dentry_path
root_path = dentry_path(bpmp->debugfs_mirror, root_path_buf,
filename = dentry_path(file->f_path.dentry, buf, size);
char *p = dentry_path(dentry, buf, size);
extern char *dentry_path(const struct dentry *, char *, int);
res = dentry_path(path->dentry, buf, buflen);
path = dentry_path(dentry, pathbuf, PATH_MAX);