There are now a minimum of 3 modules necessary for normal v9fs operation, but the module dependencies aren't expressed in the modules so users either get cryptic error messages or worse.

At the very least module dependencies between 9pnet_fd and 9pnet need to be expressed.  It would also be desirable to increment use count of transport modules while they are being used in an active mount so that the user won't accidently remove the module while an active mount is using the interfaces.