL
;
610 sysfs_drop_dentry(sd
);
611 sysfs_deactivate(sd
);
617 * sysfs_find_dirent - find sysfs_dirent with the given name
618 * @parent_sd: sysfs_dirent to search under
619 * @name: name to look for
621 * Look for sysfs_dirent with name @name under @parent_sd.
624 * mutex_lock(sysfs_mutex)
627 * Pointer to sysfs_dirent if found, NULL if not.
629 struct sysfs_dirent
*sysfs_find_dirent(struct sysfs_dirent
*parent_sd
,
630 const unsigned char *name
)
632 struct sysfs_dirent
*sd
;
634 for (sd
= parent_sd
->s_dir
.children
; sd
; sd
= sd
->s_sibling
)
635 if (!strcmp(sd
->s_name
, name
))
641 * sysfs_get_dirent - find and get sysfs_dirent with the given name
642 * @parent_sd: sysfs_dirent to search under
643 * @name: name to look for
645 * Look for sysfs_dirent with name @name under @parent_sd and get
649 * Kernel thread context (may sleep). Grabs sysfs_mutex.
652 * Pointer to sysfs_dirent if found, NULL if not.
654 struct sysfs_dirent
*sysfs_get_dirent(struct sysfs_dirent
*parent_sd
,
655 const unsigned char *name
)
657 struct sysfs_dirent
*sd
;
659 mutex_lock(&sysfs_mutex
);
660 sd
= sysfs_find_dirent(parent_sd
, name
);
662 mutex_unlock(&sysfs_mutex
);
666 EXPORT_SYMBOL_GPL(sysfs_get_dirent
);
668 static int create_dir(struct kobject
*kobj
, struct sysfs_dirent
*parent_sd
,
669 const char *name
, struct sysfs_dirent
**p_sd
)
671 umode_t mode
= S_IFDIR
| S_IRWXU
| S_IRUGO
| S_IXUGO
;
672 struct sysfs_addrm_cxt acxt
;
673 struct sysfs_dirent
*sd
;
677 sd
= sysfs_new_dirent(name
, mode
, SYSFS_DIR
);
680 sd
->s_dir
.kobj
= kobj
;
683 sysfs_addrm_start(&acxt
, parent_sd
);
684 rc
= sysfs_add_one(&acxt
, sd
);
685 sysfs_addrm_finish(&acxt
);
695 int sysfs_create_subdir(struct kobject
*kobj
, const char *name
,
696 struct sysfs_dirent
**p_sd
)
698 return create_dir(kobj
, kobj
->sd
, name
, p_sd
);
702 * sysfs_create_dir - create a directory for an object.
703 * @kobj: object we're creating directory for.
705 int sysfs_create_dir(struct kobject
* kobj
)
707 struct sysfs_dirent
*parent_sd
, *sd
;
713 parent_sd
= kobj
->parent
->sd
;
715 parent_sd
= &sysfs_root
;
717 error
= create_dir(kobj
, parent_sd
, kobject_name(kobj
), &sd
);
723 static struct dentry
* sysfs_lookup(struct inode
*dir
, struct dentry
*dentry
,
724 struct nameidata
*nd
)
726 struct dentry
*ret
= NULL
;
727 struct sysfs_dirent
*parent_sd
= dentry
->d_parent
->d_fsdata
;
728 struct sysfs_dirent
*sd
;
731 mutex_lock(&sysfs_mutex
);
733 sd
= sysfs_find_dirent(parent_sd
, dentry
->d_name
.name
);
737 ret
= ERR_PTR(-ENOENT
);
741 /* attach dentry and inode */
742 inode
= sysfs_get_inode(sd
);
744 ret
= ERR_PTR(-ENOMEM
);
748 /* instantiate and hash dentry */
749 dentry
->d_op
= &sysfs_dentry_ops
;
750 dentry
->d_fsdata
= sysfs_get(sd
);
751 d_instantiate(dentry
, inode
);
755 mutex_unlock(&sysfs_mutex
);
759 const struct inode_operations sysfs_dir_inode_operations
= {
760 .lookup
= sysfs_lookup
,
761 .setattr
= sysfs_setattr
,
764 static void remove_dir(struct sysfs_dirent
*sd
)
766 struct sysfs_addrm_cxt acxt
;
768 sysfs_addrm_start(&acxt
, sd
->s_parent
);
769 sysfs_remove_one(&acxt
, sd
);
770 sysfs_addrm_finish(&acxt
);
773 void sysfs_remove_subdir(struct sysfs_dirent
*sd
)
779 static void __sysfs_remove_dir(struct sysfs_dirent
*dir_sd
)
781 struct sysfs_addrm_cxt acxt
;
782 struct sysfs_dirent
**pos
;
787 pr_debug("sysfs %s: removing dir\n", dir_sd
->s_name
);
788 sysfs_addrm_start(&acxt
, dir_sd
);
789 pos
= &dir_sd
->s_dir
.children
;
791 struct sysfs_dirent
*sd
= *pos
;
793 if (sysfs_type(sd
) != SYSFS_DIR
)
794 sysfs_remove_one(&acxt
, sd
);
796 pos
= &(*pos
)->s_sibling
;
798 sysfs_addrm_finish(&acxt
);
804 * sysfs_remove_dir - remove an object's directory.
807 * The only thing special about this is that we remove any files in
808 * the directory before we remove the directory, and we've inlined
809 * what used to be sysfs_rmdir() below, instead of calling separately.
812 void sysfs_remove_dir(struct kobject
* kobj
)
814 struct sysfs_dirent
*sd
= kobj
->sd
;
816 spin_lock(&sysfs_assoc_lock
);
818 spin_unlock(&sysfs_assoc_lock
);
820 __sysfs_remove_dir(sd
);
823 int sysfs_rename_dir(struct kobject
* kobj
, const char *new_name
)
825 struct sysfs_dirent
*sd
= kobj
->sd
;
826 struct dentry
*parent
= NULL
;
827 struct dentry
*old_dentry
= NULL
, *new_dentry
= NULL
;
828 const char *dup_name
= NULL
;
831 mutex_lock(&sysfs_rename_mutex
);
834 if (strcmp(sd
->s_name
, new_name
) == 0)
835 goto out
; /* nothing to rename */
837 /* get the original dentry */
838 old_dentry
= sysfs_get_dentry(sd
);
839 if (IS_ERR(old_dentry
)) {
840 error
= PTR_ERR(old_dentry
);
845 parent
= old_dentry
->d_parent
;
847 /* lock parent and get dentry for new name */
848 mutex_lock(&parent
->d_inode
->i_mutex
);
849 mutex_lock(&sysfs_mutex
);
852 if (sysfs_find_dirent(sd
->s_parent
, new_name
))
856 new_dentry
= d_alloc_name(parent
, new_name
);
860 /* rename sysfs_dirent */
862 new_name
= dup_name
= kstrdup(new_name
, GFP_KERNEL
);
866 dup_name
= sd
->s_name
;
867 sd
->s_name
= new_name
;
870 d_add(new_dentry
, NULL
);
871 d_move(old_dentry
, new_dentry
);
875 mutex_unlock(&sysfs_mutex
);
876 mutex_unlock(&parent
->d_inode
->i_mutex
);
881 mutex_unlock(&sysfs_rename_mutex
);
885 int sysfs_move_dir(struct kobject
*kobj
, struct kobject
*new_parent_kobj
)
887 struct sysfs_dirent
*sd
= kobj
->sd
;
888 struct sysfs_dirent
*new_parent_sd
;
889 struct dentry
*old_parent
, *new_parent
= NULL
;
890 struct dentry
*old_dentry
= NULL
, *new_dentry
= NULL
;
893 mutex_lock(&sysfs_rename_mutex
);
894 BUG_ON(!sd
->s_parent
);
895 new_parent_sd
= new_parent_kobj
->sd
? new_parent_kobj
->sd
: &sysfs_root
;
898 if (sd
->s_parent
== new_parent_sd
)
899 goto out
; /* nothing to move */
902 old_dentry
= sysfs_get_dentry(sd
);
903 if (IS_ERR(old_dentry
)) {
904 error
= PTR_ERR(old_dentry
);
908 old_parent
= old_dentry
->d_parent
;
910 new_parent
= sysfs_get_dentry(new_parent_sd
);
911 if (IS_ERR(new_parent
)) {
912 error
= PTR_ERR(new_parent
);
918 mutex_lock(&old_parent
->d_inode
->i_mutex
);
919 if (!mutex_trylock(&new_parent
->d_inode
->i_mutex
)) {
920 mutex_unlock(&old_parent
->d_inode
->i_mutex
);
923 mutex_lock(&sysfs_mutex
);
926 if (sysfs_find_dirent(new_parent_sd
, sd
->s_name
))
930 new_dentry
= d_alloc_name(new_parent
, sd
->s_name
);
935 d_add(new_dentry
, NULL
);
936 d_move(old_dentry
, new_dentry
);
938 /* Remove from old parent's list and insert into new parent's list. */
939 sysfs_unlink_sibling(sd
);
940 sysfs_get(new_parent_sd
);
941 sysfs_put(sd
->s_parent
);
942 sd
->s_parent
= new_parent_sd
;
943 sysfs_link_sibling(sd
);
946 mutex_unlock(&sysfs_mutex
);
947 mutex_unlock(&new_parent
->d_inode
->i_mutex
);
948 mutex_unlock(&old_parent
->d_inode
->i_mutex
);
953 mutex_unlock(&sysfs_rename_mutex
);
957 /* Relationship between s_mode and the DT_xxx types */
958 static inline unsigned char dt_type(struct sysfs_dirent
*sd
)
960 return (sd
->s_mode
>> 12) & 15;
963 static int sysfs_readdir(struct file
* filp
, void * dirent
, filldir_t filldir
)
965 struct dentry
*dentry
= filp
->f_path
.dentry
;
966 struct sysfs_dirent
* parent_sd
= dentry
->d_fsdata
;
967 struct sysfs_dirent
*pos
;
970 if (filp
->f_pos
== 0) {
971 ino
= parent_sd
->s_ino
;
972 if (filldir(dirent
, ".", 1, filp
->f_pos
, ino
, DT_DIR
) == 0)
975 if (filp
->f_pos
== 1) {
976 if (parent_sd
->s_parent
)
977 ino
= parent_sd
->s_parent
->s_ino
;
979 ino
= parent_sd
->s_ino
;
980 if (filldir(dirent
, "..", 2, filp
->f_pos
, ino
, DT_DIR
) == 0)
983 if ((filp
->f_pos
> 1) && (filp
->f_pos
< INT_MAX
)) {
984 mutex_lock(&sysfs_mutex
);
986 /* Skip the dentries we have already reported */
987 pos
= parent_sd
->s_dir
.children
;
988 while (pos
&& (filp
->f_pos
> pos
->s_ino
))
989 pos
= pos
->s_sibling
;
991 for ( ; pos
; pos
= pos
->s_sibling
) {
997 filp
->f_pos
= ino
= pos
->s_ino
;
999 if (filldir(dirent
, name
, len
, filp
->f_pos
, ino
,
1004 filp
->f_pos
= INT_MAX
;
1005 mutex_unlock(&sysfs_mutex
);
1011 const struct file_operations sysfs_dir_operations
= {
1012 .read
= generic_read_dir
,
1013 .readdir
= sysfs_readdir
,
1014 .llseek
= generic_file_llseek
,