MaxSize      int64    `msg:"ms"`           // Return error if size is exceed.
	MetadataOnly bool     `msg:"mo"`           // Read as XL meta and truncate data.
	AbortOn404   bool     `msg:"ab"`           // Stop reading after first file not found.
	MaxResults   int      `msg:"mr"`           // Stop after this many successful results. <= 0 means all.
}

		case "mo":
			z.MetadataOnly, err = dc.ReadBool()
			if err != nil {
				err = msgp.WrapError(err, "MetadataOnly")
				return
			}
		case "ab":
			z.AbortOn404, err = dc.ReadBool()
			if err != nil {
				err = msgp.WrapError(err, "AbortOn404")
				return
			}
		case "mr":
			z.MaxResults, err = dc.ReadInt()
			if err != nil {
				err = msgp.WrapError(err, "MaxResults")
				return
			}

				r.Exists = true
				r.Error = err.Error()
			}
			select {
			case <-ctx.Done():
				return ctx.Err()
			case resp <- r:
			}
			if req.AbortOn404 && !r.Exists {
				// We stop at first file not found.
				// We have already reported the error, return nil.
				return nil
			}
			continue
		}
		diskHealthCheckOK(ctx, nil)