blkfront: Lock blockfront_info during xbdev removal

	}

}

static int blkfront_remove(struct xenbus_device *dev)

static int blkfront_remove(struct xenbus_device *xbdev)

{

	struct blkfront_info *info = dev_get_drvdata(&dev->dev);

	struct blkfront_info *info = dev_get_drvdata(&xbdev->dev);

	struct block_device *bdev = NULL;

	struct gendisk *disk;

	dev_dbg(&dev->dev, "blkfront_remove: %s removed\n", dev->nodename);

	dev_dbg(&xbdev->dev, "%s removed", xbdev->nodename);

	blkif_free(info, 0);

	if(info->users == 0)

		kfree(info);

	else

	mutex_lock(&info->mutex);

	disk = info->gd;

	if (disk)

		bdev = bdget_disk(disk, 0);

	info->xbdev = NULL;

	mutex_unlock(&info->mutex);

	if (!bdev) {

		kfree(info);

		return 0;

	}

	/*

	 * The xbdev was removed before we reached the Closed

	 * state. See if it's safe to remove the disk. If the bdev

	 * isn't closed yet, we let release take care of it.

	 */

	mutex_lock(&bdev->bd_mutex);

	info = disk->private_data;

	if (info && !info->users) {

		xlvbd_release_gendisk(info);

		disk->private_data = NULL;

		kfree(info);

	}

	mutex_unlock(&bdev->bd_mutex);

	bdput(bdev);

	return 0;

}