static struct dentry *sysfs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
struct sysfs_super_info *info;
enum kobj_ns_type type;
struct super_block *sb;
int error;
info = kzalloc(sizeof(*info), GFP_KERNEL);
if (!info)
return ERR_PTR(-ENOMEM);
for (type = KOBJ_NS_TYPE_NONE; type < KOBJ_NS_TYPES; type++)
info->ns[type] = kobj_ns_grab_current(type);
sb = sget(fs_type, sysfs_test_super, sysfs_set_super, info);
if (IS_ERR(sb) || sb->s_fs_info != info)
free_sysfs_super_info(info);
if (IS_ERR(sb))
return ERR_CAST(sb);
if (!sb->s_root) {
sb->s_flags = flags;
error = sysfs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
if (error) {
deactivate_locked_super(sb);
return ERR_PTR(error);
}
sb->s_flags |= MS_ACTIVE;
}
return dget(sb->s_root);
}
static struct dentry *sysfs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
struct dentry *root;
void *ns;
bool new_sb;
if (!(flags & MS_KERNMOUNT)) {
if (!capable(CAP_SYS_ADMIN) && !fs_fully_visible(fs_type))
return ERR_PTR(-EPERM);
if (!kobj_ns_current_may_mount(KOBJ_NS_TYPE_NET))
return ERR_PTR(-EPERM);
}
ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET);
root = kernfs_mount_ns(fs_type, flags, sysfs_root, &new_sb, ns);
if (IS_ERR(root) || !new_sb)
kobj_ns_drop(KOBJ_NS_TYPE_NET, ns);
return root;
}
static struct dentry *sysfs_mount(struct file_system_type *fs_type,
int flags, const char *dev_name, void *data)
{
struct dentry *root;
void *ns;
bool new_sb;
if (!(flags & MS_KERNMOUNT)) {
if (!kobj_ns_current_may_mount(KOBJ_NS_TYPE_NET))
return ERR_PTR(-EPERM);
}
ns = kobj_ns_grab_current(KOBJ_NS_TYPE_NET);
root = kernfs_mount_ns(fs_type, flags, sysfs_root,
SYSFS_MAGIC, &new_sb, ns);
if (IS_ERR(root) || !new_sb)
kobj_ns_drop(KOBJ_NS_TYPE_NET, ns);
else if (new_sb)
root->d_sb->s_iflags |= SB_I_USERNS_VISIBLE;
return root;
}