posix_lock_file
posix_lock_file(file, fl, NULL);
err = posix_lock_file(file, fl, NULL);
if (posix_lock_file(file, flc, NULL)) {
err = posix_lock_file(file, fl, NULL);
EXPORT_SYMBOL(posix_lock_file);
return posix_lock_file(filp, fl, conf);
rc = posix_lock_file(filp, fl, NULL);
rc = posix_lock_file(file, flock, NULL);
int posix_lock_file(struct file *, struct file_lock *, struct file_lock *);