This question is kind of the opposite of Coding in Visual Studio in Linux VM?. I considered posting it on Stack Overflow, but since it isn't strictly a programming problem I thought it'd be a better fit on SuperUser.
I have a VirtualBox VM which runs Windows 7, Visual Studio 2012 and a few other odds and ends on top of my main Linux system. This works nicely, but primarily to facilitate useful backups, I would like to place the local source code tree outside of the VM. (The VM does get backed up, but only in the "all or nothing full disk image" manner rather than the much more useful individual files that the host system is backed up as.)
I tried simply creating a shared directory like ~/src
on the host and map that into the VM. The mapping itself worked fine and I was able to perform a Get Latest Version from source control to populate it, but it appears that the host side doesn't like something about how Visual Studio creates some of its working files, and I got a large number of errors because of this (including build errors from CSC and friends about invalid file formats). I imagine that the "hidden" attribute on some files may have something to do with this, since ext3 at least directly doesn't support such fancy properties on files, but there may be other factors involved as well.
So the question becomes: how can I make it possible for Windows inside a VirtualBox VM to store files as separate files on the host, in a way that works with how Visual Studio 2012 creates its working files?
I'm aware of the possibility of regularly copying the files out of the VM from within the VM, but would rather not go down that route if there is another option.