umountable file systems, hung processes, or system panics:
- Some operations could return without decrementing the vnode
reference count.
- Some operations could leave the vnode locked.
- Generalize the /kern/rootdev & rrootdev files so that they
are no longer special cased in kernfs_lookup().
Note: procfs, fdescfs, and most of the other miscfs/* file systems
also suffer from the same type of problems and I will work on
fixing them one at a time.
f03dea9996