// read to be handled correctly. On the other hand, a change to the file size
// (st_size, as made by say ftruncate(2)), would require a metadata flush.
//
// The aim of fdatasync() is to reduce disk activity for applications that
// do not require all metadata to be synchronized with the disk.
func Fdatasync(f *os.File) error {
	return syscall.Fdatasync(int(f.Fd()))
}

// FadviseDontNeed invalidates page-cache

				// Number of probes.
				// ~ cat /proc/sys/net/ipv4/tcp_keepalive_probes (defaults to 9, we reduce it to 5)
				_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_KEEPCNT, 5)

				// Wait time after successful probe in seconds.
				// ~ cat /proc/sys/net/ipv4/tcp_keepalive_intvl (defaults to 75 secs, we reduce it to 15 secs)
				_ = syscall.SetsockoptInt(fd, syscall.IPPROTO_TCP, syscall.TCP_KEEPINTVL, 15)
			}

	}

	// List all the file commit ids from parts metadata.
	modTimes := listObjectModtimes(partsMetadata, errs)

	// Count all latest updated FileInfo values
	var count int
	var latestFileInfo FileInfo

	// Reduce list of UUIDs to a single common value - i.e. the last updated Time
	modTime := commonTime(modTimes, expectedRQuorum)

	if modTime.IsZero() || modTime.Equal(timeSentinel) {
		return FileInfo{}, errErasureReadQuorum
	}

	},
	ErrSlowDownRead: {
		Code:           "SlowDownRead",
		Description:    "Resource requested is unreadable, please reduce your request rate",
		HTTPStatusCode: http.StatusServiceUnavailable,
	},
	ErrSlowDownWrite: {
		Code:           "SlowDownWrite",
		Description:    "Resource requested is unwritable, please reduce your request rate",
		HTTPStatusCode: http.StatusServiceUnavailable,
	},
	ErrMaxVersionsExceeded: {

	// if disk max timeout is smaller than checkEvery window
	// reduce checks by a second.
	if globalDriveConfig.GetMaxTimeout() <= checkEvery {
		checkEvery = globalDriveConfig.GetMaxTimeout() - time.Second
		if checkEvery <= 0 {
			checkEvery = globalDriveConfig.GetMaxTimeout()
		}
	}

	// if disk max timeout is smaller than skipIfSuccessBefore window
	// reduce the skipIfSuccessBefore by a second.

		sb.Reset()
		bytebufferpool.Put(sb)
	}()

	return pathJoinBuf(sb, elem...)
}

// pathJoinBuf - like path.Join() but retains trailing SlashSeparator of the last element.
// Provide a string builder to reduce allocation.
func pathJoinBuf(dst *bytebufferpool.ByteBuffer, elem ...string) string {
	trailingSlash := len(elem) > 0 && hasSuffixByte(elem[len(elem)-1], SlashSeparatorChar)
	dst.Reset()
	added := 0

	return "Storage reached its minimum free drive threshold."
}

// SlowDown  too many file descriptors open or backend busy .
type SlowDown struct{}

func (e SlowDown) Error() string {
	return "Please reduce your request rate"
}

// RQErrType reason for read quorum error.
type RQErrType int

const (
	// RQInsufficientOnlineDrives - not enough online drives.
	RQInsufficientOnlineDrives RQErrType = 1 << iota

	if r.ContentLength > encryptBufferThreshold {
		// The encryption reads in blocks of 64KB.
		// We add a buffer on bigger files to reduce the number of syscalls upstream.
		content = bufio.NewReaderSize(content, encryptBufferSize)
	}

	var (
		key   []byte
		keyID string
		ctx   kms.Context
		err   error
	)

				queued:    time.Now(),
				setIndex:  er.setIndex,
				poolIndex: er.poolIndex,
			})
		}

		return
	}()

	validResp := 0
	totalResp := 0

	// minDisks value is only to reduce the number of calls
	// to the disks; this value is not accurate because we do
	// not know the storage class of the object yet
	minDisks := 0
	if p := globalStorageClass.GetParityForSC(""); p > -1 {

//     Some of the Veeam products use Multi Delete operations. This setting can reduce how many objects are included in one
//     multi-delete operation. The same registry key setting overwrites the storage-defined setting.
//     Optional value, default 1000, range: 1-unlimited (S3 standard maximum is 1000 and should not be set higher)
//
//   - <StorageConcurrentTasksLimit>