blob: 0b45ff42f3741123a15f58d426e201a78d20b3d0 [file] [log] [blame]
* fs/sysfs/dir.c - sysfs core and dir operation implementation
* Copyright (c) 2001-3 Patrick Mochel
* Copyright (c) 2007 SUSE Linux Products GmbH
* Copyright (c) 2007 Tejun Heo <>
* This file is released under the GPLv2.
* Please see Documentation/filesystems/sysfs.txt for more information.
#undef DEBUG
#include <linux/fs.h>
#include <linux/kobject.h>
#include <linux/slab.h>
#include "sysfs.h"
void sysfs_warn_dup(struct kernfs_node *parent, const char *name)
char *buf, *path = NULL;
buf = kzalloc(PATH_MAX, GFP_KERNEL);
if (buf)
path = kernfs_path(parent, buf, PATH_MAX);
WARN(1, KERN_WARNING "sysfs: cannot create duplicate filename '%s/%s'\n",
path, name);
* sysfs_create_dir_ns - create a directory for an object with a namespace tag
* @kobj: object we're creating directory for
* @ns: the namespace tag to use
int sysfs_create_dir_ns(struct kobject *kobj, const void *ns)
struct kernfs_node *parent, *kn;
if (kobj->parent)
parent = kobj->parent->sd;
parent = sysfs_root_kn;
if (!parent)
return -ENOENT;
kn = kernfs_create_dir_ns(parent, kobject_name(kobj),
S_IRWXU | S_IRUGO | S_IXUGO, kobj, ns);
if (IS_ERR(kn)) {
if (PTR_ERR(kn) == -EEXIST)
sysfs_warn_dup(parent, kobject_name(kobj));
return PTR_ERR(kn);
kobj->sd = kn;
return 0;
* sysfs_remove_dir - remove an object's directory.
* @kobj: object.
* The only thing special about this is that we remove any files in
* the directory before we remove the directory, and we've inlined
* what used to be sysfs_rmdir() below, instead of calling separately.
void sysfs_remove_dir(struct kobject *kobj)
struct kernfs_node *kn = kobj->sd;
* In general, kboject owner is responsible for ensuring removal
* doesn't race with other operations and sysfs doesn't provide any
* protection; however, when @kobj is used as a symlink target, the
* symlinking entity usually doesn't own @kobj and thus has no
* control over removal. @kobj->sd may be removed anytime
* and symlink code may end up dereferencing an already freed node.
* sysfs_symlink_target_lock synchronizes @kobj->sd
* disassociation against symlink operations so that symlink code
* can safely dereference @kobj->sd.
kobj->sd = NULL;
if (kn) {
WARN_ON_ONCE(kernfs_type(kn) != KERNFS_DIR);
int sysfs_rename_dir_ns(struct kobject *kobj, const char *new_name,
const void *new_ns)
struct kernfs_node *parent;
int ret;
parent = kernfs_get_parent(kobj->sd);
ret = kernfs_rename_ns(kobj->sd, parent, new_name, new_ns);
return ret;
int sysfs_move_dir_ns(struct kobject *kobj, struct kobject *new_parent_kobj,
const void *new_ns)
struct kernfs_node *kn = kobj->sd;
struct kernfs_node *new_parent;
new_parent = new_parent_kobj && new_parent_kobj->sd ?
new_parent_kobj->sd : sysfs_root_kn;
return kernfs_rename_ns(kn, new_parent, kn->name, new_ns);