func (sCfg *Config) AvailabilityOptimized() bool {
	ConfigLock.RLock()
	defer ConfigLock.RUnlock()
	if !sCfg.initialized {
		return true
	}
	return sCfg.Optimize == "availability" || sCfg.Optimize == ""
}

// Update update storage-class with new config
func (sCfg *Config) Update(newCfg Config) {
	ConfigLock.Lock()
	defer ConfigLock.Unlock()
	sCfg.RRS = newCfg.RRS
	sCfg.Standard = newCfg.Standard

	lock := z.serverPools[0].NewNSLock(minioMetaBucket, rebalMetaName)
	lkCtx, err := lock.GetLock(ctx, globalOperationTimeout)
	if err != nil {
		rebalanceLogIf(ctx, fmt.Errorf("failed to acquire write lock on %s/%s: %w", minioMetaBucket, rebalMetaName, err))
		return err
	}
	defer lock.Unlock(lkCtx)

	ctx = lkCtx.Context()
	noLockOpts := ObjectOptions{NoLock: true}

			if idx := strings.IndexByte(forward, '/'); idx > 0 {
				forward = forward[:idx]
			}
		}

		if s.walkMu != nil {
			s.walkMu.Lock()
		}
		entries, err := s.ListDir(ctx, "", opts.Bucket, current, -1)
		if s.walkMu != nil {
			s.walkMu.Unlock()
		}
		if err != nil {
			// Folder could have gone away in-between
			if err != errVolumeNotFound && err != errFileNotFound {

	if opts.CheckPrecondFn != nil {
		if !opts.NoLock {
			ns := er.NewNSLock(bucket, object)
			lkctx, err := ns.GetLock(ctx, globalOperationTimeout)
			if err != nil {
				return nil, err
			}
			ctx = lkctx.Context()
			defer ns.Unlock(lkctx)
			opts.NoLock = true
		}

		obj, err := er.getObjectInfo(ctx, bucket, object, opts)

	}

	// if no update is needed return right away.
	if !update {
		z.poolMetaMutex.Lock()
		z.poolMeta = meta
		z.poolMetaMutex.Unlock()
	} else {
		newMeta := newPoolMeta(z, meta)
		if err = newMeta.save(ctx, z.serverPools); err != nil {
			return err
		}
		z.poolMetaMutex.Lock()
		z.poolMeta = newMeta
		z.poolMetaMutex.Unlock()
	}

	pools := meta.returnResumablePools()

					return ObjectLocked{}
				}

				if !ret.RetainUntilDate.Before(t) {
					return ObjectLocked{}
				}
				return nil
			}
			// https://docs.aws.amazon.com/AmazonS3/latest/dev/object-lock-overview.html#object-lock-retention-modes
			// If you try to delete objects protected by governance mode and have s3:BypassGovernanceRetention, the operation will succeed.

	dm.Unlock(t.Context())

	dm.Lock(id, source)
	time.Sleep(time.Duration(10+(rand.Float32()*50)) * time.Millisecond)
	dm.Unlock(t.Context())

	dm.Lock(id, source)
	time.Sleep(time.Duration(10+(rand.Float32()*50)) * time.Millisecond)
	dm.Unlock(t.Context())

	dm.Lock(id, source)
	time.Sleep(time.Duration(10+(rand.Float32()*50)) * time.Millisecond)
	dm.Unlock(t.Context())
}

	rl = wl.DRLocker()
	n := 10
	go func() {
		for range n {
			rl.Lock()
			rl.Lock()
			rlocked <- true
			wl.Lock()
			wlocked <- true
		}
	}()
	for range n {
		<-rlocked
		rl.Unlock()
		select {
		case <-wlocked:
			t.Fatal("RLocker() didn't read-lock it")
		default:
		}
		rl.Unlock()
		<-wlocked
		select {
		case <-rlocked:

type NetLocker interface {
	// Do read lock for given LockArgs.  It should return
	// * a boolean to indicate success/failure of the operation
	// * an error on failure of lock request operation.
	RLock(ctx context.Context, args LockArgs) (bool, error)

	// Do write lock for given LockArgs. It should return
	// * a boolean to indicate success/failure of the operation
	// * an error on failure of lock request operation.

	defer func() {
		if recover() == nil {
			t.Fatalf("unlock of unlocked RWMutex did not panic")
		}
	}()
	mu := NewDRWMutex(ds, "test")
	mu.Unlock(t.Context())
}

// Borrowed from rwmutex_test.go
func TestUnlockPanic2(t *testing.T) {
	mu := NewDRWMutex(ds, "test-unlock-panic-2")
	defer func() {
		if recover() == nil {
			t.Fatalf("unlock of unlocked RWMutex did not panic")
		}