/*! 2017. 1.07 study -ing */
int __init sysfs_init(void)
{
int err;
sysfs_root = kernfs_create_root(NULL, NULL);
if (IS_ERR(sysfs_root))
return PTR_ERR(sysfs_root);
sysfs_root_kn = sysfs_root->kn;
err = register_filesystem(&sysfs_fs_type);
if (err) {
kernfs_destroy_root(sysfs_root);
return err;
}
return 0;
}
static struct dentry *dslab_mount(struct file_system_type *fs_type,
int flags, const char *unused_dev_name,
void *data)
{
struct dentry *dentry = NULL;
struct kernfs_root *kf_root;
struct kernfs_node *kn;
bool new_sb;
kf_root = kernfs_create_root(&dslab_kf_syscall_ops,
KERNFS_ROOT_CREATE_DEACTIVATED,
NULL);
if (IS_ERR(kf_root))
goto out;
kn = __kernfs_create_file(kf_root->kn, "dslab", FS_MODE,
0, &dslab_kernfs_ops, NULL, NULL,
NULL);
if (IS_ERR(kn))
goto destroy_root;
dentry = kernfs_mount(fs_type, flags, kf_root,
FS_MAGIC, &new_sb);
if (IS_ERR(dentry) || !new_sb)
goto destroy_kn;
kernfs_activate(kf_root->kn);
goto out;
destroy_kn:
kernfs_remove_by_name(kf_root->kn, "dslab");
destroy_root:
kernfs_destroy_root(kf_root);
kf_root = NULL;
out:
return dentry;
}