head_file
INIT_LIST_HEAD(&blob->head_file);
list_for_each_entry_safe(blob, bt, &file_priv->blobs, head_file) {
list_del_init(&blob->head_file);
list_add_tail(&blob->head_file, &file_priv->blobs);
list_for_each_entry(bt, &file_priv->blobs, head_file) {
list_del_init(&blob->head_file);
struct list_head head_file;
int head_file(const char *, long, int);
status = head_file(NULL, linecnt, 0);
status |= head_file(*argv, linecnt, argc > 1);