lockFound := false
		for _, uid := range dm.readLocks {
			if isLocked(uid) {
				lockFound = true
				break
			}
		}
		if !lockFound {
			panic("Trying to RUnlock() while no RLock() is active")
		}

		// Copy write locks to stack array
		copy(locks, dm.readLocks)
	}

	// Tolerance is not set, defaults to half of the locker clients.

	}
	// refer https://www.kernel.org/doc/Documentation/block/stat.txt
	iostats = IOStats{
		ReadIOs:      stats[0],
		ReadMerges:   stats[1],
		ReadSectors:  stats[2],
		ReadTicks:    stats[3],
		WriteIOs:     stats[4],
		WriteMerges:  stats[5],
		WriteSectors: stats[6],
		WriteTicks:   stats[7],
		CurrentIOs:   stats[8],
		TotalTicks:   stats[9],
		ReqTicks:     stats[10],
	}

	// - missing format.json (unformatted drive)
	// - format.json is valid but invalid 'uuid'
	if err = p.checkDiskStale(); err != nil {
		return ctx, done, err
	}

	// Disallow recursive tracking to avoid deadlocks.
	if ctx.Value(healthDiskCtxKey{}) != nil {
		done = p.updateStorageMetrics(s, paths...)
		return ctx, done, nil
	}

	if contextCanceled(ctx) {
		return ctx, done, ctx.Err()
	}

	return true, nil
}

const ReadLock = 1

func (l *lockServer) RLock(args *LockArgs) (reply bool, err error) {
	if d := atomic.LoadInt64(&l.responseDelay); d != 0 {
		time.Sleep(time.Duration(d))
	}

	l.mutex.Lock()
	defer l.mutex.Unlock()
	var locksHeld int64
	if locksHeld, reply = l.lockMap[args.Resources[0]]; !reply {

	Name       string
	Rotational *bool
	NRRequests uint64
}

// IOStats contains stats of a single drive
type IOStats struct {
	ReadIOs        uint64
	ReadMerges     uint64
	ReadSectors    uint64
	ReadTicks      uint64
	WriteIOs       uint64
	WriteMerges    uint64
	WriteSectors   uint64
	WriteTicks     uint64
	CurrentIOs     uint64
	TotalTicks     uint64
	ReqTicks       uint64
	DiscardIOs     uint64

	lockSource := getSource(2)
	start := UTCNow()
	const readLock = false
	success := make([]int, len(li.paths))
	for i, path := range li.paths {
		if !li.ns.lock(ctx, li.volume, path, lockSource, li.opsID, readLock, timeout.Timeout()) {
			timeout.LogFailure()
			for si, sint := range success {
				if sint == 1 {
					li.ns.unlock(li.volume, li.paths[si], readLock)
				}
			}
			if errors.Is(ctx.Err(), context.Canceled) {

		if err == nil {
			dm.IOStats = madmin.DiskIOStats{
				ReadIOs:        st.ReadIOs,
				ReadMerges:     st.ReadMerges,
				ReadSectors:    st.ReadSectors,
				ReadTicks:      st.ReadTicks,
				WriteIOs:       st.WriteIOs,
				WriteMerges:    st.WriteMerges,
				WriteSectors:   st.WriteSectors,
				WriteTicks:     st.WriteTicks,
				CurrentIOs:     st.CurrentIOs,

	updateResourceMetrics(driveSubsystem, writesKBPerSec, writeKib/diffInSeconds, labels, false)

	rdAwait := 0.0
	if diffStats.ReadIOs > 0 {
		rdAwait = float64(diffStats.ReadTicks) / float64(diffStats.ReadIOs)
	}
	updateResourceMetrics(driveSubsystem, readsAwait, rdAwait, labels, false)

	wrAwait := 0.0
	if diffStats.WriteIOs > 0 {

			expectedIOStats: IOStats{
				ReadIOs:        1432553,
				ReadMerges:     420084,
				ReadSectors:    66247626,
				ReadTicks:      2398227,
				WriteIOs:       7077314,
				WriteMerges:    8720147,
				WriteSectors:   157049224,
				WriteTicks:     7469810,
				CurrentIOs:     0,
				TotalTicks:     7580552,
				ReqTicks:       9869354,

		ReadSectors:  currentStats.ReadSectors - initialStats.ReadSectors,
		WriteSectors: currentStats.WriteSectors - initialStats.WriteSectors,
		ReadTicks:    currentStats.ReadTicks - initialStats.ReadTicks,
		WriteTicks:   currentStats.WriteTicks - initialStats.WriteTicks,
		TotalTicks:   currentStats.TotalTicks - initialStats.TotalTicks,
	}
}