var ErrAlreadyLocked = errors.New("file already locked")

// RLockedFile represents a read locked file, implements a special
// closer which only closes the associated *os.File when the ref count.
// has reached zero, i.e when all the readers have given up their locks.
type RLockedFile struct {
	*LockedFile
	mutex sync.Mutex
	refs  int // Holds read lock refs.
}

// IsClosed - Check if the rlocked file is already closed.

		select {
		case <-ctx.Done():
			doneCh <- ctx.Err()
			return
		default:
		}

		bucket, ok := z.nextRebalBucket(poolIdx)
		if !ok {
			// no more buckets to rebalance or target free_space/capacity reached
			break
		}

		stopFn := globalRebalanceMetrics.log(rebalanceMetricRebalanceBucket, poolIdx, bucket)
		if err = z.rebalanceBucket(ctx, bucket, poolIdx); err != nil {
			stopFn(err)

			})
		}
	}

	return res, nil
}

// Enabled returns if configURL is enabled.
func Enabled(kvs config.KVS) bool {
	return kvs.Get(ConfigURL) != ""
}

// GetSettings - fetches OIDC settings for site-replication related validation.
// NOTE that region must be populated by caller as this package does not know.
func (r *Config) GetSettings() madmin.OpenIDSettings {
	res := madmin.OpenIDSettings{}

}

// StorageFull storage ran out of space.
type StorageFull struct{}

func (e StorageFull) Error() string {
	return "Storage reached its minimum free drive threshold."
}

// SlowDown  too many file descriptors open or backend busy .
type SlowDown struct{}

func (e SlowDown) Error() string {
	return "Please reduce your request rate"
}

		HTTPStatusCode: http.StatusBadRequest,
	},

	// MinIO extensions.
	ErrStorageFull: {
		Code:           "XMinioStorageFull",
		Description:    "Storage backend has reached its minimum free drive threshold. Please delete a few objects to proceed.",
		HTTPStatusCode: http.StatusInsufficientStorage,
	},
	ErrRequestBodyParse: {
		Code:           "XMinioRequestBodyParse",

		atTotal += pool.Available
		if atTotal > choose && pool.Available > 0 {
			return pool.Index
		}
	}
	// Should not happen, but print values just in case.
	storageLogIf(ctx, fmt.Errorf("reached end of serverPools (total: %v, atTotal: %v, choose: %v)", total, atTotal, choose))
	return -1
}

// getServerPoolsAvailableSpace will return the available space of each pool after storing the content.

		metrics = append(metrics, MetricV2{
			Description: getMinIOGORoutineCountMD(),
			Value:       float64(runtime.NumGoroutine()),
		})
		return
	})
	return mg
}

// getHistogramMetrics fetches histogram metrics and returns it in a []Metric
// Note: Typically used in MetricGroup.RegisterRead
//
// The last parameter is added for compatibility - if true it lowercases the
// `api` label values.

		return 0, 0, nil
	}
	partOffset = offset
	// Seek until object offset maps to a particular part offset.
	for i, part := range fi.Parts {
		partIndex = i
		// Offset is smaller than size we have reached the proper part offset.
		if partOffset < part.Size {
			return partIndex, partOffset, nil
		}
		// Continue to towards the next part.
		partOffset -= part.Size
	}
	internalLogIf(ctx, InvalidRange{})

	b.mu.Lock()
	defer b.mu.Unlock()
	for k, v := range b.caches {
		if time.Since(v.lastUpdate) > metacacheMaxRunningAge {
			v.delete(context.Background())
			continue
		}
		v.error = "Bucket deleted"
		v.status = scanStateError
		m.mu.Lock()
		m.trash[k] = v
		m.mu.Unlock()
	}
}

// deleteAll will delete all caches.
func (m *metacacheManager) deleteAll() {
	m.init.Do(m.initManager)

type LookupHost func(ctx context.Context, host string) (addrs []string, err error)

// DialContextWithLookupHost is a helper function which returns `net.DialContext` function.
// It randomly fetches an IP via custom LookupHost function and dials it by the given dial
// function. LookupHost may implement an internal DNS caching implementation, lookupHost
// input if nil then net.DefaultResolver.LookupHost is used.
//