C++ (Cpp) xen_update_blkif_status Examples

Example #1

File: xenbus.c Project: AbdulrahmanAmir/Dorimanx-LG-G2-D802-Kernel

/*
 * Callback received when the frontend's state changes.
 */
static void frontend_changed(struct xenbus_device *dev,
			     enum xenbus_state frontend_state)
{
	struct backend_info *be = dev_get_drvdata(&dev->dev);
	int err;

	DPRINTK("%s", xenbus_strstate(frontend_state));

	switch (frontend_state) {
	case XenbusStateInitialising:
		if (dev->state == XenbusStateClosed) {
			pr_info(DRV_PFX "%s: prepare for reconnect\n",
				dev->nodename);
			xenbus_switch_state(dev, XenbusStateInitWait);
		}
		break;

	case XenbusStateInitialised:
	case XenbusStateConnected:
		/*
		 * Ensure we connect even when two watches fire in
		 * close succession and we miss the intermediate value
		 * of frontend_state.
		 */
		if (dev->state == XenbusStateConnected)
			break;

		/*
		 * Enforce precondition before potential leak point.
		 * xen_blkif_disconnect() is idempotent.
		 */
		xen_blkif_disconnect(be->blkif);

		err = connect_ring(be);
		if (err)
			break;
		xen_update_blkif_status(be->blkif);
		break;

	case XenbusStateClosing:
		xenbus_switch_state(dev, XenbusStateClosing);
		break;

	case XenbusStateClosed:
		xen_blkif_disconnect(be->blkif);
		xenbus_switch_state(dev, XenbusStateClosed);
		if (xenbus_dev_is_online(dev))
			break;
		/* fall through if not online */
	case XenbusStateUnknown:
		/* implies xen_blkif_disconnect() via xen_blkbk_remove() */
		device_unregister(&dev->dev);
		break;

	default:
		xenbus_dev_fatal(dev, -EINVAL, "saw state %d at frontend",
				 frontend_state);
		break;
	}
}

Example #2

File: xenbus.c Project: jthatch12/STi

/*
 * Callback received when the hotplug scripts have placed the physical-device
 * node.  Read it and the mode node, and create a vbd.  If the frontend is
 * ready, connect.
 */
static void backend_changed(struct xenbus_watch *watch,
			    const char **vec, unsigned int len)
{
	int err;
	unsigned major;
	unsigned minor;
	struct backend_info *be
		= container_of(watch, struct backend_info, backend_watch);
	struct xenbus_device *dev = be->dev;
	int cdrom = 0;
	unsigned long handle;
	char *device_type;

	DPRINTK("");

	err = xenbus_scanf(XBT_NIL, dev->nodename, "physical-device", "%x:%x",
			   &major, &minor);
	if (XENBUS_EXIST_ERR(err)) {
		/*
		 * Since this watch will fire once immediately after it is
		 * registered, we expect this.  Ignore it, and wait for the
		 * hotplug scripts.
		 */
		return;
	}
	if (err != 2) {
		xenbus_dev_fatal(dev, err, "reading physical-device");
		return;
	}

	if (be->major | be->minor) {
		if (be->major != major || be->minor != minor)
			pr_warn(DRV_PFX "changing physical device (from %x:%x to %x:%x) not supported.\n",
				be->major, be->minor, major, minor);
		return;
	}

	be->mode = xenbus_read(XBT_NIL, dev->nodename, "mode", NULL);
	if (IS_ERR(be->mode)) {
		err = PTR_ERR(be->mode);
		be->mode = NULL;
		xenbus_dev_fatal(dev, err, "reading mode");
		return;
	}

	device_type = xenbus_read(XBT_NIL, dev->otherend, "device-type", NULL);
	if (!IS_ERR(device_type)) {
		cdrom = strcmp(device_type, "cdrom") == 0;
		kfree(device_type);
	}

	/* Front end dir is a number, which is used as the handle. */
	err = strict_strtoul(strrchr(dev->otherend, '/') + 1, 0, &handle);
	if (err)
		return;

	be->major = major;
	be->minor = minor;

	err = xen_vbd_create(be->blkif, handle, major, minor,
			     !strchr(be->mode, 'w'), cdrom);

	if (err)
		xenbus_dev_fatal(dev, err, "creating vbd structure");
	else {
		err = xenvbd_sysfs_addif(dev);
		if (err) {
			xen_vbd_free(&be->blkif->vbd);
			xenbus_dev_fatal(dev, err, "creating sysfs entries");
		}
	}

	if (err) {
		kfree(be->mode);
		be->mode = NULL;
		be->major = 0;
		be->minor = 0;
	} else {
		/* We're potentially connected now */
		xen_update_blkif_status(be->blkif);
	}
}