static int cdrom_select_disc()

in cdrom.c [1417:1469]

• 37 lines of code
• 11 McCabe index (conditional complexity)

static int cdrom_select_disc(struct cdrom_device_info *cdi, int slot)
{
	struct cdrom_changer_info *info;
	int curslot;
	int ret;

	cd_dbg(CD_CHANGER, "entering cdrom_select_disc()\n");
	if (!CDROM_CAN(CDC_SELECT_DISC))
		return -EDRIVE_CANT_DO_THIS;

	if (cdi->ops->check_events)
		cdi->ops->check_events(cdi, 0, slot);

	if (slot == CDSL_NONE) {
		signal_media_change(cdi);
		return cdrom_load_unload(cdi, -1);
	}

	info = kmalloc(sizeof(*info), GFP_KERNEL);
	if (!info)
		return -ENOMEM;

	if ((ret = cdrom_read_mech_status(cdi, info))) {
		kfree(info);
		return ret;
	}

	curslot = info->hdr.curslot;
	kfree(info);

	if (cdi->use_count > 1 || cdi->keeplocked) {
		if (slot == CDSL_CURRENT) {
	    		return curslot;
		} else {
			return -EBUSY;
		}
	}

	/* Specifying CDSL_CURRENT will attempt to load the currnet slot,
	which is useful if it had been previously unloaded.
	Whether it can or not, it returns the current slot. 
	Similarly,  if slot happens to be the current one, we still
	try and load it. */
	if (slot == CDSL_CURRENT)
		slot = curslot;

	/* set media changed bits on both queues */
	signal_media_change(cdi);
	if ((ret = cdrom_load_unload(cdi, slot)))
		return ret;

	return slot;
}