/**
* sysfs_update_file - update the modified timestamp on an object attribute.
* @kobj: object we're acting for.
* @attr: attribute descriptor.
*/
int sysfs_update_file(struct kobject * kobj, const struct attribute * attr)
{
struct sysfs_dirent *victim_sd = NULL;
struct dentry *victim = NULL;
int rc;
rc = -ENOENT;
victim_sd = sysfs_get_dirent(kobj->sd, attr->name);
if (!victim_sd)
goto out;
victim = sysfs_get_dentry(victim_sd);
if (IS_ERR(victim)) {
rc = PTR_ERR(victim);
victim = NULL;
goto out;
}
mutex_lock(&victim->d_inode->i_mutex);
victim->d_inode->i_mtime = CURRENT_TIME;
fsnotify_modify(victim);
mutex_unlock(&victim->d_inode->i_mutex);
rc = 0;
out:
dput(victim);
sysfs_put(victim_sd);
return rc;
}
/**
* sysfs_chmod_file - update the modified mode value on an object attribute.
* @kobj: object we're acting for.
* @attr: attribute descriptor.
* @mode: file permissions.
*
*/
int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)
{
struct sysfs_dirent *victim_sd = NULL;
struct dentry *victim = NULL;
struct inode * inode;
struct iattr newattrs;
int rc;
rc = -ENOENT;
victim_sd = sysfs_get_dirent(kobj->sd, attr->name);
if (!victim_sd)
goto out;
victim = sysfs_get_dentry(victim_sd);
if (IS_ERR(victim)) {
rc = PTR_ERR(victim);
victim = NULL;
goto out;
}
inode = victim->d_inode;
mutex_lock(&inode->i_mutex);
newattrs.ia_mode = (mode & S_IALLUGO) | (inode->i_mode & ~S_IALLUGO);
newattrs.ia_valid = ATTR_MODE | ATTR_CTIME;
rc = notify_change(victim, &newattrs);
mutex_unlock(&inode->i_mutex);
out:
dput(victim);
sysfs_put(victim_sd);
return rc;
}
int sysfs_make_shadowed_dir(struct kobject *kobj,
void * (*follow_link)(struct dentry *, struct nameidata *))
{
struct dentry *dentry;
struct inode *inode;
struct inode_operations *i_op;
/* get dentry for @kobj->sd, dentry of a shadowed dir is pinned */
dentry = sysfs_get_dentry(kobj->sd);
if (IS_ERR(dentry))
return PTR_ERR(dentry);
inode = dentry->d_inode;
if (inode->i_op != &sysfs_dir_inode_operations) {
dput(dentry);
return -EINVAL;
}
i_op = kmalloc(sizeof(*i_op), GFP_KERNEL);
if (!i_op)
return -ENOMEM;
memcpy(i_op, &sysfs_dir_inode_operations, sizeof(*i_op));
i_op->follow_link = follow_link;
/* Locking of inode->i_op?
* Since setting i_op is a single word write and they
* are atomic we should be ok here.
*/
inode->i_op = i_op;
return 0;
}
/**
* sysfs_chmod_file - update the modified mode value on an object attribute.
* @kobj: object we're acting for.
* @attr: attribute descriptor.
* @mode: file permissions.
*
*/
int sysfs_chmod_file(struct kobject *kobj, struct attribute *attr, mode_t mode)
{
struct dentry *dir = kobj->dentry;
struct dentry *victim;
struct sysfs_dirent *sd;
umode_t umode = (mode & S_IALLUGO) | S_IFREG;
int res = -ENOENT;
down(&dir->d_inode->i_sem);
victim = sysfs_get_dentry(dir, attr->name);
if (!IS_ERR(victim)) {
if (victim->d_inode &&
(victim->d_parent->d_inode == dir->d_inode)) {
sd = victim->d_fsdata;
attr->mode = mode;
sd->s_mode = umode;
victim->d_inode->i_mode = umode;
dput(victim);
res = 0;
}
}
up(&dir->d_inode->i_sem);
return res;
}
/**
* sysfs_update_file - update the modified timestamp on an object attribute.
* @kobj: object we're acting for.
* @attr: attribute descriptor.
*
* Also call dnotify for the dentry, which lots of userspace programs
* use.
*/
int sysfs_update_file(struct kobject * kobj, const struct attribute * attr)
{
struct dentry * dir = kobj->dentry;
struct dentry * victim;
int res = -ENOENT;
down(&dir->d_inode->i_sem);
victim = sysfs_get_dentry(dir, attr->name);
if (!IS_ERR(victim)) {
/* make sure dentry is really there */
if (victim->d_inode &&
(victim->d_parent->d_inode == dir->d_inode)) {
victim->d_inode->i_mtime = CURRENT_TIME;
dnotify_parent(victim, DN_MODIFY);
/**
* Drop reference from initial sysfs_get_dentry().
*/
dput(victim);
res = 0;
}
/**
* Drop the reference acquired from sysfs_get_dentry() above.
*/
dput(victim);
}
up(&dir->d_inode->i_sem);
return res;
}
void sysfs_hash_and_remove(struct dentry * dir, const char * name)
{
struct dentry * victim;
down(&dir->d_inode->i_sem);
victim = sysfs_get_dentry(dir,name);
if (!IS_ERR(victim)) {
/* make sure dentry is really there */
if (victim->d_inode &&
(victim->d_parent->d_inode == dir->d_inode)) {
pr_debug("sysfs: Removing %s (%d)\n", victim->d_name.name,
atomic_read(&victim->d_count));
d_drop(victim);
/* release the target kobject in case of
* a symlink
*/
if (S_ISLNK(victim->d_inode->i_mode))
kobject_put(victim->d_fsdata);
simple_unlink(dir->d_inode,victim);
}
/*
* Drop reference from sysfs_get_dentry() above.
*/
dput(victim);
}
up(&dir->d_inode->i_sem);
}
struct sysfs_dirent *sysfs_create_shadow_dir(struct kobject *kobj)
{
struct sysfs_dirent *parent_sd = kobj->sd->s_parent;
struct dentry *dir, *parent, *shadow;
struct inode *inode;
struct sysfs_dirent *sd;
struct sysfs_addrm_cxt acxt;
dir = sysfs_get_dentry(kobj->sd);
if (IS_ERR(dir)) {
sd = (void *)dir;
goto out;
}
parent = dir->d_parent;
inode = dir->d_inode;
sd = ERR_PTR(-EINVAL);
if (!sysfs_is_shadowed_inode(inode))
goto out_dput;
shadow = d_alloc(parent, &dir->d_name);
if (!shadow)
goto nomem;
sd = sysfs_new_dirent("_SHADOW_", inode->i_mode, SYSFS_DIR);
if (!sd)
goto nomem;
sd->s_elem.dir.kobj = kobj;
sysfs_addrm_start(&acxt, parent_sd);
/* add but don't link into children list */
sysfs_add_one(&acxt, sd);
/* attach and instantiate dentry */
sysfs_attach_dentry(sd, shadow);
d_instantiate(shadow, igrab(inode));
inc_nlink(inode); /* tj: synchronization? */
sysfs_addrm_finish(&acxt);
dget(shadow); /* Extra count - pin the dentry in core */
goto out_dput;
nomem:
dput(shadow);
sd = ERR_PTR(-ENOMEM);
out_dput:
dput(dir);
out:
return sd;
}
int sysfs_add_file(struct dentry * dir, const struct attribute * attr)
{
struct dentry * dentry;
int error;
down(&dir->d_inode->i_sem);
dentry = sysfs_get_dentry(dir,attr->name);
if (!IS_ERR(dentry)) {
error = sysfs_create(dentry,
(attr->mode & S_IALLUGO) | S_IFREG,
init_file);
if (!error)
dentry->d_fsdata = (void *)attr;
dput(dentry);
} else
error = PTR_ERR(dentry);
up(&dir->d_inode->i_sem);
return error;
}
void sysfs_rename_dir(struct kobject * kobj, const char *new_name)
{
struct dentry * new_dentry, * parent;
if (!strcmp(kobject_name(kobj), new_name))
return;
if (!kobj->parent)
return;
parent = kobj->parent->dentry;
down(&parent->d_inode->i_sem);
new_dentry = sysfs_get_dentry(parent, new_name);
d_move(kobj->dentry, new_dentry);
kobject_set_name(kobj,new_name);
up(&parent->d_inode->i_sem);
}
/**
* sysfs_create_link - create symlink between two objects.
* @kobj: object whose directory we're creating the link in.
* @target: object we're pointing to.
* @name: name of the symlink.
*/
int sysfs_create_link(struct kobject * kobj, struct kobject * target, char * name)
{
struct dentry * dentry = kobj->dentry;
struct dentry * d;
int error = 0;
down(&dentry->d_inode->i_sem);
d = sysfs_get_dentry(dentry,name);
if (!IS_ERR(d)) {
error = sysfs_create(d, S_IFLNK|S_IRWXUGO, init_symlink);
if (!error)
/*
* associate the link dentry with the target kobject
*/
d->d_fsdata = kobject_get(target);
dput(d);
} else
error = PTR_ERR(d);
up(&dentry->d_inode->i_sem);
return error;
}
static int create_dir(struct kobject * k, struct dentry * p,
const char * n, struct dentry ** d)
{
int error;
down(&p->d_inode->i_sem);
*d = sysfs_get_dentry(p,n);
if (!IS_ERR(*d)) {
error = sysfs_create(*d,
S_IFDIR| S_IRWXU | S_IRUGO | S_IXUGO,
init_dir);
if (!error) {
(*d)->d_fsdata = k;
p->d_inode->i_nlink++;
}
dput(*d);
} else
error = PTR_ERR(*d);
up(&p->d_inode->i_sem);
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;
}
