saver := z.serverPools[o.pool].sets[o.set]

	// Disconnect from call above, but cancel on exit.
	listCtx, cancel := context.WithCancel(GlobalContext)
	saveCh := make(chan metaCacheEntry, metacacheBlockSize)
	inCh := make(chan metaCacheEntry, metacacheBlockSize)
	outCh := make(chan metaCacheEntry, o.Limit)

	filteredResults := o.gatherResults(ctx, outCh)

	mc := o.newMetacache()

		// not be required but makes reproduction much easier.
		nsLk.lockMapMutex.Lock()

		// lk3 blocks.
		lk3ch := make(chan bool)
		go func() {
			lk3ch <- nsLk.lock(ctx, "volume", "path", "source", "opsID", false, 0)
		}()

		// lk4, blocks.
		lk4ch := make(chan bool)
		go func() {
			lk4ch <- nsLk.lock(ctx, "volume", "path", "source", "opsID", false, 0)
		}()
		runtime.Gosched()

		if r.Flags.Filter.OlderThan > 0 && time.Since(oi.ModTime) < r.Flags.Filter.OlderThan.D() {
			// skip all objects that are newer than specified older duration
			return true
		}

		if r.Flags.Filter.NewerThan > 0 && time.Since(oi.ModTime) >= r.Flags.Filter.NewerThan.D() {
			// skip all objects that are older than specified newer duration
			return true
		}

	mrfMU    sync.Mutex
	resyncer *replicationResyncer

	// workers:
	workers    []chan ReplicationWorkerOperation
	lrgworkers []chan ReplicationWorkerOperation

	// mrf:
	mrfWorkerKillCh chan struct{}
	mrfReplicaCh    chan ReplicationWorkerOperation
	mrfSaveCh       chan MRFReplicateEntry
	mrfStopCh       chan struct{}
	mrfWorkerSize   int
}

)

var sharedLockTimeout = newDynamicTimeoutWithOpts(dynamicTimeoutOpts{
	timeout:       30 * time.Second,
	minimum:       10 * time.Second,
	retryInterval: time.Minute,
})

type sharedLock struct {
	lockContext chan LockContext
}

func (ld sharedLock) backgroundRoutine(ctx context.Context, objAPI ObjectLayer, lockName string) {
	for {
		locker := objAPI.NewNSLock(minioMetaBucket, lockName)

//           value: image/* # match objects with 'content-type', all values starting with 'image/'
//       size:
//         lessThan: "10MiB" # match objects with size less than this value (e.g. 10MiB)
//         greaterThan: 1MiB # match objects with size greater than this value (e.g. 1MiB)
//       purge:
//           # retainVersions: 0 # (default) delete all versions of the object. This option is the fastest.

// Updates are sent on a regular basis and the caller *must* consume them.
func (er erasureObjects) nsScanner(ctx context.Context, buckets []BucketInfo, wantCycle uint32, updates chan<- dataUsageCache, healScanMode madmin.HealScanMode) error {
	if len(buckets) == 0 {
		return nil
	}

	// Collect disks we can use.
	disks, healing := er.getOnlineDisksWithHealing(false)
	if len(disks) == 0 {

	xioutil "github.com/minio/minio/internal/ioutil"
	"github.com/minio/minio/internal/logger"
	"github.com/minio/minio/internal/mcontext"
)

type apiConfig struct {
	mu sync.RWMutex

	requestsPool           chan struct{}
	clusterDeadline        time.Duration
	listQuorum             string
	corsAllowOrigins       []string
	replicationPriority    string
	replicationMaxWorkers  int
	replicationMaxLWorkers int

	es := &expiryState{
		ctx:    ctx,
		objAPI: objAPI,
	}
	workers := make([]chan expiryOp, 0, n)
	es.workers.Store(&workers)
	es.ResizeWorkers(n)
	return es
}

func (es *expiryState) getWorkerCh(h uint64) chan<- expiryOp {
	w := es.workers.Load()
	if w == nil || len(*w) == 0 {
		return nil
	}
	workers := *w

}

// Get the max throughput and iops numbers.
func objectSpeedTest(ctx context.Context, opts speedTestOpts) chan madmin.SpeedTestResult {
	ch := make(chan madmin.SpeedTestResult, 1)
	go func() {
		defer xioutil.SafeClose(ch)

		concurrency := opts.concurrencyStart

		if opts.autotune {
			// if we have less drives than concurrency then choose
			// only the concurrency to be number of drives to start