VOP_INACTIVE is called when the kernel is no longer using the vnode. This may be because the reference count reaches zero or it may be that the file system is being forcibly unmounted while there are open files. It can be used to reclaim space for 'open but deleted' files.
VOP_RECLAIM is called when a vnode is being reused for a different file system. Any file system specific resources associated with the vnode should be freed.