// Check if there is a parent device:
					//   e.g. if the mount is based on /dev/nvme0n1p1, let's calculate the
					//        real device name (nvme0n1) to get its sysfs information
					parentDevPath, e := os.Readlink("/sys/class/block/" + devName)
					if e == nil {
						parentDev := filepath.Base(filepath.Dir(parentDevPath))
						qst, err = bfs.SysBlockDeviceQueueStats(parentDev)
					}
				}
				if err == nil {

		},
		config.HelpKV{
			Key:         apiRequestsDeadline,
			Description: `set the deadline for API requests waiting to be processed` + defaultHelpPostfix(apiRequestsDeadline),
			Optional:    true,
			Type:        "duration",
		},
		config.HelpKV{
			Key:         apiClusterDeadline,
			Description: `set the deadline for cluster readiness check` + defaultHelpPostfix(apiClusterDeadline),
			Optional:    true,

		Description:    "Client disconnected before response was ready",
		HTTPStatusCode: 499, // No official code, use nginx value.
	},
	ErrTooManyRequests: {
		Code:           "TooManyRequests",
		Description:    "Deadline exceeded while waiting in incoming queue, please reduce your request rate",
		HTTPStatusCode: http.StatusServiceUnavailable,
	},
	ErrUnsupportedMetadata: {
		Code:           "InvalidArgument",

type DeadlineConn struct {
	net.Conn
	readDeadline  time.Duration // sets the read deadline on a connection.
	writeDeadline time.Duration // sets the write deadline on a connection.
}

// Sets read deadline
func (c *DeadlineConn) setReadDeadline() {
	if c.readDeadline > 0 {
		c.SetReadDeadline(time.Now().UTC().Add(c.readDeadline))
	}
}

)

// API sub-system constants
const (
	apiRequestsMax             = "requests_max"
	apiRequestsDeadline        = "requests_deadline"
	apiClusterDeadline         = "cluster_deadline"
	apiCorsAllowOrigin         = "cors_allow_origin"
	apiRemoteTransportDeadline = "remote_transport_deadline"
	apiListQuorum              = "list_quorum"
	apiReplicationPriority     = "replication_priority"

	deadline := UTCNow().Add(leakDetectDeadline * time.Second)
	for {
		// get sack snapshot of relevant go routines.
		leaked := initialSnapShot.CompareCurrentSnapshot()
		// current stack snapshot matches the initial one, no leaks, return.
		if len(leaked) == 0 {
			return
		}
		// wait a test again will deadline.
		if UTCNow().Before(deadline) {

func (c *Connection) newMuxClient(ctx context.Context) (*muxClient, error) {
	client := newMuxClient(ctx, atomic.AddUint64(&c.NextID, 1), c)
	if dl, ok := ctx.Deadline(); ok {
		client.deadline = getDeadline(time.Until(dl))
		if client.deadline == 0 {
			client.cancelFn(context.DeadlineExceeded)
			return nil, context.DeadlineExceeded
		}
	}
	for {
		// Handle the extremely unlikely scenario that we wrapped.

}

// Call the remote with the request and return the response.
// The response should be returned with PutResponse when no error.
// If no deadline is set, a 1-minute deadline is added.
func (h *SingleHandler[Req, Resp]) Call(ctx context.Context, c Requester, req Req) (resp Resp, err error) {
	if c == nil {
		if h.ignoreNilConn {
			return resp, nil
		}

		Payload:    req,
		DeadlineMS: uint32(m.deadline.Milliseconds()),
	}
	if m.subroute != nil {
		msg.Flags |= FlagSubroute
	}
	ch := make(chan Response, 1)
	m.respMu.Lock()
	if m.closed {
		m.respMu.Unlock()
		return nil, ErrDisconnected
	}
	m.respWait = ch
	m.respMu.Unlock()
	ctx := m.ctx

	// Add deadline if none.
	if msg.DeadlineMS == 0 {

//
//msgp:tuple message
type message struct {
	MuxID      uint64    // Mux to receive message if any.
	Seq        uint32    // Sequence number.
	DeadlineMS uint32    // If non-zero, milliseconds until deadline (max 1193h2m47.295s, ~49 days)
	Handler    HandlerID // ID of handler if invoking a remote handler.
	Op         Op        // Operation. Other fields change based on this value.
	Flags      Flags     // Optional flags.