// errDiskNotFound - cannot find the underlying configured disk anymore.
var errDiskNotFound = StorageErr("drive not found")

// errDiskOngoingReq - indicates if the disk has an on-going request in progress.
var errDiskOngoingReq = StorageErr("drive still did not complete the request")

// errDriveIsRoot - cannot use the disk since its a root disk.

	if err != nil {
		if _, ok := err.(InsufficientReadQuorum); ok {
			return objInfo, InsufficientWriteQuorum{}
		}
		return objInfo, err
	}

	// Delete marker already present we are not going to create new delete markers.
	if pinfo.ObjInfo.DeleteMarker && opts.VersionID == "" {
		pinfo.ObjInfo.Name = decodeDirObject(object)
		return pinfo.ObjInfo, nil
	}

	if err != nil {
		dg := errgroup.WithNErrs(len(disks))
		for index, nerr := range errs {
			if nerr != nil {
				continue
			}
			index := index
			// When we are going to return error, attempt to delete success
			// on some of the drives, if we cannot we do not have to notify
			// caller this dangling object will be now scheduled to be removed
			// via active healing.

	msgLine2Fmt := " Update: %s "

	// Calculate length *without* color coding: with ANSI terminal
	// color characters, the result is incorrect.
	line1Length := len(fmt.Sprintf(msgLine1Fmt, newerThan))
	line2Length := len(fmt.Sprintf(msgLine2Fmt, updateString))

	// Populate lines with color coding.
	line1InColor := fmt.Sprintf(msgLine1Fmt, color.YellowBold(newerThan))

		var hint string
		if endpoint.URL != nil {
			hint = fmt.Sprintf("Drive '%s' does not support O_DIRECT flags, MinIO erasure coding requires filesystems with O_DIRECT support", endpoint.Path)
		} else {
			hint = "Drives do not support O_DIRECT flags, MinIO erasure coding requires filesystems with O_DIRECT support"
		}
		logger.Fatal(config.ErrUnsupportedBackend(err).Hint(hint), "Unable to initialize backend")

	}
	result = totalSizes[0]
	for i := 1; i < len(totalSizes); i++ {
		result = gcd(result, totalSizes[i])
	}
	return result
}

// isValidSetSize - checks whether given count is a valid set size for erasure coding.
var isValidSetSize = func(count uint64) bool {
	return (count >= setSizes[0] && count <= setSizes[len(setSizes)-1])
}

func commonSetDriveCount(divisibleSize uint64, setCounts []uint64) (setSize uint64) {

}

// IsValid - tells if erasure info fields are valid.
func (fi FileInfo) IsValid() bool {
	if fi.Deleted {
		// Delete marker has no data, no need to check
		// for erasure coding information
		return true
	}
	dataBlocks := fi.Erasure.DataBlocks
	parityBlocks := fi.Erasure.ParityBlocks
	correctIndexes := (fi.Erasure.Index > 0 &&
		fi.Erasure.Index <= dataBlocks+parityBlocks &&

}

// hasSpaceFor returns whether the disks in `di` have space for and object of a given size.
func hasSpaceFor(di []*DiskInfo, size int64) (bool, error) {
	// We multiply the size by 2 to account for erasure coding.
	size *= 2
	if size < 0 {
		// If no size, assume diskAssumeUnknownSize.
		size = diskAssumeUnknownSize
	}

	var available uint64
	var total uint64
	var nDisks int

}

// ErasureInfo holds erasure coding and bitrot related information.
type ErasureInfo struct {
	// Algorithm is the string representation of erasure-coding-algorithm
	Algorithm string `json:"algorithm"`
	// DataBlocks is the number of data blocks for erasure-coding
	DataBlocks int `json:"data"`
	// ParityBlocks is the number of parity blocks for erasure-coding
	ParityBlocks int `json:"parity"`

	)

	ErrInvalidNumberOfErasureEndpoints = newErrFn(
		"Invalid total number of endpoints for erasure mode",
		"Please provide number of endpoints greater or equal to 2",
		"For more information, please refer to https://min.io/docs/minio/linux/operations/concepts/erasure-coding.html",
	)

	ErrStorageClassValue = newErrFn(