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_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_active - get an active reference to sysfs_dirent
88 * @sd: sysfs_dirent to get an active reference to
90 * Get an active reference of @sd. This function is noop if @sd
94 * Pointer to @sd on success, NULL on failure.
96 struct sysfs_dirent
*sysfs_get_active(struct sysfs_dirent
*sd
)
104 v
= atomic_read(&sd
->s_active
);
108 t
= atomic_cmpxchg(&sd
->s_active
, v
, v
+ 1);
109 if (likely(t
== v
)) {
110 rwsem_acquire_read(&sd
->dep_map
, 0, 1, _RET_IP_
);
121 * sysfs_put_active - put an active reference to sysfs_dirent
122 * @sd: sysfs_dirent to put an active reference to
124 * Put an active reference to @sd. This function is noop if @sd
127 void sysfs_put_active(struct sysfs_dirent
*sd
)
129 struct completion
*cmpl
;
135 rwsem_release(&sd
->dep_map
, 1, _RET_IP_
);
136 v
= atomic_dec_return(&sd
->s_active
);
137 if (likely(v
!= SD_DEACTIVATED_BIAS
))
140 /* atomic_dec_return() is a mb(), we'll always see the updated
143 cmpl
= (void *)sd
->s_sibling
;
148 * sysfs_deactivate - deactivate sysfs_dirent
149 * @sd: sysfs_dirent to deactivate
151 * Deny new active references and drain existing ones.
153 static void sysfs_deactivate(struct sysfs_dirent
*sd
)
155 DECLARE_COMPLETION_ONSTACK(wait
);
158 BUG_ON(sd
->s_sibling
|| !(sd
->s_flags
& SYSFS_FLAG_REMOVED
));
160 if (!(sysfs_type(sd
) & SYSFS_ACTIVE_REF
))
163 sd
->s_sibling
= (void *)&wait
;
165 rwsem_acquire(&sd
->dep_map
, 0, 0, _RET_IP_
);
166 /* atomic_add_return() is a mb(), put_active() will always see
167 * the updated sd->s_sibling.
169 v
= atomic_add_return(SD_DEACTIVATED_BIAS
, &sd
->s_active
);
171 if (v
!= SD_DEACTIVATED_BIAS
) {
172 lock_contended(&sd
->dep_map
, _RET_IP_
);
173 wait_for_completion(&wait
);
176 sd
->s_sibling
= NULL
;
178 lock_acquired(&sd
->dep_map
, _RET_IP_
);
179 rwsem_release(&sd
->dep_map
, 1, _RET_IP_
);
182 static int sysfs_alloc_ino(ino_t
*pino
)
187 spin_lock(&sysfs_ino_lock
);
188 rc
= ida_get_new_above(&sysfs_ino_ida
, 2, &ino
);
189 spin_unlock(&sysfs_ino_lock
);
192 if (ida_pre_get(&sysfs_ino_ida
, GFP_KERNEL
))
201 static void sysfs_free_ino(ino_t ino
)
203 spin_lock(&sysfs_ino_lock
);
204 ida_remove(&sysfs_ino_ida
, ino
);
205 spin_unlock(&sysfs_ino_lock
);
208 void release_sysfs_dirent(struct sysfs_dirent
* sd
)
210 struct sysfs_dirent
*parent_sd
;
213 /* Moving/renaming is always done while holding reference.
214 * sd->s_parent won't change beneath us.
216 parent_sd
= sd
->s_parent
;
218 if (sysfs_type(sd
) == SYSFS_KOBJ_LINK
)
219 sysfs_put(sd
->s_symlink
.target_sd
);
220 if (sysfs_type(sd
) & SYSFS_COPY_NAME
)
222 if (sd
->s_iattr
&& sd
->s_iattr
->ia_secdata
)
223 security_release_secctx(sd
->s_iattr
->ia_secdata
,
224 sd
->s_iattr
->ia_secdata_len
);
226 sysfs_free_ino(sd
->s_ino
);
227 kmem_cache_free(sysfs_dir_cachep
, sd
);
230 if (sd
&& atomic_dec_and_test(&sd
->s_count
))
234 static int sysfs_dentry_delete(const struct dentry
*dentry
)
236 struct sysfs_dirent
*sd
= dentry
->d_fsdata
;
237 return !!(sd
->s_flags
& SYSFS_FLAG_REMOVED
);
240 static int sysfs_dentry_revalidate(struct dentry
*dentry
, struct nameidata
*nd
)
242 struct sysfs_dirent
*sd
= dentry
->d_fsdata
;
245 mutex_lock(&sysfs_mutex
);
247 /* The sysfs dirent has been deleted */
248 if (sd
->s_flags
& SYSFS_FLAG_REMOVED
)
251 /* The sysfs dirent has been moved? */
252 if (dentry
->d_parent
->d_fsdata
!= sd
->s_parent
)
255 /* The sysfs dirent has been renamed */
256 if (strcmp(dentry
->d_name
.name
, sd
->s_name
) != 0)
259 mutex_unlock(&sysfs_mutex
);
263 /* Remove the dentry from the dcache hashes.
264 * If this is a deleted dentry we use d_drop instead of d_delete
265 * so sysfs doesn't need to cope with negative dentries.
267 * If this is a dentry that has simply been renamed we
268 * use d_drop to remove it from the dcache lookup on its
269 * old parent. If this dentry persists later when a lookup
270 * is performed at its new name the dentry will be readded
271 * to the dcache hashes.
273 is_dir
= (sysfs_type(sd
) == SYSFS_DIR
);
274 mutex_unlock(&sysfs_mutex
);
276 /* If we have submounts we must allow the vfs caches
277 * to lie about the state of the filesystem to prevent
278 * leaks and other nasty things.
280 if (have_submounts(dentry
))
282 shrink_dcache_parent(dentry
);
288 static void sysfs_dentry_iput(struct dentry
*dentry
, struct inode
*inode
)
290 struct sysfs_dirent
* sd
= dentry
->d_fsdata
;
296 static const struct dentry_operations sysfs_dentry_ops
= {
297 .d_revalidate
= sysfs_dentry_revalidate
,
298 .d_delete
= sysfs_dentry_delete
,
299 .d_iput
= sysfs_dentry_iput
,
302 struct sysfs_dirent
*sysfs_new_dirent(const char *name
, umode_t mode
, int type
)
304 char *dup_name
= NULL
;
305 struct sysfs_dirent
*sd
;
307 if (type
& SYSFS_COPY_NAME
) {
308 name
= dup_name
= kstrdup(name
, GFP_KERNEL
);
313 sd
= kmem_cache_zalloc(sysfs_dir_cachep
, GFP_KERNEL
);
317 if (sysfs_alloc_ino(&sd
->s_ino
))
320 atomic_set(&sd
->s_count
, 1);
321 atomic_set(&sd
->s_active
, 0);
330 kmem_cache_free(sysfs_dir_cachep
, sd
);
337 * sysfs_addrm_start - prepare for sysfs_dirent add/remove
338 * @acxt: pointer to sysfs_addrm_cxt to be used
339 * @parent_sd: parent sysfs_dirent
341 * This function is called when the caller is about to add or
342 * remove sysfs_dirent under @parent_sd. This function acquires
343 * sysfs_mutex. @acxt is used to keep and pass context to
344 * other addrm functions.
347 * Kernel thread context (may sleep). sysfs_mutex is locked on
350 void sysfs_addrm_start(struct sysfs_addrm_cxt
*acxt
,
351 struct sysfs_dirent
*parent_sd
)
353 memset(acxt
, 0, sizeof(*acxt
));
354 acxt
->parent_sd
= parent_sd
;
356 mutex_lock(&sysfs_mutex
);
360 * __sysfs_add_one - add sysfs_dirent to parent without warning
361 * @acxt: addrm context to use
362 * @sd: sysfs_dirent to be added
364 * Get @acxt->parent_sd and set sd->s_parent to it and increment
365 * nlink of parent inode if @sd is a directory and link into the
366 * children list of the parent.
368 * This function should be called between calls to
369 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
370 * passed the same @acxt as passed to sysfs_addrm_start().
373 * Determined by sysfs_addrm_start().
376 * 0 on success, -EEXIST if entry with the given name already
379 int __sysfs_add_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
381 struct sysfs_inode_attrs
*ps_iattr
;
383 if (sysfs_find_dirent(acxt
->parent_sd
, sd
->s_ns
, sd
->s_name
))
386 sd
->s_parent
= sysfs_get(acxt
->parent_sd
);
388 sysfs_link_sibling(sd
);
390 /* Update timestamps on the parent */
391 ps_iattr
= acxt
->parent_sd
->s_iattr
;
393 struct iattr
*ps_iattrs
= &ps_iattr
->ia_iattr
;
394 ps_iattrs
->ia_ctime
= ps_iattrs
->ia_mtime
= CURRENT_TIME
;
401 * sysfs_pathname - return full path to sysfs dirent
402 * @sd: sysfs_dirent whose path we want
403 * @path: caller allocated buffer
405 * Gives the name "/" to the sysfs_root entry; any path returned
406 * is relative to wherever sysfs is mounted.
408 * XXX: does no error checking on @path size
410 static char *sysfs_pathname(struct sysfs_dirent
*sd
, char *path
)
413 sysfs_pathname(sd
->s_parent
, path
);
416 strcat(path
, sd
->s_name
);
421 * sysfs_add_one - add sysfs_dirent to parent
422 * @acxt: addrm context to use
423 * @sd: sysfs_dirent to be added
425 * Get @acxt->parent_sd and set sd->s_parent to it and increment
426 * nlink of parent inode if @sd is a directory and link into the
427 * children list of the parent.
429 * This function should be called between calls to
430 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
431 * passed the same @acxt as passed to sysfs_addrm_start().
434 * Determined by sysfs_addrm_start().
437 * 0 on success, -EEXIST if entry with the given name already
440 int sysfs_add_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
444 ret
= __sysfs_add_one(acxt
, sd
);
445 if (ret
== -EEXIST
) {
446 char *path
= kzalloc(PATH_MAX
, GFP_KERNEL
);
448 "sysfs: cannot create duplicate filename '%s'\n",
449 (path
== NULL
) ? sd
->s_name
:
450 strcat(strcat(sysfs_pathname(acxt
->parent_sd
, path
), "/"),
459 * sysfs_remove_one - remove sysfs_dirent from parent
460 * @acxt: addrm context to use
461 * @sd: sysfs_dirent to be removed
463 * Mark @sd removed and drop nlink of parent inode if @sd is a
464 * directory. @sd is unlinked from the children list.
466 * This function should be called between calls to
467 * sysfs_addrm_start() and sysfs_addrm_finish() and should be
468 * passed the same @acxt as passed to sysfs_addrm_start().
471 * Determined by sysfs_addrm_start().
473 void sysfs_remove_one(struct sysfs_addrm_cxt
*acxt
, struct sysfs_dirent
*sd
)
475 struct sysfs_inode_attrs
*ps_iattr
;
477 BUG_ON(sd
->s_flags
& SYSFS_FLAG_REMOVED
);
479 sysfs_unlink_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
;
488 sd
->s_flags
|= SYSFS_FLAG_REMOVED
;
489 sd
->s_sibling
= acxt
->removed
;
494 * sysfs_addrm_finish - finish up sysfs_dirent add/remove
495 * @acxt: addrm context to finish up
497 * Finish up sysfs_dirent add/remove. Resources acquired by
498 * sysfs_addrm_start() are released and removed sysfs_dirents are
502 * sysfs_mutex is released.
504 void sysfs_addrm_finish(struct sysfs_addrm_cxt
*acxt
)
506 /* release resources acquired by sysfs_addrm_start() */
507 mutex_unlock(&sysfs_mutex
);
509 /* kill removed sysfs_dirents */
510 while (acxt
->removed
) {
511 struct sysfs_dirent
*sd
= acxt
->removed
;
513 acxt
->removed
= sd
->s_sibling
;
514 sd
->s_sibling
= NULL
;
516 sysfs_deactivate(sd
);
523 * sysfs_find_dirent - find sysfs_dirent with the given name
524 * @parent_sd: sysfs_dirent to search under
525 * @name: name to look for
527 * Look for sysfs_dirent with name @name under @parent_sd.
530 * mutex_lock(sysfs_mutex)
533 * Pointer to sysfs_dirent if found, NULL if not.
535 struct sysfs_dirent
*sysfs_find_dirent(struct sysfs_dirent
*parent_sd
,
537 const unsigned char *name
)
539 struct sysfs_dirent
*sd
;
541 for (sd
= parent_sd
->s_dir
.children
; sd
; sd
= sd
->s_sibling
) {
542 if (ns
&& sd
->s_ns
&& (sd
->s_ns
!= ns
))
544 if (!strcmp(sd
->s_name
, name
))
551 * sysfs_get_dirent - find and get sysfs_dirent with the given name
552 * @parent_sd: sysfs_dirent to search under
553 * @name: name to look for
555 * Look for sysfs_dirent with name @name under @parent_sd and get
559 * Kernel thread context (may sleep). Grabs sysfs_mutex.
562 * Pointer to sysfs_dirent if found, NULL if not.
564 struct sysfs_dirent
*sysfs_get_dirent(struct sysfs_dirent
*parent_sd
,
566 const unsigned char *name
)
568 struct sysfs_dirent
*sd
;
570 mutex_lock(&sysfs_mutex
);
571 sd
= sysfs_find_dirent(parent_sd
, ns
, name
);
573 mutex_unlock(&sysfs_mutex
);
577 EXPORT_SYMBOL_GPL(sysfs_get_dirent
);
579 static int create_dir(struct kobject
*kobj
, struct sysfs_dirent
*parent_sd
,
580 enum kobj_ns_type type
, const void *ns
, const char *name
,
581 struct sysfs_dirent
**p_sd
)
583 umode_t mode
= S_IFDIR
| S_IRWXU
| S_IRUGO
| S_IXUGO
;
584 struct sysfs_addrm_cxt acxt
;
585 struct sysfs_dirent
*sd
;
589 sd
= sysfs_new_dirent(name
, mode
, SYSFS_DIR
);
593 sd
->s_flags
|= (type
<< SYSFS_NS_TYPE_SHIFT
);
595 sd
->s_dir
.kobj
= kobj
;
598 sysfs_addrm_start(&acxt
, parent_sd
);
599 rc
= sysfs_add_one(&acxt
, sd
);
600 sysfs_addrm_finish(&acxt
);
610 int sysfs_create_subdir(struct kobject
*kobj
, const char *name
,
611 struct sysfs_dirent
**p_sd
)
613 return create_dir(kobj
, kobj
->sd
,
614 KOBJ_NS_TYPE_NONE
, NULL
, name
, p_sd
);
618 * sysfs_read_ns_type: return associated ns_type
619 * @kobj: the kobject being queried
621 * Each kobject can be tagged with exactly one namespace type
622 * (i.e. network or user). Return the ns_type associated with
625 static enum kobj_ns_type
sysfs_read_ns_type(struct kobject
*kobj
)
627 const struct kobj_ns_type_operations
*ops
;
628 enum kobj_ns_type type
;
630 ops
= kobj_child_ns_ops(kobj
);
632 return KOBJ_NS_TYPE_NONE
;
635 BUG_ON(type
<= KOBJ_NS_TYPE_NONE
);
636 BUG_ON(type
>= KOBJ_NS_TYPES
);
637 BUG_ON(!kobj_ns_type_registered(type
));
643 * sysfs_create_dir - create a directory for an object.
644 * @kobj: object we're creating directory for.
646 int sysfs_create_dir(struct kobject
* kobj
)
648 enum kobj_ns_type type
;
649 struct sysfs_dirent
*parent_sd
, *sd
;
650 const void *ns
= NULL
;
656 parent_sd
= kobj
->parent
->sd
;
658 parent_sd
= &sysfs_root
;
660 if (sysfs_ns_type(parent_sd
))
661 ns
= kobj
->ktype
->namespace(kobj
);
662 type
= sysfs_read_ns_type(kobj
);
664 error
= create_dir(kobj
, parent_sd
, type
, ns
, kobject_name(kobj
), &sd
);
670 static struct dentry
* sysfs_lookup(struct inode
*dir
, struct dentry
*dentry
,
671 struct nameidata
*nd
)
673 struct dentry
*ret
= NULL
;
674 struct dentry
*parent
= dentry
->d_parent
;
675 struct sysfs_dirent
*parent_sd
= parent
->d_fsdata
;
676 struct sysfs_dirent
*sd
;
678 enum kobj_ns_type type
;
681 mutex_lock(&sysfs_mutex
);
683 type
= sysfs_ns_type(parent_sd
);
684 ns
= sysfs_info(dir
->i_sb
)->ns
[type
];
686 sd
= sysfs_find_dirent(parent_sd
, ns
, dentry
->d_name
.name
);
690 ret
= ERR_PTR(-ENOENT
);
694 /* attach dentry and inode */
695 inode
= sysfs_get_inode(dir
->i_sb
, sd
);
697 ret
= ERR_PTR(-ENOMEM
);
701 /* instantiate and hash dentry */
702 ret
= d_find_alias(inode
);
704 dentry
->d_op
= &sysfs_dentry_ops
;
705 dentry
->d_fsdata
= sysfs_get(sd
);
706 d_add(dentry
, inode
);
713 mutex_unlock(&sysfs_mutex
);
717 const struct inode_operations sysfs_dir_inode_operations
= {
718 .lookup
= sysfs_lookup
,
719 .permission
= sysfs_permission
,
720 .setattr
= sysfs_setattr
,
721 .getattr
= sysfs_getattr
,
722 .setxattr
= sysfs_setxattr
,
725 static void remove_dir(struct sysfs_dirent
*sd
)
727 struct sysfs_addrm_cxt acxt
;
729 sysfs_addrm_start(&acxt
, sd
->s_parent
);
730 sysfs_remove_one(&acxt
, sd
);
731 sysfs_addrm_finish(&acxt
);
734 void sysfs_remove_subdir(struct sysfs_dirent
*sd
)
740 static void __sysfs_remove_dir(struct sysfs_dirent
*dir_sd
)
742 struct sysfs_addrm_cxt acxt
;
743 struct sysfs_dirent
**pos
;
748 pr_debug("sysfs %s: removing dir\n", dir_sd
->s_name
);
749 sysfs_addrm_start(&acxt
, dir_sd
);
750 pos
= &dir_sd
->s_dir
.children
;
752 struct sysfs_dirent
*sd
= *pos
;
754 if (sysfs_type(sd
) != SYSFS_DIR
)
755 sysfs_remove_one(&acxt
, sd
);
757 pos
= &(*pos
)->s_sibling
;
759 sysfs_addrm_finish(&acxt
);
765 * sysfs_remove_dir - remove an object's directory.
768 * The only thing special about this is that we remove any files in
769 * the directory before we remove the directory, and we've inlined
770 * what used to be sysfs_rmdir() below, instead of calling separately.
773 void sysfs_remove_dir(struct kobject
* kobj
)
775 struct sysfs_dirent
*sd
= kobj
->sd
;
777 spin_lock(&sysfs_assoc_lock
);
779 spin_unlock(&sysfs_assoc_lock
);
781 __sysfs_remove_dir(sd
);
784 int sysfs_rename(struct sysfs_dirent
*sd
,
785 struct sysfs_dirent
*new_parent_sd
, const void *new_ns
,
786 const char *new_name
)
788 const char *dup_name
= NULL
;
791 mutex_lock(&sysfs_mutex
);
794 if ((sd
->s_parent
== new_parent_sd
) && (sd
->s_ns
== new_ns
) &&
795 (strcmp(sd
->s_name
, new_name
) == 0))
796 goto out
; /* nothing to rename */
799 if (sysfs_find_dirent(new_parent_sd
, new_ns
, new_name
))
802 /* rename sysfs_dirent */
803 if (strcmp(sd
->s_name
, new_name
) != 0) {
805 new_name
= dup_name
= kstrdup(new_name
, GFP_KERNEL
);
809 dup_name
= sd
->s_name
;
810 sd
->s_name
= new_name
;
813 /* Remove from old parent's list and insert into new parent's list. */
814 if (sd
->s_parent
!= new_parent_sd
) {
815 sysfs_unlink_sibling(sd
);
816 sysfs_get(new_parent_sd
);
817 sysfs_put(sd
->s_parent
);
818 sd
->s_parent
= new_parent_sd
;
819 sysfs_link_sibling(sd
);
825 mutex_unlock(&sysfs_mutex
);
830 int sysfs_rename_dir(struct kobject
*kobj
, const char *new_name
)
832 struct sysfs_dirent
*parent_sd
= kobj
->sd
->s_parent
;
833 const void *new_ns
= NULL
;
835 if (sysfs_ns_type(parent_sd
))
836 new_ns
= kobj
->ktype
->namespace(kobj
);
838 return sysfs_rename(kobj
->sd
, parent_sd
, new_ns
, new_name
);
841 int sysfs_move_dir(struct kobject
*kobj
, struct kobject
*new_parent_kobj
)
843 struct sysfs_dirent
*sd
= kobj
->sd
;
844 struct sysfs_dirent
*new_parent_sd
;
845 const void *new_ns
= NULL
;
847 BUG_ON(!sd
->s_parent
);
848 if (sysfs_ns_type(sd
->s_parent
))
849 new_ns
= kobj
->ktype
->namespace(kobj
);
850 new_parent_sd
= new_parent_kobj
&& new_parent_kobj
->sd
?
851 new_parent_kobj
->sd
: &sysfs_root
;
853 return sysfs_rename(sd
, new_parent_sd
, new_ns
, sd
->s_name
);
856 /* Relationship between s_mode and the DT_xxx types */
857 static inline unsigned char dt_type(struct sysfs_dirent
*sd
)
859 return (sd
->s_mode
>> 12) & 15;
862 static int sysfs_dir_release(struct inode
*inode
, struct file
*filp
)
864 sysfs_put(filp
->private_data
);
868 static struct sysfs_dirent
*sysfs_dir_pos(const void *ns
,
869 struct sysfs_dirent
*parent_sd
, ino_t ino
, struct sysfs_dirent
*pos
)
872 int valid
= !(pos
->s_flags
& SYSFS_FLAG_REMOVED
) &&
873 pos
->s_parent
== parent_sd
&&
879 if (!pos
&& (ino
> 1) && (ino
< INT_MAX
)) {
880 pos
= parent_sd
->s_dir
.children
;
881 while (pos
&& (ino
> pos
->s_ino
))
882 pos
= pos
->s_sibling
;
884 while (pos
&& pos
->s_ns
&& pos
->s_ns
!= ns
)
885 pos
= pos
->s_sibling
;
889 static struct sysfs_dirent
*sysfs_dir_next_pos(const void *ns
,
890 struct sysfs_dirent
*parent_sd
, ino_t ino
, struct sysfs_dirent
*pos
)
892 pos
= sysfs_dir_pos(ns
, parent_sd
, ino
, pos
);
894 pos
= pos
->s_sibling
;
895 while (pos
&& pos
->s_ns
&& pos
->s_ns
!= ns
)
896 pos
= pos
->s_sibling
;
900 static int sysfs_readdir(struct file
* filp
, void * dirent
, filldir_t filldir
)
902 struct dentry
*dentry
= filp
->f_path
.dentry
;
903 struct sysfs_dirent
* parent_sd
= dentry
->d_fsdata
;
904 struct sysfs_dirent
*pos
= filp
->private_data
;
905 enum kobj_ns_type type
;
909 type
= sysfs_ns_type(parent_sd
);
910 ns
= sysfs_info(dentry
->d_sb
)->ns
[type
];
912 if (filp
->f_pos
== 0) {
913 ino
= parent_sd
->s_ino
;
914 if (filldir(dirent
, ".", 1, filp
->f_pos
, ino
, DT_DIR
) == 0)
917 if (filp
->f_pos
== 1) {
918 if (parent_sd
->s_parent
)
919 ino
= parent_sd
->s_parent
->s_ino
;
921 ino
= parent_sd
->s_ino
;
922 if (filldir(dirent
, "..", 2, filp
->f_pos
, ino
, DT_DIR
) == 0)
925 mutex_lock(&sysfs_mutex
);
926 for (pos
= sysfs_dir_pos(ns
, parent_sd
, filp
->f_pos
, pos
);
928 pos
= sysfs_dir_next_pos(ns
, parent_sd
, filp
->f_pos
, pos
)) {
938 filp
->private_data
= sysfs_get(pos
);
940 mutex_unlock(&sysfs_mutex
);
941 ret
= filldir(dirent
, name
, len
, filp
->f_pos
, ino
, type
);
942 mutex_lock(&sysfs_mutex
);
946 mutex_unlock(&sysfs_mutex
);
947 if ((filp
->f_pos
> 1) && !pos
) { /* EOF */
948 filp
->f_pos
= INT_MAX
;
949 filp
->private_data
= NULL
;
955 const struct file_operations sysfs_dir_operations
= {
956 .read
= generic_read_dir
,
957 .readdir
= sysfs_readdir
,
958 .release
= sysfs_dir_release
,
959 .llseek
= generic_file_llseek
,