func GetBlockDeviceInfo()

in utils/sysinfo/sysinfo.go [46:95]
44 lines of code
13 McCabe index (conditional complexity)

func GetBlockDeviceInfo(sysfs sysfs.SysFs) (map[string]info.DiskInfo, error) {
	disks, err := sysfs.GetBlockDevices()
	if err != nil {
		return nil, err
	}

	diskMap := make(map[string]info.DiskInfo)
	for _, disk := range disks {
		name := disk.Name()
		// Ignore non-disk devices.
		// TODO(rjnagal): Maybe just match hd, sd, and dm prefixes.
		if strings.HasPrefix(name, "loop") || strings.HasPrefix(name, "ram") || strings.HasPrefix(name, "sr") {
			continue
		}
		diskInfo := info.DiskInfo{
			Name: name,
		}
		dev, err := sysfs.GetBlockDeviceNumbers(name)
		if err != nil {
			return nil, err
		}
		n, err := fmt.Sscanf(dev, "%d:%d", &diskInfo.Major, &diskInfo.Minor)
		if err != nil || n != 2 {
			return nil, fmt.Errorf("could not parse device numbers from %s for device %s", dev, name)
		}
		out, err := sysfs.GetBlockDeviceSize(name)
		if err != nil {
			return nil, err
		}
		// Remove trailing newline before conversion.
		size, err := strconv.ParseUint(strings.TrimSpace(out), 10, 64)
		if err != nil {
			return nil, err
		}
		// size is in 512 bytes blocks.
		diskInfo.Size = size * 512

		diskInfo.Scheduler = "none"
		blkSched, err := sysfs.GetBlockDeviceScheduler(name)
		if err == nil {
			matches := schedulerRegExp.FindSubmatch([]byte(blkSched))
			if len(matches) >= 2 {
				diskInfo.Scheduler = string(matches[1])
			}
		}
		device := fmt.Sprintf("%d:%d", diskInfo.Major, diskInfo.Minor)
		diskMap[device] = diskInfo
	}
	return diskMap, nil
}