[LTP] [PATCH v2] syscalls/keyctl02: wait for last key to be garbage collected

[Jan Stancek]

----- Original Message -----
> Hi!
> >  static void do_test(void)
> >  {
> > -	int i;
> > -	key_serial_t key;
> > +	int i, ret;
> > +	key_serial_t key, key_inv;
> >  	pthread_t pth[4];
> >  
> >  	for (i = 0; i < LOOPS; i++) {
> > @@ -94,13 +95,45 @@ static void do_test(void)
> >  		SAFE_PTHREAD_JOIN(pth[3], NULL);
> >  	}
> >  
> > +	/*
> > +	 * Kernel should start garbage collect when last reference to key
> > +	 * is removed (see key_put()). Since we are adding keys with identical
> > +	 * description and type, each replacement should schedule a gc run,
> > +	 * see comment at __key_link().
> > +	 *
> > +	 * We create extra key here, to remove reference to last revoked key.
> > +	 */
> > +	key_inv = add_key("user", "ltptestkey", "foo", 3,
> > +		KEY_SPEC_PROCESS_KEYRING);
> > +	if (key_inv == -1)
> > +		tst_brk(TBROK | TERRNO, "Failed to add key");
> > +
> > +	/*
> > +	 * If we have invalidate, we can drop extra key immediately as well,
> > +	 * which also schedules gc.
> > +	 */
> > +	if (keyctl(KEYCTL_INVALIDATE, key_inv) == -1 && errno != EOPNOTSUPP)
> > +		tst_brk(TBROK | TERRNO, "Failed to invalidate key");
> > +
> > +	/*
> > +	 * At this point we are quite confident that gc has been scheduled,
> > +	 * so we wait and periodically check for last test key to be removed.
> > +	 */
> > +	for (i = 0; i < MAX_WAIT_FOR_GC_MS; i += 100) {
> > +		ret = keyctl(KEYCTL_REVOKE, key);
> > +		if (ret == -1 && errno == ENOKEY)
> > +			break;
> > +		usleep(100*1000);
> > +	}
> > +
> > +	tst_res(TINFO, "waiting for key gc took: %d ms", i);
> 
> Minor enhancement may be:
> 
> 	if (i)
> 		tst_res(TINFO, "waiting for key gc took: %d ms", i);
> 
> 
> Anyways, the patch looks good, acked.

Pushed with "if (i)" above.

Regards,
Jan

> 
> --
> Cyril Hrubis
> chrubis@suse.cz
>