static void scsiback_do_1lun_hotplug()

in xen-scsiback.c [1019:1097]

• 69 lines of code
• 13 McCabe index (conditional complexity)

static void scsiback_do_1lun_hotplug(struct vscsibk_info *info, int op,
				     char *ent)
{
	int err;
	struct ids_tuple vir;
	char *val;
	int device_state;
	char phy[VSCSI_NAMELEN];
	char str[64];
	char state[64];
	struct xenbus_device *dev = info->dev;

	/* read status */
	snprintf(state, sizeof(state), "vscsi-devs/%s/state", ent);
	err = xenbus_scanf(XBT_NIL, dev->nodename, state, "%u", &device_state);
	if (XENBUS_EXIST_ERR(err))
		return;

	/* physical SCSI device */
	snprintf(str, sizeof(str), "vscsi-devs/%s/p-dev", ent);
	val = xenbus_read(XBT_NIL, dev->nodename, str, NULL);
	if (IS_ERR(val)) {
		err = xenbus_printf(XBT_NIL, dev->nodename, state,
			      "%d", XenbusStateClosed);
		if (err)
			xenbus_dev_error(info->dev, err,
				"%s: writing %s", __func__, state);
		return;
	}
	strlcpy(phy, val, VSCSI_NAMELEN);
	kfree(val);

	/* virtual SCSI device */
	snprintf(str, sizeof(str), "vscsi-devs/%s/v-dev", ent);
	err = xenbus_scanf(XBT_NIL, dev->nodename, str, "%u:%u:%u:%u",
			   &vir.hst, &vir.chn, &vir.tgt, &vir.lun);
	if (XENBUS_EXIST_ERR(err)) {
		err = xenbus_printf(XBT_NIL, dev->nodename, state,
			      "%d", XenbusStateClosed);
		if (err)
			xenbus_dev_error(info->dev, err,
				"%s: writing %s", __func__, state);
		return;
	}

	switch (op) {
	case VSCSIBACK_OP_ADD_OR_DEL_LUN:
		switch (device_state) {
		case XenbusStateInitialising:
			scsiback_do_add_lun(info, state, phy, &vir, 0);
			break;
		case XenbusStateConnected:
			scsiback_do_add_lun(info, state, phy, &vir, 1);
			break;
		case XenbusStateClosing:
			scsiback_do_del_lun(info, state, &vir);
			break;
		default:
			break;
		}
		break;

	case VSCSIBACK_OP_UPDATEDEV_STATE:
		if (device_state == XenbusStateInitialised) {
			/* modify vscsi-devs/dev-x/state */
			if (xenbus_printf(XBT_NIL, dev->nodename, state,
					  "%d", XenbusStateConnected)) {
				pr_err("xenbus_printf error %s\n", str);
				scsiback_del_translation_entry(info, &vir);
				xenbus_printf(XBT_NIL, dev->nodename, state,
					      "%d", XenbusStateClosed);
			}
		}
		break;
	/* When it is necessary, processing is added here. */
	default:
		break;
	}
}