// into an SSE-S3 request. If enabled a valid, non-empty KMS
	// configuration must be present.
	globalAutoEncryption bool

	// Is compression enabled?
	globalCompressConfigMu sync.Mutex
	globalCompressConfig   compress.Config

	// Some standard object extensions which we strictly dis-allow for compression.

	"math/rand"
	"sync"
	"time"

	"github.com/minio/pkg/v2/sync/errgroup"
)

func (er erasureObjects) getOnlineDisks() (newDisks []StorageAPI) {
	disks := er.getDisks()
	var wg sync.WaitGroup
	var mu sync.Mutex
	r := rand.New(rand.NewSource(time.Now().UnixNano()))
	for _, i := range r.Perm(len(disks)) {
		i := i
		wg.Add(1)
		go func() {
			defer wg.Done()
			if disks[i] == nil {
				return
			}

// object sets. NOTE: There is no dynamic scaling allowed or intended in
// current design.
type erasureSets struct {
	sets []*erasureObjects

	// Reference format.
	format *formatErasureV3

	// erasureDisks mutex to lock erasureDisks.
	erasureDisksMu sync.RWMutex

	// Re-ordered list of disks per set.
	erasureDisks [][]StorageAPI

	// Distributed locker clients.
	erasureLockers setsDsyncLockers

	resultsDone := make(chan metaCacheEntriesSorted)
	// Copy so we can mutate
	resCh := resultsDone
	var done bool
	var mu sync.Mutex
	resErr := io.EOF

	go func() {
		var results metaCacheEntriesSorted
		var returned bool
		for entry := range in {
			if returned {
				// past limit
				continue
			}
			mu.Lock()

	errors map[int]error
	// The error to return when no error value is programmed
	defaultErr error
	// The current API call number
	callNR int
	// Data protection
	mu sync.Mutex
}

func newNaughtyDisk(d StorageAPI, errs map[int]error, defaultErr error) *naughtyDisk {
	return &naughtyDisk{disk: d, errors: errs, defaultErr: defaultErr}
}

func (d *naughtyDisk) String() string {

	return err
}

type writerAt struct {
	w      *io.PipeWriter
	r      *io.PipeReader
	wg     *sync.WaitGroup
	buffer map[int64][]byte
	err    error

	nextOffset int64
	m          sync.Mutex
}

func (w *writerAt) WriteAt(b []byte, offset int64) (n int, err error) {
	w.m.Lock()
	defer w.m.Unlock()

	if w.nextOffset == offset {
		n, err = w.w.Write(b)
		w.nextOffset += int64(n)

			runtime.SetBlockProfileRate(0)
			return buf.Bytes(), err
		}
	case madmin.ProfilerMutex:
		prof.record("mutex", 0, "before")
		runtime.SetMutexProfileFraction(1)
		prof.stopFn = func() ([]byte, error) {
			var buf bytes.Buffer
			err := pprof.Lookup("mutex").WriteTo(&buf, 0)
			runtime.SetMutexProfileFraction(0)
			return buf.Bytes(), err
		}
	case madmin.ProfilerThreads:

	getEndpoints func() []Endpoint

	// getEndpoints returns list of endpoint strings belonging this set.
	// some may be local and some remote.
	getEndpointStrings func() []string

	// Locker mutex map.
	nsMutex *nsLockMap
}

// NewNSLock - initialize a new namespace RWLocker instance.
func (er erasureObjects) NewNSLock(bucket string, objects ...string) RWLocker {

// found, otherwise use default parameters
func newSrvConfig(objAPI ObjectLayer) error {
	// Initialize server config.
	srvCfg := newServerConfig()

	// hold the mutex lock before a new config is assigned.
	globalServerConfigMu.Lock()
	globalServerConfig = srvCfg
	globalServerConfigMu.Unlock()

	// Save config into file.
	return saveServerConfig(GlobalContext, objAPI, srvCfg)

	sync.RWMutex
	formatData []byte

	nrRequests   uint64
	major, minor uint32
	fsType       string

	immediatePurge chan string

	// mutex to prevent concurrent read operations overloading walks.
	rotational bool
	walkMu     *sync.Mutex
	walkReadMu *sync.Mutex
}

// checkPathLength - returns error if given path name length more than 255
func checkPathLength(pathName string) error {