func (er erasureObjects) newMultipartUpload(ctx context.Context, bucket string, object string, opts ObjectOptions) (*NewMultipartUploadResult, error) {
	if opts.CheckPrecondFn != nil {
		// Lock the object before reading.
		lk := er.NewNSLock(bucket, object)
		lkctx, err := lk.GetRLock(ctx, globalOperationTimeout)
		if err != nil {
			return nil, err
		}
		rctx := lkctx.Context()

			case ObjectNotFound, InsufficientReadQuorum:
				retryWait()
				continue
			}
			// Allow one fast retry for other errors.
			if retries > 0 {
				return entries, fmt.Errorf("reading first part metadata: %v", err)
			}
			retryWait()
			continue
		}

		partN, err := o.findFirstPart(fi)
		switch {
		case err == nil:
		case errors.Is(err, io.ErrUnexpectedEOF):

		}
		// read the response body.
		actualContent, err := io.ReadAll(rec.Body)
		if err != nil {
			t.Fatalf("Test %d: %s: Failed reading response body: <ERROR> %v", i+1, instanceType, err)
		}

		if rec.Code == http.StatusOK || rec.Code == http.StatusPartialContent {
			if !bytes.Equal(testCase.expectedContent, actualContent) {

		}
	}()

	buf := NewBuffer(make([]byte, 1))
	const maxInt = int(^uint(0) >> 1)
	buf.Grow(maxInt)
}

// Was a bug: used to give EOF reading empty slice at EOF.
func TestReadEmptyAtEOF(t *testing.T) {
	b := new(Buffer)
	slice := make([]byte, 0)
	n, err := b.Read(slice)
	if err != nil {
		t.Errorf("read error: %v", err)
	}
	if n != 0 {

// for io.EOF.
//
// If an EOF happens after reading some but not all the bytes,
// ReadFile returns ErrUnexpectedEOF.
//
// If the BitrotVerifier is not nil or not verified ReadFile
// tries to verify whether the disk has bitrot.
//
// Additionally ReadFile also starts reading from an offset. ReadFile
// semantics are same as io.ReadFull.

		readMsgpReaderPool.Put(r)
	}
}

func (client *storageRESTClient) ReadVersion(ctx context.Context, origvolume, volume, path, versionID string, opts ReadOptions) (fi FileInfo, err error) {
	// Use websocket when not reading data.
	if !opts.ReadData {
		resp, err := storageReadVersionRPC.Call(ctx, client.gridConn, grid.NewMSSWith(map[string]string{
			storageRESTDiskID:     *client.diskID.Load(),
			storageRESTOrigVolume: origvolume,

	return nil
}

// IAMStorageAPI defines an interface for the IAM persistence layer
type IAMStorageAPI interface {
	// The role of the read-write lock is to prevent go routines from
	// concurrently reading and writing the IAM storage. The (r)lock()
	// functions return the iamCache. The cache can be safely written to
	// only when returned by `lock()`.
	lock() *iamCache
	unlock()
	rlock() *iamCache
	runlock()

	if !opts.NoAuditLog {
		auditObjectErasureSet(ctx, object, &er)
	}

	if !opts.NoLock {
		// Lock the object before reading.
		lk := er.NewNSLock(bucket, object)
		lkctx, err := lk.GetRLock(ctx, globalOperationTimeout)
		if err != nil {
			return ObjectInfo{}, err
		}
		ctx = lkctx.Context()
		defer lk.RUnlock(lkctx)
	}

		// coming up and trying to read format.json or create format.json
		return nil
	}
	storedDiskID, err := p.storage.GetDiskID()
	if err != nil {
		// return any error generated while reading `format.json`
		return err
	}
	if err == nil && *p.diskID.Load() == storedDiskID {
		return nil
	}
	// not the same disk we remember, take it offline.
	return errDiskNotFound
}

			return &GetObjectReader{
				ObjInfo: objInfo,
			}, toObjectErr(errMethodNotAllowed, bucket, object)
		}
		return nil, err
	}

	// check preconditions before reading the stream.
	if checkPrecondFn != nil && checkPrecondFn(objInfo) {
		return nil, PreConditionFailed{}
	}

	opts.NoLock = true
	gr, err = z.serverPools[zIdx].GetObjectNInfo(ctx, bucket, object, rs, h, opts)