static int sysfs_readdir(struct file *file, struct dir_context *ctx)
{
struct dentry *dentry = file->f_path.dentry;
struct sysfs_dirent *parent_sd = dentry->d_fsdata;
struct sysfs_dirent *pos = file->private_data;
enum kobj_ns_type type;
const void *ns;
type = sysfs_ns_type(parent_sd);
ns = sysfs_info(dentry->d_sb)->ns[type];
if (!dir_emit_dots(file, ctx))
return 0;
mutex_lock(&sysfs_mutex);
for (pos = sysfs_dir_pos(ns, parent_sd, ctx->pos, pos);
pos;
pos = sysfs_dir_next_pos(ns, parent_sd, ctx->pos, pos)) {
const char *name = pos->s_name;
unsigned int type = dt_type(pos);
int len = strlen(name);
ino_t ino = pos->s_ino;
ctx->pos = pos->s_hash;
file->private_data = sysfs_get(pos);
mutex_unlock(&sysfs_mutex);
if (!dir_emit(ctx, name, len, ino, type))
return 0;
mutex_lock(&sysfs_mutex);
}
mutex_unlock(&sysfs_mutex);
file->private_data = NULL;
ctx->pos = INT_MAX;
return 0;
}
/**
* __sysfs_add_one - add sysfs_dirent to parent without warning
* @acxt: addrm context to use
* @sd: sysfs_dirent to be added
* @parent_sd: the parent sysfs_dirent to add @sd to
*
* Get @parent_sd and set @sd->s_parent to it and increment nlink of
* the parent inode if @sd is a directory and link into the children
* list of the parent.
*
* This function should be called between calls to
* sysfs_addrm_start() and sysfs_addrm_finish() and should be
* passed the same @acxt as passed to sysfs_addrm_start().
*
* LOCKING:
* Determined by sysfs_addrm_start().
*
* RETURNS:
* 0 on success, -EEXIST if entry with the given name already
* exists.
*/
int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd,
struct sysfs_dirent *parent_sd)
{
struct sysfs_inode_attrs *ps_iattr;
int ret;
if (!!sysfs_ns_type(parent_sd) != !!sd->s_ns) {
WARN(1, KERN_WARNING "sysfs: ns %s in '%s' for '%s'\n",
sysfs_ns_type(parent_sd) ? "required" : "invalid",
parent_sd->s_name, sd->s_name);
return -EINVAL;
}
sd->s_hash = sysfs_name_hash(sd->s_name, sd->s_ns);
sd->s_parent = sysfs_get(parent_sd);
ret = sysfs_link_sibling(sd);
if (ret)
return ret;
/* Update timestamps on the parent */
ps_iattr = parent_sd->s_iattr;
if (ps_iattr) {
struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
}
/* Mark the entry added into directory tree */
sd->s_flags &= ~SYSFS_FLAG_REMOVED;
return 0;
}
static int internal_create_group(struct kobject *kobj, int update,
const struct attribute_group *grp)
{
struct sysfs_dirent *sd;
int error;
BUG_ON(!kobj || (!update && !kobj->sd));
/* Updates may happen before the object has been instantiated */
if (unlikely(update && !kobj->sd))
return -EINVAL;
if (!grp->attrs && !grp->bin_attrs) {
WARN(1, "sysfs: (bin_)attrs not set by subsystem for group: %s/%s\n",
kobj->name, grp->name ? "" : grp->name);
return -EINVAL;
}
if (grp->name) {
error = sysfs_create_subdir(kobj, grp->name, &sd);
if (error)
return error;
} else
sd = kobj->sd;
sysfs_get(sd);
error = create_files(sd, kobj, grp, update);
if (error) {
if (grp->name)
sysfs_remove_subdir(sd);
}
sysfs_put(sd);
return error;
}
static int internal_create_group(struct kobject *kobj, int update,
const struct attribute_group *grp)
{
struct sysfs_dirent *sd;
int error;
BUG_ON(!kobj || (!update && !kobj->sd));
/* Updates may happen before the object has been instantiated */
if (unlikely(update && !kobj->sd))
return -EINVAL;
if (grp->name) {
error = sysfs_create_subdir(kobj, grp->name, &sd);
if (error)
return error;
} else
sd = kobj->sd;
sysfs_get(sd);
error = create_files(sd, kobj, grp, update);
if (error) {
if (grp->name)
sysfs_remove_subdir(sd);
}
sysfs_put(sd);
return error;
}
/**
* sysfs_add_one - add sysfs_dirent to parent
* @acxt: addrm context to use
* @sd: sysfs_dirent to be added
*
* Get @acxt->parent_sd and set sd->s_parent to it and increment
* nlink of parent inode if @sd is a directory. @sd is NOT
* linked into the children list of the parent. The caller
* should invoke sysfs_link_sibling() after this function
* completes if @sd needs to be on the children list.
*
* This function should be called between calls to
* sysfs_addrm_start() and sysfs_addrm_finish() and should be
* passed the same @acxt as passed to sysfs_addrm_start().
*
* LOCKING:
* Determined by sysfs_addrm_start().
*/
void sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
{
sd->s_parent = sysfs_get(acxt->parent_sd);
if (sysfs_type(sd) == SYSFS_DIR && acxt->parent_inode)
inc_nlink(acxt->parent_inode);
acxt->cnt++;
}
static int sysfs_do_create_link(struct kobject *kobj, struct kobject *target,
const char *name, int warn)
{
struct sysfs_dirent *parent_sd = NULL;
struct sysfs_dirent *target_sd = NULL;
struct sysfs_dirent *sd = NULL;
struct sysfs_addrm_cxt acxt;
int error;
BUG_ON(!name);
if (!kobj)
parent_sd = &sysfs_root;
else
parent_sd = kobj->sd;
error = -EFAULT;
if (!parent_sd)
goto out_put;
/* target->sd can go away beneath us but is protected with
* sysfs_assoc_lock. Fetch target_sd from it.
*/
spin_lock(&sysfs_assoc_lock);
if (target->sd)
target_sd = sysfs_get(target->sd);
spin_unlock(&sysfs_assoc_lock);
error = -ENOENT;
if (!target_sd)
goto out_put;
error = -ENOMEM;
sd = sysfs_new_dirent(name, S_IFLNK|S_IRWXUGO, SYSFS_KOBJ_LINK);
if (!sd)
goto out_put;
sd->s_symlink.target_sd = target_sd;
target_sd = NULL; /* reference is now owned by the symlink */
sysfs_addrm_start(&acxt, parent_sd);
if (warn)
error = sysfs_add_one(&acxt, sd);
else
error = __sysfs_add_one(&acxt, sd);
sysfs_addrm_finish(&acxt);
if (error)
goto out_put;
return 0;
out_put:
sysfs_put(target_sd);
sysfs_put(sd);
return error;
}
/**
* sysfs_attach_dentry - associate sysfs_dirent with dentry
* @sd: target sysfs_dirent
* @dentry: dentry to associate
*
* Associate @sd with @dentry. This is protected by
* sysfs_assoc_lock to avoid race with sysfs_d_iput().
*
* LOCKING:
* mutex_lock(sysfs_mutex)
*/
static void sysfs_attach_dentry(struct sysfs_dirent *sd, struct dentry *dentry)
{
dentry->d_op = &sysfs_dentry_ops;
dentry->d_fsdata = sysfs_get(sd);
/* protect sd->s_dentry against sysfs_d_iput */
spin_lock(&sysfs_assoc_lock);
sd->s_dentry = dentry;
spin_unlock(&sysfs_assoc_lock);
d_rehash(dentry);
}
/**
* sysfs_get_dirent - find and get sysfs_dirent with the given name
* @parent_sd: sysfs_dirent to search under
* @name: name to look for
*
* Look for sysfs_dirent with name @name under @parent_sd and get
* it if found.
*
* LOCKING:
* Kernel thread context (may sleep). Grabs sysfs_mutex.
*
* RETURNS:
* Pointer to sysfs_dirent if found, NULL if not.
*/
struct sysfs_dirent *sysfs_get_dirent(struct sysfs_dirent *parent_sd,
const unsigned char *name)
{
struct sysfs_dirent *sd;
mutex_lock(&sysfs_mutex);
sd = sysfs_find_dirent(parent_sd, name);
sysfs_get(sd);
mutex_unlock(&sysfs_mutex);
return sd;
}
static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode)
{
struct bin_attribute *bin_attr;
struct sysfs_inode_attrs *iattrs;
inode->i_private = sysfs_get(sd);
inode->i_mapping->a_ops = &sysfs_aops;
inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
inode->i_op = &sysfs_inode_operations;
inode->i_ino = sd->s_ino;
lockdep_set_class(&inode->i_mutex, &sysfs_inode_imutex_key);
iattrs = sd->s_iattr;
if (iattrs) {
/* sysfs_dirent has non-default attributes
* get them for the new inode from persistent copy
* in sysfs_dirent
*/
set_inode_attr(inode, &iattrs->ia_iattr);
if (iattrs->ia_secdata)
security_inode_notifysecctx(inode,
iattrs->ia_secdata,
iattrs->ia_secdata_len);
} else
set_default_inode_attr(inode, sd->s_mode);
/* initialize inode according to type */
switch (sysfs_type(sd)) {
case SYSFS_DIR:
inode->i_op = &sysfs_dir_inode_operations;
inode->i_fop = &sysfs_dir_operations;
inode->i_nlink = sysfs_count_nlink(sd);
break;
case SYSFS_KOBJ_ATTR:
inode->i_size = PAGE_SIZE;
inode->i_fop = &sysfs_file_operations;
break;
case SYSFS_KOBJ_BIN_ATTR:
bin_attr = sd->s_bin_attr.bin_attr;
inode->i_size = bin_attr->size;
inode->i_fop = &bin_fops;
break;
case SYSFS_KOBJ_LINK:
inode->i_op = &sysfs_symlink_inode_operations;
break;
default:
BUG();
}
unlock_new_inode(inode);
}
/**
* sysfs_remove_file_from_group - remove an attribute file from a group.
* @kobj: object we're acting for.
* @attr: attribute descriptor.
* @group: group name.
*/
void sysfs_remove_file_from_group(struct kobject *kobj,
const struct attribute *attr, const char *group)
{
struct sysfs_dirent *dir_sd;
if (group)
dir_sd = sysfs_get_dirent(kobj->sd, NULL, group);
else
dir_sd = sysfs_get(kobj->sd);
if (dir_sd) {
sysfs_hash_and_remove(dir_sd, NULL, attr->name);
sysfs_put(dir_sd);
}
}
static int sysfs_readdir(struct file * filp, void * dirent, filldir_t filldir)
{
struct dentry *dentry = filp->f_path.dentry;
struct sysfs_dirent * parent_sd = dentry->d_fsdata;
struct sysfs_dirent *pos = filp->private_data;
ino_t ino;
if (filp->f_pos == 0) {
ino = parent_sd->s_ino;
if (filldir(dirent, ".", 1, filp->f_pos, ino, DT_DIR) == 0)
filp->f_pos++;
}
if (filp->f_pos == 1) {
if (parent_sd->s_parent)
ino = parent_sd->s_parent->s_ino;
else
ino = parent_sd->s_ino;
if (filldir(dirent, "..", 2, filp->f_pos, ino, DT_DIR) == 0)
filp->f_pos++;
}
mutex_lock(&sysfs_mutex);
for (pos = sysfs_dir_pos(parent_sd, filp->f_pos, pos);
pos;
pos = sysfs_dir_next_pos(parent_sd, filp->f_pos, pos)) {
const char * name;
unsigned int type;
int len, ret;
name = pos->s_name;
len = strlen(name);
ino = pos->s_ino;
type = dt_type(pos);
filp->f_pos = ino;
filp->private_data = sysfs_get(pos);
mutex_unlock(&sysfs_mutex);
ret = filldir(dirent, name, len, filp->f_pos, ino, type);
mutex_lock(&sysfs_mutex);
if (ret < 0)
break;
}
mutex_unlock(&sysfs_mutex);
if ((filp->f_pos > 1) && !pos) { /* EOF */
filp->f_pos = INT_MAX;
filp->private_data = NULL;
}
return 0;
}
static int sysfs_dir_open(struct inode *inode, struct file *file)
{
struct dentry * dentry = file->f_path.dentry;
struct sysfs_dirent * parent_sd = dentry->d_fsdata;
struct sysfs_dirent * sd;
sd = sysfs_new_dirent("_DIR_", 0, 0);
if (sd) {
mutex_lock(&sysfs_mutex);
sd->s_parent = sysfs_get(parent_sd);
sysfs_link_sibling(sd);
mutex_unlock(&sysfs_mutex);
}
file->private_data = sd;
return sd ? 0 : -ENOMEM;
}
void sysfs_remove_group(struct kobject * kobj,
const struct attribute_group * grp)
{
struct sysfs_dirent *dir_sd = kobj->sd;
struct sysfs_dirent *sd;
if (grp->name) {
sd = sysfs_get_dirent(dir_sd, grp->name);
BUG_ON(!sd);
} else
sd = sysfs_get(dir_sd);
remove_files(sd, grp);
if (grp->name)
sysfs_remove_subdir(sd);
sysfs_put(sd);
}
/**
* sysfs_add_file_to_group - add an attribute file to a pre-existing group.
* @kobj: object we're acting for.
* @attr: attribute descriptor.
* @group: group name.
*/
int sysfs_add_file_to_group(struct kobject *kobj,
const struct attribute *attr, const char *group)
{
struct sysfs_dirent *dir_sd;
int error;
if (group)
dir_sd = sysfs_get_dirent(kobj->sd, NULL, group);
else
dir_sd = sysfs_get(kobj->sd);
if (!dir_sd)
return -ENOENT;
error = sysfs_add_file(dir_sd, attr, SYSFS_KOBJ_ATTR);
sysfs_put(dir_sd);
return error;
}
int sysfs_rename(struct sysfs_dirent *sd, struct sysfs_dirent *new_parent_sd,
const char *new_name, const void *new_ns)
{
int error;
mutex_lock(&sysfs_mutex);
error = 0;
if ((sd->s_parent == new_parent_sd) && (sd->s_ns == new_ns) &&
(strcmp(sd->s_name, new_name) == 0))
goto out; /* nothing to rename */
error = -EEXIST;
if (sysfs_find_dirent(new_parent_sd, new_name, new_ns))
goto out;
/* rename sysfs_dirent */
if (strcmp(sd->s_name, new_name) != 0) {
error = -ENOMEM;
new_name = kstrdup(new_name, GFP_KERNEL);
if (!new_name)
goto out;
kfree(sd->s_name);
sd->s_name = new_name;
}
/*
* Move to the appropriate place in the appropriate directories rbtree.
*/
sysfs_unlink_sibling(sd);
sysfs_get(new_parent_sd);
sysfs_put(sd->s_parent);
sd->s_ns = new_ns;
sd->s_hash = sysfs_name_hash(sd->s_name, sd->s_ns);
sd->s_parent = new_parent_sd;
sysfs_link_sibling(sd);
error = 0;
out:
mutex_unlock(&sysfs_mutex);
return error;
}
int sysfs_rename(struct sysfs_dirent *sd,
struct sysfs_dirent *new_parent_sd, const char *new_name)
{
const char *dup_name = NULL;
int error;
mutex_lock(&sysfs_mutex);
error = 0;
if ((sd->s_parent == new_parent_sd) &&
(strcmp(sd->s_name, new_name) == 0))
goto out; /* nothing to rename */
error = -EEXIST;
if (sysfs_find_dirent(new_parent_sd, new_name))
goto out;
/* rename sysfs_dirent */
if (strcmp(sd->s_name, new_name) != 0) {
error = -ENOMEM;
new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
if (!new_name)
goto out;
dup_name = sd->s_name;
sd->s_name = new_name;
}
/* Remove from old parent's list and insert into new parent's list. */
if (sd->s_parent != new_parent_sd) {
sysfs_unlink_sibling(sd);
sysfs_get(new_parent_sd);
sysfs_put(sd->s_parent);
sd->s_parent = new_parent_sd;
sysfs_link_sibling(sd);
}
error = 0;
out:
mutex_unlock(&sysfs_mutex);
kfree(dup_name);
return error;
}
/**
* __sysfs_add_one - add sysfs_dirent to parent without warning
* @acxt: addrm context to use
* @sd: sysfs_dirent to be added
*
* Get @acxt->parent_sd and set sd->s_parent to it and increment
* nlink of parent inode if @sd is a directory and link into the
* children list of the parent.
*
* This function should be called between calls to
* sysfs_addrm_start() and sysfs_addrm_finish() and should be
* passed the same @acxt as passed to sysfs_addrm_start().
*
* LOCKING:
* Determined by sysfs_addrm_start().
*
* RETURNS:
* 0 on success, -EEXIST if entry with the given name already
* exists.
*/
int __sysfs_add_one(struct sysfs_addrm_cxt *acxt, struct sysfs_dirent *sd)
{
struct sysfs_inode_attrs *ps_iattr;
if (sysfs_find_dirent(acxt->parent_sd, sd->s_name))
return -EEXIST;
sd->s_parent = sysfs_get(acxt->parent_sd);
sysfs_link_sibling(sd);
/* Update timestamps on the parent */
ps_iattr = acxt->parent_sd->s_iattr;
if (ps_iattr) {
struct iattr *ps_iattrs = &ps_iattr->ia_iattr;
ps_iattrs->ia_ctime = ps_iattrs->ia_mtime = CURRENT_TIME;
}
return 0;
}
static struct dentry * sysfs_lookup(struct inode *dir, struct dentry *dentry,
struct nameidata *nd)
{
struct dentry *ret = NULL;
struct sysfs_dirent *parent_sd = dentry->d_parent->d_fsdata;
struct sysfs_dirent *sd;
struct inode *inode;
mutex_lock(&sysfs_mutex);
sd = sysfs_find_dirent(parent_sd, dentry->d_name.name);
/* no such entry */
if (!sd) {
ret = ERR_PTR(-ENOENT);
goto out_unlock;
}
/* attach dentry and inode */
inode = sysfs_get_inode(dir->i_sb, sd);
if (!inode) {
ret = ERR_PTR(-ENOMEM);
goto out_unlock;
}
/* instantiate and hash dentry */
ret = d_find_alias(inode);
if (!ret) {
dentry->d_op = &sysfs_dentry_ops;
dentry->d_fsdata = sysfs_get(sd);
d_add(dentry, inode);
} else {
d_move(ret, dentry);
iput(inode);
}
out_unlock:
mutex_unlock(&sysfs_mutex);
return ret;
}
void sysfs_remove_group(struct kobject * kobj,
const struct attribute_group * grp)
{
struct sysfs_dirent *dir_sd = kobj->sd;
struct sysfs_dirent *sd;
if (grp->name) {
sd = sysfs_get_dirent(dir_sd, NULL, grp->name);
if (!sd) {
WARN(!sd, KERN_WARNING "sysfs group %p not found for "
"kobject '%s'\n", grp, kobject_name(kobj));
return;
}
} else
sd = sysfs_get(dir_sd);
remove_files(sd, kobj, grp);
if (grp->name)
sysfs_remove_subdir(sd);
sysfs_put(sd);
}
static struct dentry *sysfs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
struct dentry *ret = NULL;
struct dentry *parent = dentry->d_parent;
struct sysfs_dirent *parent_sd = parent->d_fsdata;
struct sysfs_dirent *sd;
struct inode *inode;
enum kobj_ns_type type;
const void *ns;
mutex_lock(&sysfs_mutex);
type = sysfs_ns_type(parent_sd);
ns = sysfs_info(dir->i_sb)->ns[type];
sd = sysfs_find_dirent(parent_sd, dentry->d_name.name, ns);
/* no such entry */
if (!sd) {
ret = ERR_PTR(-ENOENT);
goto out_unlock;
}
dentry->d_fsdata = sysfs_get(sd);
/* attach dentry and inode */
inode = sysfs_get_inode(dir->i_sb, sd);
if (!inode) {
ret = ERR_PTR(-ENOMEM);
goto out_unlock;
}
/* instantiate and hash dentry */
ret = d_materialise_unique(dentry, inode);
out_unlock:
mutex_unlock(&sysfs_mutex);
return ret;
}
int sysfs_create_group(struct kobject * kobj,
const struct attribute_group * grp)
{
struct sysfs_dirent *sd;
int error;
BUG_ON(!kobj || !kobj->sd);
if (grp->name) {
error = sysfs_create_subdir(kobj, grp->name, &sd);
if (error)
return error;
} else
sd = kobj->sd;
sysfs_get(sd);
error = create_files(sd, grp);
if (error) {
if (grp->name)
sysfs_remove_subdir(sd);
}
sysfs_put(sd);
return error;
}
static void sysfs_init_inode(struct sysfs_dirent *sd, struct inode *inode)
{
struct bin_attribute *bin_attr;
inode->i_private = sysfs_get(sd);
inode->i_mapping->a_ops = &sysfs_aops;
inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;
inode->i_op = &sysfs_inode_operations;
set_default_inode_attr(inode, sd->s_mode);
sysfs_refresh_inode(sd, inode);
/* initialize inode according to type */
switch (sysfs_type(sd)) {
case SYSFS_DIR:
inode->i_op = &sysfs_dir_inode_operations;
inode->i_fop = &sysfs_dir_operations;
break;
case SYSFS_KOBJ_ATTR:
inode->i_size = PAGE_SIZE;
inode->i_fop = &sysfs_file_operations;
break;
case SYSFS_KOBJ_BIN_ATTR:
bin_attr = sd->s_bin_attr.bin_attr;
inode->i_size = bin_attr->size;
inode->i_fop = &bin_fops;
break;
case SYSFS_KOBJ_LINK:
inode->i_op = &sysfs_symlink_inode_operations;
break;
default:
BUG();
}
unlock_new_inode(inode);
}
static int sysfs_open_file(struct inode *inode, struct file *file)
{
struct sysfs_dirent *attr_sd = file->f_path.dentry->d_fsdata;
struct kobject *kobj = attr_sd->s_parent->s_elem.dir.kobj;
struct sysfs_buffer * buffer;
struct sysfs_ops * ops = NULL;
int error;
/* need attr_sd for attr and ops, its parent for kobj */
if (!sysfs_get_active_two(attr_sd))
return -ENODEV;
/* if the kobject has no ktype, then we assume that it is a subsystem
* itself, and use ops for it.
*/
if (kobj->kset && kobj->kset->ktype)
ops = kobj->kset->ktype->sysfs_ops;
else if (kobj->ktype)
ops = kobj->ktype->sysfs_ops;
else
ops = &subsys_sysfs_ops;
error = -EACCES;
/* No sysfs operations, either from having no subsystem,
* or the subsystem have no operations.
*/
if (!ops)
goto err_out;
/* File needs write support.
* The inode's perms must say it's ok,
* and we must have a store method.
*/
if (file->f_mode & FMODE_WRITE) {
if (!(inode->i_mode & S_IWUGO) || !ops->store)
goto err_out;
}
/* File needs read support.
* The inode's perms must say it's ok, and we there
* must be a show method for it.
*/
if (file->f_mode & FMODE_READ) {
if (!(inode->i_mode & S_IRUGO) || !ops->show)
goto err_out;
}
/* No error? Great, allocate a buffer for the file, and store it
* it in file->private_data for easy access.
*/
error = -ENOMEM;
buffer = kzalloc(sizeof(struct sysfs_buffer), GFP_KERNEL);
if (!buffer)
goto err_out;
init_MUTEX(&buffer->sem);
buffer->needs_read_fill = 1;
buffer->ops = ops;
file->private_data = buffer;
/* open succeeded, put active references and pin attr_sd */
sysfs_put_active_two(attr_sd);
sysfs_get(attr_sd);
return 0;
err_out:
sysfs_put_active_two(attr_sd);
return error;
}
int sysfs_move_dir(struct kobject *kobj, struct kobject *new_parent_kobj)
{
struct sysfs_dirent *sd = kobj->sd;
struct sysfs_dirent *new_parent_sd;
struct dentry *old_parent, *new_parent = NULL;
struct dentry *old_dentry = NULL, *new_dentry = NULL;
int error;
BUG_ON(!sd->s_parent);
new_parent_sd = new_parent_kobj->sd ? new_parent_kobj->sd : &sysfs_root;
/* get dentries */
old_dentry = sysfs_get_dentry(sd);
if (IS_ERR(old_dentry)) {
error = PTR_ERR(old_dentry);
goto out_dput;
}
old_parent = sd->s_parent->s_dentry;
new_parent = sysfs_get_dentry(new_parent_sd);
if (IS_ERR(new_parent)) {
error = PTR_ERR(new_parent);
goto out_dput;
}
if (old_parent->d_inode == new_parent->d_inode) {
error = 0;
goto out_dput; /* nothing to move */
}
again:
mutex_lock(&old_parent->d_inode->i_mutex);
if (!mutex_trylock(&new_parent->d_inode->i_mutex)) {
mutex_unlock(&old_parent->d_inode->i_mutex);
goto again;
}
new_dentry = lookup_one_len(kobj->name, new_parent, strlen(kobj->name));
if (IS_ERR(new_dentry)) {
error = PTR_ERR(new_dentry);
goto out_unlock;
} else
error = 0;
d_add(new_dentry, NULL);
d_move(sd->s_dentry, new_dentry);
dput(new_dentry);
/* Remove from old parent's list and insert into new parent's list. */
mutex_lock(&sysfs_mutex);
sysfs_unlink_sibling(sd);
sysfs_get(new_parent_sd);
sysfs_put(sd->s_parent);
sd->s_parent = new_parent_sd;
sysfs_link_sibling(sd);
mutex_unlock(&sysfs_mutex);
out_unlock:
mutex_unlock(&new_parent->d_inode->i_mutex);
mutex_unlock(&old_parent->d_inode->i_mutex);
out_dput:
dput(new_parent);
dput(old_dentry);
dput(new_dentry);
return error;
}
int sysfs_rename_dir(struct kobject *kobj, struct sysfs_dirent *new_parent_sd,
const char *new_name)
{
struct sysfs_dirent *sd = kobj->sd;
struct dentry *new_parent = NULL;
struct dentry *old_dentry = NULL, *new_dentry = NULL;
const char *dup_name = NULL;
int error;
/* get dentries */
old_dentry = sysfs_get_dentry(sd);
if (IS_ERR(old_dentry)) {
error = PTR_ERR(old_dentry);
goto out_dput;
}
new_parent = sysfs_get_dentry(new_parent_sd);
if (IS_ERR(new_parent)) {
error = PTR_ERR(new_parent);
goto out_dput;
}
/* lock new_parent and get dentry for new name */
mutex_lock(&new_parent->d_inode->i_mutex);
new_dentry = lookup_one_len(new_name, new_parent, strlen(new_name));
if (IS_ERR(new_dentry)) {
error = PTR_ERR(new_dentry);
goto out_unlock;
}
/* By allowing two different directories with the same
* d_parent we allow this routine to move between different
* shadows of the same directory
*/
error = -EINVAL;
if (old_dentry->d_parent->d_inode != new_parent->d_inode ||
new_dentry->d_parent->d_inode != new_parent->d_inode ||
old_dentry == new_dentry)
goto out_unlock;
error = -EEXIST;
if (new_dentry->d_inode)
goto out_unlock;
/* rename kobject and sysfs_dirent */
error = -ENOMEM;
new_name = dup_name = kstrdup(new_name, GFP_KERNEL);
if (!new_name)
goto out_drop;
error = kobject_set_name(kobj, "%s", new_name);
if (error)
goto out_drop;
mutex_lock(&sysfs_mutex);
dup_name = sd->s_name;
sd->s_name = new_name;
/* move under the new parent */
d_add(new_dentry, NULL);
d_move(sd->s_dentry, new_dentry);
sysfs_unlink_sibling(sd);
sysfs_get(new_parent_sd);
sysfs_put(sd->s_parent);
sd->s_parent = new_parent_sd;
sysfs_link_sibling(sd);
mutex_unlock(&sysfs_mutex);
error = 0;
goto out_unlock;
out_drop:
d_drop(new_dentry);
out_unlock:
mutex_unlock(&new_parent->d_inode->i_mutex);
out_dput:
kfree(dup_name);
dput(new_parent);
dput(old_dentry);
dput(new_dentry);
return error;
}
/**
* sysfs_get_dentry - get dentry for the given sysfs_dirent
* @sd: sysfs_dirent of interest
*
* Get dentry for @sd. Dentry is looked up if currently not
* present. This function climbs sysfs_dirent tree till it
* reaches a sysfs_dirent with valid dentry attached and descends
* down from there looking up dentry for each step.
*
* LOCKING:
* Kernel thread context (may sleep)
*
* RETURNS:
* Pointer to found dentry on success, ERR_PTR() value on error.
*/
struct dentry *sysfs_get_dentry(struct sysfs_dirent *sd)
{
struct sysfs_dirent *cur;
struct dentry *parent_dentry, *dentry;
int i, depth;
/* Find the first parent which has valid s_dentry and get the
* dentry.
*/
mutex_lock(&sysfs_mutex);
restart0:
spin_lock(&sysfs_assoc_lock);
restart1:
spin_lock(&dcache_lock);
dentry = NULL;
depth = 0;
cur = sd;
while (!cur->s_dentry || !cur->s_dentry->d_inode) {
if (cur->s_flags & SYSFS_FLAG_REMOVED) {
dentry = ERR_PTR(-ENOENT);
depth = 0;
break;
}
cur = cur->s_parent;
depth++;
}
if (!IS_ERR(dentry))
dentry = dget_locked(cur->s_dentry);
spin_unlock(&dcache_lock);
spin_unlock(&sysfs_assoc_lock);
/* from the found dentry, look up depth times */
while (depth--) {
/* find and get depth'th ancestor */
for (cur = sd, i = 0; cur && i < depth; i++)
cur = cur->s_parent;
/* This can happen if tree structure was modified due
* to move/rename. Restart.
*/
if (i != depth) {
dput(dentry);
goto restart0;
}
sysfs_get(cur);
mutex_unlock(&sysfs_mutex);
/* look it up */
parent_dentry = dentry;
dentry = lookup_one_len_kern(cur->s_name, parent_dentry,
strlen(cur->s_name));
dput(parent_dentry);
if (IS_ERR(dentry)) {
sysfs_put(cur);
return dentry;
}
mutex_lock(&sysfs_mutex);
spin_lock(&sysfs_assoc_lock);
/* This, again, can happen if tree structure has
* changed and we looked up the wrong thing. Restart.
*/
if (cur->s_dentry != dentry) {
dput(dentry);
sysfs_put(cur);
goto restart1;
}
spin_unlock(&sysfs_assoc_lock);
sysfs_put(cur);
}
mutex_unlock(&sysfs_mutex);
return dentry;
}
