With this setup, malware installed on Windows can still access your Linux partition. I have no idea how likely this is (but I wouldn't want Windows to ever touch my partitions).
Then it's better to have Linux as main operating system and install Windows as a guest machine on that system using a software like Virtual box. We really need some features of the Windows and some of the applications are mainly created for Windows OS and that's why we need to have Windows operating system installed on a virtual machine to perform those task.
I think that way we and our files are safe even if Windows operating system gets infected with malware. I'm very sure that it would be a tough task for malware developers to access the files of the host system when their malware is installed in the guest system.